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Xu S, Yang N. The Role and Research Progress of Mitochondria in Sensorineural Hearing Loss. Mol Neurobiol 2024:10.1007/s12035-024-04470-4. [PMID: 39292339 DOI: 10.1007/s12035-024-04470-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Accepted: 08/30/2024] [Indexed: 09/19/2024]
Abstract
Hearing loss is one of the most common human diseases, seriously affecting everyday lives. Mitochondria, as the energy metabolism center in cells, are also involved in regulating active oxygen metabolism and mediating the occurrence of inflammation and apoptosis. Mitochondrial defects are closely related to hearing diseases. Studies have shown that mitochondrial DNA mutations are one of the causes of hereditary hearing loss. In addition, changes in mitochondrial homeostasis are directly related to noise-induced hearing loss and presbycusis. This review mainly summarizes and discusses the effects of mitochondrial dysfunction and mitophagy on hearing loss. Subsequently, we introduce the recent research progress of targeted mitochondria therapy in the hearing system.
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Affiliation(s)
- Shan Xu
- Department of Otolaryngology, The First Hospital of China Medical University, Shenyang, 110001, China
| | - Ning Yang
- Department of Otolaryngology, The First Hospital of China Medical University, Shenyang, 110001, China.
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2
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Zhang T, Su R, Xiang W, Wang W. Maternally inherited non-syndromic hearing loss is linked with a novel mitochondrial ND6 gene mutation. Ir J Med Sci 2024; 193:937-943. [PMID: 37561388 DOI: 10.1007/s11845-023-03484-6] [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: 06/02/2023] [Accepted: 07/26/2023] [Indexed: 08/11/2023]
Abstract
BACKGROUND Maternally inherited non-syndromic hearing loss is linked with mitochondrial DNA mutations. AIM This investigation demonstrates the features of a Chinese pedigree suffering from maternally inherited non-syndromic hearing loss. METHODS Biochemical characterizations included the measurements ofprotein synthesis levels, membrane potential, and the synthesis of reactive oxygen species (ROS) and adenosine triphosphate (ATP) using cybrid cell lines derived from an affected matrilineal subject and control subject. RESULTS Non-congenital early or late-onset/development hearing impairment has been observed in 4 of 9 in a family (matrilineal), with different degrees of hearing impairment, ranging from normal to severe. A pedigree's whole mitochondrial genome sequence analysis revealed the homoplasmic m.14502 T > C (I58V) mutation at ND6's isoleucine location-58, and specific mitocchondrial DNA polymorphisms set haplogroups M10 were highly conserved. In vitro models indicated that m.14502 T > C mutation-derived respiratory deficiency decreases ND6 protein synthesis, mitochondrial membrane potential, and ATP synthesis. These mitochondrial dysregulations enhance the generation of ROS in the mutant cells. Identifying nuclear modifiers is essential for elucidating hearing loss's pathogenesis and furnishing novel therapeutic interventions. CONCLUSIONS The m.14502 T > C mutation should be considered an inherited risk factor that can help diagnose. The data of this investigation help counsel families of individuals with hearing loss.
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Affiliation(s)
- Ting Zhang
- Department of Clinical Laboratory, The Affiliated Wenling Hospital, Wenzhou Medical University, Wenling, 317500, Zhejiang, China
| | - Renjie Su
- ENT Department, The First People's Hospital of Wenling, Taizhou University, Taizhou, China
- ENT Department, The Affiliated Wenling Hospital of Wenzhou Medical University, Taizhou, China
| | - Wen Xiang
- ENT Department, The First People's Hospital of Wenling, Taizhou University, Taizhou, China
- ENT Department, The Affiliated Wenling Hospital of Wenzhou Medical University, Taizhou, China
| | - Wenbin Wang
- ENT Department, The First People's Hospital of Wenling, Taizhou University, Taizhou, China.
- ENT Department, The Affiliated Wenling Hospital of Wenzhou Medical University, Taizhou, China.
- The First People's Hospital of Wenling, Taizhou University, 333 Chuanannan Road, Taizhou, 317500, China.
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3
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Wang S, Li M, Liu P, Dong Y, Geng R, Zheng T, Zheng Q, Li B, Ma P. Col1a1 mediates the focal adhesion pathway affecting hearing in miR-29a mouse model by RNA-seq analysis. Exp Gerontol 2024; 185:112349. [PMID: 38103809 DOI: 10.1016/j.exger.2023.112349] [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: 09/27/2023] [Revised: 11/29/2023] [Accepted: 12/13/2023] [Indexed: 12/19/2023]
Abstract
Age-related hearing loss (ARHL) is a common neurodegenerative disease. Its molecular mechanisms have not been fully elucidated. In the present study, we obtained differential mRNA expression in the cochlea of 2-month-old miR-29a+/+ mice and miR-29a-/- mice by RNA-seq. Gene ontology (GO) analysis was used to identify molecular functions associated with hearing in miR-29a-/- mice, including being actin binding (GO: 0003779) and immune processes. We focused on the intersection of differential genes, miR-29a target genes and the sensory perception of sound (GO:0007605) genes, with six mRNA at this intersection, and we selected Col1a1 as our target gene. We validated Col1a1 as the direct target of miR-29a by molecular and cellular experiments. Total 6 pathways involved in Col1a1 were identified by through Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. We selected the focal adhesion pathway as our target pathway based. Their expression levels in miR-29a-/- mice were verified by qRT-PCR and Western blot. Compared with miR-29a+/+ mice, the expression levels of Col1a1, Itga4, Itga2, Itgb3, Itgb7, Pik3r3 and Ptk2 were different in miR-29a-/- mice. Immunofluorescence was used to locate genes in the cochlea. Col1a1, Itga4 and Itgb3 were differentially expressed in the basilar membranes and stria vascularis and spiral ganglion neurons compared to miR-29a+/+ mice. Pik3r3 and Ptk2 were differentially expressed in the basilar membranes and stria vascularis, but not at the s spiral ganglion neurons compared to miR-29a+/+ mice. Our results show that when miR-29a is knocked out, the Col1a1 mediates the focal adhesion pathway may affect the hearing of miR-29a-/- mice. These findings may provide a new direction for effective treatment of age-related hearing loss.
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Affiliation(s)
- Shuli Wang
- Hearing and Speech Rehabilitation Institute, School of Special Education, Binzhou Medical University, Yantai, China
| | - Mulan Li
- Hearing and Speech Rehabilitation Institute, School of Special Education, Binzhou Medical University, Yantai, China
| | - Pengcheng Liu
- Hearing and Speech Rehabilitation Institute, School of Special Education, Binzhou Medical University, Yantai, China
| | - Yaning Dong
- Hearing and Speech Rehabilitation Institute, School of Special Education, Binzhou Medical University, Yantai, China
| | - Ruishuang Geng
- Hearing and Speech Rehabilitation Institute, School of Special Education, Binzhou Medical University, Yantai, China
| | - Tihua Zheng
- Hearing and Speech Rehabilitation Institute, School of Special Education, Binzhou Medical University, Yantai, China
| | - Qingyin Zheng
- Hearing and Speech Rehabilitation Institute, School of Special Education, Binzhou Medical University, Yantai, China
| | - Bo Li
- Hearing and Speech Rehabilitation Institute, School of Special Education, Binzhou Medical University, Yantai, China.
| | - Peng Ma
- Hearing and Speech Rehabilitation Institute, School of Special Education, Binzhou Medical University, Yantai, China; School of Basic Medicine, Binzhou Medical University, Yantai, China.
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4
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Maraş Genç H, Akpınar G, Kasap M, Uyur Yalçın E, Üstek D, Aslanger AD, Kara B. Proteomic Analysis of m.8296A>G Variation in the Mitochondrial tRNA Lys Gene. Mol Syndromol 2022; 13:305-317. [PMID: 36158049 PMCID: PMC9421666 DOI: 10.1159/000519526] [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: 04/17/2021] [Accepted: 09/07/2021] [Indexed: 01/03/2023] Open
Abstract
Variation in the mitochondrial tRNA Lys gene at position 8296 was previously found to be associated with maternally inherited diabetes mellitus and deafness, hypertrophic cardiomyopathy, myoclonic epilepsy with ragged-red fibers and mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes. The pathogenicity of the m.8296A>G variation is unclear. In this study, we aimed to analyze the mitochondrial proteome in a patient with m.8296A>G variation to elucidate the effects of this mutation at the protein level. Whole-exome sequencing and mitochondrial genome analysis were performed in a patient with sensorineural hearing impairment, cognitive impairment, leukodystrophy, migraine-like headaches, and gastrointestinal dysmotility. Mitochondrial genome analysis identified a homoplasmic m.8296A>G variation in the mitochondrial tRNA Lys gene in the proband and unaffected mother. Global mitochondrial proteome analysis was carried out in the muscle mitochondria of the index patient and a control subject. Comparative muscle mitochondrial proteome analysis revealed a total of 13 nuclear-encoded mitochondrial proteins differently expressed with respect to the control. Ten of the 13 proteins were downregulated. Most of the proteins were involved in ATP synthesis and Krebs cycle and have strong interactions with each other. We considered the m.8296A>G variation to be pathogenic with variable penetrance for our patient's phenotype, and this variation led to different expressions of nuclear-encoded proteins involved in energy metabolism.
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Affiliation(s)
- Hülya Maraş Genç
- Department of Pediatrics, Division of Child Neurology, Kocaeli University Faculty of Medicine, Kocaeli, Turkey,*Hülya Maraş Genç,
| | - Gürler Akpınar
- Department of Medical Biology, Kocaeli University Faculty of Medicine, Kocaeli, Turkey
| | - Murat Kasap
- Department of Medical Biology, Kocaeli University Faculty of Medicine, Kocaeli, Turkey
| | - Emek Uyur Yalçın
- Department of Pediatrics, Division of Child Neurology, Kocaeli University Faculty of Medicine, Kocaeli, Turkey
| | - Duran Üstek
- Department of Molecular Genetics, Istanbul University Institute of Experimental Medicine, Istanbul, Turkey
| | - Ayça Dilruba Aslanger
- Department of Medical Genetics, Istanbul University Faculty of Medicine, Istanbul, Turkey
| | - Bülent Kara
- Department of Pediatrics, Division of Child Neurology, Kocaeli University Faculty of Medicine, Kocaeli, Turkey
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5
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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: 1] [Impact Index Per Article: 0.5] [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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6
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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: 21] [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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7
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Cui L, Zheng J, Zhao Q, Chen JR, Liu H, Peng G, Wu Y, Chen C, He Q, Shi H, Yin S, Friedman RA, Chen Y, Guan MX. Mutations of MAP1B encoding a microtubule-associated phosphoprotein cause sensorineural hearing loss. JCI Insight 2020; 5:136046. [PMID: 33268592 PMCID: PMC7714412 DOI: 10.1172/jci.insight.136046] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Accepted: 10/28/2020] [Indexed: 12/20/2022] Open
Abstract
The pathophysiology underlying spiral ganglion cell defect–induced deafness remains elusive. Using the whole exome sequencing approach, in combination with functional assays and a mouse disease model, we identified the potentially novel deafness-causative MAP1B gene encoding a highly conserved microtubule-associated protein. Three novel heterozygous MAP1B mutations (c.4198A>G, p.1400S>G; c.2768T>C, p.923I>T; c.5512T>C, p.1838F>L) were cosegregated with autosomal dominant inheritance of nonsyndromic sensorineural hearing loss in 3 unrelated Chinese families. Here, we show that MAP1B is highly expressed in the spiral ganglion neurons in the mouse cochlea. Using otic sensory neuron–like cells, generated by pluripotent stem cells from patients carrying the MAP1B mutation and control subject, we demonstrated that the p.1400S>G mutation caused the reduced levels and deficient phosphorylation of MAP1B, which are involved in the microtubule stability and dynamics. Strikingly, otic sensory neuron–like cells exhibited disturbed dynamics of microtubules, axonal elongation, and defects in electrophysiological properties. Dysfunctions of these derived otic sensory neuron–like cells were rescued by genetically correcting MAP1B mutation using CRISPR/Cas9 technology. Involvement of MAP1B in hearing was confirmed by audiometric evaluation of Map1b heterozygous KO mice. These mutant mice displayed late-onset progressive sensorineural hearing loss that was more pronounced in the high frequencies. The spiral ganglion neurons isolated from Map1b mutant mice exhibited the deficient phosphorylation and disturbed dynamics of microtubules. Map1b deficiency yielded defects in the morphology and electrophysiology of spiral ganglion neurons, but it did not affect the morphologies of cochlea in mice. Therefore, our data demonstrate that dysfunctions of spiral ganglion neurons induced by MAP1B deficiency caused hearing loss. Dysfunctions of spiral ganglion neurons caused by Map1b deficiency leads to sensorineural hearing loss.
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Affiliation(s)
- Limei Cui
- Division of Medical Genetics and Genomics, The Children's Hospital.,Institute of Genetics and.,Department of Human Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Jing Zheng
- Division of Medical Genetics and Genomics, The Children's Hospital
| | - Qiong Zhao
- Division of Medical Genetics and Genomics, The Children's Hospital.,Institute of Genetics and.,Department of Human Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Jia-Rong Chen
- Division of Medical Genetics and Genomics, The Children's Hospital.,Institute of Genetics and
| | | | - Guanghua Peng
- Deaprtment of Otorhinolaryngology, the Affiliated Hospital, Hangzhou Normal University, Hangzhou, Zhejiang, China
| | - Yue Wu
- Division of Medical Genetics and Genomics, The Children's Hospital
| | - Chao Chen
- Division of Medical Genetics and Genomics, The Children's Hospital.,Institute of Genetics and
| | | | - Haosong Shi
- Department of Otorhinolaryngology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Shankai Yin
- Department of Otorhinolaryngology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Rick A Friedman
- Division of Otolaryngology, University of California at San Diego School of Medicine, La Jolla California, USA
| | - Ye Chen
- Division of Medical Genetics and Genomics, The Children's Hospital.,Institute of Genetics and.,Department of Human Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Min-Xin Guan
- Division of Medical Genetics and Genomics, The Children's Hospital.,Institute of Genetics and.,Department of Human Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Division of Otolaryngology, University of California at San Diego School of Medicine, La Jolla California, USA.,Zhejiang Provincial Key Laboratory of Genetic and Developmental Disorders, Hangzhou, Zhejiang, China.,Joint Institute of Genetics and Genomic Medicine between Zhejiang University and University of Toronto, Zhejiang University, Hangzhou, Zhejiang, China
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8
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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: 8] [Impact Index Per Article: 2.0] [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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9
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Guo L, Wang X, Ji H. Clinical Phenotype and Genetic Features of a Pair of Chinese Twins with Kearns-Sayre Syndrome. DNA Cell Biol 2020; 39:1449-1457. [PMID: 32609007 DOI: 10.1089/dna.2019.5010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Kearns-Sayre Syndrome (KSS) is a severe mitochondrial disorder involving the central nervous system, eyes, ears, skeletal muscles, and heart. The mitochondrial DNA (mtDNA) rearrangements, especially the deletions, are present in almost all KSS patients and considered as the disease-causing factor. However, the size and position of mtDNA deletions are distinct in different individuals. In this study, we report the case of a pair of Chinese twins with KSS. The twin patients revealed typical KSS clinical symptoms, including heart block, bilateral sensorineural hearing loss, progressive external ophthalmoplegia, exercise intolerance, proximal limb weakness, and endocrine disorders. Using long-range polymerase chain reactions (long-range PCR) and next-generation sequencing (NGS), the genetic features of the twin patients were investigated. A large 6600 bp mtDNA deletion, ranging from position 8702 to 15,302, was detected in both patients. To our knowledge, this kind of mtDNA deletion has never been described previously. Our study enriched the mutation spectrum of KSS and showed that NGS is a powerful tool for detecting mtDNA large variants.
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Affiliation(s)
- Luo Guo
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, ENT Institute and Otorhinolaryngology Department, Fudan University Eye & ENT Hospital, Shanghai, People's Republic of China.,NHC Key Laboratory of Hearing Medicine and Fudan University, Shanghai, People's Republic of China
| | - Xin Wang
- Institutes of Biomedical Sciences, Fudan University, Shanghai, People's Republic of China.,Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Nantong University, Nantong, People's Republic of China
| | - Haiting Ji
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, ENT Institute and Otorhinolaryngology Department, Fudan University Eye & ENT Hospital, Shanghai, People's Republic of China.,NHC Key Laboratory of Hearing Medicine and Fudan University, Shanghai, People's Republic of China.,Department of Otorhinolaryngology, Affiliated Eye and ENT Hospital of Fudan University, Shanghai, China
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10
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Ding Y, Teng YS, Zhuo GC, Xia BH, Leng JH. The Mitochondrial tRNAHis G12192A Mutation May Modulate the Clinical Expression of Deafness-Associated tRNAThr G15927A Mutation in a Chinese Pedigree. Curr Mol Med 2020; 19:136-146. [PMID: 30854964 DOI: 10.2174/1566524019666190308121552] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 03/02/2019] [Accepted: 03/04/2019] [Indexed: 12/19/2022]
Abstract
BACKGROUND Mutations in mitochondrial tRNA (mt-tRNA) genes have been found to be associated with both syndromic and non-syndromic hearing impairment. However, the pathophysiology underlying mt-tRNA mutations in clinical expression of hearing loss remains poorly understood. OBJECTIVE The aim of this study was to explore the potential association between mttRNA mutations and hearing loss. METHODS AND RESULTS We reported here the molecular features of a pedigree with maternally transmitted non-syndromic hearing loss. Among 12 matrilineal relatives, five of them suffered variable degree of hearing impairment, but none of them had any medical history of using aminoglycosides antibiotics (AmAn). Genetic screening of the complete mitochondrial genomes from the matrilineal relatives identified the coexistence of mt-tRNAHis G12192A and mt-tRNAThr G15927A mutations, together with a set of polymorphisms belonging to human mitochondrial haplogroup B5b1b. Interestingly, the G12192A mutation occurred 2-bp from the 3' end of the TψC loop of mt-tRNAHis, which was evolutionarily conserved from various species. In addition, the well-known G15927A mutation, which disrupted the highly conserved C-G base-pairing at the anticodon stem of mt-tRNAThr, may lead to the failure in mt-tRNA metabolism. Furthermore, a significant decreased in ATP production and an increased ROS generation were observed in polymononuclear leukocytes (PMNs) which were isolated from the deaf patients carrying these mt-tRNA mutations, suggested that the G12192A and G15927A mutations may cause mitochondrial dysfunction that was responsible for deafness. However, the absence of any functional mutations/variants in GJB2, GJB3, GJB6 and TRMU genes suggested that the nuclear genes may not play important roles in the clinical expression of non-syndromic hearing loss in this family. CONCLUSION Our data indicated that mt-tRNAHis G12192A mutation may increase the penetrance and expressivity of deafness-associated m-tRNAThr G15927A mutation in this family.
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Affiliation(s)
- Yu Ding
- Central Laboratory, Hangzhou First People's Hospital, Zhejiang University, School of Medicine, Hangzhou, China
| | - Yao-Shu Teng
- Department of Otolaryngology, Hangzhou First People's Hospital, Zhejiang University, School of Medicine, Hangzhou, China
| | - Guang-Chao Zhuo
- Central Laboratory, Hangzhou First People's Hospital, Zhejiang University, School of Medicine, Hangzhou, China
| | - Bo-Hou Xia
- Department of Pharmacy, Hunan Chinese Medical University, Changsha, China
| | - Jian-Hang Leng
- Central Laboratory, Hangzhou First People's Hospital, Zhejiang University, School of Medicine, Hangzhou, China
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11
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Zheng J, Bai X, Xiao Y, Ji Y, Meng F, Aishanjiang M, Gao Y, Wang H, Fu Y, Guan MX. Mitochondrial tRNA mutations in 887 Chinese subjects with hearing loss. Mitochondrion 2020; 52:163-172. [PMID: 32169613 DOI: 10.1016/j.mito.2020.03.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 01/13/2020] [Accepted: 03/09/2020] [Indexed: 01/24/2023]
Abstract
Mutations in the mitochondrial tRNAs have been reported to be the important cause of hearing loss. However, only a few cases have been identified thus far and the prevalence of mitochondrial tRNA mutations in hearing-impaired patients remain unclear. Here we performed the mutational analysis of 22 mitochondrial tRNA genes in a large cohort of 887 Han Chinese subjects with hearing loss by Sanger sequencing. The systemic evaluation of putative pathogenic variants was further carried out by frequency in controls (<1%), phylogenetic analysis, structural analysisandfunctionalprediction. As a result, a total of 147 variants on 22 tRNA genes were identified. Among these, 39 tRNA mutations (10 pathogenic and 29 likely pathogenic) which absent or present <1% in 773 Chinese controls, localized at highly conserved nucleotides, or changed the modified nucleotides, could have potential structural alterations and functional significance, thereby considered to be deafness-associated mutations. Furthermore, 44 subjects carried one of these 39 pathogenic/likely pathogenic tRNA mutations with a total prevalence of 4.96%. However, the phenotypic variability and incomplete penetrance of hearing loss in pedigrees carrying these tRNA mutations indicate the involvement of modifier factors, such as nuclear encoded genes associated with mitochondrion biogenesis, mitochondrial haplotypes, epigenetic and environmental factors. Thus, our data provide the evidence that mitochondrial tRNA mutations are the important causes of hearing loss among Chinese population. These findings further increase our knowledge on the clinical relevance of tRNA mutations in the mitochondrial genome, and should be helpful to elucidate the pathogenesis of maternal hearing loss.
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Affiliation(s)
- Jing Zheng
- Division of Medical Genetics and Genomics, and Department of Genetic and Metabolic Diseases, The Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, Zhejiang 310052, China; Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Xiaohui Bai
- Department of Otorhinolaryngology-Head and Neck Surgery, Shandong Provincial ENT Hospital, Shandong University, Jinan, Shandong 250022, China
| | - Yun Xiao
- Division of Medical Genetics and Genomics, and Department of Genetic and Metabolic Diseases, The Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, Zhejiang 310052, China; Department of Otorhinolaryngology-Head and Neck Surgery, Shandong Provincial ENT Hospital, Shandong University, Jinan, Shandong 250022, China
| | - Yanchun Ji
- Division of Medical Genetics and Genomics, and Department of Genetic and Metabolic Diseases, The Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, Zhejiang 310052, China; Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Feilong Meng
- Division of Medical Genetics and Genomics, and Department of Genetic and Metabolic Diseases, The Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, Zhejiang 310052, China; Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Maerhaba Aishanjiang
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Yinglong Gao
- Division of Medical Genetics and Genomics, and Department of Genetic and Metabolic Diseases, The Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, Zhejiang 310052, China; Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Haibo Wang
- Department of Otorhinolaryngology-Head and Neck Surgery, Shandong Provincial ENT Hospital, Shandong University, Jinan, Shandong 250022, China.
| | - Yong Fu
- Division of Medical Genetics and Genomics, and Department of Genetic and Metabolic Diseases, The Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, Zhejiang 310052, China; Department of Otorhinolaryngology Head and Neck Surgery, The Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, Zhejiang 310052, China.
| | - Min-Xin Guan
- Division of Medical Genetics and Genomics, and Department of Genetic and Metabolic Diseases, The Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, Zhejiang 310052, China; Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
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12
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Gao Z, Yuan YS. Screening for mitochondrial 12S rRNA C1494T mutation in 655 patients with non-syndromic hearing loss: An observational study. Medicine (Baltimore) 2020; 99:e19373. [PMID: 32221064 PMCID: PMC7220552 DOI: 10.1097/md.0000000000019373] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Mutations in mitochondrial DNA, especially in 12S rRNA gene, are the most important causes for hearing loss. In particular, the A1555G and C1494T mutations have been found to be associated with both aminoglycoside-induced and non-syndromic hearing loss in many families worldwide. To determine the frequency of C1494T mutation in deaf patients, in the current study, we screened this mutation in 655 patients with non-syndromic hearing loss and 300 control subjects. After PCR amplification of mitochondrial 12S rRNA gene and direct sequence analysis, we found that there were 2 patients carrying the C1494T mutation; however, this mutation was not detected in 300 healthy subjects. Further genetic counseling suggested that only 1 patient had an obvious family history of hearing impairment. Clinical evaluation showed that 3 of 10 matrilineal relatives suffered from hearing loss, with different age at onset of hearing loss. Molecular analysis revealed the presence of homoplasmic 12S rRNA C1494T and ND5 T12338C mutations, together with a set of polymorphisms belonging to human mitochondrial haplogroup F2. Interestingly, T12338C mutation resulted in the replacement of the first amino acid, a translation-initiating methionine with a threonine, shortening 2 amino acids of ND5 polypeptide. Moreover, this mutation is located in 2 nucleotides adjacent to the 3' end of the mt-tRNALeu(CUN) gene. Therefore, this mutation may alter ND5 mRNA metabolism and the processing of RNA precursors. Thus, the combination of T12338C and C1494T mutations may contribute to deafness expression in this family. Taken together, our data suggested that the C1494T mutation was the molecular basis for hearing loss, screening for the mitochondrial DNA pathogenic mutations was recommended for early detection, prevention, and diagnosis of mitochondrial deafness.
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Affiliation(s)
- Zhen Gao
- Department of Otology and Skull Base Surgery, Eye & ENT Hospital
- NHC Key Laboratory of Hearing Medicine, Fudan University, Shanghai, China
| | - Ya-Sheng Yuan
- Department of Otology and Skull Base Surgery, Eye & ENT Hospital
- NHC Key Laboratory of Hearing Medicine, Fudan University, Shanghai, China
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13
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Gong S, Wang X, Meng F, Cui L, Yi Q, Zhao Q, Cang X, Cai Z, Mo JQ, Liang Y, Guan MX. Overexpression of mitochondrial histidyl-tRNA synthetase restores mitochondrial dysfunction caused by a deafness-associated tRNAHis mutation. J Biol Chem 2020. [DOI: 10.1016/s0021-9258(17)49906-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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14
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Gong S, Wang X, Meng F, Cui L, Yi Q, Zhao Q, Cang X, Cai Z, Mo JQ, Liang Y, Guan MX. Overexpression of mitochondrial histidyl-tRNA synthetase restores mitochondrial dysfunction caused by a deafness-associated tRNA His mutation. J Biol Chem 2019; 295:940-954. [PMID: 31819004 DOI: 10.1074/jbc.ra119.010998] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 11/27/2019] [Indexed: 01/19/2023] Open
Abstract
The deafness-associated m.12201T>C mutation affects the A5-U68 base-pairing within the acceptor stem of mitochondrial tRNAHis The primary defect in this mutation is an alteration in tRNAHis aminoacylation. Here, we further investigate the molecular mechanism of the deafness-associated tRNAHis 12201T>C mutation and test whether the overexpression of the human mitochondrial histidyl-tRNA synthetase gene (HARS2) in cytoplasmic hybrid (cybrid) cells carrying the m.12201T>C mutation reverses mitochondrial dysfunctions. Using molecular dynamics simulations, we demonstrate that the m.12201T>C mutation perturbs the tRNAHis structure and function, supported by decreased melting temperature, conformational changes, and instability of mutated tRNA. We show that the m.12201T>C mutation-induced alteration of aminoacylation tRNAHis causes mitochondrial translational defects and respiratory deficiency. We found that the transfer of HARS2 into the cybrids carrying the m.12201T>C mutation raises the levels of aminoacylated tRNAHis from 56.3 to 75.0% but does not change the aminoacylation of other tRNAs. Strikingly, HARS2 overexpression increased the steady-state levels of tRNAHis and of noncognate tRNAs, including tRNAAla, tRNAGln, tRNAGlu, tRNALeu(UUR), tRNALys, and tRNAMet, in cells bearing the m.12201T>C mutation. This improved tRNA metabolism elevated the efficiency of mitochondrial translation, activities of oxidative phosphorylation complexes, and respiration capacity. Furthermore, HARS2 overexpression markedly increased mitochondrial ATP levels and membrane potential and reduced production of reactive oxygen species in cells carrying the m.12201T>C mutation. These results indicate that HARS2 overexpression corrects the mitochondrial dysfunction caused by the tRNAHis mutation. These findings provide critical insights into the pathophysiology of mitochondrial disease and represent a step toward improved therapeutic interventions for mitochondrial disorders.
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Affiliation(s)
- Shasha Gong
- Taizhou University Hospital, Taizhou University, Taizhou, Zhejiang 318000, China.,Institute of Genetics, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Xiaoqiong Wang
- Department of Otolaryngology, Taizhou Municipal Hospital, Taizhou, Zhejiang 318000, China.,Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Feilong Meng
- Institute of Genetics, Zhejiang University, Hangzhou, Zhejiang 310058, China.,Division of Medical Genetics and Genomics, the Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Limei Cui
- Institute of Genetics, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Qiuzi Yi
- Institute of Genetics, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Qiong Zhao
- Institute of Genetics, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Xiaohui Cang
- Institute of Genetics, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Zhiyi Cai
- Department of Otolaryngology, Taizhou Municipal Hospital, Taizhou, Zhejiang 318000, China
| | - Jun Qin Mo
- Department of Pathology, Rady Children's Hospital, University of California School of Medicine, San Diego, California 92123
| | - Yong Liang
- Taizhou University Hospital, Taizhou University, Taizhou, Zhejiang 318000, China
| | - Min-Xin Guan
- Institute of Genetics, Zhejiang University, Hangzhou, Zhejiang 310058, China .,Division of Medical Genetics and Genomics, the Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,Key Laboratory of Reproductive Genetics, Ministry of Education of PRC, Zhejiang University, Hangzhou, Zhejiang 310058, China.,Joint Institute of Genetics and Genomic Medicine between Zhejiang University and University of Toronto, Hangzhou, Zhejiang 310058, China
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15
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Fan W, Zheng J, Kong W, Cui L, Aishanjiang M, Yi Q, Wang M, Cang X, Tang X, Chen Y, Mo JQ, Sondheimer N, Ge W, Guan MX. Contribution of a mitochondrial tyrosyl-tRNA synthetase mutation to the phenotypic expression of the deafness-associated tRNA Ser(UCN) 7511A>G mutation. J Biol Chem 2019; 294:19292-19305. [PMID: 31685661 DOI: 10.1074/jbc.ra119.010598] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 10/29/2019] [Indexed: 01/01/2023] Open
Abstract
Nuclear modifier genes have been proposed to modify the phenotypic expression of mitochondrial DNA mutations. Using a targeted exome-sequencing approach, here we found that the p.191Gly>Val mutation in mitochondrial tyrosyl-tRNA synthetase 2 (YARS2) interacts with the tRNASer(UCN) 7511A>G mutation in causing deafness. Strikingly, members of a Chinese family bearing both the YARS2 p.191Gly>Val and m.7511A>G mutations displayed much higher penetrance of deafness than those pedigrees carrying only the m.7511A>G mutation. The m.7511A>G mutation changed the A4:U69 base-pairing to G4:U69 pairing at the aminoacyl acceptor stem of tRNASer(UCN) and perturbed tRNASer(UCN) structure and function, including an increased melting temperature, altered conformation, instability, and aberrant aminoacylation of mutant tRNA. Using lymphoblastoid cell lines derived from symptomatic and asymptomatic members of these Chinese families and control subjects, we show that cell lines harboring only the m.7511A>G or p.191Gly>Val mutation revealed relatively mild defects in tRNASer(UCN) or tRNATyr metabolism, respectively. However, cell lines harboring both m.7511A>G and p.191Gly>Val mutations displayed more severe defective aminoacylations and lower tRNASer(UCN) and tRNATyr levels, aberrant aminoacylation, and lower levels of other tRNAs, including tRNAThr, tRNALys, tRNALeu(UUR), and tRNASer(AGY), than those in the cell lines carrying only the m.7511A>G or p.191Gly>Val mutation. Furthermore, mutant cell lines harboring both m.7511A>G and p.191Gly>Val mutations exhibited greater decreases in the levels of mitochondrial translation, respiration, and mitochondrial ATP and membrane potentials, along with increased production of reactive oxygen species. Our findings provide molecular-level insights into the pathophysiology of maternally transmitted deafness arising from the synergy between tRNASer(UCN) and mitochondrial YARS mutations.
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Affiliation(s)
- Wenlu Fan
- Division of Medical Genetics and Genomics, Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,Attardi Institute of Biomedicine, School of Life Sciences and Laboratory Medicine, Wenzhou Medical University, Wenzhou, Zhejiang 325600, China
| | - Jing Zheng
- Division of Medical Genetics and Genomics, Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Wanzhong Kong
- Attardi Institute of Biomedicine, School of Life Sciences and Laboratory Medicine, Wenzhou Medical University, Wenzhou, Zhejiang 325600, China
| | - Limei Cui
- Division of Medical Genetics and Genomics, Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Maerhaba Aishanjiang
- Division of Medical Genetics and Genomics, Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Qiuzi Yi
- Division of Medical Genetics and Genomics, Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Min Wang
- Attardi Institute of Biomedicine, School of Life Sciences and Laboratory Medicine, Wenzhou Medical University, Wenzhou, Zhejiang 325600, China
| | - Xiaohui Cang
- Division of Medical Genetics and Genomics, Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Xiaowen Tang
- Attardi Institute of Biomedicine, School of Life Sciences and Laboratory Medicine, Wenzhou Medical University, Wenzhou, Zhejiang 325600, China
| | - Ye Chen
- Division of Medical Genetics and Genomics, Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Jun Qin Mo
- Department of Pathology, Rady Children's Hospital, University of California School of Medicine, San Diego, California 92123
| | - Neal Sondheimer
- Department of Molecular Genetics, University of Toronto School of Medicine and the Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
| | - Wanzhong Ge
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Min-Xin Guan
- Division of Medical Genetics and Genomics, Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China .,Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,Key Laboratory 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 the University of Toronto, Hangzhou, Zhejiang 310058, China
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16
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Ibrahim I, Dominguez-Valentin M, Segal B, Zeitouni A, da Silva SD. Mitochondrial mutations associated with hearing and balance disorders. Mutat Res 2018; 810:39-44. [PMID: 29615272 DOI: 10.1016/j.mrfmmm.2018.03.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 12/20/2017] [Accepted: 03/09/2018] [Indexed: 06/08/2023]
Abstract
Hearing and balance disorders are related to the inner ear and are among the major cause of falls in older adults. Hearing loss that commonly occurs with aging (aka presbyacusis) can result from noise exposure, smoking, ototoxic drugs and genetic factors such as mutations in nuclear and mitochondrial genes. Mutations in mitochondrial DNA (mtDNA) have been reported to play an important role in cell function by providing energy, as well as, cell death (apoptosis). This study aims to systematically review mitochondrial mutations associated with presbyacusis and suggests preventive measurements to improve the quality of life in older adults.
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Affiliation(s)
- Iman Ibrahim
- Department of Otolaryngology-Head and Neck Surgery, McGill University, Canada.
| | - Mev Dominguez-Valentin
- Department of Tumor Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway.
| | - Bernard Segal
- Department of Otolaryngology-Head and Neck Surgery, McGill University, Canada.
| | - Anthony Zeitouni
- Department of Otolaryngology-Head and Neck Surgery, McGill University, Canada.
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Chen X, Nie Z, Wang F, Wang J, Liu XW, Zheng J, Guo YF, Guan MX. Late onset nonsyndromic hearing loss in a Dongxiang Chinese family is associated with the 593T>C variant in the mitochondrial tRNA Phe gene. Mitochondrion 2017; 35:111-118. [PMID: 28579530 DOI: 10.1016/j.mito.2017.05.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 05/31/2017] [Accepted: 05/31/2017] [Indexed: 11/19/2022]
Abstract
We report here the clinical, genetic, molecular and biochemical characterization of a four-generation Dongxiang Chinese pedigree with suggestively maternally transmitted non-syndromic hearing loss. Five of 10 matrilineal relatives exhibited variable severity and age at onset of sensorineural hearing loss. The average ages at onset of hearing loss in matrilineal relatives of this family were 29years. Molecular analysis of their mitochondrial genomes identified the tRNAPhe 593T>C variant belonging to Asian haplogroup G2a2a. The m.593T>C variant resided at the position 17 of DHU-loop, where the position is important for the structure and function of tRNA. It was anticipated that the m.593T>C variant altered the structure and function of tRNAPhe. By using lymphoblastoid cell lines derived from the Chinese family, we showed a 46% decreases in the steady-state level of tRNAPhe in mutant cell lines. Western blotting analysis showed ∼35% reduction in the levels of mitochondrial translation in mutant cell lines carrying the m.593T>C variant. Impaired mitochondrial translation is apparently a primary contributor to the marked reduction in the rate of respiratory capacity. The respiratory deficiency lowed mitochondrial ATP production in the mutant cell lines. These data provide the evidence that mitochondrial dysfunctions caused by the m.593T>C variant lead to late-onset nonsyndromic hearing loss. Thus, our findings may provide the new insights into the understanding of pathophysiology and valuable information for management and treatment of maternally inherited hearing loss.
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Affiliation(s)
- Xiaowan Chen
- Department of Otolaryngology-Head and Neck Surgery, Lanzhou University Second Hospital, Lanzhou, Gansu730000, China; Institute of Genetics, Zhejiang University, School of Medicine, Hangzhou, Zhejiang 310058, China; Department of Otolaryngology-Head and Neck Surgery, Lanzhou University First Hospital, Lanzhou, Gansu 730000, China
| | - Zhipeng Nie
- Institute of Genetics, Zhejiang University, School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Fang Wang
- Department of Otolaryngology-Head and Neck Surgery, Lanzhou University Second Hospital, Lanzhou, Gansu730000, China
| | - Jianchao Wang
- Department of Otolaryngology-Head and Neck Surgery, Lanzhou University Second Hospital, Lanzhou, Gansu730000, China
| | - Xiao-Wen Liu
- Department of Otolaryngology-Head and Neck Surgery, Lanzhou University Second Hospital, Lanzhou, Gansu730000, China
| | - Jing Zheng
- Institute of Genetics, Zhejiang University, School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Yu-Fen Guo
- Department of Otolaryngology-Head and Neck Surgery, Lanzhou University Second Hospital, Lanzhou, Gansu730000, China; Health and Family Planning Commission of Gansu Province, Lanzhou, Gansu 730000, China.
| | - Min-Xin Guan
- Institute of Genetics, Zhejiang University, School of Medicine, Hangzhou, Zhejiang 310058, China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou, Zhejiang 310058, China.
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18
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Mutai H, Watabe T, Kosaki K, Ogawa K, Matsunaga T. Mitochondrial mutations in maternally inherited hearing loss. BMC MEDICAL GENETICS 2017; 18:32. [PMID: 28320335 PMCID: PMC5359870 DOI: 10.1186/s12881-017-0389-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 03/02/2017] [Indexed: 11/18/2022]
Abstract
Background Although the mitochondrial DNA (mtDNA) mutations m.1555A > G and m.3243A > G are the primary causes of maternally inherited sensorineural hearing loss (SNHL), several other mtDNA mutations are also reported to be associated with SNHL. Methods Screening of m.1555A > G and m.3243A > G mutations was performed for 145 probands. Nine probands fulfilled the following criteria: 1) bilateral and symmetric SNHL, 2) ≥ 4 family members with SNHL with a maternal trait of inheritance in ≥ 2 generations, 3) onset of SNHL before the age of 40 years, 4) high-frequency SNHL, and 5) no record of environmental factors related to SNHL. Sequencing of additional mtDNA regions was performed for five subjects meeting the clinical criteria, but the screening results were negative. Results Among the nine cases meeting the five clinical criteria detailed above, three had the m.1555A > G mutation in MTRNR1, one had a m.3243A > G mutation in MTTL1, and one case had a m.7511T > C mutation in MTTS1. In the family with the m.7511T > C mutation, penetrance of SNHL among maternally related subjects was 9/17 (53%). The age at onset varied from birth (congenital) to adulthood. Hearing levels varied from normal to moderately impaired, unlike previously reported subjects with this mutation, where some maternal family members presented with profound SNHL. Family members with the m.7511T > C mutation and SNHL did not exhibit any specific clinical characteristics distinct from those of other individuals with SNHL and different mtDNA mutations. Among the 136 probands who did not meet the criteria detailed above, one case had the m.1555A > G mutation, and three cases had the m.3243A > G mutation. Conclusions Since five of nine probands with the clinical criteria used in this study had mtDNA mutations, these criteria may be helpful for identification of candidate patients likely to have mtDNA mutations. Electronic supplementary material The online version of this article (doi:10.1186/s12881-017-0389-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hideki Mutai
- Division of Hearing and Balance Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, 2-5-1 Higashigaoka, Meguro, Tokyo, 152-8902, Japan
| | - Takahisa Watabe
- Department of Otolaryngology, Head and Neck Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo, 160-8582, Japan
| | - Kenjiro Kosaki
- Center for Medical Genetics, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo, 160-8582, Japan
| | - Kaoru Ogawa
- Department of Otolaryngology, Head and Neck Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo, 160-8582, Japan
| | - Tatsuo Matsunaga
- Division of Hearing and Balance Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, 2-5-1 Higashigaoka, Meguro, Tokyo, 152-8902, Japan.
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Cao X, Qin Y. Mitochondrial translation factors reflect coordination between organelles and cytoplasmic translation via mTOR signaling: Implication in disease. Free Radic Biol Med 2016; 100:231-237. [PMID: 27101739 DOI: 10.1016/j.freeradbiomed.2016.04.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 04/11/2016] [Accepted: 04/13/2016] [Indexed: 12/24/2022]
Abstract
Mitochondria are semi-autonomous organelle possessing their own translation machinery to biosynthesize mitochondrial DNA (mtDNA)-encoded polypeptides, which are the core subunits of oxidative phosphorylation (OXPHOS) complexes. Mitochondrial translation elongation factor 4 (mtEF4) is a key quality control factor in mitochondrial translation (mt-translation) that regulates mitochondrial tRNA translocation and modulates cellular responses by influencing cytoplasmic translation (ct-translation). In addition to mtEF4, mt-translational activators, mitochondrial microRNAs (mitomiRs), and MITRAC have been reported recently as crucial mt-translation regulators. Here, we focus on the novel ways how these factors regulate mt-translation, discuss the main cellular response of mammalian target of rapamycin (mTOR) signalling upon mt-translation defects, and summarize the related human diseases.
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Affiliation(s)
- Xintao Cao
- Key Laboratory of RNA Biology, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yan Qin
- Key Laboratory of RNA Biology, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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20
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Wang M, Liu H, Zheng J, Chen B, Zhou M, Fan W, Wang H, Liang X, Zhou X, Eriani G, Jiang P, Guan MX. A Deafness- and Diabetes-associated tRNA Mutation Causes Deficient Pseudouridinylation at Position 55 in tRNAGlu and Mitochondrial Dysfunction. J Biol Chem 2016; 291:21029-21041. [PMID: 27519417 DOI: 10.1074/jbc.m116.739482] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Indexed: 02/03/2023] Open
Abstract
Several mitochondrial tRNA mutations have been associated with maternally inherited diabetes and deafness. However, the pathophysiology of these tRNA mutations remains poorly understood. In this report, we identified the novel homoplasmic 14692A→G mutation in the mitochondrial tRNAGlu gene among three Han Chinese families with maternally inherited diabetes and deafness. The m.14692A→G mutation affected a highly conserved uridine at position 55 of the TΨC loop of tRNAGlu The uridine is modified to pseudouridine (Ψ55), which plays an important role in the structure and function of this tRNA. Using lymphoblastoid cell lines derived from a Chinese family, we demonstrated that the m.14692A→G mutation caused loss of Ψ55 modification and increased angiogenin-mediated endonucleolytic cleavage in mutant tRNAGlu The destabilization of base-pairing (18A-Ψ55) caused by the m.14692A→G mutation perturbed the conformation and stability of tRNAGlu An approximately 65% decrease in the steady-state level of tRNAGlu was observed in mutant cells compared with control cells. A failure in tRNAGlu metabolism impaired mitochondrial translation, especially for polypeptides with a high proportion of glutamic acid codons such as ND1, ND6, and CO2 in mutant cells. An impairment of mitochondrial translation caused defective respiratory capacity, especially reducing the activities of complexes I and IV. Furthermore, marked decreases in the levels of mitochondrial ATP and membrane potential were observed in mutant cells. These mitochondrial dysfunctions caused an increasing production of reactive oxygen species in the mutant cells. Our findings may provide new insights into the pathophysiology of maternally inherited diabetes and deafness, which is primarily manifested by the deficient nucleotide modification of mitochondrial tRNAGlu.
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Affiliation(s)
- Meng Wang
- From the Division of Clinical Genetics and Genomics, Children's Hospital and the Institute of Genetics, Department of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China 310001
| | - Hao Liu
- the Institute of Genetics, Department of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China 310001
| | - Jing Zheng
- From the Division of Clinical Genetics and Genomics, Children's Hospital and the Institute of Genetics, Department of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China 310001
| | - Bobei Chen
- the Department of Otolaryngology, Second Affiliated Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China 325035, the Attardi Institute of Mitochondrial Biomedicine, School of Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China 325035
| | - Mi Zhou
- From the Division of Clinical Genetics and Genomics, Children's Hospital and the Institute of Genetics, Department of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China 310001
| | - Wenlu Fan
- the Attardi Institute of Mitochondrial Biomedicine, School of Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China 325035
| | - Hen Wang
- the Attardi Institute of Mitochondrial Biomedicine, School of Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China 325035
| | - Xiaoyang Liang
- From the Division of Clinical Genetics and Genomics, Children's Hospital and the Institute of Genetics, Department of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China 310001
| | - Xiaolong Zhou
- the Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China 200031, and
| | - Gilbert Eriani
- the Architecture et Réactivité de l'ARN, Université de Strasbourg, CNRS, Institut de Biologie Moléculaire et Cellulaire, 15 rue René Descartes, 67084 Strasbourg, France
| | - Pingping Jiang
- From the Division of Clinical Genetics and Genomics, Children's Hospital and the Institute of Genetics, Department of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China 310001
| | - Min-Xin Guan
- From the Division of Clinical Genetics and Genomics, Children's Hospital and the Institute of Genetics, Department of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China 310001, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, and Joining Institute of Genetics and Genomic Medicine between Zhejiang University and University of Toronto, Zhejiang University, Hangzhou, Zhejiang, China 310058,
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21
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Mutational screening in patients with profound sensorineural hearing loss and neurodevelopmental delay: Description of a novel m.3861A > C mitochondrial mutation in the MT-ND1 gene. Biochem Biophys Res Commun 2016; 474:702-708. [PMID: 27155156 DOI: 10.1016/j.bbrc.2016.05.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 05/03/2016] [Indexed: 11/22/2022]
Abstract
Mitochondrial diseases caused by mitochondrial dysfunction are a clinically and genetically, heterogeneous group of disorders involving multiple organs, particularly tissues with high-energy demand. Hearing loss is a recognized symptom of a number of mitochondrial diseases and can result from neuronal or cochlear dysfunction. The tissue affected in this pathology is most probably the cochlear hair cells, which are essential for hearing function since they are responsible for maintaining the ionic gradients necessary for sound signal transduction. Several mitochondrial DNA mutations have been associated with hearing loss and since mitochondria are crucial for the cellular energy supply in many tissues, most of these mtDNA mutations affect several tissues and will cause syndromic hearing loss. In the present study, we described 2 patients with sensorineural hearing loss and neurodevelopmental delay in whom we tested mitochondrial genes described to be associated with syndromic hearing loss. One of these patients showed a novel heteroplasmic mitochondrial mutation m.3861A > C (W185C) which lead to a loss of stability of the ND1 protein since it created a new hydrogen bund between the unique created cystein C185 and the A182 residue. In the second patient, we detected two novel heteroplasmic variations m.12350C > A (T5N) and m.14351T > C (E108G) respectively in the MT-ND5 and the MT-ND6 genes. The TopPred II prediction for the E108G variation revealed a decrease of the hydrophobicity in the mutated MT-ND6.
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22
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Kang E, Wang X, Tippner-Hedges R, Ma H, Folmes CDL, Gutierrez NM, Lee Y, Van Dyken C, Ahmed R, Li Y, Koski A, Hayama T, Luo S, Harding CO, Amato P, Jensen J, Battaglia D, Lee D, Wu D, Terzic A, Wolf DP, Huang T, Mitalipov S. Age-Related Accumulation of Somatic Mitochondrial DNA Mutations in Adult-Derived Human iPSCs. Cell Stem Cell 2016; 18:625-36. [PMID: 27151456 DOI: 10.1016/j.stem.2016.02.005] [Citation(s) in RCA: 168] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 01/05/2016] [Accepted: 02/15/2016] [Indexed: 12/21/2022]
Abstract
The genetic integrity of iPSCs is an important consideration for therapeutic application. In this study, we examine the accumulation of somatic mitochondrial genome (mtDNA) mutations in skin fibroblasts, blood, and iPSCs derived from young and elderly subjects (24-72 years). We found that pooled skin and blood mtDNA contained low heteroplasmic point mutations, but a panel of ten individual iPSC lines from each tissue or clonally expanded fibroblasts carried an elevated load of heteroplasmic or homoplasmic mutations, suggesting that somatic mutations randomly arise within individual cells but are not detectable in whole tissues. The frequency of mtDNA defects in iPSCs increased with age, and many mutations were non-synonymous or resided in RNA coding genes and thus can lead to respiratory defects. Our results highlight a need to monitor mtDNA mutations in iPSCs, especially those generated from older patients, and to examine the metabolic status of iPSCs destined for clinical applications.
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Affiliation(s)
- Eunju Kang
- Center for Embryonic Cell and Gene Therapy, Oregon Health & Science University, 3303 SW Bond Avenue, Portland, OR 97239, USA; Division of Reproductive and Developmental Sciences, Oregon National Primate Research Center, Oregon Health & Science University, 505 NW 185th Avenue, Beaverton, OR 97006, USA
| | - Xinjian Wang
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH 45229, USA
| | - Rebecca Tippner-Hedges
- Center for Embryonic Cell and Gene Therapy, Oregon Health & Science University, 3303 SW Bond Avenue, Portland, OR 97239, USA; Division of Reproductive and Developmental Sciences, Oregon National Primate Research Center, Oregon Health & Science University, 505 NW 185th Avenue, Beaverton, OR 97006, USA
| | - Hong Ma
- Center for Embryonic Cell and Gene Therapy, Oregon Health & Science University, 3303 SW Bond Avenue, Portland, OR 97239, USA; Division of Reproductive and Developmental Sciences, Oregon National Primate Research Center, Oregon Health & Science University, 505 NW 185th Avenue, Beaverton, OR 97006, USA
| | - Clifford D L Folmes
- Department of Medicine, Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN 55905, USA
| | - Nuria Marti Gutierrez
- Center for Embryonic Cell and Gene Therapy, Oregon Health & Science University, 3303 SW Bond Avenue, Portland, OR 97239, USA; Division of Reproductive and Developmental Sciences, Oregon National Primate Research Center, Oregon Health & Science University, 505 NW 185th Avenue, Beaverton, OR 97006, USA
| | - Yeonmi Lee
- Center for Embryonic Cell and Gene Therapy, Oregon Health & Science University, 3303 SW Bond Avenue, Portland, OR 97239, USA; Division of Reproductive and Developmental Sciences, Oregon National Primate Research Center, Oregon Health & Science University, 505 NW 185th Avenue, Beaverton, OR 97006, USA
| | - Crystal Van Dyken
- Center for Embryonic Cell and Gene Therapy, Oregon Health & Science University, 3303 SW Bond Avenue, Portland, OR 97239, USA; Division of Reproductive and Developmental Sciences, Oregon National Primate Research Center, Oregon Health & Science University, 505 NW 185th Avenue, Beaverton, OR 97006, USA
| | - Riffat Ahmed
- Center for Embryonic Cell and Gene Therapy, Oregon Health & Science University, 3303 SW Bond Avenue, Portland, OR 97239, USA; Division of Reproductive and Developmental Sciences, Oregon National Primate Research Center, Oregon Health & Science University, 505 NW 185th Avenue, Beaverton, OR 97006, USA
| | - Ying Li
- Center for Embryonic Cell and Gene Therapy, Oregon Health & Science University, 3303 SW Bond Avenue, Portland, OR 97239, USA; Division of Reproductive and Developmental Sciences, Oregon National Primate Research Center, Oregon Health & Science University, 505 NW 185th Avenue, Beaverton, OR 97006, USA
| | - Amy Koski
- Center for Embryonic Cell and Gene Therapy, Oregon Health & Science University, 3303 SW Bond Avenue, Portland, OR 97239, USA; Division of Reproductive and Developmental Sciences, Oregon National Primate Research Center, Oregon Health & Science University, 505 NW 185th Avenue, Beaverton, OR 97006, USA
| | - Tomonari Hayama
- Center for Embryonic Cell and Gene Therapy, Oregon Health & Science University, 3303 SW Bond Avenue, Portland, OR 97239, USA; Division of Reproductive and Developmental Sciences, Oregon National Primate Research Center, Oregon Health & Science University, 505 NW 185th Avenue, Beaverton, OR 97006, USA
| | - Shiyu Luo
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH 45229, USA
| | - Cary O Harding
- Department of Molecular and Medical Genetics, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
| | - Paula Amato
- Division of Reproductive Endocrinology, Department of Obstetrics and Gynecology, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
| | - Jeffrey Jensen
- Division of Reproductive Endocrinology, Department of Obstetrics and Gynecology, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
| | - David Battaglia
- Division of Reproductive Endocrinology, Department of Obstetrics and Gynecology, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
| | - David Lee
- Division of Reproductive Endocrinology, Department of Obstetrics and Gynecology, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
| | - Diana Wu
- Division of Reproductive Endocrinology, Department of Obstetrics and Gynecology, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
| | - Andre Terzic
- Department of Medicine, Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN 55905, USA
| | - Don P Wolf
- Center for Embryonic Cell and Gene Therapy, Oregon Health & Science University, 3303 SW Bond Avenue, Portland, OR 97239, USA; Division of Reproductive and Developmental Sciences, Oregon National Primate Research Center, Oregon Health & Science University, 505 NW 185th Avenue, Beaverton, OR 97006, USA
| | - Taosheng Huang
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH 45229, USA.
| | - Shoukhrat Mitalipov
- Center for Embryonic Cell and Gene Therapy, Oregon Health & Science University, 3303 SW Bond Avenue, Portland, OR 97239, USA; Division of Reproductive and Developmental Sciences, Oregon National Primate Research Center, Oregon Health & Science University, 505 NW 185th Avenue, Beaverton, OR 97006, USA; Department of Molecular and Medical Genetics, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA; Division of Reproductive Endocrinology, Department of Obstetrics and Gynecology, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA; Knight Cardiovascular Institute, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA; Department of Biomedical Engineering, Oregon Health & Science University, 3303 SW Bond Avenue, Portland, OR 97239, USA.
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23
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Tang X, Zheng J, Ying Z, Cai Z, Gao Y, He Z, Yu H, Yao J, Yang Y, Wang H, Chen Y, Guan MX. Mitochondrial tRNA(Ser(UCN)) variants in 2651 Han Chinese subjects with hearing loss. Mitochondrion 2015; 23:17-24. [PMID: 25968158 DOI: 10.1016/j.mito.2015.05.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Revised: 04/14/2015] [Accepted: 05/04/2015] [Indexed: 12/17/2022]
Abstract
Mutations in the mitochondrial DNA have been associated with hearing loss. However, the prevalence and spectrum of mitochondrial tRNA mutations in hearing-impaired subjects are poorly understood. In this report, we have investigated the prevalence and spectrum of mitochondrial tRNA(Ser(UCN)) mutations in a large cohort of 2651 Han Chinese subjects with hearing loss. The clinical evaluation showed that 744 subjects (432 males and 312 females) had a history of exposure to aminoglycosides and other probands exhibited nonsyndromic hearing loss. Mutational analysis of tRNA(Ser(UCN)) gene identified 9 (8 known and 1 novel) variants. The prevalence of the known deafness-associated 7511T>C, 7505T>C and 7445A>C mutations was 0.04%, 0.04% and 0.04%, respectively. Other variants were evaluated by the evolutionary conservation, allelic frequency of Chinese controls, potential structural and functional alterations and pedigree analysis. Three variants were polymorphisms, while the 7444G>A, 7471DelG and 7496A>G variants were putative deafness-associated mutations. These putative deafness-associated variants accounted for 0.68% cases of hearing-impaired subjects in this cohort. The low penetrance of hearing loss in pedigrees carrying one of these putative deafness-associated mutations indicated that the mutation(s) is necessary but itself insufficient to produce a clinical phenotype. Other genetic or environmental factor(s) may influence the phenotypic manifestation of these tRNA(Ser(UCN)) mutations. Moreover, mtDNAs in 20 probands carrying one of the putative deafness-associated mutations were widely dispersed among 8 Eastern Asian haplogroups. In particular, the occurrences of haplogroups D4a, M22, and H2 in patients carrying the deafness-associated variants were higher than those in Chinese controls. These data further support that the mitochondrial tRNA(Ser(UCN)) gene is the hot spot for mutations associated with hearing loss. Thus, our findings may provide valuable information for the further understanding of pathophysiology and management of hearing loss.
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Affiliation(s)
- Xiaowen Tang
- Attardi Institute of Mitochondrial Biomedicine, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Jing Zheng
- Institute of Genetics, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Zhengbiao Ying
- Department of Otolaryngology, Wenling People's Hospital, Wenzhou Medical University, Wenling, Zhejiang, China
| | - Zhaoyang Cai
- Department of Otolaryngology, Wenling People's Hospital, Wenzhou Medical University, Wenling, Zhejiang, China
| | - Yinglong Gao
- Attardi Institute of Mitochondrial Biomedicine, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Zheyun He
- Attardi Institute of Mitochondrial Biomedicine, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Han Yu
- Attardi Institute of Mitochondrial Biomedicine, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Juan Yao
- Attardi Institute of Mitochondrial Biomedicine, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Yaling Yang
- Attardi Institute of Mitochondrial Biomedicine, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Hui Wang
- Attardi Institute of Mitochondrial Biomedicine, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Ye Chen
- Institute of Genetics, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Min-Xin Guan
- Attardi Institute of Mitochondrial Biomedicine, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China; Institute of Genetics, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China.
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24
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Luo Z. Mitochondrial tRNAArg T10454C variant may not influence the clinical expression of deafness associated 12S rRNA A1555G mutation. Mitochondrial DNA A DNA Mapp Seq Anal 2014; 27:1137-40. [PMID: 24983150 DOI: 10.3109/19401736.2014.933337] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
In this study, we examined the "pathogenic" role of the T10454C mutation in mitochondrial tRNA(Arg) gene in deafness expression as increasing reports provided an active role of this mutation in clinical manifestation of deafness associated 12S rRNA A1555G mutation. For this purpose, we reanalyzed the complete mitochondrial DNA (mtDNA) sequence data containing the T10454C mutation. Moreover, we analyzed the reported "polymorphisms" of mtDNA in the proband using the phylogentic approach. To our surprise, other mutations which occurred at protein-coding genes played more important roles in resulting mitochondrial dysfunctions by using the bioinformatic tool. In addition, evolutionary conservation analysis of the T10454C mutation indicated that this mutation was not conserved between different species. To our knowledge, this is the first report that the T10454C variant may not modulate the phenotypic expression of the deafness associated A1555G mutation.
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Affiliation(s)
- Zhiyi Luo
- a Department of the Emergency Center , The First Affiliated Hospital of Zhengzhou University , Zhengzhou , China
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25
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Gong S, Peng Y, Jiang P, Wang M, Fan M, Wang X, Zhou H, Li H, Yan Q, Huang T, Guan MX. A deafness-associated tRNAHis mutation alters the mitochondrial function, ROS production and membrane potential. Nucleic Acids Res 2014; 42:8039-48. [PMID: 24920829 PMCID: PMC4081083 DOI: 10.1093/nar/gku466] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
In this report, we investigated the molecular genetic mechanism underlying the deafness-associated mitochondrial tRNAHis 12201T>C mutation. The destabilization of a highly conserved base-pairing (5A-68U) by the m.12201T>C mutation alters structure and function of tRNAHis. Using cybrids constructed by transferring mitochondria from lymphoblastoid cell lines derived from a Chinese family into mtDNA-less (ρo) cells, we showed ∼70% decrease in the steady-state level of tRNAHis in mutant cybrids, compared with control cybrids. The mutation changed the conformation of tRNAHis, as suggested by slower electrophoretic mobility of mutated tRNA with respect to the wild-type molecule. However, ∼60% increase in aminoacylated level of tRNAHis was observed in mutant cells. The failure in tRNAHis metabolism was responsible for the variable reductions in seven mtDNA-encoded polypeptides in mutant cells, ranging from 37 to 81%, with the average of ∼46% reduction, as compared with those of control cells. The impaired mitochondrial translation caused defects in respiratory capacity in mutant cells. Furthermore, marked decreases in the levels of mitochondrial ATP and membrane potential were observed in mutant cells. These mitochondrial dysfunctions caused an increase in the production of reactive oxygen species in the mutant cells. The data provide the evidence for a mitochondrial tRNAHis mutation leading to deafness.
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Affiliation(s)
- Shasha Gong
- Institute of Genetics, Zhejiang University, Hangzhou, Zhejiang, China 310058
| | - Yanyan Peng
- Institute of Genetics, Zhejiang University, Hangzhou, Zhejiang, China 310058 Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA 45229
| | - Pingping Jiang
- Institute of Genetics, Zhejiang University, Hangzhou, Zhejiang, China 310058
| | - Meng Wang
- Institute of Genetics, Zhejiang University, Hangzhou, Zhejiang, China 310058
| | - Mingjie Fan
- Institute of Genetics, Zhejiang University, Hangzhou, Zhejiang, China 310058
| | - Xinjian Wang
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA 45229
| | - Hong Zhou
- Institute of Genetics, Zhejiang University, Hangzhou, Zhejiang, China 310058
| | - Huawei Li
- Department of Otology and Skull Base Surgery, Eye and ENT Hospital, Fudan University, Shanghai, China 200031
| | - Qingfeng Yan
- Institute of Genetics, Zhejiang University, Hangzhou, Zhejiang, China 310058
| | - Taosheng Huang
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA 45229
| | - Min-Xin Guan
- Institute of Genetics, Zhejiang University, Hangzhou, Zhejiang, China 310058 Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA 45229
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26
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Abbott JA, Francklyn CS, Robey-Bond SM. Transfer RNA and human disease. Front Genet 2014; 5:158. [PMID: 24917879 PMCID: PMC4042891 DOI: 10.3389/fgene.2014.00158] [Citation(s) in RCA: 150] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Accepted: 05/14/2014] [Indexed: 12/25/2022] Open
Abstract
Pathological mutations in tRNA genes and tRNA processing enzymes are numerous and result in very complicated clinical phenotypes. Mitochondrial tRNA (mt-tRNA) genes are “hotspots” for pathological mutations and over 200 mt-tRNA mutations have been linked to various disease states. Often these mutations prevent tRNA aminoacylation. Disrupting this primary function affects protein synthesis and the expression, folding, and function of oxidative phosphorylation enzymes. Mitochondrial tRNA mutations manifest in a wide panoply of diseases related to cellular energetics, including COX deficiency (cytochrome C oxidase), mitochondrial myopathy, MERRF (Myoclonic Epilepsy with Ragged Red Fibers), and MELAS (mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes). Diseases caused by mt-tRNA mutations can also affect very specific tissue types, as in the case of neurosensory non-syndromic hearing loss and pigmentary retinopathy, diabetes mellitus, and hypertrophic cardiomyopathy. Importantly, mitochondrial heteroplasmy plays a role in disease severity and age of onset as well. Not surprisingly, mutations in enzymes that modify cytoplasmic and mitochondrial tRNAs are also linked to a diverse range of clinical phenotypes. In addition to compromised aminoacylation of the tRNAs, mutated modifying enzymes can also impact tRNA expression and abundance, tRNA modifications, tRNA folding, and even tRNA maturation (e.g., splicing). Some of these pathological mutations in tRNAs and processing enzymes are likely to affect non-canonical tRNA functions, and contribute to the diseases without significantly impacting on translation. This chapter will review recent literature on the relation of mitochondrial and cytoplasmic tRNA, and enzymes that process tRNAs, to human disease. We explore the mechanisms involved in the clinical presentation of these various diseases with an emphasis on neurological disease.
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Affiliation(s)
- Jamie A Abbott
- Department of Biochemistry, College of Medicine, University of Vermont Burlington, VT, USA
| | | | - Susan M Robey-Bond
- Department of Biochemistry, College of Medicine, University of Vermont Burlington, VT, USA
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27
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Blakely EL, Yarham JW, Alston CL, Craig K, Poulton J, Brierley C, Park SM, Dean A, Xuereb JH, Anderson KN, Compston A, Allen C, Sharif S, Enevoldson P, Wilson M, Hammans SR, Turnbull DM, McFarland R, Taylor RW. Pathogenic mitochondrial tRNA point mutations: nine novel mutations affirm their importance as a cause of mitochondrial disease. Hum Mutat 2014; 34:1260-8. [PMID: 23696415 PMCID: PMC3884772 DOI: 10.1002/humu.22358] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Accepted: 05/10/2013] [Indexed: 11/26/2022]
Abstract
Mutations in the mitochondrial genome, and in particular the mt-tRNAs, are an important cause of human disease. Accurate classification of the pathogenicity of novel variants is vital to allow accurate genetic counseling for patients and their families. The use of weighted criteria based on functional studies—outlined in a validated pathogenicity scoring system—is therefore invaluable in determining whether novel or rare mt-tRNA variants are pathogenic. Here, we describe the identification of nine novel mt-tRNA variants in nine families, in which the probands presented with a diverse range of clinical phenotypes including mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes, isolated progressive external ophthalmoplegia, epilepsy, deafness and diabetes. Each of the variants identified (m.4289T>C, MT-TI; m.5541C>T, MT-TW; m.5690A>G, MT-TN; m.7451A>T, MT-TS1; m.7554G>A, MT-TD; m.8304G>A, MT-TK; m.12206C>T, MT-TH; m.12317T>C, MT-TL2; m.16023G>A, MT-TP) was present in a different tRNA, with evidence in support of pathogenicity, and where possible, details of mutation transmission documented. Through the application of the pathogenicity scoring system, we have classified six of these variants as “definitely pathogenic” mutations (m.5541C>T, m.5690A>G, m.7451A>T, m.12206C>T, m.12317T>C, and m.16023G>A), whereas the remaining three currently lack sufficient evidence and are therefore classed as ‘possibly pathogenic’ (m.4289T>C, m.7554G>A, and m.8304G>A).
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Affiliation(s)
- Emma L Blakely
- Wellcome Trust Centre for Mitochondrial Research, Institute for Ageing and Health, Newcastle University, Newcastle upon Tyne, UK
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Qin Y, Xue L, Jiang P, Xu M, He Y, Shi S, Huang Y, He J, Mo JQ, Guan MX. Mitochondrial tRNA variants in Chinese subjects with coronary heart disease. J Am Heart Assoc 2014; 3:e000437. [PMID: 24470521 PMCID: PMC3959674 DOI: 10.1161/jaha.113.000437] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND Coronary heart disease is the leading cause of death worldwide. Mitochondrial genetic determinants for the development of this disorder remain less explored. METHODS AND RESULTS We performed a clinical and genetic evaluation and mutational screening of 22 mitochondrial tRNA genes in a cohort of 80 genetically unrelated Han Chinese subjects and 125 members of 4 families with coronary heart disease and 512 Chinese control subjects. This analysis identified 16 nucleotide changes among 9 tRNA genes. Of these, the T5592C mutation creates a highly conservative base pairing (5G-68C) on the acceptor stem of tRNA(Gln), whereas the G15927A mutation destabilizes a highly conserved base pairing (28C-42G) in the anticodon stem of tRNA(Thr). However, the other tRNA variants were polymorphisms. The pedigrees of BJH24 carrying the T5592C mutation, BJH15, and BJH45 harboring the G15927A mutation exhibited maternal transmission of coronary heart disease. Sequence analysis of their mitochondrial genomes revealed the presence of T5592C or G15927A mutation but the absence of other functionally significant mutations in all matrilineal relatives of these families. CONCLUSIONS Our previous observations showed that altered structures of tRNAs by these mtDNA mutations caused mitochondrial dysfunction. These may be the first evidence that mtDNA mutations increase the risk of coronary heart disease. Our findings may provide new insights into the pathophysiology of this disorder.
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Affiliation(s)
- Yanwen Qin
- Beijing An Zhen Hospital, Capital Medical University, Beijing Institute of Heart Lung and Blood Vessel Diseases, Beijing, China
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29
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Liu Z, Song Y, Li D, He X, Li S, Wu B, Wang W, Gu S, Zhu X, Wang X, Zhou Q, Dai Y, Yan Q. The novel mitochondrial 16S rRNA 2336T>C mutation is associated with hypertrophic cardiomyopathy. J Med Genet 2013; 51:176-84. [PMID: 24367055 PMCID: PMC3932983 DOI: 10.1136/jmedgenet-2013-101818] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Background Hypertrophic cardiomyopathy (HCM) is a primary disorder characterised by asymmetric thickening of septum and left ventricular wall, with a prevalence of 0.2% in the general population. Objective To describe a novel mitochondrial DNA mutation and its association with the pathogenesis of HCM. Methods and results All maternal members of a Chinese family with maternally transmitted HCM exhibited variable severity and age at onset, and were implanted permanent pacemakers due to complete atrioventricular block (AVB). Nuclear gene screening (MYH7, MYBPC3, TNNT2 and TNNI3) was performed, and no potential pathogenic mutation was identified. Mitochondrial DNA sequencing analysis identified a novel homoplasmic 16S rRNA 2336T>C mutation. This mutation was exclusively present in maternal members and absent in non-maternal members. Conservation index by comparison to 16 other vertebrates was 94.1%. This mutation disturbs the 2336U-A2438 base pair in the stem–loop structure of 16S rRNA domain III, which is involved in the assembly of mitochondrial ribosome. Oxygen consumption rate of the lymphoblastoid cells carrying 2336T>C mutation had decreased by 37% compared with controls. A reduction in mitochondrial ATP synthesis and an increase in reactive oxidative species production were also observed. Electron microscopic analysis indicated elongated mitochondria and abnormal mitochondrial cristae shape in mutant cells. Conclusions It is suggested that the 2336T>C mutation is one of pathogenic mutations of HCM. This is the first report of mitochondrial 16S rRNA 2336T>C mutation and an association with maternally inherited HCM combined with AVB. Our findings provide a new insight into the pathogenesis of HCM.
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Affiliation(s)
- Zhong Liu
- The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
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Bandelt HJ, Kloss-Brandstätter A, Richards MB, Yao YG, Logan I. The case for the continuing use of the revised Cambridge Reference Sequence (rCRS) and the standardization of notation in human mitochondrial DNA studies. J Hum Genet 2013; 59:66-77. [PMID: 24304692 DOI: 10.1038/jhg.2013.120] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Revised: 09/29/2013] [Accepted: 10/25/2013] [Indexed: 02/06/2023]
Abstract
Since the determination in 1981 of the sequence of the human mitochondrial DNA (mtDNA) genome, the Cambridge Reference Sequence (CRS), has been used as the reference sequence to annotate mtDNA in molecular anthropology, forensic science and medical genetics. The CRS was eventually upgraded to the revised version (rCRS) in 1999. This reference sequence is a convenient device for recording mtDNA variation, although it has often been misunderstood as a wild-type (WT) or consensus sequence by medical geneticists. Recently, there has been a proposal to replace the rCRS with the so-called Reconstructed Sapiens Reference Sequence (RSRS). Even if it had been estimated accurately, the RSRS would be a cumbersome substitute for the rCRS, as the new proposal fuses--and thus confuses--the two distinct concepts of ancestral lineage and reference point for human mtDNA. Instead, we prefer to maintain the rCRS and to report mtDNA profiles by employing the hitherto predominant circumfix style. Tree diagrams could display mutations by using either the profile notation (in conventional short forms where appropriate) or in a root-upwards way with two suffixes indicating ancestral and derived nucleotides. This would guard against misunderstandings about reporting mtDNA variation. It is therefore neither necessary nor sensible to change the present reference sequence, the rCRS, in any way. The proposed switch to RSRS would inevitably lead to notational chaos, mistakes and misinterpretations.
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Affiliation(s)
| | - Anita Kloss-Brandstätter
- Division of Genetic Epidemiology, Department of Medical Genetics, Molecular and Clinical Pharmacology, Innsbruck Medical University, Innsbruck, Austria
| | - Martin B Richards
- School of Applied Sciences, University of Huddersfield, Queensgate, Huddersfield, UK
| | - Yong-Gang Yao
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Kunming, Yunnan, China
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31
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Association study of mitochondrial genetic polymorphisms in asthmatic children. Mitochondrion 2013; 14:49-53. [PMID: 24270090 DOI: 10.1016/j.mito.2013.11.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Revised: 09/03/2013] [Accepted: 11/13/2013] [Indexed: 11/21/2022]
Abstract
It has been suggested that mitochondrial dysfunction plays a role in the pathogenesis of asthma. To test whether mitochondrial variants influence the risk of asthma, we analyzed 16,158 mtSNPs in a sample of 372 asthmatic children and 395 healthy children using the DNA pooling technique and genome wide association analysis. Stratified analysis by sex was performed to explain the differences observed between sexes in the etiology of asthma. Different variants were detected to be significant in the sample of girls and boys with the smallest adjusted p values being 1.4 × 10(-09) (mt5295) and 3.6 × 10(-12) (mt16158), respectively. Most of the significant locations found in boys are within the CYB gene and the non-coding region. For girls, most of the significant mtSNPs lie within NADH-dehydrogenase-subunits. The variants reported here have not previously been described in connection with asthma. Although further studies in other cohorts are needed to confirm these findings our study highlights the importance of the mitochondria among the factors that contribute to the risk of asthma.
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Zheng J, Sha-sha G, Xiao-wen T, Yi Z, Min-xin G. Human Mitochondrial tRNA Mutations in Maternally Inherited Deafness. J Otol 2013. [DOI: 10.1016/s1672-2930(13)50006-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Ding Y, Leng J, Fan F, Xia B, Xu P. The role of mitochondrial DNA mutations in hearing loss. Biochem Genet 2013; 51:588-602. [PMID: 23605717 DOI: 10.1007/s10528-013-9589-6] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Accepted: 10/10/2012] [Indexed: 11/29/2022]
Abstract
Mutations in mitochondrial DNA (mtDNA) are one of the most important causes of hearing loss. Of these, the homoplasmic A1555G and C1494T mutations at the highly conserved decoding site of the 12S rRNA gene are well documented as being associated with either aminoglycoside-induced or nonsyndromic hearing loss in many families worldwide. Moreover, five mutations associated with nonsyndromic hearing loss have been identified in the tRNA(Ser(UCN)) gene: A7445G, 7472insC, T7505C, T7510C, and T7511C. Other mtDNA mutations associated with deafness are mainly located in tRNA and protein-coding genes. Failures in mitochondrial tRNA metabolism or protein synthesis were observed from cybrid cells harboring these primary mutations, thereby causing the mitochondrial dysfunctions responsible for deafness. This review article provides a detailed summary of mtDNA mutations that have been reported in deafness and further discusses the molecular mechanisms of these mtDNA mutations in deafness expression.
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Affiliation(s)
- Yu Ding
- Central Laboratory, Hangzhou First People's Hospital, Nanjing Medical University, Huansha Road, Hangzhou, China.
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Non-syndromic Hearing Impairment in a Hungarian Family with the m.7510T>C Mutation of Mitochondrial tRNA(Ser(UCN)) and Review of Published Cases. JIMD Rep 2012; 9:105-111. [PMID: 23430555 DOI: 10.1007/8904_2012_187] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Revised: 09/19/2012] [Accepted: 09/24/2012] [Indexed: 04/06/2023] Open
Abstract
The m.7510T>C mitochondrial DNA (mtDNA) mutation is a tRNA(Ser(UCN)) alteration leading to matrilineal isolated hearing impairment. The current paper reviews the available reports on the m.7510T>C mtDNA mutation, with special attention to phenotypic variations and haplogroup background. A Hungarian family, the fourth family reported in the literature, is presented, in which analysis of three generations with bilateral isolated hearing loss revealed the m.7510T>C tRNA(Ser(UCN)) mutation in homoplasmic form in the affected members. Haplogroup analysis verified an unnamed subgroup of mitochondrial haplogroup H. Previously reported Spanish and North American Caucasian families belong to different subgroups of haplogroup H. Analyzing our biobank of Hungarian patients with sensorineural hearing loss, we did not detect this mutation in any other patient, nor was it found in Caucasian haplogroup H control samples. Comparing the cases reported so far, there is interfamilial variablity in the age of onset, accompanying symptoms, and haplogroup background. Our case adds further genetic evidence for the pathogenicity of the m.7510T>C mutation and underlines the need to include full mtDNA sequencing in the screening for unexplained hearing loss.
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Jing Z, Yan–chun J, Min–Xin G. Mitochondrial tRNA mutations associated with deafness. J Otol 2012. [DOI: 10.1016/s1672-2930(12)50009-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Zheng J, Ji Y, Guan MX. Mitochondrial tRNA mutations associated with deafness. Mitochondrion 2012; 12:406-13. [PMID: 22538251 DOI: 10.1016/j.mito.2012.04.001] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Revised: 03/15/2012] [Accepted: 04/09/2012] [Indexed: 10/28/2022]
Abstract
Mitochondrial tRNA mutations are one of the important causes of both syndromic and non-syndromic deafness. Of those, syndromic deafness-associated tRNA mutations such as tRNA(Leu(UUR)) 3243A>G are often present in heteroplasmy, while non-syndromic deafness-associated tRNA mutations including tRNA(Ser(UCN)) 7445A>G often occur in homplasmy or in high levels of heteroplasmy. These tRNA mutations are the primary mutations leading to hearing loss. However, other tRNA mutations such as tRNA(Thr) 15927G>A and tRNA(Ser(UCN)) 7444G>A may act in synergy with the primary mitochondrial DNA mutations, modulating the phenotypic manifestation of the primary mitochondrial DNA mutations. Theses tRNA mutations cause structural and functional alteration. A failure in tRNA metabolism caused by these tRNA mutations impaired mitochondrial translation and respiration, thereby causing mitochondrial dysfunctions responsible for deafness. These data offer valuable information for the early diagnosis, management and treatment of maternally inherited deafness.
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Affiliation(s)
- Jing Zheng
- Attardi Institute of Mitochondrial Biomedicine, Wenzhou Medical College, Wenzhou, Zhejiang, China
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Chen H, Zheng J, Xue L, Meng Y, Wang Y, Zheng B, Fang F, Shi S, Qiu Q, Jiang P, Lu Z, Mo JQ, Lu J, Guan MX. The 12S rRNA A1555G mutation in the mitochondrial haplogroup D5a is responsible for maternally inherited hypertension and hearing loss in two Chinese pedigrees. Eur J Hum Genet 2012; 20:607-12. [PMID: 22317974 DOI: 10.1038/ejhg.2011.259] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
We reported here clinical, genetic evaluations and molecular analysis of mitochondrial DNA (mtDNA) in two Han Chinese families carrying the known mitochondrial 12S rRNA A1555G mutation. In contrast with the previous data that hearing loss as a sole phenotype was present in the maternal lineage of other families carrying the A1555G mutation, matrilineal relatives among these two Chinese families exhibited both hearing loss and hypertension. Of 21 matrilineal relatives, 9 subjects exhibited both hearing loss and hypertension, 2 individuals suffered from only hypertension and 1 member had only hearing loss. The average age at onset of hypertension in the affected matrilineal relatives of these families was 60 and 46 years, respectively, whereas those of hearing loss in these two families were 33 and 55 years, respectively. Molecular analysis of their mtDNA identified distinct sets of variants belonging to the Eastern Asian haplogroup D5a. In contrast, the A1555G mutation occurred among other mtDNA haplogroups D, B, R, F, G, Y, M and N, respectively. Our data further support that the A1555G mutation is necessary but by itself insufficient to produce the clinical phenotype. The other modifiers are responsible for the phenotypic variability of matrilineal relatives within and among these families carrying the A1555G mutation. Our investigation provides the first evidence that the 12S rRNA A1555G mutation leads to both of hearing loss and hypertension. Thus, our findings may provide the new insights into the understanding of pathophysiology and valuable information for management and treatment of maternally inherited hearing loss and hypertension.
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Affiliation(s)
- Hong Chen
- Attardi Institute of Mitochondrial Biomedicine and Zhejiang Provincial Key Laboratory of Medical Genetics, Wenzhou Medical College, Wenzhou, Zhejiang, China
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