The Transition of Cadherin Expression in Osteoblast Differentiation from Mesenchymal Cells: Consistent Expression of Cadherin‐11 in Osteoblast Lineage

Osteoblasts are derived originally from pluripotent mesenchymal stem cells on migration into the bone matrix. To elucidate the contribution of classical cadherins in this differentiation pathway, we developed a new protocol for their analysis and studied their specific expressions in various cell lines of the mesenchymal lineage, including osteoblasts. N‐cadherin was expressed constitutively in all cell lines examined except an osteocyte‐like cell line whereas cadherin‐11 was expressed selectively in preosteoblast and preadipocyte cell lines. P‐cadherin also was expressed in primary cultures of calvarial cells and mature osteoblasts at a relatively low level compared with N‐cadherin and cadherin‐11. M‐cadherin was expressed only in a premyoblast cell line. We observed the transition of cadherin expression from M‐cadherin to cadherin‐11 in the premyoblast cell line when osteogenic differentiation was induced by treatment with bone morphogenetic protein 2 (BMP‐2), while the expression of N‐cadherin remained unchanged. In contrast, when a preadipocyte cell line, which shows a similar pattern of cadherin expression to osteoblasts, was induced to undergo adipogenic differentiation, the expression of N‐cadherin and cadherin‐11 was decreased. These observations characterize the cadherin expression profile of mesenchymal lineage cells, especially osteoblasts, which regularly express cadherin‐11. Cadherin‐11 may affect cell sorting, alignment, and separation through differentiation.