Abstract: SA-OR55
Extracellular Vesicles of Podocytes Impact Intraglomerular Signaling and Parietal Epithelial Cell Activation
Session Information
- Glomerular Diseases: All about Podocytes
October 26, 2024 | Location: Room 1, Convention Center
Abstract Time: 04:30 PM - 04:40 PM
Category: Glomerular Diseases
- 1401 Glomerular Diseases: Mechanisms, including Podocyte Biology
Authors
- Sendon, Pamella Marie, Universitatsklinikum Hamburg-Eppendorf, Hamburg, Hamburg, Germany
- Pausch, Alexander, Universitatsklinikum Hamburg-Eppendorf, Hamburg, Hamburg, Germany
- Gathmann, Annika, Universitatsklinikum Hamburg-Eppendorf, Hamburg, Hamburg, Germany
- Teicher, Kilian, Universitatsklinikum Hamburg-Eppendorf, Hamburg, Hamburg, Germany
- Homeyer, Inka Christina, Universitatsklinikum Hamburg-Eppendorf, Hamburg, Hamburg, Germany
- Lassé, Moritz, Universitatsklinikum Hamburg-Eppendorf, Hamburg, Hamburg, Germany
- Obser, Anja, Universitatsklinikum Hamburg-Eppendorf, Hamburg, Hamburg, Germany
- Wong, Hetty N., University of Pennsylvania, Philadelphia, Pennsylvania, United States
- Lindenmeyer, Maja, Universitatsklinikum Hamburg-Eppendorf, Hamburg, Hamburg, Germany
- Holzman, Lawrence B., University of Pennsylvania, Philadelphia, Pennsylvania, United States
- Rinschen, Markus M., Universitatsklinikum Hamburg-Eppendorf, Hamburg, Hamburg, Germany
- Ricklefs, Franz Lennard, Universitatsklinikum Hamburg-Eppendorf, Hamburg, Hamburg, Germany
- Erdbruegger, Uta, University of Virginia, Charlottesville, Virginia, United States
- Puelles, Victor G., Universitatsklinikum Hamburg-Eppendorf, Hamburg, Hamburg, Germany
- Huber, Tobias B., Universitatsklinikum Hamburg-Eppendorf, Hamburg, Hamburg, Germany
- Braun, Fabian, Universitatsklinikum Hamburg-Eppendorf, Hamburg, Hamburg, Germany
Group or Team Name
- Braun Lab.
Background
Extracellular vesicles (EVs) have the ability to impact basic pathological processes such as malignant, metabolic and autoimmune diseases through intercellular signaling. However, we lack a concise knowledge about their role in kidney health and disease. Our study aims to characterize the intraglomerular signalling propagated by medium-sized (mEVs) and small EVs (sEVs) shed by podocytes.
Methods
Using differential (ultra-)centrifugation we separated mEVs and sEVs from cell culture supernatants, kidney tissue and urine samples. Using Western Blot, immunofluorescence microscopy employing antibody stainings and pKH membrane dyes as well as image flow cytometry and cryo-electron microscopy (cryo-EM) we investigated the release dynamics of podocyte-specific EVs in different models of murine podocyte damage in vitro and in vivo. Potential signaling factors contained in EVs were analysed through proteomics. Live microscopy and cross-culture experiments were used to determine the effect of podocyte specific EVs on parietal epithelial cells (PECs).
Results
Upon podocyte damage, we detected a unified response in the form of an increase in EV release with a size-shift towards larger vesicles revealed in Cryo-EM. Depending on EV size and the initial insult, podocyte-specific EVs exerted different effects on the migratory behavior and proliferation of PECs while proteomics revealed limited differences in the EV proteome in different stress conditions. We shortlisted the first candidate proteins potentially propagating the effect on PECs. In vivo, decreased EV release by podocytes resulted in reduced PEC activation and limited recruitment of macrophages in a model of crescentic glomerulonephritis.
Conclusion
We present essential insights on podocyte-specific release of different sizes of EVs, their protein contents and functional implications in health and upon podocyte damage. Ongoing experiments focus on further elucidating the impact of podocyte-specific release in vivo and the impact of knocking-out identified EV candidate proteins.
Funding
- Government Support – Non-U.S.