Most cited article - PubMed ID 12855221
Genetic variants of homocysteine metabolizing enzymes and the risk of coronary artery disease
Decreasing the dietary intake of methionine exerts robust anti-adiposity effects in rodents but modest effects in humans. Since cysteine can be synthesized from methionine, animal diets are formulated by decreasing methionine and eliminating cysteine. Such diets exert both methionine restriction (MR) and cysteine restriction (CR), that is, sulfur amino acid restriction (SAAR). Contrarily, SAAR diets formulated for human consumption included cysteine, and thus might have exerted only MR. Epidemiological studies positively correlate body adiposity with plasma cysteine but not methionine, suggesting that CR, but not MR, is responsible for the anti-adiposity effects of SAAR. Whether this is true, and, if so, the underlying mechanisms are unknown. Using methionine- and cysteine-titrated diets, we demonstrate that the anti-adiposity effects of SAAR are due to CR. Data indicate that CR increases serinogenesis (serine biosynthesis from non-glucose substrates) by diverting substrates from glyceroneogenesis, which is essential for fatty acid reesterification and triglyceride synthesis. Molecular data suggest that CR depletes hepatic glutathione and induces Nrf2 and its downstream targets Phgdh (the serine biosynthetic enzyme) and Pepck-M. In mice, the magnitude of SAAR-induced changes in molecular markers depended on dietary fat concentration (60% fat >10% fat), sex (males > females), and age-at-onset (young > adult). Our findings are translationally relevant as we found negative and positive correlations of plasma serine and cysteine, respectively, with triglycerides and metabolic syndrome criteria in a cross-sectional epidemiological study. Controlled feeding of low-SAA, high-polyunsaturated fatty acid diets increased plasma serine in humans. Serinogenesis might be a target for treating hypertriglyceridemia.
- Keywords
- aging, caloric restriction, cysteine, metabolic syndrome, methionine, nutrition, sulfur amino acids, triglycerides,
- MeSH
- Amino Acids, Sulfur * metabolism MeSH
- Cysteine * metabolism MeSH
- Humans MeSH
- Lipid Metabolism MeSH
- Methionine metabolism MeSH
- Mice MeSH
- Obesity metabolism MeSH
- Cross-Sectional Studies MeSH
- Serine metabolism MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Mice MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- Amino Acids, Sulfur * MeSH
- Cysteine * MeSH
- Methionine MeSH
- Serine MeSH
OBJECTIVE: Using European descent Czech populations, we performed a study of SLC2A9 and SLC22A12 genes previously identified as being associated with serum uric acid concentrations and gout. This is the first study of the impact of non-synonymous allelic variants on the function of GLUT9 except for patients suffering from renal hypouricemia type 2. METHODS: The cohort consisted of 250 individuals (150 controls, 54 nonspecific hyperuricemics and 46 primary gout and/or hyperuricemia subjects). We analyzed 13 exons of SLC2A9 (GLUT9 variant 1 and GLUT9 variant 2) and 10 exons of SLC22A12 by PCR amplification and sequenced directly. Allelic variants were prepared and their urate uptake and subcellular localization were studied by Xenopus oocytes expression system. The functional studies were analyzed using the non-parametric Wilcoxon and Kruskall-Wallis tests; the association study used the Fisher exact test and linear regression approach. RESULTS: We identified a total of 52 sequence variants (12 unpublished). Eight non-synonymous allelic variants were found only in SLC2A9: rs6820230, rs2276961, rs144196049, rs112404957, rs73225891, rs16890979, rs3733591 and rs2280205. None of these variants showed any significant difference in the expression of GLUT9 and in urate transport. In the association study, eight variants showed a possible association with hyperuricemia. However, seven of these were in introns and the one exon located variant, rs7932775, did not show a statistically significant association with serum uric acid concentration. CONCLUSION: Our results did not confirm any effect of SLC22A12 and SLC2A9 variants on serum uric acid concentration. Our complex approach using association analysis together with functional and immunohistochemical characterization of non-synonymous allelic variants did not show any influence on expression, subcellular localization and urate uptake of GLUT9.
- MeSH
- Alleles MeSH
- White People MeSH
- Biological Transport MeSH
- Gout genetics pathology MeSH
- Adult MeSH
- Gene Expression MeSH
- Gene Frequency MeSH
- Hyperuricemia genetics pathology MeSH
- Polymorphism, Single Nucleotide * MeSH
- Middle Aged MeSH
- Humans MeSH
- Organic Anion Transporters genetics MeSH
- Organic Cation Transport Proteins genetics MeSH
- Glucose Transport Proteins, Facilitative genetics MeSH
- Aged MeSH
- Case-Control Studies MeSH
- Animals MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Aged MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Geographicals
- Czech Republic MeSH
- Names of Substances
- Organic Anion Transporters MeSH
- Organic Cation Transport Proteins MeSH
- Glucose Transport Proteins, Facilitative MeSH
- SLC22A12 protein, human MeSH Browser
- SLC2A9 protein, human MeSH Browser
OBJECTIVE: Uric acid is the end product of purine metabolism in humans, and increased serum uric acid concentrations lead to gout. The objective of the current study was to identify factors that are independently associated with serum uric acid concentrations in a cohort of Czech control individuals. METHODS: The cohort consisted of 589 healthy subjects aged 18-65 years. We studied the associations between the serum uric acid concentration and the following: (i) demographic, anthropometric and other variables previously reported to be associated with serum uric acid concentrations; (ii) the presence of metabolic syndrome and the levels of metabolic syndrome components; and (iii) selected genetic variants of the MTHFR (c.665C>T, c.1286A>C), SLC2A9 (c.844G>A, c.881G>A) and ABCG2 genes (c.421C>A). A backward model selection procedure was used to build two multiple linear regression models; in the second model, the number of metabolic syndrome criteria that were met replaced the metabolic syndrome-related variables. RESULTS: The models had coefficients of determination of 0.59 and 0.53. The serum uric acid concentration strongly correlated with conventional determinants including male sex, and with metabolic syndrome-related variables. In the simplified second model, the serum uric acid concentration positively correlated with the number of metabolic syndrome criteria that were met, and this model retained the explanatory power of the first model. Moderate wine drinking did not increase serum uric acid concentrations, and the urate transporter ABCG2, unlike MTHFR, was a genetic determinant of serum uric acid concentrations. CONCLUSION: Metabolic syndrome, moderate wine drinking and the c.421C>A variant in the ABCG gene are independently associated with the serum uric acid concentration. Our model indicates that uric acid should be clinically monitored in persons with metabolic syndrome.
- MeSH
- ATP Binding Cassette Transporter, Subfamily G, Member 2 MeSH
- ATP-Binding Cassette Transporters blood genetics MeSH
- Adult MeSH
- Gene Expression MeSH
- Polymorphism, Single Nucleotide * MeSH
- Cohort Studies MeSH
- Uric Acid blood MeSH
- Middle Aged MeSH
- Humans MeSH
- Metabolic Syndrome blood genetics pathology MeSH
- Methylenetetrahydrofolate Reductase (NADPH2) blood genetics MeSH
- Adolescent MeSH
- Models, Genetic MeSH
- Neoplasm Proteins blood genetics MeSH
- Alcohol Drinking blood genetics pathology MeSH
- Glucose Transport Proteins, Facilitative blood genetics MeSH
- Regression Analysis MeSH
- Aged MeSH
- Sex Factors MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Adolescent MeSH
- Male MeSH
- Aged MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- ATP Binding Cassette Transporter, Subfamily G, Member 2 MeSH
- ATP-Binding Cassette Transporters MeSH
- ABCG2 protein, human MeSH Browser
- Uric Acid MeSH
- Methylenetetrahydrofolate Reductase (NADPH2) MeSH
- MTHFR protein, human MeSH Browser
- Neoplasm Proteins MeSH
- Glucose Transport Proteins, Facilitative MeSH
- SLC2A9 protein, human MeSH Browser
INTRODUCTION: Given the physiological role of placental growth hormone (PGH) during intrauterine development and growth, genetic variation in the coding Growth hormone 2 (GH2) gene may modulate developmental programming of adult stature. Two major GH2 variants were described worldwide, determined by single polymorphism (rs2006123; c.171 + 50C > A). We sought to study whether GH2 variants may contribute to adult anthropometric measurements. METHODS: Genotyping of GH2 SNP rs2006123 by RFLP, testing its genetic association with adult height and Body Mass Index (BMI) by linear regression analysis, and combining the results of three individual study samples in meta-analysis. STUDY SAMPLES: HYPEST (Estonia), n = 1464 (506 men/958 women), CADCZ (Czech), n = 871 (518/353); UFA (Bashkortostan), n = 954 (655/299); meta-analysis, n = 3289 (1679/1610). RESULTS: Meta-analysis across HYPEST, CADCZ and UFA samples (n = 3289) resulted in significant association of GH2 rs2006123 with height (recessive model: AA-homozygote effect: beta (SE) = 1.26 (0.46), P = 5.90 × 10⁻³; additive model: A-allele effect: beta (SE) = 0.45 (0.18), P = 1.40 × 10⁻²). Among men (n = 1679), the association of the A-allele with taller stature remained significant after multiple-testing correction (additive effect: beta = 0.86 (0.28), P = 1.83 × 10⁻³). No association was detected with BMI. Notably, rs2006123 was in strong LD (r² ≥ 0.87) with SNPs significantly associated with height (rs2665838, rs7209435, rs11658329) and mapped near GH2 in three independent meta-analyses of GWA studies. CONCLUSIONS: This is the first study demonstrating a link between a placental gene variant and programming of growth potential in adulthood. The detected association between PGH encoding GH2 and adult height promotes further research on the role of placental genes in prenatal programming of human metabolism.
- Keywords
- Association study, Developmental programming, GH2 gene, Human height and BMI, Placental growth hormone, Polymorphism,
- MeSH
- Adult MeSH
- Gene Frequency MeSH
- Genetic Association Studies MeSH
- Body Mass Index MeSH
- Polymorphism, Single Nucleotide * MeSH
- Middle Aged MeSH
- Humans MeSH
- Multigene Family MeSH
- Placental Hormones genetics metabolism MeSH
- Growth Hormone genetics metabolism MeSH
- Aged MeSH
- Pregnancy MeSH
- Body Height MeSH
- Linkage Disequilibrium MeSH
- Bone Development * MeSH
- Fetal Development * MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Aged MeSH
- Pregnancy MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Meta-Analysis MeSH
- Research Support, Non-U.S. Gov't MeSH
- Geographicals
- Bashkiria MeSH
- Czech Republic MeSH
- Estonia MeSH
- Names of Substances
- GH2 protein, human MeSH Browser
- Placental Hormones MeSH
- Growth Hormone MeSH
BACKGROUND: Human linkage and animal QTL studies have indicated the contribution of genes on Chr17 into blood pressure regulation. One candidate gene is PNMT, coding for phenylethanolamine-N-methyltransferase, catalyzing the synthesis of epinephrine from norepinephrine. METHODS: Fine-scale variation of PNMT was screened by resequencing hypertensive (n = 50) and normotensive (n = 50) individuals from two European populations (Estonians and Czechs). The resulting polymorphism data were analyzed by statistical genetics methods using Genepop 3.4, PHASE 2.1 and DnaSP 4.0 software programs. In silico prediction of transcription factor binding sites for intron 1 was performed with MatInspector 2.2 software. RESULTS: PNMT was characterized by minimum variation and excess of rare SNPs in both normo- and hypertensive individuals. None of the SNPs showed significant differences in allelic frequencies among population samples, as well as between screened hypertensives and normotensives. In the joint case-control analysis of the Estonian and the Czech samples, hypertension patients had a significant excess of heterozygotes for two promoter region polymorphisms (SNP-184; SNP-390). The identified variation pattern of PNMT reflects the effect of purifying selection consistent with an important role of PNMT-synthesized epinephrine in the regulation of cardiovascular and metabolic functions, and as a CNS neurotransmitter. A striking feature is the lack of intronic variation. In silico analysis of PNMT intron 1 confirmed the presence of a human-specific putative Glucocorticoid Responsive Element (GRE), inserted by Alu-mediated transfer. Further analysis of intron 1 supported the possible existence of a full Glucocorticoid Responsive Unit (GRU) predicted to consist of multiple gene regulatory elements known to cooperate with GRE in driving transcription. The role of these elements in regulating PNMT expression patterns and thus determining the dynamics of the synthesis of epinephrine is still to be studied. CONCLUSION: We suggest that the differences in PNMT expression between normotensives and hypertensives are not determined by the polymorphisms in this gene, but rather by the interplay of gene expression regulators, which may vary among individuals. Understanding the determinants of PNMT expression may assist in developing PNMT inhibitors as potential novel therapeutics.
- MeSH
- Phenylethanolamine N-Methyltransferase genetics MeSH
- Genetic Predisposition to Disease * MeSH
- Genetic Variation MeSH
- Hypertension genetics MeSH
- Introns MeSH
- Middle Aged MeSH
- Humans MeSH
- Quantitative Trait Loci MeSH
- Polymerase Chain Reaction MeSH
- Gene Expression Regulation, Enzymologic MeSH
- Sequence Analysis, DNA MeSH
- Case-Control Studies MeSH
- Check Tag
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Geographicals
- Czech Republic MeSH
- Estonia MeSH
- Names of Substances
- Phenylethanolamine N-Methyltransferase MeSH
Homozygosity or compound heterozygosity for the c.833T>C transition (p.I278 T) in the cystathionine beta-synthase (CBS) gene represents the most common cause of pyridoxine-responsive homocystinuria in Western Eurasians. However, the frequency of the pathogenic c.833C allele, as observed in healthy newborns from several European countries (q(c.833C) approximately equals 3.3 x 10(-3)), is approximately 20-fold higher than expected on the basis of the observed number of symptomatic homocystinuria patients carrying this mutation (q(c.833C) approximately equals 0.18 x 10(-3)), implying clinical underascertainment. Intriguingly, the c.833C mutation is also present in combination with a 68-bp insertion, c.[833C; 844_845ins68], in a substantial proportion of chromosomes from nonhomocystinuric individuals worldwide. We have sought to study the relationship between the pathogenic and nonpathogenic c.833C-bearing chromosomes and to determine whether the pathogenic c.[833C; -] chromosomes are identical-by-descent or instead arose by recurrent mutation. Initial haplotype analysis of 780 randomly selected Czech and sub-Saharan African wild-type chromosomes, employing 12 intragenic markers, revealed 29 distinct CBS haplotypes, of which 10 carried the c.[833C; 844_845ins68] combination; none carried an isolated c.833C or c.844_845ins68 mutation. Subsequent examination of 69 pathogenic c.[833C; -] chromosomes, derived from homocystinuria patients of predominantly European origin, disclosed three unrelated haplotypes that differed from their wild-type counterparts by virtue of the presence of c.833C, thereby indicating that c.833T>C transition has occurred repeatedly and independently in the past. Since c.833T does not reside within an obvious mutational hotspot, we surmise that the three pathogenic and comparatively prevalent c.[833C; -] chromosomes may have originated by recurrent gene conversion employing the common nonpathogenic c.[833C; 844_845ins68] chromosomes as templates.
- MeSH
- Cystathionine beta-Synthase genetics MeSH
- Gene Frequency MeSH
- Genetic Variation * MeSH
- Genetic Testing MeSH
- Gene Conversion physiology MeSH
- Haplotypes * MeSH
- Homocystinuria genetics MeSH
- Humans MeSH
- Molecular Sequence Data MeSH
- Base Sequence MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Research Support, N.I.H., Extramural MeSH
- Geographicals
- Africa MeSH
- Europe MeSH
- Names of Substances
- Cystathionine beta-Synthase MeSH