FIGURE 3.

Recombinant human calreticulin (rhCRT) inhibited key transcription factors and calcium oscillation during osteoclastogenesis. a. Raw264.7 cells were either untreated or treated with RANKL with or without 500ng/ml of rhCRT for 3 days, whole cell extracts were separated by SDS-PAGE and blotted for different antibodies against NFATc1, c-Fos, phospho-CREB, total CREB, IκB, and GAPDH, respectively. b. RAW264.7 cells were treated with RANKL alone (top) or with rhCRT (bottom) for 3 days, total cell lysates were made every 24 hours and subjected to SDS-PAGE and probed with NFATc1 and GAPDH antibodies. The numbers on the left indicate the molecular weight. c. Calreticulin inhibits cell Ca²⁺ oscillation. Mouse bone marrow derived macrophages were treated with M-CSF and RANKL without CRT (top) or with rhCRT (bottom) for 3 days. The cells were labeled with Fluo-4 AM and FuraRed and Ca2+ oscillation signal was presented as ratio of Fluo-4 AM to FuraRed fluorescent intensity. Each color line represented an individual cell in the same field. Arrows indicate when ionomycin was added.