中文摘要：

背景：Micro RNAs在椎间盘退变的疾病中起重要作用,缺氧诱导因子缺失可加速椎间盘的退变。目的：检测缺氧诱导因子1α后小鼠椎间盘内micro RNAs的变化情况,探究microR NAs与椎间盘退变的关系及缺氧诱导因子1α调控椎间盘退变机制和通路。方法：通过前期构建的条件性敲除髓核细胞缺氧诱导因子1α基因的小鼠,分别取基因敲除组与正常对照组4周龄小鼠的椎间盘组织进行组织学染色观察;通过提取标本的总RNAs,从中分离microR NAs,荧光标记后与微阵列芯片杂交,扫描检测后数据经分析处理,筛选椎间盘组织中microR NA差异表达谱。采用实时荧光定量RT-PCR技术验证在椎间盘组织中均存在显著差异表达的micro RNAs。分析差异表达micro RNAs的靶基因及通路,预测其在椎间盘退变中的作用。结果与结论：缺氧诱导因子1α基因缺失小鼠椎间盘髓核细胞数量减少,细胞形态变小,细胞质着色加深;两组小鼠椎间盘中的micro RNAs的芯片筛选结果中,10个micro RNAs发生了明显的差异表达,其中有7个microR NAs发生上调,3个microR NAs发生下调。结果提示缺氧诱导因子1α缺失后可能引起某些重要的micro RNAs调节失衡,引起椎间盘髓核细胞大量的死亡,加速椎间盘的退变。

英文摘要：

BACKGROUND： It is confirmed that the absence of hypoxia-inducible factor-1α（HIF-1α） accelerates the degenerative process in the intervertebral discs, and microR NAs have an important role in degeneration of the intervertebral discs. OBJECTIVE： To evaluate the changes of microR NAs in the intervertebral discs of HIF-1α-deficient（HIF-1α-/-） mice which may mediate the signaling pathway of HIF-1α in the intervertebral discs. METHODS： As previously reported, HIF-1α-/- mice were established. HIF-1α-/- mice and HIF-1αflox/flox mice（control mice） aged 4 weeks were used. MRI and histological staining were used to evaluate the degeneration of the intervertebral discs. Total RNAs were extracted from the intervertebral discs tissues by Trizol, and the differential expression profile of microR NAs was harvested by significance analysis of microarrays and Cluster, based on microarray screening. Real-time quantitative reverse transcription-PCR was applied to verify the reliability of micro RNA array results. RESULTS AND CONCLUSION： The number of nucleus pulposus cells in the intervertebral discs of HIF-1α-/-mice was decreased, the cells presented with small size and the color deepened in the cytoplasm. Finally, differential expression profile of microR NAs（n=10） was obtained, seven of which were upregulated and three were downregulated. In conclusion, the loss of HIF-1α may cause the imbalance of some important miR NAs, which may result in a large amount of dead nuclear pulposus cells and mediate disc degeneration in HIF-1α-/-mice.