miR-146b负调控NF-κB信号通路抑制异常应力下椎间盘退变的机制

Inflammation, which could be induced by abnormal loading, is one of the main cause of intervertebral disc degeneration(IVDD). It has been demonstrated that miR-146b played an important role in immunoregulation, which could repress inflammation and endothelial activity by inhibiting NF-κB pathway, however, it is still unclear whether it can inhibit intervertebral disc degeneration through above-mentioned way. According to microRNA array analysis of rats and mice respectively, we found that there was significant difference of miR-146b expression between normal and degenerative intervertebral discs. Our preliminary work also demonstrated that miR-146b expression decreased significantly in nucleus pulposus(NP) and was negatively correlated with IL-1β expression. So, we hypothesize that miR-146b inhibit IVDD following abnormal loading through down-regulating IL-1β signaling to NF-κB pathway. In order to verify this hypothesis, we will investigate the mechanism of miR-146b in inhibiting intervertebral disc degeneration following abnormal loading trough down-regulating NF-κB signaling pathway and its influence on vascular inflammation around the intervertebral disc by designing multi-level experiments using human intervertebral disc tissues, IVDD models of SD rats, miR-146b knock-out mice, through polymerase chain reaction (PCR),Western blot, small interference RNA(siRNA), lentivirus transfection, and tissue staining techniques et al. Our purpose is to determine the effects and mechanism of miR-146b on intervertebral disc degeneration and provide new clues of targeted therapy for primary IVDD.

异常应力可诱发椎间盘炎性反应，导致其退变。研究表明miR-146在免疫调节中发挥重要作用，可通过下调NF-κB通路抑制炎性反应及血管内皮细胞活性。但能否通过上述途径抑制异常应力下椎间盘退变，尚不清楚。预实验结果显示，退变髓核中miR-146b表达明显降低，且与IL-1β表达呈负相关。故我们提出假说，miR-146b通过下调髓核细胞IL-1β介导的NF-κB通路，抑制异常应力下椎间盘退变。为验证该假说，我们将通过人椎间盘组织、SD大鼠应力诱导椎间盘退变模型、miR-146b基因敲除小鼠，采用PCR、Western blot、RNA干扰、病毒转染、组织学染色等手段，从分子、细胞、组织以及动物体内多层次探讨miR-146b调控NF-κB通路在异常应力下椎间盘退变中的作用及可能机制，并阐明其对椎间盘退变周围微血管炎性反应的影响，为椎间盘退变早期阶段靶向干预治疗提供新的思路。