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Articles de revues sur le sujet "Amyloid beta-protein. Spectrum analysis"
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Mollee, Peter, Patricia Renaut, Samuel Boros, Dorothy Loo et Michelle Hill. « Diagnosis of Amyloidosis Subtype By Laser-Capture Microdissection (LCM) and Tandem Mass Spectrometry (MS/MS) Proteomic Analysis ». Blood 126, no 23 (3 décembre 2015) : 1779. http://dx.doi.org/10.1182/blood.v126.23.1779.1779.
Texte intégralRésumé :
Abstract Aim Correct identification of the protein that is causing amyloidosis is crucial for clinical management. Current standard laboratory methods have limited ability to detect the full range of amyloid forming proteins. We assessed the diagnostic value of LCM-MS/MS, which combines specific sampling of amyloid deposits by LCM with protein identification by MS/MS. Methods Biopsy specimens were referred to the Princess Alexandra Hospital Amyloidosis Centre. For all specimens, 10µm sections of formalin-fixed paraffin embedded tissue were stained with Congo Red using a standard technique. LCM was performed using an Arcturus XT instrument with an infrared capture laser. Proteins were extracted with FFPE Protein Extraction Solution (Agilent Technologies), digested with trypsin and peptides were analysed by nano-liquid chromatography-coupled MS/MS using an Agilent Chip CUBE-QTOF. Database searching was performed using Spectrum Mill (Agilent) with the NCBInr human protein database. Results Biopsies were received on 136 patients: there was insufficient tissue in the block in 7, repeat LCM was required in15 cases and no amyloid forming protein was identified in 8. In 121/136 (89%) an amyloid forming protein was identified. Proteins identified included immunoglobulin light chain (localised amyloid n=25, systemic AL n=45), immunoglobulin heavy chain (AH n=6), transthyretin (senile amyloid n=25, hereditary ATTR n=6), serum amyloid A (AA n=7), fibrinogen alpha chain (AFib n=2), LECT2 (ALect2 n=2), TGFb (corneal lattice amyloid n=1) and semenogelin (seminal vesicle amyloid n=2). It was not infrequent, particularly in cases of localised amyloidosis (>80% of cases), for smaller amounts of other amyloid forming proteins to be present especially immunoglobulins, transthyretin and ApoA1 (Table 1). This suggests that these inherently amyloidogenic proteins are capable of integrating within the amyloid deposit. An amyloid proteomic signature as previously defined by the Mayo Clinic (at least two of SAP, ApoE and ApoA4; Haematologica 2014;99(7):1239) was present in 76% of cases and was more likely to be found if larger amounts of amyloid could be dissected (p=0.0001). In terms of clinical impact, amyloid typing by immunohistochemical stains had been attempted in 87 cases and reported as diagnostic in 39. Five of these were subsequently revealed by proteomic analysis to be incorrect. Overall, the clinical diagnosis of amyloid subtype was altered by proteomic analysis in 24% of cases. Conclusion. LCMMS/MS identifies an amyloid forming protein in ~90% of clinical biopsy samples. Amyloid deposits often contain small amounts of other amyloid forming proteins which may reflect not just contamination but co-deposition of fibrils due to a shared beta pleated sheet conformation. Because of this, results need to be interpreted in the context of full clinical information to enable correct diagnosis of amyloid subtype. Table 1. LCM-MS/MS results Amyloidosis subtype AL-lambda AL-kappa AH Localised lambda Localised kappa ATTRwt ATTRmut AA Number of subtype cases 32 13 5 16 9 25 6 7 Amyloid forming proteins Lambda light chain 32 16 1 2 Kappa light chain 4 13 2 5 9 4 1 Ig heavy chain 8 5 6 6 4 1 3 Transthyretin 1 3 3 25 6 ApoA1 2 3 7 3 SAA 7 Fibrinogen alpha chain 2 1 2 1 Lysozyme 1 1 1 Cases with low levels of 2nd amyloid forming protein 34% 46% 40% 81% 89% 20% 17% 57% Amyloid associated proteins ApoE 21 12 2 16 7 19 6 5 SAP 16 8 13 6 24 6 4 ApoA4 23 10 1 16 8 22 6 2 Amyloid proteomic signature 63% 77% 0% 100% 78% 92% 100% 57% Disclosures Mollee: Onyx: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau.
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Radko, S. P., S. A. Khmeleva, E. V. Suprun, S. A. Kozin, N. V. Bodoev, A. A. Makarov, A. I. Archakov et V. V. Shumyantseva. « Physico-chemical methods for studing beta-amyloid aggregation ». Biomeditsinskaya Khimiya 61, no 2 (2015) : 203–18. http://dx.doi.org/10.18097/pbmc20156102203.
Texte intégralRésumé :
Alzheimer's disease is the most prevalent neurodegenerative pathology. According to the amyloid cascade hypothesis, a key event of the Alzheimer's disease pathogenesis is a transition of the b-amyloid peptide (Аb) from the monomeric form to the aggregated state. The mechanism of Аb aggregation is intensively studied in vitro, by means of synthetic peptides and various physico-chemical methods allowing evaluation of size, molecular structure, and morphology of the formed aggregates. The paper reviews both the well-known and recently introduced physico-chemical methods for analysis of Аb aggregation, including microscopу, optical and fluorescent methods, method of electron paramagnetic resonance, electrochemical and electrophoretic methods, gel-filtration, and mass spectrometric methods. Merits and drawbacks of the methods are discussed. The unique possibility to simultaneously observe Аb monomers as well oligomers and large aggregates by means of atomic force microscopy or fluorescence correlation spectroscopy is emphasized. The high detection sensitivity of the latter method, monitoring the aggregation process in Аb solutions at low peptide concentrations is underlined. Among mass spectrometric methods, the ion mobility mass spectrometry is marked out as a method enabling to obtain information about both the spectrum of Аb oligomers and their structure. It is pointed out that the use of several methods giving the complementary data about Аb aggregates is the best experimental approach to studying the process of b-amyloid peptide aggregation in vitro.
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Bourbouli, Mara, Michael Rentzos, Anastasia Bougea, Vasiliki Zouvelou, Vasilios C. Constantinides, Ioannis Zaganas, Ioannis Evdokimidis, Elisabeth Kapaki et George P. Paraskevas. « Cerebrospinal Fluid TAR DNA-Binding Protein 43 Combined with Tau Proteins as a Candidate Biomarker for Amyotrophic Lateral Sclerosis and Frontotemporal Dementia Spectrum Disorders ». Dementia and Geriatric Cognitive Disorders 44, no 3-4 (2017) : 144–52. http://dx.doi.org/10.1159/000478979.
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Background: Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are nowadays recognized as spectrum disorders with a molecular link, the TAR DNA-binding protein 43 (TDP-43), rendering it a surrogate biomarker for these disorders. Methods: We measured cerebrospinal fluid (CSF) levels of TDP-43, beta-amyloid peptide with 42 amino acids (Aβ42), total tau protein (τT), and tau protein phosphorylated at threonine 181 (τP-181) in 32 patients with ALS, 51 patients with FTD, and 17 healthy controls. Double-sandwich commercial enzyme-linked immunosorbent assays were used for measurements. Results: Both ALS and FTD patients presented with higher TDP-43 and τT levels compared to the control group. The combination of biomarkers in the form of the TDP-43 × τT / τP-181 formula achieved the best discrimination between ALS or FTD and controls, with sensitivities and specificities >0.8. Conclusion: Combined analysis of TDP-43, τT, and τP-181 in CSF may be useful for the antemortem diagnosis of ALS and FTD.
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Mollee, Peter, Patricia Renaut, Samuel Boros, Dorothy Loo et Michelle Hill. « Diagnosis Of Amyloidosis Subtype By Laser-Capture Microdissection (LCM) and Tandem Mass Spectrometry (MS) Proteomic Analysis ». Blood 122, no 21 (15 novembre 2013) : 5295. http://dx.doi.org/10.1182/blood.v122.21.5295.5295.
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Abstract Aim Correct identification of the protein that is causing amyloidosis is crucial for clinical management. Current standard diagnostic methods have limited ability to detect the full range of amyloid forming proteins. We assessed combining specific sampling of amyloid deposits by LCM and analysis of tryptic digests by tandem MS proteomic analysis to determine whether the majority of amyloidosis clinical samples can be correctly classified as reported by the Mayo Clinic pathology department. Methods We studied 58 cases of well characterised amyloid deposition and 10 cases in which the amyloid subtype was unable to be diagnosed with confidence. For all specimens, 10µm sections of formalin-fixed paraffin embedded tissue were stained with Congo Red using a standard technique. LCM was performed using an Arcturus XT instrument with an infrared capture laser. Proteins were digested with trypsin and peptides were analysed by nano-liquid chromatography-coupled tandem mass spectrometry using a Chip CUBE-QTOF. Database searching was performed using Spectrum Mill (Agilent) with the NCBInr human protein database. Protein identification cut-offs were protein score > 11, peptide score > 10 and % scored peak intensity >60. Results Biopsy sites included: GIT (n=16), cardiac (n=12), soft tissue (n=8), renal (n=9), liver (n=3) and other (n=20). The amyloid subtype was able to be determined in 64 cases analysed. In 7 of these cases a second sample or second LCM was required as the first analysis was non-diagnostic. In 4 cases the amyloidogenic protein was not identified mostly due to the amyloid deposits being very small. Proteins identified included immunoglobulin light chain (localised amyloid n=6, systemic AL n=32), transthyretin (senile amyloid n=17, hereditary ATTR n=2), serum amyloid A (AA n=4), fibrinogen (AFib n=1), TGFb (corneal lattice amyloid n=1) and semenogelin (seminal vesicle amyloid n=1). Three diagnostically challenging cases are detailed as examples of the utility of LCM and tandem MS. The first case had extensive gastrointestinal amyloidosis and no evidence of clonal light chain disease; negative kappa, lambda, SAA and transthyretin immunohistochemistry; and negative genetic studies. Tandem MS revealed immunoglobulin lambda light chain type. The second diagnostically challenging case had: isolated renal amyloidosis with a positive AA stain and kappa restricted serum free light chains. Tandem MS revealed serum amyloid A2 protein. The third case had: cardiac, neurological and gastrointestinal involvement; and equivocal immunohistochemistry. Tandem MS demonstrated transthyretin and genetic studies showed a A97S ATTR mutation. Various other proteins were identified by tandem MS in amyloid extracts. Of particular interest is the presence of proteins typically known to be co-located in amyloid deposits which helps confirm that the microdissected tissue is amyloid. Typical amyloid-associated proteins were identified in the following number of cases: SAP (n=36), apolipoprotein A4 (n=42), vitronectin (n=44), apolipoprotein E (n=40) and clusterin (n=21). Various types of collagen were frequently present (n=29) and various, presumably contaminating, keratins were identified (n=24). Conclusion LCM and tandem MS allows correct typing of amyloid deposits in the majority of clinical biopsy samples. Disclosures: No relevant conflicts of interest to declare.
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Hasani, Seyede Anis, Mahsa Mayeli, Mohammad Amin Salehi et Rezvan Barzegar Parizi. « A Systematic Review of the Association between Amyloid-β and τ Pathology with Functional Connectivity Alterations in the Alzheimer Dementia Spectrum Utilizing PET Scan and rsfMRI ». Dementia and Geriatric Cognitive Disorders Extra 11, no 2 (6 mai 2021) : 78–90. http://dx.doi.org/10.1159/000516164.
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The association between functional connectivity (FC) alterations with amyloid-β (Aβ) and τ protein depositions in Alzheimer dementia is a subject of debate in the current literature. Although many studies have suggested a declining FC accompanying increased Aβ and τ concentrations, some investigations have contradicted this hypothesis. Therefore, this systematic review was conducted to sum up the current literature in this regard. The PROSPERO guideline for systematic reviews was applied for development of a research protocol, and this study was initiated after getting the protocol approval. Studies were screened, and those investigating FC measured by resting-state functional MRI and Aβ and τ protein depositions using amyloid and τ positron emission tomography were included. We categorized the included studies into 3 groups methodologically, addressing the question using global connectivity analysis (examining all regions of interest across the brain based on a functional atlas), seed-based connectivity analysis, or within-networks connectivity analysis. The quality of the studies was assessed using the Newcastle-Ottawa Scale. Among 31 included studies, 14 found both positive and negative correlations depending on the brain region and stage of the investigated disease, while 7 showed an overall negative correlation, 8 indicated an overall positive correlation, and 2 found a nonsignificant association between protein deposition and FC. The investigated regions were illustrated using tables. The posterior default mode network, one of the first regions of amyloid accumulation, and the temporal lobe, the early τ deposition region, are the 2 most investigated regions where inconsistencies exist. In conclusion, our study indicates that transneuronal spreading of τ and the amyloid hypothesis can justify higher FC related to higher protein depositions when global connectivity analysis is applied. However, the discrepancies observed when investigating the brain locally could be due to the varying manifestations of the amyloid and τ overload compensatory mechanisms in the brain at different stages of the disease with hyper- and hypoconnectivity cycles that can occur repeatedly. Nevertheless, further studies investigating both amyloid and τ deposition simultaneously while considering the stage of Alzheimer dementia are required to assess the accuracy of this hypothesis.
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D'Souza, Anita, Jason D. Theis, Julie A. Vrana et Ahmet Dogan. « Drug-Induced Amyloidosis : A Proteomic Insight Into 52 Cases ». Blood 122, no 21 (15 novembre 2013) : 1871. http://dx.doi.org/10.1182/blood.v122.21.1871.1871.
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Abstract The amyloidoses are heterogeneous diseases associated with the deposition of insoluble proteins or peptides with a characteristic beta-diffraction pattern extracellularly. At the current time, over 27 different extracellular fibril proteins are known to cause disease in humans. Iatrogenic amyloidosis is a rare, often not sought diagnosis. On occasion, patients with drug induced amyloidosis can present with other systemic features reminiscent of systemic immunoglobulin-derived (AL) amyloidosis, and may present a diagnostic challenge. Treatment of the latter often involves chemotherapy and/or stem cell transplantation, while the former tends to remain localized and needs local therapy; thus accurate diagnosis is critical. To this end, proteomic analysis of amyloid tissue has proven to be an invaluable tool in amyloid typing. We have analyzed the biochemical composition of iatrogenic amyloid using laser capture/tandem mass spectrometry (LC-MS/MS)-based proteomic analysis in 52 cases of insulin and enfuvirtide (Fuzeon¨) associated amyloidosis. In brief, 10-μm-thick sections of formalin-fixed paraffin-embedded tissues were stained with Congo red. Congo red positively staining tissue as viewed with a fluorescent light source appeared bright red. Positive areas were dissected using laser microdissection to a volume of at least 60,000 μm2; three microdissections were analyzed for each case. The microdissected material was collected into 0.5-ml microcentrifuge tube caps containing 35 μL Tris/EDTA/0.002% Zwittergent buffer. Microdissected fragments were subjected to a heat-mediated antigen retrieval method (98C for 90minutes) before being denatured via sonication and subsequently digested into tryptic peptides overnight using 0.5ug of trypsin. The resulting digests were then analyzed with nanoflow LC-MS/MS. The MS/MS spectra of each case were matched against a composite protein sequence database using three different search algorithms (Sequest, X!Tandem, and Mascot). The composite database contained the human SwissProt entries but was also augmented with known immunoglobulin variant domains, known amyloidogenic mutations from literature, the enfuvirtide amino acid sequence, and common contaminants. Reversed protein sequences were appended to the database for estimating the false discovery rates of the identifications. The peptide identification results were filtered using Scaffold software (Proteome Software, Portland, OR) and then filtered peptides were assembled into protein identifications. Candidate proteins with at least one high-confident (probability of identification >90%) unique peptide identification and at least four MS/MS spectral matches were considered for clinical interpretation. For each case, we created a personalized proteomic profile that lists all the confident protein identifications in each of the microdissection along with their respective MS/MS spectral counts. The number of MS/MS spectra matching to a protein is considered as a semi-quantitative measure of its abundance. The most abundant amyloidogenic protein detected across all microdissections and as interpreted in the context of the clinical history is considered to be the amyloid subtype. Figure 1 shows the results of insulin amyloidosis. Figure 2 shows the results of enfuvirtide amyloidosis. Amyloid deposits are shown to be composed of the recombinant drug in addition to amyloid precursor proteins such as apolipoprotein A-I, A-IV, E and serum amyloid P (SAP).Figure 1. Insulin-associated amyloidosisFigure 1. Insulin-associated amyloidosisFigure 2Enfuvirtide (Fuzeon¨)-associated amyloidosisFigure 2. Enfuvirtide (Fuzeon¨)-associated amyloidosis In conclusion, we show the biochemical composition of all known drug-induced iatrogenic amyloidosis and provide the utility of proteomic analysis in elucidating amyloid subtyping for accurate diagnosis and management. Legend: A spectral count number of greater than 4 is significant. The green boxes denote protein identification at a probability of over 95%, and yellow 80-94%. In figure 1, insulin (# 2) and in figure 2, enfuvirtide (#5) are shown in abundance, additionally other amyloid precursors such as apolipoproteins A-IV, E, A-I and SAP are also seen. Disclosures: No relevant conflicts of interest to declare.
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Micsonai, András, Frank Wien, Linda Kernya, Young-Ho Lee, Yuji Goto, Matthieu Réfrégiers et József Kardos. « Accurate secondary structure prediction and fold recognition for circular dichroism spectroscopy ». Proceedings of the National Academy of Sciences 112, no 24 (2 juin 2015) : E3095—E3103. http://dx.doi.org/10.1073/pnas.1500851112.
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Circular dichroism (CD) spectroscopy is a widely used technique for the study of protein structure. Numerous algorithms have been developed for the estimation of the secondary structure composition from the CD spectra. These methods often fail to provide acceptable results on α/β-mixed or β-structure–rich proteins. The problem arises from the spectral diversity of β-structures, which has hitherto been considered as an intrinsic limitation of the technique. The predictions are less reliable for proteins of unusual β-structures such as membrane proteins, protein aggregates, and amyloid fibrils. Here, we show that the parallel/antiparallel orientation and the twisting of the β-sheets account for the observed spectral diversity. We have developed a method called β-structure selection (BeStSel) for the secondary structure estimation that takes into account the twist of β-structures. This method can reliably distinguish parallel and antiparallel β-sheets and accurately estimates the secondary structure for a broad range of proteins. Moreover, the secondary structure components applied by the method are characteristic to the protein fold, and thus the fold can be predicted to the level of topology in the CATH classification from a single CD spectrum. By constructing a web server, we offer a general tool for a quick and reliable structure analysis using conventional CD or synchrotron radiation CD (SRCD) spectroscopy for the protein science research community. The method is especially useful when X-ray or NMR techniques fail. Using BeStSel on data collected by SRCD spectroscopy, we investigated the structure of amyloid fibrils of various disease-related proteins and peptides.
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Qin, Qiu, Ronghua Song, Peng Du, Chaoqun Gao, Qiuming Yao et Jin-an Zhang. « Systemic Proteomic Analysis Reveals Distinct Exosomal Protein Profiles in Rheumatoid Arthritis ». Journal of Immunology Research 2021 (18 août 2021) : 1–11. http://dx.doi.org/10.1155/2021/9421720.
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Objective. Rheumatoid arthritis (RA) is a complex disease with unknown pathogenesis. In recent years, fewer have paid attention to the broad spectrum of systemic markers of RA. The aim of this study was to identify exosomal candidate proteins in the pathogenesis of RA. Methods. Totally, 12 specimens of plasma from 6 RA patients and 6 age- and gender-matched controls from the Chinese population were obtained for nanoscale liquid chromatography coupled to tandem mass spectrometry (nano-LC-MS/MS) analysis to identify exosomal profiles. Results. A total of 278 exosomal proteins were detected. Among them, 32 proteins were significantly upregulated ( FC ≥ 2.0 and P < 0.05 ) and 5 proteins were downregulated ( FC ≤ 0.5 and P < 0.05 ). Bioinformatics analysis revealed that transthyretin (TTR), angiotensinogen (AGT), lipopolysaccharide-binding protein (LBP), monocyte differentiation antigen CD14 (CD14), cartilage oligomeric matrix protein (COMP), serum amyloid P (SAP/APCS), and tenascin (TNC) can interact with each other. Subsequently, these cross-linked proteins may be mainly involved in the inflammatory-related pathways to mediate the onset of RA. Noteworthy, the LBP/CD14 complex can promote the expression of IL-8 and TNF-α, eventually leading to the development of RA. Conclusions. Our findings suggest distinct plasmatic exosomal protein profiles in RA patients. These proteins not only take important parts in the vicious circle in the pathogenic process of RA but also serve as novel biomarkers in RA diagnosis and prognosis.
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Bell, Lauren N., Lydia Lee, Romil Saxena, Kerry G. Bemis, Mu Wang, Janice L. Theodorakis, Raj Vuppalanchi, Mouhamad Alloosh, Michael Sturek et Naga Chalasani. « Serum proteomic analysis of diet-induced steatohepatitis and metabolic syndrome in the Ossabaw miniature swine ». American Journal of Physiology-Gastrointestinal and Liver Physiology 298, no 5 (mai 2010) : G746—G754. http://dx.doi.org/10.1152/ajpgi.00485.2009.
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We recently developed a nutritional model of steatohepatitis and metabolic syndrome in Ossabaw pigs. Here we describe changes in the serum proteome of pigs fed standard chow (control group; n = 7), atherogenic diet ( n = 5), or modified atherogenic diet (M-ath diet group; n = 6). Pigs fed atherogenic diet developed metabolic syndrome and mildly abnormal liver histology, whereas pigs fed M-ath diet exhibited severe metabolic syndrome and liver injury closely resembling human nonalcoholic steatohepatitis (NASH). Using a label-free mass spectrometry-based proteomics approach, we identified 1,096 serum proteins, 162 of which changed significantly between any two diet groups (false discovery rate <5%). Biological classification of proteins with significant changes revealed functions previously implicated in development of NASH in humans, including immune system regulation and inflammation (orosomucoid 1, serum amyloid P component, paraoxonase 1, protein similar to α-2-macroglobulin precursor, β-2-microglobulin, p101 protein, and complement components 2 and C8G), lipid metabolism (apolipoproteins C-III, E, E precursor, B, and N), structural and extracellular matrix proteins (transthyretin and endopeptidase 24.16 type M2), and coagulation [carboxypeptidase B2 (plasma)]. Several proteins with significant differential expression in pigs were also identified in our recent human proteomics study as changing significantly in serum from patients across the spectrum of nonalcoholic fatty liver disease, including apolipoproteins C-III and B, orosomucoid 1, serum amyloid P component, transthyretin, paraoxonase 1, and a protein similar to α-2-macroglobulin precursor. This serum proteomic analysis provides additional information about the pathogenesis of NASH and further characterizes our large animal model of diet-induced steatohepatitis and metabolic syndrome in Ossabaw pigs.
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Bevan-Jones, W. Richard, Thomas E. Cope, P. Simon Jones, Sanne S. Kaalund, Luca Passamonti, Kieren Allinson, Oliver Green et al. « Neuroinflammation and protein aggregation co-localize across the frontotemporal dementia spectrum ». Brain 143, no 3 (1 mars 2020) : 1010–26. http://dx.doi.org/10.1093/brain/awaa033.
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Abstract The clinical syndromes of frontotemporal dementia are clinically and neuropathologically heterogeneous, but processes such as neuroinflammation may be common across the disease spectrum. We investigated how neuroinflammation relates to the localization of tau and TDP-43 pathology, and to the heterogeneity of clinical disease. We used PET in vivo with (i) 11C-PK-11195, a marker of activated microglia and a proxy index of neuroinflammation; and (ii) 18F-AV-1451, a radioligand with increased binding to pathologically affected regions in tauopathies and TDP-43-related disease, and which is used as a surrogate marker of non-amyloid-β protein aggregation. We assessed 31 patients with frontotemporal dementia (10 with behavioural variant, 11 with the semantic variant and 10 with the non-fluent variant), 28 of whom underwent both 18F-AV-1451 and 11C-PK-11195 PET, and matched control subjects (14 for 18F-AV-1451 and 15 for 11C-PK-11195). We used a univariate region of interest analysis, a paired correlation analysis of the regional relationship between binding distributions of the two ligands, a principal component analysis of the spatial distributions of binding, and a multivariate analysis of the distribution of binding that explicitly controls for individual differences in ligand affinity for TDP-43 and different tau isoforms. We found significant group-wise differences in 11C-PK-11195 binding between each patient group and controls in frontotemporal regions, in both a regions-of-interest analysis and in the comparison of principal spatial components of binding. 18F-AV-1451 binding was increased in semantic variant primary progressive aphasia compared to controls in the temporal regions, and both semantic variant primary progressive aphasia and behavioural variant frontotemporal dementia differed from controls in the expression of principal spatial components of binding, across temporal and frontotemporal cortex, respectively. There was a strong positive correlation between 11C-PK-11195 and 18F-AV-1451 uptake in all disease groups, across widespread cortical regions. We confirmed this association with post-mortem quantification in 12 brains, demonstrating strong associations between the regional densities of microglia and neuropathology in FTLD-TDP (A), FTLD-TDP (C), and FTLD-Pick's. This was driven by amoeboid (activated) microglia, with no change in the density of ramified (sessile) microglia. The multivariate distribution of 11C-PK-11195 binding related better to clinical heterogeneity than did 18F-AV-1451: distinct spatial modes of neuroinflammation were associated with different frontotemporal dementia syndromes and supported accurate classification of participants. These in vivo findings indicate a close association between neuroinflammation and protein aggregation in frontotemporal dementia. The inflammatory component may be important in shaping the clinical and neuropathological patterns of the diverse clinical syndromes of frontotemporal dementia.
Thèses sur le sujet "Amyloid beta-protein. Spectrum analysis"
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Schmidt, Emily Ann. « Spectroscopic investigations of the beta-amyloid peptide ». Diss., Columbia, Mo. : University of Missouri-Columbia, 2008. http://hdl.handle.net/10355/5668.
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Thesis (M.S.)--University of Missouri-Columbia, 2008.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on August 14, 2009) Includes bibliographical references.
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Dooley, Nora P. « Analysis of beta-amyloid precursor protein in Alzheimer's fibroblasts ». Thesis, McGill University, 1992. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=56982.
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One of the hallmarks of Alzheimer's disease is the accumulation of beta-amyloid protein in the core of neuritic plaques. This 38-40 amino acid polypeptide is derived from a larger precursor known as beta-amyloid precursor protein (BAPP). In this thesis the expression of this precursor in cultured human fibroblasts obtained from Alzheimer's patients and age-matched controls is examined at the mRNA and protein level. Using the technique of reverse transcriptase-polymerase chain reaction, human fibroblasts were found to express BAPP transcripts encoding 770, 751, 714, and 695 amino acids. In immunocytochemical studies employing a monoclonal antibody to BAPP, this precursor was determined to be associated with the intermediate filament network. As well, on Western blots, aside from the bands of predicted molecular weights, a Triton-soluble 57 kDn band was detected. These findings lend support to the theory that aside from its putative extracellular functions, BAPP may play a vital intracellular role.
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Golde, Todd Eliot. « Analysis of the beta amyloid precursor protein mRNAs in Alzheimer's disease ». Case Western Reserve University School of Graduate Studies / OhioLINK, 1991. http://rave.ohiolink.edu/etdc/view?acc_num=case1056572599.
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Palmert, Mark Raney. « The beta amyloid protein precursor of Alzheimer's disease : Analysis of mRNAs and protein products ». Case Western Reserve University School of Graduate Studies / OhioLINK, 1990. http://rave.ohiolink.edu/etdc/view?acc_num=case1054920188.
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Rijal, Upadhaya Ajeet [Verfasser]. « Analysis of Amyloid beta (Aβ) protein in Amyloid precursor protein (APP) transgenic mouse models of Alzheimer’s disease (AD) and in human brains / Ajeet Rijal Upadhaya ». Ulm : Universität Ulm. Medizinische Fakultät, 2012. http://d-nb.info/1025715012/34.
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Pasternack, Jennifer Martine. « The Alzheimer's disease beta amyloid protein precursor : Analysis of the carboxyl terminus of its soluble derivatives ». Case Western Reserve University School of Graduate Studies / OhioLINK, 1992. http://rave.ohiolink.edu/etdc/view?acc_num=case1060094123.
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Luheshi, Leila Mohamed. « Mutational analysis of the aggregation and toxicity of the amyloid beta peptide in a Drosophila model of Alzheimer's Disease ». Thesis, University of Cambridge, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.612965.
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Smotherman, Jesse M. « The Impact of Causative Genes on Neuropsychological Functioning in Familial Early-Onset Alzheimer's Disease : A Meta-Analysis ». Thesis, University of North Texas, 2017. https://digital.library.unt.edu/ark:/67531/metadc984161/.
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Mutations of three genes encoding amyloid precursor protein (APP), presenilin-1 (PSEN1), and presenilin-2 (PSEN2) have been shown to reliably result in familial early-onset Alzheimer's disease (FAD); a rare, but catastrophic, subtype of Alzheimer's disease (AD) marked by symptom emergence before age 65 as well as accelerated cognitive deterioration. The current study represents the first known meta-analysis on the association of APP, PSEN1 or PSEN2 on neurocognitive variables. A total of 278 FAD mutation-carriers (FAD-MC) and 284 cognitively healthy non-mutation-carriers (NC) across 10 independent investigations meeting inclusion criteria were chosen for the current meta-analysis (random effects design). Findings revealed an overarching trend of poorer performance by FAD-MC individuals compared to NC individuals across the majority of cognitive domains identified. Significant differences in effect sizes suggested FAD-MC individuals exhibited worse performance on measures of attention, explicit memory, fluency, primary memory, verbal, and visuospatial functioning. Findings indicative of differential sensitivity to cognitive domain impairments across FAD-MC and NC groups inform neuropsychological descriptions of individuals in preclinical phases of FAD.
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Gösch, Michael. « Microfluidic analysis and parallel confocal detection of single molecules / ». Stockholm, 2003. http://diss.kib.ki.se/2003/91-7349-663-4/.
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Wu, Di. « Proximity Ligation and Barcoding Assays : Tools for analysis of proteins and protein complexes ». Doctoral thesis, Uppsala universitet, Molekylära verktyg, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-220070.
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Proteins are fundamental structural, enzymatic and regulatory components of cells. Analysis of proteins, such as by measuring their concentrations, characterizing their modifications, and detecting their interactions, provides insights in how biological systems work physiologically or pathologically at the molecular level. To perform such analysis, molecular tools with good sensitivity, specificity, high multiplexing and throughput capacity are needed. In this thesis, four different assays were developed and applied to detect and profile proteins and protein complexes in human body fluids, and in cells or tissues. These assays are based on targeting proteins or protein complexes by oligonucleotide-conjugated antibodies, and subsequent proximity dependent enzymatic reactions involving the attached DNA reporter sequences. In paper I, a solid-phase proximity ligation assay (SP-PLA) was applied to detect synthetic and endogenous amyloid beta protofibrils. The SP-PLA provided better sensitivity and increased dynamic range than a traditional enzyme-linked immunosorbent assay (ELISA). In paper II, in situ PLA was applied to investigate the correlation between MARK2-dependent phosphorylation of tau and Alzheimer’s disease. Greater numbers of MARK2-tau interactions and of phosphorylated tau proteins were observed in brain tissues from Alzheimer’s patients than in healthy controls. In paper III, a multiplex SP-PLA was applied to identify protein biomarker candidates in amyotrophic lateral sclerosis (ALS) disease and in the analgesic mechanism of spinal cord stimulation (SCS). Among 47 proteins in human cerebrospinal fluid (CSF) samples, four were found at significantly lower concentrations (p-values < 0.001) in the samples from ALS patients compared to those from healthy controls (follistatin, IL-1α, IL-1β, and KLK5). No significant changes of the analyzed proteins were found in the CSF samples of neuropathic pain patients in the stimulated vs. non-stimulated condition using SCS. In paper IV, a new technology termed the proximity barcoding assay (PBA) was developed to profile individual protein complexes. The performance of PBA was demonstrated on artificially assembled streptavidin-biotin oligonucleotide complexes. PBA was also proven to be capable of profiling transcriptional pre-initiation complexes from nuclear extract of a hepatic cell line.
Livres sur le sujet "Amyloid beta-protein. Spectrum analysis"
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Gorman, Paul M. Analysis of beta-amyloid aggregation and amyloid precursor protein dimerization. 2006.
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Safar, Jiri G. Prion Paradigm of Human Neurodegenerative Diseases Caused by Protein Misfolding. Oxford University Press, 2016. http://dx.doi.org/10.1093/med/9780190233563.003.0005.
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Data accumulated from different laboratories argue that a growing number of proteins causing neurodegeneration share certain characteristics with prions. Prion-like particles were produced from synthetic amyloid beta (Aβ) peptides of Alzheimer’s disease (AD), from recombinant α-synuclein linked to Parkinson’s disease (PD), and from recombinant tau associated with frontotemporal dementias (FTD). Evidence from human prions reveals that variable disease phenotypes, rates of propagation, and targeting of different brain structures are determined by distinct conformers (strains) of pathogenic prion protein. Recent progress in the development of advanced biophysical tools identified the structural characteristics of Aβ in the brain cortex of phenotypically diverse AD patients and thus allowed an investigation of the prion paradigm of AD. The findings of distinctly structured strains of human brain Aβ, forming a unique spectrum of oligomeric particles in the cortex of rapidly progressive cases, implicates these structures in variable rates of propagation in the brain.
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M, Hooper N., dir. Alzheimer's disease : Methods and protocols. Totowa, N.J : Humana Press, 2000.
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Micsonai, András, Éva Bulyáki et József Kardos. « BeStSel : From Secondary Structure Analysis to Protein Fold Prediction by Circular Dichroism Spectroscopy ». Dans Methods in Molecular Biology, 175–89. New York, NY : Springer US, 2020. http://dx.doi.org/10.1007/978-1-0716-0892-0_11.
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Abstract Far-UV circular dichroism (CD) spectroscopy is a classical method for the study of the secondary structure of polypeptides in solution. It has been the general view that the α-helix content can be estimated accurately from the CD spectra. However, the technique was less reliable to estimate the β-sheet contents as a consequence of the structural variety of the β-sheets, which is reflected in a large spectral diversity of the CD spectra of proteins containing this secondary structure component. By taking into account the parallel or antiparallel orientation and the twist of the β-sheets, the Beta Structure Selection (BeStSel) method provides an improved β-structure determination and its performance is more accurate for any of the secondary structure types compared to previous CD spectrum analysis algorithms. Moreover, BeStSel provides extra information on the orientation and twist of the β-sheets which is sufficient for the prediction of the protein fold. The advantage of CD spectroscopy is that it is a fast and inexpensive technique with easy data processing which can be used in a wide protein concentration range and under various buffer conditions. It is especially useful when the atomic resolution structure is not available, such as the case of protein aggregates, membrane proteins or natively disordered chains, for studying conformational transitions, testing the effect of the environmental conditions on the protein structure, for verifying the correct fold of recombinant proteins in every scientific fields working on proteins from basic protein science to biotechnology and pharmaceutical industry. Here, we provide a brief step-by-step guide to record the CD spectra of proteins and their analysis with the BeStSel method.