Objective: To observe the expression changes and relationship of Micro RNA-97a (miRNA-97a) and TGF-β1 protein in the myocardial tissue of spontaneously hypertensive rats (SHR).
Methods: Eight 8-week-old male spontaneously hypertensive rats were selected as the SHR group, and eight 8-week-old male Wistar rats were used as the control group. The rat tail artery blood pressure was measured by the non-invasive blood pressure measurement and analysis system. The femoral artery was measured after 8 weeks. Rats were sacrificed by bloodletting. The morphological changes of rat hearts were observed by HE staining. The expression of miRNA-97a in rat hearts was detected by PCR. TGF-β1, angiotensin Ⅱ (Ang Ⅱ) protein and type I collagen (Col- Ⅰ) and Ⅲ collagen (Col-Ⅲ) protein expression level.
Results: The systolic and diastolic blood pressure in the SHR group were significantly increased, the myocardial CVF and PVCA were significantly increased, the expression levels of TGF-β1 protein, Col-I and Col-III protein were significantly increased, and the expression level of miRNA-97a was significantly decreased. Compared with the control group, the differences were statistically significant (P<0.01). PCR results showed that the expression level of myocardial miRNA-97a in the SHR group was (24.6±4.7)% of that of the control group, and the expression level of miRNA-97a in myocardial tissue in the SHR group was negatively correlated with the expression level of TGF-β1 protein (r=-0.785, P<0.01) .
Conclusion: The expression of miRNA-97a in SHR myocardial tissue is down-regulated, accompanied by an increase in the expression of TGF-β1 protein and an increase in collagen synthesis. miRNA-97a and TGF-β1 may be involved in myocardial fibrosis in SHR rats.