Synergistic effects of connective tissue growth factor on M-CSF/sRANKL-mediated osteoclastic function. Figure 5A shows the results of the resorption of osteoclasts on calcium phosphate. Vacant regions indicated by arrows represent the areas where the osteoclasts actually absorbed. There was no vacant region in negative control cells (M-CSF alone). In contrast to negative control, significant vacant regions were observed in osteoclasts induced by M-CSF/sRANKL. CTGF further expanded the vacant areas in combination with M-CSF/sRANKL and anti-CTGF antibody neutralized this effect. Figure 5B shows the levels of expression of osteoclasts specific proteases (MMP-9 and cathepsin-K) measured by quantitative real time RT-PCR. Synergistic effect of CTGF was also observed for M-CSF/sRANKL-mediated osteoclastogenesis. Bars in Figure 5B indicate the SD.