Shur I, Socher R, Hameiri M, Fried A, Benayahu D
Department of Cell and Developmental Biology, Sackler School of Medicine, Tel-Aviv University, Israel.
J Cell Physiol. 2006 Feb;206(2):420-7. doi: 10.1002/jcp.20497.
We describe a novel human gene, named SEL-OB/SVEP1, expressed by skeletal tissues in vivo and by cultured osteogenic cells. The mRNA expression was analyzed on frozen tissues retrieved by laser-capture microscope dissection (LCM) and was detected in osteogenic tissues (periosteum and bone) but not in cartilage or skeletal muscle. The SEL-OB/SVEP1 cDNA of 11,139 bp was in silico translated into a 3574AA protein with expected molecular weight of 370 kDa. The protein is composed of multiple domains including complement control protein (CCP) modules with selectin superfamily signature; sushi and other domains, such as vWA, EGF, PTX, and HYR. Stromal osteogenic cells were analyzed for the protein expression using anti-SEL-OB/SVEP1 for immuno-precipitation and Western blot application confirm the presence of high molecular weight protein. Immuno-histochemistry and fluorescence-activated cell sorting (FACS) were applied to detect SEL-OB/SVEP1 on the surface of stromal cells. ELISA quantified the dependence of protein expression on cell density. Bioinformatic analysis of SEL-OB/SVEP1 revealed domains compositions recognized in cell surface molecules and suggested its role in cell adhesion. Analysis of mesechymal osteogenic cells' adhesion in presence of anti-SEL-OB/SVEP1 antibody demonstrated its interference with initial adhesion stages. In summary, present study describes novel SEL-OB/SVEP1 protein with a unique composition of functional domains, restricted pattern of expression in skeletal cells and demonstrated involvement in attachment of mesenchymal cells. The unusual composition of functional domains puts SEL-OB/SVEP1 in the discrete new group of membrane proteins involved in cell adhesion processes. All together makes SEL-OB/SVEP1 an attractive marker for studying the role of stromal osteogenic cells and their interactions within the bone marrow microenvironment creating a network that regulates the skeletal homeostasis.
我们描述了一种名为SEL-OB/SVEP1的新型人类基因，它在体内由骨骼组织以及培养的成骨细胞表达。通过激光捕获显微切割（LCM）获取的冷冻组织对mRNA表达进行了分析，结果发现在成骨组织（骨膜和骨骼）中有表达，而在软骨或骨骼肌中未检测到。11,139 bp的SEL-OB/SVEP1 cDNA经电子计算机翻译为一个3574个氨基酸的蛋白质，预期分子量为370 kDa。该蛋白质由多个结构域组成，包括具有选择素超家族特征的补体控制蛋白（CCP）模块；寿司结构域以及其他结构域，如vWA、EGF、PTX和HYR。使用抗SEL-OB/SVEP1抗体进行免疫沉淀和蛋白质印迹分析，以检测基质成骨细胞中的蛋白质表达，证实存在高分子量蛋白质。应用免疫组织化学和荧光激活细胞分选（FACS）来检测基质细胞表面的SEL-OB/SVEP1。酶联免疫吸附测定（ELISA）定量了蛋白质表达对细胞密度的依赖性。对SEL-OB/SVEP1的生物信息学分析揭示了在细胞表面分子中识别出的结构域组成，并暗示了其在细胞黏附中的作用。在抗SEL-OB/SVEP1抗体存在的情况下，对间充质成骨细胞黏附的分析表明其对初始黏附阶段有干扰作用。总之，本研究描述了一种新型的SEL-OB/SVEP1蛋白质，其具有独特的功能结构域组成、在骨骼细胞中受限的表达模式，并证明其参与间充质细胞的黏附。功能结构域的异常组成使SEL-OB/SVEP1属于参与细胞黏附过程的离散新膜蛋白组。所有这些使得SEL-OB/SVEP1成为研究基质成骨细胞的作用及其在骨髓微环境中相互作用的有吸引力的标志物，骨髓微环境形成了一个调节骨骼稳态的网络。
