Figure 3.

The adenosine A_2A receptor agonist, CGS21680 (10 nM), mimicked the effect of AMP on collagen production (Sirius Red staining, panel B) while having no effect on human subcutaneous fibroblasts (HSCF) growth (MTT assay, panel A). The pro-fibrotic effect of CGS21680 (10 nM) was abrogated by the selective A_2A receptor antagonist, SCH442416 (10 nM). Boxes and whiskers represent pooled data from at least three different individuals; 4–6 replicas were performed for each individual. *** p < 0.001 (two-way ANOVA) represent significant differences compared to control conditions; ^### p < 0.001 (two-way ANOVA) represent significant differences compared to the effect of CGS21680 in the same set of experiments. Panel C shows that A_2A receptor expression (green) increases from day seven to 28, as evidenced both by immunofluorescence confocal microscopy and by Western blot analysis normalized by the GAPDH content of the cells. Nuclei are stained in blue with DAPI. Shown are representative data from three (7 days) to five (28 days) different individuals; experiments were performed in triplicate. * p < 0.05 (Student’s t-test) represent significant differences compared to culture day seven.