'Tricked' stem cells hold key for regenerating tissue
UK scientists boost hopes of employing stem cells to combat heart and autoimmune diseases
Also In The News
|
Andy Murray will lock horns with Roger Federer again after he beat Ukrainian Sergiy Stakhovsky in the quarter-finals of the Qatar Open. |  |
Friday, 09, Jan 2009 12:01
The prospects of employing stem cells to counteract heart and autoimmune diseases, as well as heal serious injuries, have been raised by new UK-based research.
Scientists from Imperial College London say they have succeeded in 'tricking' bone marrow into releasing extra adult stem cells used to repair heart damage or mend broken bones into the bloodstream.
Previous research had already shown the body's ability to repair itself, a natural process where bone marrow uses stem cells to repair and regenerate tissue, can be augmented by stem cells.
Researchers aimed to use different new drug combinations to put the bone marrow into a state of 'red alert' and send specific kinds of stem cells into action.
In the new study, researchers tricked the bone marrow of healthy mice into releasing two types of adult stem cells: mesenchymal stem cells, which can turn into bone and cartilage and that can also suppress the immune system, and endothelial progenitor cells, which can make blood vessels and therefore have the potential to repair damage in the heart.
Their tests are the first to mobilise these cells from bone marrow; previous research only mobilising haematopoietic stem cells, which create new blood cells.
"The body repairs itself all the time," said study author Sara Rankin in journal Cell Stem Cell.
"We know that the skin heals over when we cut ourselves and, similarly, inside the body there are stem cells patrolling around and carrying out repair where it's needed. However, when the damage is severe, there are limits to what the body can do of its own accord," Dr Rankin, from Imperial's national heart and lung institute continued.
"We hope that by releasing extra stem cells, as we were able to do in mice in our new 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. Further down the line, our work could lead to new treatments to fight various diseases and injuries which work by mobilising a person's own stem cells from within."
The scientists reached their conclusions after treating healthy mice with one of two different 'growth factors' - proteins that occur naturally in the bone marrow - called VEGF and G-CSF. Following this treatment, the mice were given a new drug called Mozobil.
The researchers found that the bone marrow released around 100 times as many endothelial and mesenchymal stem cells into the bloodstream when the mice were treated with VEGF and Mozobil, compared with mice that received no treatment. Treating the mice with G-CSF and Mozobil mobilised the haematopoietic stem cells - this treatment is already used in bone marrow transplantation.
They now want to investigate whether releasing repair stem cells into the blood really does accelerate the rate and degree of tissue regeneration in mice that have had a heart attack. Depending on the outcome of this work, they hope to conduct clinical trials of the new drug combinations in humans within the next ten years.
The study authors are also keen to explore whether ageing or having a disease affects the bone marrow's ability to produce different kinds of adult stem cells. They want to investigate if the new technique might help to reinvigorate the body's repair mechanisms in older people, to help them fight disease and injury.