Anita B. Roberts

Transforming Growth Factor β: A Multifunctional Regulatory Peptide with Actions in the Reproductive System

Transforming growth factor β (TGFβ) was first identified as a factor that could induce normal rat kidney (NRK) fibroblasts to form colonies in soft agar in the presence of epidermal growth factor (EGF) (1). Even though TGFβ has the ability to act in this classical assay for transformation, we now know that it is also a mediator of normal cellular physiology and has especially important actions in the processes of embryonic development, tissue remodeling, and wound healing (2). Almost all cells in culture synthesize TGFβ and have TGFβ receptors (3), and immunoreactive TGFβ has been found in a number of embryonic and adult murine tissues (4–5). These data suggest that TGFβ has widespread biological actions. In this chapter we review the chemistry and biology of the TGFβ family, with special emphasis on some of the biological actions of TGFβ that are most likely to be important in the function of the reproductive tract. A brief overview of the actions of TGFβ on gonadal cell types is given here; more details can be found in other chapters of this volume.