ANA-12通过靶向阻断BDNF/TrkB信号通路降低大鼠的脊髓炎症和缓解病理性疼痛

ANA 12 inhibits spinal inflammation and alleviates acute and chronic pain in rats by targeted blocking of BDNF/TrkB signaling

目的探讨ANA-12靶向阻断脑源性神经营养因子(BDNF)/原肌球蛋白受体激酶B(TrkB)信号对炎症痛的抑制作用及机制。方法将42只大鼠随机分为7组(6只/组):BDNF处理下的对照组、ANA-12处理组、BDNF处理组以及BDNF和ANA-12联合处理组(BDNF+ANA-12);炎症痛模型下的对照组、CFA处理组以及CFA和ANA-12联合处理组(CFA+ANA-12)。给药完毕后,对各组大鼠进行痛觉行为学检测,记录ANA-12处理对BDNF-急性痛和CFA-慢性炎症痛大鼠痛觉行为的影响;采用免疫印迹法检测各组大鼠脊髓组织TrkB信号、小胶质细胞标记蛋白Iba1和促炎细胞因子TNF-α以及炎症因子IL-1β、Caspase-1、NLRP3的表达水平。结果与对照组相比,BDNF增加自发缩足次数(P<0.05);与BDNF组相比,ANA-12降低自发缩足次数(P<0.05)。与对照组相比,CFA增加同侧机械刺激敏感性(P<0.05);与CFA组相比,ANA-12增加同侧缩足阈值(P<0.05)。与对照组相比,BDNF和CFA增加磷酸化TrkB(Y705)水平(P<0.05);与BDNF或CFA组相比,ANA-12降低TrkB(Y705)磷酸化水平(P<0.05)。与对照组相比,BDNF和CFA上调Iba1、TNF-α以及炎症因子表达(P<0.05);与BDNF或CFA组相比,ANA-12降低Iba1、TNF-α以及炎症因子表达水平(P<0.05)。结论ANA-12靶向阻断BDNF/TrkB信号可降低脊髓炎症并缓解急性痛和慢性痛。

Objective To investigate the inhibitory effect of ANA-12 that blocks brain-derived neurotrophic factor(BDNF)/tropomyosin receptor kinase B(TrkB)signaling on inflammatory pain in rats and explore the underlying mechanism.Methods Forty-two adult SD rats were randomized into BDNF-induced acute pain group(n=24)and CFA-induced chronic pain group.The former group were randomly divided into 4 subgroups,including a control group,ANA-12 treatment group,BDNF treatment group,and BDNF+ANA-12 treatment group;the latter group were subgrouped into control group,CFA treatment group(CFA)and CFA+ANA-12 treatment group.The effects of ANA-12 treatment on pain behaviors of the rats with BDNF-induced acute pain and CFA-induced chronic inflammatory pain were observed.Western blotting was used to examine TrkB signaling and expressions of microglia marker protein Iba1 and TNF-αin the spinal cord of the rats.Results BDNF injection into the subarachnoid space significantly increased the number of spontaneous paw withdrawal of the rats(P<0.05),which was obviously reduced by ANA-12 treatment(P<0.05).The rats with intraplantar injection of CFA,showed significantly increased ipsilateral mechanical stimulation sensitivity(P<0.05),and ANA-12 treatment obviously increased the ipsilateral foot withdrawal threshold(P<0.05).Treatment with either BDNF or CFA significantly increased the phosphorylation level of TrkB(Y705)in the spinal cord of the rats(P<0.05),which was significantly lowered by ANA-12 treatment(P<0.05).Treatment with BDNF and CFA both significantly up-regulated the expressions of Iba1 and TNF-αin the spinal cord(P<0.05),but ANA-12 significantly reduced their expression levels(P<0.05).Conclusion ANA-12 can reduce spinal cord inflammation and relieve acute and chronic pain in rats by targeted blocking of BDNF/TrkB signaling.