1
|
Asadullah, Ud Din A, Ul Ghafoor S, Akbar F, Akhtar N, Fiaz Khan M, Ullah Z, Kareem A. Analysis of mutations in leu tRNA gene in patients of heart diseases. Saudi J Biol Sci 2022; 29:436-443. [PMID: 35002439 PMCID: PMC8716966 DOI: 10.1016/j.sjbs.2021.09.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 08/05/2021] [Accepted: 09/05/2021] [Indexed: 11/23/2022] Open
Abstract
Cardiovascular diseases (CVD) are the leading cause of death all over the world. Beside general risk factors, there are some genetic factors which lead to cardiovascular diseases. Various nuclear DNA mutation and also mitochondrial DNA mutations have been related with cardiovascular diseases. In the present study, a total of 21 samples were collected from different families residing in district Dir. DNA was extracted from buccal epithelial cells using saliva. The mitochondrial tRNA leu (MT TL1) gene was amplified by PCR and 10 samples of different families were sequenced. The sequence was aligned with revised Cambridge Reference Sequence (rCRS) accession # NC-012920.1. It is concluded that cardiovascular diseases in our subjects are not due to mutation in the mitochondrial leucine tRNA gene. However, a large population of subjects with cardiovascular diseases needs to be studied and whole mitochondrial DNA is needed to be sequenced in the subjects with CVD. This will give an idea about the probable DNA marker which can be used to prevent loses due to these diseases at a very early stages.
Collapse
Affiliation(s)
- Asadullah
- Department of Genetics, Hazara University, Mansehra, Pakistan
| | - Aziz Ud Din
- Department of Genetics, Hazara University, Mansehra, Pakistan
| | | | - Fazal Akbar
- Centre for Biotechnology and Microbiology, University of Swat, Pakistan
| | - Naveed Akhtar
- Department of Zoology, Hazara University Sub Campus, Battagram, Pakistan
| | | | - Zaib Ullah
- Department of Zoology, Hazara University Sub Campus, Battagram, Pakistan
| | - Abdul Kareem
- Department of Life Sciences, Sana'a University, Yemen
| |
Collapse
|
2
|
Zeviani M, Carelli V. Mitochondrial Retinopathies. Int J Mol Sci 2021; 23:210. [PMID: 35008635 PMCID: PMC8745158 DOI: 10.3390/ijms23010210] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 12/14/2021] [Accepted: 12/18/2021] [Indexed: 12/13/2022] Open
Abstract
The retina is an exquisite target for defects of oxidative phosphorylation (OXPHOS) associated with mitochondrial impairment. Retinal involvement occurs in two ways, retinal dystrophy (retinitis pigmentosa) and subacute or chronic optic atrophy, which are the most common clinical entities. Both can present as isolated or virtually exclusive conditions, or as part of more complex, frequently multisystem syndromes. In most cases, mutations of mtDNA have been found in association with mitochondrial retinopathy. The main genetic abnormalities of mtDNA include mutations associated with neurogenic muscle weakness, ataxia and retinitis pigmentosa (NARP) sometimes with earlier onset and increased severity (maternally inherited Leigh syndrome, MILS), single large-scale deletions determining Kearns-Sayre syndrome (KSS, of which retinal dystrophy is a cardinal symptom), and mutations, particularly in mtDNA-encoded ND genes, associated with Leber hereditary optic neuropathy (LHON). However, mutations in nuclear genes can also cause mitochondrial retinopathy, including autosomal recessive phenocopies of LHON, and slowly progressive optic atrophy caused by dominant or, more rarely, recessive, mutations in the fusion/mitochondrial shaping protein OPA1, encoded by a nuclear gene on chromosome 3q29.
Collapse
Affiliation(s)
- Massimo Zeviani
- Department of Neurosciences, The Clinical School, University of Padova, 35128 Padova, Italy
- Veneto Institute of Molecular Medicine, Via Orus 2, 35128 Padova, Italy
| | - Valerio Carelli
- Department of Biomedical and Neuromotor Sciences, University of Bologna, 40139 Bologna, Italy
- Programma di Neurogenetica, IRCCS Istituto delle Scienze Neurologiche di Bologna, Via Altura 6, 40139 Bologna, Italy
| |
Collapse
|
3
|
Liu Y, Chen Y. Mitochondrial tRNA Mutations Associated With Essential Hypertension: From Molecular Genetics to Function. Front Cell Dev Biol 2021; 8:634137. [PMID: 33585472 PMCID: PMC7874112 DOI: 10.3389/fcell.2020.634137] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 12/28/2020] [Indexed: 11/13/2022] Open
Abstract
Essential hypertension (EH) is one of the most common cardiovascular diseases worldwide, entailing a high level of morbidity. EH is a multifactorial disease influenced by both genetic and environmental factors, including mitochondrial DNA (mtDNA) genotype. Previous studies identified mtDNA mutations that are associated with maternally inherited hypertension, including tRNAIle m.4263A>G, m.4291T>C, m.4295A>G, tRNAMet m.4435A>G, tRNAAla m.5655A>G, and tRNAMet/tRNAGln m.4401A>G, et al. These mtDNA mutations alter tRNA structure, thereby leading to metabolic disorders. Metabolic defects associated with mitochondrial tRNAs affect protein synthesis, cause oxidative phosphorylation defects, reduced ATP synthesis, and increase production of reactive oxygen species. In this review we discuss known mutations of tRNA genes encoded by mtDNA and the potential mechanisms by which these mutations may contribute to hypertension.
Collapse
Affiliation(s)
- Yuqi Liu
- Cardiac Department, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China.,Department of Cardiology & National Clinical Research Center of Geriatrics Disease, Chinese PLA General Hospital, Beijing, China.,Beijing Key Laboratory of Chronic Heart Failure Precision Medicine, Chinese PLA General Hospital, Beijing, China.,National Key Laboratory of Kidney Diseases, Chinese PLA General Hospital, Beijing, China
| | - Yundai Chen
- Cardiac Department, Chinese PLA General Hospital, Beijing, China
| |
Collapse
|
4
|
Bugiardini E, Bottani E, Marchet S, Poole OV, Beninca C, Horga A, Woodward C, Lam A, Hargreaves I, Chalasani A, Valerio A, Lamantea E, Venner K, Holton JL, Zeviani M, Houlden H, Quinlivan R, Lamperti C, Hanna MG, Pitceathly RDS. Expanding the molecular and phenotypic spectrum of truncating MT-ATP6 mutations. NEUROLOGY-GENETICS 2020; 6:e381. [PMID: 32042910 PMCID: PMC6984135 DOI: 10.1212/nxg.0000000000000381] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 10/22/2019] [Indexed: 01/26/2023]
Abstract
Objective To describe the clinical and functional consequences of 1 novel and 1 previously reported truncating MT-ATP6 mutation. Methods Three unrelated probands with mitochondrial encephalomyopathy harboring truncating MT-ATP6 mutations are reported. Transmitochondrial cybrid cell studies were used to confirm pathogenicity of 1 novel variant, and the effects of all 3 mutations on ATPase 6 and complex V structure and function were investigated. Results Patient 1 presented with adult-onset cerebellar ataxia, chronic kidney disease, and diabetes, whereas patient 2 had myoclonic epilepsy and cerebellar ataxia; both harbored the novel m.8782G>A; p.(Gly86*) mutation. Patient 3 exhibited cognitive decline, with posterior white matter abnormalities on brain MRI, and severely impaired renal function requiring transplantation. The m.8618dup; p.(Thr33Hisfs*32) mutation, previously associated with neurogenic muscle weakness, ataxia, and retinitis pigmentosa, was identified. All 3 probands demonstrated a broad range of heteroplasmy across different tissue types. Blue-native gel electrophoresis of cultured fibroblasts and skeletal muscle tissue confirmed multiple bands, suggestive of impaired complex V assembly. Microscale oxygraphy showed reduced basal respiration and adenosine triphosphate synthesis, while reactive oxygen species generation was increased. Transmitochondrial cybrid cell lines studies confirmed the deleterious effects of the novel m.8782 G>A; p.(Gly86*) mutation. Conclusions We expand the clinical and molecular spectrum of MT-ATP6-related mitochondrial disorders to include leukodystrophy, renal disease, and myoclonic epilepsy with cerebellar ataxia. Truncating MT-ATP6 mutations may exhibit highly variable mutant levels across different tissue types, an important consideration during genetic counseling.
Collapse
Affiliation(s)
- Enrico Bugiardini
- Department of Neuromuscular Diseases (E. Bugiardini, O.V.P, A.H., H.H., R.Q., M.G.H., R.D.S.P.), UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, United Kingdom; Mitochondrial Medicine Group (E. Bottani, C.B., M.Z.), Medical Research Council Mitochondrial Biology Unit, Cambridge, United Kingdom; Department of Molecular and Translational Medicine (E. Bottani, A.V.), University of Brescia; Medical Genetics and Neurogenetics Unit (S.M., E.L., C.L.), Fondazione IRCCS Istituto Neurologico, "C. Besta," Milan, Italy; Neurogenetics Unit (C.W.), and Neurometabolic Unit (A.L., I.H., A.C.), The National Hospital for Neurology and Neurosurgery; Division of Neuropathology (K.V., J.L.H.), UCL Queen Square Institute of Neurology; and Dubowitz Neuromuscular Centre (R.Q.), Great Ormond Street Hospital, London, United Kingdom
| | - Emanuela Bottani
- Department of Neuromuscular Diseases (E. Bugiardini, O.V.P, A.H., H.H., R.Q., M.G.H., R.D.S.P.), UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, United Kingdom; Mitochondrial Medicine Group (E. Bottani, C.B., M.Z.), Medical Research Council Mitochondrial Biology Unit, Cambridge, United Kingdom; Department of Molecular and Translational Medicine (E. Bottani, A.V.), University of Brescia; Medical Genetics and Neurogenetics Unit (S.M., E.L., C.L.), Fondazione IRCCS Istituto Neurologico, "C. Besta," Milan, Italy; Neurogenetics Unit (C.W.), and Neurometabolic Unit (A.L., I.H., A.C.), The National Hospital for Neurology and Neurosurgery; Division of Neuropathology (K.V., J.L.H.), UCL Queen Square Institute of Neurology; and Dubowitz Neuromuscular Centre (R.Q.), Great Ormond Street Hospital, London, United Kingdom
| | - Silvia Marchet
- Department of Neuromuscular Diseases (E. Bugiardini, O.V.P, A.H., H.H., R.Q., M.G.H., R.D.S.P.), UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, United Kingdom; Mitochondrial Medicine Group (E. Bottani, C.B., M.Z.), Medical Research Council Mitochondrial Biology Unit, Cambridge, United Kingdom; Department of Molecular and Translational Medicine (E. Bottani, A.V.), University of Brescia; Medical Genetics and Neurogenetics Unit (S.M., E.L., C.L.), Fondazione IRCCS Istituto Neurologico, "C. Besta," Milan, Italy; Neurogenetics Unit (C.W.), and Neurometabolic Unit (A.L., I.H., A.C.), The National Hospital for Neurology and Neurosurgery; Division of Neuropathology (K.V., J.L.H.), UCL Queen Square Institute of Neurology; and Dubowitz Neuromuscular Centre (R.Q.), Great Ormond Street Hospital, London, United Kingdom
| | - Olivia V Poole
- Department of Neuromuscular Diseases (E. Bugiardini, O.V.P, A.H., H.H., R.Q., M.G.H., R.D.S.P.), UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, United Kingdom; Mitochondrial Medicine Group (E. Bottani, C.B., M.Z.), Medical Research Council Mitochondrial Biology Unit, Cambridge, United Kingdom; Department of Molecular and Translational Medicine (E. Bottani, A.V.), University of Brescia; Medical Genetics and Neurogenetics Unit (S.M., E.L., C.L.), Fondazione IRCCS Istituto Neurologico, "C. Besta," Milan, Italy; Neurogenetics Unit (C.W.), and Neurometabolic Unit (A.L., I.H., A.C.), The National Hospital for Neurology and Neurosurgery; Division of Neuropathology (K.V., J.L.H.), UCL Queen Square Institute of Neurology; and Dubowitz Neuromuscular Centre (R.Q.), Great Ormond Street Hospital, London, United Kingdom
| | - Cristiane Beninca
- Department of Neuromuscular Diseases (E. Bugiardini, O.V.P, A.H., H.H., R.Q., M.G.H., R.D.S.P.), UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, United Kingdom; Mitochondrial Medicine Group (E. Bottani, C.B., M.Z.), Medical Research Council Mitochondrial Biology Unit, Cambridge, United Kingdom; Department of Molecular and Translational Medicine (E. Bottani, A.V.), University of Brescia; Medical Genetics and Neurogenetics Unit (S.M., E.L., C.L.), Fondazione IRCCS Istituto Neurologico, "C. Besta," Milan, Italy; Neurogenetics Unit (C.W.), and Neurometabolic Unit (A.L., I.H., A.C.), The National Hospital for Neurology and Neurosurgery; Division of Neuropathology (K.V., J.L.H.), UCL Queen Square Institute of Neurology; and Dubowitz Neuromuscular Centre (R.Q.), Great Ormond Street Hospital, London, United Kingdom
| | - Alejandro Horga
- Department of Neuromuscular Diseases (E. Bugiardini, O.V.P, A.H., H.H., R.Q., M.G.H., R.D.S.P.), UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, United Kingdom; Mitochondrial Medicine Group (E. Bottani, C.B., M.Z.), Medical Research Council Mitochondrial Biology Unit, Cambridge, United Kingdom; Department of Molecular and Translational Medicine (E. Bottani, A.V.), University of Brescia; Medical Genetics and Neurogenetics Unit (S.M., E.L., C.L.), Fondazione IRCCS Istituto Neurologico, "C. Besta," Milan, Italy; Neurogenetics Unit (C.W.), and Neurometabolic Unit (A.L., I.H., A.C.), The National Hospital for Neurology and Neurosurgery; Division of Neuropathology (K.V., J.L.H.), UCL Queen Square Institute of Neurology; and Dubowitz Neuromuscular Centre (R.Q.), Great Ormond Street Hospital, London, United Kingdom
| | - Cathy Woodward
- Department of Neuromuscular Diseases (E. Bugiardini, O.V.P, A.H., H.H., R.Q., M.G.H., R.D.S.P.), UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, United Kingdom; Mitochondrial Medicine Group (E. Bottani, C.B., M.Z.), Medical Research Council Mitochondrial Biology Unit, Cambridge, United Kingdom; Department of Molecular and Translational Medicine (E. Bottani, A.V.), University of Brescia; Medical Genetics and Neurogenetics Unit (S.M., E.L., C.L.), Fondazione IRCCS Istituto Neurologico, "C. Besta," Milan, Italy; Neurogenetics Unit (C.W.), and Neurometabolic Unit (A.L., I.H., A.C.), The National Hospital for Neurology and Neurosurgery; Division of Neuropathology (K.V., J.L.H.), UCL Queen Square Institute of Neurology; and Dubowitz Neuromuscular Centre (R.Q.), Great Ormond Street Hospital, London, United Kingdom
| | - Amanda Lam
- Department of Neuromuscular Diseases (E. Bugiardini, O.V.P, A.H., H.H., R.Q., M.G.H., R.D.S.P.), UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, United Kingdom; Mitochondrial Medicine Group (E. Bottani, C.B., M.Z.), Medical Research Council Mitochondrial Biology Unit, Cambridge, United Kingdom; Department of Molecular and Translational Medicine (E. Bottani, A.V.), University of Brescia; Medical Genetics and Neurogenetics Unit (S.M., E.L., C.L.), Fondazione IRCCS Istituto Neurologico, "C. Besta," Milan, Italy; Neurogenetics Unit (C.W.), and Neurometabolic Unit (A.L., I.H., A.C.), The National Hospital for Neurology and Neurosurgery; Division of Neuropathology (K.V., J.L.H.), UCL Queen Square Institute of Neurology; and Dubowitz Neuromuscular Centre (R.Q.), Great Ormond Street Hospital, London, United Kingdom
| | - Iain Hargreaves
- Department of Neuromuscular Diseases (E. Bugiardini, O.V.P, A.H., H.H., R.Q., M.G.H., R.D.S.P.), UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, United Kingdom; Mitochondrial Medicine Group (E. Bottani, C.B., M.Z.), Medical Research Council Mitochondrial Biology Unit, Cambridge, United Kingdom; Department of Molecular and Translational Medicine (E. Bottani, A.V.), University of Brescia; Medical Genetics and Neurogenetics Unit (S.M., E.L., C.L.), Fondazione IRCCS Istituto Neurologico, "C. Besta," Milan, Italy; Neurogenetics Unit (C.W.), and Neurometabolic Unit (A.L., I.H., A.C.), The National Hospital for Neurology and Neurosurgery; Division of Neuropathology (K.V., J.L.H.), UCL Queen Square Institute of Neurology; and Dubowitz Neuromuscular Centre (R.Q.), Great Ormond Street Hospital, London, United Kingdom
| | - Annapurna Chalasani
- Department of Neuromuscular Diseases (E. Bugiardini, O.V.P, A.H., H.H., R.Q., M.G.H., R.D.S.P.), UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, United Kingdom; Mitochondrial Medicine Group (E. Bottani, C.B., M.Z.), Medical Research Council Mitochondrial Biology Unit, Cambridge, United Kingdom; Department of Molecular and Translational Medicine (E. Bottani, A.V.), University of Brescia; Medical Genetics and Neurogenetics Unit (S.M., E.L., C.L.), Fondazione IRCCS Istituto Neurologico, "C. Besta," Milan, Italy; Neurogenetics Unit (C.W.), and Neurometabolic Unit (A.L., I.H., A.C.), The National Hospital for Neurology and Neurosurgery; Division of Neuropathology (K.V., J.L.H.), UCL Queen Square Institute of Neurology; and Dubowitz Neuromuscular Centre (R.Q.), Great Ormond Street Hospital, London, United Kingdom
| | - Alessandra Valerio
- Department of Neuromuscular Diseases (E. Bugiardini, O.V.P, A.H., H.H., R.Q., M.G.H., R.D.S.P.), UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, United Kingdom; Mitochondrial Medicine Group (E. Bottani, C.B., M.Z.), Medical Research Council Mitochondrial Biology Unit, Cambridge, United Kingdom; Department of Molecular and Translational Medicine (E. Bottani, A.V.), University of Brescia; Medical Genetics and Neurogenetics Unit (S.M., E.L., C.L.), Fondazione IRCCS Istituto Neurologico, "C. Besta," Milan, Italy; Neurogenetics Unit (C.W.), and Neurometabolic Unit (A.L., I.H., A.C.), The National Hospital for Neurology and Neurosurgery; Division of Neuropathology (K.V., J.L.H.), UCL Queen Square Institute of Neurology; and Dubowitz Neuromuscular Centre (R.Q.), Great Ormond Street Hospital, London, United Kingdom
| | - Eleonora Lamantea
- Department of Neuromuscular Diseases (E. Bugiardini, O.V.P, A.H., H.H., R.Q., M.G.H., R.D.S.P.), UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, United Kingdom; Mitochondrial Medicine Group (E. Bottani, C.B., M.Z.), Medical Research Council Mitochondrial Biology Unit, Cambridge, United Kingdom; Department of Molecular and Translational Medicine (E. Bottani, A.V.), University of Brescia; Medical Genetics and Neurogenetics Unit (S.M., E.L., C.L.), Fondazione IRCCS Istituto Neurologico, "C. Besta," Milan, Italy; Neurogenetics Unit (C.W.), and Neurometabolic Unit (A.L., I.H., A.C.), The National Hospital for Neurology and Neurosurgery; Division of Neuropathology (K.V., J.L.H.), UCL Queen Square Institute of Neurology; and Dubowitz Neuromuscular Centre (R.Q.), Great Ormond Street Hospital, London, United Kingdom
| | - Kerrie Venner
- Department of Neuromuscular Diseases (E. Bugiardini, O.V.P, A.H., H.H., R.Q., M.G.H., R.D.S.P.), UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, United Kingdom; Mitochondrial Medicine Group (E. Bottani, C.B., M.Z.), Medical Research Council Mitochondrial Biology Unit, Cambridge, United Kingdom; Department of Molecular and Translational Medicine (E. Bottani, A.V.), University of Brescia; Medical Genetics and Neurogenetics Unit (S.M., E.L., C.L.), Fondazione IRCCS Istituto Neurologico, "C. Besta," Milan, Italy; Neurogenetics Unit (C.W.), and Neurometabolic Unit (A.L., I.H., A.C.), The National Hospital for Neurology and Neurosurgery; Division of Neuropathology (K.V., J.L.H.), UCL Queen Square Institute of Neurology; and Dubowitz Neuromuscular Centre (R.Q.), Great Ormond Street Hospital, London, United Kingdom
| | - Janice L Holton
- Department of Neuromuscular Diseases (E. Bugiardini, O.V.P, A.H., H.H., R.Q., M.G.H., R.D.S.P.), UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, United Kingdom; Mitochondrial Medicine Group (E. Bottani, C.B., M.Z.), Medical Research Council Mitochondrial Biology Unit, Cambridge, United Kingdom; Department of Molecular and Translational Medicine (E. Bottani, A.V.), University of Brescia; Medical Genetics and Neurogenetics Unit (S.M., E.L., C.L.), Fondazione IRCCS Istituto Neurologico, "C. Besta," Milan, Italy; Neurogenetics Unit (C.W.), and Neurometabolic Unit (A.L., I.H., A.C.), The National Hospital for Neurology and Neurosurgery; Division of Neuropathology (K.V., J.L.H.), UCL Queen Square Institute of Neurology; and Dubowitz Neuromuscular Centre (R.Q.), Great Ormond Street Hospital, London, United Kingdom
| | - Massimo Zeviani
- Department of Neuromuscular Diseases (E. Bugiardini, O.V.P, A.H., H.H., R.Q., M.G.H., R.D.S.P.), UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, United Kingdom; Mitochondrial Medicine Group (E. Bottani, C.B., M.Z.), Medical Research Council Mitochondrial Biology Unit, Cambridge, United Kingdom; Department of Molecular and Translational Medicine (E. Bottani, A.V.), University of Brescia; Medical Genetics and Neurogenetics Unit (S.M., E.L., C.L.), Fondazione IRCCS Istituto Neurologico, "C. Besta," Milan, Italy; Neurogenetics Unit (C.W.), and Neurometabolic Unit (A.L., I.H., A.C.), The National Hospital for Neurology and Neurosurgery; Division of Neuropathology (K.V., J.L.H.), UCL Queen Square Institute of Neurology; and Dubowitz Neuromuscular Centre (R.Q.), Great Ormond Street Hospital, London, United Kingdom
| | - Henry Houlden
- Department of Neuromuscular Diseases (E. Bugiardini, O.V.P, A.H., H.H., R.Q., M.G.H., R.D.S.P.), UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, United Kingdom; Mitochondrial Medicine Group (E. Bottani, C.B., M.Z.), Medical Research Council Mitochondrial Biology Unit, Cambridge, United Kingdom; Department of Molecular and Translational Medicine (E. Bottani, A.V.), University of Brescia; Medical Genetics and Neurogenetics Unit (S.M., E.L., C.L.), Fondazione IRCCS Istituto Neurologico, "C. Besta," Milan, Italy; Neurogenetics Unit (C.W.), and Neurometabolic Unit (A.L., I.H., A.C.), The National Hospital for Neurology and Neurosurgery; Division of Neuropathology (K.V., J.L.H.), UCL Queen Square Institute of Neurology; and Dubowitz Neuromuscular Centre (R.Q.), Great Ormond Street Hospital, London, United Kingdom
| | - Rosaline Quinlivan
- Department of Neuromuscular Diseases (E. Bugiardini, O.V.P, A.H., H.H., R.Q., M.G.H., R.D.S.P.), UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, United Kingdom; Mitochondrial Medicine Group (E. Bottani, C.B., M.Z.), Medical Research Council Mitochondrial Biology Unit, Cambridge, United Kingdom; Department of Molecular and Translational Medicine (E. Bottani, A.V.), University of Brescia; Medical Genetics and Neurogenetics Unit (S.M., E.L., C.L.), Fondazione IRCCS Istituto Neurologico, "C. Besta," Milan, Italy; Neurogenetics Unit (C.W.), and Neurometabolic Unit (A.L., I.H., A.C.), The National Hospital for Neurology and Neurosurgery; Division of Neuropathology (K.V., J.L.H.), UCL Queen Square Institute of Neurology; and Dubowitz Neuromuscular Centre (R.Q.), Great Ormond Street Hospital, London, United Kingdom
| | - Costanza Lamperti
- Department of Neuromuscular Diseases (E. Bugiardini, O.V.P, A.H., H.H., R.Q., M.G.H., R.D.S.P.), UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, United Kingdom; Mitochondrial Medicine Group (E. Bottani, C.B., M.Z.), Medical Research Council Mitochondrial Biology Unit, Cambridge, United Kingdom; Department of Molecular and Translational Medicine (E. Bottani, A.V.), University of Brescia; Medical Genetics and Neurogenetics Unit (S.M., E.L., C.L.), Fondazione IRCCS Istituto Neurologico, "C. Besta," Milan, Italy; Neurogenetics Unit (C.W.), and Neurometabolic Unit (A.L., I.H., A.C.), The National Hospital for Neurology and Neurosurgery; Division of Neuropathology (K.V., J.L.H.), UCL Queen Square Institute of Neurology; and Dubowitz Neuromuscular Centre (R.Q.), Great Ormond Street Hospital, London, United Kingdom
| | - Michael G Hanna
- Department of Neuromuscular Diseases (E. Bugiardini, O.V.P, A.H., H.H., R.Q., M.G.H., R.D.S.P.), UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, United Kingdom; Mitochondrial Medicine Group (E. Bottani, C.B., M.Z.), Medical Research Council Mitochondrial Biology Unit, Cambridge, United Kingdom; Department of Molecular and Translational Medicine (E. Bottani, A.V.), University of Brescia; Medical Genetics and Neurogenetics Unit (S.M., E.L., C.L.), Fondazione IRCCS Istituto Neurologico, "C. Besta," Milan, Italy; Neurogenetics Unit (C.W.), and Neurometabolic Unit (A.L., I.H., A.C.), The National Hospital for Neurology and Neurosurgery; Division of Neuropathology (K.V., J.L.H.), UCL Queen Square Institute of Neurology; and Dubowitz Neuromuscular Centre (R.Q.), Great Ormond Street Hospital, London, United Kingdom
| | - Robert D S Pitceathly
- Department of Neuromuscular Diseases (E. Bugiardini, O.V.P, A.H., H.H., R.Q., M.G.H., R.D.S.P.), UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, United Kingdom; Mitochondrial Medicine Group (E. Bottani, C.B., M.Z.), Medical Research Council Mitochondrial Biology Unit, Cambridge, United Kingdom; Department of Molecular and Translational Medicine (E. Bottani, A.V.), University of Brescia; Medical Genetics and Neurogenetics Unit (S.M., E.L., C.L.), Fondazione IRCCS Istituto Neurologico, "C. Besta," Milan, Italy; Neurogenetics Unit (C.W.), and Neurometabolic Unit (A.L., I.H., A.C.), The National Hospital for Neurology and Neurosurgery; Division of Neuropathology (K.V., J.L.H.), UCL Queen Square Institute of Neurology; and Dubowitz Neuromuscular Centre (R.Q.), Great Ormond Street Hospital, London, United Kingdom
| |
Collapse
|
5
|
Rocha MC, Rosa HS, Grady JP, Blakely EL, He L, Romain N, Haller RG, Newman J, McFarland R, Ng YS, Gorman GS, Schaefer AM, Tuppen HA, Taylor RW, Turnbull DM. Pathological mechanisms underlying single large-scale mitochondrial DNA deletions. Ann Neurol 2019; 83:115-130. [PMID: 29283441 PMCID: PMC5893934 DOI: 10.1002/ana.25127] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2017] [Revised: 12/01/2017] [Accepted: 12/21/2017] [Indexed: 12/17/2022]
Abstract
OBJECTIVE Single, large-scale deletions in mitochondrial DNA (mtDNA) are a common cause of mitochondrial disease. This study aimed to investigate the relationship between the genetic defect and molecular phenotype to improve understanding of pathogenic mechanisms associated with single, large-scale mtDNA deletions in skeletal muscle. METHODS We investigated 23 muscle biopsies taken from adult patients (6 males/17 females with a mean age of 43 years) with characterized single, large-scale mtDNA deletions. Mitochondrial respiratory chain deficiency in skeletal muscle biopsies was quantified by immunoreactivity levels for complex I and complex IV proteins. Single muscle fibers with varying degrees of deficiency were selected from 6 patient biopsies for determination of mtDNA deletion level and copy number by quantitative polymerase chain reaction. RESULTS We have defined 3 "classes" of single, large-scale deletion with distinct patterns of mitochondrial deficiency, determined by the size and location of the deletion. Single fiber analyses showed that fibers with greater respiratory chain deficiency harbored higher levels of mtDNA deletion with an increase in total mtDNA copy number. For the first time, we have demonstrated that threshold levels for complex I and complex IV deficiency differ based on deletion class. INTERPRETATION Combining genetic and immunofluorescent assays, we conclude that thresholds for complex I and complex IV deficiency are modulated by the deletion of complex-specific protein-encoding genes. Furthermore, removal of mt-tRNA genes impacts specific complexes only at high deletion levels, when complex-specific protein-encoding genes remain. These novel findings provide valuable insight into the pathogenic mechanisms associated with these mutations. Ann Neurol 2018;83:115-130.
Collapse
Affiliation(s)
- Mariana C Rocha
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Hannah S Rosa
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - John P Grady
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Emma L Blakely
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom.,National Health Service Highly Specialised Mitochondrial Diagnostic Laboratory, Newcastle upon Tyne Hospitals, National Health Service Foundation Trust, Newcastle upon Tyne, United Kingdom
| | - Langping He
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom.,National Health Service Highly Specialised Mitochondrial Diagnostic Laboratory, Newcastle upon Tyne Hospitals, National Health Service Foundation Trust, Newcastle upon Tyne, United Kingdom
| | - Nadine Romain
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX.,Institute for Exercise and Environmental Medicine of Texas Health Presbyterian Hospital, Dallas, TX
| | - Ronald G Haller
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX.,Institute for Exercise and Environmental Medicine of Texas Health Presbyterian Hospital, Dallas, TX
| | - Jane Newman
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Robert McFarland
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Yi Shiau Ng
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Grainne S Gorman
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Andrew M Schaefer
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Helen A Tuppen
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Robert W Taylor
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom.,National Health Service Highly Specialised Mitochondrial Diagnostic Laboratory, Newcastle upon Tyne Hospitals, National Health Service Foundation Trust, Newcastle upon Tyne, United Kingdom
| | - Doug M Turnbull
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| |
Collapse
|
6
|
Girolimetti G, Guerra F, Iommarini L, Kurelac I, Vergara D, Maffia M, Vidone M, Amato LB, Leone G, Dusi S, Tiranti V, Perrone AM, Bucci C, Porcelli AM, Gasparre G. Platinum-induced mitochondrial DNA mutations confer lower sensitivity to paclitaxel by impairing tubulin cytoskeletal organization. Hum Mol Genet 2018; 26:2961-2974. [PMID: 28486623 DOI: 10.1093/hmg/ddx186] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 05/05/2017] [Indexed: 12/21/2022] Open
Abstract
Development of chemoresistance is a cogent clinical issue in oncology, whereby combination of anticancer drugs is usually preferred also to enhance efficacy. Paclitaxel (PTX), combined with carboplatin, represents the standard first-line chemotherapy for different types of cancers. We here depict a double-edge role of mitochondrial DNA (mtDNA) mutations induced in cancer cells after treatment with platinum. MtDNA mutations were positively selected by PTX, and they determined a decrease in the mitochondrial respiratory function, as well as in proliferative and tumorigenic potential, in terms of migratory and invasive capacity. Moreover, cells bearing mtDNA mutations lacked filamentous tubulin, the main target of PTX, and failed to reorient the Golgi body upon appropriate stimuli. We also show that the bioenergetic and cytoskeletal phenotype were transferred along with mtDNA mutations in transmitochondrial hybrids, and that this also conferred PTX resistance to recipient cells. Overall, our data show that platinum-induced deleterious mtDNA mutations confer resistance to PTX, and confirm what we previously reported in an ovarian cancer patient treated with carboplatin and PTX who developed a quiescent yet resistant tumor mass harboring mtDNA mutations.
Collapse
Affiliation(s)
- Giulia Girolimetti
- Department of Medical and Surgical Sciences, Unit of Medical Genetics, University Hospital S.Orsola-Malpighi, 40138 Bologna, Italy
| | - Flora Guerra
- Department of Biological and Environmental Sciences and Technologies, University of Salento, 73100 Lecce, Italy
| | - Luisa Iommarini
- Department of Pharmacy and Biotechnology, University of Bologna, 40126 Bologna, Italy
| | - Ivana Kurelac
- Department of Medical and Surgical Sciences, Unit of Medical Genetics, University Hospital S.Orsola-Malpighi, 40138 Bologna, Italy
| | - Daniele Vergara
- Department of Biological and Environmental Sciences and Technologies, University of Salento, 73100 Lecce, Italy
| | - Michele Maffia
- Department of Biological and Environmental Sciences and Technologies, University of Salento, 73100 Lecce, Italy
| | - Michele Vidone
- Department of Medical and Surgical Sciences, Unit of Medical Genetics, University Hospital S.Orsola-Malpighi, 40138 Bologna, Italy
| | - Laura Benedetta Amato
- Department of Medical and Surgical Sciences, Unit of Medical Genetics, University Hospital S.Orsola-Malpighi, 40138 Bologna, Italy
| | - Giulia Leone
- Department of Pharmacy and Biotechnology, University of Bologna, 40126 Bologna, Italy
| | - Sabrina Dusi
- Department of Medical and Surgical Sciences, Unit of Medical Genetics, University Hospital S.Orsola-Malpighi, 40138 Bologna, Italy
| | - Valeria Tiranti
- Unit of Molecular Neurogenetics, Pierfranco and Luisa Mariani Centre for the Study of Mitochondrial Disorders in Children, Foundation IRCCS Neurological Institute Carlo Besta, 20126 Milan, Italy
| | - Anna Myriam Perrone
- Unit of Gynecologic Oncology, S.Orsola-Malpighi Hospital, 40138 Bologna, Italy
| | - Cecilia Bucci
- Department of Biological and Environmental Sciences and Technologies, University of Salento, 73100 Lecce, Italy
| | - Anna Maria Porcelli
- Department of Pharmacy and Biotechnology, University of Bologna, 40126 Bologna, Italy.,Interdepartmental Center for Industrial Research, Health Sciences and Technologies (CIRI-HST), University of Bologna, 40126 Bologna, Italy
| | - Giuseppe Gasparre
- Department of Medical and Surgical Sciences, Unit of Medical Genetics, University Hospital S.Orsola-Malpighi, 40138 Bologna, Italy
| |
Collapse
|
7
|
Ahmed ST, Alston CL, Hopton S, He L, Hargreaves IP, Falkous G, Oláhová M, McFarland R, Turnbull DM, Rocha MC, Taylor RW. Using a quantitative quadruple immunofluorescent assay to diagnose isolated mitochondrial Complex I deficiency. Sci Rep 2017; 7:15676. [PMID: 29142257 PMCID: PMC5688115 DOI: 10.1038/s41598-017-14623-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 10/12/2017] [Indexed: 11/21/2022] Open
Abstract
Isolated Complex I (CI) deficiency is the most commonly observed mitochondrial respiratory chain biochemical defect, affecting the largest OXPHOS component. CI is genetically heterogeneous; pathogenic variants affect one of 38 nuclear-encoded subunits, 7 mitochondrial DNA (mtDNA)-encoded subunits or 14 known CI assembly factors. The laboratory diagnosis relies on the spectrophotometric assay of enzyme activity in mitochondrially-enriched tissue homogenates, requiring at least 50 mg skeletal muscle, as there is no reliable histochemical method for assessing CI activity directly in tissue cryosections. We have assessed a validated quadruple immunofluorescent OXPHOS (IHC) assay to detect CI deficiency in the diagnostic setting, using 10 µm transverse muscle sections from 25 patients with genetically-proven pathogenic CI variants. We observed loss of NDUFB8 immunoreactivity in all patients with mutations affecting nuclear-encoding structural subunits and assembly factors, whilst only 3 of the 10 patients with mutations affecting mtDNA-encoded structural subunits showed loss of NDUFB8, confirmed by BN-PAGE analysis of CI assembly and IHC using an alternative, commercially-available CI (NDUFS3) antibody. The IHC assay has clear diagnostic potential to identify patients with a CI defect of Mendelian origins, whilst highlighting the necessity of complete mitochondrial genome sequencing in the diagnostic work-up of patients with suspected mitochondrial disease.
Collapse
Affiliation(s)
- Syeda T Ahmed
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle Upon Tyne, UK
| | - Charlotte L Alston
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle Upon Tyne, UK.,NHS Highly Specialised Mitochondrial Diagnostic Laboratory, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Sila Hopton
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle Upon Tyne, UK.,NHS Highly Specialised Mitochondrial Diagnostic Laboratory, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Langping He
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle Upon Tyne, UK.,NHS Highly Specialised Mitochondrial Diagnostic Laboratory, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Iain P Hargreaves
- The National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Foundation Trust, London, UK.,School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Byrom Street, Liverpool, L3 3AF, UK
| | - Gavin Falkous
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle Upon Tyne, UK.,NHS Highly Specialised Mitochondrial Diagnostic Laboratory, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Monika Oláhová
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle Upon Tyne, UK
| | - Robert McFarland
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle Upon Tyne, UK
| | - Doug M Turnbull
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle Upon Tyne, UK
| | - Mariana C Rocha
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle Upon Tyne, UK.,BHF Centre of Research Excellence, The James Black Centre, King's College London, University of London, 125 Coldharbour Lane, London, SE5 9NU, UK
| | - Robert W Taylor
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle Upon Tyne, UK. .,NHS Highly Specialised Mitochondrial Diagnostic Laboratory, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK.
| |
Collapse
|
8
|
Pathological Mutations of the Mitochondrial Human Genome: the Instrumental Role of the Yeast S. cerevisiae. Diseases 2014. [DOI: 10.3390/diseases2010024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
|
9
|
Lamperti C, Diodato D, Lamantea E, Carrara F, Ghezzi D, Mereghetti P, Rizzi R, Zeviani M. MELAS-like encephalomyopathy caused by a new pathogenic mutation in the mitochondrial DNA encoded cytochrome c oxidase subunit I. Neuromuscul Disord 2012; 22:990-4. [DOI: 10.1016/j.nmd.2012.06.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2011] [Revised: 05/14/2012] [Accepted: 06/01/2012] [Indexed: 12/16/2022]
|
10
|
Mazzaccara C, Iafusco D, Liguori R, Ferrigno M, Galderisi A, Vitale D, Simonelli F, Landolfo P, Prisco F, Masullo M, Sacchetti L. Mitochondrial diabetes in children: seek and you will find it. PLoS One 2012; 7:e34956. [PMID: 22536343 PMCID: PMC3334935 DOI: 10.1371/journal.pone.0034956] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Accepted: 03/08/2012] [Indexed: 11/18/2022] Open
Abstract
Maternally Inherited Diabetes and Deafness (MIDD) is a rare form of diabetes due to defects in mitochondrial DNA (mtDNA). 3243 A>G is the mutation most frequently associated with this condition, but other mtDNA variants have been linked with a diabetic phenotype suggestive of MIDD. From 1989 to 2009, we clinically diagnosed mitochondrial diabetes in 11 diabetic children. Diagnosis was based on the presence of one or more of the following criteria: 1) maculopathy; 2) hearing impairment; 3) maternal heritability of diabetes/impaired fasting glucose and/or hearing impairment and/or maculopathy in three consecutive generations (or in two generations if 2 or 3 members of a family were affected). We sequenced the mtDNA in the 11 probands, in their mothers and in 80 controls. We identified 33 diabetes-suspected mutations, 1/33 was 3243A>G. Most patients (91%) and their mothers had mutations in complex I and/or IV of the respiratory chain. We measured the activity of these two enzymes and found that they were less active in mutated patients and their mothers than in the healthy control pool. The prevalence of hearing loss (36% vs 75–98%) and macular dystrophy (54% vs 86%) was lower in our mitochondrial diabetic adolescents than reported in adults. Moreover, we found a hitherto unknown association between mitochondrial diabetes and celiac disease. In conclusion, mitochondrial diabetes should be considered a complex syndrome with several phenotypic variants. Moreover, deafness is not an essential component of the disease in children. The whole mtDNA should be screened because the 3243A>G variant is not as frequent in children as in adults. In fact, 91% of our patients were mutated in the complex I and/or IV genes. The enzymatic assay may be a useful tool with which to confirm the pathogenic significance of detected variants.
Collapse
Affiliation(s)
- Cristina Mazzaccara
- CEINGE – Advanced Biotechnologies S. C. a R. L., Naples, Italy
- Department of Biochemistry and Medical Biotechnologies, University of Naples Federico II, Naples, Italy
| | - Dario Iafusco
- Department of Pediatrics, Second University of Naples, Naples, Italy
| | - Rosario Liguori
- CEINGE – Advanced Biotechnologies S. C. a R. L., Naples, Italy
- Department of Biochemistry and Medical Biotechnologies, University of Naples Federico II, Naples, Italy
| | | | - Alfonso Galderisi
- Department of Pediatrics, Second University of Naples, Naples, Italy
| | - Domenico Vitale
- CEINGE – Advanced Biotechnologies S. C. a R. L., Naples, Italy
| | | | - Paolo Landolfo
- Department of Ophthalmology, Second University of Naples, Naples, Italy
| | - Francesco Prisco
- Department of Pediatrics, Second University of Naples, Naples, Italy
| | - Mariorosario Masullo
- Department of Biochemistry and Medical Biotechnologies, University of Naples Federico II, Naples, Italy
- Department of Study of the Institutions and Territorial Systems, University of Naples “Parthenope”, Naples, Italy
| | - Lucia Sacchetti
- CEINGE – Advanced Biotechnologies S. C. a R. L., Naples, Italy
- Department of Biochemistry and Medical Biotechnologies, University of Naples Federico II, Naples, Italy
- * E-mail:
| |
Collapse
|
11
|
Greaves LC, Reeve AK, Taylor RW, Turnbull DM. Mitochondrial DNA and disease. J Pathol 2011; 226:274-86. [PMID: 21989606 DOI: 10.1002/path.3028] [Citation(s) in RCA: 199] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2011] [Revised: 09/27/2011] [Accepted: 10/05/2011] [Indexed: 12/28/2022]
Abstract
Mitochondrial DNA (mtDNA) defects are a relatively common cause of inherited disease and have been implicated in both ageing and cancer. MtDNA encodes essential subunits of the mitochondrial respiratory chain and defects result in impaired oxidative phosphorylation (OXPHOS). Similar OXPHOS defects have been shown to be present in a number of neurodegenerative conditions, including Parkinson's disease, as well as in normal ageing human tissues. Additionally, a number of tumours have been shown to contain mtDNA mutations and an altered metabolic phenotype. In this review we outline the unique characteristics of mitochondrial genetics before detailing important pathological features of mtDNA diseases, focusing on adult neurological disease as well as the role of mtDNA mutations in neurodegenerative diseases, ageing and cancer.
Collapse
Affiliation(s)
- Laura C Greaves
- Mitochondrial Research Group, Institute for Ageing and Health, Newcastle University, UK.
| | | | | | | |
Collapse
|
12
|
|
13
|
De Luca C, Zhou Y, Montanari A, Morea V, Oliva R, Besagni C, Bolotin-Fukuhara M, Frontali L, Francisci S. Can yeast be used to study mitochondrial diseases? Biolistic tRNA mutants for the analysis of mechanisms and suppressors. Mitochondrion 2009; 9:408-17. [DOI: 10.1016/j.mito.2009.07.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2009] [Revised: 07/07/2009] [Accepted: 07/17/2009] [Indexed: 10/20/2022]
|
14
|
TOWBIN JEFFREYA. Hypertrophic Cardiomyopathy. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2009; 32 Suppl 2:S23-31. [DOI: 10.1111/j.1540-8159.2009.02381.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
15
|
Valente L, Piga D, Lamantea E, Carrara F, Uziel G, Cudia P, Zani A, Farina L, Morandi L, Mora M, Spinazzola A, Zeviani M, Tiranti V. Identification of novel mutations in five patients with mitochondrial encephalomyopathy. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2008; 1787:491-501. [PMID: 18977334 DOI: 10.1016/j.bbabio.2008.10.001] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2008] [Revised: 09/26/2008] [Accepted: 10/01/2008] [Indexed: 10/21/2022]
Abstract
MELAS, MERRF, LHON and NARP, are well-established mitochondrial syndromes associated with specific point mutations of mitochondrial DNA (mtDNA). However, these recurrent mtDNA mutations account for only a minority of mitochondrial disease cases. To evaluate the impact of novel mtDNA mutations, we performed mtDNA sequence analysis in muscle and other tissues of 240 patients with different mitochondrial neuromuscular syndromes. We identified a total of 33 subjects with novel, private or uncommon mutations. Among these, five novel mutations were found in both paediatric and adult cases. We here report on the clinical description of these patients, as well as the biochemical and molecular genetic characterization of the corresponding mutations. Patients 1 and 2 showed changes in ND genes, patient 3 carried a heteroplasmic deletion in the COI gene, patients 4 and 5 carried heteroplasmic mutations in tRNA(Trp) and tRNA(Phe), respectively. Altogether, these data indicate that mtDNA analysis must become part of the routine screening for mitochondrial disorders.
Collapse
Affiliation(s)
- Lucia Valente
- IRCCS Foundation Neurological Institute C. Besta, Milan, Italy
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
|
17
|
Santos C, Montiel R, Arruda A, Alvarez L, Aluja MP, Lima M. Mutation patterns of mtDNA: empirical inferences for the coding region. BMC Evol Biol 2008; 8:167. [PMID: 18518963 PMCID: PMC2438339 DOI: 10.1186/1471-2148-8-167] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2007] [Accepted: 06/02/2008] [Indexed: 01/22/2023] Open
Abstract
Background Human mitochondrial DNA (mtDNA) has been extensively used in population and evolutionary genetics studies. Thus, a valid estimate of human mtDNA evolutionary rate is important in many research fields. The small number of estimations performed for the coding region of the molecule, showed important differences between phylogenetic and empirical approaches. We analyzed a portion of the coding region of mtDNA (tRNALeu, ND1 and tRNAIle genes), using individuals belonging to extended families from the Azores Islands (Portugal) with the main aim of providing empirical estimations of the mutation rate of the coding region of mtDNA under different assumptions, and hence to better understand the mtDNA evolutionary process. Results Heteroplasmy was detected in 6.5% (3/46) of the families analyzed. In all of the families the presence of mtDNA heteroplasmy resulted from three new point mutations, and no cases of insertions or deletions were identified. Major differences were found in the proportion and type of heteroplasmy found in the genes studied when compared to those obtained in a previous report for the D-loop. Our empirical estimation of mtDNA coding region mutation rate, calculated taking into account the sex of individuals carrying new mutations, the probability of intra-individual fixation of mutations present in heteroplasmy and, to the possible extent, the effect of selection, is similar to that obtained using phylogenetic approaches. Conclusion Based on our results, the discrepancy previously reported between the human mtDNA coding region mutation rates observed along evolutionary timescales and estimations obtained using family pedigrees can be resolved when correcting for the previously cited factors.
Collapse
Affiliation(s)
- Cristina Santos
- Center for Research in Natural Resources (CIRN), University of the Azores, 9500 Ponta Delgada, S, Miguel, Azores, Portugal.
| | | | | | | | | | | |
Collapse
|
18
|
Scaglia F, Wong LJC. Human mitochondrial transfer RNAs: role of pathogenic mutation in disease. Muscle Nerve 2008; 37:150-71. [PMID: 17999409 DOI: 10.1002/mus.20917] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The human mitochondrial genome encodes 13 proteins. All are subunits of the respiratory chain complexes involved in energy metabolism. These proteins are translated by a set of 22 mitochondrial transfer RNAs (tRNAs) that are required for codon reading. Human mitochondrial tRNA genes are hotspots for pathogenic mutations and have attracted interest over the last two decades with the rapid discovery of point mutations associated with a vast array of neuromuscular disorders and diverse clinical phenotypes. In this review, we use a scoring system to determine the pathogenicity of the mutations and summarize the current knowledge of structure-function relationships of these mutant tRNAs. We also provide readers with an overview of a large variety of mechanisms by which mutations may affect the mitochondrial translation machinery and cause disease.
Collapse
Affiliation(s)
- Fernando Scaglia
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA
| | | |
Collapse
|
19
|
|
20
|
Lorenc A, Bryk J, Golik P, Kupryjańczyk J, Ostrowski J, Pronicki M, Semczuk A, Szołkowska M, Bartnik E. Homoplasmic MELAS A3243G mtDNA mutation in a colon cancer sample. Mitochondrion 2005; 3:119-24. [PMID: 16120350 DOI: 10.1016/s1567-7249(03)00106-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2003] [Revised: 07/24/2003] [Accepted: 07/29/2003] [Indexed: 10/27/2022]
Abstract
We have analyzed mtDNA variation in various cancer samples, comparing them with normal tissue controls, and identified mutations and polymorphisms, both known and novel, in mitochondrial tRNA, rRNA and protein genes. Most remarkably, in a colon cancer sample we have found the A3243G mutation in the homoplasmic state. This mutation is known to cause severe mitochondrial dysfunction and, until now, has not been found in cancer cells, nor in the homoplasmic state in living subjects. The mutation was absent from normal tissue, suggesting that mtDNA mutation and resulting respiratory deficiency played a role in carcinogenesis.
Collapse
Affiliation(s)
- Anna Lorenc
- Postgraduate School of Molecular Medicine, ul. Chalubinskiego 5, 02-004 Warsaw, Poland
| | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Turner CJ, Granycome C, Hurst R, Pohler E, Juhola MK, Juhola MI, Jacobs HT, Sutherland L, Holt IJ. Systematic segregation to mutant mitochondrial DNA and accompanying loss of mitochondrial DNA in human NT2 teratocarcinoma Cybrids. Genetics 2005; 170:1879-85. [PMID: 15944344 PMCID: PMC1449769 DOI: 10.1534/genetics.105.043653] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2005] [Accepted: 05/05/2005] [Indexed: 02/03/2023] Open
Abstract
In this study a well-characterized pathological mutation at nucleotide position 3243 of human mitochondrial DNA was introduced into human rho(0) teratocarcinoma (NT2) cells. In cloned and mixed populations of NT2 cells heteroplasmic for the mutation, mitotic segregation toward increasing levels of mutant mitochondrial DNA always occurred. Rapid segregation was frequently followed by complete loss of mitochondrial DNA. These findings support the idea that pathological mitochondrial DNA mutations are particularly deleterious in specific cell types, which can explain some of the tissue-specific aspects of mitochondrial DNA diseases. Moreover, these findings suggest that mitochondrial DNA depletion may be an important and widespread feature of mitochondrial DNA disease.
Collapse
Affiliation(s)
- Carrie J Turner
- MRC Dunn Human Nutrition Unit, Wellcome Trust, Cambridge CB2 2XY, United Kingdom
| | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Pallotti F, Baracca A, Hernandez-Rosa E, Walker W, Solaini G, Lenaz G, Melzi d'ERIL G, DiMAURO S, Schon E, Davidson M. Biochemical analysis of respiratory function in cybrid cell lines harbouring mitochondrial DNA mutations. Biochem J 2005; 384:287-93. [PMID: 15324306 PMCID: PMC1134112 DOI: 10.1042/bj20040561] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We analysed key biochemical features that reflect the balance between glycolysis and glucose oxidation in cybrids (cytoplasmic hybrids) harbouring a representative sample of mitochondrial DNA point mutations and deletions. The cybrids analysed had the same 143B cell nuclear background and were isogenic for the mitochondrial background. The 143B cell line and its rho(0) counterpart were used as controls. All cells analysed were in a dynamic state, and cell number, time of plating, culture medium, extracellular volume and time of harvest and assay were strictly controlled. Intra- and extra-cellular lactate and pyruvate levels were measured in homoplasmic wild-type and mutant cells, and correlated with rates of ATP synthesis and O2 consumption. In all mutant cell lines, except those with the T8993C mutation in the ATPase 6 gene, glycolysis was increased even under conditions of low glucose, as demonstrated by increased levels of extracellular lactate and pyruvate. Extracellular lactate levels were strictly and inversely correlated with rates of ATP synthesis and O2 consumption. These results show increased glycolysis and defective oxidative phosphorylation, irrespective of the type or site of the point mutation or deletion in the mitochondrial genome. The different biochemical consequences of the T8993C mutation suggest a uniquely different pathogenic mechanism for this mutation. However, the distinct clinical features associated with some of these mutations still remain to be elucidated.
Collapse
Affiliation(s)
- Francesco Pallotti
- *Department of Neurology, College of Physicians and Surgeons, Columbia University, 630 West 168th Street, New York, NY 10032, U.S.A
- †Dipartimento Scienze Biomediche Sperimentali e Cliniche, Università degli Studi dell'Insubria, Via Dunant 5, 21100 Varese, Italy
| | - Alessandra Baracca
- ‡Dipartimento Biochimica ‘G. Moruzzi’, Università degli Studi di Bologna, Via Irnerio 48, 40126 Bologna, Italy
| | - Evelyn Hernandez-Rosa
- *Department of Neurology, College of Physicians and Surgeons, Columbia University, 630 West 168th Street, New York, NY 10032, U.S.A
| | - Winsome F. Walker
- *Department of Neurology, College of Physicians and Surgeons, Columbia University, 630 West 168th Street, New York, NY 10032, U.S.A
| | - Giancarlo Solaini
- §Scuola Superiore di Studi Universitari e di Perfezionamento ‘S. Anna’, Piazza dei Martiri 33, Pisa, Italy
| | - Giorgio Lenaz
- ‡Dipartimento Biochimica ‘G. Moruzzi’, Università degli Studi di Bologna, Via Irnerio 48, 40126 Bologna, Italy
| | - Gian Vico Melzi d'ERIL
- †Dipartimento Scienze Biomediche Sperimentali e Cliniche, Università degli Studi dell'Insubria, Via Dunant 5, 21100 Varese, Italy
| | - Salvatore DiMAURO
- *Department of Neurology, College of Physicians and Surgeons, Columbia University, 630 West 168th Street, New York, NY 10032, U.S.A
| | - Eric A. Schon
- *Department of Neurology, College of Physicians and Surgeons, Columbia University, 630 West 168th Street, New York, NY 10032, U.S.A
- ∥Department of Genetics and Development, College of Physicians and Surgeons, Columbia University, 630 West 168th Street, New York, NY 10032, U.S.A
| | - Mercy M. Davidson
- *Department of Neurology, College of Physicians and Surgeons, Columbia University, 630 West 168th Street, New York, NY 10032, U.S.A
- To whom correspondence should be addressed (email )
| |
Collapse
|
23
|
Danielson SR, Carelli V, Tan G, Martinuzzi A, Schapira AHV, Savontaus ML, Cortopassi GA. Isolation of transcriptomal changes attributable to LHON mutations and the cybridization process. ACTA ACUST UNITED AC 2005; 128:1026-37. [PMID: 15728653 DOI: 10.1093/brain/awh447] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Leber's hereditary optic neuropathy (LHON) is thought to be the most common disease resulting from mitochondrial DNA (mtDNA) point mutations, and transmitochondrial cytoplasmic hybrid (cybrid) cell lines are the most frequently used model for understanding the pathogenesis of mitochondrial disorders. We have used oligonucleotide microarrays and a novel study design based on shared transcripts to allocate transcriptomal changes into rho-zero-dependent, cybridization-dependent and LHON-dependent categories in these cells. The analysis indicates that the rho-zero process has the largest transcriptomal impact, followed by the cybridization process, and finally the LHON mutations. The transcriptomal impacts of the rho-zero and cybridization processes preferentially and significantly affect the mitochondrial compartment, causing upregulation of many transcripts involved in oxidative phosphorylation, presumably in response to the mtDNA depletion that occurs at the rho-zero step. Nine LHON-specific transcriptional alterations were shared among osteosarcoma cybrids and lymphoblasts bearing LHON mutations. Notably, the aldose reductase transcript was overexpressed in LHON cybrids and lymphoblasts. Aldose reductase is also overexpressed in diabetic retinopathy, leading to optic nerve and retinal complications. The LHON-specific increase in transcript level was confirmed by quantitative reverse transcription-polymerase chain reaction (RT-PCR), and a western blot confirmed a higher level of aldose reductase in mutant mitochondria. One product of aldose reductase is sorbitol, which has been linked to osmotic stress, oxidative stress and optic neuropathy, and sorbitol levels were increased in LHON cybrids. If these results are confirmed in patient tissues, aldose reductase inhibitors could have some therapeutic value for LHON.
Collapse
Affiliation(s)
- Steven R Danielson
- Department of Molecular Biosciences, University of California Davis, Davis, CA 95616, USA
| | | | | | | | | | | | | |
Collapse
|
24
|
Limongelli A, Schaefer J, Jackson S, Invernizzi F, Kirino Y, Suzuki T, Reichmann H, Zeviani M. Variable penetrance of a familial progressive necrotising encephalopathy due to a novel tRNA(Ile) homoplasmic mutation in the mitochondrial genome. J Med Genet 2004; 41:342-9. [PMID: 15121771 PMCID: PMC1735786 DOI: 10.1136/jmg.2003.016048] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
INTRODUCTION We present a family comprising a clinically normal mother and two daughters, each with severe encephalopathy with onset in late childhood. A third daughter had died previously of an earlier onset but neuropathologically similar disease. METHODS Sequence analysis of the entire mtDNA was carried out in muscle, fibroblasts, and lymphocytes of the affected daughters and unaffected mother. Biochemical analysis of individual respiratory chain enzymes was performed on the same tissues, and on several transmitochondrial cybrid clones containing the nucleus of a 143B.206 osteosarcoma cell line and the mutant mtDNA. RESULTS Genetic analyses revealed in both daughters and mother the presence of a novel mutation in the tRNA(Ile) gene of mtDNA, which was homoplasmic in fibroblasts, lymphocytes, and skeletal muscle of the two patients. It was also homoplasmic in fibroblast and skeletal muscle samples of the mother, and approximately 97% heteroplasmic in her lymphocytes. Combined defects of complexes I and IV of the mitochondrial respiratory chain were found not only in fibroblasts of the two probands, but surprisingly also in those of their clinically unaffected mother. The respiratory chain defect segregated in transmitochondrial cybrids containing the nucleus of a 143B.206 osteosarcoma cell line and the mutant mtDNA, indicating that the latter was responsible for the biochemical phenotype. DISCUSSION Our results support the concept that homoplasmic mutations in tRNA genes can be responsible for mitochondrial disorders characterised by extremely variable penetrance. Albeit still unexplained, this phenomenon has important consequences in the nosological characterisation, clinical management, and genetic counselling of mitochondrial disorders.
Collapse
MESH Headings
- Adolescent
- Base Sequence
- Brain Diseases, Metabolic, Inborn/diagnosis
- Brain Diseases, Metabolic, Inborn/enzymology
- Brain Diseases, Metabolic, Inborn/genetics
- Cell Line
- Child
- DNA Mutational Analysis
- DNA, Mitochondrial/genetics
- Electron Transport Complex IV/metabolism
- Female
- Fibroblasts/enzymology
- Genome, Human
- Humans
- Infant
- Middle Aged
- Mitochondrial Diseases/diagnosis
- Mitochondrial Diseases/genetics
- Molecular Sequence Data
- Muscle, Skeletal/enzymology
- Pedigree
- Penetrance
- Point Mutation
- Protein Biosynthesis
- RNA, Transfer, Ile/genetics
Collapse
Affiliation(s)
- A Limongelli
- Unit of Molecular Neurogenetics-Pierfranco and Luisa Mariani Centre for the Study of Children's Mitochondrial Disorders, National Neurological Institute Carlo Besta, Milan, Italy
| | | | | | | | | | | | | | | |
Collapse
|
25
|
Perucca-Lostanlen D, Taylor RW, Narbonne H, Mousson de Camaret B, Hayes CM, Saunieres A, Paquis-Flucklinger V, Turnbull DM, Vialettes B, Desnuelle C. Molecular and functional effects of the T14709C point mutation in the mitochondrial DNA of a patient with maternally inherited diabetes and deafness. BIOCHIMICA ET BIOPHYSICA ACTA 2002; 1588:210-6. [PMID: 12393175 DOI: 10.1016/s0925-4439(02)00167-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
A heteroplasmic T to C transition at nucleotide position 14709 in the mitochondrial tRNA glutamic acid (tRNA(Glu)) gene has previously been associated with maternally inherited diabetes and deafness (MIDD). To investigate the pathogenic mechanism of the T14709C mutation, we have constructed transmitochondrial cell lines by transferring fibroblasts mitochondria from a patient with the mutation into human cells lacking mitochondrial DNA (mtDNA) (rho degrees cells). Clonal cybrid cell lines were obtained containing various levels of the heteroplasmic mutation, or exclusively mutated or wild-type mtDNA. Measurement of respiratory chain enzymatic activities failed to detect a difference between the homoplasmic mutant and homoplasmic wild-type cybrid cell lines. However, a subtle decrease in the steady-state levels of tRNA(Glu) transcripts in some mutant clones. Our studies suggest that the T14709C mutation is insufficient to lead impairment of mitochondrial function in homoplasmic osteosarcoma cybrid clones, and that we cannot exclude that the T14709C mutation affects mitochondrial function by a yet unidentified mechanism.
Collapse
Affiliation(s)
- D Perucca-Lostanlen
- UMR 6549 CNRS/UNSA, Faculté de Médecine, Avenue de Valombrose, 06107 Nice Cedex 02, France.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Bayona-Bafaluy MP, Fernández-Silva P, Enríquez JA. The thankless task of playing genetics with mammalian mitochondrial DNA: a 30-year review. Mitochondrion 2002; 2:3-25. [PMID: 16120305 DOI: 10.1016/s1567-7249(02)00044-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2002] [Revised: 05/22/2002] [Accepted: 06/05/2002] [Indexed: 10/27/2022]
Abstract
The advances obtained through the genetic tools available in yeast for studying the oxidative phosphorylation (OXPHOS) biogenesis and in particular the role of the mtDNA encoded genes, strongly contrast with the very limited benefits that similar approaches have generated for the study of mammalian mtDNA. Here we review the use of the genetic manipulation in mammalian mtDNA, its difficulty and the main types of mutants accumulated in the past 30 years and the information derived from them. We also point out the need for a substantial improvement in this field in order to obtain new tools for functional genetic studies and for the generation of animal models of mtDNA-linked diseases.
Collapse
Affiliation(s)
- M Pilar Bayona-Bafaluy
- Departamento de Bioquímica y Biología Molecular y Celular, Universidad de Zaragoza, Miguel Servet 177, Zaragoza 50013, Spain
| | | | | |
Collapse
|
27
|
Corona P, Lamantea E, Greco M, Carrara F, Agostino A, Guidetti D, Dotti MT, Mariotti C, Zeviani M. Novel heteroplasmic mtDNA mutation in a family with heterogeneous clinical presentations. Ann Neurol 2002; 51:118-22. [PMID: 11782991 DOI: 10.1002/ana.10059] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The protean manifestations of a novel maternally inherited point mutation of the mitochondrial genome are reported. The proband showed isolated, spastic paraparesis. A brother, who had suffered from a multisystem progressive disorder, ultimately died of cardiomyopathy. Another brother is healthy. The proband's mother showed truncal ataxia, dysarthria, severe hearing loss, mental regression, ptosis, ophthalmoparesis, distal cyclones, and diabetes mellitus. A muscle biopsy performed in the proband failed to show the morphological abnormalities typical of mitochondrial disorders; the activities of respiratory chain complexes were normal. However, complex I and IV activities were low in the muscle homogenate of the affected mother and brother. Sequence analysis of mtDNA showed a heteroplasmic mutation of the tRNA(Ile) gene (G4284A). The mutation load was approximately 55%, 80%, and 90% in the muscle mtDNA of the proband, his mother, and his affected brother, respectively. Mutation was undetected in the healthy brother, as well as in 100 control samples. Several cybrid clones containing homoplasmic mutant mtDNA from the proband showed significant reductions of complex IV activity and maximum oxygen consumption rate, compared with homoplasmic wild-type clones derived from the same subject.
Collapse
Affiliation(s)
- P Corona
- Division of Biochemistry and Genetics, National Neurological Institute C. Besta, Milan, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Clay AS, Behnia M, Brown KK. Mitochondrial disease: a pulmonary and critical-care medicine perspective. Chest 2001; 120:634-48. [PMID: 11502670 DOI: 10.1378/chest.120.2.634] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
The clinical spectrum of mitochondrial diseases has expanded dramatically in the last decade. Abnormalities of mitochondrial function are now thought to participate in a number of common adult diseases, ranging from exercise intolerance to aging. This review outlines the common presentations of mitochondrial disease in ICUs and in the outpatient setting and discusses current diagnostic and therapeutic options as they pertain to the pulmonary and critical-care physician.
Collapse
Affiliation(s)
- A S Clay
- Department of Internal Medicine, Indiana University School of Medicine, Indianapolis, IN, USA
| | | | | |
Collapse
|
29
|
Raha S, Merante F, Shoubridge E, Myint AT, Tein I, Benson L, Johns T, Robinson BH. Repopulation of rho0 cells with mitochondria from a patient with a mitochondrial DNA point mutation in tRNA(Gly) results in respiratory chain dysfunction. Hum Mutat 2000; 13:245-54. [PMID: 10090480 DOI: 10.1002/(sici)1098-1004(1999)13:3<245::aid-humu9>3.0.co;2-b] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Familial hypertrophic ventricular cardiomyopathy has been demonstrated to be associated with a number of mitochondrial DNA (mtDNA) mutations. A fibroblast cell line carrying a mutation in its mtDNA at position 9997 in the gene encoding tRNA glycine was obtained from a patient with hypertrophic cardiomyopathy. To demonstrate that the etiology of this disease was a result of the mtDNA mutation, cybrid clones were constructed by fusion of enucleated patient skin fibroblasts to rho0 osteosarcoma cells. Clones carrying high levels of mutant mtDNA showed predominantly cytochrome c oxidase and complex I deficiency, as well as an elevated lactate/pyruvate (L/P) ratio, a biochemical marker characteristic of respiratory chain deficiencies. Pulse-labeling experiments demonstrated a strong negative correlation between the levels of newly synthesized mtDNA-encoded polypeptides and glycine content. These data suggest that the T9997C mutation in mtDNA is causative of respiratory chain dysfunction when present at high levels of heteroplasmy.
Collapse
Affiliation(s)
- S Raha
- Department of Biochemistry, University of Toronto, Canada
| | | | | | | | | | | | | | | |
Collapse
|
30
|
Tiranti V, Galimberti C, Nijtmans L, Bovolenta S, Perini MP, Zeviani M. Characterization of SURF-1 expression and Surf-1p function in normal and disease conditions. Hum Mol Genet 1999; 8:2533-40. [PMID: 10556302 DOI: 10.1093/hmg/8.13.2533] [Citation(s) in RCA: 109] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Loss-of-function mutations of the SURF-1 gene have been associated with Leigh syndrome with cytochrome c oxidase (COX) deficiency. Mature Surf-1 protein (Surf-1p) is a 30 kDa hydrophobic polypeptide whose function is still unknown. Using antibodies against a recombinant, hemagglutinin-tagged Surf-1p, we have demonstrated that this protein is imported into mitochondria as a larger precursor, which is then processed into the mature product by cleaving off an N-terminal leader polypeptide of approximately 40 amino acids. By using western blot analysis with specific antibodies, we showed that Surf-1p is localized in and tightly bound to the mitochondrial inner membrane. The same analysis revealed that no protein is present in cell lines harboring loss-of-function mutations of SURF-1, regardless of their type and position. Northern blot analysis showed the virtual absence of specific SURF-1 transcripts in different mutant cell lines. This result suggests that several mutations of SURF-1 are associated with severe mRNA instability. To understand better whether and which domains of the protein are essential for function, we generated several constructs with truncated or partially deleted SURF-1 cDNAs. None of these constructs, expressed into Surf-1p null mutant cells, were able to rescue the COX phenotype, suggesting that different regions of the protein are all essential for function. Finally, experiments based on blue native two-dimensional gel electrophoresis indicated that assembly of COX in Surf-1p null mutants is blocked at an early step, most likely before the incorporation of subunit II in the nascent intermediates composed of subunit I alone or subunit I plus subunit IV. However, detection of residual amounts of fully assembled complex suggests a certain degree of redundancy of this system.
Collapse
Affiliation(s)
- V Tiranti
- Istituto Nazionale Neurologico 'C. Besta', Via Celoria 11, 20133 Milano, Italy
| | | | | | | | | | | |
Collapse
|
31
|
Vergani L, Rossi R, Brierley CH, Hanna M, Holt IJ. Introduction of heteroplasmic mitochondrial DNA (mtDNA) from a patient with NARP into two human rho degrees cell lines is associated either with selection and maintenance of NARP mutant mtDNA or failure to maintain mtDNA. Hum Mol Genet 1999; 8:1751-5. [PMID: 10441339 DOI: 10.1093/hmg/8.9.1751] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Mitochondria from a patient heteroplasmic at nucleo-tide position 8993 of mitochondrial DNA (mtDNA) were introduced into two human tumour cell lines lacking mtDNA. The donor mitochondria contained between 85 and 95% 8993G:C mtDNA. All detectable mtDNA in the mitochondrially transformed cells contained the pathological 8993G:C mutation 3 months after transformation. These results suggest that 8993G:C mtDNA had a selective advantage over 8993T:A mtDNA in both lung carcinoma and osteo-sarcoma cell backgrounds. In contrast, two other presumed pathological mtDNA variants were lost in favour of 'wild-type' mtDNA molecules in the same lung carcinoma cell background. Taken together, these findings suggest that the transmission bias of mtDNA variants is dependent upon a combination of nuclear background and mtDNA genotype. A second phenomenon observed was a marked decrease in the growth rate of many putative transformed cell lines after 6 weeks of culturing in selective medium, and in these cell lines mtDNA was not readily detectable by Southern blotting. Restriction endonuclease analysis and sequencing of amplified mtDNA demonstrated that the slow growing cells contained little or no mtDNA. It is concluded that these cells represented transient mitochondrial transformants.
Collapse
Affiliation(s)
- L Vergani
- Department of Molecular Pathology, University of Dundee, UK
| | | | | | | | | |
Collapse
|
32
|
Williams AJ, Murrell M, Brammah S, Minchenko J, Christodoulou J. A novel system for assigning the mode of inheritance in mitochondrial disorders using cybrids and rhodamine 6G. Hum Mol Genet 1999; 8:1691-7. [PMID: 10441332 DOI: 10.1093/hmg/8.9.1691] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
When normal human cultured skin fibroblasts were treated with the fluorescent dye rhodamine 6G (R6G), there was a drastic reduction in numbers of intact mitochondria and electron transport chain enzyme activities, despite the fact that mitochondrial DNA (mtDNA) was still present in treated cells. We used this observation to develop a novel system for generating cybrids. When cultured skin fibroblast cells from a patient with the mitochondrial encephalopathy and ragged-red fibers (MERRF) syndrome harboring the A8344G mtDNA mutation and which showed a severe reduction in cytochrome c oxidase activity were treated with R6G and fused to enucleated HeLaCOT cells, the resulting cybrid clones showed recovery of cytochrome c oxidase activity, and were shown to have mtDNA derived solely from the HeLaCOT cell line. R6G has significant advantages over ethidium bromide in removing the mitochondrial elements from cultured cells, and the results reported here demonstrate that this strategy can be used to determine the origin of the genetic defect in patients with electron transport chain abnormalities.
Collapse
Affiliation(s)
- A J Williams
- Department of Clinical Biochemistry, Royal Alexandra Hospital for Children, Westmead, Australia
| | | | | | | | | |
Collapse
|
33
|
Abstract
Cardiomyopathies, primary disorders of the myocardium, are a leading cause of morbidity and mortality in children and adults, and these disorders are responsible for a significant percentage of sudden cardiac deaths and cardiac transplants. Neonatal cardiomyopathies commonly are associated with poor prognosis, and the underlying etiology of this disorder differs considerably from cardiomyopathies in older children, adolescents, and adults with similar phenotypes. In this review, the major causes of neonatal cardiomyopathy are described.
Collapse
Affiliation(s)
- J A Towbin
- Department of Pediatrics (Cardiology), Baylor College of Medicine, Texas Children's Hospital, Houston, USA.
| | | |
Collapse
|
34
|
Morgan-Hughes JA, Hanna MG. Mitochondrial encephalomyopathies: the enigma of genotype versus phenotype. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1410:125-45. [PMID: 10076022 DOI: 10.1016/s0005-2728(98)00162-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Over the past decade a large body of evidence has accumulated implicating defects of human mitochondrial DNA in the pathogenesis of a group of disorders known collectively as the mitochondrial encephalomyopathies. Although impaired oxidative phosphorylation is likely to represent the final common pathway leading to cellular dysfunction in these diseases, fundamental issues still remain elusive. Perhaps the most challenging of these is to understand the mechanisms which underlie the complex relationship between genotype and phenotype. Here we examine this relationship and discuss some of the factors which are likely to be involved.
Collapse
Affiliation(s)
- J A Morgan-Hughes
- University Department of Clinical Neurology, Institute of Neurology, Queen Square, London WC1H 3BG, UK
| | | |
Collapse
|
35
|
|
36
|
Rossmanith W, Karwan RM. Impairment of tRNA processing by point mutations in mitochondrial tRNA(Leu)(UUR) associated with mitochondrial diseases. FEBS Lett 1998; 433:269-74. [PMID: 9744809 DOI: 10.1016/s0014-5793(98)00928-4] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Several point mutations in mitochondrial tRNA genes have been linked to distinct clinical subgroups of mitochondrial diseases. A particularly large number of different mutations is found in the tRNA(Leu)(UUR) gene. We show that base substitutions at nucleotide position 3256, 3260, and 3271 of the mitochondrial genome, located in the D and anticodon stem of this tRNA, and mutation 3243 changing a base involved in a tertiary interaction, significantly impair the processing of the tRNA precursor in vitro. In correlation with other studies, our results suggest that inefficient processing of certain mutant variants of mitochondrial tRNA(Leu)(UUR) is a primary molecular impairment leading to mitochondrial dysfunction and consequently to disease.
Collapse
Affiliation(s)
- W Rossmanith
- Institut für Tumorbiologie-Krebsforschung der Universität Wien, PG Genexpression, Austria.
| | | |
Collapse
|
37
|
Abstract
Mitochondrial respiration, the most efficient metabolic pathway devoted to energy production, is at the crosspoint of 2 quite different genetic systems, the nuclear genome and the mitochondrial genome (mitochondrial DNA, mtDNA). The latter encodes a few essential components of the mitochondrial respiratory chain and has unique molecular and genetic properties that account for some of the peculiar features of mitochondrial disorders. However, the perpetuation, propagation, and expression of mtDNA, the majority of the subunits of the respiratory complexes, as well as a number of genes involved in their assembly and turnover, are contained in the nuclear genome. Although mitochondrial disorders have been known for more than 30 years, a major breakthrough in their understanding has come much later, with the discovery of an impressive, ever-increasing number of mutations of mitochondrial DNA. Partial deletions or duplications of mtDNA, or maternally inherited point mutations, have been associated with well-defined clinical syndromes. However, phenotypes transmitted as mendelian traits have also been identified. These include clinical entities defined on the basis of specific biochemical defects, and also a few autosomal dominant or recessive syndromes associated with multiple deletions or tissue-specific depletion of mtDNA. Given the complexity of mitochondrial genetics and biochemistry, the clinical manifestations of mitochondrial disorders are extremely heterogenous. They range from lesions of single tissues or structures, such as the optic nerve in Leber hereditary optic neuropathy or the cochlea in maternally inherited nonsyndromic deafness, to more widespread lesions including myopathies, encephalomyopathies, cardiopathies, or complex multisystem syndromes. The recent advances in genetic studies provide both diagnostic tools and new pathogenetic insights in this rapidly expanding area of human pathology.
Collapse
Affiliation(s)
- M Zeviani
- Division of Biochemistry and Genetics, National Neurological Institute-IRCCS C. Besta, Milan, Italy.
| | | | | |
Collapse
|
38
|
Michikawa Y, Hofhaus G, Lerman LS, Attardi G. Comprehensive, rapid and sensitive detection of sequence variants of human mitochondrial tRNA genes. Nucleic Acids Res 1997; 25:2455-63. [PMID: 9171099 PMCID: PMC146751 DOI: 10.1093/nar/25.12.2455] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
In the present study, a comprehensive, rapid and sensitive method for screening sequence variation of the human mitochondrial tRNA genes has been developed. For this purpose, the denaturing gradient gel electrophoresis (DGGE) technique has been appropriately modified for simultaneous mutation analysis of a large number of samples and adapted so as to circumvent the problems caused by the anomalous electrophoretic behavior of DNA fragments encoding tRNA genes. Eighteen segments of mitochondrial DNA (mtDNA), each containing a single uniform melting domain, were selected to cover all tRNA-encoding regions using the computer program MELT94. All 18 segments were simultaneously analyzed by electrophoresis through a single broad range denaturing gradient gel under rigorously defined conditions, which prevent band broadening and other migration abnormalities from interfering with detection of sequence variants. All base substitutions tested, which include six natural mutations and 14 artificially introduced ones, have been detected successfully in the present study. Several types of evidence strongly suggest that the anomalous behavior in DGGE of tRNA gene-containing mtDNA fragments reflects their tendency to form temporary or stable alternative secondary structures under semi-denaturing conditions. The high sensitivity of the method, which can detect as low as 10% of mutant mtDNA visually, makes it valuable for the analysis of heteroplasmic mutations.
Collapse
MESH Headings
- Cell Line
- DNA, Mitochondrial/genetics
- Genetic Variation
- Humans
- Nucleic Acid Heteroduplexes/biosynthesis
- Point Mutation
- RNA/biosynthesis
- RNA/genetics
- RNA, Mitochondrial
- RNA, Transfer, Amino Acid-Specific/biosynthesis
- RNA, Transfer, Amino Acid-Specific/genetics
- RNA, Transfer, Leu/biosynthesis
- RNA, Transfer, Leu/genetics
- RNA, Transfer, Lys/biosynthesis
- RNA, Transfer, Lys/genetics
Collapse
Affiliation(s)
- Y Michikawa
- Division of Biology, California Institute of Technology, Pasadena, CA 91125, USA
| | | | | | | |
Collapse
|
39
|
Weber K, Wilson JN, Taylor L, Brierley E, Johnson MA, Turnbull DM, Bindoff LA. A new mtDNA mutation showing accumulation with time and restriction to skeletal muscle. Am J Hum Genet 1997; 60:373-80. [PMID: 9012410 PMCID: PMC1712391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
We have identified a new mutation in mtDNA, involving tRNALeu(CUN) in a patient manifesting an isolated skeletal myopathy. This heteroplasmic A-->G transition at position 12320 affects the T psi C loop at a conserved site and was not found in 120 controls. Analysis of cultured fibroblasts, white blood cells/platelets, and skeletal muscle showed that only skeletal muscle contained the mutation and that only this tissue demonstrated a biochemical defect of respiratory-chain activity. In a series of four muscle-biopsy specimens taken over a 12-year period, there was a gradual increase, from 70% to 90%, in the overall level of mutation, as well as a marked clinical deterioration. Single-fiber PCR confirmed that the proportion of mutant mtDNA was highest in cytochrome c oxidase-negative fibers. This study, which reports a mutation involving tRNALeu(CUN), demonstrates clearly that mtDNA point mutations can accumulate over time and may be restricted in their tissue distribution. Furthermore, clinical deterioration seemed to follow the increase in the level of mutation, although, interestingly, the appearance of fibers deficient in respiratory-chain activity showed a lag period.
Collapse
Affiliation(s)
- K Weber
- Division of Neurology, The Medical School, Newcastle upon Tyne, United Kingdom
| | | | | | | | | | | | | |
Collapse
|
40
|
Advances in Human Mitochondrial Diseases Molecular Genetic Analysis of Pathogenic mtDNA Mutations. Trends Cardiovasc Med 1997; 7:16-24. [DOI: 10.1016/s1050-1738(96)00122-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
41
|
Nishino I, Komatsu M, Kodama S, Horai S, Nonaka I, Goto Y. The 3260 mutation in mitochondrial DNA can cause mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes (MELAS). Muscle Nerve 1996; 19:1603-4. [PMID: 8941275 DOI: 10.1002/(sici)1097-4598(199612)19:12<1603::aid-mus10>3.0.co;2-s] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- I Nishino
- Department of Ultrastructural Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Tokyo, Japan
| | | | | | | | | | | |
Collapse
|
42
|
de Coo IF, Smeets HJ, Gabreëls FJ, Arts N, van Oost BA. Isolated case of mental retardation and ataxia due to a de novo mitochondrial T8993G mutation. Am J Hum Genet 1996; 58:636-8. [PMID: 8644724 PMCID: PMC1914555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
|
43
|
Bentlage HA, Attardi G. Relationship of genotype to phenotype in fibroblast-derived transmitochondrial cell lines carrying the 3243 mutation associated with the MELAS encephalomyopathy: shift towards mutant genotype and role of mtDNA copy number. Hum Mol Genet 1996; 5:197-205. [PMID: 8824875 DOI: 10.1093/hmg/5.2.197] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Transmitochondrial cell lines were isolated by fusing mtDNA-less rho degrees 206 cells with enucleated fibroblasts derived from four members of a pedigree carrying in their muscle varying proportions of the mutation at position 3243 in the tRNA(Leu(UUR)) gene associated with the MELAS encephalomyopathy. The mitochondrial transformants derived from an asymptomatic individual were all homoplasmic for wild-type mtDNA. The proportion of wild-type transformants derived from clinically affected members of the pedigree appeared to decrease in correspondence with an increase in severity of the clinical symptoms of the cell donor. Furthermore, the average proportion of wild-type mtDNA in the transformants derived from each member of the pedigree was very similar to that found in mtDNA from the fibroblasts of that individual, suggesting that the distribution of genotypes in the transformants reflected fairly closely that in the fibroblasts. The genotype and phenotype of ten transformants derived from one severely affected individual were investigated during continuous culture up to 17-24 weeks after the transformation step. Six heteroplasmic clones showed a progressive increase in the proportion of mutant mtDNA, whereas the mitochondrial genotype remained constant in four clones apparently homoplasmic for wild-type mtDNA or nearly homoplasmic for mutant mtDNA. An analysis of the rate of repopulation of rho degrees 206 cells with fibroblast-derived mtDNA revealed a large variability among different transformants, with the full re-establishment of the control ratio of mtDNA to nuclear DNA being observed between approximately 6 weeks and more than 22 weeks after the transformation step. An increase in rate of O2 consumption generally accompanied the increase in mtDNA copy number of the transformants, pointing to the important role of the mtDNA copy number in determining the phenotype of a cell. The observation that a very small amount of wild-type mtDNA (2 to 5% of the control level), coexisting with strongly predominant mutant mtDNA, conferred upon the transformants a substantial respiratory capacity (50% or more) and the evidence of proportionality between O2 consumption rate and mtDNA copy number, which occurred at widely different mutant to wild-type mtDNA ratios, strongly suggest a contribution of the mutant mtDNA to the cell respiratory competence.
Collapse
Affiliation(s)
- H A Bentlage
- Division of Biology, California Institute of Technology, Pasadena 91125, USA
| | | |
Collapse
|
44
|
Hao H, Moraes CT. Functional and molecular mitochondrial abnormalities associated with a C --> T transition at position 3256 of the human mitochondrial genome. The effects of a pathogenic mitochondrial tRNA point mutation in organelle translation and RNA processing. J Biol Chem 1996; 271:2347-52. [PMID: 8567699 DOI: 10.1074/jbc.271.4.2347] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
We have previously identified a mitochondrial DNA polymorphism (a C --> T transition at position 3256, within the mitochondrial tRNALeu(UUR) gene in a patient with a multisystem disorder. Although there were several indicators suggesting a pathogenetic role for this mtDNA polymorphism, its heteroplasmic nature made functional and molecular studies difficult to interpret. We have now fused enucleated fibroblasts from the patient with a mtDNA-less cell line to generate transmitochondrial cybrids harboring different proportions of mutated and wild-type mtDNA. Individual clones harboring essentially 100% wild-type or > 99% mutated mtDNAs were characterized and studied for respiratory capacity, respiratory chain enzymes activity, mitochondrial protein synthesis, and RNA steady-state levels and processing. Our results showed that cell lines containing exclusively mutated mtDNAs respire poorly, overproduce lactic acid, and have significantly impaired activity of respiratory complexes I and IV. Molecular studies showed that mutant clones have a decrease in steady-state levels of mitochondrial tRNALeu(UUR), and a partial impairment of mitochondrial protein synthesis and steady-state levels, suggesting that these molecular abnormalities are involved in the pathogenetic mechanism of the mtDNA 3256 mutation.
Collapse
Affiliation(s)
- H Hao
- Department of Neurology, University of Miami, Florida 33136, USA
| | | |
Collapse
|
45
|
Abstract
We present here a report on a 5-year experience in clinical investigation, diagnostic management and molecular genetic studies of neuromitochondrial disorders, defined on the basis of morphological, biochemical and genetic findings. Leigh disease is the most frequent clinical presentation in infancy and childhood, but symptoms at onset are poorly informative. In paediatric cases, lactic acidosis and neuroradiological abnormalities are frequent, and can be of help for the diagnostic orientation. In the adult population, muscle weakness, ophthalmoplegia with ragged-red fibres, retinitis pigmentosa, progressive myoclonal ataxia, and early-onset stroke-like episodes, are frequently combined in complex syndromes that are often familial (maternally inherited) and/or associated with well-established mutations in mitochondrial DNA (mtDNA). However, the presence of overlap syndromes and features common to many neuromitochondrial diseases can complicate the clinical evaluation and the diagnostic approach. The pathogenicity of a given mtDNA mutation can frequently be ascertained by correlating the degree of heteroplasmy with the clinical or biochemical phenotypes. Moreover, transmitochondrial cybrids can be used to test the effects of either mitochondrial or nuclear gene abnormalities in a fully controlled, user-friendly and highly informative system.
Collapse
Affiliation(s)
- M Zeviani
- Division of Biochemistry & Genetics, Istituto Nazionale Neurologico C. Besta, Milan, Italy
| | | | | |
Collapse
|
46
|
Merante F, Myint T, Tein I, Benson L, Robinson BH. An additional mitochondrial tRNA(Ile) point mutation (A-to-G at nucleotide 4295) causing hypertrophic cardiomyopathy. Hum Mutat 1996; 8:216-22. [PMID: 8889580 DOI: 10.1002/(sici)1098-1004(1996)8:3<216::aid-humu4>3.0.co;2-7] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A third point mutation in the mitochondrial tRNA(Ile) gene associated with hypertrophic cardiomyopathy and respiratory chain dysfunction in heart is reported. An A-to-G transition at nucleotide position 4295 was shown to be highly evolutionarily conserved, never present in control individuals, and to segregate with the disease. A PCR-based diagnostic test and endomyocardial biopsies were used to detect both the biochemical deficiency and the level of heteroplasmy in heart. The implications of this new mitochondrial DNA point mutation are discussed.
Collapse
Affiliation(s)
- F Merante
- Department of Biochemistry, University of Toronto, Ontario, Canada
| | | | | | | | | |
Collapse
|
47
|
Dunbar DR, Moonie PA, Jacobs HT, Holt IJ. Different cellular backgrounds confer a marked advantage to either mutant or wild-type mitochondrial genomes. Proc Natl Acad Sci U S A 1995; 92:6562-6. [PMID: 7604033 PMCID: PMC41558 DOI: 10.1073/pnas.92.14.6562] [Citation(s) in RCA: 151] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
After the introduction of mitochondria with a mixture of mutant and wild-type mitochondrial DNA (mtDNA) into a human rho degree cell line (143B.206), Yoneda et al. [Yoneda, M., Chomyn, A., Martinuzzi, A., Hurko, O. & Attardi, G. (1992) Proc. Natl. Acad. Sci. USA 89, 11164-11168] observed a shift in the proportion of the two mitochondrial genotypes in a number of cybrid clones. In every case where a shift was observed, there was an increase in the proportion of mutant mtDNA. By using the same cell line (143B.206 rho degree), we also generated cybrids that were either stable in their mitochondrial genotype or showed an increase in the proportion of mutant mtDNA. However, temporal analysis of the same mutant mtDNA type in another rho degree cell line revealed a quite distinct outcome. Those clones that showed a change shifted toward higher levels of wild-type rather than mutant mtDNA. These results indicate that the nuclear genetic background of the recipient (rho degree) cell can influence the segregation of mutant and wild-type mitochondrial genomes in cell cybrids.
Collapse
Affiliation(s)
- D R Dunbar
- Department of Biochemical Medicine, Ninewells Hospital, Dundee, United Kingdom
| | | | | | | |
Collapse
|
48
|
Zeviani M, Mariotti C, Antozzi C, Fratta GM, Rustin P, Prelle A. OXPHOS defects and mitochondrial DNA mutations in cardiomyopathy. Muscle Nerve 1995; 3:S170-4. [PMID: 7603520 DOI: 10.1002/mus.880181433] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Defects of the mitochondrial respiratory chain in cardiac muscle are an important, yet still overlooked cause of heart failure. In 16 of 32 endocardial biopsies from infants affected by "idiopathic" hypertrophic cardiomyopathy we demonstrated a remarkable decrease of activity of either complex I, or complex IV, or both, relative to complex II + III activity which was taken as an index of mitochondrial proliferation. At the molecular level, several mtDNA mutations have been associated with cardiomyopathy. For instance, MIMyCa is a maternally inherited syndrome presenting with a variable combination of skeletal and heart muscle failure associated with a heteroplasmic A3260G transition in the tRNALeu(UUR) gene. To study the effects of the mutation in a controlled system, we prepared clones of transmitochondrial cybrids by fusing mutant cytoplasts with mtDNA-less tumor cells. Two groups of clones were identified: nearly 100% mutant (M group) and nearly 100% wild-type (WT group). The means of complex I and IV in the M group were 63% and 67% relative to the WT group. The O2 consumption in the M group was 36%, and the lactate production was 218% of that in the WT group. MtDNA-specific translation was defective in M clones. The study of transmitochondrial cybrids is an important clue to test the pathogenicity of mtDNA mutations.
Collapse
Affiliation(s)
- M Zeviani
- Istituto Nazionale Neurologico Carlo Besta, Milano, Italy
| | | | | | | | | | | |
Collapse
|