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【Objective】 To clarify the role and molecular mechanism of Tanshinone ⅡA (TanⅡA) in the pathological integration of granule cells in the dentate gyrus (DG) by using the mouse model of temporal lobe epilepsy (TLE). 【Methods】 Status epilepticus (SE) was induced in the mice with pilocarpine and treated with TanⅡA 5 mg/kg. After two months, Morris water maze was used to examine the spatial learning and memory ability and video surveillance was used to monitor spontaneous seizures. The DG was removed for staining of Timm, Prox-1, DCX and SynⅠ. PTEN, p-AKT, and p-S6 expressions were observed by Western blotting. 【Results】 TanⅡA decreased Timm score, SynⅠ, PSD-95 and pS6 levels, and increased the level of PTEN in the DG, and attenuated the formation of mossy fiber sproutings and basal dendrites of the granule cells. Video surveillance showed that TanⅡA reduced the frequency of Racine’ grade 5 seizures. 【Conclusion】 TanⅡA can effectively attenuate the abnormal integration of the granule cells in the DG by regulating PTEN/AKT/mTOR pathway and thus plays an anti-epileptic role.
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<p><b>OBJECTIVE</b>To observe the morphological changes during development of the ventricular zone (VZ) and subventricular zone (SVZ) of human fetus and the distribution pattern of neural stem cells in the VA and SVZ.</p><p><b>METHODS</b>Human fetuses at the gestational ages of 9-11 weeks, 14-16 weeks, 22-24 weeks and 32-36 weeks were collected, and the brain sections of the VZ/SVZ under the frontal lobe were examined for cytoarchitecture and distribution of nestin-positive cells with HE staining, immunohistochemistry or immunofluorescence.</p><p><b>RESULTS</b>The thickness of VZ underwent no significant changes at the gestational ages of 9-24 weeks (P>0.05) and became obviously thinner at 32 weeks (P<0.05), while the thickness of SVZ increased during 9-24 weeks (P<0.05) without obvious thinning at 32 weeks (P>0.05). VZ was thicker than SVZ at 9-11 weeks but became markedly thinner than SVZ after 14 weeks (P<0.05). The VZ contained denser cells than SVZ and showed a distinct boundary between the VZ and SVZ. Large numbers of nestin-positive cells were detected in the VZ and SVZ, and nestin immunoreactivity was found primarily in the cell processes and occasionally in the soma. Some nestin-positive cells in the SVZ had 1-3 processes. Nestin immunoreactivity in the VZ and SVZ gradually grew weak with development. The cells positive for both nestin and Ki67 were located mainly in the inner zone of the VZ and throughout the SVZ, where some nestin-positive but Ki67-negative cells were also found.</p><p><b>CONCLUSION</b>The SVZ fully extends and the neural stem cells in the VZ/SVZ can be morphologically heterogeneous during the development of fetal human brain.</p>
Subject(s)
Humans , Fetus , Frontal Lobe , Cell Biology , Embryology , Metabolism , Nestin , Metabolism , Neural Stem Cells , Metabolism , Neurons , MetabolismABSTRACT
<p><b>OBJECTIVE</b>To investigate the expression of metabotropic glutamate receptor 5 (mGluR5) and its cellular distribution in the frontal cortex, ventricular zone (VZ) and subventricular zone (SVZ) in human fetuses.</p><p><b>METHODS</b>According to the gestational age, the collected fetuses were divided into 4 groups, namely 9-11 weeks, 14-16 weeks, 22-24 weeks and 32-36 weeks. Brain tissue blocks including the frontal lobe or VZ/SVZ were prepared into slices, and the expression pattern and cellular distribution of mGluR5 in the frontal cortex and VZ/SVZ were observed by immunohistochemistry or immunofluorescence.</p><p><b>RESULTS</b>mGluR5 immunoreactivity was present in the cell membrane in the frontal cortex, VZ and SVZ from the 9th to 36th weeks and the immunoreactivity in the marginal zone (MZ) and cortical plate (CP) was markedly stronger than that in VZ and SVZ. The cells expressing mGluR5 included neural stem/progenitor cells in the VZ and SVZ, immature neurons in the VZ and MZ, and numerous mature neurons in the CP.</p><p><b>CONCLUSION</b>mGluR5 is expressed by a variety of cells such as neural stem cells in the frontal cortex, VZ and SVZ in human fetus, suggesting a role of mGluR5 in the development of human cerebral cortex.</p>
Subject(s)
Humans , Cerebral Cortex , Cell Biology , Cerebral Ventricles , Cell Biology , Metabolism , Fetus , Cell Biology , Metabolism , Frontal Lobe , Cell Biology , Metabolism , Neural Stem Cells , Cell Biology , Metabolism , Receptor, Metabotropic Glutamate 5 , Receptors, Metabotropic Glutamate , MetabolismABSTRACT
Objective To study the effect of glutamate on the expression of vascular endothelial growth factor (VEGF) mRNA and protein in cultured rat astrocytes. Methods Cultured rat astrocytes were randomly divided into 6 groups: control group (C), glutamate group (G), QA group (Q), DCG-IV group (D), L-AP4 group (L) and glutanmte-FMCPG gronp (G+M). Cells were cultured under nomoxic condition (95% air, 5% CO2). RT-PCR and ELISA methods were used to detect the expression of VEGF mRNA and protein in cultured astrocytes, respectively. G+ M group was preincubated with lmM MCPG for 30 min prior to the stimulation with glutamate. There were 7 time points at 0,4,8,12,16,24 and 48 h in each group except G+M group. Results The expression of VEGF mRNA and protein did not differ significantly among D group, L group and C group. Different from that in C group, the expression of VEGF mRNA and protein could be enhanced both in a dose-dependent and time-dependent manner in G group and Q group. Meanwhile, the enhanced expression of VEGF mRNA and protein in G group was completely suppressed by MCPG after 24 h. Conclusion Glutamate can increase the expression of VEGF mRNA and protein in cultured astrocytes, which may be due to the activation of group I metabotropic glutamate receptors in astrocytes.
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BACKGROUND: When central nervous system is injured, re-expression of nestin protein may enhance the anti-injury ability of cells and be advantageous to the repair of focus of injury.OBJECTIVE: To explore the reaction of nerve stem cell (NSC) in permanent brain ischemia through NSC migration and the change of nestin protein expression.DESIGN: A randomized and controlled verification research with experimental animals as subjects.SETTING: Anatomy teaching and research offices in a training school and a university.MATERIALS: The experiment was done in the Teaching and Research Office of Humane Anatomy in Medical College of Xi'an Jiaotong University from October 1999 to January 2001. Totally 75 healthy SD rats were selected and randomly divided into normal control group, experiment group and sham-operation group. Twenty-five animals were in each group. Heads of animals were cut and brain was got out at the 1st, 3rd, 7th, 14th and 28thdays after operation, 5 animals at each time.METHODS: The model was rats with permanent cerebral ischemia. Immunohistochemical dyeing methods were used to observe NSC migration,change of marker of NSC and nestin protein at the 1st, 3rd, 7th, 14th and 28th day after cerebral ischemia.MAIN OUTCOME MEASURES: ①Results of immunohostochemicaldyeing. ②Migration length of nestin+ cells in anterior subentricular zone (SZa) region of brain tissue at normal status and at different time points after cerebral ischemia. ③Number variation of nestin+ cells at different timepoits after ischemia near the ischemic region.RESULTS: Through nestin immunohistochemical dyeing, it was found that NSC in normal brain tissue mainly existed in subependymal zone (SEZ)region. NSC of SEZ migrated in the direction of ischemic region along ventri- corpus callosum after ischemia. Among them, it reached the farthest at the 7th day after ischemia. More nestin+ cells appeared near ischemic region at the 1st day, and then reduced little by little 3 days later.CONCLUSION: NSC has certain reactive ability to ischemic brain injury.Expression of nestin protein near ischemic region may be a kind of protection to injury.
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Objective To study the relationship between the reexpression of nestin protein and the expression of basic fibroblast growth factor (bFGF) protein in cerebral ischemia. Methods By using rat permanent cerebral ischemia as a model, immunohistochemical staining was used to observe the expression of nestin protein and the bFGF protein 1,3,7,14 and 28 days after cerebral ischemia. Results The number of nestin cells around the ischemic area increased 1 to 3 days after cerebral ischemia,but it decreased 7 days after cerebral ischemia. However, the number of bFGF cells around the ischemic area increased obviously 14 days after cerebral ischemia, but it decreased 28 days after cerebral ischemia. Conclusion Reexpression of nestin protein around ischemic cerebral tissues does not need the nourishment and susteinance of bFGF protein; nestin cells around ischemic foci are originated from astrocytes which replay the course of fetation.