Department of Clinical Sciences, Ophthalmology, Umeå University, Umeå, Sweden.
Department of Integrative Medical Biology, Section for Anatomy, Umeå University, Umeå, Sweden.
Invest Ophthalmol Vis Sci. 2018 Oct 1;59(12):4847-4855. doi: 10.1167/iovs.18-24508.
To investigate the effect of absence of desmin on the extraocular muscles (EOMs) with focus on the structure and composition of the cytoskeleton.
The distribution of synemin, syncoilin, plectin, nestin, and dystrophin was evaluated on cross and longitudinal sections of EOMs and limb muscles from 1-year-old desmin knockout mice (desmin-/-) by immunofluorescence. General morphology was evaluated with hematoxylin and eosin while mitochondrial content and distribution were evaluated by succinate dehydrogenase (SDH) and modified Gomori trichrome stainings.
The muscle fibers of the EOMs in desmin-/- mice were remarkably well preserved in contrast to those in the severely affected soleus and the slightly affected gastrocnemius muscles. There were no signs of muscular pathology in the EOMs and all cytoskeletal proteins studied showed a correct location at sarcolemma and Z-discs. However, an increase of SDH staining and mitochondrial aggregates under the sarcolemma was detected.
The structure of the EOMs was well preserved in the absence of desmin. We suggest that desmin is not necessary for correct synemin, syncoilin, plectin, and dystrophin location on the cytoskeleton of EOMs. However, it is needed to maintain an appropriate mitochondrial distribution in both EOMs and limb muscles.
研究无结蛋白对眼外肌（EOMs）的影响，重点关注细胞骨架的结构和组成。
通过免疫荧光法，在 1 岁的结蛋白敲除鼠（desmin-/-）的横切和纵切 EOMs 和四肢肌肉上评估神经原黏附蛋白、突触黏合蛋白、纽蛋白、巢蛋白和 dystrophin 的分布。苏木精和伊红染色评估一般形态，琥珀酸脱氢酶（SDH）和改良 Gomori 三色染色评估线粒体含量和分布。
与严重受累的比目鱼肌和轻度受累的腓肠肌相比，desmin-/- 鼠的 EOMs 肌纤维保存完好。EOMs 无肌肉病理学迹象，研究的所有细胞骨架蛋白均正确定位于肌膜和 Z 盘。然而，在肌膜下检测到 SDH 染色增加和线粒体聚集。
在没有结蛋白的情况下，EOMs 的结构得到了很好的保存。我们认为，结蛋白对于 EOMs 细胞骨架上正确的神经原黏附蛋白、突触黏合蛋白、纽蛋白和 dystrophin 定位不是必需的。然而，它对于维持 EOMs 和四肢肌肉中适当的线粒体分布是必需的。
