Direct imaging of flow-induced oscillatory calcium rise in living bone

骨细胞形成一个复杂的三维网络，由成骨细胞和嵌入矿化细胞外基质的骨细胞组成。在细胞的各种生理过程中，Ca~(2+)作为一种普遍存在的次要信使，向细胞内部和细胞间传递大量信号。然而，在活骨中，骨细胞内钙离子的动态变化还没有被研究过。在本研究中，我们开发了一种新颖的体外活体钙离子成像系统，该系统可以在不破坏骨骼网络的情况下观察完整鸡颅骨外植体细胞内钙离子浓度的动态变化。我们的实时成像分析首次显示，成骨细胞和骨细胞在体外都表现出重复的和自主的[Ca^&lt；2+&gt；]i振荡。

Bone cells form a complex three-dimensional network consisting of osteoblasts and osteocytes embedded in a mineralized extracellular matrix. Ca^<2+> acts as a ubiquitous secondary messenger in various physiological cellular processes and transduces numerous signals to the cell interior and between cells. However, the intracellular Ca^<2+> dynamics of bone cells have not been evaluated in living bone. In the present study, we developed a novel ex-vivo live Ca^<2+> imaging system that allows the dynamic intracellular Ca^<2+> concentration([Ca^<2+>] i) responses of intact chick calvaria explants to be observed without damaging the bone network. Our live imaging analysis revealed for the first time that both osteoblasts and osteocytes display repetitive and autonomic[Ca^<2+>] i oscillations ex vivo.