Branching ducts similar to mesonephric ducts or ureteric buds in teratomas originating from mouse embryonic stem cells

Abstract

Ureteric bud epithelial cells and metanephric mesenchymal cells that comprise the metanephric kidney primordium are capable of producing nephrons and collecting ducts through reciprocal inductive interaction. Once these cells are induced from pluripotent embryonic stem (ES) cells, they have the potential to become powerful tools in the regeneration of kidney tissues. In this study, we investigated these renal primordial cells and structures in mouse ES cell outgrowths and their transplants. Gene expression essential for early kidney development was examined by RT-PCR in embryoid body (EB) outgrowths and their transplants in adult mice. Histochemical detection of kidney primordial structures and gene expression analysis coupled with laser microdissection were performed in transplant tissues. RT-PCR analysis detected gene expression of Pax-2, Lim-1, c-Ret, Emx2, Sall1, WT-1, Eya-1, GDNF, and Wnt-4 in the EB outgrowths from days 6-9 of expansion onward, and also in the teratoma tissues 14 and 28 days after transplantation. Histochemical analysis 14 days after transplantation showed that some ducts were positive for Pax-2, endo A cytokeratin, kidney-specific cadherin, and Dolichos biflorus agglutinin and that dichotomous branching of these ducts had occurred. These staining patterns and morphological features are intrinsic for mesonephric ducts and ureteric buds. In long-term survival of 28 days, Pax-2-immunoreactivity disappeared in some renal primordia-like structures, indicating their differentiation. Some ducts were accompanied by mesonephric nephron-like convoluted tubules. RT-PCR analysis of those structures collected by microdissection confirmed that they expressed kidney development-related genes. In conclusion, these data suggest the potential of ES cells to produce renal primordial duct structures and provides an insight into the regeneration of kidney tissues.

In vitro and in vivo differentiation of human embryonic stem cells into retina‐like organs and comparison with that from mouse pluripotent epiblast stem cells

“…An impressive case for renal promodial-like ducts induced from mouse ES cells was reported (Yamamoto et al, 2005). They allowed the outgrowth of ES cell-derived embryoid bodies for a week in vitro, then the harvested cells were transplanted to adult nu/nu host retroperitoneum.…”

Stem cell options for kidney disease

“…With respect to technical risks, in vivo injection of these pluripotent cells can give rise to teratomas, as demonstrated by Yamamoto et al [57], who reported the generation of teratomas containing metanephric-mesenchyme-related structures after injection of undifferentiated ES cells within the peritoneum of nude mice [57]. In contrast, Steenhard et al [58] reported a 50% integration of undifferentiated ES cells into the tubules of embryonic kidneys without evidence of teratoma formation.…”

Regrow or Repair

“…While impressive, the developing kidney may better provide the full signals required to direct onward renal tubular development than an adult kidney. Yamamoto et al (72) did not direct their murine ES cells in any way. Conventional EB culture also induced the expression of most of the markers that were seen by Kim and Dressler (75).…”