Ocalan M, Goodman S L, Kühl U, Hauschka S D, von der Mark K
Department of Connective Tissue Research, Max-Planck-Institut für Biochemie, Martinsried, Federal Republic of Germany.
Dev Biol. 1988 Jan;125(1):158-67. doi: 10.1016/0012-1606(88)90068-1.
Proliferating skeletal myoblasts show multiple specific responses to laminin, one of the major glycoprotein components of basement membranes. Using MM14Dy myoblasts, a myogenic cell strain derived from a normal adult mouse skeletal muscle, we show in this study that substrate-bound laminin but not other matrix proteins such as collagens or fibronectin specifically and rapidly induces the outgrowth of cell processes, resulting in bipolar, spindle-shaped cells. This effect is independent from the presence of collagens or serum, and was also observed in primary cultures of fetal mouse skeletal myoblasts. The outgrowth of cell processes on laminin is associated with a dramatic stimulation of cell motility: MM14 myoblasts migrate about five times faster on laminin than on fibronectin. In another series of experiments the effect of laminin and fibronectin on thymidine uptake and proliferation of myoblasts was tested. On top of a type I collagen substrate which was provided to ensure complete adhesion even at low doses of laminin or fibronectin, laminin stimulated myoblast proliferation and incorporation of [3H]thymidine in a dose-dependent manner. The stimulation is two- to threefold higher than on dishes coated with equivalent amounts of fibronectin and is observed both in the presence and in the absence of serum. These results suggest that laminin, a major component of the muscle basal lamina, may be actively involved in the development and regeneration of skeletal muscle.
增殖的骨骼肌成肌细胞对层粘连蛋白（基底膜的主要糖蛋白成分之一）表现出多种特异性反应。在本研究中，我们使用MM14Dy成肌细胞（一种源自正常成年小鼠骨骼肌的成肌细胞系）发现，与底物结合的层粘连蛋白而非其他基质蛋白（如胶原蛋白或纤连蛋白）能特异性且快速地诱导细胞突起生长，形成双极的纺锤形细胞。这种效应不依赖于胶原蛋白或血清的存在，在胎鼠骨骼肌成肌细胞的原代培养中也观察到了。层粘连蛋白上细胞突起的生长与细胞运动性的显著刺激相关：MM14成肌细胞在层粘连蛋白上的迁移速度比在纤连蛋白上快约五倍。在另一系列实验中，测试了层粘连蛋白和纤连蛋白对成肌细胞胸苷摄取和增殖的影响。在提供I型胶原蛋白底物以确保即使在低剂量的层粘连蛋白或纤连蛋白下也能完全黏附的基础上，层粘连蛋白以剂量依赖的方式刺激成肌细胞增殖和[3H]胸苷掺入。这种刺激比在涂有等量纤连蛋白的培养皿上高两到三倍，并且在有血清和无血清的情况下均能观察到。这些结果表明，作为肌肉基底膜主要成分的层粘连蛋白可能积极参与骨骼肌的发育和再生。
