糖酵解致Fascin乳酰化增强周细胞跨内皮迁移对脓毒症血管渗漏的保护作用及机制

血管渗漏是脓毒症等临床重症致多器官功能损伤甚至死亡的重要原因。我们前一国家自然基金基于周细胞对血管屏障的重要作用，发现外源性周细胞对脓毒症血管渗漏有一定改善作用，但效果不理想，其主要原因在于跨内皮迁移至目标部位的周细胞数量较少。通过预实验及文献分析推测丝状伪足蛋白Fascin的乳酰化可能增强周细胞跨内皮迁移的能力，进而提高对血管屏障功能的保护作用；其机制可能与Fascin lys241位点与乳酰基团结合，封闭其原有的泛素化降解位点，增强Fascin活性，进而促进微丝聚合成束和丝状伪足的形成有关。为此，本项目拟采用脓毒症模型，从整体、离体和细胞水平，通过蛋白组、修饰组以及基因突变等方法，研究糖酵解通过Fascin乳酰化修饰增强周细胞跨内皮迁移发挥对脓毒症血管屏障功能的保护作用，并阐明其机制。研究将为脓毒症血管渗漏防治提供新思路和措施。

Vascular leakage is an important cause of multiple organ function injury and even death caused by severe clinical diseases such as sepsis. Based on the important role of pericyte on vascular barrier, our previous research found that exogenous pericytes had a slight improvement on vascular leakage in sepsis, but the efficiency was not satisfactory, the main reason was that a relatively small number of pericytes migrated across the endothelium. Through pilot study and literature analysis, we hypothesize that the lactylation of Fascin in filopodia may play an important role in enhancing the capacity of pericyte transendothelial migration, thereby enhancing the protective effect of the vascular barrier function. The mechanism may be that the lactylation of Fascin on the lysine 241 residue blocks the original monoubiquitination sites, which enhances Fascin bundling activity and dynamics, and promotes the actin bundle assembly and the formation of filopodia. Based on this hypothesis, using septic shock rat model and cultured pericyte and vascular endothelial cell (VEC), proteomics and HPLC-MS/MS analysis and gene mutation method, we intend to investigate that glycolysis enhances the capacity of pericyte transendothelial migration through Fascin lactylation to play a protective role in vascular barrier function and illustrates its precise mechanism. This study will provide new ideas and measures for the treatment of vascular leakage in sepsis.