LncRNA-LUCAT1靶向作用JMJD6调控P53乙酰化影响骨髓间充质干细胞凋亡的机制研究

Mesenchymal stem cell (MSC) transplantation for myocardium salvage is hot issue of myocardial infarction treatment. However, low survival rate of engrafted MSC in infarct area mainly limits therapeutic efficacy. Our preliminary data indicated hypoxia preconditioning enhanced anti-apoptosis ability of MSC, and LncRNA sequencing manifested LUCAT1 was most up-regulated. The silence of LUCAT1 obviously activated acetylation of P53 at the site of K382, obviously induced MSC apoptosis, otherwise, over-expressed LUCAT1 reduced apoptosis. The results of RNA Pull Down combined with mass spectrum have proved interaction of LUCAT1 and JMJD6, while the acetylation of P53 was controlled by JMJD6. We established hypothesis: LUCTA1 may modulate acetylation of P53-K382 by the activity of JMJD6, and regulated MSC apoptosis via manipulating PUMA/Bcl-2/Bax/Casp3 pathway. We employed RNA Pull Down combined with mass spectrum, RNA-IP and CO-IP to investigate mechanism LUCAT1 regulated acetylation of P53 by targeting JMJD6 to modulate MSC’s apoptosis at the molecular, cellular and animal levels, offering new viewpoint for stem cell therapy.

骨髓间充质干细胞(MSC)移植修复损伤心肌是心梗治疗的热点，但移植后细胞存活率低是限制疗效的主要原因。我们前期数据显示，低氧预处理能增强MSC的抗凋亡能力，lncRNA测序发现LUCAT1在低氧预处理的MSC中表达上调最明显。抑制LUCAT1表达后能激活其下游凋亡相关蛋白P53的K382位点乙酰化，显著促进MSC的凋亡。我们通过RNA Pull Down联合质谱分析发现LUCAT1和JMJD6存在相互作用，而P53-K382乙酰化受到JMJD6的调控。我们提出假说:LUCAT1可能通过调控JMJD6表达影响P53-K382的乙酰化，并调控PUMA/Bcl-2/Bax/Casp3通路影响MSC的凋亡。本研究拟通过质谱分析、RNA-IP、CO-IP等技术，从分子、细胞和动物水平深入研究LUCAT1靶向作用JMJD6调控P53乙酰化来影响MSC的凋亡，为提高移植干细胞的存活提供新思路。

心肌梗死是导致充血性心力衰竭的重要病因，目前骨髓干细胞（Mesenchymal stem cells, MSCs）移植治疗能促进心梗周边区域血管新生以及心肌保护作用，但移植后MSCs存活率低是限制其疗效的问题。立足于该问题，我们通过前期LncRNA测序研究结果发现缺氧预处理的MSCs能高表达LUCAT1，抑制LUCAT1表达能显著促进MSCs的凋亡，然后我们利用RNA Pull down，RIP和CHIP技术通过进一步实验验证发现LUCAT1通过募集JMJD6作用于叉头状转录因子的启动子FOXQ1，使其去甲基化，影响H4R3me和H3R2me的表达，进而下调Bax以及上调Bcl-2的表达，改善MSC的凋亡。本研究揭示了LUCAT1对于MSC凋亡的保护作用以及调控JMJD6-FOXQ1信号通路的机制，为改善MSC的凋亡提供潜在的作用靶点。