Complement regulated IL-6 expression is involved in OC differentiation. (A) Quantification of IL-6 levels in supernatants cultured with WT, C3−/−, and C3aR−/−C5aR−/− BM cells during differentiation. BM cells (2 × 106) were cultured in differentiation media in each well of a 24-well plate together with 1 × 10−8M 1,25(OH)2 vitamin, and IL-6 levels were measured in supernatants on day 12. (B) Supplementing IL-6 into C3−/− BM cell cultures restored their OC differentiation capabilities. (C) Exogenous C3a/C5a augmented OC differentiation from WT BM cells, while neutralization of IL-6 abolished the stimulating effect. (D) Exogenous C3a/C5a augmented OC differentiation from C3−/− BM cells, while neutralization of IL-6 abolished the stimulating effect. Results are representative from 2 independent experiments performed in triplicate. Data are mean ± SD: *P < .05, #P < .05.
