FIG. 9.

CCN2(IV) via EGFR pathway activation regulates vascular responses. (A) CCN2(IV) increased EGFR phosphorylation in VSMCs. Time course of EGFR activation in VSMC were treated with CCN2(IV) 50 ng/ml. Figure shows a representative Western blot, and the data are expressed as mean±SEM of fold increase over control of five independent experiments. *p<0.05 versus control. (B–D) C57BL/6 mice received a single i.p. injection of recombinant CCN2(IV) (2.5 ng/g body weight) or saline and were sacrificed after 24 h. Some mice were pretreated with erlotinib (40 mg/kg/i.p) 24 h before CCN2(IV) administration (B). O₂^•− production was determined by an increase in 2-OH-E⁺ generation by HPLC analysis of DHE fluorescence (C). Phosphorylated levels of EGFR or p65 NF-κB subunit (p-p65) were evaluated by immunostaining in paraffin-embedded aortic sections. (D) Gene expression was evaluated by real-time PCR in aortic samples. Data are expressed as mean±SEM of fold increase over saline of 8–10 animals per group. *p<0.05 versus saline. ^†p<0.05 versus CCN2(IV). EGFR, epidermal growth factor receptor. To see this illustration in color, the reader is referred to the web version of this article at www.liebertpub.com/ars