Fig. 4From: CREB-dependent LPA-induced signaling initiates a pro-fibrotic feedback loop between small airway basal cells and fibroblastsEffect of ERK1/2 inhibitor (ERK1/2 inh) on growth factor expression. Primary basal cells from each of 3 non-smoking donors were plated in triplicate in the presence or absence of 1 μg/ml LPA, 5 µM ERK1/2 inhibitor (LY32149966) and a combination of LPA and ERK1/2 inhibitor (LY32149966). a mRNA. Shown are expression levels of connective tissue growth factor (CTGF), endothelin-1 (EDN1), transforming growth factor beta (TGFB1) and platelet derived growth factor B (PDGFB) determined after 3 h of LPA exposure with and without ERK1/2 inhibitor (LY32149966) using qRT-PCR using 18S RNA to normalize the samples. b Protein. Shown are growth factor levels in the conditioned media. After 3 h of LPA with and without CREB inhibitor (666-15) exposure, LPA with or without ERK1/2 inhibitor was removed and cells were incubated with un-supplemented basal media for 24 h. Conditioned media was harvested and evaluated for growth factor content by ELISA. Data are expressed as the mean value of the 3 donors ± SEM. ND—not detected. *p < 0.05, **p < 0.01, ***p < 0.001Back to article page