Integrins expressed with bladder extracellular matrix after stretch injury in vivo mediate bladder smooth muscle cell growth in vitro.

To our knowledge these results demonstrate for the first time that that bladder distention initiates dynamic alterations in ECM expression. The ability of integrin blockade to suppress stretch induced bladder smooth muscle cell proliferation and the coordinate changes in bladder ECM and integrin expression suggest that integrins mediate key responses to mechanical stimuli in the bladder. Furthermore, cell cycle analysis of resting and stretched bladder smooth muscle cells revealed novel avenues for the examination of integrin and stretch regulation of bladder smooth muscle cell growth.