Lee Won-Hyung, Abe Shinichi, Kim Hee-Jin, Usami Akinobu, Honda Atsuro, Sakiyama Koji, Ide Yoshinobu
Department of Anatomy, Tokyo Dental College, 1-2-2 Masago, Mihama-ku, Chiba 261-8502, Japan.
J Muscle Res Cell Motil. 2006;27(3-4):235-40. doi: 10.1007/s10974-006-9066-5. Epub 2006 Jun 4.
Mdx mice, which lack dystrophin, were examined for changes in the properties of muscle fibers in the growth process of the masseter muscle at the morphological, protein and transcriptional levels. The slow-type isoform, MyHC-1, and the fast-type isoforms, MyHC-2a, MyHC-2d and MyHC-2b, were examined at the protein and the transcriptional level. Morphological examination showed that in the mdx mouse masseter muscle, degeneration, necrosis, and regeneration occurred, particularly at the age of 4 weeks, and many regenerated muscle fibers with centrally located nuclei were observed at the age of 9 weeks. The results of examination at the protein and the transcriptional level showed that in the process of muscle fiber degeneration, necrosis, and regeneration, the mdx mouse masseter muscle acquires muscle fiber characteristics entirely different from those in the normal mouse masseter muscle. In particular, MyHC-1, which is rarely found in normal mice, was very strongly expressed.
对缺乏抗肌萎缩蛋白的mdx小鼠，在咬肌生长过程中的形态学、蛋白质和转录水平上，检测其肌纤维特性的变化。在蛋白质和转录水平上检测慢肌型异构体MyHC-1以及快肌型异构体MyHC-2a、MyHC-2d和MyHC-2b。形态学检查显示，mdx小鼠咬肌出现变性、坏死和再生，尤其是在4周龄时，并且在9周龄时观察到许多核位于中央的再生肌纤维。蛋白质和转录水平的检测结果显示，在肌纤维变性、坏死和再生过程中，mdx小鼠咬肌获得了与正常小鼠咬肌完全不同的肌纤维特征。特别是，在正常小鼠中很少发现的MyHC-1表达非常强烈。
