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Abstract: FR-PO753

Development of a New Nephron Progenitor Cell Replacement System for Application in Human Induced Pluripotent Stem (iPS) Cell-Derived Nephron Progenitor Cells (NPCs)

Session Information

Category: Development, Stem Cells, and Regenerative Medicine

  • 500 Development, Stem Cells, and Regenerative Medicine

Authors

  • Takamura, Tsuyoshi, Jikei University School of Medicine, Tokyo, Japan
  • Fujimoto, Toshinari, Jikei University School of Medicine, Tokyo, Japan
  • Tajiri, Susumu, Jikei University School of Medicine, Tokyo, Japan
  • Saito, Yatsumu, Jikei University School of Medicine, Tokyo, Japan
  • Yamanaka, Shuichiro, Jikei University School of Medicine, Tokyo, Japan
  • Matsumoto, Kei, Jikei University School of Medicine, Tokyo, Japan
  • Yokoo, Takashi, Jikei University School of Medicine, Tokyo, Japan
Background

Previously, we generated a transgenic mouse model that enabled diphtheria toxin (DT)-induced ablation of Six2-positive NPC s (Six2-iDTR mouse). After eliminating host NPCs, we transplanted allogenic or xenogeneic NPCs into the metanephric mesenchyme. Donor NPCs were differentiated into neo-nephrons, which have the ability to filter and produce urine, and were connected to the host mouse ureteric bud. In the future, we aim to use this system in kidney regeneration using human iPS cell-derived NPCs. However, human cells permanently express diphtheria toxin receptors and can undergo apoptosis when treated with DT. Therefore, a new NPC elimination system is warranted. In this study, we developed a new transgenic mouse model to ablate NPCs without affecting human cells using tamoxifen instead of DT (six2 CreERT2-DTA mouse) for application in human cells.

Methods

Six2-CreERT2 mice were crossbred with Rosa26-floxed stop DTA mice to obtain Six2CreERT2-DTA mouse offsprings, which were used as hosts. We attempted regeneration from dissociated cells derived from E13 mice and E15 rats metanephros, and NPCs differentiated from human iPS cells. We injected these dissociated cells below the renal capsule of the E13 transgenic mice metanephros. The injected metanephros were isolated, and the organs were cultured for 7 days with 4OH-tamoxifen. After culturing, the metanephros were analyzed using immunofluorescent staining. To verify the blood-inducing ability of the regenerated nephrons in vivo, we additionally transplanted Six2CreERT2-DTA mice metanephros injected with dissociated cells derived from E13 mice into immunodeficient mice under tamoxifen administration and evaluated the results.

Results

We successfully eliminated Six2-positive NPCs from the cap mesenchyme by this system and regenerated nephrons derived from mouse or rat metanephros. In vivo, we successfully regenerated chimera kidneys that have blood-inducing ability from mouse metanephros. Human iPS cell-derived NPCs were engrafted in the Six2CreERT2-DTA mouse metanephros cap mesenchyme.

Conclusion

We developed a new nephron progenitor cell elimination and replacement system that can be utilized in human cells.