Thursday, 4 June 2009

Cloning Technology to Treat Parkinson's Disease

This study represents a major breakthrough in the controversial science of cloning. For the first time, cloning has been shown to successfully treat Parkinson’s disease in an animal. The success is attributed to the fact that this time researchers from Sloan-Kettering Institute gave mice suffering from Parkinson’s disease back their own cloned repaired brain cells. That cut down on the possibility of rejection, common when transplanted cells are not a genetic match.

Researchers report in Nature Medicine that the mice received cloned cells converted into the repaired brain cells that produced dopamine, the chemical missing in Parkinson’s disease which allows smooth muscle movements.

The team first created Parkinson’s disease in mice by destroying their brain cells. They took cells from the tail of the mouse and using the nuclei of mouse egg cells created an embryonic clone of the mouse. The dopamine-producing neurons are removed from the cloned embryos and given to the diseased mice. Those receiving the dopamine-producing neurons showed significant signs of improvement.

Before the transplant, the mice could only move in one direction, but once they received the repaired cells their movement returned to normal. An autopsy revealed the neural cells had grown to form normal connections with other cells.

The key appears to using the mouse’s own cloned embryonic stem cells.

"It demonstrated what we suspected all along -- that genetically matched tissue works better," said Viviane Tabar of Memorial Sloan-Kettering Institute in New York told Reuters.

The stem cells that did not come from the matched cells did poorly compared to the mice which received cells from their own clones.

Stem cell therapy offers great hope for a cure to Parkinson’s disease which afflicts about 1.5 million in the U.S. and creates a jerking or shaking movement in the muscles. It is an incurable and fatal disease sometimes treated with brain cells from aborted fetuses or cadavers.

The challenge so far has been in cloning nerve cells that survive after they are transplanted.

Dr Kieran Breen, director of research and development at the Parkinson's Disease Society tells the BBC: "This is an exciting development, as for the first time, we can see that it may be possible to create a person's own embryonic stem cells to potentially treat their Parkinson's.

More studies will be carried out for safety. These mice only lived 11 weeks until the study was suspended so the continuation of repair needs to be studied further.

There is a great deal of opposition to using cloning to make human embryos to treat disease.

Researchers from University College London, in a separate study, have identified mutations in a gene which may be responsible for causing Parkinson’s. This may represent the importance of family history and the possibility of an inherited genetic mutation. That discovery could help boost the discovery of new treatments.