STEM CELLS REPAIR HEART DAMAGE IN MICE

MDA grantee Margaret Goodell at Baylor College of Medicine's Center for Cell and Gene Therapy in Houston recently led a team that demonstrated a possible new approach to treating damaged heart muscle. The finding could eventually have application in neuromuscular disease.

The team studied mice exposed to conditions that simulated a heart attack (a blockage in the heart's blood supply) and then gave some of the mice an infusion of stem cells from the bone marrow of donor mice.

The stem cells were selected for special characteristics that suggested they'd be able to generate new heart tissue. Goodell and her colleagues have developed the procedures for isolating such cells during the last few years.

The selected stem cells contributed to the growth of new cardiac blood vessels and cardiac muscle tissue, leading the researchers to announce in the June issue of the Journal of Clinical Investigation that the finding might eventually result in a therapy for treatment of damaged human hearts.

In the Baylor experiments, the researchers destroyed with high-dose radiation the bone marrow of the mice that received the infusion, a technique unlikely to be used in humans. The high-dose radiation may have contributed to the effectiveness of the treatment, however, so a substitute for its effects may have to be found.

Even with the radiation, Goodell emphasizes, the number of donor cells that actually became heart cells was very small. Much more work needs to be done before such techniques can be considered an option for human patients, she adds.

Still, the team considers the work an encouraging first step that could eventually apply to the heart damage seen in some neuromuscular disorders. In genetic disorders, the patients' own stem cells could be modified via gene therapy before being reinfused; or, donated cells without genetic defects could be used.