Mechanism of FTO-mediated and m6A-modified PRKD2 Inhibiting Podocyte Injury in Diabetic Kidney Disease through the SIRT1/HIF-1 Pathway / 现代检验医学杂志

ABSTRACT

Objective To explore the regulatory role of fat mass and obesity-associated protein(FTO)and serine-threonine kinase protein kinase D2(PRKD2)in progression of diabetic kidney disease(DKD)and its regulatory mechanisms.Methods DKD model in vitro was constructed by podocytes(MPC5 cells)treated with high glucose(HG,35 mmol/L glucose)for 24 h.HG-induced MPC5 cells were transfected with FTO overexpression vector(pcDNA-FTO)and PRKD2 overexpression vector(pcDNA-PRKD2),or empty vector.The overexpression efficiency of FTO and PRKD2 were detected with RT-qPCR.MeRIP was used to detect the N6-methyladenosine(m6A)modification level of PRKD2 mRNA.The activity of Caspase-3 and the secretion of IL-6,TNF-α and monocyte chemotactic protein-1(MCP-1)were detected by ELISA.Cell apoptosis rate was analyzed by flow cytometry.The protein levels of FTO and PRKD2,as well as the key proteins in SIRT1/HIF-1α pathway,were evaluated by Western blot.Pearson analysis was used to analyze the correlation between FTO levels and PRKD2 levels.Results Compared with the control group without HG-induction,the protein expression of FTO(0.51±0.04 vs 1.00±0.03)and PRKD2(0.45±0.03 vs 1.01±0.04)was significantly down-regulated in HG-induced podocytes,and the differences were statistically significant(t=13.17,16.76,all P＜0.001).FTO protein levels were positively correlated with PRKD2 protein levels in HG-induced podocytes(r2=0.705 1,P＜0.001).Compared with the vector group,the m6A levels of PRKD2 mRNA(0.56±0.09 vs 1.01±0.13)in the pcDNA-FTO group were decreased,and the mRNA levels of PRKD2(3.16±0.14 vs 1.03±0.02)were increased,with significant differences(t=51.37,11.82,all P＜0.001).Compared with the control group(IL-6512.76±61.85 pg/ml,TNF-α28.17±2.83 pg/ml,MCP-1157.31±17.69 pg/ml)and the vector group(IL-6498.41±87.51 pg/ml,TNF-α26.35±5.47 pg/ml,MCP-1165.52±16.87 pg/ml),the secretion of IL-6(301.86±21.85 pg/ml),TNF-α(11.06±4.12 pg/ml)and MCP-1(81.45±9.03 pg/ml)were significantly decreased in the pcDNA-PRKD2 group,and the differences were statistically significant(F=7.51,10.47,61.97,all P＜0.01).Compared with the control group(caspase-3 activity689.65±79.5 U/L,cell apoptosis22.31%±2.69%)and the vector group(Caspase-3 activity715.91±113.58 U/L,cell apoptosis21.07%±3.28%),Caspase-3 activity(437.64±104.76 U/L)and the rate of apoptosis(8.41%±3.15%)were significantly decreased in the pcDNA-PRKD2 group,and the differences were statistically significant(F=2.35,79.13,all P＜0.01).Compared with the control group(SIRT11.01±0.05,HIF-1α1.03±0.07)and the vector group(SIRT10.97±0.05,HIF-1α1.02±0.03),SIRT1 protein levels(3.51±0.15)were increased and HIF-1α protein levels(0.37±0.07)were decreased in the pcDNA-PRKD2 group,and the differences were statistically significant(F=31.54,8.31,all P＜0.01).Conclusion FTO-mediated and m6A-modified PRKD2 suppresses inflammation and apoptosis in HG-induced podocytes through the SIRT1/HIF-1 pathway.