In vivo regeneration of interspecies chimeric kidneys using a nephron progenitor cell replacement system

Toshinari Fujimoto,Kentaro Takase,Kei Matsumoto,Yatsumu Saito,Shohei Fukunaga,Takashi Yokoo,Tsuyoshi Takamura,Shuichiro Yamanaka,Susumu Tajiri,Hirotaka James Okano

doi:10.1038/s41598-019-43482-2

Toshinari Fujimoto, Kentaro Takase + Show 8 more

Open Access

https://doi.org/10.1038/s41598-019-43482-2

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Abstract

Kidney regeneration is expected to be a new alternative treatment to the currently limited treatments for chronic kidney disease. By transplanting exogeneous nephron progenitor cells (NPCs) into the metanephric mesenchyme of a xenogeneic foetus, we aimed to regenerate neo-kidneys that originate from transplanted NPCs. Previously, we generated a transgenic mouse model enabling drug-induced ablation of NPCs (the Six2-iDTR mouse). We demonstrated that eliminating existing native host NPCs allowed their 100% replacement with donor mouse or rat NPCs, which could generate neo-nephrons on a culture dish. To apply this method to humans in the future, we examined the possibility of the in vivo regeneration of nephrons between different species via NPC replacement. We injected NPCs-containing rat renal progenitor cells and diphtheria toxin below the renal capsule of E13.5 metanephroi (MNs) of Six2-iDTR mice; the injected MNs were then transplanted into recipient rats treated with immunosuppressants. Consequently, we successfully regenerated rat/mouse chimeric kidneys in recipient rats receiving the optimal immunosuppressive therapy. We revealed a functional connection between the neo-glomeruli and host vessels and proper neo-glomeruli filtration. In conclusion, we successfully regenerated interspecies kidneys in vivo that acquired a vascular system. This novel strategy may represent an effective method for human kidney regeneration.

Highlights

The increasing number of patients with chronic kidney disease is a serious public health issue
The obtained rat GFP-renal progenitor cells (RPCs) were injected below the renal capsule of E13.5 MNs of Six2-iDTR mice, followed by the culturing of injected MNs in a diphtheria toxin (DT)-supplemented medium
The Six2-iDTR mouse MNs with bladder (MNB) containing DT-ineffective exogenous rat RPCs were transplanted into the vicinity of the aorta of an adult NOG mouse (Fig. 2e)

Summary

Introduction

The increasing number of patients with chronic kidney disease is a serious public health issue. Previous studies have considered several methods of regenerating solid organs that are capable of functioning in vivo from transplanted exogenous cells by borrowing a xenogeneic development programme. We have reported on the organogenic niche method in which exogenous human mesenchymal stem cells were injected into the metanephric mesenchyme of xenogeneic rat foetuses and those human cells differentiated into kidneys[13,14,15] This method is novel because stem cells, which have limited potency, are used as a cell source instead of PSCs. We used embryos from mid-to-late gestational stages instead of early embryos as a host because the transplantation of donor cells into developmental-stage-matched host tissue may be critical for the efficient engraftment of cells into chimeras[16]. We demonstrated that by administering diphtheria toxin (DT), the elimination of existing native host mouse NPCs allowed their 100% replacement with donor mouse or rat NPCs, which could generate neo-nephrons on a culture dish

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