Tscheudschilsuren G, Bosserhoff A K, Schlegel J, Vollmer D, Anton A, Alt V, Schnettler R, Brandt J, Proetzel G
Scil Proteins GmbH, Heinrich-Damerow-Strasse 1, 06120 Halle/Saale, Germany.
Exp Cell Res. 2006 Jan 1;312(1):63-72. doi: 10.1016/j.yexcr.2005.09.017. Epub 2005 Oct 27.
Melanoma inhibitory activity (MIA), also referred to as cartilage-derived retinoic acid-sensitive protein (CD-RAP), an 11-kDa secreted protein, is mainly expressed in cartilaginous tissue during embryogenesis and adulthood. Currently, the function of MIA in cartilage tissue is not understood. Here, we describe that MIA acts as a chemotactic factor on the mesenchymal stem cell line C3H10T1/2, stimulating cell migration significantly at concentrations from 0.24 to 240 ng/ml, while inhibiting cell migration at higher doses of 2.4 microg/ml. When analyzing the role of MIA during differentiation processes, we show that MIA by itself is not capable to induce the differentiation of murine or human mesenchymal stem cells. However, MIA influences the action of bone morphogenetic protein (BMP)-2 and transforming growth factor (TGF)-beta 3 during mesenchymal stem cell differentiation, supporting the chondrogenic phenotype while inhibiting osteogenic differentiation. Quantitative RT-PCR analysis revealed the up-regulation of the cartilage markers MIA, collagen type II and aggrecan in human mesenchymal stem cell (HMSC) cultures differentiated in the presence of MIA and TGF-beta 3 or BMP-2 when compared to HMSC cultures differentiated in the presence of TGF-beta 3 or BMP-2 alone. Further, MIA down-regulates gene expression of osteopontin and osteocalcin in BMP-2 treated HMSC cultures inhibiting the osteogenic potential of BMP-2. In the case of human primary chondrocytes MIA stimulates extracellular matrix deposition, increasing the glycosaminoglycan content. Therefore, we postulate that MIA is an important regulator during chondrogenic differentiation and maintenance of cartilage.
黑色素瘤抑制活性蛋白（MIA），也被称为软骨衍生视黄酸敏感蛋白（CD - RAP），是一种11千道尔顿的分泌蛋白，在胚胎发育和成年期主要表达于软骨组织。目前，MIA在软骨组织中的功能尚不清楚。在此，我们描述了MIA对间充质干细胞系C3H10T1/2具有趋化因子的作用，在浓度为0.24至240纳克/毫升时显著刺激细胞迁移，而在2.4微克/毫升的更高剂量下抑制细胞迁移。在分析MIA在分化过程中的作用时，我们发现MIA自身不能诱导小鼠或人间充质干细胞的分化。然而，MIA在间充质干细胞分化过程中影响骨形态发生蛋白（BMP）-2和转化生长因子（TGF）-β3的作用，支持软骨生成表型，同时抑制成骨分化。定量逆转录聚合酶链反应（RT - PCR）分析显示，与仅在TGF -β3或BMP -2存在下分化的人间充质干细胞（HMSC）培养物相比，在MIA与TGF -β3或BMP -2共同存在下分化的HMSC培养物中，软骨标志物MIA、II型胶原蛋白和聚集蛋白聚糖的表达上调。此外，MIA下调BMP -2处理的HMSC培养物中骨桥蛋白和骨钙素的基因表达，抑制BMP -2的成骨潜能。对于人原代软骨细胞，MIA刺激细胞外基质沉积，增加糖胺聚糖含量。因此，我们推测MIA是软骨生成分化和软骨维持过程中的重要调节因子。
