Estradiol promotes fibronectin production via specific signaling cascades. (A) Fibronectin (FN) protein levels in the cellular lysates of normal skin fibroblasts. Normal skin fibroblasts were stimulated with 17β-estradiol (E2) for 48 hours in the presence or absence of the following chemical inhibitors: MEK inhibitor (MEKi), phosphoinositol 3-kinase inhibitor (PI3Ki), and p38 kinase inhibitor (p38Ki). Cellular lysates were analyzed by western blot using anti-EDA-FN, estrogen receptor (ER)α, ERβ, and GAPDH antibodies. (B) Effect of E2 ligands on the expression and deposition of FN in the extracellular matrix (ECM) of normal skin fibroblasts. PPT, propyl-pyrazole-triol. Primary fibroblasts were cultured with vehicle (dimethylsulfoxide (DMSO), ethanol (EtOH)), E2, PPT, or genistein for 48 hours. ECM was analyzed by western blot using anti-EDA-FN and anti-vitronectin antibodies. Ethanol was used as vehicle for E2 and PPT. DMSO was used as a vehicle for genistein.