α11β1 Integrin Is a Receptor for Interstitial Collagens Involved in Cell Migration and Collagen Reorganization on Mesenchymal Nonmuscle Cells

Abstractα11β1 integrin constitutes a recent addition to the integrin family. Here, we present the first in vivo analysis of α11 protein and mRNA distribution during human embryonic development. α11 protein and mRNA were present in various mesenchymal cells around the cartilage anlage in the developing skeleton in a pattern similar to that described for the transcription factor scleraxis. α11 was also expressed by mesenchymal cells in intervertebral discs and in keratocytes in cornea, two sites with highly organized collagen networks. Neither α11 mRNA nor α11 protein could be detected in myogenic cells in human embryos. The described expression pattern is compatible with α11β1 functioning as a receptor for interstitial collagens in vivo. To test this hypothesis in vitro, full-length human α11 cDNA was stably transfected into the mouse satellite cell line C2C12, lacking endogenous collagen receptors. α11β1 mediated cell adhesion to collagens I and IV (with a preference for collagen I) and formed focal contacts on collagens. In addition, α11β1 mediated contraction of fibrillar collagen gels in a manner similar to α2β1, and supported migration on collagen I in response to chemotactic stimuli. Our data support a role for α11β1 as a receptor for interstitial collagens on mesenchymally derived cells and suggest a multifunctional role of α11β1 in the recognition and organization of interstitial collagen matrices during development