Human kidney tissue successfully grown from stem cells

In
what is thought to be a first, stem cells have been used to generate human kidney
tissue.

Experiments
led by Dr Kenji Osafune at Kyoto University in Japan, used human
induced pluripotent stem cells, which can be programmed to become any of the cells in
the body. The scientists first grew a kind of tissue called intermediate
mesoderm - a middle point between the stem cells and specialised
kidney tissue.

'There are about 200 types of cells in the human body,
but this tissue grows into only three types of cells', Dr Osafune told AFP. As
well as kidney cells, intermediate mesoderm tissue can develop into adrenal
cells or reproductive gland cells.

From the intermediate mesoderm, the scientists
were able to generate part of the urinary tubule, which is important in the
production of urine.

The study is significant because it points
towards future clinical applications. Kidney tissue cannot regenerate or repair
itself and currently patients with damaged or diseased kidneys rely on time-consuming
dialysis until they are matched with an organ donor.

Kidney transplantation is far from risk-free and
donor shortages are widespread. Even successful transplant patients require
another transplant after 10-15 years.

Dr Osafune stressed
that the study, published in Nature Communications, is only a small step
towards kidney tissue grown from stem cells being used clinically. 'It is not known yet if simply
transplanting regenerated cells would really cure kidney ailments', he said.

Dr Takahashi Yokoo, of Jikei University,
Tokyo, who was not involved with the study, agreed, telling AFP: 'Yes, a tubule
structure was generated, but an enormous amount of research is still necessary
to create an orderly structure that produces urine'.

Nonetheless, Dr Osafune said that his team
had taken 'the preliminary step on the road to the clinical level'.