Mitochondrial Disorders Caused By Nuclear Genes

Mitochondrial cytopathies are mutations in the inherited maternal mitochondrial genome, or the nuclear DNA-mutation. Mitochondrial respiratory chain disorders (RCD) are a group of genetically and clinically heterogeneous diseases, due to the fact that protein components of the respiratory chain are encoded by both mitochondrial and nuclear genomes and are essential in all cells. In addition, the biogenesis, structure and function of mitochondria, including DNA replication, transcription, and translation, all require nuclear encoded genes. Since mitochondria are present in every cell, every tissue, mitochondrial disorder usually affects multiple organs.

Methods in Toxicology, Volume 2: Mitochondrial Dysfunction provides a source of methods, techniques, and experimental approaches for studying the role of abnormal mitochondrial function in cell injury. The book discusses the methods for the preparation and basic functional assessment of mitochondria from liver, kidney, muscle, and brain; the methods for assessing mitochondrial dysfunction in vivo and in intact organs; and the structural aspects of mitochondrial dysfunction are addressed. The text also describes chemical detoxification and metabolism as well as specific metabolic reactions that are especially important targets or indicators of damage. The methods for measurement of alterations in fatty acid and phospholipid metabolism and for the analysis and manipulation of oxidative injury and antioxidant systems are also considered. The book further tackles additional methods on mitochondrial energetics and transport processes; approaches for assessing impaired function of mitochondria; and genetic and developmental aspects of mitochondrial disease and toxicology. The text also looks into mitochondrial DNA synthesis, covalent binding to mitochondrial DNA, DNA repair, and mitochondrial dysfunction in the context of developing individuals and cellular differentiation. Microbiologists, toxicologists, biochemists, and molecular pharmacologists will find the book invaluable.

Mitochondrial Disorders in Neurology provides an overview of mitochondrial diseases. This book discusses the effects of mitochondrial dysfunction based on the relevant biochemistry and molecular genetics. The abnormal muscle and mitochondrial morphology in a variety of clinical presentations from isolated ophthalmoplegia to severe encephalopathy are also elaborated. This text likewise deliberates Leber's hereditary optic neuropathy, neurodegenerative disorders, and respiratory chain defects. Other topics covered include mitochondrial DNA and the genetics of mitochondrial disease; cytochrome oxidase deficiency; use of tissue culture in the diagnosis of mitochondrial disease; and advances in mitochondrial genetics. This publication is a good source for clinicians and students concerned with the defective mitochondrial function.

The concept of mitochondrial diseases originated in 1962 with the description by Luft and coworkers of a patient with nonthyroidal hypermetabolism due to loose coupling of oxidation and phosphorylation in muscle mitochondria. Over the following quarter of a century, thanks to W. King Engel's "ragged-red fibres" as convenient markers for mitochondrial pathology, numerous papers described clinical, morphological, and biochemical features of "mitochondrial myopathies." In 1988 the discovery of mutations in mitochondrial DNA led to an explosive expansion of research into mitochondrial disorders. Throughout the 1990s the rapid identification of multiple mitochondrial gene defects associated with clinically diverse disorders has left practitioners puzzled about diagnosing such heterogeneous and complex syndromes. Through updated data, this book discusses now what Luft aptly called "mitochondrial medicine." In so doing, it considers the pivotal role of mitochondria in drug sensitivity, their key roles in ageing, apoptosis, and neurodegeneration along with primary mitochondrial diseases due to mutations in the nuclear genome, in the mitochondrial genome, or in the cross-talk between the two genomes.

This collection of reviews and protocols provides the reader with an introduction to the current state of knowledge on how various diseases are related to mitochondrial dysfunction. Mitochondria contain their own genome, a small, circular double-stranded DNA (mtDNA), and alterations in mtDNA may play an important role in the multistep carcinogenesis of at least some types of human cancer. In addition to mutations of mtDNA, many mitochondrial syndromes are due to abnormalities in nuclear genes related to oxidative phosphorylation (OXPHOS). Mitochondrial tRNA (MTT) gene mutations are an important cause of human morbidity and are associated with a wide range of pathology, from isolated organ?]specific diseases such as myopathy or hearing loss, to multisystem disorders with encephalopathy, gastrointestinal dysmotility, and life?]threatening cardiomyopathy. The relationship of the mitochondrion organelle to aging and longevity is also discussed. Laboratory protocols describe methodology to characterize mtDNA heteroplasmy by parallel sequencing. Each eukaryotic cell contains hundreds of mitochondria with hundreds of mitochondria genomes. Mutant and wild-type mtDNA may co-exist as heteroplasmy, and cause human disease. The purpose of this protocol is to simultaneously determine mtDNA sequence and quantify the heteroplasmic level. Another protocol describes procedures for obtaining tissue sections and cell material suitable for histological evaluation of OXPHOS activity and integrity and immunodetection of the complexes in tissue from patients suspected of mitochondrial disease. Emphasis lies on the diagnostic potential of these techniques to differentiate mtDNA from nuclear mutations. This e-book — a curated collection from eLS, WIREs, and Current Protocols — offers a fantastic introduction to the field of mitochondrial diseases for students or interdisciplinary collaborators. Table of Contents: Introduction Mitochondrial DNA Copy Number Alterations in Human Cancers eLS Man Yu Mitochondrial Disorders: Nuclear Gene Mutations eLS Daniele Ghezzi and Massimo Zeviani Mitochondria as a Key Determinant of Aging eLS Ludivine Walter and Siu Sylvia Lee Advanced Reviews Mitochondrial tRNA Mutations and Disease WIREs RNA John W. Yarham, Joanna L. Elson, Emma L. Blakely, Robert McFarland, Robert W. Taylor Human Mitochondrial Diseases Caused by Lack of Taurine Modification in Mitochondrial tRNAs WIREs RNA Suzuki Tsutomu, Nagao Asuteka, Suzuki Takeo Protocols Next Generation Sequencing to Characterize Mitochondrial Genomic DNA Heteroplasmy Current Protocols in Human Genetics Taosheng Huang Histochemical Methods for the Diagnosis of Mitochondrial Diseases Current Protocols in Human Genetics Boel De Paepe, Jan L. De Bleecker, Rudy Van Coster

Mitochondrial dysfunction is increasingly being recognized as the basis of a wide variety of human diseases. Providing an authoritative update on our current knowledge of mitochondrial medicine, this text draws together world authorities from various fields to present general therapeutic strategies, as well as the treatments presently available in different specialties - thus making it essential reading for clinicians involved with the management of patients with mitochondrial diseases. A unique work, this text covers a range of specialties, including cardiology, ophthalmology, otology, nephrology, gastroenterology, hematology-oncology, and reproductive medicine, and does not focus exclusively on the more commonly known neurologic conditions. An accessible, user-friendly text, it also presents translational concepts of mitochondrial biogenesis and genetics in vignettes related to specific questions raised by the disease under discussion, rather than concentrating on basic science, which can often intimidate clinicians. This pioneering work is primarily directed to a clinical audience who are interested in the diverse and diagnostically challenging clinical presentations of mitochondrial diseases and their pathophysiology.

This interactive clinical textbook takes a system- and case-based approach in understanding mitochondrial disorders in clinical practice.

Mitochondrial replacement techniques (MRTs) are designed to prevent the transmission of mitochondrial DNA (mtDNA) diseases from mother to child. While MRTs, if effective, could satisfy a desire of women seeking to have a genetically related child without the risk of passing on mtDNA disease, the technique raises significant ethical and social issues. It would create offspring who have genetic material from two women, something never sanctioned in humans, and would create mitochondrial changes that could be heritable (in female offspring), and therefore passed on in perpetuity. The manipulation would be performed on eggs or embryos, would affect every cell of the resulting individual, and once carried out this genetic manipulation is not reversible. Mitochondrial Replacement Techniques considers the implications of manipulating mitochondrial content both in children born to women as a result of participating in these studies and in descendants of any female offspring. This study examines the ethical and social issues related to MRTs, outlines principles that would provide a framework and foundation for oversight of MRTs, and develops recommendations to inform the Food and Drug Administration's consideration of investigational new drug applications.