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Open Life Sciences Jan 2019The sialylation of the glycoproteins in skeletal muscle tissue is not well investigated, even though the essential role of the sialic acids for the proper muscular...
The sialylation of the glycoproteins in skeletal muscle tissue is not well investigated, even though the essential role of the sialic acids for the proper muscular function has been proven by many researchers. The invasion of the parasitic nematode in the muscles with subsequent formation of Nurse cell-parasite complex initiates increased accumulation of sialylated glycoproteins within the affected area of the muscle fiber. The aim of this study is to describe some details of the α-2,6-sialylation in invaded muscle cells. Asynchronous invasion with infectious larvae was experimentally induced in mice. The areas of the occupied sarcoplasm were reactive towards α-2,6-sialic acid specific agglutinin during the whole process of transformation to a Nurse cell.The cytoplasm of the developing Nurse cell reacted with agglutinin, agglutinin and lectin-B4 after neuraminidase pretreatment.Up-regulation of the enzyme ST6GalNAc1 and down-regulation of the enzyme ST6GalNAc3 were detected throughout the course of this study. The results from our study assumed accumulation of sialyl-Tn-Ag, 6`-sialyl lactosamine, SiA-α-2,6-Gal-β-1,3-GalNAc-α-Ser/Thr and Gal-β-1,3-GalNAc(SiA-α-2,6-)-α-1-Ser/Thr oligosaccharide structures into the occupied sarcoplasm. Further investigations in this domain will develop the understanding about the amazing adaptive capabilities of skeletal muscle tissue.
PubMed: 33817183
DOI: 10.1515/biol-2019-0053 -
Nature Medicine Nov 2020Ribonucleoprotein (RNP) granules are biomolecular condensates-liquid-liquid phase-separated droplets that organize and manage messenger RNA metabolism, cell signaling,...
Ribonucleoprotein (RNP) granules are biomolecular condensates-liquid-liquid phase-separated droplets that organize and manage messenger RNA metabolism, cell signaling, biopolymer assembly, biochemical reactions and stress granule responses to cellular adversity. Dysregulated RNP granules drive neuromuscular degenerative disease but have not previously been linked to heart failure. By exploring the molecular basis of congenital dilated cardiomyopathy (DCM) in genome-edited pigs homozygous for an RBM20 allele encoding the pathogenic R636S variant of human RNA-binding motif protein-20 (RBM20), we discovered that RNP granules accumulated abnormally in the sarcoplasm, and we confirmed this finding in myocardium and reprogrammed cardiomyocytes from patients with DCM carrying the R636S allele. Dysregulated sarcoplasmic RBM20 RNP granules displayed liquid-like material properties, docked at precisely spaced intervals along cytoskeletal elements, promoted phase partitioning of cardiac biomolecules and fused with stress granules. Our results link dysregulated RNP granules to myocardial cellular pathobiology and heart failure in gene-edited pigs and patients with DCM caused by RBM20 mutation.
Topics: Alleles; Animals; Cardiomyopathy, Dilated; Cellular Reprogramming; Disease Models, Animal; Female; Gene Editing; Humans; Male; Mutation; Myocardium; Myocytes, Cardiac; RNA, Messenger; RNA-Binding Proteins; Ribonucleoproteins; Sarcoplasmic Reticulum; Secretory Vesicles; Swine
PubMed: 33188278
DOI: 10.1038/s41591-020-1087-x -
Romanian Journal of Morphology and... 2012We present the case of a female patient, aged 12 years, with fatigability and exertional myalgias, progressively developed within the last two years. Negative family...
We present the case of a female patient, aged 12 years, with fatigability and exertional myalgias, progressively developed within the last two years. Negative family history, as well as negative personal medical history, were found. At physical examination, short stature, proximal muscle weakness and mild hepatomegaly were noted. Urine ketones level was slightly decreased, serum transaminases, creatine kinase and lactate dehydrogenase levels were increased. Electromyographical examination showed a myopathic non-specific pattern. Deltoid muscle biopsy revealed: small, clear vesicles are present on Hematoxylin-Eosin and modified Gömöri trichrome stains; modified Gömöri trichrome stain also revealed muscle fibers (especially type I of muscle fibers) having mild to moderate mitochondrial proliferation (red rim and speckled sarcoplasm). The lipid storage has been well demonstrated by Sudan Black stain, which revealed small lipid droplets in type I muscle fibers. Abnormal internal architecture with a punctate pattern was showed by adenine dinucleotide tetrazolium reductase and succinate dehydrogenase stains. Electron microscopy showed small inter-myofibrillar accumulations of round, amorphous, homogeneous acellular substances that are not membrane bounded. These features indicate that these are neutral fat (lipid) droplets. Subsarcolemmal accumulations of mitochondria were also revealed. The differential diagnosis of this case is discussed, and the up to date general data concerning carnitine deficiency are presented. The aim of our case-report is to emphasize the role of muscle biopsy in carnitine deficiency, as well as to remind the necessity of keeping in mind such metabolic disorders when doing the differential diagnostic of a muscular weakness.
Topics: Biopsy; Carnitine; Child; Diagnosis, Differential; Disease Progression; Electromyography; Female; Hepatomegaly; Humans; Lipids; Microscopy, Electron; Mitochondria; Muscle Weakness; Muscles; Muscular Diseases
PubMed: 22395524
DOI: No ID Found -
Food Chemistry Mar 2024This study aimed to investigate the effect of magnetic fields (0, 3, 6, 12 mT) on the oxidation characteristics of myoglobin (Mb) in the sarcoplasmic protein (SP) system...
This study aimed to investigate the effect of magnetic fields (0, 3, 6, 12 mT) on the oxidation characteristics of myoglobin (Mb) in the sarcoplasmic protein (SP) system and to understander the underlying mechanism. The metmyoglobin content, Soret band of heme iron porphyrin, protein conformation and molecular weight distribution were measured in different Mb and SP samples. The results showed that the primary oxidation site of hydroxyl radical on Mb was likely to be the porphyrin ring structure and the side chain group of protein rather than the central iron atoms, what's more, 12 mT magnetic field treatment had an inhibitory effect on the oxidative damage induced by hydroxyl radical.
Topics: Myoglobin; Hydroxyl Radical; Metmyoglobin; Oxidation-Reduction; Iron; Oxidative Stress; Porphyrins; Magnetic Fields
PubMed: 37837684
DOI: 10.1016/j.foodchem.2023.137691 -
Current Rheumatology Reports Jul 2021To review recent advances in immunopathology for idiopathic inflammatory myopathies, focusing on widely available immunohistochemical analyses. (Review)
Review
PURPOSE OF REVIEW
To review recent advances in immunopathology for idiopathic inflammatory myopathies, focusing on widely available immunohistochemical analyses.
RECENT FINDINGS
Sarcoplasmic expression of myxovirus resistance protein A (MxA) is specifically observed in all types of dermatomyositis and informs that type I interferons are crucially involved in its pathogenesis. It is a more sensitive diagnostic marker than perifascicular atrophy. Diffuse tiny dots in the sarcoplasm highlighted by p62 immunostaining are characteristically seen in immune-mediated necrotizing myopathy. This feature is linked to a chaperone-assisted selective autophagy pathway. Myofiber invasion by highly differentiated T cells, a marker of which is KLRG1, is specific to inclusion body myositis and has a crucial role in its pathogenesis. The recent advances in immunopathology contribute to increased diagnostic accuracy and a better understanding of the underlying pathophysiology in different types of idiopathic inflammatory myopathies.
Topics: Autoimmune Diseases; Biomarkers; Dermatomyositis; Humans; Myositis; Myositis, Inclusion Body
PubMed: 34212266
DOI: 10.1007/s11926-021-01017-7 -
The Journal of Experimental Biology Jun 2003The heart and those striated muscles that contract for long periods, having available almost limitless oxygen, operate in sustained steady states of low sarcoplasmic... (Review)
Review
The heart and those striated muscles that contract for long periods, having available almost limitless oxygen, operate in sustained steady states of low sarcoplasmic oxygen pressure that resist change in response to changing muscle work or oxygen supply. Most of the oxygen pressure drop from the erythrocyte to the mitochondrion occurs across the capillary wall. Within the sarcoplasm, myoglobin, a mobile carrier of oxygen, is developed in response to mitochondrial demand and augments the flow of oxygen to the mitochondria. Myoglobin-facilitated oxygen diffusion, perhaps by virtue of reduction of dimensionality of diffusion from three dimensions towards two dimensions in the narrow spaces available between mitochondria, is rapid relative to other parameters of cell respiration. Consequently, intracellular gradients of oxygen pressure are shallow, and sarcoplasmic oxygen pressure is nearly the same everywhere. Sarcoplasmic oxygen pressure, buffered near 0.33 kPa (2.5 torr; equivalent to approximately 4 micro mol l(-1) oxygen) by equilibrium with myoglobin, falls close to the operational K(m) of cytochrome oxidase for oxygen, and any small increment in sarcoplasmic oxygen pressure will be countered by increased oxygen utilization. The concentration of nitric oxide within the myocyte results from a balance of endogenous synthesis and removal by oxymyoglobin-catalyzed dioxygenation to the innocuous nitrate. Oxymyoglobin, by controlling sarcoplasmic nitric oxide concentration, helps assure the steady state in which inflow of oxygen into the myocyte equals the rate of oxygen consumption.
Topics: Animals; Diffusion; Electron Transport Complex IV; Heart; Muscle, Skeletal; Myoglobin; Oxygen; Sarcolemma
PubMed: 12756283
DOI: 10.1242/jeb.00243 -
Tsitologiia Feb 1968
Review
Topics: Microscopy, Fluorescence; Microscopy, Polarization; Muscles; Staining and Labeling; Viscosity
PubMed: 4179124
DOI: No ID Found -
Tissue & Cell Aug 2004Previous investigations of the T-system in skeletal muscle fibres described the inter-myofibrillar relationships between T-tubules and the sarcoplasmic reticulum. They...
Previous investigations of the T-system in skeletal muscle fibres described the inter-myofibrillar relationships between T-tubules and the sarcoplasmic reticulum. They disregarded the arrangement of the T-system in the myofibril-free sarcoplasm in the area of muscle fibre nuclei. In the present investigation, the T-system was filled by means of lanthanum incubation and the myofibril-free sarcoplasm was ultrastructural examined by means of thin (< or = 100 nm) as well as thick sections (> 300 nm-1 microm) with the electron microscope. The investigation of thick sections revealed that T-tubules meander through this myofibril-free sarcoplasm and tangle up at the poles of muscle fibre nuclei and in the area of fundamental nuclei of the motor end plate. They are, far from myofibrils, in proximity to these nuclei, the Golgi apparatus and mitochondria. On basis of this proximity and their openings at the muscle fibre surface, a contribution at the drainage of metabolic products and at the local calcium control is discussed.
Topics: Animals; Cell Nucleus; Mitochondria, Muscle; Motor Endplate; Rana temporaria; Sarcomeres; Sarcoplasmic Reticulum
PubMed: 15261743
DOI: 10.1016/j.tice.2004.03.004 -
European Neurology 2000The expression of thrombomodulin and neural cell adhesion molecule (NCAM) was studied immunocytochemically in biopsied muscle specimens from 10 patients with...
The expression of thrombomodulin and neural cell adhesion molecule (NCAM) was studied immunocytochemically in biopsied muscle specimens from 10 patients with rhabdomyolysis with different etiologic factors, including 5 with malignant hyperthermia. We have already reported that thrombomodulin was expressed on regenerating muscle cell membranes as well as on vessel walls in patients with various neuromuscular diseases, including Duchenne muscular dystrophy, Becker muscular dystrophy and inflammatory myopathy. We found increased expression of thrombomodulin not only on the sarcolemma, but also in the sarcoplasm of a fair number of muscle fibers in the acute phase of rhabdomyolysis. The granular pattern of thrombomodulin expression in the sarcoplasm seems to be a characteristic finding in the acute phase of rhabdomyolysis. Most muscle fibers which expressed NCAM on the sarcolemma also expressed thrombomodulin. However, the muscle fibers which expressed thrombomodulin in the sarcoplasm did not express NCAM, and showed a degenerative appearance on electron microscopic examination. These results suggest that thrombomodulin is expressed in the sarcoplasm during the acute degeneration phase of rhabdomyolysis in addition to the expression on the sarcolemma during the muscle fiber regeneration as shown in our previous study, and the former process, which is characterized by the granular expression of thrombomodulin in the sarcoplasm, may be a characteristic finding in rhabdomyolysis.
Topics: Adolescent; Adult; Biopsy; Child; Child, Preschool; Cytoplasm; Female; Humans; Male; Malignant Hyperthermia; Microscopy, Electron; Middle Aged; Muscle, Skeletal; Neural Cell Adhesion Molecules; Neuromuscular Diseases; Rhabdomyolysis; Sarcolemma; Thrombomodulin
PubMed: 10765059
DOI: 10.1159/000008159