Experimental Study Of Effects Of Simvastatin And Ligustrazine On TNF-α-induced T-PA And PAI-1Expressions In Cultured Human Peritoneal Mesothelial Cells

Background Peritoneal fibrosis (PF) is a serious complication in long-term Peritoneal dialysis(PD) patients, which is characterized by extracellular matrix (ECM) accumulation in human peritoneal mesothelial cells (HPMCs). Previous studies have demonstrated that recurrent episodes of peritonitis produce inflammatory mediators, which can induce the accumulation of extracellular matrix, eventually leading to peritoneal fibrosis. The expression of t-PA and PAI-1plays an important role in this process.Objective This study was to investigate the effects of ligustrazine and simvastatin on TNF-a-induced tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor-1(PAI-1) expressions in human peritoneal mesothelial cells (HPMCs).Methods HPMCs were isolated from human omenta by trypsin digestion method and subcultured. After synchronization of cells growth, HPMCs were divided into normal control group, TNF-a-induced group, TNF-a-induced plus low-, medium-and high-dose Simvastatin (2.5,5and10μmol/L Simvastatin respectively) groups, TNF-a-induced plus low-, medium-and high-dose Ligustrazine (10,20and40mg/L Ligustrazine respectively) groups. The viability of HPMCs was measured by MTT assay. Semi-quantitative reverse transcriptive-polymerase chain reaction (RT-PCR) was used to detect the mRNA expressions of t-PA and PAI-1in HPMCs. Protein levels of t-PA and PAI-1in culture supernatants were measured by enzyme linked immunosorbent assay (ELISA). Cells protein concentration measured by trace BCA method was to correct the ELISA assay results.Results①Significant decreased cell viability, increased PAI-1and decreased expresssions in HPMCs were observed in TNF-a-induced group compared with those in normal control group (P<0.01).②To compared with TNF-a-induced group, Simvastatin could significantly ameliorate the viability of HPMCs inhibited by TNF-a-induced conditions (P<0.01). In addition, Simvastatin significantly decreased PAI-1and increased t-PA expressions in HPMCs in a dose-dependent manner both in protein and gene levels (P<0.01).③To compared with TNF-a-induced group, Ligustrazine also significantly ameliorate the viability of HPMCs cultured under TNF-a-induced conditions (P<0.01). What’s more, Ligustrazine significantly decreased PAI-1expressions and increased t-PA in HPMCs in a dose-dependent manner both in protein and gene levels (P<0.01).④To compared with TNF-a-induced group, the viability of HPMCs was significantly increased and marked low levels of TGF-β1and bFGF expressions were observed in cocultured group (P<0.01). However, there were no such significant changes in cocultured group to compared with those in high-dose Simvastain group and high-dose Ligustrazine group (P>0.05).Conclusion Simvastatin and Ligustrazine could decrease TNF-a-induced PAI-1and increase t-PA expressions and ameliorate the viability of HPMCs cultured under TNF-a-induced conditions in vitro, which may demonstrate that Simvastatin and Ligustrazine take role of protecting HPMCs and decreasing the accumulation of ECM on peritoneum, and thus preventing and/or delaying the process of PF in patients with CAPD.