Role of Nod-like receptor family pyrin domain-containing 3 in dorsal root ganglion in persistent postoperative pain in rats / 中华麻醉学杂志

ABSTRACT

Objective:To evaluate the role of Nod-like receptor family pyrin domain-containing 3 (NLRP3) in the dorsal root ganglion (DRG) in persistent postoperative pain in rats.Methods:Forty-eight male Sprague-Dawley rats, in which IT catheters were successfully implanted, weighing 200-250 g, aged 2-3 months, were divided into 4 groups ( n=12 each) using a random number table method: sham operation group (S group), persistent postoperative pain group (P group), persistent postoperative pain+ NLRP3-siRNA group (P+ siRNA group) and persistent postoperative pain+ NLRP3-scrRNA group (P+ scrRNA group). A persistent postoperative pain model was established by skin/muscle incision and retraction (SMIR) in anesthetized animals.Normal saline 10 μl were intrathecally injected in S group and P group, NLRP3-siRNA 10 μl and NLRP3-scrRNA 10 μl were intrathecally injected in CP+ siRNA group and CP+ scrRNA group, respectively, at 3 days before operation.The mechanical paw withdrawal threshold (MWT) was measured at 1 day before operation (T 0) and 1, 5, 10, 15 and 20 days after operation (T 1-5). Six rats in each group were randomly selected and sacrificed at T 3, and the L 4-5 DRGs on the operated side were harvested for determination of the expression of NLRP3 and caspase-1 (by Western blot), NLRP3 mRNA expression (by real-time polymerase chain reaction) and content of interleukin-1beta (IL-1β) (by enzyme-linked immunosorbent assay). Results:Compared with group S, the MWT was significantly decreased at T 2-5, the expression of NLRP3 protein and mRNA in DRGs was up-regulated, and the content of IL-1β was increased in group P ( P<0.05). Compared with group P, the MWT was significantly increased at T 2-5, the expression of NLRP3 protein and mRNA and caspase-1 was down-regulated, and the content IL-1β was decreased in group P+ siRNA ( P<0.05), and no significant change was found in the parameters mentioned above in group P+ scrRNA ( P>0.05). Conclusion:NLRP3 in DRGs is involved in the development of persistent postoperative pain, and the mechanism may be related to the development of NLPR3 inflammasomes which further induces peripheral neuroinflammatory response in rats.