H 2 S Regulates the Phenotypic Transformation of Astrocytes Following Cerebral Ischemia/Reperfusion via Inhibiting the RhoA/ROCK Pathway.

The role of hydrogen sulfide (H 2 S) on the phenotypic change of astrocytes following cerebral ischemia/reperfusion (I/R) in mice was investigated in present study. We tested the expression of glial fibrillary acidic protein (GFAP), A2 phenotype marker S100a10, and A1 phenotype marker C3 protein and assessed the change of BrdU/GFAP-positive cells, GFAP/C3-positive cells, and GFAP/S100a10-positive cells in mice hippocampal tissues to evaluate the change of astrocyte phenotypes following cerebral I/R. The role of H 2 S on the phenotypic change of astrocytes following cerebral I/R in mice was investigated by using H 2 S synthase cystathionine-γ-lyase (CSE) knockout mice (KO). The results revealed that cerebral I/R injury promoted the astrocytes proliferation of both A1 and A2 phenotypes, which were more significant in mice of H 2 S synthase CSE KO than in mice of wild type (WT). Interestingly, supplement with H 2 S could inhibit the A1 phenotype proliferation but promote the proliferation of A2 phenotype, suggesting that H 2 S could regulate the transformation of astrocytes to A2 phenotype following cerebral I/R, which is beneficial for neuronal recovery. Besides, we found that H 2 S-mediated change of astrocyte phenotype is related to inhibiting the RhoA/ROCK pathway. Furthermore, both H 2 S and ROCK inhibitor could ameliorate the brain injury of mice at 9 days after cerebral I/R. In conclusion, H 2 S regulates the phenotypic transformation of astrocytes to A2 phenotype following the cerebral I/R via inhibiting RhoA/ROCK pathway and then exerts the neuroprotective effect against the subacute brain injury.