Abstract: FR-PO0759
CD2-Associated Protein Expression in Podocytes Regulates Cell Contractility and Contributes to Cell Attachment
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
- Jiang, Shumeng, The University of Texas Southwestern Medical Center, Dallas, Texas, United States
- Genin, Guy M., Washington University in St Louis, St. Louis, Missouri, United States
- Miner, Jeffrey H., Washington University in St Louis School of Medicine, St. Louis, Missouri, United States
- Suleiman, Hani, The University of Texas Southwestern Medical Center, Dallas, Texas, United States
Background
CD2 associated protein (CD2AP), has been identified to be essential for the proper filtration function of the glomerulus. In Cd2ap-/- mice, podocyte foot process organization is lost shortly after birth, leading to glomerulosclerosis, severe kidney injury, and death by approximately six weeks of age. However, the precise function of CD2AP and the mechanism underlying Cd2ap-/- induced kidney injury remains unclear.
Methods
We characterized cytoskeleton organization in both Cd2ap-/- primary podocytes and Cd2ap-/- immortalized podocyte cell lines to investigate how CD2AP deficiency compromises podocyte structure and glomerular filtration.
Results
In both primary and immortalized Cd2ap-/- podocytes, we observed notable disruptions in the actin cytoskeleton: While WT podocytes exhibited clearly defined sarcomere-like structures (SLSs), characterized by striated synaptopodin and myosin patterns, Cd2ap-/- podocytes largely lacked these structures and showed significantly reduced contractility.
To understand how this difference matters in glomerular filtration, podocyte adhesion while exposed to shear stress was tested, and it was demonstrated that Cd2ap-/- podocytes have impaired adhesion under increasing shear stress, suggesting that reduced contractility weakens podocyte resistance to mechanical stress and compromises attachment.
We further explored the molecular mechanisms and found that the Rho signaling pathway is highly related. Phosphorylation of myosin light chain, a direct effector of Rho signaling pathway, was significantly reduced in Cd2ap-/- podocytes. Additionally, Inhibition of RhoA signaling pathway in WT podocytes could partially reproduce the Cd2ap-/- phenotype with reduced SLSs, while treatment with a RhoA activator restored contractility, SLSs formation, and adhesion in Cd2ap-/- podocytes.
Conclusion
Our findings demonstrate that CD2AP is involved in the contractility generation in podocytes and is important for maintaining the proper attachment of these podocytes especially when exposed to shear stress. Also, Rho signaling pathway were proved to be involved in this regulation that activated RhoA could effectively rescue the Cd2ap-/- phenotype, highlighting a potential therapeutic target for kidney diseases involving impaired podocyte contractility.
Funding
- NIDDK Support