Laboratory-grown kidneys move closer to the real thing
A renowned Kiwi scientist’s research could point the way to bioengineering new kidneys.
The bean-shaped organs play a crucial role by filtering waste from all of the blood in our bodies as often as several times a day.
But high nationwide rates of kidney disease — particularly among Ma¯ ori and Pasifika — have brought an urgent need for new therapies.
One promising avenue is using kidney stem cells to effectively grow new kidneys for affected patients, yet this can’t be done until we properly understand how they normally form within an embryo.
It’s here that Associate Professor Alan Davidson, the head of the University of Auckland’s Department of Molecular Medicine and Pathology, has made some exciting strides.
During embryonic development, different progenitor cells migrate from particular developmental structures to other sites to form the various organs found in an adult. In the kidney’s case, the organ comes from one of three germ layers of vertebrate embryos, the mesoderm.
Within the mesoderm it originates from a subset that lies between one region that makes muscle from blocks called somites, and another called the lateral plate, which creates the lining of some blood vessels and tissue around the intestines.
Studies dating back more than 150 years indicated this was the only place kidney cells could come from.
But Davidson has found a new source in the area that makes somites.
This breakthrough was made by studying zebrafish, which share nearly three-quarters of our genes.
And he has shown these recently identified cells can form new functional tissue when transplanted into damaged kidneys. In a new, threeyear study, being supported with a $934,000 grant from the Marsden Fund, Davidson will characterise these cells and find out whether they can be exploited for new therapies.
If the study proves successful, the textbook description of kidney formation will be turned on its head.
In a separate programme, Davidson and colleagues have been turning human stem cells into kidney “organoids”, mini-organs grown in a dish.
This could offer hope to those needing kidney transplants.