Mesenchymal Cells and EMT

In early embryos, the mesenchyme is a transient tissue that is primarily derived from the mesoderm layer and gives rise to blood vessels, lymphatic vessels, and connective tissues. Fibroblasts are the most common type of cell in connective tissues, and they share many characteristics with mesenchymal cells. In contrast to the polarized shape of non-motile epithelial cells, mesenchymal cells are spindle-shaped and have migratory capabilities. Mesenchymal cells typically express markers such as the intermediate filament protein Vimentin and the cell adhesion molecule N-Cadherin. N-Cadherin mediates the adhesion of mesenchymal cells to adjacent stromal cells, and its expression is associated with increased cell migration and invasiveness. The ability of mesenchymal cells to migrate and differentiate is physiologically relevant for their roles in early embryonic development and during wound healing in adults. Pathologically, mesenchymal cells that arise during an epithelial to mesenchymal transition (EMT) are thought to contribute to metastatic lesions during the progression of epithelial cancers.