Objective To investigate the role of vitamin D receptor (VDR) in the protection of bufalin on podocyte injury induced by adriamycin (ADR).Methods (1) In vitro:the toxic effect of different concentrations of bufalin (10-9,10-8,10-7,104 mol/L) on podocyte was evaluated by lactate dehydrogenase (LDH) test;Annexin V-FITC and RT-PCR were utilized for podocyte apoptosis and VDR mRNA level respectively.Western blotting was used to analyze the protein expression of VDR and nephrin.SiRNA intervene was also applied to evaluate the role of VDR in bufalin's protective effect on podocyte injury induced by ADR.(2) In vitro:24 SD rats were randomly divided into three groups:control group,ADR group and ADR+bufalin group.TUNEL assay was applied to detect the apoptosis of podocytes in the kidney.Immunofluorescence and transmission electron microscope (TEM) were applied to analyze the expression of VDR and the ultrastructure of the glomerulus.Results Bufalin concentration lower than 10-7 mol/L had no toxicity on normal podocyte.Bufalin reduced the urinary protein excretion (P ＜ 0.05),alleviated the removal of podocyte foot processes and attenuated the changes in nephrin expression in the glomerulus of the adriamycin (ADR) rats (P ＜ 0.05).Bufalin notably inhibited the down-regulation of VDR in protein levels on the glomerulus of the ADR rats.Additionally,bufalin inhibited the down-regulation of VDR in both mRNA levels and protein levels (P ＜ 0.05),nephrin protein expression (P＜ 0.05),and apoptosis induced by ADR in cultured podocytes.Additionally,VDR specific siRNA intervene abolished the protective effect of bufalin in ADR-induced podocyte injury.Conclusion Bufalin can alleviate ADR-induced podocyte injury via enhancing VDR expression.

Objective To investigate the effect and molecular mechanism of tRF-1:30-Gln-CTG-4(tRF-1:30)on the expression of inflammatory factors in high glucose(HG)-induced renal tubular epithelial cells(RTECs).Methods RTECs were divided into the control group,the HG group,the HG+tRF-1:30 mimic group,the HG+tRF-1:30 negative control(NC)group,the HG+si-IKZF2 group and the HG+si-NC group.Real-time quantitative polymerase chain reaction(RT-qPCR)was used to detect the expression levels of tRF-1:30,tumor necrosis factor-α(TNF-α),interleukin-6(IL-6),monocyte chemoattractant protein-1(MCP-1)and IKAROS family zinc finger protein 2(IKZF2).Enzyme-linked immunosorbent assay(ELISA)was used to detect levels of TNF-α,IL-6 and MCP-1.Protein expression of IKZF2 was detected by Western blot assay.Dual-luciferase reporter assay was used to detect the targeting relationship between tRF-1:30 and IKZF2.Results The expression levels of inflammatory factors were elevated in HG-induced RTECs,and the expression level of tRF-1:30 was decreased(P＜0.05).Overexpression of tRF-1:30 significantly decreased expression levels of inflammatory factors in HG-induced RTECs(P＜0.05),and the expression level of IKZF2 was significantly increased(P＜0.05).Further knockdown of IKZF2 can inhibit the release of inflammatory factors,and the expression level of IKZF2 was down-regulated after overexpression of tRF-1:30.Double luciferase reporting experiment further verified the possible targeting relationship between tRF-1:30 and IKZF2.Conclusion Overexpression of tRF-1:30 inhibits the expression of inflammatory factors in HG-induced RTECs by target binding and negatively regulating the expression of IKZF2.

Objective To investigate the role and mechanism of zinc finger protein 281(ZNF281)in high glucose(HG)-induced epithelial-mesenchymal transition(EMT)and extracellular matrix(ECM)synthesis in renal tubular epithelial cells(RTECs).Methods HG induced RTECs were used to construct a diabetic kidney disease cell model,and cells were divided into the control group,the HG group and the mannitol group.Cell proliferation viability was detected by CCK-8.The expression of ZNF281 was knocked down in HG-treated RTECs using small interfering RNA(siRNA).HG-induced RTECs after knockdown of ZNF281 were divided into the control group,the HG group,the HG+ZNF281 siRNA group and the HG+ZNF281 vector group.Adenosine monophosphate-activated protein kinase(AMPK)was activated using AMPK agonist,acadexin(AICAR),and then cells were divided into the control group,the HG group,the HG+AICAR group and the HG+dimethyl sulfoxide group.The expression levels of ZNF281,EMT and ECM synthesis-related indexes were detected by qPCR and Western blot assay.Results Compared with the control group,the protein and mRNA expression levels of vimentin,α-smooth muscle actin(α-SMA),fibronectin(FN)and collagen Ⅰ(Col Ⅰ)were significantly higher,and the expression of E-cadherin was significantly lower in the HG group.Compared with the HG group,the protein and mRNA expression levels of EMT and ECM synthesis-related indexes were significantly changed in the HG+ZNF281 siRNA group and the HG+AICAR group.The protein and mRNA expression levels of ZNF281 were significantly reduced in the HG+AICAR group compared with the HG group.In cells co-treated with AICAR and transfected with ZNF281 plasmid,the expression levels of vimentin,α-SMA,FN and Col Ⅰ were significantly higher in the AICAR+ZNF281 group,and E-cadherin was significantly lower compared with that of the vector group.Conclusion AMPK inhibits EMT and ECM synthesis in HG-treated RTECs by negatively regulating the expression level of ZNF281.