Stem Cell Therapy Repairs Heart Defect in Mouse Model

Cardiovascular disease researchers have used stem cells to repair damaged heart muscle in a mouse model of dilated cardiomyopathy, a potentially fatal, congenital heart defect.

Investigators at the Mayo Clinic (Rochester, MN, USA) developed a mouse line where the gene for critical heart-protective proteins called ATP-sensitive (KATP) channel subunits was "knocked-out.” The animals mimicked the symptoms of human dilated cardiomyopathy, typified by poor survival due to compromised heart contractions and ventricular dilation.

In an attempt to repair this condition, the investigators transplanted 200,000 embryonic stem cells into the wall of the left ventricle of the knockout mice. They reported in the July 31, 2008, online edition of the journal Stem Cells that after one month the treatment improved heart performance, synchronized electrical impulses, and stopped heart deterioration. The presence of the lacZ reporter transgene in the rejuvenated heart tissue showed that the stem cells had grafted into the heart to form new cardiac tissue. Stem cell transplantation restarted cell cycle activity in the heart tissue and reduced fibrosis by 50%. Improved systemic function induced by the stem cell therapy translated into increased stamina, absence of swelling due to the accumulation of serous fluids, and benefit to overall survivorship.

"We have shown in this transgenic animal model that embryonic stem cells may offer an option in repairing genetic heart problems,” said first author Dr. Satsuki Yamada, cardiovascular researcher at the Mayo Clinic.

Related Links:
Mayo Clinic