miR-382调控在椎间盘退变中的作用研究

Intervertebral disc degeneration (IDD) acts as pathological basis of most spinal degenerative diseases. We found the miRNAs expression profiles in human degenerative nucleus pulposus using miRNA microarray, amongst which the expression of miR-382 was decreased. Furthermore, the biological effects of miR-382 in IDD remain unreported. MMP16 mRNA were predicted as putative targets of miR-382 by bioinformatics methods, the increase of MMP-16 in degenerative nucleus pulposus was confirmed in preliminary experiment. Apart from degradation of extracellular matrix (ECM) by itself, MMP-16 was reported to be able to activate MMP-2, amplificating the degradation cascade effect. On the basis of the aforementioned findings, a novel hypothesis of mechanism of IDD was put forward: deregulated miR-382 cause up-regulation of MMP-16, which further activate MMP-2 and degrade ECM altogether in IDD pathology. Lentivirus transfection, dual luciferase reporter, cell biology experiments, and X-ray technique will be conducted both in vitro and in vivo in the present study, with the hope of elucidating the detailed mechanisms of extracellular matrix alterations during IDD and providing novel therapeutic targets for the treatment of IDD.

椎间盘退变(IDD)是大多数脊柱退行性疾病的病理基础，我们通过miRNA芯片分析确定了人退变椎间盘髓核中miRNA 的表达谱，发现miR-382在退变椎间盘髓核中明显下调，而其在椎间盘退变中的作用尚无报道。生物信息法预测MMP16为miR-382的潜在靶基因，同时预实验提示退变椎间盘髓核中MMP-16上调。既往报道MMP-16除自身可降解细胞外基质(ECM)外，尚可激活MMP-2，使降解作用瀑布式的放大。基于前期研究，提出如下IDD机制假说：下调的miR-382靶向调控MMP-16上调，进一步激活MMP-2并与之共同降解ECM。通过体外及体内实验，采用慢病毒转染调控、双荧光素酶报告基因、细胞功能学实验、X线摄片等技术验证上述假说，以期阐明椎间盘退变中细胞外基质改变的分子机制，并可能为治疗椎间盘退变提供新靶点。

椎间盘退变(IDD)是大多数脊柱退行性疾病的病理基础，椎间盘退变过程中细胞外基质(ECM)的崩解越来越受到学界的关注。我们通过体外及体内研究，发现miR-382在退变椎间盘髓核中明显下调，MMP16为miR-382的下游靶基因。在椎间盘退变的病理过程中，miR-382的下调引起MMP16的表达上调，且上调的MMP-16进一步激活MMP-2，并与之共同降解椎间盘ECM中的Ⅱ型胶原、Aggrecan，使ECM的降解得到瀑布式放大，进而引起椎间盘退变的不断加剧。本研究阐明了椎间盘退变过程中miR-382调控MMP-16进一步引起的细胞外基质改变的分子机制，为治疗椎间盘退变的治疗提供了新靶点和新思路。