RESUMO
PURPOSE: To analyze the transdifferentiation of cultured human lens epithelial cells(LECs) by oxidative stress using fibronectin and to evaluate the efficacy of the antioxidant for suppression of this process. METHODS: Human B-3 LECs, a line of immortalized human LECs, were exposed to different concentrations of H2O2 and the maximum concentration of H2O2 without significant toxicity to cells was determined by MTT assay. LECs exposed to H2O2 at the concentration determined by the previous procedure were analyzed by RT-PCR for the expression of mRNAs encoding fibronectin(FN) and by western blot analysis for the proteins encoded by these mRNAs. We examined the inhibiting effects of N-acetyl-L-cysteine(NAC) as an antioxidant on the transdifferentiation. RESULTS: Transdifferentiation of human B-3 LECs occurred at the maximum concentration of 100microM of H2O2 without significant cell toxicity. Although there was no significant change in the expression of mRNAs for FN, the protein expression of FN was increased after exposure to H2O2. NAC showed inhibiting effect on the transdifferentiation. CONCLUSIONS: Transdifferentiation of cultured human LECs is induced by oxidative stress and the expression of FN may be regulated at post-transcriptional level in transdifferentiated LECs. NCA is effective in inhibiting the oxidative stress.