The development of noninvasive and economical method to evaluate the bone quality using the measurement of serum levels of osteocyte-specific-proteins

初步分析表明，血清中骨细胞特异性蛋白之一的基质细胞外磷酸糖蛋白（MEPE）水平与骨质疏松性椎体骨折的多发性相关。然而，使用抗MEPE的单克隆抗体对血清中存在的MEPE衍生片段的氨基酸序列分析显示，mAb也与MEPE以外的一些蛋白衍生的未知肽结合。不幸的是，由于这种外源肽的量小且在mAb中本身具有交叉反应性，因此鉴定这种外源肽太困难，因此尚未建立使用针对MEPE的mAb的ELISA的临床应用。然而，我们的体外研究证实了骨细胞特异性蛋白测量的可能重要性，并显示了开发临床适用的血浆浓度测量的下一个目标蛋白。

It is revealed by our preliminary analysis that serum level of matrix extracellular phosphoglycoprotein (MEPE) that is one of osteocyte-specific-proteins is correlated with the multiplicity of osteoporotic vertebral fracture. However, the amino sequence analysis of MEPE derived fragment present in serum using monoclonal antibodies against MEPE revealed that mAb also bind with the unknown peptide derived from some protein other than MEPE. Identification of this foreign peptide is unfortunately too difficult due to its small amount and the cross reactivity itself in mAb, so clinical application of ELISA using mAb against MEPE has not been established. However, our in vitro study confirmed that the possible importance of the measurement of osteocyte-specific protein and showed the next target protein for development of clinically applicable plasma concentration measurement.