MiR-139-3p通过靶向下调TRPV1缓解大鼠神经病理性疼痛

目的:研究miR-139-3p在大鼠神经病理性疼痛发生发展中的作用及其作用机制。方法:将大鼠随机分为假手术组(sham)、坐骨神经慢性压迫损伤模型组(chronic constriction injury group,CCI)、2 mg/kg miR-139-3p模拟物(mimic)鞘内注射组、4 mg/kg miR-139-3p mimic鞘内注射组。术后的第14 d,Real-time PCR法检测大鼠背根神经节(DRG)中miR-139-3p及TRPV1的表达。于注射前及注射后的第1、3、7、14 d,利用von Frey检测大鼠机械性痛阈及热辐射法检测大鼠热痛阈值。Western Blot法检测DRG中TRPV1的表达;ELISA法检测脊髓L4-L5组织中TNF-α及IL-1β的含量;双荧光素酶报告基因法检测miR-139-3p与TRPV1的靶向关系。结果:(1)与sham组相比较,miR-139-3p在CCI大鼠DRG中的表达显著下降,而TRPV1的表达显著上升(P0.05)。(2)与sham组相比较,CCI组中大鼠机械刺激缩足反射阈值及热刺激缩足反射潜伏期显著下降(P0.05);而与CCI组相比较,鞘内注射miR-139-3p mimic可显著促进大鼠机械刺激缩足反射阈值及热刺激缩足反射潜伏期的上升,抑制TRPV1的表达(P0.05)。(3)与sham组相比较,CCI组大鼠TNF-α及IL-1β含量显著上升(P0.05);而与CCI组相比较,鞘内注射miR-139-3p mimic可显著抑制TNF-α及IL-1β的产生(P0.05)。(4)miR-139-3p mimic转染可显著降低荧光素酶报告基因的荧光强度。结论:miR-139-3p通过靶向下调TRPV1的表达缓解大鼠神经病理性疼痛。

MiR-139-3p attenuates neuropathic pain in rat by down-regulating TRPV1

Objective:To analyze the effect of miR-139-3p on the progression of neuropathic pain in rat and explore the underlying mechanism.Methods:The rats were randomly divided into following groups:sham group,sciatic nerve chronic constriction injury group (CCI group),intrathecal injection of 2 mg/kg miR-139-3p mimic group,intrathecal injection of 4 mg/kg miR-139-3p mimic group.On day 14 after surgey,the expression of miR-139-3p and TRPV1 in DRG was measured by Real-time PCR.Bebavior test of the mechanical and thermal pain thresholds was measured by von Frey filement on the day before intrathecal injection and on day 1,3,7,14 after intrathecal injection.Western Blot was used to measure the expression of TRPV1.ELISA was used to measure the production of TNF-α and IL-1 β in L4-L5 segmenfs of spinal cord.The target relationship was measured by dual-luciferase reporter gene assay.Results:(1) Compared with sham group,the expression of miR-139-3p was significantly decreased and TRPV1 was increased in DRG of CCI rats (P ＜0.05).(2) The mechanical and thermal pain thresholds were significantly decreased in CCI group compared with sham group;but dramatically increased in miR-139-3p mimic group compared with CCI group (P ＜ 0.05).In addation,miR-139-3p mimic down-regulated the expression of TRPV1 (P ＜ 0.05);(3) The production of TNF-α and IL-1β was significantly increased in CCI group compared with sham group (P ＜ 0.05),whereas they were noticeably decreased in miR-139-3p mimic group compared with CCI group (P ＜0.05).(4)MiR-139-3p mimic significantly decreased the luciferase activity.Conclusion:MiR-139-3p attenuates neuropathic pain in rat by targeted down-regulating TRPV1 expression.