Fig. 4

TNF-α-induced upregulation of HBMEC integrins is mediated through TNFR1, but not TNFR2. The HBMECs were pre-incubated with 10 μg/ml neutralizing antibodies to TNFR1 or TNFR2 for 30 min and then stimulated with or without 10 ng/ml rhTNF-α. The cultures were incubated for 12 or 24 h before being harvested and analyzed for expression of α5β1 and αVβ3 integrins by flow cytometry (a). Integrin subunit α5 is shown in (a). b Quantification of α5β1 and αVβ3 integrin expression on HBMECs. For each integrin subunit, the mean fluorescent intensity (MFI) was measured and expression shown as a percentage of the control values. All points represent the mean ± SEM of four experiments. Note that TNF-α significantly increased HBMEC expression of the α5β1 and αVβ3 integrins relative to control (**P < 0.01), and this effect was abrogated by the anti-TNFR1 antibody but not the anti-TNFR2 antibody. #P < 0.05