Japan researchers grow kidney tissue from stem cells

Researchers in Japan said Wednesday they have succeeded in growing human kidney tissue from stem cells for the first time in a potential breakthrough for millions with damaged organs who are dependent on dialysis. Kidneys have a complex structure that is not easily repaired once damaged, but the latest findings put scientists on the road to helping a diseased or distressed organ fix itself. Kenji Osafune of Kyoto University said his team had managed to take stem cells -- the "blank slates" capable of being programmed to become any kind of cell in the body -- and nudge them specifically in the direction of kidney tissue. "It was a very significant step," he told AFP. Osafune said they had succeeded in generating intermediate mesoderm tissue from the stem cells, a middle point between the blank slate and the finished kidney tissue. "There are about 200 types of cells in the human body, but this tissue grows into only three types of cells," namely adrenal cells, reproductive gland cells and kidney cells, he said, adding that as much as 90 percent of cultures in their research developed into viable mesoderm tissue. This embryonic intermediary can be grown either in test tubes or in a living host into specific kidney cells. Osafune and his team created part of a urinary tubule, a small tube in the kidney that is used in the production of urine. While the research is not aimed at growing an entire working kidney, he said the method his team had developed would help scientists learn more about intermediate mesoderm development and may provide a source of cells for regenerative therapy. "I would say that we have arrived at the preliminary step on the road to the clinical level," he said. Osafune's research is published in online science journal Nature Communications.