Filamentous structures in skeletal muscle: anchors for the subsarcolemmal space
Filamentous structures in skeletal muscle: anchors for the subsarcolemmal space
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骨骼肌中的丝状结构：肌膜下空间的锚
DOI：
10.1007/s00795-014-0070-3
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发表时间：
2014
影响因子：
1.8
通讯作者：
Arifin Soenggono & Hiroshi Yorifuji
中科院分区：
文献类型：
--
作者：
Astrid Feinisa Khairani;Yuki Tajika;Maiko Takahashi;Hitoshi Ueno;Tohru Murakami;Arifin Soenggono & Hiroshi Yorifuji
在骨骼肌纤维中，中间丝和肌动蛋白丝为肌原纤维和肌膜提供结构支持。多年来，从超微结构观察中对这些丝状结构如何保持锚定知之甚少。本研究旨在确定肌膜下空间和肌原纤维间的丝状锚定结构的结构。成年野生型和mdx小鼠（mdx是杜氏肌营养不良症的模型）的横膈膜（Dp）经受垂直于肌纤维长轴施加的张力，用或不用1%Triton X-100或0.03%皂苷处理。进行这些实验是为了确认丝状锚定结构的存在和完整性。透射电子显微镜显示，这些结构提供了坚实的肌膜和外周肌原纤维之间的横向连接。大多数的丝状结构似乎插入到肌膜下密度，形成锚定连接之间的肌膜和外周肌原纤维。在某些情况下，肌动蛋白丝被发现纵向运行在肌膜下的空间连接到肌膜或在某些情况下，连接到肌间原纤维作为细长的细丝。这些丝状锚定结构在themdxDp中不太常见。我们的数据表明，横向和纵向的丝状结构在肌膜下空间和肌原纤维间形成一个锚定系统。
In skeletal muscle fibers, intermediate filaments and actin filaments provide structural support to the myofibrils and the sarcolemma. For many years, it was poorly understood from ultrastructural observations that how these filamentous structures were kept anchored. The present study was conducted to determine the architecture of filamentous anchoring structures in the subsarcolemmal space and the intermyofibrils. The diaphragms (Dp) of adult wild type andmdxmice (mdxis a model for Duchenne muscular dystrophy) were subjected to tension applied perpendicular to the long axis of the muscle fibers, with or without treatment with 1 % Triton X-100 or 0.03 % saponin. These experiments were conducted to confirm the presence and integrity of the filamentous anchoring structures. Transmission electron microscopy revealed that these structures provide firm transverse connections between the sarcolemma and peripheral myofibrils. Most of the filamentous structures appeared to be inserted into subsarcolemmal densities, forming anchoring connections between the sarcolemma and peripheral myofibrils. In some cases, actin filaments were found to run longitudinally in the subsarcolemmal space to connect to the sarcolemma or in some cases to connect to the intermyofibrils as elongated thin filaments. These filamentous anchoring structures were less common in themdxDp. Our data suggest that the transverse and longitudinal filamentous structures form an anchoring system in the subsarcolemmal space and the intermyofibrils.