Kidney Week

Abstract: TH-PO572

Translational Strategy to Evaluate Urinary Plasminogen as a Targetable Biomarker of Glomerular Diseases

Session Information

• Glomerular Diseases: Omics, Biomarkers, and Tools
  October 24, 2024 | Location: Exhibit Hall, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Glomerular Diseases

• 1401 Glomerular Diseases: Mechanisms, including Podocyte Biology

Authors

• de Cos, Marina, Icahn School of Medicine at Mount Sinai, New York, New York, United States

Marina de Cos, MD, MS

• Mosoyan, Gohar, Icahn School of Medicine at Mount Sinai, New York, New York, United States

Gohar Mosoyan, MS

• Wong, Jenny, Icahn School of Medicine at Mount Sinai, New York, New York, United States

Jenny Wong, PhD

• Ray, Justina, Icahn School of Medicine at Mount Sinai, New York, New York, United States

Justina Ray, MD

• Coca, Steven G., Icahn School of Medicine at Mount Sinai, New York, New York, United States

Steven G. Coca, DO, MS

• Campbell, Kirk N., Icahn School of Medicine at Mount Sinai, New York, New York, United States

Kirk N. Campbell, MD, FASN

Background

Given the heterogeneity of glomerular diseases and necessity of kidney biopsies for predictive purposes, non-invasive biomarkers defining mechanisms underlying progression are needed. Our previous work identified plasminogen as a cause of podocyte injury and established a correlation between plasminogenuria and renal dysfunction. Here, we propose a translational strategy to evaluate the plasminogen as a mediator of podocyte damage and the potential utility of plasminogen inactivation, through urokinase-type plasminogen activator (uPA) inhibition, as a protective strategy.

Methods

To evaluate the predictive value of the basal plasminogen, we performed a multicenter cohort study that included 1010 patients from CureGN with biopsy-proven glomerular disease. The main predictor was urine plasminogen at baseline and Cox regression was used to examine ESKD progression. To test uPA inhibition as a protective strategy, we developed a podocyte surface uPA activity assay in immortalized human podocytes, followed by High-Content Image Analysis of the cytoskeleton and focal adhesions by TIRF-Microscopy of podocytes treated with/without human plasminogen and uPA inhibitors.

Results

In the cohort of patients, adjusted Log₂uPlasminogen/Cr was significantly associated with ESKD (HR per doubling Log₂uPlasminogen/Cr 1.31 (95%CI 1.22-1.40), P < 0.001). Comparison of the predictive performance of models including Log2uPlasminogen/Cr, Log₂UPCR or both markers showed plasminogen model superiority. In the cell-surface uPA activity assay, amiloride had a IC50 of 8824 nM (5964-12661), compared to Candidates A and B (amiloride derivatives with computationally predicted increased uPA inhibitory activity), whose IC50 were 334.0 nM (249-397) and 643 (385-955). Quantitative high-content image analysis showed that plasminogen treatment resulted in a reduction in cell area and focal adhesions in plasminogen treated cells. Partial rescue was achieved after amiloride cotreatment whereas Candidates A and B completely reversed the phenotype.

Conclusion

Urinary plasmin(ogen) is independently associated with ESKD in patients with glomerular disease. Plasminogen inactivation by uPA inhibition may be a strategy to reduce podocyte damage. Patients most likely to respond to uPA inhibition could potentially be identified using our urinary biomarker approach.

Funding

• NIDDK Support