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He Y, Tang Z, Zhu G, Cai L, Chen C, Guan MX. Deafness-associated mitochondrial 12S rRNA mutation reshapes mitochondrial and cellular homeostasis. J Biol Chem 2025; 301:108124. [PMID: 39716492 PMCID: PMC11791119 DOI: 10.1016/j.jbc.2024.108124] [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: 11/18/2024] [Revised: 12/09/2024] [Accepted: 12/17/2024] [Indexed: 12/25/2024] Open
Abstract
Human mitochondrial 12S ribosomal RNA (rRNA) 1555A>G mutation has been associated with aminoglycoside-induced and nonsyndromic deafness in many families worldwide. Our previous investigation revealed that the m.1555A>G mutation impaired mitochondrial translation and oxidative phosphorylation (OXPHOS). However, the mechanisms by which mitochondrial dysfunctions induced by m.1555A>G mutation regulate intracellular signaling for mitochondrial and cellular integrity remain poorly understood. Here, we demonstrated that the m.1555A>G mutation downregulated the expression of nucleus-encoded subunits of complexes I and IV but upregulated the expression of assemble factors for OXPHOS complexes, using cybrids derived from one hearing-impaired Chinese subject bearing the m.1555A>G mutation and from one hearing normal control lacking the mutation. These alterations resulted in the aberrant assembly, instability, and reduced activities of respiratory chain enzyme complexes I, IV, and V, rate of oxygen consumption, and diminished ATP production. Furthermore, the mutant cell lines carrying the m.1555A>G mutation exhibited decreased membrane potential and increased the production of reactive oxygen species. The aberrant assembly and biogenesis of OXPHOS impacted mitochondrial quality controls, including the imbalance of mitochondrial dynamics via increasing fission with abnormal mitochondrial morphology and impaired mitophagy. Strikingly, the cells bearing the m.1555A>G mutation revealed the upregulation of both ubiquitin-dependent and independent mitophagy pathways, evidenced by increasing levels of Parkin, Pink, BNIP3 and NIX, respectively. The m.1555A>G mutation-induced deficiencies ameliorate the cell homeostasis via elevating the autophagy process and upregulating apoptotic pathways. Our findings provide new insights into pathophysiology of mitochondrial deafness arising from reshaping mitochondrial and cellular homeostasis due to 12S rRNA 1555A>G mutation.
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Affiliation(s)
- Yunfan He
- Center for Mitochondrial Biomedicine and Department of Otolaryngology-Head and Neck Surgery, 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
| | - Zhining Tang
- Clinical Laboratory, Huzhou Central Hospital, Affiliated Central Hospital of Huzhou University, Huzhou, Zhejiang, China
| | - Gao Zhu
- Institute of Genetics, Zhejiang University International School of Medicine, Hangzhou, Zhejiang, China
| | - Luhang Cai
- Center for Mitochondrial Biomedicine and Department of Otolaryngology-Head and Neck Surgery, The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, Zhejiang, China; Institute of Genetics, Zhejiang University International School of Medicine, Hangzhou, Zhejiang, China
| | - Chao Chen
- Center for Mitochondrial Biomedicine and Department of Otolaryngology-Head and Neck Surgery, The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, Zhejiang, China; Institute of Genetics, Zhejiang University International School of Medicine, Hangzhou, Zhejiang, China
| | - Min-Xin Guan
- Center for Mitochondrial Biomedicine and Department of Otolaryngology-Head and Neck Surgery, 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; Joint Institute of Genetics and Genomic Medicine Between Zhejiang University and University of Toronto, Hangzhou, Zhejiang, China.
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2
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Yin X, Dong Q, Fan S, Yang L, Li H, Jin Y, Laurentinah MR, Chen X, Sysa A, Fang H, Lyu J, Yu Y, Wang Y. A novel pathogenic mitochondrial DNA variant m.4344T>C in tRNA Gln causes developmental delay. J Hum Genet 2024; 69:381-389. [PMID: 38730005 DOI: 10.1038/s10038-024-01254-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 03/26/2024] [Accepted: 04/17/2024] [Indexed: 05/12/2024]
Abstract
Mitochondrial diseases are a group of genetic diseases caused by mutations in mitochondrial DNA and nuclear DNA. However, the genetic spectrum of this disease is not yet complete. In this study, we identified a novel variant m.4344T>C in mitochondrial tRNAGln from a patient with developmental delay. The mutant loads of m.4344T>C were 95% and 89% in the patient's blood and oral epithelial cells, respectively. Multialignment analysis showed high evolutionary conservation of this nucleotide. TrRosettaRNA predicted that m.4344T>C variant would introduce an additional hydrogen bond and alter the conformation of the T-loop. The transmitochondrial cybrid-based study demonstrated that m.4344T>C variant impaired the steady-state level of mitochondrial tRNAGln and decreased the contents of mitochondrial OXPHOS complexes I, III, and IV, resulting in defective mitochondrial respiration, elevated mitochondrial ROS production, reduced mitochondrial membrane potential and decreased mitochondrial ATP levels. Altogether, this is the first report in patient carrying the m.4344T>C variant. Our data uncover the pathogenesis of the m.4344T>C variant and expand the genetic mutation spectrum of mitochondrial diseases, thus contributing to the clinical diagnosis of mitochondrial tRNAGln gene variants-associated mitochondrial diseases.
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Affiliation(s)
- Xiaojie Yin
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, School of Laboratory Medicine and Life sciences, Wenzhou Medical University, Wenzhou, 325035, Zhejiang, China
| | - Qiyu Dong
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, School of Laboratory Medicine and Life sciences, Wenzhou Medical University, Wenzhou, 325035, Zhejiang, China
| | - Shuanglong Fan
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, School of Laboratory Medicine and Life sciences, Wenzhou Medical University, Wenzhou, 325035, Zhejiang, China
| | - Lina Yang
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, School of Laboratory Medicine and Life sciences, Wenzhou Medical University, Wenzhou, 325035, Zhejiang, China
| | - Hao Li
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, School of Laboratory Medicine and Life sciences, Wenzhou Medical University, Wenzhou, 325035, Zhejiang, China
| | - Yijun Jin
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, School of Laboratory Medicine and Life sciences, Wenzhou Medical University, Wenzhou, 325035, Zhejiang, China
| | - Mahlatsi Refiloe Laurentinah
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, School of Laboratory Medicine and Life sciences, Wenzhou Medical University, Wenzhou, 325035, Zhejiang, China
| | - Xiandan Chen
- International Sakharov Environmental Institute of Belarusian State University, Minsk, 220070, Republic of Belarus
| | - Aliaksei Sysa
- International Sakharov Environmental Institute of Belarusian State University, Minsk, 220070, Republic of Belarus
| | - Hezhi Fang
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, School of Laboratory Medicine and Life sciences, Wenzhou Medical University, Wenzhou, 325035, Zhejiang, China
| | - Jianxin Lyu
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, School of Laboratory Medicine and Life sciences, Wenzhou Medical University, Wenzhou, 325035, Zhejiang, China.
- Laboratory Medicine Center, Department of Clinical Laboratory, Zhejiang Provincial People's Hospital, Affiliated People's Hospital, Hangzhou Medical College, Hangzhou, 310053, Zhejiang, China.
| | - Yongguo Yu
- Department of Pediatric Endocrinology and Genetics, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Institute for Pediatric Research, Shanghai, 200092, China.
- Shanghai Key Laboratory of Pediatric Gastroenterology and Nutrition, Shanghai, 200092, China.
| | - Ya Wang
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, School of Laboratory Medicine and Life sciences, Wenzhou Medical University, Wenzhou, 325035, Zhejiang, China.
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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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Yu X, Li S, Guo Q, Leng J, Ding Y. The Association Between Mitochondrial tRNA Glu Variants and Hearing Loss: A Case-Control Study. Pharmgenomics Pers Med 2024; 17:77-89. [PMID: 38562431 PMCID: PMC10984097 DOI: 10.2147/pgpm.s441281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 03/16/2024] [Indexed: 04/04/2024] Open
Abstract
Purpose This study aimed to examine the frequencies of mt-tRNAGlu variants in 180 pediatric patients with non-syndromic hearing loss (NSHL) and 100 controls. Methods Sanger sequencing was performed to screen for mt-tRNAGlu variants. These mitochondrial DNA (mtDNA) pathogenic mutations were further assessed using phylogenetic conservation and haplogroup analyses. We also traced the origins of the family history of probands carrying potential pathogenic mtDNA mutations. Mitochondrial functions including mtDNA content, ATP and reactive oxygen species (ROS) were examined in cells derived from patients carrying the mt-tRNAGlu A14692G and CO1/tRNASer(UCN) G7444A variants and controls. Results We identified four possible pathogenic variants: m.T14709C, m.A14683G, m.A14692G and m.A14693G, which were found in NSHL patients but not in controls. Genetic counseling suggested that one child with the m.A14692G variant had a family history of NSHL. Sequence analysis of mtDNA suggested the presence of the CO1/tRNASer(UCN) G7444A and mt-tRNAGlu A14692G variants. Molecular analysis suggested that, compared with the controls, patients with these variants exhibited much lower mtDNA copy numbers, ATP production, whereas ROS levels increased (p<0.05 for all), suggesting that the m.A14692G and m.G7444A variants led to mitochondrial dysfunction. Conclusion mt-tRNAGlu variants are important risk factors for NSHL.
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Affiliation(s)
- Xuejiao Yu
- Department of Clinical Laboratory, Quzhou People’s Hospital, the Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou, Zhejiang Province, 324000, People’s Republic of China
| | - Sheng Li
- Department of Otolaryngology, Quzhou People’s Hospital, the Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou, Zhejiang Province, 324000, People’s Republic of China
| | - Qinxian Guo
- Central Laboratory, Hangzhou First People’s Hospital, Hangzhou, Zhejiang Province, 310006, People’s Republic of China
| | - Jianhang Leng
- Central Laboratory, Hangzhou First People’s Hospital, Hangzhou, Zhejiang Province, 310006, People’s Republic of China
| | - Yu Ding
- Central Laboratory, Hangzhou First People’s Hospital, Hangzhou, Zhejiang Province, 310006, People’s Republic of China
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Jiang QQ, Zhu JJ, Fan SL, Hou YP, Hu XY, Shi J, Wu L, Luo Y. Establishment and application of a reverse dot blot assay for 13 mutations of hearing-loss genes in primary hospitals in China. ASIAN BIOMED 2024; 18:11-17. [PMID: 38515630 PMCID: PMC10953844 DOI: 10.2478/abm-2024-0003] [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] [Indexed: 03/23/2024]
Abstract
Background Hearing loss is a common sensorineural dysfunction with a high incidence in China. Although genetic factors are important causes of hearing loss, hearing-related gene detection has not been widely adopted in China. Objective Establishing a rapid and efficient method to simultaneously detect hotspot hearing loss gene mutations. Methods A reverse dot blot assay combined with a flow-through hybridization technique was developed for the simultaneous detection of 13 hotspot mutations of 4 hearing loss-related genes including GJB2, GJB3, SLC26A4, and the mitochondrial gene MT-RNR1. This method involved PCR amplification systems and a hybridization platform. Results The technique can detect 13 hotspot mutations of 4 hearing loss-related genes. And a total of 213 blood samples were used to evaluate the availability of this method. Discussion Our reverse dot blot assay was a simple, rapid, accurate, and cost-effective method to identify hotspot mutations of 4 hearing loss-related genes in a Chinese population.
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Affiliation(s)
- Qing-Qing Jiang
- Department of Clinical Laboratory, Changning Maternity and Infant Health Hospital, East China Normal University, Shanghai200050, China
| | - Juan-Juan Zhu
- Chaozhou Hybribio Limited Corporation, Guangdong, China
| | - Shu-Ling Fan
- Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai200072, China
| | - Ya-Ping Hou
- Department of Clinical Laboratory, Changning Maternity and Infant Health Hospital, East China Normal University, Shanghai200050, China
| | - Xie-Ying Hu
- Department of Clinical Laboratory, Changning Maternity and Infant Health Hospital, East China Normal University, Shanghai200050, China
| | - Jie Shi
- Nanjing Red Cross Blood Center, Nanjing, Jiangsu210037, China
| | - Lei Wu
- Department of Clinical Laboratory, Changning Maternity and Infant Health Hospital, East China Normal University, Shanghai200050, China
| | - Ying Luo
- Department of Clinical Laboratory, Changning Maternity and Infant Health Hospital, East China Normal University, Shanghai200050, China
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6
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Wu YT, Huang SC, Shiao YM, Syu WC, Wei YH, Hsu YC. Identification of new variants in MTRNR1 and MTRNR2 genes using whole mitochondrial genome sequencing in a Taiwanese family with MERRF (myoclonic epilepsy with ragged-red fibers) syndrome. Hear Res 2023; 438:108876. [PMID: 37683310 DOI: 10.1016/j.heares.2023.108876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 07/30/2023] [Accepted: 08/18/2023] [Indexed: 09/10/2023]
Abstract
Mitochondrial encephalomyopathy is a multi-system disorder mostly caused by inborn errors of the oxidative phosphorylation (OXPHOS) system and usually manifested as complex neurological disorder and muscle weakness. Myoclonic epilepsy with ragged-red fibers (MERRF) syndrome is one of the major subtypes of mitochondrial disease associated with the m.8344A>G mutation in mitochondrial tRNALys gene. In addition to the symptoms in central nervous and muscle systems, a portion of the patients may develop hearing loss, which has been linked to the genetic mutations of mitochondrial DNA (mtDNA) especially in the mitochondrial ribosome RNA (rRNA) gene. Despite a great number of studies focusing on the consequences of mtDNA mutations, the mechanism of pathogenesis of these overt diseases has remained unclear, and there is no specific and effective treatment for MERRF syndromes. In this study, we developed a high-quality mtDNA sequencing method by next generation sequencing technology to search for the additional pathogenic variations of mtDNA from skin fibroblasts of four members in a Taiwanese family with MERRF syndrome. Through uncovering the signatures of all mtDNA variants in the MERRF family, we identified novel mtDNA variants in the genes encoding mitochondrial 12S and 16S rRNAs. The finding from this study will give us further insight into the molecular mechanisms driving the phenotypic variability and timing of onset of the MERRF syndrome.
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Affiliation(s)
- Yu-Ting Wu
- Center for Mitochondrial Medicine and Free Radical Research, Changhua Christian Hospital, Changhua City 50046, Taiwan
| | | | | | - Wei-Chi Syu
- Union Clinical Laboratory, Taipei 10665, Taiwan
| | - Yau-Huei Wei
- Center for Mitochondrial Medicine and Free Radical Research, Changhua Christian Hospital, Changhua City 50046, Taiwan
| | - Yi-Chao Hsu
- Department of Audiology and Speech-Language Pathology, Mackay Medical College, New Taipei City 25245, Taiwan; Institute of Biomedical Sciences, Mackay Medical College, New Taipei City 25245, Taiwan
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Chou CW, Hsu YC. Current development of patient-specific induced pluripotent stem cells harbouring mitochondrial gene mutations and their applications in the treatment of sensorineural hearing loss. Hear Res 2023; 429:108689. [PMID: 36649664 DOI: 10.1016/j.heares.2023.108689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 12/30/2022] [Accepted: 01/03/2023] [Indexed: 01/06/2023]
Abstract
Of all the human body's sensory systems, the auditory system is perhaps its most intricate. Hearing loss can result from even modest damage or cell death in the inner ear, and is the most common form of sensory loss. Human hearing is made possible by the sensory epithelium, the lateral wall, and auditory nerves. The most prominent functional cells in the sensory epithelium are outer hair cells (OHCs), inner hair cells (IHCs), and supporting cells. Different sound frequencies are processed by OHCs and IHCs in different cochlear regions, with those in the apex responsible for low frequencies and those in the basal region responsible for high frequencies. Hair cells can be damaged or destroyed by loud noise, aging process, genetic mutations, ototoxicity, infection, and illness. As such, they are a primary target for treating sensorineural hearing loss. Other areas known to affect hearing include spiral ganglion neurons (SGNs) in the auditory nerve. Age-related degradation of HCs and SGNs can also cause hearing loss. The aim of this review is to introduce the roles of mitochondria in human auditory system and the inner ear's main cell types and cellular functions, before going on to detail the likely health benefits of iPSC technology. We posit that patient-specific iPSCs with mitochondrial gene mutations will be an important aspect of regenerative medicine and will lead to significant progress in the treatment of SNHL.
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Affiliation(s)
- Chao-Wen Chou
- Department of Audiology and Speech-Language Pathology, Mackay Medical College, New Taipei City, Taiwan
| | - Yi-Chao Hsu
- Department of Audiology and Speech-Language Pathology, Mackay Medical College, New Taipei City, Taiwan; Institute of Biomedical Sciences, Mackay Medical College, New Taipei City, Taiwan
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8
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The Mitochondrial tRNA Ser(UCN) Gene: A Novel m.7484A>G Mutation Associated with Mitochondrial Encephalomyopathy and Literature Review. Life (Basel) 2023; 13:life13020554. [PMID: 36836911 PMCID: PMC9963529 DOI: 10.3390/life13020554] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 01/26/2023] [Accepted: 02/14/2023] [Indexed: 02/18/2023] Open
Abstract
Mitochondrial tRNASer(UCN) is considered a hot-spot for non-syndromic and aminoglycoside-induced hearing loss. However, many patients have been described with more extensive neurological diseases, mainly including epilepsy, myoclonus, ataxia, and myopathy. We describe a novel homoplasmic m.7484A>G mutation in the tRNASer(UCN) gene affecting the third base of the anticodon triplet in a girl with profound intellectual disability, spastic tetraplegia, sensorineural hearing loss, a clinical history of epilepsia partialis continua and vomiting, typical of MELAS syndrome, leading to a myoclonic epilepticus status, and myopathy with severe COX deficiency at muscle biopsy. The mutation was also found in the homoplasmic condition in the mother who presented with mild cognitive deficit, cerebellar ataxia, myoclonic epilepsy, sensorineural hearing loss and myopathy with COX deficient ragged-red fibers consistent with MERRF syndrome. This is the first anticodon mutation in the tRNASer(UCN) and the second homoplasmic mutation in the anticodon triplet reported to date.
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Miyamoto A, Tomotaka U, Takaaki K, Kenichi M, Chimi M. Molecular characterization of two pedigrees with maternally inherited diabetes mellitus. Mitochondrial DNA B Resour 2022. [DOI: 10.1080/23802359.2022.2050474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022] Open
Affiliation(s)
- Akira Miyamoto
- Faculty of Rehabilitation, Kobe International University, Hyogo, Japan
| | - Ueda Tomotaka
- Faculty of Rehabilitation, Nishikyushu University, Saga, Japan
| | - Kubo Takaaki
- Faculty of health science, Kumamoto Health Science University, Kumamoto, Japan
| | - Mori Kenichi
- Omote Orthopedic Osteoporosis Clinic, Toyonaka, Japan
| | - Miyamoto Chimi
- Department of Occupational Therapy, Faculty of Health Science, Aino University, Osaka, Japan
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Meng F, Jia Z, Zheng J, Ji Y, Wang J, Xiao Y, Fu Y, Wang M, Ling F, Guan MX. A deafness-associated mitochondrial DNA mutation caused pleiotropic effects on DNA replication and tRNA metabolism. Nucleic Acids Res 2022; 50:9453-9469. [PMID: 36039763 PMCID: PMC9458427 DOI: 10.1093/nar/gkac720] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Accepted: 08/09/2022] [Indexed: 12/24/2022] Open
Abstract
In this report, we investigated the molecular mechanism underlying a deafness-associated m.5783C > T mutation that affects the canonical C50-G63 base-pairing of TΨC stem of tRNACys and immediately adjacent to 5' end of light-strand origin of mitochondrial DNA (mtDNA) replication (OriL). Two dimensional agarose gel electrophoresis revealed marked decreases in the replication intermediates including ascending arm of Y-fork arcs spanning OriL in the mutant cybrids bearing m.5783C > T mutation. mtDNA replication alterations were further evidenced by decreased levels of PolγA, Twinkle and SSBP1, newly synthesized mtDNA and mtDNA contents in the mutant cybrids. The m.5783C > T mutation altered tRNACys structure and function, including decreased melting temperature, conformational changes, instability and deficient aminoacylation of mutated tRNACys. The m.5783C > T mutation impaired the 5' end processing efficiency of tRNACys precursors and reduced the levels of tRNACys and downstream tRNATyr. The aberrant tRNA metabolism impaired mitochondrial translation, which was especially pronounced effects in the polypeptides harboring higher numbers of cysteine and tyrosine codons. These alterations led to deficient oxidative phosphorylation including instability and reduced activities of the respiratory chain enzyme complexes I, III, IV and intact supercomplexes overall. Our findings highlight the impact of mitochondrial dysfunction on deafness arising from defects in mitochondrial DNA replication and tRNA metabolism.
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Affiliation(s)
| | | | - Jing Zheng
- 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 School of Medicine, Hangzhou, Zhejiang, China,Zhejiang Provincial Key Lab of Genetic and Developmental Disorder, Hangzhou, Zhejiang, 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, China,Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China,Zhejiang Provincial Key Lab of Genetic and Developmental Disorder, Hangzhou, Zhejiang, China
| | - Jing Wang
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Yun Xiao
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Yong Fu
- Division of Otolaryngology-Head and Neck Surgery, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Meng Wang
- 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 School of Medicine, Hangzhou, Zhejiang, China,Zhejiang Provincial Key Lab of Genetic and Developmental Disorder, Hangzhou, Zhejiang, China
| | - Feng Ling
- Chemical Genomics Research Group, RIKEN Center for Sustainable Resource Science, Hirosawa 2-1, Wako, Saitama, Japan
| | - Min-Xin Guan
- To whom correspondence should be addressed. Tel: +86 571 88206916; Fax: +86 571 88982377;
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11
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Hou L, Hu C, Ji L, Wang Q, Liang M. The Mitochondrial tRNA Phe 625G>A Mutation in Three Han Chinese Families With Cholecystolithiasis. Front Genet 2022; 13:814729. [PMID: 35719381 PMCID: PMC9198646 DOI: 10.3389/fgene.2022.814729] [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: 11/18/2021] [Accepted: 04/19/2022] [Indexed: 11/16/2022] Open
Abstract
In this study, we assessed three Chinese families with inherited cholecystolithiasis and conducted the clinical, genetic, and molecular characterization of these subjects. Eight of eighteen matrilineal relatives had a clinical phenotype in these three families. Sequence analysis of complete mitochondrial genomes in these probands identified the homoplasmic tRNAPhe 625 G > A mutation and distinct sets of mtDNA polymorphisms belonging to haplogroups H2, F4b, and M10a. The 625G > A mutation disturbed the classic G-C base-pairings at a highly conserved position 49 in the T-stem of mitochondrial tRNAs. Molecular dynamics simulation showed that the structure of tRNAphe with 625 G > A mutation was noticeably remodeled while compared with the isoform of the wild type. The occurrence of tRNAPhe 625 G > A mutation in these various genetically unrelated subjects strongly indicates that this mutation is involved in the pathogenesis of cholecystolithiasis. This is the first evidence that tRNA mutations are associated with cholecystolithiasis, and it provided more insights into the genetic mechanism of cholecystolithiasis.
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Affiliation(s)
- Lingling Hou
- Department of Medical Laboratory, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Cuifang Hu
- Attardi Institute of Mitochondrial Biomedicine, Wenzhou Medical University, Wenzhou, China
| | - Lili Ji
- Department of Medical Laboratory, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Qiongdan Wang
- Department of Medical Laboratory, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Min Liang
- Department of Medical Laboratory, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China.,Attardi Institute of Mitochondrial Biomedicine, Wenzhou Medical University, Wenzhou, China
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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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Kuan SW, Chua KH, Tan EW, Tan LK, Loch A, Kee BP. Whole mitochondrial genome sequencing of Malaysian patients with cardiomyopathy. PeerJ 2022; 10:e13265. [PMID: 35441061 PMCID: PMC9013480 DOI: 10.7717/peerj.13265] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 03/23/2022] [Indexed: 01/13/2023] Open
Abstract
Cardiomyopathy (CMP) constitutes a diverse group of myocardium diseases affecting the pumping ability of the heart. Genetic predisposition is among the major factors affecting the development of CMP. Globally, there are over 100 genes in autosomal and mitochondrial DNA (mtDNA) that have been reported to be associated with the pathogenesis of CMP. However, most of the genetic studies have been conducted in Western countries, with limited data being available for the Asian population. Therefore, this study aims to investigate the mutation spectrum in the mitochondrial genome of 145 CMP patients in Malaysia. Long-range PCR was employed to amplify the entire mtDNA, and whole mitochondrial genome sequencing was conducted on the MiSeq platform. Raw data was quality checked, mapped, and aligned to the revised Cambridge Reference Sequence (rCRS). Variants were named, annotated, and filtered. The sequencing revealed 1,077 variants, including 18 novel and 17 CMP and/or mitochondrial disease-associated variants after filtering. In-silico predictions suggested that three of the novel variants (m.8573G>C, m.11916T>A and m.11918T>G) in this study are potentially pathogenic. Two confirmed pathogenic variants (m.1555A>G and m.11778G>A) were also found in the CMP patients. The findings of this study shed light on the distribution of mitochondrial mutations in Malaysian CMP patients. Further functional studies are required to elucidate the role of these variants in the development of CMP.
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Affiliation(s)
- Sheh Wen Kuan
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Kek Heng Chua
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - E-Wei Tan
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Lay Koon Tan
- National Heart Institute, Kuala Lumpur, Malaysia
| | - Alexander Loch
- Department of Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Boon Pin Kee
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
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van Kempen CMA, Beynon AJ, Smits JJ, Janssen MCH. A retrospective cohort study exploring the association between different mitochondrial diseases and hearing loss. Mol Genet Metab 2022; 135:333-341. [PMID: 35190254 DOI: 10.1016/j.ymgme.2022.02.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 01/08/2022] [Accepted: 02/11/2022] [Indexed: 10/19/2022]
Abstract
Some pathogenic variants in mtDNA and nuclear DNA, affecting mitochondrial function, are associated with hearing loss. Behavioral and electrophysiological auditory performance are obtained from 62 patients, clinically diagnosed with different mitochondrial diseases (MD) using tone/speech audiometry and Auditory Brainstem Responses (ABR). Audiological variables (hearing loss type, pure tone average (PTA), interaural asymmetry, speech perception and brainstem neural conductivity) were analyzed and related to Newcastle Mitochondrial Disease Scale for Adults (NMDAS). In 35% of MDs, a mild to severe symmetrical sensorineural hearing loss (SNHL) was found. Patients with Maternally Inherited Diabetes and Deafness (MIDD) show significantly higher PTAs compared to other MDs. For all MDs, speech recognition scores were in accordance with their individual age- and gender-corrected tone audiometry, but ABR peak latencies were prolonged in patients with MIDD, Mitochondrial Encephalopathy Lactate acidosis and Stroke-like episodes (MELAS), Chronic Progressive External Ophthalmoplegia (CPEO) and Subacute necrotizing encephalopathy (Leigh). Correlations between NMDAS and audiological variables were low.
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Affiliation(s)
- Carlijn M A van Kempen
- Dept. Oto-Rhino-Laryngology, Head and Neck Surgery, Radboudumc Nijmegen, the Netherlands
| | - Andy J Beynon
- Dept. Oto-Rhino-Laryngology, Head and Neck Surgery, Radboudumc Nijmegen, the Netherlands.
| | - Jeroen J Smits
- Dept. Oto-Rhino-Laryngology, Head and Neck Surgery, Radboudumc Nijmegen, the Netherlands
| | - Mirian C H Janssen
- Dept. Internal Medicine, Radboud Center for Mitochondrial Medicine, Radboudumc Nijmegen, the Netherlands
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Yang H, Zhang VW, Ai L, Gan S, Wu L. Multisystem Mitochondrial Disease Associated With a Mare m.10000G>A Mitochondrial tRNAGly (MT-TG) Variant. Front Neurol 2022; 13:795060. [PMID: 35432167 PMCID: PMC9005803 DOI: 10.3389/fneur.2022.795060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 02/15/2022] [Indexed: 12/01/2022] Open
Abstract
Background Mitochondrial diseases are clinically heterogeneous, can occur at any age, and can manifest with a wide range of clinical symptoms. They can involve any organ or tissue, characteristically involve multiple systems, typically affecting organs that are highly dependent on aerobic metabolism, and making a definitive molecular diagnosis of a mitochondrial disorder is challenging. Methods Clinical data of the proband and his family members were gathered in a retrospective study. Whole-exome sequencing and full-length sequencing of the mitochondrial genome that were performed on peripheral blood, urine, and oral mucosa cells were applied for genetic analysis. Results In this study, we reported a childhood-onset mitochondrial phenotype in a 13-year-old patient. Analysis of the next-generation sequencing data of the nuclear genome and the full-length sequencing of the mitochondrial genome revealed the rare m.10000G>A variant in MT-TG that was present at variable heteroplasmy levels across tissue types: 32.7% in the blood, 56.15% in urinary epithelial cells, and 27.3% in oral mucosa cells. No variant was found in the peripheral blood of his mother and sister. No pathogenic mutation of nDNA was found. Conclusion Our results added evidence that the de novo m.10000G>A variation in the highly conserved sequence of MT-TG appears to suggest a childhood-onset mitochondrial phenotype in the 13-year-old patient, thus broadening the genotypic interpretation of mitochondrial DNA-related diseases.
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Affiliation(s)
- Haiyan Yang
- Neurology Department, Hunan Children's Hospital, The School of Pediatrics, Hengyang Medical School, University of South China, Changsha, China
| | - Victor Wei Zhang
- Department of Human and Molecular Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Liang Ai
- Neurology Department, Hunan Children's Hospital, The School of Pediatrics, Hengyang Medical School, University of South China, Changsha, China
| | - Siyi Gan
- Neurology Department, Hunan Children's Hospital, The School of Pediatrics, Hengyang Medical School, University of South China, Changsha, China
| | - Liwen Wu
- Neurology Department, Hunan Children's Hospital, The School of Pediatrics, Hengyang Medical School, University of South China, Changsha, China
- *Correspondence: Liwen Wu
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Yu X, Li S, Ding Y. Maternally transmitted nonsyndromic hearing impairment may be associated with mitochondrial tRNA Ala 5601C>T and tRNA Leu(CUN) 12311T>C mutations. J Clin Lab Anal 2022; 36:e24298. [PMID: 35218233 PMCID: PMC8993639 DOI: 10.1002/jcla.24298] [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: 12/31/2021] [Revised: 01/31/2022] [Accepted: 02/08/2022] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Sequence alternations in mitochondrial genomes, especially in genes encoding mitochondrial tRNA (mt-tRNA), were the important contributors to nonsyndromic hearing loss (NSHL); however, the molecular mechanisms remained largely undetermined. METHODS A maternally transmitted Chinese pedigree with NSHL underwent clinical, genetic, and biochemical assessment. PCR and direct sequence analyses were performed to detect mitochondrial DNA (mtDNA), GJB2, and SLC26A4 gene mutations from matrilineal relatives of this family. Mitochondrial functions including mitochondrial membrane potential (MMP), ATP, and ROS were evaluated in polymononuclear leukocytes (PMNs) derived from three deaf patients and three controls from this pedigree. RESULTS Four of nine matrilineal relatives developed hearing loss at the variable age of onset. Two putative pathogenic mutations, m.5601C>T in tRNAAla and m.12311T>C in tRNALeu(CUN) , were identified via PCR-Sanger sequencing, as well as 34 variants that belonged to mtDNA haplogroup G2b2. Intriguingly, m.5601C>T mutation resided at very conserved nucleotide in the TψC loop of tRNAAla (position 59), while the T-to-C substitution at position 12311 located at position 48 in the variable stem of tRNALeu(CUN) and was believed to alter the aminoacylation and the steady-state level of tRNA. Biochemical analysis revealed the impairment of mitochondrial functions including the significant reductions of ATP and MMP, whereas markedly increased ROS levels were found in PMNs derived from NSHL patients with m.5601C>T and m.12311T>C mutations. However, we did not detect any mutations in GJB2 and SLC26A4 genes. CONCLUSION Our data indicated that mt-tRNAAla m.5601C>T and tRNALeu(CUN) 12311T>C mutations were associated with NSHL.
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Affiliation(s)
- Xuejiao Yu
- Department of Clinical LaboratoryQuzhou People's Hospitalthe Quzhou Affiliated Hospital of Wenzhou Medical UniversityQuzhouChina
| | - Sheng Li
- Department of OtolaryngologyQuzhou People's Hospitalthe Quzhou Affiliated Hospital of Wenzhou Medical UniversityQuzhouChina
| | - Yu Ding
- Central LaboratoryHangzhou First People’s HospitalZhejiang University School of MedicineHangzhouChina
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Li M, Gong S, Han X, Zhou L, Zhang S, Ren Q, Cai X, Luo Y, Liu W, Zhu Y, Zhou X, Li Y, Ji L. Contribution of mitochondrial gene variants in diabetes and diabetic kidney disease. Front Endocrinol (Lausanne) 2022; 13:953631. [PMID: 36313763 PMCID: PMC9597463 DOI: 10.3389/fendo.2022.953631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 08/04/2022] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVES Mitochondrial DNA (mtDNA) plays an important role in the pathogenesis of diabetes. Variants in mtDNA have been reported in diabetes, but studies on the whole mtDNA variants were limited. Our study aims to explore the association of whole mtDNA variants with diabetes and diabetic kidney disease (DKD). METHODS The whole mitochondrial genome was screened by next-generation sequencing in cohort 1 consisting of 50 early-onset diabetes (EOD) patients with a maternally inherited diabetes (MID) family history. A total of 42 variants possibly associated with mitochondrial diseases were identified according to the filtering strategy. These variants were sequenced in cohort 2 consisting of 90 EOD patients with MID. The association between the clinical phenotype and these variants was analyzed. Then, these variants were genotyped in cohort 3 consisting of 1,571 type 2 diabetes mellitus patients and 496 subjects with normal glucose tolerance (NGT) to analyze the association between variants with diabetes and DKD. RESULTS Patients with variants in the non-coding region had a higher percentage of obesity and levels of fasting insulin (62.1% vs. 24.6%, P = 0.001; 80.0% vs. 26.5% P < 0.001). The patients with the variants in rRNA had a higher prevalence of obesity (71.4% vs. 30.3%, P = 0.007), and the patients with the variants in mitochondrial complex I had a higher percentage of the upper tertile of FINS (64.3% vs. 34.3%, P = 0.049). Among 20 homogeneous variants successfully captured, two known variants (m.A3943G, m.A10005G) associated with other mitochondrial diseases were only in the diabetic group, but not in the NGT group, which perhaps indicated its possible association with diabetes. The prevalence of DKD was significantly higher in the group with the 20 variants than those without these variants (18.7% vs. 14.6%, P = 0.049) in the participants with diabetes of cohort 3. CONCLUSION MtDNA variants are associated with MID and DKD, and our findings advance our understanding of mtDNA in diabetes and DKD. It will have important implications for the individual therapy of mitochondrial diabetes.
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Affiliation(s)
- Meng Li
- Department of Endocrinology and Metabolism, Peking University People’s Hospital, Peking University Diabetes Center, Beijing, China
| | - Siqian Gong
- Department of Endocrinology and Metabolism, Peking University People’s Hospital, Peking University Diabetes Center, Beijing, China
| | - Xueyao Han
- Department of Endocrinology and Metabolism, Peking University People’s Hospital, Peking University Diabetes Center, Beijing, China
| | - Lingli Zhou
- Department of Endocrinology and Metabolism, Peking University People’s Hospital, Peking University Diabetes Center, Beijing, China
| | - Simin Zhang
- Department of Endocrinology and Metabolism, Peking University People’s Hospital, Peking University Diabetes Center, Beijing, China
| | - Qian Ren
- Department of Endocrinology and Metabolism, Peking University People’s Hospital, Peking University Diabetes Center, Beijing, China
| | - Xiaoling Cai
- Department of Endocrinology and Metabolism, Peking University People’s Hospital, Peking University Diabetes Center, Beijing, China
| | - Yingying Luo
- Department of Endocrinology and Metabolism, Peking University People’s Hospital, Peking University Diabetes Center, Beijing, China
| | - Wei Liu
- Department of Endocrinology and Metabolism, Peking University People’s Hospital, Peking University Diabetes Center, Beijing, China
| | - Yu Zhu
- Department of Endocrinology and Metabolism, Peking University People’s Hospital, Peking University Diabetes Center, Beijing, China
| | - Xianghai Zhou
- Department of Endocrinology and Metabolism, Peking University People’s Hospital, Peking University Diabetes Center, Beijing, China
| | - Yufeng Li
- Department of Endocrinology, Pinggu Teaching Hospital, Capital Medical University, Beijing, China
| | - Linong Ji
- Department of Endocrinology and Metabolism, Peking University People’s Hospital, Peking University Diabetes Center, Beijing, China
- *Correspondence: Linong Ji,
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Meng F, Zhou M, Xiao Y, Mao X, Zheng J, Lin J, Lin T, Ye Z, Cang X, Fu Y, Wang M, Guan MX. A deafness-associated tRNA mutation caused pleiotropic effects on the m1G37 modification, processing, stability and aminoacylation of tRNAIle and mitochondrial translation. Nucleic Acids Res 2021; 49:1075-1093. [PMID: 33398350 PMCID: PMC7826259 DOI: 10.1093/nar/gkaa1225] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 11/29/2020] [Accepted: 12/03/2020] [Indexed: 01/16/2023] Open
Abstract
Defects in the posttranscriptional modifications of mitochondrial tRNAs have been linked to human diseases, but their pathophysiology remains elusive. In this report, we investigated the molecular mechanism underlying a deafness-associated tRNAIle 4295A>G mutation affecting a highly conserved adenosine at position 37, 3′ adjacent to the tRNA’s anticodon. Primer extension and methylation activity assays revealed that the m.4295A>G mutation introduced a tRNA methyltransferase 5 (TRMT5)-catalyzed m1G37 modification of tRNAIle. Molecular dynamics simulations suggested that the m.4295A>G mutation affected tRNAIle structure and function, supported by increased melting temperature, conformational changes and instability of mutated tRNA. An in vitro processing experiment revealed that the m.4295A>G mutation reduced the 5′ end processing efficiency of tRNAIle precursors, catalyzed by RNase P. We demonstrated that cybrid cell lines carrying the m.4295A>G mutation exhibited significant alterations in aminoacylation and steady-state levels of tRNAIle. The aberrant tRNA metabolism resulted in the impairment of mitochondrial translation, respiratory deficiency, decreasing membrane potentials and ATP production, increasing production of reactive oxygen species and promoting autophagy. These demonstrated the pleiotropic effects of m.4295A>G mutation on tRNAIle and mitochondrial functions. Our findings highlighted the essential role of deficient posttranscriptional modifications in the structure and function of tRNA and their pathogenic consequence of deafness.
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Affiliation(s)
- 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
| | - Mi Zhou
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Yun Xiao
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Xiaoting Mao
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Jing Zheng
- 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
| | - Jiaxi Lin
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Tianxiang Lin
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Zhenzhen Ye
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Xiaohui Cang
- 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
| | - Yong Fu
- Division of Otolaryngology-Head and Neck Surgery, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Meng Wang
- 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
| | - 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 Lab of Genetic and Developmental Disorder, Hangzhou, Zhejiang 310058, China.,Joint Institute of Genetics and Genome Medicine between Zhejiang University and University of Toronto, Hangzhou, Zhejiang 310058, China
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19
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Xiao Y, Wang M, He Q, Xu L, Zhang Q, Meng F, Jia Z, Zhang F, Wang H, Guan MX. Asymmetrical effects of deafness-associated mitochondrial DNA 7516delA mutation on the processing of RNAs in the H-strand and L-strand polycistronic transcripts. Nucleic Acids Res 2020; 48:11113-11129. [PMID: 33045734 PMCID: PMC7641755 DOI: 10.1093/nar/gkaa860] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 09/10/2020] [Accepted: 09/23/2020] [Indexed: 12/31/2022] Open
Abstract
In this report, we investigated the molecular mechanism underlying a deafness-associated m.7516delA mutation affecting the 5′ end processing sites of mitochondrial tRNAAsp and tRNASer(UCN). An in vitro processing experiment demonstrated that m.7516delA mutation caused the aberrant 5′ end processing of tRNASer(UCN) and tRNAAsp precursors, catalyzed by RNase P. Using cytoplasmic hybrids (cybrids) derived from one hearing-impaired Chinese family bearing the m.7516delA mutation and control, we demonstrated the asymmetrical effects of m.7516delA mutation on the processing of tRNAs in the heavy (H)-strand and light (L)-strand polycistronic transcripts. Specially, the m.7516delA mutation caused the decreased levels of tRNASer(UCN) and downstream five tRNAs, including tRNATyr from the L-strand transcripts and tRNAAsp from the H-strand transcripts. Strikingly, mutant cybrids exhibited the lower level of COX2 mRNA and accumulation of longer and uncleaved precursors of COX2 from the H-strand transcripts. Aberrant RNA metabolisms yielded variable reductions in the mitochondrial proteins, especially marked reductions in the levels of ND4, ND5, CO1, CO2 and CO3. The impairment of mitochondrial translation caused the proteostasis stress and respiratory deficiency, diminished ATP production and membrane potential, increased production of reactive oxygen species and promoted apoptosis. Our findings provide new insights into the pathophysiology of deafness arising from mitochondrial tRNA processing defects.
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Affiliation(s)
- Yun Xiao
- 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.,Department of Otolaryngology-Head and Neck Surgery, Shandong Provincial ENT Hospital, Shandong University, Jinan, Shandong 250022, China
| | - Meng Wang
- 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
| | - Qiufen He
- 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
| | - Lei Xu
- Department of Otolaryngology-Head and Neck Surgery, Shandong Provincial ENT Hospital, Shandong University, Jinan, Shandong 250022, China
| | - Qinghai Zhang
- 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
| | - 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
| | - Zidong Jia
- 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
| | - Fengguo Zhang
- Department of Otolaryngology-Head and Neck Surgery, Shandong Provincial ENT Hospital, Shandong University, Jinan, Shandong 250022, China
| | - Haibo Wang
- Department of Otolaryngology-Head and Neck Surgery, Shandong Provincial ENT Hospital, Shandong University, Jinan, Shandong 250022, 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.,Key Lab of Reproductive Genetics, Ministry of Education of PRC, Zhejiang University, Hangzhou, Zhejiang 310058, China.,Joint Institute of Genetics and Genome Medicine between Zhejiang University and University of Toronto, Hangzhou, Zhejiang 310058, China
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Webb M, Sideris DP. Intimate Relations-Mitochondria and Ageing. Int J Mol Sci 2020; 21:ijms21207580. [PMID: 33066461 PMCID: PMC7589147 DOI: 10.3390/ijms21207580] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 10/05/2020] [Accepted: 10/06/2020] [Indexed: 12/14/2022] Open
Abstract
Mitochondrial dysfunction is associated with ageing, but the detailed causal relationship between the two is still unclear. We review the major phenomenological manifestations of mitochondrial age-related dysfunction including biochemical, regulatory and energetic features. We conclude that the complexity of these processes and their inter-relationships are still not fully understood and at this point it seems unlikely that a single linear cause and effect relationship between any specific aspect of mitochondrial biology and ageing can be established in either direction.
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Affiliation(s)
- Michael Webb
- Mitobridge Inc., an Astellas Company, 1030 Massachusetts Ave, Cambridge, MA 02138, USA
| | - Dionisia P Sideris
- Mitobridge Inc., an Astellas Company, 1030 Massachusetts Ave, Cambridge, MA 02138, USA
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21
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Finsterer J. Recognise subtle manifestations for classifying MELAS. J Neurol Sci 2020; 414:116926. [DOI: 10.1016/j.jns.2020.116926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 05/13/2020] [Indexed: 10/24/2022]
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