Kidney Week

Abstract: FR-PO310

Single-Cell Transcriptomics Reveals Disrupted Cell Communication in the Glomerular Niche in the Initiation of Childhood WT1 Glomerulopathy

Session Information

• Genetic Diseases: Models, Mechanisms, Treatments
  November 04, 2022 | Location: Exhibit Hall, Orange County Convention Center‚ West Building
  Abstract Time: 10:00 AM - 12:00 PM

Category: Genetic Diseases of the Kidneys

• 1102 Genetic Diseases of the Kidneys: Non-Cystic

Authors

• Chandler, Jennifer C., University College London Institute of Child Health, London, London, United Kingdom

Jennifer C. Chandler,

• Jafree, Daniyal J., University College London Institute of Child Health, London, London, United Kingdom

Daniyal J. Jafree,

• Malik, Saif N., University College London Institute of Child Health, London, London, United Kingdom

Saif N. Malik,

• Pomeranz, Gideon, University College London Institute of Child Health, London, London, United Kingdom

Gideon Pomeranz,

• Joannou, Maria K., University College London Institute of Child Health, London, London, United Kingdom

Maria K. Joannou,

• Mason, Andrew S., University of York, York, North Yorkshire, United Kingdom

Andrew S. Mason,

• Waters, Aoife M., University College London Institute of Child Health, London, London, United Kingdom

Aoife M. Waters,

• Long, David A., University College London Institute of Child Health, London, London, United Kingdom

David A. Long,

Group or Team Name

• Long Research Group

Background

The glomerulus is comprised of podocytes and glomerular endothelial cells that enclose a core of mesangial cells; parietal epithelial cells enclose this specialised niche from the tubulointerstitium. Cellular communication within the glomerulus is critical for healthy filtration and its disruption is associated with adult diseases such as diabetic nephropathy. However, little is known about glomerular communication in childhood glomerulopathies.

Methods

Disease progression was characterised in a murine model (Wt1^R394W/+) of childhood WT1 glomerulopathy, using biochemical and histological analyses. Single-cell RNA sequencing (scRNA-seq) and bioinformatic analyses were conducted on glomeruli isolated from wildtype (Wt1^+/+) and mutant (Wt1^R394W/+) mice. Validation was performed using tissue immunofluorescence and RT-qPCR.

Results

Wt1^R394W/+ mice have elevated urinary albumin (p<0.0001) from 4 weeks of age, prior to any histological features of glomerulosclerosis which occur by 8 weeks. To identify changes in cell communication that initiate glomerular damage, we performed scRNA-seq at 4 weeks, generating a dataset enriched for podocytes. Podocytes exhibited the most differentially expressed genes between Wt1^R394W/+ and Wt1^+/+ and changes in pathways associated with cell death were paralleled by a reduced WT1+ cell count (p<0.0001). Using ligand-receptor analysis, we identified vascular signalling to be the cellular interaction most disrupted in Wt1^R394W/+ glomeruli and CD31+ staining showed a loss of the glomerular endothelium by 8 weeks of age (p<0.0001). Finally, we performed a cross-disease comparison of Wt1^R394W/+ with other models of early glomerular disease (nephrotoxic nephritis, diabetes and Cd2ap^-/-). This highlighted a common signature of podocyte transcripts that are upregulated or downregulated across early disease and others which are unique to each pathology.

Conclusion

This work has generated a glomerular dataset for childhood WT1 glomerulopathy. Wt1^R394W/+ podocytes have a unique transcriptional profile in early disease, driving endothelial loss. Signatures of podocyte injury exist across glomerulopathies, revealing therapeutic candidates of a disease-specific and generic nature that offer future promise in disease management.