抑制BET蛋白对心梗预后影响的延伸研究

#1. Supported by three consecutive programs from NSFC, we found that BET bromodomain inhibition attenuated pathological processes and improved the prognosis in mouse myocardial infarction model. #2. Recent studies showed that myocardial infarction activates Wnt signaling in bone marrow cells and ignites the inflammation. These findings further deepened our recognition of myocardial infarction as a global inflammatory disease...Our recently published two studies demonstrated that inhibition of BET bromodomain suppressed Wnt signaling activity in bone marrow cells. Based on our studies and that of others, we considered that BET bromodomain inhibition could not only suppress local inflammation in myocardial infarction site, but also downregulate Wnt signaling activity in bone marrow cells to alleviate global inflammatory response. Integration of both local and global anti-inflammatory effects, BET bromodomain inhibition improved myocardial infarction...We will demonstrate above-mentioned hypothesis from the following three aspects: #1. Determining the effects of BET bromodomain inhibition in inflammatory hematopoiesis and global inflammatory response. #2. Specifically knockout BRD4 gene in bone marrow cells and observe its effects on myocardial infarction mouse model. #3. In combination with recently proposed Super Enhancer theory, we try to investigate the molecular mechanism of myocardial infarction induced inflammatory response.

1.在3项国家自然基金连续资助下我们发现抑制BET蛋白改善了小鼠心梗表型与预后，并证实心梗局部炎症反应减轻；2.最近发现心梗导致了骨髓造血细胞Wnt通路激活，进而促进了炎症细胞增殖与全身炎症反应。这些研究从整体水平重新审视被认为是“局部疾病”的心梗，加深了我们对于心梗病理机制的认识。.我们最近发表的两项研究证实抑制BET蛋白下调了骨髓细胞Wnt通路活性。基于此，我们推测抑制BET蛋白不仅可以减轻局部炎症反应改善心梗，同时也可能通过抑制造血细胞Wnt通路减轻全身炎症反应，进而达到局部与全身双重抗炎效果，协同改善心梗病程。.我们将从以下三方面论证假说：1.观察BET抑制剂（JQ1）对心梗后“炎性造血”及全身炎症反应的影响；2.特异性敲除小鼠骨髓细胞BRD4后观察其对心梗的影响；3. 结合最近本课题组提出的“炎症超级增强子”学说探索BET蛋白参与心梗诱发炎症反应的分子机制。

在我们前期研究中发现BET蛋白参与了炎症基因转录，利用合作课题组开发的小分子抑制剂JQ1处理脐静脉内皮细胞能减轻TNFa诱导的炎症反应，也能减轻高胆固醇喂养小鼠的动脉粥样硬化病理过程。基于此，我们拟探索BET蛋白对心梗及心梗后缺血再灌注诱导的炎症反应的影响。在本次申报项目中我们发现JQ35减轻了心梗诱导的炎症反应，减轻了小鼠心肌纤维化。机制上利用染色质免疫共沉淀技术我们发现NF-kB和BRD4共同招募到了炎症基因启动子区。此外，基于这一项目我们也发现BET蛋白在成脂过程中发挥了关键作用，并且证实PPARγ与BRD4共同参与了超级增强子形成驱动成脂基因转录。本项目进一步证实了BET蛋白在炎症、成脂基因转录调控中的关键作用，为炎症、肥胖的干预提供了表观遗传研究数据的支持。在本项目资助下到目前为止已经发表SCI研究论文6篇，培养硕士博士共计10人。局限性：心脏特异性敲除BRD4导致了小鼠死亡，所以未能证实基因敲除是否导致心梗炎症减轻。