Stem cells from muscle may address diabetes-related circulation problems: study

CHICAGO, Nov. 6 (Xinhua) -- Stem cells taken from muscle tissue (MSCs) could promote better blood flow in patients with diabetes who develop peripheral artery disease (PAD), a painful complication that can require surgery or lead to amputation.

A study of the University of Illinois (UI) found that an injection of the stem cells in mice prompted new blood vessels to grow, improving circulation in the affected tissues and function in the affected limbs.

The stem cells also induced changes in gene expression in the surrounding tissues, prompting the release of factors to reduce inflammation and increase circulation.

The researchers surgically narrowed the femoral artery in one leg of diabetic mice. They injected MSCs taken from the muscles of young mice into the legs of the experimental mice, while the control group got a saline injection.

Then they used noninvasive imaging techniques to monitor blood flow and blood vessel formation in the mice, comparing both the experimental and control groups and the affected and non-affected legs in each mouse.

"We clearly demonstrated the capacity for MSCs to increase angiogenesis, peripheral perfusion and muscle function," said Marni Boppart, UI professor of kinesiology and community health. "We saw that MSCs promoted muscle healing by creating new vessels in the tissue that compensated for restricted blood flow. MSC transplantation provides the opportunity to maximize vessel growth in PAD to maintain or rejuvenate skeletal muscle."

The researchers also performed an analysis of gene expression within the tissue and found that, in mice given the stem cell injections, the gene expression in the leg with PAD was close to that of the unaffected leg.

They also found that compared with the mice that did not get the stem cells, there were genes activated to combat some of the diabetic complications, for example, genes associated with inflammation were repressed.

"Our results suggest that stem cell treatment could be used for those patients at severe stages of PAD who cannot exercise," said study leader Wawrzyniec Lawrence Dobrucki, UI professor of bioengineering and of medicine. "Stem cell treatment could help bring them to the level where they can start exercising, or it could save an extremity before it needs amputation."

In the next step, the researchers are hoping to identify subpopulations of MSCs that demonstrate the most potential to treat PAD, as well as optimizing the conditions to isolate these rare cells from human fat tissue and skeletal muscle. They are also studying how long the MSCs stay active after injection, and what kind of immune response they may trigger.

PAD is very common in diabetic patients, and if left untreated, it often leads to foot ulcerations and limb amputations. Treatment options for PAD are few.

The study has been published in the journal Theranostics, which focuses on the integration of therapeutics and diagnostics.