Abstract: FR-PO930
Targeting Podocyte Calcium Influx with TRPC6 Inhibitor BI 764198: Implications for Glomerular Filtration Barrier Protection
Session Information
- Glomerular Diseases: Potpourri
October 25, 2024 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics
Authors
- Da Sacco, Stefano, Children's Hospital Los Angeles, Los Angeles, California, United States
- Zhang, Qi, Children's Hospital Los Angeles, Los Angeles, California, United States
- Pullen, Steven S., Boehringer Ingheleim Pharmaceuticals, Ridgefield, Connecticut, United States
- Perin, Laura, Children's Hospital Los Angeles, Los Angeles, California, United States
Background
The glomerular filtration barrier (GFB) is essential for blood homeostasis, with podocyte function being vital for GFB integrity. Damage to podocytes leads to foot process effacement, apoptosis, and compromised glomerular permselectivity. Activation of the TRPC6 channel-mediated calcium influx in podocytes induces actin cytoskeleton rearrangement, leading to impaired filtration barrier function. This study evaluates the efficacy of TRPC6 inhibitor BI 764198 in mitigating TRPC6-mediated podocyte effects and elucidates its action mechanism.
Methods
Primary human podocytes and glomerular endothelial cells (GECs) were cultured in high glucose and exposed to angiotensin II, with or without TRPC6 inhibitor BI 764198. Cellular responses were gauged using immunofluorescence and qPCR. Calcium influx was monitored with Fura Red and Fluo-4 dyes. The inhibitor's protective effect on the GFB was also tested using a glomerulus-on-a-chip model and single cell-RNAseq and proteomics analyses were performed on collected cells and filtrate.
Results
High glucose upregulated TRPC6 expression in podocytes but not in GECs, thus highlighting the specificity of the TRPC6 activity in podocytes. Angiotensin II induced a significant calcium influx in podocytes, which BI 764198 effectively inhibited. GECs showed no calcium response to angiotensin. BI 764198 successfully reduced albumin leakage in the glomerulus-on-a-chip, indicating barrier protection. Preliminary scRNAseq and proteomics data support BI 764198's role in preventing TRPC6-mediated podocyte injury.
Conclusion
The findings provide in vitro validation of the therapeutic potential of the selective TRPC6 inhibitor BI 764198, shedding light on its protective mechanism of action.
Funding
- Commercial Support – Boehringer Ingelheim