基质囊泡及其在骨矿化过程中的作用

摘要

基质囊泡(Matrix vesicles,MVs)是骨矿物初始形核生长的场所.骨矿化过程中,钙、磷酸根等离子经通道蛋白跨膜运输进入 MVs内,当局部浓度达到一定值时,磷酸钙晶体开始沉积.磷酸钙的存在形态包括无定形磷酸钙、磷酸八钙及羟基磷灰石等.MVs可以调节细胞内外基质中的钙和磷酸根离子的稳态及无机磷酸盐/无机焦磷酸盐的比值,提供磷酸钙晶体成核位点,在骨矿化的初始启动过程中发挥重要作用.本文概述了 MVs的生物来源、分子组分、提取方法,MVs介导的骨矿化过程,以及近年来利用囊泡作为体外矿化模型模拟 MVs矿化过程的研究进展.%The initial deposition of bone mineral occurs within matrix vesicles (MVs).Calcium phosphate deposition within MVs is triggered by the transmembrane transport and aggregation of calcium & phosphate ions within the MVs lumina through membrane proteins and enzymes when local concentration of calcium &phosphate ions approaches to the certain value.The existence form of calcium phosphate includes amorphous calcium phosphate (ACP),octacalcium phosphate (OCP),and hydroxyapatite (HA).MVs play an important role in initiating bone mineralization process,including controlling calcium & phosphate ions homeo-stasis,regulating the inorganic phosphate/inorganic pyrophosphate (Pi/PPi)ratio in the intra- and extra-cellular fluid and managing mineral nucleation,etc.This paper introduces the biogenesis,molecular components and extraction method of MVs,illuminates the role and the kinetics of MVs in bone mineralization process.Finally,the research progress of biomimetic mineralization using syn-thetic phospholipid vesicles as an in vitro mineralization model are discussed.