1
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Anatomical and molecular studies of cytochrome P450 family CYP7A1 gene polymorphism and its association with gallstone in north Indian population. J ANAT SOC INDIA 2018. [DOI: 10.1016/j.jasi.2018.05.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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2
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Al-sheikh NM, El-Hefnway SM, El-Shetahy AA. Cholesterol 7- alpha hydroxylase gene ( CYP7A1 ) promoter polymorphism rs3808607 as a risk factor for pulmonary tuberculosis in Egypt. Meta Gene 2018. [DOI: 10.1016/j.mgene.2018.01.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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3
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Effect of dietary cholesterol and plant sterol consumption on plasma lipid responsiveness and cholesterol trafficking in healthy individuals. Br J Nutr 2017; 117:56-66. [DOI: 10.1017/s0007114516004530] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
AbstractDietary cholesterol and plant sterols differentially modulate cholesterol kinetics and circulating cholesterol. Understanding how healthy individuals with their inherent variabilities in cholesterol trafficking respond to such dietary sterols will aid in improving strategies for effective cholesterol lowering and alleviation of CVD risk. The objectives of this study were to assess plasma lipid responsiveness to dietary cholesterolv. plant sterol consumption, and to determine the response in rates of cholesterol absorption and synthesis to each sterol using stable isotope approaches in healthy individuals. A randomised, double-blinded, crossover, placebo-controlled clinical trial (n49) with three treatment phases of 4-week duration were conducted in a Manitoba Hutterite population. During each phase, participants consumed one of the three treatments as a milkshake containing 600 mg/d dietary cholesterol, 2 g/d plant sterols or a control after breakfast meal. Plasma lipid profile was determined and cholesterol absorption and synthesis were measured by oral administration of [3, 4-13C] cholesterol and2H-labelled water, respectively. Dietary cholesterol consumption increased total (0·16 (sem0·06) mmol/l,P=0·0179) and HDL-cholesterol (0·08 (sem0·03) mmol/l,P=0·0216) concentrations with no changes in cholesterol absorption or synthesis. Plant sterol consumption failed to reduce LDL-cholesterol concentrations despite showing a reduction (6 %,P=0·0004) in cholesterol absorption. An over-compensatory reciprocal increase in cholesterol synthesis (36 %,P=0·0026) corresponding to a small reduction in absorption was observed with plant sterol consumption, possibly resulting in reduced LDL-cholesterol lowering efficacy of plant sterols. These data suggest that inter-individual variability in cholesterol trafficking mechanisms may profoundly impact plasma lipid responses to dietary sterols in healthy individuals.
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Arbour L, Asuri S, Whittome B, Polanco F, Hegele RA. The Genetics of Cardiovascular Disease in Canadian and International Aboriginal Populations. Can J Cardiol 2015; 31:1094-115. [DOI: 10.1016/j.cjca.2015.07.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Revised: 07/08/2015] [Accepted: 07/09/2015] [Indexed: 12/16/2022] Open
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Cai Q, Wang ZQ, Cai Q, Li C, Chen EZ, Jiang ZY. Relationship between CYP7A1 -204A>C polymorphism with gallbladder stone disease and serum lipid levels: a meta-analysis. Lipids Health Dis 2014; 13:126. [PMID: 25103562 PMCID: PMC4267418 DOI: 10.1186/1476-511x-13-126] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Accepted: 07/29/2014] [Indexed: 12/12/2022] Open
Abstract
Background The CYP7A1 gene polymorphism has been
reported to be associated with gallbladder stone disease (GSD) and serum lipid
levels, but the results were inconsistent. This meta-analysis aimed to evaluate
the influence of the -204A > C polymorphism in the promoter of CYP7A1 gene on the GSD and serum lipid levels. Methods According to inclusion/exclusion criteria, eligible studies on CYP7A1 gene -204A > C polymorphism of serum lipid
levels and the risk of GSD were retrieved. Depending on the between-study
heterogeneity, the fixed- or random-effects model was applied, and the data were
analyzed using the RevMan software (V5.2). Results Five studies totaling 830 GSD patients and 882 healthy controls were used to
evaluate the relation of CYP7A1 -204A > C
polymorphism with GSD. Overall comparison of alleles A with C in all study
population yielded 5% but non-significant increased risk of GSD (OR = 1.05, 95%
CI: 0.91 − 1.22, P = 0.48). Subgroup analysis by ethnic differences did not show
any association between CYP7A1 -204A > C
polymorphism and GSD either. Four studies totaling 802 cases and 691 controls were
used to assess the relation of CYP7A1
-204A > C polymorphism with serum lipid levels. All the subjects were from the
Asian population. The pooled effects indicated that AC genotype had higher levels
of TG than AA (MD = -0.42, 95% CI: -0.76 − -0.08, P = 0.01). CC genotype in cases
had higher levels of TC (MD = 0.65, 95% CI: 0.25 − 1.05, P = 0.001) and LDL-C
(MD = 0.40, 95% CI: 0.06 − 0.73, P = 0.02) than AA, AA (MD = -0.35, 95% CI: -0.60
− -0.10, P = 0.007) and AC (MD = −0.35, 95% CI: -0.61 − -0.08, P = 0.01) genotypes
in controls had higher levels of TC than CC, and AA genotype in controls had
higher levels of HDL-C than CC (MD = -0.15, 95% CI: -0.21 − -0.09,
P < 0.00001). Conclusions The CYP7A1 -204A > C polymorphism is
significantly associated with serum lipid levels in Asian population, but not
gallbladder stone disease. Electronic supplementary material The online version of this article (doi:10.1186/1476-511X-13-126) contains supplementary material, which is available to authorized
users.
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Affiliation(s)
| | | | | | | | | | - Zhao-Yan Jiang
- Department of Surgery, Shanghai Institute of Digestive Surgery, Ruijin Hospital, Shanghai JiaoTong University School of Medicine, 200025 Shanghai, China.
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Qrafli M, Amar Y, Bourkadi J, Ben Amor J, Iraki G, Bakri Y, Amzazi S, Lahlou O, Seghrouchni F, El Aouad R, Sadki K. The CYP7A1 gene rs3808607 variant is associated with susceptibility of tuberculosis in Moroccan population. Pan Afr Med J 2014; 18:1. [PMID: 25360185 PMCID: PMC4212432 DOI: 10.11604/pamj.2014.18.1.3397] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Accepted: 04/22/2014] [Indexed: 11/11/2022] Open
Abstract
Introduction Despite the medical progress in treatment. Tuberculosis (TB) continues to be a serious global health problem. A genome-wide linkage study identified a major susceptibility locus on chromosomal region 8q12-q13 in Moroccan TB patients. The CYP7A1 gene is located in this region and codes for cholesterol 7a-hydroxylase, an enzyme involved in cholesterol catabolism. Methods We selected three SNPs (rs3808607, rs8192875 and rs8192879) and studied their genotype and allele frequencies distribution in patients with pulmonary (PTB) or pleural TB (pTB), and compared them to Healthy Controls (HC). Genotyping of rs8192875 and rs8192879 SNPs was carried out using the Taq Man SNP genotyping Assay while rs3808607 was investigated by PCR-RFLP. Results We reported here for the first time a statistically significant increase in the AA homozygote genotype frequency of rs3808607 in PTB patients compared to HC (p = 0.02, OR = 1.93, 95% CI: 1.93 (1.07;3.49). The increased risk of developing TB was maintained when we combined the groups of patients (PTB-pTB) (p = 0.01, OR= 1.91, 95% CI = (1.07 - 3.42). In contrast, no genetic association was observed between the rs8192875 or rs8192879 polymorphisms and TB. Conclusion Our investigations suggest that rs3808607 may play a role in susceptibility to TB in a Moroccan population.
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Affiliation(s)
- Mounia Qrafli
- Laboratory of Human Genomic, National Institute of Hygiene, Rabat, Morocco ; Laboratory of Biochemistry and Immunology, Faculty of Sciences, University Mohammed V, Rabat, Morocco
| | - Youssef Amar
- Laboratory of Biochemistry and Immunology, Faculty of Sciences, University Mohammed V, Rabat, Morocco
| | | | - Jouda Ben Amor
- Department of Pneumophtisiology, Moulay Youssef Hospital, Rabat, Morocco
| | - Ghali Iraki
- Department of Pneumophtisiology, Moulay Youssef Hospital, Rabat, Morocco
| | - Youssef Bakri
- Laboratory of Biochemistry and Immunology, Faculty of Sciences, University Mohammed V, Rabat, Morocco
| | - Saaîd Amzazi
- Laboratory of Biochemistry and Immunology, Faculty of Sciences, University Mohammed V, Rabat, Morocco
| | - Ouafae Lahlou
- Laboratory of Human Genomic, National Institute of Hygiene, Rabat, Morocco
| | - Fouad Seghrouchni
- Laboratory of Human Genomic, National Institute of Hygiene, Rabat, Morocco
| | - Rajae El Aouad
- Laboratory of Human Genomic, National Institute of Hygiene, Rabat, Morocco
| | - Khalid Sadki
- Laboratory of Biochemistry and Immunology, Faculty of Sciences, University Mohammed V, Rabat, Morocco
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7
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Xiang X, Backman JT, Neuvonen PJ, Niemi M. Gender, but not CYP7A1 or SLCO1B1 Polymorphism, Affects the Fasting Plasma Concentrations of Bile Acids in Human Beings. Basic Clin Pharmacol Toxicol 2011; 110:245-52. [DOI: 10.1111/j.1742-7843.2011.00792.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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8
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Barcelos ALV, Chies R, Almeida SEM, Fiegenbaum M, Schweigert ID, Chula FGL, Rossetti ML, Silva CMD. Association of CYP7A1 -278A>C polymorphism and the response of plasma triglyceride after dietary intervention in dyslipidemic patients. Braz J Med Biol Res 2010; 42:487-93. [PMID: 19448895 DOI: 10.1590/s0100-879x2009000600003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2008] [Accepted: 03/03/2009] [Indexed: 11/22/2022] Open
Abstract
We investigated the effect of the -278A>C polymorphism in the CYP7A1 gene on the response of plasma lipids to a reduced-fat diet for 6 to 8 weeks in a group of 82 dyslipidemic males with a mean age of 46.0 +/- 11.7 years. Individuals who presented at least one high alteration in total cholesterol, low-density lipoprotein cholesterol or triglyceride values were considered to be dyslipidemic. Exclusion criteria were secondary dyslipidemia due to diabetes mellitus, renal, liver, or thyroid disease. None of the subjects were using lipid-lowering medication. Baseline and follow-up lipid concentrations were measured. The genotypes were determined by the digestion of PCR products with the BsaI restriction endonuclease. There were statistically significant reductions in plasma total cholesterol, low-density lipoprotein cholesterol and triglyceride concentrations after dietary intervention. The minor allele C has a frequency of 43%. Carriers of the C allele had significantly lower triglyceride concentrations (P = 0.02) than AA homozygotes. After adjustment of covariates, subjects with the AC and CC genotypes showed a greater reduction in triglyceride concentrations compared to subjects with the AA genotype. Multiple linear regression analyses showed that the AC and CC CYP7A1 genotypes accounted for 5.2 and 6.2% of triglyceride concentration during follow-up and adjusted percent of change of triglyceride concentration, respectively. The present study provides evidence that -278A>C polymorphism in the CYP7A1 gene can modify triglyceride concentrations in response to a reduced fat diet in a dyslipidemic male population. This gene represents a potential locus for a nutrigenetic directed approach.
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Affiliation(s)
- A L V Barcelos
- Curso de Pós-graduação em Genética e Toxicologia Aplicada, Universidade Luterana do Brasil, Canoas, RS, Brasil
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Lu Y, Feskens EJM, Boer JMA, Müller M. The potential influence of genetic variants in genes along bile acid and bile metabolic pathway on blood cholesterol levels in the population. Atherosclerosis 2009; 210:14-27. [PMID: 19932478 DOI: 10.1016/j.atherosclerosis.2009.10.035] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2009] [Revised: 10/22/2009] [Accepted: 10/26/2009] [Indexed: 01/10/2023]
Abstract
The liver is currently known to be the major organ to eliminate excess cholesterol from our body. It accomplishes this function in two ways: conversion of cholesterol molecules into bile acids (BAs) and secretion of unesterified cholesterol molecules into bile. BAs are synthesized in the hepatocytes, secreted into bile and delivered to the lumen of the small intestine where they act as detergents to facilitate absorption of fats and fat-soluble vitamins. About 95% of BAs are recovered in the ileum during each cycle of the enterohepatic circulation. Five percent are lost and replaced by newly synthesized BAs, which amounts to approximately 500 mg/day in adult humans. In contrast to the efficiency of the BAs' enterohepatic circulation, 50% of the 1000 mg of cholesterol secreted daily into bile is lost in feces. It is known that rare human mutations in certain genes in bile acid and bile metabolic pathway influence blood cholesterol levels. With the recent success of genome-wide association studies, we are convinced that common genetic variants also play a role in the genetic architecture of plasma lipid traits. In this review, we summarized the current state of knowledge about genetic variations in bile acid and bile metabolic pathway, and assessed their impact on blood cholesterol levels and cholesterol metabolic kinetics in the population.
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Affiliation(s)
- Yingchang Lu
- Division of Human Nutrition, Wageningen University and Research Center, PO Box 8129, 6700 EV Wageningen, The Netherlands.
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10
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Pikuleva IA. Cholesterol-metabolizing cytochromes P450: implications for cholesterol lowering. Expert Opin Drug Metab Toxicol 2008; 4:1403-14. [PMID: 18950282 PMCID: PMC2957831 DOI: 10.1517/17425255.4.11.1403] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Cardiovascular disease (CVD) continues to be a leading cause of death worldwide. Elevated serum cholesterol is one of the classical risk factors for CVD, which also include age, hypertension, smoking, diabetes mellitus, obesity and family history. Several therapeutic drug classes have been developed to treat hypercholesterolemia; yet, an important percentage of patients do not reach their treatment goals. Therefore, new cholesterol-lowering medications that have sites of action different from that of drugs available at present need to be developed. This review summarizes new information about cytochrome P450 enzymes 7A1, 27A1 and 46A1. These enzymes play key roles in cholesterol elimination and have the potential to serve as targets for cholesterol-lowering.
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Affiliation(s)
- Irina A Pikuleva
- Case Western Reserve University, University Hospitals Case Medical Center, Department of Ophthalmology and Visual Sciences, Cleveland, OH 44106, USA.
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11
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Lenícek M, Komárek V, Zimolová M, Kovár J, Jirsa M, Lukás M, Vítek L. CYP7A1 promoter polymorphism -203A>C affects bile salt synthesis rate in patients after ileal resection. J Lipid Res 2008; 49:2664-7. [PMID: 18728290 DOI: 10.1194/jlr.m800364-jlr200] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cholesterol 7alpha-hydroxylase (CYP7A1) plays a crucial role in cholesterol metabolism and has been implicated in genetic susceptibility to atherosclerosis. Thus, an understanding of its transcriptional regulation is of considerable importance. We evaluated the effect of a common -203A>C polymorphism in the CYP7A1 promoter region on the activity of CYP7A1, estimated as the ratios of serum 7alpha-hydroxycholest-4-en-3-one (C4) to either total or non-HDL-cholesterol. The study was performed on patients after resection of the distal ileum, leading to upregulation of CYP7A1 activity (n = 65). Healthy volunteers served as the control group (n = 66). Whereas higher CYP7A1 activity was associated with the -203A allele in the patient group (C4/cholesterol ratio, 29.0 vs. 14.8 microg/mmol, P = 0.032; C4/non-HDL-cholesterol ratio, 53.3 vs. 21.3 microg/mmol in -203AA and -203CC, P = 0.017, respectively), no differences were observed in the healthy controls. We conclude that under physiological conditions, the -203A>C polymorphism in the CYP7A1 gene promoter region does not seem to have any clinically relevant effect. However, in patients with severe bile salt malabsorption, this polymorphism markedly affects CYP7A1 activity.
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Affiliation(s)
- Martin Lenícek
- Department of Clinical Biochemistry and Laboratory Diagnostics, 1st Faculty of Medicine, Charles University in Prague.
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12
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Genetic determinants of plasma lipoproteins. ACTA ACUST UNITED AC 2007; 4:600-9. [PMID: 17957207 DOI: 10.1038/ncpcardio1005] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2007] [Accepted: 07/28/2007] [Indexed: 02/07/2023]
Abstract
The search for common genetic determinants of plasma lipoproteins began in the early 1980s. Despite some exceptions, these efforts have not yet yielded a set of biological markers that can be used in clinical practice. By contrast, successes in defining the molecular basis of rare single-gene disorders, such as familial hypoalphalipoproteinemia, have shown the value of experimental designs that focus on genomic analysis of individuals within the tails of Gaussian distributions of quantitative lipoprotein traits. For example, this strategy showed that a small but relevant proportion of individuals within the <5% tail of plasma HDL-cholesterol distribution have mutations in genes that cause familial hypoalphalipoproteinemia. The value of clinical testing for genomic variants as an adjunct to a biochemical measurement of plasma lipoproteins, however, is at best questionable. A more direct impact of genetic studies is that definitions of 'common' and 'large genetic effects' have become more tempered, reflecting perhaps the biological reality that plasma lipoproteins are probably determined by the aggregate of numerous modest and occasional large genetic effects in addition to environmental factors. Here, we review recent progress on genomic variants and cholesterol metabolism, and discuss the impact these genetic studies will have on clinical cardiology.
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Abstract
By participating in pathways of cholesterol biosynthesis and elimination, different cytochrome P450 (P450 or CYP) enzymes play an important role in maintenance of cholesterol homeostasis. CYP51 is involved in cholesterol biosynthesis, whereas CYP 7A1, 27A1, 46A1, 7B1, 39A1, and 8B1 are the key enzymes in cholesterol catabolism to bile acids, the major route of cholesterol elimination in mammals. Cholesterol transformations to steroid hormones are also initiated by the P450 enzyme CYP11A1. Finally, one of the major drug-metabolizing P450s CYP3A4 seems to contribute to bile acid biosynthesis as well. The 9 P450s will be the focus of this review and assessed as drug targets for cholesterol lowering.
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Affiliation(s)
- Irina A Pikuleva
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555-1031, USA.
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14
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Nakamoto K, Wang S, Jenison RD, Guo GL, Klaassen CD, Wan YJY, Zhong XB. Linkage disequilibrium blocks, haplotype structure, and htSNPs of human CYP7A1 gene. BMC Genet 2006; 7:29. [PMID: 16709249 PMCID: PMC1488870 DOI: 10.1186/1471-2156-7-29] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2006] [Accepted: 05/18/2006] [Indexed: 11/10/2022] Open
Abstract
Background Cholesterol 7-alpha-hydroxylase (CYP7A1) is the rate limiting enzyme for converting cholesterol into bile acids. Genetic variations in the CYP7A1 gene have been associated with metabolic disorders of cholesterol and bile acids, including hypercholesterolemia, hypertriglyceridemia, arteriosclerosis, and gallstone disease. Current genetic studies are focused mainly on analysis of a single nucleotide polymorphism (SNP) at A-278C in the promoter region of the CYP7A1 gene. Here we report a genetic approach for an extensive analysis on linkage disequilibrium (LD) blocks and haplotype structures of the entire CYP7A1 gene and its surrounding sequences in Africans, Caucasians, Asians, Mexican-Americans, and African-Americans. Result The LD patterns and haplotype blocks of CYP7A1 gene were defined in Africans, Caucasians, and Asians using genotyping data downloaded from the HapMap database to select a set of haplotype-tagging SNPs (htSNP). A low cost, microarray-based platform on thin-film biosensor chips was then developed for high-throughput genotyping to study transferability of the HapMap htSNPs to Mexican-American and African-American populations. Comparative LD patterns and haplotype block structure was defined across all test populations. Conclusion A constant genetic structure in CYP7A1 gene and its surrounding sequences was found that may lead to a better design for association studies of genetic variations in CYP7A1 gene with cholesterol and bile acid metabolism.
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Affiliation(s)
- Kaori Nakamoto
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, Kansas 66160, USA
| | - Shuang Wang
- Department of Biostatistics, Mailman School of Public Health, Columbia University, New York, NY 10032, USA
| | | | - Grace L Guo
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, Kansas 66160, USA
| | - Curtis D Klaassen
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, Kansas 66160, USA
| | - Yu-Jui Yvonne Wan
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, Kansas 66160, USA
| | - Xiao-bo Zhong
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, Kansas 66160, USA
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Abstract
By catalyzing the first steps in different pathways of cholesterol degradation, cytochromes P450 (P450s) 7A1, 27A1, 11A1, and 46A1 play key roles in cholesterol homeostasis. CYP7A1 is a microsomal liver-specific enzyme that converts cholesterol to 7alpha-hydroxycholesterol. CYP27A1 is a ubiquitously expressed mitochondrial P450 that metabolizes cholesterol to 27-hydroxycholesterol. CYP11A1 also resides in mitochondria but is expressed mainly in steroidogenic tissues, where it catalyzes the conversion of cholesterol to pregnenolone. Finally, CYP46A1 is a brain-selective microsomal monooxygenase producing 24S-hydroxycholesterol from cholesterol. Catalytic efficiencies of cholesterol-metabolizing P450s vary significantly and probably reflect physiological requirements of different organs for the rate of cholesterol turnover. P450s 7A1, 27A1, 11A1, and 46A1 represent a unique system for elucidation of how different enzymes have adapted to fit their specific roles in cholesterol elimination. Studies of cholesterol-metabolizing P450s suggest that their activities could be modulated post-translationally and that they should also be considered as targets for regulation of cholesterol homeostasis.
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Affiliation(s)
- Irina A Pikuleva
- Department of Pharmacology and Toxicology, University of Texas, Medical Branch, 301 University Blvd., Galveston, TX 77555-1031, USA.
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Kajinami K, Brousseau ME, Ordovas JM, Schaefer EJ. A promoter polymorphism in cholesterol 7alpha-hydroxylase interacts with apolipoprotein E genotype in the LDL-lowering response to atorvastatin. Atherosclerosis 2005; 180:407-15. [PMID: 15910869 DOI: 10.1016/j.atherosclerosis.2004.12.019] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2004] [Revised: 11/15/2004] [Accepted: 12/07/2004] [Indexed: 12/01/2022]
Abstract
Bile-acid biosynthesis is a key determinant of intracellular cholesterol and, in turn, cholesterol synthesis rate in hepatocytes. This suggests that variation in the cholesterol 7alpha-hydroxylase gene (CYP7A1), a key enzyme in bile-acid biosynthesis, may influence the statin response. To test this hypothesis, a promoter polymorphism (A-204C) in CYP7A1 was examined in 324 hypercholesterolemic patients treated with atorvastatin 10mg. The variant C allele was significantly and independently associated with poor LDL cholesterol reductions; -39% in wild type allele homozygotes, -37% in variant allele heterozygotes, and -34% in variant allele homozygotes (p<0.0001 for trend). Differences were more striking in men, and were enhanced by the coexistence of common variants of apolipoprotein E gene (APOE), epsilon2 or epsilon4. In subjects having wild type alleles at both loci, the mean reduction in LDL cholesterol was -40%, while the value in subjects having two CYP7A1 variant alleles and at least one variant APOE allele was -31% (p<0.0001). Combination analysis of these two loci more accurately predicted the achievement of goal LDL cholesterol, than did both single locus analysis. We concluded that the CYP7A1 A-204C promoter variant was associated with poor response to atorvastatin, which were additively enhanced by common variants in another locus, APOE.
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Affiliation(s)
- Kouji Kajinami
- Lipid Research Laboratory, Division of Endocrinology Metabolism and Molecular Biology, Tufts-New England Medical Center, Boston, USA.
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Hofman MK, Princen HMG, Zwinderman AH, Jukema JW. Genetic variation in the rate-limiting enzyme in cholesterol catabolism (cholesterol 7alpha-hydroxylase) influences the progression of atherosclerosis and risk of new clinical events. Clin Sci (Lond) 2005; 108:539-45. [PMID: 15707388 DOI: 10.1042/cs20040339] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
CHD (coronary heart disease) is a complex disorder which is, in part, related to serum cholesterol levels. The rate-limiting enzyme in the catabolism of cholesterol into bile acids is CYP7A1 (cholesterol 7alpha-hydroxylase). The effect of the CYP7A1 A-278C promoter polymorphism on the progression of atherosclerosis, risk of a new clinical event and the influence of this variant on cholesterol-lowering therapy was investigated in 715 male patients with coronary atherosclerosis participating in REGRESS (Regression Growth Evaluation Statin Study). Genotype distributions were as follows: 283 with AA; 330 with AC and 102 with CC. There were no significant differences in baseline characteristics and serum lipids between genotypes. After 2 years, CC carriers had more progression of diffuse and focal atherosclerosis compared with AA carriers, as indicated by a larger decrease in MSD (mean segment diameter; 0.09 mm compared with 0.06 mm respectively; P=0.009) and MOD (minimum obstruction diameter; 0.09 mm compared with 0.05 mm respectively; P=0.024). Inclusion of risk factors for CHD in the model showed the same trend, although not significant for MOD (P=0.01 for MSD, and P=0.06 for MOD). In addition, CC carriers had an almost 2-fold higher risk of a new clinical event compared with AA carriers [RR (95% CI) 1.93 (1.11-3.36); P=0.02; where RR is relative risk and CI is confidence interval]. Inclusion of risk factors for CHD in the model showed the same trend, although not significant [RR (95% CI), 1.74 (0.96-3.12); P=0.06]. In conclusion, we present evidence that the CC variant of the A-278C polymorphism in the rate-limiting enzyme in the catabolism of cholesterol, CYP7A1, increases the progression of atherosclerosis and possibly the risk of a new clinical event.
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Affiliation(s)
- Maaike K Hofman
- TNO Prevention and Health, Gaubius Laboratory, Leiden, The Netherlands
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18
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Hofman MK, Groenendijk M, Verkuijlen PJJH, Jonkers IJAM, Mohrschladt MF, Smelt AHM, Princen HMG. Modulating effect of the A-278C promoter polymorphism in the cholesterol 7alpha-hydroxylase gene on serum lipid levels in normolipidaemic and hypertriglyceridaemic individuals. Eur J Hum Genet 2005; 12:935-41. [PMID: 15241483 DOI: 10.1038/sj.ejhg.5201236] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The rate-limiting enzyme in the conversion of cholesterol into bile acids is cholesterol 7alpha-hydroxylase (CYP7A1). An A to C substitution 278 bp upstream in the promoter of the CYP7A1 gene was found to be associated with variations in serum lipid levels in normolipidaemic populations. In the present study, we investigated the involvement of this polymorphism in four different lipid disorders: hypertriglyceridaemia (HTG), combined hyperlipidaemia (CH), familial dysbetalipoproteinaemia (FD) and familial hypercholesterolaemia (FH). In a normolipidaemic male population, homozygous for the apoE3 isoform, an association was found between the AA genotype and higher levels of serum triglycerides (AA: +34%, P = 0.036). In HTG patients, the AA genotype was associated with significantly higher concentrations of total cholesterol (+23%, P = 0.005). There was a tendency towards increased levels of serum triglycerides (+39%, P = 0.06), VLDL-triglycerides (+48%, P = 0.053) and VLDL-cholesterol (+35%, P = 0.059). No significant associations were found between serum lipid levels and the CYP7A1 polymorphism in patients with CH, FD and FH. Our results show that the A-278C polymorphism in the CYP7A1 gene has an effect on triglyceride levels in normolipidaemic males and on cholesterol levels in patients with hypertriglyceridaemia..
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Affiliation(s)
- M K Hofman
- TNO Prevention and Health, Gaubius Laboratory, Leiden, The Netherlands
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Li Y, Hou MJ, Ma J, Tang ZH, Zhu HL, Ling WH. Dietary fatty acids regulate cholesterol induction of liver CYP7α1 expression and bile acid production. Lipids 2005; 40:455-62. [PMID: 16094854 DOI: 10.1007/s11745-005-1404-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
In the present study we investigated the effects of dietary fats containing predominantly PUFA, monounsaturated FA (MUFA), or saturated FA (SFA) on lipid profile and liver cholesterol 7alpha-hydroxylase (CYP7alpha1) mRNA expression and bile acid production in C57BL/6J mice. The animals (n = 75) were randomly divided into five groups and fed a basic chow diet (AIN-93G) (BC diet), a chow diet with 1 g/100 g of cholesterol (Chol diet), a chow diet with 1 g/100 g of cholesterol and 14 g/100 g of safflower oil (Chol + PUFA diet), a chow diet with 1 g/100 g of cholesterol and olive oil (Chol + MUFA diet), or a chow diet with 1 g/100 g of cholesterol and myristic acid (Chol + SFA diet) for 6 wk. The results showed that the Chol + SFA diet decreased CYP7alpha1 gene expression and bile acid pool size, resulting in increased blood and liver cholesterol levels. Addition of PUFA and MUFA to a 1% cholesterol diet increased the bile acid pool production or bile acid excretion and simultaneously decreased liver cholesterol accumulation despite decreased CYP7alpha1 mRNA expression. The results indicate that the decreased bile acid pool size induced by the SFA diet is related to inhibition of the liver CYP7alpha1 gene expression, but an increased bile acid pool size and improved cholesterol homeostasis are disassociated from the liver CYP7alpha1 gene expression.
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Affiliation(s)
- Yan Li
- Department of Clinical Nutrition, Sun Yat-sen University Northern Campus, Guangzhou, 510080, People's Republic of China
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20
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Al-Shali K, House AA, Hanley AJG, Khan HMR, Harris SB, Mamakeesick M, Zinman B, Fenster A, Spence JD, Hegele RA. Differences between carotid wall morphological phenotypes measured by ultrasound in one, two and three dimensions. Atherosclerosis 2005; 178:319-25. [PMID: 15694940 DOI: 10.1016/j.atherosclerosis.2004.08.016] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2004] [Revised: 07/20/2004] [Accepted: 08/10/2004] [Indexed: 10/26/2022]
Abstract
Ultrasound measurements are both surrogate markers and risk factors for atherosclerosis end points. Carotid intima-media thickness (IMT) is most commonly used, but ultrasound can also define structures in higher spatial dimensions, such as total plaque area (TPA) and total plaque volume (TPV). Because there are minimal data regarding the relationship between IMT, TPA and TPV, we measured these variables in 272 Oji-Cree subjects. We found pairwise correlations for IMT:TPA, IMT:TPV and TPA:TPV of 0.507, 0.588 and 0.846, respectively (transformed variables, all P <0.0001). In a subset of 168 subjects with complete cardiovascular risk factor data, we performed multivariate regression analysis to identify sources of variation for IMT, TPA and TPV. We found that the ultrasound traits showed different correlations with individual cardiovascular risk factors. In particular, IMT was significantly associated with hypertension, TPA with smoking and plasma cholesterol, and TPV with diabetes. Therefore, these ultrasound measures of carotid artery morphology, while somewhat correlated, likely represent distinctive quantitative traits with different biological determinants, as underscored by different risk factor associations in the multivariate regression analysis. Because the measurements have different implications and determinants, investigators might need to be selective about the particular measurements they choose for specific applications.
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Affiliation(s)
- Khalid Al-Shali
- Blackburn Cardiovascular Genetics Laboratory, Robarts Research Institute, 406-100 Perth Drive, London, Ont., Canada N6A 5K8
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Hegele RA, Zinman B, Hanley AJG, Harris SB, Barrett PH, Cao H. Genes, environment and Oji-Cree type 2 diabetes. Clin Biochem 2003; 36:163-70. [PMID: 12726923 DOI: 10.1016/s0009-9120(03)00004-3] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The prevalence of type 2 diabetes in Canadian Oji-Cree is among the highest in the world. Our research has uncovered genetic determinants of Oji-Cree type 2 diabetes and related metabolic traits. The most important genetic discovery by far was the private G319S mutation in transcription factor HNF-1alpha, encoded by the HNF1A gene. HNF1A G319S was discovered by candidate gene sequencing and would have been missed using the currently favored strategy of genome-wide scanning. G319S was associated with increased odds of having type 2 diabetes across the whole study sample and in all subgroups, including adolescent Oji-Cree. Furthermore, G319S had specificity and positive predictive value of 97% and 95%, respectively, for developing type 2 diabetes by age 50. The protein bearing the G319S mutation had impaired function in vitro. Sigmoidal modeling showed that each dose of the G319S allele accelerated the median age of diabetes onset by about 7 yr. This approach also showed that environment more strongly accelerated the median age-of-onset of Oji-Cree diabetes onset than did G319S, which could have implications for intervention strategies to reduce the burden of this epidemic. There is also evidence for genetic determination of related metabolic traits in the Oji-Cree.
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Abstract
BACKGROUND The notion that the incidence of ischemic heart disease (IHD) is low among the Inuit subsisting on a traditional marine diet has attained axiomatic status. The scientific evidence for this is weak and rests on early clinical evidence and uncertain mortality statistics. METHODS We reviewed the literature and performed new analyses of the mortality statistics from Greenland, Canada, and Alaska. FINDINGS The evidence for a low mortality from IHD among the Inuit is fragile and rests on unreliable mortality statistics. Mortality from stroke, however, is higher among the Inuit than among other western populations. Based on the examination of 15 candidate gene polymorphisms, the Inuit genetic architecture does not obviously explain putative differences in cardiovascular disease prevalence. INTERPRETATION The mortality from all cardiovascular diseases combined is not lower among the Inuit than in white comparison populations. If the mortality from IHD is low, it seems not to be associated with a low prevalence of general atherosclerosis. A decreasing trend in mortality from IHD in Inuit populations undergoing rapid westernization supports the need for a critical rethinking of cardiovascular epidemiology among the Inuit and the role of a marine diet in this population.
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Affiliation(s)
- Peter Bjerregaard
- Division for Research in Greenland, National Institute of Public Health, Svanemøllevej 25 Copenhagen Ø, Denmark.
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Newman DL, Abney M, McPeek MS, Ober C, Cox NJ. The importance of genealogy in determining genetic associations with complex traits. Am J Hum Genet 2001; 69:1146-8. [PMID: 11590549 PMCID: PMC1274359 DOI: 10.1086/323659] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Affiliation(s)
- Dina L. Newman
- Departments of Human Genetics and Statistics, University of Chicago, Chicago
| | - Mark Abney
- Departments of Human Genetics and Statistics, University of Chicago, Chicago
| | - Mary Sara McPeek
- Departments of Human Genetics and Statistics, University of Chicago, Chicago
| | - Carole Ober
- Departments of Human Genetics and Statistics, University of Chicago, Chicago
| | - Nancy J. Cox
- Departments of Human Genetics and Statistics, University of Chicago, Chicago
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