Body repair could be controlled and urged

Friday, 9 January 2009

Body repair 'could be ramped up'


http://news.bbc.co.uk/go/pr/fr/-/2/hi/health/7815449.stm

A combination of drugs could trick the body into sending its repair mechanisms into overdrive, say scientists.

The technique could be used to speed the healing of heart or bone damage, they claim.

The bone marrow of treated mice released 100 times as many stem cells - which help to regenerate tissue.

Imperial College London scientists reported their work in the journal Cell Stem Cell, but said human trials were some years away.

The release of stem cells by the bone marrow is a natural part of the repair process - different types are sent to replenish tissue depending on the nature of the injury.

However, in some cases, for example the damage caused by heart disease, the repair is not entirely successful, and loss of function persists.

The theory behind the Imperial College research is to boost the quantity of stem cells released, which will hopefully mean a swifter and more complete recovery.

Techniques already exist to increase the numbers of blood cell producing stem cells from the bone marrow, but the study focuses on two other types - endothelial, which produce the cells which make up our blood vessels, and mesenchymal, which can become bone or cartilage cells.

The mice were given firstly a "growth factor" drug - substances that already occur naturally in the bone marrow, then a new drug called Mozobil.

Both endothelial and mesenchymal cells were released at a much greater rate.

Arthritis hope

Dr Sara Rankin, one of the researchers, said: "The body repairs itself all the time, However, when the damage is severe, there are limits to what it can do of its own accord.

"We hope that by releasing extra stem cells, as we were able to do in mice in our study, we could potentially call up extra numbers of whichever stem cells the body needs, in order to boost its ability to mend itself and accelerate the repair process."

There are also hopes that the technique could help damp down autoimmune diseases such as rheumatoid arthritis, where the body's immune system attacks its own tissues.

Mesenchymal stem cells are known to have the ability to damp down the immune system.

The next stage of the research is to see if the extra stem cells circulating in the mice can have a practical benefit - repairing more quickly or more thoroughly the damage caused by a heart attack, for example.

Their hope is that clinical trials in humans may be possible within the next 10 years.

Professor Peter Weissberg, Medical Director at the British Heart Foundation, said: "It has long been known that the bone marrow contains cells that can replace lost or aged blood cells.

"It now seems increasingly likely that the bone marrow also contains cells that have the capacity to repair damaged internal organs, such as the heart and blood vessels, but that too few of them are released to be effective.

"This research has identified some important molecular pathways involved in mobilising these cells.

"It may be possible to develop a drug that interacts with these pathways to encourage the right number and type of stem cells to enter the circulation and repair damage to the heart."