Submitted on May 23, 2008
Revised on July 17, 2008
Accepted on August 12, 2008
Corticotropin-Releasing Hormone Stimulates SGK-1 Kinase Expression in Cultured Hippocampal Neurons via CRH-R1
Hui Sheng1, Tingting Sun1, Binhai Cong1, Ping He1, Yanmin Zhang, Jin Yan1, Changlin Lu1, and Xin Ni1*
1 Second Military Medical University
* To whom correspondence should be addressed. E-mail: nxljq2003{at}yahoo.com.cn.
Corticotropin-releasing hormone (CRH) has been shown to exhibit various functions in hippocampus. In the present study, we examined the effect of CRH on the expression of serum/glucocorticoid-inducible protein kinase-1 (SGK-1), a novel protein kinase, in primary cultured hippocampal neurons. A dose-dependent increase in mRNA and protein levels of SGK-1 as well as frequency of SGK-1-positive neurons was occurred upon exposure to CRH (1pmol/l-10nmol/l). These effects can be reversed by the specific CRH-R1 antagonist antalarmin but not by CRH-R2 antagonist astressin 2B. Blocking adenylate cyclase (AC) activity with SQ22536 and PKA with H89 completely prevented CRH-induced mRNA and protein expression of SGK-1. Blockage of PLC or PKC did not block CRH-induced SGK-1 expression. Our results suggest that CRH act on CRH-R1 to stimulate SGK-1 mRNA and protein expression in cultured hippocampal neurons via a mechanism that is involved in AC/PKA signaling pathways.
