Endothelial Dysfunction in the Development of Aortic Degeneration, Dissection, and Rupture

项目总结 升主动脉瘤和夹层(ATAAD)是一种极其致命的疾病。所做的贡献 ATAAD中内皮细胞功能障碍的研究受到的关注有限，因此仍知之甚少。COM- 我们初步研究的有力证据表明，内皮细胞(EC)损伤和内皮细胞内皮细胞损伤的关键作用。 主动脉变性和ATAAD发展过程中的内皮高通透性。中国人主动脉的scRNA-seq分析 散发性ATAAD患者表现出显著的EC功能障碍，RIP3和GSDMD上调触发- 下垂分别为坏死性下垂和下垂。在一种散发性ATAAD小鼠模型中，用高- 高脂饮食和血管紧张素II输注诱导内皮细胞RIP3和GSDMD，导致内皮高通透性， 纳米颗粒渗透、层间空间膨胀、弹性纤维分层和微观解剖。EC-RIP3- /-或EC-Gsdmd-/-显示纳米颗粒浸润和主动脉退变明显减少。]进一步调查- 与scatac-seq的对比显示，主动脉挑战增加了染色质在启动子/增强子上的可及性。 致炎/致死基因，可能通过激活促炎转录因子(TF)，如 作为IRF3。在人内皮细胞中，胞质DNA和STINT-TBK1信号是一种有效的上游触发活性的信号。 IRF3和BRG1的克隆及GSDMD表达的诱导。此应用程序的目标是测试 中心假说认为，主动脉应激激活内皮细胞内的炎症信号，从而触发表观遗传学。 诱导促炎和促死亡程序，导致EC坏死性下垂/下垂，屏障功能障碍- 血栓、血液成分渗入、主动脉壁退变和ATAAD形成。[目标1号将测试假设- RIP3介导的EC坏死性下垂和GSDMD介导的EC下垂损害了EC屏障功能， 从而促进炎性血液成分的渗入，促进主动脉退变和 ATAAD队形。在我们的零星ATAAD模型中，我们将比较主动脉退变和ATAAD形成 在对照组小鼠、EC-RIP3-/-小鼠、EC-Gsdmd-/-小鼠和WT小鼠中，用坏死性下垂/下垂抑制 Tor.]目标2将验证主动脉应激激活炎症信号(例如，刺痛通路)的假设 在内皮细胞内，这触发了促炎和促死亡计划的表观遗传诱导。我们将表演 用scRNA-seq和scATAC-seq分析未攻击和攻击的WT小鼠和EC的主动脉内皮细胞 特定的Sting KO小鼠。目标3将测试压力信号(例如胞浆DNA)触发感知的假设- 直接激活染色质重塑复合体的信号通路(例如， BRG1/SWI/SNF)和转录因子(如IRF3)诱导GSDMD表达并促进EC上睑下垂。我们将测试 在培养的人内皮细胞中的假说(Aim 3A)和[确认人ATAAD主动脉中的机械联系 (目标3B)]。我们期望，拟议的研究将提供新的见解，以了解分子机制。 零星的主动脉变性和ATAAD的形成，这反过来将使新的治疗方法的开发成为可能 用于预防疾病进展及其致命的后遗症。 1

PROJECT SUMMARY Ascending thoracic aortic aneurysms and dissections (ATAAD) are extremely lethal diseases. The contribution of endothelial dysfunction in ATAAD has received limited attention and thus remains poorly understood. Com- pelling evidence from our preliminary studies suggests a critical role for endothelial cell (EC) injury and endo- thelial hyperpermeability in aortic degeneration and ATAAD development. [scRNA-seq analysis of aortas from sporadic ATAAD patients revealed significant EC dysfunction with upregulation of RIP3 and GSDMD that trig- ger necroptosis and pyroptosis, respectively. In a sporadic ATAAD mouse model, aortic challenge with high- fat diet and angiotensin II infusion induced RIP3 and GSDMD in ECs, caused endothelial hyperpermeability, nanoparticle infiltration, interlaminar space expansion, elastic fiber delamination, and microdissection. EC-Rip3- /- or EC-Gsdmd-/- showed markedly reduced nanoparticle infiltration and aortic degeneration.] Further investiga- tion with scATAC-seq showed that aortic challenge increased chromatin accessibility at promoters/enhancers of the pro-inflammatory/pro-death genes, likely by activating pro-inflammatory transcription factors (TFs) such as IRF3. In human ECs, cytosolic DNA and STING-TBK1 signaling was a potent upstream trigger for the acti- vation of IRF3 and BRG1 and induction of GSDMD expression. The objective of this application is to test the central hypothesis that aortic stress activates inflammatory signaling within ECs that triggers epigenetic in- duction of a pro-inflammatory and pro-death program, leading to EC necroptosis/pyroptosis, barrier dysfunc- tion, blood component infiltration, aortic wall degeneration, and ATAAD formation. [Aim 1 will test the hypothe- sis that RIP3-mediated EC necroptosis and GSDMD-mediated EC pyroptosis compromise EC barrier function, thereby facilitating the infiltration of inflammatory blood components and promoting aortic degeneration and ATAAD formation. In our sporadic ATAAD model, we will compare aortic degeneration and ATAAD formation in control mice, EC-Rip3-/- mice, EC-Gsdmd-/- mice, and WT mice treated with a necroptosis/pyroptosis inhibi- tor.] Aim 2 will test the hypothesis that aortic stress activates inflammatory signaling (e.g., STING pathway) within ECs that triggers epigenetic induction of a pro-inflammatory and pro-death program. We will perform scRNA-seq and scATAC-seq analyses of ECs in aortas from unchallenged and challenged WT mice and EC- specific Sting KO mice. Aim 3 will test the hypothesis that stress signals (e.g., cytosolic DNA) trigger sensing- signaling pathways (e.g., STING-TBK) that directly activates chromatin remodeling complexes (e.g., BRG1/SWI/SNF) and TFs (e.g., IRF3) that induce GSDMD expression and promote EC pyroptosis. We will test the hypothesis in cultured human ECs (Aim 3A) and [confirm the mechanistic links in human ATAAD aortas (Aim 3B)]. We expect that the proposed studies will provide novel insight into the molecular mechanisms of sporadic aortic degeneration and ATAAD formation, which will in turn enable development of new treatments for preventing disease progression and its fatal sequelae. 1