A negative correlation between hsa-miR29a-3p level and HIV-1 viral load in human serum; potentiate criteria for patients screening

Human Immunodeficiency Virus type-1 (HIV-1) causes persistent and life-threatening infection, leading to progressive disease. MicroRNAs (miRNAs) are regulators of gene expression which can be found in circulating human blood samples. hsa-miR-29a-3p has been identified as a potential regulator of the Negative Regulatory Factor (Nef) gene from the HIV-1 viral genome. In this study, we aimed to compare the serum levels of hsa-miR-29a-3p with HIV-1 viral load in a substantial number of infected individuals. We collected serum samples from a total of 48 participants, including 36 untreated HIV-positive patients, and 12 HIV-negative individuals as a control group, matched for age and sex. The HIV-1 viral load in both the case and control groups was confirmed using qRT-PCR. Subsequent qRT-PCR analysis of circulating hsa-miR-29a-3p levels revealed lower miRNA expression in the groups with higher viral loads. A negative correlation (r = -0.58) was calculated between hsa-miR-29a-3p levels and HIV-1 viral load. These findings suggest that the expression level of hsa-miR-29a-3p may serve as an indicator of HIV-1 viral load in human serum samples. Additionally, this miR may hold promise as a potential tool for enhancing HIV-1 treatment strategies.

Modulation of ALDH5A1 and SLC22A7 by microRNA hsa-miR-29a-3p in human liver cells

Observed variations in drug responses among patients may result from differences in heritable genetic traits or from alterations in the epigenetic regulation of drug metabolizing enzymes and transporters (DMETs). MicroRNAs (miRNAs), a group of small non-coding RNAs, provide an epigenetic mechanism for fine-tuning the expression of targeted DMET genes by regulating the efficiency of protein translation and by decreasing mRNA stability via enhanced degradation. In the current study we systematically screened 374 important genes encoding DMETs for potential response elements to hsa-miR-29a-3p, a highly abundant miRNA in human liver. RNA electrophoresis mobility shift assays displayed direct interactions between hsa-miR-29a-3p and its cognate targets within the mRNA transcripts for the ABCC6, SLC22A7 and ALDH5A1 genes. The expression of luciferase reporter genes containing the 3'-UTRs of SLC22A7 or ALDH5A1 and the expression of endogenous SLC22A7 and ALDH5A1 were each suppressed by transfection with hsa-miR-29a-3p mimics. Importantly, chemically-induced up-regulation of hsa-miR-29a-3p correlated inversely with the expression of SLC22A7 and ALDH5A1. However, our studies failed to detect suppressive effects of hsa-miR-29a-3p on ABCC6 expression, which might be explained by the notion that the interaction of hsa-miR-29a-3p and ABCC6 mRNA was unable to recruit ribonucleoproteins to form a RNA-induced silencing complex.

MicroRNA hsa-miR-29a-3p modulates CYP2C19 in human liver cells

Cytochrome P450 2C19 (CYP2C19) is involved in the metabolism of many drugs. Extensive studies have demonstrated that genetic variants and endogenous and environmental factors play important roles in the expression of CYP2C19. However, the role of microRNAs (miRNAs) in controlling CYP2C19 expression has not been investigated completely. In the present study, we performed in silico analysis to rank putative miRNA/CYP2C19 hybrids with regards to the predicted stabilities of their duplexes and then we applied a series of biochemical and molecular assays to elucidate the underlying functional mechanisms for the regulation of CYP2C19 by miRNAs. In silico analysis indicated that hsa-miR-23a-3p and hsa-miR-29a-3p target the coding region of CYP2C19 with hybrid stabilities of -27.5kcal/mol and -23.3kcal/mol, respectively. RNA electrophoresis mobility shift assays showed that both hsa-miR-23a-3p and hsa-miR-29a-3p miRNAs were able to bind directly to their cognate targets in the CYP2C19 transcript. Further, a significant inverse correlation was found between chemically-induced up-regulation of hsa-miR-29a-3p and CYP2C19 expression in HepaRG cells. In addition, inverse correlations were also observed in human liver tissue samples between the level of CYP2C19 mRNA expression and both hsa-miR-23a-3p and hsa-miR-29a-3p levels. All these results demonstrated the suppressing role of hsa-miR-29a-3p on CYP2C19 expression.