Dissertations / Theses: 'CYP46'

1

GARCIA, Analia Nusya de Medeiros. "Polimorfismos dos genes CYP 46 e APOE e declínio cognitivo em idosos residentes no distrito de Fernando de Noronha-PE." Universidade Federal de Pernambuco, 2011. https://repositorio.ufpe.br/handle/123456789/8317.

Full text

Abstract:

Made available in DSpace on 2014-06-12T22:59:08Z (GMT). No. of bitstreams: 2 arquivo5593_1.pdf: 9647965 bytes, checksum: 23ac0509ddb6353a3c91975edec8f243 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2011
O Declínio Cognitivo Leve (DCL) é um estado mental considerado a zona de transição entre o envelhecimento normal e a fase mais inicial de demência, sendo uma fase importante para a precocidade diagnóstica. Nos últimos anos, pesquisas estão sendo desenvolvidas na busca de marcadores genéticos para esta zona de pré-demência, como os polimorfismos dos genes da apolipoproteína E (APOE) representada por 3 alelos (E2, E3, E4) e do colesterol 24S-hidroxilase (CYP46) com alelos T e C. Indivíduos portadores do APOE E4 tem fator de risco quatro vezes maior de desenvolver a Demência de Alzheimer e dez vezes mais probabilidade se tiver associado os polimorfismos dos genes APOE e CYP46. O objetivo deste estudo foi investigar a possível associação entre o polimorfismo dos genes CYP46(T/C), APOE E4 e a presença de DCL na população idosa do Distrito de Fernando de Noronha, totalizando uma seleção de 52 indivíduos. A avaliação clínica foi realizada através de exame físico, funcional e mental. Foram aplicados testes neuropsiquiátricos (Mini Exame do Estado Mental, Teste de Fluência Verbal, Teste do Relógio) e a identificação do genótipo dos polimorfismos do APOE e CYP46 pelo método de PCR-RFLP. Como resultados observou-se que 87% da amostra apresentou declínio cognitivo leve. No Mini Exame do Estado Mental, Teste de Fluência Verbal e Teste do Relógio foi observado declínio cognitivo em 42,8%, 31,9% e 53,2% respectivamente. Foi observada uma frequência alélica de 10% para o alelo E4. Não foi observada associação entre APOE E4 e declínio cognitivo. Os alelos T (p = 0,628) e C (p = 0,2076) do gene Cyp46 não estão associadas ao DCL na população estudada. Não foi observada associação (p = 0,4286), quando analisado o sinergismo entre o polimorfismo dos genes Cyp46(T/C) e APOE E4 no desenvolvimento do DCL. Nesta população, os resultados sugerem que os polimorfismos dos genes Cyp46(T/C) e APOE E4 não estão associados ao DCL

APA, Harvard, Vancouver, ISO, and other styles

2

Sundin, Johanna. "Expression and Purification of Full-length CYP26 B1 and Spliced CYP26 B1." Thesis, Örebro University, School of Science and Technology, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-7394.

Full text

Abstract:

The goal of this project is to express both the normal CYP26 B1 and the spliced CYP26 B1 from human in Escherichia coli (E.coli) cells for further crystallization. This will be achieved by cloning in the DNA fragments into the Champion pET SUMO vector that is later transformed into E.coli cells. The CYP26 B1 contains a hydrophobic helix at the N-terminal of the protein, making both protein expression and crystallization difficult. Two variants of both full-length CYP26 B1 and the spliced variant will therefore be made, one with the trans-membrane helix present and one without the helix. The SUMO-vector will produce a fusion protein that will make CYP26 B1 more hydrophilic and improve the purification of the two proteins.

APA, Harvard, Vancouver, ISO, and other styles

3

Rydeen, Ariel B. "Requirements for Cyp26 enzymes in cardiovascular development." University of Cincinnati / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1468335415.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Graham, Richard Alan LeCluyse Edward L. "Biochemical and molecular characterization of beagle dog CYP4A." Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2006. http://dc.lib.unc.edu/u?/etd,290.

Full text

Abstract:

Thesis (Ph. D.)--University of North Carolina at Chapel Hill, 2006.
Title from electronic title page (viewed Oct. 10, 2007). "... in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the School of Pharmacy." Discipline: Pharmacy; Department/School: Pharmacy.

APA, Harvard, Vancouver, ISO, and other styles

5

Hood, Steven Richard. "Isolation and characterisation of a human CYP4A gene." Thesis, University of Surrey, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.359859.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Pautus, Stephane. "Design, synthesis and binding studies of novel CYP26 inhibitors." Thesis, Cardiff University, 2008. http://orca.cf.ac.uk/55730/.

Full text

Abstract:

All-frans-retinoic acid ATRA has shown spectacular success in the treatment of cancer and leukaemia, however ATRA is rapidly metabolised by the P450 enzyme CYP26. In order to enhance endogenous levels of ATRA and/or to extend the half life of externally administered ATRA, a CYP26 inhibitor is required. Two series of CYP26 inhibitors were synthesised a series of 4-alkyl/aryl-substituted 1-joeiizofuran-2-yl-phenylmethyl-1-triazoles and a series of benzoxazol-2-yl-phenylinn lazol The triazole derivatives were prepared using methodology previously described by our group. The aminobenzoxazole derivatives were envisaged from a docking experiment using a CYP26A1 homology model based on CYP3A4 template docking experiments were performed with MOE. The molecular docking of the amino-benzooxazole imidazole derivatives indicated multiple hydrogen bonding in addition to coordination between the imidazole nitrogen and the P450 haem transition metal. The triazole derivatives were evaluated for CYP26A1 inhibitory activity using a MCF-7 cell-based assay. The 4-ethyl-l,2,4-triazole and the 4-phenyl-l,2,4-triazole derivatives displayed inhibitory activity ICso 4.5 and ICso 7 uM respectively comparable with liarozole ICso 7 uM. On the other hand the aminobenzooxazole imidazole derivatives were only moderate inhibitors of the CYP26A1 enzyme in MCF-7 cells and did not achieve the promise shown in docking studies. The most potent inhibitor was the unsubstituted derivative IC5o 0.9 uM. Studies of the interaction of some of these inhibitors with hemin and TPP were also performed using different spectroscopic techniques mass spectrometry, X-ray crystallography, H NMR and UV/VIS spectroscopy and the binding constant was determined from the UV/VIS data for the unsubstituted compound of the aminobenzoxazole derivative with both hemin Km 1-69 0.31.105 M 1 and TPP Kt2 1.08 0.18.107 M2.

APA, Harvard, Vancouver, ISO, and other styles

7

Kuo, Chien-Wen Sharon. "The genomic structure of the CYP4 gene family." Thesis, University of Nottingham, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310930.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Gillett, Lorna. "Function of cytochrome P450s in the CYP4 family." Thesis, University of Nottingham, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.408051.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Heng, Yee M. "Genomic cloning and identification of a novel murine Cyp4a gene." Thesis, University of Nottingham, 1997. http://eprints.nottingham.ac.uk/10399/.

Full text

Abstract:

The mouse cytochrome P450 4a family of genes is poorly characterised. This thesis describes a detailed study of these genes. Using primers derived from exon 1 of the mouse cyp3a10 cDNA sequence, a 1.4kb genomic fragment was cloned which contained the promoter region of the gene. Additionally, a lambda genomic library was screened with probes derived from the partial cDNA clones of the mouse cyp4a10 and cyp4a12. Originally, two classes of phage lambda clones were isolated. One clone, lambda 16, was partially sequenced and was found to contain the 3' end of the cyp4a12 gene. The second clone, lambda 4, was subcloned and found to be distinct from previously known murine cyp4a genes. This novel gene has been designated cyp4a14. To obtain the full cyp4a14 gene, the genomic library was rescreened. Lambda clone 12 was subsequently isolated from the library, which was found to contain exons 1 to 5 of Cyp4a14. In order to study the promoter region of cyp4a14, a pcr-based approach was undertaken to clone 4.4 kb upstream of exon 1 of the gene and a 1.2kb fragment has been sequenced. Cyp4a14 RNA was also found to be highly induced by a peroxisome proliferator, methylclofenapate. Primer extension analyses were performed to determine the start of transcription of Cyp4a14, which was mapped to a single T nucleotide 26bp upstream of the putative start site of protein translation. The promoter region of Cyp4a14 is highly similar to the corresponding regions of the rat CYP4A2 genes. however, similarity is dramatically reduced about 350bp upstream of the start of transcription, which coincides with the presence of two 358bp repeats in teh CYP4A2 gene. The promoter also contains a highly conserved 19bp element which is also found in the promoter regions of the CYP4A1 and CYP4A2 genes. Cyp4a14 is a novel member of the murine Cyp4a subfamily. It contains 12 exons and is highly similar to the rat CYP4A2/3 genes. However, there is high conservation in exon 3 between Cyp4a14 and cyp4a3, which makes it marginally more related to this gene. In addition, cyp4a14 shows very high similarity in exons 4,8, 11 and 12 with other known CYP4A genes. Correspondingly, the peptide sequences encoded by these exons are highly conserved. Exon 8 encodes a 16 amino acid motif, LRAEVDTFMGEGHDTT, which is highly conserved in the CYP4 family. Exons 22 and 12 encode the well known RNCIG motif, containing the haem-binding domain, which is the proposed signature for a P450 protein. Exon 4 in the CYP4A genes encodes for a highly conserved, but previously unreported motif, HRRMLLTPGFHYDIL. Primary sequence alignments indicate that these motifs map very close to or within predicted substrate recognition sites and thus could have an important role in the enzyme activities of the CYP4A enzyme. The identification of Cyp4a14 also enables the analysis of the evolution of the murine Cyp4a subfamily. The mouse has 4 genes in the Cyp4a subfamily; however, the closely related rat has four CYP4A members. As the rat CYP4A2, which is very similar to CYP4AA3, was not to have a homologue in the mouse, it must have arisen after the mouse lineage had diverged from the rat in evolutionary history. As all three mouse Cyp4a genes are significantly more similar to their equivalents in the rat than to other murine Cyp4a genes, the gene duplication events giving rise to these three genes must have occurred before the mouse had diverged from the rat. Phylogenetic analyses of the CYP4A, CYP4B and CYp4F subfamilies demonstrate that CYP4A genes are more similar to the CYP4B family than to the CYP4F subfamily. This suggests that the gene duplication event giving rise to the CYP4A and CYP4B genes must be a more recent event than that giving rise to the CYP4F subfamily. In addition, the CYP4A subfamily of genes is more divergent than the CYP4B subfamily across species.

APA, Harvard, Vancouver, ISO, and other styles

10

Ning, Jia. "Allosteric effects of TPR domain-mediated protein-protein interactions." Thesis, University of Edinburgh, 2018. http://hdl.handle.net/1842/31145.

Full text

Abstract:

The tetratricopeptide repeat (TPR) motif contains 34 amino acids forming a helix-turn-helix structure. Different numbers of tandem TPR motifs assemble to form a TPR domain, thereby generating a polypeptide-binding interaction surface. The TPR domain provides a scaffold for mediating protein-protein interactions. Proteins that contain TPR domains exist in a broad range of organisms. These proteins have various functions. Cyclophilin 40 (Cyp40) and C-terminal Hsc70 interaction protein (CHIP) are two typical members of the family of TPR-containing proteins. Both proteins have the ability to bind the molecular chaperones Hsp70 and Hsp90. In most cases, TPR domains act as a scaffold to link chaperone and substrate or multi-protein complexes. Recent evidence suggests that Hsp90 binding to TPR domains can change the overall protein conformation but the allosteric mechanism triggered by ligand binding to the TPR domain remained unknown. This study focuses on using biophysical methods on the two TPR domain containing proteins Cyp40 and CHIP. In particular, this study reveals how the binding of the molecular chaperones Hsp70/90 to the TPR domains of Cyp40 and CHIP influences protein conformation and function. Here we show how conformational changes of the TPR domains affect structure and activity of Cyp40 and CHIP. By using biophysical methods, including thermal denaturation assay (TDA), differential scanning calorimetry (DSC), hydrogen deuterium exchange with mass spectrometry (HDX-MS) and small angle X-ray scattering (SAXS), together with enzymatic assays, we showed that (1) heat shock proteins allosterically affect the enzyme activity of both Cyp40 and CHIP, (2) heat shock proteins bind to the TPR domains of both Cyp40 and CHIP; (3) the binding increases the thermostability of both proteins. Further, by mutating an essential lysine in the TPR1 domain of both proteins (K30 for CHIP, and K227 for Cyp40) to alanine, the thermostability was significantly affected. The SAXS data showed in addition of the SRMEEVD peptide reduced the flexibility of CHIP. HDX-MS experiments suggest that the dynamic alteration due to binding with the Hsp90 peptide or the mutations further reduce the flexibility of the catalytic domains of both proteins. The results imply that the allosteric effects on the enzymatic activity are consequences of dynamic changes of the TPR domains. Hsp70 was also found to bind less tightly to CHIP-K30A than to wild-type CHIP, and thus showed less inhibition of enzymatic activity. These results further confirmed the discovery, that the dynamics of TPR domains allosterically affect enzymatic activity.

APA, Harvard, Vancouver, ISO, and other styles

11

Pianezza, Michael L. "The influence of genetically variable CYP246 on tobacco dependence and smoking behaviour." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0012/MQ40847.pdf.

Full text

APA, Harvard, Vancouver, ISO, and other styles

12

Wang, Xiaodong. "Studies of CyP40 and β-tubulin in the Arnt-dependent signaling pathways." Scholarly Commons, 2006. https://scholarlycommons.pacific.edu/uop_etds/2634.

Full text

Abstract:

Upon ligand binding, the aryl hydrocarbon receptor (AhR) translocates into the nucleus and dimerizes with its partner Ah receptor nuclear translocator (Arnt). The AhR/Arnt heterodimer binds to the enhancer element DRE to regulate target gene expression. It is known that the formation of the ligand-dependent AhR/Arnt/DRE complex requires protein factors in vitro. The first aim is to determine whether two other Hsp90-associated proteins present in rabbit reticulocyte lysate (RRL), namely CyP40 and Hsp70, play any role in forming the AhR/Arnt/DRE complex. Fractionation and immunodepletion experiments revealed that Hsp70 is not necessary for the formation of this complex. In contrast, CYP40 is involved in forming the complex since (1) immunodepletion of CyP40 from a RRL fraction reduces the intensity of the AhR-Arnt-DRE complex by 48% and (2) recombinant human CyP40 alone causes the formation of this complex. In addition, CyP40-interacting proteins appear to be essential for the full CyP40 effect on the AhR gel shift complex. The second aim is to determine the role of β-tubulin in Amt-dependent signaling pathways. From the insect Sf9 cytosol, β-tubulin enriched fraction (F5) was isolated which suppresses the AhR/Arnt/DRE complex formation in a gel shift assay. Tubulin enriched from pig brain had a similar inhibition of the AhR gel shift complex, suggesting that β-tubulin in F5 is likely responsible for the action. Using the TALON resin, β-tubulin was co-precipitated with the baculovirus 6His-Arnt, showing that β-tubulin interacts with Arnt. β-tubulin was examined to decide its role in the hypoxia inducible factor-1α (HIF-1α) signaling which is also Arnt-dependent. Gel shift data using HIF-1α and Arnt showed that F5 suppressed the formation of the HIF-1α/Arnt/HRE complex. Subsequently the Sf9 β-tubulin was cloned and about 95% of its full-length sequence was identified. The amino acid sequence of Sf9 β-tubulin shares high sequence identity with human β-tubulin. Upon transient transfection of a plasmid containing a human β-tubulin cDNA into MGF7 or Hep3B cells, the HRE-driven luciferase activity was clearly suppressed. In conclusion, we have evidence supporting that β-tubulin inhibits the Arnt-dependent signaling and the mechanism may involve the interaction between Arnt and β-tubulin.

APA, Harvard, Vancouver, ISO, and other styles

13

Simpson, AnneMarie Elizabeth Claire Merryman. "The ontogeny of cytochrome P450 4A (CYP4A) gene expression in the rat." Thesis, University of Leicester, 1994. http://hdl.handle.net/2381/34231.

Full text

Abstract:

Cytochrome P450s (P450s) play a major role in the metabolism of endogenous and exogenous chemicals. P450-metabolism generally converts compounds into more hydrophilic derivatives, which can then be excreted. In contrast, it can lead to the formation of reactive intermediates, which can attack cellular macromolecules leading to mutagenesis. The cytochrome P450 4A (CYP4A) subfamily encodes proteins involved in lipid metabolism. The CYP4A1, CYP4A2 and CYP4A3 genes are expressed constitutively in the adult rat, elevated expression being seen after administration of a hypolipidemic drug, clofibrate. The interest in the CYP4A subfamily is partly related to the apparent close association between CYP4A1 induction and the phenomenon of sustained peroxisome proliferation. It is also believed that the CYP4A proteins may be involved in the production of physiologically important renal metabolites. The aim of this thesis was a systematic study of the ontogeny and inducibility of CYP4A1 mRNA and protein levels in embryonic, fetal and post-natal rats. Constitutive and induced hepatic expression of the CYP4A1, CYP4A2 and CYP4A3 mRNAs was demonstrated in the 24 day, 10.5 day and day 1 neonates, in addition to the 18.5 day fetal expression. Renal expression was not detected prenatally, and was only apparent in the day 1 neonates following induction. The mRNAs were also present in induced adult brown fat; induced and control adult and 24 day neonatal small intestine; induced 18.5 day fetal placenta and, induced and control 11.5 day embryonic decidua. The demonstration of inducible CYP4A1 gene expression is potentially important, as in conjunction with peroxisome proliferation, it may result in an increased susceptibility of the tissue to carcinogenesis. The P450 inductive response may also play an important role in elevating the rate of metabolism of foreign compounds to detoxified forms, or in some cases to harmful reactive intermediates. If this were to occur during pregnancy it could potentially have important consequences for the developing embryo/fetus.

APA, Harvard, Vancouver, ISO, and other styles

14

Pirkl, Franziska. "Funktionelle Analyse der grossen Peptidyl-Prolyl-cis/trans-Isomerasen FKBP51, FKBP52 und Cyp40." [S.l.] : [s.n.], 2001. http://deposit.ddb.de/cgi-bin/dokserv?idn=96279127X.

Full text

APA, Harvard, Vancouver, ISO, and other styles

15

Luu, Tony C. "Investigation of the role of CyP40 in the aryl hydrocarbon receptor signaling pathway." Scholarly Commons, 2008. https://scholarlycommons.pacific.edu/uop_etds/2383.

Full text

Abstract:

Cyclophilin-40 (CyP40) promotes the formation of the gel shift complex containing baculovirus aryl hydrocarbon receptor (AhR), AhR nuclear translocator (Arnt) and dioxin response element (DRE). CyP40 was found to play a role in the AhR signaling since when the CyP40 content in MCF-7 cells is reduced, up-regulation of cyp1a1 and cyp1b1 by 3-methylcholanthrene (3MC) is also reduced, suggesting that CyP40 is essential for maximal AhR function. The CyP40 region containing amino acids 186-215, but not the peptidylprolyl cis-trans isomerase and tetratricopeptide repeat domains, is essential for forming the AhR/Arnt/DRE complex. CyP40 is found in the cell nucleus after 3MC treatment and appears to promote the DRE binding form of the AhR/Arnt heterodimer. Coprecipitation data suggests CyP40 binds weakly to AhR, but not Arnt. We report on the progress of applying bioluminescence resonance energy transfer and chromatin immunoprecipitation techniques to further elucidate the role of CyP40 in the aryl hydrocarbon receptor signaling pathway.

APA, Harvard, Vancouver, ISO, and other styles

16

Jones, Paul S. "Expression and induction, by peroxisome proliferators, of the CYP4A and PPAR gene families in mouse." Thesis, University of Nottingham, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.283640.

Full text

APA, Harvard, Vancouver, ISO, and other styles

17

Idres, Nadia. "Propriétés biologiques des métabolites de l'acide rétinoi͏̈que et régulation du gène CYP26 dans les cellules leucémiques promyélocytaires humaines NB4." Paris 5, 2002. http://www.theses.fr/2002PA05S012.

Full text

Abstract:

Le métabolisme de l'acide rétinoi͏̈que tout-trans (ARtt) est en partie responsable de la résistance à l'ARtt observée "in vivo" chez l'homme au cours du traitement de la leucémie aigue͏̈ promyélocytaire (LAP). Cependant, il a été observé que des métabolites de l'ARtt étaient capables d'inhiber la croissance de plusieurs lignées cellulaires. Au cours de ce travail de thèse, nous avons montré que la lignée cellulaire NB4 humaine de LAP métabolisait l'ARtt en 4-oxo-ARtt, 4-OH-ARtt, 18-OH-ARtt et 5,6-époxy-ARtt. Nous avons montré que ces 4 métabolites inhibaient la prolifération et induisaient la différenciation granulocytaire des cellules NB4. Nous avons également mis en évidence que la différenciation des cellules NB4 induite par les métabolites faisait intervenir le récepteur à l'acide rétinoi͏̈de RARalpha.

APA, Harvard, Vancouver, ISO, and other styles

18

Lundell, Kerstin. "Cytochrome P450 Enzymes in Bile Acid Biosynthesis and Fatty Acid Metabolism : Studies on Members of the Porcine CYP4A and CYP8B Subfamilies." Doctoral thesis, Uppsala University, Department of Pharmaceutical Biosciences, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-3419.

Full text

Abstract:

The present investigation is devoted to studies on porcine members of the cytochrome P450 4A (CYP4A) and CYP8B1 subfamilies, which are involved in bile acid biosynthesis and fatty acid metabolism.

Hyocholic acid is considered to fulfil the requirements for trihydroxy bile acids in the domestic pig (Sus scrofa) in the absence of cholic acid. Hyocholic acid is a 6α-hydroxylated product of chenodeoxycholic acid and the enzyme catalyzing the 6α-hydroxylation was cloned and found to be an atypical member of the CYP4A subfamily. The primary structure of this porcine enzyme, designated CYP4A21, shows about 75% overall sequence identity to members of the CYP4A subfamily expressed in rabbit and man. Divergent amino acids in a “signature sequence” in the active site of all hitherto known CYP4A fatty acid hydroxylases, were found to be important determinants for the 6α-hydroxylase activity of CYP4A21.

Two homologous CYP4A fatty acid hydroxylases, designated CYP4A24 and CYP4A25, expressed in pig liver and kidney were cloned. These two cDNAs encode proteins of 504 amino acids similar to CYP4A21. The overall identity between CYP4A24 and CYP4A25 is 97% compared to 94% identity to CYP4A21. Whereas CYP4A21 clearly deviates regarding structural features and catalytic activity it is more difficult to establish whether CYP4A24 and CYP4A25 are distinct enzymes or allelic variants of a single enzyme.

Cloning of the CYP4A21 gene showed a conserved organization compared to CYP4A genes in other species. A segment of the CYP4A24 gene was also cloned and comparison with the CYP4A21 gene revealed an extensive sequence identity also within introns as well as within the proximal promoter regions. This indicates that CYP4A21 and CYP4A fatty acid hydroxylases have a common origin and evolved by gene duplication. The CYP4A21 and CYP4A fatty acid hydroxylases, however, show distinct patterns of expression.

The key enzyme in cholic acid biosynthesis, CYP8B1, was markedly expressed in fetal pig liver compared to livers from young pigs. The opposite was shown for the expression of CYP4A21. An apparently conserved pig CYP8B1 gene was cloned and was intronless, similar to CYP8B1 genes from other species. The pig gene encoded a protein of 501 amino acids with 81% identity to CYP8B1 expressed in rabbit and man. Unlike other CYP8B1 genes, the pig promoter lacked a TATA-box. This might offer one explanation for the unusual expression pattern, which appears to be restricted to pig fetal life.

APA, Harvard, Vancouver, ISO, and other styles

19

Pavez, Loriè Elizabeth. "Retinoic Acid Metabolism Blocking Agents and the Skin : In vivo and in vitro Studies of the Effects on Normal and Diseased Human Epidermis." Doctoral thesis, Uppsala universitet, Institutionen för medicinska vetenskaper, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-9325.

Full text

Abstract:

Retinoic Acid Metabolism Blocking Agents (RAMBAs) increase the endogenous levels of all-trans retinoic acid (RA) by inhibiting CYP26 enzymes. Thus they are believed to mimic the effects of retinoid treatment. Their mechanism of action and effects on vitamin A metabolism in keratinocytes are however uncertain. To explore this and the function of CYP26 in human skin was the main purpose of the project. The effects of two RAMBAs (talarozole and liarozole) on the expression of retinoid biomarkers in epidermis were studied in vivo and in vitro. Normal human skin (n=16) exposed to topical talarozole for 9 days showed similar response as previously reported for topical RA, even though no skin inflammation occurred. Lamellar ichthyosis patients (n=11) treated systemically with liarozole showed variable clinical improvement after 4 weeks with only mild effects on the retinoid biomarkers and the expression did not always correlate at the protein and mRNA levels. In these studies the proinflammatory transcripts IL-1α and TNFα were down-regulated by RAMBAs. In vitro, using an organotypic epidermis model we first studied how the RA metabolism was affected by adding RA and/or RAMBAs. We next examined the effects of the same agents on the expression of vitamin A metabolising enzymes in monolayer cultures of proliferating and differentiating keratinocytes. The results show among other things that CYP26 A1 and B1 are both involved in the catabolism of RA, and that talarozole potently increases the level of endogenous RA, primarily by inhibiting CYP26B1. However the drug´s biological effects cannot be solely attributed to increased RA levels. In conclusion, RAMBAs are promising new drugs for treatment of skin disorders, but further studies on their mechanism of action are needed.

APA, Harvard, Vancouver, ISO, and other styles

20

Nilsson, Tomas. "Mass Spectrometric Analysis of Oxylipins : Application to Cytochrome P450-Dependent Metabolism." Doctoral thesis, Uppsala universitet, Institutionen för farmaceutisk biovetenskap, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-109715.

Full text

Abstract:

Cytochrome P450 (CYP) family 4 constitutes monoxygenases responsible for hydroxylation of fatty acids and other lipids. For example, CYP4F3 metabolizes leukotrienes and CYP4F8 prostaglandin H. Importantly, six of the twelve CYP4 enzymes are orphans, i.e., with an unknown biological function. The catalytic activity of the enzyme CYP4F8 is known in seminal vesicles, but not in skin or psoriatic lesions, where CYP4F8 is highly expressed. The orphan CYP4F22 is also expressed in skin, and mutations in its gene has been linked to the rare skin disease lamellar ichthyosis, together with, inter alia, mutations in the genes of 12R-LOX and eLOX3. These enzymes appear to constitute a pathway producing hydroperoxides and epoxyalcohols from arachidonic acid. CYP4F22 is hypothesized to act in a consecutive step within this pathway. The aim of this thesis was to develop analytical methods to prepare and analyze hydroperoxides and epoxyalcohols derived from fatty acids by LC-MS/MS, and to investigate the catalytic performance of CYP4F8 and CYP4F22 for these substrates. The 12R-hydroperoxide of arachidonic acid (12R-HPETE) was prepared by autoxidation and separated from other hydroperoxides by chiral HPLC. MS/MS analysis showed that the hydroperoxides were unstable within the ion trap, but were stabilized by an increase in the isolation width. From the hydroperoxides, epoxyalcohols were generated by hematin treatment, and separated by normal phase HPLC. MS/MS spectra of several epoxyalcohols, derived both from arachidonic acid and linoleic acid, were characterized with aid of [2H]isotopomers and MS3 analysis. Apart from metabolic studies the thesis also include detailed information on MS/MS analysis of several oxygenated fatty acids, with proposed fragmentation mechanisms. The open reading frame of CYP4F22 was expressed in a recombinant yeast system, and LC-MS/MS analysis revealed that CYP4F22 catalyzed ω3 hydroxylation of arachidonic acid, but not any of the tested epoxyalcohols. In contrast, CYP4F8 metabolizes an epoxyalcohol derived from 12R-HPETE, 11R,12R-epoxy-10-hydroxyeicosatrienoic acid, to the ω3 hydroxy metabolite. Conclusively, it was demonstrated that LC-MS/MS could be used for the analysis and separation of hydroperoxides and epoxyalcohols for metabolic studies.

APA, Harvard, Vancouver, ISO, and other styles

21

Schmidt, Cosima. "Identifizierung, molekulare Eigenschaften und Regulation einer renalen 20-Hydroxyeicosatetraensäure-Synthase." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2009. http://dx.doi.org/10.18452/15876.

Full text

Abstract:

Cytochrom P450 (CYP)-Enzyme hydroxylieren und epoxydieren Arachidonsäure (AA) zu bioaktiven Metaboliten wie 20-Hydroxyeicosatetraensäure (20-HETE) und Epoxyeicosatriensäuren (EETs). Diese CYP-abhängigen Eicosanoide fungieren als Mediatoren bei der Regulation der Gefäß-, Nieren- und Herzfunktion. Hauptziel der vorliegenden Arbeit war es, die Identität der 20-HETE bildenden CYP-Isoformen in der Mausniere aufzuklären. Ein weiterer Schwerpunkt war die Bestimmung von Veränderungen im Metabolismus CYP-abhängiger Eicosanoide in Tiermodellen des akuten Nieren- und Herzversagens. Zur Identifizierung der 20-HETE bildenden CYP-Isoform wurde die Substrat- und Wirkungsspezifität von Cyp4a10, Cyp4a12a, Cyp4a12b und Cyp4a14, sowie ihre geschlechts- und stammspezifische Expression charakterisiert. Die Ergebnisse dieser Arbeit zeigen, dass Cyp4a12a die 20-HETE Synthase der Mausniere ist. Cyp4a12a wird durch Androgene induziert und seine Expressionshöhe ist für geschlechts- und stammspezifische Unterschiede in der 20-HETE Bildung verantwortlich. Im Rattenmodell des Ischämie/Reperfusions (I/R)-induzierten Nierenschadens wird eine 20-HETE Freisetzung durch I/R induziert. Wir konnten zeigen, dass der I/R-Schaden durch Hemmung der 20-HETE Bildung signifikant reduziert wird. Im Rattenmodell der Herzinsuffizienz (SHHF) ist das Herzversagen mit einer Variante des EPHX2 Gens assoziiert. EPHX2 kodiert für die lösliche Epoxidhydrolase (sEH), die den Abbau von EETs katalysiert. Wir konnten zeigen, dass die Genvariation zu signifikant höheren sEH-Aktivitäten im Herzen (3-fachen) und in der Niere (30-fachen) führt, im Vergleich zu Rattenstämmen, die keine Herzinsuffizienz entwickeln. Die vorliegende Arbeit unterstreicht die pathophysiologische Bedeutung von Veränderungen im Metabolismus von 20-HETE und EETs. Daher erscheint es vielversprechend, den CYP-Eicosanoid Stoffwechsel als neuen Angriffspunkt für die pharmakologische Behandlung kardiovaskulärer Erkrankungen zu erschließen.
Cytochrome P450 (CYP) enzymes hydroxylate and epoxidize arachidonic acid (AA) to bioactive metabolites such as 20-hydroxyeicosatetraenoic acid (20-HETE) and epoxyeicosatrienoic acids (EETs). These CYP-dependent eicosanoids serve as mediators in the regulation of vascular, renal and cardiac function. The main objective of the present study was to identify the 20-HETE producing CYP isoforms in the mouse kidney. Another focus was to determine changes in the metabolism of CYP-dependent eicosanoids in animal models of acute renal and heart failure. To identify the 20-HETE producing CYP-isoform the substrate and reaction specificity of Cyp4a10, Cyp4a12a, Cyp4a12b and Cyp4a14, as well as their sex- and strain-specific expression were characterized. The present study shows that Cyp4a12a is the predominant AA hydroxylase in the mouse kidney. Cyp4a12a is induced by androgens and its expression determines the sex and strain-specific differences in 20-HETE generation. In a rat model of renal ischemia/reperfusion (I/R) injury, I/R triggered the release of 20-HETE and we were able to ameliorate renal injury by pharmacological inhibition of 20-HETE production. In a rat model of heart failure (spontaneously hypertensive heart failure rats, SHHF) the heart failure phenotype is associated with a variant of the EPHX2 gene. EPHX2 is coding for the soluble epoxide hydrolase (sEH) which catalyze the degradation of EETs. We found that the gene variation leads to significantly higher sEH activities in the heart (3-fold) and in the kidney (30-fold) compared to rat strains not prone to the development of heart failure. The present study emphasizes the pathophysiological relevance of changes in the biosynthesis and degradation of 20-HETE and EETs. Therefore, it appears promising to develop the CYP-eicosanoid pathway as a novel clinical target for the treatment of cardiovascular diseases.

APA, Harvard, Vancouver, ISO, and other styles

22

Huang, Yen-Ning, and 黃彥寧. "Cholesterol exposure induced SH-SY5Y cell apoptosis is associated with lipid raft content, tyrosine kinase B (TrkB) activity and Cyp46 protein expression." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/936jz5.

Full text

Abstract:

碩士
臺北醫學大學
保健營養學研究所
102
Background: In epidemiology, Alzheimer’s disease (AD) is one of the most common forms of neurodegenerative disease. It has been shown that the disturbances in brain cholesterol metabolism are associated with the major pathological features of AD. Purpose: Our purpose was to investigate the effects of cholesterol towards neurodegeneration. Methods: We examed the content of SH-SY5Y cellular cholesterol and 24-hydroxycholesterol (24-OHC) production after cholesterol was treated. We examed the effects of cholesterol on lipid raft conents, protein expressions of β-amyloid (Aβ), β-secretase (BACE), brain-derived neurotrophic factor (BDNF)/tyrosine kinase B (TrkB) and its’ downstream signaling transduction proteins, cell morphology, synaptic length and mechanisms of cell apoptosis in SH-SY5Y human neuroblastoma cell. Results: We found that high cholesterol increases the contents of lipid raft and decreases the protein expressions of BDNF, full-length TrkB (TrkBfl) and p-TrkB, but increases the protein expressions of truncated TrkB (TrkBtc). It could cause the dysfunction of the PI3K-Akt-GSK-3β cascade and lead to phosphorylation of tau at Ser396 and cell apoptosis. Furthermore, elevations of Aβ, BACE and reactive oxygen species (ROS) were also observed. Conclusion: These findings suggest that cholesterol induced neuronal cell apoptosis is associated with contents of lipid raft, activity of TrkB and protein expression of Cyp46.

APA, Harvard, Vancouver, ISO, and other styles

23

"Regulation of chick CYP26 developmental signaling pathways." Tulane University, 2001.

Find full text

Abstract:

It has been known for over three quarters of a century that Vitamin A and its derivatives (retinoids) are essential for both normal embryonic development and in the maintenance of adult tissues (Collins and Mao, 2000). Classical data demonstrated that high levels of all-trans-retinoic acid (RA) or a deficiency of vitamin A in vertebrates can lead to a number of birth defects (Ross et al., 2000). These observations suggest that a precise control of the levels of RA in cells and tissues is required for proper development and function. In vertebrates, one mechanism by which the levels of RA can he regulated involves the action of CYP26 enzymes, which are members of the cytochrome P450 superfamily of catabolizing enzymes. Members of the CYP26 family have been isolated from different systems, including the chick embryo. In the chick, RA found to induce the expression of the CYP26 (cCYP26) gene in the limb bud in vivo (Swindell et al., 1999). However, whether the induction of cCYP26 by RA was a dose- or stage-dependent process in vivo was not addressed in that study. In addition, whether all the regions of the limb bud respond equally to RA by inducing the expression of cCYP26 or whether other signaling pathways are involved in this inductive mechanism is still not known. In the present work, implantation of RA-soaked beads at different stages and position in the chicken wing bud demonstrated that cCYP26 is induced by RA in a stage-, dose-, and position-specific manner, and that cells in the posterior limb mesenchyme are more resistant to the induction of cCYP26 by RA. Subsequent experiments demonstrated that the ZPA, acting through Shh, contributes to the differential induction of cCYP26 expression by RA in the anterior versus posterior limb mesenchyme. Thus, these results suggest a mechanism by which Shh signaling can regulate the induction of expression of certain RA-responsive genes in the developing chicken limb bud. Finally, effort was done in order to characterize a suitable in vitro model for the study of the regulatory mechanism exerted by Shh on the RA-induced cCYP26 expression
acase@tulane.edu

APA, Harvard, Vancouver, ISO, and other styles

24

Raposo, Ana Cristina Baptista. "Variação genética do gene CYPD6 na analgesia do parto : abordagem farmacogenómica." Master's thesis, 2011. http://hdl.handle.net/10316/18449.

Full text

Abstract:

Dissertação de mestrado em Medicina (Investigação Biomédica), apresentada à Faculdade de Medicina da Universidade de Coimbra
Nas parturientes, a dor, moderada ou severa, é comum após o trabalho de parto por cesariana. A administração intravenosa de morfina no período imediato à operação é um procedimento usual para o alívio da dor. Contudo, verifica-se uma grande variabilidade inter-individual na sua eficácia, conduzindo a perfis de tolerância e diversidade de aparecimento de efeitos secundários, como o prurido, náuseas e vómitos. A grande variabilidade inter-individual é devida a variações genéticas que influenciam a metabolização e/ou a acção dos fármacos, ou seja, está relacionado com a farmacogenómica. A enzima CYP2D6 tem uma elevada importância neste processo, por ser responsável pela metabolização oxidativa de vários fármacos e substâncias endógenas. O precursor da dopamina e da serotonina, dois neurotransmissores, são um exemplo de substâncias endógenas metabolizadas pela CYP2D6. A morfina promove a actividade dos neurónios dopaminérgicos, levando a um aumento na libertação de dopamina, responsável pelo controlo da dor. O gene CYP2D6 responsável pela codificação desta enzima é altamente polimórfico, resultando numa grande variabilidade de fenótipos de metabolização. A combinação de vários SNPs resulta em diferentes haplótipos que estão associados igualmente a diferentes perfis de metabolização. O presente estudo é pioneiro ao relacionar os três haplótipos (CYP2D6*4A, CYP2D6*10A e CYP2D6*2E) do gene CYP2D6 que definem diferentes perfis de metabolização (lento, intermediário e extensivo) com a dor e o surgimento de efeitos secundários, como o prurido, numa amostragem de parturientes sujeitas a analgesia com morfina após a cesariana. Os resultados mais evidentes deste estudo sugerem que estes haplótipos, quando presentes em heterozigotia ou homozigotia para o alelo variante, levam a um aumento da dor após a cesariana. O aumento da incidência do prurido está associado ao haplótipo CYP2D6*10A quando presente em heterozigotia ou homozigotia para o alelo variante. Este trabalho contribui para uma melhor compreensão do modo como as variantes alélicas do CYP2D6 poderão afectar a dor e o surgimento de efeitos secundários na analgesia do trabalho de parto.
In pregnant women, pain, moderate or severe, is common, after caesarean. Intravenous administration of morphine, immediately following the surgery is an usual procedure for the relief of pain. However, there is a large inter-individual variability in efficacy, leading to profiles of tolerance and side effects like pruritus, nausea and vomiting. The large inter-individual variability is due to genetic variations that influence metabolism and/or the action of drugs; in other word, it is related to pharmacogenomics. The CYP2D6 enzyme has high importance in this process, given the fact that it is responsible for the oxidative metabolism of various drugs and endogenous substances. The precursor of dopamine and serotonin, two neurotransmitters, are an example of endogenous substances metabolized by CYP2D6. Morphine promotes the activity of dopaminergic neurons, causing an increase in the release of dopamine, responsible for pain control. The gene CYP2D6 responsible for encoding this enzyme, is highly polymorphic, causing a considerable variability of metabolic phenotypes. The combinations of several SNPs that are associated to in different haplotypes are also related to with different metabolic profiles. This study is original, considering the correlation of the three haplotypes (CYP2D6*4A, CYP2D6*10A e CYP2D6*2E) of the CYP2D6 gene, that define different profiles of metabolism (poor, intermediate and extensive), with pain and the incidence of secundary effects, such as pruritus, in a population of pregnant women submitted to analgesia with morphine after cesarean section. The most prominent results of this study suggest that these haplotypes, when present in heterozygous or homozygous for the variant allele, lead to an increase prevalence of pain after cesarean section. The increase of pruritus is associated with the CYP2D6*10A haplotye, when heterozygous or homozygous for the variant allele. This work contributes to a better understanding of how the CYP2D6 allelic variants may affect pain and treatment of secundary effects on analgesia of labor.

APA, Harvard, Vancouver, ISO, and other styles

25

Pirkl, Franziska [Verfasser]. "Funktionelle Analyse der großen Peptidyl-Prolyl-cis/trans-Isomerasen FKBP51, FKBP52 und Cyp40 / Franziska Pirkl." 2001. http://d-nb.info/96279127X/34.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Dissertations / Theses on the topic 'CYP46'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles