Effect of high glucose on the expression of KLF6 in human lens epithelial cell

Abstract

Background Epithelial-mesenchymal transition (EMT) is a major contributor to the pathogenesis of posterior capsular opacification(PCO).Kruppel-like factor 6 (KLF6) is a zinc finger protein,which can be stimulated by high glucose in proximal tubule cells and involved in transforming growth factor beta (TGF-β)induced EMT of diabetic nephropathy. Objective This study was designed to investigate the effect of high glucose on the expression of KLF6 and its target genes( TGFB1,TGFBR1,COLIA1,HSP47) in human lens epithelial cells (LECs). MethodsHuman LECs(SRA01/04) were cultured and exposed to different concentration of glucose.The expressions of KLF6 mRNA and protein were analyzed by real time polymerase chain reaction( real time PCR) and western blot after treatment with high glucose.The expressions of KLF6 target genes were analyzed by real time PCR to evaluate the EMT of SRA01/04 cells. Results Compared with the control group(5.5 mmol/L),the relative mRNA levels of t-KLF6 and wt-KLF6 in SRA01/04 treated with high glucose(22.2,44.4,66.6 mmol/L) increased obviously (F =72.53,42.02,P＜0.01 ).Then,the concentration of 22.2 mmol/L was used in the next experiments.The relative mRNA levels of t-KLF6 and wt-KLF6 increased to the peaks after treatment with high glucose for 12 h,and began to decrease after 24 h until lower levels after 48 h ( F =100.12,125.52,P ＜ 0.01 ).Western blot showed that the expression of KLF6 protein was also upregulated by high glucose treatment.With the promotion of the expression of KLF6 gene,the relative mRNA levels of TGFB1,TGFBR1,COLlAl and HSP47 of treated cells also respectively increased after treatment for 12 h,and began to decrease after 24 h until nearly at the levels of the control groups after 48 h( F=6.73,162.35,64.39,12.05,P＜0.05 ). Conclusions It was concluded that high glucose induced the expression of KLF6 in human LECs,and KLF6 transiently stimulated the expression of target genes TGFB1,TGFBRl,COLlAl and HSP47 which were mainly involved in the mechanism of EMT. Key words: Human lens epithelial cell; High glucose; Kruppel-like factor 6; Epithelial-mesenchymal transition