Rho kinase (ROCK) was the first downstream Rho effector found to mediate RhoA-induced actin cytoskeletal changes through effects on
myosin light chain phosphorylation. There is abundant evidence that the ROCK pathway participates in the pathogenesis of
retinal endothelial injury and proliferative
epiretinal membrane traction. In this study, we investigated the effect of the ROCK pathway inhibitor
Y-27632 on
retinal Müller cells subjected to
hypoxia or oxidative stress. Müller cells were subjected to
hypoxia or oxidative stress by exposure to CoCl2 or H2O2. After a 24-hour treatment with
Y-27632, the
3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay was used to assess the survival of Müller cells.
Hoechst 33258 was used to detect apoptosis, while
2',7'-dichlorodihydrofluorescein diacetate was used to measure
reactive oxygen species generation. A transwell chamber system was used to examine the migration ability of Müller cells. Western blot assay was used to detect the expression levels of α-smooth muscle actin,
glutamine synthetase and
vimentin.
After treatment with
Y-27632, Müller cells subjected to
hypoxia or oxidative stress exhibited a morphology similar to control cells.
Y-27632 reduced apoptosis, α-smooth muscle actin expression and
reactive oxygen species generation under oxidative stress, and it reduced cell migration under
hypoxia.
Y-27632 also upregulated
glutamine synthetase expression under
hypoxia but did not impact
vimentin expression. These findings suggest that
Y-27632 protects Müller cells against cellular injury caused by oxidative stress and
hypoxia by inhibiting the ROCK pathway.