BACKGROUND： Exogenous ganglioside-1 （GM1） can cross the blood-brain barrier and play a protective role against hypoxia-ischemia-induced brain damage. OBJECTIVE： To examine the possible mechanisms of exogenous GM1 ...BACKGROUND： Exogenous ganglioside-1 （GM1） can cross the blood-brain barrier and play a protective role against hypoxia-ischemia-induced brain damage. OBJECTIVE： To examine the possible mechanisms of exogenous GM1 protection in hypoxia-ischemia-induced brain damage in a neonatal rat model by measuring changes in brain mass, pathological morphology, growth-associated protein-43 expression, and neurobehavioral manifestations. DESIGN, TIME AND SETTING： A randomized block-design study was performed at the Immunohistochemistry Laboratory of the Pediatric Research Institute, Children＇s Hospital of Chongqing Medical University from August 2005 to August 2006. MATERIALS： A total of 36 neonatal, 7-day-old, Sprague Dawley rats were used in this experiment. The hypoxia-ischemia-induced brain damage model was established by permanently occluding the right carotid artery, followed by oxygen inhalation at a low concentration （8% O2, 92% N2） for 2 hours, METHODS： All rats were randomly divided into the following groups： GMI, model, and sham operation, with 12 rats each group. Rats in the GM 1 and model groups received hypoxic/ischemic-induced brain damage. Rats in the GM1 group received injections of GM1 （i.p., 20 mg/kg） at 0, 24, 48, 72, 96, 120, and 144 hours following models established, and rats in the model group were administered （i.p.） the same amount of saline. The right carotid artery was separated, but not ligated, in the sham operation group rats. MAIN OUTCOME MEASURES： At 1 week after surgery, expression of growth-associated protein-43, a marker of neural development and plasticity, was detected in the hippocampal CA3 region by immunohistochemistry. Brain mass was measured, and the pathological morphology was observed. At 4 weeks after surgery, behavioral changes in the remaining rats were tested by Morris water maze, and growth-associated protein-43 expression was measured. RESULTS： （1） In the GMI and sham operation groups, growth-associated protein-43 expression was greater in the hippocampal CA3 region compared to the model group 1 week after surgery （P 〈 0.05）. In all three groups, brain weight of the right hemisphere was significantly less than the left hemisphere, in particular in the model group （P 〈 0.05）. In the GMI group, the weight difference between two hemispheres, as well as the extent of damage in the right hemisphere, was less than the model group （P 〈 0.01 ）. In the sham operation Uoup, brain tissue consisted of integrated structures and ordered cells. In the model group, the cerebral cortex layers of the right hemisphere were not defined, neurons were damaged, and neurons were disarranged in the hippocampal area. In the GM1 group, neurons were dense in the right cerebral cortex and hippocampal area, with no significant change in glial proliferation. （2） The average time of escape latency in the GM1 group was shortened 4 weeks alter surgery, and significantly less than the model group （P 〈 0.05）. In addition, the frequency platform passing in the GMI group was significantly greater than the model group （P 〈 0.01）. CONCLUSION： Exogenous GM1 may reduce brain injury and improve learning and memory in hypoxia-ischemia-induced brain damage rats. This protection may be associated with increased growth-associated protein-43 expression, which is involved in neuronal remodeling processes.展开更多
目的:研究天麻素对激活的小胶质细胞miR-124和miR-155表达含量的影响。方法:分为体内实验和体外实验,体内实验:将新生3 d的SD大鼠随机分为假手术组(sham)、缺血缺氧模型组(HIBD)、缺血缺氧+天麻素干预组(G+HIBD),体外实验:将BV2细胞随...目的:研究天麻素对激活的小胶质细胞miR-124和miR-155表达含量的影响。方法:分为体内实验和体外实验,体内实验:将新生3 d的SD大鼠随机分为假手术组(sham)、缺血缺氧模型组(HIBD)、缺血缺氧+天麻素干预组(G+HIBD),体外实验:将BV2细胞随机分为对照组(control)、氧糖剥夺组(OGD)、天麻素+氧糖剥夺组(G+OGD),real time RT-PCR检测大鼠胼胝体及BV2细胞miR-124和miR-155的表达变化。结果:体内、体外real time RT-PCR结果显示:与sham、control组相比,HIBD组大鼠胼胝体及OGD处理的BV2细胞、OGD组的miR-155表达水平升高,miR-124表达水平降低(P<0.05);使用天麻素干预后,miR-155表达水平降低,miR-124表达水平升高(P<0.05)。结论:天麻素能促进激活的小胶质细胞miR-124的表达,抑制miR-155表达,从而发挥其神经保护作用。展开更多
基金supported by the Chongqing Municipal Health Bureau "Effect of ephedrine on neuronal plasticity of hypoxic-ischemic brain damage in neonatal rats" (Grant No. [Yu health science and education (2007) NO.1 (07-2-153)]).
文摘BACKGROUND： Exogenous ganglioside-1 （GM1） can cross the blood-brain barrier and play a protective role against hypoxia-ischemia-induced brain damage. OBJECTIVE： To examine the possible mechanisms of exogenous GM1 protection in hypoxia-ischemia-induced brain damage in a neonatal rat model by measuring changes in brain mass, pathological morphology, growth-associated protein-43 expression, and neurobehavioral manifestations. DESIGN, TIME AND SETTING： A randomized block-design study was performed at the Immunohistochemistry Laboratory of the Pediatric Research Institute, Children＇s Hospital of Chongqing Medical University from August 2005 to August 2006. MATERIALS： A total of 36 neonatal, 7-day-old, Sprague Dawley rats were used in this experiment. The hypoxia-ischemia-induced brain damage model was established by permanently occluding the right carotid artery, followed by oxygen inhalation at a low concentration （8% O2, 92% N2） for 2 hours, METHODS： All rats were randomly divided into the following groups： GMI, model, and sham operation, with 12 rats each group. Rats in the GM 1 and model groups received hypoxic/ischemic-induced brain damage. Rats in the GM1 group received injections of GM1 （i.p., 20 mg/kg） at 0, 24, 48, 72, 96, 120, and 144 hours following models established, and rats in the model group were administered （i.p.） the same amount of saline. The right carotid artery was separated, but not ligated, in the sham operation group rats. MAIN OUTCOME MEASURES： At 1 week after surgery, expression of growth-associated protein-43, a marker of neural development and plasticity, was detected in the hippocampal CA3 region by immunohistochemistry. Brain mass was measured, and the pathological morphology was observed. At 4 weeks after surgery, behavioral changes in the remaining rats were tested by Morris water maze, and growth-associated protein-43 expression was measured. RESULTS： （1） In the GMI and sham operation groups, growth-associated protein-43 expression was greater in the hippocampal CA3 region compared to the model group 1 week after surgery （P 〈 0.05）. In all three groups, brain weight of the right hemisphere was significantly less than the left hemisphere, in particular in the model group （P 〈 0.05）. In the GMI group, the weight difference between two hemispheres, as well as the extent of damage in the right hemisphere, was less than the model group （P 〈 0.01 ）. In the sham operation Uoup, brain tissue consisted of integrated structures and ordered cells. In the model group, the cerebral cortex layers of the right hemisphere were not defined, neurons were damaged, and neurons were disarranged in the hippocampal area. In the GM1 group, neurons were dense in the right cerebral cortex and hippocampal area, with no significant change in glial proliferation. （2） The average time of escape latency in the GM1 group was shortened 4 weeks alter surgery, and significantly less than the model group （P 〈 0.05）. In addition, the frequency platform passing in the GMI group was significantly greater than the model group （P 〈 0.01）. CONCLUSION： Exogenous GM1 may reduce brain injury and improve learning and memory in hypoxia-ischemia-induced brain damage rats. This protection may be associated with increased growth-associated protein-43 expression, which is involved in neuronal remodeling processes.
文摘目的:研究天麻素对激活的小胶质细胞miR-124和miR-155表达含量的影响。方法:分为体内实验和体外实验,体内实验:将新生3 d的SD大鼠随机分为假手术组(sham)、缺血缺氧模型组(HIBD)、缺血缺氧+天麻素干预组(G+HIBD),体外实验:将BV2细胞随机分为对照组(control)、氧糖剥夺组(OGD)、天麻素+氧糖剥夺组(G+OGD),real time RT-PCR检测大鼠胼胝体及BV2细胞miR-124和miR-155的表达变化。结果:体内、体外real time RT-PCR结果显示:与sham、control组相比,HIBD组大鼠胼胝体及OGD处理的BV2细胞、OGD组的miR-155表达水平升高,miR-124表达水平降低(P<0.05);使用天麻素干预后,miR-155表达水平降低,miR-124表达水平升高(P<0.05)。结论:天麻素能促进激活的小胶质细胞miR-124的表达,抑制miR-155表达,从而发挥其神经保护作用。
