1
|
Mossman JA, Biancani LM, Rand DM. Mitochondrial genomic variation drives differential nuclear gene expression in discrete regions of Drosophila gene and protein interaction networks. BMC Genomics 2019; 20:691. [PMID: 31477008 PMCID: PMC6719383 DOI: 10.1186/s12864-019-6061-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 08/26/2019] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Mitochondria perform many key roles in their eukaryotic hosts, from integrating signaling pathways through to modulating whole organism phenotypes. The > 1 billion years of nuclear and mitochondrial gene co-evolution has necessitated coordinated expression of gene products from both genomes that maintain mitochondrial, and more generally, eukaryotic cellular function. How mitochondrial DNA (mtDNA) variation modifies host fitness has proved a challenging question but has profound implications for evolutionary and medical genetics. In Drosophila, we have previously shown that recently diverged mtDNA haplotypes within-species can have more impact on organismal phenotypes than older, deeply diverged haplotypes from different species. Here, we tested the effects of mtDNA haplotype variation on gene expression in Drosophila under standardized conditions. Using the Drosophila Genetic Reference Panel (DGRP), we constructed a panel of mitonuclear genotypes that consists of factorial variation in nuclear and mtDNA genomes, with mtDNAs originating in D. melanogaster (2x haplotypes) and D. simulans (2x haplotypes). RESULTS We show that mtDNA haplotype variation unequivocally alters nuclear gene expression in both females and males, and mitonuclear interactions are pervasive modifying factors for gene expression. There was appreciable overlap between the sexes for mtDNA-sensitive genes, and considerable transcriptional variation attributed to particular mtDNA contrasts. These genes are generally found in low-connectivity gene co-expression networks, occur in gene clusters along chromosomes, are often flanked by non-coding RNA, and are under-represented among housekeeping genes. Finally, we identify the giant (gt) transcription factor motif as a putative regulatory sequence associated with mtDNA-sensitive genes. CONCLUSIONS There are predictive conditions for nuclear genes that are influenced by mtDNA variation.
Collapse
Affiliation(s)
- Jim A Mossman
- Department of Ecology and Evolutionary Biology, Box G, Brown University, Providence, RI, 02912, USA.
| | - Leann M Biancani
- Department of Ecology and Evolutionary Biology, Box G, Brown University, Providence, RI, 02912, USA
- Present Address: Department of Biology, University of Maryland, College Park, MD, 20742, USA
| | - David M Rand
- Department of Ecology and Evolutionary Biology, Box G, Brown University, Providence, RI, 02912, USA.
| |
Collapse
|
2
|
Mahalaxmi I, Santhy K. An overview about mitochondrial DNA mutations in ovarian cancer. ALEXANDRIA JOURNAL OF MEDICINE 2019. [DOI: 10.1016/j.ajme.2017.05.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Affiliation(s)
- Iyer Mahalaxmi
- Department of Zoology, Avinashilingam Institute for Home Science and Higher Education for Women, India
| | | |
Collapse
|
3
|
Caporali L, Iommarini L, La Morgia C, Olivieri A, Achilli A, Maresca A, Valentino ML, Capristo M, Tagliavini F, Del Dotto V, Zanna C, Liguori R, Barboni P, Carbonelli M, Cocetta V, Montopoli M, Martinuzzi A, Cenacchi G, De Michele G, Testa F, Nesti A, Simonelli F, Porcelli AM, Torroni A, Carelli V. Peculiar combinations of individually non-pathogenic missense mitochondrial DNA variants cause low penetrance Leber's hereditary optic neuropathy. PLoS Genet 2018; 14:e1007210. [PMID: 29444077 PMCID: PMC5828459 DOI: 10.1371/journal.pgen.1007210] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 02/27/2018] [Accepted: 01/21/2018] [Indexed: 12/23/2022] Open
Abstract
We here report on the existence of Leber’s hereditary optic neuropathy (LHON) associated with peculiar combinations of individually non-pathogenic missense mitochondrial DNA (mtDNA) variants, affecting the MT-ND4, MT-ND4L and MT-ND6 subunit genes of Complex I. The pathogenic potential of these mtDNA haplotypes is supported by multiple evidences: first, the LHON phenotype is strictly inherited along the maternal line in one very large family; second, the combinations of mtDNA variants are unique to the two maternal lineages that are characterized by recurrence of LHON; third, the Complex I-dependent respiratory and oxidative phosphorylation defect is co-transferred from the proband’s fibroblasts into the cybrid cell model. Finally, all but one of these missense mtDNA variants cluster along the same predicted fourth E-channel deputed to proton translocation within the transmembrane domain of Complex I, involving the ND1, ND4L and ND6 subunits. Hence, the definition of the pathogenic role of a specific mtDNA mutation becomes blurrier than ever and only an accurate evaluation of mitogenome sequence variation data from the general population, combined with functional analyses using the cybrid cell model, may lead to final validation. Our study conclusively shows that even in the absence of a clearly established LHON primary mutation, unprecedented combinations of missense mtDNA variants, individually known as polymorphisms, may lead to reduced OXPHOS efficiency sufficient to trigger LHON. In this context, we introduce a new diagnostic perspective that implies the complete sequence analysis of mitogenomes in LHON as mandatory gold standard diagnostic approach. Leber’s hereditary optic neuropathy (LHON) is a common cause of maternally inherited vision loss. In the large majority of cases LHON is due to mitochondrial DNA (mtDNA) point mutations, clearly distinct from common polymorphisms normally found in the general population, affecting the mitochondrial function, thus defined as pathogenic. For the first time, we here demonstrate, on the genetic and functional ground, that unusual combinations of otherwise polymorphic and non-pathogenic mtDNA variants are sufficient for causing low-penetrance maternally inherited optic neuropathy in pedigrees fitting the LHON clinical diagnosis. Our findings bridge the blurry border between “pathogenic” and “neutral” mutations in an overall continuum that truly depends on the specific and sometime unique combination of variants characterizing each mitogenome. As a result, we conclude that, for an accurate diagnosis of LHON and possibly of other mitochondrial diseases, the only approach that can disclose all possible causative sources is complete mitogenome sequencing.
Collapse
Affiliation(s)
- Leonardo Caporali
- Neurology Unit, IRCCS Institute of Neurological Sciences of Bologna, Bologna, Italy
| | - Luisa Iommarini
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, Bologna, Italy
| | - Chiara La Morgia
- Neurology Unit, IRCCS Institute of Neurological Sciences of Bologna, Bologna, Italy
- Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | - Anna Olivieri
- Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, Pavia, Italy
| | - Alessandro Achilli
- Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, Pavia, Italy
| | - Alessandra Maresca
- Neurology Unit, IRCCS Institute of Neurological Sciences of Bologna, Bologna, Italy
| | - Maria Lucia Valentino
- Neurology Unit, IRCCS Institute of Neurological Sciences of Bologna, Bologna, Italy
- Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | | | - Francesca Tagliavini
- Neurology Unit, IRCCS Institute of Neurological Sciences of Bologna, Bologna, Italy
| | - Valentina Del Dotto
- Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | - Claudia Zanna
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, Bologna, Italy
| | - Rocco Liguori
- Neurology Unit, IRCCS Institute of Neurological Sciences of Bologna, Bologna, Italy
- Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | | | - Michele Carbonelli
- Neurology Unit, IRCCS Institute of Neurological Sciences of Bologna, Bologna, Italy
- Studio Oculistico D’Azeglio, Bologna, Italy
| | - Veronica Cocetta
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padua, Italy
| | - Monica Montopoli
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padua, Italy
| | - Andrea Martinuzzi
- IRCCS "E. Medea" Scientific Institute Conegliano-Pieve di Soligo Research Center, Pieve di Soligo, Italy
| | - Giovanna Cenacchi
- Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | - Giuseppe De Michele
- Department of Neuroscience, Reproductive Sciences and Dentistry, University of Naples “Federico II”, Naples, Italy
| | - Francesco Testa
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, University of Campania “Luigi Vanvitelli”, Naples, Italy
| | - Anna Nesti
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, University of Campania “Luigi Vanvitelli”, Naples, Italy
| | - Francesca Simonelli
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, University of Campania “Luigi Vanvitelli”, Naples, Italy
| | - Anna Maria Porcelli
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, Bologna, Italy
- Health Sciences & Technologies (HST) CIRI, University of Bologna, Bologna, Italy
| | - Antonio Torroni
- Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, Pavia, Italy
| | - Valerio Carelli
- Neurology Unit, IRCCS Institute of Neurological Sciences of Bologna, Bologna, Italy
- Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
- * E-mail:
| |
Collapse
|
4
|
Structural significance of modified nucleoside 5-taurinomethyl-2-thiouridine, τm5s2U, found at ‘wobble’ position in anticodon loop of human mitochondrial tRNALys. Struct Chem 2015. [DOI: 10.1007/s11224-015-0642-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
5
|
Cardoso AM, Morais CM, Cruz AR, Cardoso AL, Silva SG, do Vale ML, Marques EF, Pedroso de Lima MC, Jurado AS. Gemini surfactants mediate efficient mitochondrial gene delivery and expression. Mol Pharm 2015; 12:716-30. [PMID: 25634573 DOI: 10.1021/mp5005349] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Gene delivery targeting mitochondria has the potential to transform the therapeutic landscape of mitochondrial genetic diseases. Taking advantage of the nonuniversal genetic code used by mitochondria, a plasmid DNA construct able to be specifically expressed in these organelles was designed by including a codon, which codes for an amino acid only if read by the mitochondrial ribosomes. In the present work, gemini surfactants were shown to successfully deliver plasmid DNA to mitochondria. Gemini surfactant-based DNA complexes were taken up by cells through a variety of routes, including endocytic pathways, and showed propensity for inducing membrane destabilization under acidic conditions, thus facilitating cytoplasmic release of DNA. Furthermore, the complexes interacted extensively with lipid membrane models mimicking the composition of the mitochondrial membrane, which predicts a favored interaction of the complexes with mitochondria in the intracellular environment. This work unravels new possibilities for gene therapy toward mitochondrial diseases.
Collapse
Affiliation(s)
- Ana M Cardoso
- CNC-Center for Neuroscience and Cell Biology, ‡Department of Life Sciences, and §Faculty of Pharmacy, University of Coimbra , Coimbra, Portugal
| | | | | | | | | | | | | | | | | |
Collapse
|
6
|
Morris G, Maes M. Mitochondrial dysfunctions in myalgic encephalomyelitis/chronic fatigue syndrome explained by activated immuno-inflammatory, oxidative and nitrosative stress pathways. Metab Brain Dis 2014; 29:19-36. [PMID: 24557875 DOI: 10.1007/s11011-013-9435-x] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2013] [Accepted: 08/22/2013] [Indexed: 02/07/2023]
Abstract
Myalgic encephalomyelitis/chronic fatigue syndrome (ME/cfs) is classified by the World Health Organization as a disorder of the central nervous system. ME/cfs is an neuro-immune disorder accompanied by chronic low-grade inflammation, increased levels of oxidative and nitrosative stress (O&NS), O&NS-mediated damage to fatty acids, DNA and proteins, autoimmune reactions directed against neoantigens and brain disorders. Mitochondrial dysfunctions have been found in ME/cfs, e.g. lowered ATP production, impaired oxidative phosphorylation and mitochondrial damage. This paper reviews the pathways that may explain mitochondrial dysfunctions in ME/cfs. Increased levels of pro-inflammatory cytokines, such as interleukin-1 and tumor necrosis factor-α, and elastase, and increased O&NS may inhibit mitochondrial respiration, decrease the activities of the electron transport chain and mitochondrial membrane potential, increase mitochondrial membrane permeability, interfere with ATP production and cause mitochondrial shutdown. The activated O&NS pathways may additionally lead to damage of mitochondrial DNA and membranes thus decreasing membrane fluidity. Lowered levels of antioxidants, zinc and coenzyme Q10, and ω3 polyunsaturated fatty acids in ME/cfs may further aggravate the activated immuno-inflammatory and O&NS pathways. Therefore, it may be concluded that immuno-inflammatory and O&NS pathways may play a role in the mitochondrial dysfunctions and consequently the bioenergetic abnormalities seen in patients with ME/cfs. Defects in ATP production and the electron transport complex, in turn, are associated with an elevated production of superoxide and hydrogen peroxide in mitochondria creating adaptive and synergistic damage. It is argued that mitochondrial dysfunctions, e.g. lowered ATP production, may play a role in the onset of ME/cfs symptoms, e.g. fatigue and post exertional malaise, and may explain in part the central metabolic abnormalities observed in ME/cfs, e.g. glucose hypometabolism and cerebral hypoperfusion.
Collapse
|
7
|
Transmission of human mitochondrial DNA along the paternal lineage in transmitochondrial mice. Mitochondrion 2013; 13:330-6. [DOI: 10.1016/j.mito.2013.03.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Revised: 03/08/2013] [Accepted: 03/15/2013] [Indexed: 11/18/2022]
|
8
|
Vivero RJ, Ouyang X, Kim YG, Liu W, Du L, Yan D, Liu XZ. Audiologic and genetic features of the A3243G mtDNA mutation. Genet Test Mol Biomarkers 2013; 17:383-9. [PMID: 23477312 DOI: 10.1089/gtmb.2012.0403] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Mitochondrial mutations have been shown to be responsible for syndromic and nonsyndromic hearing impairment. AIM To assess the genotypic-phenotypic correlation of mitochondrial DNA mutations in three generations of a single family. METHODS A single family with maternally inherited diabetes and hearing loss was recruited. Genomic DNA was subject to polymerase chain reaction-restriction fragment length polymorphism analysis (ApaI) for A3243G mutation detection and confirmation with direct DNA sequencing. The degree of heteroplasmy for the A3243G mutation in blood DNA samples was quantified. In addition, we reviewed audiological data of A3243G-associated hearing loss cases from the literature to provide details of audiologic features. RESULTS Six of 11 family members were recruited. All affected members harbored the A3243G mutation. Four of six members had diabetes. Five of five affected members demonstrated hearing loss ranging from mild to severe. The degree of heteroplasmy ranged from 5.51% to 27.74%. CONCLUSIONS Patients with a greater percentage of heteroplasmy have a trend toward more severe phenotypic presentations. Hearing loss is bilateral, sensorineural, and symmetric. The main audiogram shapes found were sloping. Additional studies are necessary to clarify the relationship between degree of heteroplasmy and phenotypic presentation.
Collapse
Affiliation(s)
- Richard J Vivero
- Department of Otolaryngology, University of Miami Ear Institute, Miami, Florida 33136, USA
| | | | | | | | | | | | | |
Collapse
|
9
|
Cui G, Ding H, Xu Y, Li B, Wang DW. Applications of the method of high resolution melting analysis for diagnosis of Leber's disease and the three primary mutation spectrum of LHON in the Han Chinese population. Gene 2012; 512:108-12. [PMID: 23063736 DOI: 10.1016/j.gene.2012.09.110] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2012] [Revised: 09/28/2012] [Accepted: 09/29/2012] [Indexed: 12/28/2022]
Abstract
Current screening methods, such as single strand conformational polymorphism (SSCP), denaturing high performance liquid chromatography (dHPLC) and direct DNA sequencing that are used for detecting mutation in Leber's hereditary optic neuropathy (LHON) subjects are time consuming and costly. Here we tested high-resolution melt (HRM) analysis for mtDNA primary mutations in LHON patients. In this study, we applied the high resolution melting (HRM) technology to screen mtDNA primary mutations in 50 LHON patients from their peripheral blood. In order to evaluate the reliability of this technique, we compared the results obtained by HRM and direct mtDNA sequencing. We also investigated the spectrum of three most common mtDNA mutations implicated in LHON in the Han Chinese population. The results showed HRM analysis differentiated all of the mtDNA primary mutations and identified 4 additional mtDNA mutations from 50 patients in the blind study. The prevalence of three primary mutations were 11778G>A (87.9%), 14484T>C (6.5%) and 3460G>A (1.7%) in the Han Chinese population. In conclusion, HRM analysis is a rapid, reliable, and low-cost tool for detecting mtDNA primary mutations and has practical applications in molecular genetics.
Collapse
Affiliation(s)
- Guanglin Cui
- The Institute of Hypertension and Department of Internal Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan People's Republic of China
| | | | | | | | | |
Collapse
|
10
|
Milesi J, Rocca MA, Bianchi-Marzoli S, Petrolini M, Pagani E, Falini A, Comi G, Filippi M. Patterns of white matter diffusivity abnormalities in Leber’s hereditary optic neuropathy: a tract-based spatial statistics study. J Neurol 2012; 259:1801-7. [PMID: 22249289 DOI: 10.1007/s00415-011-6406-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2011] [Revised: 12/21/2011] [Accepted: 12/28/2011] [Indexed: 11/25/2022]
Affiliation(s)
- Jacopo Milesi
- Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy
| | | | | | | | | | | | | | | |
Collapse
|
11
|
Kirches E. LHON: Mitochondrial Mutations and More. Curr Genomics 2011; 12:44-54. [PMID: 21886454 PMCID: PMC3129042 DOI: 10.2174/138920211794520150] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2010] [Revised: 12/14/2010] [Accepted: 12/28/2010] [Indexed: 11/22/2022] Open
Abstract
Leber’s hereditary optic neuropathy (LHON) is a mitochondrial disorder leading to severe visual impairment or even blindness by death of retinal ganglion cells (RGCs). The primary cause of the disease is usually a mutation of the mitochondrial genome (mtDNA) causing a single amino acid exchange in one of the mtDNA-encoded subunits of NADH:ubiquinone oxidoreductase, the first complex of the electron transport chain. It was thus obvious to accuse neuronal energy depletion as the most probable mediator of neuronal death. The group of Valerio Carelli and other authors have nicely shown that energy depletion shapes the cell fate in a LHON cybrid cell model. However, the cybrids used were osteosarcoma cells, which do not fully model neuronal energy metabolism. Although complex I mutations may cause oxidative stress, a potential pathogenetic role of the latter was less taken into focus. The hypothesis of bioenergetic failure does not provide a simple explanation for the relatively late disease onset and for the incomplete penetrance, which differs remarkably between genders. It is assumed that other genetic and environmental factors are needed in addition to the ‘primary LHON mutations’ to elicit RGC death. Relevant nuclear modifier genes have not been identified so far. The review discusses the unresolved problems of a pathogenetic hypothesis based on ATP decline and/or ROS-induced apoptosis in RGCs.
Collapse
Affiliation(s)
- E Kirches
- Department of Neuropathology, Otto-von-Guericke University, Leipziger Str. 44, 39120 Magdeburg, Germany
| |
Collapse
|
12
|
Abstract
The mitochondrial genomes of most eukaryotes lack a variable number of tRNA genes. This lack is compensated for by import of a small fraction of the corresponding cytosolic tRNAs. There are two broad mechanisms for the import of tRNAs into mitochondria. In the first one, the tRNA is coimported together with a mitochondrial precursor protein along the protein import pathway. It applies to the yeast tRNA(Lys) and has been elucidated in great detail. In the second more vaguely defined mechanism, which is mainly found in plants and protozoa, tRNAs are directly imported independent of cytosolic factors. However, results in plants indicate that direct import of tRNAs may nevertheless require some components of the protein import machinery. All imported tRNAs in all systems are of the eukaryotic type but need to be functionally integrated into the mitochondrial translation system of bacterial descent. For some tRNAs, this is not trivial and requires unique evolutionary adaptations.
Collapse
Affiliation(s)
- André Schneider
- Department of Chemistry and Biochemistry, University of Bern, CH-3012 Bern, Switzerland.
| |
Collapse
|
13
|
Rinner BP, Matson CW, Islamzadeh A, McDonald TJ, Donnelly KC, Bickham JW. Evolutionary toxicology: contaminant-induced genetic mutations in mosquitofish from Sumgayit, Azerbaijan. ECOTOXICOLOGY (LONDON, ENGLAND) 2011; 20:365-376. [PMID: 21312027 DOI: 10.1007/s10646-010-0587-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 12/18/2010] [Indexed: 05/30/2023]
Abstract
This study builds on a long-term program that has shown Sumgayit, Azerbaijan to contain wetlands with high levels of a diversity of chemical contaminants. Previous contaminant and biomarker studies of turtles and frogs showed a correlation between somatic chromosomal damage and chemical contaminants at Sumgayit. The objective of this study was to determine if a recently arrived species (mosquitofish) has genetic impacts similar to native species (marsh frogs) thus confirming the pattern is not the result of historical events such as glacial cycles, but is associated with recent chemical contamination. Nucleotide sequences of the mtDNA control region of invasive mosquitofish (Gambusia holbrooki) from Sumgayit were compared to mosquitofish from pristine sites in Europe and Azerbaijan and to native North American populations. Persistent heteroplasmy for a hyper-mutable simple sequence repeat and low haplotype and nucleotide diversities were observed in all invasive populations. However, Sumgayit possessed four de novo haplotypes and heteroplasmic conditions. All of the observed variable nucleotide positions were within or adjacent to a cytosine mononucleotide repeat. This repeat was within a conserved secondary structure; the region likely undergoes expansion and contraction at a rate sufficient to prevent fixation of the common 1/3 heteroplasmy. Whereas the 1/3 heteroplasmy appeared coincident with the establishment of mosquitofish in Europe, other forms of heteroplasmy resulted from contaminant-induced de novo mutations in Sumgayit. We conclude that Sumgayit is a mutational hotspot caused by legacy contaminants from chemical factories from the era of the Soviet Union.
Collapse
Affiliation(s)
- Brian P Rinner
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, IN, USA
| | | | | | | | | | | |
Collapse
|
14
|
Szaflik JP, Janik-Papis K, Synowiec E, Ksiazek D, Zaras M, Wozniak K, Szaflik J, Blasiak J. DNA damage and repair in age-related macular degeneration. Mutat Res 2009; 669:169-76. [PMID: 19559717 DOI: 10.1016/j.mrfmmm.2009.06.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2009] [Revised: 05/26/2009] [Accepted: 06/18/2009] [Indexed: 05/18/2023]
Abstract
Age-related macular degeneration (AMD) is a retinal degenerative disease that is the main cause of vision loss in individuals over the age of 55 in the Western world. Clinically relevant AMD results from damage to the retinal pigment epithelial (RPE) cells thought to be mainly caused by oxidative stress. The stress also affects the DNA of RPE cells, which promotes genome instability in these cells. These effects may coincide with the decrease in the efficacy of DNA repair with age. Therefore individuals with DNA repair impaired more than average for a given age may be more susceptible to AMD if oxidative stress affects their RPE cells. This may be helpful in AMD risk assessment. In the present work we determined the level of basal (measured in the alkaline comet assay) endogenous and endogenous oxidative DNA damage, the susceptibility to exogenous mutagens and the efficacy of DNA repair in lymphocytes of 100 AMD patients and 110 age-matched individuals without visual disturbances. The cells taken from AMD patients displayed a higher extent of basal endogenous DNA damage without differences between patients of dry and wet forms of the disease. DNA double-strand breaks did not contribute to the observed DNA damage as checked by the neutral comet assay and pulsed field gel electrophoresis. The extent of oxidative modification to DNA bases was greater in AMD patients than in the controls, as probed by DNA repair enzymes NTH1 and Fpg. Lymphocytes from AMD patients displayed a higher sensitivity to hydrogen peroxide and UV radiation and repaired lesions induced by these factors less effectively than the cells from the control individuals. We postulate that the impaired efficacy of DNA repair may combine with enhanced sensitivity of RPE cells to blue and UV lights, contributing to the pathogenesis of AMD.
Collapse
Affiliation(s)
- Jacek P Szaflik
- Department of Ophthalmology, Medical University of Warsaw and Samodzielny Publiczny Szpital Okulistyczny, Warsaw, Poland
| | | | | | | | | | | | | | | |
Collapse
|
15
|
Yang J, Zhu Y, Chen L, Zhang H, Tong Y, Huang D, Zhang Z, Chen S, Han X, Ma X. Novel A14841G mutation is associated with high penetrance of LHON/C4171A family. Biochem Biophys Res Commun 2009; 386:693-6. [DOI: 10.1016/j.bbrc.2009.06.102] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2009] [Accepted: 06/17/2009] [Indexed: 10/20/2022]
|
16
|
Yang J, Zhu Y, Tong Y, Chen L, Liu L, Zhang Z, Wang X, Huang D, Qiu W, Zhuang S, Ma X. Confirmation of the mitochondrial ND1 gene mutation G3635A as a primary LHON mutation. Biochem Biophys Res Commun 2009; 386:50-4. [DOI: 10.1016/j.bbrc.2009.05.127] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2009] [Accepted: 05/28/2009] [Indexed: 01/30/2023]
|
17
|
Edwards TL, Buttery RG, Mackey DA. Is Second Eye Involvement in Leber's Hereditary Optic Neuropathy Due to Retro-Chiasmal Spread of Apoptosis? Neuroophthalmology 2009. [DOI: 10.1080/01658100701501125] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
|
18
|
The novel G10680A mutation is associated with complete penetrance of the LHON/T14484C family. Mitochondrion 2009; 9:273-8. [DOI: 10.1016/j.mito.2009.04.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2008] [Revised: 03/29/2009] [Accepted: 04/15/2009] [Indexed: 01/31/2023]
|
19
|
|
20
|
Abstract
Much attention has been focused on the hypothesis that oxidative damage plays a part in cellular and organismal aging. Oxygen is initially converted to superoxide anion (O2), one of the reactive oxygen species (ROS), by electrons mainly leaked from complex III in the electron transport system present in mitochondria, where it is the major endogenous source of ROS. We have shown that a mutation in a subunit, cytochrome b large subunit (SDHC), of complex II, also results in increasing O2 production and therefore leads to apoptosis and precocious aging in Caenorhabditis elegans. Recently, individuals with an inherited propensity for vascularized head and neck tumors (ie, paragangliomas) have been shown to possess one of several mutations in complex II. To further explore the role of oxidative stress from mitochondria on apoptosis and cancer, we established a transgenic cell line with a point mutation at the ubiquinone binding region in the SDHC gene. As expected, this mutation increased O2 production from complex II and led to excess apoptosis. Moreover, a significant fraction of the surviving cells from the apoptosis were transformed, as evidenced by increased tumor formation, after injection into mice. Oxidative stress results in damage to the cellular components including mitochondria and therefore leads to apoptosis. Furthermore, oxidative stress seems to cause mutations in DNA and leads to cancer. It is suggested that oxidative stress from mitochondria plays an important role in apoptosis, which leads to precocious aging and cancer.
Collapse
Affiliation(s)
- Naoaki Ishii
- Department of Molecular Life Science, Tokai University School of Medicine, Isehara, Kanagawa 259-1193, Japan.
| |
Collapse
|
21
|
Metabolic cardiomyopathy and mitochondrial disorders in the pediatric intensive care unit. J Pediatr 2007; 151:538-41. [PMID: 17961702 DOI: 10.1016/j.jpeds.2007.05.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2007] [Revised: 04/03/2007] [Accepted: 05/01/2007] [Indexed: 11/24/2022]
|
22
|
Hudson G, Carelli V, Spruijt L, Gerards M, Mowbray C, Achilli A, Pyle A, Elson J, Howell N, La Morgia C, Valentino ML, Huoponen K, Savontaus ML, Nikoskelainen E, Sadun AA, Salomao SR, Belfort R, Griffiths P, Yu-Wai-Man P, de Coo RFM, Horvath R, Zeviani M, Smeets HJT, Torroni A, Chinnery PF. Clinical expression of Leber hereditary optic neuropathy is affected by the mitochondrial DNA-haplogroup background. Am J Hum Genet 2007; 81:228-33. [PMID: 17668373 PMCID: PMC1950812 DOI: 10.1086/519394] [Citation(s) in RCA: 270] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2007] [Accepted: 04/24/2007] [Indexed: 12/16/2022] Open
Abstract
Leber hereditary optic neuropathy (LHON) is due primarily to one of three common point mutations of mitochondrial DNA (mtDNA), but the incomplete penetrance implicates additional genetic or environmental factors in the pathophysiology of the disorder. Both the 11778G-->A and 14484T-->C LHON mutations are preferentially found on a specific mtDNA genetic background, but 3460G-->A is not. However, there is no clear evidence that any background influences clinical penetrance in any of these mutations. By studying 3,613 subjects from 159 LHON-affected pedigrees, we show that the risk of visual failure is greater when the 11778G-->A or 14484T-->C mutations are present in specific subgroups of haplogroup J (J2 for 11778G-->A and J1 for 14484T-->C) and when the 3460G-->A mutation is present in haplogroup K. By contrast, the risk of visual failure is significantly less when 11778G-->A occurs in haplogroup H. Substitutions on MTCYB provide an explanation for these findings, which demonstrate that common genetic variants have a marked effect on the expression of an ostensibly monogenic mtDNA disorder.
Collapse
Affiliation(s)
- Gavin Hudson
- Mitochondrial Research Group, Department of Ophthalmology and Institute of Human Genetics, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Ishii N, Ishii T, Hartman PS. The role of the electron transport SDHC gene on lifespan and cancer. Mitochondrion 2007; 7:24-8. [PMID: 17321223 DOI: 10.1016/j.mito.2006.11.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2006] [Accepted: 09/22/2006] [Indexed: 10/23/2022]
Abstract
Much attention has been focused on the hypothesis that oxidative damage plays in cellular and organismal aging. It is known that oxygen is initially converted to superoxide anion (O2-), one of reactive oxygen species (ROS), by electron leaked from mainly complex III in the electron transport system present in mitochondria, where it is the major endogenous source of ROS. We have shown that a mutation in a subunit, cytochrome b large subunit (SDHC), of complex II, also results in increasing O2- production and therefore lead to apoptosis and precocious aging in Caenorhabditis elegans. Recently, individuals with an inherited propensity for vascularized head and neck tumors (i.e., paragangliomas) have been demonstrated to contain one of several mutations in complex II. To further explore the role of oxidative stress from mitochondria on apoptosis and cancer, we established a transgenic cell line with a point mutation at the ubiquinone binding region in the SDHC gene. As expected, this mutation increased O2- production from complex II and led to excess apoptosis. Moreover, a significant fraction of the surviving cells from the apoptosis were transformed, as evidenced by increased tumor formation after injection into mice. Oxidative stress results in the damage to the cellular components including mitochondria and, therefore leads to apoptosis. Furthermore, oxidative stress must cause mutations in DNA and leads to cancer. It is suggested that oxidative stress from mitochondria play an important role of both apoptosis, which leads to precocious aging, and cancer.
Collapse
Affiliation(s)
- Naoaki Ishii
- Department of Molecular Life Science, Tokai University School of Medicine, Isehara, Kanagawa 259-1193, Japan.
| | | | | |
Collapse
|
24
|
Ishii N, Ishii T, Hartman PS. The role of the electron transport gene SDHC on lifespan and cancer. Exp Gerontol 2006; 41:952-6. [PMID: 16962276 DOI: 10.1016/j.exger.2006.06.037] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2006] [Revised: 06/07/2006] [Accepted: 06/12/2006] [Indexed: 11/22/2022]
Abstract
Much attention has been focused on the hypothesis that oxidative damage contributes to cellular and organismal aging. A mev-1 mutation in the cytochrome b large subunit (SDHC) of complex II results in superoxide anion (O(2)(-)) overproduction and therefore leads to apoptosis and precocious aging in the nematode Caenorhabditis elegans. To extend these data, a transgenic mouse cell line was constructed with a homologous mutation to mev-1. Many of the mutant nematode phenotypes (e.g., increased superoxide anion production, apoptosis) were recapitulated in the mouse. In addition, a significant fraction of the cells that survived apoptosis were transformed. These data support the notion that oxidative stress from mitochondria play an important role of both apoptosis, which leads to precocious aging, and cancer.
Collapse
Affiliation(s)
- Naoaki Ishii
- Department of Molecular Life Science, Tokai University School of Medicine, Isehara, Kanagawa 259-1193, Japan.
| | | | | |
Collapse
|
25
|
Duszyński J, Kozieł R, Brutkowski W, Szczepanowska J, Zabłocki K. The regulatory role of mitochondria in capacitative calcium entry. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2006; 1757:380-7. [PMID: 16777055 DOI: 10.1016/j.bbabio.2006.04.017] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2005] [Revised: 04/13/2006] [Accepted: 04/20/2006] [Indexed: 11/19/2022]
Abstract
Capacitative regulation of calcium entry is a major mechanism of Ca2+ influx into electrically non-excitable cells, but it also operates in some excitable ones. It participates in the refilling of intracellular calcium stores and in the generation of Ca2+ signals in excited cells. The mechanism which couples depletion of intracellular calcium stores located in the endoplasmic reticulum with opening of store-operated calcium channels in the plasma membrane is not clearly understood. Mitochondria located in close proximity to Ca2+ channels are exposed to high Ca2+ concentration, and therefore, they are able to accumulate this cation effectively. This decreases local Ca2+ concentration and thereby affects calcium-dependent processes, such as depletion and refilling of the intracellular calcium stores and opening of the store-operated channels. Finally, mitochondria modulate the intensity and the duration of calcium signals induced by extracellular stimuli. Ca2+ uptake by mitochondria requires these organelles to be in the energized state. On the other hand, Ca2+ flux into mitochondria stimulates energy metabolism. To sum up, mitochondria couple cellular metabolism with calcium homeostasis and signaling.
Collapse
Affiliation(s)
- Jerzy Duszyński
- Nencki Institute of Experimental Biology, 3 Pasteur Str., 02-093 Warsaw, Poland
| | | | | | | | | |
Collapse
|
26
|
Bass MG, Sokolova VA, Kustova ME, Grachyova EV, Kidgotko OV, Sorokin AV, Vasilyev VB. Assaying the probabilities of obtaining maternally inherited heteroplasmy as the basis for modeling OXPHOS diseases in animals. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2006; 1757:679-85. [PMID: 16829232 DOI: 10.1016/j.bbabio.2006.05.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2005] [Revised: 05/02/2006] [Accepted: 05/13/2006] [Indexed: 10/24/2022]
Abstract
Gross alterations in cell energy metabolism underlie manifestations of hereditary OXPHOS (oxidative phosphorylation) diseases, many of which depend on proportion of mutant mitochondrial DNA (mtDNA) in tissues. An animal model of OXPHOS disease with maternal inheritance of mitochondrial heteroplasmy might help understanding the peculiarities of abnormal mtDNA distribution and its effect on pre- and postnatal development. Previously we obtained mice that carry human mtDNA in some tissues. It co-existed with murine mtDNA (heteroplasmy) and was transmitted maternally to the progeny of animals developed from zygotes injected with human mitochondria. To analyze the probability of obtaining heteroplasmic mice we increased the number of experiments with early embryos and obtained more specimens from F1. About 33% of zygotes injected with human mtDNA developed into post-implantation embryos (7th-13th days). Lower amount of such developed into neonate mice (ca. 21%). Among post-implantation embryos and in generations F0 and F1 percentages of human mtDNA-carriers were ca. 14-16%. Such percentages are sufficient for modeling maternally inherited heteroplasmy in small animal groups. More data are needed to understand the regularities of anomalous mtDNA distribution among cells and tissues and whether heart and muscles frequently carrying human mtDNA in our experiments are particularly susceptible to heteroplasmy.
Collapse
Affiliation(s)
- Mikhail G Bass
- Department of Molecular Genetics, Institute of Experimental Medicine, 12 Pavlov Street, Saint-Petersburg 197376, Russia
| | | | | | | | | | | | | |
Collapse
|
27
|
Lee JY, Kim HS, Ha BJ, Park YH. Phylogenetic analysis by RFLP and sequencing of mitochondrial DNA in a Korean population. Arch Pharm Res 2006; 29:88-95. [PMID: 16491849 DOI: 10.1007/bf02977474] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Analysis of molecular nature of mitochondrial DNA (mtDNA) could be powerful marker for anthropological studies of modern populations. While population genetic studies on mtDNA have been reported for several ethnic groups, no such study has been documented for the Korean population. We surveyed mtDNA polymorphisms in the HVS I of noncoding D-loop region and its upstream region from 430 unrelated healthy Korean population by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and direct sequencing analysis. PCR product with 2,790 bp spanning the specific mtDNA region (mt13715-16504) was subjected to RFLP analysis using 6 restriction enzyme (Hinf I, Hae III, Alu I, Dde I, Mbo I, Rsa I). On the PAUP analysis of PCR-RFLP results, 38 mtDNA haplotypes (Hap 1-38) were detected in the Korean populations, which were classified into 11 haplogroups (Grp 1-11) of related haplotypes encompassing all 38 haplotypes. In comparison of sequencing data with Anderson's reference sequence, the transition type was more prevalent than the transversion type. Insertions or deletions were not found. In addition, three of the polymorphic sites (A16240C, A16351G, G16384A) in HVS-I region are determined newly. The polymorphic sites were distributed randomly in the region, though the frequency at each site was variable. Thus, this research might be required for the genealogical study of Orientals.
Collapse
Affiliation(s)
- Jin-Young Lee
- Department of Biochemistry, College of Medicine, Inje University, Busan 614-735, Korea
| | | | | | | |
Collapse
|
28
|
Volodko NV, L’vova MA, Starikovskaya EB, Derbeneva OA, Bychkov IY, Mikhailovskaya IE, Pogozheva IV, Fedotov FF, Soyan GV, Procaccio V, Wallace DC, Sukernik RI. Spectrum of pathogenic mtDNA mutations in Leber’s hereditary optic neuropathy families from Siberia. RUSS J GENET+ 2006. [DOI: 10.1134/s102279540601011x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
29
|
Kornblum C, Schröder R, Müller K, Vorgerd M, Eggers J, Bogdanow M, Papassotiropoulos A, Fabian K, Klockgether T, Zange J. Creatine has no beneficial effect on skeletal muscle energy metabolism in patients with single mitochondrial DNA deletions: a placebo-controlled, double-blind 31P-MRS crossover study. Eur J Neurol 2005; 12:300-9. [PMID: 15804248 DOI: 10.1111/j.1468-1331.2004.00970.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The purpose of our randomized, double-blind, placebo-controlled crossover study in 15 patients with chronic progressive external ophthalmoplegia (CPEO) or Kearns-Sayre syndrome (KSS) because of single large-scale mitochondrial (mt) DNA deletions was to determine whether oral creatine (Cr) monohydrate can improve skeletal muscle energy metabolism in vivo. Each treatment phase with Cr in a dosage of 150 mg/kg body weight/day or placebo lasted 6 weeks. The effect of Cr was estimated by phosphorus-31 magnetic resonance spectroscopy ((31)P-MRS), clinical and laboratory tests. (31)P-MRS analysis prior to treatment showed clear evidence of severe mitochondrial dysfunction. However, there were no relevant changes in (31)P-MRS parameters under Cr. In particular, phosphocreatine (PCr)/ATP at rest did not increase, and there was no facilitation of post-exercise PCr recovery. Clinical scores and laboratory tests did not alter significantly under Cr, which was tolerated without major side-effects in all patients. Cr supplementation did not improve skeletal muscle oxidative phosphorylation in our series of patients. However, one explanation for our negative findings may be the short study duration or the limited number of patients included.
Collapse
Affiliation(s)
- C Kornblum
- Department of Neurology, University of Bonn, Bonn, Germany.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Valentino ML, Barboni P, Ghelli A, Bucchi L, Rengo C, Achilli A, Torroni A, Lugaresi A, Lodi R, Barbiroli B, Dotti M, Federico A, Baruzzi A, Carelli V. The ND1 gene of complex I is a mutational hot spot for Leber's hereditary optic neuropathy. Ann Neurol 2005; 56:631-41. [PMID: 15505787 DOI: 10.1002/ana.20236] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A novel mitochondrial DNA (mtDNA) transition (3733G-->A) inducing the E143 K amino acid change at a very conserved site of the NADH dehydrogenase subunit 1 (ND1) was identified in a family with six maternally related individuals with Leber's hereditary optic neuropathy (LHON) and in an unrelated sporadic case, all negative for known mutations and presenting with the canonical phenotype. The transition was not detected in 1,082 control mtDNAs and was heteroplasmic in several individuals from both pedigrees. In addition, the mtDNAs of the two families were found to belong to different haplogroups (H and X), thus confirming that the 3733G-->A mutation occurred twice independently. Phosphorus magnetic resonance spectroscopy disclosed an in vivo brain and skeletal muscle energy metabolism deficit in the four examined patients. Muscle biopsy from two patients showed slight mitochondrial proliferation with abnormal mitochondria. Biochemical investigations in platelets showed partially insensitive complex I to rotenone inhibition. We conclude that the 3733G-->A transition is a novel cause of LHON and, after those at positions 3460 and 4171, is the third ND1 mutation to be identified in multiple unrelated families. This finding shows that, in addition to ND6, the ND1 subunit gene is also a mutational hot spot for LHON.
Collapse
MESH Headings
- Adult
- Aged
- DNA Mutational Analysis
- DNA, Mitochondrial/drug effects
- DNA, Mitochondrial/genetics
- Family Health
- Female
- Ferricyanides/metabolism
- Glutamic Acid/genetics
- Haplotypes
- Humans
- Inhibitory Concentration 50
- Lysine/genetics
- Magnetic Resonance Spectroscopy/methods
- Male
- Microscopy, Electron, Transmission/methods
- Middle Aged
- Mitochondria, Muscle/pathology
- Mitochondria, Muscle/ultrastructure
- Models, Molecular
- Muscle, Skeletal/diagnostic imaging
- Muscle, Skeletal/pathology
- Muscle, Skeletal/ultrastructure
- Mutation
- NAD/metabolism
- NADH Dehydrogenase/genetics
- NADH Dehydrogenase/metabolism
- Occipital Lobe/diagnostic imaging
- Optic Atrophy, Hereditary, Leber/genetics
- Optic Atrophy, Hereditary, Leber/metabolism
- Pedigree
- Polymorphism, Restriction Fragment Length
- Radionuclide Imaging
- Rotenone/pharmacology
- Sequence Analysis, Protein/methods
- Succinate Dehydrogenase/metabolism
- Visual Acuity/physiology
- Visual Fields/physiology
Collapse
|
31
|
Affiliation(s)
- Astrid Lièvre
- Laboratoire de Toxicologie Moléculaire, INSERM U490, 45 rue des Saints-Pères, 75006 Paris, France
| | | |
Collapse
|
32
|
Abstract
The small circle of mitochondrial DNA (mtDNA) present in all human cells has proven to be a veritable Pandora's box of pathogenic mutations and rearrangements. In this review, we summarize the distinctive rules of mitochondrial genetics (maternal inheritance, mitotic segregation, heteroplasmy and threshold effect), stress the relatively high prevalence of mtDNA-related diseases, and consider recent additions to the already long list of pathogenic mutations (especially mutations affecting protein-coding genes). We then discuss more controversial issues, including the functional or pathological role of mtDNA haplotypes, the pathogenicity of homoplasmic mutations and the still largely obscure pathophysiology of mtDNA mutations.
Collapse
Affiliation(s)
- Salvatore Dimauro
- Department of Neurology, Columbia University Medical Center, New York, NY, USA.
| | | |
Collapse
|
33
|
Salomão SR, Berezovsky A, Andrade RE, Belfort R, Carelli V, Sadun AA. Visual electrophysiologic findings in patients from an extensive Brazilian family with Leber's hereditary optic neuropathy. Doc Ophthalmol 2004; 108:147-55. [PMID: 15455797 DOI: 10.1023/b:doop.0000036829.37053.31] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Leber's hereditary optic neuropathy (LHON) is a maternally inherited disease, associated with mitochondrial DNA (mtDNA) point mutations and characterized by bilateral, usually sequential, rapid loss of central vision. The purpose of this study was to investigate electrophysiologically a small cohort of members from an extensive Brazilian family affected by LHON. Pattern-reversal visual evoked potentials (PVEP), and full-field electroretinograms (ERG) were performed on the four index members, all carrying the 11778 homoplasmic mtDNA mutation. They were a 14-year-old recently affected male, his unaffected mother, and her two affected brothers. The three affected members all had bilateral profound visual loss with visual acuities that ranged from 20/250 to CF, cecocentral defects, and severe dyschromatopsia (by FM-100). The unaffected (carrier) female had normal visual acuities, visual fields and color discrimination. Severely prolonged P100 latencies and decreased N75-P100 peak amplitudes were found in pattern-reversal VEPs for three affected members. Normal PVEP responses were found in the carrier female. Rod and cone ERG responses were normal in two affected members, but both the carrier mother and her affected son showed reduced peak-to-peak amplitude for single-flash cone response and 30 Hz flicker, with normal b-wave implicit times. Thus, optic nerve function, evaluated by PVEP, was severely reduced in LHON affected members and normal in the carrier female. However, reduced ERG cone responses suggest that LHON can also affect retinal elements, even in the absence of fundus and other clinical changes that constitute the full and classical expression of LHON.
Collapse
Affiliation(s)
- Solange R Salomão
- Department of Ophthalmology, Federal University of São Paulo-Paulista School of Medicine, São Paulo, Brazil.
| | | | | | | | | | | |
Collapse
|
34
|
Abstract
Mitochondria are increasingly recognized as central players in the life and death of cells and especially of neurons. The energy-dependence of retinal ganglion cells (RGC) and their axons, which form the optic nerve, is singularly skewed. In fact, while mitochondria are very abundant in the initial, unmyelinated part of the axons anterior to the lamina cribrosa, their number suddenly decreases as the myelin sheath begins more posteriorly. The vascular system also presents different blood-brain barrier properties anterior and posterior to the lamina, possibly reflecting the different metabolic needs of the optic nerve head (unmyelinated) and of the retrobulbar optic nerve (myelinated). Mitochondrial biogenesis occurs within the cellular somata of RGC in the retina. It needs the coordinated interaction of nuclear and mitochondrial genomes. Mitochondria are then transported down the axons and distributed where they are needed. These locations are along the unmyelinated portion of the nerve, under the nodes of Ranvier in the retrobulbar nerve, and at the synaptic terminals. Efficient transportation of mitochondria depends on multiple factors, including their own energy production, the integrity of the cytoskeleton and its protein components (tubulin, etc.), and adequate myelination of the axons. Any dysfunction of these systems may be of pathological relevance for optic neuropathies with primary or secondary involvement of mitochondria. Leber's hereditary optic neuropathy (LHON) is the paradigm of mitochondrial optic neuropathies where a primary role for mitochondrial dysfunction is certified by maternal inheritance and association with specific mutations in the mitochondrial DNA (mtDNA). Clinical phenocopies of this pathology are represented by the wide array of optic neuropathies associated with vitamin depletion, toxic exposures, alcohol and tobacco abuse, and use of certain drugs. Moreover, the recent identification of mutations in the nuclear gene OPA1 as the causative factor in dominant optic atrophy (DOA, Kjer's type) brought the unexpected finding that this gene encodes for a mitochondrial protein, suggesting that DOA and LHON may be linked by similar pathogenesis. Polymorphisms in this very same gene may be associated with normal tension glaucoma (NTG), which might be considered a genetically determined optic neuropathy that again shows similarities with both LHON and DOA. Exciting new developments come from first examples of mitochondrial optic neuropathies in animal models that are genetically determined or are the result of ingenious engineering of mitochondrial gene expression, or from biochemical manipulations of the respiratory complexes. Even more exciting is the first successful attempt to correct the LHON-related complex I dysfunction by the allotopic nuclear expression of the recoded mitochondrial gene. There is hope that the genetic complexities, biochemical dysfunctions, and integrated anatomical-physiological cellular relationships will soon be precisely delineated and that promising therapeutic and prophylactic strategies will be proposed.
Collapse
Affiliation(s)
- Valerio Carelli
- Doheny Eye Institute and Department of Ophthalmology, Keck School of Medicine of the University of Southern California, Los Angeles, CA, USA.
| | | | | |
Collapse
|
35
|
Qi X, Lewin AS, Sun L, Hauswirth WW, Guy J. SOD2 gene transfer protects against optic neuropathy induced by deficiency of complex I. Ann Neurol 2004; 56:182-91. [PMID: 15293270 DOI: 10.1002/ana.20175] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Mutations in genes encoding the NADH ubiquinone oxidoreductase, complex I of the respiratory chain, cause a diverse group of diseases. They include Leber hereditary optic neuropathy, Leigh syndrome, and mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes. There is no effective treatment for these or any other mitochondrial disorder. Using a unique animal model of severe complex I deficiency induced by ribozymes targeted against a critical complex I subunit gene (NDUFA1), we attempted rescue of the optic nerve degeneration associated with Leber hereditary optic neuropathy. We used adenoassociated virus to deliver the human gene for SOD2 to the visual system of disease-induced mice. Relative to mock infection, SOD2 reduced apoptosis of retinal ganglion cells and degeneration of optic nerve fibers, the hallmarks of this disease. Rescue of this animal model supports a critical role for oxidative injury in disorders with complex I deficiency and shows that a respiratory deficit may be effectively treated in mammals, thus offering hope to patients.
Collapse
Affiliation(s)
- Xiaoping Qi
- Department of Ophthalmology, University of Florida, College of Medicine, Gainesville, FL 32610-0284, USA
| | | | | | | | | |
Collapse
|
36
|
Rossmanith W, Raffelsberger T, Roka J, Kornek B, Feucht M, Bittner RE. The expanding mutational spectrum of MERRF substitution G8361A in the mitochondrial tRNALys gene. Ann Neurol 2003; 54:820-3. [PMID: 14681892 DOI: 10.1002/ana.10753] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In a case of childhood-onset myoclonus epilepsy with "ragged-red fibers" (MERRF), a hitherto unreported mutation within the mitochondrial tRNA(Lys) gene was identified as the cause of the disease. Substitution G8361A was maternally inherited, heteroplasmic in all tissues tested, and correlated with mitochondrial dysfunction in individual muscle fibers. The growing number of MERRF-associated mutations within the tRNA(Lys) gene affirms the specific role of this mitochondrial tRNA in the pathogenesis of the disease.
Collapse
Affiliation(s)
- Walter Rossmanith
- Neuromuscular Research Department, Institute of Anatomy, University of Vienna Medical School, Währinger Strasse 13, 1090 Vienna, Austria
| | | | | | | | | | | |
Collapse
|
37
|
Sadun AA, Carelli V, Salomao SR, Berezovsky A, Quiros PA, Sadun F, DeNegri AM, Andrade R, Moraes M, Passos A, Kjaer P, Pereira J, Valentino ML, Schein S, Belfort R. Extensive investigation of a large Brazilian pedigree of 11778/haplogroup J Leber hereditary optic neuropathy. Am J Ophthalmol 2003; 136:231-8. [PMID: 12888043 DOI: 10.1016/s0002-9394(03)00099-0] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
PURPOSE To conduct systematic epidemiologic, neuro-ophthalmologic, psychophysical, and mitochondrial DNA (mtDNA) genetic examinations on a newly identified pedigree with Leber hereditary optic neuropathy (LHON). DESIGN Observational population cohort study. METHODS A prospective investigation of an entire Brazilian LHON family. SETTING A field investigation by an international team conducted in a remote part of Brazil. STUDY POPULATION We evaluated 265 (both eyes) of the 328 living family members of this LHON pedigree. Only members of this pedigree were studied. Those entering the pedigree as spouses were used as controls. OBSERVATION PROCEDURES We conducted epidemiologic interviews emphasizing possible environmental risk factors, comprehensive neuro-ophthalmologic examinations, psychophysical tests, Humphrey visual field studies, fundus photography, and blood testing for mitochondrial genetic analysis. RESULTS We reconstructed a seven-generation maternal lineage descended from a common ancestor dating to the 1870s. All maternally related family members were invariably homoplasmic 11778 with a haplogroup J mtDNA, 33 being affected, of which 22 are still living. With each subsequent generation, there was a progressive decrease of penetrance, and only males were affected in the last two generations. A significant exposure (greater than 95% confidence intervals) to a variety of environmental risk factors characterized the affected individuals, with smoking as the most common (P <.01). Both affected and carriers (95% confidence intervals) presented with a significantly lower incidence of hypertension and high cholesterol compared with the control group (P <.05). CONCLUSIONS Almost 95% of a 328-living-member pedigree with LHON 11778/J haplogroup was comprehensively studied. Our initial results indicate the strong influence of environmental risk factors. The remarkably reduced incidence of cardiovascular risk in the maternal lineage is discussed. Further genetic analysis may reveal a role for the nuclear genome.
Collapse
Affiliation(s)
- Alfredo A Sadun
- Keck-University of Southern California School of Medicine/Doheny Eye Institute, Los Angeles, CA 90033, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
38
|
|
39
|
Pegoraro E, Vettori A, Valentino ML, Molon A, Mostacciuolo ML, Howell N, Carelli V. X-inactivation pattern in multiple tissues from two Leber's hereditary optic neuropathy (LHON) patients. Am J Med Genet A 2003; 119A:37-40. [PMID: 12707956 DOI: 10.1002/ajmg.a.10211] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The more frequent manifestation of ophthalmological abnormalities in males, relative to females, is an unexplained feature of Leber's hereditary optic neuropathy (LHON) that suggests an X-linked modifying gene acting in concert with the pathogenic LHON mitochondrial DNA (mtDNA) mutation. In addition, segregation analysis of the optic neuropathy in LHON pedigrees was compatible with the presence of a recessive-modifying gene on chromosome X. According to this two-locus model, females would be affected only if homozygous or if they were susceptible to skewed X-inactivation. Attempts both to localize the putative LHON-modifying gene by linkage analysis and to find an excess of skewed X-inactivation in affected females were unsuccessful, although the inactivation pattern was only studied in DNA isolated from blood cells. We had the opportunity to analyze a wide range of tissues at autopsy, including the optic nerves and the retina, from two LHON female patients. We found no evidence of skewed X-inactivation in the affected tissues, thus weakening further the hypothesized involvement of a specific X chromosome locus in the pathophysiological expression of LHON.
Collapse
Affiliation(s)
- Elena Pegoraro
- Department of Neurological and Psychiatric Sciences, University of Padova, Italy.
| | | | | | | | | | | | | |
Collapse
|
40
|
Bosbach S, Kornblum C, Schröder R, Wagner M. Executive and visuospatial deficits in patients with chronic progressive external ophthalmoplegia and Kearns-Sayre syndrome. Brain 2003; 126:1231-40. [PMID: 12690061 DOI: 10.1093/brain/awg101] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Although neuropsychological deficits have been reported in mitochondrial cytopathies, patients with chronic progressive external ophthalmoplegia (CPEO) or Kearns-Sayre syndrome (KSS) have not been studied systematically using a comprehensive test battery. The aim of our study was to assess the range and extent of putative cognitive dysfunction in 22 patients with CPEO or KSS, and to compare cognitive performance of patients with healthy control subjects matched for age, sex and years of education. Genetic analysis of skeletal muscle tissue from 22 patients with CPEO or KSS included screening for mitochondrial DNA (mtDNA) point mutations (3243/8344) and mtDNA deletions. All patients were examined by a neuropsychological test battery covering verbal skills, verbal and visual memory, visuo-spatial perception, visual construction, attention, abstraction and flexibility, and Quality of Life. Molecular genetic analysis of mtDNA revealed single large-scale deletions in 15 out of 22 patients and the tRNA (Leu) A3243G point mutation in two out of 22 patients. In five out of 22 patients none of the frequently encountered mtDNA mutations could be detected. Neuropsychological testing did not reveal general intellectual deterioration, but specific cognitive deficits, particularly in visual construction, attention and abstraction/flexibility. Subgroup analysis of 15 patients with mtDNA deletions showed similar results when compared with the full group. In our series of patients with CPEO or KSS neuropsychological testing did not reveal signs that would suggest general intellectual decline or dementia, but provided evidence of specific focal neuropsychological deficits, suggesting particular impairment of visuospatial perception associated to parieto-occipital lobes and executive deficits associated to the prefrontal cortex.
Collapse
Affiliation(s)
- Simone Bosbach
- Department of Psychiatry and. Department of Neurology, University of Bonn, Germany
| | | | | | | |
Collapse
|
41
|
Ghelli A, Zanna C, Porcelli AM, Schapira AHV, Martinuzzi A, Carelli V, Rugolo M. Leber's hereditary optic neuropathy (LHON) pathogenic mutations induce mitochondrial-dependent apoptotic death in transmitochondrial cells incubated with galactose medium. J Biol Chem 2003; 278:4145-50. [PMID: 12446713 DOI: 10.1074/jbc.m210285200] [Citation(s) in RCA: 142] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Leber's hereditary optic neuropathy (LHON), a maternally inherited form of central vision loss, is associated with mitochondrial DNA pathogenic point mutations affecting different subunits of complex I. We here report that osteosarcoma-derived cytoplasmic hybrids (cybrid) cell lines harboring one of the three most frequent LHON pathogenic mutations, at positions 11778/ND4, 3460/ND1, and 14484/ND6, undergo cell death when galactose replaces glucose in the medium, contrary to control cybrids that maintain some growth capabilities. This is a well known way to produce a metabolic stress, forcing the cells to rely on the mitochondrial respiratory chain to produce ATP. We demonstrate that LHON cybrid cell death is apoptotic, showing chromatin condensation and nuclear DNA laddering. Moreover, we also document the mitochondrial involvement in the activation of the apoptotic cascade, as shown by the increased release of cytochrome c into the cytosol in LHON cybrid cells as compared with controls. Cybrids bearing the 3460/ND1 and 14484/ND6 mutations seemed more readily prone to undergo apoptosis as compared with the 11778/ND4 mutation. In conclusion, LHON cybrid cells forced by the reduced rate of glycolytic flux to utilize oxidative metabolism are sensitized to an apoptotic death through a mechanism involving mitochondria.
Collapse
Affiliation(s)
- Anna Ghelli
- Dipartimento di Biologia Evoluzionistica Sperimentale, Università di Bologna, Italy.
| | | | | | | | | | | | | |
Collapse
|
42
|
Yu-Wai-Man P, Griffiths PG, Brown DT, Howell N, Turnbull DM, Chinnery PF. The epidemiology of Leber hereditary optic neuropathy in the North East of England. Am J Hum Genet 2003; 72:333-9. [PMID: 12518276 PMCID: PMC379226 DOI: 10.1086/346066] [Citation(s) in RCA: 324] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2002] [Accepted: 10/29/2002] [Indexed: 11/03/2022] Open
Abstract
We performed the first population-based clinical and molecular genetic study of Leber hereditary optic neuropathy (LHON) in a population of 2,173,800 individuals in the North East of England. We identified 16 genealogically unrelated families who harbor one of the three primary mitochondrial DNA (mtDNA) mutations that cause LHON. Two of these families were found to be linked genetically to a common maternal founder. A de novo mtDNA mutation (G3460A) was identified in one family. The minimum point prevalence of visual failure due to LHON within this population was 3.22 per 100,000 (95% CI 2.47-3.97 per 100,000), and the minimum point prevalence for mtDNA LHON mutations was 11.82 per 100,000 (95% CI 10.38-13.27 per 100,000). These results indicate that LHON is not rare but has a population prevalence similar to autosomally inherited neurological disorders. The majority of individuals harbored only mutant mtDNA (homoplasmy), but heteroplasmy was detected in approximately 12% of individuals. Overall, however, approximately 33% of families with LHON had at least one heteroplasmic individual. The high incidence of heteroplasmy in pedigrees with LHON raises the possibility that a closely related maternal relative of an index case may not harbor the mtDNA mutation, highlighting the importance of molecular genetic testing for each maternal family member seeking advice about their risks of visual failure.
Collapse
MESH Headings
- Adult
- Age of Onset
- DNA, Mitochondrial/blood
- DNA, Mitochondrial/genetics
- England/epidemiology
- Female
- Founder Effect
- Genetic Linkage
- Humans
- Male
- Middle Aged
- Mutation
- Optic Atrophy, Hereditary, Leber/diagnosis
- Optic Atrophy, Hereditary, Leber/epidemiology
- Optic Atrophy, Hereditary, Leber/etiology
- Optic Atrophy, Hereditary, Leber/physiopathology
- Pedigree
- Penetrance
- Prevalence
- Prospective Studies
- Sex Factors
Collapse
Affiliation(s)
- P Yu-Wai-Man
- Department of Neurology, The Medical School, University of Newcastle upon Tyne, Newcastle upon Tyne, United Kingdom
| | | | | | | | | | | |
Collapse
|
43
|
Feetham S, Knisley M, Parker RS, Gallo A, Kenner C. Families and genetics: Bridging the gap between knowledge and practice. ACTA ACUST UNITED AC 2002. [DOI: 10.1053/nbin.2002.35892] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
44
|
Gruber AD, Wessmann A, Vandevelde M, Summers BA, Tipold A. Mitochondriopathy with regional encephalic mineralization in a Jack Russell Terrier. Vet Pathol 2002; 39:732-6. [PMID: 12450205 DOI: 10.1354/vp.39-6-732] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A 10-month-old female Parson Jack Russell Terrier was euthanatized because of therapy-resistant ataxia, hypermetria, and deafness that had first been observed at 10 weeks of age. Severe, bilateral, symmetrical neuronal degeneration and mineralization of the brain were found in the cochlear and cerebellar nuclei, dorsal areas of the medulla oblongata, the vestibulocochlear nerve, plexus choroideus, and within the granule cell layer of the ventral cerebellar hemispheres. The mineralized deposits were located free in the parenchyma, around intact or degenerate neurons, in myocytes of small- and medium-sized arteries, and around capillaries. Hepatocytes and cardiac myocytes showed oncocytotic change with increased numbers of enlarged or misshapen mitochondria filled with densely packed cristae and electron-dense inclusions. Skeletal myocytes had only minor increases in the number of mitochondria. The microscopic and ultrastructural lesions were consistent with mitochondrial encephalopathy with similarities to mitochondrial encephalomyopathy with lactic acidosis and strokelike episodes in humans.
Collapse
Affiliation(s)
- A D Gruber
- Department of Pathology, School of Veterinary Medicine Hannover, Germany.
| | | | | | | | | |
Collapse
|
45
|
Carelli V, Vergani L, Bernazzi B, Zampieron C, Bucchi L, Valentino M, Rengo C, Torroni A, Martinuzzi A. Respiratory function in cybrid cell lines carrying European mtDNA haplogroups: implications for Leber's hereditary optic neuropathy. BIOCHIMICA ET BIOPHYSICA ACTA 2002; 1588:7-14. [PMID: 12379308 DOI: 10.1016/s0925-4439(02)00097-2] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The possibility that some combinations of mtDNA polymorphisms, previously associated with Leber's hereditary optic neuropathy (LHON), may affect mitochondrial respiratory function was tested in osteosarcoma-derived transmitochondrial cytoplasmic hybrids (cybrids). In this cellular system, in the presence of the same nuclear background, different exogenous mtDNAs are used to repopulate a parental cell line previously devoid of its original mtDNA. No detectable differences in multiple parameters exploring respiratory function were observed when mtDNAs belonging to European haplogroups X, H, T and J were used. Different possible explanations for the previously established association between haplogroup J and LHON 11778/ND4 and 14484/ND6 pathogenic mutations are discussed, including the unconventional proposal that mtDNA haplogroup J may exert a protective rather than detrimental effect.
Collapse
Affiliation(s)
- Valerio Carelli
- Istituto di Clinica Neurologica, Università di Bologna, Bologna, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
46
|
Moalem S, Percy ME, Kruck TPA, Gelbart RR. Epidemic pathogenic selection: an explanation for hereditary hemochromatosis? Med Hypotheses 2002; 59:325-9. [PMID: 12208162 DOI: 10.1016/s0306-9877(02)00179-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Hereditary hemochromatosis (HH) is a disorder associated with progressive iron overload and deposition in multiple organs. It is the most common inherited single gene disorder in people of Northern and Western European descent. About 80% of individuals of European descent with HH are homozygous for a cysteine-to-tyrosine substitution (C282Y) in the gene now called HFE. The function of HFE protein, a major histocompatibility class I-like transmembrane protein, has not been fully elucidated. Three consequences of the C282Y mutation are lack of expression of HFE on the cellular surface, a lowered iron level in macrophages, and an increased rate of clearance of iron from the intestinal lumen. These changes could confer protection against certain pathogens early in life before iron overload occurs. Furthermore, the C282Y mutation might have been selected for during the European plagues caused by Yersinia spp. and other pathogens because of the conferred resistance to infection, i.e., by epidemic pathogenic selection.
Collapse
Affiliation(s)
- Sharon Moalem
- Department of Physiology, University of Toronto, Neurogenetics Laboratory, Surrey Place Centre, Toronto, Canada.
| | | | | | | |
Collapse
|
47
|
Huang SG. Development of a high throughput screening assay for mitochondrial membrane potential in living cells. JOURNAL OF BIOMOLECULAR SCREENING 2002; 7:383-9. [PMID: 12230893 DOI: 10.1177/108705710200700411] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The mitochondrion plays a pivotal role in energy metabolism in eukaryotic cells. The electrochemical potential across the mitochondrial inner membrane is regulated to cope with cellular energy needs and thus reflects the bioenergetic state of the cell. Traditional assays for mitochondrial membrane potential are not amenable to high-throughput drug screening. In this paper, I describe a high-throughput assay that measures the mitochondrial membrane potential of living cells in 96- or 384-well plates. Cells were first treated with test compounds and then with a fluorescent potentiometric probe, the cationic-lipophilic dye tetramethylrhodamine methyl ester (TMRM). The cells were then washed to remove free compounds and probe. The amount of TMRM retained in the mitochondria, which is proportional to the mitochondrial membrane potential, was measured on an LJL Analyst fluorescence reader. Under optimal conditions, the assay measured only the mitochondrial membrane potential. The chemical uncouplers carbonylcyanide m-chlorophenyl hydrazone and dinitrophenol decreased fluorescence intensity, with IC(50) values (concentration at 50% inhibition) similar to those reported in the literature. A Z' factor of greater than 0.5 suggests that this cell-based assay can be adapted for high-throughput screening of chemical libraries. This assay may be used in screens for drugs to treat metabolic disorders such as obesity and diabetes, as well as cancer and neurodegenerative diseases.
Collapse
Affiliation(s)
- Shu-Gui Huang
- Biology II, Tularik Inc., South San Francisco, CA 94080, USA.
| |
Collapse
|
48
|
Herrnstadt C, Elson JL, Fahy E, Preston G, Turnbull DM, Anderson C, Ghosh SS, Olefsky JM, Beal MF, Davis RE, Howell N. Reduced-median-network analysis of complete mitochondrial DNA coding-region sequences for the major African, Asian, and European haplogroups. Am J Hum Genet 2002; 70:1152-71. [PMID: 11938495 PMCID: PMC447592 DOI: 10.1086/339933] [Citation(s) in RCA: 415] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2001] [Accepted: 01/30/2002] [Indexed: 11/03/2022] Open
Abstract
The evolution of the human mitochondrial genome is characterized by the emergence of ethnically distinct lineages or haplogroups. Nine European, seven Asian (including Native American), and three African mitochondrial DNA (mtDNA) haplogroups have been identified previously on the basis of the presence or absence of a relatively small number of restriction-enzyme recognition sites or on the basis of nucleotide sequences of the D-loop region. We have used reduced-median-network approaches to analyze 560 complete European, Asian, and African mtDNA coding-region sequences from unrelated individuals to develop a more complete understanding of sequence diversity both within and between haplogroups. A total of 497 haplogroup-associated polymorphisms were identified, 323 (65%) of which were associated with one haplogroup and 174 (35%) of which were associated with two or more haplogroups. Approximately one-half of these polymorphisms are reported for the first time here. Our results confirm and substantially extend the phylogenetic relationships among mitochondrial genomes described elsewhere from the major human ethnic groups. Another important result is that there were numerous instances both of parallel mutations at the same site and of reversion (i.e., homoplasy). It is likely that homoplasy in the coding region will confound evolutionary analysis of small sequence sets. By a linkage-disequilibrium approach, additional evidence for the absence of human mtDNA recombination is presented here.
Collapse
|
49
|
Danielson SR, Wong A, Carelli V, Martinuzzi A, Schapira AHV, Cortopassi GA. Cells bearing mutations causing Leber's hereditary optic neuropathy are sensitized to Fas-Induced apoptosis. J Biol Chem 2002; 277:5810-5. [PMID: 11741983 DOI: 10.1074/jbc.m110119200] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Three prevalent mitochondrial DNA pathogenic mutations at positions 11778, 3460, and 14484, which affect different subunits of Complex I, cause retinal ganglion cell death and optic nerve atrophy in Leber's hereditary optic neuropathy (LHON). The cell death is painless and without inflammation, consistent with an apoptotic mechanism. We have investigated the possibility that the LHON mutation confers a pro-apoptotic stimulus and have tested the sensitivity of osteosarcoma-derived cybrid cells carrying the most common and severe mutations (11778 and 3460) to cell death induced by Fas. We observed that LHON cybrids were sensitized to Fas-dependent death. Control cells that bear the same mitochondrial genetic background (the J haplogroup) without the pathogenic 11778 mutation are no more sensitive than other controls, indicating that increased Fas-dependent death in LHON cybrids was induced by the LHON pathogenic mutations. The type of death was apoptotic by several criteria, including induction by Fas, inhibition by the caspase inhibitor zVAD-fmk (zVal-Ala-Asp-fluoro-methyl ketone), activation of DEVDase activity (Asp-Glu-Val-Asp protease), specific cleavage of caspase-3, DNA fragmentation, and increased Annexin-V labeling. These data indicate that the most common and severe LHON pathogenic mutations 11778 and 3460 predispose cells to apoptosis, which may be relevant for the pathophysiology of cell death in LHON, and potential therapy.
Collapse
Affiliation(s)
- Steven R Danielson
- Department of Molecular Biosciences, University of California Davis, School of Veterinary Medicine, Davis, California 95616, USA
| | | | | | | | | | | |
Collapse
|
50
|
Chinnery PF, Turnbull DM. Epidemiology and treatment of mitochondrial disorders. AMERICAN JOURNAL OF MEDICAL GENETICS 2002; 106:94-101. [PMID: 11579428 DOI: 10.1002/ajmg.1426] [Citation(s) in RCA: 124] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The last ten years have seen a huge increase in the number of different genetic defects found in patients with mitochondrial disorders, but the true impact of mitochondrial disease is only just becoming apparent. Mitochondrial diseases are far more common than was anticipated. Although there have also been major advances in our understanding of mitochondrial pathology, the clinical management of patients with mitochondrial disease is largely supportive. In this article, we focus on primary disorders of the mitochondrial respiratory chain and mtDNA defects. We review the available epidemiological data, outline current strategies for the management of mitochondrial disease, and highlight new therapeutic approaches that may prove useful in the future.
Collapse
Affiliation(s)
- P F Chinnery
- Department of Neurology, Medical School, University of Newcastle upon Tyne, UK.
| | | |
Collapse
|