Osteoclasts are present in gp130-deficient mice.
Interleukin (IL)-6, IL-11, leukemia inhibitory factor, and oncostatin M similarly induce osteoclast formation in cocultures of osteoblastic cells and bone marrow cells. These cytokines share a common signal transducer, gp130, which forms a receptor complex with the specific receptor for each cytokine. To investigate the role of gp130 in osteoclast development, we examined bone tissues in gp130-deficient and wild-type newborn mice of the ICR background. Soft x-ray radiographs and microfocus x-ray computed tomographs revealed that bone marrow cavities were present in tibiae and radii of both wild-type and gp130-deficient mice. Microfocus x-ray computed tomography and histological examination demonstrated a decrease in the amount of trabeculae at the metaphysial region in tibiae and radii of the gp130-deficient mice compared with the wild-type mice. The number ofosteoclasts in gp130-deficient mice was about double that in the wild-type mice. There were no apparent differences in the distributions of alkaline phosphatase-positive osteoblasts and the osteoid surface on the trabecular bone at the metaphysial region between the wild-type and gp130-deficient mice. The volume of mineralized trabecular bones was also decreased at mandibulae, accompanied by the increased number of osteoclasts in gp130-deficient mice compared with the wild-type and heterozygous mice. These results suggest that the formation of osteoclasts is not solely dependent on gp130 signaling, at least during fetal development. The osteoclastic bone resorption in gp130-deficient mice may be caused by the functional redundancy of bone-resorbing hormones and cytokines other than those of the IL-6 family.
Kawasaki
K
K
Department of Oral Pathology, School of Dentistry, Showa University, Tokyo, Japan.
Gao
Y H
YH
Yokose
S
S
Kaji
Y
Y
Nakamura
T
T
Suda
T
T
Yoshida
K
K
Taga
T
T
Kishimoto
T
T
Kataoka
H
H
Yuasa
T
T
Norimatsu
H
H
Yamaguchi
A
A
D000818:Animals; D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism*; D001853:Bone Marrow / Q000000981:diagnostic imaging / Q000473:pathology; D050822:Cytokine Receptor gp130; D005360:Fibula / Q000000981:diagnostic imaging / Q000473:pathology; D018390:Gene Targeting; D008334:Mandible / Q000473:pathology; D008562:Membrane Glycoproteins / Q000172:deficiency* / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL / Q000235:genetics; D010010:Osteoclasts / Q000473:pathology*; D012016:Reference Values; D013977:Tibia / Q000000981:diagnostic imaging / Q000473:pathology; D014057:Tomography, X-Ray Computed
D015703:Antigens, CD; C494200:Il6st protein, mouse; D008562:Membrane Glycoproteins; D050822:Cytokine Receptor gp130