discrepant gene expression profile and phenotype changes in human lens epithelial cells after oxidative damage

METHODS:Human lens epithelial cell line(HLE-B3)were cultured in normal condition or with H₂O₂ for 24h. Total RNA were extracted for gene expression profiling assay and gene ontology analysis was performed for the significantly up-regulated genes using bioinformational database DAVID. The elevated expressions of up-regulated genes in HLEC after oxidative stimulation were confirmed by RT-qPCR. The apoptosis of HLEC induced by oxidative damage was detected using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide(MTT)assay and flow cytometry.

RESULTS:Gene expression profiling assay demonstrated that 367 genes were up-regulated in HLEC after oxidative stimulation. These genes were enriched in 310 biological processes mainly associated with p53-related signaling pathways, apoptosis, programed cell death and etc. Six genes mainly pro- or anti-apoptotic, including BCL2A1,TP53I3,FAS,ZMAT3,DDB2 and BCL2L1, were confirmed to be up-regulated by oxidative stimulation using RT-qPCR(P<0.05). Results of MTT assay and flow cytometry showed that apoptosis of HLEC gradually appeared after cells were treated with H₂O₂ and became the main consequence of oxidative stimulation.

CONCLUSION:Oxidative stimulation can induce up-regulation of proapoptotic genes and lead to apoptosis of HLEC, even though antiapoptotic genes can also be promoted.