HA induces expression of RHAMM, a HA-binding protein, by PKCδ. (A) HUVECs were treated with or without HA (1 mDa, 200 μg/ml) for various time intervals. Cell lysates were immunoprecipitated with anti-CD44 antibody (2 μg/ml), followed by Western blot analysis. (B) HUVECs were transiently transfected with control vector (1 μg) or dominant negative PKCδ (1 μg). At 48 h after transfection, cell lysates were prepared and subjected to Western blot analysis. (C) HUVECs were transfected with control SiRNA (10 nM) or RHAMM SiRNA (10 nM). At 48 h after transfection, cell lysates were prepared and subjected to Western blot analysis. (D) HUVECs were treated with or without various sizes of HA at an equi-molar concentration for various time intervals (upper panel). HUVECs were treated with or without each size of HA for 1 h at various concentrations (lower panel). Cell lysates were then subjected to Western blot analysis.