摘要目的 评价外周神经IL-17在神经病理性痛(NP)大鼠血神经屏障损伤中的作用.方法 健康成年雄性SD大鼠40只,体重250～280 g,采用随机数字表法分为4组(n=10):假手术组(Sham组)、NP组、空载体组(BV组)和IL-17 siRNA重组慢病毒组(siRNA组).采用坐骨神经慢性束缚性损伤(CCI)法制备NP模型.CCI后3d时Sham组和NP组鞘内注射生理盐水10μl,BV组和siRNA组分别鞘内注射空载体和IL-17 siRNA-GFP重组慢病毒1×107TU各10μl,再用生理盐水10μl冲管,总容量20μl,每天1次,连续4d.于CCI前1 d、CCI后1、7、10、11、12、13、14 d时测定热缩足潜伏期(TWL)和机械缩足反应阈(MWT).于CCI后14 d痛阈测定结束后,取坐骨神经组织,观察超微结构,采用Western blot法检测坐骨神经IL-17、occludin和claudin-5的表达.结果 与Sham组比较,其余3组CCI后各时点MWT降低,TWL缩短,坐骨神经IL-17表达上调,occludin和claudin-5表达下调(P＜0.05或0.01).与NP组和BV组比较,siRNA组CCI后10-14 d时MWT升高,TWL延长,坐骨神经L-17表达下调,occludin和claudin-5表达上调(P＜0.05),坐骨神经病理学损伤减轻.结论 NP大鼠血神经屏障损伤的机制可能与外周神经IL-17水平升高有关.

abstractsObjective To evaluate the role of interleukin-17 (IL-17) in the peripheral nerve in blood-nerve barrier injury in a rat model of neuropathic pain (NP).Methods Forty healthy adult male Sprague-Dawley rats,weighing 250-280 g,were divided into 4 groups (n=10 each) using a random number table method:sham operation group (Sham group),NP group,blank vector group (BV group) and IL-17 siRNA recombinant lentivirus group (siRNA group).The rats were anesthetized with chloral hydrate,and intrathecal catheters were implanted.NP was produced by chronic constriction injury (CCI) to the sciatic nerve.Normal saline 10 μl was intrathecally injected at day 3 after CCI in Sham and NP groups.Blank vector and IL-17 siRNA-GFP recombinant lentivirus 1× 107 TU 10 μl were intrathecally injected,and then the tube was washed using normal saline 10 μl with the total volume of 20 μl once a day for 4 consecutive days.The mechanical paw withdrawal threshold (MWT) and thermal paw withdrawal latency (TWL) were measured on day 1 before CCI and days 1,7,10,11,12,13 and 14 after CCI.Animals were sacrificed after the last behavior testing,and a segment of injured sciatic nerve 7 mm in length and containing 3 ligatures were harvested for examination of the ultrastructure and for detection of the expression of IL-17,occludin and claudin-5 by Western blot.Results Compared with Sham group,the MWT was significantly decreased,TWL was shortened,the expression of IL-17 was up-regulated,and the expression of occludin and claudin-5 was down-regulated at each time point after CCI in the other groups (P＜0.05 or 0.01).Compared with NP group or with BV group,the MWT was significantly increased,TWL was prolonged,the expression of IL-17 was down-regulated,the expression of occludin and claudin-5 was up-regulated (P＜0.05),and the pathological changes of sciatic nerve were significantly attenuated in siRNA group.Conclusion The mechanism of blood-nerve barrier injury may be related to increased level of IL-17 in the peripheral nerve in a rat model of NP.