BET蛋白调控“成脂超级增强子”的理论研究及其靶向抑制剂的研发与应用探索

The BET bromodomain family members are epigenetic readers able to recognize the acetylated lysine side chain on histones and they play critical regulatory roles in gene transcription. Our previous study showed that BET bromodomain inhibition broke the formation of “pro-inflammatory super enhancers” and attenuate the pathological outcome of atherosclerosis. The data of this study has been published in Molecular Cell...Adipogenesis is a transcriptional cascade that under tight control by transcriptional factors, such as CEBPα and PPARγ, however, very few studies focused on the relationship between BET bromodomain and adipogenesis...In the preliminary study we found that JQ1 (a BET inhibitor) significantly suppressed adipogenesis in wild-type mice, which suggests that BET bromodomain involves in the adipogenic biology. Given this finding, we will further push the study forward in the next three aspects: .#1. Demonstrating whether the formation of “super enhancers” mediated by BET bromodomain and PPARγ drives the transcription of adipogenic genes; .#2. Determining whether specific knockout of BRD4 in adipose tissue influences in vivo adipogenesis; .and #3. Specifically release adipose-targeting-aptamer-JQ1 to fat tissue to observe the changes of metabolism and adipogenesis of the mice. This study will be undertaken in the State Key Laboratory directed by Dr. Tan, Weihong.

溴结构域蛋白（BET）家族是目前表观遗传研究热点，BET蛋白通过参与基因转录调控在生理及病理过程中发挥关键作用。申请者在哈佛医学院联合培养期间发现抑制BET蛋白阻碍了“促炎超级增强子”形成，并改善了小鼠动脉粥样硬化病程，该研究已在Cell子刊Molecular Cell发表。.成脂是转录因子调控下成脂相关基因程序性表达过程，然而BET蛋白对成脂影响还研究极少，且机制不详。申请者回国后在前期工作中发现JQ1（BET抑制剂）减轻了小鼠肥胖，提示BET蛋白参与了成脂调控。.基于此，本项目拟进一步探索：1. 细胞水平阐明机制，探索BET蛋白是否与PPARγ共同形成“超级增强子”并驱动成脂基因转录；2. 特异性敲除脂肪组织BRD4基因（最重要的BET家族成员）后观察对小鼠成脂影响；3. 利用湖南大学谭蔚泓院士主持的国家重点实验室平台，将核酸适配体与JQ1交联后靶向至脂肪组织，观察对小鼠成脂影响。

溴结构域蛋白（BET）家族是目前表观遗传研究热点，BET蛋白通过参与基因转录调控在生理及病理过程中发挥关键作用。我们前期已经发现抑制BET蛋白阻碍了“促炎超级增强子”形成，并改善了小鼠动脉粥样硬化病程，该研究已在Cell子刊Molecular Cell发表。.成脂是转录因子调控下成脂相关基因程序性表达过程，然而BET蛋白对成脂影响还研究极少，且机制不详。在我们的预实验中发现JQ1（BET抑制剂）减轻了小鼠肥胖，提示BET蛋白参与了成脂调控；在此基础上我们进步构建了BRD4（BET蛋白最关键的家族成员）flox小鼠，拟探索包括成脂调控在内的BRD4介导的生物学功能。.在本项目中我们完成了如下工作：1. 证实抑制BET蛋白在体内、体外实验中均减少了成脂，改善了小鼠糖耐量，提示其改善代谢的作用，并且在细胞水平阐明了机制，证实BET蛋白与PPARγ共同形成“超级增强子”并驱动成脂基因转录；2. 特异性敲除脂肪组织BRD4基因后发现小鼠白色脂肪和棕色脂肪组织成脂均减少；3. 目前正在进一步将核酸适配体与JQ1交联后靶向至脂肪组织，观察对小鼠成脂影响，但在从事这一部分研究工作中遇到了一些技术障碍，目前也正在改良之中。