In-situ quasi-static and dynamic nanoindentation tests on calcified nodules formed by osteoblasts: Implication of glucocorticoids responsible for osteoblast calcification
In-situ quasi-static and dynamic nanoindentation tests on calcified nodules formed by osteoblasts: Implication of glucocorticoids responsible for osteoblast calcification
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对成骨细胞形成的钙化结节进行原位准静态和动态纳米压痕测试：糖皮质激素对成骨细胞钙化的影响
DOI：
10.1016/j.actbio.2014.10.038
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发表时间：
2015
影响因子：
9.7
通讯作者：
Kamijo R.
中科院分区：
文献类型：
--
作者：
Miyamoto S.;Miyamoto Y.;Shibata Y.;Yoshimura K.;Izumida E.;Suzuki H.;Miyazaki T.;Maki K.;Kamijo R.
再生的钙化组织的功能要求是使组织能够承受各种施加的应力和随之而来的接触引起的应变，而不发生实质性骨折。在含抗坏血酸和β-甘油磷酸盐的诱导分化介质中，我们研究了糖皮质激素如地塞米松和氢化可的松对小鼠成骨细胞MC3T3-E1细胞形成的钙化结节纳米力学特性的影响。用茜素红和von Kossa染色评价细胞增殖和钙沉积均不受地塞米松的影响。另一方面，在地塞米松存在的情况下形成的钙化结节比在没有地塞米松的情况下形成的钙化结节明显更硬和更硬。特别是，一系列纳米压痕测试表明，与准静态载荷相比，在地塞米松存在下形成的钙化结节在动态应变下表现出更高的硬度。此外，拉曼光谱显示，地塞米松和氢化可的松增加了结节中磷灰石/基质的比例，降低了碳酸盐的比例。我们的结果提示，成骨细胞在体外形成更成熟的含有磷灰石/磷酸盐的钙化结节需要糖皮质激素。
The functional requirements of regenerated calcified tissues are that they enable the tissues to bear a variety of imposed stress and consequent contact-induced strain without substantial fracture. Here we demonstrate the effects of glucocorticoid hormones such as dexamethasone and hydrocortisone on the nanomechanical properties of calcified nodules formed by mouse osteoblastic MC3T3-E1 cells in differentiation-inducing medium containing ascorbic acid and β-glycerophosphate. Neither cell proliferation nor calcium deposition, evaluated using alizarin red and von Kossa staining, was affected by dexamethasone. On the other hand, calcified nodules formed in the presence of dexamethasone were significantly harder and stiffer than those formed in their absence. In particular, a series of nanoindentation tests revealed that the calcified nodules formed in the presence of dexamethasone showed enhanced stiffness against dynamic strain as compared to a quasi-static load. Furthermore, Raman spectroscopy revealed that dexamethasone and hydrocortisone increased the apatite/matrix ratio and lowered that of carbonate in the nodules. Our results suggest that glucocorticoids are required for in vitro formation by osteoblasts of more mature calcified nodules containing apatite/phosphate.