Urine Excretion From Stem Cell-Derived Kidneys
News Sep 29, 2015
The number of patients with end-stage renal disease is increasing worldwide due to a shortage of donor organs. Researchers have recently succeeded in growing functional kidneys from human stem cells, but these kidneys are unable to grow to full size because they have no pathway for excreting urine, resulting in a condition called hydronephrosis. Takashi Yokoo and colleagues developed a potential solution to this problem by implanting embryonic rat kidneys with bladders into adult rat hosts.
Four weeks after transplantation, the authors connected one of the host rat’s ureters to the transplanted bladder. This approach allowed the urine from the transplanted kidneys to pass into the transplanted bladder and then into the host bladder, thereby avoiding hydronephrosis. Eight weeks after transplantation, the kidney tissues contained structures characteristic of mature kidneys.
To test the clinical feasibility of this system, called the stepwise peristaltic ureter (SWPU) system, the authors repeated the experiments using pigs and achieved results similar to those observed in rats. By providing a urine excretion pathway and allowing long-term growth of newly generated kidneys, the SWPU system can potentially overcome challenges in generating functional kidneys from stem cells.