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Familial hypercholesterolemia (FH) is caused by deleterious mutations in the LDLR that increase markedly low-density lipoprotein (LDL) cholesterol and cause premature atherosclerotic cardiovascular disease. Functional effects of pathogenic LDLR variants identified in Brazilian FH patients were assessed using in vitro and in silico studies. Variants in LDLR and other FH-related genes were detected by exon-target gene sequencing. T-lymphocytes were isolated from 26 FH patients, and 3 healthy controls and LDLR expression and activity were assessed by flow cytometry and confocal microscopy. The impact of LDLR missense variants on protein structure was assessed by molecular modeling analysis. Ten pathogenic or likely pathogenic LDLR variants (six missense, two stop-gain, one frameshift, and one in splicing region) and six non-pathogenic variants were identified. Carriers of pathogenic and non-pathogenic variants had lower LDL binding and uptake in activated T-lymphocytes compared to controls (p 0.05), but these variants did not influence LDLR expression on cell surface. Reduced LDL binding and uptake was also observed in carriers of LDLR null and defective variants. Modeling analysis showed that p.(Ala431Thr), p.(Gly549Asp) and p.(Gly592Glu) disturb intramolecular interactions of LDLR, and p.(Gly373Asp) and p.(Ile488Thr) reduce the stability of the LDLR protein. Docking and molecular interactions analyses showed that p.(Cys184Tyr) and p.(Gly373Asp) alter interaction of LDLR with Apolipoprotein B (ApoB). In conclusion, LDLR null and defective variants reduce LDL binding capacity and uptake in activated T-lymphocytes of FH patients and LDLR missense variants affect LDLR conformational stability and dissociation of the LDLR-ApoB complex, having a potential role in FH pathogenesis.

This study aimed to compare the action of a drug (ezetimibe) and a functional food containing plant sterol esters on oxidative stress biomarkers. In this double-blind study, 37 type 2 diabetic patients on statin treatment were randomly assigned to receive ezetimibe 10.0 mg/day or to consume a chocolate containing 2.1 g of plant sterol esters for 6 weeks. It was observed that ezetimibe promoted an increase of superoxide dismutase and glutathione reductase activities, while plant sterols did not change these biomarkers. Among individuals who showed the greatest LDL-C and oxLDL-C reduction, the oxLDL-C reduction observed in individuals under plant sterol treatment (−20.0%) did not differ from the values found in individuals treated with ezetimibe (−21.1%). In addition, 16 patients on plant sterol treatment reached the optimal therapeutic goal for LDL-C (

Background The 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. Objective To investigate the influence of PCSK9 variants on plasma lipid profile and response to atorvastatin in Brazilian subjects. Methods PCSK9 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. Results Frequencies 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. Conclusions PCSK9 E670G polymorphism but not I474V contributes to the variability on plasma LDL cholesterol levels in hypercholesterolemic subjects. Both PCSK9 variants have no influence on cholesterol-lowering response to atorvastatin.

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.

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

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.c.4GA, c.726+54CT and c.1050CT 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).Frequencies of SCARB1 polymorphisms were similar between the HC and NL groups (p0.05). The T allele for c.726+54CT was associated with higher LDL-c in NL and with higher apoB and apoB/apoAI in HC (p0.05). HC individuals carrying c.1050C allele carriers (CC and CT genotypes) had lower change of total cholesterol, LDL-c, apoB and apoB/apoAI ratio (p0.05) than the TT genotype carriers in response to atorvastatin.The SCARB1 polymorphisms are related with variations in serum lipids in the Brazilian population and c.1050CT SNP is associated with lipid-lowering atorvastatin response.

This study investigated the effects of atorvastatin on ABCB1 and ABCC1 mRNA expression on peripheral blood mononuclear cells (PBMC) and their relationship with gene polymorphisms and lowering-cholesterol response. One hundred and thirty-six individuals with hypercholesterolemia 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) (p0.05). After atorvastatin treatment, both ABCB1 and ABCC1 genes showed 50% reduction of the mRNA expression (p0.05). Reduction of ABCB1 expression was associated with ABCB1 G2677T/A polymorphism (p=0.039). Basal ABCB1 mRNA in the lower quartile (0.024) was associated with lower reduction rate of serum low-density lipoprotein (LDL) cholesterol (33.4+/-12.4%) and apolipoprotein B (apoB) (17.0+/-31.3%) when compared with the higher quartile (0.085: LDL-c=40.3+/-14.3%; apoB=32.5+/-10.7%; p0.05). ABCB1 substrates or inhibitors did not affect the baseline expression, while ABCB1 inhibitors reversed the 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.

Objectives To evaluate biomarkers of endothelial dysfunction and oxidative stress in glucose intolerance (GI) compared to overt diabetes (DM2). Design and methods 140 volunteers including 96 with DM2, 32 with GI and 12 controls (C) were studied. NO metabolites, NO synthase inhibitors, thiols and N-acetyl-β-glucosaminidase (NAGase) activity were analyzed by chemiluminescence, capillary electrophoresis, ELISA and colorimetric assay, respectively. Results NO metabolites were higher in GI (NOx: p = 0.03; S-nitrosothiols: p = 0.001) and DM2 (p = 0.006; p = 0.0006) groups in relation to group C, while nitrotyrosine was higher only in the DM2 group in comparison to the other groups. NAGase activity was elevated in GI (p = 0.003) and DM2 (p = 0.0004) groups in relation to group C, as well as, ADMA (p = 0.01; p = 0.003) and GSSG (p = 0.01; p = 0.002). Conclusions NO metabolites, NO synthase inhibitors, thiols and NAGase are biomarkers suitable to indicate endothelial dysfunction and oxidative stress in the early stages of impaired response to insulin.

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.