ABSTRACT
Objective To explore the effects of two routes of melatonin (MT) administration including intraperitoneal and caudal vein injection on the behavior,histopathology and the expression of myelin basic protein (MBP) and active caspase-3 protein in focal cerebral ischemic rats.Methods 84 male Sprangue-Dawley rats were randomly divided into normal control group (CON,n=12),middle cerebral artery occlusion group(MCAO,n=24),MT-intraperitoneal group (n=24) and MT-intravenous injection group (n=24) by random number table.Twenty-four hours after ischemia reperfusion (IR),Morris water maze was used to observe the effects of two routes of MT administration on behavior in focal cerebral ischemic rats.7 d after IR,MBP immunohistochemical and hematoxylin eosin (HE) staining were used to examine the expression of MBP in striatum and histopathological changes in hippocampal CA1 region.24 h,72 h and 7 d after IR,the expression of active caspase-3 in hippocampal CA1 region was observed by immunohistochemical staining.Results The average escape latencies in Morris water maze in MT-intravenous injection group at different time points were all lower than those of the MT-intraperitoneal,and they were all lower than those of the MCAO group.Swimming time percentage of target quadrant in MT-intravenous injection group were higher than those of the MT-intraperitoneal,and they were all higher than those of the MCAO group (all P＜0.01);7 d after IR,the results of HE staining showed that the hippocampus cells in MCAO group were disarranged with hyperchromatic nucleus and cytoplasm.More hippocampal cells were observed in MT-intraperitoheal and MT-intravenous injection groups,and they were relatively well arranged.The optical density (OD)of MBP in MT-intravenous injection group (105.60±4.04) was significantly higher than those in MCAO group (95.60±2.07) and MT-intraperitoneal injection group (98.00±4.18) (both P＜0.01).Immunohistochemical results showed that the number of active caspase-3 positive cells in MT-intravenous injection group ((116.93± 12.58)/mm2,(130.16±21.22)/mm2,(88.25±7.80)/mm2) at each time point were significantly lower than those in MT-intraperitoneal injection group ((156.64± 32.54)/mm2,(176.49± 17.44)/mm2,(127.96±16.73)/mm2) (all P＜0.05).At the time points of 24 h and 72 h after IR,there were less active caspase-3 positive cells in MT-intraperitoneal and MT-intravenous injection group compared with those in MCAO group((273.56±32.54)/mm2,(288.63±35.17)/mm2)(all P＜0.01).Conclusion MT administration by both intraperitoneal and intravenous injection can significantly improve the behavior and attenuate the histopathology and white matter damage,and reduce the cell apoptosis in hippocampal CA1 region in focal cerebral ischemic rats,and the therapeutic effects of MT-intravenous injection are better than MT-intraperitoneal injection.
ABSTRACT
Objective Based on middle cerebral artery occlusion (MCAO) model,to investigate the effects of melatonin (MT) on DWI and expression of Fas,FasL and cleaved Caspase-3 proteins in rat model with focal cerebral ischemia.Methods Eighty SD rats were randomly divided into Sham group (n=16),MCAO group (n=32) and MT group (n=32).The rats in sham group were treated with sham-operation.And the rats in MCAO and MT groups were peritoneally injected with saline and MT respectively.The behavioral scores were assessed in the three groups.The rats in MCAO and MT group with the behavioral scores of 1 3 points were selected in the study.The DWI relative signal intensity (rDWI-SI),Fas,FasL and cleaved Caspase-3 proteins were respectively examined by MR scaning and immunohistochemical staining in all rats of each group at 6 h,24 h,72 h and 7 days after ischemia reperfusion (IR) or sham-operation.And the DWI and immunohistochemical results for each group were compared.Results At last,there were 16 rats in sham group,29 rats in MCAO group and 30 rats in MT group,respectively.There was significant difference of the behavioral scores among the three groups (x2 =50.125,P＜0.01).The behavioral scores of MT and MCAO groups were higher than those of sham group (all P ＜0.05).And the behavior scores of the MT group were lower compared with MCAO group after IR.Compared with the rDWI-SI values measured at 6 h,24 h and 72 h,7 days in sham group,the rDWLSI values of MT and MCAO groups were significantly higher (all P＜0.01).And the rDWI-SI was higher in MCAO group than those in MT group at 6 h,24 h and 72 h after IR (all P＜0.01).And there was no significant difference of rDWI-SI at 7 days after IR between MT and MCAO groups (P＞0.05).The immunohistochemical staining results showed that the number of Fas,FasL and cleaved Caspase-3 positive cells in MCAO and MT groups were significantly higher than those in sham group (all P＜0.01).And there were less Fas,FasL and cleaved Caspase-3 positive cells in MT groups compared with MCAO group (all P＜0.05) at 6 h,24 h and 72 h after IR.There was no significant difference of Fas,FasL and cleaved Caspase-3 positive cells among the three groups at 7 days after IR (P＞0.05).Conclusion MT can effectively alleviate the rDWI-SI value and inhibit the expression of Fas,FasL and cleaved Caspase-3 proteins in rats of focal cerebral ischemia.
ABSTRACT
The Hippo pathway plays a crucial role in controlling organ size by inhibiting cell proliferation and promoting cell death. Recent findings implicate that this pathway is involved in the process of intestinal regeneration and tumorigenesis. Here we summarize current studies for the function of the Hippo signaling pathway in intestinal homeostasis, regeneration and tumorigenesis, and the crosstalk between the Hippo signaling pathway and other major signaling pathways, i.e. Wnt, Notch and Jak/Stat signaling pathways in intestinal compartment.