Dr. Nadal-Ginard was convinced the cells were the product of stem cells arising in the body's bone marrow, circulating to the heart, and differentiating into the various cardiac cell types needed to regenerate the myocardium. His presentation showed two types of new evidence that myocardium-regenerating cells exist in the bone marrow and are able to differentiate into bona fide cardiac cells and coronary vessels. These findings, he told the multi-disciplinary scientists gathered at the meeting, open the possibility for development of true restorative therapies following heart attack and other cardiovascular diseases.
Until recently, scientists and clinicians believed that the heart had no self-renewal capability. That perception has "straight-jacketed" cardiovascular research, says Dr. Nadal-Ginard. Scientists reasoned that if no new myocytes could be generated in adult hearts, then all therapeutic interventions had to focus on preserving the heart cells remaining after the destruction of heart attack or simply the wear and tear of age or physiological or pathological stress. Furthermore, if no new myocytes were being generated, that by definition meant all the body's heart muscles had to be the same age. That would mean, for example, a 90-year-old man had nothing but 90 year old heart muscles.
Fortunately, says Dr. Nadal-Ginard, this view is changing. He reported two new studies supporting the fact that cells with stem cell characteristics reside in the adult myocardium or heart muscles.
First, he and his colleagues demonstrated that single stem-
Contact: Sarah Goodwin
Federation of American Societies for Experimental Biology