Inorganic phosphate induces apoptosis of osteoblast-like cells in culture
Inorganic phosphate induces apoptosis of osteoblast-like cells in culture
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DOI：
10.1016/s8756-3282(00)00346-x
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发表时间：
2000-09-01
期刊：
影响因子：
4.1
通讯作者：
Adams, CS
中科院分区：
文献类型：
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作者：
Meleti, Z;Shapiro, IM;Adams, CS
这项研究的主要目标是检验骨吸收的主要产物之一无机磷酸盐 (Pi) 激活成骨细胞凋亡的假设。从人骨外植体中分离出成骨细胞样细胞，在单层培养中，这些细胞表现出成骨表型，因此，细胞表现出升高的碱性磷酸酶活性，表达成骨信使RNA转录本，并形成生物矿物质。当这些细胞用 1-7 mmol/L Pi 处理时，细胞活力出现剂量和时间依赖性下降。因此，48小时后，5 mmol/L Pi使存活的成骨细胞样细胞数量减少了25%； 7 mmol/L Pi 使细胞数量减少 60%。到 96 小时，用 5 mmol/L Pi 处理后，活细胞的百分比为 30%，而 7 mmol/L Pi 导致成骨细胞活力几乎完全丧失，用磷酸甲酸（质膜 Na-Pi 转运蛋白的抑制剂）处理细胞可阻止成骨细胞死亡。使用形态学和末端标记程序，我们证实细胞死亡是通过细胞凋亡实现的。为了探究细胞死亡的机制，用罗丹明 123（一种对膜电位敏感的染料）探测成骨细胞样细胞。我们注意到，经 Pi 处理的细胞显示出线粒体膜电位的严重丧失，这表明阴离子通过诱导线粒体膜通透性转变来激活死亡程序。我们得出的结论是，在骨吸收部位观察到的高水平成骨细胞凋亡可能与骨矿物质中 Pi 的释放有关，(C) 2000，Elsevier Science Inc. 保留所有权利。
The major goal of this investigation was to test the hypothesis that one of the major products of bone resorption, inorganic phosphate (Pi), activates osteoblast apoptosis. Osteoblast-like cells were isolated from explants of human bone, In monolayer culture, these cells showed an osteogenic phenotype, Thus, the cells exhibited raised alkaline phosphatase activity, expressed osteogenic messenger RNA transcripts, and formed biological mineral. When these cells were treated with 1-7 mmol/L Pi there was a dose- and time-dependent decrease in cell viability. Accordingly, after 48 h, 5 mmol/L Pi reduced the number of viable osteoblast-like cells by 25%; 7 mmol/L Pi reduced the number of cells by 60%. By 96 h, following treatment with 5 mmol/L, Pi, the percentage of viable cells was 30%, whereas 7 mmol/L Pi caused an almost complete loss of osteoblast viability, Osteoblast death was blocked by treating the cells with phosphonoformic acid, an inhibitor of the plasma-membrane Na-Pi transporter. Using morphological and end-labeling procedures, we confirmed that cell death was through apoptosis, To probe the mechanism of cell death, osteoblast-like cells were probed with rhodamine 123, a dye that is responsive to the membrane potential. We noted that Pi-treated cells displayed a profound loss of mitochondrial membrane potential, suggesting that the anion activated the death program through the induction of a mitochondrial membrane permeability transition. We conclude that high levels of osteoblast apoptosis observed at sites of bone resorption may be linked to release of Pi from bone mineral, (C) 2000 by Elsevier Science Inc. All rights reserved.