The disintegrin domain of ADAM-9 mediates interactions with the αvβ5 integrin and induces interleukin-6 production (hOB). (A) Northern blot analysis of IL-6 mRNA expression in hOBs incubated alone or in the presence of recombinantADAM-9 disintegrin domain (D9) or control protein (D9C). The 5637 cell line served as a negative control. Blots were reprobed with GAPDH to demonstrate equal loading between D9 and control protein. (B) Northern blot analysis of IL-1β mRNA expression in hOBs incubated alone or in the presence of recombinant D9 or D9C control protein. The 5637 cell line served as a positive control. (C) hOBs were incubated in the presence of recombinant D9 (10 μg/mL) or D9C, and IL-6 concentrations were measured by ELISA at the stated time points. (D) hOBs were incubated in the presence of increasing concentrations of recombinant D9, or control protein D9C, for 24 hours, and IL-6 concentrations were measured by ELISA. Data are the means of samples from a representative experiment (n = 4-8), and error bars are 95% CI. IL-6 production is shown as percentage of the mean + 95% CI of the maximum bar in the graph. *P < .001 compared with untreated cells by the Dunnett test. (E) hOBs were incubated alone or in the presence of recombinant D9 (10 μg/mL) or D9C for 24 hours, and IL-1β concentrations were determined by ELISA. The 5637 cells were cultured in the same way and served as a control. (F) hOBs were incubated alone (con) or in the presence of recombinant D9 with or without IgG or αvβ5-integrin antibody. IL-6 concentrations were determined by ELISA. *P < .01 compared with control; and †P < .01 compared with IgG (Mann-Whitney U test).
