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.