Functional analysis of PCSK9 3'UTR variants and mRNA-miRNA 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.

Atorvastatin and hormone therapy influence expression of ABCA1, APOA1 and SCARB1 in mononuclear cells from hypercholesterolemic postmenopausal women.

BACKGROUND: Reverse cholesterol transport (RCT) has been inversely related to atherosclerosis and cardiovascular risk. The influence of menopause in the RCT process is poorly understood and the effects of cholesterol-lowering interventions, including statins and hormone therapy (HT), on genes controlling the RCT in postmenopausal women are also unknown. METHODS: The effects on serum lipids and expression profile of genes involved in RCT - APOA1, ABCA1, ABCG1, SCARB1 and LXRA - were evaluated by TaqMan(®) quantitative PCR in peripheral blood mononuclear cells (PBMC) from 87 postmenopausal hypercholesterolemic women treated with atorvastatin (AT, n=17), estrogen or estrogen plus progestin (HT, n=34) and estrogen or estrogen plus progestin associated with atorvastatin (HT+AT, n=36). RESULTS: Atorvastatin and HT treatments reduced the mRNA levels of APOA1 and SCARB1, respectively, whereas ABCA1 expression was reduced after all treatments. Although the expression of LXRA, an important transcription factor controlling the expression of genes involved in RCT, was not modified after any treatment, it was correlated with ABCA1, APOA1 and SCARB1 RNAm values before and after treatments, however no correlation with ABCG1 was observed. In a linear regression analysis, HT was related to an increase in apoAI levels after treatment when compared to atorvastatin and, moreover, higher SCARB1 and ABCA1 basal expression were also associated with decreased apoAI levels after treatments. CONCLUSION: ABCA1 mRNA levels are decreased by atorvastatin and HT, however these treatments have a differential effect on APOA1 and SCARB1 expression in PBMC from postmenopausal women. Basal ABCA1 and SCARB1 expression profile could be helpful markers in predicting the effect of atorvastatin and HT on RCT, according to the changes in apoAI levels in this sample population.

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 and cardiovascular events. Hormone therapy (HT) and atorvastatin have been used to improve lipid profile in postmenopausal women. Effects of HT, atorvastatin and APOE polymorphisms on serum lipids and APOE and LXRA expression were evaluated in 87 hypercholesterolemic postmenopausal women, randomly selected for treatment with atorvastatin (AT, n=17), estrogen or estrogen plus progestagen (HT, n=34) and estrogen or estrogen plus progestagen associated with atorvastatin (HT+AT, n=36). RNA was extracted from peripheral blood mononuclear cells (PBMC) and mRNA expression was measured by TaqMan(®) PCR. APOE ɛ2/ɛ3/ɛ4 genotyping 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 were increased after HT (p=0.01). HT women had lower reduction on TC, LDL-c and apoB than AT and HT+AT groups (p<0.05). APOE mRNA expression was reduced after atorvastatin treatment (p=0.03). Although LXRA gene expression was not modified by atorvastatin, it was correlated with APOE mRNA before and after treatments. Basal APOE mRNA expression was not influenced by gene polymorphisms, however the reduction on APOE expression was more pronounced in ɛ3ɛ3 than in ɛ3ɛ4 carriers. Atorvastatin down-regulates APOE mRNA expression and it is modified by APOE genotypes in PBMC from 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 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.

Antioxidant effect of simvastatin is not enhanced by its association with alpha-tocopherol in hypercholesterolemic patients.

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 alpha-tocopherol, on levels of electronegative low-density lipoprotein (LDL-), nitrotyrosine, thiols (homocysteine, glutathione, cysteine, methionine), and lipid-soluble antioxidants in blood plasma of hypercholesterolemic subjects. In this study, 25 hypercholesterolemic subjects were treated for 2 months with simvastatin (20 mg/day) and with simvastatin (20 mg/day) + alpha-tocopherol (400 IU/day). Concentrations of thiols were determined by high-performance capillary electrophoresis-laser-induced fluorescene. Lipid-soluble antioxidants were determined by HPLC, and LDL-, and nitrotyrosine by ELISA. Simvastatin, independent of its association with alpha-tocopherol, reduced plasma concentrations of LDL-, nitrotyrosine, total cholesterol, and LDL cholesterol and the LDL cholesterol/HDL cholesterol ratio. Neither simvastatin nor simvastatin plus alpha-tocopherol altered plasma levels of the thiols analyzed. alpha-Tocopherol did not change the antioxidant effect of simvastatin on the levels of LDL- and nitrotyrosine in hypercholesterolemic subjects. The reduction of LDL- and nitrotyrosine by simvastatin seems to be related to the pleiotropic effects of this statin, and it may have an important protective 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