The effects of qindan-capsule-containing serum on the TGF-β1/ERK signaling pathway, matrix metalloproteinase synthesis and cell function in adventitial fibroblasts

Abstract

Context: Qindan capsule (QC), a compound used in traditional Chinese medicine, has been used as an anti-hypertensive agent in clinical settings for years. Our previous studies have shown that QC can improve the morphological index of the artery, down-regulate the collagen volume fraction in the media and inhibit the transformation of smooth muscle cells. However, the detailed mechanisms underlying its effects require further investigation, which might provide more scientific evidence for the clinical treatment of hypertensive vascular remodeling (VR).Objective: We investigated the effects of QC-containing serum on the TGF-β1/ERK signaling pathway, cell proliferation, migration, the cell cycle, apoptosis and matrix metalloproteinase synthesis (MMPs) in rat aortic adventitial fibroblasts (AFs).Materials and methods: AFs were cultured through tissue explants in vitro. The levels of extracellular signal-regulated kinase 1/2 (ERK1/2), phospho-ERK1/2 (p-ERK1/2), connective tissue growth factor (CTGF), MMP2 and MMP9 expression were measured by western blotting and RT-PCR. The proliferation and migration of AFs were measured by MTT and transwell migration assays. Cell cycle progression and apoptosis in AFs were analyzed by flow cytometry.Results: The proliferation and migration rates of AFs treated with transforming growth factor β1 (TGF-β1) for 24 h were 2.4 ± 0.75 and 2.2 ± 0.06 times higher than those of untreated AFs, and increases in the expression of p-ERK1/2 (3.7 ± 0.15 times), CTGF (3.3 ± 0.24 times), MMP2 (5.7 ± 0.37 times) and MMP9 (5.4 ± 0.46 times) (p < 0.05) were observed. Treatment with QC-containing serum significantly down-regulated cell proliferation (1.9 ± 0.06 times), migration (1.6 ± 0.05 times) and the expression of p-ERK1/2 (1.3 ± 0.75 times), CTGF (1.8 ± 0.64 times), MMP2 (1.6 ± 0.65 times) and MMP9 (1.4 ± 0.46 times) (p < 0.05). We also found that QC-containing serum down-regulated the percentage of cells in the G1 phase by 1.6 ± 0.43 times and increased early-phase apoptosis by 2.3 ± 0.33 times (p < 0.05) in AFs.Conclusions: QC effectively inhibits the proliferation and migration of AFs and changes cell bioactivity and MMPs, possibly through the TGF-β/ERK/CTGF signaling pathway. Our findings may provide new insights into the potential function of QC in preventing or treating hypertension.