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Chen Y, Wei X, Ci X, Ji Y, Zhang J. Dysregulation of mitochondria, apoptosis and mitophagy in Leber's hereditary optic neuropathy with MT-ND1 3635G>A mutation. Gene 2024; 930:148853. [PMID: 39147111 DOI: 10.1016/j.gene.2024.148853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2024] [Revised: 07/14/2024] [Accepted: 08/12/2024] [Indexed: 08/17/2024]
Abstract
Leber's hereditary optic neuropathy (LHON) is a maternal inherited disorder, primarily due to mitochondrial DNA (mtDNA) mutations. This investigation aimed to assess the pathogenicity of m.3635G>A alteration known to confer susceptibility to LHON. The disruption of electrostatic interactions among S110 of the MT-ND1 and the side chain of E4, along with the carbonyl backbone of M1 in the NDUFA1, was observed in complex I of cybrids with m.3635G>A. This disturbance affected the complex I assembly activity by changing the mitochondrial respiratory chain composition and function. In addition, the affected cybrids exhibited notable deficiencies in complex I activities, including impaired mitochondrial respiration and depolarization of its membrane potential. Apoptosis was also stimulated in the mutant group, as witnessed by the secretion of cytochrome c and activation of PARP, caspase 3, 7, and 9 compared to the control. Furthermore, the mutant group exhibited decreased levels of autophagy protein light chain 3, accumulation of autophagic substrate P62, and impaired PINK1/Parkin-dependent mitophagy. Overall, the current study has confirmed the crucial involvement of the alteration of the m.3635G>A gene in the development of LHON. These findings contribute to a deeper comprehension of the pathophysiological mechanisms underlying LHON, providing a fundamental basis for further research.
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Affiliation(s)
- Yingqi Chen
- State Key Laboratory of Ophthalmology, Optometry and Vision Science, Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
| | - Xiaoyang Wei
- State Key Laboratory of Ophthalmology, Optometry and Vision Science, Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
| | - Xiaorui Ci
- Attardi Institute of Mitochondrial Biomedicine, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Yanchun Ji
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine and National Clinical Research Center for Child Health, Hangzhou, Zhejiang 310058, China; Institute of Genetics, Zhejiang University, School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Juanjuan Zhang
- State Key Laboratory of Ophthalmology, Optometry and Vision Science, Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China; Attardi Institute of Mitochondrial Biomedicine, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China.
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2
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Mandic M, Paunovic V, Vucicevic L, Kosic M, Mijatovic S, Trajkovic V, Harhaji-Trajkovic L. No energy, no autophagy-Mechanisms and therapeutic implications of autophagic response energy requirements. J Cell Physiol 2024:e31366. [PMID: 38958520 DOI: 10.1002/jcp.31366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 05/29/2024] [Accepted: 06/20/2024] [Indexed: 07/04/2024]
Abstract
Autophagy is a lysosome-mediated self-degradation process of central importance for cellular quality control. It also provides macromolecule building blocks and substrates for energy metabolism during nutrient or energy deficiency, which are the main stimuli for autophagy induction. However, like most biological processes, autophagy itself requires ATP, and there is an energy threshold for its initiation and execution. We here present the first comprehensive review of this often-overlooked aspect of autophagy research. The studies in which ATP deficiency suppressed autophagy in vitro and in vivo were classified according to the energy pathway involved (oxidative phosphorylation or glycolysis). A mechanistic insight was provided by pinpointing the critical ATP-consuming autophagic events, including transcription/translation/interaction of autophagy-related molecules, autophagosome formation/elongation, autophagosome fusion with the lysosome, and lysosome acidification. The significance of energy-dependent fine-tuning of autophagic response for preserving the cell homeostasis, and potential implications for the therapy of cancer, autoimmunity, metabolic disorders, and neurodegeneration are discussed.
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Affiliation(s)
- Milos Mandic
- Institute of Microbiology and Immunology, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Verica Paunovic
- Institute of Microbiology and Immunology, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Ljubica Vucicevic
- Department of Neurophysiology, Institute for Biological Research "Sinisa Stankovic", National Institute of Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Milica Kosic
- Institute of Microbiology and Immunology, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Srdjan Mijatovic
- Clinic for Emergency Surgery, University Clinical Centre of Serbia, Belgrade, Serbia
| | - Vladimir Trajkovic
- Institute of Microbiology and Immunology, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Ljubica Harhaji-Trajkovic
- Department of Neurophysiology, Institute for Biological Research "Sinisa Stankovic", National Institute of Republic of Serbia, University of Belgrade, Belgrade, Serbia
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3
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Chen X, Meng F, Chen C, Li S, Chou Z, Xu B, Mo JQ, Guo Y, Guan MX. Deafness-associated tRNA Phe mutation impaired mitochondrial and cellular integrity. J Biol Chem 2024; 300:107235. [PMID: 38552739 PMCID: PMC11046301 DOI: 10.1016/j.jbc.2024.107235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2024] [Revised: 03/06/2024] [Accepted: 03/18/2024] [Indexed: 04/23/2024] Open
Abstract
Defects in mitochondrial RNA metabolism have been linked to sensorineural deafness that often occurs as a consequence of damaged or deficient inner ear hair cells. In this report, we investigated the molecular mechanism underlying a deafness-associated tRNAPhe 593T > C mutation that changed a highly conserved uracil to cytosine at position 17 of the DHU-loop. The m.593T > C mutation altered tRNAPhe structure and function, including increased melting temperature, resistance to S1 nuclease-mediated digestion, and conformational changes. The aberrant tRNA metabolism impaired mitochondrial translation, which was especially pronounced by decreases in levels of ND1, ND5, CYTB, CO1, and CO3 harboring higher numbers of phenylalanine. These alterations resulted in aberrant assembly, instability, and reduced activities of respiratory chain enzyme complexes I, III, IV, and intact supercomplexes overall. Furthermore, we found that the m.593T > C mutation caused markedly diminished membrane potential, and increased the production of reactive oxygen species in the mutant cell lines carrying the m.593T > C mutation. These mitochondrial dysfunctions led to the mitochondrial dynamic imbalance via increasing fission with abnormal mitochondrial morphology. Excessive fission impaired the process of autophagy including the initiation phase, formation, and maturation of the autophagosome. In particular, the m.593T > C mutation upregulated the PARKIN-dependent mitophagy pathway. These alterations promoted an intrinsic apoptotic process for the removal of damaged cells. Our findings provide critical insights into the pathophysiology of maternally inherited deafness arising from tRNA mutation-induced defects in mitochondrial and cellular integrity.
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Affiliation(s)
- Xiaowan Chen
- Department of Otolaryngology-Head and Neck Surgery, Lanzhou University First Hospital, Lanzhou, Gansu, China; Institute of Genetics, Zhejiang University International School of Medicine, Hangzhou, Zhejiang, China
| | - Feilong Meng
- Institute of Genetics, Zhejiang University International School of Medicine, Hangzhou, Zhejiang, China; Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Chao Chen
- Institute of Genetics, Zhejiang University International School of Medicine, Hangzhou, Zhejiang, China; Center for Mitochondrial Biomedicine, The Fourth Affiliated Hospital Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Shujuan Li
- Department of Otolaryngology-Head and Neck Surgery, Gansu Provincial Hospital, Lanzhou, Gansu, China
| | - Zhiqiang Chou
- Department of Otolaryngology-Head and Neck Surgery, Lanzhou University First Hospital, Lanzhou, Gansu, China
| | - Baicheng Xu
- Department of Otolaryngology-Head and Neck Surgery, Lanzhou University Second Hospital, Lanzhou, Gansu, China
| | - Jun Q Mo
- Department of Pathology, Rady Children's Hospital, University of California School of Medicine, San Diego, California, USA
| | - Yufen Guo
- Department of Otolaryngology-Head and Neck Surgery, Lanzhou University Second Hospital, Lanzhou, Gansu, China
| | - Min-Xin Guan
- Institute of Genetics, Zhejiang University International School of Medicine, Hangzhou, Zhejiang, China; Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China; Center for Mitochondrial Biomedicine, The Fourth Affiliated Hospital Zhejiang University School of Medicine, Hangzhou, Zhejiang, China; Zhejiang Provincial Lab of Genetics and Genomics, Zhejiang University, Hangzhou, Zhejiang, China.
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4
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Lin X, Zhou Y, Xue L. Mitochondrial complex I subunit MT-ND1 mutations affect disease progression. Heliyon 2024; 10:e28808. [PMID: 38596130 PMCID: PMC11002282 DOI: 10.1016/j.heliyon.2024.e28808] [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: 01/21/2024] [Revised: 03/24/2024] [Accepted: 03/25/2024] [Indexed: 04/11/2024] Open
Abstract
Mitochondrial respiratory chain complex I is an important component of the oxidative respiratory chain, with the mitochondrially encoded NADH:ubiquinone oxidoreductase core subunit 1 (MT-ND1) being one of the core subunits. MT-ND1 plays a role in the assembly of complex I and its enzymatic function. MT-ND1 gene mutation affects pathophysiological processes, such as interfering with the early assembly of complex I, affecting the ubiquinone binding domain and proton channel of complex I, and affecting oxidative phosphorylation, thus leading to the occurrence of diseases. The relationship between MT-ND1 gene mutation and disease has been has received increasing research attention. Therefore, this article reviews the impact of MT-ND1 mutations on disease progression, focusing on the impact of such mutations on diseases and their possible mechanisms, as well as the application of targeting MT-ND1 gene mutations in disease diagnosis and treatment. We aim to provide a new perspective leading to a more comprehensive understanding of the relationship between MT-ND1 gene mutations and diseases.
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Affiliation(s)
- Xi Lin
- Department of Pathology, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, 410013, China
- Cancer Research Institute, Basic School of Medicine, Central South University, Changsha, Hunan 410078, China
| | - Yanhong Zhou
- Cancer Research Institute, Basic School of Medicine, Central South University, Changsha, Hunan 410078, China
| | - Lei Xue
- Department of Pathology, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, 410013, China
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Yang HK, Seong MW, Kim JY, Park SS, Hwang JM. Poor visual prognosis of Asian patients with 3460 mitochondrial DNA mutation in Leber's hereditary optic neuropathy. CANADIAN JOURNAL OF OPHTHALMOLOGY 2024:S0008-4182(24)00095-4. [PMID: 38593981 DOI: 10.1016/j.jcjo.2024.03.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 03/07/2024] [Accepted: 03/19/2024] [Indexed: 04/11/2024]
Abstract
BACKGROUND Among the 3 primary mutations of Leber's hereditary optic neuropathy (LHON), the incidence of LHON with a mutation at nucleotide position 3460 is the lowest in Asians. Therefore, information about the clinical manifestations of LHON mutations in Asians with the 3460 mutation is limited. OBJECTIVE To determine the clinical manifestations including visual prognosis of Asians with the LHON 3460 mutation. METHODS We performed a retrospective study of 5 Korean LHON patients with the 3460 mutation. RESULTS All patients were male, and the age of onset for visual impairment varied from 17 to 35 years, with an average of 25.4 ± 7.16 years. Among the 10 affected eyes, only 1 eye of 1 patient showed visual improvement to 20/50 at 2 years after onset. The remaining patients had a visual acuity of worse than 20/200. CONCLUSION The visual prognosis of Korean patients with the LHON 3460 mutation was generally poor. Further studies regarding Asian patients with the LHON 3460 mutation are necessary.
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Affiliation(s)
- Hee Kyung Yang
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Moon-Woo Seong
- Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, Korea
| | - Ji Yeon Kim
- Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea
| | - Sung Sup Park
- Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, Korea; Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea; Clavis Therapeutics, Inc, Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea
| | - Jeong-Min Hwang
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
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He Y, Zhu G, Li X, Zhou M, Guan MX. Deficient tRNA posttranscription modification dysregulated the mitochondrial quality controls and apoptosis. iScience 2024; 27:108883. [PMID: 38318358 PMCID: PMC10838789 DOI: 10.1016/j.isci.2024.108883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 10/26/2023] [Accepted: 01/08/2024] [Indexed: 02/07/2024] Open
Abstract
Mitochondria are dynamic organelles in cellular metabolism and physiology. Mitochondrial DNA (mtDNA) mutations are associated with a broad spectrum of clinical abnormalities. However, mechanisms underlying mtDNA mutations regulate intracellular signaling related to the mitochondrial and cellular integrity are less explored. Here, we demonstrated that mt-tRNAMet 4435A>G mutation-induced nucleotide modification deficiency dysregulated the expression of nuclear genes involved in cytosolic proteins involved in oxidative phosphorylation system (OXPHOS) and impaired the assemble and integrity of OXPHOS complexes. These dysfunctions caused mitochondrial dynamic imbalance, thereby increasing fission and decreasing fusion. Excessive fission impaired the process of autophagy including initiation phase, formation, and maturation of autophagosome. Strikingly, the m.4435A>G mutation upregulated the PARKIN dependent mitophagy pathways but downregulated the ubiquitination-independent mitophagy. These alterations promoted intrinsic apoptotic process for the removal of damaged cells. Our findings provide new insights into mechanism underlying deficient tRNA posttranscription modification regulated intracellular signaling related to the mitochondrial and cellular integrity.
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Affiliation(s)
- Yunfan He
- Center for Mitochondrial Biomedicine, the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, Zhejiang, China
- Institute of Genetics, Zhejiang University International School of Medicine, Hangzhou, Zhejiang, China
- Center for Genetic Medicine, Zhejiang University International Institute of Medicine, Yiwu, Zhejiang, China
| | - Gao Zhu
- Center for Mitochondrial Biomedicine, the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, Zhejiang, China
- Institute of Genetics, Zhejiang University International School of Medicine, Hangzhou, Zhejiang, China
- Center for Genetic Medicine, Zhejiang University International Institute of Medicine, Yiwu, Zhejiang, China
- Zhejiang Provincial Key Laboratory of Genetic & Developmental Disorders, Hangzhou, Zhejiang, China
| | - Xincheng Li
- Institute of Genetics, Zhejiang University International School of Medicine, Hangzhou, Zhejiang, China
| | - Mi Zhou
- Institute of Genetics, Zhejiang University International School of Medicine, Hangzhou, Zhejiang, China
| | - Min-Xin Guan
- Center for Mitochondrial Biomedicine, the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, Zhejiang, China
- Institute of Genetics, Zhejiang University International School of Medicine, Hangzhou, Zhejiang, China
- Center for Genetic Medicine, Zhejiang University International Institute of Medicine, Yiwu, Zhejiang, China
- Zhejiang Provincial Key Laboratory of Genetic & Developmental Disorders, Hangzhou, Zhejiang, China
- Key Lab of Reproductive Genetics, Ministry of Education of PRC, Zhejiang University, Hangzhou, Zhejiang, China
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7
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Conti F, Di Martino S, Drago F, Bucolo C, Micale V, Montano V, Siciliano G, Mancuso M, Lopriore P. Red Flags in Primary Mitochondrial Diseases: What Should We Recognize? Int J Mol Sci 2023; 24:16746. [PMID: 38069070 PMCID: PMC10706469 DOI: 10.3390/ijms242316746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 11/22/2023] [Accepted: 11/23/2023] [Indexed: 12/18/2023] Open
Abstract
Primary mitochondrial diseases (PMDs) are complex group of metabolic disorders caused by genetically determined impairment of the mitochondrial oxidative phosphorylation (OXPHOS). The unique features of mitochondrial genetics and the pivotal role of mitochondria in cell biology explain the phenotypical heterogeneity of primary mitochondrial diseases and the resulting diagnostic challenges that follow. Some peculiar features ("red flags") may indicate a primary mitochondrial disease, helping the physician to orient in this diagnostic maze. In this narrative review, we aimed to outline the features of the most common mitochondrial red flags offering a general overview on the topic that could help physicians to untangle mitochondrial medicine complexity.
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Affiliation(s)
- Federica Conti
- Department of Biomedical and Biotechnological Science, School of Medicine, University of Catania, 95123 Catania, Italy; (F.C.); (S.D.M.); (C.B.); (V.M.)
| | - Serena Di Martino
- Department of Biomedical and Biotechnological Science, School of Medicine, University of Catania, 95123 Catania, Italy; (F.C.); (S.D.M.); (C.B.); (V.M.)
| | - Filippo Drago
- Department of Biomedical and Biotechnological Science, School of Medicine, University of Catania, 95123 Catania, Italy; (F.C.); (S.D.M.); (C.B.); (V.M.)
| | - Claudio Bucolo
- Department of Biomedical and Biotechnological Science, School of Medicine, University of Catania, 95123 Catania, Italy; (F.C.); (S.D.M.); (C.B.); (V.M.)
- Center for Research in Ocular Pharmacology-CERFO, University of Catania, 95213 Catania, Italy
| | - Vincenzo Micale
- Department of Biomedical and Biotechnological Science, School of Medicine, University of Catania, 95123 Catania, Italy; (F.C.); (S.D.M.); (C.B.); (V.M.)
| | - Vincenzo Montano
- Neurological Institute, Department of Clinical and Experimental Medicine, University of Pisa, 56126 Pisa, Italy (P.L.)
| | - Gabriele Siciliano
- Neurological Institute, Department of Clinical and Experimental Medicine, University of Pisa, 56126 Pisa, Italy (P.L.)
| | - Michelangelo Mancuso
- Neurological Institute, Department of Clinical and Experimental Medicine, University of Pisa, 56126 Pisa, Italy (P.L.)
| | - Piervito Lopriore
- Neurological Institute, Department of Clinical and Experimental Medicine, University of Pisa, 56126 Pisa, Italy (P.L.)
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8
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Burke PJ. How defective mitochondrial electrical activity leads to inherited blindness. Proc Natl Acad Sci U S A 2023; 120:e2315649120. [PMID: 37878684 PMCID: PMC10636301 DOI: 10.1073/pnas.2315649120] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2023] Open
Affiliation(s)
- Peter J. Burke
- Department of Electrical Engineering and Computer Science, University of California, Irvine, CA92697
- Department of Biomedical Engineering, University of California, Irvine, CA92697
- Department of Chemical and Biomolecular Engineering, University of California, Irvine, CA92697
- Department of Materials Science and Engineering, University of California, Irvine, CA92697
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9
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Fuller JT, Barnes S, Sadun LA, Ajmera P, Alexandrova AN, Sadun AA. Coenzyme Q10 trapping in mitochondrial complex I underlies Leber's hereditary optic neuropathy. Proc Natl Acad Sci U S A 2023; 120:e2304884120. [PMID: 37733737 PMCID: PMC10523484 DOI: 10.1073/pnas.2304884120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 06/21/2023] [Indexed: 09/23/2023] Open
Abstract
How does a single amino acid mutation occurring in the blinding disease, Leber's hereditary optic neuropathy (LHON), impair electron shuttling in mitochondria? We investigated changes induced by the m.3460 G>A mutation in mitochondrial protein ND1 using the tools of Molecular Dynamics and Free Energy Perturbation simulations, with the goal of determining the mechanism by which this mutation affects mitochondrial function. A recent analysis suggested that the mutation's replacement of alanine A52 with a threonine perturbs the stability of a region where binding of the electron shuttling protein, Coenzyme Q10, occurs. We found two functionally opposing changes involving the role of Coenzyme Q10. The first showed that quantum electron transfer from the terminal Fe/S complex, N2, to the Coenzyme Q10 headgroup, docked in its binding pocket, is enhanced. However, this positive adjustment is overshadowed by our finding that the mobility of Coenzyme Q10 in its oxidized and reduced states, entering and exiting its binding pocket, is disrupted by the mutation in a manner that leads to conditions promoting the generation of reactive oxygen species. An increase in reactive oxygen species caused by the LHON mutation has been proposed to be responsible for this optic neuropathy.
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Affiliation(s)
- Jack T. Fuller
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA90095
| | - Steven Barnes
- Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, CA90095
- Doheny Eye Institute, Pasadena, CA91103
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Lorenzo A. Sadun
- Department of Mathematics, University of Texas at Austin, Austin, TX78712
| | - Pujan Ajmera
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA90095
| | | | - Alfredo A. Sadun
- Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, CA90095
- Doheny Eye Institute, Pasadena, CA91103
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10
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Chen C, Guan MX. Induced pluripotent stem cells: ex vivo models for human diseases due to mitochondrial DNA mutations. J Biomed Sci 2023; 30:82. [PMID: 37737178 PMCID: PMC10515435 DOI: 10.1186/s12929-023-00967-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 08/16/2023] [Indexed: 09/23/2023] Open
Abstract
Mitochondria are essential organelles for cellular metabolism and physiology in eukaryotic cells. Human mitochondria have their own genome (mtDNA), which is maternally inherited with 37 genes, encoding 13 polypeptides for oxidative phosphorylation, and 22 tRNAs and 2 rRNAs for translation. mtDNA mutations are associated with a wide spectrum of degenerative and neuromuscular diseases. However, the pathophysiology of mitochondrial diseases, especially for threshold effect and tissue specificity, is not well understood and there is no effective treatment for these disorders. Especially, the lack of appropriate cell and animal disease models has been significant obstacles for deep elucidating the pathophysiology of maternally transmitted diseases and developing the effective therapy approach. The use of human induced pluripotent stem cells (iPSCs) derived from patients to obtain terminally differentiated specific lineages such as inner ear hair cells is a revolutionary approach to deeply understand pathogenic mechanisms and develop the therapeutic interventions of mitochondrial disorders. Here, we review the recent advances in patients-derived iPSCs as ex vivo models for mitochondrial diseases. Those patients-derived iPSCs have been differentiated into specific targeting cells such as retinal ganglion cells and eventually organoid for the disease modeling. These disease models have advanced our understanding of the pathophysiology of maternally inherited diseases and stepped toward therapeutic interventions for these diseases.
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Affiliation(s)
- Chao Chen
- Center for Mitochondrial Biomedicine, The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Min-Xin Guan
- Center for Mitochondrial Biomedicine, The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine and National Clinical Research Center for Child Health, Hangzhou, Zhejiang, China.
- Institute of Genetics, Zhejiang University International School of Medicine, 866 Yuhangtang Road, Hangzhou, 310058, Zhejiang, China.
- Zhejiang Provincial Key Laboratory of Genetic and Developmental Disorders, Hangzhou, Zhejiang, China.
- Key Lab of Reproductive Genetics, Ministry of Education of PRC, Zhejiang University, Hangzhou, Zhejiang, China.
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11
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Alkabie S, Fraser JA, Racosta J. Painful vision loss in Leber hereditary optic neuropathy with novel ND1 variant mimicking optic neuritis. CANADIAN JOURNAL OF OPHTHALMOLOGY 2023; 58:e40-e42. [PMID: 35809626 DOI: 10.1016/j.jcjo.2022.06.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 05/26/2022] [Accepted: 06/08/2022] [Indexed: 11/26/2022]
Affiliation(s)
- Samir Alkabie
- London Health Sciences Centre and Schulich Medicine and Dentistry, Western University, London, ON.
| | - J Alexander Fraser
- London Health Sciences Centre and Schulich Medicine and Dentistry, Western University, London, ON; Schulich Medicine and Dentistry, Western University, London, ON
| | - Juan Racosta
- London Health Sciences Centre and Schulich Medicine and Dentistry, Western University, London, ON
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12
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Naren P, Cholkar A, Kamble S, Khan SS, Srivastava S, Madan J, Mehra N, Tiwari V, Singh SB, Khatri DK. Pathological and Therapeutic Advances in Parkinson's Disease: Mitochondria in the Interplay. J Alzheimers Dis 2023; 94:S399-S428. [PMID: 36093711 PMCID: PMC10473111 DOI: 10.3233/jad-220682] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/08/2022] [Indexed: 11/15/2022]
Abstract
Parkinson's disease (PD) is the second most common neurodegenerative illness majorly affecting the population between the ages of 55 to 65 years. Progressive dopaminergic neuronal loss and the collective assemblage of misfolded alpha-synuclein in the substantia nigra, remain notable neuro-pathological hallmarks of the disease. Multitudes of mechanistic pathways have been proposed in attempts to unravel the pathogenesis of PD but still, it remains elusive. The convergence of PD pathology is found in organelle dysfunction where mitochondria remain a major contributor. Mitochondrial processes like bioenergetics, mitochondrial dynamics, and mitophagy are under strict regulation by the mitochondrial genome and nuclear genome. These processes aggravate neurodegenerative activities upon alteration through neuroinflammation, oxidative damage, apoptosis, and proteostatic stress. Therefore, the mitochondria have grabbed a central position in the patho-mechanistic exploration of neurodegenerative diseases like PD. The management of PD remains a challenge to physicians to date, due to the variable therapeutic response of patients and the limitation of conventional chemical agents which only offer symptomatic relief with minimal to no disease-modifying effect. This review describes the patho-mechanistic pathways involved in PD not only limited to protein dyshomeostasis and oxidative stress, but explicit attention has been drawn to exploring mechanisms like organelle dysfunction, primarily mitochondria and mitochondrial genome influence, while delineating the newer exploratory targets such as GBA1, GLP, LRRK2, and miRNAs and therapeutic agents targeting them.
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Affiliation(s)
- Padmashri Naren
- Department of Pharmacology & Toxicology, National Institute of Pharmaceutical Education and Research, Hyderabad, Telangana, India
| | - Anjali Cholkar
- Department of Pharmacology & Toxicology, National Institute of Pharmaceutical Education and Research, Hyderabad, Telangana, India
| | - Suchita Kamble
- Department of Pharmacology & Toxicology, National Institute of Pharmaceutical Education and Research, Hyderabad, Telangana, India
| | - Sabiya Samim Khan
- Department of Pharmacology & Toxicology, National Institute of Pharmaceutical Education and Research, Hyderabad, Telangana, India
| | - Saurabh Srivastava
- Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research (NIPER)-Hyderabad, Telangana, India
| | - Jitender Madan
- Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research (NIPER)-Hyderabad, Telangana, India
| | - Neelesh Mehra
- Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research (NIPER)-Hyderabad, Telangana, India
| | - Vinod Tiwari
- Department of Pharmaceutical Engineering & Technology, Indian Institute of Technology (B.H.U.) Varanasi (U.P.), India
| | - Shashi Bala Singh
- Department of Pharmacology & Toxicology, National Institute of Pharmaceutical Education and Research, Hyderabad, Telangana, India
| | - Dharmendra Kumar Khatri
- Department of Pharmacology & Toxicology, National Institute of Pharmaceutical Education and Research, Hyderabad, Telangana, India
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13
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Lambiri DW, Levin LA. Modeling Reactive Oxygen Species-Induced Axonal Loss in Leber Hereditary Optic Neuropathy. Biomolecules 2022; 12:biom12101411. [PMID: 36291620 PMCID: PMC9599876 DOI: 10.3390/biom12101411] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 09/29/2022] [Accepted: 09/30/2022] [Indexed: 11/17/2022] Open
Abstract
Leber hereditary optic neuropathy (LHON) is a rare syndrome that results in vision loss. A necessary but not sufficient condition for its onset is the existence of known mitochondrial DNA mutations that affect complex I biomolecular structure. Cybrids with LHON mutations generate higher rates of reactive oxygen species (ROS). This study models how ROS, particularly H2O2, could signal and execute the axonal degeneration process that underlies LHON. We modeled and explored several hypotheses regarding the influence of H2O2 on the dynamics of propagation of axonal degeneration in LHON. Zonal oxidative stress, corresponding to H2O2 gradients, correlated with the morphology of injury exhibited in the LHON pathology. If the axonal membrane is highly permeable to H2O2 and oxidative stress induces larger production of H2O2, small injuries could trigger cascading failures of neighboring axons. The cellular interdependence created by H2O2 diffusion, and the gradients created by tissue variations in H2O2 production and scavenging, result in injury patterns and surviving axonal loss distributions similar to LHON tissue samples. Specifically, axonal degeneration starts in the temporal optic nerve, where larger groups of small diameter fibers are located and propagates from that region. These findings correlate well with clinical observations of central loss of visual field, visual acuity, and color vision in LHON, and may serve as an in silico platform for modeling the mechanism of action for new therapeutics.
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Affiliation(s)
- Darius W. Lambiri
- Department of Physiology, McGill University, Montreal, QC H3G 1Y6, Canada
| | - Leonard A. Levin
- Department of Ophthalmology and Visual Sciences, McGill University, Montreal, QC H4A 3S5, Canada
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC H3A 2B4, Canada
- Correspondence:
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14
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Nie Z, Wang C, Chen J, Ji Y, Zhang H, Zhao F, Zhou X, Guan MX. Abnormal morphology and function in retinal ganglion cells derived from patients-specific iPSCs generated from individuals with Leber's hereditary optic neuropathy. Hum Mol Genet 2022; 32:231-243. [PMID: 35947995 PMCID: PMC9840204 DOI: 10.1093/hmg/ddac190] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 07/11/2022] [Accepted: 08/07/2022] [Indexed: 01/19/2023] Open
Abstract
Leber's hereditary optic neuropathy (LHON) is a maternally inherited eye disease that results from degeneration of retinal ganglion cells (RGC). Mitochondrial ND4 11778G > A mutation, which affects structural components of complex I, is the most prevalent LHON-associated mitochondrial DNA (mtDNA) mutation worldwide. The m.11778G > A mutation is the primary contributor underlying the development of LHON and X-linked PRICKLE3 allele (c.157C > T, p.Arg53Trp) linked to biogenesis of ATPase interacts with m.11778G > A mutation to cause LHON. However, the lack of appropriate cell and animal models of LHON has been significant obstacles for deep elucidation of disease pathophysiology, specifically the tissue-specific effects. Using RGC-like cells differentiated from induced pluripotent stem cells (iPSCs) from members of one Chinese family (asymptomatic subjects carrying only m.11778G > A mutation or PRICKLE3 p.Arg53Trp mutation, symptomatic individuals bearing both m.11778G > A and PRICKLE3 p.Arg53Trp mutations and control lacking these mutations), we demonstrated the deleterious effects of mitochondrial dysfunctions on the morphology and functions of RGCs. Notably, iPSCs bearing only m.11778G > A or p.Arg53Trp mutation exhibited mild defects in differentiation to RGC-like cells. The RGC-like cells carrying only m.11778G > A or p.Arg53Trp mutation displayed mild defects in RGC morphology, including the area of soma and numbers of neurites, electrophysiological properties, ATP contents and apoptosis. Strikingly, those RGC-like cells derived from symptomatic individuals harboring both m.11778G > A and p.Arg53Trp mutations displayed greater defects in the development, morphology and functions than those in cells bearing single mutation. These findings provide new insights into pathophysiology of LHON arising from RGC deficiencies caused by synergy between m.11778G > A and PRICKLE3 p.Arg53Trp mutation.
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Affiliation(s)
| | | | | | - Yanchun Ji
- Division of Medical Genetics and Genomics, The Children’s Hospital, Zhejiang University School of Medicine and National Clinical Research Center for Child Health, Hangzhou, Zhejiang, China,Institute of Genetics and Department of Human Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Hongxing Zhang
- Department of Ophthalmology, The First Affiliated Hospital, Shandong First Medical University, Jinan, Shandong, China
| | - Fuxin Zhao
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Xiangtian Zhou
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Min-Xin Guan
- To whom correspondence should be addressed at: Institute of Genetics, Zhejiang University School of Medicine, 866 Yuhangtang Road, Hangzhou, Zhejiang 310058, China. Tel: 86-571-88206916; Fax: 86-571-88982377;
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15
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Ji Y, Zhang J, Liang M, Meng F, Zhang M, Mo JQ, Wang M, Guan MX. Mitochondrial tRNA variants in 811 Chinese probands with Leber's hereditary optic neuropathy. Mitochondrion 2022; 65:56-66. [PMID: 35623556 DOI: 10.1016/j.mito.2022.05.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 04/26/2022] [Accepted: 05/22/2022] [Indexed: 11/27/2022]
Abstract
Leber's hereditary optic neuropathy (LHON) is the maternal inheritance of eye disorder. LHON-linked mitochondrial DNA (mtDNA) mutations affect the ND1, ND4 or ND6 genes encoding essential subunits of complex I. However, the role of mitochondrial tRNA defects in the pathogenesis of LHON is poorly understood. In this report, Sanger sequence analysis of 22 mitochondrial tRNA genes identified 139 variants in a cohort of 811 Han Chinese probands and 485 control Chinese subjects. Among these, 32 (4 known and 28 novel/putative) tRNA variants in 69 probands may contribute to pathogenesis of LHON, as these exhibited (1) present in <1% of controls; (2) evolutionary conservation; (3) potential and significance of structural and functional modifications. Such variants may have potentially compromised structural and functional aspects in the processing of tRNAs, structure stability, tRNA charging, or codon-anticodon interactions during translation. These 32 variants presented either singly or with multiple mutations, with the primary LHON-linked ND1 3640G>A, ND4 11778G>A or ND6 14484T>C mutations in the probands. The thirty-eight pedigrees carrying only one of tRNA variants exhibited relatively low penetrances of LHON, ranging from 5.7% to 42.9%, with an average of 19%. Strikingly, the average penetrances of optic neuropathy among 33 Chinese families carrying both a known/putative tRNA variant and a primary LHON-associated mtDNA mutation were 40.1%. These findings suggested that mitochondrial tRNA variants represent a significant causative factor for LHON, accounting for 8.75% cases in this cohort. These new insights may lead to beneficial applications in the pathophysiology, disease management, and genetic counseling of LHON.
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Affiliation(s)
- Yanchun Ji
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine and National Clinical Research Center for Child Health, Hangzhou, Zhejiang 310058, China; Institute of Genetics, Zhejiang University, School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Juanjuan Zhang
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
| | - Min Liang
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
| | - Feilong Meng
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine and National Clinical Research Center for Child Health, Hangzhou, Zhejiang 310058, China; Institute of Genetics, Zhejiang University, School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Minglian Zhang
- Department of Ophthalmology, Hebei Provincial Eye Hospital, Xingtai, Hebei 051730, China
| | - Jun Q Mo
- Department of Pathology, Rady Children's Hospital, University of California at San Diego School of Medicine, San Diego, California 92123, USA
| | - Meng Wang
- Institute of Genetics, Zhejiang University, School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Min-Xin Guan
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine and National Clinical Research Center for Child Health, Hangzhou, Zhejiang 310058, China; Institute of Genetics, Zhejiang University, School of Medicine, Hangzhou, Zhejiang 310058, China; Zhejiang Provincial Key Laboratory of Genetic & Developmental Disorders, Zhejiang University, Hangzhou, Zhejiang 310058, China; Division of Mitochondrial Biomedicine, Joint Institute of Genetics and Genome Medicine between Zhejiang University and University of Toronto, Hangzhou, Zhejiang, China.
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16
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Liang M, Ji C, Zhang L, Wang X, Hu C, Zhang J, Zhu Y, Mo JQ, Guan MX. Leber's hereditary optic neuropathy (LHON)-associated ND6 14 484 T > C mutation caused pleiotropic effects on the complex I, RNA homeostasis, apoptosis and mitophagy. Hum Mol Genet 2022; 31:3299-3312. [PMID: 35567411 DOI: 10.1093/hmg/ddac109] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 04/25/2022] [Accepted: 05/09/2022] [Indexed: 11/12/2022] Open
Abstract
Leber's hereditary optic neuropathy (LHON) is a maternally inherited eye disease due to mitochondrial DNA (mtDNA) mutations. LHON-linked ND6 14 484 T > C (p.M64V) mutation affected structural components of complex I but its pathophysiology is poorly understood. The structural analysis of complex I revealed that the M64 forms a nonpolar interaction Y59 in the ND6, Y59 in the ND6 interacts with E34 of ND4L, and L60 of ND6 interacts with the Y114 of ND1. These suggested that the m.14484 T > C mutation may perturb the structure and function of complex I. Mutant cybrids constructed by transferring mitochondria from lymphoblastoid cell lines of one Chinese LHON family into mtDNA-less (ρo) cells revealed decreases in the levels of ND6, ND1 and ND4L. The m.14484 T > C mutation may affect mitochondrial mRNA homeostasis, supported by reduced levels of SLIRP and SUPV3L1 involved in mRNA degradation and increasing expression of ND6, ND1 and ND4L genes. These alterations yielded decreased activity of complex I, respiratory deficiency, diminished mitochondrial ATP production and reduced membrane potential, and increased production of reactive oxygen species in the mutant cybrids. Furthermore, the m.14484 T > C mutation promoted apoptosis, evidenced by elevating Annexin V-positive cells, release of cytochrome c into cytosol, levels in apoptotic proteins BAX, caspases 3, 7, 9 and decreasing levels in anti-apoptotic protein Bcl-xL in the mutant cybrids. Moreover, the cybrids bearing the m.14484 T > C mutation exhibited the reduced levels of autophagy protein LC3, increased levels of substrate P62 and impaired PINK1/Parkin-dependent mitophagy. Our findings highlighted the critical role of m.14484 T > C mutation in the pathogenesis of LHON.
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Affiliation(s)
- Min Liang
- Department of Medical Laboratory, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325000, China.,Attardi Institute of Mitochondrial Biomedicine, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China.,Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Chun Ji
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, and National Clinic Research Center for Child Health, Hangzhou, Zhejiang 310058, China
| | - Liyao Zhang
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Xuan Wang
- Attardi Institute of Mitochondrial Biomedicine, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Cuifang Hu
- Attardi Institute of Mitochondrial Biomedicine, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Juanjuan Zhang
- Attardi Institute of Mitochondrial Biomedicine, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China.,School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
| | - Yiwei Zhu
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Jun Q Mo
- Department of Pathology, Rady Children's Hospital, University of California at San Diego School of Medicine, San Diego, California 92123, USA
| | - Min-Xin Guan
- Attardi Institute of Mitochondrial Biomedicine, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China.,Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, and National Clinic Research Center for Child Health, Hangzhou, Zhejiang 310058, China.,Zhejiang Provincial Key Laboratory of Genetic & Developmental Disorders, Hangzhou, Zhejiang 310058, China
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17
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Myrgorodska O. COINCIDENCE OF IDIOPATHIC INTRACRANIAL HYPERTENSION AND LEBER HEREDITARY OPTIC NEUROPATHY. A CASE REPORT. CESKA A SLOVENSKA OFTALMOLOGIE : CASOPIS CESKE OFTALMOLOGICKE SPOLECNOSTI A SLOVENSKE OFTALMOLOGICKE SPOLECNOSTI 2022; 78:197-204. [PMID: 35922147 DOI: 10.31348/2022/18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
GOAL This paper describes a case of a long-term monitoring of a patient with optic nerve swelling on the ocular background (papilledema), accompanied by symptoms of intracranial hypertension, on whom a genetic examination was performed as part of differential diagnosis, confirming Leber Hereditary Optic Neuropathy with the m.3460G>A mutation. Casuistry: During the examination of a 5-year-old patient after an alleged head injury at a bouncy castle, an optic nerve papilla with unclear boundaries was described on the ocular background of both eyes. Neurological examination, including brain Magnetic Resonance Imaging, was indicated to rule out possible intracranial hypertension. Both examinations yielded a finding within the norm. After eight years of regular follow-up, the patient attended to our clinic with acute problems in terms of sudden visual impairment during baseball training. The performed eye examination revealed a deterioration of the vision of the right eye on counting fingers to 50 cm, vision of the left eye to 0.4 naturally, a slowed photoreaction of the right pupil, prominent optic nerve papilla with unclear boundaries on both eyes, dilated and more coiled vessels with a crossing phenomenon, the retinal periphery shows no focal changes. Due to the swelling of the papilla, acute deterioration of the vision and the suspected intracranial hypertension, the patient was immediately referred for neurological examination and subsequent hospitalization. There, the patient underwent computer tomography of the brain, venography of the dural venous sinuses and an initial laboratory examination that showed no pathology. There was increasing headache, nausea and vomiting throughout the period. A lumbar puncture was performed. The cerebrospinal fluid pressure before sampling was 285 mmH2O and 100 mmH2O after sampling. The biochemistry of the fluid was normal with negative microbiology. Evoked visual potentials had bilaterally prolonged latencies, which corresponds to optic nerve compression. An ophthalmological examination ruled out a drusen papilla. Using Optical Coherence Tomography, a 600 μm edema was detected. The patient underwent two relieving lumbar punctures, which led to a subjective improvement without objective improvement. Finally, the neurosurgeon referred the patient for ventriculoperitoneal drainage. Due to the impaired vision and lack of response to the therapy induced, a genetic test was performed, which confirmed Leber Hereditary Optic Neuropathy with the mutation of m.3460G>A. CONCLUSION Despite the substantially improved identification of the Leber Hereditary Optic Neuropathy, the diagnosis may still be significantly delayed. The variability of initial findings, the rare incidence of the disease and few well-defined symptoms of the disease lead to significant diagnostic difficulties and late commencement of treatment. It is not possible to say whether there was a coincidence of IIH and LHON or whether the signs of IIH are a possible concomitant of the acute phase of LHON.
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