Distal Myopathy Histochemical and Ultrastructural Studies

Kumamoto, Toshihide; Fukuhara, Nobuyoshi; Nagashima, Masaru; Kanda, Takemasa; Wakabayashi, Masatoshi

doi:10.1001/archneur.1982.00510180045011

Cited by 52 publications

(28 citation statements)

References 17 publications

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“…Histologic, histochemical, and immunohistochemicai studies Our histologic and histochemical findings in DMRV muscles corresponded to previous reports (1)(2)(3)18). All muscles of DMRV showed mild to moderate accumulations of rimmed vacuoles, predominantly in the atrophic fibers.…”

Section: Resultssupporting

confidence: 90%

“…In distal myopathy with rimmed vacuoles (DMRV),which may be inherited as an autosomal recessive trait, muscle fibers show numerous rimmed vacuoles with the properties of autophagosomes or autolysosomes (1)(2)(3). Our previous ultrastructural and immunohistochemical studies of rimmed vacuole contents have revealed numerousdegenerating mitochondria, glycogen granules, and cell membrane fragments, and myofibrillar proteins such as myosin, oc-actinin, and actin (3).…”

Section: Introductionmentioning

confidence: 99%

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Proteasomes in Distal Myopathy with Rimmed Vacuoles.

et al. 1998

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In a previous report we suggested that muscle fibers in distal myopathywith rimmedvacuoles (DMRV) were degraded by both lysosomal proteolysis (cathepsins) and Ca2+-dependent, nonlysosomal proteolysis (calpain). Given recent evidence of abnormal ubiquitin accumulation in rimmed vacuoles, we examined the role of the ATP-ubiquitin-dependent proteolytic pathway (proteasomes) in myofiber degradation in this myopathy. Immunohistochemically, proteasomes (26S) were located in the cytoplasm in normal human muscle, but the staining intensity was weak. Quantitative analysis showed more reactivity for proteasomes in DMRV muscles and, to a lesser extent, in muscles from muscular dystrophy, polymyositis, and amyotrophic lateral sclerosis patients. In DMRV, proteasomes often were located within or on the rim of rimmedvacuoles, and in the cytoplasm of atrophic fibers. Ubiquitin accumulation was marked within rimmedvacuoles and was seen less extensively in the cytoplasm of atrophic fibers. The latter proteins colocalized well. In other diseased muscles, proteasomes and ubiquitin showed a positive reaction in the atrophic or necrotic fibers. The results indicate increased proteasome and ubiquitin in these muscle fibers as well as in other diseased muscle fibers. Wesuggest that the ATP-ubiquitin-proteasome proteolytic pathway as well as the nonlysosomal calpain and the lysosomal proteolytic pathway may participate in the muscle fiber degradation in DMRV.

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Section: Resultssupporting

confidence: 90%

Section: Introductionmentioning

confidence: 99%

Proteasomes in Distal Myopathy with Rimmed Vacuoles.

et al. 1998

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“…We suggested that autophagic vacuoles and secondary lysosomes were increased, and that the degen erative process in those myopathies, especially distal myopathy, progressed mainly through the lysosomal sys tem [8,[11][12][13],…”

Section: Discussionmentioning

confidence: 99%

“…On the other hand, there was no remarkable accumulation of glycogen particles or glycogenosomes in the myofibrillar or subsarcolemmal spaces of CQ-treated muscles. Also, there was no mass of randomly oriented abnormal fila ments in the cytoplasm [8,[11][12][13], The myofibrils sur rounding the autophagic vacuoles or dense bodies were undulated or narrowed by those abnormal structures. However, the composition and population of myofibrils were preserved in many muscle fibers, although disrup tion of filament arrangement, narrowing of individual myofibrils, and streaming or loss of the Z band had occurred in some fibers.…”

Section: Histopathological Findings In Soleus Musclesmentioning

confidence: 99%

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Experimental Chloroquine Myopathy: Morphological and Biochemical Studies

et al. 1989

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Morphological and biochemical studies were performed on the soleus muscles of rats receiving a daily intraperitoneal injection of 50 mg chloroquine chloride (CQ) per kilogram of body weight. Light microscopy showed mild to moderate variations in fiber size, numerous dense membranous bodies and vacuoles. The vacuoles were ringed by material that was intensely basophilic in hematoxylin-eosin preparations, resembling rimmed vacuoles in the muscle fibers of distal myopathy. Segmental degradation or necrosis was often observed. The ³H-leucine uptake by myofibrillar and soluble sarcoplasmic fractions in CQ-treated muscles was the same as in the controls. The significant increases in lysosomal (cathepsin B & L, B and D) proteases and thiol protease inhibitor occurred in the earlier stages of CQ-induced myopathy, when hardly any autophagic vacuoles or dense bodies were observable by light microscopy. We conclude that the overdevelopment of autophagic vacuoles and the significant increases in lysosomal protease activity in muscle tissues may be important in the development of the focal degradation and necrosis of CQ-treated muscles.

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