Abstract:
In order to investigate the role and relationship between transforming growth factor-beta1 （TGF-β1）and selenoprotein P in depression induced by chronic unpredictable mild stress (CUMS), the effects of intrahippocampal microinjections of TGF-β1 and its receptor kinase inhibitor (LY-364947) on CUMS-induced depression and anxiety-like behaviors were investigated.The levels of depression like behaviors and related properties were measured using open-field test,tail suspension test, sucrose consumption and the body weight.The content level of TGF-β1 and the selenoprotein P were detected by Elisa and Western blot respectively.The results show that compared with control group, CUMS rats showed significant depression-like behaviors, lower levels of selenoprotein P and higher levels of TGF-β1 in the hippocampus.Microinjection of recombined TGF-β1 didn′t result in increase of depressive-like behaviors; however, intrahippocampal injection of recombined TGF-β1 can effectively reduced the depressive-like behaviors induced by CUMS.TGF-β1 inhibited the expression of selenoprotein P.Interestingly, microinjection of LY-364947, the inhibitor of TGF-beta type 1 receptor kinase into hippocampus also showed anti-depression effect and the expression of selenoprotein P was higher compared with CUMS/SAL group.These data suggest that selenoprotein P and TGF-β1 in the hippocampus are involved in chronic stress induced depression.Selenoprotein P may play a role in the protection of hippocampus.It may be involved in the occurrence of depression in which TGF-β1 inhibits the expression of selenoprotein P via TGF-beta type 1 receptor .The antidepressant effects of TGF-beta 1 may be via other ways without the TGF-beta type 1 receptor.
