👤 Taciana Furtado de Mendonça Belmont

The pathogenesis of lipodystrophy in people living with HIV (PLWHIV) receiving antiretrovirals appears to be multifactorial and may involve genetic factors; however, it is not yet fully understood. We verified the association between single nucleotide polymorphisms in the APOC3-rs2854116, ESR2-rs3020450, HFE-rs1799945 and MMP1-rs1799750 genes and lipodystrophy and its subtypes in PLWHIV receiving antiretroviral. Design: cross-sectional study. Lipodystrophy definition was based on self-report. Genotyping of the polymorphisms was performed using real-time polymerase chain reaction. Lipodystrophy was reported in 204/404 participants (51%), being 89/204 with mixed lipodystrophy, 72/204 with lipohypertrophy, and 43/204 with lipoatrophy. There was no association between APOC3, HFE, and MMP1 polymorphisms and lipodystrophy. The frequency of AA genotype ( Participants with lipoatrophy had higher frequency of the AA genotype and the A allele of the ESR2-rs3020450 polymorphism. In addition, viral load >40 copies/mL and current use of zidovudine were associated with lipoatrophy, suggesting a potential involvement of this genetic variant in the pathogenesis of lipoatrophy in PLWHIV receiving antiretroviral. Show less

The aim of this study was to perform a systematic review to identify data reported in the literature concerning the association of APOC3 (rs2854116), ESR2 (rs3020450), HFE (rs1799945), MMP1 (rs1799750) and PPARG (rs1801282) polymorphisms with lipodystrophy in people living with HIV (PLWHIV) on antirretroviral therapy. The research was conducted in six databases and the studies were selected in two steps. First, a search was undertaken in the following electronic databases: PubMed, Science Direct, Medline, World Wide Science, Directory of Open Access Journals, Scielo, Lilacs and Medcarib. The titles and abstracts of 24,859 articles were read to select those that match the elegibilty criteria. Five papers that addressed the association of HAART, lipodystrophy and polymorphisms were selected for the review. There was no association between the polymorphisms of the genes APOC3 and PPARG and lipodystrophy. Another study described an association between the variant allele (G) of HFE and protection concerning the development of lipoatrophy (0.02) when compared with the reference allele (C). On the other hand, the variant allele (T) of the ESR2 gene was associated with the development of lipoatrophy (p = 0.007) when compared with the reference allele (C). In addition, the genotype and the variant allele of the gene MMP1 (2G) were associated with lipodystrophy in PLWHIV on HAART (p = 0.0002 and p = 0.0008, respectively). Therefore, further studies with other populations, involving PLWHIV on HAART are necessary to better understand the role of genetic markers, which may be involved in a predisposition to lipodystrophy. Show less

Individuals with mixed dyslipidemia, including high triglycerides (TGs) and low high density lipoprotein cholesterol (HDL-C), have increased risk for coronary events. We examined the effect of rare genetic variants in the APOA5 gene region on plasma HDL-C, apolipoprotein A-I (apoA-I), and TG response to fenofibric acid monotherapy and in combination with statins. The APOA5 gene region was sequenced in 1,612 individuals with mixed dyslipidemia in a randomized trial of fenofibric acid alone and in combination with statins. Student's t-test and rare variant burden tests were used to examine plasma HDL-C, apoA-I, and TG response. Rare APOA5 promoter region variants were associated with decreased HDL-C and apoA-I levels in response to fenofibric acid therapy; rare missense variants were associated with increased TG response to combination therapy. Further study is needed to examine the effect of these rare variants on coronary outcomes in this population in response to fenofibric acid monotherapy or combined with statins. Show less

Atherogenic dyslipidemia is highly associated with coronary heart disease and is characterized by elevated triglycerides (TG), low high-density lipoprotein cholesterol (HDL-C), and elevated low-density lipoprotein cholesterol (LDL-C). The combination of statins and fibrates is a common modality to treat individuals with atherogenic dyslipidemia. We sought to identify single nucleotide polymorphisms (SNPs) associated with HDL-C, TG, and apolipoprotein A1 (ApoA-I) response to combination therapy with statins and fenofibric acid (FA) in individuals with atherogenic dyslipidemia. 2228 individuals with mixed dyslipidemia who were participating in a multicenter, randomized, double-blind, active-controlled study comparing FA alone, in combination with a statin, or statin alone for a 12-week period, were genotyped for 304 candidate SNPs. A multivariate linear regression analysis for percent change in HDL-C, ApoA-I and TG levels was performed. SNPs in the apolipoprotein (APO) A5-ZNF259 region rs3741298 (P = 1.8 × 10(-7)), rs964184 (P = 3.6 × 10(-6)), rs651821 (P = 4.5 × 10(-5)), and rs10750097 (P = 1 × 10(-4)), were significantly associated with HDL-C response to combination therapy with statins and FA, with a similar association identified for ApoA-I. A haplotype composed of the minor alleles of SNPs rs3741298, rs964184, and rs10750097, was associated with a positive response to statins and FA (P = 8.7 × 10(-7)) and had a frequency of 18% in the study population. In a population with atherogenic dyslipidemia, common SNPs and haplotypes within the APOA5-ZNF259 region are highly associated with HDL-C and ApoA-I response to combination therapy with statins and FA. Show less

Packaging of the eukaryotic genome into higher order chromatin structures is tightly related to gene expression. Pericentromeric heterochromatin is typified by accumulations of heterochromatin protein 1 (HP1), methylation of histone H3 at lysine 9 (MeH3K9) and global histone deacetylation. HP1 interacts with chromatin by binding to MeH3K9 through the chromodomain (CD). HP1 dimerizes with itself and binds a variety of proteins through its chromoshadow domain. We have analyzed at the single cell level whether HP1 lacking its functional CD is able to induce heterochromatinization in vivo. We used a lac-operator array-based system in mammalian cells to target EGFP-lac repressor tagged truncated HP1alpha and HP1beta to a lac operator containing gene-amplified chromosome region in living cells. After targeting truncated HP1alpha or HP1beta we observe enhanced tri-MeH3K9 and recruitment of endogenous HP1alpha and HP1beta to the chromosome region. We show that CD-less HP1alpha can induce chromatin condensation, whereas the effect of truncated HP1beta is less pronounced. Our results demonstrate that after lac repressor-mediated targeting, HP1alpha and HP1beta without a functional CD are able to induce heterochromatinization. Show less

Changes in chromatin structure are a key aspect in the epigenetic regulation of gene expression. We have used a lac operator array system to visualize by light microscopy the effect of heterochromatin protein 1 (HP1) alpha (HP1alpha) and HP1beta on large-scale chromatin structure in living mammalian cells. The structure of HP1, containing a chromodomain, a chromoshadow domain, and a hinge domain, allows it to bind to a variety of proteins. In vivo targeting of an enhanced green fluorescent protein-tagged HP1-lac repressor fusion to a lac operator-containing, gene-amplified chromosome region causes local condensation of the higher-order chromatin structure, recruitment of the histone methyltransferase SETDB1, and enhanced trimethylation of histone H3 lysine 9. Polycomb group proteins of both the HPC/HPH and the EED/EZH2 complexes, which are involved in the heritable repression of gene activity, are not recruited to the amplified chromosome region by HP1alpha and HP1beta in vivo targeting. HP1alpha targeting causes the recruitment of endogenous HP1beta to the chromatin region and vice versa, indicating a direct interaction between the two HP1 homologous proteins. Our findings indicate that HP1alpha and HP1beta targeting is sufficient to induce heterochromatin formation. Show less