Washington, May 29 : For the first time, researchers at the University at Buffalo have shown that it is possible to repair cardiac tissue and, in turn, reverse heart failure by injecting adult bone marrow stem cells into skeletal muscle.

The researchers used an animal model to demonstrate that the non-invasive procedure could increase myocytes, or heart cells, by two-fold and reduce cardiac tissue injury by 60 percent.

In addition, the therapy improved function of the left ventricle-the primary pumping chamber of the heart-by 40 percent.

It even reduced fibrosis-the hardening of the heart lining that impairs its ability to contract-by up to 50 percent.

"This work demonstrates a novel non-invasive mesenchymal stem cell (MSC) therapeutic regimen for heart failure based on an intramuscular delivery route," said Dr. Techung Lee, UB associate professor of biochemistry and senior author on the paper.

Mesenchymal stem cells are found in the bone marrow, and can differentiate into a variety of cell types.

Lee said: "Injecting MSCs or factors released by MSCs improved ventricular function, promoted myocardial regeneration, lessened apoptosis (cell death) and fibrotic remodeling, recruited bone marrow progenitor cells and induced myocardial expression of multiple growth factor genes.

"These findings highlight the critical ''cross-talks'' between the injected MSCs and host tissues, culminating in effective cardiac repair for the failing heart.

"An important feature of MSCs is their ability to produce a plethora of tissue healing effects, known as "tropic factors," which can be harnessed for stem cell therapy for heart failure.

The multiple trophic factors produced by MSCs have already been shown to be capable of reducing tissue injury, inhibiting fibrosis, promoting angiogenesis, stimulating recruitment and proliferation of tissue stem cells, and reducing inflammatory oxidative stress, a common cause of cardiovascular disease and heart failure.

Lee added: "Since skeletal muscle is the most abundant tissue in the body and can withstand repeated injection of large number of stem cells, we thought it would be a good method to deliver MSCs. We hypothesized that MSCs, via secretion of these functionally synergistic trophic factors, would be able to rescue the failing heart even when delivered away from the myocardium.

"This study proves our hypothesis. We''ve demonstrated that injecting MSCs, or trophic factors released by MSCs, into skeletal muscle improved ventricular function, promoted regeneration of heart tissue, decreased cell death and improved other factors that cause heart failure.

"This non-invasive stem cell administration regimen, if validated clinically, is expected to facilitate future stem cell therapy for heart failure."

The development has been reported in a paper appearing online in the Articles-in-Press section of the American Journal of Physiology -- Heart Circulation Physiology. (ANI)