Lung Endothelial Aß in infectious proteinopathy

项目摘要/摘要 引起医院获得性肺炎的病原体会引起肺内皮细胞淀粉样蛋白的产生。这些 淀粉样蛋白可以具有抗菌特性，对宿主有益，也可以具有细胞毒性特性 对寄主不利。在后一种情况下，内皮源性淀粉样蛋白可能对终末器官有贡献 危重疾病后的功能障碍。细菌毒力因子，如假单胞菌 铜绿假单胞菌III型分泌系统效应器，最显著的是外酶Y，转化内皮淀粉样蛋白 从抗菌物质到细胞毒性物质。淀粉样β蛋白(Aβ)是一种细胞毒性淀粉样蛋白 内皮细胞感染。β从内皮细胞中释放出来，在那里它成为可传播和自我复制的 普恩细胞毒素。我们的初步数据显示，γ-分泌酶激活蛋白在 产生细胞毒性的A-β。我们发现γ-分泌酶激活蛋白在内皮细胞中的表达 偏置微阵列、RNAseq、甲基化和miRNA筛选，并确认蛋白质表达和功能 在微血管内皮细胞。γ-分泌酶激活蛋白缺失阻止细胞毒素Aβ的形成 物种。相反，在γ分泌酶激活蛋白缺失后，铜绿假单胞菌-和 胞外酶Y诱导的A-β具有抗菌特性。外切酶Y是一种杂乱的核苷酸环化酶 导致蛋白激酶A激活，这可能使Aβ磷酸化，从而增加其细胞毒活性。 这些数据表明，细胞毒性Aβ的产生是由于两种相互关联的机制，包括 γ-分泌酶激活蛋白的功能和A-β一旦产生就被磷酸化。因此，这项提议 验证外酶Y依赖于β分泌酶促进细胞毒素Aγ产生的假说 激活蛋白质。

PROJECT SUMMARY/ABSTRACT Pathogens responsible for nosocomial pneumonia elicit production of lung endothelial cell amyloids. These amyloids can have antimicrobial properties and be beneficial to the host, or they can have cytotoxic properties and be detrimental to the host. In the latter case, endothelial-derived amyloids may contribute to end organ dysfunction in the aftermath of critical illness. Bacterial virulence factors, such as the Pseudomonas aeruginosa type III secretion system effectors, and most notably exoenzyme Y, convert endothelial amyloids from antimicrobial to cytotoxic species. Amyloid-beta (Aβ) is one of the cytotoxic amyloids generated following endothelial infection. Aβ is released from endothelium where it becomes a transmissible and self-replicating prion cytotoxin. Our preliminary data reveals that γ-secretase activating protein plays a critical role in generating cytotoxic Aβ. We found γ-secretase activating protein expression in endothelial cells using non- biased microarray, RNAseq, methylation and miRNA screens, and confirmed protein expression and function in microvascular endothelium. γ-secretase activating protein deletion prevented formation of the cytotoxic Aβ species. Rather, following γ-secretase activating protein deletion the Pseudomonas aeruginosa- and exoenzyme Y-induced Aβ had antimicrobial properties. Exoenzyme Y is a promiscuous nucleotidyl cyclase that results in protein kinase A activation, which may phosphorylate Aβ necessary to increase its cytotoxic activity. These data suggest production of cytotoxic Aβ is due to two inter-related mechanisms, including an increase in γ-secretase activating protein function and the phosphorylation of Aβ once it is produced. Hence, this proposal tests the hypothesis that exoenzyme Y promotes the production of cytotoxic Aβ, dependent upon γ-secretase activating protein.