针刺对强迫游泳应激抑郁模型大鼠海马半胱氨酸天冬氨酸蛋白酶-3、c-Jun 表达的影响

目的探讨针刺对海马神经元凋亡的干预作用及是否涉及c-Jun氨基末端激酶(c-Jun N-terminal Kinase,JNK)信号通路,以揭示针刺的相关抗抑郁机制。方法将36只SD大鼠随机分成空白组、空白阻断剂组、模型组、模型阻断剂组、针刺组、针刺阻断剂组,阻断剂为JNK通路阻断剂SP600125,每组6只,采用强迫游泳应激结合孤养方法造模,针刺干预选取百会、印堂穴,每次20min,每天1次,治疗2 d。采用蛋白免疫印迹法检测大鼠海马JNK信号通路的底物c-Jun蛋白表达水平;采用实时荧光定量PCR(RT-PCR)技术检测大鼠海马凋亡相关因子半胱氨酸天冬氨酸蛋白酶-3(Caspase-3)基因表达水平。结果与空白组比较,Caspase-3基因表达、c-Jun蛋白表达,空白阻断剂组无显著差异(P0.05),模型组显著升高(P0.01);与模型组比较,模型阻断剂组、针刺组、针刺阻断剂组Caspase-3基因表达均显著降低(P0.01),模型阻断剂组、针刺组、针刺阻断剂组c-Jun的蛋白表达显著降低(P0.05、P0.05、P0.01)。结论针刺干预治疗可能通过抑制大鼠海马JNK信号通路活性,降低c-Jun的蛋白水平,减少促凋亡蛋白Caspase-3基因表达,从而抑制海马神经元凋亡,这可能是针刺抗抑郁作用所涉及到的分子机制之一。

Effects of acupuncture on cysteine-containing aspartate-specific proteases 3 and c-Jun in the hippocampus of depression rats induced by force swimming stress

Objective To observe the interventional effect of acupuncture on apoptosis of hippocampal neuron of depression model rats,and the effect on the c-Jun N-terminal kinase(JNK)pathway,so as to reveal the mechanism of anti-depression of acupuncture.Methods Altogether 36 Sprague-Dawley rats were randomly divided into six groups (each n =6):control group,control + inhibitor (SP600125,a JNK inhibitor )group,model group,model +inhibitor group,acupuncture group and acupuncture +inhibitor group.Except the control group and control +inhibitor group,the rats in the other four groups were forced to swim and be bred solitarily to establish the rat depression model.Baihui (GV20)and Yin-tang (GV29),the acupoints selected in rats of acupuncture group and acupuncture +inhibitor group, were needled for 20 minutes,once daily for two days.Using Western blot to detect the protein expression of c-Jun,the substrate of JNK pathway,in hippocampus of all groups of rats,and using RT-PCR to ex-amine the gene expression of apoptosis-related caspase-3 in hippocampus of rats.Results Compared with the control group,caspase-3 gene expression and c-Jun protein expression showed no significant difference in control +inhibitor group(P >0.05),but both were higher in those of model group(P <0.01).Compared with model group,the expression levels of caspase-3 were lower significantly in model+inhibitor group,acupuncture group and acupuncture + inhibitor group(P <0.01 ),and the protein expression levels of c-Jun were lower significantly in model +inhibitor group,acupuncture group and acu-puncture +inhibitor group(P <0.05,P <0.05,P <0.01 ).Conclusion Apoptosis of hippocampal neurons may be inhibited via the interventional effect of acupuncture on JNK pathway activities which down-regulate c-Jun protein expression and apoptosis-related caspase-3 gene expression.It may be one of the potential molecular mechanisms of antidepressant effect of acupuncture.