The Functional Mechanisms Of P38MAPK In Perihematomal Tissue Injury After Experimental Intracerebral Hemorrhage And The Protection Effect Of Batroxobin

Intracerebral hemorrhage (ICH) is a devastating clinical condition, the incidence of mobidity and mortality from ICH remains high. Currently, there is no medical therapy available for these patients except neurosurgical evacuation of the hematoma. Patients who survive ICH are usually severely disabled. The mechanisms of brain injury after ICH are not fully understood.The study of ICH in the rat attracted increasing attention. Inflammatory response and kinds of cytokines expression occur in hematoma and its surrounding tissues after acute intracerebral hemorrhage.These cytokines such as IL-1,IL-6,IL-10 and ICAM-1 play an important role in the pathophysiological process of perihematomal tissue injury.Little is known about the expression of p38MAPK in case of ICH,we want to investigated the role of p38MAPK signal transduction pathway in the production of the proinflammatory factors such as IL-1βand MMP-9.We also investigated the effects of SB203580 on IL-1βand MMP-9 synthesis, release and signaling.we determine whether SB203580 provides direct neuronal protection in vivo. Part one Review At the beginning of this paper, The review was finished in three aspects:1)The reseach development of model of intracerebral hemorrhage;2) The reseach development of the perihematoma tissue injury after intracerebral hemorrhage;3)the relationship between p38MAPK snd ischemic brain injury. Part Two Making and evaluating a rat model of ICH We established the medel of the ICH by stereotaxically infusing 50ul of the autologous blood into the right caudate nucleus in the rats. The brain edema and the change in the cerebral histology were observed by optical microscope and electric microscope.The perihematomal tissue looked loose with varied edematous cells. Astrocytes appeared swollen and neural cells looked degenerated and necrosis. By the electron microscope, swelling of neurocyte, cavitation, membrane of neurocyte and nucleus lesion, cristae disruption of mitochondrion, rarefaction of neuropil and karyopyknosis could be observed. HE staining showed that the edema of the brain increased gradually when compared with the normal control group after ICH. Water content of the brain in the perihematomal brain regions increased sharply(P<0.05) on the first day after ICH when compared with the normal control group,on the 3d attained the peak,which indicates the formation of brain edema after ICH.Brain water contentchanged in parallel with the changes in BBB permeability. Part Three Dynamic expression of p38MAPK ,IL-1β,ICAM-1 and MMP-9 after ICH in Rats Recent studies demonstrate that the members of p38MAPK are activated in brain after ischemia and ischemia-reperfusion and suggest that the signaling pathway of the kinase may be important and responsible for tissue injury after ischemia-reperfusion.but the Dynamic expression of p38MAPK has not reported after ICH. In the present study, we investigated the expression of p38,IL-1β,ICAM-1 and MMP-9 after ICH. P38MAPK expression was detected by immunohistochemical method and Western blot analysis and the expression of IL-1β,and MMP-9 was measured by immuno-histochemical method. We investigated the expression of p38MAPK started to increase three hours after the intracerebral hemorrhage, peaked at 24h hours and enhanced further reaching maximum induction around 4 days following ICH and the numbers were significantly different from those of the sham group.The expression of MMP-9 started to increase 12 hours after ICH, peaked at 72 hours and continued for 120 hours.The expression of ICAM-1 started to increase at 6 hours,peaked at the 48 hours. IL-1βin the area increased 6 hours , reached a high level at 48 hours, and peaked at 72 hours after hemorrhage , mostly paralleling the increase in P38mapk expression. Part Four Effect of SB203580 on brain injury after ICH in Rats p38MAPK has been linked to the production of inflammatorycytokines and apoptosis following cerebral ischemia,There has been little information regarding the relationship between p38 MAPK pathway and ICH..In this study,SB203580,a selective inhibitor of p38MAPK,was used to examine the effects on the expression of inflammatory cytokines and apotosis.The rats were assigned to two groups:ICH and SB203580-treated (5mg/kg/d,i.v) group. we demonstrated that SB203580 inhibited the expression of IL-1β,ICAM-1 and MMP-9.We also found that brain water content were decreased significantly different from those of the ICH group. The apoptotic cells in perihematomal tissue were tested with method of TUNEL in the rats, the number of apoptosis cells reduced significantly in SB203580-treated group.The results indicate that administration of SB203580 may reduce the apoptosis of neurons and afford significant cerebroprotection in the model of ICH.These results indicate that SB203580 is a potent inhibitor of inflammatory cytokine production and. p38MAPK play an important role in secondary tissues injury in perihematoma after ICH,possibly through the upregulation of inflammatory cytokines. Part Five Effect of Batroxobin on brain injury after ICH in Rats Batroxobin , a serine protease used in defibrinogenation and thrombolysis, is widely used in ischemic stroke treatment. Experi-mental research showed that the mechanisms of Batroxobin that atenuating brain injury and brain edema induced clearance of free radical,downregulating the expression of c-fos gene, reducing the...