Bone Development Depends on Insulin-Like Growth Factor-I
Mouse study shows deficiency results in severe dwarfism of the axial and appendicular skeleton
TUESDAY, Oct. 17 (HealthDay News) -- Insulin-like growth factor-I (IGF-I) is essential for embryonic bone development, researchers report in the October issue of Endocrinology.
Daniel D. Bikle, M.D., of the Veterans Affairs Medical Center in San Francisco, and colleagues studied IGF-I-deficient mice.
The researchers found that IGF-I deficiency resulted in significantly reduced chondrocyte proliferation, increased chondrocyte apoptosis and abnormal chondrocyte differentiation and maturation. They also found that it resulted in severe dwarfism of the axial and appendicular skeleton, and reduction in mineralization of the spinal column.
"IGF-I promotes chondrocyte proliferation and differentiation while inhibiting chondrocyte apoptosis," the authors conclude. "IGF-I is shown for the first time to be an important regulator of the Indian hedgehog-PTHrP feedback loop, and many of the changes observed in the [IGF-I-deficient] embryos can be attributed to the disruption of this feedback loop."