Abstract: SA-PO608
Glomerular Endothelial Cell Heterogeneity and Contribution to Kidney Disease
Session Information
- Glomerular Diseases: Immunology, Inflammation - II
November 09, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1202 Glomerular Diseases: Immunology and Inflammation
Authors
- Sedrakyan, Sargis, Children's Hospital Los Angeles, Los Angeles, California, United States
- Soloyan, Hasmik, Children's Hospital Los Angeles, Los Angeles, California, United States
- Thornton, Matthew Edward, University of Southern California, Los Angeles, California, United States
- Villani, Valentina, Children's Hospital Los Angeles, Los Angeles, California, United States
- Khatchadourian, Patrick, Children's Hospital Los Angeles, Los Angeles, California, United States
- Gyarmati, Georgina, University of Southern California, Los Angeles, California, United States
- Peti-Peterdi, Janos, University of Southern California, Los Angeles, California, United States
- De Filippo, Roger E., Children's Hospital Los Angeles, Los Angeles, California, United States
- Perin, Laura, Children's Hospital Los Angeles, Los Angeles, California, United States
Group or Team Name
- GOFARR Laboratory for Organ Regenerative Research and Cell Therapeutics in Urology
Background
Glomerular endothelial dysfunction plays a key role in the development of chronic kidney disease (CKD), but its impact on Alport syndrome (AS, characterized by mutations in collagen IVα3α4α5) is unknown. In AS, we reported structural changed and upregulation of VEGF pathway in the glomerular endothelial cells (GEC) in the early stage of the disease and we hypothesized that GEC dysfunction is important in AS pathogenesis.
Methods
To test our hypothesis, we generated GEC specific (Tek-Cre driven) tdTomato reporter AS mice and isolated GEC by FACS. We studied GEC by flow cytometry, WB, and by multiphoton and confocal microscopy, and by RNA-seq analysis. Data were analyzed and AS-GEC compared to WT-GEC in terms of their morphology and gene expression.
Results
tdTomato signal identified two distinct GEC subsets (bright and dim) in both wild type and AS mice, which presented with transcriptional heterogeneity in ECM and glycocalyx-associated proteins, immune cell activation and cellular metabolism. In AS-GEC vs WT-GEC, genes with a well-established functional role in mitochondrial dysfunction, glucose and lipid metabolism, and inflammation were most significantly enriched. In particular, the bright cells were enriched in (upregulated) genes controlling cytoskeleton organization and inflammatory cell-cell adhesion (such as Icam1, Vcam1, Ccl2, Spon2, Sele, etc). In contrast, the dim cells were highly enriched in (upregulated) genes related to chemokine signaling but downregulated for genes and pathways associated with mitochondrial function. Both bright and dim cells were enriched in downregulated genes linked to glucose and lipid metabolism. In terms of cell-ECM interactions, Itgβ9 was highly reduced in both subsets in AS. Among other differentially expressed genes related to ECM composition, Svep1 expression was highly increased in the bright cells and Col17α1 in the dim cells exclusively.
Conclusion
In conclusion, we identified two GEC subpopulations and showed glomerular endothelial dysfunction in the early stages of AS. Importantly, GEC subsets contributed to endothelial dysfunction differently. A better understanding of the functional role of the glomerular endothelium could lead to the development of targeted new therapies for the treatment of CKD.
Funding
- Private Foundation Support