血管局部炎症免疫调控网络及干预靶点

Recent studies indicate that both innate and acquired host immune responses play critical roles in the pathogenesis and progression of vascular disease. However, the molecular processes that initiate inflammation in the arterial wall are not fully understood. This proposal derives from 1 key and 2 pilot projects by the inaugural round of funding of NSFC Vascular Homeostasis and Remodeling Initiative in 2013. Our original results demonstrate that 1) high mobility group box-1 (HMGB1), a ubiquitous non-histone biding nuclear protein and damage-associated molecular pattern (DAMP) molecule, is a potent activator of macrophages (MΦ) via its pattern recognition receptor (PRR) TLR4-mediated MyD88 and TRIF signal pathways, 2) extracellular HMGB1 induces the release of pro-inflammatory monocyte chemotactic protein 1 (MCP-1), from MΦ, which via MCP-1 inducing protein (MCPIP), dynamically regulates the balance of MΦ Type I () and Type II (reparative) phenotypes, resulting in the activation of vascular endothelial cells (ECs) and smooth muscle cells (SMCs), and 3) T cell subtypes 9 (Th9) and 17 (Th17), by producing specific cytokines IL-9 and IL-17, respectively, up-regulates VCAM-1 positive ECs, whereas activated MΦ also generates IL-9. Accumulatively, these immune responses cause sterile inflammation in the arterial wall, critically contribute to acute (such as restenosis) or chronic (such as atherosclerotic plaque formation) vascular remodeling and injury. The above novel findings rise an intriguing possibility that a complex interplay exists among HMGB1, MΦ, Th9/Th17 (affectors), and ECs/SMCs (effectors), forming a local immune network in the vasculature. Therefore, our central hypothesis is that HMGB1 serves as a bridge linking both innate and acquired immunities (MΦ, Th9/Th17) to activate vascular ECs/SMCs, leading to a set of feedback responses from the latter. We plan to test our hypothesis by carrying out the following 3 specific aims: 1) how HMGB1 initiates both innate and acquired vascular immune responses in acute (i.e. neointimal hyperplasia) and chronic (i.e. atherosclerosis) vascular disease; 2) the molecular basis underlying HMGB1 linkage of MΦ, Th9/Th17 and ECs/SMCs; and 3) overall effect of targeting MΦ, Th9/Th17 and ECs/SMCs local network, using specific neutralizing antibodies and synthesized small peptides. Our object is to delineate the dynamical nature of the cross-talks in the above network. Comprehensive approaches will be utilized, including HMGB1-, IL-9, IL-17 and MΦ cell-specific cross-bred mice, Crispr/Cas9 mediated gene editing in selected cells, lineage tracing technique of living cells, and system biology analyses of the involving local immune network in both disease animal models and human patients. The anticipated outcome of the proposed research may not only unveil, for the first time, the complex molecular interplay in injured arterial wall, but also may provide a mechanistic basis for developing new therapeutic interventions to combat inflammatory vascular disease.

免疫炎症反应在血管稳态失衡与重构异常中发挥关键作用。先天与获得性免疫均参与血管局部炎症反应，构成多种细胞参与的炎症调控网络。本项目是由2013年首批获得资助的、三个均聚焦于血管免疫炎症反应项目的延伸和集成。各课题组均已取得重要进展，发表多篇高影响力论文，为深入开展集成研究提供了坚实的基础。我们最新研究表明：巨噬细胞(MΦ)和T细胞亚群(T-sub)以及HMGB1、MCPIP、MCP-1、IL9等在血管稳态失衡及重构异常中相互交联对话，至关重要 (详见正文)。本集成项目拟通过谱系示踪技术和生物信息学分析等多学科交叉的研究手段，首次阐明MΦ-Tsub-ECs/SMCs网络稳态失衡在血管再狭窄和AS进程中的调控机制和关键节点；同时，通过临床结合研究和药物干预实验开展转化医学研究，为发现炎症性血管疾病早期诊断和转归的分子标志及干预靶点奠定基础。

本课题关注免疫炎症反应在血管稳态失衡与重构异常中的关键作用及其相关分子机制，以期为发现炎症性血管疾病早期诊断和转归的分子标志及干预靶点奠定基础。整体项目围绕“HMGB1为关键节点介导的Mø和T-sub免疫调控网络紊乱导致血管稳态失衡和重构异常”这一关键科学问题展开研究。取得下列主要研究成果：1.组织蛋白酶Cathepsin L/V调控血管内皮细胞炎症促进内皮功能障碍及损伤;2.调控内皮细胞HMGB1表达影响血管疾病中的免疫炎症反应;3.脓毒血症中的磷脂酶C/钙信号通路调控血管内皮细胞焦亡介导的内皮细胞高通透性;4.炎性细胞因子及Ang II等其它相关致病因子通过巨噬细胞引发血管稳态失衡和疾病发生的分子机制研究;5.血管稳态失衡发生过程中的内皮细胞功能异常及其机制研究;6.T细胞亚群与其它炎症免疫调控网络关键节点之间的相互调节反馈机制和相应分子机理.综上所述，通过本课题的研究，我们从平滑肌/内皮细胞、T细胞亚群以及巨噬细胞等不同角度解析局部免疫炎症反应，由此深入研究免疫炎症过程对血管稳态和重构异常的调控机制，并且进一步确认HMGB1作为关键节点和潜在干预靶点的理论基础。