1
|
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.
Collapse
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.
| |
Collapse
|
2
|
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.
Collapse
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.
| |
Collapse
|
3
|
Jerome MS, Nanjappa DP, Chakraborty A, Chakrabarty S. Molecular etiology of defective nuclear and mitochondrial ribosome biogenesis: Clinical phenotypes and therapy. Biochimie 2023; 207:122-136. [PMID: 36336106 DOI: 10.1016/j.biochi.2022.11.001] [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: 08/01/2022] [Revised: 10/27/2022] [Accepted: 11/01/2022] [Indexed: 11/06/2022]
Abstract
Ribosomopathies are rare congenital disorders associated with defective ribosome biogenesis due to pathogenic variations in genes that encode proteins related to ribosome function and biogenesis. Defects in ribosome biogenesis result in a nucleolar stress response involving the TP53 tumor suppressor protein and impaired protein synthesis leading to a deregulated translational output. Despite the accepted notion that ribosomes are omnipresent and essential for all cells, most ribosomopathies show tissue-specific phenotypes affecting blood cells, hair, spleen, or skin. On the other hand, defects in mitochondrial ribosome biogenesis are associated with a range of clinical manifestations affecting more than one organ. Intriguingly, the deregulated ribosomal function is also a feature in several human malignancies with a selective upregulation or downregulation of specific ribosome components. Here, we highlight the clinical conditions associated with defective ribosome biogenesis in the nucleus and mitochondria with a description of the affected genes and the implicated pathways, along with a note on the treatment strategies currently available for these disorders.
Collapse
Affiliation(s)
- Maria Sona Jerome
- Department of Cell and Molecular Biology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, 576104, Karnataka, India
| | - Dechamma Pandyanda Nanjappa
- Division of Molecular Genetics and Cancer, Nitte University Centre for Science Education and Research (NUCSER), NITTE (Deemed to Be University), Deralakate, Mangaluru, 575018, India
| | - Anirban Chakraborty
- Division of Molecular Genetics and Cancer, Nitte University Centre for Science Education and Research (NUCSER), NITTE (Deemed to Be University), Deralakate, Mangaluru, 575018, India.
| | - Sanjiban Chakrabarty
- Department of Cell and Molecular Biology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, 576104, Karnataka, India.
| |
Collapse
|
4
|
Chou CW, Hsu YC. Current development of patient-specific induced pluripotent stem cells harbouring mitochondrial gene mutations and their applications in the treatment of sensorineural hearing loss. Hear Res 2023; 429:108689. [PMID: 36649664 DOI: 10.1016/j.heares.2023.108689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 12/30/2022] [Accepted: 01/03/2023] [Indexed: 01/06/2023]
Abstract
Of all the human body's sensory systems, the auditory system is perhaps its most intricate. Hearing loss can result from even modest damage or cell death in the inner ear, and is the most common form of sensory loss. Human hearing is made possible by the sensory epithelium, the lateral wall, and auditory nerves. The most prominent functional cells in the sensory epithelium are outer hair cells (OHCs), inner hair cells (IHCs), and supporting cells. Different sound frequencies are processed by OHCs and IHCs in different cochlear regions, with those in the apex responsible for low frequencies and those in the basal region responsible for high frequencies. Hair cells can be damaged or destroyed by loud noise, aging process, genetic mutations, ototoxicity, infection, and illness. As such, they are a primary target for treating sensorineural hearing loss. Other areas known to affect hearing include spiral ganglion neurons (SGNs) in the auditory nerve. Age-related degradation of HCs and SGNs can also cause hearing loss. The aim of this review is to introduce the roles of mitochondria in human auditory system and the inner ear's main cell types and cellular functions, before going on to detail the likely health benefits of iPSC technology. We posit that patient-specific iPSCs with mitochondrial gene mutations will be an important aspect of regenerative medicine and will lead to significant progress in the treatment of SNHL.
Collapse
Affiliation(s)
- Chao-Wen Chou
- Department of Audiology and Speech-Language Pathology, Mackay Medical College, New Taipei City, Taiwan
| | - Yi-Chao Hsu
- Department of Audiology and Speech-Language Pathology, Mackay Medical College, New Taipei City, Taiwan; Institute of Biomedical Sciences, Mackay Medical College, New Taipei City, Taiwan
| |
Collapse
|
5
|
Ren B, Guan MX, Zhou T, Cai X, Shan G. Emerging functions of mitochondria-encoded noncoding RNAs. Trends Genet 2023; 39:125-139. [PMID: 36137834 DOI: 10.1016/j.tig.2022.08.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 08/03/2022] [Accepted: 08/11/2022] [Indexed: 01/27/2023]
Abstract
Mitochondria, organelles that harbor their own circular genomes, are critical for energy production and homeostasis maintenance in eukaryotic cells. Recent studies discovered hundreds of mitochondria-encoded noncoding RNAs (mt-ncRNAs), including novel subtypes of mitochondria-encoded circular RNAs (mecciRNAs) and mitochondria-encoded double-stranded RNAs (mt-dsRNAs). Here, we discuss the emerging field of mt-ncRNAs by reviewing their expression patterns, biogenesis, metabolism, regulatory roles, and functional mechanisms. Many mt-ncRNAs have regulatory roles in cellular physiology, and some are associated with, or even act as, causal factors in human diseases. We also highlight developments in technologies and methodologies and further insights into future perspectives and challenges in studying these noncoding RNAs, as well as their potential biomedical applications.
Collapse
Affiliation(s)
- Bingbing Ren
- Department of Pulmonary and Critical Care Medicine, Regional Medical Center for National Institute of Respiratory Disease, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou 310016, China; Cancer Center, Zhejiang University, Hangzhou 310058, China; Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou 310016, China
| | - Min-Xin Guan
- Division of Medical Genetics and Genomics, The Children's Hospital, School of Medicine, Zhejiang University, Hangzhou 310052, China; Zhejiang Provincial Key Lab of Genetic and Developmental Disorder, Institute of Genetics, School of Medicine, Zhejiang University, Hangzhou 310058, China
| | - Tianhua Zhou
- Cancer Center, Zhejiang University, Hangzhou 310058, China; Department of Cell Biology and Department of Gastroenterology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou 310016, China; Institute of Gastroenterology, Zhejiang University, Hangzhou 310016, China
| | - Xiujun Cai
- Cancer Center, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Laparoscopic Technology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou 310016, China; Department of General Surgery, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou 310016, China; Zhejiang Minimal Invasive Diagnosis and Treatment Technology Research Center of Severe Hepatobiliary Disease, Zhejiang University, Hangzhou 310016, China; Zhejiang Research and Development Engineering Laboratory of Minimally Invasive Technology and Equipment, Zhejiang University, Hangzhou 310016, China
| | - Ge Shan
- Department of Pulmonary and Critical Care Medicine, Regional Medical Center for National Institute of Respiratory Disease, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou 310016, China; Cancer Center, Zhejiang University, Hangzhou 310058, China; Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou 310016, China; Department of Clinical Laboratory, The First Affiliated Hospital of USTC, the CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Science and Medicine, University of Science and Technology of China, Hefei 230027, China.
| |
Collapse
|
6
|
Mitochondrial tRNAGln 4394C>T Mutation May Contribute to the Clinical Expression of 1555A>G-Induced Deafness. Genes (Basel) 2022; 13:genes13101794. [PMID: 36292680 PMCID: PMC9602358 DOI: 10.3390/genes13101794] [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: 07/28/2022] [Revised: 09/08/2022] [Accepted: 09/12/2022] [Indexed: 11/17/2022] Open
Abstract
The mitochondrial 1555A>G mutation plays a critical role in aminoglycoside-induced and non-syndromic hearing loss (AINSHL). Previous studies have suggested that mitochondrial secondary variants may modulate the clinical expression of m.1555A>G-induced deafness, but the molecular mechanism has remained largely undetermined. In this study, we investigated the contribution of a deafness-associated tRNAGln 4394C>T mutation to the clinical expression of the m.1555A>G mutation. Interestingly, a three-generation family with both the m.1555A>G and m.4394C>T mutations exhibited a higher penetrance of hearing loss than another family harboring only the m.1555A>G mutation. At the molecular level, the m.4394C>T mutation resides within a very conserved nucleotide of tRNAGln, which forms a new base-pairing (7T-66A) and may affect tRNA structure and function. Using trans-mitochondrial cybrid cells derived from three subjects with both the m.1555A>G and m.4394C>T mutations, three patients with only the m.1555A>G mutation and three control subjects without these primary mutations, we observed that cells with both the m.1555A>G and m.4394C>T mutations exhibited more severely impaired mitochondrial functions than those with only the m.1555A>G mutation. Furthermore, a marked decrease in mitochondrial RNA transcripts and respiratory chain enzymes was observed in cells harboring both the m.1555A>G and m.4394C>T mutations. Thus, our data suggest that the m.4394C>T mutation may play a synergistic role in the m.1555A>G mutation, enhancing mitochondrial dysfunctions and contributing to a high penetrance of hearing loss in families with both mtDNA pathogenic mutations.
Collapse
|
7
|
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.
Collapse
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;
| |
Collapse
|
8
|
Kuan SW, Chua KH, Tan EW, Tan LK, Loch A, Kee BP. Whole mitochondrial genome sequencing of Malaysian patients with cardiomyopathy. PeerJ 2022; 10:e13265. [PMID: 35441061 PMCID: PMC9013480 DOI: 10.7717/peerj.13265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 03/23/2022] [Indexed: 01/13/2023] Open
Abstract
Cardiomyopathy (CMP) constitutes a diverse group of myocardium diseases affecting the pumping ability of the heart. Genetic predisposition is among the major factors affecting the development of CMP. Globally, there are over 100 genes in autosomal and mitochondrial DNA (mtDNA) that have been reported to be associated with the pathogenesis of CMP. However, most of the genetic studies have been conducted in Western countries, with limited data being available for the Asian population. Therefore, this study aims to investigate the mutation spectrum in the mitochondrial genome of 145 CMP patients in Malaysia. Long-range PCR was employed to amplify the entire mtDNA, and whole mitochondrial genome sequencing was conducted on the MiSeq platform. Raw data was quality checked, mapped, and aligned to the revised Cambridge Reference Sequence (rCRS). Variants were named, annotated, and filtered. The sequencing revealed 1,077 variants, including 18 novel and 17 CMP and/or mitochondrial disease-associated variants after filtering. In-silico predictions suggested that three of the novel variants (m.8573G>C, m.11916T>A and m.11918T>G) in this study are potentially pathogenic. Two confirmed pathogenic variants (m.1555A>G and m.11778G>A) were also found in the CMP patients. The findings of this study shed light on the distribution of mitochondrial mutations in Malaysian CMP patients. Further functional studies are required to elucidate the role of these variants in the development of CMP.
Collapse
Affiliation(s)
- Sheh Wen Kuan
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Kek Heng Chua
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - E-Wei Tan
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Lay Koon Tan
- National Heart Institute, Kuala Lumpur, Malaysia
| | - Alexander Loch
- Department of Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Boon Pin Kee
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| |
Collapse
|
9
|
OUP accepted manuscript. Hum Mol Genet 2022; 31:3068-3082. [DOI: 10.1093/hmg/ddac096] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 03/28/2022] [Accepted: 04/20/2022] [Indexed: 11/14/2022] Open
|
10
|
Mechanistic insights into mitochondrial tRNA Ala 3'-end metabolism deficiency. J Biol Chem 2021; 297:100816. [PMID: 34023389 PMCID: PMC8212662 DOI: 10.1016/j.jbc.2021.100816] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 05/10/2021] [Accepted: 05/19/2021] [Indexed: 12/14/2022] Open
Abstract
Mitochondrial tRNA 3’-end metabolism is critical for the formation of functional tRNAs. Deficient mitochondrial tRNA 3’-end metabolism is linked to an array of human diseases, including optic neuropathy, but their pathophysiology remains poorly understood. In this report, we investigated the molecular mechanism underlying the Leber’s hereditary optic neuropathy (LHON)-associated tRNAAla 5587A>G mutation, which changes a highly conserved adenosine at position 73 (A73) to guanine (G73) on the 3’-end of the tRNA acceptor stem. The m.5587A>G mutation was identified in three Han Chinese families with suggested maternal inheritance of LHON. We hypothesized that the m.5587A>G mutation altered tRNAAla 3’-end metabolism and mitochondrial function. In vitro processing experiments showed that the m.5587A>G mutation impaired the 3’-end processing of tRNAAla precursors by RNase Z and inhibited the addition of CCA by tRNA nucleotidyltransferase (TRNT1). Northern blot analysis revealed that the m.5587A>G mutation perturbed tRNAAla aminoacylation, as evidenced by decreased efficiency of aminoacylation and faster electrophoretic mobility of mutated tRNAAla in these cells. The impact of m.5587A>G mutation on tRNAAla function was further supported by increased melting temperature, conformational changes, and reduced levels of this tRNA. Failures in tRNAAla metabolism impaired mitochondrial translation, perturbed assembly and activity of oxidative phosphorylation complexes, diminished ATP production and membrane potential, and increased production of reactive oxygen species. These pleiotropic defects elevated apoptotic cell death and promoted mitophagy in cells carrying the m.5587A>G mutation, thereby contributing to visual impairment. Our findings may provide new insights into the pathophysiology of LHON arising from mitochondrial tRNA 3’-end metabolism deficiency.
Collapse
|
11
|
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.
Collapse
|
12
|
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.
Collapse
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.
| |
Collapse
|
13
|
Jiang P, Ling Y, Zhu T, Luo X, Tao Y, Meng F, Cheng W, Ji Y. Mitochondrial tRNA mutations in Chinese Children with Tic Disorders. Biosci Rep 2020; 40:BSR20201856. [PMID: 33289513 PMCID: PMC7755120 DOI: 10.1042/bsr20201856] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 11/09/2020] [Accepted: 11/18/2020] [Indexed: 12/17/2022] Open
Abstract
AIMS To conduct the clinical, genetic and molecular characterization of 494 Han Chinese subjects with Tic disorders (TD). METHODS In this study, we performed the mutational analysis of 22 mitochondrial tRNA genes in a large cohort of 494 Han Chinese subjects with TD via Sanger sequencing. These variants were then assessed for their pathogenic potential via phylogenetic, functional, and structural analyses. RESULTS A total of 73 tRNA gene variants (49 known and 24 novel) on 22 tRNA genes were identified. Among these, 18 tRNA variants that were absent or present in <1% of 485 Chinese control patient samples were localized to highly conserved nucleotides, or changed the modified nucleotides, and had the potential structural to alter tRNA structure and function. These variants were thus considered to be TD-associated mutations. In total, 25 subjects carried one of these 18 putative TD-associated tRNA variants with the total prevalence of 4.96%. LIMITATIONS The phenotypic variability and incomplete penetrance of tic disorders in pedigrees carrying these tRNA mutations suggested the involvement of modifier factors, such as nuclear encoded genes associated mitochondrion, mitochondrial haplotypes, epigenetic and environmental factors. CONCLUSION Our data provide the evidence that mitochondrial tRNA mutations are the important causes of tic disorders among Chinese population. These findings also advance current understanding regarding the clinical relevance of tRNA mutations, and will guide future studies aimed at elucidating the pathophysiology of maternal tic disorders.
Collapse
Affiliation(s)
- Peifang Jiang
- Department of Neurology, The Children’s Hospital, Zhejiang University School of Medicine, National Clinical Research Center For Child Health, Hangzhou, China
| | - Yinjie Ling
- Department of Neurology, The Children’s Hospital, Zhejiang University School of Medicine, National Clinical Research Center For Child Health, Hangzhou, China
- Department of Pediatrics, First People’s Hospital of Huzhou, Huzhou, China
| | - Tao Zhu
- Department of Critical Care Medicine, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Xiaoying Luo
- Department of Neurology, The Children’s Hospital, Zhejiang University School of Medicine, National Clinical Research Center For Child Health, Hangzhou, China
| | - Yilin Tao
- Department of Neurology, The Children’s Hospital, Zhejiang University School of Medicine, National Clinical Research Center For Child Health, Hangzhou, China
| | - Feilong Meng
- Division of Medical Genetics and Genomics, The Children’s Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Zhejiang, China
- Institute of Genetics, Zhejiang University, Hangzhou, Zhejiang, China
| | - Weixin Cheng
- Institute of Genetics, Zhejiang University, Hangzhou, Zhejiang, China
| | - Yanchun Ji
- Division of Medical Genetics and Genomics, The Children’s Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Zhejiang, China
- Institute of Genetics, Zhejiang University, Hangzhou, Zhejiang, China
| |
Collapse
|
14
|
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.
Collapse
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
| |
Collapse
|
15
|
Habbane M, Llobet L, Bayona-Bafaluy MP, Bárcena JE, Ceberio L, Gómez-Díaz C, Gort L, Artuch R, Montoya J, Ruiz-Pesini E. Leigh Syndrome in a Pedigree Harboring the m.1555A>G Mutation in the Mitochondrial 12S rRNA. Genes (Basel) 2020; 11:genes11091007. [PMID: 32867169 PMCID: PMC7565518 DOI: 10.3390/genes11091007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 07/28/2020] [Accepted: 08/24/2020] [Indexed: 12/17/2022] Open
Abstract
Background: Leigh syndrome (LS) is a serious genetic disease that can be caused by mutations in dozens of different genes. Methods: Clinical study of a deafness pedigree in which some members developed LS. Cellular, biochemical and molecular genetic analyses of patients’ tissues and cybrid cell lines were performed. Results: mitochondrial DNA (mtDNA) m.1555A>G/MT-RNR1 and m.9541T>C/MT-CO3 mutations were found. The first one is a well-known pathologic mutation. However, the second one does not appear to contribute to the high hearing loss penetrance and LS phenotype observed in this family. Conclusion: The m.1555A>G pathological mutation, accompanied with an unknown nuclear DNA (nDNA) factor, could be the cause of the phenotypic manifestations in this pedigree.
Collapse
Affiliation(s)
- Mouna Habbane
- Departamento de Bioquímica, Biología Molecular y Celular, Universidad de Zaragoza, 50013 Zaragoza, Spain; (M.H.); (L.L.); (M.P.B.-B.); (J.M.)
- Laboratoire Biologie et Santé, Faculté des Sciences Ben M’Sik, Université Hassan II, 20670 Casablanca, Morocco
| | - Laura Llobet
- Departamento de Bioquímica, Biología Molecular y Celular, Universidad de Zaragoza, 50013 Zaragoza, Spain; (M.H.); (L.L.); (M.P.B.-B.); (J.M.)
| | - M. Pilar Bayona-Bafaluy
- Departamento de Bioquímica, Biología Molecular y Celular, Universidad de Zaragoza, 50013 Zaragoza, Spain; (M.H.); (L.L.); (M.P.B.-B.); (J.M.)
- Instituto de Investigación Sanitaria (IIS) de Aragón, 50009 Zaragoza, Spain
- Centro de Investigaciones Biomédicas en Red de Enfermedades Raras (CIBERER), 28029 Madrid, Spain; (L.G.); (R.A.)
| | - José E. Bárcena
- Servicio de Neurología, Hospital Universitario Cruces, 48903 Baracaldo, Vizcaya, Spain;
| | - Leticia Ceberio
- Servicio de Medicina Interna, Hospital Universitario Cruces, 48903 Baracaldo, Vizcaya, Spain;
| | - Covadonga Gómez-Díaz
- Servicio de Otorrinolaringología, Hospital Universitario Miguel Servet, 50009 Zaragoza, Spain;
| | - Laura Gort
- Centro de Investigaciones Biomédicas en Red de Enfermedades Raras (CIBERER), 28029 Madrid, Spain; (L.G.); (R.A.)
- Errors Congènits del Metabolisme, Servicio de Bioquímica i Genètica Molecular, CDB, Hospital Clínic, IDIBAPS, 08036 Barcelona, Spain
| | - Rafael Artuch
- Centro de Investigaciones Biomédicas en Red de Enfermedades Raras (CIBERER), 28029 Madrid, Spain; (L.G.); (R.A.)
- Servicio de Bioquímica Clínica, Institut de Recerca Sant Joan de Déu, 08950 Barcelona, Spain
| | - Julio Montoya
- Departamento de Bioquímica, Biología Molecular y Celular, Universidad de Zaragoza, 50013 Zaragoza, Spain; (M.H.); (L.L.); (M.P.B.-B.); (J.M.)
- Instituto de Investigación Sanitaria (IIS) de Aragón, 50009 Zaragoza, Spain
- Centro de Investigaciones Biomédicas en Red de Enfermedades Raras (CIBERER), 28029 Madrid, Spain; (L.G.); (R.A.)
| | - Eduardo Ruiz-Pesini
- Departamento de Bioquímica, Biología Molecular y Celular, Universidad de Zaragoza, 50013 Zaragoza, Spain; (M.H.); (L.L.); (M.P.B.-B.); (J.M.)
- Instituto de Investigación Sanitaria (IIS) de Aragón, 50009 Zaragoza, Spain
- Centro de Investigaciones Biomédicas en Red de Enfermedades Raras (CIBERER), 28029 Madrid, Spain; (L.G.); (R.A.)
- Fundación Araid, 50018 Zaragoza, Spain
- Correspondence: ; Tel.: +34-976761646
| |
Collapse
|
16
|
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.
Collapse
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.
| |
Collapse
|
17
|
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.
Collapse
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
| |
Collapse
|
18
|
Ahmadmehrabi S, Brant J, Epstein DJ, Ruckenstein MJ, Rader DJ. Genetics of Postlingual Sensorineural Hearing Loss. Laryngoscope 2020; 131:401-409. [PMID: 32243624 DOI: 10.1002/lary.28646] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 02/19/2020] [Accepted: 02/28/2020] [Indexed: 12/11/2022]
Abstract
Literature and clinical practice around adult-onset hearing loss (HL) has traditionally focused on environmental risk factors, including noise exposure, ototoxic drug exposure, and cardiovascular disease. The most common diagnosis in adult-onset HL is presbycusis. However, the age of onset of presbycusis varies, and patients often describe family history of HL as well as individual variation in progression and severity. In recent years, there has been accumulating evidence of gene-environment interactions underlying adult cases of HL. Susceptibility loci for age-related HL have been identified, and genes related to postlingual nonsyndromic HL continue to be discovered through individual reports and genome-wide association studies. This review will outline main concepts in genetics as related to HL, identify implicated genes, and discuss clinical implications. Laryngoscope, 131:401-409, 2021.
Collapse
Affiliation(s)
- Shadi Ahmadmehrabi
- Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, Ohio, USA.,Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Jason Brant
- Department of Otorhinolaryngology Head and Neck Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Douglas J Epstein
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Michael J Ruckenstein
- Department of Otorhinolaryngology Head and Neck Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Daniel J Rader
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| |
Collapse
|
19
|
Ji Y, Zhang J, Yu J, Wang Y, Lu Y, Liang M, Li Q, Jin X, Wei Y, Meng F, Gao Y, Cang X, Tong Y, Liu X, Zhang M, Jiang P, Zhu T, Mo JQ, Huang T, Jiang P, Guan MX. Contribution of mitochondrial ND1 3394T>C mutation to the phenotypic manifestation of Leber's hereditary optic neuropathy. Hum Mol Genet 2020; 28:1515-1529. [PMID: 30597069 DOI: 10.1093/hmg/ddy450] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Revised: 11/05/2018] [Accepted: 12/22/2018] [Indexed: 11/14/2022] Open
Abstract
Mitochondrial DNA (mtDNA) mutations have been associated with Leber's hereditary optic neuropathy (LHON) and their pathophysiology remains poorly understood. In this study, we investigated the pathophysiology of a LHON susceptibility allele (m.3394T>C, p.30Y>H) in the Mitochondrial (MT)-ND1 gene. The incidence of m.3394T>C mutation was 2.7% in the cohort of 1741 probands with LHON. Extremely low penetrances of LHON were observed in 26 pedigrees carrying only m.3394T>C mutation, while 21 families bearing m.3394T>C, together with m.11778G>A or m.14484T>C mutation, exhibited higher penetrance of LHON than those in families carrying single mtDNA mutation(s). The m.3394T>C mutation disrupted the specific electrostatic interactions between Y30 of p.MT-ND1 with the sidechain of E4 and backbone carbonyl group of M1 of NDUFA1 (NADH dehydrogenase [ubiquinone] 1 alpha subcomplex subunit 1) of complex I, thereby altering the structure and function of complex I. We demonstrated that these cybrids bearing only m.3394T>C mutation caused mild mitochondrial dysfunctions and those harboring both m.3394T>C and m.11778G>A mutations exhibited greater mitochondrial dysfunctions than cybrids carrying only m.11778G>A mutation. In particular, the m.3394T>C mutation altered the stability of p.MT-ND1 and complex I assembly. Furthermore, the m.3394T>C mutation decreased the activities of mitochondrial complexes I, diminished mitochondrial ATP levels and membrane potential and increased the production of reactive oxygen species in the cybrids. These m.3394T>C mutation-induced alterations aggravated mitochondrial dysfunctions associated with the m.11778G>A mutation. These resultant biochemical defects contributed to higher penetrance of LHON in these families carrying both mtDNA mutations. Our findings provide new insights into the pathophysiology of LHON arising from the synergy between mitochondrial ND1 and ND4 mutations.
Collapse
Affiliation(s)
- Yanchun Ji
- Division of Medical Genetics and Genomics, the Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Juanjuan Zhang
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China.,Attardi Institute of Mitochondrial Biomedicine, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Jialing Yu
- Division of Medical Genetics and Genomics, the Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Ying Wang
- Department of Ophthalmology, Chinese Academy of Traditional Chinese Medicine, Beijing, China
| | - Yuanyuan Lu
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China.,Attardi Institute of Mitochondrial Biomedicine, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Min Liang
- Attardi Institute of Mitochondrial Biomedicine, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Qiang Li
- Division of Medical Genetics and Genomics, the Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Xiaofen Jin
- Division of Medical Genetics and Genomics, the Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Yinsheng Wei
- 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, Hangzhou, Zhejiang, China.,Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Yinglong Gao
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Xiaohui Cang
- Division of Medical Genetics and Genomics, the Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Yi Tong
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China.,Attardi Institute of Mitochondrial Biomedicine, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Xiaoling Liu
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China.,Attardi Institute of Mitochondrial Biomedicine, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Minglian Zhang
- Department of Ophthalmology, Hebei Provincial Eye Hospital, Xingtai, Hebei, China
| | - Peifang Jiang
- Division of Medical Genetics and Genomics, the Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Tao Zhu
- Department of Critical Care Medicine, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Jun Qin Mo
- Department of Pathology, Rady Children's Hospital, University of California School of Medicine, San Diego, California, USA
| | - Taosheng Huang
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Pingping Jiang
- Division of Medical Genetics and Genomics, the Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Min-Xin Guan
- Division of Medical Genetics and Genomics, the Children's Hospital, 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, China.,Joint Institute of Genetics and Genomic Medicine between Zhejiang University and University of Toronto, Hangzhou, Zhejiang, China
| |
Collapse
|
20
|
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.
Collapse
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
| |
Collapse
|
21
|
Sherpa C, Grice SFJL. Structural Fluidity of the Human Immunodeficiency Virus Rev Response Element. Viruses 2020; 12:v12010086. [PMID: 31940828 PMCID: PMC7019801 DOI: 10.3390/v12010086] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 01/07/2020] [Accepted: 01/09/2020] [Indexed: 01/22/2023] Open
Abstract
Nucleocytoplasmic transport of unspliced and partially spliced human immunodeficiency virus (HIV) RNA is mediated in part by the Rev response element (RRE), a ~350 nt cis-acting element located in the envelope coding region of the viral genome. Understanding the interaction of the RRE with the viral Rev protein, cellular co-factors, and its therapeutic potential has been the subject of almost three decades of structural studies, throughout which a recurring discussion theme has been RRE topology, i.e., whether it comprises 4 or 5 stem-loops (SLs) and whether this has biological significance. Moreover, while in vitro mutagenesis allows the construction of 4 SL and 5 SL RRE conformers and testing of their roles in cell culture, it has not been immediately clear if such findings can be translated to a clinical setting. Herein, we review several articles demonstrating remarkable flexibility of the HIV-1 and HIV-2 RREs following initial observations that HIV-1 resistance to trans-dominant Rev therapy was founded in structural rearrangement of its RRE. These observations can be extended not only to cell culture studies demonstrating a growth advantage for the 5 SL RRE conformer but also to evolution in RRE topology in patient isolates. Finally, RRE conformational flexibility provides a target for therapeutic intervention, and we describe high throughput screening approaches to exploit this property.
Collapse
|
22
|
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
|
23
|
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.
Collapse
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
| |
Collapse
|
24
|
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.
Collapse
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
| |
Collapse
|
25
|
Jia Z, Zhang Y, Li Q, Ye Z, Liu Y, Fu C, Cang X, Wang M, Guan MX. A coronary artery disease-associated tRNAThr mutation altered mitochondrial function, apoptosis and angiogenesis. Nucleic Acids Res 2019; 47:2056-2074. [PMID: 30541130 PMCID: PMC6393294 DOI: 10.1093/nar/gky1241] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 10/31/2018] [Accepted: 11/30/2018] [Indexed: 12/14/2022] Open
Abstract
The tissue specificity of mitochondrial tRNA mutations remains largely elusive. In this study, we demonstrated the deleterious effects of tRNAThr 15927G>A mutation that contributed to pathogenesis of coronary artery disease. The m.15927G>A mutation abolished the highly conserved base-pairing (28C-42G) of anticodon stem of tRNAThr. Using molecular dynamics simulations, we showed that the m.15927G>A mutation caused unstable tRNAThr structure, supported by decreased melting temperature and slower electrophoretic mobility of mutated tRNA. Using cybrids constructed by transferring mitochondria from a Chinese family carrying the m.15927G>A mutation and a control into mitochondrial DNA (mtDNA)-less human umbilical vein endothelial cells, we demonstrated that the m.15927G>A mutation caused significantly decreased efficiency in aminoacylation and steady-state levels of tRNAThr. The aberrant tRNAThr metabolism yielded variable decreases in mtDNA-encoded polypeptides, respiratory deficiency, diminished membrane potential and increased the production of reactive oxygen species. The m.15927G>A mutation promoted the apoptosis, evidenced by elevated release of cytochrome c into cytosol and increased levels of apoptosis-activated proteins: caspases 3, 7, 9 and PARP. Moreover, the lower wound healing cells and perturbed tube formation were observed in mutant cybrids, indicating altered angiogenesis. Our findings provide new insights into the pathophysiology of coronary artery disease, which is manifested by tRNAThr mutation-induced alterations.
Collapse
Affiliation(s)
- Zidong Jia
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,Institute of Genetics, Zhejiang University and Department of Human Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Ye Zhang
- Institute of Genetics, Zhejiang University and Department of Human Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Qiang Li
- Institute of Genetics, Zhejiang University and Department of Human Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Zhenzhen Ye
- Institute of Genetics, Zhejiang University and Department of Human Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Yuqi Liu
- Cardiac Department, PLA General Hospital, Beijing 100853, China
| | - Changzhu Fu
- Institute of Genetics, Zhejiang University and Department of Human 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, Hangzhou, Zhejiang 310058, China.,Institute of Genetics, Zhejiang University and Department of Human Genetics, 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, Hangzhou, Zhejiang 310058, China.,Institute of Genetics, Zhejiang University and Department of Human 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, Hangzhou, Zhejiang 310058, China.,Institute of Genetics, Zhejiang University and Department of Human 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
| |
Collapse
|
26
|
Lant JT, Berg MD, Heinemann IU, Brandl CJ, O'Donoghue P. Pathways to disease from natural variations in human cytoplasmic tRNAs. J Biol Chem 2019; 294:5294-5308. [PMID: 30643023 DOI: 10.1074/jbc.rev118.002982] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Perfectly accurate translation of mRNA into protein is not a prerequisite for life. Resulting from errors in protein synthesis, mistranslation occurs in all cells, including human cells. The human genome encodes >600 tRNA genes, providing both the raw material for genetic variation and a buffer to ensure that resulting translation errors occur at tolerable levels. On the basis of data from the 1000 Genomes Project, we highlight the unanticipated prevalence of mistranslating tRNA variants in the human population and review studies on synthetic and natural tRNA mutations that cause mistranslation or de-regulate protein synthesis. Although mitochondrial tRNA variants are well known to drive human diseases, including developmental disorders, few studies have revealed a role for human cytoplasmic tRNA mutants in disease. In the context of the unexpectedly large number of tRNA variants in the human population, the emerging literature suggests that human diseases may be affected by natural tRNA variants that cause mistranslation or de-regulate tRNA expression and nucleotide modification. This review highlights examples relevant to genetic disorders, cancer, and neurodegeneration in which cytoplasmic tRNA variants directly cause or exacerbate disease and disease-linked phenotypes in cells, animal models, and humans. In the near future, tRNAs may be recognized as useful genetic markers to predict the onset or severity of human disease.
Collapse
Affiliation(s)
| | | | | | | | - Patrick O'Donoghue
- From the Departments of Biochemistry and .,Chemistry, The University of Western Ontario, London, Ontario N6A 5C1, Canada
| |
Collapse
|
27
|
Zhang J, Lu B, Xia WW, Fang B, Ding XX, Hu GW. The mitochondrial transfer RNAAsp A7551G mutation may contribute to the clinical expression of deafness associated with the A1555G mutation in a pedigree with hearing impairment. Mol Med Rep 2018; 19:1797-1802. [PMID: 30592262 DOI: 10.3892/mmr.2018.9790] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2018] [Accepted: 11/23/2018] [Indexed: 11/05/2022] Open
Abstract
The role of mitochondrial (mt)DNA variations in hearing loss have been studied extensively; in particular, the well‑known pathogenic A1555G mutation in the human mitochondrial 12S ribosomal RNA gene is associated with aminoglycoside‑induced and non‑syndromic hearing loss. The present paper described a Chinese pedigree with hearing impairments. We first performed polymerase chain reaction and direct sequence analysis for the mtDNA genes. Additionally, the GJB2 gene mutations were also genotyped. Notably, this family had a very high penetrance of deafness (66.7 and 33.3%; including and excluding aminoglycoside use, respectively). Sequence analysis of the mtDNA genes from the matrilineal relatives identified the occurrence of A1555G mutation, as well as the tRNAAsp A7551G mutation. The A7551G mutation occurred at position 37 in the anticodon stem of tRNAAsp, which is extremely conserved among various species. The nucleotide at this position is often chemically modified and thus contributes to the maintenance of functional tRNAAsp, therefore, this mutation may cause an imbalance in the level of tRNAAsp and lead to mitochondrial dysfunction which is involved in the pathogenesis of hearing loss. Taken together, the findings of the present study demonstrated that the A7551G mutation may have contributed to the deafness phenotype caused by the A1555G mutation.
Collapse
Affiliation(s)
- Jing Zhang
- Department of Otolaryngology, Zhoushan Hospital, Zhejiang University School of Medicine, Zhoushan, Zhejiang 316021, P.R. China
| | - Bo Lu
- Department of Otolaryngology, Zhoushan Hospital, Zhejiang University School of Medicine, Zhoushan, Zhejiang 316021, P.R. China
| | - Wei-Wei Xia
- Department of Otolaryngology, Zhoushan Hospital, Zhejiang University School of Medicine, Zhoushan, Zhejiang 316021, P.R. China
| | - Bin Fang
- Department of Otolaryngology, Zhoushan Hospital, Zhejiang University School of Medicine, Zhoushan, Zhejiang 316021, P.R. China
| | - Xiao-Xia Ding
- Central Laboratory, Hangzhou First People's Hospital, Hangzhou, Zhejiang 310006, P.R. China
| | - Guang-Wei Hu
- Department of Otolaryngology, Zhoushan Hospital, Zhejiang University School of Medicine, Zhoushan, Zhejiang 316021, P.R. China
| |
Collapse
|
28
|
Xue L, Chen Y, Tang X, Yao J, Huang H, Wang M, Ye S, Wang M, Guan MX. A deafness-associated mitochondrial DNA mutation altered the tRNA Ser(UCN) metabolism and mitochondrial function. Mitochondrion 2018; 46:370-379. [PMID: 30336267 DOI: 10.1016/j.mito.2018.10.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 09/09/2018] [Accepted: 10/08/2018] [Indexed: 11/28/2022]
Abstract
Mutations in mitochondrial DNA (mtDNA) have been associated with deafness and their pathophysiology remains poorly understood. In this study, we investigated the pathogenic mechanism of deafness-associated 7505A > G variant in the mitochondrial tRNASer(UCN). The m.7505A > G variant affected the highly conserved adenine at position 11 (A11), disrupted the highly conserved A11-U24 base-pairing of DHU stem of tRNASer(UCN) and introduced a tertiary base pairing (G11-C56) with the C56 in the TΨC loop. We therefore hypothesized that the m.7505A > G variant altered both structure and function of tRNASer(UCN). We demonstrated that the m.7505A > G variant perturbed the conformation and stability of tRNASer(UCN), as indicated by an increased melting temperature and electrophoretic mobility of the mutated tRNA compared with the wild type molecule. Using the cybrids constructed by transferring mitochondria from the Chinese family into mitochondrial DNA (mtDNA)-less cells, we demonstrated the m.7505A > G variant led to significantly decreased steady-state levels of tRNASer(UCN) in the mutant cybrids, as compared with those of control cybrids. The aberrant tRNASer(UCN) metabolism resulted in the variable decreases in mtDNA-encoded polypeptides in the mutant cybrids. Furthermore, we demonstrated that the m.7505A > G variant decreased the activities of mitochondrial respiratory complexes I, III and IV, markedly diminished mitochondrial ATP levels and membrane potential, and increased the production of reactive oxygen species in the mutant cybrids. These results demonstrated that the m.7505A > G variant affected both structure and function of tRNASer(UCN) and consequently altered mitochondrial function. Our findings highlighted critical insights into the pathophysiology of maternally inherited deafness, which is manifested by the aberrant tRNA metabolism.
Collapse
Affiliation(s)
- Ling Xue
- Attardi Institute of Mitochondrial Biomedicine, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Zhejiang 325035, China
| | - Yaru Chen
- Attardi Institute of Mitochondrial Biomedicine, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Zhejiang 325035, China; Institute of Genetics, Zhejiang University School of Medicine, Zhejiang, Hangzhou 310058, China; Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, Zhejiang, Hangzhou, China
| | - Xiaowen Tang
- Attardi Institute of Mitochondrial Biomedicine, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Zhejiang 325035, China
| | - Juan Yao
- Attardi Institute of Mitochondrial Biomedicine, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Zhejiang 325035, China
| | - Huimin Huang
- Attardi Institute of Mitochondrial Biomedicine, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Zhejiang 325035, China
| | - Min Wang
- Attardi Institute of Mitochondrial Biomedicine, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Zhejiang 325035, China
| | - Shixin Ye
- Laboratory of Computational and Quantitative Biology, Université Pierre-et-Marie-Curie, CNRS, Paris, France
| | - Meng Wang
- Institute of Genetics, Zhejiang University School of Medicine, Zhejiang, Hangzhou 310058, China; Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, Zhejiang, Hangzhou, China
| | - Min-Xin Guan
- Attardi Institute of Mitochondrial Biomedicine, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Zhejiang 325035, China; Institute of Genetics, Zhejiang University School of Medicine, Zhejiang, Hangzhou 310058, China; Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, Zhejiang, Hangzhou, China; Key Laboratory of Reproductive Genetics, Ministry of Education of PRC, Zhejiang University, Hangzhou, China; Joint Institute of Genetics and Genomic Medicine, University of Toronto, Zhejiang University, Hangzhou, Zhejiang, China.
| |
Collapse
|
29
|
Zhao X, Han J, Zhu L, Xiao Y, Wang C, Hong F, Jiang P, Guan MX. Overexpression of human mitochondrial alanyl-tRNA synthetase suppresses biochemical defects of the mt-tRNA Ala mutation in cybrids. Int J Biol Sci 2018; 14:1437-1444. [PMID: 30262995 PMCID: PMC6158735 DOI: 10.7150/ijbs.27043] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 07/17/2018] [Indexed: 11/13/2022] Open
Abstract
Mutations of mitochondrial transfer RNAs (mt-tRNAs) play a major role in a wide range of mitochondrial diseases because of the vital role of these molecules in mitochondrial translation. It has previously been reported that the overexpression of mitochondrial aminoacyl tRNA synthetases is effective at partially suppressing the defects resulting from mutations in their cognate mt-tRNAs in cells. Here we report a detailed analysis of the suppressive activities of mitochondrial alanyl-tRNA synthetase (AARS2) on mt-tRNAAla 5655 A>G mutant. Mitochondrial defects in respiration, activity of oxidative phosphorylation complexes, ATP production, mitochondrial superoxide, and membrane potential were consistently rescued in m.5655A>G cybrids upon AARS2 expression. However, AARS2 overexpression did not result in a detectable increase in mutated mt-tRNAAla but caused an increase incharged mt-tRNAAla in mutant cybrids, leading to enhanced mitochondrial translation. This indicated that AARS2 improved the aminoacylation activity in the case of m.5655A>G, rather than having a stabilizing effect on the tRNA structure. The data presented in this paper deepen our understanding of the pathogenesis of mt-tRNA diseases.
Collapse
Affiliation(s)
- Xiaoxu Zhao
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China.,Institute of Genetics Zhejiang University, and Department of Human Genetics, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Jiamin Han
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China.,Institute of Genetics Zhejiang University, and Department of Human Genetics, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Ling Zhu
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Yun Xiao
- Institute of Genetics Zhejiang University, and Department of Human Genetics, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Chenghui Wang
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China.,Institute of Genetics Zhejiang University, and Department of Human Genetics, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Fang Hong
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Pingping Jiang
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China.,Institute of Genetics Zhejiang University, and Department of Human Genetics, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Min-Xin Guan
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China.,Institute of Genetics Zhejiang University, and Department of Human Genetics, Zhejiang University School of Medicine, Hangzhou, 310058, China
| |
Collapse
|