Cloned Stem Cells Regenerate Heart Muscle Following a Heart Attack
Tuesday February 10, 10:52 am ET
WORCESTER, Mass., Feb. 10 /PRNewswire/ -- Advanced Cell Technology, Inc. (ACT) reports that nuclear transfer cloning can be used to regenerate infarcted heart. The results of a study, which appear online (ahead of print) in the American Heart Association's journal, Circulation Research, by ACT and its collaborators at New York Medical College and the Memorial Sloan-Kettering Cancer Center, provide the first experimental evidence in animals of the successful use of cloning techniques to repair a severely damaged organ.
One aspect of the debate over the use of cloning in medicine (therapeutic cloning) has centered on the question of whether cloned cells would be healthy enough to be of practical use in cell therapy. This paper addressed that question. A heart attack results in the destruction of heart muscle that cannot normally be repaired by the body. Using a mouse model, ACT and its collaborators isolated and injected cloned stem cells into the region of the heart adjacent to the damaged heart tissue. The cloned stem cells replace nearly 40% of the scar tissue at the site of injury and improved the ability of the heart to beat normally.
"This study introduces an important new paradigm," said Robert Lanza, Vice President of Medical & Scientific Development at ACT, and lead author of the study. "Cloned cells are not only histocompatible, but are more youthful, and potentially of greater therapeutic value than adult stem cells."
Significantly, the regenerated heart tissue was composed of not only of heart muscle cells but also of blood vessels that connected with the coronary circulation. The cloned myocytes were functionally competent, expressed contractile proteins, and were electrically and mechanically coupled to other heart cells. Similarly the newly formed coronary arterioles and capillary structures contained blood and likely contributed to tissue oxygenation. Cardiac replacement resulted in an improvement of ventricular hemodynamics and in a reduction of diastolic wall stress. Importantly, a relatively small number of cells were injected in the region bordering the infarct, suggesting that the magnitude of myocardial regeneration obtained with stem cells from cloned embryos was superior to that previously achieved with adult bone marrow cells. Complete healing of the infarcted region in the mouse occurred in three weeks, strengthening the relevance of the present study to ischemic heart disease and post-infarction heart failure in humans.
"Heart disease remains the number one killer of Americans," said Michael D. West, Chief Executive Officer of ACT. "But medical researchers are beginning to imagine a day when science can conquer this dreaded disease, unlocking the power of stem cells to mend broken hearts. The ability of therapeutic cloning to theoretically make any cell or tissue type in the human body, and cells that would likely be accepted by the body as 'self' underscores the importance of our nation leading the world in the science of regenerative medicine."
The researchers of the paper from Advanced Cell Technology, collaborated with scientists from the Cardiovascular Research Institute at New York Medical College; Memorial Sloan-Kettering Cancer Center, New York; and the RIKEN Center of Developmental Biology, Kobe, Japan. The paper's other authors are Piero Anversa (senior author), Annarosa Leri, Stefano Chimenti, Alyssa Monsen, Daria Nurzynska, and Jan Kajstura of the Cardiovascular Research Institute; Malcolm A.S. Moore, Jae- Hung Shieh, and Jan Hendrikx of the Memorial Sloan- Kettering Cancer Center; and Teruhiko Wakayama and Anthony C.F. Perry of RIKEN.
Advanced Cell Technology is a biotechnology company focused on discovering and commercializing the applications of cloning and stem cell technology in human medicine.
