Kidney Regeneration in Later-Stage Mouse Embryos via Transplanted Renal Progenitor Cells

Abstract

BackgroundThe limited availability of donor kidneys for transplantation has spurred interest in investigating alternative strategies, such as regenerating organs from stem cells transplanted into animal embryos. However, there is no known method for transplanting cells into later-stage embryos, which may be the most suitable host stages for organogenesis, particularly into regions useful for kidney regeneration.MethodsWe demonstrated accurate transplantation of renal progenitor cells expressing green fluorescent protein to the fetal kidney development area by incising the opaque uterine muscle layer but not the transparent amniotic membrane. We allowed renal progenitor cell–transplanted fetuses to develop for 6 days postoperatively before removal for analysis. We also transplanted renal progenitor cells into conditional kidney-deficient mouse embryos. We determined growth and differentiation of transplanted cells in all cases.ResultsRenal progenitor cell transplantation into the retroperitoneal cavity of fetuses at E13–E14 produced transplant-derived, vascularized glomeruli with filtration function and did not affect fetal growth or survival. Cells transplanted to the nephrogenic zone produced a chimera in the cap mesenchyme of donor and host nephron progenitor cells. Renal progenitor cells transplanted to conditional kidney-deficient fetuses induced the formation of a new nephron in the fetus that is connected to the host ureteric bud.ConclusionsWe developed a cell transplantation method for midstage to late-stage fetuses. In vivo kidney regeneration from renal progenitor cells using the renal developmental environment of the fetus shows promise. Our findings suggest that fetal transplantation methods may contribute to organ regeneration and developmental research.

Roxadustat (FG‐4592) protects against ischaemia/reperfusion‐induced acute kidney injury through inhibiting the mitochondrial damage pathway in mice

“…Protein samples for western blotting were obtained from kidney tissue with pre-cooled RIPA buffer (Beyotime) containing a protease inhibitor cocktail. 35 The protein samples were boiled with SDS loading buffer after the protein concentration was measured using the BCA protein assay kit (#PC0020, Solarbio). A total of 25 μg of proteins were separated by 10-15% SDS-PAGE and transferred to PVDF membrane.…”

Generation of chimeric kidneys using progenitor cell replacement: Oshima Award Address 2021

“…Of these technologies, chimeric technology, which has the capability for blood filtration and endocrine secretion in vivo, is promising for the regeneration of 3D organs. Not included (or rebuild) [7,39] Included (rebuild/native) [40,41] Included (rebuild/native) [7,27] Included (native) [8,28] Included (native) [10] Urinary tract…”

Prioritizing Functional Goals as We Rebuild the Kidney

“…With this progress, investigators are beginning to set their sights on function. An article in this issue of JASN by Yamanaka et al 9 reports a step in the right direction. The authors have shown that the vascular-epithelial interface in implanted, vascularized kidney organoids demonstrates the property of selective permeation.…”

“…The authors did not work out the mechanism of dextran permeation (i.e., whether it was due to simple diffusion or solvent drag due to ultrafiltration), nor did they identify the specific path that the dextran molecules take. 9 However, as in the glomerulus, the dextrans must traverse cells, basement membranes, and epithelial cells, and it is reasonable to view the demonstrated permselectivity as being dependent on the special characteristics of the cells that make up these three barriers as in the native glomerulus. The question that we ask here is, from a functional perspective, what are reasonable goals in the development of organoids for renal repair or replacement?…”

“…Steady-state ultrafiltration, reabsorption, and secretion require a conduit for steady-state excretion of urine. Thus, looking beyond the work by Yamanaka et al 9 and focusing on nephron structures in renal organoids, we will have to find a way to make organoids connect, presumably to existing drainage pathways or drainage pathways that we can make using tissue engineering approaches.…”