CSE-Derived H2S Inhibits Reactive Astrocytes Proliferation and Promotes Neural Functional Recovery after Cerebral Ischemia/Reperfusion Injury in Mice Via Inhibition of RhoA/ROCK2 Pathway.

The effect of cystathionine-γ-lyase (CSE)-derived hydrogen sulfide (H2S) on the reactive proliferation of astrocytes and neural functional recovery over 30 d after acute cerebral ischemia and reperfusion (I/R) was determined by applying wild-type (WT) and CSE knockout (KO) mice. The changes of glial fibrillary acidic protein (GFAP) expression in hippocampal tissues was tested. Besides, we assessed the changes of mice spatial learning memory ability, neuronal damage, RhoA, Rho kinase 2 (ROCK2), and myelin basic protein (MBP) expressions in hippocampal tissues. The results revealed that cerebral I/R resulted in obvious increase of GFAP expression in hippocampal tissues. Besides, we found the neuronal damage, learning, and memory deficits of mice induced by cerebral I/R as well as revealed the upregulation of RhoA and ROCK2 expressions and reduced MBP expression in hipppcampal tissues of mice following cerebral I/R. Not surprisingly, the GFAP expression and cerebral injury as well as the upregulation of the RhoA/ROCK2 pathway were more remarkable in CSE KO mice, compared with those in WT mice over 30 d following acute cerebral I/R, which could be blocked by NaHS treatment, a donor of exogenous H2S. In addition, the ROCK inhibitor Fasudil also inhibited the reactive proliferation of astrocytes and ameliorated the recovery of neuronal function over 30 d after cerebral I/R. For the purpose of further confirmation of the role of H2S on the astrocytes proliferation following cerebral I/R, the immunofluorescence double staining: bromodeoxyuridine (BrdU) and GFAP was evaluated. There was a marked upregulation of BrdU-labeled cells coexpressed with GFAP in hippocampal tissues at 30 d after acute cerebral I/R; however, the increment of astrocytes proliferation could be ameliorated by both NaHS and Fasudil. These findings indicated that CSE-derived H2S could inhibit the reactive proliferation of astrocytes and promote the recovery of mice neural functional deficits induced by a cerebral I/R injury via inhibition of the RhoA/ROCK2 signal pathway.