What Potential Functions in Testicular Physiology ?
Based on the described functions of proteases and inhibitors and considering testicular architecture and physiology, proteases and antiproteases may have a unique function in delivering growth factors trapped in the ECM , in activating growth factors or growth factor receptors, or in the shedding of transmembrane receptors generating soluble forms that woud act as dominant negative and impede normal signal transducing pathway following ligand binding to its receptor. ECM is known to function as a reservoir of endogeneous growth factors, sequestering them in an inactive state and protecting them from proteolytic degradation. For example FGF2 which is deeply involved in testicular physiology61 does not contain a sequence signal for secretion, and it has been proposed that following environmental stimuli, FGF2 is released from the ECM through the action of proteases allowing it to bind to specific transmembrane FGF receptors and transduce a signal.104 In addition to release growth factors
