The effect of age on biochemical and morphological changes in the semitendinosus muscle of cattle with generalized glycogenosis type II

Glicogenose hereditária em bovinos Brahman no Brasil

Relata-se uma enfermidade hereditária em bovinos caracterizada por acúmulo lisossomal de glicogênio em diversos órgãos. A doença foi diagnosticada em um rebanho da raça Brahman, no município de Porto Lucena, Rio Grande do Sul, Brasil. Os animais afetados, a partir de 1 mês de idade, apresentavam dificuldade em acompanhar a mãe e crescimento retardado, desenvolviam fraqueza e tremores musculares, letargia e perda de condição corporal progressivos. Todos os bezerros eram descendentes do mesmo touro. Foi realizada necropsia em três bezerros doentes; palidez muscular do tronco e membros foi a única alteração macroscópica encontrada. Vacuolização citoplasmática de diversos órgãos foi a principal alteração histológica observada. Os vacúolos citoplasmáticos eram mais evidentes na musculatura esquelética, miocárdio, especialmente nas fibras de Purkinje e em neurônios do Sistema Nervoso Central (SNC). Nos tecidos mais afetados foi observada grande quantidade de grânulos ácido periódico de Schiff (PAS), positivos e negativos quando o tecido era tratado previamente com diastase. Uma mutação no gene da glicosidase alfa ácida, causadora da glicogenose generalizada em bovinos Brahman, a 1057?TA, foi detectada pela técnica de reação em cadeia de polimerase (PCR) em tecidos dos animais necropsiados. Também foi detectada a presença dessa mutação em amostras de sangue de animais parentes dos bezerros doentes. Os achados clínicos, patológicos e moleculares são semelhante ás descrições de glicogenose tipo II em bovinos da raça Brahman descritos na Austrália. Não foram encontrados relatos anteriores em revistas indexadas sobre glicogenose hereditária em bovinos Brahman no Brasil.

Evaluation of muscle glycogen content by 13C NMR spectroscopy in adult-onset acid maltase deficiency

Muscle glycogen storage was measured by in vivo, natural abundance 13C nuclear magnetic resonance spectroscopy in distal and proximal lower limb segments of patients suffering from adult-onset acid maltase deficiency. Interleaved T1-weighted acquisitions of glycogen and creatine served to quantify glycogen excess. For acid maltase deficient patients (n=11), glycogen:creatine was higher than controls (n=12), (1.20+/-0.39 vs. 0.83+/-0.18, P=0.0005). Glycogen storage was above the normal 95% confidence limits in at least one site for 7/11 patients. The intra-individual coefficient of reproducibility was 12%. This totally atraumatic measurement of glycogen allows repeated measurement at different muscle sites of acid maltase deficient patients, despite selective fatty replacement of tissue. This could provide an additional parameter to follow the development of disease in individual patients, including in the perspective of forthcoming therapeutic trials. It may also offer an appropriate tool to study the role of glycogen accumulation in progression of the pathology.

Clinical, diagnostic and biochemical features of generalised glycogenosis type II in Brahman cattle

Clinical, diagnostic and biochemical features of generalised glycogenosis are described in 96 Brahman-type calves. Typically the calves were presented when about 6 months of age, with ill-thrift and muscular weakness as the most common signs. Acidic alpha-glucosidase activity was reduced in peripheral blood lymphocytes and skeletal muscle. Muscle glycogen concentration was consistently higher in affected animals than in clinically normal cattle. Other observations in affected calves included elevation of serum aspartate aminotransferase and creatine kinase activities and excessive amounts of high molecular weight oligosaccharides in urine. Fine cytoplasmic vacuolation of neurones in the brain and spinal cord, skeletal muscle, myocardium and of Purkinje fibres were consistent histological observations. Periodic acid-Schiff staining revealed the presence of glycogen-like material in peripheral blood lymphocytes of all affected calves, indicating that this is a useful aid for the diagnosis of glycogenosis. While 3 of the 96 calves showed somewhat different clinical signs, the similarity of pathology and the biochemical and clinical evidence in the remainder suggested that, in these animals, the disease was expressed as a single syndrome.

Natural bone marrow transplantation in cattle with Pompe's disease

Adding acid alpha-glucosidase to cultures of Pompe's disease muscle has resulted in enzyme uptake and reduction in concentration of glycogen. However, bone marrow transplantation has been unsuccessful as a treatment. Immune rejection may have contributed to this failure. Twin calves share a placenta and carry lymphoreticular cells of each other's type, they become lymphoreticular chimeras in utero and immune rejection does not occur. One natural and three sets of twins produced by embryo transfer were studied in Pompe's disease cattle. Chimerism persisted throughout life and the situation was analogous to a transplant of histocompatible bone marrow stem cells. The activity of acid alpha-glucosidase in leucocytes and in biopsies of the semitendinosus muscle and the mean activity in diaphragm, spleen and lymph node obtained after death from affected twins were significantly higher than in single affected calves. Glycogen concentration was lowered in liver, spleen and lymph node but not in muscles. The affected twins showed clinical signs and changes in muscle similar to those seen in affected single calves. It is concluded that bone marrow transplantation is unlikely to be a successful treatment for Pompe's disease.

Rat skeletal muscle lysosomes contain glycogen

1. A lysosome- and mitochondria-enriched fraction was obtained from rat skeletal muscle using a differential centrifugation procedure. This fraction contained a proportion (3-4%) of the tissue glycogen content. 2. Lysosomes and mitochondria were separated from one another by centrifugation of a cell-free extract upon discontinuous Ficoll-sucrose gradients. Little glycogen was associated with the resulting mitochondrial fraction. The lysosomal fraction, however, contained a significant amount of glycogen, accounting for 5% of the skeletal muscle glycogen. 3. The lysosomal glycogen was purified and found to be enriched in high molecular weight material. 4. The compartmentation of skeletal muscle glycogen metabolism is suggested.

Bovine glycogenosis type II. Biochemical and morphological characteristics of skeletal muscle in culture

The biochemical and morphological properties of cultured skeletal muscle from calves born into a herd of cattle, which are heterozygous for glycogenosis type II, were studied over 17 days. Muscle was cultured by a modification of the explant technique in which the mononucleated cells that grew from the explants were subcultured. Skeletal muscle from animals up to 15 months of age grew in culture to produce mature, cross-striated and spontaneously contractile myotubes. The creatine kinase activity was 310 (+/- 45.4) mU/mg protein on day 7 when fusion was complete, and 210 (+/- 15.1) mU/mg protein on day 17 of culture. Mature muscle cultures from animals affected by glycogenosis type II showed the characteristic biochemical and morphological abnormalities previously observed in vivo. Acid alpha-glucosidase activity was absent whereas the activities of neutral alpha-glucosidase, lysosomal alpha-mannosidase and creatine kinase were the same as in cultures of unaffected muscle. The concentration of glycogen was higher in cultured affected muscle than in cultured unaffected muscle. On days 7, 9 and 17 of culture the glycogen concentrations were 66.7 (+/- 2.7), 89.0 (+/- 5.5) and 120.3 (+/- 34.2) micrograms/mg protein respectively in affected muscle and 51.8 (+/- 3.6), 59.9 (+/- 5.4) and 55.4 (+/- 1.0) micrograms/mg protein respectively in non-affected muscle. Electron microscopic studies showed that the glycogen accumulated within the lysosomes. These results indicate that bovine glycogenosis type II is expressed in tissue culture since the cultured skeletal muscle from affected animals shows the same abnormalities as skeletal muscle in vivo.