Dystrophy In Man Research Articles

P.343 - Xenografts of human myogenic cells into mice form pure human muscle: a new model for FSHD

Facioscapulohumeral Muscular Dystrophy (FSHD) is one of the most common muscular dystrophies in man, with a prevalence of 1 in ~8,000 individuals worldwide. Studies of the pathogenic mechanisms underlying human myopathies and muscular dystrophies often require animal models, but a model that recapitulates the signature pathophysiology of FSHD is not yet available. Our laboratory has developed a novel mouse model for FSHD. We optimized methods to xenograft immortalized human muscle precursor cells (hMPCs) to promote the formation of mature human myofibers following implantation into the hindlimbs of NOD-Rag1nullIL2rγnull immune-deficient mice. Specifically, intermittent neuromuscular electrical stimulation (iNMES) increases the number and size of the engrafted human myofibers, and decreases the distances between the largest fibers and their neighbours. Some grafts are comprised of only human myofibers, >1000 in all, with no murine fibers remaining. The human myofibers are innervated, their contractile apparatus is fully differentiated, and they are comprised of human myonuclei, with minimal contamination by murine myonuclei. We used these methods to generate mature human muscle tissue from immortalized FSHD and control hMPCs. FSHD but not control xenografts express DUX4 and several downstream gene products, such as ZSCAN4 and TRIM43. Furthermore, the FSHD grafts but not controls have D4Z4 repeats that are hypomethylated. Our results are consistent with the properties of biopsies of FSHD and healthy muscles. Thus, our methods provide a novel tool for studying FSHD-derived human muscle under controlled conditions within the mouse hindlimb and for testing new therapeutic agents in vivo.

Muscular Dystrophy in a Dog Resembling Human Becker Muscular Dystrophy

A 3-year-old, male Labrador retriever dog was presented with clinical signs of progressive exercise intolerance, bilateral elbow extension, rigidity of the forelimbs, hindlimb flexion and kyphosis. Microscopical examination of muscle tissue showed marked variability in myofibre size, replacement of muscle with mature adipose tissue and degeneration/regeneration of muscle fibres, consistent with muscular dystrophy. Immunohistochemical examination for dystrophin showed markedly reduced labelling with monoclonal antibodies specific for the rod domain and the carboxy-terminal of dystrophin, while expression of β-sarcoglycan, γ-sarcoglycan and β-dystroglycan was normal. Immunoblotting revealed a truncated dystrophin protein of approximately 135 kDa. These findings supported a diagnosis of congenital canine muscular dystrophy resembling Becker muscular dystrophy in man.

AGE‐RELATED THORACIC RADIOGRAPHIC CHANGES IN GOLDEN AND LABRADOR RETRIEVER MUSCULAR DYSTROPHY

Golden retriever and Labrador retriever muscular dystrophy are inherited progressive degenerative myopathies that are used as models of Duchenne muscular dystrophy in man. Thoracic lesions were reported to be the most consistent radiographic finding in golden retriever dogs in a study where radiographs were performed at a single-time point. Muscular dystrophy worsens clinically over time and longitudinal studies in dogs are lacking. Thus our goal was to describe the thoracic abnormalities of golden retriever and Labrador retriever dogs, to determine the timing of first expression and their evolution with time. To this purpose, we retrospectively reviewed 390 monthly radiographic studies of 38 golden retrievers and six Labrador retrievers with muscular dystrophy. The same thoracic lesions were found in both golden and Labrador retrievers. They included, in decreasing frequency, flattened and/or scalloped diaphragmatic shape (43/44), pulmonary hyperinflation (34/44), hiatal hernia (34/44), cranial pectus excavatum (23/44), bronchopneumonia (22/44), and megaesophagus (14/44). The last three lesions were not reported in a previous radiographic study in golden retriever dogs. In all but two dogs the thoracic changes were detected between 4 and 10 months and were persistent or worsened over time. Clinically, muscular dystrophy should be included in the differential diagnosis of dogs with a combination of these thoracic radiographic findings.

Distinct Effects of Contraction-Induced InjuryIn Vivoon Four Different Murine Models of Dysferlinopathy

Mutations in the DYSF gene, encoding dysferlin, cause muscular dystrophies in man. We compared 4 dysferlinopathic mouse strains: SJL/J and B10.SJL-Dysfim/AwaJ (B10.SJL), and A/J and B6.A-Dysfprmd/GeneJ (B6.A/J). The former but not the latter two are overtly myopathic and weaker at 3 months of age. Following repetitive large-strain injury (LSI) caused by lengthening contractions, all except B6.A/J showed ~40% loss in contractile torque. Three days later, torque in SJL/J, B10.SJL and controls, but not A/J, recovered nearly completely. B6.A/J showed ~30% torque loss post-LSI and more variable recovery. Pre-injury, all dysferlinopathic strains had more centrally nucleated fibers (CNFs) and all but A/J showed more inflammation than controls. At D3, all dysferlinopathic strains showed increased necrosis and inflammation, but not more CNFs; controls were unchanged. Dystrophin-null DMDmdx mice showed more necrosis and inflammation than all dysferlin-nulls. Torque loss and inflammation on D3 across all strains were linearly related to necrosis. Our results suggest that (1) dysferlin is not required for functional recovery 3 days after LSI; (2) B6.A/J mice recover from LSI erratically; (3) SJL/J and B10.SJL muscles recover rapidly, perhaps due to ongoing myopathy; (4) although they recover function to different levels, all 4 dysferlinopathic strains show increased inflammation and necrosis 3 days after LSI.

Genetic aspects of labrador retriever myopathy

Labrador Retriever myopathy (LRM) has become a relatively common muscular disease. The objective of our prospective study was to determine by segregation analyses a plausible mode of inheritance within a Labrador Retriever population. Therefore we performed neurological examinations, as well as electromyographic and histopathological evaluations of 58 closely related dogs. Seven dogs with an average age of 27.8 months had clinical signs consistent with LRM including exercise intolerance or fatigue. The diagnosis was based on neurological deficits and confirmed by histopathological results of muscle biopsy. We found in all cases obvious differences in fiber calibre size associated with texture disturbances. In addition, we found 41 clinically normal dogs with histological findings consistent with LRM. Three genetic models, the major gene, the mixed inheritance as well as the environmental model, were evaluated by segregation analyses. They were applied to an extended pedigree including 164 non-randomly ascertained related Labradors. According to phenotype the clinically examined dogs were divided into two different data sets. One data set distinguished between clinically normal and abnormal dogs, the second data set between histopathologically normal and abnormal dogs. We concluded that the clinical form of LRM is transmitted by a major gene and controlled by an autosomal recessive mode of inheritance. Furthermore, for expression of the subclinical form an additional gene or an environmental factor is responsible. Our findings suggest that LRM is similar to limb-girdle muscular dystrophy in man and therefore, may be used in the future as an animal model.

Animal models of human retinal dystrophies.

Naturally occurring retinal dystrophies in laboratory and companion animals represent a wealth of different conditions, some of which are important from a comparative point of view, and all of which offer opportunities to further the understanding of retinal function and reaction in health and disease. The study of animal models of retinal dystrophies has provided candidate genes for investigation in conditions of man such as retinitis pigmentosa and has also led to the identification of new genes and even new families of genes. Mutations in the gene for the beta subunit of cyclic GMP phosphodiesterase cause retinal dystrophies in man, mice and dog, and mutations in the gene for the structural protein peripherin/RDS result in a retinal dystrophy in the mouse and a spectrum of differing retinal dystrophies in man. Animals with homologous retinal dystrophies to man may make useful models for investigation of treatment either by drugs or by gene therapy. Furthermore the use of transgenics and gene targeting in laboratory mice offers the opportunity to create new models of human retinal dystrophies and also to investigate the effect of gene dysfunction.

Structure and function of basement membranes.

The importance of basement membranes in development and adult tissue function has been inferred from a number of observations. Cells migrate along basement membranes during development, basement membranes are required for the polarization of cells in both the embryo and the adult, and basement membranes serve as substrates for cell adhesion and migration during wound healing and nerve regeneration. The importance of basement membranes in adult tissue function has been directly demonstrated by the genetic diseases caused by mutations in the genes for structural basement membrane components. Examples of such diseases are Alport syndrome and junctional epidermolysis bullosa. Recently, defects in the major laminin variant in muscle, merosin, has been shown to be correlated with muscular dystrophies in man and animals. We are using the dystrophic mutant mouse dy, which lacks laminin-2, to analyze the function of laminin-2 in different tissues. Studies of laminin defects in animals and humans are expected to give new information on the function of basement membrane in general and on laminin in particular. Such information may give directions for future diagnosis and treatment of diseases involving basement membranes.

A new inherited muscular disorder in Japanese quails (Coturnix coturnix japonica).

Thirteen adult mutant (LWC strain) Japanese quails (Coturnix coturnix japonica), between the ages of 8 and 60 weeks were examined for a progressive muscular disorder. The disorder, inherited as an autosomal dominant trait, was clinically apparent as early as 28 days of age; it was characterized by generalized myotonia, muscle stiffness, and muscle weakness. Affected birds were identified by their inability to lift their wings vertically upward and by their inability to right themselves when placed on their dorsum. Electromyographic studies in two mutant quails showed high-frequency repetitive discharges comparable to those of myotonic runs. These discharges persisted after nerve resection. The distinctive histopathologic changes in the various muscles examined were ring fibers, sarcoplasmic masses, and internal migration of sarcolemmal nuclei. A slight decrease in the size of type IIB muscle fibers and a slight increase in the size of type IIA fibers were observed in the M. pectoralis thoracicus of affected quails. In older affected birds, inter- and intrafascicular fatty infiltration with replacement of type IIB fibers by fat cells was seen in the pectoral muscles. Single fiber necrosis, nonspecific lymphorrages, and variations in the muscle fiber size and shape were also noted. The typical muscle lesions and multisystem involvement, which was manifested by testicular degeneration and atrophy in the male LWC specimens and bilateral lenticular cataracts in 6 of 13 affected mutant quails, suggest resemblance of this new inherited muscular disorder to myotonic dystrophy in man.

Canine X‐linked muscular dystrophy as an animal model of Duchenne muscular dystrophy: A review

Canine X-linked muscular dystrophy is a spontaneously occurring, progressive, degenerative myopathy of dogs that is clinically and pathologically similar to Duchenne muscular dystrophy in man. The molecular basis for the disease has been shown to be a lack of dystrophin, the protein product of the Duchenne muscular dystrophy gene. Breeding colonies of dystrophic dogs have been established. This report reviews the findings of genetic, clinical, pathologic, molecular biologic, and immunocytochemical studies of the canine model, and compares the features of the canine disease to those of Duchenne dystrophy in man.

Muscular dystrophy-like disease in a thoroughbred foal

A 1-month-old male thoroughbred foal, which had difficulty in walking, was killed and examined by histological, histochemical and ultrastructural methods. The muscles of the trunk and upper hind limbs were chiefly affected, and changes in the affected muscles resembled those in muscular dystrophy in man. The type of muscular dystrophy present in this foal and the significance of this disease in thoroughbred horses are discussed. The dystrophy in this foal resembled the limb-girdle type or myotonic dystrophy of muscular dystrophy in man.

Regenerating myofibers in tibialis anterior muscles of young ‘MDX’ mice

A recently discovered mouse model (‘mdx’) for muscular dystrophy in man may be of considerable interest, since the disease in ‘mdx’ mice is inherited by the same mode of inheritance (X-linked) as the human Duchenne (DMD) muscular dystrophy. Unlike DMD, which results in a situation in which the continual muscle destruction cannot keep up with abortive regenerative attempts of the musculature, and the sufferers of the disease die early, the disease in ‘mdx’ mice appears to be transient, and the mice do not die as a result of it. In fact, it has been reported that the severely damaged Tibialis anterior (TA) muscles of ‘mdx’ mice seem to display exceptionally good regenerative powers at 4-6 weeks, so much so, that these muscles are able to regenerate spontaneously up to their previous levels of physiological activity.

Localization of the region homologous to the Duchenne muscular dystrophy locus on the mouse X chromosome.

Recent progress has resulted in part of the gene mutated in Duchenne and the milder Becker muscular dystrophies being cloned and has suggested that the gene itself extends over 1,000 to 2,000 kilobases (kb). To study how mutations in this gene affect muscle development and integrity, it would be of interest to have available a mouse model of the human disease. The mouse mdx mutation affects muscle and confers a mild dystrophic syndrome, but it is not clear whether this mutation is equivalent to Duchenne/Becker muscular dystrophy in man. Here we describe the use of two sequences from the human Duchenne muscular dystrophy (DMD) gene that cross-hybridize to mouse X-linked sequences to localize the gene homologous to DMD in the mouse. Both sequences map to the region of 10 centimorgan lying between the Tabby (Ta) and St14-1 (DxPas8) loci, close to the phosphorylase b kinase locus (Phk). By analogy with the human X-chromosome, we conclude that the region in the mouse around the G6pd and St14-1 loci may contain two genes corresponding to distinct human myopathies: Emery Dreifuss muscular dystrophy which is known to be closely linked to St14-1 in man and the DMD homologue described here.

Ca2-activated proteinases, protein degradation and muscular dystrophy.

Progressive muscular dystrophies in man are characterised by muscle degeneration and weakness. A gradual loss of muscle tissue takes place until, in the late stages of most dystrophies (and particularly in the X-linked Duchenne type), very little functional muscle remains. During necrosis, there is a marked loss of both myofibrillar and soluble proteins from the muscle fibres. While the underlying causes may in part be related to membrane defects (1), alterations in protein turnover in the muscle tissue must be involved in the development of the condition to some extent. The level of protein in any tissue is determined, under steady state conditions, as a balance between the rate of protein synthesis and its rate of degradation. The observed loss of muscle mass in wasting disorders would appear then to be explained most readily by an increase in the rate of protein degradation and, indeed, such measurements have been made in patients with Duchenne dystrophy (2). However, the same net effect i.e. muscle degeneration, can be achieved as a result of a diminished rate of protein synthesis in muscle and very recently, measurements made in vivo with dystrophic boys have suggested that in all types of dystrophy, muscle protein synthesis is depressed and that there is little change in protein breakdown from the rates observed with unafflicted male patients (3).KeywordsMuscular DystrophyDuchenne DystrophyMuscle Protein SynthesisNeutral ProteaseProtein BreakdownThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Oval lipid corneal opacities in beagles: VI. Quantitation of excess stromal cholesterol and phospholipid

We identified and quantitated the following lipids in corneas of normolipemic beagles that had oval corneal opacities: total lipids, cholesterol esters, free cholesterol, total phospholipids, phosphatidyl choline, phosphatidyl ethanolamine, sphingomyelin and total triacylglycerols. All except the total triacylglycerols were significantly higher in the 20 affected corneas than in ten normal age and sex-matched controls ( P < 0·005 for each). Few long-chain unsaturated fatty acids were detected. This lipid analysis and the previously reported natural history, ultrastructure, and histochemistry indicate that these opacities result from a primary disorder of corneal lipid metabolism that closely resembles central crystalline corneal dystrophy in man.

PHARMACOLOGIC THERAPY OF DYSTROPHY IN MAN AND ANIMALS

PHARMACOLOGIC THERAPY OF DYSTROPHY IN MAN AND ANIMALS

PHARMACOLOGIC THERAPY OF DYSTROPHY IN MAN AND ANIMALS *

PHARMACOLOGIC THERAPY OF DYSTROPHY IN MAN AND ANIMALS *

Beneficial effects of penicillamine treatment on hereditary avian muscular dystrophy.

Hereditary muscular dystrophy in chickens of the New Hampshire strain was treated with penicillamine from the 9th day after hatching to the 425th day. The adult maintenance dose for males was 50 mg/kg per day and for females, 13-65 mg/kg per day. In avian dystrophy, deterioration of the muscle fibers is evidenced in the 2nd mo by an inability of the birds to rise after falling on their backs and by a progressive rigidity of the wings. The drug delayed the onset of symptoms and partially alleviated the debilitating aspects of the disease. Penicillamine produced three major improvements: (a) better righting ability when birds were placed on their backs; (b) greater wing flexibility; (c) and suppression of plasma creatine phosphokinase activity. The results are statistically analyzed and discussed in relationship to Duchenne dystrophy. Normal birds were not affected by penicillamine as judged by these parameters. The rationale for using penicillamine, a sulfhydryl compound with reducing properties, was (a) to attempt to protect essential thiol enzymes in the anabolic and glycolytic pathways against inactivation and (b) to prevent collagen cross-linking and deposition in muscle. Although the precise mechanism of drug action has not been determined. the possible role of penicillamine in mitigating the symptoms of genetic dystrophy in man is under consideration. Further, penicillamine may have a more generalized application i the prevention of contractures in a variety of neuromuscular disorders.

Neuroaxonal dystrophy in man: character and natural history.

A short correlative review is given of the light and electron microscopical features and histochemical reactions of dystrophic axons in the mature human CNS. Their ultrastruc- tural similarities to axonal changes in the disease entity of the neuroaxonal dystrophies and various experimental conditions are confirmed. The incidence of axonal spheroids in the gracile and cuneate nuclei and in the reticular zone of the substantia nigra was studied in 1450 consecutive autopsies and correlated with age and underlying disease process. Axonal dystrophy of posterior column nuclei and substantia nigra showed a significant age-dependancy without predilection for either sex. The incidence of dystrophic axons in the globus pallidus and other sites was also examined. No clear relationship of the severity and frequency of the involvement of gracile nucleus with any underlying disease was established, while axonal dystrophy in substantia nigra showed significant correlations to alcoholic encephalopathies and Parkinson’s syndrome, and a trend to negative relationship with presenile cerebral atrophies. In addition to the natural occurrence of dystrophic axons as a physiological, age-dependant phenomenon, these lesions may arise prematurely and to excess in a variety of natural and experimental disorders. The reported findings suggest that some metabolic factors are involved in the pathogenesis of dystrophic axonal changes. Relations to axonal dying-back processes are discussed.

Catecholamine distribution in mice afflicted with muscular dystrophy.

ARTICLESCatecholamine distribution in mice afflicted with muscular dystrophyP Gordon, and RM DowbenP Gordon, and RM DowbenPublished Online:01 Apr 1966https://doi.org/10.1152/ajplegacy.1966.210.4.728MoreSectionsPDF (1 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformation Cited ByMonoamine oxidase inhibition prevents mitochondrial dysfunction and apoptosis in myoblasts from patients with collagen VI myopathiesFree Radical Biology and Medicine, Vol. 75Oxidative stress in muscular dystrophy: from generic evidence to specific sources and targets12 March 2014 | Journal of Muscle Research and Cell Motility, Vol. 35, No. 1Adverse Effects of Drugs on the Respiratory MusclesClinics in Chest Medicine, Vol. 11, No. 1Serotonin uptake in blood platelets of duchenne muscular dystrophy patientsMuscle & Nerve, Vol. 10, No. 4The influence of ketanserin, a new S2 receptor antagonist on experimentally induced skeletal muscle myopathy in the ratVirchows Archiv A Pathological Anatomy and Histology, Vol. 393, No. 3The pattern of urinary catecholamines and their metabolites in Duchenne myopathy, in relation to disease evolutionJournal of Neural Transmission, Vol. 46, No. 1Insulin secretion and carbohydrate metabolism in the dystrophic mouseEuropean Journal of Pharmacology, Vol. 53, No. 4BIOCHEMICAL STUDIES IN DYSTROPHIC MOUSE MUSCLEAnnals of the New York Academy of Sciences, Vol. 317, No. 1 Muscular DystENDOCRINE PANCREAS IN THE DYSTROPHIC MOUSEAnnals of the New York Academy of Sciences, Vol. 317, No. 1 Muscular DystPHARMACOLOGIC THERAPY OF DYSTROPHY IN MAN AND ANIMALSAnnals of the New York Academy of Sciences, Vol. 317, No. 1 Muscular DystA possible change in the rate-limiting step for cardiac norepinephrine synthesis in the cardiomyopathic Syrian hamster.Circulation Research, Vol. 41, No. 6Effects of serotonin antagonists on the development of inherited muscular dystrophy in the chickenExperimental Neurology, Vol. 55, No. 3Monoamine oxidase activity in normal and dystrophic human muscleClinica Chimica Acta, Vol. 50, No. 3Platelet diphenoloxidases in Progressive Muscular Dystrophy (P.M.D.)23 April 2008 | Clinical Genetics, Vol. 4, No. 2REFERENCESDie Biochemie der progressiven MuskeldystrophieREGIONAL DISTRIBUTION OF CATECHOLAMINES IN THE HEARTS OF VARIOUS SPECIESAnnals of the New York Academy of Sciences, Vol. 156, No. 1 ExperimentalMicrocirculation: Loss of an Enzyme Activity in Chickens with Hereditary Muscular DystrophyScience, Vol. 160, No. 3825Morphologic changes in skeletal muscle induced by serotonin treatment:Experimental and Molecular Pathology, Vol. 7, No. 2 More from this issue > Volume 210Issue 4April 1966Pages 728-732 Copyright & PermissionsCopyright © 1966 by American Physiological Societyhttps://doi.org/10.1152/ajplegacy.1966.210.4.728PubMed5906801History Published online 1 April 1966 Published in print 1 April 1966 Metrics

LIPID COMPOSITION OF THE PECTORAL MUSCLES OF CHICKENS WITH INHERITED MUSCULAR DYSTROPHY.

Asmundson and Julian (1,2) reported the presence of a recessive autosomal gene (am) in New Hampshire chickens which produces in the homozygous bird a condition quite similar to certain forms of muscular dystrophy in man(3). The superficial pectoral muscles of such adult birds contained considerably more fat than those of normal birds (4,5). Elevated fat content has also been found in certain muscles of mice with muscular dystrophy by Shull and Alfm-Slater(6) and in some types of muscular dystrophy in man (3). This investigation was undertaken to determine the nature of the fat deposited intramuscularly in chickens with inherited muscular dystrophy. An increase in the triglyceride fraction and a decrease in the phospholipid fraction relative to other lipids constitute the major differences in the dystrophic muscle when compared with the normal muscle. Methods. Seven pairs of 36-week-old normal and muscular dystrophic female New Hampshire birds were used in the study. The animals were sacrificed and the left superficial pectoral muscles were excised, quick-frozen in a dry ice-acetone bath and stored at —20°C. They were thawed and used as needed. A 0.5-0.8 sample g of wet muscle was placed in a vacuum oven at 70° for 12 hours to determine the moisture content by weight difference. Protein was determined by the Kjeldahl method (N × 6.25) and hydroxyproline was determined by the technique of Neuman and Logan(7). The hydroxyproline content was used as a measure of collagen or connective tissue. The fat was extracted from the muscle by the CHCl3:CH3OH:H2O method of Bligh and Dyer(8). The CHCl3 layer containing the lipid, was evaporated in a 60° C water bath under a stream of N2. Approximately 70 mg of this fat was chromatographed on a 3.0 g silicic acid-Hiflo Supercell column (70: 30 w/w), and eluted by the scheme of Barron and Hanahan(9).