TET3调控OGFR-AS1 5hmC在激素性股骨头坏死骨微血管内皮细胞凋亡中的机制研究

骨微血管内皮细胞(BMECs)构成的骨内微血管内衬损伤是激素性股骨头坏死(SONFH)启动的关键因素，但机制未清。5-羟甲基胞嘧啶(5hmC)富集作为长久动态的表观遗传标记在调控基因表达中起重要作用。同时lncRNA可通过多种途径和方式参与基因表达调控，且预实验结果提示其参与了BMECs凋亡的调节，故推测：5hmC富集调控特异性lncRNA引起BMECs凋亡是SONFH发生的重要机制。为了验证该假说，筛选并确定OGFR-AS1是SONFH发生的特异性lncRNA；构建其及功能性靶基因PDK2腺病毒载体并转染细胞，地塞米松干预后分析BMECs凋亡情况，明确OGFR-AS1和PDK2在SONFH中的作用；观察5hmC富集在SONFH中的变化，并确定TET3为关键调控因子；探讨TET3调控OGFR-AS1启动子区5hmC动态修饰介导PDK2表达的机制，探寻关键靶点，为防治SONFH提供理论依据。

Bone microvascular endothelial cells (BMECs) constitute the intraosseous microvascular lining injury is a key factor for the initiation of steroid-induced osteonecrosis of femoral head (SONFH), but the mechanism is unclear. 5-Hydroxymethylcytosine (5hmC) enrichment as a long-term dynamic epigenetic marker plays an important role in regulating gene expression. Meanwhile, lncRNA can regulate gene expression in various approach and methodology, and preliminary results suggest that it participates in the regulation of BMECs apoptosis. Therefore, it is speculated that 5hmC enrichment regulates the specific lncRNA leading to apoptosis of BMECs, which is an important mechanism for the occurrence of SONFH. In order to verify this hypothesis, screen and validate that OGFR-AS1 is a specific lncRNA that occurs in SONFH. Construct the adenoviral vector of OGFR-AS1 and its functional target gene PDK2 to transfect the cells. After dexamethasone intervention, analyze the apoptosis of BMECs to clarify the role of OGFR-AS1 and PDK2 in SONFH. Observe the change of 5hmC enrichment in SONFH and determine TET3 as a key regulator. To explore the mechanism of TET3 regulating the 5hmC dynamic modification of OGFR-AS1 promoter to mediate PDK2 expression and explore key targets, which provide a theoretical basis for the prevention and treatment of SONFH.