THE ROLE OF CALCIUM SIGNALLING IN THE CHONDROGENIC RESPONSE OF MESENCHYMAL STEM CELLS TO HYDROSTATIC PRESSURE
THE ROLE OF CALCIUM SIGNALLING IN THE CHONDROGENIC RESPONSE OF MESENCHYMAL STEM CELLS TO HYDROSTATIC PRESSURE
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DOI：
10.22203/ecm.v028a25
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发表时间：
2014-07-01
影响因子：
3.1
通讯作者：
Wagner, D. R.
中科院分区：
文献类型：
--
作者：
Steward, A. J.;Kelly, D. J.;Wagner, D. R.
本研究的目的是阐明钙（Ca++）信号在间充质干细胞（MSCs）对静水压力（HP）的软骨形成反应中的作用。将MSC接种到琼脂糖水凝胶中，进行HP或保持在自由溶胀条件下，并在有或没有Ca++迁移率和下游靶点的药理学抑制剂的情况下培养。螯合游离Ca++、抑制电压门控性钙通道和消耗细胞内钙库抑制了HP对软骨形成的有益作用，表明Ca++流动性可能在HP的机械转导中起重要作用。然而，在当前的实验中，拉伸激活的钙通道的抑制产生了与对照组相似的结果，这表明HP的机械转导与产生细胞变形的负荷不同。下游靶点钙调蛋白、钙调蛋白激酶II和钙调神经磷酸酶的抑制均降低了HP对软骨形成的作用，暗示这些靶点参与了MSC对HP的反应。所有的药理学抑制剂，消除了软骨形成的反应，HP也保持了点状波形蛋白组织的存在下，HP，而不是机械反应组的波形蛋白结构变得更加分散。这些结果表明，Ca++信号转导可能通过波形蛋白适应负荷来抑制HP。
The objective of this study was to elucidate the role of calcium (Ca++) signalling in the chondrogenic response of mesenchymal stem cells (MSCs) to hydrostatic pressure (HP). MSCs were seeded into agarose hydrogels, subjected to HP or kept in free swelling conditions, and cultured either with or without pharmacological inhibitors of Ca++ mobility and downstream targets. Chelating free Ca++, inhibiting voltage-gated calcium channels, and depleting intracellular calcium stores suppressed the beneficial effect of HP on chondrogenesis, indicating that Ca++ mobility may play an important role in the mechanotransduction of HP. However, inhibition of stretch-activated calcium channels in the current experiment yielded similar results to the control group, suggesting that mechanotransduction of HP is distinct from loads that generate cell deformations. Inhibition of the downstream targets calmodulin, calmodulin kinase II, and calcineurin all knocked down the effect of HP on chondrogenesis, implicating these targets in MSCs response to HP. All of the pharmacological inhibitors that abolished the chondrogenic response to HP also maintained a punctate vimentin organisation in the presence of HP, as opposed to the mechanoresponsive groups where the vimentin structure became more diffuse. These results suggest that Ca++ signalling may transduce HP via vimentin adaptation to loading.