Drugs unlock the body's own stem cell cabinet !!

.The discovery could lead to simple new treatments to accelerate repair of broken bones and ligaments, or damaged cardiac tissue following heart attacks.


The scope for patients to be treated with
their own stem cells has been boosted by
discovery of drug regimes that liberate specific
types of stem cells from the bone marrow

Instead of injecting patients with stem cells from donors, embryos or stem cell banks, doctors could simply inject the drugs and the patients would produce the cells themselves. This would avoid complications of tissue rejection and sidestep ethical objections to using stem cells originating from embryos.

"It's promoting self-healing," says Sara Rankin of Imperial College London, and a member of the team that discovered the stem-cell liberating effects. "We're simply boosting what's going on naturally."

It has been previously possible to promote the release of stem cells that develop into blood cells. Now, for the first time, stem cells have been liberated that regenerate other tissues, such as bone and blood vessels, widening options for treatment.

Twin approach

The researchers used a two-prong approach to produce - in mice - each type of stem cell. First, they gave the mice a natural growth factor for four days or so. Finally, they administered a drug called Mozobil, which unlocks the cells so they can escape into the bloodstream from the bone marrow.

To boost levels of haematopoietic stem cells, which create all blood cells, the researchers first gave the mice granulocyte colony stimulating factor (GCSF) followed by Mozobil.

This procedure is already well known and has been practised extensively in trials to boost blood stem cell production in patients undergoing treatment for various forms of lymphoma. It boosts blood stem cell production so that enough can be saved and transplanted back into the patient once their cancer, which destroys blood cells, has been eradicated.

However, the real breakthrough of the work at Imperial was to show that by giving a different combination - Mozobil preceded by vascular endothelial growth factor (VEGF) - they could boost levels of two other types of stem cell.

Mesenchymal stem cells (MSCs) promote regeneration of bone and tissue, and so could be used for bone repair. They also damp down inflammation, and could be used to treat conditions such as rheumatoid arthritis.

Epithelial progenitor cells (EPCs), meanwhile, stimulate the growth and repair of blood vessels, and could prove useful in restoring blood flow to the heart or brain following heart attacks or strokes.

Mystery cells

Intriguingly, Rankin and her colleagues also found that both treatments block production of other types of stem cells in the bone marrow. They found, for example, that the GCSF-based treatment doesn't stimulate production of any MSCs for tissue repair. This could explain the failure of attempts to stimulate stem-cell repair with GCSF in patients with heart attacks.

Likewise, no blood stem cells were produced when the mice received the VEGF-based treatment.

This is the first time, says Rankin, that anyone has demonstrated that different mechanisms release different types of stem cell. She says that there are other types of stem cell produced in the bone marrow, but not enough is known yet about what they do.

Rankin says that through further research it might be possible to identify other stem cells that work even better. She and her colleagues also hope next to do experiments in mice demonstrating that the additional cells accelerate healing. They are also investigating whether these natural repair processes become less efficient with age.

'Powerful tool'

Other researchers were impressed by the breakthrough. "The ability to selectively stimulate a patient's own stem cells could be a powerful tool for treating disease, and to speed up the repair of damaged and worn-out tissues," says Robert Lanza, chief scientist at Advanced Cell Technology in Worcestor, Massachusetts.

Lanza stresses, however, that the work was done in mice, not humans. "And we still don't know if, or to what extent, this approach can actually orchestrate repairs in the body."

Lanza, whose company has developed ways of making red blood cells from stem cells, says that it may be possible to combine the two methods - using stem cells in the lab to make a new organ, for example, then using the Mobozil treatment to provide it with a blood supply by stimulating blood vessel formation.

NewSci

------------------------- *Leave a comments, questions or even a suggestions below this post. Your expressions are always welcomed.

Posted in: blood,drug,stem cells.