Division of Biomedical Sciences, Faculty of Dentistry, McGill University, Montreal, QC, CA.
Cell Adh Migr. 2011 Jan-Feb;5(1):65-72. doi: 10.4161/cam.5.1.13369. Epub 2011 Jan 1.
Tissue transglutaminase (TG2) is a widely distributed, protein-crosslinking enzyme having a prominent role in cell adhesion as a β1 integrin co-receptor for fibronectin. In bone and teeth, its substrates include the matricellular proteins osteopontin (OPN) and bone sialoprotein (BSP). The aim of this study was to examine effects of TG2-mediated crosslinking and oligomerization of OPN and BSP on osteoblast cell adhesion. We show that surfaces coated with oligomerized OPN and BSP promote MC3T3-E1/C4 osteoblastic cell adhesion significantly better than surfaces coated with the monomeric form of the proteins. Both OPN and BSP oligomer-adherent cells showed more cytoplasmic extensions than those cells grown on the monomer-coated surfaces indicative of increased cell connectivity. Our study suggests a role for TG2 in promoting the cell adhesion function of two matricellular substrate proteins prominent in bone, tooth cementum and certain tumors.
组织转谷氨酰胺酶（TG2）是一种广泛分布的蛋白交联酶，作为纤维连接蛋白的β1 整合素共受体，在细胞黏附中起重要作用。在骨骼和牙齿中，其底物包括细胞外基质蛋白骨桥蛋白（OPN）和骨唾液蛋白（BSP）。本研究旨在探讨 TG2 介导的 OPN 和 BSP 交联和寡聚化对成骨细胞黏附的影响。我们发现，与涂有单体形式蛋白的表面相比，涂有寡聚 OPN 和 BSP 的表面显著促进 MC3T3-E1/C4 成骨细胞黏附。与在单体涂覆表面上生长的细胞相比，OPN 和 BSP 寡聚体附着的细胞显示出更多的细胞质延伸，表明细胞连接性增加。我们的研究表明，TG2 在促进两种在骨骼、牙骨质和某些肿瘤中很突出的细胞外基质底物蛋白的细胞黏附功能中发挥作用。
