Inhibition of ROCK2 kinase activity improved behavioral deficits and reduced neuron damage in a DEACMP rat model

The main pathological changes that occur in delayed encephalopathy after acute carbon monoxide poisoning (DEACMP) are extensive demyelination of brain white matter and neuron damage. Previous studies suggested that demyelination and neuron injury are related to activating the Rho/ROCK signaling pathway. Inhibition of the Rho/ROCK signaling pathway can alleviate neuron injury and promote myelin repair. This study utilized a DEACMP model in which rats were prepared by space injection of CO gas intraperitoneally (CO group), and the association between the Rho/ROCK signaling pathway and DEACMP was investigated. The ROCK2 kinase inhibitor Y-27632 was used to prevent the effects of the DEACMP model to elucidate its protective mechanism. The results demonstrated that the cognitive and motor functions were significantly impaired, and the GFAP, NSE, RhoA, and ROCK2 protein levels were significantly increased in the CO group within three weeks after the model was established. After Y-27632 intervention, the cognitive and motor functions of the CO+Y-27632 group were significantly improved within three weeks after the model was established. In the CO+Y-27632 group, the RhoA, ROCK2, GFAP, and NSE (indicating neuron injury) protein levels decreased significantly, and the MBP protein levels (indicating myelin repair) increased significantly within three weeks after the model was established. These results suggested that the pathogenesis of DEACMP was associated with activation of the Rho/ROCK pathway and that Y-27632 inhibited ROCK2 kinase activity in the CO exposed rats, resulting in improved behavioral deficits, reduced neuron damage, and promotion of myelin repair. Therefore, Y-27632 might be a potentially effective drug for the treatment of DEACMP-induced brain damage.