Luteolin Inhibits Vascular Smooth Muscle Cell Proliferation and Migration by Inhibiting TGFBR1 Signaling.

Yu-Ting Wu,Bin Liu,Ling-Peng Xie,Ling Chen,Jun Li,Hui-Jie Fan,Ying-Chun Zhou,Hong-Mei Chen,Zhang-Bin Tan,Wen-Tong Zhang

doi:10.3389/fphar.2018.01059

Abstract

Vascular smooth muscle cell (VSMC) proliferation and migration play a critical role in the development of arterial remodeling during various vascular diseases including atherosclerosis, hypertension, and related diseases. Luteolin is a food-derived flavonoid that exerts protective effects on cardiovascular diseases. Here, we investigated whether transforming growth factor-β receptor 1 (TGFBR1) signaling underlies the inhibitory effects of luteolin on VSMC proliferation and migration. We found that luteolin reduced the proliferation and migration of VSMCs, specifically A7r5 and HASMC cells, in a dose-dependent manner, based on MTS and EdU, and Transwell and wound healing assays, respectively. We also demonstrated that it inhibited the expression of proliferation-related proteins including PCNA and Cyclin D1, as well as the migration-related proteins MMP2 and MMP9, in a dose-dependent manner by western blotting. In addition, luteolin dose-dependently inhibited the phosphorylation of TGFBR1, Smad2, and Smad3. Notably, adenovirus-mediated overexpression of TGFBR1 enhanced TGFBR1, Smad2, and Smad3 activation in VSMCs and partially blocked the inhibitory effect of luteolin on TGFBR1, Smad2, and Smad3. Moreover, overexpression of TGFBR1 rescued the inhibitory effects of luteolin on the proliferation and migration of VSMCs. Additionally, molecular docking showed that this compound could dock onto an agonist binding site of TGFBR1, and that the binding energy between luteolin and TGFBR1 was -10.194 kcal/mol. Simulations of molecular dynamics showed that TGFBR1-luteolin binding was stable. Collectively, these data demonstrated that luteolin might inhibit VSMC proliferation and migration by suppressing TGFBR1 signaling.

Highlights

Atherosclerosis is a chronic inflammatory disease of the arteries and is the leading cause of morbidity and mortality worldwide (Weber and von Hundelshausen, 2017)
These results indicated that luteolin inhibited Vascular smooth muscle cell (VSMC) proliferation without inducing apoptosis
Su et al (2015) reported that luteolin effects decline in media thickness of vascular wall and attenuates hypertensive vascular remodeling through inhibiting the proliferation and migration of VSMCs

Summary

Introduction

Atherosclerosis is a chronic inflammatory disease of the arteries and is the leading cause of morbidity and mortality worldwide (Weber and von Hundelshausen, 2017). Recent evidence indicates that abnormal VSMC proliferation and migration play a vital role in the pathologies and development of AS. Suppressing the proliferation and migration of these cells could play an important role in preventing the pathological process of AS and might become a novel therapeutic strategy. Preclinical in vitro and in vivo studies have provided reasonable evidence of the cardioprotective effects of luteolin (Lopez-Lazaro, 2009). Previous studies have demonstrated that luteolin treatment inhibits the proliferation of VSMCs (Lang et al, 2012; Jiang et al, 2013; Xu et al, 2015). The underlying mechanisms associated with its inhibitory effects on VSMC proliferation and migration are still unclear

Methods

Results

Conclusion