脑卒中后抑郁大鼠海马和丘脑神经生长因子及其受体的表达变化

Expression of NGF and its receptor in hippocampus and thalamus of depression rats after cerebral stroke

目的探讨脑卒中后抑郁(post stroke depression,PSD)大鼠海马和丘脑神经生长因子(nerve growth factor,NGF)及其高亲和力受体TrkA mRNA和蛋白的表达变化。方法选择健康成年SD大鼠52只,随机分为对照组、抑郁组、脑卒中组和PSD组,每组13只。应用RT-PCR检测各组大鼠造模后第29天海马及丘脑NGF和TrkA mRNA的表达变化;利用免疫组织化学方法检测各组大鼠海马及丘脑NGF和TrkA免疫阳性细胞数的表达变化。结果各组海马及丘脑均有NGF和TrkA mRNA的表达。PSD组海马NGF mRNA表达较对照组明显降低(0.646±0.264 vs 0.956±0.263,P<0.05);各组TrkA mRNA在海马的表达无统计学差异(P>0.05);各组丘脑NGF和TrkA mRNA表达差异无统计学意义(P>0.05)。PSD组海马NGF阳性细胞较对照组明显减少[(14.46±2.64)个vs(19.56±2.63)个,P<0.05];各组丘脑NGF阳性细胞差异无统计学意义(P>0.05);各组海马TrkA阳性细胞及丘脑TrkA阳性细胞数无统计学差异(P>0.05)。结论 PSD大鼠海马NGF mRNA及蛋白表达减少可能与PSD发病相关。

Objective To study the expression of NGF and its high affinity receptor TrkA mRNA and protein in hippocampus and thalamus of depression rats after cerebral stroke.Methods Fiftytwo healthy adult SD rats were randomly divided into control group,depression group,stroke group and post cerebral stroke group（13in each group）.Expressions of NGF and TrkA mRNA in rat hippocampus and thalamus were detected by reverse transcriptase polymerase chain reaction and immunohistochemistry respectively.Results The NGF and TrkA mRNA were expressed in rat hippocampus.The NGF mRNA expression level was significantly lower in post cerebral stroke group than in control group（0.646±0.264 vs0.956±0.263,P0.05）.However,there was no significant difference compared with the other groups（P0.05）.The gene expression of TrkA in the hippocampus of each group was not significatly different（P0.05）.The expression of NGF mRNA and TrkA mRNA in the thalamus not significatly different in all groups（P0.05）.The number of NGF-positive cells was significantly less in post cerebral stroke group than in control group（14.46±2.64 vs 19.56±2.63,P0.05）.However,no significant difference was found in the number of NGF-positive cells in thalamus and TrkA-positive cells in hippocampus and thalamus（P0.05）.Conclusion Low NGF mRNA and protein expression levels in rat hippocampus are associated with post cerebral stroke.