Role of matrix metalloproteinase-3 in development of neuropathic pain in rats / 中华麻醉学杂志

ABSTRACT

Objective To investigate the effects of matrix metalloproteinase-3 (MMP-3) in the development of neuropathic pain (NP) in rats.Methods One hundred and eighty male Wistar rats weighing 200-250 g were randomly divided into 4 groups (n =45 each)sham operation group (S group),NP group,MMP-3-siRNA group (Msi group) and MMP-3-siRNA negative control group (NC group).NP was induced by ligation of L5 spinal nerve (SNL).Lentivirus with MMP-3-siRNA was injected intrathecally after SNL in group Msi.Lentivirus with NC-siRNA was injected intrathecally after SNL in group NC.The mechanical pain threshold was measured at day 7,14 and 21 after SNL.The rats were then sacrificed after the last measurement of the mechanical pain threshold.The lumbar segment of the spinal cord (L4-6) was removed for determination of the expression of MMP-3 and TNF-a protein and mRNA by RT-PCR and Western blot.Results The mechanical pain threshold was significantly decreased and the expression of MMP-3 and TNF-α protein and mRNA was up-regulated at each time point in groups NP and NC as compared with group S (P ＜ 0.05).The mechanical pain threshold was significantly higher and the expression of MMP-3 and TNF-α protein and mRNA was lower at each time point in Msi group than in NP group (P ＜ 0.05).Conclusion Up-regulation of the expression of MMP-3 activates microglia and induces the release of TNF-α,resulting in NP in rats.