Loss of α10β1 integrin expression leads to moderate dysfunction of growth plate chondrocytes

Integrin alpha 10 beta 1 is a collagen-binding integrin expressed on chondrocytes. In order to unravel the role of the alpha 10 integrin during development, we generated mice carrying a constitutive deletion of the alpha 10 integrin gene. The mutant mice had a normal lifespan and were fertile but developed a growth retardation of the long bones. Analysis of the skeleton revealed defects in the growth plate after birth characterized by a disturbed columnar arrangement of chondrocytes, abnormal chondrocyte shape and reduced chondrocyte proliferation. Electron microscopy of growth plates from newborn mice revealed an increased number of apoptotic chondrocytes and reduced density of the collagen fibrillar network compared to these structures in control mice. These results demonstrate that integrin alpha 10 beta 1 plays a specific role in growth plate morphogenesis and function.