Structure, composition, and maturation of newly deposited calcium-phosphate crystals in chicken osteoblast cell cultures
Structure, composition, and maturation of newly deposited calcium-phosphate crystals in chicken osteoblast cell cultures
复制标题
DOI：
10.1359/jbmr.2000.15.7.1301
复制
发表时间：
2000-07-01
影响因子：
6.2
通讯作者：
Glimcher, MJ
中科院分区：
文献类型：
--
作者：
Kuhn, LT;Xu, YT;Glimcher, MJ
沉积在骨或成骨细胞培养物中的非常早期的磷酸钙（CaP）晶体的表征一直受到阻碍的压倒性存在的有机基质成分和细胞，模糊光谱分析。我们已经克服了这个问题，使用分离的无蛋白质晶体，并获得了新的数据，包括P-31核磁共振（NMR）光谱的第一次从培养成骨细胞钙化过程中沉积的矿物晶体。在两个时间点从培养物中分离晶体：（a）在第一次钙积累时（第8-10天）和（B）培养60天后，以评估成熟变化。分析表明，早期和成熟晶体的化学成分总体上和短程有序性是在体内年轻胚胎鸡骨中发现的磷灰石晶体的特征。除磷灰石外，未通过所用的任何方法检测到矿物相。P-31 NMR光谱鉴定了骨磷灰石中存在的HPO 4基团，与骨磷灰石相似，傅立叶变换红外（FTIR）光谱未检测到OH基团。矿物相的组成和结构的时间成熟变化是难以评估的，因为在整个培养过程中晶体的连续沉积。所观察到的成熟变化的途径与体内鸡骨和体外合成磷灰石晶体中发生的相似，尽管程度要小得多。
Characterization of the very early calcium phosphate (CaP) crystals deposited in bone or in osteoblast cell cultures has been hampered by the overwhelming presence of organic matrix components and cells that obscure spectral analyses. We have overcome this problem using isolated protein-free crystals and have obtained new data including P-31 nuclear magnetic resonance (NMR) spectra for the first time from mineral crystals deposited during osteoblast calcification in culture. Crystals were isolated from cultures at two time points: (a) at first calcium accumulation (day 8-10) and (b) after 60 days of culture, to assess maturational changes. The analyses show that the chemical composition overall and short range order of the early and mature crystals are characteristic of the apatite crystals found in young embryonic chick bone in vivo. No mineral phase other than apatite was detected by any of the methods used. P-31 NMR spectroscopy identified the HPO4 groups as those present in bone apatite, Similar to bone apatites, no OH groups were detected by Fourier transform infrared (FTIR) spectroscopy. The temporal maturational changes in composition and structure of the mineral phase were difficult to assess because of the continuous deposition of crystals throughout culturing. The pathway of the maturational changes observed were similar to those occurring in chick bone in vivo and synthetic apatite crystals in vitro although to a much smaller extent.