Only 50% Effectiveness Required in Stem Cell and Gene Therapy to Yield Healthy Heart

University of Missouri - Columbia, November 1, 2007

The length and quality of life for individuals with specific forms of muscular dystrophy is greatly affected by heart disease, which is also the leading cause of death in the United States.  Until now, scientists have been unsure whether the heart could benefit from treatments involving gene and/or stem cell therapy.  Recent discoveries have shown that a variety of organs could be helped by such treatment.

If only 50 percent of the cells in the heart are healthy, a muscular dystrophy patient should be able to maintain a normal lifestyle.  This is according to researchers as to University of Missouri-Columbia, whose study was published in a journal of the American Heart Association titled Circulation Research.

The production of a protein known as dystrophin is disrupted by a gene mutation in patients with Becker muscular dystrophy and Duchenne muscular dystrophy.  Muscle cell degeneration and death are the eventual outcome of the domino effect that is initiated by the absence of this protein.  Fibrous fatty or bony tissue eventually replaces the damaged muscle tissue causing it to lose function.  Patients become severely limited when this occurs in the heart, as it leads to severe heart disease.

Getting rid of the damaged tissue in the heart used to be the only way to have a healthy heart according to scientists.  It was believed that the heart needed to maintain 100 percent normal cells in order to stay healthy since the heart was considered to be a "synchronized organ".

Healthy cells replace diseased cells in stem cell therapy.  Healthy genes replace mutated genes during gene therapy.  However, it is not feasible to repair every cell in the heart with stem cell and gene therapies.  Previously, scientists were uncertain whether partial correction could benefit patients.

"In our study, we found that a heart with 50 percent normal cells looks like a normal heart," said Dongsheng Duan, an associate professor of molecular microbiology and immunology at the MU School of Medicine. "More importantly, it acts like a normal heart. This is the first time that we have concrete evidence that partial gene or cell therapies will be effective for preventing heart disease in a mouse model of muscular dystrophy."

"It's important to note that this could improve the quality of life for individuals who have this heart condition," said Brian Bostick, a doctoral student in molecular microbiology and immunology and the first author of the study. "We're also looking at this as a possible way to prevent heart disease. If we can treat it early through gene therapy or cell therapy, we know now that it can be very beneficial for patients."

In animal models of muscular dystrophy as well as in human patients, ongoing gene and cell therapy studies should benefit positively from the finding said University of Missouri-Columbia researchers.  Patients suffering from other heart diseases should also benefit from a natural tangent of the study, with the development of effective gene and cell therapies for those patients being a distinct possibility as well.