Oxymatrine inhibits aldosterone-induced rat cardiac fibroblast proliferation and differentiation by attenuating smad-2,-3 and-4 expression: an in vitro study.

Lingyun Fu,Yanyan Zhang,Yini Xu,Ling Tu,Ling Tao,Xiangchun Shen,Haifeng Huang,Yan Chen

doi:10.1186/s12906-016-1231-9

Lingyun Fu, Yanyan Zhang + Show 6 more

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https://doi.org/10.1186/s12906-016-1231-9

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Abstract

BackgroundWe previously demonstrated oxymatrine, an alkaloid from the Chinese medicine radix Sophorae flavescentis, ameliorates hemodynamic disturbances and cardiac fibrosis; however, the underlying mechanisms are unclear. Here, we investigated the effect and mechanism of action of oxymatrine on aldosterone-induced cardiac fibroblast to myofibroblast differentiation in vitro.MethodsCardiac fibroblasts were isolated purified from neonatal Sprague Dawley rats. The optimal concentration of aldosterone to stimulate cardiac fibroblast proliferation was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cardiac fibroblasts were pretreated with 7.57 × 10−4 mol/L or 3.78 × 10−4 mol/L oxymatrine or without oxymatrine for 2 h, and then coincubated with 1 × 10−8 mol/L aldosterone for 48 h. The MTT assay and Masson staining were used to detect the cardiac fibroblast proliferation and myofibroblast differentiation. The secretion of type I and III collagen was measured by commercial ELISA kits, and the hydroxyproline content was determined by the colorimetric assay. Western blotting assayed the Smad-2, Smad-3, and Smad-4 protein expression in cardiac fibroblasts.Results The present results confirmed that aldosterone induced cardiac fibroblast to myofibroblast proliferation and differentiation. The MTT assay and Masson staining indicated oxymatrine significantly inhibited aldosterone-induced cardiac fibroblast proliferation and myofibroblast differentiation. Oxymatrine significantly inhibited aldosterone-induced secretion of type I and III collagen, as indicated by commercial ELISA kits, and aldosterone-induced increase in hydroxyproline content, as indicated by a colorimetric assay. Western blotting revealed oxymatrine attenuated aldosterone-induced Smad-2, Smad-3, and Smad-4 expression in cardiac fibroblasts.ConclusionOxymatrine can inhibit cardiac fibroblast proliferation and differentiation into myofibroblasts via a mechanism linked to attenuation of the Smad signaling pathway.

Highlights

We previously demonstrated oxymatrine, an alkaloid from the Chinese medicine radix Sophorae flavescentis, ameliorates hemodynamic disturbances and cardiac fibrosis; the underlying mechanisms are unclear
It is well recognized that cardiac remodeling, the final pathophysiological process of cardiovascular diseases [3], is characterized by three phases: cardiomyocyte hypertrophy and apoptosis, proliferation and differentiation of cardiac fibroblasts, and extracellular matrix deposition
Ltd., Shanghai, China; ALD was from Fluka, Switzerland; Trypsin was from Solarbio, Beijing, China; Dulbecco’s modified Eagle’s medium (DMEM) was from GIBCO, Gaithersburg, USA; Penicillin and streptomycin were from Sigma, St

Summary

Introduction

An alkaloid from the Chinese medicine radix Sophorae flavescentis, ameliorates hemodynamic disturbances and cardiac fibrosis; the underlying mechanisms are unclear. We investigated the effect and mechanism of action of oxymatrine on aldosterone-induced cardiac fibroblast to myofibroblast differentiation in vitro. Cardiovascular diseases are a serious threat to health and are the leading cause of death in humans [1, 2]. The mechanisms leading to cardiovascular diseases and novel drug treatments have undergone intensive research. It is well recognized that cardiac remodeling, the final pathophysiological process of cardiovascular diseases [3], is characterized by three phases: cardiomyocyte hypertrophy and apoptosis, proliferation and differentiation of cardiac fibroblasts, and extracellular matrix deposition. Most drugs in clinical application aim to prevent cardiomyocyte hypertrophy and apoptosis, including angiotensin converting enzyme inhibitors, beta-receptor blockers and calcium antagonists. The key pathological changes during cardiac remodeling involve cardiac fibroblasts (CFs), especially CF differentiation into myofibroblasts. The differentiation of CFs results in increased secretion and deposition of myocardial collagen, which induces myocardial stiffness and myocardial diastolic and systolic dysfunction [4,5,6]

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