鞘内注射慢病毒载体-SOCS3缓解骨癌痛大鼠痛行为及其机制

摘要

目的:观察鞘内注射慢病毒(LV)过表达细胞因子信号转导抑制蛋白3(suppressor of cytokine signaling 3,SOCS3)对骨癌痛大鼠疼痛行为的影响并探讨其分子机制.方法:SD大鼠胫骨内注射乳腺癌Walker 256细胞建立骨癌痛模型,另以等体积生理盐水注射于大鼠胫骨内建立对照组.取12只造模1周的骨癌痛大鼠,6只鞘内注射LV-SOCS3,另外6只鞘内注射LV-NC.应用行为学方法分别检测对照组、模型组、LV-SOCS3组及LV-NC组大鼠的机械性缩足反射阈值(PWT)、热刺激后爪退缩潜伏期(PWL).蛋白质印迹法分别检测4组大鼠L2-L5背根神经节(dorsal root ganglion,DRG)中SOCS3、核转录因子(NF)-κB及P2X3受体的表达.结果:骨癌大鼠表现出明显的机械痛敏和热痛敏,PWT和PWL显著降低;L2~L5 DRG中SOCS3蛋白表达降低.鞘内注射LV-SOCS3后1周,骨癌大鼠的PWT和PWL值无明显变化,2周时PWT和PWL值明显升高(均P<0.05).鞘内注射LV-SOCS3后1周,可上调SOCS3在L2-L5DRG中的表达,同时降低NF-κB的蛋白表达,但P2X3受体表达无明显改变;鞘内注射LV-SOCS3后2周,可使NF-κB的表达维持低水平,同时降低了P2X3受体的表达.结论:骨癌痛大鼠鞘内注射LV-SOCS3可通过调节NF-κB与P2X3受体的表达缓解骨癌痛.%Objective:To investigate the effects of suppressor of cytokine signaling 3(SOCS3) overexpression by intrathecal injection lentiviral(LV)-SOCS3 on the pain behaviors and potential mechanism in a rat model of bone cancer pain induced by breast cancer cells.Methods:Rats were injected with breast cancer cells to establish the models of bone cancer pain and control rats were injected with equal volume of normal saline (NS).Six model rats were treated by intrathecal LV-SOCS3 injection,and the other six rats were treated by intrathecal injection of LV-NC after one week of cancer cells injection.The paw withdrawal latency(PWL) to thermal stimulation and paw withdrawal threshold(PWT) to von Frey filament stimulation were carried out on control group,bone cancer group,LV-SOCS3 group and LV-NC group.Western blotting was performed to detect changes of SOCS3,NF-κB and P2X3 receptors(P2X3R) at protein levels in L2-L5 dorsal root ganglion(DRGs) in different groups.Results:All rats presented enhanced mechanical and thermal hyperalgesia after intra-tibial injection of breast cancer cells,whose PWT and PWL were lower than those of control group.The protein level of SOCS3 was obviously reduced in bone cancer group.The PWT and PWL were higher than those of LV-NC group at two weeks after intrathecal injection of LV-SOCS3 but not at the time of one week after injection.SOCS3could be significantly increased and NF-κBreduced in L2-L5DRGs at one week after intrathecal LV-SOCS3 injection,but no change in P2X3R protein level was observed.At two weeks after intrathecal injection of LV-SOCS3,the protein level of NF-κBwas maintained at low level and P2X3R protein level was also significantly reduced.Conclusion:Intrathecal injection of LV-SOCS3 could modulate the expression of NF-κB and P2X3R in bone cancer pain rats,which resulted in attenuation of bone cancer pain.