Effect of Notch Signal and Autophage on MTA induced Proliferation of Human Dental Pulp Cells in Vitro / 现代生物医学进展

ABSTRACT

Objective:Mineral trioxide aggregate (MTA),a wildly used pulp capping material,could affect the proliferation and differentiation of dental pulp cells.The aim of this study is to study the roles of Notch signalling and autophagy in MTA induced human dental pulp cells (hDPCs) proliferation promotions.Methods:Healthy human third molars were collected and hDPCs were isolated by a combined digestion of collagenase Ⅰ and dispase Ⅱ.MTA extracts of different concentrations (0.5,1.0,2.0,5.0,10.0 mg/mL) were used to test the cytotoxicity by cells counting kit (CCK-8) assays and to select the optimum concentration for hDPCs survival..Expressions of Notch1,Hes1,LC3Ⅱ / Ⅰ and p62 in wild type and MTA treated hDPCs were detected by western blotting.Results:MTA extracts in a concentration of 1.0 mg/mL exerted most profoundly promotion effects on the proliferation of hDPCs among all concentrations tested.MTA of high concentration (10 mg/mL) was toxically to cells.Compared with that of wild type hDPCs,the expressions of Notch1 and Hes1(P＜0.05),or p62 and LC3Ⅱ/Ⅰ (P＜0.01) in MTA treated hDPCs were significantly increased.Much lower expression of Notch1 was detected in hDPCs when autophagy was induced by Earle's balanced salt solution (EBSS) starvation for 24 h.Conclusions:MTA could up-regulated hDPCs proliferation with highly relevant in stimulating Notch1-Hes1 signalling and inhibition of autophagy.The study is supposed to provide new insight in unrevealing the mechanisms of MTA mediated dental pulp cells proliferation.