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Rosa H, Malik AN. Accurate Measurement of Cellular and Cell-Free Circulating Mitochondrial DNA Content from Human Blood Samples Using Real-Time Quantitative PCR. Methods Mol Biol 2021; 2277:247-268. [PMID: 34080155 DOI: 10.1007/978-1-0716-1270-5_15] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023]
Abstract
Changes in circulating mitochondrial DNA (mtDNA) are widely used to indicate mitochondrial dysfunction in common non-genetic diseases where mitochondrial dysfunction may play a role. However, the methodology being used is not always specific and reproducible, and most studies use whole blood rather than evaluating cellular and cell-free mtDNA separately. Cellular mtDNA is contained within the mitochondrion and encodes vital subunits of the OXPHOS machinery. Conversely, cell-free mtDNA can have harmful effects, triggering inflammatory responses and potentially contributing to pathogenic processes. In this chapter, we describe a protocol to accurately measure the amount of cellular and cell-free human mtDNA in peripheral blood. Absolute quantification is carried out using real-time quantitative PCR (qPCR) to quantify cellular mtDNA, measured as the mitochondrial genome to nuclear genome ratio (designated the Mt/N ratio) in whole blood and peripheral blood mononuclear cells (PBMCs) and the number of mtDNA copies per μL in plasma and serum. We describe how to (1) separate whole blood into PBMCs, plasma, and serum fractions, (2) prepare DNA from each of these fractions, (3) prepare dilution standards for absolute quantification, (4) carry out qPCR for either relative or absolute quantification from test samples, (5) analyze qPCR data, and (6) calculate the sample size to adequately power studies. The protocol presented here is suitable for high-throughput use and can be modified to quantify mtDNA from other body fluids, human cells, and tissues.
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Affiliation(s)
- Hannah Rosa
- Department of Diabetes, Faculty of Life Sciences and Medicine, School of Life Course Sciences, King's College London, London, UK
| | - Afshan N Malik
- Department of Diabetes, Faculty of Life Sciences and Medicine, School of Life Course Sciences, King's College London, London, UK.
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52
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Peng YB, He W, Niu Q, Tao C, Zhong XL, Tan CP, Zhao P. Mitochondria-targeted cyclometalated rhodium(III) complexes: synthesis, characterization and anticancer research. Dalton Trans 2021; 50:9068-9075. [PMID: 34113944 DOI: 10.1039/d1dt01053k] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Over the past few decades, the landscape of inorganic medicinal chemistry has been dominated by investigations on platinum or ruthenium, while the research based on other metal centers such as rhodium has been relatively insufficient. In this work, a series of cyclometalated rhodium(iii) complexes with imidazo[4,5-f][1,10]phenanthroline containing different aromatic rings were synthesized and characterized. Notably, all the complexes displayed stronger anticancer activity against various cancer cells compared with cisplatin. A mechanism study revealed that the rhodium complexes accumulated in the mitochondria, elevated the levels of mitochondrial reactive oxygen species (ROS) and released cytochrome c, indicating severe mitochondrial damage during the anticancer activity. Further studies illustrated that the rhodium complexes caused cell cycle arrest at the G2/M phase, upregulated the expression of p53 and reduced the ratio of B-cell lymphoma-2 (Bcl-2)/Bcl-2-associated x (Bax), which ultimately resulted in cellular apoptosis. Overall, through mitochondrial pathways, these Rh(iii) complexes could induce cellular apoptosis to a larger extent than cisplatin and should be paid close attention as promising chemotherapeutic drugs in anticancer research.
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Affiliation(s)
- Yan-Bo Peng
- School of Chemistry and Chemical Engineering, Guangdong Pharmaceutical University, Education Mega Centre, No. 280, Waihuandong Road, Guangzhou 510006, P.R. China. and MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-Sen University, Guangzhou 510275, P.R. China.
| | - Wei He
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-Sen University, Guangzhou 510275, P.R. China.
| | - Qiang Niu
- School of Chemistry and Chemical Engineering, Guangdong Pharmaceutical University, Education Mega Centre, No. 280, Waihuandong Road, Guangzhou 510006, P.R. China.
| | - Can Tao
- School of Chemistry and Chemical Engineering, Guangdong Pharmaceutical University, Education Mega Centre, No. 280, Waihuandong Road, Guangzhou 510006, P.R. China.
| | - Xiao-Lan Zhong
- College of Materials and Energy, South China Agricultural University, Guangzhou 510642, P.R. China
| | - Cai-Ping Tan
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-Sen University, Guangzhou 510275, P.R. China.
| | - Ping Zhao
- School of Chemistry and Chemical Engineering, Guangdong Pharmaceutical University, Education Mega Centre, No. 280, Waihuandong Road, Guangzhou 510006, P.R. China.
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53
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Cheng H, Yang B, Ke T, Li S, Yang X, Aschner M, Chen P. Mechanisms of Metal-Induced Mitochondrial Dysfunction in Neurological Disorders. TOXICS 2021; 9:142. [PMID: 34204190 PMCID: PMC8235163 DOI: 10.3390/toxics9060142] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 06/12/2021] [Accepted: 06/14/2021] [Indexed: 01/31/2023]
Abstract
Metals are actively involved in multiple catalytic physiological activities. However, metal overload may result in neurotoxicity as it increases formation of reactive oxygen species (ROS) and elevates oxidative stress in the nervous system. Mitochondria are a key target of metal-induced toxicity, given their role in energy production. As the brain consumes a large amount of energy, mitochondrial dysfunction and the subsequent decrease in levels of ATP may significantly disrupt brain function, resulting in neuronal cell death and ensuing neurological disorders. Here, we address contemporary studies on metal-induced mitochondrial dysfunction and its impact on the nervous system.
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Affiliation(s)
- Hong Cheng
- Department of Occupational Health and Environmental Health, School of Public Health, Guangxi Medical University, Nanning 530021, China; (H.C.); (X.Y.)
| | - Bobo Yang
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; (B.Y.); (T.K.)
| | - Tao Ke
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; (B.Y.); (T.K.)
| | - Shaojun Li
- Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning 530021, China;
| | - Xiaobo Yang
- Department of Occupational Health and Environmental Health, School of Public Health, Guangxi Medical University, Nanning 530021, China; (H.C.); (X.Y.)
- Department of Public Health, School of Medicine, Guangxi University of Science and Technology, Liuzhou 545006, China
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; (B.Y.); (T.K.)
| | - Pan Chen
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; (B.Y.); (T.K.)
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54
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Mazzaccara C, Mirra B, Barretta F, Caiazza M, Lombardo B, Scudiero O, Tinto N, Limongelli G, Frisso G. Molecular Epidemiology of Mitochondrial Cardiomyopathy: A Search Among Mitochondrial and Nuclear Genes. Int J Mol Sci 2021; 22:ijms22115742. [PMID: 34072184 PMCID: PMC8197938 DOI: 10.3390/ijms22115742] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 05/18/2021] [Accepted: 05/22/2021] [Indexed: 12/23/2022] Open
Abstract
Mitochondrial Cardiomyopathy (MCM) is a common manifestation of multi-organ Mitochondrial Diseases (MDs), occasionally present in non-syndromic cases. Diagnosis of MCM is complex because of wide clinical and genetic heterogeneity and requires medical, laboratory, and neuroimaging investigations. Currently, the molecular screening for MCM is fundamental part of MDs management and allows achieving the definitive diagnosis. In this article, we review the current genetic knowledge associated with MDs, focusing on diagnosis of MCM and MDs showing cardiac involvement. We searched for publications on mitochondrial and nuclear genes involved in MCM, mainly focusing on genetic screening based on targeted gene panels for the molecular diagnosis of the MCM, by using Next Generation Sequencing. Here we report twelve case reports, four case-control studies, eleven retrospective studies, and two prospective studies, for a total of twenty-nine papers concerning the evaluation of cardiac manifestations in mitochondrial diseases. From the analysis of published causal mutations, we identified 130 genes to be associated with mitochondrial heart diseases. A large proportion of these genes (34.3%) encode for key proteins involved in the oxidative phosphorylation system (OXPHOS), either as directly OXPHOS subunits (22.8%), and as OXPHOS assembly factors (11.5%). Mutations in several mitochondrial tRNA genes have been also reported in multi-organ or isolated MCM (15.3%). This review highlights the main disease-genes, identified by extensive genetic analysis, which could be included as target genes in next generation panels for the molecular diagnosis of patients with clinical suspect of mitochondrial cardiomyopathies.
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Affiliation(s)
- Cristina Mazzaccara
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, 80131 Naples, Italy; (B.M.); (F.B.); (B.L.); (O.S.); (N.T.); (G.F.)
- CEINGE Advanced Biotechnologies, 80145 Naples, Italy
- Correspondence: ; Tel.: +39-0817-462-422
| | - Bruno Mirra
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, 80131 Naples, Italy; (B.M.); (F.B.); (B.L.); (O.S.); (N.T.); (G.F.)
- CEINGE Advanced Biotechnologies, 80145 Naples, Italy
| | - Ferdinando Barretta
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, 80131 Naples, Italy; (B.M.); (F.B.); (B.L.); (O.S.); (N.T.); (G.F.)
- CEINGE Advanced Biotechnologies, 80145 Naples, Italy
| | - Martina Caiazza
- Monaldi Hospital, AO Colli, 80131 Naples, Italy; (M.C.); (G.L.)
- Department of Translational Medical Sciences, University of Campania “Luigi Vanvitelli”, 80134 Naples, Italy
| | - Barbara Lombardo
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, 80131 Naples, Italy; (B.M.); (F.B.); (B.L.); (O.S.); (N.T.); (G.F.)
- CEINGE Advanced Biotechnologies, 80145 Naples, Italy
| | - Olga Scudiero
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, 80131 Naples, Italy; (B.M.); (F.B.); (B.L.); (O.S.); (N.T.); (G.F.)
- CEINGE Advanced Biotechnologies, 80145 Naples, Italy
| | - Nadia Tinto
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, 80131 Naples, Italy; (B.M.); (F.B.); (B.L.); (O.S.); (N.T.); (G.F.)
- CEINGE Advanced Biotechnologies, 80145 Naples, Italy
| | - Giuseppe Limongelli
- Monaldi Hospital, AO Colli, 80131 Naples, Italy; (M.C.); (G.L.)
- Department of Translational Medical Sciences, University of Campania “Luigi Vanvitelli”, 80134 Naples, Italy
| | - Giulia Frisso
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, 80131 Naples, Italy; (B.M.); (F.B.); (B.L.); (O.S.); (N.T.); (G.F.)
- CEINGE Advanced Biotechnologies, 80145 Naples, Italy
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55
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Pileggi CA, Parmar G, Harper ME. The lifecycle of skeletal muscle mitochondria in obesity. Obes Rev 2021; 22:e13164. [PMID: 33442950 DOI: 10.1111/obr.13164] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 10/10/2020] [Accepted: 10/12/2020] [Indexed: 12/12/2022]
Abstract
Skeletal muscle possesses dramatic metabolic plasticity that allows for the rapid adaptation in cellular energy transduction to meet the demands of the organism. Obesity elicits changes in skeletal muscle structure and function, resulting in the accumulation of intramuscular lipids. The accumulation of intramuscular lipids in obesity is associated with impaired skeletal muscle mitochondrial content and function. Mitochondria exist as a dynamic network that is regulated by the processes of biogenesis, fusion, fission, and mitophagy. In this review, we outline adaptations in molecular pathways that regulate mitochondrial structure and function in obesity. We highlight the emerging role of dysregulated skeletal muscle macroautophagy and mitochondrial turnover in obesity. Future research should further elucidate the role of mitophagy in observed reductions in mitochondrial content and function during obesity.
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Affiliation(s)
- Chantal A Pileggi
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, K1H 8M5, Canada.,Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON, K1H 8M5, Canada
| | - Gaganvir Parmar
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, K1H 8M5, Canada.,Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON, K1H 8M5, Canada
| | - Mary-Ellen Harper
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, K1H 8M5, Canada.,Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON, K1H 8M5, Canada
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56
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Sebastian W, Sukumaran S, Gopalakrishnan A. The signals of selective constraints on the mitochondrial non-coding control region: insights from comparative mitogenomics of Clupeoid fishes. Genetica 2021; 149:191-201. [PMID: 33914198 DOI: 10.1007/s10709-021-00121-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 04/22/2021] [Indexed: 11/24/2022]
Abstract
The vertebrate mitochondrial genome is characterized by an exceptional organization evolving towards a reduced size. However, the persistence of a non-coding and highly variable control region is against this evolutionary trend that is explained by the presence of conserved sequence motifs or binding sites for nuclear-organized proteins that regulate mtDNA maintenance and expression. We performed a comparative mitogenomic investigation of the non-coding control region to understand its evolutionary patterns in Clupeoid fishes which are widely distributed across oceans of the world, exhibiting exemplary evolutionary potential. We confirmed the ability of sequence flanking the conserved sequence motifs in the control region to form stable secondary structures. The existence of evolutionarily conserved secondary structures without primary structure conservation suggested the action of selective constraints towards maintaining the secondary structure. The functional secondary structure is maintained by retaining the frequency of discontinuous AT and TG repeats along with compensatory base substitutions in the stem forming regions which can be considered as a selective constraint. The nucleotide polymorphism along the flanking regions of conserved sequence motifs can be explained as errors during the enzymatic replication of secondary structure-forming repeat elements. The evidence for selective constraints on secondary structures emphasizes the role of the control region in mitogenome function. Maintenance of high frequency of discontinuous repeats can be proposed as a model of adaptive evolution against the mutations that break the secondary structure involved in the efficient regulation of mtDNA functions substantiating the efficient functioning of the control region even in a high nucleotide polymorphism environment.
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Affiliation(s)
- Wilson Sebastian
- ICAR-Central Marine Fisheries Research Institute, Ernakulam North P.O, Kochi, 682018, Kerala, India
| | - Sandhya Sukumaran
- ICAR-Central Marine Fisheries Research Institute, Ernakulam North P.O, Kochi, 682018, Kerala, India.
| | - A Gopalakrishnan
- ICAR-Central Marine Fisheries Research Institute, Ernakulam North P.O, Kochi, 682018, Kerala, India
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57
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Lan Y, Zhang S, Gong F, Lu C, Lin G, Hu L. The mitochondrial DNA copy number of cumulus granulosa cells may be related to the maturity of oocyte cytoplasm. Hum Reprod 2021; 35:1120-1129. [PMID: 32358599 DOI: 10.1093/humrep/deaa085] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2019] [Revised: 02/20/2020] [Accepted: 03/29/2020] [Indexed: 02/06/2023] Open
Abstract
STUDY QUESTION Is the mitochondrial DNA (mtDNA) copy number of cumulus granulosa cells (CGCs) related to the maturation of oocyte cytoplasm? SUMMARY ANSWER Compared with the mtDNA copy number of CGCs from germinal vesicles (GV), CGCs from Metaphase I (MI) oocytes appear to have a lower mtDNA copy number. WHAT IS KNOWN ALREADY The growth and development of CGCs and oocyte are synchronised. The interaction between CGCs and the oocyte provides the appropriate balance of energy, which is necessary for mammalian oocyte development. Moreover, in the oocyte-cumulus complex (OCC), mature oocytes with higher mtDNA copy numbers tend to have corresponding CGCs with higher mtDNA copy numbers. STUDY DESIGN, SIZE, DURATION This is a prospective study of 302 OCCs obtained from 70 women undergoing in vitro fertilisation with intracytoplasmic sperm injection (ICSI) at the Reproductive and Genetic Hospital of CITIC-Xiangya, between 24 February 2018 and 21 December 2019. The CGCs were divided into three groups (GV, MI and MII stages) based on the maturation status of their corresponding oocyte. The sample sizes (n = 302) of CGCs in the three stages were 63 (CGCGV), 70 (CGCMI) and 169 (CGCMII), respectively. Some of the samples (n = 257) was used to quantify the mtDNA copy number, while the rest (n = 45) were used to analyse the expression level of mitochondrial genes. Furthermore, we retrieved 82 immature oocytes from among the 257 OCCs used for mtDNA copy numbers, including 36 GV oocytes and 46 MI oocytes, for analysis of oocyte mtDNA. PARTICIPANTS/MATERIALS, SETTING, METHODS We selected genes with high consistency of real-time PCR results to accurately measure the mtDNA copy number by testing the efficacy and the reproducibility in whole genome amplification (WGA) samples from a human embryonic stem cell line. The CGCs of each oocyte were individually isolated. The mtDNA copy number and gene expression of the CGCs were assessed using real-time PCR techniques. Mitochondrial DNA copy number of the corresponding immature oocytes was also evaluated. MAIN RESULTS AND THE ROLE OF CHANCE MT-ND1, MT-CO1 and β-globin genes were chosen for the assessment of mtDNA content, and mRNA expressions of MT-ND1, MT-CO1, PGC-1α and TFAM were also measured. The genome of 257 CGCs and 82 immature oocytes were amplified according to the multiple displacement amplification (MDA) protocol, and RNA was extracted from 45 CGCs. Compared with CGCGV, CGCMI had a significantly lower mtDNA copy number. In the MT-ND1 assay, the CGCGV: CGCMI was [270 ± 302]: [134 ± 201], P = 0.015. In the MT-CO1 assay, CGCGV: CGCMI was [205 ± 228]: [92 ± 112], P = 0.026. There was no statistical difference in mtDNA between CGCGV and CGCMII. In the MT-ND1 assay, CGCGV: CGCMII was [270 ± 302]: [175 ± 223], P = 0.074. In the MT-CO1 assay, CGCGV: CGCMII was [205 ± 228]: [119 ± 192], P = 0.077. No statistical difference of mtDNA copy number was observed between CGCMI and CGCMII. In the MT-ND1 assay, CGCMI: CGCMII was [134 ± 201]: [175 ± 223], P = 0.422. In the MT-CO1 assay, CGCMI: CGCMII was [92 ± 112]: [119 ± 192], P = 0.478. To verify the reliability of the above results, we further analysed the mtDNA copy number of CGCs of 14 patients with GV, MI and MII oocytes, and the results showed that the mtDNA copy number of CGCMI may be lower. The mtDNA copy number of CGCGV and CGCMI was statistically different in the MT-ND1 assay where CGCGV: CGCMI was [249 ± 173]: [118 ± 113], P = 0.016, but in the MT-CO1 assay, CGCGV: CGCMI was [208 ± 199]: [83 ± 98], P = 0.109. There was no significant difference in mtDNA between CGCGV and CGCMII. In the MT-ND1 assay, CGCGV: CGCMII was [249 ± 173]: [185 ± 200], P = 0.096. In the MT-CO1 assay, CGCGV: CGCMII was [208 ± 199]: [114 ± 139], P = 0.096. There was also no significant difference in mtDNA between CGCMI and CGCMII. In the MT-ND1 assay, CGCMI: CGCMII was [118 ± 113]: [185 ± 200], P = 0.198. In the MT-CO1 assay, CGCMI: CGCMII was [83 ± 98]: [114 ± 139], P = 0.470. Moreover, there were no statistical differences in the expression levels of MT-ND1, MT-CO1, PGC-1α and TFAM between CGCGV, CGCMI and CGCMII (P > 0.05). LARGE SCALE DATA N/A. LIMITATIONS, REASONS FOR CAUTION Due to the ethical issues, the study did not quantify the mtDNA content of MII oocytes. Thus, whether the change in mtDNA copy number in CGCs is related to the different developmental stages of oocytes has not been further confirmed. Moreover, the sample size was relatively small. WIDER IMPLICATIONS OF THE FINDINGS The mtDNA copy number of CGCs decreases from the GV phase to the MI phase and stays steady from the MI to MII stage. At different stages of oocyte maturation, the mtDNA of CGCs may undergo self-degradation and replication to meet the energy requirements of the corresponding oocyte and the maturation of the oocyte cytoplasm. STUDY FUNDING/COMPETING INTEREST(S) Funding was provided by the National Key R&D Program of China (Grant 2018YFC1003100, to L.H.), the science and technology major project of the Ministry of Science and Technology of Hunan Province, China (grant 2017SK1030, to G.L.), the National Natural Science Foundation of China (grant 81873478, to L.H.), and Merck Serono China Research Fund for Fertility Experts (to L.H.). There is no conflict of interest.
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Affiliation(s)
- Yueyun Lan
- Institute of Reproduction and Stem Cell Engineering, School of Basic Medical Science, Central South University, Changsha, Hunan, China.,Reproductive and Genetic Hospital of CITIC-Xiangya, Changsha, Hunan, China.,Genetic and Metabolic Central Laboratory, Birth Defect Prevention Research Institute, Maternal and Child Health Hospital, Children's Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
| | - Shuoping Zhang
- Reproductive and Genetic Hospital of CITIC-Xiangya, Changsha, Hunan, China.,Clinical Research Center For Reproduction and Genetics in Hunan Province, Changsha, Hunan, China
| | - Fei Gong
- Institute of Reproduction and Stem Cell Engineering, School of Basic Medical Science, Central South University, Changsha, Hunan, China.,Reproductive and Genetic Hospital of CITIC-Xiangya, Changsha, Hunan, China.,NHC Key Laboratory of Human Stem Cell and Reproductive Engineering (Central South University), Changsha, Hunan, China.,Clinical Research Center For Reproduction and Genetics in Hunan Province, Changsha, Hunan, China
| | - Changfu Lu
- Institute of Reproduction and Stem Cell Engineering, School of Basic Medical Science, Central South University, Changsha, Hunan, China.,Reproductive and Genetic Hospital of CITIC-Xiangya, Changsha, Hunan, China.,NHC Key Laboratory of Human Stem Cell and Reproductive Engineering (Central South University), Changsha, Hunan, China.,Clinical Research Center For Reproduction and Genetics in Hunan Province, Changsha, Hunan, China
| | - Ge Lin
- Institute of Reproduction and Stem Cell Engineering, School of Basic Medical Science, Central South University, Changsha, Hunan, China.,Reproductive and Genetic Hospital of CITIC-Xiangya, Changsha, Hunan, China.,National Engineering and Research Center of Human Stem Cells, Changsha, Hunan, China.,NHC Key Laboratory of Human Stem Cell and Reproductive Engineering (Central South University), Changsha, Hunan, China.,Clinical Research Center For Reproduction and Genetics in Hunan Province, Changsha, Hunan, China
| | - Liang Hu
- Institute of Reproduction and Stem Cell Engineering, School of Basic Medical Science, Central South University, Changsha, Hunan, China.,Reproductive and Genetic Hospital of CITIC-Xiangya, Changsha, Hunan, China.,National Engineering and Research Center of Human Stem Cells, Changsha, Hunan, China.,NHC Key Laboratory of Human Stem Cell and Reproductive Engineering (Central South University), Changsha, Hunan, China.,Clinical Research Center For Reproduction and Genetics in Hunan Province, Changsha, Hunan, China
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58
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Niture S, Lin M, Rios-Colon L, Qi Q, Moore JT, Kumar D. Emerging Roles of Impaired Autophagy in Fatty Liver Disease and Hepatocellular Carcinoma. Int J Hepatol 2021; 2021:6675762. [PMID: 33976943 PMCID: PMC8083829 DOI: 10.1155/2021/6675762] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 03/16/2021] [Accepted: 04/06/2021] [Indexed: 02/07/2023] Open
Abstract
Autophagy is a conserved catabolic process that eliminates dysfunctional cytosolic biomolecules through vacuole-mediated sequestration and lysosomal degradation. Although the molecular mechanisms that regulate autophagy are not fully understood, recent work indicates that dysfunctional/impaired autophagic functions are associated with the development and progression of nonalcoholic fatty liver disease (NAFLD), alcoholic fatty liver disease (AFLD), and hepatocellular carcinoma (HCC). Autophagy prevents NAFLD and AFLD progression through enhanced lipid catabolism and decreasing hepatic steatosis, which is characterized by the accumulation of triglycerides and increased inflammation. However, as both diseases progress, autophagy can become impaired leading to exacerbation of both pathological conditions and progression into HCC. Due to the significance of impaired autophagy in these diseases, there is increased interest in studying pathways and targets involved in maintaining efficient autophagic functions as potential therapeutic targets. In this review, we summarize how impaired autophagy affects liver function and contributes to NAFLD, AFLD, and HCC progression. We will also explore how recent discoveries could provide novel therapeutic opportunities to effectively treat these diseases.
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Affiliation(s)
- Suryakant Niture
- Julius L. Chambers Biomedical Biotechnology Research Institute, North Carolina Central University Durham, NC 27707, USA
| | - Minghui Lin
- The Fourth People's Hospital of Ningxia Hui Autonomous Region, Yinchuan, China 750021
| | - Leslimar Rios-Colon
- Julius L. Chambers Biomedical Biotechnology Research Institute, North Carolina Central University Durham, NC 27707, USA
| | - Qi Qi
- Julius L. Chambers Biomedical Biotechnology Research Institute, North Carolina Central University Durham, NC 27707, USA
| | - John T. Moore
- Julius L. Chambers Biomedical Biotechnology Research Institute, North Carolina Central University Durham, NC 27707, USA
| | - Deepak Kumar
- Julius L. Chambers Biomedical Biotechnology Research Institute, North Carolina Central University Durham, NC 27707, USA
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59
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Sullivan ED, Longley MJ, Copeland WC. Polymerase γ efficiently replicates through many natural template barriers but stalls at the HSP1 quadruplex. J Biol Chem 2021; 295:17802-17815. [PMID: 33454015 DOI: 10.1074/jbc.ra120.015390] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 10/05/2020] [Indexed: 12/27/2022] Open
Abstract
Faithful replication of the mitochondrial genome is carried out by a set of key nuclear-encoded proteins. DNA polymerase γ is a core component of the mtDNA replisome and the only replicative DNA polymerase localized to mitochondria. The asynchronous mechanism of mtDNA replication predicts that the replication machinery encounters dsDNA and unique physical barriers such as structured genes, G-quadruplexes, and other obstacles. In vitro experiments here provide evidence that the polymerase γ heterotrimer is well-adapted to efficiently synthesize DNA, despite the presence of many naturally occurring roadblocks. However, we identified a specific G-quadruplex-forming sequence at the heavy-strand promoter (HSP1) that has the potential to cause significant stalling of mtDNA replication. Furthermore, this structured region of DNA corresponds to the break site for a large (3,895 bp) deletion observed in mitochondrial disease patients. The presence of this deletion in humans correlates with UV exposure, and we have found that efficiency of polymerase γ DNA synthesis is reduced after this quadruplex is exposed to UV in vitro.
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Affiliation(s)
- Eric D Sullivan
- Mitochondrial DNA Replication Group, Genome Integrity and Structural Biology Laboratory, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - Matthew J Longley
- Mitochondrial DNA Replication Group, Genome Integrity and Structural Biology Laboratory, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - William C Copeland
- Mitochondrial DNA Replication Group, Genome Integrity and Structural Biology Laboratory, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina, USA.
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60
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Mitochondrial genome stability in human: understanding the role of DNA repair pathways. Biochem J 2021; 478:1179-1197. [DOI: 10.1042/bcj20200920] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 02/15/2021] [Accepted: 02/17/2021] [Indexed: 11/17/2022]
Abstract
Mitochondria are semiautonomous organelles in eukaryotic cells and possess their own genome that replicates independently. Mitochondria play a major role in oxidative phosphorylation due to which its genome is frequently exposed to oxidative stress. Factors including ionizing radiation, radiomimetic drugs and replication fork stalling can also result in different types of mutations in mitochondrial DNA (mtDNA) leading to genome fragility. Mitochondria from myopathies, dystonia, cancer patient samples show frequent mtDNA mutations such as point mutations, insertions and large-scale deletions that could account for mitochondria-associated disease pathogenesis. The mechanism by which such mutations arise following exposure to various DNA-damaging agents is not well understood. One of the well-studied repair pathways in mitochondria is base excision repair. Other repair pathways such as mismatch repair, homologous recombination and microhomology-mediated end joining have also been reported. Interestingly, nucleotide excision repair and classical nonhomologous DNA end joining are not detected in mitochondria. In this review, we summarize the potential causes of mitochondrial genome fragility, their implications as well as various DNA repair pathways that operate in mitochondria.
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61
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Nikolac Perkovic M, Videtic Paska A, Konjevod M, Kouter K, Svob Strac D, Nedic Erjavec G, Pivac N. Epigenetics of Alzheimer's Disease. Biomolecules 2021; 11:biom11020195. [PMID: 33573255 PMCID: PMC7911414 DOI: 10.3390/biom11020195] [Citation(s) in RCA: 76] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/19/2021] [Accepted: 01/26/2021] [Indexed: 02/07/2023] Open
Abstract
There are currently no validated biomarkers which can be used to accurately diagnose Alzheimer’s disease (AD) or to distinguish it from other dementia-causing neuropathologies. Moreover, to date, only symptomatic treatments exist for this progressive neurodegenerative disorder. In the search for new, more reliable biomarkers and potential therapeutic options, epigenetic modifications have emerged as important players in the pathogenesis of AD. The aim of the article was to provide a brief overview of the current knowledge regarding the role of epigenetics (including mitoepigenetics) in AD, and the possibility of applying these advances for future AD therapy. Extensive research has suggested an important role of DNA methylation and hydroxymethylation, histone posttranslational modifications, and non-coding RNA regulation (with the emphasis on microRNAs) in the course and development of AD. Recent studies also indicated mitochondrial DNA (mtDNA) as an interesting biomarker of AD, since dysfunctions in the mitochondria and lower mtDNA copy number have been associated with AD pathophysiology. The current evidence suggests that epigenetic changes can be successfully detected, not only in the central nervous system, but also in the cerebrospinal fluid and on the periphery, contributing further to their potential as both biomarkers and therapeutic targets in AD.
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Affiliation(s)
- Matea Nikolac Perkovic
- Laboratory for Molecular Neuropsychiatry, Division of Molecular Medicine, Ruder Boskovic Institute, HR-10000 Zagreb, Croatia; (M.N.P.); (M.K.); (D.S.S.); (G.N.E.)
| | - Alja Videtic Paska
- Medical Center for Molecular Biology, Institute of Biochemistry and Molecular Genetics, Faculty of Medicine, University of Ljubljana, SI-1000 Ljubljana, Slovenia; (A.V.P.); (K.K.)
| | - Marcela Konjevod
- Laboratory for Molecular Neuropsychiatry, Division of Molecular Medicine, Ruder Boskovic Institute, HR-10000 Zagreb, Croatia; (M.N.P.); (M.K.); (D.S.S.); (G.N.E.)
| | - Katarina Kouter
- Medical Center for Molecular Biology, Institute of Biochemistry and Molecular Genetics, Faculty of Medicine, University of Ljubljana, SI-1000 Ljubljana, Slovenia; (A.V.P.); (K.K.)
| | - Dubravka Svob Strac
- Laboratory for Molecular Neuropsychiatry, Division of Molecular Medicine, Ruder Boskovic Institute, HR-10000 Zagreb, Croatia; (M.N.P.); (M.K.); (D.S.S.); (G.N.E.)
| | - Gordana Nedic Erjavec
- Laboratory for Molecular Neuropsychiatry, Division of Molecular Medicine, Ruder Boskovic Institute, HR-10000 Zagreb, Croatia; (M.N.P.); (M.K.); (D.S.S.); (G.N.E.)
| | - Nela Pivac
- Laboratory for Molecular Neuropsychiatry, Division of Molecular Medicine, Ruder Boskovic Institute, HR-10000 Zagreb, Croatia; (M.N.P.); (M.K.); (D.S.S.); (G.N.E.)
- Correspondence: ; Tel.: +38-514-571-207
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Darin N, Siibak T, Peter B, Hedberg-Oldfors C, Kollberg G, Kalbin V, Moslemi AR, Macao B, Oldfors A, Falkenberg M. Functional analysis of a novel POLγA mutation associated with a severe perinatal mitochondrial encephalomyopathy. Neuromuscul Disord 2021; 31:348-358. [PMID: 33579567 DOI: 10.1016/j.nmd.2021.01.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 01/05/2021] [Accepted: 01/06/2021] [Indexed: 12/18/2022]
Abstract
Mutations in the mitochondrial DNA polymerase gamma catalytic subunit (POLγA) compromise the stability of mitochondrial DNA (mtDNA) by leading to mutations, deletions and depletions in mtDNA. Patients with mutations in POLγA often differ remarkably in disease severity and age of onset. In this work we have studied the functional consequence of POLγA mutations in a patient with an uncommon and a very severe disease phenotype characterized by prenatal onset with intrauterine growth restriction, lactic acidosis from birth, encephalopathy, hepatopathy, myopathy, and early death. Muscle biopsy identified scattered COX-deficient muscle fibers, respiratory chain dysfunction and mtDNA depletion. We identified a novel POLγA mutation (p.His1134Tyr) in trans with the previously identified p.Thr251Ile/Pro587Leu double mutant. Biochemical characterization of the purified recombinant POLγA variants showed that the p.His1134Tyr mutation caused severe polymerase dysfunction. The p.Thr251Ile/Pro587Leu mutation caused reduced polymerase function in conditions of low dNTP concentration that mimic postmitotic tissues. Critically, when p.His1134Tyr and p.Thr251Ile/Pro587Leu were combined under these conditions, mtDNA replication was severely diminished and featured prominent stalling. Our data provide a molecular explanation for the patient´s mtDNA depletion and clinical features, particularly in tissues such as brain and muscle that have low dNTP concentration.
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Affiliation(s)
- Niklas Darin
- Department of Pediatrics, Institute of Clinical Sciences, University of Gothenburg, Gothenburg, Sweden.
| | - Triinu Siibak
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, University of Gothenburg, Box 440, 40530 Gothenburg, Sweden
| | - Bradley Peter
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, University of Gothenburg, Box 440, 40530 Gothenburg, Sweden
| | - Carola Hedberg-Oldfors
- Department of Laboratory Medicine, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Gittan Kollberg
- Department of Laboratory Medicine, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Vassili Kalbin
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, University of Gothenburg, Box 440, 40530 Gothenburg, Sweden
| | - Ali-Reza Moslemi
- Department of Laboratory Medicine, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Bertil Macao
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, University of Gothenburg, Box 440, 40530 Gothenburg, Sweden
| | - Anders Oldfors
- Department of Laboratory Medicine, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Maria Falkenberg
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, University of Gothenburg, Box 440, 40530 Gothenburg, Sweden.
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63
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Piotrowska-Nowak A, Krawczyński MR, Kosior-Jarecka E, Ambroziak AM, Korwin M, Ołdak M, Tońska K, Bartnik E. Mitochondrial genome variation in male LHON patients with the m.11778G > A mutation. Metab Brain Dis 2020; 35:1317-1327. [PMID: 32740724 PMCID: PMC7584531 DOI: 10.1007/s11011-020-00605-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 07/21/2020] [Indexed: 11/30/2022]
Abstract
Leber hereditary optic neuropathy (LHON) is a mitochondrial disorder with symptoms limited to a single tissue, optic nerve, resulting in vision loss. In the majority of cases it is caused by one of three point mutations in mitochondrial DNA (mtDNA) but their presence is not sufficient for disease development, since ~50% of men and ~10% women who carry them are affected. Thus additional modifying factors must exist. In this study, we use next generation sequencing to investigate the role of whole mtDNA variation in male Polish patients with LHON and m.11778G > A, the most frequent LHON mutation. We present a possible association between mtDNA haplogroup K and variants in its background, a combination of m.3480A > G, m.9055G > A, m.11299 T > C and m.14167C > T, and LHON mutation. These variants may have a negative effect on m.11778G > A increasing its penetrance and the risk of LHON in the Polish population. Surprisingly, we did not observe associations previously reported for m.11778G > A and LHON in European populations, particularly for haplogroup J as a risk factor, implying that mtDNA variation is much more complex. Our results indicate possible contribution of novel combination of mtDNA genetic factors to the LHON phenotype.
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Affiliation(s)
- Agnieszka Piotrowska-Nowak
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, 5a Pawińskiego Street, 02-106 Warsaw, Poland
| | - Maciej R. Krawczyński
- Department of Medical Genetics, Poznań University of Medical Sciences, 8 Rokietnicka Street, 60-806 Poznań, Poland
- Centers for Medical Genetics GENESIS, 4 Grudzieniec Street, 60-601 Poznań, Poland
| | - Ewa Kosior-Jarecka
- Department of Diagnostics and Microsurgery of Glaucoma, Medical University of Lublin, 1 Chmielna Street, 20-079 Lublin, Poland
| | - Anna M. Ambroziak
- Faculty of Physics, University of Warsaw, 5 Pasteur Street, 02-093 Warsaw, Poland
| | - Magdalena Korwin
- Department of Ophthalmology, Medical University of Warsaw, 13 Sierakowskiego Street, 03-709 Warsaw, Poland
| | - Monika Ołdak
- Department of Genetics, Institute of Physiology and Pathology of Hearing, 10 Mochnackiego Street, 02-042 Warsaw, Poland
- Department of Histology and Embryology, Center of Biostructure Research, Medical University of Warsaw, 5 Chałubińskiego Street, 02-004 Warsaw, Poland
| | - Katarzyna Tońska
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, 5a Pawińskiego Street, 02-106 Warsaw, Poland
| | - Ewa Bartnik
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, 5a Pawińskiego Street, 02-106 Warsaw, Poland
- Institute of Biochemistry and Biophysics Polish Academy of Sciences, 5a Pawińskiego Street, 02-106 Warsaw, Poland
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64
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Towarnicki SG, Ballard JWO. Towards understanding the evolutionary dynamics of mtDNA. Mitochondrial DNA A DNA Mapp Seq Anal 2020; 31:355-364. [PMID: 33026269 DOI: 10.1080/24701394.2020.1830076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Historically, mtDNA was considered a selectively neutral marker that was useful for estimating the population genetic history of the maternal lineage. Over time there has been an increasing appreciation of mtDNA and mitochondria in maintaining cellular and organismal health. Beyond energy production, mtDNA and mitochondria have critical cellular roles in signalling. Here we briefly review the structure of mtDNA and the role of the mitochondrion in energy production. We then discuss the predictions that can be obtained from quaternary structure modelling and focus on mitochondrial complex I. Complex I is the primary entry point for electrons into the electron transport system is the largest respiratory complex of the chain and produces about 40% of the proton flux used to synthesize ATP. A focus of the review is Drosophila's utility as a model organism to study the selective advantage of specific mutations. However, we note that the incorporation of insights from a multitude of systems is necessary to fully understand the range of roles that mtDNA has in organismal fitness. We speculate that dietary changes can illicit stress responses that influence the selective advantage of specific mtDNA mutations and cause spatial and temporal fluctuations in the frequencies of mutations. We conclude that developing our understanding of the roles mtDNA has in determining organismal fitness will enable increased evolutionary insight and propose we can no longer assume it is evolving as a strictly neutral marker without testing this hypothesis.
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Affiliation(s)
- Samuel G Towarnicki
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, Australia
| | - J William O Ballard
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, Australia
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65
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Chapman J, Ng YS, Nicholls TJ. The Maintenance of Mitochondrial DNA Integrity and Dynamics by Mitochondrial Membranes. Life (Basel) 2020; 10:life10090164. [PMID: 32858900 PMCID: PMC7555930 DOI: 10.3390/life10090164] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 08/20/2020] [Accepted: 08/23/2020] [Indexed: 12/18/2022] Open
Abstract
Mitochondria are complex organelles that harbour their own genome. Mitochondrial DNA (mtDNA) exists in the form of a circular double-stranded DNA molecule that must be replicated, segregated and distributed around the mitochondrial network. Human cells typically possess between a few hundred and several thousand copies of the mitochondrial genome, located within the mitochondrial matrix in close association with the cristae ultrastructure. The organisation of mtDNA around the mitochondrial network requires mitochondria to be dynamic and undergo both fission and fusion events in coordination with the modulation of cristae architecture. The dysregulation of these processes has profound effects upon mtDNA replication, manifesting as a loss of mtDNA integrity and copy number, and upon the subsequent distribution of mtDNA around the mitochondrial network. Mutations within genes involved in mitochondrial dynamics or cristae modulation cause a wide range of neurological disorders frequently associated with defects in mtDNA maintenance. This review aims to provide an understanding of the biological mechanisms that link mitochondrial dynamics and mtDNA integrity, as well as examine the interplay that occurs between mtDNA, mitochondrial dynamics and cristae structure.
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Affiliation(s)
- James Chapman
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK;
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
- Correspondence: (J.C.); (T.J.N.)
| | - Yi Shiau Ng
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK;
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Thomas J. Nicholls
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK;
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
- Correspondence: (J.C.); (T.J.N.)
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66
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Puertas MJ, González-Sánchez M. Insertions of mitochondrial DNA into the nucleus—effects and role in cell evolution. Genome 2020; 63:365-374. [DOI: 10.1139/gen-2019-0151] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
We review the insertion of mitochondrial DNA (mtDNA) fragments into nuclear DNA (NUMTS) as a general and ongoing process that has occurred many times during genome evolution. Fragments of mtDNA are generated during the lifetime of organisms in both somatic and germinal cells, by the production of reactive oxygen species in the mitochondria. The fragments are inserted into the nucleus during the double-strand breaks repair via the non-homologous end-joining machinery, followed by genomic instability, giving rise to the high variability observed in NUMT patterns among species, populations, or genotypes. Some de novo produced mtDNA insertions show harmful effects, being involved in human diseases, carcinogenesis, and ageing. NUMT generation is a non-stop process overpassing the Mendelian transmission. This parasitic property ensures their survival even against their harmful effects. The accumulation of mtDNA fragments mainly at pericentromeric and subtelomeric regions is important to understand the transmission and integration of NUMTs into the genomes. The possible effect of female meiotic drive for mtDNA insertions at centromeres remains to be studied. In spite of the harmful feature of NUMTs, they are important in cell evolution, representing a major source of genomic variation.
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Affiliation(s)
- María J. Puertas
- Departamento de Genética, Fisiología y Microbiología, Facultad de Biología, Universidad Complutense, José Antonio Novais 2, 28040 Madrid, Spain
| | - Mónica González-Sánchez
- Departamento de Genética, Fisiología y Microbiología, Facultad de Biología, Universidad Complutense, José Antonio Novais 2, 28040 Madrid, Spain
- Departamento de Genética, Fisiología y Microbiología, Facultad de Biología, Universidad Complutense, José Antonio Novais 2, 28040 Madrid, Spain
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67
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TaqMan-MGB probe quantitative PCR assays to genotype and quantify three mtDNA mutations of Leber hereditary optic neuropathy. Sci Rep 2020; 10:12264. [PMID: 32704028 PMCID: PMC7378831 DOI: 10.1038/s41598-020-69220-7] [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: 12/28/2019] [Accepted: 06/23/2020] [Indexed: 11/08/2022] Open
Abstract
Leber hereditary optic neuropathy (LHON) is a degenerative disease of the optic nerve associated with one of three mitochondrial DNA (mtDNA) m.3460G>A, m.11778G>A and m.14484T>C mutations. Although several procedures are available to genotype these mutations, quantitative approaches with rapid, low-cost and easy to handle advantages for three LHON mtDNA mutations are rarely reported. Here, we firstly developed a “one-step” tetra-primer amplification-refractory mutation system (T-ARMS) PCR for qualitative genotyping of three LHON mtDNA mutations. Subsequently, we established single, duplex and triplex TaqMan MGB probe-based fluorescence quantitative PCR (qPCR) assays to perform both qualitative and quantitative analyses of three LHON mtDNA mutations. Standard curves based on tenfold diluted plasmid standard exhibited high specificity and sensitivity, stable repeatability and reliable detectable ability of TaqMan probe qPCR assays without cross-reactivity upon probes combination. Moreover, by comparing with SYBR Green qPCR, we further validated the feasibility of the triplex-probe qPCR assay for the quantitative detection of mtDNA copy number in blood samples. In conclusion, our study describes a rapid, low-cost, easy to-handle, and high-throughput TaqMan-MGB probe qPCR assay to perform both qualitative and quantitative analysis of three primary LHON mtDNA mutations, offering a promising approach for genetic screening and testing of LHON mutations.
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68
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Yang G, Liu Z, Zhang R, Tian X, Chen J, Han G, Liu B, Han X, Fu Y, Hu Z, Zhang Z. A Multi‐responsive Fluorescent Probe Reveals Mitochondrial Nucleoprotein Dynamics with Reactive Oxygen Species Regulation through Super‐resolution Imaging. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202005959] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Guanqing Yang
- School of Chemistry and Chemical Engineering and Institute of Physical Science and Information Technology Anhui University Hefei Anhui 230601 China
| | - Zhengjie Liu
- School of Chemistry and Chemical Engineering and Institute of Physical Science and Information Technology Anhui University Hefei Anhui 230601 China
| | - Ruilong Zhang
- School of Chemistry and Chemical Engineering and Institute of Physical Science and Information Technology Anhui University Hefei Anhui 230601 China
- Key Laboratory of Structure and Functional Regulation of Hybrid Materials (Anhui University) Ministry of Education Hefei Anhui 230601 China
| | - Xiaohe Tian
- School of Chemistry and Chemical Engineering and Institute of Physical Science and Information Technology Anhui University Hefei Anhui 230601 China
| | - Juan Chen
- School of Chemistry and Chemical Engineering and Institute of Physical Science and Information Technology Anhui University Hefei Anhui 230601 China
| | - Guangmei Han
- School of Chemistry and Chemical Engineering and Institute of Physical Science and Information Technology Anhui University Hefei Anhui 230601 China
| | - Bianhua Liu
- Institute of Intelligent Machines Chinese Academy of Sciences Hefei Anhui 230031 China
| | - Xinya Han
- School of Chemistry and Chemical Engineering Anhui University of Technology Ma'anshan Anhui 243032 China
| | - Yao Fu
- Department of Chemistry University of Science and Technology of China Hefei Anhui 230026 China
| | - Zhangjun Hu
- Department of Physics, Chemistry and Biology Linköping University Linköping 58183 Sweden
| | - Zhongping Zhang
- School of Chemistry and Chemical Engineering and Institute of Physical Science and Information Technology Anhui University Hefei Anhui 230601 China
- Key Laboratory of Structure and Functional Regulation of Hybrid Materials (Anhui University) Ministry of Education Hefei Anhui 230601 China
- Institute of Intelligent Machines Chinese Academy of Sciences Hefei Anhui 230031 China
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69
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Yang G, Liu Z, Zhang R, Tian X, Chen J, Han G, Liu B, Han X, Fu Y, Hu Z, Zhang Z. A Multi-responsive Fluorescent Probe Reveals Mitochondrial Nucleoprotein Dynamics with Reactive Oxygen Species Regulation through Super-resolution Imaging. Angew Chem Int Ed Engl 2020; 59:16154-16160. [PMID: 32573047 DOI: 10.1002/anie.202005959] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 06/11/2020] [Indexed: 11/06/2022]
Abstract
Understanding the biomolecular interactions in a specific organelle has been a long-standing challenge because it requires super-resolution imaging to resolve the spatial locations and dynamic interactions of multiple biomacromolecules. Two key difficulties are the scarcity of suitable probes for super-resolution nanoscopy and the complications that arise from the use of multiple probes. Herein, we report a quinolinium derivative probe that is selectively enriched in mitochondria and switches on in three different fluorescence modes in response to hydrogen peroxide (H2 O2 ), proteins, and nucleic acids, enabling the visualization of mitochondrial nucleoprotein dynamics. STED nanoscopy reveals that the proteins localize at mitochondrial cristae and largely fuse with nucleic acids to form nucleoproteins, whereas increasing H2 O2 level leads to disassociation of nucleic acid-protein complexes.
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Affiliation(s)
- Guanqing Yang
- School of Chemistry and Chemical Engineering and Institute of Physical Science and Information Technology, Anhui University, Hefei, Anhui, 230601, China
| | - Zhengjie Liu
- School of Chemistry and Chemical Engineering and Institute of Physical Science and Information Technology, Anhui University, Hefei, Anhui, 230601, China
| | - Ruilong Zhang
- School of Chemistry and Chemical Engineering and Institute of Physical Science and Information Technology, Anhui University, Hefei, Anhui, 230601, China.,Key Laboratory of Structure and Functional Regulation of Hybrid Materials (Anhui University), Ministry of Education, Hefei, Anhui, 230601, China
| | - Xiaohe Tian
- School of Chemistry and Chemical Engineering and Institute of Physical Science and Information Technology, Anhui University, Hefei, Anhui, 230601, China
| | - Juan Chen
- School of Chemistry and Chemical Engineering and Institute of Physical Science and Information Technology, Anhui University, Hefei, Anhui, 230601, China
| | - Guangmei Han
- School of Chemistry and Chemical Engineering and Institute of Physical Science and Information Technology, Anhui University, Hefei, Anhui, 230601, China
| | - Bianhua Liu
- Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei, Anhui, 230031, China
| | - Xinya Han
- School of Chemistry and Chemical Engineering, Anhui University of Technology, Ma'anshan, Anhui, 243032, China
| | - Yao Fu
- Department of Chemistry, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Zhangjun Hu
- Department of Physics, Chemistry and Biology, Linköping University, Linköping, 58183, Sweden
| | - Zhongping Zhang
- School of Chemistry and Chemical Engineering and Institute of Physical Science and Information Technology, Anhui University, Hefei, Anhui, 230601, China.,Key Laboratory of Structure and Functional Regulation of Hybrid Materials (Anhui University), Ministry of Education, Hefei, Anhui, 230601, China.,Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei, Anhui, 230031, China
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70
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Signal transducer and activator of transcription 5a (STAT5a) represses mitochondrial gene expression through direct binding to mitochondrial DNA. Biochem Biophys Res Commun 2020; 527:974-978. [PMID: 32446558 DOI: 10.1016/j.bbrc.2020.04.152] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 04/30/2020] [Indexed: 11/23/2022]
Abstract
Signal transducer and activator of transcription (STAT) proteins are latent cytoplasmic transcription factors essential for cytokine signaling. Our previous study showed that interleukin-3 (IL-3) induced STAT5 translocation to mitochondria and binding to mitochondrial DNA (mtDNA) in vitro. In this report, we further demonstrated in vivo binding of endogenous STAT5a to mtDNA transcriptional control region and reduced gene expression from all three mtDNA promoters after IL-3 stimulation. To specifically define the function of mitochondrial STAT5a, we generated mitochondrial-targeting wild-type and mutant STAT5a proteins. Compared with non-targeting STAT5a, mitochondrial-targeting wild-type STAT5a significantly reduced mitochondrial gene expression in transfected HEK293 cells. The level of attenuation was amplified in cells expressing constitutively active STAT5a, but abrogated in cells expressing DNA-binding-defective STAT5a. STAT5a-mediated repression of mtDNA expression also positively correlated with STAT5a binding to the E2 subunit of pyruvate dehydrogenase complex (PDC-E2), both a gate-keeping metabolic enzyme and a component of mtDNA nucleoid in mitochondrial matrix. Metabolic shift away from mitochondrial respiration is known in many cytokine-stimulated cells and cancer cells. STAT5a-mediated repression of mitochondrial gene expression and its interaction with PDC-E2 may provide important insights into its underlying mechanisms.
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71
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Black M, Arumugam P, Shukla S, Pradhan A, Ustiyan V, Milewski D, Kalinichenko VV, Kalin TV. FOXM1 nuclear transcription factor translocates into mitochondria and inhibits oxidative phosphorylation. Mol Biol Cell 2020; 31:1411-1424. [PMID: 32348194 PMCID: PMC7353143 DOI: 10.1091/mbc.e19-07-0413] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 04/17/2020] [Accepted: 04/22/2020] [Indexed: 12/31/2022] Open
Abstract
Forkhead box M1 (FOXM1), a nuclear transcription factor that activates cell cycle regulatory genes, is highly expressed in a majority of human cancers. The function of FOXM1 independent of nuclear transcription is unknown. In the present study, we found the FOXM1 protein inside the mitochondria. Using site-directed mutagenesis, we generated FOXM1 mutant proteins that localized to distinct cellular compartments, uncoupling the nuclear and mitochondrial functions of FOXM1. Directing FOXM1 into the mitochondria decreased mitochondrial mass, membrane potential, respiration, and electron transport chain (ETC) activity. In mitochondria, the FOXM1 directly bound to and increased the pentatricopeptide repeat domain 1 (PTCD1) protein, a mitochondrial leucine-specific tRNA binding protein that inhibits leucine-rich ETC complexes. Mitochondrial FOXM1 did not change cellular proliferation. Thus, FOXM1 translocates into mitochondria and inhibits mitochondrial respiration by increasing PTCD1. We identify a new paradigm that FOXM1 regulates mitochondrial homeostasis in a process independent of nuclear transcription.
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Affiliation(s)
- Markaisa Black
- Perinatal Institute and Division of Neonatology, Perinatal and Pulmonary Biology
| | - Paritha Arumugam
- Translational Pulmonary Science Center and Division of Pulmonary Biology, Cincinnati, OH 45229-3039
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45267
| | - Samriddhi Shukla
- Perinatal Institute and Division of Neonatology, Perinatal and Pulmonary Biology
| | - Arun Pradhan
- Perinatal Institute and Division of Neonatology, Perinatal and Pulmonary Biology
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45267
| | - Vladimir Ustiyan
- Perinatal Institute and Division of Neonatology, Perinatal and Pulmonary Biology
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45267
| | - David Milewski
- Perinatal Institute and Division of Neonatology, Perinatal and Pulmonary Biology
| | - Vladimir V. Kalinichenko
- Perinatal Institute and Division of Neonatology, Perinatal and Pulmonary Biology
- Center for Lung Regenerative Medicine, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229-3039
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45267
| | - Tanya V. Kalin
- Perinatal Institute and Division of Neonatology, Perinatal and Pulmonary Biology
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45267
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72
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Koonin EV, Krupovic M, Ishino S, Ishino Y. The replication machinery of LUCA: common origin of DNA replication and transcription. BMC Biol 2020; 18:61. [PMID: 32517760 PMCID: PMC7281927 DOI: 10.1186/s12915-020-00800-9] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Origin of DNA replication is an enigma because the replicative DNA polymerases (DNAPs) are not homologous among the three domains of life, Bacteria, Archaea, and Eukarya. The homology between the archaeal replicative DNAP (PolD) and the large subunits of the universal RNA polymerase (RNAP) responsible for transcription suggests a parsimonious evolutionary scenario. Under this model, RNAPs and replicative DNAPs evolved from a common ancestor that functioned as an RNA-dependent RNA polymerase in the RNA-protein world that predated the advent of DNA replication. The replicative DNAP of the Last Universal Cellular Ancestor (LUCA) would be the ancestor of the archaeal PolD.
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Affiliation(s)
- Eugene V Koonin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD, 20892, USA.
| | - Mart Krupovic
- Archaeal Virology Unit, Institut Pasteur, 75015, Paris, France
| | - Sonoko Ishino
- Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka, 819-0395, Japan
| | - Yoshizumi Ishino
- Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka, 819-0395, Japan
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73
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Zekonyte U, Bacman SR, Moraes CT. DNA-editing enzymes as potential treatments for heteroplasmic mtDNA diseases. J Intern Med 2020; 287:685-697. [PMID: 32176378 PMCID: PMC7260085 DOI: 10.1111/joim.13055] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 12/04/2019] [Accepted: 12/11/2019] [Indexed: 12/13/2022]
Abstract
Mutations in the mitochondrial genome are the cause of many debilitating neuromuscular disorders. Currently, there is no cure or treatment for these diseases, and symptom management is the only relief doctors can provide. Although supplements and vitamins are commonly used in treatment, they provide little benefit to the patient and are only palliative. This is why gene therapy is a promising research topic to potentially treat and, in theory, even cure diseases caused by mutations in the mitochondrial DNA (mtDNA). Mammalian cells contain approximately a thousand copies of mtDNA, which can lead to a phenomenon called heteroplasmy, where both wild-type and mutant mtDNA molecules co-exist within the cell. Disease only manifests once the per cent of mutant mtDNA reaches a high threshold (usually >80%), which causes mitochondrial dysfunction and reduced ATP production. This is a useful feature to take advantage of for gene therapy applications, as not every mutant copy of mtDNA needs to be eliminated, but only enough to shift the heteroplasmic ratio below the disease threshold. Several DNA-editing enzymes have been used to shift heteroplasmy in cell culture and mice. This review provides an overview of these enzymes and discusses roadblocks of applying these to gene therapy in humans.
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Affiliation(s)
- U Zekonyte
- From the, Graduate Program in Human Genetics and Genomics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - S R Bacman
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - C T Moraes
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA
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74
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Lee YY, Choi YS, Kim DW, Cheong JY, Song KY, Ryu MS, Lim IK. Mitochondrial nucleoid remodeling and biogenesis are regulated by the p53-p21 WAF1-PKCζ pathway in p16 INK4a-silenced cells. Aging (Albany NY) 2020; 12:6700-6732. [PMID: 32330121 PMCID: PMC7202532 DOI: 10.18632/aging.103029] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 02/22/2020] [Indexed: 11/25/2022]
Abstract
Mitochondrial dysfunction is linked to age-related senescence phenotypes. We report here the pathway increasing nucleoid remodeling and biogenesis in mitochondria during the senescence of foreskin human diploid fibroblasts (fs-HDF) and WI-38 cells. Replicative senescence in fs-HDF cells increased mitochondrial nucleoid remodeling as indicated by 5-bromo-2'-deoxyuridine (BrdU) incorporation and mitochondrial transcription factor A (TFAM) expression in enlarged and fused mitochondria. Mitochondrial nucleoid remodeling was accompanied by mitochondrial biogenesis in old cells, and the expression levels of OXPHOS complex-I, -IV and -V subunits, PGC-1α and NRF1 were greatly increased compared to young cells. Activated protein kinase C zeta (PKCζ) increased mitochondrial activity and expressed phenotypes of delayed senescence in fs-HDF cells, but not in WI-38 cells. The findings were reproduced in the doxorubicin-induced senescence of young fs-HDF and WI-38 cells via the PKCζ-LKB1-AMPK signaling pathway, which was regulated by the p53-p21WAF1 pathway when p16INK4a was silenced. The signaling enhanced PGC-1α-NRF1-TFAM axis in mitochondria, which was demonstrated by Ingenuity Pathway Analysis of young and old fs-HDF cells. Activation of the p53-p21WAF1 pathway and silencing of p16INK4a are responsible for mitochondrial reprogramming in senescent cells, which may be a compensatory mechanism to promote cell survival under senescence stress.
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Affiliation(s)
- Yun Yeong Lee
- Department of Biochemistry and Molecular Biology, Ajou University School of Medicine, Suwon 16499, Korea.,Department of Otolaryngology, Ajou University School of Medicine, Suwon 16499, Korea
| | - Yeon Seung Choi
- Department of Biochemistry and Molecular Biology, Ajou University School of Medicine, Suwon 16499, Korea.,Department of Biomedical Sciences, The Graduate School, Ajou University, Suwon 16499, Korea
| | - Do Wan Kim
- Omics Center, Ajou University School of Medicine, Suwon 16499, Korea
| | - Jae Youn Cheong
- Omics Center, Ajou University School of Medicine, Suwon 16499, Korea.,Department of Gastroenterology, Ajou University of Medicine, Suwon 16499, Korea
| | - Kye Yong Song
- Department of Pathology, Chung-Ang University College of Medicine, Seoul 156-756, Korea
| | - Min Sook Ryu
- Department of Biomedical Sciences, The Graduate School, Ajou University, Suwon 16499, Korea
| | - In Kyoung Lim
- Department of Biochemistry and Molecular Biology, Ajou University School of Medicine, Suwon 16499, Korea.,Department of Biomedical Sciences, The Graduate School, Ajou University, Suwon 16499, Korea
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75
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Kojer K, Hering T, Bazenet C, Weiss A, Herrmann F, Taanman JW, Orth M. Huntingtin Aggregates and Mitochondrial Pathology in Skeletal Muscle but not Heart of Late-Stage R6/2 Mice. J Huntingtons Dis 2020; 8:145-159. [PMID: 30814364 DOI: 10.3233/jhd-180324] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND Cell or tissue specific background may influence the consequences of expressing the Huntington's disease (HD) mutation. Aggregate formation is known to occur in skeletal muscle, but not heart of the R6/2 fragment HD model. OBJECTIVE We asked whether aggregate formation and the expression and subcellular localization of huntingtin species was associated with mitochondrial dysfunction. METHODS We analyzed levels of soluble HTT and HTT aggregates, as well as important fission and fusion proteins and mitochondrial respiratory chain activities, in quadriceps and heart of the R6/2 N-terminal fragment mouse model (12 weeks, 160±10 CAG repeats). RESULTS Soluble mutant HTT was present in both tissues with expression higher in cytoplasmic/mitochondrial than nuclear fractions. HTT aggregates were only detectable in R6/2 quadriceps, in association with increased levels of the pro-fission factor DRP1 and its phosphorylated active form, and decreased levels of the pro-fusion factor MFN2. In addition, respiratory chain complex activities were decreased. In heart that was without detectable HTT aggregates, we found no evidence for mitochondrial dysfunction. CONCLUSION Tissue specific factors may exist that protect the R6/2 heart from HTT aggregate formation and mitochondrial pathology.
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Affiliation(s)
- Kerstin Kojer
- Department of Neurology, Ulm University, Ulm, Germany
| | - Tanja Hering
- Department of Neurology, Ulm University, Ulm, Germany
| | | | | | | | - Jan-Willem Taanman
- Department of Clinical Neurosciences, UCL Institute of Neurology, London, UK
| | - Michael Orth
- Department of Neurology, Ulm University, Ulm, Germany
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76
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Ma X, McKeen T, Zhang J, Ding WX. Role and Mechanisms of Mitophagy in Liver Diseases. Cells 2020; 9:cells9040837. [PMID: 32244304 PMCID: PMC7226762 DOI: 10.3390/cells9040837] [Citation(s) in RCA: 133] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 03/23/2020] [Accepted: 03/28/2020] [Indexed: 12/12/2022] Open
Abstract
The mitochondrion is an organelle that plays a vital role in the regulation of hepatic cellular redox, lipid metabolism, and cell death. Mitochondrial dysfunction is associated with both acute and chronic liver diseases with emerging evidence indicating that mitophagy, a selective form of autophagy for damaged/excessive mitochondria, plays a key role in the liver’s physiology and pathophysiology. This review will focus on mitochondrial dynamics, mitophagy regulation, and their roles in various liver diseases (alcoholic liver disease, non-alcoholic fatty liver disease, drug-induced liver injury, hepatic ischemia-reperfusion injury, viral hepatitis, and cancer) with the hope that a better understanding of the molecular events and signaling pathways in mitophagy regulation will help identify promising targets for the future treatment of liver diseases.
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Affiliation(s)
- Xiaowen Ma
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, KS 66160, USA; (X.M.); (T.M.)
| | - Tara McKeen
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, KS 66160, USA; (X.M.); (T.M.)
| | - Jianhua Zhang
- Department of Pathology, Division of Molecular Cellular Pathology, University of Alabama at Birmingham, 901 19th street South, Birmingham, AL 35294, USA;
| | - Wen-Xing Ding
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, KS 66160, USA; (X.M.); (T.M.)
- Correspondence: ; Tel.: +1-913-588-9813
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77
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Affiliation(s)
- Mikhail Alexeyev
- Physiology and Cell Biology, University of South Alabama, Mobile, AL, USA
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78
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Cai N, Fňašková M, Konečná K, Fojtová M, Fajkus J, Coomber E, Watt S, Soranzo N, Preiss M, Rektor I. No Evidence of Persistence or Inheritance of Mitochondrial DNA Copy Number in Holocaust Survivors and Their Descendants. Front Genet 2020; 11:87. [PMID: 32211017 PMCID: PMC7069217 DOI: 10.3389/fgene.2020.00087] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 01/27/2020] [Indexed: 12/19/2022] Open
Abstract
Mitochondrial DNA copy number has been previously shown to be elevated with severe and chronic stress, as well as stress-related pathology like Major Depressive Disorder (MDD) and post-traumatic stress disorder (PTSD). While experimental data point to likely recovery of mtDNA copy number changes after the stressful event, time needed for full recovery and whether it can be achieved are still unknown. Further, while it has been shown that stress-related mtDNA elevation affects multiple tissues, its specific consequences for oogenesis and maternal inheritance of mtDNA has never been explored. In this study, we used qPCR to quantify mtDNA copy number in 15 Holocaust survivors and 102 of their second- and third-generation descendants from the Czech Republic, many of whom suffer from PTSD, and compared them to controls in the respective generations. We found no significant difference in mtDNA copy number in the Holocaust survivors compared to controls, whether they have PTSD or not, and no significant elevation in descendants of female Holocaust survivors as compared to descendants of male survivors or controls. Our results showed no evidence of persistence or inheritance of mtDNA changes in Holocaust survivors, though that does not rule out effects in other tissues or mitigating mechanism for such changes.
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Affiliation(s)
- Na Cai
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, United Kingdom.,European Bioinformatics Institute (EMBL-EBI), Wellcome Genome Campus, Hinxton, United Kingdom
| | - Monika Fňašková
- Neuroscience Centre, CEITEC, Masaryk University, Brno, Czechia.,1st Neurology Department, Hospital St Anne and School of Medicine, Masaryk University, Brno, Czechia
| | - Klára Konečná
- Mendel Centre for Plant Genomics and Proteomics, CEITEC, Masaryk University, Brno, Czechia.,National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno, Czechia
| | - Miloslava Fojtová
- Mendel Centre for Plant Genomics and Proteomics, CEITEC, Masaryk University, Brno, Czechia.,National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno, Czechia
| | - Jiří Fajkus
- Mendel Centre for Plant Genomics and Proteomics, CEITEC, Masaryk University, Brno, Czechia.,National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno, Czechia
| | - Eve Coomber
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, United Kingdom
| | - Stephen Watt
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, United Kingdom
| | - Nicole Soranzo
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, United Kingdom
| | - Marek Preiss
- Neuroscience Centre, CEITEC, Masaryk University, Brno, Czechia
| | - Ivan Rektor
- Neuroscience Centre, CEITEC, Masaryk University, Brno, Czechia
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79
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Reynolds JC, Bwiza CP, Lee C. Mitonuclear genomics and aging. Hum Genet 2020; 139:381-399. [PMID: 31997134 PMCID: PMC7147958 DOI: 10.1007/s00439-020-02119-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Accepted: 01/17/2020] [Indexed: 12/25/2022]
Abstract
Our cells operate based on two distinct genomes that are enclosed in the nucleus and mitochondria. The mitochondrial genome presumably originates from endosymbiotic bacteria. With time, a large portion of the original genes in the bacterial genome is considered to have been lost or transferred to the nuclear genome, leaving a reduced 16.5 Kb circular mitochondrial DNA (mtDNA). Traditionally only 37 genes, including 13 proteins, were thought to be encoded within mtDNA, its genetic repertoire is expanding with the identification of mitochondrial-derived peptides (MDPs). The biology of aging has been largely unveiled to be regulated by genes that are encoded in the nuclear genome, whereas the mitochondrial genome remained more cryptic. However, recent studies position mitochondria and mtDNA as an important counterpart to the nuclear genome, whereby the two organelles constantly regulate each other. Thus, the genomic network that regulates lifespan and/or healthspan is likely constituted by two unique, yet co-evolved, genomes. Here, we will discuss aspects of mitochondrial biology, especially mitochondrial communication that may add substantial momentum to aging research by accounting for both mitonuclear genomes to more comprehensively and inclusively map the genetic and molecular networks that govern aging and age-related diseases.
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Affiliation(s)
- Joseph C Reynolds
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, 90089, USA
| | - Conscience P Bwiza
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, 90089, USA
| | - Changhan Lee
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, 90089, USA.
- USC Norris Comprehensive Cancer Center, Los Angeles, CA, 90089, USA.
- Biomedical Sciences, Graduate School, Ajou University, Suwon, 16499, South Korea.
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80
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Ma Y, Yin J, Li G, Gao W, Lin W. Simultaneous sensing of nucleic acid and associated cellular components with organic fluorescent chemsensors. Coord Chem Rev 2020. [DOI: 10.1016/j.ccr.2019.213144] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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81
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McLaughlin KL, Kew KA, McClung JM, Fisher-Wellman KH. Subcellular proteomics combined with bioenergetic phenotyping reveals protein biomarkers of respiratory insufficiency in the setting of proofreading-deficient mitochondrial polymerase. Sci Rep 2020; 10:3603. [PMID: 32107436 PMCID: PMC7046634 DOI: 10.1038/s41598-020-60536-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 02/13/2020] [Indexed: 11/23/2022] Open
Abstract
The mitochondrial mutator mouse is a well-established model of premature aging. In addition to accelerated aging, these mice develop hypertrophic cardiomyopathy at ~13 months of age, presumably due to overt mitochondrial dysfunction. Despite evidence of bioenergetic disruption within heart mitochondria, there is little information about the underlying changes to the mitochondrial proteome that either directly underly or predict respiratory insufficiency in mutator mice. Herein, nLC-MS/MS was used to interrogate the mitochondria-enriched proteome of heart and skeletal muscle of aged mutator mice. The mitochondrial proteome from heart tissue was then correlated with respiratory conductance data to identify protein biomarkers of respiratory insufficiency. The majority of downregulated proteins in mutator mitochondria were subunits of respiratory complexes I and IV, including both nuclear and mitochondrial-encoded proteins. Interestingly, the mitochondrial-encoded complex V subunits, were unchanged or upregulated in mutator mitochondria, suggesting a robustness to mtDNA mutation. Finally, the proteins most strongly correlated with respiratory conductance were PPM1K, NDUFB11, and C15orf61. These results suggest that mitochondrial mutator mice undergo a specific loss of mitochondrial complexes I and IV that limit their respiratory function independent of an upregulation of complex V. Additionally, the role of PPM1K in responding to mitochondrial stress warrants further exploration.
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Affiliation(s)
- Kelsey L McLaughlin
- Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, 27834, USA.,East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, 27834, USA
| | - Kimberly A Kew
- Department of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, NC, 27834, USA
| | - Joseph M McClung
- Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, 27834, USA.,Department of Cardiovascular Sciences, Brody School of Medicine, East Carolina University, Greenville, NC, 27834, USA.,East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, 27834, USA
| | - Kelsey H Fisher-Wellman
- Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, 27834, USA. .,East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, 27834, USA.
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82
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Nissanka N, Moraes CT. Mitochondrial DNA heteroplasmy in disease and targeted nuclease-based therapeutic approaches. EMBO Rep 2020; 21:e49612. [PMID: 32073748 DOI: 10.15252/embr.201949612] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 12/11/2019] [Accepted: 01/29/2020] [Indexed: 12/31/2022] Open
Abstract
Mitochondrial DNA (mtDNA) encodes a subset of the genes which are responsible for oxidative phosphorylation. Pathogenic mutations in the human mtDNA are often heteroplasmic, where wild-type mtDNA species co-exist with the pathogenic mtDNA and a bioenergetic defect is only seen when the pathogenic mtDNA percentage surpasses a threshold for biochemical manifestations. mtDNA segregation during germline development can explain some of the extreme variation in heteroplasmy from one generation to the next. Patients with high heteroplasmy for deleterious mtDNA species will likely suffer from bona-fide mitochondrial diseases, which currently have no cure. Shifting mtDNA heteroplasmy toward the wild-type mtDNA species could provide a therapeutic option to patients. Mitochondrially targeted engineered nucleases, such as mitoTALENs and mitoZFNs, have been used in vitro in human cells harboring pathogenic patient-derived mtDNA mutations and more recently in vivo in a mouse model of a pathogenic mtDNA point mutation. These gene therapy tools for shifting mtDNA heteroplasmy can also be used in conjunction with other therapies aimed at eliminating and/or preventing the transfer of pathogenic mtDNA from mother to child.
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Affiliation(s)
- Nadee Nissanka
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Carlos T Moraes
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA
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83
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Heinonen S, Jokinen R, Rissanen A, Pietiläinen KH. White adipose tissue mitochondrial metabolism in health and in obesity. Obes Rev 2020; 21:e12958. [PMID: 31777187 DOI: 10.1111/obr.12958] [Citation(s) in RCA: 99] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2019] [Revised: 08/27/2019] [Accepted: 09/03/2019] [Indexed: 12/11/2022]
Abstract
White adipose tissue is one of the largest organs of the body. It plays a key role in whole-body energy status and metabolism; it not only stores excess energy but also secretes various hormones and metabolites to regulate body energy balance. Healthy adipose tissue capable of expanding is needed for metabolic well-being and to prevent accumulation of triglycerides to other organs. Mitochondria govern several important functions in the adipose tissue. We review the derangements of mitochondrial function in white adipose tissue in the obese state. Downregulation of mitochondrial function or biogenesis in the white adipose tissue is a central driver for obesity-associated metabolic diseases. Mitochondrial functions compromised in obesity include oxidative functions and renewal and enlargement of the adipose tissue through recruitment and differentiation of adipocyte progenitor cells. These changes adversely affect whole-body metabolic health. Dysfunction of the white adipose tissue mitochondria in obesity has long-term consequences for the metabolism of adipose tissue and the whole body. Understanding the pathways behind mitochondrial dysfunction may help reveal targets for pharmacological or nutritional interventions that enhance mitochondrial biogenesis or function in adipose tissue.
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Affiliation(s)
- Sini Heinonen
- Obesity Research Unit, Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Riikka Jokinen
- Obesity Research Unit, Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Aila Rissanen
- Obesity Research Unit, Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland.,Department of Psychiatry, Helsinki University Hospital, Helsinki, Finland
| | - Kirsi H Pietiläinen
- Obesity Research Unit, Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland.,Endocrinology, Abdominal Center, Helsinki University Hospital, Helsinki, Finland
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84
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Liu S, Wei Y, Zhang SH. The C3HC type zinc-finger protein (ZFC3) interacting with Lon/MAP1 is important for mitochondrial gene regulation, infection hypha development and longevity of Magnaporthe oryzae. BMC Microbiol 2020; 20:23. [PMID: 32000669 PMCID: PMC6993355 DOI: 10.1186/s12866-020-1711-4] [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: 09/03/2019] [Accepted: 01/22/2020] [Indexed: 12/20/2022] Open
Abstract
Background The rice blast is a typical fungal disease caused by Magnaporthe oryzae, and the mitochondrial ATP-dependent Lon protease (MAP1) has been proven to be involved in blast development. We previously screened a C3HC type Zinc-finger domain protein (ZFC3), which is interacted with MAP1. The purpose of this research was to study the biological function of ZFC3 protein in M. oryzae. Results We first confirmed that the ZFC3-RFP fusion protein is localized within the mitochondria. The deleted mutant strains of ZFC3 (∆ZFC3) showed the enhanced expression level of mtATP6, particularly mtATP8, and almost unchanged nATP9. ΔZFC3 produces more conidia and more tolerance to multiple stressors. The knock-out strain shows more melanin accumulation suggests the susceptibility to aging. ΔZFC3 displays faster early-stage hypha infiltration involved in MAP1-mediated pathogenicity in host rice. Conclusion These results support the view that ZFC3 is a key regulator involved in gene regulation, stress response, cell wall integrity, longevity, conidiation, infection hypha development and MAP1-mediated pathogenicity in M. oryzae.
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Affiliation(s)
- Shaoshuai Liu
- College of Plant Sciences, Jilin University, Changchun, China.,Present address: Institute of Phytopathology, Centre for BioSystems, Land Use and Nutrition, Justus Liebig University, Heinrich Buff-Ring 26-32, D-35392, Giessen, Germany
| | - Yi Wei
- College of Plant Sciences, Jilin University, Changchun, China
| | - Shi-Hong Zhang
- College of Plant Sciences, Jilin University, Changchun, China.
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85
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Schaack S, Ho EKH, Macrae F. Disentangling the intertwined roles of mutation, selection and drift in the mitochondrial genome. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190173. [PMID: 31787045 PMCID: PMC6939366 DOI: 10.1098/rstb.2019.0173] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/16/2019] [Indexed: 12/31/2022] Open
Abstract
Understanding and quantifying the rates of change in the mitochondrial genome is a major component of many areas of biological inquiry, from phylogenetics to human health. A critical parameter in understanding rates of change is estimating the mitochondrial mutation rate (mtDNA MR). Although the first direct estimates of mtDNA MRs were reported almost 20 years ago, the number of estimates has not grown markedly since that time. This is largely owing to the challenges associated with time- and labour-intensive mutation accumulation (MA) experiments. But even MA experiments do not solve a major problem with estimating mtDNA MRs-the challenge of disentangling the role of mutation from other evolutionary forces acting within the cell. Now that it is widely understood that any newly generated mutant allele in the mitochondria will initially be at very low frequency (1/N, where N is the number of mtDNA molecules in the cell), the importance of understanding the effective population size (Ne) of the mtDNA and the size of genetic bottlenecks during gametogenesis and development has come into the spotlight. In addition to these factors regulating the role of genetic drift, advances in our understanding of mitochondrial replication and turnover allow us to more easily envision how natural selection within the cell might favour or purge mutations in multi-copy organellar genomes. Here, we review the unique features of the mitochondrial genome that pose a challenge for accurate MR estimation and discuss ways to overcome those challenges. Estimates of mtDNA MRs remain one of the most widely used parameters in biology, thus accurate quantification and a deeper understanding of how and why they may vary within and between individuals, populations and species is an important goal. This article is part of the theme issue 'Linking the mitochondrial genotype to phenotype: a complex endeavour'.
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Affiliation(s)
- Sarah Schaack
- Department of Biology, Reed College, Portland, OR 97202, USA
| | - Eddie K H Ho
- Department of Biology, Reed College, Portland, OR 97202, USA
| | - Fenner Macrae
- Department of Biology, Reed College, Portland, OR 97202, USA
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86
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Pronsato L, Milanesi L, Vasconsuelo A. Testosterone induces up-regulation of mitochondrial gene expression in murine C2C12 skeletal muscle cells accompanied by an increase of nuclear respiratory factor-1 and its downstream effectors. Mol Cell Endocrinol 2020; 500:110631. [PMID: 31676390 DOI: 10.1016/j.mce.2019.110631] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 10/25/2019] [Accepted: 10/25/2019] [Indexed: 01/03/2023]
Abstract
The reduction in muscle mass and strength with age, sarcopenia, is a prevalent condition among the elderly, linked to skeletal muscle dysfunction and cell apoptosis. We demonstrated that testosterone protects against H2O2-induced apoptosis in C2C12 muscle cells. Here, we analyzed the effect of testosterone on mitochondrial gene expression in C2C12 skeletal muscle cells. We found that testosterone increases mRNA expression of genes encoded by mitochondrial DNA, such as NADPH dehydrogenase subunit 1 (ND1), subunit 4 (ND4), cytochrome b (CytB), cytochrome c oxidase subunit 1 (Cox1) and subunit 2 (Cox2) in C2C12. Additionally, the hormone induced the expression of the nuclear respiratory factors 1 and 2 (Nrf-1 and Nrf-2), the mitochondrial transcription factors A (Tfam) and B2 (TFB2M), and the optic atrophy 1 (OPA1). The simultaneous treatment with testosterone and the androgen receptor antagonist, Flutamide, reduced these effects. H2O2-oxidative stress induced treatment, significantly decreased mitochondrial gene expression. Computational analysis revealed that mitochondrial DNA contains specific sequences, which the androgen receptor could recognize and bind, probably taking place a direct regulation of mitochondrial transcription by the receptor. These findings indicate that androgen plays an important role in the regulation of mitochondrial transcription and biogenesis in skeletal muscle.
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Affiliation(s)
- Lucía Pronsato
- Instituto de Investigaciones Biológicas y Biomédicas del Sur (INBIOSUR-CONICET), 8000, Bahía Blanca, Argentina.
| | - Lorena Milanesi
- Instituto de Investigaciones Biológicas y Biomédicas del Sur (INBIOSUR-CONICET), 8000, Bahía Blanca, Argentina.
| | - Andrea Vasconsuelo
- Instituto de Investigaciones Biológicas y Biomédicas del Sur (INBIOSUR-CONICET), 8000, Bahía Blanca, Argentina
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87
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Chłopik A, Wysokińska A. Canine spermatozoa-What do we know about their morphology and physiology? An overview. Reprod Domest Anim 2019; 55:113-126. [PMID: 31782838 DOI: 10.1111/rda.13596] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 11/25/2019] [Indexed: 11/27/2022]
Abstract
Spermatozoa are unique cells because of their morphological and physiological characteristics. They are produced during the process called spermatogenesis. Spermatogenesis consists of three phases: spermatocytogenesis, spermiogenesis and spermiation, during which spermatozoa undergo several changes. Spermatogenesis takes place within the seminiferous tubules containing two types of cells-the germ cells and the Sertoli cells-that alongside the Leydig cells, which play an important role when it comes to normal fertility. Everything is regulated by the hypothalamic-pituitary-gonadal axis and specific hormones due to multi-hormonal feedback systems. Spermatozoa possess morphological and physiological features, which are sometimes completely different from what is observed in various somatic cells. What is more, canine spermatozoa have specific characteristics making them special compared to the spermatozoa of other mammalian species. The metabolic energy production, which is crucial for the appropriate functioning of spermatozoa, can be fuelled by different metabolic pathways utilizing different chemical substrates. Inseparable from the oxidative phosphorylation process is the production of reactive oxygen species, which are both essential and toxic to spermatozoa. Furthermore, epididymis is a very important structure, responsible for the transport and maturation of spermatozoa, which are then stored in the last segment of epididymis-the epididymal cauda. Moreover, the retrieval of spermatozoa from the epididymides is crucial for the development of assisted reproduction techniques and sperm cryopreservation methods. The information gained from the research on domestic dogs might be transferred to their wild relatives, especially those species categorized as endangered.
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Affiliation(s)
- Angelika Chłopik
- Department of Animal Reproduction and Hygiene, Faculty of Life Sciences, Siedlce University of Natural Sciences and Humanities, Siedlce, Poland
| | - Anna Wysokińska
- Department of Animal Reproduction and Hygiene, Faculty of Life Sciences, Siedlce University of Natural Sciences and Humanities, Siedlce, Poland
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88
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Whitehall JC, Greaves LC. Aberrant mitochondrial function in ageing and cancer. Biogerontology 2019; 21:445-459. [PMID: 31802313 PMCID: PMC7347693 DOI: 10.1007/s10522-019-09853-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 11/23/2019] [Indexed: 12/12/2022]
Abstract
Alterations in mitochondrial metabolism have been described as one of the major hallmarks of both ageing cells and cancer. Age is the biggest risk factor for the development of a significant number of cancer types and this therefore raises the question of whether there is a link between age-related mitochondrial dysfunction and the advantageous changes in mitochondrial metabolism prevalent in cancer cells. A common underlying feature of both ageing and cancer cells is the presence of somatic mutations of the mitochondrial genome (mtDNA) which we postulate may drive compensatory alterations in mitochondrial metabolism that are advantageous for tumour growth. In this review, we discuss basic mitochondrial functions, mechanisms of mtDNA mutagenesis and their metabolic consequences, and review the evidence for and against a role for mtDNA mutations in cancer development.
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Affiliation(s)
- Julia C Whitehall
- The Medical School, Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Laura C Greaves
- The Medical School, Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.
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89
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Zhao X, Guo S, Lu C, Chen J, Le S, Fu H, Yan J. Single-molecule manipulation quantification of site-specific DNA binding. Curr Opin Chem Biol 2019; 53:106-117. [DOI: 10.1016/j.cbpa.2019.08.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 07/24/2019] [Accepted: 08/24/2019] [Indexed: 10/25/2022]
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90
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da Silva Sergio LP, Mencalha AL, de Souza da Fonseca A, de Paoli F. DNA repair and genomic stability in lungs affected by acute injury. Biomed Pharmacother 2019; 119:109412. [PMID: 31514069 PMCID: PMC9170240 DOI: 10.1016/j.biopha.2019.109412] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 08/26/2019] [Accepted: 08/28/2019] [Indexed: 12/28/2022] Open
Abstract
Acute pulmonary injury, or acute respiratory distress syndrome, has a high incidence in elderly individuals and high mortality in its most severe degree, becoming a challenge to public health due to pathophysiological complications and increased economic burden. Acute pulmonary injury can develop from sepsis, septic shock, and pancreatitis causing reduction of alveolar airspace due to hyperinflammatory response. Oxidative stress acts directly on the maintenance of inflammation, resulting in tissue injury, as well as inducing DNA damages. Once the DNA is damaged, enzymatic DNA repair mechanisms act on lesions in order to maintain genomic stability and, consequently, contribute to cell viability and homeostasis. Although palliative treatment based on mechanical ventilation and antibiotic using have a kind of efficacy, therapies based on modulation of DNA repair and genomic stability could be effective for improving repair and recovery of lung tissue in patients with acute pulmonary injury.
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Affiliation(s)
- Luiz Philippe da Silva Sergio
- Departamento de Biofísica e Biometria, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro, Boulevard Vinte e Oito de Setembro, 87, Vila Isabel, Rio de Janeiro, 20551030, Brazil.
| | - Andre Luiz Mencalha
- Departamento de Biofísica e Biometria, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro, Boulevard Vinte e Oito de Setembro, 87, Vila Isabel, Rio de Janeiro, 20551030, Brazil
| | - Adenilson de Souza da Fonseca
- Departamento de Biofísica e Biometria, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro, Boulevard Vinte e Oito de Setembro, 87, Vila Isabel, Rio de Janeiro, 20551030, Brazil; Departamento de Ciências Fisiológicas, Instituto Biomédico, Universidade Federal do Estado do Rio de Janeiro, Rua Frei Caneca, 94, Rio de Janeiro, 20211040, Brazil; Centro de Ciências da Saúde, Centro Universitário Serra dos Órgãos, Avenida Alberto Torres, 111, Teresópolis, Rio de Janeiro, 25964004, Brazil
| | - Flavia de Paoli
- Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Juiz de Fora, Rua José Lourenço Kelmer - s/n, Campus Universitário, São Pedro, Juiz de Fora, Minas Gerais, 36036900, Brazil
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91
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Janas MM, Zlatev I, Liu J, Jiang Y, Barros SA, Sutherland JE, Davis WP, Liu J, Brown CR, Liu X, Schlegel MK, Blair L, Zhang X, Das B, Tran C, Aluri K, Li J, Agarwal S, Indrakanti R, Charisse K, Nair J, Matsuda S, Rajeev KG, Zimmermann T, Sepp-Lorenzino L, Xu Y, Akinc A, Fitzgerald K, Vaishnaw AK, Smith PF, Manoharan M, Jadhav V, Wu JT, Maier MA. Safety evaluation of 2'-deoxy-2'-fluoro nucleotides in GalNAc-siRNA conjugates. Nucleic Acids Res 2019; 47:3306-3320. [PMID: 30820542 PMCID: PMC6468299 DOI: 10.1093/nar/gkz140] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Revised: 02/07/2019] [Accepted: 02/19/2019] [Indexed: 11/29/2022] Open
Abstract
For oligonucleotide therapeutics, chemical modifications of the sugar-phosphate backbone are frequently used to confer drug-like properties. Because 2′-deoxy-2′-fluoro (2′-F) nucleotides are not known to occur naturally, their safety profile was assessed when used in revusiran and ALN-TTRSC02, two short interfering RNAs (siRNAs), of the same sequence but different chemical modification pattern and metabolic stability, conjugated to an N-acetylgalactosamine (GalNAc) ligand for targeted delivery to hepatocytes. Exposure to 2′-F-monomer metabolites was low and transient in rats and humans. In vitro, 2′-F-nucleoside 5′-triphosphates were neither inhibitors nor preferred substrates for human polymerases, and no obligate or non-obligate chain termination was observed. Modest effects on cell viability and mitochondrial DNA were observed in vitro in a subset of cell types at high concentrations of 2′-F-nucleosides, typically not attained in vivo. No apparent functional impact on mitochondria and no significant accumulation of 2′-F-monomers were observed after weekly administration of two GalNAc–siRNA conjugates in rats for ∼2 years. Taken together, the results support the conclusion that 2′-F nucleotides can be safely applied for the design of metabolically stabilized therapeutic GalNAc–siRNAs with favorable potency and prolonged duration of activity allowing for low dose and infrequent dosing.
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Affiliation(s)
- Maja M Janas
- Alnylam Pharmaceuticals, Inc., Cambridge, MA 02142, USA
| | - Ivan Zlatev
- Alnylam Pharmaceuticals, Inc., Cambridge, MA 02142, USA
| | - Ju Liu
- Alnylam Pharmaceuticals, Inc., Cambridge, MA 02142, USA
| | | | | | | | | | - Jingxuan Liu
- Alnylam Pharmaceuticals, Inc., Cambridge, MA 02142, USA
| | | | - Xiumin Liu
- Alnylam Pharmaceuticals, Inc., Cambridge, MA 02142, USA
| | | | - Lauren Blair
- Alnylam Pharmaceuticals, Inc., Cambridge, MA 02142, USA
| | - Xuemei Zhang
- Alnylam Pharmaceuticals, Inc., Cambridge, MA 02142, USA
| | - Biplab Das
- Alnylam Pharmaceuticals, Inc., Cambridge, MA 02142, USA
| | - Chris Tran
- Alnylam Pharmaceuticals, Inc., Cambridge, MA 02142, USA
| | - Krishna Aluri
- Alnylam Pharmaceuticals, Inc., Cambridge, MA 02142, USA
| | - Jing Li
- Alnylam Pharmaceuticals, Inc., Cambridge, MA 02142, USA
| | - Saket Agarwal
- Alnylam Pharmaceuticals, Inc., Cambridge, MA 02142, USA
| | | | | | | | | | | | | | | | - Yuanxin Xu
- Alnylam Pharmaceuticals, Inc., Cambridge, MA 02142, USA
| | - Akin Akinc
- Alnylam Pharmaceuticals, Inc., Cambridge, MA 02142, USA
| | | | | | - Peter F Smith
- Alnylam Pharmaceuticals, Inc., Cambridge, MA 02142, USA
| | | | - Vasant Jadhav
- Alnylam Pharmaceuticals, Inc., Cambridge, MA 02142, USA
| | - Jing-Tao Wu
- Alnylam Pharmaceuticals, Inc., Cambridge, MA 02142, USA
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92
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Wang ZH, Liu Y, Chaitankar V, Pirooznia M, Xu H. Electron transport chain biogenesis activated by a JNK-insulin-Myc relay primes mitochondrial inheritance in Drosophila. eLife 2019; 8:49309. [PMID: 31612862 PMCID: PMC6809605 DOI: 10.7554/elife.49309] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 10/13/2019] [Indexed: 12/25/2022] Open
Abstract
Oogenesis features an enormous increase in mitochondrial mass and mtDNA copy number, which are required to furnish mature eggs with an adequate supply of mitochondria and to curb the transmission of deleterious mtDNA variants. Quiescent in dividing germ cells, mtDNA replication initiates upon oocyte determination in the Drosophila ovary, which necessitates active mitochondrial respiration. However, the underlying mechanism for this dynamic regulation remains unclear. Here, we show that an feedforward insulin-Myc loop promotes mitochondrial respiration and biogenesis by boosting the expression of electron transport chain subunits and of factors essential for mtDNA replication and expression, and for the import of mitochondrial proteins. We further reveal that transient activation of JNK enhances the expression of the insulin receptor and initiates the insulin-Myc signaling loop. This signaling relay promotes mitochondrial biogenesis in the ovary, and thereby plays a role in limiting the transmission of deleterious mtDNA mutations. Our study demonstrates cellular mechanisms that couple mitochondrial biogenesis and inheritance with oocyte development.
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Affiliation(s)
- Zong-Heng Wang
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, United States
| | - Yi Liu
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, United States
| | - Vijender Chaitankar
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, United States
| | - Mehdi Pirooznia
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, United States
| | - Hong Xu
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, United States
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93
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Kondadi AK, Anand R, Reichert AS. Functional Interplay between Cristae Biogenesis, Mitochondrial Dynamics and Mitochondrial DNA Integrity. Int J Mol Sci 2019; 20:ijms20174311. [PMID: 31484398 PMCID: PMC6747513 DOI: 10.3390/ijms20174311] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 08/30/2019] [Accepted: 08/30/2019] [Indexed: 12/11/2022] Open
Abstract
Mitochondria are vital cellular organelles involved in a plethora of cellular processes such as energy conversion, calcium homeostasis, heme biogenesis, regulation of apoptosis and ROS reactive oxygen species (ROS) production. Although they are frequently depicted as static bean-shaped structures, our view has markedly changed over the past few decades as many studies have revealed a remarkable dynamicity of mitochondrial shapes and sizes both at the cellular and intra-mitochondrial levels. Aberrant changes in mitochondrial dynamics and cristae structure are associated with ageing and numerous human diseases (e.g., cancer, diabetes, various neurodegenerative diseases, types of neuro- and myopathies). Another unique feature of mitochondria is that they harbor their own genome, the mitochondrial DNA (mtDNA). MtDNA exists in several hundreds to thousands of copies per cell and is arranged and packaged in the mitochondrial matrix in structures termed mt-nucleoids. Many human diseases are mechanistically linked to mitochondrial dysfunction and alteration of the number and/or the integrity of mtDNA. In particular, several recent studies identified remarkable and partly unexpected links between mitochondrial structure, fusion and fission dynamics, and mtDNA. In this review, we will provide an overview about these recent insights and aim to clarify how mitochondrial dynamics, cristae ultrastructure and mtDNA structure influence each other and determine mitochondrial functions.
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Affiliation(s)
- Arun Kumar Kondadi
- Institute of Biochemistry and Molecular Biology I, Medical Faculty, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany.
| | - Ruchika Anand
- Institute of Biochemistry and Molecular Biology I, Medical Faculty, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany
| | - Andreas S Reichert
- Institute of Biochemistry and Molecular Biology I, Medical Faculty, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany.
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94
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Mitochondria and Female Germline Stem Cells-A Mitochondrial DNA Perspective. Cells 2019; 8:cells8080852. [PMID: 31398797 PMCID: PMC6721711 DOI: 10.3390/cells8080852] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 08/06/2019] [Accepted: 08/06/2019] [Indexed: 02/06/2023] Open
Abstract
Mitochondria and mitochondrial DNA have important roles to play in development. In primordial germ cells, they progress from small numbers to populate the maturing oocyte with high numbers to support post-fertilization events. These processes take place under the control of significant changes in DNA methylation and other epigenetic modifiers, as well as changes to the DNA methylation status of the nuclear-encoded mitochondrial DNA replication factors. Consequently, the differentiating germ cell requires significant synchrony between the two genomes in order to ensure that they are fit for purpose. In this review, I examine these processes in the context of female germline stem cells that are isolated from the ovary and those derived from embryonic stem cells and reprogrammed somatic cells. Although our knowledge is limited in this respect, I provide predictions based on other cellular systems of what is expected and provide insight into how these cells could be used in clinical medicine.
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95
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Jurkute N, Leu C, Pogoda HM, Arno G, Robson AG, Nürnberg G, Altmüller J, Thiele H, Motameny S, Toliat MR, Powell K, Höhne W, Michaelides M, Webster AR, Moore AT, Hammerschmidt M, Nürnberg P, Yu-Wai-Man P, Votruba M. SSBP1 mutations in dominant optic atrophy with variable retinal degeneration. Ann Neurol 2019; 86:368-383. [PMID: 31298765 DOI: 10.1002/ana.25550] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 07/10/2019] [Accepted: 07/10/2019] [Indexed: 12/31/2022]
Abstract
OBJECTIVE Autosomal dominant optic atrophy (ADOA) starts in early childhood with loss of visual acuity and color vision deficits. OPA1 mutations are responsible for the majority of cases, but in a portion of patients with a clinical diagnosis of ADOA, the cause remains unknown. This study aimed to identify novel ADOA-associated genes and explore their causality. METHODS Linkage analysis and sequencing were performed in multigeneration families and unrelated patients to identify disease-causing variants. Functional consequences were investigated in silico and confirmed experimentally using the zebrafish model. RESULTS We defined a new ADOA locus on 7q33-q35 and identified 3 different missense variants in SSBP1 (NM_001256510.1; c.113G>A [p.(Arg38Gln)], c.320G>A [p.(Arg107Gln)] and c.422G>A [p.(Ser141Asn)]) in affected individuals from 2 families and 2 singletons with ADOA and variable retinal degeneration. The mutated arginine residues are part of a basic patch that is essential for single-strand DNA binding. The loss of a positive charge at these positions is very likely to lower the affinity of SSBP1 for single-strand DNA. Antisense-mediated knockdown of endogenous ssbp1 messenger RNA (mRNA) in zebrafish resulted in compromised differentiation of retinal ganglion cells. A similar effect was achieved when mutated mRNAs were administered. These findings point toward an essential role of ssbp1 in retinal development and the dominant-negative nature of the identified human variants, which is consistent with the segregation pattern observed in 2 multigeneration families studied. INTERPRETATION SSBP1 is an essential protein for mitochondrial DNA replication and maintenance. Our data have established pathogenic variants in SSBP1 as a cause of ADOA and variable retinal degeneration. ANN NEUROL 2019;86:368-383.
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Affiliation(s)
- Neringa Jurkute
- Moorfields Eye Hospital National Health Service Foundation Trust, London, United Kingdom.,University College London Institute of Ophthalmology, University College London, London, United Kingdom
| | - Costin Leu
- Cologne Center for Genomics, University of Cologne, Cologne, Germany.,Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, OH.,Genomic Medicine Institute, Lerner Research Institute Cleveland Clinic, Cleveland, OH.,Stanley Center for Psychiatric Research, Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA
| | - Hans-Martin Pogoda
- Institute for Zoology, Developmental Biology Unit, University of Cologne, Cologne, Germany
| | - Gavin Arno
- Moorfields Eye Hospital National Health Service Foundation Trust, London, United Kingdom.,University College London Institute of Ophthalmology, University College London, London, United Kingdom
| | - Anthony G Robson
- Moorfields Eye Hospital National Health Service Foundation Trust, London, United Kingdom.,University College London Institute of Ophthalmology, University College London, London, United Kingdom
| | - Gudrun Nürnberg
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Janine Altmüller
- Cologne Center for Genomics, University of Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Holger Thiele
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Susanne Motameny
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | | | - Kate Powell
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom
| | - Wolfgang Höhne
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Michel Michaelides
- Moorfields Eye Hospital National Health Service Foundation Trust, London, United Kingdom.,University College London Institute of Ophthalmology, University College London, London, United Kingdom
| | - Andrew R Webster
- Moorfields Eye Hospital National Health Service Foundation Trust, London, United Kingdom.,University College London Institute of Ophthalmology, University College London, London, United Kingdom
| | - Anthony T Moore
- Moorfields Eye Hospital National Health Service Foundation Trust, London, United Kingdom.,University College London Institute of Ophthalmology, University College London, London, United Kingdom.,Department of Ophthalmology, University of California, San Francisco, San Francisco, CA
| | - Matthias Hammerschmidt
- Institute for Zoology, Developmental Biology Unit, University of Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, Cologne, Germany
| | - Peter Nürnberg
- Cologne Center for Genomics, University of Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, Cologne, Germany
| | - Patrick Yu-Wai-Man
- Moorfields Eye Hospital National Health Service Foundation Trust, London, United Kingdom.,University College London Institute of Ophthalmology, University College London, London, United Kingdom.,Cambridge Eye Unit, Addenbrooke's Hospital, Cambridge University Hospitals, Cambridge, United Kingdom.,Cambridge Centre for Brain Repair and Medical Research Council Mitochondrial Biology Unit, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | - Marcela Votruba
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom.,Cardiff Eye Unit, University Hospital Wales, Cardiff, United Kingdom
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96
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Scott S, Shaheen C, McGuinness B, Metera K, Kouzine F, Levens D, Benham CJ, Leslie S. Single-molecule visualization of the effects of ionic strength and crowding on structure-mediated interactions in supercoiled DNA molecules. Nucleic Acids Res 2019; 47:6360-6368. [PMID: 31106378 PMCID: PMC6614806 DOI: 10.1093/nar/gkz408] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 05/02/2019] [Accepted: 05/06/2019] [Indexed: 12/22/2022] Open
Abstract
DNA unwinding is an important cellular process involved in DNA replication, transcription and repair. In cells, molecular crowding caused by the presence of organelles, proteins, and other molecules affects numerous internal cellular structures. Here, we visualize plasmid DNA unwinding and binding dynamics to an oligonucleotide probe as functions of ionic strength, crowding agent concentration, and crowding agent species using single-molecule CLiC microscopy. We demonstrate increased probe–plasmid interaction over time with increasing concentration of 8 kDa polyethylene glycol (PEG), a crowding agent. We show decreased probe–plasmid interactions as ionic strength is increased without crowding. However, when crowding is introduced via 10% 8 kDa PEG, interactions between plasmids and oligos are enhanced. This is beyond what is expected for normal in vitro conditions, and may be a critically important, but as of yet unknown, factor in DNA’s proper biological function in vivo. Our results show that crowding has a strong effect on the initial concentration of unwound plasmids. In the dilute conditions used in these experiments, crowding does not impact probe–plasmid interactions once the site is unwound.
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Affiliation(s)
- Shane Scott
- Department of Physics, McGill University, Montreal, Quebec, Canada H3A 2T8
| | - Cynthia Shaheen
- Department of Physics, McGill University, Montreal, Quebec, Canada H3A 2T8
| | - Brendon McGuinness
- Department of Physics, McGill University, Montreal, Quebec, Canada H3A 2T8
| | - Kimberly Metera
- Department of Physics, McGill University, Montreal, Quebec, Canada H3A 2T8
| | - Fedor Kouzine
- Center for Cancer Research, National Cancer Institute, Bethesda, MS 20892, USA
| | - David Levens
- Center for Cancer Research, National Cancer Institute, Bethesda, MS 20892, USA
| | - Craig J Benham
- Genome Center, University of California Davis, Davis, CA 95616, USA
| | - Sabrina Leslie
- Department of Physics, McGill University, Montreal, Quebec, Canada H3A 2T8
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97
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Guo J, Li Y, Zhao R, Yang X. Adipokine zinc-α2-glycoprotein alleviates lipopolysaccharide-induced inflammatory responses through the β3-AR/PKA/CREB pathway. Cytokine 2019; 123:154742. [PMID: 31260855 DOI: 10.1016/j.cyto.2019.154742] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 05/31/2019] [Accepted: 06/03/2019] [Indexed: 12/25/2022]
Abstract
Humans and animals frequently experience dysmetabolism induced by inflammation. Zinc-α2-glycoprotein (ZAG), a newly identified adipokine, is potentially involved in lipid metabolism. Our previous study revealed that the ZAG content increased after lipopolysaccharide (LPS) treatment. To clarify ZAG's possible effects on inflammatory responses and lipid metabolism, we used gene overexpression and knockout mice as models to investigate the function of ZAG during inflammation. The results showed that LPS increased plasma triglyceride, non-esterified fatty acid and hepatic triglyceride, while ZAG overexpression decreased these effects. Furthermore, ZAG overexpression weakened inflammatory responses, suppressed lipogenesis, and improved mitochondrial function during inflammation. ZAG overexpression also increased β3-adrenoreceptor, protein kinase A, and phosphorylated cyclic adenosine monophosphate-response element binding protein (CREB), promoted the combination of CREB and CREB-binding protein (CBP), and competitively inhibited the combination of nuclear factor-κB and CBP. After ZAG knockout, LPS-induced the hyperlipidemia worsened. ZAG knockout aggravated inflammatory responses, promoted lipogenesis, and weakened mitochondrial function during inflammation. ZAG knockout also decreased β3-adrenoreceptor and protein kinase A. The present study demonstrated that ZAG alleviated lipid metabolism disorders by weakening inflammatory responses. The β3-adrenoreceptor/protein kinase A/CREB pathway mediated the effects of ZAG on inflammation. These results will provide new insight for research on anti-inflammation.
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Affiliation(s)
- Jun Guo
- MOE Joint International Research Laboratory of Animal Health and Food Safety, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Yanfei Li
- MOE Joint International Research Laboratory of Animal Health and Food Safety, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Ruqian Zhao
- MOE Joint International Research Laboratory of Animal Health and Food Safety, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Xiaojing Yang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, Nanjing Agricultural University, Nanjing 210095, PR China.
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98
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Abstract
Replication stalling has been associated with the formation of pathological mitochondrial DNA (mtDNA) rearrangements. Yet, almost nothing is known about the fate of stalled replication intermediates in mitochondria. We show here that replication stalling in mitochondria leads to replication fork regression and mtDNA double-strand breaks. The resulting mtDNA fragments are normally degraded by a mechanism involving the mitochondrial exonuclease MGME1, and the loss of this enzyme results in accumulation of linear and recombining mtDNA species. Additionally, replication stress promotes the initiation of alternative replication origins as an apparent means of rescue by fork convergence. Besides demonstrating an interplay between two major mechanisms rescuing stalled replication forks – mtDNA degradation and homology-dependent repair – our data provide evidence that mitochondria employ similar mechanisms to cope with replication stress as known from other genetic systems.
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99
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Hood WR, Williams AS, Hill GE. An Ecologist’s Guide to Mitochondrial DNA Mutations and Senescence. Integr Comp Biol 2019; 59:970-982. [DOI: 10.1093/icb/icz097] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Abstract
Longevity plays a key role in the fitness of organisms, so understanding the processes that underlie variance in senescence has long been a focus of ecologists and evolutionary biologists. For decades, the performance and ultimate decline of mitochondria have been implicated in the demise of somatic tissue, but exactly why mitochondrial function declines as individual’s age has remained elusive. A possible source of decline that has been of intense debate is mutations to the mitochondrial DNA. There are two primary sources of such mutations: oxidative damage, which is widely discussed by ecologists interested in aging, and mitochondrial replication error, which is less familiar to most ecologists. The goal of this review is to introduce ecologists and evolutionary biologists to the concept of mitochondrial replication error and to review the current status of research on the relative importance of replication error in senescence. We conclude by detailing some of the gaps in our knowledge that currently make it difficult to deduce the relative importance of replication error in wild populations and encourage organismal biologists to consider this variable both when interpreting their results and as viable measure to include in their studies.
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Affiliation(s)
- Wendy R Hood
- Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA
| | - Ashley S Williams
- Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA
| | - Geoffrey E Hill
- Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA
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100
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Kaufman BA, Picard M, Sondheimer N. Mitochondrial DNA, nuclear context, and the risk for carcinogenesis. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2019; 60:455-462. [PMID: 29332303 PMCID: PMC6045969 DOI: 10.1002/em.22169] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 11/25/2017] [Accepted: 12/20/2017] [Indexed: 05/05/2023]
Abstract
The inheritance of mitochondrial DNA (mtDNA) from mother to child is complicated by differences in the stability of the mitochondrial genome. Although the germ line mtDNA is protected through the minimization of replication between generations, sequence variation can occur either through mutation or due to changes in the ratio between distinct genomes that are present in the mother (known as heteroplasmy). Thus, the unpredictability in transgenerational inheritance of mtDNA may cause the emergence of pathogenic mitochondrial and cellular phenotypes in offspring. Studies of the role of mitochondrial metabolism in cancer have a long and rich history, but recent evidence strongly suggests that changes in mitochondrial genotype and phenotype play a significant role in the initiation, progression and treatment of cancer. At the intersection of these two fields lies the potential for emerging mtDNA mutations to drive carcinogenesis in the offspring. In this review, we suggest that this facet of transgenerational carcinogenesis remains underexplored and is a potentially important contributor to cancer. Environ. Mol. Mutagen. 60:455-462, 2019. © 2018 Wiley Periodicals, Inc.
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Affiliation(s)
- Brett A. Kaufman
- Center for Metabolism and Mitochondrial Medicine, Division of Cardiology, Vascular Medicine Institute, Department of Medicine, University of Pittsburgh Medical School, Pittsburgh, PA (USA)
| | - Martin Picard
- Department of Psychiatry, Division of Behavioral Medicine, Columbia University Medical Center, New York, NY 10032 USA
- Department of Neurology, H. Houston Merritt Center, Columbia Translational Neuroscience Initiative, Columbia University Medical Center, New York, NY 10032 USA
- Columbia Aging Center, Columbia University Mailman School of Public Health, New York, NY 10032 USA
| | - Neal Sondheimer
- Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, Toronto, ON, Canada M5G1X8
- Department of Paediatrics, The University of Toronto School of Medicine, Toronto, ON, Canada M5G1X8
- Correspondence to: Neal Sondheimer, 555 University Avenue, Toronto ON M5G 1X8, p – 416-813-7654 x 301480, f – 416-813-5345,
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