PM2.5 inducing myocardial fibrosis mediated by Ang II/ERK1/2/TGF-β1 signaling pathway in mice model

Objects: To discuss the influence of PM2.5 on myocardial fibrosis and related mechanism. Methods: PM2.5 particles were prepared into different concentrations of solution to drip into the mice's trachea twice each week. The mice were divided into five groups, Blank control group (C group), NS control group (J group), high dose group (G group, 10 mg/kg), medium dose group (Z group, 5 mg/kg), and 1ow dose group (D group, 2.5 mg/kg). After 6 weeks, the myocardial fibrosis was observed by HE and Masson staining. The expression of Ang II, ERK1/2, and TGF-beta(1) was examined by Western Blotting (WB) and Real time PCR (RT-PCR). Results: The higher dose PM2.5 was administrated, the worse the myocardial fibrosis was in PM2.5 groups. The expression of Ang II, ERK1/2, and TGF-beta(1) was increased in higher dose groups in protein and mRNA level. Conclusion: 1. PM2.5 induced the cardiac fibrosis. 2. PM2.5 dripped into trachea in mice model activated the expression of Ang II, ERK1/2, and TGF-beta(1). The activation of renin-angiotensin system (RAS) was suggested to participate in the cardiac fibrosis induced by PM2.5.