To see the other types of publications on this topic, follow the link: GM1.
Dissertations / Theses on the topic 'GM1'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'GM1.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Arthur, Julian. "Novel Therapies and Biochemical Insights for the GM1 and GM2 Gangliosidoses." Thesis, Boston College, 2011. http://hdl.handle.net/2345/3855.
Full textAbstract:
Thesis advisor: Thomas N. SeyfriedGangliosides are glycosphingolipids (GSLs) containing sialic acids that play numerous roles in neuronal maturation, apoptotic signaling, angiogenesis, and cell surface receptor activity. The GM1 and GM2 gangliosidoses are a series of autosomal recessive lysosomal storage disorders (LSDs) characterized by an inability to degrade these lipid molecules. GM1 gangliosidosis is caused by a mutation in the lysosomal hydrolase β-galactosidase, resulting in neuronal storage of ganglioside GM1 and asialo GA1. Tay-Sachs (TS) and Sandhoff Disease (SD) are GM2 gangliosidoses caused by mutations in either the α or β subunits, respectively, of the heterodimeric protein β- hexosaminidase A, resulting in the storage of ganglioside GM2 and asialo GA2. The accumulation of excess ganglioside in the central nervous system leads to abnormal intracellular vacuoles, neuronal loss, demyelination, ataxia, dementia, and premature death. In my studies, I have shown that accumulation of GM1 ganglioside may not coincide with secondary storage of cholesterol, by providing evidence that cholesterol-binding fluorescent molecule filipin reacted to GM1 ganglioside in the absence of cholesterol. In an effort to combat the early-onset gangliosidoses, I have explored the effects of combining Neural Stem Cells (NSCs) with Substrate Reduction Therapy (SRT) in juvenile Sandhoff mice. The analysis showed that SRT was more effective than NSCs in reducing stored GM2 and GA2 in young mice, and no synergy was observed. In adult GM1 gangliosidosis, Tay- Sachs, and Sandhoff mice, Adeno-Associated Viral (AAV) vector gene therapy was used to restore therapeutic levels of wild-type enzyme to the CNS. AAV therapy corrected ganglioside storage and ameliorated myelin-associated lipid loss in all tissues assayed, increasing motor performance and life in effected animals. Lastly, AAV therapy was also successful in a feline model of Sandhoff disease. These results in juvenile and adult model systems point the way towards multiple effective clinical therapies in the near future
Thesis (PhD) — Boston College, 2011
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Biology
2
Elliot-Smith, Elena. "GM1 gangliosidosis : therapy and pathogenesis." Thesis, University of Oxford, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.425028.
Full text
3
DI, BIASE ERIKA. "GM1 OLIGOSACCHARIDE ACCOUNTS FOR GM1 ROLE IN ENHANCING NEURONAL DEVELOPMENT ACTING ON TRKA-MAPK PATHWAY." Doctoral thesis, Università degli Studi di Milano, 2019. http://hdl.handle.net/2434/692335.
Full textAbstract:
Il ganglioside GM1 è un glicosfingolipide mono-sialilato presente nello strato esterno della membrana plasmatica cellulare ed è particolarmente abbondante nei neuroni. Numerosi studi in vitro e in vivo evidenziano il ruolo del GM1 non solo come componente strutturale ma anche come regolatore di diversi processi cellulari. Infatti, l'arricchimento di GM1 nei microdomini di membrana promuove il differenziamento e la protezione neuronale. Inoltre il contenuto di GM1 è essenziale per la sopravvivenza e il mantenimento dei neuroni. Nonostante vi siano numerose evidenze sugli effetti neuronotrofici mediati dal GM1, la conoscenza del meccanismo d'azione sottostante è scarsa. Recentemente, la catena oligosaccaridica del GM1 (oligoGM1) è stata identificata come responsabile delle proprietà neuritogeniche del ganglioside GM1 nelle cellule di neuroblastoma. Gli effetti mediati dall’oligoGM1 dipendono dal suo legame con il recettore specifico dell’ NGF, il TrkA, determinando così l'attivazione della via TrkA-MAPK. In questo contesto, il mio lavoro di dottorato mirava a confermare il ruolo dell’oligoGM1, come componente bioattiva dell’intero ganglioside GM1, capace di stimolare i processi di differenziaziamento e maturazione dei neuroni granulari cerebellari di topo. Come prima cosa, abbiamo eseguito analisi morfologiche in time -course sui neuroni primari coltivati in presenza o in assenza dei gangliosidi GM1 o GD1a (il quale rappresenta il diretto precursore catabolico del GM1), somministrati esogenamente. Abbiamo osservato che entrambi i gangliosidi aumentavano l’aggregazione e l'arborizzazione dei neuroni. Dopo successiva somministrazione dei rispettivi oligosaccaridi, abbiamo osservato che solo l’oligoGM1 favoriva la migrazione dei neuroni, mentre l’oligoGD1a non induceva nessun effetto discriminante rispetto alle cellule controllo. Questo risultato suggerisce l'importanza della specifica struttura saccaridica del GM1 nella mediazione degli effetti neuronotrofici del ganglioside. Quindi abbiamo caratterizzato biochimicamente l'effetto mediato dall’oligoGM1 nei neuroni e abbiamo osservato un più elevato tasso di fosforilazione delle proteine FAK e Src, le quali rappresentano i regolatori intracellulari chiave della motilità neuronale. Inoltre, in presenza dell’ oligoGM1 i neuroni granulari cerebellari mostravano un aumento del livello di marcatori neuronali specifici (ad es. β3-Tubulina, Tau, Neuroglicano C, Sinapsina), suggerendo uno stadio di maturazione più avanzato rispetto ai controlli. Inoltre, abbiamo scoperto che l'oligoGM1 accelera l'espressione del pattern di gangliosidi tipico dei neuroni maturi che è caratterizzato da alti livelli di gangliosidi complessi (cioè GM1, GD1a, GD1b e GT1b) e basso livello del ganglioside più semplice GM3. Per studiare il meccanismo d'azione dell'oligoGM1, abbiamo usato il suo derivato marcato con il trizio e abbiamo scoperto che l'oligoGM1 interagisce con la superficie cellulare senza entrare nelle cellule. Questa scoperta suggerisce la presenza di un bersaglio biologico sulla membrana plasmatica neuronale. È interessante notare che abbiamo riscontrato una precoce attivazione della via di segnalazione del TrkA associata alle MAP chinasi in seguito alla somministrazione dell’oligoGM1 nelle culture neuronali. Questo risultato suggerisce che questo evento rappresenti un punto di partenza degli effetti dell’ oligoGM1 nei neuroni. I nostri dati rivelano che gli effetti del ganglioside GM1 sul differenziamento e la maturazione neuronale sono mediati dalla sua porzione di oligosaccaride. Infatti, l’oligoGM1 interagisce con la superficie cellulare, innescando così l'attivazione di processi biochimici intracellulari che sono responsabili della migrazione neuronale, dell'emissione dei dendriti e della crescita degli assoni. Nel complesso, i nostri risultati sottolineano l'importanza dell’ oligoGM1 come un nuovo e promettente fattore neurotrofico.The GM1 ganglioside is a mono-sialylated glycosphingolipid present in the outer layer of the cell plasma membrane and abundant in neurons. Numerous in vitro and in vivo studies highlight the role of GM1 not only as a structural component but also as a functional regulator. Indeed, GM1 enrichment in membrane microdomains promotes neuronal differentiation and protection, and the GM1 content is essential for neuronal survival and maintenance. Despite many lines of evidence on the GM1-mediated neuronotrophic effects, our knowledge on the underlying mechanism of action is scant. Recently, the oligosaccharide chain of GM1 (oligoGM1) has been identified as responsible for the neuritogenic properties of the GM1 ganglioside in neuroblastoma cells. The oligoGM1-mediated effects depend on its binding to the NGF specific receptor TrkA, thus resulting in the TrkA-MAPK pathway activation. In this context, my PhD work aimed to confirm the role of the oligoGM1, as the bioactive portion of the entire GM1 ganglioside, capable of enhancing the differentiation and maturation processes of mouse cerebellar granule neurons. First, we performed time course morphological analyses on mouse primary neurons plated in the presence or absence of exogenously administered gangliosides GM1 or GD1a (direct GM1 catabolic precursor). We found that both gangliosides increased neuron clustering and arborization, however only oligoGM1 and not oligoGD1a induced the same effects in prompting neuron migration. This result suggests the importance of the specific GM1 saccharide structure in mediating neuronotrophic effects. Then we characterized biochemically the oligoGM1-mediated effect in mouse primary neurons, and we observed a higher phosphorylation rate of FAK and Src proteins which are the intracellular key regulators of neuronal motility. Moreover, in the presence of oligoGM1 cerebellar granule neurons showed increased level of specific neuronal markers (e.g., β3-Tubulin, Tau, Neuroglycan C, Synapsin), suggesting an advanced stage of maturation compared to controls. In addition, we found that the oligoGM1 accelerates the expression of the typical ganglioside pattern of mature neurons which is characterized by high levels of complex gangliosides (i.e., GM1, GD1a, GD1b, and GT1b) and low level of the simplest one, the GM3 ganglioside. To study the mechanism of action of the oligoGM1, we used its tritium labeled derivative and we found that the oligoGM1 interacts with the cell surface without entering the cells. This finding suggests the presence of a biological target at the neuronal plasma membrane. Interestingly, we observed the TrkA-MAP kinase pathway activation as an early event underlying oligoGM1 effects in neurons. Our data reveal that the effects of GM1 ganglioside on neuronal differentiation and maturation are mediated by its oligosaccharide portion. Indeed, oligoGM1 interacts with the cell surface, thus triggering the activation of intracellular biochemical pathways that are responsible for neuronal migration, dendrites emission and axon growth. Overall, our results point out the importance of oligoGM1 as a new promising neurotrophic player.
4
Kannebley, João Stein 1971. "Aspectos clínicos, radiológicos e neuroimagem em 12 pacientes com Gangliosidose GM1, formas juvenil e crônica." [s.n.], 2015. http://repositorio.unicamp.br/jspui/handle/REPOSIP/312528.
Full textAbstract:
Orientador: Carlos Eduardo SteinerDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas
Made available in DSpace on 2018-08-26T23:18:35Z (GMT). No. of bitstreams: 1 Kannebley_JoaoStein_M.pdf: 9118721 bytes, checksum: 33988e2512a8c525b91c3d93a783a368 (MD5) Previous issue date: 2015
Resumo: A gangliosidose GM1 é uma doença rara causada pela deficiência da enzima ?-galactosidase, decorrente de mutações no gene GLB1, acarretando o acúmulo de gangliosídeos, principalmente o GM1. É classificada em três formas dependendo da idade de início dos sintomas. Em todas ocorrem alterações esqueléticas e deterioração neurológica, sendo que na forma adulta predominam sinais extrapiramidais como distonia. No presente estudo descrevemos as características de 12 pacientes com gangliosidose GM1 nas formas juvenil e crônica de 10 famílias não aparentadas provenientes da região de Campinas, SP, e do sul do estado de Minas Gerais. Foram detalhados a história clínica e o exame físico, em especial o neurológico, bem como de aspectos radiológicos, ultrassonográficos, ecocardiográficos e de neuroimagem. Metade dos casos iniciou com queixas ósteo-articulares e outra metade com sintomas neurológicos, porém com a evolução todos apresentaram uma combinação de disostose múltipla e neurodegeneração. Opacificação de córnea e angioqueratomas foram vistos em um caso, cada. Outros sinais comumente associados às doenças de depósito lisossômico não foram vistos nesta casuística. Todos apresentaram baixa estatura, disostose múltipla, disartria e prejuízo nas atividades de vida diária, 10 tinham distonia e disfagia, nove atrofia muscular e oito sinais piramidais e alterações da movimentação ocular. Barra óssea e os odontoideum foram vistos em dois casos, sendo alterações previamente não descritas nessa condição. Exames de neuroimagem mostraram aumento do sistema ventricular e hipointensidade de sinal em globos pálidos em todos, além de deformidades vertebrais, hiperintensidade de sinal de putâmen e atrofia cortical na maioria. Alterações em tálamo, substância branca ou atrofia cerebelar não foram identificadas nessa série
Abstract: GM1 gangliosidosis is a rare disorder caused by deficiency in ?-galactosidase activity due to mutations in the GLB1 gene, leading to acumulation of gangliosides in multiple organs. Three main clinical forms have been described according to the age of onset. All present with skeletal deformities and neurologic deterioration, and in the adult form extrapyramidal signs including dystonia are frequent. In the present study we describe 12 subjects of 10 unrelated families from the region of Campinas and the southern state of Minas Gerais. Clinical information included detailed history, full neurologic examination, radiologic, ultrasonographic, echocardiographic, and neuroimaging description. Half of subjects presented initially with skeletal deformities, while the remaining opened clinical presentation with neurologic features. However, over time all presented dysostosis multiplex and neurodegeneration. Corneal clouding and angiokeratomas were seen in one individual each. Other features commonly described in lysosomal storage disorders were not found in this series. All subjects presented with short stature, dysostosis multiplex, dysarthria, and impairment of activities of daily living, 10 had extrapyramidal signs, nine had muscular atrophy, and eight had pyramidal signs and mild oculomotor abnormalities. A vertebral bone bar and os odontoideum were found in two patients, being previously undescribed in this condition. Neuroimaging revealed enlargement of the ventricular system and hypointensity of globus pallidus in all, besides vertebral deformities, putaminal hyperintensity, and cortical atrophy in most patients. Thalamic changes, abnormal white matter or cerebellar atrophy were not seen in this series
Mestrado
Genetica Medica
Mestre em Ciências Médicas
5
Fink, Erin Nicole. "GM1 signaling through the GDNF receptor complex." Columbus, Ohio : Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1198013799.
Full text
6
Baptista, Marcella Bergamini de 1988. "Análise de mutações no gene GLB1 em pacientes com gangliosidose GM1 formas juvenil e crônica." [s.n.], 2013. http://repositorio.unicamp.br/jspui/handle/REPOSIP/308543.
Full textAbstract:
Orientador: Carlos Eduardo SteinerDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas
Made available in DSpace on 2018-08-23T05:21:25Z (GMT). No. of bitstreams: 1 Baptista_MarcellaBergaminide_M.pdf: 1959777 bytes, checksum: 5e9549a5e21a411c116468e665693472 (MD5) Previous issue date: 2013
Resumo: Gangliosidose GM1 é uma doença autossômica recessiva rara, classificada em três formas clínicas de acordo com a idade de apresentação dos sintomas e a gravidade, provocada pela deficiência da enzima lisossômica ?-galactosidase que leva ao acúmulo, principalmente, do gangliosídeo GM1. A forma juvenil geralmente apresenta início entre sete meses e três anos de idade, com progressão lenta dos sinais neurológicos, dimorfismos menos graves que na forma infantil e deformidades ósseas. A forma crônica é caracterizada por apresentações clínicas mais leves e sintomas extrapiramidais. O gene codificador da enzima é o GLB1, no qual mais de 130 mutações foram descritas. No presente estudo foi realizada a caracterização molecular de 10 indivíduos de nove famílias não relacionadas diagnosticados com gangliosidose GM1, nas formas juvenil e crônica. Todas as famílias são originárias do interior do estado de São Paulo ou do sul do estado de Minas Gerais. Para a análise realizada foi possível identificar a mutação anteriormente descrita p.T500A, em sete das nove famílias estudadas, a inserção c.1717- 1722insG e a mutação p.R59H foram encontradas em duas famílias (a última segregou juntamente com o polimorfismo descrito IVS12+8T>C). As demais mutações descritas (p.F107L, p.L173P, p.R201H, p.G311R) foram encontradas em uma família cada. Uma alteração neutra (p.P152P) e duas mutações (p.I354S e p.T384S) são inéditas. Foi possível identificar a ocorrência de uma mutação de novo em uma família. Todas as mutações foram encontradas em heterozigose
Abstract: GM1 gangliosidosis is a rare autosomal recessive, classified in three clinical types according to age of onset and severity. The disease is caused by the deficiency of lysosomal enzyme ?-galactosidase that leads to the accumulation of GM1 ganglioside. The juvenile form usually shows an onset between seven months and three years of age, with slowly progressive neurological signs, less severe dysmorphisms than the infantile form and skeletal changes. The adult form is specified by a milder clinical manifestations and extrapyramidal signs. The lysossomal enzyme is coded by the GLB1 gene which more than 130 mutations have been decribed. In the present study it was genotyped 10 individuals of nine unrelated families originated from the States of São Paulo and Minas Gerais diagnosed with the juvenile and chronic forms of the disease. It was possible to find the previously described mutations p.T500A in seven of the nine families, c.1717-1722insG and p.R59H in two alleles (the latter also segregating with IVS12+8T>C), and p.F107L, p.L173P, p.R201H, and p.G311R in one familie each. One neutral alteration (p.P152P) and two mutations (p.I354S and p.T384S) are described for the first time. The occurrence of a de novo mutation was seen in one family. All patients presented as heterozygous compound
Mestrado
Ciencias Biomedicas
Mestra em Ciências Médicas
7
Maggioni, M. "GM1-MEDIATED NEURODIFFERENTIATION IS PROMOTED BY OLIGOGM1-TRKA INTERACTION." Doctoral thesis, Università degli Studi di Milano, 2018. http://hdl.handle.net/2434/543684.
Full textAbstract:
The present study proposes a clarification on the molecular mechanism by which ganglioside GM1 promotes neurodifferentiation, demonstrating in vitro that neurotrophic functions are exerted by an interaction between the oligosaccharide portion (OligoGM1) and an extracellular domain of TrkA receptor.
Similarly to the entire molecule, the oligosaccharide portion of ganglioside GM1, rather than ceramide, is responsible for neurodifferentiation by augmenting neurite elongation and by increasing the expression of neurofilament proteins in mouse neuroblastoma cell line Neuro2a (N2a).
Conversely, the single components of OligoGM1 (asialo-OligoGM1, OligoGM2, OligoGM3, sialic acid or galactose) are not able to induce a neuro-like morphology. The neurodifferentiative effect is exerted instead by fucosyl-OligoGM1.
Contrarily to GM1, exogenous OligoGM1 never integrates in the plasma membrane composition and does not belong to the intracellular metabolism: the unique interaction with N2a is characterized by a weak non-covalent association to the plasma membrane that suggests the existence of an OligoGM1-stimulated target on the cell surface.
In fact, the neurotrophic properties of GM1 oligosaccharide are exerted by activating TrkA receptor and the following cascade leading to neurodifferentiation event.
The second part of this study elucidates the interaction between GM1 and TrkA, revealing a direct association of OligoGM1 to an extracellular domain of the receptor.
Photolabeling experiments, performed employing nitrogen azide radiolabeled GM1 derivatives, show a direct association of the oligosaccharide chain to TrkA.
Moreover, a bioinformatics study reveals that OligoGM1 fits perfectly in a pocket of the TrkA-NGF complex, stabilizing and favoring their intermolecular interactions as revealed by the increase in energy associated to the new complex TrkA-NGF-OligoGM1. A precise molecular recognition process between OligoGM1 and a specific extracellular domain of the TrkA receptor is supposed. According to the weak association of OligoGM1 to the cell surface, no covalent bounds between OligoGM1 and TrkA-NGF complex were found.
For the first time the molecular mechanism by which GM1 exerts its neurodifferentiative potential was identified, finding out a direct interaction between the oligosaccharide portion and an extracellular domain of TrkA receptor responsible for enhancing the signal transduction related to the neurodifferentiation pathway.
8
FATO, PAMELA. "EVALUATION OF THE GM1 OLIGOSACCHARIDE ROLE IN NEURONAL DIFFERENTIATION." Doctoral thesis, Università degli Studi di Milano, 2020. http://hdl.handle.net/2434/796885.
Full textAbstract:
GM1 is a mono-sialo ganglioside with amphiphilic character due to the presence of a hydrophobic group, ceramide, and a hydrophilic head (oligosaccharide chain). GM1 represents one of the most important modulator in the nervous system where it is involve in maturations of neurons, differentiation, increase responses to neurotrophic factors, protection against neuronal death and reduction brain damage. The effects of GM1 are known in vitro and in vivo, but the molecular mechanism of action underlying the GM1 properties is unknown. The present work aims to analyze the mechanism of action of GM1, and in particular to demonstrate that the effects of this ganglioside are attributable to the action of its oligosaccharide portion (OligoGM1) and not to the entire molecule. To reach our purpose we used mouse neuroblastoma cell line Neuro2a (N2a). Like GM1, OligoGM1 promotes neurodifferentiation by increasing both neurite elongation and the expression of neurofilament proteins in N2a cell. A similar effect was obtained with the use of fucosyl-OligoGM1 but not with the administration of asialo-OligoGM1, OligoGM2, OligoGM3, sialic acid or galactose (single components of Oligo GM1). OligoGM1, in N2a cells, activates ERK1/2 pathway binding to the NGF specific receptor TrkA present on the cell surface. To study this mechanism of action we used tritium labeled derivative of OligoGM1. The activator for GM1 mediated functions (differentiation and protection) is the interaction between OligoGM1 and TrkA. This was established with the use of a TrkA inhibition.
With a bioinformatics study it was established that OligoGM1 inserts in a pocket of the TrkA-NGF complex. An increase in energy associated to the complex TrkA-NGF-OligoGM1 indicates greater stability of intermolecular interactions.
All the results lead to the conclusion that the bioactive portion of GM1, in neuronal differentiation and protection, is represented by its hydrophilic chain (OligoGM1). These conclusions open up new perspectives on the therapeutic use of gangliosides.
9
LUNGHI, GIULIA. "GM1 OLIGOSACCHARIDE MODULATION OF CALCIUM SIGNALLING IN NEURONAL FUNCTIONS." Doctoral thesis, Università degli Studi di Milano, 2020. http://hdl.handle.net/2434/792078.
Full textAbstract:
It has been already demonstrated that the oligosaccharide chain (OligoGM1) of the ganglioside GM1, β-Gal-(1-3)-β-GalNAc-(1-4)-[α-Neu5Ac-(2-3)]-β-Gal-(1-4)-β-Glc-(1-1)-Ceramide, promotes neurodifferentiation in the Neuro2a murine neuroblastoma cells, used as a model, by directly interacting with the NGF specific receptor TrkA, leading to the activation of ERK1/2 downstream pathway. In this context, my PhD work aimed to investigate which other biochemical pathways, in addition to TrkA-MAPK cascade activation, are prompted by OligoGM1, with an emphasis on Ca2+ modulating factors.
A proteomic analysis (nLC-ESi-MS-MS) performed on Neuro2a cells treated with 50 µM OligoGM1 for 24 hours led to the identification and quantification of 324 proteins exclusively expressed by OligoGM1-treated cells. Interestingly, some of these proteins are involved in the regulation of Ca2+ homeostasis and in Ca2+-dependent differentiative pathways. In order to evaluate if OligoGM1 administration was able to modulate Ca2+ flow, we performed calcium-imaging experiments on Neuro2a cells using the Ca2+-sensitive Fluo-4 probe. Starting from 5 minutes upon OligoGM1 administration to undifferentiated Neuro2a, a significant increase in Ca2+ influx occurs. At the same time an increased activation of TrkA membrane receptor was observed and, importantly, the addition of a specific TrkA inhibitor abolished the OligoGM1 mediated increase of the cytosolic Ca2+, suggesting that the opening of the cell Ca2+ channels following OligoGM1 administration depends on the activation of TrkA receptor. To unveil which cellular pathway activated by OligoGM1 could lead to the increase of intracellular Ca2+, time-course immunoblotting analyses were performed. The data revealed that following TrkA activation, OligoGM1 induced the activation of phospholipase PLCγ1 which converts phosphatidylinositol 4,5-bisphosphate (PIP2) to diacyglycerol (DAG) and inositol 1,4,5-trisphosphate (IP3), the second messengers that propagate cellular signalling via Ca2+ mobilization. Moreover, we observed a hyperphosphorylation of the DAG substrate, protein kinase C (PKC), which is a priming event that enables its catalytic activation in response to lipid second messengers, and we found its enrichment in lipid rafts, events that consolidate its activation. When calcium-imaging experiments where performed in the presence of xestospongin C, a potent inhibitor of IP3 receptors on endoplasmic reticulum, a reduction of about 50% of Ca2+ influx was observed, suggesting that the Ca2+ flows moved by the OligoGM1 come not only from intracellular storages, but probably also from the extracellular environment. Accordingly, in the presence of both extracellular (EGTA) and intracellular (BAPTA-AM) Ca2+ chelators the neuritogenic effect induced by OligoGM1 was abolished.
The work described in this thesis confirms that the effects of GM1 ganglioside on neuronal differentiation are mediated by its oligosaccharide portion.
In particular, here I highlight that the oligosaccharide, initiating a signalling cascade on the cell surface, is responsible alone for the balancing of the intracellular Ca2+ levels that underlie neurite sprouting, which have historically been attributed to the whole GM1 ganglioside and its role as lipid inserted into the plasma membrane. In this way, these data give additional information on the molecular characterization of the mechanisms by which GM1 exerts its neuronal functions.
10
Kreutzer, Robert. "Charakterisierung des genetischen Defektes der GM1-Gangliosidose beim Alaskan Husky." Wettenberg : VVB Laufersweiler, 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=976072424.
Full text
11
CORMIER, PHILIPPE. "Neuropathies multifocales avec blocs de conduction persistants, anticorps anti-gm1." Angers, 1993. http://www.theses.fr/1993ANGE1099.
Full text
12
Meehan, Gavin Robertson. "The roles of anti-GM1 complex antibodies in autoimmune neuropathies." Thesis, University of Glasgow, 2015. http://theses.gla.ac.uk/7145/.
Full textAbstract:
Anti-ganglioside antibodies have been implicated in autoimmune neuropathies for several decades. They are thought to elicit injury through binding to sites in the peripheral nervous system, where they activate the complement pathway to induce cell death. Patient serum is therefore regularly screened for these antibodies to aid in the diagnosis of various conditions. Recent work has found that complexes composed of gangliosides and other glycolipids can improve the detection of these antibodies beyond the signals detected to the single ganglioside species. In MMN research, complexes comprised of GM1 and GalC have been found to significantly enhance antibody detection in patient sera. In certain patients, however, antibody binding was only detected against these complexes and not the single antigens. This led some researchers to hypothesise that an unidentified class of antibody may have arisen that binds specifically to a neoepitope formed by the combination of the two glycolipids. It has also been hypothesised that that this complex may be the true target of immune mediated attack in MMN. This thesis sought to address this hypothesis by either cloning these antibodies directly from patient serum or through active immunisations with mice. Analysis of previously generated human monoclonal antibodies indicated that their behaviours were modified by complexes containing particular gangliosides or glycolipids. Furthermore, the antibodies behaviours were found to diverge, when they were screened against complexes comprised of gangliosides and different concentrations of accessory lipids. These findings suggested that the accessory lipids were interacting with the ganglioside headgroups to modify the presentation of different binding epitopes. This indicated that conformational modulation, rather than neo-epitope formation, may be responsible for complex enhancement Cloning antibodies from patient sera was unsuccessful but examination of the screening techniques suggested that the appearance of complex-dependent antibodies may have been an artefact. Attempts to induce complex-specific responses in mice were similarly unsuccessful but several anti-ganglioside and anti-sulfatide antibodies were created. The subsequent chapters focused on the characterisation of these antibodies and indicated that most of them bound well to solid-phase assays, cells and tissue and may therefore be of use in future studies. Taken together, the data from this thesis suggests that complex-dependent antibodies may not exist but are merely low concentrations of anti-ganglioside antibodies that are cis-enhanced by particular lipids. Future work should therefore focus on assessing how the ganglioside microenvironment modifies epitope presentation and how this affects the binding capabilities of antiganglioside antibodies.
13
Coburg, Alexander von. "Untersuchung der Lipidnachbarschaft von derivatisiertem GM1 in Modellmembranen und kultivierten Zellen." [S.l.] : [s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=970110855.
Full text
14
Vieira, Matheus Barbosa. "Detecção de cinco novas mutações em pacientes brasileiros com gangliosidose GM1." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2006. http://hdl.handle.net/10183/6718.
Full textAbstract:
A Gangliosidose GM1 é um Erro Inato do Metabolismo (EIM) causado pela deficiência da enzima B-galactosidase ácida. Essa doença é caracterizada pelo acúmulo de metabólitos não degradados, principalmente gangliosídeo GM1, nos lisossomos de vários tipos celulares. Baseado na idade de início e na atividade residual da enzima, a Gangliosidose GM1 é classificada em três diferentes tipos: infantil, juvenil e adulto. O gene da B-galactosidase ácida (GLB1, GeneBank M27507) está situado no cromossomo 3 e possui mais de 60 kb, contendo 16 exons. Cerca de 50 mutações associadas à doença estão descritas na literatura. No sul do Brasil, há uma alta freqüência dessa doença (1:17.000 nascidos vivos). Neste trabalho, vinte pacientes diagnosticados no Hospital de Clínicas de Porto Alegre (Brasil) tiveram o gene GLB1 investigado por SSCP (Single Strand Conformational Polymorphism) usando DNA extraído de sangue periférico. Através desta triagem foram encontradas 52 alterações de mobilidade do DNA, indicando a presença de mutações. As amostras relativas aos exons 2 e 15 foram submetidas a sequenciamento direto com seqüenciador ABI31O(Applied Biosystens) utilizado kit BigDye 3.1. Cinco novas mutações no gene GLB1 (F63Y, R38G, Y36S, Y64F e R59C) e duas mutações já descritas (R59H e 1622-1627insG) foram encontradas. Este trabalho possibilitou a genotipagem completa de 6 pacientes e parcial de 5, e direcionou a investigação de mutações, contribuindo diretamente no diagnóstico da enfermidade e permitindo a realização de estudos de correlação genótipo/fenótipo destes pacientes.GM1 Gangliosidosis is a Iysosomal storage disease caused by r3- galactosidase deficiency. As a result of this defect there is a huge accumulation of GM1 ganglioside in tissues of affected patients. Gangliosides are glycosphingolipids present in high concentration in neural tissues. The localization of these lipids explain in part the neurodegeneration present in patients. The r3-galactosidasegene (GLB1-Gene Bank M27507) is located on chromosome 3 and spands more than 60 kb and it is formed by 16 exons. Over than 45 mutations were found in this gene up to now. In southern Brazil the high frequency of GM1 Gangliosidosis (1:17.000 live born) justify the aim of this work, that is to genotype those patients with GM1 Gangliosidosis, by, fist screening they DNA by SSCP (Single Strand Conformational Polimorphism) and than, sequencing in automated apparatus. The screening of 16 exons from 20 patiens gave us the information that 52 mobility changes of DNA Single Strand were found, suggesting possibility of mutations. Samples from exons 2 and 15 were submitted to direct sequencing in ABI310 (Applied Biosystems) using Big Dye3.1 terminator Kit. Five new mutations were found in GLB1 gene (F63Y, R38G, Y36S, Y64F and R59C) and two mutations described previously (R59H and 1627insG). This investigation gave support to complete genotype 6 patients with GM1 Gangliosidosis, partial genotype 5 patients and gave a good support for future analysis in GLB1 gene to correlate genotype and phenotype easily.
15
Oblinger, Janet L. "Cell-context dependent modulation of receptor tyrosine kinases by ganglioside GM1 /." The Ohio State University, 2002. http://rave.ohiolink.edu/etdc/view?acc_num=osu1486402544589353.
Full text
16
Sperb, Fernanda. "Gangliosidose GM1 : aspectos clínicos e moleculares da população brasileira e a busca de novas terapias para o tratamento da doença." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2012. http://hdl.handle.net/10183/54444.
Full textAbstract:
A deficiência hereditária da enzima lisossômica G-galactosidase, codificada pelo gene GLB1, causa duas doenças humanas clinicamente distintas, a Gangliosidose GM1 e Morquio B. Clinicamente, pacientes com Gangliosidose GM1 mostram graus variados de neurodegeneração e anormalidades esqueléticas, enquanto que os com Mórquio B apresentam displasia esquelética e opacidade de córnea, sem envolvimento do sistema nervoso central. Neste trabalho foi realizada a análise da freqüência populacional das mutações mais comuns no Brasil para Gangliosidose GM1, e a tentativa de comprovação da hipótese de efeito fundador destas mutações. Também foi realizada a pesquisa clínica e molecular de pacientes com Gangliosidose GM1 na tentativa de caracterizar os pacientes brasileiros, identificando novas mutações e traçando um panorama clínico e genético dessa população. Com a intenção de compreender os efeitos das novas mutações encontradas entre os pacientes brasileiros sobre a estrutura da proteína codificada por GLB1, modelos tridimensionais foram gerados através de ferramentas de bioinformática. Neste estudo foi possível predizer as conseqüências biológicas destas mutações, correlacionando às mesmas com os achados fenotípicos dos pacientes. Um esforço na busca de novas terapias para a doença também foi realizado, visto que não existe tratamento eficaz contra a Gangliosidose GM1. Para tanto, três terapias foram testadas em fibroblastos de paciente com a mutação mais comum encontrada na população brasileira: a terapia de tradução alternativa com o uso de geneticina e cloranfenicol, e a terapia de chaperonas farmacológicas, através do uso de galactose. Nenhuma das terapias foi eficaz no aumento da atividade enzimática da G-galactosidase, mas um aumento da expressão gênica pode ser observado para o gene GLB1.The inherited deficiency of the lysosomal enzyme G-galactosidase, encoded by the gene GLB1, causes two clinically distinct human diseases: GM1Gangliosidosis and Morquio B. Clinically, patients with GM1 Gangliosidosis show varying degrees of neurodegeneration and skeletal abnormalities, while Morquio B shows skeletal dysplasia and corneal opacity, without involving the central nervous system. This work was performed to analyze the population frequency of the most common mutations in Brazil for Gangliosidosis GM1, and the attempt to prove the hypothesis of a founder effect for these mutations. A clinical and molecular research in patients with Gangliosidosis GM1 was also performed, in an attempt to characterize Brazilian patients, identifying new mutations and drawing a picture of the clinical and genetic aspects of this population. Trying to understand the effects of new mutations found among Brazilian patients on the structure of the protein encoded by GLB1, threedimensional models were generated using bioinformatics tools. In this study it was possible to predict the biological consequences of these mutations, correlating them with the phenotypic findings of the patients. An effort in finding new therapies for the disease was also performed, since there is no effective treatment for GM1 Gangliosidosis. Therefore, three treatments were tested in fibroblasts from patients with the most common mutation found in Brazil: the alternative translation therapy using geneticin and chloramphenicol, and the pharmacological chaperone therapy, using galactose. None of these therapies was effective in increasing the enzyme activity of G-galactosidase, but an increase in gene expression could be observed in the GLB1 gene.
17
Santamaría, Merino Raúl. "Anàlisi genètica i molecular de les malalties Gangliosidosi GM1 i Morquio B." Doctoral thesis, Universitat de Barcelona, 2007. http://hdl.handle.net/10803/1881.
Full textAbstract:
En aquesta tesi s'ha realitzat una aproximació genètica i molecular a les malalties Gangliosidosi GM1 i Morquio B. Aquestes dues malalties són causades per mutacions en un únic gen, el gen GLB1. Aquest gen codifica per la proteïna beta-galactosidasa lisosòmica, de manera que mutacions al gen GLB1 alteren la funcionalitat d'aquesta proteïna. Això pot conduir a l'acumulació dels diferents substrats que normalment són degradats per la beta-galactosidasa: el gangliòsid GM1, el queratà sulfat i diferents oligasacàrids proteics. En aquesta tesi es presenten els resultats de la cerca de mutacions en 49 pacients amb Gangliosidosi GM1 i 5 amb Morquio B. Els pacients estudiats provenien bàsicament d'Espanya i d'Argentina. Es van poder identificar 52 mutacions diferents de les que 32 no havien estat descrites prèviament. A més a més, per a la majoria de mutacions identificades es va poder establir una correlació entre la mutació trobada i un fenotip determinat de la malaltia. La mutació R59H va ser la mutació més prevalent a les poblacions analitzades, essent especialment prevalent als pacients d'ètnia gitana, on aquesta va ser l'única mutació descrita. A més a més, en aquests pacients la mutació R59H sempre es va trobar associada a un mateix haplotip, cosa que indicaria un origen únic del canvi R59H dins de la població gitana.Posteriorment, algunes de les mutacions identificades van ser expressades in vitro utilitzant com a sistema d'expressió les cèl.lules COS-7 transfectades amb Lipofectamina. D'aquesta manera es van expressar 15 variants mutades de la beta-galactosidasa. Les variants causants de la forma infantil (la forma més severa) van mostrar una activitat enzimàtica residual nul.la, mentre que 3 variants associades a formes més lleus (el tipus adult i la malaltia de Morquio B) van resultar en activitats residuals amb un rang del 7-15%. Per altra banda, 3 canvis que eren polimòrfics (no patogènics) van ser els que van presentar una activitat enzimàtica residual més elevada, al voltant del 30-60%. Així doncs, es va poder concloure que el sistema d'expressió emprat era un bon sistema per establir correlacions entre les activitats residuals de les variants mutades i el fenotip associat a cadascuna d'elles.
Finalment, es van dur a terme una sèrie d'experiments per entendre el mecanisme que regula el procés d'splicing alternatiu del gen GLB1. Aquest gen codifica dues proteïnes diferents (la beta-galactosidasa i l'EBP) gràcies a un mecanisme d'splicing alternatiu. Al transcrit de l'EBP, els exons 3, 4 i 6 són exclosos del transcrit madur. Diferents experiments van mostrar que el mecanisme d'NMD ("Nonsense-mediated decay") s'encarrega d'eliminar les combinacions d'exons errònies, fent que únicament els dos transcrits funcionals romanguin estables a la cèl.lula. Paral.lelament, mitjançant la cotransfecció de plasmidis que codificaven diferents proteïnes SR junt amb un minigèn construït amb els exons implicats en l'splicing alternatiu del gen GLB1, es va poder comprovar que les proteïnes SR tenien la capacitat de modificar la proporció en que es generaven les diferents combinacions d'exons en els transcrits obtinguts a partir del minigèn. Això indicaria que les proteïnes SR, que juguen un paper essencial en el procés d'splicing cel.lular, podrien tenir també una funció en la regulació de l'splicing alternatiu del gen GLB1.
18
Valls, Comamala Victòria 1987. "Targeting aging and Alzheimer's disease : from GM1 ganglioside to amyloide-β peptide." Doctoral thesis, Universitat Pompeu Fabra, 2018. http://hdl.handle.net/10803/664938.
Full textAbstract:
Aging is the main challenge that humanity will face on the near future. Brain aging is associated with cognitive deficiencies and is the main risk factor for Alzheimer’s Disease (AD). AD is the most common neurodegenerative disease leading to dementia caused by the aggregation of amyloid-β peptide (Aβ). In this thesis, we have shown that neuronal aging leads to alteration in the ganglioside membrane content. Specifically, increased levels of GM1 ganglioside in membrane leads to a decrease in the calcium entry through NMDA receptors and a reduction of dendritic spines. Overall, pointing a role in the alterations in learning and memory associated to aging. On the other hand, we have showed the inhibitory effect of the human gamma immunoglobulins (IgG) in Aβ aggregation through the antigen-binding fragment (Fab), which binds to Aβ blocking fibrillation progression.L’envelliment de la població és i serà un gran repte per la nostra societat en els pròxims anys. L’envelliment cerebral està associat amb deficiències cognitives i és el principal factor de risc pel desenvolupament de la malaltia d’Alzheimer. L’Alzheimer és la malaltia neurodegenerativa que més freqüentment provoca demència i és causada per l’agregació del pèptid β-amiloide (Aβ). En aquesta tesis hem demostrat que l’envelliment neuronal condueix a alteracions en el contingut de gangliòsids de les membranes. Particularment, l’increment del gangliòsid GM1 en la membrana condueix a una disminució en l’entrada de calci a través dels receptors de NMDA i a una reducció de les espines dendrítiques. En conjunt, indicant el rol de GM1 en les alteracions en l’aprenentatge i la memòria que es produeixen en l’envelliment. Per una altra banda, hem demostrat l’efecte inhibitori de gamma immunoglobulina humana (IgG) en la inhibició de l’agregació de l’Aβ a través del contacte del fragment d’unió a l’antigen (Fab). Fab s’uneix a Aβ inhibint la progressió de la fibril·lació.
19
Fletcher, Marianne Elizabeth. "The interaction of GM1 ganglioside with cholera toxin on membranes of cells." Thesis, University of Edinburgh, 1991. http://hdl.handle.net/1842/26508.
Full textAbstract:
Cholera toxin (molecular weight 84kD) binds with high affinity (Kd = 10 -9M) to GM1 ganglioside on the outer surface of most eukaryotic cells before all or part of the molecule is internalised and activation of adenylate cyclase occurs. The GM1 ganglioside is believed to diffuse laterally on the cell surface. There is also evidence to suggest that cholera toxin requires multivalent binding to GM1 before it can activate adenylate cyclase. The effect of cholera toxin binding on the lateral diffusion of GM1 was examined using the Fluorescence Recovery after Photobleaching technique either with fluorescently labelled toxin or with inserted, fluorescently labelled GM1 ganglioside. Both toxin-receptor complex and receptor alone showed the same percentage mobility (about 60-70%) on the surface of the NIH 3T3 cells (a fibroblast cell line) and both had a lateral diffusion coefficient of about 1 x 10-9 cm2s-1. This result shows that bound toxin mobility does not differ from inserted ganglioside mobility. An interpretation of the results may be that GM1 molecules were compartmentalised on the fibroblast cell surface into mobile and immobile areas. The involvement of non-coated invaginations in cholera toxin internalisation was confirmed by preliminary binding experiments with colloidal gold conjugated cholera toxin. The cholera toxin was also used as a probe to locate GM1 intracellularly by the Post-Embedding Immunogold technique on mouse small intestine (target tissue for cholera toxin). A previously unreported, specific binding to the heterochromatin of the nucleus of mouse intestinal cell was discovered. The intracellular localisation of GM1 has previously mainly been studied by cell fractionation studies which indicated that only a small amount of total cell ganglioside is found within the nucleus. This binding of cholera toxin to the nucleus was further investigated using biochemical binding studies which also appeared to indicate a specific binding site for the toxin within the nucleus which has not been fully characterised.
20
Kreutzer, Robert [Verfasser]. "Charakterisierung des genetischen Defektes der GM1-Gangliosidose beim Alaskan Husky / Robert Kreutzer." Wettenberg : VVB Laufersweiler, 2005. http://d-nb.info/976072424/34.
Full text
21
Müller, Gundi. "Die GM1-Gangliosidose beim Alaskan Husky unter besonderer Berücksichtigung der neuropathologischen Veränderungen /." Göttingen : Cuvillier, 2001. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=009411136&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
Full text
22
Oliveira, Filho Osvaldo Mendes de 1964. "Functional and histomorphometric evaluation of median nerve lesion in wistar rats treated with GM1 = Avaliação funcional e histomorfométrica da lesão de nervo mediano em ratos wistar tratados com GM1." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/313131.
Full textAbstract:
Orientador: William Dias BelangeroTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas
Made available in DSpace on 2018-08-26T07:47:22Z (GMT). No. of bitstreams: 1 OliveiraFilho_OsvaldoMendesde_D.pdf: 2509545 bytes, checksum: 6effb16e1eedd8b6d33c41daea640b76 (MD5) Previous issue date: 2014
Resumo: O objetivo deste trabalho foi comparar através da avaliação funcional pelo grasping test e análise histomorfométrica o tratamento da lesão do nervo mediano em ratos de linhagem Wistar através da microneurorrafia tradicional com a microneurorrafia associada à administração do monossialogangliosídeo (GM1) e avaliar especificamente se o GM1 melhora a regeneração axonal do nervo mediano e a função da musculatura por ele inervado. Material e Método: Foram empregados 32 ratos machos de linhagem Wistar. Destes, foram selecionados aleatoriamente 10 animais, grupo 0, para obtenção da força de preensão média em ratos normais, antes do procedimento cirúrgico. Esses animais foram reintegrados aos grupos. Foram criados o grupo I, com 10 animais, em que foi feita ressecção de 5 mm do nervo mediano do membro anterior direito e não foi submetido a nenhum tratamento. Nos outros grupos foi produzida uma lesão transversa do nervo mediano proximalmente ao epicôndilo medial criando-se os grupos II, tratados com microneurorrafia epineural externa e o grupo III, tratado com a microneurorrafia epineural externa associada à administração intraperitoneal de GM1. A cirurgia foi realizada imediatamente após a lesão e a técnica utilizada foi a sutura término-terminal. Foi realizada análise funcional semanal durante seis semanas através do teste de preensão da musculatura flexora dos dedos, que é específico para avaliar a ação do nervo mediano. Após esse período, os animais foram submetidos a eutanásia. As porções proximal e distal dos nervos foram coradas com azul de toluidina a 1% e realizada a análise histológica. Pela análise morfométrica obteve-se o número e diâmetro dos axônios nos cotos proximais e distais, criando-se uma nova fórmula com inclusão tanto do número como do diâmetro dos axônios para a avaliação da regeneração nervosa. Resultados: Os valores médios da força de preensão exercida pelos ratos do grupo 0 foram comparados aos animais dos grupos II e III através da análise de variância (ANOVA one way). Para a comparação dos valores médios da força realizada pelos ratos do grupo II e III foi feito o teste de Wilkoxon. Do ponto de vista funcional, o grupo III imprimiu uma maior força média com erro menor que 5% e realizou o teste de preensão mais precocemente. O grupo tratado com o GM1 apresentou um número 28% maior de axônios regenerados no segmento distal, com padrão histológico mais organizado e homogêneo e uma diferença significativa no diâmetro médio dos mesmos. Conclusão: Pode-se afirmar com erro menor que 5% que os grupos II (microneurorrafia) e III (microneurorrafia e GM1) apresentaram diferenças em relação à recuperação funcional, tendo o grupo III reagido melhor ao teste de preensão. O padrão histológico do grupo III apresentou maior grau de mielinização, tendo-se observado maior diâmetro médio nos axônios dos cotos distais (p=0,0056). Há um significativo indicio (p=0,0536) de que a utilização do GM1 nas cirurgias dos nervos periféricos melhora o padrão de regeneração axonal. Palavras Chaves: GM1, nervo mediano, regeneração axonal, ratos Wistar, avaliação funcional, morfometria
Abstract: Summary OBJECTIVES: The objective of this study was to compare the treatment of nerve median injuries in Wistar rats submitted to traditional microneurorraphy with the treatment that combined microneurorraphy and monossialoganglioside (GM1) administration while also specifically evaluating if GM1 promotes an increase in median nerve axonal regeneration, thus improving the function of the muscles in its territory of innervation. This comparison was done through functional evaluation measured by the grasping test and histomorphometric analysis. MATERIAL AND METHODS: Experiments were performed in thirty-two Wistar rats. Among them, 10 were randomly selected (group 0) to determine the average grasping strength in normal rats. These animals were then reunited with the others. There were three groups: group I (control group), submitted to a 5 mm lesion in the median nerve of the right forelimb and no treatment. Group II, submitted to lesion of the median nerve proximal to the medial epicondyle, treated with external epineural microneurorraphy, and group III, submitted to the same lesion and treated with external epineural microneurorraphy associated with intraperitoneal administration of GM1. Surgery was undertaken immediately after the damage to the nerve and end-to-end suture was used. Functional analysis through the grasping test of the flexor muscles of the fingers was assessed weekly; this test is specific to evaluate the action of the median nerve. In this experimental model, the animal is lifted by the tail and is stimulated to grasp a bar with its paw; the bar is located on the top of a conventional digital balance. While grasping the bar with its paw, the rat continued to be held by the tail until it releases the bar and the number on the scale is registered. After the functional evaluation the animals were euthanized. The proximal and distal portions of the nerves were colored with 1% toluidine blue dye. After the histologic exam, morphometric analysis was done by counting the number and diameter of the axons in the proximal and distal stumps. A new formula was designed including the number and diameter of the axons to evaluate nerve regeneration. RESULTS: The mean values of grasping strength exerted by rats in group I (control), were compared with group II (only microneurorraphy) and group III (microneurorraphy and GM1) through the analysis of variance (ANOVA one way). To compare the mean values of the strength sustained by rats in groups II and III, the Wilkoxon test was applied. From the functional perspective, the group that received GM1 performed the grasping test earlier, exerting a greater mean strength (error inferior to 5%). The microscopic analysis demonstrated that the group treated with GM1 showed a higher number of regenerated axons better organized and homogenous. And also that this group had a slightly thicker myelin sheath. There was a significant difference in the mean diameter of the axons of the distal segment and a number 28% higher of regenerated axons in the group treated with GM1. CONCLUSIONS: The authors can state with error inferior to 5% that the groups II and III showed differences in relation to functional recovery, group III performing better when submitted to the grasping test. Histological pattern of the group that received GM1 showed a higher degree of myelination. It was observed a greater mean diameter in the axons of distal stumps (p=0,0056). There is a significant indication (p=0,0536) that the use of GM1 in peripheral nerve surgery improves the pattern of axonal regeneration. Key Words: GM1, median nerve, axonal regeneration, Wistar rats, functional evaluation, morphometry
Doutorado
Medicina Interna
Doutor em Ciências Médicas
23
Verachini, Laurence. "Rôle de la compartimentation subcellulaire des tyrosine kinases Src dans la signalisation induite par le PDGF." Montpellier 2, 2007. http://www.theses.fr/2007MON20160.
Full textAbstract:
Mon travail de thèse a consisté en l'étude de la régulation spatiale des tyrosine kinases Src dans la signalisation induite par le PDGF. J'ai montré que deux populations de Src étaient impliquées dans deux réponses cellulaires distinctes : la première localisée dans les caveolae est impliquée dans la synthèse d'ADN et la seconde située en dehors de ces structures induit la formation des ruffles dorsaux d'actine. Ce travail a également révelé une nouvelle fonction de la protéine adaptatrice transmembranaire CBP/PAG. En modulant le taux membranaire du ganglioside GM1, CBP/PAG affecte la localisation du récepteur du PDGF dans les caveolae inhibant ainsi son association avec Src. Cette nouvelle fonction est dépendante de l'enzyme sialidase Neu3 qui permet la synthèse du GM1 dans les caveolae. Ce travail met en évidence le rôle crucial de la compartimentation subcellulaire des kinases Src dans la régulation de leur fonction et un nouveau mécanisme de régulation de la voie Src mitogénique via CBP/PAGDuring the course of my work, I focused on the study of Src kinases regulation in PDGF-induced signaling. Firstly, we show that PDGF uses two distinct pools of Src kinases for mitogenesis and cystoskeleton rearrangement: the first one localized in caveolae is involved in DNA synthesis and the second one localized outside these structures induces dorsal ruffles formation. Secondly, our data identify a new mechanism for Src mitogenic regulation involving the transmembrane adaptor protein CBP/PAG. By modulating ganglioside GM1 membrane level, CBP/PAG displaces PDGF receptor from caveolae which prevents Src activation and mitogenic signaling. In addition, CBP/PAG-induced GM1 accumulation depends on the Neu3 sialidase, an enzyme of gangliosides metabolism. In conclusion, this work provides strong evidence that spatial regulation of Src kinases is an important feauture of signaling specificity and report a novel regulatory mechanism of Src mitogenic function by CBP/PAG
24
MENA, CHANTAL. "Approche clinique et paraclinique du diagnostic des encephalopathies metaboliques progressives : a propos d'un cas de gangliosidose a gm 1 de type ii." Nantes, 1989. http://www.theses.fr/1989NANT114M.
Full text
25
Ikeda, Keisuke. "Physicochemical study on Alzheimer's amyloid-β fibril formation mediated by GM1 ganglioside cluster." 京都大学 (Kyoto University), 2009. http://hdl.handle.net/2433/124045.
Full text
26
Heinecke, Karie A. "Myelin abnormalities in the optic and sciatic nerves of mice with GM1-gangliosidosis." Thesis, Boston College, 2014. http://hdl.handle.net/2345/bc-ir:103611.
Full textAbstract:
Thesis advisor: Thomas N. SeyfriedGM1 gangliosidosis is a glycosphingolipid lysosomal storage disease caused by a genetic deficiency of acid b-galactosidase (β-gal), the enzyme that catabolyzes GM1 within lysosomes. Accumulation of GM1 and its asialo form (GA1) occurs primarily in the brain, leading to progressive neurodegeneration and brain dysfunction. Less information is available on the neurochemical pathology in optic nerve and sciatic nerve of GM1- gangliosidosis. Here we analyzed the lipid content and myelin structure in optic and sciatic nerve in 7 and 10 month old normal β-gal (+/?) and GM1-gangliosidosis β-gal (-/-) mice. Optic nerve weight was lower in the β-gal -/- mice than in unaffected β-gal +/? mice, but no difference was seen between the normal and the β-gal -/- mice for sciatic nerve weight. The concentrations of GM1 and GA1 were significantly higher in optic nerve and sciatic nerve in the β-gal -/- mice than in β-gal +/? mice. The content and composition of myelin-enriched cerebrosides, sulfatides, plasmalogen ethanolamines were significantly lower in optic nerve of β-gal -/- mice than in β-gal +/? mice, however cholesteryl esters were enriched in the β-gal -/- mice. No significant abnormalities in these myelin enriched lipids were detected in sciatic nerve of the β-gal -/- mice. The abnormalities in GM1 and myelin lipids in optic nerve of β-gal -/- mice were also associated with abnormalities in the X-ray diffraction pattern including myelin content in fresh nerves [M/(M +B)] and periodicity (d). With the exception of a slight reduction in myelin content, no abnormalities in the X-ray diffraction pattern were observed in sciatic nerve of β-gal -/- mice. The results indicate that neurochemical pathology is greater in optic nerve than in sciatic nerve of β-gal -/- mice
Thesis (MS) — Boston College, 2014
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Biology
27
Fong, Tamara G. "Effects of GM1 Ganglioside on the aged brain : biochemical, morphological, and behavioral considerations /." The Ohio State University, 1996. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487941504294598.
Full text
28
Cadot, Bruno. "P63alpha, membre de la famille de p53 : structure, interaction et importance du domaine SAM de p63alpha." Paris 6, 2005. http://www.theses.fr/2005PA066045.
Full text
29
Furian, Ana Flávia. "Papel do óxido nítrico e de canais de potássio na vasodilatação induzida pelo gangliosídeo GM1." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2009. http://hdl.handle.net/10183/17746.
Full textAbstract:
O monossialotetra-hexosilgangliosídeo (GM1) é um glicoesfingolipídio presente nas membranas celulares que exerce propriedades antioxidantes e neuroprotetoras. Os mecanismos neuroquímicos envolvidos na neuroproteção induzida pelo GM1 não são completamente conhecidos. Recentemente, foi demonstrado que o GM1 aumenta a quantidade da enzima catalase no SNC por causar vasodilatação, e sugeriu-se que a vasodilatação possa ser responsável pelas suas propriedades neuroprotetoras. Contudo, o mecanismo pelo qual o GM1 causa vasodilatação não foi determinado. Dado o papel central do óxido nítrico (NO), bem como de canais de potássio no controle do tonus do músculo liso, o objetivo deste trabalho foi determinar a participação do NO e de canais de K+ na vasodilatação induzida pelo GM1. Primeiramente, avaliamos o efeito da administração de L-NAME (metil éster de NGnitro- L-arginina, 60 mg/kg, i.p.), um inibidor da enzima óxido nítrico sintase (NOS), na vasodilatação cerebral induzida pelo GM1 (50 mg/kg, i.p.) em ratos Wistar machos adultos. Verificamos que o L-NAME preveniu o aumento do diâmetro dos vasos cerebrais induzido pelo GM1. Tendo em vista a participação do NO no efeito vasodilatador do GM1, determinamos o conteúdo de nitritos e nitratos (NOx), bem como de hemoglobina (Hb) no hipocampo e no córtex cerebral, 15, 30 e 60 min após a administração de GM1. Observamos um aumento no conteúdo de Hb e uma redução dos níveis de NOx após 60 min. Dado que nitritos e nitratos podem ser removidos in vivo pelo sangue por ligação com a Hb, um possível efeito do GM1 sobre o conteúdo de NOx poderia ser mascarado. No intuito de contornar essa situação, determinamos os níveis de NOx em fatias de córtex cerebral incubadas com GM1 (0, 10, 30 e 100 µM). Verificamos que o GM1 (100 µM) aumentou os níveis de NOx em 30 min e, reduziu o conteúdo em 60 min, sem alterar o conteúdo de Hb. Ainda, mostramos que o L-NAME (100 µM) reverte o aumento de NOx induzida pela incubação com GM1 (100 µM, por 30 minutos) em fatias de córtex cerebral, sem alterar o conteúdo de Hb. Tendo em vista a participação do NO no efeito vasodilatador do GM1, e conhecendo a capacidade de ligação da Hb com o NO, determinamos a via de relaxamento muscular mediada pelo NO em anéis de artéria mesentérica superior isolada de ratos. Verificamos que o GM1 causou relaxamento vascular através de uma curva cumulativa de concentrações (10 nM a 3 mM), e também determinamos que a participação do endotélio é fundamental para este efeito. O efeito vasorelaxante do GM1 além de ser dependente da presença do endotélio vascular, é completamente bloqueado pela presença de L-NAME (1 µM), da mesma forma que os resultados encontrados nos experimentos com vasos cerebrais. Considerando que o NO formado no endotélio ativa a guanilato ciclase (GCs), também testamos o efeito do inibidor desta enzima (ODQ-1H-[1,2,4]oxadiazolo[4,3-alpha]quinoxalin-1-one) no efeito vasorelaxante do GM1. Neste caso, o efeito do GM1 foi bloqueado parcialmente pelo ODQ (10 µM). Além da participação da GCs, avaliamos o papel dos canais de K+ no efeito vasorelaxante do GM1. Verificamos que o tetraetilamônio (1 mM), um bloqueador não seletivo, assim como a glibenclamida (10 µM), bloqueador dos canais de K+ sensíveis ao ATP bloquearam parcialmente o efeito do GM1. Por outro lado, a apamina (50 nM), um bloqueador de canais de K+ dependentes voltagem e Ca²+ (KCa) de baixa condutância não alterou o efeito do GM1, enquanto que a caribdotoxina (50 nM), um bloqueador de KCa de alta condutância deslocou a curva de relaxamento para a direita. Em resumo, neste trabalho mostramos a participação do NO e dos canais de K+ na vasodilatação induzida pelo GM1. Embora mais estudos sejam necessários para estabelecer o mecanismo vasodilatador do GM1, sugerimos que uma terapia adjunta com GM1 ou com drogas correlatas é válida em condições clínicas onde o aumento do fluxo sanguíneo é associado a um melhor prognóstico, como doenças vasculares obstrutivas e doenças neurodegenerativas.Monosialotetra-hexosylganglioside (GM1) is a glycosphingolipid present in most cell membranes which displays antioxidant and neuroprotective properties. Additionally, it has been recently demonstrated that GM1 increases catalase content in the CNS due to vasodilation, and it has been suggested that vasodilation may be responsible, at least in part, for the neuroprotective properties of GM1. However, the mechanisms underlying GM1-induced vasodilation have not been determined. Given the pivotal role of nitric oxide and potassium channels in the control of vascular tonus, we decided to investigate whether these mediators are involved in the vasodilation induced by GM1. Initially, we investigated the effect of L-NAME (NG-nitro-L-arginine methyl ester, 60 mg/kg, i.p.), an inhibitor of nitric oxide sinthase (NOS), on the cerebral vasodilation induced by GM1 (50 mg/kg, i.p.) in male wistar rats. L-NAME fully prevented the increase in outer diameter of pial vessels induced by GM1. In addition, we investigated the content of stable NO end products, namely, nitrites and nitrates (NOx), as well as the content of the hemoglobin (Hb) in the hipocampus and cerebral cortex 15, 30 and 60 min after GM1 administration. Interestingly, GM1 increased Hb content and decreased NOx content 60 min after administration. Since it has been demonstrated that NO end products like NOx can be removed from brain in vivo by blood flow, a possible effect of GM1 on NOx levels could be masked. Therefore, we decided to investigated the effect of GM1 (0, 10, 30 e 100 µM) on NOx content in slices of cerebral cortex. The incubation of slices with GM1 (100 µM) for 30 min significantly increased NOx levels. In addition, we observed decreased NOx levels after 60 min of incubation, without changes in Hb content. In order to obtain pharmacological evidence for the role of nitric oxide synthase (NOS) in GM1-induced increase of NOx content in situ, cortical slices were incubated with L-NAME (100 µM) in the presence or absence of GM1 (100 µM) for 30 minutes, and the NOx content was measured. L-NAME blunted GM1-induced increase of NOx content. Since it has been demonstrated that GM1 induces pial vessel vasodilation and increases NOx content in cerebral cortex, which are fully prevented by the nitric oxide synthase inhibitor L-NAME, we further investigated whether GM1 relaxes larger vessels, as well as the mechanisms by which GM1 causes vasorelaxation. We found that GM1 (10, 30, 100, 300 µM, 1 and 3 mM) induced vascular relaxation of the rat mesenteric artery, as determined by isometric tension studies in arterial rings contracted with 1 µM phenylephrine. The vasorelaxation induced by GM1 was abolished by endothelium removal, by incubation with LNAME (1 µM) and partially inhibited by the blockade of potassium channels by 1 mM tetraethylammonium, 10 μM glibenclamide, by the soluble guanylate cyclase inhibitor 1H- [1,2,4]oxadiazolo[4,3-alpha]quinoxalin-1-one (10 µM), and by 50 nM charybdotoxin, a blocker of large and intermediate conductance calcium-activated potassium channels. Moreover, GM1- induced relaxation was not affected by apamin (50 nM), a small conductance calcium-activated potassium channel blocker. Althogether, these results indicate that nitric oxide and potassium channels participate in the vasodilation induced by GM1. Although more studies are necessary to definitely establish the mechanisms underlying the GM1-induced vasodilation, we suggest that vasodilation may underlie some of the biological effects of exogenous GM1 ganglioside and that adjunct therapy with GM1 may be of value in clinical conditions in which increased blood flow is associated to a better prognosis, such as obstructive vascular and neurodegenerative diseases. We found that GM1 (10, 30, 100, 300 µM, 1 and 3 mM) induced vascular relaxation of the rat mesenteric artery, as determined by isometric tension studies in arterial rings contracted with 1 µM phenylephrine. The vasorelaxation induced by GM1 was abolished by endothelium removal, by incubation with LNAME (1 µM) and partially inhibited by the blockade of potassium channels by 1 mM tetraethylammonium, 10 μM glibenclamide, by the soluble guanylate cyclase inhibitor 1H- [1,2,4]oxadiazolo[4,3-alpha]quinoxalin-1-one (10 µM), and by 50 nM charybdotoxin, a blocker of large and intermediate conductance calcium-activated potassium channels. Moreover, GM1- induced relaxation was not affected by apamin (50 nM), a small conductance calcium-activated potassium channel blocker. Althogether, these results indicate that nitric oxide and potassium channels participate in the vasodilation induced by GM1. Although more studies are necessary to definitely establish the mechanisms underlying the GM1-induced vasodilation, we suggest that vasodilation may underlie some of the biological effects of exogenous GM1 ganglioside and that adjunct therapy with GM1 may be of value in clinical conditions in which increased blood flow is associated to a better prognosis, such as obstructive vascular and neurodegenerative diseases.
30
Finck, Sonja. "Gangliosidose generalisee a gmi type i : a propos d'une observation avec avance staturale et hypersecretion d'hormone de croissance." Université Louis Pasteur (Strasbourg) (1971-2008), 1989. http://www.theses.fr/1989STR1M063.
Full text
31
Wang, Yimin [Verfasser]. "Characterization of canine dorsal root ganglion neurons and growth promoting effects of GM1-gangliosides / Yimin Wang." Hannover : Bibliothek der Tierärztlichen Hochschule Hannover, 2014. http://d-nb.info/1065321368/34.
Full text
32
Okada, Takuma. "Formation of toxic fibrils of Alzheimer's amyloid β-proteins mediated by GM1 ganglioside and its inhibition." 京都大学 (Kyoto University), 2008. http://hdl.handle.net/2433/137149.
Full text
33
Garofalo, Lorella. "Nerve growth factor- andor monosialoganglioside GM1-induced neuroplasticity in brain of decorticated adult and aged rats." Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=41292.
Full textAbstract:
The ability of two putative trophic agents, nerve growth factor (NGF) and the monosialoganglioside GM1, to induce neurochemical, morphological and behavioral recovery following injury to the adult rat basalo-cortical cholinergic pathway was studied. Treatment of unilaterally decorticated rats with these agents was shown to: attenuate deficits in holinergic markers of the nucleus basalis magnocellularis (NBM), prevent shrinkage of choline acetyltransferase (ChAT)- and p75$ sp{ rm NGFR}$-immunoreactive (IR) NBM neurons, and stimulate cortical ChAT activity and high affinity choline uptake, in a dose-dependent manner with equal efficacies but different potencies. Quantitative light and electron microscopic studies, assisted by image analysis, showed that GM1 or NGF treatment also similarly attenuated lesion-induced deficits in cortical ChAT-IR fiber length. By contrast, NGF, but not GM1, treatment caused significant synaptic remodelling in the remaining cortex of adult lesioned rats; this was reflected by increases in ChAT-IR varicosity number, presynaptic terminal size, and in the number of boutons with synaptic contacts. GM1 treatment only attenuated such lesion-induced deficits. Exogenous GM1 was also shown to potentiate NGF-reduced effects on basalo-cortical cholinergic markers and on cortical synaptic remodelling, but did not affect the affinity or number of NGF binding sites in brain membranes isolated from lesioned animals. This suggests that GM1 probably affects an alternative step of the NGF signal transduction cascade to potentiate NGF effects. Moreover, NGF or GM1 treatment were also shown to: distinctly regulate striatal cholinergic markers, differ with respect to the delay possible in treatment time onset for effective protection from retrograde regeneration, and diversely affect the behaviour of these animals in passive avoidance and Morris water maze tasks. In aged rats ($>$20 months), NGF and/or GM1 treatment were also shown to effectively prevent deThe work of this thesis has thus provided evidence that the injured adult rat basalo-cortical cholinergic pathway can exhibit substantial neurochemical and morphological plasticity in response to NGF and/or GM1 treatment. In particular, it has been shown that these agents cause significant alterations in cholinergic innervation.
34
Rossi, Thiago. "Estudo do efeito do gangliosideo GM1 sobre os nervos perifericos do camundongo NOD (Non Obese Diabetic)." [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/311769.
Full textAbstract:
Orientador: Ricardo de Lima ZollnerDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas
Made available in DSpace on 2018-08-11T03:27:40Z (GMT). No. of bitstreams: 1 Rossi_Thiago_M.pdf: 1494758 bytes, checksum: f7e58a6f6f514ba2db33bcbae7ab9586 (MD5) Previous issue date: 2007
Resumo: A linhagem de camundongos NOD (non obese diabetic) desenvolve espontaneamente diabetes mellitus tipo 1 (DM-1) com marcante similaridade ao observado em humanos, que se estabelece entre 12ª e 24ª semana de vida. Os gangliosideos são glicoesfingolipídeos de membrana que contém ácido siálico em sua composição e estão presentes na maioria das células dos vertebrados sendo particularmente abundantes no sistema nervoso. Gangliosídeos exógenos são capazes de acelerar a regeneração de nervos periféricos danificados, porém tem sido relacionados com síndromes neuropáticas periféricas como a síndrome de Guilláin Barret onde os pacientes apresentam anticorpos anti-gangliosídeos especificamente contra o gangliosídeo GM1. Entretanto os mecanismos ainda permanecem controversos. Nossos resultados sugerem que administração de GM1 na dose de 100mg/kg/dia em camundongos NOD e Balb/C fêmeas a partir da 4ª semana de vida não é capaz de provocar neuropatia clínica e que animais diabéticos apresentaram maior imunoreatividade para GM1 nos nervos periféricos com presença de marcação para NGF somente em camundongos Balb/C. Os animais diabéticos tratados com GM1 demonstraram queda na atividade nervosa, em contraste os camundongos Balb/C tratados com GM1 apresentaram aumento significativo na atividade nervosa
Abstract: The strain of NOD mice (non obese diabetic) spontaneously develops diabetes mellitus type 1 (DM-1) similarity to the observed in humans. In this model, the diabetes manifestation occurs between 12th and 24th weeks of life, with presence of pancreas-specific autoantibodies. The gangliosides are glycosphingolipids of membrane that contains sialic acid in their composition and are present in the majority of cells from vertebrates and are particularly abundant in the nervous system. Exogenous gangliosides are capable to increase regeneration in damaged peripheral nerves. However, the gangliosides are related with peripheral neuropathics syndromes as the syndrome of Guilláin Barret in which the patients specifically present antibodies against gangliosides GM1, however these mechanisms still remain controversial. Our results suggest that administration of GM1 in the dose of 100mg/kg/day in female NOD and Balb/C mice at the 4th week of life is not capable to provoke clinical peripheral neuropathy and that diabetic animals present major immunoreactivity for GM1 in peripheral nerves with the presence of immunoreactivity to NGF only in Balb/C mice. Diabetic animals treated with GM1 showed lower nervous activity when compared to Balb/C mice, which presented significant increase
Mestrado
Ciencia Basica
Mestre em Clinica Medica
35
Marcon, Raphael Martus. "Estudo dos efeitos do monossialogangliosídio (GM1) e da câmara de oxigenoterapia hiperbárica na lesão medular aguda em ratos." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/5/5140/tde-08032010-103409/.
Full textAbstract:
O objetivo deste trabalho foi avaliar os efeitos do monossialogangliosídio (GM1), da câmara de oxigenoterapia hiperbárica e de ambos no tratamento da lesão medular experimental em ratos. Trinta e dois ratos Wistar com lesão medular foram divididos em 4 grupos: um grupo recebeu o monossialogangliosídio (GM1), um segundo foi submetido à oxigenoterapia hiperbárica, um terceiro recebeu os dois tratamentos e um quarto não recebeu tratamento (controle). Não houve diferença significativa entre os grupos na análise histológica, em todas as variáveis (necrose, hemorragia, hiperemia e degeneração cística, p>0,06). Também não houve nenhuma diferença na comparação entre os lados direito e esquerdo nos testes funcionais (p>0,06 para todos). Não foram encontradas diferenças nos testes motores, na comparação entre os grupos após 2, 7 21 e 28 dias de lesão medular. Mas, na avaliação após 14 dias, o Grupo 3, o qual recebeu a terapia combinada, mostrou um escore BBB significantemente maior que os outros grupos (p=0,015). Na avaliação de 28 dias, houve uma tendência dos Grupos 1 (GM1) e 3 (terapia combinada) apresentarem um escore BBB maior que o do Grupo 4 (controle), embora sem significância estatística (p=0,057). Concluiu-se que, quanto aos índices motores, a utilização do GM-1 tem efeito benéfico, embora sem diferença estatisticamente significante e que o efeito benéfico do GM-1 é antecipado através da utilização concomitante da oxigênio terapia hiperbárica.The objectives were to evaluate the effect of GM1 ganglioside, hyperbaric oxygen, and both in combination, in the treatment of experimental spinal cord lesions in rats. Thirty-two Wistar rats with spinal cord lesions were divided into four groups: one group received GM1 ganglioside, one was submitted to hyperbaric oxygen therapy, the third received both treatments, and the fourth received no treatment (control). There were no significant differences between the groups in the histological analysis, for any of the variables (necrosis, hemorrhage, hyperemia, cystic degeneration, p > 0.06). Neither were there any significant differences in the comparison of left and right sides in the functional tests (p > 0.06 for all). No significant differences were found in the locomotor ratings, in the comparison of groups at 2 days, 7 days, 21 days and 28 days after the surgical procedure. However, in the evaluation on day 14, Group 3, which received the combined therapy, showed a significantly higher BBB score than the other groups (p = 0.015). In the evaluation on day 28, there was a trend to Group 1 (GM1) and 3 (combined therapy) showed a higher BBB score than the group 4 (control), but with no significance (p=0,057). In conclusion, the is a benefit in the use of GM1 ganglioside, but with no significance and the therapeutic effect of GM1 in locomotor evaluation of rats submitted to spinal cord lesion is anticipated by hyperbaric oxygen therapy.
36
Furian, Ana Flávia. "Efeito do gangliosídeo GM1 sobre a atividade da catalase em estriado, hipocampo e córtex cerebral de ratos." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2007. http://hdl.handle.net/10183/8909.
Full textAbstract:
O monossialogangliosídeo (GM1) é um glicoesfingolipídio presente na maioria das membranas celulares que possui propriedades antioxidantes e neuroprotetoras. O GM1 protege o sistema nervoso central de vários agentes ou condições neurotóxicas, como exposição ao ácido aspártico, MPTP, ácido glutâmico, metilmalônico e glutárico, anóxia e isquemia, doença de Parkinson e Alzheimer. Os mecanismos neuroquímicos envolvidos na neuroproteção induzida pelo GM1 não são completamente conhecidos, mas a variedade de situações em que ele tem efeito neuroprotetor sugere que o GM1 interage com uma via comum, envolvida no desenvolvimento de dano celular, como o estresse oxidativo. A catalase (EC 1.11.1.6) é uma enzima antioxidante intracelular que catalisa a reação do peróxido de hidrogênio à água e oxigênio molecular, e é particularmente abundante nos eritrócitos, onde metaboliza cerca de 90% do peróxido de hidrogênio. Devido à sua baixa expressão no cérebro, ela tem sido considerada uma enzima secundária no controle dos radicais livres neste órgão. Contudo, alguns autores argumentam que, devido à sua baixa atividade ela seria um ponto de vulnerabilidade no metabolismo das espécies reativas no sistema nervoso central. Neste estudo, investigamos o efeito do GM1 sobre a atividade da catalase ex vivo e in vitro. Além disso, avaliamos o efeito da remoção dos eritrócitos dos vasos sanguíneos cerebrais, sobre a atividade da catalase, com a finalidade de estimar a contribuição da catalase eritrocitária para o aumento da catalase cerebral induzida por GM1. Nós também avaliamos se o GM1 altera o conteúdo de hemoglobina nas amostras cerebrais e a espessura dos vasos sanguíneos cerebrais. Os animais receberam duas injeções de GM1 (50 mg/kg, i.p.) ou salina (0.9 % NaCl, 1 ml/kg, i.p.), em 24 h. Trinta minutos após a segunda injeção, eles foram sacrificados por decapitação e seus cérebros foram removidos e usados nos ensaios bioquímicos. A atividade da catalase e o conteúdo de hemoglobina foram analisados no hipocampo, córtex e estriado de ratos. A administração de GM1 aumentou a atividade da catalase e o conteúdo de hemoglobina nas amostras cerebrais, mas não teve efeito sobre a catalase sanguínea. Esses efeitos foram abolidos pela perfusão transcardíaca com solução salina heparinizada. Calculamos a atividade da catalase cerebral na ausência de eritrócitos por regressão linear, utilizando os dados dos animais perfundidos e não-perfundidos, e não foi observada alteração pelo tratamento com GM1. Além disso, a adição de GM1 (100 – 1000 μM) não aumentou a atividade da catalase em fatias de córtex cerebral in vitro, sugerindo que a integridade do sistema vascular é requerida para o efeito facilitatório sobre a atividade da catalase pelo GM1. O efeito vasodilatador do GM1 foi confirmado in vivo, pois a injeção sistêmica de GM1 (50 mg/kg, i.p.) aumentou (1.5-2.5 vezes) a espessura dos vasos sanguíneos cerebrais de pequeno diâmetro. Neste estudo, nós mostramos que a vasodilatação está envolvida no aumento da atividade da catalase cerebral induzida pelo GM1. Nós sugerimos que a atividade da catalase eritrocitária tem papel antioxidante no sistema nervoso central, e que uma terapia adjunta com GM1 é válida em condições clínicas onde o aumento do fluxo sanguíneo é associado a um melhor prognóstico, como doenças vasculares obstrutivas e doenças neurodegenerativas.Monosialoganglioside (GM1) is a glycosphingolipid present in most cell membranes that has antioxidant and neuroprotective properties. GM1 protects the central nervous system against various neurotoxic agents or conditions, such as aspartic acid, MPTP, glutamic acid, methylmalonic acid and glutaric acid exposure, anoxia and ischemia, Parkinson’s and Alzheimer’s diseases. The neurochemical mechanisms underlying GM1-induced neuroprotection are not completely known, but the wide range of situations in which GM1 is neuroprotective suggests that it may interact with common pathways involved in the development of cell injury, such as oxidative stress. Catalase (EC 1.11.1.6) is an intracellular antioxidant enzyme that catalyzes the reaction of hydrogen peroxide to water and molecular oxygen, and is particularly enriched in erythrocytes, where it metabolizes 90% of the hydrogen peroxide. Due to its poor expression in the brain, catalase has been considered a secondary enzyme in controlling free radical-induced damage in this organ. In the present study we evaluated the effect of GM1 on cerebral catalase activity ex vivo and in vitro. Moreover, the effect of erythrocyte removal on cerebral catalase activity of control and GM1-treated animals was also evaluated, in order to estimate the contribution of erythrocyte-derived catalase for the increase of catalase activity in the brain induced by the systemic injection of GM1. In addition, we investigated whether GM1 alters the content of hemoglobin in cerebral samples and the width of pial vessels of rats. Animals received two injections of GM1 (50 mg/kg, i.p.) or saline (0.9 % NaCl, 1 ml/kg, i.p.), spaced 24 h apart. Thirty minutes after the second GM1 or saline injection, they were sacrificed by decapitation and their brains were rapidly removed and used for biochemical assays. Catalase activity and content of hemoglobin were analyzed in hippocampus, cortex and striatum and blood of rats. GM1 administration increased catalase activity and hemoglobin content in brain samples, but had no effect on blood catalase activity. GM1-induced increase of catalase activity and the content of hemoglobin were abolished by transcardiac perfusion with heparinized ice-cold saline. Brain catalase activity in the absence of erythrocytes, estimated by regression analysis of data from perfused and non-perfused animals, was not altered by the systemic injection of GM1. Moreover, the addition of GM1 (100 – 1000 μM) did not increase catalase activity in slices of cerebral cortex in vitro, further suggesting that an intact vascular system is required for the facilitatory effect of GM1 on brain catalase activity. The vasodilatory effect of GM1 was confirmed in vivo, since the systemic injection of GM1 (50 mg/kg, i.p.) increased (1.5-2.5 times) the width of pial vessels. In summary, in this study we showed that vasodilation underlies the GM1- induced increase of catalase activity in brain homogenates. We suggest that erythrocyte catalase activity may play an important antioxidant role in the central nervous system, and that the adjunct therapy with GM1 may be of value in clinical conditions in which increased blood flow is associated to a better prognosis, such as obstructive vascular and neurodegenerative diseases.
37
Kreutz, Fernando. "Efeito do peptídeo beta-amilóide sobre a biossíntese de gangliosídeos e avaliação da atividade neuroprotetora do GM1." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2010. http://hdl.handle.net/10183/22065.
Full textAbstract:
A doença de Alzheimer é uma desordem neurodegenerativa cuja patogenia não é completamente elucidada. Atribui-se ao peptídeo beta-amilóide (A ), em sua forma oligomérica ou fibrilada, um importante papel neste processo. Uma vez que a produção e a fibrilação do peptídeo ocorrem ao nível de membrana neural, sua dinâmica e composição lipídica podem modular a cascata amilóide e/ou interferir na extensão do dano gerado pela mesma. Tendo isto em vista e considerando o potencial sinalizatório dos glicoesfingolipídios, o objetivo deste trabalho foi avaliar o efeito do peptídeo betaamilóide (A 25-35), em sua forma fibrilada ou não-fibrilada, sobre a biossíntese dos gangliosídios em modelo de cultura organotípica de hipocampo. Para tanto, foram utilizados ratos Wistar de 6-8 dias, dos quais o hipocampo foi dissecado, fatiado e submetido à cultura. No 28º dia de cultura foi adicionado A 25- 35 (25μM), em sua forma fibrilada ou não fibrilada; após 24h adicionou-se ao meio D- [1-14C]-galactose para avaliar a biossíntese dos gangliosídios; no 30º dia a morte celular foi analisada com iodeto de propídio. A partir das fatias, os gangliosídios radiomarcados foram extraídos, purificados, analisados por HPTLC, fluorografia e densitometria. Nossos resultados demonstraram uma alteração na biossíntese de gangliosídios induzida pelo peptídeo beta-amilóide A 25-35, um efeito que foi dependente de seu estado de fibrilação. Desta maneira, o A 25-35, em sua forma fibrilada, promoveu um aumento na biossíntese de GM3 e uma redução na biossíntese de GD1b, ao passo que o peptídeo não fibrilado levou a um aumento na síntese do gangliosídio GM1. Uma vez que o GM3 é considerado um gangliosídio apoptótico, quando expresso em neurônios adultos, um aumento em sua síntese pode estar relacionado aos eventos tóxicos desencadeados pelo peptídeo beta-amilóide fibrilado. O GM1, por sua vez, ainda não possui um papel suficientemente claro no desenvolvimento da doença de Alzheimer. Uma série de efeitos neuroprotetores são atribuídos a este gangliosídio enquanto fortes evidências sugerem que o GM1 poderia acelerar o processo de fibrilação do beta-amilóide, e assim influenciar a progressão da doença. A fim de investigar o papel do GM1 no presente modelo, realizamos uma série de experimentos com a finalidade de avaliar uma possível ação neuroprotetora deste gangliosídio. Como resultado, um pré-tratamento das fatias hipocampais com GM1(10μM) foi capaz de prevenir a toxicidade induzida pelo peptídeo beta-amilóide em sua forma fibrilada, como demonstram os resultados da captação de iodeto de propídio. Com o intuito de corroborar sua ação neuroprotetora, bem como investigar o mecanismo pelo qual esta neuroproteção seria mediada, analisamos o efeito de um tratamento com GM1 (1h, 6h, 12h ou 24h) sobre as alterações induzidas pelo peptídeo beta-amilóide no estado de fosforilação (ativação/inativação) da GSK3b. Nossos resultados demonstraram um importante efeito neuroprotetor do GM1 após 24 horas de tratamento, uma vez que nestas circunstâncias este gangliosídio foi capaz de reverter a ativação (defosforilação) da GSK3b, uma via de sinalização associada à morte celular programada. Como conclusão, nossos resultados dão suporte a participação dos gangliosídios em modelos de doença de Alzheimer, e sugerem uma ação neuroprotetora do gangliosídio GM1 frente à toxicidade induzida pelo beta-amilóide, o que, no futuro, pode ser explorado como uma alternativa terapêutica ao tratamento do Alzheimer.Alzheimer disease (AD) is a neurodegenerative disorder whose pathogenesis is still poorly understood. It is attributed to beta-amyloid peptide, in its fibrillar or nonfibrillar forms, an important role in the disease development and progression. Once the production and fibrillation of beta-amyloid peptide occurs on the neural membrane surface, the lipid dynamic and composition of these membranes could modulate amyloid cascade and/or interfere in the damage triggered by it. Taking this into account, and considering the potential signalling role of glycosphingolipids, the objective of this study was to investigate the effect of fibrillar and non-fibrillar beta-amyloid peptide (Ab25-35) upon ganglioside biosynthesis in a model of organotypic hippocampal culture. In order to do this, we used 6-8 days old Wistar rats, whose hippocampi were dissected, sliced and subjected to culture. On the 28th in vitro day, A 25-35 (25μM) was added to the culture medium, in its fibrillar or non-fibrillar forms. After 24h incubation, D-[1-C14]-galactose was added to the medium with the purpose of labeling ganglioside; on day 30th in vitro day cell death was analyzed by PI uptake. The radiolabeled gangliosides were extracted from the hippocampal slices, purified, and analyzed by HPTLC, fluorography and densitometry. Our results demonstrated an Ab25-35 induced alteration in ganglioside biosynthesis, an effect which seemed to be dependent on the peptide fibrillation state. Furthermore, the fibrillar Ab25-35 caused an increase in GM3 and a reduction in GD1b biosynthesis, whereas the non-fibrillar form of this peptide was able to enhance the synthesis of GM1 ganglioside. Once GM3 is an apoptotic ganglioside, when expressed in adult neurons, an increase in its synthesis could take part of the toxic events triggered by the fibrillar betaamyloid peptide. GM1, in turn, has a still poorly understood participation in Alzheimer development. A sort of neuroprotective effects are attributed to this ganglioside while several evidences suggest that GM1 could accelerate the endogenous fibril formation, and thence influence the disease progression. To further investigate the role of GM1 ganglioside in our model, we have performed some experiments in order to test a possible neuroprotective effect of this gangliosides. As a result, a pre-treatment of the hippocampal slices with 10μM GM1 was able to prevent the toxicity triggered by the fibrillar beta-amyloid peptide, when measured by PI uptake protocol. In order to corroborate its neuroprotective action, as well as to investigate a candidate mechanism by which GM1 could promote neuroprotection, we have analyzed the effect of GM1 treatment (1h, 6h, 12h and 24h) upon the amyloid-induced alterations in GSK3b phosphorylation/dephosphorylation state. Our results demonstrated an important effect of GM1 after 24h incubation, once it was able to reverse the amyloid-induced dephosphorilation (activation) of GSK3b, a signalling pathway involved in apoptosis triggering. Taken together, our results provides new and important support for the ganglioside participation in Alzheimer models, and suggests a protective role of GM1 upon the amyloid induced toxicity, which, in the future, could expand the therapeutic strategy available for Alzheimer disease treatment.
38
MANCINI, GIULIA. "GANGLIOSIDE GM1 AS ADJUVANT FOR ORKAMBI® THERAPY TO RESTORE PLASMA MEMBRANE STABILITY AND FUNCTION OF F508DEL-CFTR." Doctoral thesis, Università degli Studi di Milano, 2018. http://hdl.handle.net/2434/604127.
Full textAbstract:
Cystic fibrosis (CF) is the most common, fatal genetic disease in the Caucasian population caused by loss of function mutations in gene encoding for the cystic fibrosis transmembrane conductance regulator (CFTR). CFTR is expressed at the apical surface of epithelial cells of different organs, such as: lungs, pancreas, gut, and testes. For this reason even if in CF the pulmonary manifestations are the most severe, CF is considered a multi-system disease, which affects several bodily districts.
The new challenge for the CF therapy is based on the development of small molecules able to rescue the function of the mutated CFTR. Many pharmacological agents have been designed to increase the surface level of mutated CFTR (correctors), as well as its plasma membrane (PM) activity (potentiators).
Recently, combined therapy that includes a corrector of the CFTR folding (lumacaftor or VX-809) and a potentiator of the channel activity (ivacaftor or VX-770) called Orkambi®, was approved for CF patients homozygous for the deletion of phenylalanine at position 508 (F508del), the most common CF-causing mutation. Unfortunately, clinical studies revealed that the effects of Orkambi® on lung function were modest, due to low stability of rescued F508del-CFTR at the PM level.
Indeed, many factors contribute to PM CFTR stability, including its compartmentalization in PM macromolecular complexes composed of phospholipids, sphingolipids, with particular regards for monosialoganglioside 1 (GM1), and scaffolding proteins such as ezrin and NHERF-1.
Interestingly, it has been proved that in bronchial epithelial cells the lack of CFTR in the cell PM, such as in the case of the patients carrying the mutation F508del, is associated with a decreased content of GM1. By performing photolabelling experiments, I demonstrated for the first time that GM1 and CFTR at PM level reside in the same microdomain, suggesting a direct interaction between them. Then I investigated on the potential effect of the exogenous administration of ganglioside GM1 on the PM stabilization and function of F508del-CFTR rescued by Orkambi® treatment. In particular, I proved that in CF bronchial epithelial cells GM1 antagonizes the negative effect of VX-770, increasing F508del-CFTR maturation and its channel activity by the recruitment of the scaffolding proteins NHERF-1 and ezrin.
Taken together the results obtained during my PhD project pointed out the role of GM1 as possible adjuvant to Orkambi® therapy to restore the function of F508del-CFTR.
39
Tajrine, Dima D. "Effect of nerve growth factor and monosialoganglioside GM1 on non-cholinergic pathways in the cortex of lesioned rats." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ29796.pdf.
Full text
40
Tajrine, Dima D. "Effect of nerve growth factor and monosialoganglioside GM1 on non-cholinergic pathways in the cortex of lesioned rats." Thesis, McGill University, 1996. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=27421.
Full textAbstract:
In this study, light and electron microscopic quantitative analyses were used to examine whether exogenous nerve growth factor (NGF) and/or monosialoganglioside GM1 treatment could affect non-cholinergic systems in the neocortex of the adult rat brain after a devascularising lesion. The two neuronal systems I looked at were the extrinsic noradrenergic and intrinsic somatostatinergic systems. Immediately after unilateral vascular decortication, adult rats received for seven days, via minipump, vehicle, NGF (12 $ mu$g/day) and/or GM1 (1.5 mg/day) into the cerebroventricular space. Thirty days after the lesion, the animals were perfused with histological fixatives, the brains removed and relevant sections processed for dopamine $ beta$-hydroxylase (DBH) and somatostatin immunocytochemist at the light and electron microscopic levels. The lesion caused a reduction in the total length of the DBH immunoreactive (IR) fiber segments, which was not attenuated by either NGF or GM1 treatment or both combined. The somatostatin-IR network, on the other hand, was unaffected by the lesion and there was no sprouting of the somatostatin fibers with trophic factor therapy. I observed, however, a marginally significant decrease in the somatostatin fiber network when NGF and GM1 were administered simultaneously. I also found no significant differences in the size and number of synapses of both the DBH-IR and somatostatin-IR boutons, following lesion and drug treatments. These results suggest that NGF and/or GM1 therapy does not cause regrowth in the noradrenergic and somatostatinergic cortical fiber networks and presynaptic elements following a devascularizing lesion.
41
Dalia, Asad Dawoud. "GM1 ganglioside, nerve growth factor, and epidermal growth factor, enhance mesencephalic dopaminergic markers after a lesion with MPP? /." The Ohio State University, 1992. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487779914825189.
Full text
42
Yamanokuchi, Satoshi. "Asialo GM1 positive CD8[+] T cells induce skin allograft rejection in the absence of the secondary lymphoid organs." Kyoto University, 2006. http://hdl.handle.net/2433/143849.
Full text
43
Weismann, Cara M. "Approaches and Considerations Towards a Safe and Effective Adeno-Associated Virus Mediated Therapeutic Intervention for GM1-Gangliosidosis: A Dissertation." eScholarship@UMMS, 2014. http://escholarship.umassmed.edu/gsbs_diss/767.
Full textAbstract:
GM1 gangliosidosis is a lysosomal storage disorder caused by a deficiency in the catabolizing enzyme β-galactosidase (βgal). This leads to accumulation of GM1-ganglioside (GM1) in the lysosome inducing ER stress and cell death. GM1 gangliosidosis is primarily a disorder of the central nervous system (CNS) with peripheral organ involvement. In this work we report two major findings, 1) systemic treatment of GM1 gangliosidosis with an adenoassociated virus (AAV9) encoding mouse-βgal (mβgal) in a GM1 gangliosidosis mouse model (βGal-/-), and 2) an investigation into an intracranial injection of a therapeutic AAVrh8 encoding mβgal. Systemic treatment of GM1 gangliosidosis with AAV9 resulted in a moderate expression of enzyme in the CNS, reduction of GM1 storage, significant retention of motor function and a significant increase in lifespan. Interestingly, the therapeutic effect was more robust in females. Intracranial injections of AAVrh8 vector expressing high levels of βgal resulted in enzyme spread throughout the brain, significant retention of motor function and a significant increase in lifespan. Histological alterations were also found at the injection site in both βGal-/- and normal animals. We constructed a series of vectors with a range of decreasing enzyme expression levels to investigate the cause for the unanticipated result. Microarrays were performed on the injection site and we showed that a lower expressing AAVrh8-mβgal vector mitigated the negative response. Intracranial injection of this newly developed vector was shown to clear lysosomal storage throughout the CNS of βGal-/- mice. Taken together, these studies indicate that a combined systemic and fine-tuned intracranial approach may be the most effective in clearing lysosomal storage completely in the CNS while providing therapeutic benefit to the periphery.
44
Kreutzer, Robert. "Molecular pathogenesis, differential transcription of enzymes forming the lysosomal multienzymic complex and microsatellite based genotyping in canine GM1-gangliosidosis." Giessen : DVG-Service, 2008. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=017137159&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
Full text
45
Whalen, Michael. "Treating GM1 Gangliosidosis With Ex Vivo Hematopoietic Stem Cell Gene Therapy Without Using Total Body Irradiation: A Masters Thesis." eScholarship@UMMS, 2011. https://escholarship.umassmed.edu/gsbs_diss/558.
Full textAbstract:
GM1 gangliosidosis is an autosomal recessive lysosomal storage disease, caused by a deficiency in the enzyme β-galactosidase. The disease affects the CNS, liver, kidney, heart and skeletal system, leading to severe neurodegeneration and death. We propose to treat this disorder using ex vivo hematopoietic stem cell therapy. The effectiveness of this therapy requires the recruitment of transduced donor cells to the CNS. This is only found to occur after mice are conditioned with total body irradiation, due to the increase in CNS cytokine production and blood brain barrier permeability that occurs. As the use of total body irradiation in pediatric patients has been linked to future developmental problems, this myeloablation approach is often avoided in younger patients in favor of a conditioning regimen using the chemotherapy drugs, busulfan and cyclophosphamide. Whether donor cells can enter the CNS when a busulfan and cyclophosphamide conditioning regimen is used has not been determined. In this study we plan to quantify the cytokine and blood-brain barrier permeability increases necessary for donor cells to be recruited to the CNS after total body irradiation. We will then investigate whether busulfan and cyclophosphamide conditioning and/or the chronic neuroinflammation present in GM1 mice can produce similar conditions and facilitate the recruitment of donor hematopoietic stem cells to the CNS. Finally we will assess whether ex vivo hematopoietic stem cell gene therapy is still an effective therapy when busulfan and cyclophosphamide are used for myeloablative conditioning.
46
Moura, Sérgio de Paula. "Adsorção ótima de bicamada fosfolipídica sobre sílica e reconstituição do reconhecimento receptor-ligante." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/46/46131/tde-29112006-194153/.
Full textAbstract:
Este projeto teve como objetivo geral continuar a avaliar a adequação de anfifílicos que se agregam em solução aquosa formando bicamadas, para recobrir superfícies de sílica. Em paralelo, foi objetivada a reconstituição do reconhecimento receptor-ligante, tendo como modelo o monosialogangliosídio GM1 e a enterotoxina do vibrião da cólera. Os resultados obtidos poderão se mostrar de grande valor em aplicações práticas que envolvem a construção de sistemas de detecção e quantificação de substâncias ou moléculas específicas. A adsorção e estabilidade de bicamadas contendo fosfatidilcolina (PC) ou misturas de brometo de dioctadecildimetilamônio (DODAB) e dipalmitoilfosfatidilcolna (DPPC) sobre a superfície de nanopartículas de sílica foi estudada através de isotermas de adsorção por dosagem do fosfato inorgânico, análises de sedimentação por imagens fotográficas e medidas dos diâmetros médios (Dz) e potenciais-zeta (ζ) de partículas por espectroscopia de correlação de fótons. Foram avaliadas as afinidades entre as bicamadas e a superfície das nanopartículas e a estabilidade do sistema em função da força iônica, do pH e da concentração adicionada de lipídio. A afinidade das bicamadas pela superfície da sílica apresentou uma correlação com as forças de van der Waals e as pontes de hidrogênio que se formam entre os grupos químicos do anfifílico e aqueles de superfície da sílica. A formação de uma única bicamada lipídica de PC sobre a sílica foi detectada, o que levou à estabilidade coloidal do sistema particulado. As bicamadas mistas de DPPC/DODAB por sua vez apresentaram uma afinidade decrescente pela sílica com a elevação da porcentagem de DODAB na bicamada. Os dados de isoterma e de ζ das partículas sugerem uma separação física entre o DPPC e o DODAB. O conjunto otimizado partícula de sílica/bicamada de PC (partícula biomimética) foi assim utilizado para promover a incorporação do GM1 micelar nas bicamadas, medida por fluorescência com a utilização da sonda GM1 pireno, seguida do reconhecimento e ligação da toxina da cólera (CT) ao complexo formado. A transferência do GM1 das micelas para as partículas se mostrou dependente da disponibilidade de bicamadas adsorvidas nestas e da ausência de bicamadas não-adsorvidas, livres em dispersão. Para avaliar a ligação da toxina da cólera às partículas biomiméticas foram calculadas isotermas de adsorção a partir da dosagem de proteína não ligada que resta no sobrenadante. A ligação específica da CT na presença de bicamadas de PC e GM1 foi de 67% em massa do total da proteína adicionada, revelando uma ligação positiva entre receptor e ligante. A estequiometria revela que a proporção molar PC: GM1: CT é de 300: 5: 1 respectivamente. A proporção de 1 CT: 5 GM1 está de acordo com a literatura onde experimentos de difração de raios-X mostram a estrutura tridimensional do pentâmero CTB5 ligado a cinco unidades de pentasacarídeo do GM1.The general objective of this project was to continue evaluating the suitability of amphiphiles that aggregate in aqueous solution forming bilayers, to cover surfaces of silica. A secondary objective pursued was to promote the reconstitution of the receptor-ligand function, having as a model the monosialoganglioside GM1 and the enterotoxin of the choleric vibrio. The results may prove to be valuable in pure research or practical applications for sensing and detection of biomolecules. The adsorption and stability of phosphatidylcholine (PC) bilayers or mixtures of dipalmitoylphosphatidylcholine (DPPC) and dioctadecyldimethylammonium bromide (DODAB) over surfaces of silica nanoparticles were evaluated through adsorption isotherms by inorganic phosphate dosage, sedimentation analysis by means of photographic images and measurements of hydrodynamic diameter (Dz) and zeta-potentials (ζ) of particles by photon correlation spectroscopy. The affinity between the bilayers and the nanoparticles surfaces and the general system stability were evaluated as a function of ionic strength, pH and added lipid concentration. The affinity showed a correlation with the van der Waals and the hydrogen bridges forces that form between the chemical groups of the amphiphile and the silica surface. The formation of a single lipid PC bilayer over the silica was detected, leading to the colloidal stability of the particulate system. Mixed bilayers of DPPC/DODAB on the other hand showed a decreasing affinity for silica with an increasing DODAB percentage in the bilayer. Data from isotherms and ζ of particles suggests a physical separation of the DPPC and DODAB. The optimized array of silica particle/PC bilayer (biomimetic particles) was thus used to promote the incorporation of micellar GM1 into the bilayers, measured by fluorescence with a GM1 pirene probe, followed by the cholera toxin (CT) binding to the resulting array. GM1 transfer from micelles to particles showed dependence on the adsorbed bilayers availability and on the absence of non-adsorbed bilayers, free in the bulk solution. To evaluate CT binding to biomimetic particles adsorption isotherms were calculated from the dosage of unbound protein remaining in the supernatant. Specific binding of CT in the presence of PC and GM1 bilayer was 67% mass of total protein added, indicating a positive binding between receptor and ligand. Stoichiometry revealed that the molar proportion PC: GM1: CT is 300: 5: 1 respectively. The proportion of 1 CT: 5 GM1 is in good agreement with data in the literature where X-ray diffraction tests show the 3-dimensional structure of the CTB5 pentamer bound to five units of the pentasaccharide GM1.
47
Biraboneye, Alain César. "Innovation moléculaire à visée thérapeutique : conception, synthèse et évaluation biologique des nouveaux dérivés contre l'ischemie cérébrale." Thesis, Aix-Marseille 2, 2011. http://www.theses.fr/2011AIX22006/document.
Full textAbstract:
Accidents Vasculaire Cérébraux (parfois appelés AVC ou attaques cérébrales) sont les 3èmes causes principales de mortalité et les causes de handicap dans les pays industrialisés. Ils représentent un problème de santé publique en raison de leurs fréquences, de leurs mortalités et des handicaps physiques et cognitifs qu'ils entraînent. Malgré d’importants progrès réalisés dans le domaine de la physiopathogénie de l’ischémie cérébrale, on ne dispose pas encore, aujourd’hui, de thérapeutiques efficaces pour traiter un accident vasculaire cérébral lors de sa phase aiguë. Les gangliosides GM1 sont des composants majeurs du feuillet externe de la membrane cellulaire au niveau du système nerveux central. Ces gangliosides ont des effets antineurotoxiques, neuroprotecteurs et les propriétés neurorestoratrices sur les divers neurotransmetteurs du SNC mais pour le moment ils n’ont pas des valeurs thérapeutiques en raison de leurs manques de biodisponibilités et de leurs manques de perméabilité de la barrière hématoencéphalique (BHE). Nous avons synthétisé les structures simplifiées de ces gangliosides GM1, L’idée qui a prévalu pour la conception, des nouvelles structures a été : d’introduire des chaînes grasses saturées ou insaturées sur un motif sérine, tyrosine ou cystéine, de remplacer la fonction carboxylique par des groupements reconnus comme bioisostères classiques ou non classiques de cette fonction ; comme par exemple les fonctions phosphonique, tétrazolique, 2,4-oxadiazolidine-3,5-dione. Nous avons élaboré un nouveau modèle de composé neuroprotecteur dans lequel une chaîne grasse est couplée à une entité acide ascorbique pour améliorer le passage de la BHE. Pour étudier l’activité neuroprotectrice des composés synthétisés nous avons utilisé deux modèles biologiques in vitro : un modèle cellulaire (cellules HT22) et un modèle tissulaire (tranches de cerveaux)Stroke is the third leading cause of mortality and the primary cause of disability in adults. Therefore, it is critical to identify new, efficacious pharmacological treatments. One pharmacological approach for treatment of stroke is called neuroprotective therapy. It has been reported that the amphiphilic, monosialotetrahexosylganglioside (GM1) (II3 NeuAc-GgOsc4Cer) has antineurotoxic, neuroprotective, and neurorestorative effects on various central neurotransmitter systems. Since GM1 is not of therapeutic value because of its lack of bioavailability and its low blood-brain barrier (BBB) permeation. Thus, molecules that mimic GM1 represent a novel approach to neuroprotection. We have synthesized the smalls GM1-like analogues whose simplified structure includes various lipophilic saturated, unsaturated, or cyclic polyunsaturated moieties have been introduced, while in the second series, thecarboxylic acid function was replaced by different hydrophilic groups including bioisosters of the carboxylate, such as a phosphonic acid, a tetrazole, the 1,2,4-oxadiazolidine-3,5-dione or an ascorbic acid moiety. Introduction of ascorbic acid was supported by several reports that showed that ascorbic acid conjugates can improve BBB permeation properties. We report their neuroprotective effects in two distinct models of nerve cell death using hippocampus-derived HT22 cells and an additional neuroprotective assays using cortical slices injured by glutamate confirmed these results
48
Kreutz, Fernando. "Avaliação da atividade neuroprotetora do gangliosídio GM1 em modelo in vivo e in vitro de toxicidade do peptídeo β-amiloide." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2014. http://hdl.handle.net/10183/115589.
Full textAbstract:
A doença de Alzheimer (DA) é uma desordem neurodegenerativa caracterizada por perda da memória e das demais funções cognitivas. Sua patogenia envolve a produção do peptídeo β-amiloide (Aβ), através da clivagem da proteína precursora amiloide (APP) por β- e γ-secretases (amiloidogênese), e a posterior agregação do Aβ em oligômeros e/ou fibrilas. A toxicidade do Aβ tem sido associada a diversos mecanismos, a incluir desde seu efeito oxidante e inflamatório, até sua propriedade de induzir necrose por ruptura das membranas neurais, ou apoptose via ativação de cascatas sinalizatórias. Como etapa comum a estes mecanismos de toxicidade, a interação do peptídeo com membranas neurais, em particular com o gangliosídio GM1 (constituinte dos rafts), parece ser indispensável ao dano neural associado ao peptídeo, bem como à ativação da cascata amiloide que caracteriza o ciclo patológico Aβ-amiloidogênese. O GM1 é um gangliosídio de membrana que, quando administrado exogenamente, apresenta propriedades neurotróficas e neuroprotetoras, inclusive em modelos de DA. Os mecanismos envolvidos nesta neuroproteção, no entanto, ainda precisam ser melhor elucidados. Com isto, o objetivo da presente tese foi avaliar o potencial efeito neuroprotetor do GM1 em modelo in vivo e in vitro de toxicidade do Aβ1-42 fibrilado, e propor mecanismos para esta neuroproteção. Inicialmente, demonstramos que o GM1 (0,30 mg/kg), quando co-administrado (icv) com Aβ (2 nmol) previne o déficit cognitivo induzido pelo peptídeo (teste de reconhecimento de objetos), bem como a redução na atividade da Na+,K+-ATPase (enzima envolvida na regulação da transmissão sináptica) no hipocampo de ratos Wistar machos. Demonstrou-se, além disso, que este efeito neuroprotetor do GM1 é acompanhado de aumento nas defesas antioxidantes, em córtex e hipocampo (TRAP). Como a toxicidade do Aβ e a modulação da amiloidogênese parecem ser dependentes de alterações na estrutura dos microdomínios de membrana (rafts), investigamos o efeito da injeção (icv) de Aβ e do tratamento (icv) com GM1 sobre a integridade dos rafts e sobre a distribuição das proteínas APP e BACE1 (β-secretase) nestes microdomínios. Observamos que o Aβ promoveu um desmonte parcial nos rafts, acompanhado de um aumento na distribuição de APP e BACE1 nestes microdomínios, efeitos estes que foram prevenidos pelo tratamento com GM1. Em virtude de os rafts modularem diversas funções neurais, e de a co-localização de APP e BACE1 nos rafts ser um evento necessário a amiloidogênese, os resultados aqui obtidos, reforçam a ideia de que o GM1 exerça sua função neuroprotetora ao preservar a arquitetura das membranas e que o mesmo poderia frear a ativação da amiloidogênese induzida pelo Aβ, ao prevenir a redistribuição das proteínas APP e BACE1 aos rafts lipídicos. A fim de avaliar a atividade neuroprotetora do GM1 em modelo in vitro da DA, e de investigar a sua propriedade de interagir com o Aβ impedindo a interação deste às membranas neurais, avaliamos o efeito da incubação de GM1 (10, 20 e 30μM) frente à toxicidade do Aβ (0,5μM) em células de neuroblastoma humano SH-SY5Y, bem como, verificamos o efeito de uma prévia incubação Aβ-GM1 (in vitro) sobre a toxicidade induzida pelo peptídeo. Como resultado, observamos que o GM1 promoveu neuroproteção nas três concentrações testadas e que esta neuroproteção foi, pelo menos parcialmente, mediada por sua capacidade de interagir in vitro com o Aβ. Nossos dados, em conjunto, reforçam as evidências que apontam o GM1 como uma potencial droga neuroprotetora em modelos de DA.Alzheimer's disease (AD) is a neurodegenerative disorder characterized by a loss of memory and impairment of other cognitive functions. Its pathogenesis involves the production of β-amyloid peptide (Aβ) by cleavage of the amyloid precursor protein (APP) by β- and γ-secretases (amyloidogenesis) and the subsequent aggregation of Aβ into oligomers and/or fibrils. Aβ toxicity has been associated with several mechanisms, ranging from its oxidant and inflammatory effects until their property to induce necrosis by neural membrane rupture, or apoptosis via activation of signaling cascades. As a common step to these toxicity mechanisms, the peptide interaction with neural membranes, particularly with GM1 ganglioside (component of membrane rafts), seems to be pivotal to the peptide induced neural damage, as well as the amyloid cascade activation that characterizes the pathological vicious cycle Aβ- amyloidogenesis. GM1 is a membrane ganglioside provided of neurotrophic and neuroprotective properties in AD models, when exogenously administered. The mechanisms of neuroprotection, however, need to be further elucidated. By this way, the aim of this PhD thesis was to evaluate the potential neuroprotective effect of GM1 in in vivo and in vitro models of fibrilar Aβ1-42 toxicity, and to propose mechanisms for this neuroprotection. Initially, we demonstrated that GM1 (0.30 mg/kg.), when co-administered (icv) with Aβ (2nmol), prevents the peptide induced cognitive deficit (object recognition task), as well as Aβ induced reduction in Na+,K+-ATPase activity (a enzyme involved in synaptic transmission regulation) in the hippocampus from male Wistar rats. We have shown, furthermore, that this neuroprotective effect of GM1 is accompanied by an increase in antioxidant defenses in the cortex and hippocampus (TRAP). As Aβ toxicity, as well as the modulation of amyloidogenesis, appear to be dependent on changes in the structure of membrane microdomains (rafts), we have investigated the effect of Aβ icv injection and GM1icv treatment on raft integrity and on the distribution of APP and BACE1 (β- secretase) proteins in these microdomains. As result, Aβ promoted a partial raft disassemble, accompanied by an increase in the distribution of APP and BACE1 to these microdomains, effects that were prevented by GM1 treatment. Considering that rafts modulate several neural functions, and that APP and BACE1 co-localization into lipid rafts is pivotal to amyloidogenesis, our results reinforce the idea that GM1 neuroprotection is mediated by membrane architecture preservation, and that GM1 treatment could slow down the Aβ induced activation of amyloidogenesis, by prevention of APP and BACE1 redistribution into lipid rafts. In order to evaluate the GM1 neuroprotective activity in an in vitro AD model, and to investigate GM1 property of interacting with Aβ and preventing its interaction with neuronal membranes, we evaluated GM1 (10, 20 and 30μM) effect against Aβ (0,5 μM)-induced toxicity in SHSY5Y human neuroblastoma cells, as well as, we verified the effect of a Aβ-GM1 in vitro preincubation on the peptide-induced toxicity. As our results indicate, the three tested GM1 concentrations promoted neuroprotection and this effect was, at least partially, mediated by its ability to in vitro interact with Aβ peptide. Our data, when taken together, reinforce the evidence suggesting GM1 as a potential neuroprotective drug in AD models.
49
Kalluri, Anila. "EXPRESSION OF CHOLERA TOXIN B SUBUNIT-ROTAVIRUS NSP4 ENTEROTOXIN FUSION PROTEIN IN TRANSGENIC CHLOROPLASTS." Master's thesis, University of Central Florida, 2005. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3069.
Full textAbstract:
Rotavirus, the major cause of life-threatening infantile gastroenteritis, is a member of the Reoviridae family and is considered to be the single most important cause of virus-based severe diarrheal illness in infants and young children particularly 6 months to 2 years of age in industrialized and developing countries. Infection in infants and young children is often accompanied by severe life threatening diarrhea, most commonly following primary infection. Diarrhea is the major cause of death among children around the world. Responsible for 4 to 6 million deaths per year according to the World Health Organization (WHO), diarrhea is especially dangerous for infants and young children. Globally, it is estimated that 1.4 billion episodes of diarrhea occur in children less than five years of age annually. In the United States alone, rotavirus causes more than 3 million cases of childhood diarrhea each year, leading to an estimated 55,000 to 100,000 hospitalizations and 20 to 100 deaths. And is a major cause of mortality for children in developing countries with approximately one million deaths annually. Rotaviruses belong to the family Reoviridae and are spherical 70-nm particles. The virus genome contains 11 segments of double-stranded RNA, each encoding a viral capsid or nonstructural protein. The identification of a rotavirus nonstructural protein gene (NSP4) encoding a peptide, which functions both as a viral enterotoxin and as a factor involved in the acquisition of host cell membrane during virus budding from cells, provides a new approach for mucosal immunization. Protein expression through chloroplast transformation system offers a number of advantages like high level of transgene expression, transgene containment via maternal inheritance, lack of gene silencing and position effect due to site specific gene integration and also the possibility of multi gene engineering in single transformation event. It is also an environmentally friendly approach due to effective gene containment and lack of transgene expression in pollen. To achieve an enhanced immune response to rotavirus infection, a fusion gene encoding the cholera toxin B subunit linked to rotavirus enterotoxin 90 aa protein (CTB-NSP490) was introduced into transgenic chloroplast and was transformed into chloroplast genome of Nicotiana tabacum by homologous recombination. The chloroplast integration of CTB-NSP4(90) fusion gene was confirmed in transgenic tobacco plants by PCR analysis. Southern blot analysis further confirmed site specific gene integration and homoplasmy. Immunoblot analysis of transformed chloroplast confirmed the expression of CTBNSP490 fusion protein both in monomeric and pentameric forms that retained the binding affinity to the enterocytes GM1 ganglioside receptor. Expression levels of CTB-NSP4 protein was quantified by GM1 ganglioside binding ELISA assay; mature leaves expressed CTB-NSP4 fusion protein to upto 2.45 % in total soluble protein, 100-400 fold higher than nuclear expression which was only 0.006%-0.026%. Antibody titration and virus challenge experiments will be performed in mice at Loma Linda University to evaluate the antigenic and protective properties of the chloroplast derived CTB-NSP4 fusion protein.M.S.
Department of Molecular Biology and Microbiology
Burnett College of Biomedical Sciences
Molecular Biology and Microbiology
50
Souza, Fabiano Inácio de. "Estudo dos efeitos do monossialogangliosídeo (GM1) administrado pela via transdérmica por laser a baixa temperatura, após lesão medular experimental em ratos." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/5/5140/tde-23022012-122731/.
Full textAbstract:
Objetivo: avaliar os efeitos do monossialogangliosídeo (GM1) administrado pela via de transdérmica por laser a baixa temperatura, após lesão medular experimental em ratos. Métodos: o estudo incluiu 40 ratos Wistar, machos, com idade entre 20 e 21 semanas, submetidos à lesão medular contusa pelo equipamento NYU Impactor, a altura de 25 mm, de acordo com o protocolo MASCIS. Foram formados 4 grupos de 10 animais. No grupo 1, os ratos receberam diariamente 0,2 ml de soro fisiológico, via intraperitoneal; no grupo 2, GM1 via intraperitoneal, na concentração 30 mg/kg por dia; no grupo 3, sessão diária de laser a baixa temperatura na topografia da lesão; no grupo 4 sessão diária de laser contendo GM1 na concentração de 30 mg/kg pela via transcutânea por Laser Ice. Todos os animais foram tratados por 42 dias. Foram avaliados por meio da escala de avaliação funcional Basso, Baettie e Bresnahan (BBB) em 7, 14, 21, 28, 35 e 42 dias após a lesão, pelo exame histopatológico e por potencial evocado motor após 42 dias da lesão. Resultados: os animais do grupo 4 apresentaram os escores da escala BBB superiores aos demais grupos até a quarta semana, sendo equiparado aos demais na sexta semana. Não houve diferença estatisticamente significante entre os grupos e as semanas. A avaliação histológica não demonstrou resultados com significância estatística. Os exames de potencial evocado motor demonstraram maior latência média no grupo 1, sem significância estatística. Conclusão: o emprego de GM1 associado a laser em baixa temperatura demonstra resultados funcionais superiores nas primeiras semanas, mas sem evidenciar diferença estatisticamente significanteObjective: To evaluate the effects of monossialoganglioside (GM1) administered transdermally, and laser at low temperature, in the functional and histological recovery of spinal cord injury in rats. Methods: Forty male Wistar rats, aged between 20 and 21 weeks, underwent spinal cord contusion at NYU Impactor, according to the MASCIS protocol. They were divided into four groups: in Group 1, rats received 0.2 ml of saline intraperitoneally daily; in Group 2, GM1 was administered intraperitoneally at a concentration 30 mg/kg per day; in Group 3, rats were treated with laser at low temperature on the skin, daily and in Group 4, the daily laser session also contained GM1. All the groups were treated for 42 days. The animals were evaluated by the Basso, Baettie and Bresnahan (BBB) functional scale on days 7, 14, 21, 28, 35 and 42 after injury, and by histopathology and motor evoked potentials after 42 days of injury. Results: The animals in Group 4 had higher BBB scores compared to the other groups, until the 4th week. There were no statistically significant differences between the groups, or in the comparisons over time, i.e. from one week to the next. Histological evaluation showed no statistically significant results, and no significant differences were found in the motor evoked potential tests either. Conclusion: GM1 associated with the use of low-temperature laser shows no superior functional, neurological or histological results in the treatment of spinal cord lesions in rats