Distribution of the collagen-binding integrin α10β1 during mouse development

We have previously identified and characterised the collagen type II-binding integrin subunit alpha 10, which is a member of the beta1 family and is expressed by chondrocytes. In the present study, we examined the expression of the alpha 10 integrin in various mouse tissues. Immunohistochemical analysis of alpha 10 on cryosections from 3-day-old mice demonstrated that alpha 10 beta1 was present in the hyaline cartilage of joints. vertebral column, trachea and bronchi. In addition, alpha 10 was found in the ossification groove of Ranvier, in the aortic and atrioventricular valves of the heart and in the fibrous tissue lining skeletal muscle and ligaments. Overall, the distribution was distinct from that of the collagen-binding integrins alpha1 beta1 and alpha2 beta1. We also found that alpha 10 beta1 was the dominating collagen-binding integrin during cartilage development. Expression of alpha 10 appeared at embryonic day 11.5 (E11.5) at the same time as chondrogenesis started as judged by collagen type II expression. At E13.5, alpha 10 was present throughout the anlage as well as in the perichondrium and in mesenchyme just outside the perichondrium, where it localised with collagen type I. Four weeks after birth, alpha 10 was prominent both at the articular surface and in the growth plate. In conclusion, we found that integrin alpha 10 beta1 was a major collagen-binding integrin during cartilage development and in mature hyaline cartilage. In addition, we found that alpha 10 beta1 was present in some fibrous tissues.