Heart muscle in young children may be capable of regeneration
Image: Cardiac muscle from a 15 day old mouse. Red staining indicates the presence of a protein involved in cell division. In similar images from a mouse at day 14 and 16, none of the cells are red.
The entire heart muscle in young children may hold untapped potential for regeneration, new research suggests.
For decades, scientists believed that after a child’s first few days of life, cardiac muscle cells did not divide. Instead, the assumption was that the heart could only grow by having the muscle cells become larger.
Cracks were already appearing in that theory. But new findings in mice, published in May in Cell, provide a dramatic counterexample — with implications for the treatment of congenital heart disorders in humans.
Researchers at Emory University School of Medicine have discovered that in young mice 15 days old, cardiac muscle cells undergo a precisely timed spurt of cell division lasting around a day. The total number of cardiac muscle cells increases by about 40 percent during this time, when the rest of the body is growing rapidly. [A 15-day-old mouse is roughly comparable to a child in kindergarten; puberty occurs at day 30-35 in mice.]
Funding: the research was supported by the National Heart Lung and Blood Institute, the American Heart Association, and the John and Mary Brock Diagnostic and Discovery Fund.
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