Long non-coding RNA MALAT1 contributes to inflammatory response of microglia following spinal cord injury via modulating miR-199b/IKKβ/NF-κB signaling pathway

【作者】 周衡俊； 俞建波； 朱昱； 徐庆生； 郑秀珏； 詹仁雅；

【机构】 浙江大学医学院附属第一医院神经外科；

【摘要】 Purpose Long non-coding RNA(lncRNA) metastasis associated lung adenocarcinoma transcript 1(MALAT1) was widely recognized to be implicated in human cancer, vascular diseases and neurological disorders. This study was to explore the role and underlying mechanism of MALAT1 in acute spinal cord injury(ASCI).Materials and Methods ASCI models in adult rats were established and demonstrated by a numerical decrease in BBB scores. Expression profile of MALAT1 and miR-199 b following ASCI in rats and in vitro was determined using RT-qPCR. RNA pull-down assays combined with RIP assays were performed to explore the interaction between MALAT1 and miR-199 b.Results In the present study, MALAT1 expression was significantly increased in the spinal cord of the rat contusion epicenter accompanied by activation of IKKβ/NF-κB signaling pathway and an increase in the level of proinflammatory cytokines TNF-α and IL-1β. Upon treatment with LPS, MALAT1 expression dramatically increased in the microglia in vitro, but knockdown of MALAT1 attenuated LPS-induced activation of MGs and TNF-α and IL-1β production. Next, we confirmed that LPS-induced MALAT1 activated IKKβ/NF-κB signaling pathway and promoted the production of proinflammatory cytokines TNF-α and IL-1β through down-regulating miR-199 b. More importantly, MALAT1 knockdown gradually improved the hindlimb locomotor activity of ASCI rats, as well as inhibited TNF-α, IL-1β levels and Iba-1 protein, the marker of activated microglia in injured spinal cords.Conclusion Our study demonstrated that MALAT1 was dysregulated in ASCI rats and in LPS-activated MGs, and MALAT1 was expected to attenuate ASCI through repressing inflammatory response of MGs.更多还原

【Abstract】 Purpose Long non-coding RNA(lncRNA) metastasis associated lung adenocarcinoma transcript 1(MALAT1) was widely recognized to be implicated in human cancer, vascular diseases and neurological disorders. This study was to explore the role and underlying mechanism of MALAT1 in acute spinal cord injury(ASCI).Materials and Methods ASCI models in adult rats were established and demonstrated by a numerical decrease in BBB scores. Expression profile of MALAT1 and miR-199 b following ASCI in rats and in vitro was determined using RT-qPCR. RNA pull-down assays combined with RIP assays were performed to explore the interaction between MALAT1 and miR-199 b.Results In the present study, MALAT1 expression was significantly increased in the spinal cord of the rat contusion epicenter accompanied by activation of IKKβ/NF-κB signaling pathway and an increase in the level of proinflammatory cytokines TNF-α and IL-1β. Upon treatment with LPS, MALAT1 expression dramatically increased in the microglia in vitro, but knockdown of MALAT1 attenuated LPS-induced activation of MGs and TNF-α and IL-1β production. Next, we confirmed that LPS-induced MALAT1 activated IKKβ/NF-κB signaling pathway and promoted the production of proinflammatory cytokines TNF-α and IL-1β through down-regulating miR-199 b. More importantly, MALAT1 knockdown gradually improved the hindlimb locomotor activity of ASCI rats, as well as inhibited TNF-α, IL-1β levels and Iba-1 protein, the marker of activated microglia in injured spinal cords.Conclusion Our study demonstrated that MALAT1 was dysregulated in ASCI rats and in LPS-activated MGs, and MALAT1 was expected to attenuate ASCI through repressing inflammatory response of MGs.更多还原