TY - JOUR
T1 - Static and dynamic hypergravity responses of osteoblasts and osteoclasts in medaka scales
AU - Yano, Sachiko
AU - Kitamura, Kei Ichiro
AU - Satoh, Yusuke
AU - Nakano, Masaki
AU - Hattori, Atsuhiko
AU - Sekiguchi, Toshio
AU - Ikegame, Mika
AU - Nakashima, Hiroshi
AU - Omori, Katsunori
AU - Hayakawa, Kazuichi
AU - Chiba, Atsuhiko
AU - Sasayama, Yuichi
AU - Ejiri, Sadakazu
AU - Mikuni-Takagaki, Yuko
AU - Mishima, Hiroyuki
AU - Funahashi, Hisayuki
AU - Sakamoto, Tatsuya
AU - Suzuki, Nobuo
PY - 2013/3
Y1 - 2013/3
N2 - Fish scales are a form of calcified tissue similar to that found in human bone. In medaka scales, we detected both osteoblasts and osteoclasts and subsequently developed a new scale assay system. Using this system, we analyzed the osteoblastic and osteoclastic responses under 2-, 3-, and 4-gravity (G) loading by both centrifugation and vibration. After loading for 10 min, the scales from centrifugal and vibration loading were incubated for 6 and 24 hrs, respectively, after which the osteoblastic and osteoclastic activities were measured. Osteoblastic activity significantly increased under 2- to 4-G loading by both centrifugation and vibration. In contrast, we found that osteoclastic activity significantly decreased under 2- and 3-G loading in response to both centrifugation and vibration. Under 4-G loading, osteoclastic activity also decreased on centrifugation, but significantly increased under 4-G loading by vibration, concomitant with markedly increased osteoblastic activity. Expression of the receptor activator of the NF-αB ligand (RANKL), an activation factor of osteoclasts expressed in osteoblasts, increased significantly under 4-G loading by vibration but was unchanged by centrifugal loading. A protein sequence similar to osteoprotegerin (OPG), which is known as an osteoclastogenesis inhibitory factor, was found in medaka using our sequence analysis. The ratio of RANKL/OPG-like mRNAs in the vibration-loaded scales was significantly higher than that in the control scales, although there was no difference between centrifugal loaded scales and the control scales. Accordingly, medaka scales provide a useful model by which to analyze bone metabolism in response to physical strain.
AB - Fish scales are a form of calcified tissue similar to that found in human bone. In medaka scales, we detected both osteoblasts and osteoclasts and subsequently developed a new scale assay system. Using this system, we analyzed the osteoblastic and osteoclastic responses under 2-, 3-, and 4-gravity (G) loading by both centrifugation and vibration. After loading for 10 min, the scales from centrifugal and vibration loading were incubated for 6 and 24 hrs, respectively, after which the osteoblastic and osteoclastic activities were measured. Osteoblastic activity significantly increased under 2- to 4-G loading by both centrifugation and vibration. In contrast, we found that osteoclastic activity significantly decreased under 2- and 3-G loading in response to both centrifugation and vibration. Under 4-G loading, osteoclastic activity also decreased on centrifugation, but significantly increased under 4-G loading by vibration, concomitant with markedly increased osteoblastic activity. Expression of the receptor activator of the NF-αB ligand (RANKL), an activation factor of osteoclasts expressed in osteoblasts, increased significantly under 4-G loading by vibration but was unchanged by centrifugal loading. A protein sequence similar to osteoprotegerin (OPG), which is known as an osteoclastogenesis inhibitory factor, was found in medaka using our sequence analysis. The ratio of RANKL/OPG-like mRNAs in the vibration-loaded scales was significantly higher than that in the control scales, although there was no difference between centrifugal loaded scales and the control scales. Accordingly, medaka scales provide a useful model by which to analyze bone metabolism in response to physical strain.
KW - OPG
KW - RANKL
KW - gravity response
KW - medaka
KW - osteoblast
KW - osteoclast
KW - scale
UR - http://www.scopus.com/inward/record.url?scp=84874988881&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84874988881&partnerID=8YFLogxK
U2 - 10.2108/zsj.30.217
DO - 10.2108/zsj.30.217
M3 - Article
C2 - 23480382
AN - SCOPUS:84874988881
VL - 30
SP - 217
EP - 223
JO - Zoological Science
JF - Zoological Science
SN - 0289-0003
IS - 3
ER -