Li S F, Klajn E, Marotta R, Parish R W
School of Botany, La Trobe University, Melbourne, Victoria, Australia.
J Muscle Res Cell Motil. 1997 Apr;18(2):133-48. doi: 10.1023/a:1018601504848.
A cell line of mesodermal origin, FS9, was found to release a Cell Orienting Factor into its culture medium. In contrast with the random migration of controls, the orienting activity causes migrating mesenchymal cells to form an orderly "halo' surrounding tissue explants; individual cells and their cytoskeletons are elongated and parallel to each other but at right angle to the explant. No effect on the rate of cell movement was apparent. The orienting activity could be quantified by counting the number of cells found within strings radiating at right angles to a single tissue explant in the presence of FS9 conditioned medium or by using NIH image analysis. A dose dependent relationship with half maximal activity occurring at a 25% dilution of conditioned medium was observed. Cells that migrated randomly in the absence of conditioned medium became oriented within 4 h of exposure to 50% conditioned medium. Conversely, when the conditioned medium was removed, parallel alignment was rapidly lost. The orienting activity was found in conditioned media from a variety of mesodermal derivatives. Transformation of Balb/c 3T3 cells using EJ-ras oncogene led to augmented production of the activity. Furthermore, insulin was required in serum-free medium to support its production, Laminin, fibronectin and collagen and a range of pure cytokines, neither promoted nor inhibited orientation. Cell alignment was also unaffected by treatments which interfered with cell-substrate interactions and motility including the addition of the RGD peptide or anti-integrin beta 1 and beta 3 antibodies. A protein is likely to be involved since the activity was heat and trypsin sensitive and non-dialysable. The possibility is discussed that the orienting activity is a novel protein(s) which alters intercellular interactions to promote the formation of an aligned pattern by migrating mesenchymal cells.
一种中胚层来源的细胞系FS9被发现能向其培养基中释放一种细胞定向因子。与对照组细胞的随机迁移不同，这种定向活性会使迁移的间充质细胞围绕组织外植体形成一个有序的“晕圈”；单个细胞及其细胞骨架会伸长并相互平行，但与外植体呈直角。对细胞移动速率没有明显影响。可以通过计算在FS9条件培养基存在下与单个组织外植体呈直角辐射的条带内发现的细胞数量，或使用NIH图像分析来量化这种定向活性。观察到存在剂量依赖关系，在条件培养基25%稀释时出现半数最大活性。在没有条件培养基时随机迁移的细胞在暴露于50%条件培养基4小时内会变得定向。相反，当去除条件培养基时，平行排列会迅速消失。在来自各种中胚层衍生物的条件培养基中都发现了这种定向活性。用EJ - ras癌基因转化Balb/c 3T3细胞会导致这种活性的产生增加。此外，在无血清培养基中需要胰岛素来支持其产生，层粘连蛋白、纤连蛋白、胶原蛋白以及一系列纯细胞因子，既不促进也不抑制定向。细胞排列也不受干扰细胞 - 底物相互作用和运动性的处理的影响，包括添加RGD肽或抗整合素β1和β3抗体。由于这种活性对热和胰蛋白酶敏感且不可透析，可能涉及一种蛋白质。讨论了这种定向活性是一种新型蛋白质的可能性，它改变细胞间相互作用以促进迁移的间充质细胞形成排列模式。
