My research attempts to identify specific factors regulating this process. Embryonic mesenchyme cells are employed which, under appropriate culture conditions, will become cartilage cells.
Undifferentiated mesenchyme is removed from chick embryo limb buds and cultured.
Within three to four days nearly all the cells have differentiated into chrondrocytes and begin secreting an extracellular matrix containing specific cartilage gene products. By studying this process in cell culture we are able to vary, in a controlled environment, the many components in the microenvironment of the cells. We are also able to examine biochemically changes in their intracellular components. While a number of intracellular factors are undoubtedly important in the changes occurring during chondrogenesis, my laboratory and others have provided evidence that cyclic AMP is an important signal in activating genes that regulate the synthesis of cartilage cell products. While this group of genes is activated, other genes, coding for products produced by the undifferentiated mesenchyme cell, are repressed.