Abstract: SA-PO0757
Laser Microdissection and Mass Spectrometry Shows Loss of Podocyte Proteins in Minimal Change Disease and FSGS
Session Information
- Glomerular Diseases: Profiling Through Multiomics
November 08, 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
- Fervenza, Fernando C., Mayo Clinic Minnesota, Rochester, Minnesota, United States
- Vargas-Brochero, Maria J., Mayo Clinic Minnesota, Rochester, Minnesota, United States
- Debiec, Hanna, Inserm unit 1155, Hôpital Tenon, Paris, France
- Andrade, Luciana Barreira de alencar, Escola Bahiana de Medicina e Saude Publica, Salvador, BA, Brazil
- Madden, Benjamin J., Mayo Clinic Minnesota, Rochester, Minnesota, United States
- Ronco, Pierre M., Inserm unit 1155, Hôpital Tenon, Paris, France
- Sethi, Sanjeev, Mayo Clinic Minnesota, Rochester, Minnesota, United States
Background
The relation between MCD and pFSGS remains debatable, and recent discovery of anti-nephrin and anti -slit antibodies, supports the hypothesis of a continuum disease. However, the overall expression of podocyte proteins in these disease states is not known
Methods
We used laser microdissection and mass spectrometry (LMD/MS) to determine the proteomic profile of podocyte proteins in kidney biopsies of patients with MCD (n=6), pFSGS (n=7), sFSGS (n=10). Time zero kidney transplant (T0) (n=6) and membranous nephropathy (MN) (n=8) served as non-proteinuric and proteinuric controls, respectively. MS results are expressed as total spectral counts (TSC) representing the relative abundance of the specific protein. Confocal IF staining assessing nephrin and podocin were also performed.
Results
LMD/MS show moderate baseline TSC of podocyte protein NPHS1 (nephrin), NPHS2 (podocin), CD2AP, ACTN4, INF2, and DAG1 in time zero kidney transplant and MN controls. On the other hand, there was significant loss of all 6 podocyte proteins in MCD, pFSGS and sFSGS but not in T0 or MN cases. Confocal IF staining showed podocyte loss of nephrin and podocin in MCD, pFSGS and sFSGS but not in T0 or MN
Conclusion
LMD/MS and confocal IF staining show signficant and comparable loss of podocyte proteins involving the slit diaphragm and actin cytoskeleton in MCD, pFSGS, and sFSGS, suggesting a common final pathway of podocyte injury. Suprisingly, despite similar degres of proteinuria, MN was not associated with signifcant loss of podocyte proteins.