Fixing The Plumbing Issue In Stem Cell-Generated Kidneys

Lab-grown kidneys are now one step closer to reality with the demonstration that stem cell-derived kidneys can successfully excrete urine.

AsianScientist (Nov. 30, 2015) – Researchers have generated a urine excretion strategy for embryonic kidneys generated from stem cells. Publishing their findings in the Proceedings of the National Academy of Sciences, the researchers showed that their approach allowed the sustainable growth and maturation of these transplanted kidneys in their host environment.

Chronic kidney diseases have become a major complication observed in patients globally in the recent years. The loss of our kidneys, which are necessary to filter off metabolic waste products from blood, can result in the increased risk of cardiovascular diseases and death if consistent dialysis or organ transplant is not conducted.

Due to the shortage of kidney donors, much research has gone into generating a de novo kidney from stem cells. Though there have been successes in creating the overall structure, however, creating a fully functional kidney equipped with a functional system has been challenging due to the delicate and complicated structure.

Dr. Takashi Yokoo and his team from the Jikei University School of Medicine in Tokyo, Japan, has successfully generated a functional kidney from human stems cells in his previous work. However, it did not have a urine excretion pathway which resulted in hydronephrosis, swelling of the kidneys due to urine build up. This also prevented the kidney from achieving maximal growth in size.

To overcome this challenge, Yokoo and his colleagues employed a technique called the stepwise peristaltic ureter (SWPU) system to connect make successful connections between the donor kidney with the host recipient environment.

To show that SWPU was able to generate a urinary excretion channel, Yokoo first conducted it in the rat whereby he connected the recipient ureter to the newly developed bladder from the donor four weeks after transplantation and allowed it to mature. Four weeks later, urine was generated from the bladder and was successfully discharged continuously from the connected recipient ureter, which failed to occur in previous kidneys generated from stem cells.

Yokoo and his colleagues then showed that this worked in the pig, a larger organism that more closely reflects what may occur in humans. Using the same SWPU system of connecting the recipient ureter to the bladder generated from the donor, a functioning urinary excretion pathway was generated and even allowed the transplanted neo-kidney to develop further.

With such promise in bypassing the shortage in kidney donors, Yokoo now hopes to regenerate human derived pre-kidney structures and transplant them directly into humans and construct a functioning urinary excretion channel using the SWPU system.

The article can be found at: Yokote et al. (2015) Urine Excretion Strategy for Stem Cell-Generated Embryonic Kidneys.


Copyright: Asian Scientist Magazine; Photo: Shutterstock.
Disclaimer: This article does not necessarily reflect the views of AsianScientist or its staff.

Jeremy is a finishing his PhD in regenerative biology at the Australian Regenerative Medicine Institute (ARMI), Monash University in Melbourne, Australia. In his spare time, he enjoys cooking, traveling, science jokes and teaching Australians how to pronounce his last name.

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