Effects of atorvastatin on CYP3A4 and CYP3A5 mRNA expression in mononuclear cells and CYP3A activity in hypercholeresterolemic patients.

BACKGROUND: Variability of response to statins has been related to polymorphisms in genes involved in cholesterol homeostasis and statin metabolism, such as CYP3A4 and CYP3A5. We investigated the effects of atorvastatin on CYP3A4 and CYP3A5 mRNA expression in mononuclear cells and on CYP3A activity and their interactions with common variants. METHODS: Unrelated individuals (n=121) with hypercholesterolemia (HC) were treated with atorvastatin (10 mg/day/4 weeks). Ninety-two normolipidemic (NL) subjects were selected as a control group. Genotype analysis of CYP3A4*1B (rs2740574), CYP3A4*22 (rs35599367), CYP3A5*3C (rs776746), and CYP3A5*1D (rs15524) and mRNA levels in peripheral blood mononuclear cells (PBMCs) were estimated. CYP3A activity was phenotyped by the urinary cortisol to 6-beta-hydroxy-cortisol ratio. RESULTS: LDL cholesterol reduction in response to atorvastatin was positively correlated with change in CYP3A4 (R(2)=0.039, p=0.037) and CYP3A5 (R(2)=0.047, p=0.019) mRNA levels and negatively correlated with CYP3A activity (R(2)=0.071, p=0.022). CYP3A5*3C (AGT haplotype) was associated to lower basal CYP3A5 mRNA expression in HC (p<0.045), however none of the haplotype groups impacted treatment. CONCLUSION: It is likely that cholesterolemia status changes promoted by atorvastatin play a role in regulating CYP3A4 and CYP3A5 mRNA expression in PBMCs, as well as CYP3A activity. CYP3A5*3C (AGT haplotype) also contributes for the variability of CYP3A5 mRNA levels in PBMCs.

Relationship of short tandem repeats flanking leptin-melanocortin pathway genes with anthropometric profile and leptinemia in Brazilian individuals.

OBJECTIVE: To investigate the relationship of short tandem repeats (STR) near genes involved in the leptin-melanocortin pathway with body mass index (BMI) and leptinemia. SUBJECTS AND METHODS: Anthropometric variables and leptinemia were measured in 100 obese and 110 nonobese individuals. D1S200, D2S1788, DS11912, and D18S858 loci were analyzed by PCR and high-resolution electrophoresis. RESULTS: Overall STR allele frequencies were similar between the obese and non-obese group (p > 0.05). Individual alleles D1S200 (17), D11S912 (43), D18S858 (11/12) were associated with obesity (p < 0.05). Individuals carrying these alleles showed higher BMI than non-carriers (p < 0.05). Moreover, a relationship between D18S858 11/12 alleles and increased waist circumference was found (p = 0.040). On the other hand, leptinemia was not influenced by the studied STRs (p > 0.05). CONCLUSIONS: D1S200, D11S912, and D18S858 loci are associated with increased BMI and risk for obesity in this sample.

Differentiation of African components of ancestry to stratify groups in a case-control study of a Brazilian urban population.

BACKGROUND: Balancing the subject composition of case and control groups to create homogenous ancestries between each group is essential for medical association studies. METHODS: We explored the applicability of single-tube 34-plex ancestry informative markers (AIM) single nucleotide polymorphisms (SNPs) to estimate the African Component of Ancestry (ACA) to design a future case-control association study of a Brazilian urban sample. RESULTS: One hundred eighty individuals (107 case group; 73 control group) self-described as white, brown-intermediate or black were selected. The proportions of the relative contribution of a variable number of ancestral population components were similar between case and control groups. Moreover, the case and control groups demonstrated similar distributions for ACA <0.25 and >0.50 categories. Notably a high number of outlier values (23 samples) were observed among individuals with ACA <0.25. These individuals presented a high probability of Native American and East Asian ancestral components; however, no individuals originally giving these self-described ancestries were observed in this study. CONCLUSIONS: The strategy proposed for the assessment of ancestry and adjustment of case and control groups for an association study is an important step for the proper construction of the study, particularly when subjects are taken from a complex urban population. This can be achieved using a straight forward multiplexed AIM-SNPs assay of highly discriminatory ancestry markers.

Relationship of short tandem repeats flanking leptin-melanocortin pathway genes with anthropometric profile and leptinemia in Brazilian individuals / Relação de short tandem repeats (STR) em genes envolvidos na via da leptina-melanocortina com o perfil antropométrico e a leptinemia em brasileiros

OBJECTIVE: To investigate the relationship of short tandem repeats (STR) near genes involved in the leptin-melanocortin pathway with body mass index (BMI) and leptinemia. SUBJECTS AND METHODS: Anthropometric variables and leptinemia were measured in 100 obese and 110 nonobese individuals. D1S200, D2S1788, DS11912, and D18S858 loci were analyzed by PCR and high-resolution electrophoresis. RESULTS: Overall STR allele frequencies were similar between the obese and non-obese group (p > 0.05). Individual alleles D1S200 (17), D11S912 (43), D18S858 (11/12) were associated with obesity (p < 0.05). Individuals carrying these alleles showed higher BMI than non-carriers (p < 0.05). Moreover, a relationship between D18S858 11/12 alleles and increased waist circumference was found (p = 0.040). On the other hand, leptinemia was not influenced by the studied STRs (p > 0.05). CONCLUSIONS: D1S200, D11S912, and D18S858 loci are associated with increased BMI and risk for obesity in this sample.

OBJETIVO: Investigar a relação de short tandem repeats (STR) em genes envolvidos na via da leptina-melanocortina com índice de massa corporal (IMC) e leptinemia. SUJEITOS E MÉTODOS: Variáveis antropométricas e leptinemia foram medidas em 100 indivíduos obesos e 110 não obesos. Os loci D1S200, D2S1788, DS11912 e D18S858 foram analisados por PCR e eletroforese de alta resolução. RESULTADOS: As frequências globais dos alelos da STR foram similares entre os grupos obeso e não obeso (p > 0,05). Alelos individuais de D1S200 (17), D11S912 (43), D18S858 (11/12) foram associados com obesidade (p < 0,05). Indivíduos portadores desses alelos apresentaram valores de IMC maiores que os dos não portadores (p < 0,05). Além disso, a presença dos alelos D18S858 11/12 foi relacionada com circunferência abdominal elevada (p = 0,040). Por outro lado, a leptinemia não foi influenciada pelos STRs estudados (p > 0,05). CONCLUSÕES: Os loci D1S200, D11S912 e D18S858 são associados com IMC aumentado e risco de obesidade nesta amostra populacional.

Differentiation of african components of ancestry to stratify groups in a Case–control study of a brazilian urban population

Background: Balancing the subject composition of case and control groups to create homogenous ancestries between each group is essential for medical association studies. Methods: We explored the applicability of single-tube 34-plex ancestry informative markers (AIM) single nucleotide polymorphisms (SNPs) to estimate the African Component of Ancestry (ACA) to design a future case-control association study of a Brazilian urban sample. Results: One hundred eighty individuals (107 case group; 73 control group) self-described as white, brown-intermediate or black were selected. The proportions of the relative contribution of a variable number of ancestral population components were similar between case and control groups. Moreover, the case and control groups demonstrated similar distributions for ACA 0.50 categories. Notably a high number of outlier values (23 samples) were observed among individuals with ACA <0.25. These individuals presented a high probability of Native American and East Asian ancestral components; however, no individuals originally giving these self-described ancestries were observed in this study. Conclusions: The strategy proposed for the assessment of ancestry and adjustment of case and control groups for an association study is an important step for the proper construction of the study, particularly when subjects are taken from a complex urban population. This can be achieved using a straight forward multiplexed AIM-SNPs assay of highly discriminatory ancestry markers.

Apolipoprotein E mRNA expression in mononuclear cells from normolipidemic and hypercholesterolemic individuals treated with atorvastatin.

BACKGROUND: Apolipoprotein E (apoE) is a key component of the lipid metabolism. Polymorphisms at the apoE gene (APOE) have been associated with cardiovascular disease, lipid levels and lipid-lowering response to statins. We evaluated the effects on APOE expression of hypercholesterolemia, APOE ε2/ε3/ε4 genotypes and atorvastatin treatment in Brazilian individuals. The relationship of APOE genotypes and plasma lipids and atorvastatin response was also tested in this population. METHODS: APOE ε2/ε3/ε4 and plasma lipids were evaluated in 181 normolipidemic (NL) and 181 hypercholesterolemic (HC) subjects. HC individuals with indication for lowering-cholesterol treatment (n = 141) were treated with atorvastatin (10 mg/day/4-weeks). APOE genotypes and APOE mRNA in peripheral blood mononuclear cells (PBMC) were analyzed by TaqMan real time PCR. RESULTS: HC had lower APOE expression than NL group (p < 0.05) and individuals with low APOE expression showed higher plasma total and LDL cholesterol and apoB, as well as higher apoAI (p < 0.05). Individuals carrying ε2 allele have reduced risk for hypercholesterolemia (OR: 0.27, 95% I.C.: 0.08-0.85, p < 0.05) and NL ε2 carriers had lower total and LDL cholesterol and apoB levels, and higher HDL cholesterol than non-carriers (p < 0.05). APOE genotypes did not affect APOE expression and atorvastatin response. Atorvastatin treatment do not modify APOE expression, however those individuals without LDL cholesterol goal achievement after atorvastatin treatment according to the IV Brazilian Guidelines for Dyslipidemia and Atherosclerosis Prevention had lower APOE expression than patients with desirable response after the treatment (p < 0.05). CONCLUSIONS: APOE expression in PBMC is modulated by hypercholesterolemia and the APOE mRNA level regulates the plasma lipid profile. Moreover the expression profile is not modulated neither by atorvastatin nor APOE genotypes. In our population, APOE ε2 allele confers protection against hypercholesterolemia and a less atherogenic lipid profile. Moreover, low APOE expression after treatment of patients with poor response suggests a possible role of APOE level in atorvastatin response.

Pharmacogenetics of OATP transporters reveals that SLCO1B1 c.388A>G variant is determinant of increased atorvastatin response.

AIMS: The relationship between variants in SLCO1B1 and SLCO2B1 genes and lipid-lowering response to atorvastatin was investigated. MATERIAL AND METHODS: One-hundred-thirty-six unrelated individuals with hypercholesterolemia were selected and treated with atorvastatin (10 mg/day/4 weeks). They were genotyped with a panel of ancestry informative markers for individual African component of ancestry (ACA) estimation by SNaPshot(®) and SLCO1B1 (c.388A>G, c.463C>A and c.521T>C) and SLCO2B1 (-71T>C) gene polymorphisms were identified by TaqMan(®) Real-time PCR. RESULTS: Subjects carrying SLCO1B1 c.388GG genotype exhibited significantly high low-density lipoprotein (LDL) cholesterol reduction relative to c.388AA+c.388AG carriers (41 vs. 37%, p = 0.034). Haplotype analysis revealed that homozygous of SLCO1B1*15 (c.521C and c.388G) variant had similar response to statin relative to heterozygous and non-carriers. A multivariate logistic regression analysis confirmed that c.388GG genotype was associated with higher LDL cholesterol reduction in the study population (OR: 3.2, CI95%:1.3-8.0, p < 0.05). CONCLUSION: SLCO1B1 c.388A>G polymorphism causes significant increase in atorvastatin response and may be an important marker for predicting efficacy of lipid-lowering therapy.

Tumor necrosis factor-α and interleukin-6 expression in leukocytes and their association with polymorphisms and bone markers in diabetic individuals treated with pioglitazone.

BACKGROUND: Pioglitazone is a peroxisome proliferator-activated receptor gamma (PPARγ) activator used in the treatment of type 2 diabetes (DM2) patients and it has been suggested that can induce bone loss. Tumor necrosis factor-α (TNFα) and interleukin-6 (IL-6) mRNA expression in blood leukocytes and the relationship with polymorphisms and bone markers in DM2 treated with pioglitazone were investigated. METHODS: DM2 (n=53) and normoglycemic (NG, n=52) individuals were included. DM2 patients were treated with pioglitazone (45 mg/day/16 weeks). mRNA expression was evaluated by real-time polymerase chain reaction (PCR). TNFA -308G>A and IL6 -174G>C polymorphisms were detected by PCR-RFLP and high resolution melting polymerase chain reaction (HRM-PCR). RESULTS: Pioglitazone reduced bone specific alkaline phosphatase (bALP) and increased TNFα in DM2 group (p<0.001). DM2 or pioglitazone did not influence TNFα and IL-6 expression (p>0.05). TNFA -308A allele was associated with reduced basal TNFα mRNA levels in NG and DM2 and reduced alkaline phosphatase (tALP) after treatment (p<0.05). IL6 -174C allele was associated with decreased oral glucose tolerance test (OGTT)-2 h in DM2 individuals (p<0.05). CONCLUSIONS: TNFA -308G >A polymorphism appear to be involved in regulation of gene expression independently of hyperglycemia and its interaction with pioglitazone may modify tALP, a important bone marker. IL6 -174G>C variant is related with reduced risk of postprandial hyperglycemia but not with mRNA expression or bone markers.

Tumor necrosis factor-á and interleukin-6 expression in leukocytes and their association with polymorphisms and bone markers in diabetic individuals treated with pioglitazone

BACKGROUND: Pioglitazone is a peroxisome proliferator-activated receptor gamma (PPARã) activator used in the treatment of type 2 diabetes (DM2) patients and it has been suggested that can induce bone loss. Tumor necrosis factor-á (TNFá) and interleukin-6 (IL-6) mRNA expression in blood leukocytes and the relationship with polymorphisms and bone markers in DM2 treated with pioglitazone were investigated.METHODS: DM2 (n=53) and normoglycemic (NG, n=52) individuals were included. DM2 patients were treated with pioglitazone (45 mg/day/16 weeks). mRNA expression was evaluated by real-time polymerase chain reaction (PCR). TNFA -308G>A and IL6 -174G>C polymorphisms were detected by PCR-RFLP and high resolution melting polymerase chain reaction (HRM-PCR).RESULTS: Pioglitazone reduced bone specific alkaline phosphatase (bALP) and increased TNFá in DM2 group (p0.05). TNFA -308A allele was associated with reduced basal TNFá mRNA levels in NG and DM2 and reduced alkaline phosphatase (tALP) after treatment (pA polymorphism appear to be involved in regulation of gene expression independently of hyperglycemia and its interaction with pioglitazone may modify tALP, a important bone marker. IL6 -174G>C variant is related with reduced risk of postprandial hyperglycemia but not with mRNA expression or bone markers.

Pharmacogenetics of OATP Transporters Reveals That SLCO1B1 c.388A>G Variant Is Determinant of Increased Atorvastatin Response

Aims: The relationship between variants in SLCO1B1 and SLCO2B1 genes and lipid-lowering response to atorvastatin was investigated. Material and Methods: One-hundred-thirty-six unrelated individuals with hypercholesterolemia were selected andOPEN ACCESStreated with atorvastatin (10 mg/day/4 weeks). They were genotyped with a panel of ancestry informative markers for individual African component of ancestry (ACA) estimation by SNaPshot® and SLCO1B1 (c.388A>G, c.463C>A and c.521T>C) and SLCO2B1 (−71T>C) gene polymorphisms were identified by TaqMan® Real-time PCR. Results: Subjects carrying SLCO1B1 c.388GG genotype exhibited significantly high low-density lipoprotein (LDL) cholesterol reduction relative to c.388AA+c.388AG carriers (41 vs. 37%, p = 0.034). Haplotype analysis revealed that homozygous of SLCO1B1*15 (c.521C and c.388G) variant had similar response to statin relative to heterozygous and non-carriers. A multivariate logistic regression analysis confirmed that c.388GG genotype was associated with higher LDL cholesterol reduction in the study population (OR: 3.2, CI95%:1.3–8.0, p G polymorphism causes significant increase in atorvastatin response and may be an important marker for predicting efficacy of lipid-lowering therapy.

Influence of SCARB1 polymorphisms on serum lipids of hypercholesterolemic individuals treated with atorvastatin.

BACKGROUND: The SR-BI is a key component on the cholesterol metabolism. Polymorphisms in the SR-BI gene (SCARB1) were related with variations on plasma lipoprotein profile and other risk factors for cardiovascular disease. We tested the relationship of 3 SCARB1 single nucleotide polymorphisms (SNPs) with hypercholesterolemia in a Brazilian population and whether these variants can influence lipid-lowering response to atorvastatin. METHODS: c.4G>A, c.726+54C>T and c.1050C>T SNPs and serum concentrations of lipid and apolipoproteins were evaluated in 147 hypercholesterolemic (HC) and 185 normolipidemic (NL) unrelated Brazilian subjects. HC patients were treated with atorvastatin (10 mg/day/4 weeks). RESULTS: Frequencies of SCARB1 polymorphisms were similar between the HC and NL groups (p>0.05). The T allele for c.726+54C>T was associated with higher LDL-c in NL and with higher apoB and apoB/apoAI in HC (p<0.05). HC individuals carrying c.1050C allele carriers (CC and CT genotypes) had lower change of total cholesterol, LDL-c, apoB and apoB/apoAI ratio (p<0.05) than the TT genotype carriers in response to atorvastatin. CONCLUSION: The SCARB1 polymorphisms are related with variations in serum lipids in the Brazilian population and c.1050C>T SNP is associated with lipid-lowering atorvastatin response.

Influence of SCARB1 polymorphisms on serum lipids of hypercholesterolemicindividuals treated with atorvastatin

Background: The SR-BI is a key component on the cholesterol metabolism. Polymorphisms in the SR-BI gene (SCARB1) were related with variations on plasma lipoprotein profile and other risk factors for cardiovasculardisease. We tested the relationship of 3 SCARB1 single nucleotide polymorphisms (SNPs) with hypercholesterolemia in a Brazilian population and whether these variants can influence lipid-lowering responseto atorvastatin. Methods: c.4GNA, c.726+54CNT and c.1050CNT SNPs and serum concentrations of lipid and apolipoproteins were evaluated in 147 hypercholesterolemic (HC) and 185 normolipidemic (NL) unrelated Brazilian subjects. HC patients were treated with atorvastatin (10 mg/day/4 weeks).Results: Frequencies of SCARB1 polymorphisms were similar between the HC and NL groups (pN0.05). TheT allele for c.726+54CNT was associated with higher LDL-c in NL and with higher apoB and apoB/apoAI inHC (pb0.05). HC individuals carrying c.1050C allele carriers (CC and CT genotypes) had lower change of totalcholesterol, LDL-c, apoB and apoB/apoAI ratio (pb0.05) than the TT genotype carriers in response to atorvastatin. Conclusion: The SCARB1 polymorphisms are relatedwith variations in serumlipids in the Brazilian population and c.1050CNT SNP is associated with lipid-lowering atorvastatin response.

Effects of APOE, APOB and LDLR variants on serum lipids and lack of association with xanthelasma in individuals from Southeastern Brazil.

Xanthelasma might be a clinical manifestation of dyslipidemia, a recognized risk factor for coronary artery disease. We investigated the association of apolipoprotein E (APOE HhaI), apolipoprotein B (APOB XbaI and Ins/Del) and LDL receptor (LDLR AvaII and HincII) gene polymorphisms with lipid profiles in 100 Brazilians with xanthelasma and 100 controls. Allele frequencies were similar in both groups. APOE, APOB and LDLR genotypes were not correlated with differences in the serum lipid profile. In individuals with xanthelasma, the APOB D allele was associated with less chance of having increased LDL-cholesterol (O.R. = 0.16, CI95% = 0.03-0.94, p = 0.042). In the control group, the APOB X+ allele was associated with less chance of having both increased total cholesterol (O.R. = 0.16, CI95% = 0.03-0.78, p = 0.023) and increased LDL-cholesterol (O.R. = 0.10, CI95% = 0.02-0.60, p = 0.012). Moreover, there was a significantly higher frequency of control individuals (68%) with elevated serum triglyceride levels, compared to patients (48%, p = 0.008). On the other hand, triglyceride levels in controls also seemed to be influenced by all other gene polymorphisms studied, an effect that might be enhanced by environmental factors.

Effects of APOE, APOB and LDLR variants on serum lipids and lack of association with xanthelasma in individuals from Southeastern Brazil

Xanthelasma might be a clinical manifestation of dyslipidemia, a recognized risk factor for coronary artery disease. We investigated the association of apolipoprotein E (APOE HhaI), apolipoprotein B (APOB XbaI and Ins/Del) and LDL receptor (LDLR AvaII and HincII) gene polymorphisms with lipid profiles in 100 Brazilians with xanthelasma and 100 controls. Allele frequencies were similar in both groups. APOE, APOB and LDLR genotypes were not correlated with differences in the serum lipid profile. In individuals with xanthelasma, the APOB D allele was associated with less chance of having increased LDL-cholesterol (O.R. = 0.16, CI95 percent = 0.03-0.94, p = 0.042). In the control group, the APOB X+ allele was associated with less chance of having both increased total cholesterol (O.R. = 0.16, CI95 percent = 0.03-0.78, p = 0.023) and increased LDL-cholesterol (O.R. = 0.10, CI95 percent = 0.02-0.60, p = 0.012). Moreover, there was a significantly higher frequency of control individuals (68 percent) with elevated serum triglyceride levels, compared to patients (48 percent, p = 0.008). On the other hand, triglyceride levels in controls also seemed to be influenced by all other gene polymorphisms studied, an effect that might be enhanced by environmental factors.

CYP3A53A allele is associated with reduced lowering-lipid response to atorvastatin in individuals with hypercholesterolemia.

BACKGROUND: The cytochrome P450 isoenzyme 3A5 (CYP3A5) has an important role on biotransformation of xenobiotics. CYP3A5 SNPs have been associated with variations on enzyme activity that can modify the metabolism of several drugs. METHODS: In order to evaluate the influence of CYP3A5 variants on response to lowering-cholesterol drugs, 139 individuals with hypercholesterolemia were selected. After a wash-out period of 4 weeks, individuals were treated with atorvastatin (10 mg/day/4 weeks). Genomic DNA was extracted by a salting-out procedure. CYP3A5*3C, CYP3A5*6 and CYP3A5*1D were analyzed by PCR-RFLP and DNA sequencing. RESULTS: >Frequencies of the CYP3A5*3C and CYP3A5*1D alleles were lower in individuals of African descent (*3C: 47.8% and *1D: 55.2%) than in non-Africans (*3C: 84.9% and *1D 84.8%, p<0.01). Non-Africans carrying *3A allele (*3C and *1D combined alleles) had lower total and LDL-cholesterol response to atorvastatin than non-*3A allele carriers (p<0.05). CONCLUSION: CYP3A5*3A allele is associated with reduced cholesterol-lowering response to atorvastatin in non-African individuals.

Effects of ABCA1 SNPs, including the C-105T novel variant, on serum lipids of Brazilian individuals.

BACKGROUND: ABCA1 plays an important role in HDL metabolism. Single nucleotide polymorphisms (SNPs) in ABCA1 gene were associated with variation in plasma HDL-c. METHODS: The effect of the ABCA1 SNPs C-14T, R219K and of a novel variant C-105T on serum lipids was investigated in 367 unrelated Brazilian individuals (224 hypercholesterolemic and 143 normolipidemic). The relation between ABCA1 SNPs and the lipid-lowering response to atorvastatin (10 mg/day/4 weeks) was also evaluated in 141 hypercholesterolemic (HC) individuals. The polymorphisms were detected by PCR-RFLP and confirmed by DNA sequencing. RESULTS: Linkage disequilibrium was found between the SNPs C-105T and C-14T in the HC group. HC individuals carrying -105CT/TT genotypes had higher serum HDL-c and lower triglyceride and VLDL-c concentrations as well as lower TG/HDL-c ratio compared to the -105CC carriers (p<0.05). The R219K SNP was associated with reduced serum triglyceride, VLDL-c and TG/HDL-c ratio in the HC group (p<0.05), and with an increased serum apoAI in NL individuals. The effects of ABCA1 SNPs on basal serum lipids of HC individuals were not modified by atorvastatin treatment. CONCLUSIONS: The ABCA1 SNPs R219K and C-105T were associated with a less atherogenic lipid profile but not with the lowering-cholesterol response to atorvastatin in a Brazilian population.