Shapiro Irving M, Landis William J, Risbud Makarand V
Department of Orthopedic Surgery, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA.
Department of Polymer Science, College of Polymer Science and Polymer Engineering, University of Akron, OH, USA.
Bone. 2015 Oct;79:29-36. doi: 10.1016/j.bone.2015.05.013. Epub 2015 May 15.
Numerous studies have documented that matrix vesicles are unique extracellular membrane-bound microparticles that serve as initial sites for mineral formation in the growth plate and most other vertebrate mineralizing tissues. Microparticle generation is not confined to hard tissues, as cells in soft tissues generate similar structures; numerous studies have shown that a common type of extracellular particle, termed an exosome, a product of the endosomal pathway, shares many characteristics of matrix vesicles. Indeed, analyses of size, morphology and lipid and protein content indicate that matrix vesicles and exosomes are homologous structures. Such a possibility impacts our understanding of the biogenesis, processing and function of matrix vesicles (exosomes) in vertebrate hard tissues and explains in part how cells control the earliest stages of mineral deposition. Moreover, since exosomes influence a spectrum of functions, including cell-cell communication, it is suggested that this type of microparticle may provide a mechanism for the transfer of signaling molecules between cells within the growth plate and thereby regulate endochondral bone development and formation.
大量研究表明，基质小泡是独特的细胞外膜结合微粒，是生长板和大多数其他脊椎动物矿化组织中矿物质形成的起始位点。微粒的产生并不局限于硬组织，因为软组织中的细胞也会产生类似的结构；许多研究表明，一种常见的细胞外颗粒，称为外泌体，是内体途径的产物，与基质小泡具有许多共同特征。事实上，对大小、形态以及脂质和蛋白质含量的分析表明，基质小泡和外泌体是同源结构。这种可能性影响了我们对脊椎动物硬组织中基质小泡（外泌体）的生物发生、加工和功能的理解，并部分解释了细胞如何控制矿物质沉积的最早阶段。此外，由于外泌体影响一系列功能，包括细胞间通讯，因此有人提出，这种类型的微粒可能为生长板内细胞间信号分子的传递提供一种机制，从而调节软骨内骨的发育和形成。
