肝细胞生长因子重组腺病毒对高血压高血脂大鼠学习记忆能力及海马凋亡蛋白表达的影响

Effect of adenovirus vector encoding hepatocyte growth factor gene on learning and memory ability and expression of apoptosis protein in hippocampus of rats with hypertension and hyperlipemia

目的探讨肝细胞生长因子重组腺病毒(Ad-HGF)对高血脂高血压大鼠学习记忆能力及海马CA1区bcl-2和bax蛋白表达的影响。方法 30只雄性Sprague Dawley大鼠随机分为对照组、模型组和Ad-HGF组,每组10只。模型组和Ad-HGF组大鼠在无菌条件下行双侧肾动脉狭窄术,造成实验性肾性高血压,术后1周给予高脂饲料喂养16周;对照组大鼠仅分离双侧肾动脉,术后给予普通饲料喂养16周。造模后,Ad-HGF组大鼠经小脑延髓池一次性注入Ad-HGF 10μL;对照组和模型组大鼠分别经小脑延髓池一次性注入生理盐水10μL。给药后10 d,采用Morris水迷宫实验评估各组大鼠的学习记忆能力;免疫组织化学法检测大鼠海马CA1区中bcl-2和bax蛋白表达。结果模型组大鼠逃避潜伏期长于对照组,穿越平台次数和在目标象限停留时间少于对照组(P<0.05);Ad-HGF组大鼠逃避潜伏期短于模型组,穿越平台次数和在目标象限停留时间多于模型组(P<0.05)。与对照组比较,模型组大鼠海马CA1区bcl-2和bax蛋白阳性细胞数均增多,bcl-2/bax比值降低(P<0.05);与模型组比较,Ad-HGF组大鼠海马CA1区bcl-2蛋白阳性细胞数升高,bax蛋白阳性细胞数降低,bcl-2/bax比值升高(P<0.05)。结论外源性Ad-HGF能显著改善高血压高血脂大鼠的学习记忆能力,发挥对大脑的神经保护作用,其机制可能与抑制海马区神经细胞凋亡相关。

Objective To investigate the effect of adenovirus vector encoding hepatocyte growth factor gene（ Ad-HGF）on learning and memory ability and expression of bcl-2 and bax protein in hippocampal CA1 region of rats with hypertension and hyperlipemia. Methods Thirty male Sprague Dawley rats were randomly divided into control group,model group and Ad-HGF group,with 10 rats in each group. The rats in model group and Ad-HGF group were given bilateral renal artery stenosis operation under aseptic condition to establish experimental renal hypertension; one week after operation,the rats were fed with high fat diet for 16 weeks. The rats in control group were only separated the bilateral renal arteries,and then were given normal diet for 16 weeks after the operation. After modeling,the rats in Ad-HGF group were injected with Ad-HGF（ 10 μL）throuth cisterna magna; the rats in control group and model group were injected with the same volume of saline through cisterna magna. The learning and memory ability of rats were evaluated by Morris water maze test at 10 d after administration; the expression of bcl-2 and bax protein in hippocampus CA1 region were detected by immunohistochemistry. Results The escape latency of rats in model group was significantly longer than that in the control group,the number of cross platform and target quadrant time were significantly less than those in the control group（ P〈 0. 05）; the escape latency of rats in Ad-HGF group was significantly shorter than that in the model group,the number of cross platform and target quadrant time were significantly more than those in the model group（ P〈 0. 05）. Compared with the control group,the number of the bcl-2 and bax protein positive cells in hippocampal CA1 region of rats in the model group was increased,and the ratio of bcl-2/bax was decreased（ P〈 0. 05）; compared with the model group,the number of the bcl-2 protein positive cells in hippocampal CA1 region of rats in AdHGF group was increased,but the number of bax protein positive cells was decreased,and the ratio of bcl-2/bax was increased（ P〈 0. 05）. Conclusion Exogenous Ad-HGF can significantly improve the learning and memory ability of rats with hypertensive and hyperlipidemia,and it play a neuroprotective role in the brain,which may be related to the inhibition of apoptosis of hippocampal neurons.