Mitochondrial disorders causing respiratory chain dysfunction comprise a group of genetically and clinically heterogeneous diseases. This heterogeneity reflects both the biochemical complexity of oxidative phosphorylation and the genetic contribution of both the n ...
Most mitochondrial cytopathies in infants are caused by mutations in nuclear genes encoding proteins targeted to the mitochondria rather than by primary mutations in the mitochondrial DNA. Over the past few years, the awareness of the number of disease-causing mutations in different n ...
Array comparative genomic hybridization (aCGH) is a powerful clinical diagnostic tool that can be used to evaluate copy number changes in the genome. Targeted aCGH provides a much higher resolution in targeted gene regions to detect copy number changes within single gene or single exon. A cus ...
The diagnosis of mitochondrial disorders has increased considerably over the past few years. However, the genetics are complex, as the causative mutations can be in either the mitochondrial or the nuclear genome. Identification of the molecular defects in the causative genes is the key to a de ...
Mitochondrial disorders are clinically and genetically heterogeneous. There are a set of recurrent point mutations in the mitochondrial DNA (mtDNA) that are responsible for common mitochondrial diseases, including MELAS (mitochondrial encephalopathy, lactic acidosis, ...
Because deoxyribonucleoside triphosphates (dNTPs) are the critical substrates for DNA replication and repair, dNTP pools have been studied in context of multiple basic biochemical processes. Over the last 12 years, interest in dNTPs, and specifically the mitochondrial dNTP pools, ...
We describe detailed methods to measure thymidine (dThd) and deoxyuridine (dUrd) concentrations and thymidine phosphorylase (TP) activity in biological samples. These protocols allow the detection of TP dysfunction in patients with mitochondrial neurogastrointestinal ...
Pyruvate dehydrogenase complex (PDC) and pyruvate carboxylase (PC) are mitochondrial enzymes that provide the initial steps of the two main alternatives for pyruvate metabolism: oxidative decarboxylation vs. anaplerotic carboxylation, gluconeogenesis, and glyceroge ...
Spectrophotometric evaluation of mitochondrial respiratory chain (MRC) enzymatic complexes is the main approach to the biochemical investigation and diagnosis in oxidative phosphorylation disorders (also known as mitochondrial cytopathies). Regular dual beam spec ...
Mitochondria require oxygen to produce ATP in sufficient quantities to drive energy-requiring reactions in eukaryotic organisms. The measurement of oxygen consumption rates from isolated mitochondria in vitro is a useful and valuable technique in the research and evaluation of m ...
In the diagnostic work-up of patients with suspected mitochondrial disease, evaluating the activity of the individual oxidative phosphorylation (OXPHOS) complexes is crucial. Here, we describe spectrophotometric assays for OXPHOS enzymology that can be applied to both tissue ...
Cellular effects of primary mitochondrial dysfunction, as well as potential mitochondrial disease therapies, can be modeled in living animals such as the microscopic nematode, Caenorhabditis elegans. In particular, molecular analyses can provide substantial insight into t ...
Fluorescence-activated cell sorting (FACS) permits specific biologic parameters of cellular populations to be quantified in a high-throughput fashion based on their unique fluorescent properties. Relative quantitation of mitochondrial-localized dyes in human cells u ...
Direct measure of coenzyme Q (CoQ) in biological specimens may provide important advantages. Precise and selective high-performance liquid chromatography (HPLC) methods with electrochemical (EC) detection have been developed for the measurement of reduced (ubiquinol) and o ...
The redox status of mitochondrial coenzyme Q (CoQ) is an important marker for oxidative stress associated with several disorders such as Parkinson disease and Alzheimer disease. Altered redox status may be present in mitochondrial electron transport complex disorders. Intracel ...
The bulk of ATP consumed by various cellular processes is normally produced by five multimeric protein complexes embedded within the inner mitochondrial membrane in a process known as oxidative phosphorylation (OXPHOS). Mutations that impair the assembly, and therefore the funct ...
In recent decades, genetic, biochemical, immunological, and cell biological techniques have been applied not only for better understanding of pathogenesis of known mitochondrial encephalomyopathies but also for exploring the possibility of mitochondrial involvement in o ...
The mammalian mitochondrial genome contains 37 genes, 13 of which encode polypeptide subunits in the enzyme complexes of the oxidative phosphorylation system. The other genes encode the rRNAs and tRNAs necessary for their translation. The mitochondrial translation machinery is l ...
Mitochondrial functions are controlled by both mitochondrial DNA (mtDNA) and nuclear DNA. Hence, it is difficult to identify whether mitochondrial or nuclear genome is responsible for a particular mitochondrial defect. Cybrid is a useful tool to overcome this difficulty, where we can c ...
Pathogenic mitochondrial DNA (mtDNA) mutations are usually present in heteroplasmic forms that vary in concentration among different tissues. Manifestation of clinical phenotypes depends on the degree of mtDNA mutation heteroplasmy (mutation load) in affected tissues. It is t ...