Objective: To observe the effect of moxibustion treatment on the expression of Nogo-A, Nogo receptor (NgR), neurotrophin receptor p75 (p75NTR) and leucine rich repeat and Ig domain containing 1 (Lingo-1) in brain tissue of rats with cerebral ischemia/reperfusion injury (CI/RI), so as to analyze its mechanism underlying improvement of CI/RI.
Methods: Male SD rats were randomly divided into sham operation group (16 rats), model group (17 rats), NEP1-40 (extracellular peptide residues 1-40, a blocker targeting NgR) group (model+blocker, 17 rats) and moxibustion group (model+moxibustion, 17 rats). The CI/RI model was established by occlusion of the left middle cerebral artery (MCAO). Moxibustion was applied to "Baihui"(GV20), right "Quchi"(LI11) and "Zusanli"(ST36) for 20 min, once a day for 14 days, with 2 days' rest after the top 7 days' intervention. For rats of the NEP1-40 group, 30 μL PBS containing 18 μg NEP 1-40 was injected into the epidural inferior vena (L5-S1) via a polyvinyl chloride conduit. The neurological deficit state in each group was evaluated by Longa's 5-point scale and Feeney's 7-point scale of beam walking test (BWT). The cerebral infarct volume was assessed by 2,3,5-triphenyltetrazole chloride staining. The brain tissue between the central anterior and posterior sulcus was taken for observing the expression of NgR and Lingo-1 by fluorescence double-label method, and for determining the expression levels of Nogo-A, NgR, p75NTR and Lingo-1 mRNAs and proteins by real-time quantitative PCR and Western blot, respectively.
Results: After modeling, the Longa's score, infarct volu-me percent, expression levels of Nogo-A, NgR, Lingo-1 and p75NTR mRNAs and proteins were significantly increased (P<0.01) and BWT score was obviously decreased (P<0.01) in the model group relevant to the sham operation group. In comparison with the model group, the increase of Longa's score, infarct volume percentage, expression levels of Nogo-A, NgR, Lingo-1 and p75NTR mRNAs and proteins and decrease of BWT score in NEP1-40 and moxibustion groups were reversed (P<0.01) except Nogo-A protein in the NEP1-40 group. The effect of moxibustion was significantly superior to that of blocker NEP1-40 in redu-cing the infarct volume percentage, and down-regulating the expression of Nogo-A mRNA and protein, p75NTR mRNA and protein, NgR and Lingo-1 proteins (P<0.01, P<0.05).
Conclusion: Moxibustion, similar to blocker NEP1-40 of NgR, can improve neurological dysfunction in CI/RI rats, which may be related to its functions in reducing cerebral infarction and down-regulating the activity of Nogo/neurotrophin receptor signaling pathway.
目的：观察艾灸治疗对脑缺血再灌注损伤(CI/RI)大鼠脑梗死区Nogo-A、Nogo-A受体(NgR)、协同受体p75神经营养素受体(p75NTR)与亮氨酸富集重复片段和Ig域包含子(Lingo-1)表达的影响, 探讨艾条悬灸治疗CI/RI的机制。方法：雄性SD大鼠按随机数字表法分为假手术组、模型组、阻断剂组和艾灸组, 假手术组16只, 其余每组17只。采用线栓法复制左侧大脑中动脉栓塞模型。造模后, 艾灸组用艾条悬灸“百会”和右侧“曲池”“足三里”20 min, 每日1次, 7次为1个疗程, 疗程中间休息2 d, 共治疗2个疗程；阻断剂组硬膜下推注Nogo分子胞外段氨基端前40个残基多肽(NEP1-40)。干预前后对各组大鼠进行神经功能评分, 干预后以Feeney走横木实验(BWT)评分对其精细运动功能恢复情况进行评估；用TTC染色法评估大鼠脑梗死体积；实时荧光定量PCR法检测梗死区脑组织Nogo-A、NgR、p75NTR、Lingo-1 mRNA表达；Western blot法检测梗死区脑组织Nogo-A、NgR、p75NTR、Lingo-1蛋白表达；免疫荧光双标法检测梗死侧脑组织NgR、Lingo-1的阳性表达。结果：与假手术组比较, 模型组大鼠神经功能评分、脑梗死体积百分比均明显升高(P<0.01), BWT评分明显下降(P<0.01), 梗死区脑组织Nogo-A、NgR、p75NTR、Lingo-1 mRNA及蛋白表达均明显升高(P<0.01), NgR和Lingo-1共表达增加(P<0.01)。与模型组比较, 除阻断剂组Nogo-A蛋白表达外, 两干预组大鼠上述其余指标都明显逆转(P<0.01)。与阻断剂组比较, 艾灸组大鼠脑梗死体积百分比、梗死区脑组织Nogo-A、p75NTR mRNA表达, Nogo-A、NgR、Lingo-1、p75NTR蛋白表达及NgR和Lingo-1共表达均降低(P<0.01, P<0.05)。结论：艾灸能产生类似于阻断剂NEP1-40的作用, 抑制脑梗死后Nogo/神经营养素受体信号通路相关分子的表达, 这可能是艾灸治疗脑梗死的机制之一。.
Keywords: Cerebral infarct volume; Cerebral ischemia/reperfusion injury; Moxibustion; Neurological deficit; Nogo/neurotrophin receptor signaling pathway.