Abstract: FR-PO727
Integrin Activation as a Novel Therapeutic Strategy for Podocytopathies
Session Information
- Glomerular Diseases: Podocyte Biology - I
November 04, 2022 | Location: Exhibit Hall, Orange County Convention Center‚ West Building
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1304 Glomerular Diseases: Podocyte Biology
Authors
- Helmuth, Richard, Drug Discovery Center, Department of Internal Medicine, Rush University Medical School, Chicago, Illinois, United States
- Li, Xiaobo, Drug Discovery Center, Department of Internal Medicine, Rush University Medical School, Chicago, Illinois, United States
- Balza Pineda, Santiago, 149 Bio, LLC, Miami, Florida, United States
- Lopez-Rodriguez, Darlah M., 149 Bio, LLC, Miami, Florida, United States
- Abrahams, Carl John, 149 Bio, LLC, Miami, Florida, United States
- Subramanian Sahasranamam, Adithya, 149 Bio, LLC, Miami, Florida, United States
- Barbosa, Antonio, 149 Bio, LLC, Miami, Florida, United States
- Gupta, Vineet, Drug Discovery Center, Department of Internal Medicine, Rush University Medical School, Chicago, Illinois, United States
Background
Podocyte damage and loss is a key determinant of proteinuria and glomerular injury. Therefore, maintaining podocyte viability and preventing their urinary loss is a validated therapeutic strategy against glomerular diseases. Podocytes selectively utilize integrin a3b1 to adhere to the glomerular basement membrane (GBM) and such attachment is essential for maintaining their viability. Using a novel high-content imaging-based assay, we previously identified small molecule integrin b1 agonists as podocyte-protective. We have recently discovered integrin a3 agonists as novel podocyte-protective agents.
Methods
K562 cells stably expressing a3b1 and differentiated podocytes (mouse and human) were used in in vitro assays. K562 cells were used in flow-cytometry based assays to characterize a3 agonists. Podocytes were utilized in cell adhesion based functional assays. Furthermore, podocyte damage was induced using puromycin aminonucleoside (PAN) and treatment in the absence or presence of various agonists, for up to 48 hours, was used to determine efficacy of a3 agonists. Podocytes were fixed and stained for detection using the confocal imaging based High-Content Screening (HCS) assays. Columbus software was used to quantify morphology properties such as roundness, as well as the overall F-actin and focal adhesion signal. Currently, the agonists are being tested for efficacy in in vivo assays.
Results
PAN damage resulted in quantitative reduction in F-actin fiber numbers and intensity, and increased roundness in podocytes. It also reduced binding of active b1 integrin probe antibody 9EG7. Newly discovered integrin a3 agonists increased a3b1-dependent cell adhesion and ameliorated PAN-mediated podocyte damage.
Conclusion
We have previously shown that integrin agonists are a novel therapeutic strategy for targeting integrins in various diseases. Activation of expressed integrin a3b1 in podocytes shows that it increases cellular adhesion to matrix proteins and protects cells from damage. Ongoing in vivo studies will demonstrate efficacy of this approach and will highlight integrin activation as a novel therapeutic strategy against various glomerulopathies.
Funding
- Commercial Support –