MISC

2013年3月

Ex vivo real-time observation of Ca2+ signaling in living bone in response to shear stress applied on the bone surface

BONE
  • Yoshihito Ishihara
  • ,
  • Yasuyo Sugawara
  • ,
  • Hiroshi Kamioka
  • ,
  • Noriaki Kawanabe
  • ,
  • Satoru Hayano
  • ,
  • Tarek A. Balam
  • ,
  • Keiji Naruse
  • ,
  • Takashi Yamashiro

53
1
開始ページ
204
終了ページ
215
記述言語
英語
掲載種別
DOI
10.1016/j.bone.2012.12.002
出版者・発行元
ELSEVIER SCIENCE INC

Bone cells respond to mechanical stimuli by producing a variety of biological signals, and one of the earliest events is intracellular calcium ([Ca2+](i)) mobilization. Our recently developed ex vivo live [Ca2+](i) imaging system revealed that bone cells in intact bone explants showed autonomous [Ca2+](i) oscillations, and osteocytes specifically modulated these oscillations through gap junctions. However, the behavior and connectivity of the [Ca2+](i) signaling networks in mechanotransduction have not been investigated in intact bone. We herein introduce a novel fluid-flow platform for probing cellular signaling networks in live intact bone, which allows the application of capillary-driven flow just on the bone explant surface while performing real-time fluorogenic monitoring of the [Ca2+](i) changes. In response to the flow, the percentage of responsive cells was increased in both osteoblasts and osteocytes, together with upregulation of c-fos expression in the explants. However, enhancement of the peak relative fluorescence intensity was not evident. Treatment with 18 alpha-GA, a reversible inhibitor of gap junction, significantly blocked the [Ca2+](i), responsiveness in osteocytes without exerting any major effect in osteoblasts. On the contrary, such treatment significantly decreased the flow-activated oscillatory response frequency in both osteoblasts and osteocytes. The stretch-activated membrane channel, when blocked by Gd3+, is less affected in the flow-induced [Ca2+](i) response. These findings indicated that flow-induced mechanical stimuli accompanied the activation of the autonomous [Ca2+](i) oscillations in both osteoblasts and osteocytes via gap junction-mediated cell-cell communication and hemichannel. Although how the bone sense the mechanical stimuli in vivo still needs to be elucidated, the present study suggests that cell-cell signaling via augmented gap junction and hemichannel-mediated [Ca2+](i) mobilization could be involved as an early signaling event in mechanotransduction. (C) 2012 Elsevier Inc. All rights reserved.

Web of Science ® 被引用回数 : 31

リンク情報
DOI
https://doi.org/10.1016/j.bone.2012.12.002
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000314257100028&DestApp=WOS_CPL
ID情報
  • DOI : 10.1016/j.bone.2012.12.002
  • ISSN : 8756-3282
  • Web of Science ID : WOS:000314257100028

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