TY - JOUR
T1 - Expression of Non-collagenous Bone Matrix Proteins in Osteoblasts Stimulated by Mechanical Stretching in the Cranial Suture of Neonatal Mice
AU - Ikegame, Mika
AU - Ejiri, Sadakazu
AU - Okamura, Hirohiko
N1 - Funding Information:
The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported in part by Grant-in-Aids from Japan Society for the Promotion of Science (No. 14571729, 16K11442).
Funding Information:
A large portion of the research presented in this article was carried out in the First Department of Oral Anatomy and in the Dental Pharmacology, both at the Niigata University. The authors particularly thank Dr. Hidehiro Ozawa (Professor Emeritus, Niigata University and Matsumoto Dental University) and Dr. Hiroyuki Kawashima (former Professor of Department of Dental Pharmacology, Niigata University), for their guidance and advice during the research. The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported in part by Grant-in-Aids from Japan Society for the Promotion of Science (No. 14571729, 16K11442).
Publisher Copyright:
© The Author(s) 2018.
PY - 2019/2/1
Y1 - 2019/2/1
N2 - We investigated the influence of mechanical stretching on the genetic expression pattern of non-collagenous bone matrix proteins in osteoblasts. The cranial sutures of neonatal mice were subjected to ex vivo mechanical stretching. In the non-stretched control group, as osteoblast differentiation progressed, the successive genetic expression of bone sialoprotein (BSP), osteopontin (OPN), and osteocalcin (OCN) was detected using in situ hybridization, in that order. In the stretched group, the sutures were widened, and after 24 hr of cultivation, a large number of osteoblasts and abundant new osteoid were observed on the borders of the parietal bones. All new osteoblasts expressed BSP and some of them expressed OPN, but very few of them expressed OCN. After 48 hr, more extensive presence of osteoid was noted on the borders of the parietal bones, and this osteoid was partially mineralized; all osteoblasts on the osteoid surface expressed BSP, and more osteoblasts expressed OPN than those after 24 hr cultivation. Surprisingly, many of the osteoblasts that did not express OPN, expressed OCN. This suggests that when osteoblast differentiation is stimulated by mechanical stress, the genetic expression pattern of non-collagenous proteins in the newly differentiated osteoblasts is affected.
AB - We investigated the influence of mechanical stretching on the genetic expression pattern of non-collagenous bone matrix proteins in osteoblasts. The cranial sutures of neonatal mice were subjected to ex vivo mechanical stretching. In the non-stretched control group, as osteoblast differentiation progressed, the successive genetic expression of bone sialoprotein (BSP), osteopontin (OPN), and osteocalcin (OCN) was detected using in situ hybridization, in that order. In the stretched group, the sutures were widened, and after 24 hr of cultivation, a large number of osteoblasts and abundant new osteoid were observed on the borders of the parietal bones. All new osteoblasts expressed BSP and some of them expressed OPN, but very few of them expressed OCN. After 48 hr, more extensive presence of osteoid was noted on the borders of the parietal bones, and this osteoid was partially mineralized; all osteoblasts on the osteoid surface expressed BSP, and more osteoblasts expressed OPN than those after 24 hr cultivation. Surprisingly, many of the osteoblasts that did not express OPN, expressed OCN. This suggests that when osteoblast differentiation is stimulated by mechanical stress, the genetic expression pattern of non-collagenous proteins in the newly differentiated osteoblasts is affected.
KW - mechanical loading
KW - non-collagenous bone proteins
KW - ossification
KW - sagittal sutures
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U2 - 10.1369/0022155418793588
DO - 10.1369/0022155418793588
M3 - Article
C2 - 30113872
AN - SCOPUS:85052577486
VL - 67
SP - 107
EP - 116
JO - Journal of Histochemistry and Cytochemistry
JF - Journal of Histochemistry and Cytochemistry
SN - 0022-1554
IS - 2
ER -