Fatal Lactic Acidosis in Infancy with a Defect of Complex III of the Respiratory Chain

Birch‐Machin, Mark A.; Shepherd, I. M.; Watmough, Nicholas J.; Sherratt, H. S. A.; Bartlett, K.; Darley‐Usmar, Victor; Milligan, David; Welch, Robert J.; Aynsley-Green, A; Turnbull, Douglass M.

doi:10.1203/00006450-198905000-00025

Cited by 99 publications

(34 citation statements)

References 34 publications

(23 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Diagnostic workup of the cultured skin fibroblasts consisted of spectrophotometric analysis of the activities of complex II (24), III (25), and IV (26) and activity staining of all complexes after separation by blue native-polyacrylamide gel electrophoresis (27) and immunocytochemical staining (28) ( Table 4). On the basis of the results obtained in skeletal muscle and other tissues, subjects were subdivided into patients with isolated OXPHOS defects and those with combined complex I and IV deficiency.…”

Section: Articlesmentioning

confidence: 99%

Fluorescence imaging of mitochondria in cultured skin fibroblasts: a useful method for the detection of oxidative phosphorylation defects

et al. 2012

View full text Add to dashboard Cite

Background: Protons are pumped from the mitochondrial matrix via oxidative phosphorylation (OXPhOs) into the intermembrane space, creating an electric membrane potential (ΔΨ) that is used for adenosine triphosphate (aTP) production. Defects in one or more of the OXPhOs complexes are associated with a variety of clinical symptoms, often making it difficult to pinpoint the causal mutation. Methods: In this article, a microscopic method for the quantitative evaluation of ΔΨ in cultured skin fibroblasts is described. The method using 5,5′,6,6′-tetraethylbenzimidazolyl-carbocyanine iodide (Jc-1) fluorescence staining was tested in a selection of OXPhOs-deficient cell lines. results: a significant reduction of ΔΨ was found in the cell lines of patients with either an isolated defect in complex I, II, or IV or a combined defect (complex I + complex IV). ΔΨ was not reduced in the fibroblasts of two patients with severe complex V deficiency. addition of the complex I inhibitor rotenone induced a significant reduction of ΔΨ and perinuclear relocalization of the mitochondria. In cells with a heteroplasmic mitochondrial DNa (mtDNa) defect, a more heterogeneous reduction of ΔΨ was detected. conclusion: Our data show that imaging of ΔΨ in cultured skin fibroblasts is a useful method for the evaluation of OXPhOs functioning in cultured cell lines.t he majority of cellular adenosine triphosphate (ATP) is supplied in the mitochondria through oxidative phosphorylation (OXPHOS). The OXPHOS system consists of five multiprotein complexes embedded within the inner mitochondrial membrane: complex I (reduced nicotinamide adenine dinucleotide: ubiquinone oxidoreductase), complex II (succinate: ubiquinone oxidoreductase), complex III (ubiquinol: cytochrome c oxidoreductase), complex IV (cytochrome c oxidase), and complex V (ATP synthase). Complexes I, III, and IV pump protons, donated by reduced nicotinamide adenine dinucleotide, ubiquinone, and cytochrome c, respectively, into the mitochondrial intermembrane space. The proton gradient that develops between the mitochondrial matrix and the intermembrane space generates an electrochemical membrane potential (ΔΨ), which is the driving force for the conversion of ADP and inorganic phosphate into ATP (1).The estimated incidence of OXPHOS defects in humans is ~1 in 5,000 live births. Isolated complex I deficiency (2) and the mitochondrial DNA (mtDNA) depletion syndromes (3) are the most commonly recognized mitochondrial disorders. Defects in OXPHOS are associated with a broad spectrum of symptoms and syndromes, ranging from mild myopathy to severe multisystem disorders. OXPHOS defects are complex due to the dual origin of genes involved and the specific nature of the mitochondrial genome. The mtDNA encodes 13 structural proteins of the complexes I, III, IV, and V; two rRNAs; and 22 transfer RNAs (tRNAs) necessary for intramitochondrial protein translation. The mitochondrial genome is polyploid, with multiple copies of mtDNA present within each individual mitochondrion. Two different populatio...

show abstract

Section: Articlesmentioning

confidence: 99%

Fluorescence imaging of mitochondria in cultured skin fibroblasts: a useful method for the detection of oxidative phosphorylation defects

et al. 2012

View full text Add to dashboard Cite

show abstract

“…Spectrophotometric assays in skeletal muscle and liver had been performed for the measurement of complex I (NADH:ubiquinone oxidoreductase, rotenone sensitive) (9), complex II (succinate:ubiquinone oxidoreductase, malonate sensitive) (10), complex III (ubiquinone:cytochrome c oxidoreductase, antimycine sensitive) (11), complex IV (cytochrome c oxidase) (12), complex V (ATPsynthase, oligomycine sensitive) (10), and citrate synthase (13) enzyme activities. In cultured skin fibroblasts, only the activities of complex II, III, and IV were measured.…”

Section: Controls and Patientsmentioning

confidence: 99%

Diagnostic Value of Immunostaining in Cultured Skin Fibroblasts from Patients with Oxidative Phosphorylation Defects

et al. 2006

View full text Add to dashboard Cite

ABSTRACT:In the last decades, a large variety of oxidative phosphorylation (OXPHOS) defects have been reported, expressed as an increasing variety of clinical phenotypes. With the expanding number of genes and proteins involved, new screening techniques leading to more effective diagnostic routes are in ever-increasing demand. Cultured skin fibroblasts from a cohort of patients with various OXPHOS defects, previously recognized by enzyme activity studies and blue native PAGE, were investigated with an immunocytochemical technique. Cytospins of cultured fibroblasts were air dried, fixed, and stained with antibodies specifically directed against subunits of each OXPHOS complex. Control cells stained homogeneously and strongly. In fibroblasts from five out of seven patients with a severe deficiency of one of the OXPHOS complexes, a homogeneous reduction of cytoimmunoreactivity of the affected complex was observed. In five out of seven fibroblast strains harboring a mitochondrial tRNA mutation, a mosaic pattern of staining was observed for both complexes I and IV, reflecting the heteroplasmic nature of the defect. The proportion of deficient fibroblasts varied considerably between cell strains from different subjects. The method described offers a convenient and rapid approach to first-line screening of OXPHOS defects. In association with routine assays of enzyme activity, the technique is helpful in orienting molecular investigation further. (Pediatr Res 59: 2-6, 2006) R ecent remarkable progress in understanding the genetics and molecular physiology of OXPHOS has revealed both its intrinsic structural complexity and the causal heterogeneity of mutations affecting mitochondrial function adversely. Moreover, besides the so-called nosological classic clinical entities mainly caused by mutations in the mitochondrial tRNA genes, genotype-phenotype correlation remains difficult in many mitochondrial disorders. The OXPHOS is run by a set of five multiprotein complexes, embedded in the lipid bilayer of the inner mitochondrial membrane: complex I (NADH:ubiquinone oxidoreductase), complex II (succinate:ubiquinone oxidoreductase), complex III (ubiquinol:cytochrome c oxidoreductase), complex IV (cytochrome c oxidase), and complex V (ATP synthase). This structural system harbors at least 85 proteins, 13 of which are encoded by the small mitochondrial genome. Coordinated function of the complexes establishes a proton gradient between the mitochondrial matrix and the intermembrane space that, by the catalytic action of complex V, generates ATP.Besides many mutations reported in the structural complexes themselves (1,2), mutations were discovered in nuclear genes encoding nonstructural proteins essential for assembly, importation, and folding of functional OXPHOS complexes. Examples of the former have been reported for complex III (3), IV (4), and V (5). Also, mutations in heat shock protein 60, a mitochondrial matrix chaperone, have been identified as the cause of fatal systemic mitochondrial disease (6).As the phenotypic spectr...

show abstract

“…Spectrophotometrical analysis of the OXPHOS complexes in liver, skeletal muscle, heart muscle, and cultured skin fibroblasts was done according to the methods described earlier: complex I (NADH coenzyme Q reductase, rotenone sensitive) (1), complex II (succinate co-enzyme Q reductase, malonate sensitive) (2), complex II ϩ III (succinate cytochrome c reductase) (3,4), complex III (ubiquinol-cytochrome c reductase) (4), complex IV (cytochrome c oxidase) (5), and citrate synthase (6). Protein content was measured according to Lowry's method (7).…”

Section: Methodsmentioning

confidence: 99%

Lactic Acidosis in a Newborn With Adrenal Calcifications

et al. 2009

View full text Add to dashboard Cite

A patient is reported who presented in the newborn period with an unusual combination of congenital lactic acidosis and bilateral calcifications in the adrenal medulla, visible on standard abdominal x-ray and ultrasound examination. At birth, the proband was hypotonic and dystrophic. She developed respiratory insufficiency, cardiomegaly, and hepatomegaly and died at the age of 38 d. Examination of postmortem heart muscle revealed multiple areas of myocardial infarction with dystrophic calcifications. In the medulla of the adrenal glands, foci of necrosis and calcifications, and in the liver, multiple zones of necrosis and iron deposition were detected. Biochemical analysis in heart muscle revealed a decreased activity of complex IV of the oxidative phosphorylation (OXPHOS) and in liver a combined deficiency involving the complexes I, III, IV, and V. The findings were suggestive of a defect in biosynthesis of the mitochondrially encoded subunits of the OXPHOS complexes. Extensive analysis of the proband's mitochondrial DNA revealed neither pathogenic deletions and point mutations nor copy number alterations. Relative amounts of mitochondrial transcripts for the ribosomal mitochondrial 12S rRNA (12S) and mitochondrial 16S rRNA (16S) were significantly increased suggesting a compensatory mechanism involving the transcription machinery to low levels of translation. The underlying molecular defect has not been identified yet.

show abstract

Fatal Lactic Acidosis in Infancy with a Defect of Complex III of the Respiratory Chain

Cited by 99 publications

References 34 publications

Fluorescence imaging of mitochondria in cultured skin fibroblasts: a useful method for the detection of oxidative phosphorylation defects

Fluorescence imaging of mitochondria in cultured skin fibroblasts: a useful method for the detection of oxidative phosphorylation defects

Diagnostic Value of Immunostaining in Cultured Skin Fibroblasts from Patients with Oxidative Phosphorylation Defects

Lactic Acidosis in a Newborn With Adrenal Calcifications

Contact Info

Product

Resources

About