Neuroprotection effect of Y-27632 against H2O2-induced cell apoptosis of primary cultured cortical neurons

Oxidative stress-mediated neuron damage is believed to contribute greatly to the pathogenesis and outcome of ischemia. Y-27632, a Rho-associated kinase (ROCK) inhibitor, has been reported to protect various cells from oxidative injury. However, whether a Rho-kinase inhibitor can directly protect neurons against oxidative damage and the molecular mechanisms underlying it is poorly understood. In the present study, we investigated the potential protective effect of Y-27632 against H2O2-induced apoptosis in cultured rat cortical neurons and potential mechanisms underlying it. Both the cell viability tests and cell apoptosis assays showed that Y-27632 effectively protected the cultured rat cortical neurons from H2O2-induced injury. Furthermore, the mechanisms underlying the protective effect were determined next. Our results revealed that Y-27632 pretreatment regulated the apoptosis-related proteins by inhibiting the H2O2-induced decrease in anti-apoptotic protein Bcl-2 and an increase in the level of pro-apoptotic protein Bax. Meanwhile, Y-27632 also significantly reduced oxidative stress and the activation of JNK1/2/3 and p38 MAPKs induced by H2O2, without affecting the phosphorylation of ERK1/2. Moreover, inhibiting the JNK and p38 pathways by SP600125 and SB203580 respectively alleviated the cell viability loss induced by H2O2 and markedly disputed the neuroprotective effect of Y-27632 against H(2)O(2)(-)induced apoptosis. Taken together, these results demonstrate that Y-27632 can directly protect cultured cortical neurons from H2O2-induced apoptosis by inhibiting oxidative stress and the activation of JNK and p38 MAPKs pathways. Our study provides useful insights into the therapeutic mechanisms of Y-27632 and further supports that ROCK is a promising drug target for neurological diseases.