IP6 directly stimulates gene expression of osteoclast functional markers and resorption activity on mature osteoclasts-like cells.

<p>Mature osteoclasts were treated with 1 µM of IP6 for 24 hours and gene expression of osteoclast functional markers was determined: <i>Car-2</i>(A), <i>H⁺-ATPase</i> (B), <i>CtsK</i> (C) and <i>Mmp-9</i> (D). Data represent fold changes of target genes normalized with <i>Gapdh</i> mRNA and 18s rRNA, expressed as a percentage of RANKL-dosed cells non-treated with IP6, which were set to 100%. Values represent the mean ± SEM. Significant differences were assessed by Student’s t test: *p≤0.05 versus control cells. (E) Bone resorption ability of mature osteoclasts treated with 1 µM of IP6 for four days was evaluated by resorption pit assay on dentine discs. Data represent the percentage of the resorbed area by mature osteoclasts. Values represent the mean ± SEM. Significant differences were assessed by Student’s t test: *p≤0.05 versus untreated cells. #p≤0.05 versus RANKL treated cells. (n = 3).