TY - JOUR
T1 - Protein N-Glycans in Healthy and Sclerotic Glomeruli in Diabetic Kidney Disease
AU - Kidney Precision Medicine Project
AU - Veličković, Dušan
AU - Shapiro, John P.
AU - Parikh, Samir V.
AU - Rovin, Brad
AU - Toto, Robert D.
AU - Vazquez, Miguel A.
AU - Poggio, Emilio D.
AU - O’Toole, John F.
AU - Sedor, John R.
AU - Alexandrov, Theodore
AU - Jain, Sanjay
AU - Bitzer, Markus
AU - Hodgin, Jeffrey
AU - Veličković, Marija
AU - Sharma, Kumar
AU - Anderton, Christopher R.
N1 - Publisher Copyright:
Copyright © 2024 by the American Society of Nephrology.
PY - 2024/9/1
Y1 - 2024/9/1
N2 - Background Diabetes is expected to directly affect renal glycosylation; yet to date, there has not been a comprehensive evaluation of alterations in N-glycan composition in the glomeruli of patients with diabetic kidney disease (DKD). Methods We used untargeted mass spectrometry imaging to identify N-glycan structures in healthy and sclerotic glomeruli in formalin-fixed paraffin-embedded sections from needle biopsies of five patients with DKD and three healthy kidney samples. Regional proteomics was performed on glomeruli from additional biopsies from the same patients to compare the abundances of enzymes involved in glycosylation. Secondary analysis of single-nucleus RNA sequencing (snRNAseq) data were used to inform on transcript levels of glycosylation machinery in different cell types and states. Results We detected 120 N-glycans, and among them, we identified 12 of these protein post-translated modifications that were significantly increased in glomeruli. All glomeruli-specific N-glycans contained an N-acetyllactosamine epitope. Five N-glycan structures were highly discriminant between sclerotic and healthy glomeruli. Sclerotic glomeruli had an additional set of glycans lacking fucose linked to their core, and they did not show tetra-antennary structures that were common in healthy glomeruli. Orthogonal omics analyses revealed lower protein abundance and lower gene expression involved in synthesizing fucosylated and branched N-glycans in sclerotic podocytes. In snRNAseq and regional proteomics analyses, we observed that genes and/or proteins involved in sialylation and N-acetyllactosamine synthesis were also downregulated in DKD glomeruli, but this alteration remained undetectable by our spatial N-glycomics assay. Conclusions Integrative spatial glycomics, proteomics, and transcriptomics revealed protein N-glycosylation characteristic of sclerotic glomeruli in DKD.
AB - Background Diabetes is expected to directly affect renal glycosylation; yet to date, there has not been a comprehensive evaluation of alterations in N-glycan composition in the glomeruli of patients with diabetic kidney disease (DKD). Methods We used untargeted mass spectrometry imaging to identify N-glycan structures in healthy and sclerotic glomeruli in formalin-fixed paraffin-embedded sections from needle biopsies of five patients with DKD and three healthy kidney samples. Regional proteomics was performed on glomeruli from additional biopsies from the same patients to compare the abundances of enzymes involved in glycosylation. Secondary analysis of single-nucleus RNA sequencing (snRNAseq) data were used to inform on transcript levels of glycosylation machinery in different cell types and states. Results We detected 120 N-glycans, and among them, we identified 12 of these protein post-translated modifications that were significantly increased in glomeruli. All glomeruli-specific N-glycans contained an N-acetyllactosamine epitope. Five N-glycan structures were highly discriminant between sclerotic and healthy glomeruli. Sclerotic glomeruli had an additional set of glycans lacking fucose linked to their core, and they did not show tetra-antennary structures that were common in healthy glomeruli. Orthogonal omics analyses revealed lower protein abundance and lower gene expression involved in synthesizing fucosylated and branched N-glycans in sclerotic podocytes. In snRNAseq and regional proteomics analyses, we observed that genes and/or proteins involved in sialylation and N-acetyllactosamine synthesis were also downregulated in DKD glomeruli, but this alteration remained undetectable by our spatial N-glycomics assay. Conclusions Integrative spatial glycomics, proteomics, and transcriptomics revealed protein N-glycosylation characteristic of sclerotic glomeruli in DKD.
UR - http://www.scopus.com/inward/record.url?scp=85203238451&partnerID=8YFLogxK
U2 - 10.1681/ASN.0000000000000393
DO - 10.1681/ASN.0000000000000393
M3 - Article
C2 - 38771634
AN - SCOPUS:85203238451
SN - 1046-6673
VL - 35
SP - 1198
EP - 1207
JO - Journal of the American Society of Nephrology
JF - Journal of the American Society of Nephrology
IS - 9
ER -