Relative abundance of different cadherins defines differentiation of mesenchymal precursors into osteogenic, myogenic, or adipogenic pathways

Cadherins, a family of cell-cell adhesion molecules, provide recognition si gnals that are important for cell sorting and aggregation during tissue dev elopment. This study was performed to determine whether distinct cadherin r epertoires define tissue-specific lineages during differentiation of immatu re C3H10T1/2 and C2C12 mesenchymal cells. Both cell lines expressed mRNA fo r N-cadherin (N-cad), cadherin-11 (C11), and R-cadherin (R-cad). After indu ction of osteogenesis by recombinant human BMP-2 (rhBMP-2) treatment, stead y state N-cad mRNA slightly increased in C3H10T1/2 cells. Likewise, the abu ndance of C11 mRNA increased in both cell lines, although the changes were more remarkable in C2C12 cells. By contrast, R-cad expression was almost sh ut off by rhBMP-2. The immature but committed osteoblastic MC3T3-E1 cells e xhibited only minor changes in N-cad and C11 mRNA abundance after rhBMP-2 t reatment. Whereas adipogenic differentiation was associated with a net decr ease of N-cad and C11 expression in C3H10T1/2 cells, induction of myogenesi s in C2C12 cells resulted in up-regulation of N-cad, while R-cad mRNA becam e undetectable in either case. Similarly, the adipocytic 3T3-L1 cells expre ssed very low levels of all cadherins when fully differentiated. Therefore, the repertoire of cadherins present in undifferentiated mesenchymal cells undergoes distinct changes during transition to mature cell phenotypes. Alt hough neither N-cad nor C11 represent strict tissue-specific markers, the r elative abundance of these mesenchymal cadherins defines lineage-specific s ignatures, perhaps providing recognition signals for aggregation and differ entiation of committed precursors. J. Cell. Biochem. 78:566-577, 2000. (C) 2000 Wiley-Liss, Inc.