Japan researchers grow kidney tissue from stem cells

TOKYO: "Researchers in Japan said (...) 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 (French Press Agency).  

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." (Source).

Contact info: osafune-g@cira.kyoto-u.ac.jp

Because of Japanese rejection of brain-death criteria, alternatives to organ (kidney) transplant, such as regenerative medicine, are well sought after... Now wonder Japan has become a leeding country in stem cell therapy...

Japon: du tissu rénal obtenu à partir de cellules iPS

"Selon le site Internet de la revue Nature communications, 'des chercheurs japonais ont annoncé avoir développé avec succès du tissu rénal à partir de cellules souches pluripotentes induites (iPS)'. Le rapport portant sur ces travaux de recherche a été publié ce mercredi. Tout en précisant que ces travaux sont 'une étape importante', le professeur Osafune a cependant précisé qu'il ne 'sait pas encore si le simple fait de greffer des cellules régénérées permettra vraiment de guérir des maladies rénales'. Contrairement aux cellules souches prélevées sur des embryons humain, 'l'usage des cellules iPS ne pose pas de problème éthique'. Au Japon, 'les travaux sur les cellules iPS sont devenus une priorité de recherche' et 'l'Etat a décidé de leur allouer des financements importants considérant qu'il s'agit d'un domaine extrêmement prometteur dans lequel les Nippons devraient prendre une longueur d'avance'." Source : AFP 23/01/13

Le Japon ayant rejeté les critères de la "mort encéphalique", ce pays s'est engagé de très bonne heure dans la recherche d'alternatives à la transplantation d'organes (rénale), comme, en l’occurrence, la médecine régénérative avec les cellules souches adultes (dites iPS) ... Il n'est donc pas étonnant que le Japon soit un pays leader en la matière ...