Invited review: Mechanochemical signal transduction in the fetal lung

Growth and maturation of fetal lungs are regulated by both humoral and phys ical factors. Mechanical stretch stimulates fetal lung cell proliferation a nd affects fetal lung maturation by influencing the production of extracell ular matrix molecules and the expression of specific genes of fetal lung ce lls. These effects are mediated through special signal transduction pathway s in fetal lung cells. Various in vivo and in vitro model systems have been developed to investigate the mechanotransduction process. The diversity an d discrepancy of these studies have raised many questions. We will briefly summarize mechanical force-induced signals in fetal lung cell proliferation and differentiation and then discuss several important issues related to t hese studies.