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Abstract: FR-PO729

Molecular Regulation of Podocyte Development by Transcription Factor 21

Session Information

Category: Glomerular Diseases

  • 1401 Glomerular Diseases: Mechanisms, including Podocyte Biology

Authors

  • Dalal, Vidhi, Ann and Robert H Lurie Children's Hospital of Chicago, Chicago, Illinois, United States
  • Zhou, Yalu, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States
  • Deb, Dilip K., Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States
  • Maekawa, Hiroshi, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States
  • Fain, Margaret E., Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States
  • Chang, Anthony, University of Chicago Pritzker School of Medicine, Chicago, Illinois, United States
  • Chung, Eunah, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States
  • Park, Joo-Seop, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States
  • Quaggin, Susan E., Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States
Background

Transcription factor 21 (Tcf21) is expressed in developing podocytes from the S-shaped body onwards. Our laboratory previously showed that deletion of Tcf21 from podocyte precursors at the S-shaped stage of glomerular development in mice resulted in abnormal podocyte morphology, impaired glomerular basement membrane (GBM) formation, and defects in foot process formation, underscoring a vital role for Tcf21 in normal podocyte development and function. However, the molecular mechanism(s) by which Tcf21 regulates podocyte development are not well-understood. To address this gap in knowledge, we performed single cell RNA sequencing (scRNAseq) of kidneys from mice with Tcf21 deletion.

Methods

Tcf21 was deleted from podocyte precursors at the S-shaped stage of glomerular development using Cre recombinase driven by the Pax8 promoter. 2 mutant mice and 2 littermate controls were euthanized at 2 weeks of age, and their kidneys were subjected to single cell digestion. 20,000 cells were captured from each of the 4 samples for scRNAseq. Library preparation was completed, and the samples are awaiting sequencing.

Results

Mutant mice had substantial proteinuria (100-500 mg/dL versus negative to trace urine protein for littermate controls). On histology, proximal tubular protein reabsorption droplets were noted in kidneys of both mutant mice, and glomerular crescent formation was noted in the kidney of one mutant mouse. Kidneys from control mice appeared normal. The mutant mice did not have significant glomerulosclerosis, suggesting that podocyte injury was still in its early stages. ScRNAseq will be used to determine changes in expression of podocyte structural genes, GBM genes, and transcription factors after Tcf21 deletion. The CellChat package in R will be used to identify changes in how mutant podocytes interact with surrounding glomerular cells.

Conclusion

Tcf21 deletion from podocyte precursors caused proteinuria and severe defects in podocyte development. ScRNAseq is a first step to unravel the molecular mechanism(s) by which Tcf21 regulates podocyte structure and the interaction of podocytes with other glomerular cells. Ultimately, understanding the mechanisms that are required for normal podocyte structure and function will also help us understand how podocytes become dysregulated in disease states.

Funding

  • NIDDK Support