OBJECTIVETo investigate the clinical and lab features of sibling brother and sister both with Duchenne muscular dystrophy (DMD).

METHODSWe conducted comprehensive clinical and lab investigations including the test of serum enzymes, electromyography (EMG), electrocardiography, color Doppler echocardiography, HE staining of skeletal muscles, immunohistochemical study of dystrophin and utrophin, multiple ligation probe amplification (MLPA) on exon 1-79 of dystrophin gene, and short tandem repeat-poly- merase chain reaction of CA repeats located in dystrophin gene.

RESULTSThese two patients were confirmed to suffer from DMD. They were characterized by typical features of DMD including typical clinical manifestations, increased serum enzymes, EMG presenting myogenic impairment, HE staining presentation belonging to DMD, negative dystrophin in brother, and inconstantly positive on the sarcolemma of sister. Furthermore, no deletion or duplication was found in the 1-79 exons of dystrophin gene. The suffering brother and sister carried the same maternal X chromosome.

CONCLUSIONSCarriers of DMD gene show typical clinical and laboratory manifestations of DMD. Comprehensive examinations should be performed for such carriers.

Dystrophin ; genetics ; Female ; Genetic Linkage ; Heterozygote ; Humans ; Male ; Muscular Dystrophy, Duchenne ; genetics ; metabolism ; physiopathology ; Siblings

OBJECTIVETo investigate the clinical features of female Duchenne muscular dystrophy(DMD), and find out the onset mechanism.

METHODSThe clinical manifestations of a female DMD family were followed; the immunofluorescence studies on muscle system and the genetic analysis were carried out.

RESULTSThe clinical manifestations and results of relevant examinations on the DMD woman in this family were in accordance with the typical characteristics of DMD. The 39-year-old mother of this proband was noted to have a clinical feature resembling that of Becker muscular dystrophy (BMD), and the immunofluorescence analysis revealed that dystrophin positive fibers and negative fibers co-existed in her muscle. The dystrophy genetic analysis of the family indicated non-deletions. The mother's karyotype was found to be normal.

CONCLUSIONThe 39-year-old female patient's clinical manifestations were similar to BMD, and only one third of her fibers were dystrophin-positive. The present authors assume that the skewed pattern of X inactivation is the likely mechanism, because the karyotype is normal.

Adult ; Dystrophin ; genetics ; metabolism ; Family Health ; Female ; Fluorescent Antibody Technique ; Humans ; Karyotyping ; Male ; Muscular Dystrophy, Duchenne ; genetics ; metabolism ; pathology ; Pedigree

OBJECTIVETo identify potential mutations in patients featuring Becker muscular dystrophy (BMD) and to enhance the understanding of non-deletion/duplication mutations of the dystrophin gene causing BMD.

METHODSClinical data of two patients affected with BMD were collected. Potential mutations in the dystrophin gene were screened with multiplex ligation-dependent probe amplification assay (MLPA). Biopsied muscle samples were examined with HE staining, immnostaining with anti-dystrophin antibody, and electronic microscopy.

RESULTSMLPA assay suggested that both cases were probably due to non-deletion/duplication mutations of the dystrophin gene. Light and electronic microcopy of skeletal muscle biopsies confirmed dystrophic changes in both patients. For patient A, immunostaining showed non-contiguous weak staining for most parts of sarcolemma. For patient B, immunostaining showed positive result with N-terminal anti-dystrophin antibody and negative result with C-terminal anti-dystrophin antibody.

CONCLUSIONFor patients with mild phenotypes but without dystrophin gene deletion/duplication, muscle biopsy and immunochemistry are helpful for diagnosis and prognosis.

Adolescent ; Adult ; Dystrophin ; genetics ; metabolism ; Humans ; Male ; Muscle, Skeletal ; pathology ; Muscular Dystrophy, Duchenne ; genetics ; metabolism ; pathology ; Mutation ; genetics

To explore the changes and regulation mechanism of dystropin and desmin under muscle injury without mechanic stress, 40 male Sprague-Dawley rats were randomly divided into 5 groups, which included normoxia control and hypoxia groups for 1, 2, 4 and 7 d with 10% O2. Two rats from each group were examined for sarcolemma integrity using Evans blue dye (EBD) and EBD-positive fiber typing by metachromatic dye-ATPase method. The rest six rats from each group were analyzed for the changes of protein content and gene expression using Western blot, RT-PCR and fluorescence assays. The results showed that the EBD-positive muscle fibers, mainly type IIA and type IIB, appeared at 1 d after hypoxia exposure. Both the ratio of EBD-positive cell and the mean fluorescence density were significantly higher in hypoxia groups than those in control group (P<0.05). The contents of dystrophin and desmin fluctuated after hypoxia exposure, increased at 1 d, decreased at 2 d, increased dramatically again at 4 d, and returned to a normal level at 7 d. Consistently, the gene expression began to increase significantly after 2 d. The total activity of calpain was significantly higher in hypoxia groups at 1, 4 and 7 d. Significantly higher levels of HSP70 and HSP90 were also observed at 4 and 7 d, respectively (P<0.05). These results suggest that the mechanical stress is not the only cause of damage of sarcolemma membrane integrity. In contrast to eccentric contraction, hypoxia-induced muscle damage is not accompanied by the loss of dystrophin and desmin. The types of muscle fibers recruited by motor units and the activities of calpain may be important in hypoxia-induced damage of sarcolemma membrane integrity.
Animals ; Calpain ; metabolism ; Desmin ; metabolism ; Dystrophin ; metabolism ; Hypoxia ; metabolism ; physiopathology ; Male ; Muscle, Skeletal ; metabolism ; pathology ; Rats ; Rats, Sprague-Dawley ; Sarcolemma ; pathology

OBJECTIVEImmunohistochemistry using antibodies to dystrophin is the pathological basis for the differential diagnosis of Duchenne and Becker muscular dystrophy (DMD and BMD). In rare cases, however, labelling dystrophin on sarcolemma is equivocal and similar to that observed in controls. This makes the diagnosis of BMD difficult. This study aimed to explore the diagnostic value of neuronal nitric oxide synthase (nNOS) antibody for clinically suspected BMD.

METHODSImmunohistochemical staining was performed on muscle specimens of 5 cases of BMD with positive expression of Dys-C (3 cases had a confirmed diagnosis of BMD, 2 cases were clinically suspected as BMD) by using dystrophin and nNOS antibodies. Normal muscle specimens from the children with fracture were used as controls.

RESULTSCompared with the controls, the expression of Dys-R, Dys-C and Dys-N was markedly reduced and nNOS was not expressed on sarcolemma in the three cases of definitely diagnosed BMD. The two cases of clinically suspected as BMD had a complete absence of sarcolemmal nNOS, even if had a similar expression of dystrophin on sarcolemma to the controls.

CONCLUSIONSnNOS antibody staining can be used for a definite diagnosis in children with clinically suspected BMD who have the almost normal expression of dystrophin.

Child ; Child, Preschool ; Dystrophin ; analysis ; chemistry ; Humans ; Immunohistochemistry ; Infant ; Muscular Dystrophy, Duchenne ; diagnosis ; metabolism ; Nitric Oxide Synthase Type I ; analysis

The aim of the present study was to explore the changes and roles of dystrophin and membrane permeability in hypoxic training. Seventy-two 8-week-old Sprague Dawley (SD) rats were randomly divided into 4 groups, normoxic non-train (NC), normoxic train (NT), hypoxic non-train (HC), and hypoxic train (HT) groups. The rats of each group were randomly divided into three subgroups, non-exhaustive, low-speed exhaustive test and high-speed exhaustive test subgroups. Rats in hypoxia groups lived and were trained in a condition of 12.7% oxygen concentration (equal to the 4 300 m altitude). NT and HT groups received 4 weeks of training exercise. Then the rats in all non-exhaustive subgroups were sacrificed, and gastrocnemii were sampled for the measurements of lactate dehydrogenase (LDH), succinatedehydrogenase (SDH), malate dehydrogenase (MDH) activities. Moreover, serum LDH activity was analyzed. Low-speed exhaustive test and high-speed exhaustive test subgroups received exhaustive tests with 20 (71% VO2max) and 30 m/min speed (86% VO2max), respectively, and their exhaustive times were recorded. The results showed that, compared with normoxic groups, the weights in hypoxia groups exhibited slower increase. The level of dystrophin in HT group without exhaustion test didn't change significantly. The muscle MDH activities were markedly affected by the different oxygen concentration, training and their interaction (P < 0.05), whereas the muscle LDH activities were only affected by the different oxygen concentration (P < 0.05). Serum LDH activities were affected by the interaction of the different oxygen concentration and training (P < 0.05), showing decreased muscle LDH and increased blood LDH activities. The exhaustion time were markedly affected by the different test speed, training and their interaction (P < 0.05), and also affected by the interaction of the different oxygen concentration and training (P < 0.05), but didn't affected by oxygen concentration. The exhaustive time of HT high-speed exhaustive test subgroup was more than NT high-speed exhaustive test subgroup in 30 m/min exhaustion test. Compared with NT high-speed exhaustive test subgroup, HT high-speed exhaustive test subgroup had an earlier fatigue in the test, but had a rapid recovery. These results suggested that hypoxic training can effectively increase the rats' high-speed exhaustive time. The mechanism may be related to an increase in serum LDH caused by the increased membrane permeability after hypoxic training.
Altitude ; Animals ; Dystrophin ; metabolism ; Fatigue ; Hypoxia ; L-Lactate Dehydrogenase ; metabolism ; Malate Dehydrogenase ; metabolism ; Muscle, Skeletal ; enzymology ; Physical Conditioning, Animal ; Rats ; Rats, Sprague-Dawley ; Succinate Dehydrogenase ; metabolism

OBJECTIVETo construct the retroviral vector containing human micro-dystrophin gene and detect the expression of human micro-dystrophin in mdx mice bone marrow-derived mesenchymal stem cells (MSCs) after retrovirus infection.

METHODSRetroviral vector for micro-dystrophin gene was constructed and transferred into the packing cell PA317 mediated by Lipofectamine 2000. The retroviral supernatant containing the target genes were subsequently used to infect mdx mice MSCs. Micro-dystrophin expression was examined by methods of immunofluorescence staining and reverse transcriptase-polymerase chain reaction.

RESULTSMicro-dystrophin retroviral vector was successfully constructed and transferred into PA317 cells, and 48 h after infection with the recombinant retrovirus in mdx mice MSCs, 319 bp fragment could be detected by electrophoresis in the RT-PCR products. The red particles could be detected in some infected mdx mice MSCs with immunofluorescence staining. CONCLUSION mdx mice MSCs infected with retrovirus containing micro-dystrophin gene can express micro-dystrophin protein.

Animals ; Bone Marrow Cells ; cytology ; metabolism ; Dystrophin ; biosynthesis ; genetics ; Humans ; Mesenchymal Stromal Cells ; cytology ; metabolism ; Mice ; Mice, Inbred mdx ; Muscular Dystrophy, Animal ; metabolism ; Retroviridae Infections ; Transfection

OBJECTIVETo explore the structural and functional changes of dystrophin molecule after exon 3 deletion.

METHODSThree-dimensional models of dystrophin comprising the major domains were established before and after exon 3 deletion using SWISS-MODEL server. The motifs and structural domains of dystrophin after exon 3 deletion were searched in Pfam database, and the crystal structure of the actin-binding domain in the dystrophin molecule was analyzed using Rasmol software.

RESULTSTorsion of the N-terminal actin-binding domain occurred in the dystrophin molecule after deletion of exon 3. Homology analysis based on Pfam database searches indicated that following exon 3 deletion, the Bit score of the first calponin homology (CH1) domain was decreased from 108 to 36.5 while its expectation value increased from 2.3e-9 to 8.1e-8. The deletion also resulted in the absence of the spiral region C from the CH1 domain.

CONCLUSIONExon 3 deletion in the dystrophin-coding sequence decreases the stability of CH1 domain and prevents the formation of the junction interface where dystrophin binds to actin. The bioinformatics approach provides a new alternative for investigation of the pathogenesis of DMD pathogenesy investigation.

Dystrophin ; chemistry ; genetics ; metabolism ; Exons ; genetics ; Humans ; Models, Molecular ; Muscular Dystrophy, Duchenne ; genetics ; metabolism ; Protein Binding ; Protein Conformation ; Protein Structure, Tertiary ; Sequence Deletion ; Structure-Activity Relationship

Recent reports indicate that the dysbindin gene located on chromosome 6p22.3 is a major susceptibility gene for schizophrenia. In the brain, the dysbindin gene may influence glutamatergic neurotransmission by multiple post- and pr- synaptic mechanisms. This paper reviews the research progress on the dysbindin gene in schizophrenia, including the dysbindin gene and its product, the possible pathogenic mechanisms, the association study of the dysbindin gene with schizophrenia, and the cognitive decline caused by the dysbind in variations.
Brain ; metabolism ; Carrier Proteins ; genetics ; physiology ; Cognition Disorders ; genetics ; physiopathology ; Dysbindin ; Dystrophin-Associated Proteins ; Genetic Predisposition to Disease ; Genotype ; Humans ; Polymorphism, Single Nucleotide ; Schizophrenia ; genetics ; metabolism ; pathology

OBJECTIVE: In order to improve the accuracy and reliability in sudden cardiac death, the pathogenesis and relationship between the viral myocarditis and dilated cardiomyopathy were investigated. METHODS: Improved immunohistochemical technique was adopted to detect the expression of the dystrophin in myocardium from 25 viral myocarditis, 28 dilated cardiomyopathy and 17 control cases including normal, coronary atherosclerotic heart disease and hypertension heart disease as control. RESULTS: The positive rate of dystrophin protein expression in control group was 100%, that in viral myocarditis was 88%, and that in dilated cardiomyopathy was 57%, There were significant differences among three groups (P<0.05), and the correlation between viral myocarditis and dilated cardiomyopathy group (r = -0.526)were also found. CONCLUSION The myocardial cytoskeletal protein is disrupted in viral myocarditis and dilated cardiomyopathy, and the dystrophin protein may be involved in the pathogenesis of viral myocarditis and dilated cardiomyopathy. The viral infect and impair heart functions by cleaving host dystrophin proteins may ultimately contributes to the viral myocarditis to the converting from dilated cardiomyopathy.
Cardiomyopathy, Dilated/metabolism* ; Case-Control Studies ; Death, Sudden, Cardiac ; Dystrophin/metabolism* ; Enterovirus Infections/complications* ; Female ; Humans ; Immunohistochemistry ; Male ; Myocarditis/virology* ; Myocardium/pathology* ; Staining and Labeling