Relationship between mechanism of spinal interleukin-17 regulating neuropathic pain and peripheral nerve-related proteins in rats

Objective To evaluate the relationship between the mechanism of spinal interleukin-17 (IL-17) regulating neuropathic pain (NP) and peripheral nerve-related proteins in rats. Methods Thirty-six healthy adult male Sprague-Dawley rats, in which IT catheters were successfully implanted, aged 10-12 weeks, weighing 240-260 g, were divided into 4 groups (n=9 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). NP was induced by chronic constriction injury (CCI) to the sciatic nerve at 5 days after IT catheters were successfully implanted.At day 7 after CCI, normal saline 20 μl was intrathecally injected in Sham and NP groups, and in BV and siRNA groups, blank vector IL-17 siRNA-GFP and recombinant lentivirus 1×107 TU 10 μl were intrathecally injected, respectively, the catheter was flushed with normal saline 10 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.Proximal sciatic nerve tissues on the operated side were obtained at 14 days after CCI, the total protein was extracted, and the isobaric tags for relative and absolute quantification and liquid chromatography-tandem mass spectrometry were performed to stratify the differentially expressed proteins. Results Compared with group Sham, the MWT was significantly decreased and TWL was shortened at each time point after CCI in the other three groups (P 0.05). Fifty-eight differentially expressed proteins were identified, and among the 58 proteins, the expression of 21 proteins was significantly up-regulated and the expression of 37 proteins was down-regulated. Conclusion Fifty-eight peripheral nerve-related proteins identified are related to the mechanism of spinal IL-17 regulating neuropathic pain in rats. Key words: Interleukin-17; Neuralgia; Proteoins