Abstract: TH-PO0348
N-Glycosylation Patterns of Urinary Clusterin Determine the Severity of Diabetic Kidney Disease
Session Information
- Glomerular Diseases: Omics
October 22, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1401 Glomerular Diseases: Mechanisms, including Podocyte Biology
Authors
- Guo, Yiqing, Stony Brook Medicine, Stony Brook, New York, United States
- Bhalla, Gulika R., Stony Brook Medicine, Stony Brook, New York, United States
- Bano, Ruqiyya, Stony Brook Medicine, Stony Brook, New York, United States
- Alkhansa, Sahar, American University of Beirut, Beirut, Beirut Governorate, Lebanon
- Krishnan, Anirudh, Stony Brook Medicine, Stony Brook, New York, United States
- Bronstein, Robert, Stony Brook Medicine, Stony Brook, New York, United States
- Ju, Wenjun, University of Michigan Michigan Medicine, Ann Arbor, Michigan, United States
- Meliambro, Kristin, Icahn School of Medicine at Mount Sinai, New York, New York, United States
- Mallipattu, Sandeep K., Stony Brook Medicine, Stony Brook, New York, United States
Background
Majority of individuals with Diabetic Kidney Disease (DKD) do not progress to ESKD, but the factors that determine the progression remain poorly understood. We reported that, under diabetic conditions, a highly N-glycosylated extracellular chaperone, Clusterin (CLU), is secreted by the podocyte and subsequently endocytosed by megalin to prime mitochondria against proximal tubule injury. While higher urine CLU levels correlate with worsening kidney function in DKD, Clusterin-/- mice develop glomerulopathy
Methods
Human patient urine samples were analyzed using western blot to detect the different forms of CLU (DM-126, IgA nephropathy-10, Lupus Nephritis-10, FSGS-10 and control-36). PNGaseF enzymatic deglycosylation was used to remove N-linked glycans and show glycosylated vs. unglycosylated forms of CLU. LC-MS glycoproteomic analysis was performed to assess CLU glycosylation site occupancy. ELISAs were performed to quantify CLU, NGAL, and KIM-1 levels. Lectin assays were performed to assess specific CLU glycoproteins. snRNA-seq analysis was performed on kidney tissues collected from db/db mice and their age-matched controls at different ages.
Results
Expression arrays from Nephroseq demonstrate that glomerular Clusterin mRNA expression inversely correlates with eGFR in kidney biopsies with DKD. Urine CLU/Cr negatively correlated with eGFR (r =-0.408, p<0.001), positively correlated with urine microalbumin/cr (r =0.734, p<0.001), urine KIM-1/Cr (r =0.705, p<0.001), and urine NGAL/Cr (r =0.798, p<0.001) in DM. Similar correlations were observed in other glomerulopathies. Western blot revealed distinct CLU bands patterns (65kD, 37-42kD) in urine samples, with PNGase treatment showing that both bands were only N-glycosylated. Glycoproteomic analysis identified site specific CLU glycoforms including HexNAc(6)Hex(5) at N103 (42.43%) and HexNAc(5)Hex(5)Fuc(1)NeuAc(1) at N354 (45.51%), while lectin binding assays demonstrated that under-glycosylated urinary CLU correlated more specifically with eGFR than total urine CLU levels. SnRNA-seq analysis showed an upregulation in genes related to N-glycosylation in db/+ mice with age, however, this age-associated upregulation was absent in db/db mice.
Conclusion
N-glycosylation patterns of urine CLU determine the severity of DKD, with under-glycosylated CLU serving as a strong indicator of renal decline.
Funding
- NIDDK Support