Functional analysis of PCSK9 3'UTR variants and mRNA­miRNA interactions in patients with familial hypercholesterolemia

AIM: functional analysis of pcsk9 3'utr variants and mrna-mirna interactions were explored in patients with familial hypercholesterolemia (fh). MATERIALS & METHODS: PCSK9 3'UTR variants were identified by exon-targeted gene sequencing. Functional effects of 3'UTR variants and mRNA-miRNA interactions were analyzed using in silico and in vitro studies in HEK293FT and HepG2 cells. RESULTS: Twelve PCSK9 3'UTR variants were detected in 88 FH patients. c.*75C >T and c.*345C >T disrupted interactions with miR-6875, miR-4721 and miR-564. Transient transfection of the c.*345C >T decreased luciferase activity in HEK293FT cells. miR-4721 and miR-564 mimics reduced PCSK9 expression in HepG2 cells. CONCLUSION: PCSK9 c.*345C >T has a possible role as loss-of-function variant. miR-4721 and miR-564 downregulate PCSK9 and may be useful to improve lipid profile in FH patients.

Adiponectin concentration data improve the estimation of atherosclerotic risk in normal and in overweight subjects

BACKGROUND: The combinations of adipokines and body mass parameters to estimate carotid atherosclerotic disease have not been completely delineated. OBJECTIVE: To test the combinations of well-established, easily accessible body mass indices and circulating biomarkers to identify increased carotid intima-media thickness (cIMT) in a primary prevention setting. DESIGN AND PATIENTS: In a cross-sectional analysis of 339 asymptomatic individuals with no history of cardiovascular events, inflammatory and insulin sensitivity biomarkers as well as adipokine levels were measured and combined with body mass parameters to evaluate the best marker for increased cIMT.RESULTS: As isolated parameters, body mass index (BMI) and adiponectin best identified abnormal cIMT (P = .04). Adiponectin levels were also linked to the relationship between BMI and cIMT (β = 0.0371; P = .01). Twenty-nine individuals with increased cIMT were missed by BMI alone but detected by combining BMI and adiponectin measurements. When compared with BMI alone, the combination of adiponectin plus BMI improved the c-statistic (0.549-0.567) and the integrated discrimination improvement index (0.01725; P = .021). Segregation of individuals by the combined use of BMI + adiponectin is associated with significant differences in insulin sensitivity, glomerular filtration rate, systemic inflammatory activity, dyslipidaemia and cIMT.

Influence of PCSK9 polymorphisms on plasma lipids and response to atorvastatin treatment in Brazilian subjects

BackgroundThe proprotein convertase subtilisin/kexin type 9 (PCSK9) has a key role in the regulation of plasma low-density lipoprotein (LDL) cholesterol by enhancing the degradation of LDL receptor. Functional variants in PCSK9 have been associated with differences in plasma lipids and may contribute to the variability of the response to cholesterol-lowering drugs.ObjectiveTo investigate the influence of PCSK9 variants on plasma lipid profile and response to atorvastatin in Brazilian subjects.MethodsPCSK9 E670G, I474V, and R46L single nucleotide polymorphisms (SNPs) and plasma lipids were evaluated in 163 hypercholesterolemics (HC) and 171 normolipidemics (NL). HC patients with indication for cholesterol-lowering drug therapy (n = 128) were treated with atorvastatin (10 mg/d/4 wk). PCSK9 SNPs were analyzed by real time polymerase chain reaction.ResultsFrequencies of the PCSK9 SNPs were similar between the HC and NL groups. Logistic regression analysis showed a trend of association between PCSK9 E670G and hypercholesterolemia after adjustment for covariates (P = .059). The 670G allele was associated with high basal levels of LDL cholesterol (P = .03) in HC patients using the extreme discordant phenotype method. No association tests were performed for R46L variant because of its very low frequency, whereas the I474V polymorphism and PCSK9 haplotypes were not related to hypercholesterolemia or variability on plasma lipids in both NL and HC groups (P > .05). LDL cholesterol reduction in response to atorvastatin was not influenced by PCSK9 genotypes or haplotypes.

Influence of PCSK9 polymorphisms on plasma lipids and response to atorvastatin treatment in Brazilian subjects

BACKGROUND: The proprotein convertase subtilisin/kexin type 9 (PCSK9) has a key role in theregulation of plasma low-density lipoprotein (LDL) cholesterol by enhancing the degradation ofLDL receptor. Functional variants in PCSK9 have been associated with differences in plasma lipidsand may contribute to the variability of the response to cholesterol-lowering drugs.OBJECTIVE: To investigate the influence of PCSK9 variants on plasma lipid profile and response toatorvastatin in Brazilian subjects.METHODS: PCSK9 E670G, I474V, and R46L single nucleotide polymorphisms (SNPs) and plasmalipids were evaluated in 163 hypercholesterolemics (HC) and 171 normolipidemics (NL). HC patientswith indication for cholesterol-lowering drug therapy (n 5 128) were treated with atorvastatin (10 mg/d/4 wk). PCSK9 SNPs were analyzed by real time polymerase chain reaction.RESULTS: Frequencies of the PCSK9 SNPs were similar between the HC and NL groups. Logisticregression analysis showed a trend of association between PCSK9 E670G and hypercholesterolemiaafter adjustment for covariates (P 5 .059). The 670G allele was associated with high basal levels ofLDL cholesterol (P 5 .03) in HC patients using the extreme discordant phenotype method. Noassociation tests were performed for R46L variant because of its very low frequency, whereas theI474V polymorphism and PCSK9 haplotypes were not related to hypercholesterolemia or variabilityon plasma lipids in both NL and HC groups (P ..05). LDL cholesterol reduction in response to atorvastatinwas not influenced by PCSK9 genotypes or haplotypes.CONCLUSIONS: PCSK9 E670G polymorphism but not I474V contributes to the variability onplasma LDL cholesterol levels in hypercholesterolemic subjects. Both PCSK9 variants have no influenceon cholesterol-lowering response to atorvastatin. 2014 National Lipid Association. All rights reserved.

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.

Atorvastatin and hormone therapy effects on APOE mRNA expression in hypercholesterolemic postmenopausal women

Menopause is associated with changes in lipid levels resulting in increased risk of atherosclerosis andcardiovascular events. Hormone therapy (HT) and atorvastatin have been used to improve lipid profilein postmenopausal women.Effects of HT, atorvastatin and APOE polymorphisms on serum lipids and APOE and LXRA expressionwere evaluated in 87 hypercholesterolemic postmenopausal women, randomly selected for treatmentwith atorvastatin (AT, n = 17), estrogen or estrogen plus progestagen (HT, n = 34) and estrogen or estrogenplus progestagen associated with atorvastatin (HT + AT, n = 36). RNA was extracted from peripheralblood mononuclear cells (PBMC) and mRNA expression was measured by TaqMan® PCR. APOE 2/ 3/ 4genotyping was performed using PCR-RFLP.Total cholesterol (TC), LDL-c and apoB were reduced after each treatment (p < 0.001). Triglycerides,VLDL-c and apoAI were reduced only after atorvastatin (p < 0.05), whereas triglycerides and VLDL-c wereincreased after HT (p = 0.01). HT women had lower reduction on TC, LDL-c and apoB than AT and HT + ATgroups (p < 0.05). APOE mRNA expression was reduced after atorvastatin treatment (p = 0.03). AlthoughLXRA gene expression was not modified by atorvastatin, it was correlated with APOE mRNA before andafter treatments. Basal APOE mRNA expression was not influenced by gene polymorphisms, however thereduction on APOE expression was more pronounced in 3 3 than in 3 4 carriers.Atorvastatin down-regulates APOE mRNA expression and it is modified by APOE genotypes in PBMCfrom postmenopausal women.

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.

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 å2/å3/å4 genotypes and atorvastatin treatment in Brazilian individuals. The relationship of APOE genotypes and plasma lipids and atorvastatin response was also tested in this population.MethodsAPOE å2/å3/å4 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.ResultsHC 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 å2 allele have reduced risk for hypercholesterolemia (OR: 0.27, 95% I.C.: 0.08-0.85, p < 0.05) and NL å2 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...

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.

Pleiotropic Effects With Equivalent Low-density Lipoprotein Cholesterol Reduction: Comparative Study Pleiotropic Effects With Equivalent Low-density

Background: Coadministration of any statin with ezetimibe is as effective as using high doses of the same statin in the reduction of low-density lipoprotein cholesterol (LDL-c). There may be other effects called pleiotropics. Objective: To compare the effectiveness of 2 different treatments that obtain equivalent LDL-c reductions (80 mg of simvastatin, once a day and coadministration of 10 mg of simvastatin and 10 mg of ezetimibe, once a day) over endothelial function and inflammation. Methods: Twenty-three randomized patients with hypercholesterolemia in a 2 3 2 crossover protocol were studied. Endothelial function was analyzed by ultrasound assessment of endothelial dependent flow-mediated vasodilation of the brachial artery, and inflammation was estimated by high-sensitivity C-reactive protein (hs-CRP). Results: LDL-c reduction was similar between the 2 treatments with simvastatin/ezetimibe and with simvastatin (P , 0.001); no difference between treatments was found (P = 0.968). Both treatments improved significantly the endothelial function [3.61% with simvastatin/

ezetimibe (P = 0.003) and 5.08% with simvastatin (P , 0.001)]; no difference was found between the 2 treatments (P = 0.291). hs-CRP had a 23% reduction with simvastatin/ezetimibe (P = 0.004) and a 30% reduction with simvastatin alone (P = 0.01), with no significant difference between the 2 treatments (P = 0.380).

Pleiotropic Effects With Equivalent Low-density Lipoprotein Cholesterol Reduction: Comparative StudyBetween Simvastatin and Simvastatin/Ezetimibe Coadministration

Background: Coadministration of any statin with ezetimibe is as effective as using high doses of the same statin in the reduction of low-density lipoprotein cholesterol (LDL-c). There may be othereffects called pleiotropics. Objective: To compare the effectiveness of 2 different treatments that obtain equivalent LDL-c reductions (80 mg of simvastatin, oncea day and coadministration of 10 mg of simvastatin and 10 mg of ezetimibe, once a day) over endothelial function and inflammation. Methods: Twenty-three randomized patients with hypercholesterolemia in a 2 3 2 crossover protocol were studied. Endothelial function was analyzed by ultrasound assessment of endothelialdependent flow-mediated vasodilation of the brachial artery, andinflammation was estimated by high-sensitivity C-reactive protein(hs-CRP). Results: LDL-c reduction was similar between the 2 treatments withsimvastatin/ezetimibe and with simvastatin (P , 0.001); no differencebetween treatments was found (P = 0.968). Both treatments improved significantly the endothelial function [3.61% with simvastatin/ ezetimibe (P = 0.003) and 5.08% with simvastatin (P , 0.001)]; no difference was found between the 2 treatments (P = 0.291). hs-CRP had a 23% reduction with simvastatin/ezetimibe (P = 0.004) and a 30% reduction with simvastatin alone (P = 0.01), with no significant difference between the 2 treatments (P = 0.380). Conclusion: The 2 forms of treatment presented similar pleiotropiceffects: improvement in endothelial function and decrease in hs-CRP levels.

ABCB1 and ABCC1 expression in peripheral mononuclear cells is influenced by gene polymorphisms and atorvastatin treatment

This study investigated the effects of atorvastatin on ABCB1 and ABCC1 mRNA expression on peripheral blood mononuclear cells (PBMC) and their relationship with gene polymorphismsand lowering-cholesterol response. One hundred and thirty-six individuals withhypercholesterolemia were selected and treated with atorvastatin (10 mg/day/4 weeks). Blood samples were collected for serum lipids and apolipoproteins measurements and DNA and RNA extraction. ABCB1 (C3435T and G2677T/A) and ABCC1 (G2012T) gene polymorphisms were identified by polymerase chain reaction-restriction (PCR)-RFLP and mRNA expression was measured in peripheral blood mononuclear cells by singleplex real-time PCR. ABCB1 polymorphisms were associated with risk for coronary artery disease (CAD) ( p 0.085: LDL-c = 40.3 14.3%; apoB = 32.5 10.7%; p < 0.05). ABCB1 substrates or inhibitors did not affect the baseline expression, while ABCB1 inhibitors reversedthe effects of atorvastatin on both ABCB1 and ABCC1 transporters. In conclusion, ABCB1 and ABCC1 mRNA levels in PBMC are modulated by atorvastatin and ABCB1 G2677T/A polymorphism and ABCB1 baseline expression is related to differences in serum LDL cholesterol and apoB in response to atorvastatin.

Antioxidant effect of simvastatin is not enhanced by its association with a-Tocopherol in hypercholesterolemic patient

Among the pleiotropic effects of statins, their antioxidant action may be involved in their protective effects.Thus, we investigated the antioxidant effect of simvastatin, associated or not with a-tocopherol, on levels ofelectronegative low-density lipoprotein (LDL ), nitrotyrosine, thiols (homocysteine, glutathione, cysteine, methionine),and lipid-soluble antioxidants in blood plasma of hypercholesterolemic subjects. In this study, 25 hypercholesterolemicsubjects were treated for 2 months with simvastatin (20 mg/day) and with simvastatin (20 mg/day) + a-tocopherol (400IU/day). Concentrations of thiols were determined by high-performance capillary electrophoresis–laser-inducedfluorescene. Lipid-soluble antioxidants were determined by HPLC, and LDL , and nitrotyrosine by ELISA. Simvastatin,independent of its association with a-tocopherol, reduced plasma concentrations of LDL , nitrotyrosine, totalcholesterol, and LDL cholesterol and the LDL cholesterol/HDL cholesterol ratio. Neither simvastatin nor simvastatinplus a-tocopherol altered plasma levels of the thiols analyzed. a-Tocopherol did not change the antioxidant effect ofsimvastatin on the levels of LDL and nitrotyrosine in hypercholesterolemic subjects. The reduction of LDL andnitrotyrosine by simvastatin seems to be related to the pleiotropic effects of this statin, and it may have an importantprotective effect against endothelial dysfunction and atherosclerosis.

Comparação entre lovastatina e o gemfibrozil no tratamento de hiperlipidemias primárias / Comparison between lovastatin and gemfibrozil in treatment of primary hyperlipidemias

Purpose - To compare the effects of lovastatin and gemfibrozil in patients with primary hyperlipidemias. Patients and Methods - Forty patients with cholesterolemia over 200 mgldl and triglyceridemia not higher than 350 mp/dl, excluded secondary causes, were selected. Twenty patients received lovastatin and 20 gemfibrozil. In order to establish the lipid profile, blood samples were taken after 2 months without medication, after 4 weeks of diet and placebo and after 6 and 12 weeks active treatment. Biochemic profile was determined before and after the treatment with active drug. Results - Thirty nine patients completed the study. Total and LDL-cholesterol were significantly reduced (p < 0.05) by both drugs but lovastatin had greater effect. Only gemfibrozil reduced triglycerides significantly. Neither drug had significant effects on HDL-cholesterol. The tolerance was satisfactory; only one patient (using gemfibrozil) needed to stop the treatment due to gastrointestinal side effects. The biochemic profïle did not present any significant alteration. Conclusion - Both drugs produced useful effects on the lipid profile. Lovastatin produced greater reductions of total and LDL-cholesterol, while gemfibrozil was more active reducing triglycerides. Neither drug changed significantly the HDL-cholesterol

Arritimias cardíacas em idosos saudáveis: detecçäo através da eletrocardiografia dinâmica / Cardiac arrhythmias in healthy elderly: detection through dynamic electrocardiography

Com o objetivo de avaliar a ocorrência de arritmias em idosos considerados "normais" do ponto de vista cardiovascular, foram estudados, através da eletrocardiografia dinâmica de 24 horas, 50 gerontes, com idades de 65 a 82 anos (média = 73,1), 44 do sexo masculino. Consideraram-se critérios de inclusäo: ausência de sintomas relacionados ao aparelho cardiovascular, de arritmias ao exame rotineiro, de bulhas acessórias e sopros; pressäo arterial sistólica menor do que 160 mmHg e diastólicas inferior a 95 mmHg. O ritmo era sinusal em todos os casos e as freqüências cardíacas mínimas variaram de 45 a 75 bpm (médio = 60,9) e as máximas de 60 a 150 bpm (média = 79,8). O intervalo PR variou de 0,10 a 0,24 s (média = 0,17); em apenas um caso era maior que 0,20. Em 30 casos (60%) foram evidenciadas arritmias cardíacas: extra-sístoles ventriculares (EV), em 22, extra-sístoles supraventriculares (ESV), em 16, e Wolff-Parkinson-White transitório, em um. As EV eram unifocais em 14 casos e polifocais em 8. Apresentavam-se isoladas em 20 casos, sendo freqüentes (> 6 EV/min) em um, e bigeminadas (curta duraçäo) em 2. As EVS eram unificais em 13 casos e polifocais em dois; isoladas em 13 casos e freqüentes em cinco; em dois casos havia bigeminismo de curta duraçäo e, em outro, episódios fugazes de taquicardia paroxística supraventricular. Näo houve registro de alteraçöes do segmento ST em nenhum caso. Esses resultados indicam que indivíduos idosos, assintomáticos e sem evidência de cardiopatia, podem apresentar arritmias relativamente freqüentes quanto avaliados pela ECD de 24 horas. Entretanto, o real significado desses achados e a necessidade de tratamento medicamentoso profilático näo estäo ainda adequadamente estabelecidos