Inhibition of Testudinis Carapax et Plastrum extracts targeting BMP4 pathway on PC12 cell apoptosis

Objective To observe the protection of Testudinis Carapax et Plastrum extracts(TCPE) on serum starvation-induced PC12 cell apoptosis and explore its mechanism.Methods The PC12 apoptosis model was established by serum starvation for 3 d.The cells were randomly divided into four groups: control group,model group,low-dose and high-dose(3 and 30 μg/mL) TCPE groups.In the three days of the treatment,cell absorbance was determined by MTT,ratio of cell apoptosis was examined by Annexin V/PI double stain flow cytometry(FCM),Caspase-3,BMP4,BMPR-IA,and p-Smad1/5/8 signaling molecular expression were detected by Western blotting,and the anti-apoptotic effect of TCPE was observed after blocking BMPs signal pathway.Semi-quantitative analysis of bands was carried out by Bio-Rad Quantity One gel analysis system.Results MTT and FCM analyses demonstrated that TCPE could increase PC12 cell viability and decrease their apoptotic ratios in a dose dependent manner.Western blotting results showed that TCPE could decrease Caspase-3 expression,promote the expression of BMP4,BMPR-IA,and p-Smad1/5/8.There was statistically significant difference between TCPE(3 and 30 μg/mL) groups and model group(P0.05,P0.01) in all above results.While TCPE had no effect on the expression of BMP2,BMP7,and BMPR-II.BMPR-IB hadn’t been detected.The anti-apoptotic activity was partially mitigated by neutralizing BMP4 antibody.Conclusion TCPE has the capacity to inhibit the apoptosis of PC12 induced by serum starvation in a dose dependent manner and its mechanism may be associated with partially activating and up-regulating the expression of BMP4 signaling pathway.