401
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Disorders of the optic nerve in mitochondrial cytopathies: new ideas on pathogenesis and therapeutic targets. Curr Neurol Neurosci Rep 2012; 12:308-17. [PMID: 22392506 PMCID: PMC3342502 DOI: 10.1007/s11910-012-0260-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Mitochondrial cytopathies are a heterogeneous group of human disorders triggered by disturbed mitochondrial function. This can be due to primary mitochondrial DNA mutations or nuclear defects affecting key components of the mitochondrial machinery. Optic neuropathy is a frequent disease manifestation and the degree of visual failure can be profound, with a severe impact on the patient’s quality of life. This review focuses on the major mitochondrial disorders exhibiting optic nerve involvement, either as the defining clinical feature or as an additional component of a more extensive phenotype. Over the past decade, significant progress has been achieved in our basic understanding of Leber hereditary optic neuropathy and autosomal-dominant optic atrophy—the two classical paradigms for these mitochondrial optic neuropathies. There are currently limited treatments for these blinding ocular disorders and, ultimately, the aim is to translate these major advances into tangible benefits for patients and their families.
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402
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Ding D, Scott NM, Thompson EE, Chaiworapongsa T, Torres R, Billstrand C, Murray K, Dexheimer PJ, Ismail M, Kay H, Levy S, Romero R, Lindheimer MD, Nicolae DL, Ober C. Increased protein-coding mutations in the mitochondrial genome of African American women with preeclampsia. Reprod Sci 2012; 19:1343-51. [PMID: 22902742 DOI: 10.1177/1933719112450337] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Preeclampsia occurs more frequently in women of African ancestry. The cause of this hypertensive complication is unclear, but placental oxidative stress may play a role. Because mitochondria are the major sites of oxidative phosphorylation, we hypothesized that placentas of preeclamptic pregnancies harbor mitochondrial DNA (mtDNA) mutations. Next-generation sequencing of placental mtDNA in African American preeclamptics (N = 30) and controls (N = 38) from Chicago revealed significant excesses in preeclamptics of nonsynonymous substitutions in protein-coding genes and mitochondrially encoded nicotinamide adenine dinucleotide dehydrogenase 5 gene and an increase in the substitution rate (P = .0001). Moreover, 88% of preeclamptics and 53% of controls carried at least one nonsynonymous substitution (P = .005; odds ratio [OR] = 6.36, 95% confidence interval [CI]: 1.5-39.1). These results were not replicated in a sample of African American preeclamptics (N = 162) and controls (N = 171) from Detroit. Differences in study design and heterogeneity may account for this lack of replication. Nonsynonymous substitutions in mtDNA may be risk factors for preeclampsia in some African American women, but additional studies are required to establish this relationship.
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Affiliation(s)
- David Ding
- Department of Obstetrics and Gynecology, The University of Chicago, Chicago, IL 60637, USA
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403
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Achilli A, Iommarini L, Olivieri A, Pala M, Hooshiar Kashani B, Reynier P, La Morgia C, Valentino ML, Liguori R, Pizza F, Barboni P, Sadun F, De Negri AM, Zeviani M, Dollfus H, Moulignier A, Ducos G, Orssaud C, Bonneau D, Procaccio V, Leo-Kottler B, Fauser S, Wissinger B, Amati-Bonneau P, Torroni A, Carelli V. Rare primary mitochondrial DNA mutations and probable synergistic variants in Leber's hereditary optic neuropathy. PLoS One 2012; 7:e42242. [PMID: 22879922 PMCID: PMC3411744 DOI: 10.1371/journal.pone.0042242] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Accepted: 07/02/2012] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Leber's hereditary optic neuropathy (LHON) is a maternally inherited blinding disorder, which in over 90% of cases is due to one of three primary mitochondrial DNA (mtDNA) point mutations (m.11778G>A, m.3460G>A and m.14484T>C, respectively in MT-ND4, MT-ND1 and MT-ND6 genes). However, the spectrum of mtDNA mutations causing the remaining 10% of cases is only partially and often poorly defined. METHODOLOGY/PRINCIPAL FINDINGS In order to improve such a list of pathological variants, we completely sequenced the mitochondrial genomes of suspected LHON patients from Italy, France and Germany, lacking the three primary common mutations. Phylogenetic and conservation analyses were performed. Sixteen mitochondrial genomes were found to harbor at least one of the following nine rare LHON pathogenic mutations in genes MT-ND1 (m.3700G>A/p.A132T, m.3733G>A-C/p.E143K-Q, m.4171C>A/p.L289M), MT-ND4L (m.10663T>C/p.V65A) and MT-ND6 (m.14459G>A/p.A72V, m.14495A>G/p.M64I, m.14482C>A/p.L60S, and m.14568C>T/p.G36S). Phylogenetic analyses revealed that these substitutions were due to independent events on different haplogroups, whereas interspecies comparisons showed that they affected conserved amino acid residues or domains in the ND subunit genes of complex I. CONCLUSIONS/SIGNIFICANCE Our findings indicate that these nine substitutions are all primary LHON mutations. Therefore, despite their relative low frequency, they should be routinely tested for in all LHON patients lacking the three common mutations. Moreover, our sequence analysis confirms the major role of haplogroups J1c and J2b (over 35% in our probands versus 6% in the general population of Western Europe) and other putative synergistic mtDNA variants in LHON expression.
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Affiliation(s)
- Alessandro Achilli
- Dipartimento di Biologia Cellulare e Ambientale, Università di Perugia, Perugia, Italy
| | - Luisa Iommarini
- IRCCS Istituto delle Scienze Neurologiche di Bologna and Dipartimento di Scienze Neurologiche, Università di Bologna, Bologna, Italy
| | - Anna Olivieri
- Dipartimento di Biologia e Biotecnologie, Università di Pavia, Pavia, Italy
| | - Maria Pala
- Dipartimento di Biologia e Biotecnologie, Università di Pavia, Pavia, Italy
| | | | - Pascal Reynier
- UMR INSERM, U1083-CNRS6214, Angers, France
- University of Angers, School of Medicine, Angers, France
- University Hospital of Angers, Department of Biochemistry and Genetics, Angers, France
| | - Chiara La Morgia
- IRCCS Istituto delle Scienze Neurologiche di Bologna and Dipartimento di Scienze Neurologiche, Università di Bologna, Bologna, Italy
| | - Maria Lucia Valentino
- IRCCS Istituto delle Scienze Neurologiche di Bologna and Dipartimento di Scienze Neurologiche, Università di Bologna, Bologna, Italy
| | - Rocco Liguori
- IRCCS Istituto delle Scienze Neurologiche di Bologna and Dipartimento di Scienze Neurologiche, Università di Bologna, Bologna, Italy
| | - Fabio Pizza
- IRCCS Istituto delle Scienze Neurologiche di Bologna and Dipartimento di Scienze Neurologiche, Università di Bologna, Bologna, Italy
| | - Piero Barboni
- IRCCS Istituto delle Scienze Neurologiche di Bologna and Dipartimento di Scienze Neurologiche, Università di Bologna, Bologna, Italy
- Studio Oculistico D’Azeglio, Bologna, Italy
| | | | | | - Massimo Zeviani
- Unit of Molecular Neurogenetics, Pierfranco and Luisa Mariani Center for the Study of Children’s Mitochondrial Disorders, Foundation “C. Besta” Neurological Institute-IRCCS, Milan, Italy
| | - Helene Dollfus
- Centre de référence pour les Affections Rares en Génétique Ophtalmologique, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Antoine Moulignier
- Service de Neurologie, Fondation Ophtalmologique Adolphe de Rothschild, Paris, France
| | - Ghislaine Ducos
- Department of Ophthalmology, Saint Jean Languedoc Clinic, Toulouse, France
| | - Christophe Orssaud
- Centre de Référence des Maladies Rares en Ophtalmologie, Consultationd ‘Ophtalmologie, HEGP, Assistance Publique – Hôpitaux de Paris, Paris, France
| | - Dominique Bonneau
- UMR INSERM, U1083-CNRS6214, Angers, France
- University of Angers, School of Medicine, Angers, France
- University Hospital of Angers, Department of Biochemistry and Genetics, Angers, France
| | - Vincent Procaccio
- UMR INSERM, U1083-CNRS6214, Angers, France
- University of Angers, School of Medicine, Angers, France
- University Hospital of Angers, Department of Biochemistry and Genetics, Angers, France
| | - Beate Leo-Kottler
- Centre for Ophthalmology, University Clinics Tuebingen, Tubingen, Germany
| | - Sascha Fauser
- Department of Vitreo-Retinal Surgery, Center of Ophthalmology, University of Cologne, Cologne, Germany
| | - Bernd Wissinger
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, Centre for Ophthalmology, University Clinics Tuebingen, Tuebingen, Germany
| | - Patrizia Amati-Bonneau
- UMR INSERM, U1083-CNRS6214, Angers, France
- University Hospital of Angers, Department of Biochemistry and Genetics, Angers, France
| | - Antonio Torroni
- Dipartimento di Biologia e Biotecnologie, Università di Pavia, Pavia, Italy
| | - Valerio Carelli
- IRCCS Istituto delle Scienze Neurologiche di Bologna and Dipartimento di Scienze Neurologiche, Università di Bologna, Bologna, Italy
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404
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Lin HZ, Pang CY, Chen SP, Tsai RK. Vision improvement in a Taiwanese (Han Chinese) family with Leber's hereditary optic neuropathy. Kaohsiung J Med Sci 2012; 28:679-82. [PMID: 23217361 DOI: 10.1016/j.kjms.2012.04.038] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2011] [Accepted: 10/26/2011] [Indexed: 11/16/2022] Open
Abstract
In this report, we describe a Taiwanese (Han Chinese) family with Leber's hereditary optic neuropathy. The family carried a mitochondrial DNA mutation (mtDNA m.14484T>C) associated with spontaneous visual improvement. A 15-year-old boy from this family was diagnosed with Leber's hereditary optic neuropathy 6 months after losing his vision. His vision recovered after 8 months of supportive treatment. His mother, older brother, and two sisters also had the same mutation and had previously experienced vision loss. In this family, there was no male predominance.
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Affiliation(s)
- Hong-Zin Lin
- Department of Ophthalmology, Buddhist Tzu Chi General Hospital, Hualien, Taiwan
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405
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Meta-analysis of the prevalence of Leber hereditary optic neuropathy mtDNA mutations in Europe. Eur J Ophthalmol 2012; 22:461-5. [PMID: 21928272 DOI: 10.5301/ejo.5000055] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/31/2011] [Indexed: 11/20/2022]
Abstract
PURPOSE A meta-analysis was conducted to estimate the prevalence of patients with molecularly confirmed Leber hereditary optic neuropathy (LHON) carrying any of the 3 primary mtDNA mutations (m.11778G>A, m.14484T>C, m.3460G>A) which cause this inherited form of blindness. METHODS A literature search was conducted to identify primary reports with LHON prevalence data reported for Europe. The overall prevalence of LHON with molecularly confirmed diagnosis was evaluated by weighting the prevalence estimates of the individual studies by the inverse of their variance. RESULTS Based on this meta-analysis of 5 European studies providing appropriate information, the estimated prevalence of LHON disease associated with the combined m.11778G>A, m.14484T>C, m.3460G>A mutations was ~1:45,000 (2.23 x 10(-5); 95% confidence interval [CI] 2.01-2.44 x 10(-5)). Patients with LHON carrying either the m.11778G>A or the m.3460G>A mutation have a more severe clinical presentation and a much lower chance of spontaneous recovery from vision loss compared to patients with the m.14484T>C mutation. The estimated prevalence for patients with LHON in Europe carrying either of these severe mutations (m.11778G>A or m.3460G>A) was ~1:65,000 (1.54 x 10(-5); 95% CI 1.33-1.74 x 10(-5)). CONCLUSIONS Although this meta-analysis summarizes the existing prevalence data for the primary, disease-causing mitochondrial DNA mutations of LHON in Europe, there is still a clear lack of reliable primary epidemiologic data for this devastating ophthalmologic disease.
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406
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Lenaers G, Hamel C, Delettre C, Amati-Bonneau P, Procaccio V, Bonneau D, Reynier P, Milea D. Dominant optic atrophy. Orphanet J Rare Dis 2012; 7:46. [PMID: 22776096 PMCID: PMC3526509 DOI: 10.1186/1750-1172-7-46] [Citation(s) in RCA: 171] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Accepted: 03/15/2012] [Indexed: 11/18/2022] Open
Abstract
Definition of the disease Dominant Optic Atrophy (DOA) is a neuro-ophthalmic condition characterized by a bilateral degeneration of the optic nerves, causing insidious visual loss, typically starting during the first decade of life. The disease affects primary the retinal ganglion cells (RGC) and their axons forming the optic nerve, which transfer the visual information from the photoreceptors to the lateral geniculus in the brain. Epidemiology The prevalence of the disease varies from 1/10000 in Denmark due to a founder effect, to 1/30000 in the rest of the world. Clinical description DOA patients usually suffer of moderate visual loss, associated with central or paracentral visual field deficits and color vision defects. The severity of the disease is highly variable, the visual acuity ranging from normal to legal blindness. The ophthalmic examination discloses on fundoscopy isolated optic disc pallor or atrophy, related to the RGC death. About 20% of DOA patients harbour extraocular multi-systemic features, including neurosensory hearing loss, or less commonly chronic progressive external ophthalmoplegia, myopathy, peripheral neuropathy, multiple sclerosis-like illness, spastic paraplegia or cataracts. Aetiology Two genes (OPA1, OPA3) encoding inner mitochondrial membrane proteins and three loci (OPA4, OPA5, OPA8) are currently known for DOA. Additional loci and genes (OPA2, OPA6 and OPA7) are responsible for X-linked or recessive optic atrophy. All OPA genes yet identified encode mitochondrial proteins embedded in the inner membrane and ubiquitously expressed, as are the proteins mutated in the Leber Hereditary Optic Neuropathy. OPA1 mutations affect mitochondrial fusion, energy metabolism, control of apoptosis, calcium clearance and maintenance of mitochondrial genome integrity. OPA3 mutations only affect the energy metabolism and the control of apoptosis. Diagnosis Patients are usually diagnosed during their early childhood, because of bilateral, mild, otherwise unexplained visual loss related to optic discs pallor or atrophy, and typically occurring in the context of a family history of DOA. Optical Coherence Tomography further discloses non-specific thinning of retinal nerve fiber layer, but a normal morphology of the photoreceptors layers. Abnormal visual evoked potentials and pattern ERG may also reflect the dysfunction of the RGCs and their axons. Molecular diagnosis is provided by the identification of a mutation in the OPA1 gene (75% of DOA patients) or in the OPA3 gene (1% of patients). Prognosis Visual loss in DOA may progress during puberty until adulthood, with very slow subsequent chronic progression in most of the cases. On the opposite, in DOA patients with associated extra-ocular features, the visual loss may be more severe over time. Management To date, there is no preventative or curative treatment in DOA; severely visually impaired patients may benefit from low vision aids. Genetic counseling is commonly offered and patients are advised to avoid alcohol and tobacco consumption, as well as the use of medications that may interfere with mitochondrial metabolism. Gene and pharmacological therapies for DOA are currently under investigation.
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Affiliation(s)
- Guy Lenaers
- Institut des Neurosciences de Montpellier, U1051 de l'INSERM, Université de Montpellier I et II, BP 74103, F-34091 Montpellier cedex 05, France.
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407
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Chadderton N, Palfi A, Millington-Ward S, Gobbo O, Overlack N, Carrigan M, O'Reilly M, Campbell M, Ehrhardt C, Wolfrum U, Humphries P, Kenna PF, Farrar GJ. Intravitreal delivery of AAV-NDI1 provides functional benefit in a murine model of Leber hereditary optic neuropathy. Eur J Hum Genet 2012; 21:62-8. [PMID: 22669418 PMCID: PMC3522193 DOI: 10.1038/ejhg.2012.112] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Leber hereditary optic neuropathy (LHON) is a mitochondrially inherited form of visual dysfunction caused by mutations in several genes encoding subunits of the mitochondrial respiratory NADH-ubiquinone oxidoreductase complex (complex I). Development of gene therapies for LHON has been impeded by genetic heterogeneity and the need to deliver therapies to the mitochondria of retinal ganglion cells (RGCs), the cells primarily affected in LHON. The therapy under development entails intraocular injection of a nuclear yeast gene NADH-quinone oxidoreductase (NDI1) that encodes a single subunit complex I equivalent and as such is mutation independent. NDI1 is imported into mitochondria due to an endogenous mitochondrial localisation signal. Intravitreal injection represents a clinically relevant route of delivery to RGCs not previously used for NDI1. In this study, recombinant adenoassociated virus (AAV) serotype 2 expressing NDI1 (AAV-NDI1) was shown to protect RGCs in a rotenone-induced murine model of LHON. AAV-NDI1 significantly reduced RGC death by 1.5-fold and optic nerve atrophy by 1.4-fold. This led to a significant preservation of retinal function as assessed by manganese enhanced magnetic resonance imaging and optokinetic responses. Intraocular injection of AAV-NDI1 overcomes many barriers previously associated with developing therapies for LHON and holds great therapeutic promise for a mitochondrial disorder for which there are no effective therapies.
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Affiliation(s)
- Naomi Chadderton
- School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland.
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408
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Abstracts of the 2012 Meeting of the International Neuro-Ophthalmology Society, Singapore. Neuroophthalmology 2012. [DOI: 10.3109/01658107.2012.690640] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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409
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Gómez-Durán A, Pacheu-Grau D, Martínez-Romero I, López-Gallardo E, López-Pérez MJ, Montoya J, Ruiz-Pesini E. Oxidative phosphorylation differences between mitochondrial DNA haplogroups modify the risk of Leber's hereditary optic neuropathy. Biochim Biophys Acta Mol Basis Dis 2012; 1822:1216-22. [PMID: 22561905 DOI: 10.1016/j.bbadis.2012.04.014] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2012] [Revised: 03/12/2012] [Accepted: 04/20/2012] [Indexed: 01/12/2023]
Abstract
Leber's hereditary optic neuropathy is a maternally inherited optic atrophy caused by mitochondrial DNA point mutations. Previous epidemiological studies have shown that individuals from mitochondrial genetic backgrounds (haplogroups) J/Uk and H have a higher and a lower risk, respectively, of suffering this disorder. To analyze the bases of these associations at cellular and molecular levels, functional studies with cybrids provide high quality evidence. Cybrids from haplogroup J contain less mitochondrial deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) and synthesize a smaller amount of mitochondrial DNA-encoded polypeptides than those from haplogroup H. Haplogroup J cybrids also display lower oxygen consumption, mitochondrial inner membrane potential and total adenosine-5'-triphosphate (ATP) levels. Moreover, mitochondrial DNA levels correlate with many parameters of the oxidative phosphorylation system. These results suggest that the mitochondrial DNA amount determines oxidative phosphorylation capacity and, along with other recently published observations, support the possibility that mitochondrial DNA levels may be responsible for the bias of the disorder toward males, for the incomplete penetrance of mutations causing Leber's hereditary optic neuropathy and for the association of the disease with particular mitochondrial DNA haplogroups.
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Affiliation(s)
- Aurora Gómez-Durán
- Departamento de Bioquímica, Biología Molecular y Celular, Centro de Investigaciones Biomédicas En Red de Enfermedades Raras, Universidad de Zaragoza, Spain
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410
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Abstract
Leber's hereditary optic neuropathy (LHON) is a rare disease primarily affecting the retinal ganglion cells. In most cases patients with LHON develop permanent visual loss with a large central scotoma in the visual field of both eyes. The optic disc becomes partially or completely pale. At the onset of the disease many patients are considered to suffer from an optic neuritis and are treated under the diagnostic and therapeutic regimen of optic neuritis. LHON is mostly only considered when high dose cortisone therapy fails to be effective or the second eye is affected. Thereafter, molecular genetic analysis will prove LHON in these cases. Detailed anamnesis including pedigree analysis in combination with observance of the peripapillary microangiopathic alterations at the fundus will help to speed up the diagnosis of LHON, but even after exact clinical and molecular genetic diagnosis of LHON some aspects of the disease still remain a mystery today.
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Affiliation(s)
- B Leo-Kottler
- Department für Augenheilkunde, Augenklinik, Schleichstr. 12-16, 72076, Tübingen, Deutschland.
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411
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Nickells RW, Howell GR, Soto I, John SWM. Under pressure: cellular and molecular responses during glaucoma, a common neurodegeneration with axonopathy. Annu Rev Neurosci 2012; 35:153-79. [PMID: 22524788 DOI: 10.1146/annurev.neuro.051508.135728] [Citation(s) in RCA: 224] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Glaucoma is a complex neurodegenerative disorder that is expected to affect 80 million people by the end of this decade. Retinal ganglion cells (RGCs) are the most affected cell type and progressively degenerate over the course of the disease. RGC axons exit the eye and enter the optic nerve by passing through the optic nerve head (ONH). The ONH is an important site of initial damage in glaucoma. Higher intraocular pressure (IOP) is an important risk factor for glaucoma, but the molecular links between elevated IOP and axon damage in the ONH are poorly defined. In this review and focusing primarily on the ONH, we discuss recent studies that have contributed to understanding the etiology and pathogenesis of glaucoma. We also identify areas that require further investigation and focus on mechanisms identified in other neurodegenerations that may contribute to RGC dysfunction and demise in glaucoma.
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Affiliation(s)
- Robert W Nickells
- Department of Ophthalmology and Visual Sciences, University of Wisconsin, Madison, Wisconsin 53706, USA.
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412
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del Olmo-Aguado S, Manso AG, Osborne NN. Light Might Directly Affect Retinal Ganglion Cell Mitochondria to Potentially Influence Function†. Photochem Photobiol 2012; 88:1346-55. [DOI: 10.1111/j.1751-1097.2012.01120.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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413
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Current World Literature. Curr Opin Ophthalmol 2012; 23:155-9. [DOI: 10.1097/icu.0b013e3283511bcf] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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414
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Kamalden TA, Ji D, Osborne NN. Rotenone-Induced Death of RGC-5 Cells is Caspase Independent, Involves the JNK and p38 Pathways and is Attenuated by Specific Green Tea Flavonoids. Neurochem Res 2012; 37:1091-101. [DOI: 10.1007/s11064-012-0713-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2011] [Revised: 01/16/2012] [Accepted: 01/19/2012] [Indexed: 12/21/2022]
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415
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Karbowski M, Neutzner A. Neurodegeneration as a consequence of failed mitochondrial maintenance. Acta Neuropathol 2012; 123:157-71. [PMID: 22143516 DOI: 10.1007/s00401-011-0921-0] [Citation(s) in RCA: 137] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2011] [Revised: 11/18/2011] [Accepted: 11/22/2011] [Indexed: 02/06/2023]
Abstract
Maintaining the functional integrity of mitochondria is pivotal for cellular survival. It appears that neuronal homeostasis depends on high-fidelity mitochondria, in particular. Consequently, mitochondrial dysfunction is a fundamental problem associated with a significant number of neurological diseases, including Parkinson's disease (PD), Huntington's disease (HD), Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS) and various peripheral neuropathies, as well as the normal aging process. To ensure optimal mitochondrial function, diverse, evolutionarily conserved mitochondrial quality control mechanisms are in place, including the scavenging of toxic reactive oxygen species (ROS) and degradation of damaged mitochondrial proteins, but also turnover of whole organelles. In this review we will discuss various mitochondria-associated conditions, focusing on the role of protein turnover in mitochondrial maintenance with special emphasis on neurodegenerative disorders.
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Affiliation(s)
- Mariusz Karbowski
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
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416
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Williams PA, Piechota M, von Ruhland C, Taylor E, Morgan JE, Votruba M. Opa1 is essential for retinal ganglion cell synaptic architecture and connectivity. Brain 2012; 135:493-505. [DOI: 10.1093/brain/awr330] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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417
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Li H, Liu D, Lu J, Bai Y. Physiology and pathophysiology of mitochondrial DNA. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 942:39-51. [PMID: 22399417 DOI: 10.1007/978-94-007-2869-1_2] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Mitochondria are the only organelles in animal cells which possess their own genomes. Mitochondrial DNA (mtDNA) alterations have been associated with various human conditions. Yet, their role in pathogenesis remains largely unclear. This review focuses on several major features of mtDNA: (1) mtDNA haplogroup, (2) mtDNA common deletion, (3) mtDNA mutations in the control region or D-loop, (4) mtDNA copy number alterations, (5) mtDNA mutations in translational machinery, (6) mtDNA mutations in protein coding genes (7) mtDNA heteroplasmy. We will also discuss their implications in various human diseases.
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Affiliation(s)
- Hongzhi Li
- Wenzhou Medical College, Wenzhou, Zhejiang, China
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418
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Angebault C, Gueguen N, Desquiret-Dumas V, Chevrollier A, Guillet V, Verny C, Cassereau J, Ferre M, Milea D, Amati-Bonneau P, Bonneau D, Procaccio V, Reynier P, Loiseau D. Idebenone increases mitochondrial complex I activity in fibroblasts from LHON patients while producing contradictory effects on respiration. BMC Res Notes 2011; 4:557. [PMID: 22192149 PMCID: PMC3285568 DOI: 10.1186/1756-0500-4-557] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2011] [Accepted: 12/22/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Leber's hereditary optic neuropathy (LHON) is caused by mutations in the complex I subunits of the respiratory chain. Although patients have been treated with idebenone since 1992, the efficacy of the drug is still a matter of debate. METHODS We evaluated the effect of idebenone in fibroblasts from LHON patients using enzymatic and polarographic measurements. RESULTS Complex I activity was 42% greater in treated fibroblasts compared to controls (p = 0.002). Despite this complex I activity improvement, the effects on mitochondrial respiration were contradictory, leading to impairment in some cases and stimulation in others. CONCLUSION These results indicate that idebenone is able to compensate the complex I deficiency in LHON patient cells with variable effects on respiration, indicating that the patients might not be equally likely to benefit from the treatment.
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419
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Rouzier C, Bannwarth S, Chaussenot A, Chevrollier A, Verschueren A, Bonello-Palot N, Fragaki K, Cano A, Pouget J, Pellissier JF, Procaccio V, Chabrol B, Paquis-Flucklinger V. The MFN2 gene is responsible for mitochondrial DNA instability and optic atrophy 'plus' phenotype. Brain 2011; 135:23-34. [PMID: 22189565 DOI: 10.1093/brain/awr323] [Citation(s) in RCA: 180] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
MFN2 and OPA1 genes encode two dynamin-like GTPase proteins involved in the fusion of the mitochondrial membrane. They have been associated with Charcot-Marie-Tooth disease type 2A and autosomal dominant optic atrophy, respectively. We report a large family with optic atrophy beginning in early childhood, associated with axonal neuropathy and mitochondrial myopathy in adult life. The clinical presentation looks like the autosomal dominant optic atrophy 'plus' phenotype linked to OPA1 mutations but is associated with a novel MFN2 missense mutation (c.629A>T, p.D210V). Multiple mitochondrial DNA deletions were found in skeletal muscle and this observation makes MFN2 a novel gene associated with 'mitochondrial DNA breakage' syndrome. Contrary to previous studies in patients with Charcot-Marie-Tooth disease type 2A, fibroblasts carrying the MFN2 mutation present with a respiratory chain deficiency, a fragmentation of the mitochondrial network and a significant reduction of MFN2 protein expression. Furthermore, we show for the first time that impaired mitochondrial fusion is responsible for a deficiency to repair stress-induced mitochondrial DNA damage. It is likely that defect in mitochondrial DNA repair is due to variability in repair protein content across the mitochondrial population and is at least partially responsible for mitochondrial DNA instability.
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Affiliation(s)
- Cécile Rouzier
- Department of Medical Genetics, National Centre for Mitochondrial Diseases, Nice Teaching Hospital, 06200, France
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420
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Yu-Wai-Man P, Chinnery PF. Leber Hereditary Optic Neuropathy - Therapeutic Challenges and Early Promise. Taiwan J Ophthalmol 2011; 1:12-15. [PMID: 25729642 DOI: 10.1016/j.tjo.2011.09.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022] Open
Abstract
Leber hereditary optic neuropathy (LHON) is the most common primary mitochondrial DNA (mtDNA) disorder in the general population. It is an important cause of severe, usually irreversible, visual loss among young adults with a peak age of onset in the second and third decades of life. Management is currently mostly supportive but recent developments in LHON research are pointing the way towards more effective treatments for this blinding mitochondrial disorder.
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Affiliation(s)
- Patrick Yu-Wai-Man
- Mitochondrial Research Group, Institute of Genetic Medicine, Centre for Life, Newcastle University, NE1 3BZ, UK ; Department of Ophthalmology, Royal Victoria Infirmary, Newcastle upon Tyne, NE1 4LP, UK
| | - Patrick F Chinnery
- Mitochondrial Research Group, Institute of Genetic Medicine, Centre for Life, Newcastle University, NE1 3BZ, UK ; Department of Neurology, Royal Victoria Infirmary, Newcastle upon Tyne, NE1 4LP, UK
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421
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Bouaita A, Augustin S, Lechauve C, Cwerman-Thibault H, Bénit P, Simonutti M, Paques M, Rustin P, Sahel JA, Corral-Debrinski M. Downregulation of apoptosis-inducing factor in Harlequin mice induces progressive and severe optic atrophy which is durably prevented by AAV2-AIF1 gene therapy. ACTA ACUST UNITED AC 2011; 135:35-52. [PMID: 22120150 DOI: 10.1093/brain/awr290] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The Harlequin mutant mouse, characterized by loss of function of apoptosis-inducing factor, represents a reliable genetic model that resembles pathologies caused by human mitochondrial complex I deficiency. Therefore, we extensively characterized the retinal morphology and function of Harlequin mice during the course of neuronal cell death leading to blindness, with the aim of preventing optic atrophy. Retinas and optic nerves from these mice showed an isolated respiratory chain complex I defect correlated with retinal ganglion cell loss, optic atrophy, glial and microglial cell activation. All of these changes led to irreversible vision loss. In control mice, retinas AIF1 messenger RNA was 2.3-fold more abundant than AIF2, both messenger RNAs being sorted to the mitochondrial surface. In Harlequin mouse retinas, there was a 96% decrease of both AIF1 and AIF2 messenger RNA steady-state levels. We attained substantial and long-lasting protection of retinal ganglion cell and optic nerve integrity, the preservation of complex I function in optic nerves, as well as the prevention of glial and microglial responses after intravitreal administration of an AAV2 vector containing the full-length open reading frame and the 3' untranslated region of the AIF1 gene. Therefore, we demonstrate that gene therapy for mitochondrial diseases due to mutations in nuclear DNA can be achieved, so long as the 'therapeutic gene' permits the accurate cellular localization of the corresponding messenger RNA.
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422
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Pätsi J, Maliniemi P, Pakanen S, Hinttala R, Uusimaa J, Majamaa K, Nyström T, Kervinen M, Hassinen IE. LHON/MELAS overlap mutation in ND1 subunit of mitochondrial complex I affects ubiquinone binding as revealed by modeling in Escherichia coli NDH-1. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2011; 1817:312-8. [PMID: 22079202 DOI: 10.1016/j.bbabio.2011.10.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2011] [Revised: 10/27/2011] [Accepted: 10/28/2011] [Indexed: 10/15/2022]
Abstract
Defects in complex I due to mutations in mitochondrial DNA are associated with clinical features ranging from single organ manifestation like Leber hereditary optic neuropathy (LHON) to multiorgan disorders like mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) syndrome. Specific mutations cause overlap syndromes combining several phenotypes, but the mechanisms of their biochemical effects are largely unknown. The m.3376G>A transition leading to p.E24K substitution in ND1 with LHON/MELAS phenotype was modeled here in a homologous position (NuoH-E36K) in the Escherichia coli enzyme and it almost totally abolished complex I activity. The more conservative mutation NuoH-E36Q resulted in higher apparent K(m) for ubiquinone and diminished inhibitor sensitivity. A NuoH homolog of the m.3865A>G transition, which has been found concomitantly in the overlap syndrome patient with the m.3376G>A, had only a minor effect. Consequences of a primary LHON-mutation m.3460G>A affecting the same extramembrane loop as the m.3376G>A substitution were also studied in the E. coli model and were found to be mild. The results indicate that the overlap syndrome-associated m.3376G>A transition in MTND1 is the pathogenic mutation and m.3865A>G transition has minor, if any, effect on presentation of the disease. The kinetic effects of the NuoH-E36Q mutation suggest its proximity to the putative ubiquinone binding domain in 49kD/PSST subunits. In all, m.3376G>A perturbs ubiquinone binding, a phenomenon found in LHON, and decreases the activity of fully assembled complex I as in MELAS.
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Affiliation(s)
- Jukka Pätsi
- Department of Medical Biochemistry and Molecular Biology, University of Oulu, Finland
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423
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Baker MR, Fisher KM, Whittaker RG, Griffiths PG, Yu-Wai-Man P, Chinnery PF. Subclinical multisystem neurologic disease in "pure" OPA1 autosomal dominant optic atrophy. Neurology 2011; 77:1309-12. [PMID: 21917770 PMCID: PMC3179647 DOI: 10.1212/wnl.0b013e318230a15a] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- M R Baker
- Institute of Neuroscience, The Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.
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424
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Van Bergen NJ, Chakrabarti R, O’Neill EC, Crowston JG, Trounce IA. Mitochondrial disorders and the eye. Eye Brain 2011; 3:29-47. [PMID: 28539774 PMCID: PMC5436186 DOI: 10.2147/eb.s16192] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The clinical significance of disturbed mitochondrial function in the eye has emerged since mitochondrial DNA (mtDNA) mutation was described in Leber's hereditary optic neuropathy. The spectrum of mitochondrial dysfunction has become apparent through increased understanding of the contribution of nuclear and somatic mtDNA mutations to mitochondrial dynamics and function. Common ophthalmic manifestations of mitochondrial dysfunction include optic atrophy, pigmentary retinopathy, and ophthalmoplegia. The majority of patients with ocular manifestations of mitochondrial disease also have variable central and peripheral nervous system involvement. Mitochondrial dysfunction has recently been associated with age-related retinal disease including macular degeneration and glaucoma. Therefore, therapeutic targets directed at promoting mitochondrial biogenesis and function offer a potential to both preserve retinal function and attenuate neurodegenerative processes.
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Affiliation(s)
- Nicole J Van Bergen
- Centre for Eye Research Australia, Department of Ophthalmology, University of Melbourne, Victoria, Australia
| | - Rahul Chakrabarti
- Centre for Eye Research Australia, Department of Ophthalmology, University of Melbourne, Victoria, Australia
| | - Evelyn C O’Neill
- Centre for Eye Research Australia, Department of Ophthalmology, University of Melbourne, Victoria, Australia
| | - Jonathan G Crowston
- Centre for Eye Research Australia, Department of Ophthalmology, University of Melbourne, Victoria, Australia
| | - Ian A Trounce
- Centre for Eye Research Australia, Department of Ophthalmology, University of Melbourne, Victoria, Australia
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425
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Affiliation(s)
- Nancy J Newman
- Department of Ophthalmology, Emory University, Atlanta, GA, USA.
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426
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Sitarz KS, Yu-Wai-Man P, Hudson G, Jacob A, Boggild M, Horvath R, Chinnery PF. Genetic variations within the OPA1 gene are not associated with neuromyelitis optica. Mult Scler 2011; 18:240-3. [PMID: 21828197 DOI: 10.1177/1352458511416838] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Neuromyelitis optica (NMO) is an idiopathic demyelinating disease which predominantly affects the optic nerve and spinal cord. Multiplex NMO pedigrees have been reported but the genetic risk factors conferring this increased familial susceptibility have not yet been determined. OPA1 mutations have recently been identified in families with progressive visual failure and spastic paraparesis, raising the possibility that OPA1 genetic variants could contribute to the aetiology of NMO. We therefore screened for OPA1 in 32 patients with NMO. No pathogenic mutations were found, and none of the 13 single-nucleotide polymorphisms identified were associated with an increased risk of developing NMO.
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Affiliation(s)
- Kamil S Sitarz
- Mitochondrial Research Group, Institute of Genetic Medicine, Newcastle University, UK
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427
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Carelli V, La Morgia C, Valentino ML, Rizzo G, Carbonelli M, De Negri AM, Sadun F, Carta A, Guerriero S, Simonelli F, Sadun AA, Aggarwal D, Liguori R, Avoni P, Baruzzi A, Zeviani M, Montagna P, Barboni P. Idebenone Treatment In Leber's Hereditary Optic Neuropathy. Brain 2011; 134:e188. [DOI: 10.1093/brain/awr180] [Citation(s) in RCA: 157] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
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428
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Ganapathy PS, Perry RL, Tawfik A, Smith RM, Perry E, Roon P, Bozard BR, Ha Y, Smith SB. Homocysteine-mediated modulation of mitochondrial dynamics in retinal ganglion cells. Invest Ophthalmol Vis Sci 2011; 52:5551-8. [PMID: 21642619 DOI: 10.1167/iovs.11-7256] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
PURPOSE To evaluate the effect of excess homocysteine on the regulation of retinal ganglion cell mitochondrial dynamics. METHODS Mice deficient in cystathionine-β-synthase (cbs) were used as a model of hyperhomocysteinemia. Gene and protein expression analyses of Opa1 and Fis1 were performed on cbs⁺/⁻ neural retinas. Mitochondria within retinal ganglion cell axons underwent systematic ultrastructural analysis to measure area, length, width, and the distance between the mitochondria and the axon wall. Primary mouse ganglion cells were cultured, treated with homocysteine, and assessed for levels of Opa1 and Fis1 protein, the number of mitochondria per length of neurite, and levels of cleaved caspase-3. RESULTS Opa1 and Fis1 protein levels in cbs⁺/⁻ neural retinas were elevated to 191.00% ± 26.40% and 226.20% ± 4.57%, respectively, compared with wild-type. Mitochondria of cbs⁺/⁻ retinas were smaller in all parameters studied, including area (0.32 ± 0.01 μm² vs. 0.42 ± 0.02 μm²), compared with wild-type. Primary ganglion cells treated with homocysteine had elevations in Opa1 and Fis1 proteins, a significantly higher number of mitochondria per length of neurite (0.1781 ± 0.017 vs. 0.1156 ± 0.012), and significantly higher levels of cleaved caspase-3 compared with control. CONCLUSIONS This study provides the first evidence that homocysteine-induced ganglion cell loss involves the dysregulation of mitochondrial dynamics, both in vivo and in vitro. The present data suggest increased mitochondrial fission as a novel mechanism of homocysteine toxicity to neurons. Of particular relevance are glaucoma and Alzheimer's disease, neurodegenerative diseases that are associated with hyperhomocysteinemia and, more recently, have implicated increased mitochondrial fission in their pathogeneses.
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Affiliation(s)
- Preethi S Ganapathy
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta, Georgia, USA
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429
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Van Bergen NJ, Crowston JG, Kearns LS, Staffieri SE, Hewitt AW, Cohn AC, Mackey DA, Trounce IA. Mitochondrial oxidative phosphorylation compensation may preserve vision in patients with OPA1-linked autosomal dominant optic atrophy. PLoS One 2011; 6:e21347. [PMID: 21731710 PMCID: PMC3120866 DOI: 10.1371/journal.pone.0021347] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2011] [Accepted: 05/27/2011] [Indexed: 02/01/2023] Open
Abstract
Autosomal Dominant Optic Atrophy (ADOA) is the most common inherited optic atrophy where vision impairment results from specific loss of retinal ganglion cells of the optic nerve. Around 60% of ADOA cases are linked to mutations in the OPA1 gene. OPA1 is a fission-fusion protein involved in mitochondrial inner membrane remodelling. ADOA presents with marked variation in clinical phenotype and varying degrees of vision loss, even among siblings carrying identical mutations in OPA1. To determine whether the degree of vision loss is associated with the level of mitochondrial impairment, we examined mitochondrial function in lymphoblast cell lines obtained from six large Australian OPA1-linked ADOA pedigrees. Comparing patients with severe vision loss (visual acuity [VA]<6/36) and patients with relatively preserved vision (VA>6/9) a clear defect in mitochondrial ATP synthesis and reduced respiration rates were observed in patients with poor vision. In addition, oxidative phosphorylation (OXPHOS) enzymology in ADOA patients with normal vision revealed increased complex II+III activity and levels of complex IV protein. These data suggest that OPA1 deficiency impairs OXPHOS efficiency, but compensation through increases in the distal complexes of the respiratory chain may preserve mitochondrial ATP production in patients who maintain normal vision. Identification of genetic variants that enable this response may provide novel therapeutic insights into OXPHOS compensation for preventing vision loss in optic neuropathies.
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Affiliation(s)
- Nicole J. Van Bergen
- Centre for Eye Research Australia, University of Melbourne, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia
| | - Jonathan G. Crowston
- Centre for Eye Research Australia, University of Melbourne, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia
| | - Lisa S. Kearns
- Centre for Eye Research Australia, University of Melbourne, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia
| | - Sandra E. Staffieri
- Centre for Eye Research Australia, University of Melbourne, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia
| | - Alex W. Hewitt
- Centre for Eye Research Australia, University of Melbourne, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia
| | - Amy C. Cohn
- Centre for Eye Research Australia, University of Melbourne, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia
| | - David A. Mackey
- University of Western Australia, Perth, Western Australia, Australia
- Lions Eye Institute, Perth, Western Australia, Australia
| | - Ian A. Trounce
- Centre for Eye Research Australia, University of Melbourne, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia
- * E-mail:
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430
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Pretegiani E, Rufa A, Gallus GN, Cardaioli E, Malandrini A, Federico A. Spastic paraplegia in 'dominant optic atrophy plus' phenotype due to OPA1 mutation. Brain 2011; 134:e195. [DOI: 10.1093/brain/awr101] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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431
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Wrightstone RN, Smith LL, Wilson JB, Vella F, Huisman TH. Some physicochemical properties of hemoglobin-manitoba (alpha2 102Ser replaced by Arg (G9) beta2). BIOCHIMICA ET BIOPHYSICA ACTA 1975; 412:283-7. [PMID: 87 DOI: 10.1016/0005-2795(75)90042-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Hb-Manitoba was discovered in 1970 [1] in a Canadian family of British origin. Recently we observed the same variant in a second family, and found that the oxy-derivative of Hb-Manitoba is slightly unstable at 65 degrees C, dissociates less readily at alkaline pH than does Hb-A, and forms asymmetric hybrids with other hemoglobins which are readily detectable by electrophoresis.
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