The Study Of The Mechanisms Of JAK2-STAT3 Signal Pathway In The Intracerebral Hemorrhage Rat Model

Objective To study the dynamic expression of JAK2, p-JAK2, STAT3 and p-STAT3 in order to investigate the role and mechanisms of JAK2/STAT3 signal pathway preliminarily in brain tissues.Methods Autologous blood from the rat caudal artery was injected into caudate nucleus of rat through microsyringe to make intracerebral hemorrhage models when the rat was firmly fixed on stereotaxic coordinates. Provided by Liaoning Changsheng Biotechnology Co.,LTD, one hundred and eight healthy male SD rats(3 ~ 5 months old, 250 ~ 300 g, permit No.SCXK(Liao)2010-0001) were randomly divided into six groups(n=18) according to the difference of bleeding time.Then every group was further divided into three sub groups(n=6): the model group(M group), the sham group(S group) and the AG-490 group(AG group). Autologous blood from rat caudal artery was injected into caudate nucleus of rat gently through microsyringe to establish intracerebral hemorrhage models in M group and the rats were performed similarly in S group that only without the injection of autologous blood. AG-490(a specific JAK2 inhibitor) 3mg/Kg was given iv at 10 min before modeling in AG group. All brain tissues were obtained after rats were sacrificed and their water content were detected. Both immunohistochemistry and Western blot analysis were used to detect the expression of JAK2, p-JAK2, STAT3 and p-STAT3 in rat brain tissues.Results The results of immunohistochemistry showed that the immunoreactivity of JAK2 and STAT3 were prominent in M group, S group and AG group. The immunoreactivity of p-JAK2 and p-STAT3 were different with statistical significance(P<0.05), negative or weak positive in S group and AG group, positive in M group reaching the peak level at 24 h. Western blot analysis showed that similar contents of JAK2 and STAT3 without statistical significance(P>0.05) in S group, M group and AG group, but different contents of p-JAK2 and p-STAT3, peaked at 24 h in M group and negative in S group or AG group. The water content of brain tissues in AG group were obviously lower than those in M group(P<0.05).Conclusions The results suggest that the JAK2-STAT3 signal pathway be activated in rats intracerebral hemorrhage models. JAK2-STAT3 pathway plays a role in the pathophysiological process in the peripheral region of intracerebral hemorrhage and contributes to brain edema.