Abstract: PO1685
The Mechanosensitive Ion Channel Piezo Activates Rho1 in Drosophila Nephrocytes
Session Information
- Podocyte Pathobiology: Basic Science Studies and Animal Models
November 04, 2021 | Location: On-Demand, Virtual Only
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1204 Podocyte Biology
Authors
- Koehler, Sybille, Biomedical Scoences, University of Edinburgh, Edinburgh, United Kingdom
- Denholm, Barry, Biomedical Scoences, University of Edinburgh, Edinburgh, United Kingdom
Background
Podocytes constantly face biomechanical forces such as shear stress and hydrostatic pressure. Increasing forces result in morphological changes, detachment from the glomerular basement membrane and loss into the primary urine. This highlights a requirement for podocytes to sense changes in their physical environment and induce a response to react to increased biomechanical force.
Methods
Here, we investigated the functional role of the mechano-sensitive ion channel Piezo in Drosophila nephrocytes.
Results
First, we confirmed Piezo expression and localisation at the nephrocyte diaphragm. Acute activation of the channel with the chemical compound YODA revealed significantly increased Ca++ signalling and Rho1 activation, suggesting a functional role of Piezo in nephrocytes and delineating the putative Piezo mechanosensitive pathway.
For further analysis, we used knockout flies and observed a filtration phenotype, while morphology and GTPase activation was not altered. In addition, we also studied the impact of elevated Piezo levels and could show, that in line with the YODA effect, Piezo overexpression revealed severely increased Rho1-GTP levels and FITC uptake, while morphology was not changed. Because of this severe pathological phenotype, we tried to rescue the effects of Piezo overexpression with pharmacological inhibition by using tarantula toxin. Intriguingly, treatment with tarantula toxin reversed the elevated Rho1-GTP levels observed upon Piezo overexpression.
Conclusion
Taken together, our data confirms the functional expression of Piezo in nephrocytes, its role in regulating GTPases and the beneficial effect of tarantula toxin to reverse the pathological effects caused by increased Piezo levels.