Yu Jin, Zhu Hong, Ko Dorothy, Kindy Mark S
Department of Neurosciences, Medical University of South Carolina, Charleston, SC 29425, USA.
Brain Res. 2008 Oct 31;1238:143-53. doi: 10.1016/j.brainres.2008.08.053. Epub 2008 Aug 29.
Motoneuronotrophic factor (MNTF) is an endogenous neurotrophin that is highly specific for the human nervous system, and some of the observed effects of MNTF include motoneuron differentiation, maintenance, survival, and reinnervation of target muscles and organs. MNTF is a neuro-signaling molecule that binds to specific receptors. Using In Silico Analysis, one of the active sites of MNTF was identified as an analog of six amino acids (GM6). The effect of chemically synthesized GM6 on ischemic stroke was studied in the middle cerebral artery occlusion (MCAo) mouse model. Mice were subjected to 1 hur of ischemia followed by 24 h of reperfusion. Mice were injected intravenously with a bolus of GM6, at various doses (1 and 5 mg/kg) immediately after the start of reperfusion and examined for changes in physiological parameters, neurological deficits and infarct volume. GM6 was able to penetrate the blood brain barrier, and at both 1 and 5 mg/kg showed a significant protection from infarct damage, which translated to improvement of neurological deficits. Administration of GM6 demonstrated no changes in HR, BP, pO(2), pCO(2), or pH. A significant increase over the control group in CBF after reperfusion was observed with GM6 administration, which helped to mitigate the ischemic effect caused by the blockage of blood flow. The time window of treatment was assessed at various times following cerebral ischemia with GM6 demonstrating a significant protective effect up to 6-12 h post ischemia. In addition, GM6 increased neurogenesis, and decreased apoptosis and inflammation in the mouse brain following cerebral ischemic injury. These data suggest that GM6 is neuroprotective to the brain following IV injection in the mouse model of MCAo.
运动神经元营养因子(MNTF)是一种对人类神经系统具有高度特异性的内源性神经营养因子,MNTF所观察到的一些作用包括运动神经元分化、维持、存活以及靶肌肉和器官的再支配。MNTF是一种与特定受体结合的神经信号分子。通过计算机分析,MNTF的一个活性位点被鉴定为六个氨基酸的类似物(GM6)。在大脑中动脉闭塞(MCAo)小鼠模型中研究了化学合成的GM6对缺血性中风的影响。小鼠经历1小时的缺血,随后再灌注24小时。在再灌注开始后立即给小鼠静脉注射不同剂量(1和5mg/kg)的GM6推注,并检查生理参数、神经功能缺损和梗死体积的变化。GM6能够穿透血脑屏障,1mg/kg和5mg/kg剂量的GM6均显示出对梗死损伤的显著保护作用,这转化为神经功能缺损的改善。GM6给药后心率、血压、pO₂、pCO₂或pH均无变化。GM6给药后再灌注时脑血流量(CBF)比对照组显著增加,这有助于减轻血流阻断引起的缺血效应。在脑缺血后的不同时间评估治疗的时间窗,GM6在缺血后6 - 12小时内均显示出显著的保护作用。此外,GM6增加了小鼠脑缺血损伤后的神经发生,并减少了细胞凋亡和炎症。这些数据表明,在MCAo小鼠模型中静脉注射后,GM6对大脑具有神经保护作用。