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The Sydney Morning Herald Thursday, August 16th. 2001 Human brain cells offer hope on diseases By Deborah Smith, Science writer Australian researchers have made a significant discovery which could lead to self-repair of damaged brains or spinal cords, avoiding the need to use ethically controversial human embryonic stem cells. The Melbourne team has succeeded in extracting stem cells from the brains of mice - master cells that can produce new nerve cells in the adult brain. The neural stem cells also changed into muscle cells under the right laboratory conditions. The Australian research, says team leader Dr Perry Bartlett, offers the first "unequivocal" evidence that adult stem cells could develop into different tissue types, just like embryonic cells. Stimulating the body's own adult stem cells to repair organs was a preferable approach to transplanting human embryonic stem cells, which could require immunosuppressive drugs to prevent rejection, said Dr Bartlett, of the Walter and Eliza Hall Institute of Medical Research. "This appears an easier way forward," he said. The development comes less than a week after United States President George Bush approved federal funding for research into embryonic stem cells, which scientists believe can grow into any type of human tissue. They offer enormous potential to cure conditions such as Alzheimer's disease, spinal cord injuries and diabetes. But they are controversial because their extraction involves the destruction of days-old human embryos. While different kinds of adult stem cells are found in different organs, they do not appear to be as versatile as embryonic cells. Dr Bartlett said one adult neural stem cell could generate tens of thousands of new nerve cells. The challenge was to find drugs that could stimulate this natural process, so the brain could repair damage caused by illnesses such as Alzheimer's, stroke and Parkinson's. "Now we have the cells in our hot little hands we can ask, 'What are the factors that regulate their change into normal nerve cells?"' The research is published today in the journal Nature. Ten years ago it was scientific heresy to suggest the adult brain could grow new nerve cells. Then, in 1992, two teams, including Dr Bartlett's, showed that mice had neural stem cells in their brains. They have since been found in human brains. Several studies have also shown that mammals are constantly growing new brain cells, particularly in the olfactory lobes, associated with smell, and in the hippocampus, where memories are formed. Team member Mr Rodney Rietze spent several years perfecting the method for identifying and isolating the neural stem cells from mice brains. Three years ago, Mr Rietze discovered that neural stem cells from mice could change into blood cells. Other studies have shown different types of adult stem cells, such as blood and skin stem cells, are also versatile, and can be transformed into fat, muscle and nerve cells. But there had been debate whether this was due to contamination. The experiment was convincing, Dr Bartlett said, because they were able to observe a single purified neural stem cell differentiate into a muscle cell. More than 50 per cent of the neural stem cells were quickly converted into muscle cells. In the US, government funding will be confined to work on previously harvested embryos - and prohibits any new ones being used. Mr Bush even stopped short of approving stem cell research using excess IVF embryos, which are routinely discarded. His decision was derided by scientists as excessively conservative but he had faced intense lobbying from right-to-life activists who believe the destruction of embryos for stem cells is equivalent to abortion. SOURCE: The Sydney Morning Herald http://www.smh.com.au/news/0108/16/national/national102.html * * * ---------------------------------------------------------------------- To sign-off Parkinsn send a message to: mailto:[log in to unmask] In the body of the message put: signoff parkinsn