Gallart-Palau Xavier, Serra Aida, Sze Siu Kwan
School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore, 637551, Singapore.
University Hospital Institut Pere Mata, Reus, Tarragona, Spain.
BMC Biol. 2020 Nov 24;18(1):175. doi: 10.1186/s12915-020-00914-0.
Inflammation affecting whole organism vascular networks plays a central role in the progression and establishment of several human diseases, including Gram-negative sepsis. Although the molecular mechanisms that control inflammation of specific vascular beds have been partially defined, knowledge lacks on the impact of these on the molecular dynamics of whole organism vascular beds. In this study, we have generated an in vivo model by coupling administration of lipopolysaccharide with stable isotope labeling in mammals to mimic vascular beds inflammation in Gram-negative sepsis and to evaluate its effects on the proteome molecular dynamics. Proteome molecular dynamics of individual vascular layers (glycocalyx (GC), endothelial cells (EC), and smooth muscle cells (SMC)) were then evaluated by coupling differential systemic decellularization in vivo with unbiased systems biology proteomics.
Our data confirmed the presence of sepsis-induced disruption of the glycocalyx, and we show for the first time the downregulation of essential molecular maintenance processes in endothelial cells affecting this apical vascular coating. Similarly, a novel catabolic phenotype was identified in the newly synthesized EC proteomes that involved the impairment of protein synthesis, which affected multiple cellular mechanisms, including oxidative stress, the immune system, and exacerbated EC-specific protein turnover. In addition, several endogenous molecular protective mechanisms involving the synthesis of novel antithrombotic and anti-inflammatory proteins were also identified as active in EC. The molecular dynamics of smooth muscle cells in whole organism vascular beds revealed similar patterns of impairment as those identified in EC, although this was observed to a lesser extent. Furthermore, the dynamics of protein posttranslational modifications showed disease-specific phosphorylation sites in the EC proteomes.
Together, the novel findings reported here provide a broader picture of the molecular dynamics that take place in whole organism vascular beds in Gram-negative sepsis inflammation. Similarly, the obtained data can pave the way for future therapeutic strategies aimed at intervening in specific protein synthesis mechanisms of the vascular unit during acute inflammatory processes.
影响整个机体血管网络的炎症在包括革兰氏阴性菌败血症在内的多种人类疾病的进展和发生过程中起着核心作用。尽管控制特定血管床炎症的分子机制已得到部分阐明，但对于这些机制对整个机体血管床分子动力学的影响仍缺乏了解。在本研究中，我们通过将脂多糖给药与哺乳动物体内稳定同位素标记相结合，建立了一种体内模型，以模拟革兰氏阴性菌败血症中的血管床炎症，并评估其对蛋白质组分子动力学的影响。然后，通过将体内差异系统性去细胞化与无偏系统生物学蛋白质组学相结合，评估各个血管层（糖萼（GC）、内皮细胞（EC）和平滑肌细胞（SMC））的蛋白质组分子动力学。
我们的数据证实了败血症诱导的糖萼破坏的存在，并且首次表明影响这种顶端血管涂层的内皮细胞中基本分子维持过程的下调。同样，在新合成的内皮细胞蛋白质组中发现了一种新的分解代谢表型，其涉及蛋白质合成受损，这影响了多种细胞机制，包括氧化应激、免疫系统，并加剧了内皮细胞特异性蛋白质周转。此外，还发现几种涉及新的抗血栓和抗炎蛋白合成的内源性分子保护机制在内皮细胞中具有活性。整个机体血管床中平滑肌细胞的分子动力学显示出与内皮细胞中类似的损伤模式，尽管程度较轻。此外，蛋白质翻译后修饰的动力学在内皮细胞蛋白质组中显示出疾病特异性的磷酸化位点。
总之，此处报道的新发现为革兰氏阴性菌败血症炎症中整个机体血管床发生的分子动力学提供了更广泛的图景。同样，所获得的数据可为未来旨在干预急性炎症过程中血管单元特定蛋白质合成机制的治疗策略铺平道路。
