The finding also helps explain how the body ensures that it can always store fat, a key to surviving when food is scarce (and an unfortunate ability when it is not). By requiring a primitive fat cell to copy itself at least twice before it matures and can't divide anymore, nature ensures a ready reservoir of the cells, say the researchers. While proliferation of these cells has long been recognized, this is the first evidence that those divisions are necessary for the cells' maturation.
"Fortunately or unfortunately, depending on how you look at it, food is not scarce in many parts of the world, and storing the excess calories can lead to obesity and many serious associated health problems," notes Daniel Lane, Ph.D., professor of biological chemistry at the school's Institute for Basic Biomedical Sciences. "Our finding may lead to new ways to tackle obesity, since we now know a crucial step in the body's ability to store additional fat, but that step would have to be targeted specifically."
Studying mouse primitive fat cells in the laboratory, the team discovered that the genes necessary for storing fat were turned on only after at least two cycles of cell division. Interfering with cell division at various points in the cycle prevented the cells from maturing, says Qi-Qun Tang, M.D., Ph.D., assistant professor of pediatric endocrinology and biological chemistry at Hopkins.
When more calories are taken in than are burned, existing fat cells make and store more fat. But the body also recruits some primitive fat cells -- preadipocytes to mature, which increases the capaci
Contact: Joanna Downer
Johns Hopkins Medical Institutions