Effects of fasudil hydrochloride on ROCK2 protein and ferroptosis in hippocampus during early brain injury in rats with subarachnoid hemorrhage / 中华行为医学与脑科学杂志

ABSTRACT

Objective:To investigate the effects of fasudil hydrochloride(FH) on Rho-associated kinase 2(ROCK2) protein and ferroptosis in hippocampal area during early brain injury in rats with subarachnoid hemorrhage(SAH).Methods:Total 36 SPF grade Sprague-Dawley rats were divided into 3 groups by random number table method: Sham group, SAH group and SAH+ FH (a ROCK2 protein inhibitor) group (FH goup) with 12 rats in each group.SAH animal model was established by internal carotid artery perforation.The rats in FH group were injected intraperitoneally with FH(15 mg/kg) 30 minutes after successful modeling, and rats in Sham group and SAH group were injected intraperitoneally with the same volume of 0.9% sodium chloride solution.Twenty-four hours after the intervention, shuttle box test was used to observe the learning and memory ability of rats.The Fe 2+ content in rat hippocampus tissue was detected by colorimetry, and the protein levels of ROCK2 and ferroptosis-related long-chain acyl-CoA synthetase 4(ACSL4) and glutathione peroxidase 4(GPX4) in hippocampus were detected by immunohistochemistry and Western blot.Statistical analysis was performed by SPSS 20.0 software.One-way ANOVA was used for multigroup comparison, and LSD test was used for further pairwise comparison. Results:(1)In the shuttle box test, there were statistically significant differences in the number of avoidance reactions and avoidance reaction time of rats among the three groups( F=20.348, 22.316, both P<0.05). The number of avoidance reaction in SAH group was less than that in Sham group ((17.92±2.94) times, (27.13±3.48) times, P<0.05), the time of avoidance reaction in SAH group was longer than that in Sham group ((9.15±2.87) s, (3.68±1.09) s, P<0.05), while the number of avoidance reaction in FH group ((21.63±4.11) times) was more than that in SAH group, and the time of avoidance reaction ((6.08±1.76) s) was shorter than that in SAH group (both P<0.05). (2) The colorimetry results showed that there was a statistically significant difference in the content of Fe 2+ in hippocampus of rats among the three groups( F=7.965, P<0.05). The Fe 2+ content in SAH group was significantly higher than that of Sham group((0.091±0.032) nmol/mg, (0.038±0.024) nmol/mg, P<0.05), and the Fe 2+ content in the FH group ((0.065±0.021) nmol/mg) was lower than that of SAH group ( P<0.05). (3) There were significant differences in the number of ROCK2, ACSL4 and GPX4 positive cells in hippocampus of rats among the three groups in immunohistochemistry ( F=7.602, 14.171, 36.077, all P<0.05). The positive cells of ROCK2 and ACSL4 in SAH group ((21.63±4.72), (55.13±19.41)) were significantly higher than those of Sham group ((11.63±3.62), (23.38±3.74)) (both P<0.05), and the positive cells of ROCK2 and ACSL4 in FH group ((15.88±6.64), (44.75±8.29)) were both lower than those of SAH group(both P<0.05), while the number of GPX4 positive cells in SAH group (25.38±6.30) was significantly lower than that of Sham group (60.25±10.36) ( P<0.05), and the number of GPX4 positive cells in FH group (45.13±7.51) was higher than that of SAH group( P<0.05). (4)The results of Western blot showed that there were significant differences in the expression levels of ROCK2, ACSL4 and GPX4 proteins in the hippocampus of rats among the three groups( F=4.812, 12.573, 10.849, all P<0.05). The protein expression levels of ROCK2 and ACSL4 in SAH group were significantly higher than those in Sham group(both P<0.05), and the protein expression levels of ROCK2 and ACSL4 in FH group were lower than those in SAH group (both P<0.05), while the expression level of GPX4 protein in SAH group (0.27±0.09) was significantly lower than that in Sham group( P<0.05), and the expression level of GPX4 protein in FH group was higher than that of SAH group ( P<0.05). Conclusion:FH can inhibit ferroptosis in the hippocampus and improve the learning and memory ability of rats, and the mechanism may be related with down-regulation of ROCK2 protein.