1
|
Kim JY, Yang HK, Kim N, Kim MJ, Cho SI, Seong M, Park SS, Hwang J. Strabismus in chronic progressive external ophthalmoplegia. Acta Ophthalmol 2021; 99:e274-e280. [PMID: 33191655 DOI: 10.1111/aos.14558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 07/02/2020] [Indexed: 11/28/2022]
Abstract
PURPOSE To elucidate the patterns of strabismus and ophthalmoplegia associated with chronic progressive external ophthalmoplegia (CPEO) confirmed by mitochondrial DNA (mtDNA) deletions in Asians. METHODS A total of 10 patients confirmed to have mtDNA deletion associated with CPEO were included. Long-range PCR encompassing the entire mtDNA was carried out. In the cases with mtDNA deletion, the exact deletion ranges of mtDNA were identified by sequencing. A full ophthalmologic examination including prism and alternate cover test in the primary position, evaluation of ductions and versions, and binocularity was performed in 10 patients with confirmed mtDNA deletions associated with CPEO. RESULTS All of the patients showed ophthalmoplegia as well as ptosis, even after eyelid surgeries. Ophthalmoplegia was symmetric between both eyes in nine patients (90%) while one patient (10%) showed asymmetric ophthalmoplegia with esotropia and left hypotropia. Among the nine patients with symmetric involvement, four patients (44%) showed exotropia, three (33%) had exotropia with vertical deviation, and the remaining two patients (22%) showed orthotropia. Five out of 10 patients (50%) complained of diplopia associated with strabismus, four of whom (80%) had vertical deviation. Three out of five patients (60%) without diplopia showed exotropia of 20 prism diopters (PD) to 50 PD. CONCLUSIONS Exotropia with/without vertical deviation is the most common form of strabismus in Asian patients with CPEO and only one of them showed a small angle of esotropia. Ophthalmoplegia could be asymmetric in 10% of CPEO patients.
Collapse
Affiliation(s)
- Ji Yeon Kim
- Biomedical Research Institute Seoul National University Hospital Seoul Korea
| | - Hee Kyung Yang
- Department of Ophthalmology Seoul National University College of MedicineSeoul National University Bundang Hospital Seongnam Korea
| | - Namju Kim
- Department of Ophthalmology Seoul National University College of MedicineSeoul National University Bundang Hospital Seongnam Korea
| | - Man Jin Kim
- Department of Laboratory Medicine Seoul National University HospitalSeoul National University College of Medicine Seoul Korea
| | - Sung Im Cho
- Department of Laboratory Medicine Seoul National University HospitalSeoul National University College of Medicine Seoul Korea
| | - Moon‐Woo Seong
- Biomedical Research Institute Seoul National University Hospital Seoul Korea
- Department of Laboratory Medicine Seoul National University HospitalSeoul National University College of Medicine Seoul Korea
| | - Sung Sup Park
- Biomedical Research Institute Seoul National University Hospital Seoul Korea
- Department of Laboratory Medicine Seoul National University HospitalSeoul National University College of Medicine Seoul Korea
| | - Jeong‐Min Hwang
- Department of Ophthalmology Seoul National University College of MedicineSeoul National University Bundang Hospital Seongnam Korea
| |
Collapse
|
2
|
Lin ZJ, Wang X, Wang J, Tan Y, Tang X, Werren JH, Zhang D, Wang X. Comparative analysis reveals the expansion of mitochondrial DNA control region containing unusually high G-C tandem repeat arrays in Nasonia vitripennis. Int J Biol Macromol 2020; 166:1246-1257. [PMID: 33159940 DOI: 10.1016/j.ijbiomac.2020.11.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Revised: 11/01/2020] [Accepted: 11/02/2020] [Indexed: 11/25/2022]
Abstract
Insect mitochondrial DNA (mtDNA) ranges from 14 to 19 kbp, and the size difference is attributed to the AT-rich control region. Jewel wasps have a parasitoid lifestyle, which may affect mitochondria function and evolution. We sequenced, assembled, and annotated mitochondrial genomes in Nasonia and outgroup species. Gene composition and order are conserved within Nasonia, but they differ from other parasitoids by two large inversion events that were not reported before. We observed a much higher substitution rate relative to the nuclear genome and mitochondrial introgression between N. giraulti and N. oneida, which is consistent with previous studies. Most strikingly, N. vitripennis mtDNA has an extremely long control region (7665 bp), containing twenty-nine 217 bp tandem repeats and can fold into a super-cruciform structure. In contrast to tandem repeats commonly found in other mitochondria, these high-copy repeats are highly conserved (98.7% sequence identity), much longer in length (approximately 8 Kb), extremely GC-rich (50.7%), and CpG-rich (percent CpG 19.4% vs. 1.1% in coding region), resulting in a 23 kbp mtDNA beyond the typical size range in insects. These N. vitripennis-specific mitochondrial repeats are not related to any known sequences in insect mitochondria. Their evolutionary origin and functional consequences warrant further investigations.
Collapse
Affiliation(s)
- Zi Jie Lin
- Department of Chemistry, Columbus State University, Columbus, GA 31909, United States of America
| | - Xiaozhu Wang
- Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, AL 36849, United States of America
| | - Jinbin Wang
- Institute of Biotechnology Research, Shanghai Academy of Agricultural Sciences, Shanghai 201106, China
| | - Yongjun Tan
- Department of Biology, College of Arts & Sciences, Saint Louis University, St. Louis, MO 63103, United States of America
| | - Xueming Tang
- Institute of Biotechnology Research, Shanghai Academy of Agricultural Sciences, Shanghai 201106, China
| | - John H Werren
- Department of Biology, University of Rochester, Rochester, NY 14627, United States of America
| | - Dapeng Zhang
- Department of Biology, College of Arts & Sciences, Saint Louis University, St. Louis, MO 63103, United States of America
| | - Xu Wang
- Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, AL 36849, United States of America; HudsonAlpha Institute for Biotechnology, Huntsville, AL 35806, United States of America; Alabama Agricultural Experiment Station, Auburn University, Auburn, AL 36849, United States of America; Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849, United States of America.
| |
Collapse
|
3
|
Whole sequence of the mitochondrial DNA genome of Kearns Sayre Syndrome patients: Identification of deletions and variants. Gene 2018; 688:171-181. [PMID: 30528267 DOI: 10.1016/j.gene.2018.11.085] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 09/04/2018] [Accepted: 11/28/2018] [Indexed: 02/07/2023]
Abstract
Mitochondria both produce the energy of the cell as ATP via respiration and regulate cellular metabolism. Accordingly, any deletion or mutation in the mitochondrial DNA (mtDNA) may result in a disease. One of these diseases is Kearns Sayre syndrome (KSS), described for the first time in 1958, where different large-scale deletions of different sizes and at different positions have been reported in the mitochondrial genome of patients with similar clinical symptoms. In this study, sequences of the mitochondrial genome of three patients with clinic features of KSS were analyzed. Our results revealed the position, heteroplasmy percentage, size of deletions, and their haplogroups. Two patients contained deletions reported previously and one patient showed a new deletion not reported previously. These results display for the first time a systematic analysis of mtDNA variants in the whole mtDNA genome of patients with KSS to help to understand their association with the disease.
Collapse
|
4
|
Kawamura K, Qi F, Kobayashi J. Potential relationship between the biological effects of low-dose irradiation and mitochondrial ROS production. JOURNAL OF RADIATION RESEARCH 2018; 59:ii91-ii97. [PMID: 29415254 PMCID: PMC5941154 DOI: 10.1093/jrr/rrx091] [Citation(s) in RCA: 94] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 09/04/2017] [Accepted: 01/05/2018] [Indexed: 05/22/2023]
Abstract
Exposure to ionizing radiation (IR) induces various types of DNA damage, of which DNA double-strand breaks are the most severe, leading to genomic instability, tumorigenesis, and cell death. Hence, cells have developed DNA damage responses and repair mechanisms. IR also causes the accumulation of endogenous reactive oxidative species (ROS) in the irradiated cells. Upon exposure to low-dose irradiation, the IR-induced biological effects mediated by ROS were relatively more significant than those mediated by DNA damage. Accumulating evidence suggests that such increase in endogenous ROS is related with mitochondria change in irradiated cells. Thus, in this review we focused on the mechanism of mitochondrial ROS production and its relationship to the biological effects of IR. Exposure of mammalian cells to IR stimulates an increase in the production of endogenous ROS by mitochondria, which potentially leads to mitochondrial dysfunction. Since the remains of damaged mitochondria could generate or leak more ROS inside the cell, the damaged mitochondria are removed by mitophagy. The disruption of this pathway, involved in maintaining mitochondrial integrity, could lead to several disorders (such as neurodegeneration) and aging. Thus, further investigation needs to be performed in order to understand the relationship between the biological effects of low-dose IR and mitochondrial integrity.
Collapse
Affiliation(s)
- Kasumi Kawamura
- Department of Interdisciplinary Environment, Graduate School of Human and Environmental Sciences, Kyoto University, Yoshidanihonmatsucho, Sakyo-ku, Kyoto 606-8501, Japan
- Department of Genome Repair Dynamics, Radiation Biology Center, Kyoto University, Yoshidakonoecho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Fei Qi
- Department of Interdisciplinary Environment, Graduate School of Human and Environmental Sciences, Kyoto University, Yoshidanihonmatsucho, Sakyo-ku, Kyoto 606-8501, Japan
- Department of Genome Repair Dynamics, Radiation Biology Center, Kyoto University, Yoshidakonoecho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Junya Kobayashi
- Department of Interdisciplinary Environment, Graduate School of Human and Environmental Sciences, Kyoto University, Yoshidanihonmatsucho, Sakyo-ku, Kyoto 606-8501, Japan
- Department of Genome Repair Dynamics, Radiation Biology Center, Kyoto University, Yoshidakonoecho, Sakyo-ku, Kyoto 606-8501, Japan
- Corresponding author. Department of Genome Repair Dynamics, Radiation Biology Center, Kyoto University, Yoshidakonoecho, Sakyo-ku, Kyoto 606-8501, Japan. Tel: +81-75-753-7554; Fax: +81-75-753-7564;
| |
Collapse
|
5
|
Lee JS, Ko YG, Shin KJ, Kim SK, Park JH, Hwang KC, Pak HN. Mitochondrial DNA 4977bp deletion mutation in peripheral blood reflects atrial remodeling in patients with non-valvular atrial fibrillation. Yonsei Med J 2015; 56:53-61. [PMID: 25510747 PMCID: PMC4276778 DOI: 10.3349/ymj.2015.56.1.53] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
PURPOSE Recently, mitochondrial DNA 4977bp deletion (mtDNA4977-mut), a somatic mutation related to oxidative stress, has been shown to be associated with atrial fibrillation (AF). We hypothesized that patient age, as well as electroanatomical characteristics of fibrillating left atrial (LA), vary depending on the presence of mtDNA4977-mut in peripheral blood among patients with non-valvular AF. MATERIALS AND METHODS Analyzing clinical and electroanatomical characteristics, we investigated the presence of the mtDNA4977-mut in peripheral blood of 212 patients (51.1±13.2 years old, 83.5% male) undergoing catheter ablation for non-valvular AF, as well as 212 age-matched control subjects. RESULTS The overall frequency of peripheral blood mtDNA4977-mut in patients with AF and controls was not significantly different (24.5% vs. 19.3%, p=0.197). When the AF patient group was stratified according to age, mtDNA4977-mut was more common (47.4% vs. 20.0%, p=0.019) in AF patients older than 65 years than their age-matched controls. Among AF patients, those with mtDNA4977-mut were older (58.1±11.9 years old vs. 48.8±11.9 years old, p<0.001). AF patients positive for the mtDNA mutation had greater LA dimension (p=0.014), higher mitral inflow peak velocity (E)/diastolic mitral annular velocity (Em) ratio (p<0.001), as well as lower endocardial voltage (p=0.035), and slower conduction velocity (p=0.048) in the posterior LA than those without the mutation. In multivariate analysis, E/Em ratio was found to be significantly associated with the presence of mtDNA4977-mut in peripheral blood. CONCLUSION mtDNA4977-mut, an age-related somatic mutation detected in the peripheral blood, is associated with advanced age and electro-anatomical remodeling of the atrium in non-valvular AF.
Collapse
Affiliation(s)
- Jihei Sara Lee
- Department of Internal Medicine, Yonsei Univerisity College of Medicine, Seoul, Korea
| | - Young-Guk Ko
- Department of Internal Medicine, Yonsei Univerisity College of Medicine, Seoul, Korea.
| | - Kyoung-Jin Shin
- Department of Forensic Medicine, Yonsei Univerisity College of Medicine, Seoul, Korea.
| | - Sook-Kyoung Kim
- Department of Internal Medicine, Yonsei Univerisity College of Medicine, Seoul, Korea
| | - Jae Hyung Park
- Department of Internal Medicine, Yonsei Univerisity College of Medicine, Seoul, Korea
| | - Ki-Cheol Hwang
- Department of Internal Medicine, Yonsei Univerisity College of Medicine, Seoul, Korea
| | - Hui-Nam Pak
- Department of Internal Medicine, Yonsei Univerisity College of Medicine, Seoul, Korea
| |
Collapse
|
6
|
Bharti SK, Sommers JA, Zhou J, Kaplan DL, Spelbrink JN, Mergny JL, Brosh RM. DNA sequences proximal to human mitochondrial DNA deletion breakpoints prevalent in human disease form G-quadruplexes, a class of DNA structures inefficiently unwound by the mitochondrial replicative Twinkle helicase. J Biol Chem 2014; 289:29975-93. [PMID: 25193669 DOI: 10.1074/jbc.m114.567073] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Mitochondrial DNA deletions are prominent in human genetic disorders, cancer, and aging. It is thought that stalling of the mitochondrial replication machinery during DNA synthesis is a prominent source of mitochondrial genome instability; however, the precise molecular determinants of defective mitochondrial replication are not well understood. In this work, we performed a computational analysis of the human mitochondrial genome using the "Pattern Finder" G-quadruplex (G4) predictor algorithm to assess whether G4-forming sequences reside in close proximity (within 20 base pairs) to known mitochondrial DNA deletion breakpoints. We then used this information to map G4P sequences with deletions characteristic of representative mitochondrial genetic disorders and also those identified in various cancers and aging. Circular dichroism and UV spectral analysis demonstrated that mitochondrial G-rich sequences near deletion breakpoints prevalent in human disease form G-quadruplex DNA structures. A biochemical analysis of purified recombinant human Twinkle protein (gene product of c10orf2) showed that the mitochondrial replicative helicase inefficiently unwinds well characterized intermolecular and intramolecular G-quadruplex DNA substrates, as well as a unimolecular G4 substrate derived from a mitochondrial sequence that nests a deletion breakpoint described in human renal cell carcinoma. Although G4 has been implicated in the initiation of mitochondrial DNA replication, our current findings suggest that mitochondrial G-quadruplexes are also likely to be a source of instability for the mitochondrial genome by perturbing the normal progression of the mitochondrial replication machinery, including DNA unwinding by Twinkle helicase.
Collapse
Affiliation(s)
- Sanjay Kumar Bharti
- From the Laboratory of Molecular Gerontology, NIA, National Institutes of Health, NIH Biomedical Research Center, Baltimore, Maryland 21224
| | - Joshua A Sommers
- From the Laboratory of Molecular Gerontology, NIA, National Institutes of Health, NIH Biomedical Research Center, Baltimore, Maryland 21224
| | - Jun Zhou
- the ARNA Laboratory, University of Bordeaux, F-33000 Bordeaux, France, INSERM U869, Institut Européen de Chimie et Biologie (IECB), F-33600 Pessac, France
| | - Daniel L Kaplan
- the Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, Florida 32312
| | - Johannes N Spelbrink
- the FinMIT Centre of Excellence, BioMediTech and Tampere University Hospital, Pirkanmaa Hospital District, University of Tampere, FI-33014 Tampere, Finland, and the Department of Pediatrics, Nijmegan Centre for Mitochondrial Disorders, Radboud University Medical Centre, Geert Grooteplein 10, P. O. Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Jean-Louis Mergny
- the ARNA Laboratory, University of Bordeaux, F-33000 Bordeaux, France, INSERM U869, Institut Européen de Chimie et Biologie (IECB), F-33600 Pessac, France
| | - Robert M Brosh
- From the Laboratory of Molecular Gerontology, NIA, National Institutes of Health, NIH Biomedical Research Center, Baltimore, Maryland 21224,
| |
Collapse
|
7
|
Kam WWY, Banati RB. Effects of ionizing radiation on mitochondria. Free Radic Biol Med 2013; 65:607-619. [PMID: 23892359 DOI: 10.1016/j.freeradbiomed.2013.07.024] [Citation(s) in RCA: 238] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Revised: 07/16/2013] [Accepted: 07/16/2013] [Indexed: 01/08/2023]
Abstract
The current concept of radiobiology posits that damage to the DNA in the cell nucleus is the primary cause for the detrimental effects of radiation. However, emerging experimental evidence suggests that this theoretical framework is insufficient for describing extranuclear radiation effects, particularly the response of the mitochondria, an important site of extranuclear, coding DNA. Here, we discuss experimental observations of the effects of ionizing radiation on the mitochondria at (1) the DNA and (2) functional levels. The roles of mitochondria in (3) oxidative stress and (4) late radiation effects are discussed. In this review, we summarize the current understanding of targets for ionizing radiation outside the cell nucleus. Available experimental data suggest that an increase in the tumoricidal efficacy of radiation therapy might be achievable by targeting mitochondria. Likewise, more specific protection of mitochondria and its coding DNA should reduce damage to healthy cells exposed to ionizing radiation.
Collapse
Affiliation(s)
- Winnie Wai-Ying Kam
- Australian Nuclear Science and Technology Organisation, Lucas Heights, Sydney, New South Wales 2234, Australia; Medical Radiation Sciences, Faculty of Health Sciences, University of Sydney, Cumberland, Sydney, New South Wales 2141, Australia.
| | - Richard B Banati
- Australian Nuclear Science and Technology Organisation, Lucas Heights, Sydney, New South Wales 2234, Australia; Medical Radiation Sciences, Faculty of Health Sciences, University of Sydney, Cumberland, Sydney, New South Wales 2141, Australia; National Imaging Facility at Brain and Mind Research Institute (BMRI), University of Sydney, Camperdown, Sydney, New South Wales 2050, Australia
| |
Collapse
|
8
|
Grady JP, Campbell G, Ratnaike T, Blakely EL, Falkous G, Nesbitt V, Schaefer AM, McNally RJ, Gorman GS, Taylor RW, Turnbull DM, McFarland R. Disease progression in patients with single, large-scale mitochondrial DNA deletions. Brain 2013; 137:323-34. [PMID: 24277717 PMCID: PMC3914470 DOI: 10.1093/brain/awt321] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Single, large-scale deletions of mitochondrial DNA are a common cause of mitochondrial disease and cause a broad phenotypic spectrum ranging from mild myopathy to devastating multi-system syndromes such as Kearns-Sayre syndrome. Studies to date have been inconsistent on the value of putative predictors of clinical phenotype and disease progression such as mutation load and the size or location of the deletion. Using a cohort of 87 patients with single, large-scale mitochondrial DNA deletions we demonstrate that a variety of outcome measures such as COX-deficient fibre density, age-at-onset of symptoms and progression of disease burden, as measured by the Newcastle Mitochondrial Disease Adult Scale, are significantly (P < 0.05) correlated with the size of the deletion, the deletion heteroplasmy level in skeletal muscle, and the location of the deletion within the genome. We validate these findings with re-analysis of 256 cases from published data and clarify the previously conflicting information of the value of these predictors, identifying that multiple regression analysis is necessary to understand the effect of these interrelated predictors. Furthermore, we have used mixed modelling techniques to model the progression of disease according to these predictors, allowing a better understanding of the progression over time of this strikingly variable disease. In this way we have developed a new paradigm in clinical mitochondrial disease assessment and management that sidesteps the perennial difficulty of ascribing a discrete clinical phenotype to a broad multi-dimensional and progressive spectrum of disease, establishing a framework to allow better understanding of disease progression.
Collapse
Affiliation(s)
- John P Grady
- 1 Wellcome Trust Centre for Mitochondrial Research, Institute for Ageing and Health, Newcastle University, Newcastle upon Tyne, UK
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Damas J, Samuels DC, Carneiro J, Amorim A, Pereira F. Mitochondrial DNA rearrangements in health and disease--a comprehensive study. Hum Mutat 2013; 35:1-14. [PMID: 24115352 DOI: 10.1002/humu.22452] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Accepted: 09/19/2013] [Indexed: 12/12/2022]
Abstract
Mitochondrial DNA (mtDNA) rearrangements cause a wide variety of highly debilitating and often fatal disorders and have been implicated in aging and age-associated disease. Here, we present a meta-analytical study of mtDNA deletions (n = 730) and partial duplications (n = 37) using information from more than 300 studies published over the last 30 years. We show that both classes of mtDNA rearrangements are unequally distributed among disorders and their breakpoints have different genomic locations. We also demonstrate that 100% of cases with sporadic mtDNA deletions and 97.3% with duplications have no breakpoints in the 16,071 breakage hotspot site, in contrast with deletions from healthy and aged tissues. Notably, most deletions removing a section of the D-loop are found in tumors. Deleted mtDNA molecules lacking the origin of L-strand replication (O(L)) represent only 9.5% of all reported cases, whereas extra origins of replication occur in all duplications. As previously shown for deletions, imperfect stretches of homology are common in duplication breakpoints. Finally, we provide a dedicated Website with detailed information on deleted/duplicated mtDNA regions to facilitate the design of efficient methods for identification and screening of rearranged mitochondrial genomes (available at http://www.portugene.com/mtDNArearrangements.html).
Collapse
Affiliation(s)
- Joana Damas
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), Rua Dr. Roberto Frias s/n, Porto, Portugal
| | | | | | | | | |
Collapse
|
10
|
Montiel-Sosa JF, Herrero MD, Munoz MDL, Aguirre-Campa LE, Pérez-Ramírez G, García-Ramírez R, Ruiz-Pesini E, Montoya J. Phylogenetic analysis of mitochondrial DNA in a patient with Kearns-Sayre syndrome containing a novel 7629-bp deletion. ACTA ACUST UNITED AC 2013; 24:420-31. [PMID: 23391298 DOI: 10.3109/19401736.2012.760550] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Mitochondrial DNA mutations have been associated with different illnesses in humans, such as Kearns-Sayre syndrome (KSS), which is related to deletions of different sizes and positions among patients. Here, we report a Mexican patient with typical features of KSS containing a novel deletion of 7629 bp in size with 85% heteroplasmy, which has not been previously reported. Sequence analysis revealed 3-bp perfect short direct repeats flanking the deletion region, in addition to 7-bp imperfect direct repeats within 9-10 bp. Furthermore, sequencing, alignment and phylogenetic analysis of the hypervariable region revealed that the patient may belong to a founder Native American haplogroup C4c.
Collapse
Affiliation(s)
- Jose Francisco Montiel-Sosa
- Department of Biochemistry and Molecular and Cellular Biology, Universidad de Zaragoza, CIBER de Enfermedades Raras, Zaragoza, Spain
| | | | | | | | | | | | | | | |
Collapse
|
11
|
Chen T, He J, Huang Y, Zhao W. The generation of mitochondrial DNA large-scale deletions in human cells. J Hum Genet 2011; 56:689-94. [DOI: 10.1038/jhg.2011.97] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
|
12
|
Alemi M, Prigione A, Wong A, Schoenfeld R, DiMauro S, Hirano M, Taroni F, Cortopassi G. Mitochondrial DNA deletions inhibit proteasomal activity and stimulate an autophagic transcript. Free Radic Biol Med 2007; 42:32-43. [PMID: 17157191 PMCID: PMC1927835 DOI: 10.1016/j.freeradbiomed.2006.09.014] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2006] [Revised: 07/29/2006] [Accepted: 09/14/2006] [Indexed: 01/01/2023]
Abstract
Deletions within the mitochondrial DNA (mtDNA) cause Kearns Sayre syndrome (KSS) and chronic progressive external opthalmoplegia (CPEO). The clinical signs of KSS include muscle weakness, heart block, pigmentary retinopathy, ataxia, deafness, short stature, and dementia. The identical deletions occur and rise exponentially as humans age, particularly in substantia nigra. Deletions at >30% concentration cause deficits in basic bioenergetic parameters, including membrane potential and ATP synthesis, but it is poorly understood how these alterations cause the pathologies observed in patients. To better understand the consequences of mtDNA deletions, we microarrayed six cell types containing mtDNA deletions from KSS and CPEO patients. There was a prominent inhibition of transcripts encoding ubiquitin-mediated proteasome activity, and a prominent induction of transcripts involved in the AMP kinase pathway, macroautophagy, and amino acid degradation. In mutant cells, we confirmed a decrease in proteasome biochemical activity, significantly lower concentration of several amino acids, and induction of an autophagic transcript. An interpretation consistent with the data is that mtDNA deletions increase protein damage, inhibit the ubiquitin-proteasome system, decrease amino acid salvage, and activate autophagy. This provides a novel pathophysiological mechanism for these diseases, and suggests potential therapeutic strategies.
Collapse
Affiliation(s)
- Mansour Alemi
- Department of Molecular Biosciences, 1311 Haring Hall, University of California, Davis, CA 95616, USA
| | - Alessandro Prigione
- Department of Molecular Biosciences, 1311 Haring Hall, University of California, Davis, CA 95616, USA
| | - Alice Wong
- Department of Molecular Biosciences, 1311 Haring Hall, University of California, Davis, CA 95616, USA
| | - Robert Schoenfeld
- Department of Molecular Biosciences, 1311 Haring Hall, University of California, Davis, CA 95616, USA
| | - Salvatore DiMauro
- Department of Neurology, Columbia University Medical Center, 630 West 168 Street, New York, NY 10032
| | - Michio Hirano
- Department of Neurology, Columbia University Medical Center, 630 West 168 Street, New York, NY 10032
| | - Franco Taroni
- Division of Biochemistry and Genetics, Istituto Nazionale Neurologico Carlo Besta, Milan, Italy
| | - Gino Cortopassi
- Department of Molecular Biosciences, 1311 Haring Hall, University of California, Davis, CA 95616, USA
| |
Collapse
|
13
|
Bhat HK, Epelboym I. Quantitative analysis of total mitochondrial DNA: competitive polymerase chain reaction versus real-time polymerase chain reaction. J Biochem Mol Toxicol 2005; 18:180-6. [PMID: 15452886 DOI: 10.1002/jbt.20024] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
An efficient and effective method for quantification of small amounts of nucleic acids contained within a sample specimen would be an important diagnostic tool for determining the content of mitochondrial DNA (mtDNA) in situations where the depletion thereof may be a contributing factor to the exhibited pathology phenotype. This study compares two quantification assays for calculating the total mtDNA molecule number per nanogram of total genomic DNA isolated from human blood, through the amplification of a 613-bp region on the mtDNA molecule. In one case, the mtDNA copy number was calculated by standard competitive polymerase chain reaction (PCR) technique that involves co-amplification of target DNA with various dilutions of a nonhomologous internal competitor that has the same primer binding sites as the target sequence, and subsequent determination of an equivalence point of target and competitor concentrations. In the second method, the calculation of copy number involved extrapolation from the fluorescence versus copy number standard curve generated by real-time PCR using various dilutions of the target amplicon sequence. While the mtDNA copy number was comparable using the two methods (4.92 +/- 1.01 x 10(4) molecules/ng total genomic DNA using competitive PCR vs 4.90 +/- 0.84 x 10(4) molecules/ng total genomic DNA using real-time PCR), both inter- and intraexperimental variance were significantly lower using the real-time PCR analysis. On the basis of reproducibility, assay complexity, and overall efficiency, including the time requirement and number of PCR reactions necessary for the analysis of a single sample, we recommend the real-time PCR quantification method described here, as its versatility and effectiveness will undoubtedly be of great use in various kinds of research related to mitochondrial DNA damage- and depletion-associated disorders.
Collapse
Affiliation(s)
- Hari K Bhat
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY 10032, USA.
| | | |
Collapse
|
14
|
Takaki A, Jimi S, Segawa M, Hisano S, Takebayashi S, Iwasaki H. Long-term cadmium exposure accelerates age-related mitochondrial changes in renal epithelial cells. Toxicology 2004; 203:145-54. [PMID: 15363590 DOI: 10.1016/j.tox.2004.06.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2004] [Revised: 06/01/2004] [Accepted: 06/04/2004] [Indexed: 11/30/2022]
Abstract
Long-term cadmium exposure leads to mitochondrial dysfunction in the proximal tubular epithelial cells. Mitochondrial DNA deletion may contribute to the pathogenesis of cadmium-induced nephropathy. The aim of our study is to clarify the accumulation of mitochondrial DNA deletion and mitochondrial dysfunction in the renal cortex of rats injected three times/week with 1 ml of 1 mM CdCl2 or saline for 80 weeks. After 40-week cadmium injection, mitochondrial number diminished, and cadmium in the renal cortex reached a saturation level. At this time interval, nearly 30% of cadmium in the whole cell fraction was found in the mitochondria. Cytochrome c oxidase (COX) activity in the proximal tubular epithelial cells decreased after 40-week exposure of cadmium. Oxidized phosphatidylcholine (oxPC) started to accumulate in the cytochrome c-positive mitochondria in some tubular epithelial cells after 80-week exposure. After 40 weeks, accumulation of the 4834-bp deletion in mitochondrial DNA was evident in both control and cadmium-treated groups. However, the amount of accumulated mitochondrial DNA deletion tended to increase after 40-week exposure, and was significantly greater after 80 weeks of exposure, compared to the control. Our results indicate that long-term cadmium exposure in rats accelerates accumulation of 4834-bp mitochondrial DNA deletions and impairment of mitochondrial function associated with accumulation of oxidized product.
Collapse
Affiliation(s)
- Aya Takaki
- Department of Pathology, School of Medicine, Fukuoka University, 7-45-1 Nanakuma, Jonanku, 814-0180, Japan
| | | | | | | | | | | |
Collapse
|
15
|
Mitochondrial DNA mutations and oxidative damage in skeletal muscle of patients with chronic uremia. J Biomed Sci 2002. [DOI: 10.1007/bf02254982] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
|
16
|
Gallagher CL, Waclawik AJ, Beinlich BR, Harding CO, Pauli RM, Poirer J, Pandolfo M, Salamat MS. Friedreich's ataxia associated with mitochondrial myopathy: clinicopathologic report. J Child Neurol 2002; 17:453-6. [PMID: 12174969 DOI: 10.1177/088307380201700612] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
A 13-year-old boy with clinical and electrophysiologic findings of Friedreich's ataxia developed unusually prominent myopathy. Skeletal muscle biopsy showed mitochondrial proliferation and structural abnormalities. No mutation was found in skeletal muscle mitochondrial DNA to explain this finding. Molecular genetic and pathologic studies confirmed a diagnosis of Friedreich's ataxia in the proband and affected relatives. Although the Friedreich's ataxia phenotype results from decreased expression of a mitochondrially targeted protein, frataxin, mitochondrial myopathy has not been described as a feature of the disease. The association between the frataxin gene mutation and mitochondrial myopathy in this case suggests that severe or cumulative insults to mitochondrial function may produce myopathic changes in some cases of Friedreich's ataxia. The patient also responded clinically to carnitine supplementation, suggesting a potential palliative therapy for the disease.
Collapse
|
17
|
Bhat HK. Depletion of mitochondrial DNA and enzyme in estrogen-induced hamster kidney tumors: a rodent model of hormonal carcinogenesis. J Biochem Mol Toxicol 2002; 16:1-9. [PMID: 11857771 DOI: 10.1002/jbt.10017] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Mitochondrial DNA (mtDNA) encodes for 13 polypeptides critical for normal functioning of the electron transport chain and damage to mtDNA has been associated with aging, and implicated in several disease processes. Although damage to mtDNA is being implicated in mutagenesis and carcinogenesis, there are limited studies demonstrating the role and extent of mtDNA damage in human or rodent cancers. Using serial dilution and competitive polymerase chain reaction analysis, we have quantitated the amount of total mtDNA and analyzed the extent of mtDNA damage in estrogen-induced and estrogen-dependent hamster kidney tumors. The hamster kidney tumor model is a useful and widely investigated rodent model of hormonal carcinogenesis, which shares several characteristics with human breast and uterine cancers, and point to a common mechanistic pathway. Our data indicate a significant decrease in the copy number of total mtDNA and the activity of a nuclear-encoded mitochondrial enzyme citrate synthase in hamster kidney tumors compared to age-matched controls. Since there are several hundred mitochondria in a cell and each mitochondrion has multiple copies of mtDNA, a very small percentage of somatic deletion mutation may not be enough to result in a decreased capacity of the mitochondrial genome. However, a significant increase in deletion mutations or a decrease in the mtDNA copy number can result in a decreased oxidative phosphorylation capacity of the mitochondria and decreased energetics, and thus increased susceptibility to the disease process. Therefore, estrogen-induced hamster kidney tumor model can be a useful rodent model of carcinogenesis to understand the role of mtDNA damage in cancer progression and development.
Collapse
Affiliation(s)
- Hari K Bhat
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY 10032, USA.
| |
Collapse
|
18
|
Ponamarev MV, Longley MJ, Nguyen D, Kunkel TA, Copeland WC. Active site mutation in DNA polymerase gamma associated with progressive external ophthalmoplegia causes error-prone DNA synthesis. J Biol Chem 2002; 277:15225-8. [PMID: 11897778 DOI: 10.1074/jbc.c200100200] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Progressive external ophthalmoplegia (PEO) is a heritable mitochondrial disorder characterized by the accumulation of multiple point mutations and large deletions in mtDNA. Autosomal dominant PEO was recently shown to co-segregate with a heterozygous Y955C mutation in the human gene encoding the sole mitochondrial DNA polymerase, DNA polymerase gamma (pol gamma). Since Tyr-955 is a highly conserved residue critical for nucleotide recognition among family A DNA polymerases, we analyzed the effects of the Y955C mutation on the kinetics and fidelity of DNA synthesis by the purified human mutant polymerase in complex with its accessory subunit. The Y955C enzyme retains a wild-type catalytic rate (k(cat)) but suffers a 45-fold decrease in apparent binding affinity for the incoming nucleoside triphosphate (K(m)). The Y955C derivative is 2-fold less accurate for base pair substitutions than wild-type pol gamma despite the action of intrinsic exonucleolytic proofreading. The full mutator effect of the Y955C substitution was revealed by genetic inactivation of the exonuclease, and error rates for certain mismatches were elevated by 10-100-fold. The error-prone DNA synthesis observed for the Y955C pol gamma is consistent with the accumulation of mtDNA mutations in patients with PEO.
Collapse
Affiliation(s)
- Mikhail V Ponamarev
- Laboratory of Molecular Genetics, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina 27709, USA
| | | | | | | | | |
Collapse
|
19
|
Affiliation(s)
- L A Tully
- Biotechnology Division, National Institute of Standards and Technology, 100 Bureau Drive, Stop 8311, Gaithersburg, MD 20899-8311, USA
| | | |
Collapse
|
20
|
Gücüyener K, Seyrantepe V, Topaloğlu H. Mitochondrial deletion in a boy with growth hormone deficiency mimicking cerebral palsy. J Inherit Metab Dis 1998; 21:173-4. [PMID: 9584270 DOI: 10.1023/a:1005304015278] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- K Gücüyener
- Department of Pediatric Neurology, Gazi University, Faculty of Medicine, Ankara, Turkey
| | | | | |
Collapse
|
21
|
Abstract
The cardinal eye manifestations of mtDNA diseases are ophthalmoplegia, optic neuropathy, and pigmentary retinopathy. A number of other eye structures may also be affected in these disorders and the ophthalmologist is in a unique position to detect and interpret these findings. The presence of these ophthalmologic manifestations may be the first clue that the patient has an underlying mitochondrial disease with the eye as the initial or most prominently affected organ. The phenotypic manifestations of mitochondrial disease are protean and variable, and there are no clear-cut, minimal features that define these disorders. The possibility of a mitochondrial disorder should be raised when any of the mitochondrial eye manifestations (Table 1) are present, either alone or in concert with the neurological and systemic (Table 2) manifestations of mitochondrial disease. A maternal family history of an ophthalmologic, neurological, or systemic illness is also compatible with a mitochondrial disorder. The ophthalmologist should not loose sight of the fact that mitochondrial disorders have systemic manifestations and implications, even when the primary manifestations are ocular. Detection of and proactive intervention into comorbid features (eg, diabetes mellitus, hearing loss, heart block) is an important component.
Collapse
Affiliation(s)
- D R Johns
- Neurology Department, Harvard Medical School, Beth Israel Hospital, Boston, MA, USA
| |
Collapse
|
22
|
Andersson SG, Kurland CG. Genomic evolution drives the evolution of the translation system. Biochem Cell Biol 1995; 73:775-87. [PMID: 8721994 DOI: 10.1139/o95-086] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Our thesis is that the characteristics of the translational machinery and its organization are selected in part by evolutionary pressure on genomic traits have nothing to do with translation per se. These genomic traits include size, composition, and architecture. To illustrate this point, we draw parallels between the structure of different genomes that have adapted to intracellular niches independently of each other. Our starting point is the general observation that the evolutionary history of organellar and parasitic bacteria have favored bantam genomes. Furthermore, we suggest that the constraints of the reductive mode of genomic evolution account for the divergence of the genetic code in mitochondria and the genetic organization of the translational system observed in parasitic bacteria. In particular, we associate codon reassignments in animal mitochondria with greatly simplified tRNA populations. Likewise, we relate the organization of translational genes in the obligate intracellular parasite Rickettsia prowazekii to the processes supporting the reductive mode of genomic evolution. Such findings provide strong support for the hypothesis that genomes of organelles and of parasitic bacteria have arisen from the much larger genomes of ancestral bacteria that have been reduced by intrachromosomal recombination and deletion events. A consequence of the reductive mode of genomic evolution is that the resulting translation systems may deviate markedly from conventional systems.
Collapse
Affiliation(s)
- S G Andersson
- Department of Molecular Biology, Uppsala University, Sweden
| | | |
Collapse
|
23
|
Affiliation(s)
- D R Johns
- Department of Neurology, Beth Israel Hospital, Boston, MA, USA
| |
Collapse
|
24
|
Yang JH, Lee HC, Wei YH. Photoageing-associated mitochondrial DNA length mutations in human skin. Arch Dermatol Res 1995; 287:641-8. [PMID: 8534127 DOI: 10.1007/bf00371736] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
It has recently been suggested that mitochondrial DNA (mtDNA) mutations are important contributors to human ageing and degenerative diseases. Using PCR techniques, we demonstrated three types of mtDNA length mutations, a 4977 bp deletion, a 7436 bp deletion and tandem duplications, in normal human skin tissues. We found that these mutations started to appear in the third decade of life, and the age at which the mutations could be detected in sun-exposed skin was usually younger than in non-exposed skin. Moreover, the incidences of these deletions and tandem duplications of mtDNA in sun-exposed skin were all significantly higher than those in non-exposed skin (P < 0.05). The 4977 bp deletion was the most prevalant mtDNA mutation in human skin, and the 7436 bp deletion was the least frequent among the three types of mtDNA mutations examined. We first demonstrated the existence of tandem duplications with sizes of about 260 bp, 200 bp and 150 bp in the D-loop region of mtDNA in the skin of elderly individuals. Among the three tandem duplications, the 200-bp duplication was found to occur most frequently in ageing skin. The tandem duplications were found to coexist with either or both of the deletions in some elderly individuals. The frequency of occurrence of mtDNA deletions and tandem duplications in skin was found to increase in an age-dependent manner. However, the incidence of tandem duplications was not well correlated with the age of the subject.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- J H Yang
- Department of Dermatology, China Medical College and Hospital, Taichung, Taiwan, ROC
| | | | | |
Collapse
|
25
|
Mitochondrial deoxyribonucleic acid deletions in oocytes and reproductive aging in women**Supported by National Institutes of Health K08 HD01099–01, Bethesda, Maryland and by The American Fertility Society-Ortho Research Award from The American Fertility Society, Birmingham, Alabama (D.K.).††Presented at the 41st Annual Meeting of the Society for Gynecologic Investigation, Chicago, Illinois, March 22 to 26, 1994. Fertil Steril 1995. [DOI: 10.1016/s0015-0282(16)57796-6] [Citation(s) in RCA: 200] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
26
|
Klopstock T, Bischof F, Gerok K, Deuschl G, Seibel P, Ketelsen UP, Reichmann H. 3.1-kb deletion of mitochondrial DNA in a patient with Kearns-Sayre syndrome. Acta Neuropathol 1995; 90:126-9. [PMID: 7484086 DOI: 10.1007/bf00294310] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Mitochondrial DNA (mtDNA) deletions have been found in the majority of patients with chronic progressive external ophthalmoplegia and Kearns-Sayre syndrome. A large number of different mtDNA deletions have been identified. They generally spare the two origins of replication and are frequently flanked by direct or indirect repeats. We have found a 3.1-kb deletion of mtDNA in a patient with Kearns-Sayre syndrome that has some unusual features. First, it encompasses nucleotides 11259 to 14368, a localization that was not described before. Second, the deletion is not flanked by direct or indirect repeats, supporting the view that homologous recombination and slip-replication do not account for all mtDNA deletions.
Collapse
Affiliation(s)
- T Klopstock
- Department of Neurology, University of Würzburg, Germany
| | | | | | | | | | | | | |
Collapse
|
27
|
Kawashima S, Ohta S, Kagawa Y, Yoshida M, Nishizawa M. Widespread tissue distribution of multiple mitochondrial DNA deletions in familial mitochondrial myopathy. Muscle Nerve 1994; 17:741-6. [PMID: 8008000 DOI: 10.1002/mus.880170707] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We used Southern blot analysis and the polymerase chain reaction to analyze the tissue distribution of multiple mitochondrial DNA (mtDNA) deletions in a 45-year-old man with familial mitochondrial myopathy-Southern blots showed two major types of abnormal mtDNA with approximately 4- and 8-kilobase deletions in the skeletal and extraocular muscles. The amount of muscle mtDNA with deletions correlated approximately with the severity of muscle involvement. The polymerase chain reaction showed multiple mtDNA deletions even in clinically asymptomatic tissues, the pattern of which differed with the type of tissue. Nucleotide sequences of several mtDNAs with deletions showed that the deletions were flanked by direct repeats consisting of 3 to 12 nucleotides. Leukocytes from the patient's affected sister and his mother exhibited the same mtDNA deletion pattern. Most of the same deletions were present in leukocytes obtained from the patient's father.
Collapse
Affiliation(s)
- S Kawashima
- Department of Neurology, Jichi Medical School, Tochigi, Japan
| | | | | | | | | |
Collapse
|
28
|
Chung SS, Weindruch R, Schwarze SR, McKenzie DI, Aiken JM. Multiple age-associated mitochondrial DNA deletions in skeletal muscle of mice. AGING (MILAN, ITALY) 1994; 6:193-200. [PMID: 7993927 DOI: 10.1007/bf03324239] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Multiple mitochondrial DNA (mtDNA) deletions have been associated with aging in humans and monkeys. Since the inbred mouse strain, C57BL/6, has been extensively studied gerontologically, we sought to investigate its utility as a model for examining the importance of mtDNA deletions in aging. Using the polymerase chain reaction (PCR), we analyzed hind limb skeletal muscle from mice of three age groups (5, 16 and 25 months) for the presence of age-associated mtDNA deletions. We observed multiple mtDNA deletions in all three age groups. Further, the number of deletions detected per mouse increased greatly with advancing age.
Collapse
Affiliation(s)
- S S Chung
- Department of Animal Health and Biomedical Sciences, University of Wisconsin-Madison 53706
| | | | | | | | | |
Collapse
|
29
|
Soong NW, Hinton DR, Cortopassi G, Arnheim N. Mosaicism for a specific somatic mitochondrial DNA mutation in adult human brain. Nat Genet 1992; 2:318-23. [PMID: 1303287 DOI: 10.1038/ng1292-318] [Citation(s) in RCA: 328] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The levels of a specific mitochondrial DNA deletion (mtDNA4977) measured in 12 brain regions of 6 normal adults 39 to 82 years old exhibited striking variation among anatomical locations. Comparisons of the same region among individuals showed an increase of mtDNA4977 with age. The three regions with the highest levels, caudate, putamen and substantia nigra, are characterized by a high dopamine metabolism. The breakdown of dopamine by mitochondrial MAO produces H2O2 which can lead to oxygen radical formation. We suggest that mtDNA4977 may be the "tip of the iceberg" of the spectrum of somatic mutations produced by oxidative damage.
Collapse
Affiliation(s)
- N W Soong
- Molecular Biology Section, University of Southern California, Los Angeles 90089-1340
| | | | | | | |
Collapse
|
30
|
Osiewacz HD, Hermanns J. The role of mitochondrial DNA rearrangements in aging and human diseases. AGING (MILAN, ITALY) 1992; 4:273-86. [PMID: 1294242 DOI: 10.1007/bf03324108] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Instabilities and point mutations of the high molecular weight mitochondrial DNA (mtDNA) were shown to be correlated with various degenerative processes in both lower eukaryotes as well as in mammals. In filamentous fungi, circular and linear plasmids were demonstrated to be involved in mtDNA rearrangements and in the genetic control of senescence. In addition, in these eukaryotic microorganisms, which have proved to be ideal model systems in experimental gerontology, a number of nuclear genes were identified controlling the stability of the mitochondrial genome. Although the mitochondrial genome of mammals, including humans, appears to be quite stable in comparison to other species, mtDNA instabilities of the type described in fungi were observed in mitochondria of patients with different mitochondrial degenerative disorders (CPEO, KSS, Pearson syndrome, LHON, MERRF, MELAS). It was later demonstrated that such mtDNA rearrangements appear to accumulate progressively during aging in human subjects. These data suggest that instabilities of the mitochondrial genome may play an important role in the control of life span not only in lower eukaryotes, but also in humans.
Collapse
Affiliation(s)
- H D Osiewacz
- Deutsches Krebsforschungszentrum, Institut für Virusforschung, Heidelberg, Germany
| | | |
Collapse
|
31
|
Abstract
Mitochondrial genomes are clearly marked by a strong tendency towards reductive evolution. This tendency has been facilitated by the transfer of most of the essential genes for mitochondrial propogation and function to the nuclear genome. The most extreme examples of genomic simplification are seen in animal mitochondria, where there also are the greatest tendencies to codon reassignment. The reassignment of codons to amino acids different from those designated in the so called universal code is seen in part as an expression of the reduction of the number of genes used by these genomes to code for tRNA species. The driving force for the reductive evolution of mitochondrial genomes is identified with two population genetic effects which may also be operating on populations of parasites.
Collapse
Affiliation(s)
- C G Kurland
- Department of Molecular Biology, Biomedical Center, Uppsala, Sweden
| |
Collapse
|
32
|
Threlkeld AB, Miller NR, Golnik KC, Griffin JW, Kuncl RW, Johns DR, Lehar M, Hurko O. Ophthalmic involvement in myo-neuro-gastrointestinal encephalopathy syndrome. Am J Ophthalmol 1992; 114:322-8. [PMID: 1524123 DOI: 10.1016/s0002-9394(14)71799-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We studied the clinical, histopathologic, neuroradiologic, biochemical, and genetic profile of a patient with the myo-neuro-gastrointestinal encephalopathy syndrome, a recently described multisystem mitochondriopathy characterized by blepharoptosis and ophthalmoparesis. The patient had severe intestinal pseudo-obstruction and a mixed demyelinating and axonal neuropathy. Abnormal collections of mitochondria in nerve and muscle as well as diffuse white matter disease were present. Cytochrome oxidase activity in muscle mitochondria was reduced. No mitochondrial DNA deletions were detected.
Collapse
Affiliation(s)
- A B Threlkeld
- Wilmer Ophthalmological Institute, Johns Hopkins Hospital, Baltimore, MD 21205
| | | | | | | | | | | | | | | |
Collapse
|
33
|
Suomalainen A, Majander A, Haltia M, Somer H, Lönnqvist J, Savontaus ML, Peltonen L. Multiple deletions of mitochondrial DNA in several tissues of a patient with severe retarded depression and familial progressive external ophthalmoplegia. J Clin Invest 1992; 90:61-6. [PMID: 1634620 PMCID: PMC443063 DOI: 10.1172/jci115856] [Citation(s) in RCA: 190] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Multiple deletions of mitochondrial DNA (mtDNA) have recently been reported in familial progressive external ophthalmoplegia (PEO), in a case of progressive encephalomyopathy, and in inherited recurrent myoglobinuria. The inheritance of familial PEO has been autosomal dominant, which indicates that a mutation in an unknown nuclear gene results in several mtDNA deletions of different sizes in these patients. We report a patient with autosomal dominant PEO, whose major clinical symptom, however, was severe retarded depression. The morphological analyses of the tissue samples derived from autopsy showed various abnormalities in the mitochondria in all the tissues studied. The activities of the respiratory chain enzymes encoded by mtDNA were remarkably reduced in the skeletal muscle. The mtDNA analyses confirmed that besides myopathy, this patient had a multisystem disorder with widespread distribution of multiple deletions of mtDNA. The highest percentage of mutated mtDNA was found in the brain, skeletal muscle and the heart, the relative quantity of mutated mtDNA correlating to the severity of the clinical symptoms.
Collapse
Affiliation(s)
- A Suomalainen
- Department of Human Molecular Genetics, National Public Health Institute, Helsinki, Finland
| | | | | | | | | | | | | |
Collapse
|
34
|
Haltia M, Suomalainen A, Majander A, Somer H. Disorders associated with multiple deletions of mitochondrial DNA. Brain Pathol 1992; 2:133-9. [PMID: 1341954 DOI: 10.1111/j.1750-3639.1992.tb00681.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Multiple deletions of mitochondrial DNA (mtDNA) have recently been described in a number of patients with neurological disorders. Most cases have been clinically characterized by autosomal dominant inheritance, adult onset, and a slowly progressive course with external ophthalmoplegia and muscle weakness. Some patients have had evidence of central or peripheral nervous system involvement or episodes of myoglobinuria. Muscle biopsy findings include ragged-red fibres (RRF), muscle fibres with absent COX-activity and abundant abnormal mitochondria with paracrystalline inclusions. Biochemically, a generalized reduction in the activities of mtDNA-encoded enzymes is observed in skeletal muscle. Southern blotting or PCR analysis reveal multiple populations of deleted mtDNA. The deletions occur at multiple sites between the replication initiation sites, involving a large portion of mtDNA, and most deletions seem to be flanked by direct sequence repeats, shown to be "hot spots" in the case of single large deletions. Apparently, a defect in a nuclear gene results in multiple deletions of mtDNA. Both clinical, genetic and molecular genetic observations indicate heterogeneity of this new disease category, apparently based on a disturbance in the "cross-talk" between the nuclear and the mitochondrial genomes.
Collapse
Affiliation(s)
- M Haltia
- Department of Pathology, University of Helsinki, Finland
| | | | | | | |
Collapse
|
35
|
Abstract
In the past few years several syndromes have been associated with lesions of the human mitochondrial DNA. MtDNA is a small, circular extra-nuclear chromosome encoding essential components of the respiratory chain. MtDNA-related syndromes can be divided into two groups: mitochondrial encephalomyopathies, characterized by the presence of ragged-red fibres (RRF) as the morphological hallmark, or "pure" encephalopathies with no gross morphological abnormalities in muscle. The first group includes myoclonic epilepsy with ragged-red fibres (MERRF), mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS), Kearns-Sayre syndrome (KSS), chronic progressive external ophthalmoplegia (CPEO) and a new entity, maternally inherited myopathy and cardiomyopathy. The second group includes Leber's Hereditary Optic Neuroretinopathy (LHON) and the newly described ataxia-retinitis pigmentosa-dementia complex. Three kinds of molecular lesions have been identified: point mutations of protein encoding mtDNA-genes (similar to yeast mit- mutations); point mutations of mtDNA-tRNA genes (similar to yeast syn- mutations); and large-scale rearrangements of mtDNA (similar to yeast rho- mutations). In general, "mit-" mutations are responsible for non-RRF encephalopathies, while "syn-" and "rho-" mutations are associated with mitochondrial encephalomyopathies with RRF. Furthermore, point mutations (mit- and syn-) are usually maternally- inherited, while large-scale mtDNA rearrangements are either sporadic or inherited as mendelian traits. In most cases, the molecular detection of the known defects of mtDNA can be carried out by non-invasive techniques, thus making it an easy and relatively inexpensive procedure in the differential diagnosis of the mitochondrial disorders, a rapidly expanding area of clinical neurology.
Collapse
Affiliation(s)
- M Zeviani
- Carlo Besta National Institute of Neurology, Milano, Italy
| | | |
Collapse
|
36
|
Johns DR. Mitochondrial ND-I mutation in Leber hereditary optic neuropathy. Am J Hum Genet 1992; 50:872-4. [PMID: 1550131 PMCID: PMC1682636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
|
37
|
Byrne E, Jean-Francois B, Thyagarajan D, Collins S, Dennett X, Marzuki S. Biochemical and molecular investigation of mitochondrial disease: an illustrative case showing the value of a multifaceted approach. AUSTRALIAN AND NEW ZEALAND JOURNAL OF MEDICINE 1991; 21:837-43. [PMID: 1818542 DOI: 10.1111/j.1445-5994.1991.tb01404.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Detailed biochemical and molecular investigations in a patient with Kearns-Sayre syndrome are presented. Polarographic studies in isolated mitochondria revealed a global impairment in respiratory capacity consistent with an admixture of functional and non-functional mitochondria. Cytochrome difference spectra revealed a selective deficiency in cytochrome aa3. Western immunoblot studies revealed normal subunit content of Complexes I, III and IV. Southern blot studies of mtDNA showed a deletion of approximately 5 Kb coexisting with wild type DNA. PCR analysis confirmed that this deletion lies between the ATPase8 and NAD coenzyme Q oxidoreductase subunit 5 (ND5) genes. Breakpoint sequencing revealed a 13 nucleotide direct repeat flanking sequence (ACCTCCCTCACCA) consistent with slippage in mtDNA during replication as the mechanism of deletion. Histochemical studies of skeletal muscle revealed many cytochrome oxidase negative fibres and immunocytochemical studies showed cytochrome oxidase negative areas with abundant respiratory complex protein suggesting upregulation. The value of a multifaceted approach in unravelling the pathophysiology of mitochondrial diseases is emphasised.
Collapse
Affiliation(s)
- E Byrne
- Department of Medicine, St Vincent's Hospital, Melbourne Victoria, Australia
| | | | | | | | | | | |
Collapse
|
38
|
Johns DR. Allelic mutations of the fourth subunit of NADH dehydrogenase are not pathogenetically important in 11778-negative Leber hereditary optic neuropathy. Am J Hum Genet 1991; 48:1209-13. [PMID: 2035540 PMCID: PMC1683097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
|
39
|
|
40
|
Lauber J, Marsac C, Kadenbach B, Seibel P. Mutations in mitochondrial tRNA genes: a frequent cause of neuromuscular diseases. Nucleic Acids Res 1991; 19:1393-7. [PMID: 1709275 PMCID: PMC333891 DOI: 10.1093/nar/19.7.1393] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
We have sequenced the tRNA genes of mtDNA from patients with chronic progressive external ophthalmoplegia (CPEO) without detectable mtDNA deletions. Four point mutations were identified, located within highly conserved regions of mitochondrial tRNA genes, namely tRNA(Leu)(UAG), tRNA(Ser)(GCU), tRNA(Gly) and tRNA(Lys). One of these mutations (tRNA(Leu)(UAG)) was found in four patients with different forms of mitochondrial myopathy. An accumulation of three different tRNA point mutations (tRNA(Leu)(UAG)), tRNA(Ser)(GCU) and tRNA(Gly) was observed in a single patient, suggesting that mitochondrial tRNA genes represent hotspots for point mutations causing neuromuscular diseases.
Collapse
Affiliation(s)
- J Lauber
- Fachbereich Chemie, Philipps-Universität, Marburg, FRG
| | | | | | | |
Collapse
|
41
|
Replication-competent human mitochondrial DNA lacking the heavy-strand promoter region. Mol Cell Biol 1991. [PMID: 1996112 DOI: 10.1128/mcb.11.3.1631] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We identified two patients with progressive external ophthalmoplegia, a mitochondrial disease, who harbored a population of partially deleted mitochondrial DNA (mtDNA) with unusual properties. These molecules were deleted from mtDNA positions 548 to 4,442 and encompassed not only rRNA sequences but the heavy-strand promoter region as well. A 13-bp direct repeat was found flanking the breakpoint precisely, with the repeat at positions 535 to 547 located within the binding site for mitochondrial transcription factor 1 (mtTF1). This is the second mtDNA deletion involving a 13-bp direct repeat reported but is at least 10 times less frequent in the patient population than the former one. In situ hybridization studies showed that transcripts under the control of the light-strand promoter were abundant in muscle fibers with abnormal proliferation of mitochondria, while transcripts directed by the heavy-strand promoter, whether of genes residing inside or outside the deleted region, were not. The efficient transcription from the light-strand promoter implies that the major heavy-and light-strand promoters, although physically close, are functionally independent, confirming previous in vitro studies.
Collapse
|
42
|
Replication-competent human mitochondrial DNA lacking the heavy-strand promoter region. Mol Cell Biol 1991; 11:1631-7. [PMID: 1996112 PMCID: PMC369459 DOI: 10.1128/mcb.11.3.1631-1637.1991] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
We identified two patients with progressive external ophthalmoplegia, a mitochondrial disease, who harbored a population of partially deleted mitochondrial DNA (mtDNA) with unusual properties. These molecules were deleted from mtDNA positions 548 to 4,442 and encompassed not only rRNA sequences but the heavy-strand promoter region as well. A 13-bp direct repeat was found flanking the breakpoint precisely, with the repeat at positions 535 to 547 located within the binding site for mitochondrial transcription factor 1 (mtTF1). This is the second mtDNA deletion involving a 13-bp direct repeat reported but is at least 10 times less frequent in the patient population than the former one. In situ hybridization studies showed that transcripts under the control of the light-strand promoter were abundant in muscle fibers with abnormal proliferation of mitochondria, while transcripts directed by the heavy-strand promoter, whether of genes residing inside or outside the deleted region, were not. The efficient transcription from the light-strand promoter implies that the major heavy-and light-strand promoters, although physically close, are functionally independent, confirming previous in vitro studies.
Collapse
|
43
|
Krawczak M, Cooper DN. Gene deletions causing human genetic disease: mechanisms of mutagenesis and the role of the local DNA sequence environment. Hum Genet 1991; 86:425-41. [PMID: 2016084 DOI: 10.1007/bf00194629] [Citation(s) in RCA: 313] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Reports describing short (less than 20 bp) gene deletions causing human genetic disease were collated in order to study underlying causative mechanisms. Deletion breakpoint junction regions were found to be non-random both at the nucleotide and dinucleotide sequence levels, an observation consistent with an endogenous sequence-directed mechanism of mutagenesis. Direct repeats of between 2bp and 8bp were found in the immediate vicinity of all but one of the 60 deletions analysed. Direct repeats are a feature of a number of recombination, replication or repair-based models of deletion mutagenesis and the possible contribution of each to the spectrum of mutations examined was assessed. The influence of parameters such as repeat length and length of DNA between repeats was studied in relation to the frequency, location and extent of these deletions. Findings were broadly consistent with a slipped mispairing model but the predicted deletion of one whole repeat copy was found only rarely. A modified version of the slipped mispairing hypothesis was therefore proposed and was shown to possess considerable explanatory value for approximately 25% of deletions examined. Whereas the frequency of inverted repeats in the vicinity of gene deletions was not significantly elevated, these elements may nevertheless promote instability by facilitating the formation of secondary structure intermediates. A significant excess of symmetrical sequence elements was however found at sites of single base deletions. A new model to explain the involvement of symmetric elements in frameshift mutagenesis was devised, which successfully accounted for a majority of the single base deletions examined. In general, the loss of one or a few base pairs of DNA was found to be more compatible with a replication-based model of mutagenesis than with a recombination or repair hypothesis. Seven hitherto unrecognized hotspots for deletion were noted in five genes (AT3, F8, HBA, HBB and HPRT). Considerable sequence homology was found between these different sites, and a consensus sequence (TGA/GA/GG/TA/C) was drawn up. Sequences fitting this consensus (i) were noted in the immediate vicinity of 41% of the other (sporadic) gene deletions, (ii) were found frequently at sites of spontaneous deletion in the hamster APRT gene, (iii) were found to be associated with many larger human gene deletions/translocations, (iv) act as arrest sites for human polymerase alpha during DNA replication and (v) have been shown by in vitro studies of human polymerase alpha to be especially prone to frameshift mutation.(ABSTRACT TRUNCATED AT 400 WORDS)
Collapse
Affiliation(s)
- M Krawczak
- Institut für Humangenetik der Universität, Göttingen, Federal Republic of Germany
| | | |
Collapse
|
44
|
Degoul F, Nelson I, Amselem S, Romero N, Obermaier-Kusser B, Ponsot G, Marsac C, Lestienne P. Different mechanisms inferred from sequences of human mitochondrial DNA deletions in ocular myopathies. Nucleic Acids Res 1991; 19:493-6. [PMID: 2011523 PMCID: PMC333638 DOI: 10.1093/nar/19.3.493] [Citation(s) in RCA: 62] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
We have sequenced the deletion borders of the muscle mitochondrial DNA from 24 patients with heteroplasmic deletions. The length of these deletions varies from 2.310 bp to 8.476 bp and spans from position 5.786 to 15.925 of the human mitochondrial genome preserving the heavy chain and light chain origins of replication. 12 cases are common deletions identical to the mutation already described by other workers and characterized by 13 bp repeats at the deletion boundaries, one of these repeats being retained during the deletion process. The other cases (10 out of 12) have shown deletions which have not been previously described. All these deletions are located in the H strand DNA region which is potentially single stranded during mitochondrial DNA replication. In two cases, the retained Adenosine from repeat closed to the heavy strand origin of replication would indicate slippage mispairing. Furthermore in one patient two mt DNA molecules have been cloned and their sequences showed the difference of four nucleotides in the breakpoint of the deletion, possibly dued to slippage mispairing. Taken together our results suggest that deletions occur either by slippage mispairing or by internal recombination at the direct repeat level. They also suggest that different mechanisms account for the deletions since similarly located deletions may display different motives at the boundaries including the absence of any direct repeat.
Collapse
Affiliation(s)
- F Degoul
- Inserm U 75, Faculté de médecine Necker-Enfants Malades, Paris, FRG
| | | | | | | | | | | | | | | |
Collapse
|
45
|
Kosmorsky G, Johns DR. Neuro-ophthalmologic Manifestations of Mitochondrial DNA Disorders: Chronic Progressive External Ophthalmoplegia, Kearns-Sayre Syndrome, and Leber’s Hereditary Optic Neuropathy. Neurol Clin 1991. [DOI: 10.1016/s0733-8619(18)30308-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
46
|
Mignotte F, Gueride M, Champagne AM, Mounolou JC. Direct repeats in the non-coding region of rabbit mitochondrial DNA. Involvement in the generation of intra- and inter-individual heterogeneity. EUROPEAN JOURNAL OF BIOCHEMISTRY 1990; 194:561-71. [PMID: 2269281 DOI: 10.1111/j.1432-1033.1990.tb15653.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
In rabbit we observed heteroplasmy at an exceptionally high level, the heterogeneity occurring within the non-coding region of the DNA. Mitochondrial DNA (mt DNA) was cloned in pBR322 and the nucleotide sequence analysis of an EcoRI-Hind III fragment encompassing the non-coding region revealed that although there are common features with other mammalian mtDNAs (termed large central-conserved-sequence block, conserved-sequence blocks 1, 2 and 3 and termination-associated elements) the non-coding region shows an unusual organization; two stretches of tandem repeats of 20 bp and 153 bp are present in a part containing the origin of H-strand replication (OH) and probably the promoters for transcription as judged from other vertebrates. The long repeats are located between tRNA(Phe) and conserved sequence block 3 and the short repeats are located between conserved sequence blocks 1 and 2. When cloned in Escherichia coli (recA or recBC sbcb) DNA fragments containing the short repeats show length differences corresponding to various copy numbers of repeats. Electrophoretic analysis of the appropriate restriction fragments of rabbit mtDNA reveals extended intra- and inter-individual length heterogeneity. Both sets of repeats are involved in the generation of heterogeneity and are present in variable copy numbers from one mtDNA molecule to another. Moreover, rearrangement of the motives of the short repeat are observed to different extents in the mtDNA from one animal to another. The occurrence, maintenance and possible involvement of these repeated sequences, capable of forming stable secondary structures, are discussed in relation to their location in the region of control signals.
Collapse
Affiliation(s)
- F Mignotte
- Laboratoire de Biologie Générale-URA 1354, Université de Paris-Sud, Orsay, France
| | | | | | | |
Collapse
|
47
|
Cortopassi GA, Arnheim N. Detection of a specific mitochondrial DNA deletion in tissues of older humans. Nucleic Acids Res 1990; 18:6927-33. [PMID: 2263455 PMCID: PMC332752 DOI: 10.1093/nar/18.23.6927] [Citation(s) in RCA: 572] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Using PCR, we found that normal heart muscle and brain from adult human individuals contain low levels of a specific mitochondrial DNA deletion, previously found only in patients affected with certain types of neuromuscular disease. This deletion was not observed in fetal heart or brain. Experimental tests support the idea that the deletion exists in vivo in adult mitochondria and is not an in vitro artifact of PCR. Our data provide direct experimental support for the idea that accumulation of mitochondrial DNA deletions may be important in aging.
Collapse
Affiliation(s)
- G A Cortopassi
- Molecular Biology Section, University of Southern California, Los Angeles 90089-1340
| | | |
Collapse
|
48
|
Zeviani M, Bresolin N, Gellera C, Bordoni A, Pannacci M, Amati P, Moggio M, Servidei S, Scarlato G, DiDonato S. Nucleus-driven multiple large-scale deletions of the human mitochondrial genome: a new autosomal dominant disease. Am J Hum Genet 1990; 47:904-14. [PMID: 1978558 PMCID: PMC1683915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
We studied several affected and one nonaffected individuals belonging to three unrelated pedigrees. The pathological trait was an autosomal dominant mitochondrial myopathy due to large-scale multiple deletions of the mitochondrial genome. Clinically, symptomatic patients had progressive external ophthalmoplegia, muscle weakness and wasting, sensorineural hypoacusia, and, in some cases, vestibular areflexia and tremor. The muscle biopsies of all patients examined showed ragged-red fibers, neurogenic changes, and a partially decreased histochemical reaction to cytochrome c oxidase. Multiple mtDNA heteroplasmy was detected in the patients by both Southern blot analysis and PCR amplification, whereas the unaffected individual had the normal homoplasmic hybridization pattern. These findings confirm and add further details to the existence of a new human disease--defined clinically as a mitochondrial myopathy, genetically as a Mendelian autosomal dominant trait, and molecularly by the accumulation of multiple, large-scale deletions of the mitochondrial genome--that is due to impaired nuclear control during mtDNA replication.
Collapse
|
49
|
Stoneking M. Departure of human mitochondrial DNA variation from neutral expectations: an alternative explanation. J Mol Evol 1990; 31:343-6; discussion 347-50. [PMID: 2124281 DOI: 10.1007/bf02101128] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- M Stoneking
- Department of Anthropology, Pennsylvania State University, University Park 16802
| |
Collapse
|
50
|
Eleff SM, Barker PB, Blackband SJ, Chatham JC, Lutz NW, Johns DR, Bryan RN. Phosphorus magnetic resonance spectroscopy of patients with mitochondrial cytopathies demonstrates decreased levels of brain phosphocreatine. Ann Neurol 1990; 27:626-30. [PMID: 2360799 DOI: 10.1002/ana.410270607] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The hypothesis that brain mitochondria are directly affected in several phenotypes associated with disordered oxidative phosphorylation was tested using phosphorus 31 (31P) magnetic resonance spectroscopy. Abnormal phosphorylation potentials in skeletal muscle have been demonstrated by 31P magnetic resonance spectroscopy in patients with mitochondrial cytopathies (heritable disorders of oxidative phosphorylation), but abnormalities of phosphorylation potentials in other organs have not been documented. Several lines of evidence suggest that these mutations may affect mitochondria in nonmuscle tissue. In this study we found that phosphocreatine-to-ATP ratios in brain were significantly reduced and that calculated brain ADP concentrations, phosphorylation potentials, and percentage of maximal rate of ATP synthesis were significantly altered in the 5 patients examined. This study indicates a primary abnormality of mitochondrial function in the brain, even in the absence of clinically evident cerebral dysfunction.
Collapse
Affiliation(s)
- S M Eleff
- Department of Anesthesiology, Johns Hopkins Medical School, Baltimore, MD
| | | | | | | | | | | | | |
Collapse
|