Department of Hematology Oncology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
The Center for Integrative Nanotechnology Sciences, University of Arkansas at Little Rock, Little Rock, AR 72204, USA.
Int J Mol Sci. 2020 Jul 8;21(14):4820. doi: 10.3390/ijms21144820.
In vertebrates, biomineralization is a feature considered unique to mature osteoblasts and odontoblasts by which they synthesize hydroxyapatite (HAP), which is deposited in the collagen matrix to construct endoskeleton. For many decades, the mechanisms that modulate differentiation and maturation of these specialized cells have been sought as a key to understanding bone-remodeling defects. Here, we report that biomineralization is an innate ability of all mammalian cells, irrespective of cell type or maturation stage. This innate biomineralization is triggered by the concomitant exposure of living cells to three indispensable elements: calcium ion, phosphoester salt, and alkaline phosphatase. Any given somatic cell, including undifferentiated mononuclear cells, can undergo a biomineralization process to produce calcium-phosphate agglomerates. The biologically generated minerals under such conditions are composed of genuine HAP crystallites of Ca(PO)(OH) and 5-10 nanometer (nm) in size. This discovery will profoundly improve our understanding of bone metabolism and ectopic calcifications.
在脊椎动物中，生物矿化被认为是成熟成骨细胞和成牙本质细胞所特有的特征，它们通过合成羟磷灰石（HAP），并将其沉积在胶原基质中构建内骨骼。几十年来，人们一直在寻找调节这些特化细胞分化和成熟的机制，以期深入了解骨骼重塑缺陷的原因。在这里，我们报告称生物矿化是所有哺乳动物细胞的固有能力，而与细胞类型或成熟阶段无关。这种内在的生物矿化是由活细胞同时暴露于三种必需元素引发的：钙离子、磷酸酯盐和碱性磷酸酶。任何给定的体细胞，包括未分化的单核细胞，都可以经历生物矿化过程，产生钙磷团聚体。在这种条件下生物生成的矿物质由真正的 HAP 晶须组成，尺寸为 Ca(PO)(OH) 和 5-10 纳米（nm）。这一发现将极大地提高我们对骨骼代谢和异位钙化的理解。
