Estrogen mediated protection of cytoskeleton against oxidative stress.

ABSTRACT

Background & objectives: Cytoskeletal proteins are deregulated during oxidative stress and cataract formation. However, estrogen which protects against cataract formation and harmful effects of oxidative stress has not been tested on the cytoskeleton of lens epithelial cells (LECs). The current study was undertaken to assess if the protection rendered to LECs by estrogen was mediated by preserving the cytoskeletal proteins. Methods: Oxidative stress was induced by 50 μM of H2O2 in cultured goat LECs (gLECs) and effect of 1 μM 17β-estradiol (E2) was tested. After treatment, morphological analysis of cells was carried out using haematoxylin-eosin staining and cell density was also quantified. Cell viability was determined using Hoechst (Ho), YO-Pro (YP) and propidium iodide (PI). F-actin and vimentin were localized using phalloidin and anti-vimentin antibody, respectively, and viewed under fluorescence microscopy. Vimentin was further analysed at protein level by Western blotting. Results: H2O2 led to increased condensation of nucleus, cell death and apoptosis but these were prevented with pre- and co-treatment of E2 with increase in cell viability (P<0.001). E2 also prevented H2O2 mediated depolymerization of cytoskeleton but was not able to reverse the changes when given after induction of oxidative stress. Interpretation & conclusions: Our findings showed that E2 helped in preventing deteriorating effect of H2O2, inhibited cell death, apoptosis and depolymerisation of cytoskeletal proteins in LECs. However, the exact mechanism by which estrogen renders this protection to cytoskeleton of lens epithelial cells remains to be determined.