Small duplications (miniduplications) of the D-loop of human mitochondrial DNA (mtDNA) have been described in patients with mtDNA deletions, mtDNA point mutations and in normal aged tissues. The origin of these miniduplications is still unknown but it is hypothesized that they could be formed after oxidative damage. The respiratory chain (RC) is the main source of free radicals in mitochondria and it is believed that a defect in RC increases free radical generation. If miniduplications are originated by oxidative damage, it is expected that they are more abundant in patients with a defect in the RC. We studied the frequency of miniduplications of D-loop in patients with a RC defect due to mtDNA deletions and in controls. We show that four types of miniduplications could be detected with a higher prevalence than in previous studies and that patients with mtDNA deletions did not have higher proportions or increased number of miniduplications, which is against the hypothesis that miniduplications are generated more abundantly in patients with RC defects. We also clearly demonstrate the age-related nature of these miniduplications by a carefully controlled study regarding the age of subjects, which was not considered in other studies on patients with a mitochondrial disease.
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http://dx.doi.org/10.1016/s0925-4439(02)00140-0 | DOI Listing |
Biol Psychiatry Glob Open Sci
March 2025
Initiative on Stress, Trauma, and Resilience, Department of Psychiatry and Human Behavior, Warren Alpert Medical School, Brown University, Providence, Rhode Island.
Background: Mounting evidence suggests that mitochondria respond to psychosocial stress. Recent studies suggest mitochondrial DNA (mtDNA) deletions may be increased in some psychiatric disorders, but no studies have examined early-life stress (ELS) and mtDNA deletions. In this study, we assessed mtDNA deletions in peripheral blood mononuclear cells of medically healthy young adults with and without ELS.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
Department of Nephrology, Xiangya Hospital, Central South University, Changsha, 410008, China.
Renal fibrosis is a common pathway involved in the progression of various chronic kidney diseases to end-stage renal disease. Recent studies show that mitochondrial injury of renal tubular epithelial cells (RTECs) is a crucial pathological foundation for renal fibrosis. However, the underlying regulatory mechanisms 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 PDFNeuropathol Appl Neurobiol
February 2025
Department of Neurology, Shandong Key Laboratory of Mitochondrial Medicine and Rare Diseases, Research Institute of Neuromuscular and Neurodegenerative Diseases, Qilu Hospital of Shandong University, Jinan, Shandong, China.
Background: Progressive external ophthalmoplegia (PEO) is a classic manifestation of mitochondrial disease. However, the link between its genetic characteristics and clinical presentations remains poorly investigated.
Methods: We analysed the clinical, pathological and genetic characteristics of a large cohort of patients with PEO, based on the type of their mtDNA variations.
Mol Genet Genomic Med
January 2025
Diagnostics and Therapeutics of Intractable Diseases, Intractable Disease Research Center, Graduate School of Medicine, Juntendo University, Tokyo, Japan.
Background: Sengers syndrome is an autosomal recessive mitochondrial DNA depletion syndrome characterized by hypertrophic cardiomyopathy, congenital cataracts, skeletal myopathy, exercise intolerance, and lactic acidosis. Dysfunction of acylglycerol kinase (AGK) is responsible for the disease, and several AGK gene variants have been reported.
Methods: We employed a comprehensive genomic analysis approach, including whole-genome sequencing and RNA sequencing, combined with various bioinformatics tools.
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