Potential prophylactic effect of chemical chaperones for alleviation of endoplasmic reticulum stress in experimental diabetic cataract

Abstract

Both ophthalmic and lens histopathologic examination revealed that treatment with 4-PBA and TUDCA retarded the occurrence of cataract markedly. Whereas, treatment with TMAO caused a partial improvement of cataract. Moreover, biochemical tests showed that both 4-PBA and TUDCA produced a remarkable improvement in the ER marker levels (VEGF and caspase-12), GSH, MDA, TAC levels in lens tissues. On the other hand, TMAO had no significant effect on these parameters. However, Western blot analysis of lens homogenates showed a suppressed expression of GRP78 and CHOP after treatment with 4-PBA, TUDCA, and TMAO. Moreover, all treated groups showed a significant improvement of lens soluble proteins and their UV spectra absorption. A significant improvement in fasting blood sugar, GSH, serum MDA, and TAC were noted in all treated groups. 4-PBA produced a significant decrease in insulin resistance, whereas TUDCA and TMAO showed insignificant change.