Brain cells and teeth from stem cells

Adult bone marrow stem cells can turn into brain cells, a finding that could lead to new treatments for brain disorders such as Parkinson's disease, US researchers say. The new study, published in the Lancet, provides more evidence that bone marrow can produce other types of tissue, as well as blood and bone. Meanwhile, UK researchers have unveiled plans to grow replacement teeth using stem cell technology.

Researchers at the University of Florida Shands Cancer Center studied three women with leukaemia, who had all received bone marrow transplants from male donors. After their deaths, post-mortem analysis showed that the brains of all the women contained male cells - identifiable by their Y chromosome. And the woman who lived the longest after the treatment, for six years, had three different types of male brain cell. They included neurons - nerve cells that transmit chemical messages in the brain. In some parts of the woman's brain, one per cent of the cells originated from the bone marrow donor. This, say the team, shows that bone marrow stem cells can migrate into the brain, be influenced by their new environment and develop into specialised brain cells.

'This study suggests that bone marrow could be used as a therapeutic source of readily harvestable cells for the regeneration of nerve cells, with potential application to various neurodegenerative diseases and central and traumatic spinal cord damage', said team leader Edward Scott.

Researchers at Kings College London have announced plans to develop replacement teeth using stem cells. The team has set up a private company, called Odontis, to develop its tooth-growing technology, which has already proved successful in mice. They will now test stem cells taken from different parts of the body - including bone marrow and teeth themselves - to find out which are most effective. Clinical trials could begin in about two years, the scientists say, and could eventually make dentures a thing of the past.