Abstract: FR-PO0787
Insertions/Deletions Upstream of ZHX2 in Hispanic Patients Cause Non-HIV Collapsing Glomerulopathy (CG) Through Podocyte ZHX2 Upregulation
Session Information
- Glomerular Diseases: Cell Homeostasis and Novel Injury Mechanisms
November 07, 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
- Ortega Lozano, Ariadna Jazmin, Rush University, Chicago, Illinois, United States
- Sanchez Gloria, Jose Luis, Rush University, Chicago, Illinois, United States
- Gomez-Sierra, Tania, Rush University, Chicago, Illinois, United States
- Zavala-Guevara, Itzel Pamela, Rush University, Chicago, Illinois, United States
- Molina-Jijon, Eduardo, Rush University, Chicago, Illinois, United States
- Mace, Camille E., Rush University, Chicago, Illinois, United States
- Clement, Lionel C., Rush University, Chicago, Illinois, United States
- Avila-Casado, Carmen, Toronto General Hospital, Toronto, Ontario, Canada
- Chugh, Sumant S., Rush University, Chicago, Illinois, United States
Group or Team Name
- Glomerular Disease Therapeutics Laboratory.
Background
We previously published 8 Hispanic patients with COVID-19 related CG and Insertions/Deletions (InDels) upstream of ZHX2, including 3 shared InDels (Del Nogal Avila M et al JCI Insight 2023). We also showed that sera from over 30 Hispanic patients with CG induce glomerular collapse when injected into Sprague Dawley (SD) rats inbred in Mexico City (Avila-Casado et al KI 2004). We replicated these InDels individually using CRISPR/Cas9 editing of iPS cell lines. We also studied if Parvovirus infection in rats predisposes to Zhx2 upregulation.
Methods
See Below
Results
Using CRISPR/Cas9, TATAAA at Chr8 122,720,313 - 122,720,318 was deleted from iPS cells and differences in Zhx2 mRNA and protein expression studied between the parent and mutated cell lines. We noted 4.85 + 0.67 fold upregulation of Zhx2 mRNA expression (P<0.0001) and increased ZHX2 protein expression (P<0.05) in the mutant clones. Two other CRISPR/Cas9 modifications are in progress. Since human transplant recipients with Parvovirus B19 infection develop CG, we injected SD rats infected with rat Parvovirus with human sera from patients with recurrent CG. These rats developed extensive CG 10 days after injection. The rats were then re-derived to make them pathogen free, and the cleaned rats did not develop proteinuria or CG after CG serum injection. Analysis of glomerular gene expression from non-injected parvovirus infected and clean rats showed significant podocyte / glomerular Zhx2 mRNA upregulation (7.16 + 2.3 fold, P<0.01) in parvovirus infected rats. After injection of CG serum, these infected rats developed further glomerular Zhx2 mRNA upregulation (Day 6, 6.3 + 0.55, P<0.001; Day 10, 5.59 + 1.84, P<0.05) compared to control serum injected rats. Finally, podocyte specific ZHX2 overexpressing transgenic rats (Mace C et al KI 2020) with > 3-fold higher podocyte Zhx2 expression develop extensive CG when injected with Adriamycin.
Conclusion
Genomic defects upstream of ZHX2 in Hispanic patients with CG induce ZHX2 upregulation, that predisposes to the development of CG. These defects are likely be prevalent worldwide except for patients of West African heritage.
Funding
- NIDDK Support