MicroRNA-195-5p Downregulation Inhibits Endothelial Mesenchymal Transition and Myocardial Fibrosis in Diabetic Cardiomyopathy by Targeting Smad7 and Inhibiting Transforming Growth Factor Beta 1-Smads-Snail Pathway

Abstract

Diabetic cardiomyopathy (DCM) is a complication of diabetes mellitus, which is associated with fibrosis and microRNAs (miRs). This study estimated the mechanism of miR-195-5p in endothelial mesenchymal transition (EndMT) and myocardial fibrosis in DCM. After the establishment of DCM rat models, miR-195-5p was silenced by miR-195-5p antagomir. The cardiac function-related indexes diastolic left ventricular anterior wall (LVAW, d), systolic LVAW (d), diastolic left ventricular posterior wall (LVPW, d), systolic LVPW (d), left ventricular ejection fraction (LVEF), and fractional shortening (FS) were measured and miR-195-5p expression in myocardial tissue was detected. Myocardial fibrosis, collagen deposition, and levels of fibrosis markers were detected. Human umbilical vein endothelial cells (HUVECs) were exposed to high glucose (HG) and miR-195-5p was silenced. The levels of fibrosis proteins, endothelial markers, fibrosis markers, EndMT markers, and transforming growth factor beta 1 (TGF-β1)/Smads pathway-related proteins were measured in HUVECs. The interaction between miR-195-5p and Smad7 was verified. In vivo, miR-195-5p was highly expressed in the myocardium of DCM rats. Diastolic and systolic LVAW, diastolic and systolic LVPW were increased and LVEF and FS were decreased. Inhibition of miR-195-5p reduced cardiac dysfunction, myocardial fibrosis, collagen deposition, and EndMT, promoted CD31 and VE-cadehrin expressions, and inhibited α-SMA and vimentin expressions. In vitro, HG-induced high expression of miR-195-5p and the expression changes of endothelial markers CD31, VE-cadehrin and fibrosis markers α-SMA and vimentin were consistent with those in vivo after silencing miR-195-5p. In mechanism, miR-195-5p downregulation blocked EndMT by inhibiting TGF-β1-smads pathway. Smad7 was the direct target of miR-195-5p and silencing miR-195-5p inhibited EndMT by promoting Smad7 expression. Collectively, silencing miR-195-5p inhibits TGF-β1-smads-snail pathway by targeting Smad7, thus inhibiting EndMT and alleviating myocardial fibrosis in DCM.

Coordinated regulation of gene expression and microRNA changes in adipose tissue and circulating extracellular vesicles in response to pioglitazone treatment in humans with type 2 diabetes

“…Therefore, reduced circulating EV-miR-195-5p could contribute to reduced liver fibrosis [as observed after pioglitazone treatment in a model of rat liver cirrhosis ( 49 )] and/or reduced liver steatosis, inflammation, and ballooning [as observed after pioglitazone treatment in NAFLD patients with prediabetes or T2D ( 50 )]. On the other hand, in rat models of diabetic cardiomyopathy (DCM), inhibition of the elevated levels of miR-195-5p reduced cardiac dysfunction, myocardial fibrosis, collagen deposition, and endothelial mesenchymal transition ( 51 ). Thus, the reduced circulating EV-miR-195-5p after pioglitazone treatment in humans with T2D could mechanistically contribute to the improved cardiovascular outcomes observed after treatment with the drug in these patients ( 52 ).…”

The Profile of Circulating Blood microRNAs in Outpatients with Vulnerable and Stable Atherosclerotic Plaques: Associations with Cardiovascular Risks

“…In studies of heart failure [ 63 ] and myocardial hypertrophy [ 64 ], miR-195 levels increase with disease progression, while there is no common understanding of the direct role of this miRNA. Thus, the researchers Okada et al and Ding et al, in their studies on biological models, draw diametrically opposite conclusions about the need to inhibit or stimulate the expression of miR-195-5p for heart failure treatment [ 65 , 66 ], and Cheng et al propose to use miR-195-5p as a treatment for ischemic and hemorrhagic strokes [ 67 ].…”

Mechanism of action of non-coding RNAs and traditional Chinese medicine in myocardial fibrosis: Focus on the TGF-β/Smad signaling pathway

“…EndMT is a cellular transdifferentiation program, in which endothelial cells partially lose their endothelial properties and acquire mesenchymal-like characteristics, thereby promoting the development of cardiac fibrosis. Partial miRNAs improve the endothelial dysfunction and inhibit EndMT by blocking the TGF-β/Smad signaling pathway, which makes for the inhibition of cardiac fibrosis development ( Ding et al, 2021 ). According to Ding et al, the miR-195-5p expression is upregulated in DCM rat myocardium and HG-induced human umbilical vein endothelial cells (HUVEC), and the inhibition of miR-195-5p reduces the EndMT in DCM rats and HG-induced EndMT in HUVEC.…”