Quantitative Glycoproteomics Reveals Distinctive N-Glycosylation Patterns in Human Kidney Tissues with Minor Glomerular Abnormalities.

Kidney diseases present substantial clinical challenges, with aberrant glycoproteins emerging as key pathogenic drivers. Minor glomerular abnormalities (MGAs), a category of unclassified glomerular lesions defined by subtle structural changes, are commonly detected in patients with persistent, asymptomatic, isolated proteinuria or microhematuria. Still their site-specific N-glycosylation patterns remain unexplored. To address this gap, a laboratory-developed pressure cycling technology-based quantitative glycoproteomics workflow was applied to compare intact N-glycopeptides (IGPs) among distant non-neoplastic tissues (DNTs; n = 24) and trace renal biopsy samples from MGA patients (n = 27). Integrated with high-resolution mass spectrometry, 672 upregulated IGPs (FC > 1.5, p < 0.05) and 573 downregulated IGPs (FC < 0.67, p < 0.05) in MGA tissues were quantified. Compared with DNTs, 24 glycoproteins associated with the PI3K-Akt signaling pathway exhibited broadly elevated IGP abundances in MGA samples. Site-specific N-glycosylation analysis further revealed distinct patterns among IgG subclasses and complement-related markers that distinguish MGA from DNT, offering new mechanistic insights into MGA pathogenesis. These novel glyco-signatures clarify the role of N-glycosylation in renal disease and validate this workflow as a powerful tool for trace-tissue analysis. This study lays the groundwork for translating N-glycosylation findings into clinical applications to improve MGA diagnosis and management.