Proteomics analysis of specific mucosal regions of Salmonella-infected mouse cecum

The continuously remodeled extracellular matrix (ECM) plays a pivotal role in gastrointestinal health and disease, yet its precise functions remain elusive. In this project, we employed laser capture microdissection of cecal mucosa combined with low-input proteomics to investigate ECM remodeling during Salmonella-driven inflammation. To complement this, we probed how fibronectin fiber tension is altered using a mechanosensitive peptide probe. While fibronectin fibers in healthy intestinal tissue are typically stretched, fibronectin fiber relaxation occurred exclusively during late-stage infection at 72 hours and was localized to already existing clusters of infiltrated neutrophils in the cecal mucosa of Salmonella-infected mice.

持续重塑的细胞外基质（extracellular matrix, ECM）在胃肠道健康与疾病发生发展中发挥关键调控作用，但其精确的生理功能仍有待进一步阐明。本研究采用盲肠黏膜激光捕获显微切割（laser capture microdissection）结合低输入蛋白质组学技术，对沙门氏菌（Salmonella）诱导的炎症过程中的ECM重塑情况进行了系统探究。为补充该研究维度，我们利用机械敏感性肽探针（mechanosensitive peptide probe）检测了纤连蛋白纤维（fibronectin fiber）的张力变化情况。研究发现，健康肠道组织中的纤连蛋白纤维通常处于拉伸状态，而纤连蛋白纤维松弛现象仅在感染后72小时的感染晚期出现，且仅定位于沙门氏菌感染小鼠盲肠黏膜中已存在的浸润性中性粒细胞（neutrophils）簇。