Abstract: FR-PO0778
Blocking Polo-Like Kinase 2 (PLK2) Activation Reduces Podocyte Loss and Protects Against Proteinuric Kidney Injury
Session Information
- Glomerular Diseases: Cell Homeostasis and Novel Injury Mechanisms
November 07, 2025 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1401 Glomerular Diseases: Mechanisms, including Podocyte Biology
Authors
- Machineni, Prathyushasai, The University of Texas Medical Branch at Galveston Department of Internal Medicine, Galveston, Texas, United States
- Youssef, Mohamed A., The University of Texas Medical Branch at Galveston Department of Internal Medicine, Galveston, Texas, United States
- Akmal, Maarya, The University of Texas Medical Branch at Galveston Department of Internal Medicine, Galveston, Texas, United States
- Helmuth, Richard, Rush University Department of Internal Medicine, Chicago, Illinois, United States
- Lee, Ha Won, Rush University Department of Internal Medicine, Chicago, Illinois, United States
- Han, Zhe, University of Maryland Baltimore School of Medicine, Baltimore, Maryland, United States
- Gupta, Vineet, The University of Texas Medical Branch at Galveston Department of Internal Medicine, Galveston, Texas, United States
Background
Podocyte loss is a hallmark of focal segmental glomerulosclerosis (FSGS) and proteinuric kidney diseases. PLK2, a stress-activated serine/threonine kinase, is upregulated during glomerular injury and phosphorylates nucleoporins—key components of the nuclear pore complex (NPC). Genetic variants in various NPCs have been linked to FSGS, implicating NPC disruption in disease pathogenesis. We hypothesize that PLK2-mediated nucleoporin phosphorylation destabilizes the actin-nuclear scaffold, leading to cytoskeletal disassembly and podocyte detachment.
Methods
To identify small molecules that protect against podocyte injury, we developed a high-content, image-based high-throughput screening (HTS) platform using conditionally immortalized mouse podocytes cultured in 1536-well plates. Podocytes were injured with puromycin aminonucleoside (PAN), and ~60,000 chemically diverse compounds were screened. Hits were selected based on preservation of actin cytoskeleton and focal adhesion patterns. Compounds were validated by single-dose and dose-response assays, followed by fresh powder retesting. Mechanistic evaluation included immunofluorescence, live imaging, and a Drosophila nephrocyte injury model.
Results
From ~2,000 initial hits, fifty validated compounds included three PLK2 inhibitors. These restored podocyte morphology, actin structure, and adhesions following PAN/LPS injury. Mechanistically, PLK2 phosphorylates nucleoporins at conserved serine residues, triggering NPC disassembly, nuclear envelope deformation, and cytoskeletal collapse. In vivo, PLK2 inhibition reversed PAN-induced nephrin loss and restored filtration function dose-dependently, mimicking phenotypic rescue in FSGS-linked nucleoporin mutants.
Conclusion
Blocking PLK2 activation mitigates nucleoporin phosphorylation, podocyte loss, and proteinuria in FSGS models. This work identifies PLK2-driven NPC dysregulation as a therapeutic target in genetic and acquired glomerular disease.
Funding
- Other U.S. Government Support