Wernig A, Irintchev A, Härtling A, Stephan G, Zimmermann K, Starzinski-Powitz A
Physiologisches Institut, Universität Bonn, FRG.
J Neurocytol. 1991 Dec;20(12):982-97. doi: 10.1007/BF01187916.
We examined the effects of implantation of cultured myogenic cells from a permanent cell line into soleus muscles of histocompatible adult mice. Myogenic cells (10(6) or 10(4)) were implanted into intact muscles, muscles frozen with liquid nitrogen, paralysed with botulinum toxin or reinnervated after long-term (seven months) denervation. Formation of numerous muscle fibres in myogenic cell-injected muscles raised the total number of fibres up to ten times above control by four weeks. Larger effects were found in freeze-damaged than in paralysed muscles. The new fibres had small calibers, considerable length (greater than 1.3 mm, maximum distance over which serial sections were made), were multinucleated and were oriented parallel to the large-diameter fibres of the host muscles. In some experiments beta-galactosidase, introduced into myogenic cells via retroviral transfection, was detected in small and large muscle fibres 4-20 weeks after implantation, indicating survival of the grafted cells and formation of mosaic (host-donor) and new fibres of donor origin. Muscle weight increased significantly and, rather surprisingly, a parallel increase was found in isometric tetanic tension of isolated nerve-muscle preparations; thus tension per mg muscle tissue was not different from normal. By eight weeks reduction of acetylcholine sensitivity and down-regulation of neural cell adhesion molecule to normal were observed, indicating that synaptic transmission at the new fibres was mature. After different periods of time (5-20 weeks, depending on the subclone used) tumours developed in most but not all injected limbs (37 out of 39). The tumours were destructive to the muscles and were classified as rhabdomyosarcomas. Prior to tumour formation, neural cell adhesion molecule positive cells reappeared in the muscles; since the myogenic cells initially produced differentiated muscle fibres, it appears that malignant growth is induced by factors in vivo. Thus, at present the outcome of such implantation is unpredictable.
我们研究了将来自永久性细胞系的培养成肌细胞植入组织相容性成年小鼠比目鱼肌后的效果。将成肌细胞（10⁶或10⁴）植入完整肌肉、经液氮冷冻的肌肉、用肉毒杆菌毒素麻痹的肌肉或长期（七个月）去神经后重新神经支配的肌肉中。在注入成肌细胞的肌肉中形成大量肌纤维，使纤维总数在四周内比对照增加了十倍。在冷冻损伤的肌肉中发现的效果比在麻痹的肌肉中更大。新纤维直径小，长度可观（大于1.3毫米，即制作连续切片的最大距离），多核，且与宿主肌肉的大直径纤维平行排列。在一些实验中，通过逆转录病毒转染引入成肌细胞的β-半乳糖苷酶在植入后4至20周在小和大的肌纤维中被检测到，表明移植细胞存活并形成了嵌合体（宿主-供体）以及供体来源的新纤维。肌肉重量显著增加，而且相当令人惊讶的是，在分离的神经-肌肉标本的等长强直张力中也发现了平行增加；因此每毫克肌肉组织的张力与正常无异。到八周时，观察到乙酰胆碱敏感性降低以及神经细胞黏附分子下调至正常水平，表明新纤维处的突触传递已成熟。在不同时间段（5至20周，取决于所使用的亚克隆）后，大多数但并非所有注射肢体（39只中的37只）出现了肿瘤。这些肿瘤对肌肉具有破坏性，被归类为横纹肌肉瘤。在肿瘤形成之前，神经细胞黏附分子阳性细胞重新出现在肌肉中；由于成肌细胞最初产生分化的肌纤维，似乎恶性生长是由体内因素诱导的。因此，目前这种植入的结果是不可预测的。
