Effects of transplanting neural stem cells transfected with cardiotrophin-1 on the injured hippocampus and mossy fiber sprouting in status epilepticus rats / 中华神经科杂志

Objective To observe the survival,migration and differentiation of grafted neural stem cells(NSCs)transfected with cardiotrophin-1(CT1)in hippocampus in status epilepticus(SE)rats,and investigate its effect on neuron loss and mossy fiber sprouting(MFS)in hippocampus of SE rats.Methods (1)Lithium-pilocarpine induced SE model rats were divided into 3 groups randomly:CT1-NSCs transplantation group(n=18);NScs transplantation group(n=18)and SE model group(n=18).Another 18 rats served as normal control group.Each group was further divided into 3 time points testing groups(n=6 at each point)corresponding to 1,4 and 8 weeks after transplantation respectively.(2)Under the confocal microscopy,the survival,migration and differentiation of the grafted cells were observed by immunofluorescenee.(3)Morphological changes and neuron loss in the hippocampal CA1 region were examined by Nissl staining.(4)MFS in hippocampal dentate gyrus in rats was obserred by Timm histochemistry.Results(1)At 4 and 8 weeks post-tmusplantation,the numbers of double-labeled NF-200 and EGFP pesitive cells in the CT1-NSCs group were significantly hisher than those in NSCs group.In the former group most of the grafted NSCs migrated away from the needle tract,but in the latter group,grafted ceHs remained at the transplantation site.(2)The numbers of neuron in the hippocampal CA1 region reduced gradually after SE.The numbers of neuron in the CA1 region in CT1-NSCs transplantation rats (68.85±11.49,60.89±12.17 and 51.51±13.34 in 1,4,8 weeks after transplantation respectivelv)were greater than that in NSCs transplantation rats(67.92±10.78,42.56±11.47 and 30.49±10.12).tvalue were 4.650 and 5.334 in 4 and 8 weeks after transplantation(P<0.05).(3)Aberrant MFS in the inner molecular layer of dentate gyrus was observed,and the scores of MFS gradually increased with timelapse.The scores of MFS in CT1-NSCs transplantation rats(0.77±0.04,2.48±0.89 and 2.39±0.82 in 1,4,8 weeks after transplantation respectively)were significant lower than that in NSCs transplantation rats (1.12±0.62,3.17±0.64 and 3.88±0.51,t=6.059,9.511 and 9.728,P<0.05).Conclusions CT1 could promote the survival,migration and differentiation of engrafted NSCs in hippocampud in SE rats.Engrafted NSCs transfected with CT1 have effect on repair of the injured hippocampus,and could inhibit hippocampus MFS in SE rats.

The Role of MMP-9 on the Hippocampal Neuronal Cell Death and Mossy Fiber Sprouting due to Pilocarpine-Induced Status Epilepticus in Mice / 대한간질학회지

PURPOSE: Matrix metalloproteinases (MMPs) have been known to participate in various pathologic situations by modulating extracellular matrix. Although MMP-9 upregulation has been reported in some experimental seizure models, the exact role of MMP-9 in hippocampal cell death during epileptogenesis and subsequent mossy fiber sprouting (MFS) is not clear. Here, we investigated the role of MMP-9 on hippocampal cell death and MFS after pilocarpine-induced status epilepticus (SE) in mice, using highly specific hydroxamic MMP-9 inhibitor. METHODS: SE was induced by intraperitoneal pilocarpine administration in adult male C57BL/6 mice. MMP-9 specific inhibitor was administered intracerebroventrically 3 h after pilocarpine-induced SE. Expression and activation of MMP-9 were assessed by zymography and Western blot analysis. TdT-mediated UTP-biotin nick end labeling (TUNEL) and caspase-3 activity assay were also performed. MFS was investigated using Timm staining. RESULTS: Increased expression and activation of MMP-9 after pilocarpine-induced SE were observed in zymography and Western blot analysis. MMP-9 specific inhibitor decreased MMP-9 activity in in situ zymography and hippocampal cell death in cresyl violet staining. DNA fragmentation and caspase-3 activity were also attenuated by MMP-9 specific inhibitor. Four months after pilocarpine-induced SE, MFS was evident in vehicle-treated mice; in contrast, MFS was barely observed in MMP-9 specific inhibitor-treated mice. CONCLUSIONS: This study suggests MMP-9 is associated with hippocampal cell death and MFS after pilocarpine-induced SE. Furthermore, the findings that MMP-9 specific inhibitor ameliorates cell death and MFS offers the possibility of MMP-9 specific hydroxamic inhibitor as novel therapeutic strategy to reduce hippocampal damage and epileptogenesis.

Expression of GABAAR?1 subunit in cortical region and hippocampal formation of rats with radiation-induced diffuse cortical dysplasia / 重庆医科大学学报

Objective:To correlate diffuse cortical dysplasia(DCD) epileptogenicity and the expression of GABAAR?1 in adult rat with DCD by ?-ray irradiated injury.Methods:To establish ?-ray-induced model of DCD in rat,and newborn Wistar rats were allowed to survive for 14~16 weeks before HE,Nissl Stain,Timm's histochemical method and SABC immunohistochemistry.We observed the structure of cortical regions and hippocampal formation with naked eyes and under a light microscope,and assessed the hippocampal mossy fiber sprouting after HE staining,Nissl staining and Timm's histochemical method.The comparisons between every two groups were performed with Nemenyi test.We observed the expression of GABAAR?1 subunit in cortical regions and hippocampal formation in the animal model and quantitatively analyzed using immunohistochemistry of GABAAR?1 subunit.Results:Normal rats and irradiated pregnant rats didn't have any seizure.F1 generation rats had seizure by chance.EEG showed no typical sharp waves,or spikes.In utero irradiation of fetal rats had served as an injury-based animal model of cortical dysplasia and neuronal heterotopia.Exposure of fetal rats to a single dose of ?-irradiation on embryonic day 17 resulted in microcephaly,diffuse cortical dysplasia,neuronal heterotopia,heterotopic neurons in the hippocampus,and hypoplasia of the corpus callosum.The mossy fiber sprouted in hippocampi CA3 area bilaterally,however there was no mossy fiber sprouting in controls or irradiated rats(P