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Ding Y, Yu XJ, Guo QX, Leng JH. Functional analysis of the novel mitochondrial tRNA Trp and tRNA Ser(AGY) variants associated with type 2 diabetes mellitus. World J Diabetes 2024; 15:1753-1763. [PMID: 39192858 PMCID: PMC11346085 DOI: 10.4239/wjd.v15.i8.1753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 05/09/2024] [Accepted: 06/18/2024] [Indexed: 07/25/2024] Open
Abstract
BACKGROUND Mutations in mitochondrial tRNA (mt-tRNA) genes that result in mitochondrial dysfunction play important roles in type 2 diabetes mellitus (T2DM). We pre-viously reported a large Chinese pedigree with maternally inherited T2DM that harbors novel mt-tRNA Trp A5514G and tRNA Ser(AGY) C12237T variants, however, the effects of these mt-tRNA variants on T2DM progression are largely unknown. AIM To assess the potential pathogenicity of T2DM-associated m.A5514G and m.C12237T variants at genetic, molecular, and biochemical levels. METHODS Cytoplasmic hybrid (cybrid) cells carrying both m.A5514G and m.C12237T variants, and healthy control cells without these mitochondrial DNA (mtDNA) variants were generated using trans-mitochondrial technology. Mitochondrial features, including mt-tRNA steady-state level, levels of adenosine triphosphate (ATP), mitochondrial membrane potential (MMP), reactive oxygen species (ROS), mtDNA copy number, nicotinamide adenine dinucleotide (NAD+)/NADH ratio, enzymatic activities of respiratory chain complexes (RCCs), 8-hydroxy-deo-xyguanine (8-OhdG), malondialdehyde (MDA), and superoxide dismutase (SOD) were examined in cell lines with and without these mt-tRNA variants. RESULTS Compared with control cells, the m.A5514G variant caused an approximately 35% reduction in the steady-state level of mt-tRNA Trp (P < 0.0001); however, the m.C12237T variant did not affect the mt-tRNA Ser(AGY) steady-state level (P = 0.5849). Biochemical analysis revealed that cells with both m.A5514G and m.C12237T variants exhibited more severe mitochondrial dysfunctions and elevated oxidative stress than control cells: ATP, MMP, NAD+/NADH ratio, enzyme activities of RCCs and SOD levels were markedly decreased in mutant cells (P < 0.05 for all measures). By contrast, the levels of ROS, 8-OhdG and MDA were significantly increased (P < 0.05 for all measures), but mtDNA copy number was not affected by m.A5514G and m.C12237T variants (P = 0.5942). CONCLUSION The m.A5514G variant impaired mt-tRNA Trp metabolism, which subsequently caused mitochondrial dysfunction. The m.C12237T variant did not alter the steady-state level of mt-tRNA Ser(AGY), indicating that it may be a modifier of the m.A5514G variant. The m.A5514G variant may exacerbate the pathogenesis and progression of T2DM in this Chinese pedigree.
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Affiliation(s)
- Yu Ding
- Central Laboratory, Hangzhou First People’s Hospital, Hangzhou 310006, Zhejiang Province, China
| | - Xue-Jiao Yu
- Clinical Laboratory, Quzhou People’s Hospital, Quzhou 324000, Zhejiang Province, China
| | - Qin-Xian Guo
- Central Laboratory, Hangzhou First People’s Hospital, Hangzhou 310006, Zhejiang Province, China
| | - Jian-Hang Leng
- Central Laboratory, Hangzhou First People’s Hospital, Hangzhou 310006, Zhejiang Province, China
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Chen X, Meng F, Chen C, Li S, Chou Z, Xu B, Mo JQ, Guo Y, Guan MX. Deafness-associated tRNA Phe mutation impaired mitochondrial and cellular integrity. J Biol Chem 2024; 300:107235. [PMID: 38552739 PMCID: PMC11046301 DOI: 10.1016/j.jbc.2024.107235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2024] [Revised: 03/06/2024] [Accepted: 03/18/2024] [Indexed: 04/23/2024] Open
Abstract
Defects in mitochondrial RNA metabolism have been linked to sensorineural deafness that often occurs as a consequence of damaged or deficient inner ear hair cells. In this report, we investigated the molecular mechanism underlying a deafness-associated tRNAPhe 593T > C mutation that changed a highly conserved uracil to cytosine at position 17 of the DHU-loop. The m.593T > C mutation altered tRNAPhe structure and function, including increased melting temperature, resistance to S1 nuclease-mediated digestion, and conformational changes. The aberrant tRNA metabolism impaired mitochondrial translation, which was especially pronounced by decreases in levels of ND1, ND5, CYTB, CO1, and CO3 harboring higher numbers of phenylalanine. These alterations resulted in aberrant assembly, instability, and reduced activities of respiratory chain enzyme complexes I, III, IV, and intact supercomplexes overall. Furthermore, we found that the m.593T > C mutation caused markedly diminished membrane potential, and increased the production of reactive oxygen species in the mutant cell lines carrying the m.593T > C mutation. These mitochondrial dysfunctions led to the mitochondrial dynamic imbalance via increasing fission with abnormal mitochondrial morphology. Excessive fission impaired the process of autophagy including the initiation phase, formation, and maturation of the autophagosome. In particular, the m.593T > C mutation upregulated the PARKIN-dependent mitophagy pathway. These alterations promoted an intrinsic apoptotic process for the removal of damaged cells. Our findings provide critical insights into the pathophysiology of maternally inherited deafness arising from tRNA mutation-induced defects in mitochondrial and cellular integrity.
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Affiliation(s)
- Xiaowan Chen
- Department of Otolaryngology-Head and Neck Surgery, Lanzhou University First Hospital, Lanzhou, Gansu, China; Institute of Genetics, Zhejiang University International School of Medicine, Hangzhou, Zhejiang, China
| | - Feilong Meng
- Institute of Genetics, Zhejiang University International School of Medicine, Hangzhou, Zhejiang, China; Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Chao Chen
- Institute of Genetics, Zhejiang University International School of Medicine, Hangzhou, Zhejiang, China; Center for Mitochondrial Biomedicine, The Fourth Affiliated Hospital Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Shujuan Li
- Department of Otolaryngology-Head and Neck Surgery, Gansu Provincial Hospital, Lanzhou, Gansu, China
| | - Zhiqiang Chou
- Department of Otolaryngology-Head and Neck Surgery, Lanzhou University First Hospital, Lanzhou, Gansu, China
| | - Baicheng Xu
- Department of Otolaryngology-Head and Neck Surgery, Lanzhou University Second Hospital, Lanzhou, Gansu, China
| | - Jun Q Mo
- Department of Pathology, Rady Children's Hospital, University of California School of Medicine, San Diego, California, USA
| | - Yufen Guo
- Department of Otolaryngology-Head and Neck Surgery, Lanzhou University Second Hospital, Lanzhou, Gansu, China
| | - Min-Xin Guan
- Institute of Genetics, Zhejiang University International School of Medicine, Hangzhou, Zhejiang, China; Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China; Center for Mitochondrial Biomedicine, The Fourth Affiliated Hospital Zhejiang University School of Medicine, Hangzhou, Zhejiang, China; Zhejiang Provincial Lab of Genetics and Genomics, Zhejiang University, Hangzhou, Zhejiang, China.
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3
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Guo M, He Y, Chen A, Zhuang Z, Pan X, Guan M. Clinical and genetic analysis of essential hypertension with mitochondrial tRNA Met 4435A>G and YARS2 mutation. Zhejiang Da Xue Xue Bao Yi Xue Ban 2024; 53:184-193. [PMID: 38562030 PMCID: PMC11057996 DOI: 10.3724/zdxbyxb-2023-0571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Accepted: 02/23/2024] [Indexed: 04/04/2024]
Abstract
OBJECTIVES To investigate the role of m.4435A>G and YARS2 c.572G>T (p.G191V) mutations in the development of essential hypertension. METHODS A hypertensive patient with m.4435A>G and YARS2 p.G191V mutations was identified from previously collected mitochondrial genome and exon sequencing data. Clinical data were collected, and a molecular genetic study was conducted in the proband and his family members. Peripheral venous blood was collected, and immortalized lymphocyte lines constructed. The mitochondrial transfer RNA (tRNA), mitochondrial protein, adenosine triphosphate (ATP), mitochondrial membrane potential (MMP), and reactive oxygen species (ROS) in the constructed lymphocyte cell lines were measured. RESULTS Mitochondrial genome sequencing showed that all maternal members carried a highly conserved m.4435A>G mutation. The m.4435A>G mutation might affect the secondary structure and folding free energy of mitochondrial tRNA and change its stability, which may influence the anticodon ring structure. Compared with the control group, the cell lines carrying m.4435A>G and YARS2 p.G191V mutations had decreased mitochondrial tRNA homeostasis, mitochondrial protein expression, ATP production and MMP levels, as well as increased ROS levels (all P<0.05). CONCLUSIONS The YARS2 p.G191V mutation aggravates the changes in mitochondrial translation and mitochondrial function caused by m.4435A>G through affecting the steady-state level of mitochondrial tRNA and further leads to cell dysfunction, indicating that YARS2 p.G191V and m.4435A>G mutations have a synergistic effect in this family and jointly participate in the occurrence and development of essential hypertension.
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Affiliation(s)
- Meili Guo
- Clinical Laboratory, Cangnan County People's Hospital, Wenzhou 325800, Zhejiang Province, China.
| | - Yunfan He
- Institute of Genetics, Zhejiang University, Zhejiang Provincial Key Lab of Genetic and Developmental Disorders, Hangzhou 310058, China
| | - Ade Chen
- Clinical Laboratory, Cangnan County People's Hospital, Wenzhou 325800, Zhejiang Province, China
| | - Zaishou Zhuang
- Clinical Laboratory, Cangnan County People's Hospital, Wenzhou 325800, Zhejiang Province, China
| | - Xiaoyong Pan
- Clinical Laboratory, Cangnan County People's Hospital, Wenzhou 325800, Zhejiang Province, China
| | - Minxin Guan
- Institute of Genetics, Zhejiang University, Zhejiang Provincial Key Lab of Genetic and Developmental Disorders, Hangzhou 310058, China.
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4
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Suo L, Liang X, Zhang W, Gao M, Ma T, Hu D, Song Y, Gao Z. Potential prognostic biomarkers of hepatocellular carcinoma based on 4D label-free quantitative proteomics analysis pilot investigation. Int J Biol Markers 2024; 39:59-69. [PMID: 37956648 DOI: 10.1177/03936155231212925] [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] [Indexed: 11/15/2023]
Abstract
BACKGROUND Hepatocellular carcinoma carries a poor prognosis and poses a serious threat to global health. Currently, there are few potential prognostic biomarkers available for the prognosis of hepatocellular carcinoma. METHODS This pilot study used 4D label-free quantitative proteomics to compare the proteomes of hepatocellular carcinoma and adjacent non-tumor tissue. A total of 66,075 peptides, 6363 identified proteins, and 772 differentially expressed proteins were identified in specimens from three hepatocellular carcinoma patients. Through functional enrichment analysis of differentially expressed proteins by Gene Ontology, KEGG pathway, and protein domain, we identified proteins with similar functions. RESULTS Twelve differentially expressed proteins (RPL17, RPL27, RPL27A, RPS5, RPS16, RSL1D1, DDX18, RRP12, TARS2, YARS2, MARS2, and NARS1) were selected for identification and validation by parallel reaction monitoring. Subsequent Western blotting confirmed overexpression of RPL27, RPS16, and TARS2 in hepatocellular carcinoma compared to non-tumor tissue in 16 pairs of clinical samples. Analysis of The Cancer Genome Atlas datasets associated the increased expression of these proteins with poor prognosis. Tissue microarray revealed a negative association between high expression of RPL27 and TARS2 and the prognosis of hepatocellular carcinoma patients, although RPS16 was not significant. CONCLUSIONS These data suggest that RPL27 and TARS2 play an important role in hepatocellular carcinoma progression and may be potential prognostic biomarkers of overall survival in hepatocellular carcinoma patients.
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Affiliation(s)
- Lida Suo
- Division of Hepatobiliary and Pancreatic Surgery, Department of General Surgery, The Second Hospital of Dalian Medical University, Dalian, China
| | - Xiangnan Liang
- Division of Hepatobiliary and Pancreatic Surgery, Department of General Surgery, The Second Hospital of Dalian Medical University, Dalian, China
| | - Weibin Zhang
- Division of Hepatobiliary and Pancreatic Surgery, Department of General Surgery, The Second Hospital of Dalian Medical University, Dalian, China
| | - Mingwei Gao
- Division of Hepatobiliary and Pancreatic Surgery, Department of General Surgery, The Second Hospital of Dalian Medical University, Dalian, China
| | - Taiheng Ma
- Division of Hepatobiliary and Pancreatic Surgery, Department of General Surgery, The Second Hospital of Dalian Medical University, Dalian, China
| | - Daosheng Hu
- Division of Hepatobiliary and Pancreatic Surgery, Department of General Surgery, The Second Hospital of Dalian Medical University, Dalian, China
| | - Yilin Song
- Division of Hepatobiliary and Pancreatic Surgery, Department of General Surgery, The Second Hospital of Dalian Medical University, Dalian, China
| | - Zhenming Gao
- Division of Hepatobiliary and Pancreatic Surgery, Department of General Surgery, The Second Hospital of Dalian Medical University, Dalian, China
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Wu TH, Peng J, Yang L, Chen YH, Lu XL, Huang JT, You JY, Ou-Yang WX, Sun YY, Xue YN, Mao X, Yan HM, Ren RN, Xie J, Chen ZH, Zhang VW, Lyu GZ, He F. Use of dual genomic sequencing to screen mitochondrial diseases in pediatrics: a retrospective analysis. Sci Rep 2023; 13:4193. [PMID: 36918699 PMCID: PMC10015028 DOI: 10.1038/s41598-023-31134-5] [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: 11/15/2022] [Accepted: 03/07/2023] [Indexed: 03/16/2023] Open
Abstract
Mitochondrial diseases (MDs) were a large group multisystem disorders, attributable in part to the dual genomic control. The advent of massively sequencing has improved diagnostic rates and speed, and was increasingly being used as a first-line diagnostic test. Paediatric patients (aged < 18 years) who underwent dual genomic sequencing were enrolled in this retrospective multicentre study. We evaluated the mitochondrial disease criteria (MDC) and molecular diagnostic yield of dual genomic sequencing. Causative variants were identified in 177 out of 503 (35.2%) patients using dual genomic sequencing. Forty-six patients (9.1%) had mitochondria-related variants, including 25 patients with nuclear DNA (nDNA) variants, 15 with mitochondrial DNA (mtDNA) variants, and six with dual genomic variants (MT-ND6 and POLG; MT-ND5 and RARS2; MT-TL1 and NARS2; MT-CO2 and NDUFS1; MT-CYB and SMARCA2; and CHRNA4 and MT-CO3). Based on the MDC, 15.2% of the patients with mitochondria-related variants were classified as "unlikely to have mitochondrial disorder". Moreover, 4.5% of the patients with non-mitochondria-related variants and 1.43% with negative genetic tests, were classified as "probably having mitochondrial disorder". Dual genomic sequencing in suspected MDs provided a more comprehensive and accurate diagnosis for pediatric patients, especially for patients with dual genomic variants.
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Affiliation(s)
- Teng-Hui Wu
- Department of Pediatrics, Xiangya Hospital Central South University, 87 Xiangya Road, Changsha, 410008, Hunan, China
| | - Jing Peng
- Department of Pediatrics, Xiangya Hospital Central South University, 87 Xiangya Road, Changsha, 410008, Hunan, China
| | - Li Yang
- Department of Pediatrics, Xiangya Hospital Central South University, 87 Xiangya Road, Changsha, 410008, Hunan, China
| | - Yan-Hui Chen
- Department of Pediatrics, Fujian Medical University Union Hospital, 29 Xinquan Road, Fuzhou, Fujian, China
| | - Xiu-Lan Lu
- Department of Pediatric Intensive Care Unit, Hunan Children's Hospital, 86 Ziyuan Road, Changsha, Hunan, China
| | - Jiao-Tian Huang
- Department of Pediatric Intensive Care Unit, Hunan Children's Hospital, 86 Ziyuan Road, Changsha, Hunan, China
| | - Jie-Yu You
- Department of Gastroenterology and Nutrition, Hunan Children's Hospital, 86 Ziyuan Road, Changsha, Hunan, China
| | - Wen-Xian Ou-Yang
- Department of Hepatopathy, Hunan Children's Hospital, 86 Ziyuan Road, Changsha, Hunan, China
| | - Yue-Yu Sun
- Department of Pediatric Intensive Care Unit, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences (GAMS), 106 Zhongshan 2nd Road, Guangzhou, Guangdong, China
| | - Yi-Nan Xue
- Department of Pediatrics, Brain Hospital of Hunan Province, 427 Furong Road, Changsha, Hunan, China
| | - Xiao Mao
- Department of Medical Genetics, Maternal,, Child Health Hospital of Hunan Province, 53 Xiangchun Road, Changsha, Hunan, China
| | - Hui-Ming Yan
- Department of Medical Genetics, Maternal,, Child Health Hospital of Hunan Province, 53 Xiangchun Road, Changsha, Hunan, China
| | - Rong-Na Ren
- Department of Pediatrics, The 900Th Hospital of Joint Logistic Support Force, PLA, Fuzhou, Fujian, China
| | - Jing Xie
- Department of Pediatrics, The First Hospital of Hunan University of Chinese Medicine, 95 Shaoshan Road, Changsha, Hunan, China
| | - Zhi-Heng Chen
- Department of Pediatrics, The Third Xiangya Hospital, Central South University, 138 Tongzipo Road, Changsha, Hunan, China
| | - Victor-Wei Zhang
- Amcare Genomics Laboratory, Guangzhou, Guangdong, China.,Department of Human and Molecular Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Gui-Zhen Lyu
- Department of Human and Molecular Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Fang He
- Department of Pediatrics, Xiangya Hospital Central South University, 87 Xiangya Road, Changsha, 410008, Hunan, China.
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6
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Meng F, Jia Z, Zheng J, Ji Y, Wang J, Xiao Y, Fu Y, Wang M, Ling F, Guan MX. A deafness-associated mitochondrial DNA mutation caused pleiotropic effects on DNA replication and tRNA metabolism. Nucleic Acids Res 2022; 50:9453-9469. [PMID: 36039763 PMCID: PMC9458427 DOI: 10.1093/nar/gkac720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Accepted: 08/09/2022] [Indexed: 12/24/2022] Open
Abstract
In this report, we investigated the molecular mechanism underlying a deafness-associated m.5783C > T mutation that affects the canonical C50-G63 base-pairing of TΨC stem of tRNACys and immediately adjacent to 5' end of light-strand origin of mitochondrial DNA (mtDNA) replication (OriL). Two dimensional agarose gel electrophoresis revealed marked decreases in the replication intermediates including ascending arm of Y-fork arcs spanning OriL in the mutant cybrids bearing m.5783C > T mutation. mtDNA replication alterations were further evidenced by decreased levels of PolγA, Twinkle and SSBP1, newly synthesized mtDNA and mtDNA contents in the mutant cybrids. The m.5783C > T mutation altered tRNACys structure and function, including decreased melting temperature, conformational changes, instability and deficient aminoacylation of mutated tRNACys. The m.5783C > T mutation impaired the 5' end processing efficiency of tRNACys precursors and reduced the levels of tRNACys and downstream tRNATyr. The aberrant tRNA metabolism impaired mitochondrial translation, which was especially pronounced effects in the polypeptides harboring higher numbers of cysteine and tyrosine codons. These alterations led to deficient oxidative phosphorylation including instability and reduced activities of the respiratory chain enzyme complexes I, III, IV and intact supercomplexes overall. Our findings highlight the impact of mitochondrial dysfunction on deafness arising from defects in mitochondrial DNA replication and tRNA metabolism.
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Affiliation(s)
| | | | - Jing Zheng
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine and National Clinical Research Center for Child Health, Hangzhou, Zhejiang, China,Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China,Zhejiang Provincial Key Lab of Genetic and Developmental Disorder, Hangzhou, Zhejiang, China
| | - Yanchun Ji
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine and National Clinical Research Center for Child Health, Hangzhou, Zhejiang, China,Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China,Zhejiang Provincial Key Lab of Genetic and Developmental Disorder, Hangzhou, Zhejiang, China
| | - Jing Wang
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Yun Xiao
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Yong Fu
- Division of Otolaryngology-Head and Neck Surgery, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Meng Wang
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine and National Clinical Research Center for Child Health, Hangzhou, Zhejiang, China,Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China,Zhejiang Provincial Key Lab of Genetic and Developmental Disorder, Hangzhou, Zhejiang, China
| | - Feng Ling
- Chemical Genomics Research Group, RIKEN Center for Sustainable Resource Science, Hirosawa 2-1, Wako, Saitama, Japan
| | - Min-Xin Guan
- To whom correspondence should be addressed. Tel: +86 571 88206916; Fax: +86 571 88982377;
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Jia Z, Meng F, Chen H, Zhu G, Li X, He Y, Zhang L, He X, Zhan H, Chen M, Ji Y, Wang M, Guan MX. Human TRUB1 is a highly conserved pseudouridine synthase responsible for the formation of Ψ55 in mitochondrial tRNAAsn, tRNAGln, tRNAGlu and tRNAPro. Nucleic Acids Res 2022; 50:9368-9381. [PMID: 36018806 PMCID: PMC9458420 DOI: 10.1093/nar/gkac698] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 07/26/2022] [Accepted: 07/30/2022] [Indexed: 12/24/2022] Open
Abstract
Pseudouridine (Ψ) at position 55 in tRNAs plays an important role in their structure and function. This modification is catalyzed by TruB/Pus4/Cbf5 family of pseudouridine synthases in bacteria and yeast. However, the mechanism of TRUB family underlying the formation of Ψ55 in the mammalian tRNAs is largely unknown. In this report, the CMC/reverse transcription assays demonstrated the presence of Ψ55 in the human mitochondrial tRNAAsn, tRNAGln, tRNAGlu, tRNAPro, tRNAMet, tRNALeu(UUR) and tRNASer(UCN). TRUB1 knockout (KO) cell lines generated by CRISPR/Cas9 technology exhibited the loss of Ψ55 modification in mitochondrial tRNAAsn, tRNAGln, tRNAGlu and tRNAPro but did not affect other 18 mitochondrial tRNAs. An in vitro assay revealed that recombinant TRUB1 protein can catalyze the efficient formation of Ψ55 in tRNAAsn and tRNAGln, but not in tRNAMet and tRNAArg. Notably, the overexpression of TRUB1 cDNA reversed the deficient Ψ55 modifications in these tRNAs in TRUB1KO HeLa cells. TRUB1 deficiency affected the base-pairing (18A/G-Ψ55), conformation and stability but not aminoacylation capacity of these tRNAs. Furthermore, TRUB1 deficiency impacted mitochondrial translation and biogenesis of oxidative phosphorylation system. Our findings demonstrated that human TRUB1 is a highly conserved mitochondrial pseudouridine synthase responsible for the Ψ55 modification in the mitochondrial tRNAAsn, tRNAGln, tRNAGlu and tRNAPro.
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Affiliation(s)
| | | | | | - Gao Zhu
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Xincheng Li
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Yunfan He
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Liyao Zhang
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Xiao He
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Huisen Zhan
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Mengquan Chen
- Department of Lab Medicine, Wenzhou Hospital of Traditional Chinese Medicine, Wenzhou, Zhejiang, China
| | - Yanchun Ji
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine and National Clinical Research Center for Child Health, Hangzhou, Zhejiang, China,Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Meng Wang
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine and National Clinical Research Center for Child Health, Hangzhou, Zhejiang, China,Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Min-Xin Guan
- To whom correspondence should be addressed. Tel: +571 88206916; Fax: +571 88982377;
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Ji Y, Zhang J, Liang M, Meng F, Zhang M, Mo JQ, Wang M, Guan MX. Mitochondrial tRNA variants in 811 Chinese probands with Leber's hereditary optic neuropathy. Mitochondrion 2022; 65:56-66. [PMID: 35623556 DOI: 10.1016/j.mito.2022.05.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 04/26/2022] [Accepted: 05/22/2022] [Indexed: 11/27/2022]
Abstract
Leber's hereditary optic neuropathy (LHON) is the maternal inheritance of eye disorder. LHON-linked mitochondrial DNA (mtDNA) mutations affect the ND1, ND4 or ND6 genes encoding essential subunits of complex I. However, the role of mitochondrial tRNA defects in the pathogenesis of LHON is poorly understood. In this report, Sanger sequence analysis of 22 mitochondrial tRNA genes identified 139 variants in a cohort of 811 Han Chinese probands and 485 control Chinese subjects. Among these, 32 (4 known and 28 novel/putative) tRNA variants in 69 probands may contribute to pathogenesis of LHON, as these exhibited (1) present in <1% of controls; (2) evolutionary conservation; (3) potential and significance of structural and functional modifications. Such variants may have potentially compromised structural and functional aspects in the processing of tRNAs, structure stability, tRNA charging, or codon-anticodon interactions during translation. These 32 variants presented either singly or with multiple mutations, with the primary LHON-linked ND1 3640G>A, ND4 11778G>A or ND6 14484T>C mutations in the probands. The thirty-eight pedigrees carrying only one of tRNA variants exhibited relatively low penetrances of LHON, ranging from 5.7% to 42.9%, with an average of 19%. Strikingly, the average penetrances of optic neuropathy among 33 Chinese families carrying both a known/putative tRNA variant and a primary LHON-associated mtDNA mutation were 40.1%. These findings suggested that mitochondrial tRNA variants represent a significant causative factor for LHON, accounting for 8.75% cases in this cohort. These new insights may lead to beneficial applications in the pathophysiology, disease management, and genetic counseling of LHON.
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Affiliation(s)
- Yanchun Ji
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine and National Clinical Research Center for Child Health, Hangzhou, Zhejiang 310058, China; Institute of Genetics, Zhejiang University, School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Juanjuan Zhang
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
| | - Min Liang
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
| | - Feilong Meng
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine and National Clinical Research Center for Child Health, Hangzhou, Zhejiang 310058, China; Institute of Genetics, Zhejiang University, School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Minglian Zhang
- Department of Ophthalmology, Hebei Provincial Eye Hospital, Xingtai, Hebei 051730, China
| | - Jun Q Mo
- Department of Pathology, Rady Children's Hospital, University of California at San Diego School of Medicine, San Diego, California 92123, USA
| | - Meng Wang
- Institute of Genetics, Zhejiang University, School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Min-Xin Guan
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine and National Clinical Research Center for Child Health, Hangzhou, Zhejiang 310058, China; Institute of Genetics, Zhejiang University, School of Medicine, Hangzhou, Zhejiang 310058, China; Zhejiang Provincial Key Laboratory of Genetic & Developmental Disorders, Zhejiang University, Hangzhou, Zhejiang 310058, China; Division of Mitochondrial Biomedicine, Joint Institute of Genetics and Genome Medicine between Zhejiang University and University of Toronto, Hangzhou, Zhejiang, China.
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9
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Fan W, Jin X, Xu M, Xi Y, Lu W, Yang X, Guan MX, Ge W. FARS2 deficiency in Drosophila reveals the developmental delay and seizure manifested by aberrant mitochondrial tRNA metabolism. Nucleic Acids Res 2021; 49:13108-13121. [PMID: 34878141 PMCID: PMC8682739 DOI: 10.1093/nar/gkab1187] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 11/08/2021] [Accepted: 11/17/2021] [Indexed: 01/16/2023] Open
Abstract
Mutations in genes encoding mitochondrial aminoacyl-tRNA synthetases are linked to diverse diseases. However, the precise mechanisms by which these mutations affect mitochondrial function and disease development are not fully understood. Here, we develop a Drosophila model to study the function of dFARS2, the Drosophila homologue of the mitochondrial phenylalanyl–tRNA synthetase, and further characterize human disease-associated FARS2 variants. Inactivation of dFARS2 in Drosophila leads to developmental delay and seizure. Biochemical studies reveal that dFARS2 is required for mitochondrial tRNA aminoacylation, mitochondrial protein stability, and assembly and enzyme activities of OXPHOS complexes. Interestingly, by modeling FARS2 mutations associated with human disease in Drosophila, we provide evidence that expression of two human FARS2 variants, p.G309S and p.D142Y, induces seizure behaviors and locomotion defects, respectively. Together, our results not only show the relationship between dysfunction of mitochondrial aminoacylation system and pathologies, but also illustrate the application of Drosophila model for functional analysis of human disease-causing variants.
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Affiliation(s)
- Wenlu Fan
- Division of Human Reproduction and Developmental Genetics, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,Institute of Genetics, Zhejiang University, 866 Yuhangtang Road, Hangzhou, Zhejiang 310058, China.,Zhejiang Provincial Key Laboratory of Precision Diagnosis and Therapy for Major Gynecological Diseases, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310006, China
| | - Xiaoye Jin
- Division of Human Reproduction and Developmental Genetics, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,Institute of Genetics, Zhejiang University, 866 Yuhangtang Road, Hangzhou, Zhejiang 310058, China.,Zhejiang Provincial Key Laboratory of Precision Diagnosis and Therapy for Major Gynecological Diseases, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310006, China
| | - Man Xu
- Division of Human Reproduction and Developmental Genetics, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,Institute of Genetics, Zhejiang University, 866 Yuhangtang Road, Hangzhou, Zhejiang 310058, China.,Zhejiang Provincial Key Laboratory of Precision Diagnosis and Therapy for Major Gynecological Diseases, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310006, China
| | - Yongmei Xi
- Division of Human Reproduction and Developmental Genetics, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,Institute of Genetics, Zhejiang University, 866 Yuhangtang Road, Hangzhou, Zhejiang 310058, China
| | - Weiguo Lu
- Department of Gynecologic Oncology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310006, China.,Cancer Center, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Xiaohang Yang
- Division of Human Reproduction and Developmental Genetics, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,Institute of Genetics, Zhejiang University, 866 Yuhangtang Road, Hangzhou, Zhejiang 310058, China.,Zhejiang Provincial Key Laboratory of Genetic and Developmental Disorders, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Min-Xin Guan
- Institute of Genetics, Zhejiang University, 866 Yuhangtang Road, Hangzhou, Zhejiang 310058, China.,Zhejiang Provincial Key Laboratory of Genetic and Developmental Disorders, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Wanzhong Ge
- Division of Human Reproduction and Developmental Genetics, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,Institute of Genetics, Zhejiang University, 866 Yuhangtang Road, Hangzhou, Zhejiang 310058, China.,Zhejiang Provincial Key Laboratory of Precision Diagnosis and Therapy for Major Gynecological Diseases, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310006, China.,Cancer Center, Zhejiang University, Hangzhou, Zhejiang 310058, China
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10
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Jin X, Zhang J, Yi Q, Meng F, Yu J, Ji Y, Mo JQ, Tong Y, Jiang P, Guan MX. Leber's Hereditary Optic Neuropathy Arising From the Synergy Between ND1 3635G>A Mutation and Mitochondrial YARS2 Mutations. Invest Ophthalmol Vis Sci 2021; 62:22. [PMID: 34156427 PMCID: PMC8237128 DOI: 10.1167/iovs.62.7.22] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Purpose To investigate the mechanism underlying the synergic interaction between Leber's hereditary optic neuropathy (LHON)-associated ND1 and mitochondrial tyrosyl-tRNA synthetase (YARS2) mutations. Methods Molecular dynamics simulation and differential scanning fluorimetry were used to evaluate the structure and stability of proteins. The impact of ND1 3635G>A and YARS2 p.G191V mutations on the oxidative phosphorylation machinery was evaluated using blue native gel electrophoresis and enzymatic activities assays. Assessment of reactive oxygen species (ROS) production in cell lines was performed by flow cytometry with MitoSOX Red reagent. Analysis of effect of mutations on autophagy was undertaken via flow cytometry for autophagic flux. Results Members of one Chinese family bearing both the YARS2 p.191Gly>Val and m.3635G>A mutations exhibited much higher penetrance of optic neuropathy than those pedigrees carrying only the m.3635G>A mutation. The m.3635G>A (p.Ser110Asn) mutation altered the ND1 structure and function, whereas the p.191Gly>Val mutation affected the stability of YARS2. Lymphoblastoid cell lines harboring both m.3635G>A and p.191Gly>Val mutations revealed more reductions in the levels of mitochondrion-encoding ND1 and CO2 than cells bearing only the m.3635G>A mutation. Strikingly, both m.3635G>A and p.191Gly>Val mutations exhibited decreases in the nucleus-encoding subunits of complex I and IV. These deficiencies manifested greater defects in the stability and activities of complex I and complex IV and overproduction of ROS and promoted greater autophagy in cell lines harboring both m.3635G>A and p.191Gly>Val mutations compared with cells bearing only the m.3635G>A mutation. Conclusions Our findings provide new insights into the pathophysiology of LHON arising from the synergy between ND1 3635G>A mutation and mitochondrial YARS2 mutations.
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Affiliation(s)
- Xiaofen Jin
- Key Laboratory of Reproductive Genetics, Ministry of Education of PRC, The Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, and National Clinic Research Center for Child Health, Hangzhou, Zhejiang, China
| | - Juanjuan Zhang
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Qiuzi Yi
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, and National Clinic Research Center for Child Health, Hangzhou, Zhejiang, China
| | - Feilong Meng
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, and National Clinic Research Center for Child Health, Hangzhou, Zhejiang, China
| | - Jialing Yu
- Key Laboratory of Reproductive Genetics, Ministry of Education of PRC, The Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, and National Clinic Research Center for Child Health, Hangzhou, Zhejiang, China
| | - Yanchun Ji
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, and National Clinic Research Center for Child Health, Hangzhou, Zhejiang, China
| | - Jun Q Mo
- Department of Pathology, Rady Children's Hospital, University of California School of Medicine, San Diego, California, United States
| | - Yi Tong
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Pingping Jiang
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, and National Clinic Research Center for Child Health, Hangzhou, Zhejiang, China
| | - Min-Xin Guan
- Key Laboratory of Reproductive Genetics, Ministry of Education of PRC, The Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, and National Clinic Research Center for Child Health, Hangzhou, Zhejiang, China.,Zhejiang Provincial Key Laboratory of Genetic and Developmental Disorders, Hangzhou, Zhejiang, China.,Zhejiang University-University of Toronto Joint Institute of Genetics and Genome Medicine, Hangzhou, Zhejiang, China
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11
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Gusic M, Prokisch H. Genetic basis of mitochondrial diseases. FEBS Lett 2021; 595:1132-1158. [PMID: 33655490 DOI: 10.1002/1873-3468.14068] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 02/17/2021] [Accepted: 02/18/2021] [Indexed: 12/13/2022]
Abstract
Mitochondrial disorders are monogenic disorders characterized by a defect in oxidative phosphorylation and caused by pathogenic variants in one of over 340 different genes. The implementation of whole-exome sequencing has led to a revolution in their diagnosis, duplicated the number of associated disease genes, and significantly increased the diagnosed fraction. However, the genetic etiology of a substantial fraction of patients exhibiting mitochondrial disorders remains unknown, highlighting limitations in variant detection and interpretation, which calls for improved computational and DNA sequencing methods, as well as the addition of OMICS tools. More intriguingly, this also suggests that some pathogenic variants lie outside of the protein-coding genes and that the mechanisms beyond the Mendelian inheritance and the mtDNA are of relevance. This review covers the current status of the genetic basis of mitochondrial diseases, discusses current challenges and perspectives, and explores the contribution of factors beyond the protein-coding regions and monogenic inheritance in the expansion of the genetic spectrum of disease.
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Affiliation(s)
- Mirjana Gusic
- Institute of Neurogenomics, Helmholtz Zentrum München, Neuherberg, Germany.,Institute of Human Genetics, Technical University of Munich, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Munich Heart Alliance, Germany
| | - Holger Prokisch
- Institute of Neurogenomics, Helmholtz Zentrum München, Neuherberg, Germany.,Institute of Human Genetics, Technical University of Munich, Germany
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12
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Abstract
Mitochondrial dysfunction has been suggested to be a risk factor for sensorineural hearing loss (SNHL) induced by aging, noise, ototoxic drugs, and gene. Reactive oxygen species (ROS) are mainly derived from mitochondria, and oxidative stress induced by ROS contributes to cochlear damage as well as mitochondrial DNA mutations, which may enhance the sensitivity and severity of hearing loss and disrupt ion homeostasis (e.g., Ca2+ homeostasis). The formation and accumulation of ROS further undermine mitochondrial components and ultimately lead to apoptosis and necrosis. SIRT3–5, located in mitochondria, belong to the family of sirtuins, which are highly conserved deacetylases dependent on nicotinamide adenine dinucleotide (NAD+). These deacetylases regulate diverse cellular biochemical activities. Recent studies have revealed that mitochondrial sirtuins, especially SIRT3, modulate ROS levels in hearing loss pathologies. Although the precise functions of SIRT4 and SIRT5 in the cochlea remain unclear, the molecular mechanisms in other tissues indicate a potential protective effect against hearing loss. In this review, we summarize the current knowledge regarding the role of mitochondrial dysfunction in hearing loss, discuss possible functional links between mitochondrial sirtuins and SNHL, and propose a perspective that SIRT3–5 have a positive effect on SNHL.
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13
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Jin X, Zhang Z, Nie Z, Wang C, Meng F, Yi Q, Chen M, Sun J, Zou J, Jiang P, Guan MX. An animal model for mitochondrial tyrosyl-tRNA synthetase deficiency reveals links between oxidative phosphorylation and retinal function. J Biol Chem 2021; 296:100437. [PMID: 33610547 PMCID: PMC8010715 DOI: 10.1016/j.jbc.2021.100437] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 02/09/2021] [Accepted: 02/16/2021] [Indexed: 12/13/2022] Open
Abstract
Mitochondria maintain a distinct pool of ribosomal machinery, including tRNAs and tRNAs activating enzymes, such as mitochondrial tyrosyl-tRNA synthetase (YARS2). Mutations in YARS2, which typically lead to the impairment of mitochondrial protein synthesis, have been linked to an array of human diseases including optic neuropathy. However, the lack of YARS2 mutation animal model makes us difficult to elucidate the pathophysiology underlying YARS2 deficiency. To explore this system, we generated YARS2 knockout (KO) HeLa cells and zebrafish using CRISPR/Cas9 technology. We observed the aberrant tRNATyr aminoacylation overall and reductions in the levels in mitochondrion- and nucleus-encoding subunits of oxidative phosphorylation system (OXPHOS), which were especially pronounced effects in the subunits of complex I and complex IV. These deficiencies manifested the decreased levels of intact supercomplexes overall. Immunoprecipitation assays showed that YARS2 bound to specific subunits of complex I and complex IV, suggesting the posttranslational stabilization of OXPHOS. Furthermore, YARS2 ablation caused defects in the stability and activities of OXPHOS complexes. These biochemical defects could be rescued by the overexpression of YARS2 cDNA in the YARS2KO cells. In zebrafish, the yars2KO larva conferred deficient COX activities in the retina, abnormal mitochondrial morphology, and numbers in the photoreceptor and retinal ganglion cells. The zebrafish further exhibited the retinal defects affecting both rods and cones. Vision defects in yars2KO zebrafish recapitulated the clinical phenotypes in the optic neuropathy patients carrying the YARS2 mutations. Our findings highlighted the critical role of YARS2 in the stability and activity of OXPHOS and its pathological consequence in vision impairments.
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Affiliation(s)
- Xiaofen Jin
- Key Laboratory of Reproductive Genetics, Ministry of Education of PRC, The Woman's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China; Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, and National Clinic Research Center for Child Health, Hangzhou, Zhejiang, China; Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Zengming Zhang
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Zhipeng Nie
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Chenghui Wang
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Feilong Meng
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, and National Clinic Research Center for Child Health, Hangzhou, Zhejiang, China; Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Qiuzi Yi
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Mengquan Chen
- Department of Lab Medicine, Wenzhou Hospital of Traditional Chinese Medicine, Wenzhou, Zhejiang, China
| | - Jiji Sun
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Jian Zou
- Insitute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Pingping Jiang
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, and National Clinic Research Center for Child Health, Hangzhou, Zhejiang, China; Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China; Zhejiang Provincial Key Laboratory of Genetic & Developmental Disorders, Zhejiang Univesity, Hangzhou, Zhejiang, China.
| | - Min-Xin Guan
- Key Laboratory of Reproductive Genetics, Ministry of Education of PRC, The Woman's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China; Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, and National Clinic Research Center for Child Health, Hangzhou, Zhejiang, China; Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China; Zhejiang Provincial Key Laboratory of Genetic & Developmental Disorders, Zhejiang Univesity, Hangzhou, Zhejiang, China; Division of Mitochondrial Biomedicine, Joint Institute of Genetics and Genome Medicine between Zhejiang University and University of Toronto, Hangzhou, Zhejiang, China.
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14
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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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15
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A mitochondrial myopathy-associated tRNA Ser(UCN) 7453G>A mutation alters tRNA metabolism and mitochondrial function. Mitochondrion 2020; 57:1-8. [PMID: 33279600 DOI: 10.1016/j.mito.2020.11.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 10/09/2020] [Accepted: 11/23/2020] [Indexed: 12/25/2022]
Abstract
BACKGROUND Mitochondrial disorders are a group of heterogeneous diseases characterized by biochemical disturbances in oxidative phosphorylation (OXPHOS). Mutations in mitochondrial transfer RNA (mt-tRNA) genes are the most frequently in mitochondrial disease. However, few studies have detailed the molecular mechanisms behind these mutations. METHODS We performed clinical evaluation, genetic analysis, muscle histochemistry, and molecular and biochemical investigations in muscle tissue and proband-derived cybrid cell lines. RESULTS We found a mitochondrial tRNASer(UCN) mutation (m.7453G>A) in a 15-year-old patient with severe mitochondrial myopathy. We demonstrated that this mutation caused impairment of mitochondrial translation, respiratory deficiency, overproduction of reactive oxygen species (ROS), and decreased mitochondrial membrane potential (MMP), which ultimately led to severe mitochondrial myopathy. CONCLUSION Our findings offer valuable new insights into the tRNASer(UCN) m.7453G>A mutation for both the pathogenic mechanism and functional consequences.
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16
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Uittenbogaard M, Chiaramello A. Maternally inherited mitochondrial respiratory disorders: from pathogenetic principles to therapeutic implications. Mol Genet Metab 2020; 131:38-52. [PMID: 32624334 PMCID: PMC7749081 DOI: 10.1016/j.ymgme.2020.06.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 06/22/2020] [Accepted: 06/23/2020] [Indexed: 01/19/2023]
Abstract
Maternally inherited mitochondrial respiratory disorders are rare, progressive, and multi-systemic diseases that remain intractable, with no effective therapeutic interventions. Patients share a defective oxidative phosphorylation pathway responsible for mitochondrial ATP synthesis, in most cases due to pathogenic mitochondrial variants transmitted from mother to child or to a rare de novo mutation or large-scale deletion of the mitochondrial genome. The clinical diagnosis of these mitochondrial diseases is difficult due to exceptionally high clinical variability, while their genetic diagnosis has improved with the advent of next-generation sequencing. The mechanisms regulating the penetrance of the mitochondrial variants remain unresolved with the patient's nuclear background, epigenomic regulation, heteroplasmy, mitochondrial haplogroups, and environmental factors thought to act as rheostats. The lack of animal models mimicking the phenotypic manifestations of these disorders has hampered efforts toward curative therapies. Patient-derived cellular paradigms provide alternative models for elucidating the pathogenic mechanisms and screening pharmacological small molecules to enhance mitochondrial function. Recent progress has been made in designing promising approaches to curtail the negative impact of dysfunctional mitochondria and alleviate clinical symptoms: 1) boosting mitochondrial biogenesis; 2) shifting heteroplasmy; 3) reprogramming metabolism; and 4) administering hypoxia-based treatment. Here, we discuss their varying efficacies and limitations and provide an outlook on their therapeutic potential and clinical application.
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Affiliation(s)
- Martine Uittenbogaard
- George Washington University School of Medicine and Health Sciences, Department of Anatomy and Cell Biology, 2300 I Street N.W., Washington, DC 20037, USA
| | - Anne Chiaramello
- George Washington University School of Medicine and Health Sciences, Department of Anatomy and Cell Biology, 2300 I Street N.W., Washington, DC 20037, USA.
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17
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Ji Y, Zhang J, Lu Y, Yi Q, Chen M, Xie S, Mao X, Xiao Y, Meng F, Zhang M, Yang R, Guan MX. Complex I mutations synergize to worsen the phenotypic expression of Leber's hereditary optic neuropathy. J Biol Chem 2020; 295:13224-13238. [PMID: 32723871 DOI: 10.1074/jbc.ra120.014603] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 07/24/2020] [Indexed: 12/15/2022] Open
Abstract
Leber's hereditary optic neuropathy (LHON) is a maternal inheritance of eye disease because of the mitochondrial DNA (mtDNA) mutations. We previously discovered a 3866T>C mutation within the gene for the ND1 subunit of complex I as possibly amplifying disease progression for patients bearing the disease-causing 11778G>A mutation within the gene for the ND4 subunit of complex I. However, whether and how the ND1 mutation exacerbates the ND4 mutation were unknown. In this report, we showed that four Chinese families bearing both m.3866T>C and m.11778G>A mutations exhibited higher penetrances of LHON than 6 Chinese pedigrees carrying only the m.3866T>C mutation or families harboring only the m.11778G>A mutation. The protein structure analysis revealed that the m.3866T>C (I187T) and m.11778G>A (R340H) mutations destabilized the specific interactions with other residues of ND1 and ND4, thereby altering the structure and function of complex I. Cellular data obtained using cybrids, constructed by transferring mitochondria from the Chinese families into mtDNA-less (ρ°) cells, demonstrated that the mutations perturbed the stability, assembly, and activity of complex I, leading to changes in mitochondrial ATP levels and membrane potential and increasing the production of reactive oxygen species. These mitochondrial dysfunctions promoted the apoptotic sensitivity of cells and decreased mitophagy. Cybrids bearing only the m.3866T>C mutation displayed mild mitochondrial dysfunctions, whereas those harboring both m.3866T>C and m.11778G>A mutations exhibited greater mitochondrial dysfunctions. These suggested that the m.3866T>C mutation acted in synergy with the m.11778G>A mutation, aggravating mitochondrial dysfunctions and contributing to higher penetrance of LHON in these families carrying both mtDNA mutations.
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Affiliation(s)
- Yanchun Ji
- Department of Genetics and Metabolic Diseases, Children's Hospital, National Clinical Research Center for Child Health, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China; Division of Medical Genetics and Genomics, Children's Hospital, National Clinical Research Center for Child Health, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China; Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Juanjuan Zhang
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Yuanyuan Lu
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China; School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Qiuzi Yi
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Mengquan Chen
- Department of Lab Medicine, Wenzhou Hospital of Traditional Chinese Medicine, Wenzhou, Zhejiang, China
| | - Shipeng Xie
- Department of Ophthalmology, Hebei Provincial Eye Hospital, Xingtai, Hebei, China
| | - Xiaoting Mao
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Yun Xiao
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Feilong Meng
- Department of Genetics and Metabolic Diseases, Children's Hospital, National Clinical Research Center for Child Health, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China; Division of Medical Genetics and Genomics, Children's Hospital, National Clinical Research Center for Child Health, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China; Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Minglian Zhang
- Department of Ophthalmology, Hebei Provincial Eye Hospital, Xingtai, Hebei, China
| | - Rulai Yang
- Department of Genetics and Metabolic Diseases, Children's Hospital, National Clinical Research Center for Child Health, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.
| | - Min-Xin Guan
- Division of Medical Genetics and Genomics, Children's Hospital, National Clinical Research Center for Child Health, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China; Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China; Key Lab of Reproductive Genetics, Ministry of Education of PRC, Zhejiang University, Hangzhou, Zhejiang, China; Joint Institute of Genetics and Genomic Medicine between Zhejiang University and University of Toronto, Hangzhou, Zhejiang, China.
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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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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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