Through thick and thin: a circulating growth factor inhibits age-related cardiac hypertrophy

Abstract

In an intriguing new study, Loffredo et al report that joining the circulation of old mice with that of young mice reduces age-related cardiac hypertrophy. They also found that the growth factor growth/differentiation factor 11 is a circulating negative regulator of cardiac hypertrophy which suggests that raising growth/differentiation factor 11 levels may be useful to treat cardiac hypertrophy associated with aging.

Figure 1

Age-related cardiac hypertrophy is inhibited by a circulating growth factor, GDF11. A) Cardiac size is greater in old mice than in young mice. After four weeks of parabiosis with young mice, cardiac size in old mice is reduced demonstrating that a circulating factor that inhibits cardiac growth changes with aging. Systemic GDF11 levels are reduced during aging, and daily administration of GDF11 for 30 days reduced cardiac size in old mice similar to parabiosis with young mice. B) The related growth factors, GDF11 and myostatin, are inhibitors of muscle growth. GDF11 inhibits cardiac muscle hypertrophy, and raising GDF11 levels may help treat age-related cardiac hypertrophy. Myostatin inhibits skeletal muscle hypertrophy, and myostatin inhibitors are in clinical trials for increasing skeletal muscle mass. Some studies have shown that myostatin appears to inhibit cardiac growth as well, but it is unclear whether GDF11 can affect skeletal muscle growth.