Figure 4. OPN isoforms differentially induce pro‐inflammatory cytokine production from human myoblasts in an RGD‐dependent manner .

Immortalized human myoblasts were cultured for 48 h with recombinant human OPN proteins treated with 0.25 or 1.0 μg ml⁻¹ human OPN‐a, OPN‐b or OPN‐c (A) or 1.0 μg ml⁻¹ recombinant human OPNa‐RGD or OPNa‐KAE (B). Interleukin‐6 (IL‐6) concentrations in the secreted media were quantified after 48 h by enzyme‐linked immunosorbent assay. Samples were run in replicates of n = 5.