Effect of electroacupuncture on neurological deficit and activity of TLR2/NF-κB signaling in ce-rebral ischemia /reperfusion injury rats / 针刺研究

ABSTRACT

OBJECTIVE: To observe the effect of electroacupuncture (EA) on neurological behavior and activity of Toll-like receptor 2 / nuclear factor kappa B (TLR2/NF-κB) signaling of the ischemic cerebral area in cerebral ischemia-reperfusion injury (CIRI) rats, so as to explore its mechanisms underlying improvement of CIRI. METHODS: A total of 120 male SD rats were randomly divided into blank control, sham operation, model, EA and EA＋NF-κB inhibitor (Pyrrolidine Dithiocarbamate Hydrochloride, PDTC, EA＋PDTC) groups which were further divided into 3, 7, 14 and 28 d subgroups (n＝6 in each subgroup). The CIRI model was established by occlusion of the middle cerebral artery for 90 min, followed by reperfusion. EA (1－20 Hz, 6 V) was applied to "Shuigou" (GV26), "Neiguan" (PC6), "Sanyinjiao" (SP6) and "Weizhong" (BL40) for 30 min, once a day for 28 days. For rats of the EA＋PDTC group, PDTC solution (120 mg/kg) was intraperitoneally injected on the 3rd day after successful modeling and before EA intervention. The neurological deficit severity (Zea Longa score) was assessed 3, 7, 14 and 28 days after modeling. The expression levels of TLR2, Interleukin-1 receptor-associated kinase (IRAK) and NF-κB mRNAs in the ischemic penumbra region of brain tissue were detected by real-time fluorescence quantitative PCR. RESULTS: Following modeling, the neurological deficit scores were significantly increased from the 3rd day on after CIRI (P<0.05), the expression levels of TLR2 mRNA on day 3, 7, 14 and 28, and IRAK mRNA on day 3 and 7, as well as NF-κB mRNA on day 3, 7 and 14 were significantly up-regulated in the model group relevant to the blank control group (P<0.05). After EA intervention, the neurological deficit scores were significantly decreased in the EA group on day 3, 7 and 28 and in the EA＋PDTC group on day 3, 7, 14 and 28 in comparison with those of the model group (P<0.05). In addition, the expression levels of TLR2 mRNA and NF-κB mRNA on day 3, 7 and 14 in the EA group, and on day 3, 7, 14 and 28 in the EA＋PDTC group, IRAK mRNA on day 3 in the EA and EA＋PDTC group were significantly down-regulated (P<0.05), but those of IRAK mRNA on day 14 and 28 in the EA group were significantly up-regulated in comparison with those of the model group (P<0.05). The effect of the EA＋PDTC was obviously superior to that of simple EA in down-regulating the expression of TLR2 (on day 28), and IRAK (on day 3, 14, 28), and NF-κB (on day 3, 7 and 14) (all P<0.05). CONCLUSION: EA stimulation can improve the symptoms of neurological deficits in CIRI rats, which may be related to its effect in suppressing the expression of TLR2, NF-κB and IRAK mRNAs of the ischemic cerebral tissue, i．e., down-regulating the activity of TLR2/NF-κB signaling.