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Abstract: FR-PO366

Centrosome Dysfunction Disrupts Nephrogenesis and Causes Cystic Kidney Disease

Session Information

Category: Development‚ Stem Cells‚ and Regenerative Medicine

  • 500 Development‚ Stem Cells‚ and Regenerative Medicine

Authors

  • Cheng, Tao, Washington University in St Louis, St Louis, Missouri, United States
  • Agwu, Chidera, Washington University in St Louis, St Louis, Missouri, United States
  • Shim, Kyuhwan, Washington University in St Louis, St Louis, Missouri, United States
  • Wang, Baolin, Weill Cornell Medicine, New York, New York, United States
  • Jain, Sanjay, Washington University in St Louis, St Louis, Missouri, United States
  • Mahjoub, Moe, Washington University in St Louis, St Louis, Missouri, United States
Background

Nephrogenesis requires coordinated signaling between progenitors of the metanephric mesenchyme (MM) and ureteric bud (UB) epithelium. Many of these pathways are organized by the centrosome, the main microtubule-organizing center, and its associated structure the cilium. Mutations in centrosomal genes cause congenital renal dysplasia and cystic-fibrotic pathologies, found in patients with Nephronophthisis, Joubert and Jeune syndromes. Yet, how these mutations impact renal development and physiology is unknown. Here, we examined the consequences of centrosome dysfunction on nephron progenitor growth, fate determination and tubule formation in mice, and compared outcomes with those caused by ciliary defect.

Methods

Conditional deletion of Cep120, critical for centrosome duplication, was induced by crossing Cep120F/F mice with Six2-Cre or Hoxb7-Cre strains. Loss of PKD1 (which causes ADPKD) was similarly induced in the two progenitors. Kidney morphology and function were tested at various stages. To identify pathways impacted by centrosome loss, we performed RNAseq of embryonic and adult kidneys from Cep120- and PKD1-null mice.

Results

Loss of Cep120 blocked centrosome biogenesis in the respective progenitor niches and led to reduced abundance of each population. This was due to delayed mitosis, activation of a mitotic surveillance pathway and apoptosis. Centrosome loss also caused premature formation of pre-tubular structures and low nephron branching morphogenesis. These defects resulted in dysplastic kidneys with low nephron endowment at birth, which mimic the human disease phenotypes. In contrast, loss of PKD1 in the MM or UB did not impact these processes, highlighting differences between centrosome and ciliary dysfunction. RNAseq of embryonic Cep120-null kidneys identified changes in signaling pathways including Wnt7-Wnt11, TGF-β and RET-MAPK. Remarkably, a developmental switch occurred postnatally whereby centrosome-less kidneys rapidly formed cysts with fibrosis and corresponding decline in kidney function. Finally, RNAseq of adult Cep120-null kidneys identified unique pathways involved in cystogenesis and fibrosis upon centrosome dysfunction compared to ADPKD.

Conclusion

Our study defines the developmental defects caused by centrosome dysfunction in nephrogenesis and identifies new therapeutic targets in patients with renal “centrosomopathies”.

Funding

  • NIDDK Support