神经生长因子在异丙酚对大鼠海马神经元缺氧/复氧损伤中的作用及机制

Hippocampal neurons protecting effect of propofol against hypoxia/reoxygenation via inducing the expression of nerve growth factor

目的探讨不同浓度的异丙酚预处理对大鼠海马神经元缺氧/复氧损伤的保护及神经生长因子(Nerve growth factor,NGF)的作用。方法取离体培养的大鼠海马神经元,随机分成7组:对照组(Con组);CoC l2组(CoC l2组):加入300μM CoC l2处理1 h,然后更换正常的培养基培养24 h,之后更换无血清的培养基培养;脂肪乳剂组(Intralipid,Intra组):加入10%脂肪乳剂90μL预处理1 h后加入300μM CoC l2;异丙酚组(prop组)培养孔中加入10、20、50、100μM浓度的异丙酚预处理1 h后,同CoC l2组。MTT法测定细胞增殖,流式细胞技术测定细胞的凋亡。为进一步研究不同浓度的异丙酚对NGF及其受体TrkA表达的影响,本研究将大鼠海马神经元分为6组,分别为对照组,CoC l2组,10、20、50、100μM浓度异丙酚组,用RT-PCR检测NGF mRNA和TrkA mRNA表达。为探讨NGF/TrkA的作用,将细胞随机分为4组:对照组,CoC l2组,50μM异丙酚组,1.0μmol/L K252a组。结果脂肪乳剂组与CoC l2组比较,细胞活性差异无统计学意义(P>0.05),50μM异丙酚预处理可以明显增加大鼠海马神经元的增殖能力,减少凋亡(P<0.01),50μM异丙酚预处理上调NGF mRNA和TrkA mRNA的表达(P<0.05或P<0.01),10、20、100μM异丙酚组与缺氧/复氧组相比差异无统计学意义(P>0.05),异丙酚对海马神经元的保护作用被K252a抑制(P<0.01)。结论 50μM异丙酚预处理对缺氧/复氧后的大鼠海马神经元有保护作用,NGF及其受体TrkA在异丙酚的预处理中起到重要的作用。

Objective To establish a model of hypoxia/re-oxygenation （H/R）injury to examine the neuroprotective effect of propofol,and explore the role of nerve growth factor （NGF） in this action.Methods Hippocampal neurons were randomly assigned to one of 7 groups：Control group （Con group） ; CoCl2 group ; intralipid group （Intra group）：pretreated the neurons with 10％ intralipid 90 μL,then added 300 μM CoCl2 ;propofol group：pretreated the neurons with 10,20,50,100 μM propofol for 1 h,then added 300 μM CoCl2,stimulated with no serum media 24 hours later.MTT method and FACS was used to detect the proliferation and apoptosis of neurons.Then RT-PCR method was used to show the regulation of NGF and TrkA in propofol preconditioning H/R with different concentrations of propofol.To further investigate the effect of NGF/TrkA signaling pathway,the neurons were stimulated with 1.0 μ mol/LK252a before treated with 50 μM propofol,expression of TrkA were measured by Western blot.Results-H/R resulted in reduced cell viability and increased cell apoptosis in Hippocampal neurons,as indicated by MTT assay and FACS respectively （P ＜ 0.01）.Pretreatment with 50 μM propofol reversed H/R-induced neurotoxicity and induced a remarkable increase in NGF mRNA and TrkA mRNA expression and the inhibition of TrkA receptor by K252a（an inhibitor of Trk family members） altered the neuro-protective effect of propofol（P ＜0.05 or 0.01）.Conclusion The findings suggest the potential effect of propofol for protecting hippocampal neuron against H/R through NGF/Trk signaling pathway partly.