Proteome Profiling Reveals Inflammation and Fibrosis Biomarkers in Urinary Migrasomes of Patients with Diabetic Kidney Disease.

Urinary extracellular vesicles are emerging markers reflecting the disease status of diabetic kidney disease (DKD), but their types and functions in DKD disease are not yet fully understood. This study applied Astral-DIA proteome for the in-depth profiling of urinary migrasomes (umig, a novel type of extracellular vesicles) and serum from DKD patients, aiming to identify protein biomarkers indicative of disease status. Proteome analysis revealed that protein-protein interactions were identified among LAMA1, ITGB3, FGG, and FGB in the differentially expressed proteins of serum and umig in the NC group and the DKD group. ITGB3 and FGB were closely related to inflammation and fibrosis pathways. The cellular source of umig may mainly come from podocytes, with some from monocytes/macrophages. NLRC4, ITGB3, and FGB were detected in umig. HK2 cells stimulated by DKD patient-derived umig showed increased expression of TLR4, p-NF-κB p65, NLRC4, caspase-1 p20, IL-1β, and TNF-α, suggesting that umig promotes inflammation through the TLR4-NF-κB pathway. In addition, inflammation and fibrosis occurred in the renal tissues of patients with DKD and db/db mice, accompanied by significantly elevated levels of NLRC4, ITGB3, and FGB. The abundance of NLRC4, ITGB3, and FGB in urinary migrasomes highlights the promise of migrasomes as noninvasive biomarkers for gauging inflammation and fibrosis status in DKD.