Fasudil hydrochloride protects neurons in rat hippocampal CA1 region through inhibiting GluR6-MLK3-JNKs signal pathway.

Abstract

Fasudil hydrochloride (FH), a Rho kinase (ROCK) inhibitor, has been reported to prevent cerebral ischemia in vivo from increasing cerebral blood flow and inhibiting inflammatory responses. However, it is uncertain by what mechanism a ROCK inhibitor can directly protect neurons against ischemic damage. The present study was designed to evaluate whether FH decreased the increased phosphorylation of glutamate receptor 6 (GluR6) and its downstream in GluR6-MLK3-JNKs signal transduction pathway following global transient cerebral ischemia, as a result of protecting against neuronal apoptosis and death. Transient cerebral ischemia was induced by the Pulsinelli-Brierley four-vessel occlusion method. FH (15 mg/kg) was administered to rats by intraperitoneal injection 30 min before ischemia. The phosphorylation and protein expression of GluR6 at 6 h during reperfusion were detected using immunoprecipitation and immunoblotting analysis. The phosphorylation and protein expression of Mixed lineage kinase 3 (MLK3) at ischemia/reperfusion (I/R) 6 h and c-Jun N-terminal kinase (JNK) at I/R 3 d were detected using immunoblotting analysis, respectively. The same method was used to detect the expression of caspase-3 at I/R 6 h. Furthermore, we also use TUNEL staining and Cresyl violet staining to examine the survival neurons in rat hippocampal CA1 regions after 3 and 5 d reperfusion, respectively. Our study indicated that FH could inhibit the increased phosphorylation of GluR6 and MLK3 and the expression of caspase-3 at peaked 6 h of reperfusion and the phosphorylation of JNK (3 d) (p < 0.5). The results of TUNEL staining and Cresyl violet showed that the number of surviving pyramidal neurons in rats hippocampal CA1 subfield increased markedly in FH-treated rats compared with ischemic groups after 3 or 5 d of reperfusion following ischemia (p < 0.5). These results suggested that FH, as a ROCK inhibitor, may be partly responsible for its protective effects against such damage by taking part in GluR6-MLK3-JNKs signaling pathway which modulates ischemic damage. Taken together, this is the first study investigating Rho and ROCK as the upstream of GluR6 taking part in GluR6-MLK3-JNKs signal transduction pathway following cerebral ischemia.

• Authors: Xiu-E Wei, Feng-Yu Zhang, Kai Wang, Qing-Xiu Zhang, Liang-Qun Rong
• Journal: Cell biochemistry and biophysics (Cell Biochem Biophys) Vol. 70 Issue 1 Pg. 415-21 (Sep 2014) ISSN: 1559-0283 [Electronic] United States
• PMID: 24793642 (Publication Type: Journal Article)

Chemical References

• Gluk2 kainate receptor
• Receptors, Kainic Acid
• Serine
• 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine
• JNK Mitogen-Activated Protein Kinases
• MAP Kinase Kinase Kinases
• mitogen-activated protein kinase kinase kinase 11
• Caspase 3
• fasudil

Topics

• 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine (analogs & derivatives, pharmacology)
• Animals
• CA1 Region, Hippocampal (cytology, drug effects)
• Caspase 3 (metabolism)
• Cytoprotection (drug effects)
• Enzyme Activation (drug effects)
• JNK Mitogen-Activated Protein Kinases (metabolism)
• MAP Kinase Kinase Kinases (metabolism)
• MAP Kinase Signaling System (drug effects)
• Male
• Neurons (cytology, drug effects, metabolism, pathology)
• Phosphorylation (drug effects)
• Rats
• Rats, Sprague-Dawley
• Receptors, Kainic Acid (chemistry, metabolism)
• Reperfusion Injury (metabolism, pathology, prevention & control)
• Serine (metabolism)