Gulati A K
J Cell Biochem. 1985;27(4):337-46. doi: 10.1002/jcb.240270404.
The basement membrane of myofibers plays an important role during orderly regeneration of skeletal muscle after injury. In this report, changes in various basement membrane components were analyzed in skeletal muscle grafts undergoing regeneration (autografts) or immune rejection (allografts). The immunofluorescence technique using specific antibodies against laminin, types IV and V collagen, heparan sulfate proteoglycan, fibronectin, in combination with binding of concanavalin A (ConA) was used to monitor basement membranes. In normal muscle, these components were localized in the pericellular region of myofiber corresponding to its basement membrane. After transplantation, the majority of myofibers underwent degeneration as a result of ischemic injury, followed by regeneration from precursor myosatellite cells. Various components of basement membrane zone disappeared from the degenerating myofibers, leaving behind some unidentifiable component that still bound ConA. A new basement membrane appeared around the regenerated myotubes which persisted during maturation of the regenerating muscle. In rejected skeletal muscles, the immunoreactivity of various components persisted even after the disappearance of myotubes and myofiber cytoplasm. In addition, an accumulation of fibronectin was seen throughout the rejected muscle with the onset of immune rejection. These results demonstrate that the major basement membrane components disappear and reappear sequentially during myofiber degeneration and regeneration. Such a turnover is not seen in rejected skeletal muscles. Thus, the myofiber basement membrane is not a static structure as previously thought but one which changes chemically during degeneration and regeneration. This feature of basement membrane may be important in the orderly regeneration of skeletal muscle after injury.
肌纤维的基底膜在骨骼肌损伤后有序再生过程中发挥着重要作用。在本报告中，分析了经历再生（自体移植）或免疫排斥（异体移植）的骨骼肌移植物中各种基底膜成分的变化。使用针对层粘连蛋白、IV型和V型胶原蛋白、硫酸乙酰肝素蛋白聚糖、纤连蛋白的特异性抗体，并结合伴刀豆球蛋白A（ConA）的免疫荧光技术来监测基底膜。在正常肌肉中，这些成分定位于与肌纤维基底膜相对应的肌纤维细胞周区域。移植后，大多数肌纤维因缺血性损伤而发生变性，随后从前体肌卫星细胞再生。基底膜区的各种成分从变性的肌纤维中消失，仅留下一些仍能结合ConA的无法识别的成分。再生的肌管周围出现了新的基底膜，其在再生肌肉成熟过程中持续存在。在被排斥的骨骼肌中，即使肌管和肌纤维细胞质消失后，各种成分的免疫反应性仍持续存在。此外，随着免疫排斥的开始，在整个被排斥的肌肉中可见纤连蛋白的积累。这些结果表明，在肌纤维变性和再生过程中，主要的基底膜成分依次消失和重新出现。在被排斥的骨骼肌中未观察到这种更替。因此，肌纤维基底膜并非如先前认为的那样是一种静态结构，而是一种在变性和再生过程中发生化学变化的结构。基底膜的这一特征可能对骨骼肌损伤后的有序再生很重要。
