Abstract
Hypertension is a multifactorial syndrome characterized by sustained high levels of blood pressure (BP). Aerobic exercise training (ET) has been used as an important non-pharmacological treatment of hypertension, since it corrects microvascular rarefaction and reduces BP; however, the mechanisms involved are poorly understood. A new class of small RNAs, called microRNAs (miRNAs), has been extensively studied because they regulate their target gene expression at the post-transcriptional level. Studies evaluating the role of miRNAs in the angiogenic process both in hypertension and exercise training are unknown. Based on the profile analysis of miRNA expression by microarray, we selected miRNA-205 for this study to be one of most miRNAs differentially expressed in HA and target a large number of genes involved in the angiogenic process; considered a potential therapeutic target across the vascular damage in the HA. Therefore, we aim to investigate the role of miRNA-205 in reduced angiogenic capacity mediated by signaling FAK/ integrin in spontaneously hypertensive rats (SHR) and check the therapeutic role of ET in correcting these parameters. In the first stage of the project, spontaneously hypertensive rats (SHR) aged 6 months at the beginning of the protocol and the respective controls Wistar Kyoto (WKY) will be divided into four experimental groups (n = 7/ group): SHR, trained SHR (SHR -T), WKY and trained WKY (WKY-T). The swimming ET will consist of 10-week, 1x day/ 5x a week/ 10 weeks. They will be analyzed BP and resting hear rate by tail plethysmography, the ability to exercise tolerance and VO2 peak post ET. After sacrifice, the morphological analysis will be made of the soleus muscle as the cross-sectional area, capillary to fiber ratio and profile of fiber types by histochemical method. Analyzes shall be performed miRNA-205 expression and their targets related to the control of the angiogenic process and vascular integrity. In the second stage of the project, we evaluate gain and loss of function of endothelial cell (HUVEC) in vitro by transfection antagomiR/ miRmimic-205 or a mismatched oligonucleotide with the miRNA studied as a control (scramble) on the proliferation, migration and formation of capillary tubes on matrigel; and expression of miRNA-205 and its target genes validated and predicted. The validation of Itga5 target gene will be held for miRNA-205 through the luciferase assay and analysis of protein expression of FAK mediated by integrin signaling. In the third stage, we evaluate the angiogenic response in aortic rings of WKY and SHR ex vivo by transfection antagomiR/ miRmimic-205 and FAK inhibitor. So, we will test the hypothesis of participation of miRNA-205 in regulating the angiogenic process, which could be further used as a therapeutic source for HA.
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