The relationship of mitochondrial DNA mutations to aging is still debated. Most mtDNA mutations are recessive: there are multiple copies per cell and mutation needs to clonally expand to cause respiratory deficiency. Overall mtDNA mutant loads are low, so effects of mutations are limited to critical areas where mutations locally reach high fractions. This includes respiratory chain deficient zones in muscle fibers, respiratory-deficient crypts in colon, and massive expansions of deleted mtDNA in substantia nigra neurons. mtDNA "mutator" mouse with increased rate of mtDNA mutations is a useful model, although rates and distribution of mutations may significantly deviate from what is observed in human aging. Comparison of species with different longevity reveals intriguing longevity-related traits in mtDNA sequence, although their significance is yet to be evaluated. The impact of somatic mtDNA mutations rapidly increases with age, so their importance is expected to grow as human life expectancy increases.
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http://dx.doi.org/10.1016/B978-0-12-394625-6.00002-7 | DOI Listing |
Sci China Life Sci
January 2025
Institute of Rare Diseases, West China Hospital of Sichuan University, Sichuan University, Chengdu, 610000, China.
Human mitochondrial DNA (mtDNA) harbors essential mutations linked to aging, neurodegenerative diseases, and complex muscle disorders. Due to its uniparental and haploid inheritance, mtDNA captures matrilineal evolutionary trajectories, playing a crucial role in population and medical genetics. However, critical questions about the genomic diversity patterns, inheritance models, and evolutionary and medical functions of mtDNA remain unresolved or underexplored, particularly in the transition from traditional genotyping to large-scale genomic analyses.
View Article and Find Full Text PDFNature
January 2025
Changping Laboratory, Beijing, The People's Republic of China.
The development of animal models is crucial for studying and treating mitochondrial diseases. Here we optimized adenine and cytosine deaminases to reduce off-target effects on the transcriptome and the mitochondrial genome, improving the accuracy and efficiency of our newly developed mitochondrial base editors (mitoBEs). Using these upgraded mitoBEs (version 2 (v2)), we targeted 70 mouse mitochondrial DNA mutations analogous to human pathogenic variants, establishing a foundation for mitochondrial disease mouse models.
View Article and Find Full Text PDFNature
January 2025
Division of Cell Therapy, Chiba Cancer Center Research Institute, Chiba, Japan.
Cancer cells in the tumour microenvironment use various mechanisms to evade the immune system, particularly T cell attack. For example, metabolic reprogramming in the tumour microenvironment and mitochondrial dysfunction in tumour-infiltrating lymphocytes (TILs) impair antitumour immune responses. However, detailed mechanisms of such processes remain unclear.
View Article and Find Full Text PDFPlant mitochondrial and plastid genomes have exceptionally slow rates of sequence evolution, and recent work has identified an unusual member of the gene family ("plant ") as being instrumental in preventing point mutations in these genomes. However, the eXects of disrupting -mediated DNA repair on "germline" mutation rates have not been quantified. Here, we used mutation accumulation (MA) lines to measure mutation rates in mutants and matched wild type (WT) controls.
View Article and Find Full Text PDFAnalyst
January 2025
College of Chemistry, Chemical Engineering and Material Science, Soochow University, 199 Ren'Ai Road, Suzhou 215123, China.
Most current nucleic acid-responsive fluorescent probes are enhanced ones with short emission wavelengths. Therefore, the development of novel near-infrared, turn-on response nucleic acid fluorescent probes is of great significance. Herein, three cationic fluorescent dyes 1a-1c were synthesized by reacting naphthalidine salt with suitable aldehydes.
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