Dual Function of Magnesium in Bone Biomineralization
Dual Function of Magnesium in Bone Biomineralization
复制标题
镁在骨生物矿化中的双重功能
DOI：
10.1002/adhm.201901030
复制
发表时间：
2019-10-04
影响因子：
10
通讯作者：
Zhang, Yufeng
中科院分区：
文献类型：
--
作者：
Zhang, Jinglun;Tang, Lin;Zhang, Yufeng
镁作为骨的主要成分，被广泛应用于促进骨生长和再生。然而，镁离子可以在化学上抑制无定形磷酸钙结晶成羟基磷灰石(HA)。镁离子促进骨骼生物矿化的潜在机制仍然不清楚。本文从发育角度论证了镁离子在骨生物矿化中的双重作用。在胚胎发育过程中，从胚胎13.5天(E13.5天)到胚胎15.5天(E15.5天)，镁离子浓度在早期阶段有所增加，但在胚胎发育后期(E15.5天)，镁离子浓度逐渐下降至稳定状态。适量的镁离子可促进骨髓间充质干细胞的矿化，过量的镁离子则会抑制其成骨作用。添加镁离子越早，对矿化的抑制作用越强。特别是，完全矿化的胶原蛋白中的镁离子比矿化较差的胶原蛋白中的镁离子少。此外，高浓度的镁离子改变了HA的结晶形态，抑制了胶原的钙化。从功能上讲，高镁饮食抑制了小鼠后代的骨生物矿化。综上所述，这些结果表明，随着时间的推移，适当调节镁离子浓度对于正常的生物矿化至关重要。本研究对今后与镁离子含量相关的骨替代材料和植入物的设计具有重要意义。
Magnesium (Mg2+), as a main component of bone, is widely applied to promote bone growth and regeneration. However, Mg2+ can chemically inhibit the crystallization of amorphous calcium phosphate into hydroxyapatite (HA). The underlying mechanisms by which Mg2+ improves bone biomineralization remain elusive. Here, it is demonstrated that Mg2+ plays dual roles in bone biomineralization from a developmental perspective. During embryonic development, the Mg2+ concentration is enriched in the early stage from embryonic day 13.5 (E13.5) to E15.5, but gradually decreases to a stable state in the late phase, after E15.5. Appropriate concentrations of Mg2+ can promote the mineralization of bone marrow mesenchymal stem cells, while excessive Mg2+ impairs their osteogenesis. The earlier the Mg2+ is added, the stronger the observed inhibition of mineralization. In particular, less Mg2+ is present in fully mineralized collagen than in poorly mineralized collagen. Furthermore, a high concentration of Mg2+ changes the crystalline morphology of HA and inhibits collagen calcification. Functionally, a high-Mg2+ diet inhibits bone biomineralization in mouse offspring. Taken together, the results suggest that appropriate regulation of Mg2+ concentration over time is vital for normal biomineralization. This study is significant for the future design of bone substitutes and implants associated with Mg2+ content.