Anti-Fibrosis Effect of Relaxin and Spironolactone Combined on Isoprenaline-Induced Myocardial Fibrosis in Rats via Inhibition of Endothelial–Mesenchymal Transition

Abstract

Background: The effect of relaxin and spironolactone combined on myocardial fibrosis has not been reported. Thus, we investigated the effect of the combined therapy on isoprenaline-induced myocardial fibrosis and the mechanism. Methods: Rats were injected subcutaneously with isoprenaline to induce myocardial fibrosis and underwent subcutaneous injection with relaxin (2 µg·kg^-1·d^-1) and given a gavage of spironolactone (30 mg·kg^-1·d^-1) alone or combined for 14 days. In vitro, the endothelial–mesenchymal transition was induced with transforming growth factor β (TGF-β) in human umbilical vein endothelial cells (HUVECs) pretreated with relaxin, 200 ng/ml, and/or spironolactone, 1uM. Results: Relaxin and spironolactone used alone or combined improved cardiac function and decreased cardiac weight indices; reduced fibrous tissue proliferation; reduced levels of type I and III collagen; decreased the expression of α–smooth muscle actin (α-SMA) and transforming growth factor-β1 (TGF-β1), and increased the expression of cluster of differentiation-31 (CD31) in rats with isoprenaline-induced myocardial fibrosis. In vitro, compared with TGF-β treatment, relaxin and spironolactone used alone or combined with TGF-β decreased cell mobility, α-SMA and vimentin levels but increased vascular endothelial cadherin (VE-cadherin) and endothelial CD31levels. Especially, combined therapy had more remarkable effect than relaxin and spironolactone used alone both in vitro and in vivo. Conclusion: Relaxin and spironolactone combined affected isoprenaline-induced myocardial fibrosis in rats that the mechanism might be inhibition of the cardiac endothelial–mesenchymal transition.

Ginsenoside Rh2 Improves Cardiac Fibrosis via PPARδ–STAT3 Signaling in Type 1-Like Diabetic Rats

“…The cardiac performance (+dP/dt max and −dP/dt max ) in the normal rats indicated responses consistent to a previous report [ 24 ]. Furthermore, the cardiac performance significantly decreased in the diabetic rats compared with the normal rats, and Rh2 treatment restored the dP/dt max in the diabetic rats ( Table 1 ).…”

Low-Intensity Pulsed Ultrasound Prevents the Oxidative Stress Induced Endothelial-Mesenchymal Transition in Human Aortic Endothelial Cells

“…EndMT is a type of EMT (Epithelial-mesenchymal transition) that specifically refers to vascular/cardiac endothelial cells undergoing mesenchymal transition [12, 36-39], which contributes to angiopoiesis and pathological fibrosis mainly in human vascular diseases [40]. EndMT can be induced by multiple factors via several interactive signaling pathways.…”

Relaxin and extracellular matrix remodeling: Mechanisms and signaling pathways

“…Similar to cardiac myofibroblasts, serelaxin also inhibited TGF-β1-induced mobility of endothelial cells through a Notch-1-dependent pathway, and increased expression of CD31 while decreasing vimentin content of human umbilical vein endothelial cells (HUVECs) in vitro (Zhou et al, 2015). In a separate study, serelaxin was capable of reducing cardiac fibrosis in vivo via the inhibition of EndMT, and by increasing VE-cadherin and CD31 levels while suppressing vimentin and α-SMA levels in HUVECs in vitro (Cai et al, 2017). While these combined findings suggest that relaxin inhibits myofibroblast-mediated aberrant ECM synthesis and deposition at multiple levels, further studies are required to fully understand the detailed mechanisms underlying its potent antifibrotic actions in various tissues and organs for future therapeutic applications.…”

“…Recent studies showed that serelaxin inhibits EndMT within the heart and kidney of isoprenaline-induced cardiomyopathy in rodents (Cai et al, 2017;Zheng et al, 2017). Zhou et al found that serelaxin improves cardiac function in rats with myocardial fibrosis, by reducing EndMT and interstitial collagens I and III, while increasing the microvascular density of the heart (Zhou et al, 2015).…”