Abstract: TH-OR038
Downregulation of PARD6B Is Associated with Irreversible Podocyte Damage in FSGS
Session Information
- Glomerular Precision Nephrology: Novel Mechanisms, Biomarkers, and Therapeutic Targets
November 06, 2025 | Location: Room 310A, Convention Center
Abstract Time: 04:40 PM - 04:50 PM
Category: Glomerular Diseases
- 1401 Glomerular Diseases: Mechanisms, including Podocyte Biology
Authors
- Shibata, Katsuaki, Nagoya University Graduate School of Medicine, Nagoya, Japan
- Maeda, Kayaho, Nagoya University Graduate School of Medicine, Nagoya, Japan
- Sato, Yuka, Nagoya University Graduate School of Medicine, Nagoya, Japan
- Kato, Noritoshi, Nagoya University Graduate School of Medicine, Nagoya, Japan
- Kosugi, Tomoki, Nagoya University Graduate School of Medicine, Nagoya, Japan
- Maruyama, Shoichi, Nagoya University Graduate School of Medicine, Nagoya, Japan
Group or Team Name
- Department of Nephrology.
Background
Focal segmental glomerulosclerosis (FSGS) often presents treatment resistance, necessitating further elucidation of its pathophysiology. Podocytes, the glomerular epithelial cells, maintain homeostasis through polarity regulation, but the role of polarity-related factors in FSGS remains poorly understood. We analyzed the expression of polarity-related factors in isolated glomeruli from human FSGS using Nephroseq, an omics analysis database for kidney diseases. As a result, we found that PARD6B was significantly downregulated in FSGS compared to normal controls, along with CRB2, which is a causative gene for hereditary FSGS. Since PARD6B is mainly expressed in podocytes within the glomerulus, this suggests a potential association with podocyte injury. This study aims to investigate the functional role of PARD6B in the pathogenesis of FSGS.
Methods
We evaluated PARD6B expression in isolated glomeruli from podocyte injury mouse models induced by adriamycin or LPS. Tamoxifen-inducible podocyte-specific PARD6B-deficient mice were generated, and urine protein and renal pathology were assessed. In vitro functional analyses were performed using human podocyte cell lines treated with TNF-α or PARD6B siRNA.
Results
Glomeruli isolated from podocyte-damaged mouse models exhibited significantly reduced PARD6B expression. Tamoxifen-induced podocyte-specific PARD6B-deficient mice showed severe proteinuria, podocyte swelling, epithelial cell hyperplasia, segmental sclerosis, and diffuse epithelial cell foot processes effacement, resembling human FSGS. Reduced nephrin expression/ abnormal localization and increased detached podocytes were also observed. In vitro, TNFα-treated human podocytes displayed significantly reduced PARD6B expression. Human podocytes treated with PARD6B siRNA demonstrated significant cell death, though no effects on the actin cytoskeleton were noted.
Conclusion
These findings suggest that reduced PARD6B expression is associated with irreversible podocyte injury and progression of FSGS.
Funding
- Private Foundation Support