Abstract: SA-PO598
A New Insight into the Pathogenesis of IgAN: Dissecting the Disease in Single Cells
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
- Zambrano Sevilla, Sonia, Karolinska Institutet, Huddinge, Sweden
- Kano, Toshiki, Juntendo University, Tokyo, Japan
- Suzuki, Yusuke, Juntendo University School of Medicine, Tokyo, Japan
- Patrakka, Jaakko, Karolinska Institutet, Huddinge, Sweden
Background
IgA nephropathy (IgAN) is the most common primary glomerulonephritis worldwide. Molecular mechanisms driving glomerular damage in the disease are poorly understood. In this study, we analysed individual glomerular cell from ddY mice, a well-established genetic model of IgAN, by using scRNA-seq.
Methods
5 control (non-proteinuric) and 5 IgAN (proteinuric) ddY mice were included in the study. Animals were sacrificed at 4 weeks of age and glomeruli isolated using the perfusion of magnetic beads. The glomeruli were treated mechanically and enzymatically to obtain single cells. Viable single cells of enriched glomeruli were unbiasedly sorted to 384-well plates and scRNA-seq performed using the Smart-seq2 protocol.
Results
A total of 3096 cells passed Quality Control. Unsupervised cell clustering demonstrated the inclusion of 11 cell types in both control and IgAN (glomerular endothelial (GEC), mesangial, parietal epithelial, podocyte, juxtaglomerular, macrophage, NK, T and B cells, as well as small contamination with tubular cells). The results showed a significant loss of podocytes in IgAN animals and revealed a number of new IgAN-associated genes/pathways in individual cell types. In podocytes, the Gene Ontology analysis revealed the emission of chemoattractant and pro-inflammatory cytokines, a role classically attributed to mesangial cells in this disease. In GECs, several cell subpopulations were detected and they showed a proinflammatory phenotype in IgAN, including for instance the up-regulation of selectin and MHC class 2 molecules. Mesangial cells seemed to be get activated and gain a migratory phenotype, which included, for instance, the up-regulation of ACTA2 expression. Moreover, several novel ligand-receptor pairs were identified in glomerular cells that are likely to play a role in the disease progression.
Conclusion
The preliminary analysis of our data suggests a crucial role of podocytes and GECs in the initiation of glomerular injury in ddY IgAN mice. Further analyses are ongoing to understand the crosstalk between the different glomerular cell types in both disease and healthy state.