MICRORNA PROFILE IN HUMAN VASCULAR SMOOTH MUSCLE CELLS FROM HYPERTENSIVE SUBJECTS: FOCUS ON OXIDATIVE AND ENDOPLASMIC RETICULUM STRESS

Abstract

Listen

Translate article

Objective: miRNAs are important to phenotypic control and function of vascular smooth muscle cells (VSMC). miRNA dysregulation is associated with vascular dysfunction, which involves oxidative and endoplasmic reticulum (ER) stress. We assessed VSMC miRNA profile in human hypertension focusing on oxidative and ER stress pathways. Design and method: VSMCs from small arteries from normotensive (NT) and hypertensive (HT) subjects were used. miRNA profiling of 758 miRNAs was performed using TaqMan advanced miRNA assay (TaqMan Low Density Array Human microRNA). Expression of vascular genes and proteins was detected by RT-PCR and immunoblotting respectively. Ingenuity Pathway Analysis (IPA) was used for miRNA target prediction (high predicted results). Results: miRNA array identified 25 miRNAs uniquely expressed in HT and 21 miRNAs uniquely expressed in NT (CT < 30). Of the 332 miRNAs present in both HT and NT, 60 miRNAs were significantly upregulated in HT (fold change >1.5), 136 miRNAs were significantly downregulated in HT (fold change >1.5). In HT, mRNA levels of Nox1 (1.71 fold) and protein levels of Nox4 (1.59 fold) and Nox5 (2.04 fold) were increased, p < 0.05. SOD2 (4.43 fold) and GPx1 (1.97 fold) protein expression were upregulated in HT, p < 0.05. PERK (1.57 fold) and elF2a (2.31 fold) protein levels were increased in HT, while ERO1A expression was decreased in HT (2.36 fold), p < 0.05. IPA was performed for the genes differentially expressed in HT compared to NT. After inversely pairing the miRNAs to the changes observed in gene and proteins expression, miR-505–5p (-2.13 fold), miR-324-5p (-1.51 fold), miR-185-5p (-1.742) and miR-491-5p (-1.667), which are predicted to target Nox5, were downregulated. miR-185-5p and miR-491-5p together with, miR-125a-3p (-2.04 fold) and miR-634 (unique in NT, CT = 27.36) were predicted to target GPx1. ER stress was also targeted by downregulated miRNAs in HT, such as miR-200b-3p (-28.57 fold), predicted to target elF2a. Conclusions: We identify a cluster of downregulated miRNAs in human hypertension that are linked to pathways that regulate oxidative and ER stress. These findings provide new molecular insights into processes underlying VSMC redox-sensitive dysfunction and may elucidate vascular miRNA signatures in human hypertension.