Fig. 7

Fibronectin aggregates induced release of nitric oxide by bone marrow-derived macrophages is integrin β1, β3, and β5 independent. a Bone marrow-derived macrophages (BMDMs) were pre-incubated with vehicle or the indicated functional blocking anti-integrin antibodies, plated on plasma fibronectin (pFn) or fibronectin aggregates (aFn) and subjected to an adhesion assay. Note that pre-incubation with anti-integrin β1 antibodies reduced the adhesion of BMDMs to pFn, but not to aFn. b BMDMs were left unstimulated (ctrl), cultured on aFn, or treated with interferon-γ (IFNγ). Cells cultured on aFn were left untreated or treated with functional anti-integrin β1, β3, or β5 antibodies. Then, nitric oxide (NO) levels in the culture medium were analyzed as described in materials and methods. Note that the aFn-mediated increase in NO release is integrin-independent. Bars represent mean values of each condition relative to control cells (set at 1 for each independent experiment, horizontal line) from four (adhesion) to five (NO assay) independent experiments. Error bars show the standard error of the mean. Statistical analyses were performed using the one-sample t test when compared to control (*p < 0.05; **p < 0.01). A student t test was performed to compare pFn with aFn (^#p < 0.05)