Role of the secretory PLA2-IB and PLA2R in human podocyte injury and its possible mechanism / 中华肾脏病杂志

ABSTRACT

Objective To investigate the role of the group IB secretory phospholipase A2 (sPLA2-IB) and M-type phospholipase A2 receptor (PLA2R) in human podocyte injury and its possible signal transduction pathway.Methods Differentiated human podocytes were exposed to PBS or different sPLA2-IB concentration conditions (10-9,10-7,10-5 mol/L) for 2 hours.The wound healing assay was used to measure cell migration rate;Apoptosis in cultured human podocytes was assessed by Hoechst 33342 staining and flow cytometry;Western blot was used to analyze the protein expression of p-cPLA2α,p-p38,and p53.Then control siRNA or PLA2R siRNA were transfected to podocytes.Podocytes were divided into normal control group,negative control siRNA group and PLA2R siRNA group.Twenty four hous later,the cells were stimulated by 105 mol/L sPLA2-IB for 2 hours.The protein expression of p-cPLA2α,p-p38,and p53 were detected by Western blot.Results Compared to PBS control group,the migration ability of podocytes decreased when stimulated with sPLA2-IB (10-7mol/L-10-5 mol/L),and the apoptosis of podocytes increased in a concentration-dependent manner,the protein level of p-cPLA2α,p-p38 and p53 protein increased too.After the knockdown of PLA2R by PLA2R siRNA transfection,stimulated the podocytes with the same dosage of sPLA2-IB,the protein expression of p-cPLA2α,p-p38 and p53 all decreased.Conclusion sPLA2-IB stimulation can increase human podocyte apoptosis and decrease its migration ability.The possible mechanism might be through p38-cPLA2α-p53 pathway.