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

项目摘要 胸升主动脉瘤和夹层（ATAAD）是非常致命的疾病。的贡献 ATAAD中的内皮功能障碍受到的关注有限，因此仍然知之甚少。通信- 我们初步研究的有力证据表明，内皮细胞（EC）损伤和内皮细胞凋亡在内皮细胞损伤中起着关键作用。 主动脉变性和ATAAD发展中的上皮通透性过高。[来自大肠杆菌的大肠杆菌的scRNA-seq分析] 散发性ATAAD患者表现出显著的EC功能障碍，RIP 3和GSDMD上调， 格尔坏死性凋亡和胃灼热性凋亡。在散发性ATAAD小鼠模型中，用高浓度- 高脂饮食和血管紧张素II输注诱导EC中的RIP 3和GSDMD，引起内皮通透性过高， 纳米颗粒渗透、层间空间膨胀、弹性纤维分层和显微切割。EC-Rip3- /-或EC-Gsdmd-/-显示显著减少的纳米颗粒浸润和主动脉变性。此外， 与scATAC-seq的比较显示，主动脉激发增加了启动子/增强子处的染色质可及性， 促炎/促死亡基因，可能是通过激活促炎转录因子（TF）， IRF3。在人类内皮细胞中，胞质DNA和STING-TBK 1信号是激活细胞凋亡的有效上游触发因子。 IRF 3和BRG 1的表达和GSDMD表达的诱导。此应用程序的目的是测试 主动脉应激激活内皮细胞内的炎症信号传导，从而触发表观遗传损伤的中心假设 诱导促炎和促死亡程序，导致EC坏死性凋亡/焦亡，屏障功能障碍， 血管壁变性、血液成分浸润、主动脉壁变性和ATAAD形成。[Aim 1.测试hypothe-- RIP 3介导EC坏死性凋亡和GSDMD介导的EC焦亡损害EC屏障功能， 从而促进炎性血液成分的浸润并促进主动脉变性， ATAAD编队。在我们的散发性ATAAD模型中，我们将比较主动脉变性和ATAAD形成 在对照小鼠中，EC-Rip 3-/-小鼠、EC-Gsdmd-/-小鼠和用坏死性凋亡/焦亡性凋亡抑制剂处理的WT小鼠， （tor.）目的2将检验主动脉应激激活炎症信号传导的假设（例如，STING途径） 在内皮细胞内触发促炎和促死亡程序的表观遗传诱导。我们将执行 来自未攻击和攻击的WT小鼠和来自未攻击和攻击的WT小鼠的大肠杆菌中EC的scRNA-seq和scATAC-seq分析。 特异性Sting KO小鼠目标3将检验压力信号（例如，胞质DNA）触发传感- 信号通路（例如，STING-TBK），其直接激活染色质重塑复合物（例如， BRG 1/SWI/SNF）和TF（例如，IRF 3），其诱导GSDMD表达并促进EC焦亡。我们将测试 在培养的人EC中的假设（目的3A）和[证实了人ATAAD细胞中的机制联系 (Aim 3B）]。我们希望这些研究将为我们提供新的见解， 散发性主动脉变性和ATAAD形成，这反过来将有助于开发新的治疗方法 用于预防疾病进展及其致命后遗症。 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