Osteoclast differentiation induced by synthetic octacalcium phosphate through receptor activator of NF-kappaB ligand expression in osteoblasts

Masamichi Takami, Ayako Mochizuki, Atsushi Yamada, Keita Tachi, Baohong Zhao, Yoichi Miyamoto, Takahisa Anada, Yoshitomo Honda, Tomio Inoue, Masanori Nakamura, Osamu Suzuki, Ryutaro Kamijo
Tissue Engineering. Part A 2009, 15 (12): 3991-4000
Synthetic octacalcium phosphate (OCP) has a potential to enhance new bone formation and exhibits biodegradable characteristics when implanted in experimentally created bone defects. The precise mechanisms of OCP biodegradation remain unclear, though histological observations have revealed that bone-resorbing osteoclasts appear and resorb implanted OCP. To investigate how osteoclasts develop around implanted OCP, we examined osteoclast differentiation using OCP crystals in vitro. Coculturing of mouse bone marrow cells and osteoblasts in OCP-coated cell culture plates induced osteoclast differentiation, whereas that did not occur without coating. Further, addition of bone morphogenetic protein-2 significantly increased the number of osteoclasts in the OCP-coated wells. In the presence of OCP, osteoblasts expressed receptor activator of NF-kappaB ligand (RANKL), an osteoclast differentiation factor. In addition, when half of each culture well was coated with OCP, osteoclasts were formed in both coated and noncoated areas, suggesting that soluble factors mediate osteoclast differentiation induced by OCP. Also, calcium levels in culture medium were significantly decreased in the presence of OCP, while experimental reduction of calcium from 8.0 to 5.0 mg/dL significantly induced RANKL mRNA expression. These results suggest that OCP itself decreases calcium levels around implanted OCP, which induces osteoclast differentiation through RANKL expression by osteoblasts.

Full Text Links

Find Full Text Links for this Article


You are not logged in. Sign Up or Log In to join the discussion.

Related Papers

Remove bar
Read by QxMD icon Read

Save your favorite articles in one place with a free QxMD account.


Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"