Figure 1. The Ron receptor is expressed and functional in primary alveolar macrophages.

Ron transcript levels were examined from mRNA isolated from primary alveolar macrophages (A) and from whole lungs (B) from wild-type (TK+/+) and Ron tyrosine kinase-deficient (TK−/−) mice by qRT-PCR. Expression was normalized to an internal control as described in the Materials and Methods section and the relative gene expression changes are reported. Data is expressed as the mean ± the standard deviation and is representative of several independent experiments. (C) Alveolar macrophages were isolated and treated with LPS (1µg/ml) with or without HGFL (400ng/ml), HGFL alone, or overnight (ON) HGFL pretreatment followed by LPS. Cell culture supernatants were collected 24 hours after final stimulation and assayed for TNFα production. Results represent data from two independent experiments with n=8 per group. *p<0.05 compared to vehicle or HGFL treated groups. †p<0.05 compared to LPS treated group. HGFL treatment was able to significantly reduce the production of TNFα from wild-type alveolar macrophages following LPS stimulation. (D) Primary alveolar macrophages were isolated from TK+/+ and TK−/− mice and pretreated in the presence or absence of HGFL overnight. The next day the cells were stimulated in the presence or absence of LPS as indicated above. Culture supernatant was isolated after 4 hours and examined for TNFα production by ELISA analysis. Data is expressed as the mean ± the standard error and is representative of experiments from n=6–10 mice.