Myopathy associated with rickets and celiac disease.
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Adolescent↗
Biomedical subjects
A Prelle
Publications and source records attributed to A Prelle.
Synergistic effect of beta-amyloid protein and interferon gamma on nitric oxide production by C2C12 muscle cells.
Nitric oxide (NO) is an important mediator of diverse physiological and pathological responses. NO-induced oxidative stress has been proposed in the pathogenesis of muscle tissue damage in inclusion-body myositis (IBM), which is characterized by deposition of beta-amyloid protein (Abeta) in vacuolated muscle fibres. To determine whether Abeta can induce NO production in skeletal muscle, we stimulated C2C12 mouse skeletal muscle cells in vitro with Abeta[1-42] or Abeta[25-35] peptides in the presence or absence of interferon gamma (IFN-gamma). Neither Abeta peptides nor IFN-gamma were able to stimulate nitrite (NO(2)(-)) production by C2C12 cells when given alone. However, combination of IFN-gamma with either Abeta[1-42] or Abeta[25-35] resulted in significant NO(2)(-) release into cell-free supernatants. Northern blot analysis of RNA obtained from Abeta/IFN-gamma-stimulated C2C12 cells revealed increased mRNA accumulation of inducible nitric oxide synthase (iNOS). Moreover, approximately 4% of muscle cells incubated with Abeta peptides and IFN-gamma showed ultrastructural features of DNA fragmentation. These findings, taken together, indicate that the association of Abeta with IFN-gamma stimulates NO(2)(-) production via induction of iNOS gene expression in skeletal muscle cells, with occasional evidence for nuclear changes suggesting apoptotic morphology. These data further support a role for Abeta deposition in the pathogenesis of postulated oxidative damage in IBM.
Amyloid beta-Peptides↗
Cytochrome c oxidase subunit I microdeletion in a patient with motor neuron disease.
An out-of-frame mutation of the mitochondrial DNA-encoded subunit I of cytochrome c oxidase (COX) was discovered during investigation of a severe isolated muscle COX deficiency in a patient with motor neuron-like degeneration. The mutation is a heteroplasmic 5-bp microdeletion located in the 5' end of the COI gene, leading to premature termination of the corresponding translation product. Western blot analysis, immunohistochemistry, and single-fiber polymerase chain reaction demonstrated a tight correlation between COX defect, COX I expression, and percentage of mutation. COX subunits II, III, and IV were decreased as well, suggesting a defective assembly of COX holoenzyme. The mutation was associated with a clinical phenotype unusual for a mitochondrial disorder, that is, an isolated motor neuron disease (MND) with some atypical findings, including early onset, preferential involvement of the upper motor neuron, and increased cerebrospinal fluid protein content. MND may arise from impaired scavenging and overproduction of free oxygen radicals, a by-product of oxidative phosphorylation (OXPHOS). Our observation suggests that OXPHOS impairment could play a role in the pathogenesis of some MND cases.
Adult↗
Sarcoglycan deficiency in a large Italian population of myopathic patients.
Autosomal recessive limb-girdle muscular dystrophies are a heterogeneous group of genetic diseases with a wide spectrum of clinical severity and age of onset; mutations in the gene encoding the dystrophin-associated sarcoglycan proteins (alpha, beta, gamma and delta) have recently been shown to cause some cases of these myopathies (primary sarcoglycanopathies, types 2D, 2E, 2C and 2F, respectively). In this study we have examined a large population of Italian myopathic patients to determine the frequency of (alpha-, beta- and gamma-sarcoglycan deficiency and to correlate molecular defects with clinical phenotypes; to exclude the presence of primary dystrophinopathies both genetic and immunological analysis of dystrophin was performed. We report 12 patients (10 male and 2 female) with deficiency of either one or more sarcoglycan proteins. They were aged 8-56 years with onset between 4 and 30 years of age; they all presented with either mild, moderate or severe limb-girdle involvement associated with elevated blood creatine kinase levels and myopathic pattern at EMG; one was also affected with a mild dilation cardiomyopathy. All patients, except one, showed pathological muscle histological changes. Absence of all three proteins always correlates with severe forms, whereas mild protein deficiencies or isolated partial alpha-sarcoglycan deficiency correlate with either severe, moderate or mild forms.
Adolescent↗
A novel mitochondrial tRNA(Ile) point mutation in chronic progressive external ophthalmoplegia.
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DNA Mutational Analysis↗
Partial depletion and multiple deletions of muscle mtDNA in familial MNGIE syndrome.
OBJECTIVE: To describe the unique combination of partial depletion and multiple deletions of mitochondrial DNA (mtDNA) on muscle DNA analysis of three siblings with mitochondrial neurogastrointestinal encephalomyopathy (MNGIE). BACKGROUND: MNGIE is a relatively homogeneous autosomal recessive disorder characterized by gastrointestinal dysmobility, ophthalmoparesis, peripheral neuropathy, mitochondrial myopathy, and altered white matter signal at brain imaging. Muscle multiple mtDNA deletions have been found in about half of the described cases. METHODS: We studied three affected siblings (two were monozygotic twins) born to nonconsanguineous parents. Muscle mtDNA was investigated by quantitative Southern and Slot blot techniques and by PCR analysis. Morphologic confirmation in the muscle tissue was achieved by using in situ hybridization with a mtDNA probe complementary to an undeleted region and by DNA immunohistochemistry. RESULTS: All three patients showed ragged red (RRF) and cytochrome c oxidase-negative fibers, as well as partial deficiency of complexes I and IV. Southern and Slot blot analyses showed mtDNA depletion in all patients. Multiple mtDNA deletions were also detected by PCR analysis. In situ hybridization demonstrated an overall signal weaker than controls, with a relatively higher signal in RRF. Antibodies against DNA showed a decreased cytoplasmic network. CONCLUSIONS: The muscle histopathology and respiratory chain enzyme defects may be accounted for by the decreased mtDNA amount and by the presence of mtDNA deleted molecules; however, relative levels of mtDNA seem to correlate with life span in these patients. The combination of partial depletion and multiple deletions of mtDNA might indicate the derangement of a common genetic mechanism controlling mtDNA copy number and integrity.
Biopsy↗
An atypical case of partial merosin deficiency congenital muscular dystrophy.
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Child↗
Myopathy and ventilatory failure in severe sepsis.
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Adult↗
Asymptomatic familial hyperCKemia associated with desmin accumulation in skeletal muscle.
We describe a family, two brothers and their mother, who came to our observation because of slight to moderate hyperCKemia. The younger brother, who had the highest CK values, was only suffering from episodic myalgia, the other two members of the family were asymptomatic. Neurological examination was normal. Both brothers underwent muscle biopsy which was significant for the presence of abnormal sarcoplasmic areas of desmin accumulation. So far, desmin abnormalities have never been reported in patients with such a mild neuromuscular pattern. We discuss possible correlations between severity of clinical phenotype and degree of desmin accumulation.
Adult↗
[Respiratory failure caused by myopathy in severe sepsis].
OBJECTIVE: To describe a generalized myopathic disorder occurred in the convalescence phase of illness of a critically ill patient. SETTING: Neurological Intensive Care Unit. PATIENT: A 43-year-old man with acute leukoencephalopathy and severe sepsis complicated by sustained and prolonged cardiovascular, respiratory and renal failure. After 15 days of complete respiratory autonomy, the patient presented an acute ventilatory failure associated with generalized muscle weakness. Neither a relapse of sepsis nor neurological worsening were detected. MEASUREMENTS AND RESULTS: Electromyogram resulted in normal conduction velocity in both motor and sensitive nervous fibers. Muscular biopsy showed marked fiber size variability with several hypotrophic fibers type II fiber grouping, several areas of degeneration-necrosis with macrophage invasion, dishomogeneous oxidative enzymatic activity, no increase in glycogen or lipid content. CONCLUSIONS: These results excluded critical illness polyneuropathy and all the other known myopathies. Prolonged period of sepsis with multiple organ failure can result in a direct generalized myopathy. This possibility should be kept in mind while treating long term critically ill survivors.
Adult↗
OXPHOS defects and mitochondrial DNA mutations in cardiomyopathy.
Defects of the mitochondrial respiratory chain in cardiac muscle are an important, yet still overlooked cause of heart failure. In 16 of 32 endocardial biopsies from infants affected by "idiopathic" hypertrophic cardiomyopathy we demonstrated a remarkable decrease of activity of either complex I, or complex IV, or both, relative to complex II + III activity which was taken as an index of mitochondrial proliferation. At the molecular level, several mtDNA mutations have been associated with cardiomyopathy. For instance, MIMyCa is a maternally inherited syndrome presenting with a variable combination of skeletal and heart muscle failure associated with a heteroplasmic A3260G transition in the tRNALeu(UUR) gene. To study the effects of the mutation in a controlled system, we prepared clones of transmitochondrial cybrids by fusing mutant cytoplasts with mtDNA-less tumor cells. Two groups of clones were identified: nearly 100% mutant (M group) and nearly 100% wild-type (WT group). The means of complex I and IV in the M group were 63% and 67% relative to the WT group. The O2 consumption in the M group was 36%, and the lactate production was 218% of that in the WT group. MtDNA-specific translation was defective in M clones. The study of transmitochondrial cybrids is an important clue to test the pathogenicity of mtDNA mutations.
Cardiomyopathies↗
High serum creatine kinase levels associated with cylindrical spirals at muscle biopsy.
We studied the muscle biopsy from an asymptomatic patient with high serum creatine kinase values. Subsarcolemmal and intermyofibrillar granular inclusions were seen at the light microscopy level. Ultrastructural observation showed clusters of cylindrical spirals (CS). CS are nonspecific, morphological finding, so far reported only in a few cases, presenting with a wide variety of clinical phenotypes. The case we describe is peculiar because of the complete lack of clinical symptoms. The nature of the CS is unknown; we studied a possible alteration of cytoskeletal proteins using a set of different antibodies against these structures, but none of them reacted with CS. Also, since CS have been described in association with mitochondrial abnormalities, and since in our case CS were strongly positive when stained for succinate dehydrogenase, we performed specific immunohistochemical and genetic studies which ruled out any major mitochondrial alterations.
Adult↗
Early-onset encephalomyopathy associated with tissue-specific mitochondrial DNA depletion: a morphological, biochemical and molecular-genetic study.
A male infant, born from consanguineous parents, suffered from birth with a progressive neuromuscular disorder characterized by psychomotor delay, hypotonia, muscle weakness and wasting, deep-tendon areflexia and spastic posture. High levels of lactic acid in blood and cerebrospinal fluid suggested a mitochondrial respiratory chain defect. Muscle biopsy revealed ragged-red and cytochrome c oxidase-negative fibres, lipid accumulation and dystrophic changes. Multiple defects of respiratory complexes were detected in muscle homogenate, but cultured fibroblasts, myoblasts and myotubes were normal. Southern blot analysis showed markedly reduced levels of mitochondrial DNA (mtDNA) in muscle, while lymphocytes, fibroblasts and muscle precursor cells were normal. Neither depletion of mtDNA nor abnormalities of the respiratory complexes were observed in innervated muscle fibres cultured for as long as 4 months. No mutations were observed in two candidate nuclear genes, mtTFA and mtSSB, retro-transcribed, amplified and sequenced from the proband's mRNA. Sequence analysis of the mtDNA D-loop and of the origin of replication of the mtDNA light strand failed to identify potentially pathogenic mutations of these replicative elements in the proband's muscle mtDNA. Our findings indicate that mtDNA depletion is due to a nuclear encoded gene and suggest that the abnormality underlying defective mtDNA propagation must occur after muscle differentiation in vivo.
Age of Onset↗
Genotype to phenotype correlations in mitochondrial encephalomyopathies associated with the A3243G mutation of mitochondrial DNA.
We studied 22 subjects carrying the A3243G point mutation of human mitochondrial DNA (mtDNA). In 14 cases the clinical phenotype was characterized by mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS), while 8 patients had chronic progressive external ophthalmoplegia (CPEO). The proportion of A3243G heteroplasmy in muscle was determined by two methods; densitometry on a diagnostic restriction-fragment length polymorphism and solid-phase mini-sequencing. We found a highly significant inverse correlation between the percentage of A3243G mutation and the specific activity of complex I, the respiratory complex with the highest number of mtDNA-encoded subunits, suggesting a direct effect of the mutation on mtDNA translation. No correlation was observed between the percentage of mutated mtDNA and the presence or absence of specific clinical features, such as stroke, ophthalmoplegia and diabetes mellitus. However, in the MELAS group the percentage of mutated mtDNA molecules was strongly correlated with the age of onset, while no such correlation was found in the CPEO group, suggesting a different time-dependent evolution of the mutation in the two groups. Finally, in contrast with other mtDNA mutations associated with ragged-red fibres (RRF), in both MELAS3243 and CPEO3243 we observed a high proportion of RRF that were positive to the histochemical reaction to cytochrome c oxidase, a morphological feature that seems to be specific for the neuromuscular phenotypes associated with mutations affecting the tRNA(Leu(UUR)) gene.
Adolescent↗
Early-onset cerebellar ataxia, myoclonus and hypogonadism in a case of mitochondrial complex III deficiency treated with vitamins K3 and C.
A 16-year-old girl presented with early-onset cerebellar ataxia, myoclonus, elevated lactic acidosis and hypogonadotropic hypogonadism. Muscle biopsy specimens revealed fibres with a "ragged" appearance with increased mitochondria and lipid droplets. Biochemical investigation revealed a deficiency of complex bc1 (complex III) of the mitochondrial respiratory chain. Genetic analysis did not show either deletions or known mutations of mitochondrial DNA (mtDNA). Phosphorus magnetic resonance spectroscopy (31P-MRS) showed defective energy metabolism in brain and gastrocnemius muscle. A decreased phosphocreatine (PCr) content was found in the occipital lobes accompanied by normal inorganic phosphate (Pi) and cytosolic pH. These findings represented evidence of a high cytosolic adenosine diphosphate concentration and a relatively high rate of metabolism accompanied by a low phosphorylation potential. Muscle 31P-MRS showed a high Pi content at rest, abnormal exercise transfer pattern and a low rate of PCr post-exercise recovery. These findings suggested a deficit of mitochondrial function. Therapy with vitamins K3 and C normalized brain 31P-MRS indices, whereas it did not affect muscle bioenergetic metabolism. In this patient, the endocrinological disorder is putatively due to a mitochondrial cytopathy. Although an unknown mtDNA mutation cannot be ruled out, the genetic defect may lie in the nuclear genome.
Adolescent↗
Ryanodine receptor gene point mutation and malignant hyperthermia susceptibility.
Malignant hyperthermia (MH) is a rare clinical syndrome, triggered in susceptible subjects by a variety of anaesthetic agents and muscle relaxants, and is the commonest cause of death due to general anaesthesia. Previous studies have reported that inherited mutations in the ryanodine receptor (RYR1) gene co-segregated, in some families, with MH susceptibility; lack of linkage between MH and the RYR1 gene in some other families indicates a heterogenous genetic basis for the syndrome. The in vitro contracture test (IVCT) on muscle biopsy specimens is considered to be the most reliable test for establishing the diagnosis of MH. With the identification of RYR1 point mutations this might in turn result in non-invasive methods for the presymptomatic diagnosis of MH. In the present study we investigated four families suspected to be at risk of MH susceptibility; in all subjects histopathological examination and IVCT were performed on muscle biopsy specimens. We undertook a mutation analysis of RYR1 gene testing for the presence of five point mutations; in one pedigree a C1840-->T point mutation was detected, strictly segregating with in vitro MH susceptibility.
Adolescent↗
Utrophin expression during human fetal development.
Utrophin, a protein encoded by chromosome 6 is highly homologous to the cysteine-rich domain and most of the C-terminal domain of dystrophin. In order to clarify its functional role we analyzed its expression during human fetal development. We carried out immunohistochemical analysis on muscle from normal human fetuses at different ages of gestation using an antibody directed against a specific COOH-terminal sequence of the protein. In addition, we stained serial sections with antibodies against dystrophin and alpha-bungarotoxin FITC-BTX. Our findings show that, at week 9 of gestation, utrophin is diffusely expressed in the cytoplasm. From week 12 to 22 the immunostaining is still cytoplasmic, though the reaction intensity progressively decreases. Moreover we observed a strong reaction in fetal nerve at week 18 and 22. There was no correlation between utrophin expression and progressive dystrophin membrane localization.
Amino Acid Sequence↗
Duplication of dystrophin gene and dissimilar clinical phenotype in the same family.
We report here three related patients with a duplication of exons 19-41 of the dystrophin gene, having dissimilar clinical phenotype and dystrophin immunohistochemistry. Two brothers aged six and three years had myalgia, proximal muscular weakness and hypertrophic calves, with 10- 20-fold increase of serum creatine kinase. Muscle biopsy showed dystrophic changes and reduced, patchy binding of dystrophin. The clinical and laboratory findings were consistent with a diagnosis of Becker muscular dystrophy with early onset. Their 14-year-old cousin had only mild hyperCKemia. His muscle biopsy was normal with only mild reduction of dystrophin immunostaining. At follow-up, he is still without symptoms and signs at age 19. All three patients had the same gene duplication and an increased dystrophin size of 507 kDa. Expression of the dystrophin-associated glycoproteins adhalin, alpha-dystroglycan, and beta-dystroglycan were normal in the three patients. An intrafamilial variability in patients carrying a partial duplication of the dystrophin gene may be related to a quantitative difference in mRNA.
Blotting, Southern↗