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Santander-Lucio H, Totomoch-Serra A, Muñoz MDL, García-Hernández N, Pérez-Ramírez G, Valladares-Salgado A, Pérez-Muñoz AA. Variants in the Control Region of Mitochondrial Genome Associated with type 2 Diabetes in a Cohort of Mexican Mestizos. Arch Med Res 2023; 54:113-123. [PMID: 36792418 DOI: 10.1016/j.arcmed.2022.12.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 11/09/2022] [Accepted: 12/20/2022] [Indexed: 02/15/2023]
Abstract
BACKGROUND According to the International Diabetes Federation, Mexico is seventh place in the prevalence of type 2 diabetes (T2D) worldwide. Mitochondrial DNA variant association studies in multifactorial diseases like T2D are scarce in Mexican populations. AIM OF THE STUDY The objective of this study was to analyze the association between 18 variants in the mtDNA control region and T2D and related metabolic traits in a Mexican mestizo population from Mexico City. METHODS This study included 1001 participants divided into 477 cases with T2D and 524 healthy controls aged between 42 and 62 years and 18 mtDNA variants with frequencies >15%. RESULTS Association analyses matched by age and sex showed differences in the distribution between cases and controls for variants m.315_316insC (p = 1.18 × 10-6), m.489T>C (p = 0.009), m.16362T>C (p = 0.001), and m.16519T>C (p = 0.004). The associations between T2D and variants m.315_316ins (OR = 6.13, CI = 3.42-10.97, p = 1.97 × 10-6), m.489T>C (OR = 1.45, CI = 1.00-2.11, p = 0.006), m.16362T>C (OR = 2.17, CI = 1.57-3.00, p = 0.001), and m.16519T>C (OR = 1.69, CI = 1.23-2.33, p = 0.006) were significant after performing logistic regression models adjusted for age, sex, and diastolic blood pressure. Metabolic traits in the control group through linear regressions, adjusted for age, sex and BMI, and corrected for multiple comparisons showed nominal association between glucose and variants m.263A>G (p <0.050), m.16183A>C (p <0.010), m.16189T>C (p <0.020), and m.16223C>T (p <0.024); triglycerides, and cholesterol and variant m.309_310insC (p <0.010 and p <0.050 respectively); urea, and creatinine, and variant m.315_316insC (p <0.007, and p <0.004 respectively); diastolic blood pressure and variants m.235A>G (p <0.016), m.263A>G (p <0.013), m.315_316insC (p <0.043), and m.16111C>T (p <0.022). CONCLUSION These results demonstrate a strong association between variant m.315_316insC and T2D and a nominal association with T2D traits.
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Affiliation(s)
- Heriberto Santander-Lucio
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Ciudad de México, México
| | - Armando Totomoch-Serra
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Ciudad de México, México; Departamento de Electrofisiología, Instituto Nacional de Cardiología, Ignacio Chávez, Ciudad de México, México
| | - María de Lourdes Muñoz
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Ciudad de México, México.
| | - Normand García-Hernández
- Unidad de Investigación Médica en Genética Humana, Hospital de Pediatría, Dr. Silvestre Frenk Freud, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Ciudad de México, México
| | - Gerardo Pérez-Ramírez
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Ciudad de México, México
| | - Adán Valladares-Salgado
- Unidad de Investigación Médica en Bioquímica, Hospital de Especialidades, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Ciudad de México, México
| | - Ashael Alfredo Pérez-Muñoz
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Ciudad de México, México; Universidad Anáhuac México Norte, Ciudad de México, México
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Al-Kafaji G, Bakheit HF, AlAli F, Fattah M, Alhajeri S, Alharbi MA, Daif A, Alsabbagh MM, Alwehaidah MS, Bakhiet M. Next-generation sequencing of the whole mitochondrial genome identifies functionally deleterious mutations in patients with multiple sclerosis. PLoS One 2022; 17:e0263606. [PMID: 35130313 PMCID: PMC8820615 DOI: 10.1371/journal.pone.0263606] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 01/22/2022] [Indexed: 12/12/2022] Open
Abstract
Multiple sclerosis (MS) is an immune-mediated disease of the central nervous system with genetics and environmental determinants. Studies focused on the neurogenetics of MS showed that mitochondrial DNA (mtDNA) mutations that can ultimately lead to mitochondrial dysfunction, alter brain energy metabolism and cause neurodegeneration. We analyzed the whole mitochondrial genome using next-generation sequencing (NGS) from 47 Saudi individuals, 23 patients with relapsing-remitting MS and 24 healthy controls to identify mtDNA disease-related mutations/variants. A large number of variants were detected in the D-loop and coding genes of mtDNA. While distinct unique variants were only present in patients or only occur in controls, a number of common variants were shared among the two groups. The prevalence of some common variants differed significantly between patients and controls, thus could be implicated in susceptibility to MS. Of the unique variants only present in the patients, 34 were missense mutations, located in different mtDNA-encoded genes. Seven of these mutations were not previously reported in MS, and predicted to be deleterious with considerable impacts on the functions and structures of encoded-proteins and may play a role in the pathogenesis of MS. These include two heteroplasmic mutations namely 10237T>C in MT-ND3 gene and 15884G>C in MT-CYB gene; and three homoplasmic mutations namely 9288A>G in MT-CO3 gene, 14484T>C in MT-ND6 gene, 15431G>A in MT-CYB gene, 8490T>C in MT-ATP8 gene and 5437C>T in MT-ND2 gene. Notably some patients harboured multiple mutations while other patients carried the same mutations. This study is the first to sequence the entire mitochondrial genome in MS patients in an Arab population. Our results expanded the mutational spectrum of mtDNA variants in MS and highlighted the efficiency of NGS in population-specific mtDNA variant discovery. Further investigations in a larger cohort are warranted to confirm the role of mtDNA MS.
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Affiliation(s)
- Ghada Al-Kafaji
- Department of Molecular Medicine and Al-Jawhara Centre for Molecular Medicine, Genetics, and Inherited Disorders, College of Medicine and Medical Sciences, Arabian Gulf University, Manama, Kingdom of Bahrain
- * E-mail:
| | - Halla F. Bakheit
- Department of Molecular Medicine and Al-Jawhara Centre for Molecular Medicine, Genetics, and Inherited Disorders, College of Medicine and Medical Sciences, Arabian Gulf University, Manama, Kingdom of Bahrain
| | - Faisal AlAli
- Department of Molecular Medicine and Al-Jawhara Centre for Molecular Medicine, Genetics, and Inherited Disorders, College of Medicine and Medical Sciences, Arabian Gulf University, Manama, Kingdom of Bahrain
| | - Mina Fattah
- Department of Molecular Medicine and Al-Jawhara Centre for Molecular Medicine, Genetics, and Inherited Disorders, College of Medicine and Medical Sciences, Arabian Gulf University, Manama, Kingdom of Bahrain
| | | | - Maram A. Alharbi
- College of Forensic Sciences, Naif Arab University for Security Sciences, Riyadh, Kingdom of Saudi Arabia
| | - Abdulqader Daif
- King Saud University Medical City, Riyadh, Kingdom of Saudi Arabia
| | - Manahel Mahmood Alsabbagh
- Department of Molecular Medicine and Al-Jawhara Centre for Molecular Medicine, Genetics, and Inherited Disorders, College of Medicine and Medical Sciences, Arabian Gulf University, Manama, Kingdom of Bahrain
| | - Materah Salem Alwehaidah
- Department of Medical Laboratory, Faculty of Allied Health, Kuwait University, Kuwait City, State of Kuwait
| | - Moiz Bakhiet
- Department of Molecular Medicine and Al-Jawhara Centre for Molecular Medicine, Genetics, and Inherited Disorders, College of Medicine and Medical Sciences, Arabian Gulf University, Manama, Kingdom of Bahrain
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Balachandar V, Rajagopalan K, Jayaramayya K, Jeevanandam M, Iyer M. Mitochondrial dysfunction: A hidden trigger of autism? Genes Dis 2021; 8:629-639. [PMID: 34291134 PMCID: PMC8278534 DOI: 10.1016/j.gendis.2020.07.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 07/07/2020] [Indexed: 02/06/2023] Open
Abstract
Autism is a heterogeneous neurodevelopmental and neuropsychiatric disorder with no precise etiology. Deficits in cognitive functions uncover at early stages and are known to have an environmental and genetic basis. Since autism is multifaceted and also linked with other comorbidities associated with various organs, there is a possibility that there may be a fundamental cellular process responsible for this. These reasons place mitochondria at the point of interest as it is involved in multiple cellular processes predominantly involving metabolism. Mitochondria encoded genes were taken into consideration lately because it is inherited maternally, has its own genome and also functions the time of embryo development. Various researches have linked mitochondrial mishaps like oxidative stress, ROS production and mt-DNA copy number variations to autism. Despite dramatic advances in autism research worldwide, the studies focusing on mitochondrial dysfunction in autism is rather minimal, especially in India. India, owing to its rich diversity, may be able to contribute significantly to autism research. It is vital to urge more studies in this domain as it may help to completely understand the basics of the condition apart from a genetic standpoint. This review focuses on the worldwide and Indian scenario of autism research; mitochondrial abnormalities in autism and possible therapeutic approaches to combat it.
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Affiliation(s)
- Vellingiri Balachandar
- Human Molecular Genetics and Stem Cell Laboratory, Department of Human Genetics and Molecular Biology, Bharathiar University, Coimbatore, Tamil Nadu 641046, India
| | - Kamarajan Rajagopalan
- Human Molecular Genetics and Stem Cell Laboratory, Department of Human Genetics and Molecular Biology, Bharathiar University, Coimbatore, Tamil Nadu 641046, India
| | - Kaavya Jayaramayya
- Department of Zoology, Avinashilingam Institute for Home Science and Higher Education for Women, Coimbatore, Tamil Nadu 641043, India
| | - Madesh Jeevanandam
- Human Molecular Genetics and Stem Cell Laboratory, Department of Human Genetics and Molecular Biology, Bharathiar University, Coimbatore, Tamil Nadu 641046, India
- Department of Biochemistry, PSG College of Arts and Sciences, Coimbatore, Tamil Nadu 641014, India
| | - Mahalaxmi Iyer
- Department of Zoology, Avinashilingam Institute for Home Science and Higher Education for Women, Coimbatore, Tamil Nadu 641043, India
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Jang YH, Ahn SR, Shim JY, Lim KI. Engineering Genetic Systems for Treating Mitochondrial Diseases. Pharmaceutics 2021; 13:810. [PMID: 34071708 PMCID: PMC8227772 DOI: 10.3390/pharmaceutics13060810] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 05/23/2021] [Accepted: 05/24/2021] [Indexed: 12/13/2022] Open
Abstract
Mitochondria are intracellular energy generators involved in various cellular processes. Therefore, mitochondrial dysfunction often leads to multiple serious diseases, including neurodegenerative and cardiovascular diseases. A better understanding of the underlying mitochondrial dysfunctions of the molecular mechanism will provide important hints on how to mitigate the symptoms of mitochondrial diseases and eventually cure them. In this review, we first summarize the key parts of the genetic processes that control the physiology and functions of mitochondria and discuss how alterations of the processes cause mitochondrial diseases. We then list up the relevant core genetic components involved in these processes and explore the mutations of the components that link to the diseases. Lastly, we discuss recent attempts to apply multiple genetic methods to alleviate and further reverse the adverse effects of the core component mutations on the physiology and functions of mitochondria.
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Affiliation(s)
- Yoon-ha Jang
- Department of Chemical and Biological Engineering, Sookmyung Women’s University, Yongsan-gu, Seoul 04310, Korea; (Y.-h.J.); (J.-y.S.)
| | - Sae Ryun Ahn
- Industry Collaboration Center, Industry-Academic Cooperation Foundation, Sookmyung Women’s University, Yongsan-gu, Seoul 04310, Korea;
| | - Ji-yeon Shim
- Department of Chemical and Biological Engineering, Sookmyung Women’s University, Yongsan-gu, Seoul 04310, Korea; (Y.-h.J.); (J.-y.S.)
| | - Kwang-il Lim
- Department of Chemical and Biological Engineering, Sookmyung Women’s University, Yongsan-gu, Seoul 04310, Korea; (Y.-h.J.); (J.-y.S.)
- Industry Collaboration Center, Industry-Academic Cooperation Foundation, Sookmyung Women’s University, Yongsan-gu, Seoul 04310, Korea;
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Lechuga-Vieco AV, Justo-Méndez R, Enríquez JA. Not all mitochondrial DNAs are made equal and the nucleus knows it. IUBMB Life 2020; 73:511-529. [PMID: 33369015 PMCID: PMC7985871 DOI: 10.1002/iub.2434] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Revised: 12/06/2020] [Accepted: 12/09/2020] [Indexed: 12/13/2022]
Abstract
The oxidative phosphorylation (OXPHOS) system is the only structure in animal cells with components encoded by two genomes, maternally transmitted mitochondrial DNA (mtDNA), and biparentally transmitted nuclear DNA (nDNA). MtDNA‐encoded genes have to physically assemble with their counterparts encoded in the nucleus to build together the functional respiratory complexes. Therefore, structural and functional matching requirements between the protein subunits of these molecular complexes are rigorous. The crosstalk between nDNA and mtDNA needs to overcome some challenges, as the nuclear‐encoded factors have to be imported into the mitochondria in a correct quantity and match the high number of organelles and genomes per mitochondria that encode and synthesize their own components locally. The cell is able to sense the mito‐nuclear match through changes in the activity of the OXPHOS system, modulation of the mitochondrial biogenesis, or reactive oxygen species production. This implies that a complex signaling cascade should optimize OXPHOS performance to the cellular‐specific requirements, which will depend on cell type, environmental conditions, and life stage. Therefore, the mitochondria would function as a cellular metabolic information hub integrating critical information that would feedback the nucleus for it to respond accordingly. Here, we review the current understanding of the complex interaction between mtDNA and nDNA.
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Affiliation(s)
- Ana Victoria Lechuga-Vieco
- Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain.,MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Raquel Justo-Méndez
- Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain
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Tobore TO. Towards a comprehensive understanding of the contributions of mitochondrial dysfunction and oxidative stress in the pathogenesis and pathophysiology of Huntington's disease. J Neurosci Res 2019; 97:1455-1468. [DOI: 10.1002/jnr.24492] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 06/06/2019] [Accepted: 06/16/2019] [Indexed: 12/21/2022]
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Mitochondrial DNA Variants and Common Diseases: A Mathematical Model for the Diversity of Age-Related mtDNA Mutations. Cells 2019; 8:cells8060608. [PMID: 31216686 PMCID: PMC6627076 DOI: 10.3390/cells8060608] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 05/30/2019] [Accepted: 06/14/2019] [Indexed: 12/18/2022] Open
Abstract
The mitochondrion is the only organelle in the human cell, besides the nucleus, with its own DNA (mtDNA). Since the mitochondrion is critical to the energy metabolism of the eukaryotic cell, it should be unsurprising, then, that a primary driver of cellular aging and related diseases is mtDNA instability over the life of an individual. The mutation rate of mammalian mtDNA is significantly higher than the mutation rate observed for nuclear DNA, due to the poor fidelity of DNA polymerase and the ROS-saturated environment present within the mitochondrion. In this review, we will discuss the current literature showing that mitochondrial dysfunction can contribute to age-related common diseases such as cancer, diabetes, and other commonly occurring diseases. We will then turn our attention to the likely role that mtDNA mutation plays in aging and senescence. Finally, we will use this context to develop a mathematical formula for estimating for the accumulation of somatic mtDNA mutations with age. This resulting model shows that almost 90% of non-proliferating cells would be expected to have at least 100 mutations per cell by the age of 70, and almost no cells would have fewer than 10 mutations, suggesting that mtDNA mutations may contribute significantly to many adult onset diseases.
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Altafi D, Sadeghi S, Hojatian H, Torabi Afra M, Pakizeh Kar S, Gorji M, Houshmand M. Mitochondrial Polymorphisms, in The D-Loop Area, Are Associated with Brain Tumors. CELL JOURNAL 2019; 21:350-356. [PMID: 31210442 PMCID: PMC6582428 DOI: 10.22074/cellj.2019.5947] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Subscribe] [Scholar Register] [Received: 04/01/2018] [Accepted: 10/29/2018] [Indexed: 11/18/2022]
Abstract
Objective This study was carried out to evaluate the relationship between mtDNA D-loop variations and the
pathogenesis of a brain tumor.
Materials and Methods In this experimental study, 25 specimens of brain tumor tissue with their adjacent tissues
from patients and 454 blood samples from different ethnic groups of the Iranian population, as the control group, were
analysed by the polymerase chain reaction (PCR)-sequencing method.
Results Thirty-six variations of the D-loop area were observed in brain tumor tissues as well as the adjacent normal
tissues. A significant difference of A750G (P=0.046), T15936C (P=0.013), C15884G (P=0.013), C16069T (P=0.049),
T16126C (P=0.006), C16186T (P=0.022), T16189C (P=0.041), C16193T (P=0.045), C16223T (P=0.001), T16224C
(P=0.013), C16234T (P=0.013), G16274A (P=0.009), T16311C (P=0.038), C16327T (P=0.045), C16355T (P=0.003),
T16362C (P=0.006), G16384A (P=0.042), G16392A (P=0.013), G16394A (P=0.013), and G16477A (P=0.013) variants
was found between the patients and the controls.
Conclusion The results indicated individuals with C16069T [odds ratio (OR): 2.048], T16126C (OR: 2.226), C16186T
(OR: 3.586), G16274A (OR: 4.831), C16355T (OR: 7.322), and T16362C (OR: 6.682) variants with an OR more than
one are probably associated with a brain tumor. However, given the multifactorial nature of cancer, more investigation
needs to be done to confirm this association.
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Affiliation(s)
- Donya Altafi
- Molecular Biology Department, NourDanesh Institute of Higher Education, Esfahan, Iran. Electronic Address:
| | - Soha Sadeghi
- Molecular Biology Department, NourDanesh Institute of Higher Education, Esfahan, Iran
| | - Hamed Hojatian
- Molecular Biology Department, NourDanesh Institute of Higher Education, Esfahan, Iran
| | - Maryam Torabi Afra
- Molecular Biology Department, NourDanesh Institute of Higher Education, Esfahan, Iran
| | | | - Mojtaba Gorji
- Department of Hematology and Oncology, Lorestan Medical University, Lorestan, Iran
| | - Massoud Houshmand
- Department of Medical Genetics, National Institutes for Genetic Engineering and Biotechnology, Tehran, Iran.,Research Center, Knowledge University, Erbil, Kurdistan Region, Iraq.Electronic Address:
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Kamfar S, Alavian SM, Hasrak K, Houshmand M, Seifi Zarei B, Khalaj A, Homaunpur F, Saidijam M. Analysis of Mitochondrial 4977-bp Deletion and D-Loop Variation in Iranian Non-Alcoholic Fatty Liver Disease Patients. HEPATITIS MONTHLY 2019; In Press. [DOI: 10.5812/hepatmon.84553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
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Rodrigues-Antunes S, Borges BN. Alterations in mtDNA, gastric carcinogenesis and early diagnosis. Mitochondrial DNA A DNA Mapp Seq Anal 2018; 30:226-233. [DOI: 10.1080/24701394.2018.1475478] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- S. Rodrigues-Antunes
- Laboratório de Biologia Molecular “Francisco Mauro Salzano”, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Brazil
| | - B. N. Borges
- Laboratório de Biologia Molecular “Francisco Mauro Salzano”, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Brazil
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Falah M, Farhadi M, Kamrava SK, Mahmoudian S, Daneshi A, Balali M, Asghari A, Houshmand M. Association of genetic variations in the mitochondrial DNA control region with presbycusis. Clin Interv Aging 2017; 12:459-465. [PMID: 28424544 PMCID: PMC5344408 DOI: 10.2147/cia.s123278] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Background The prominent role of mitochondria in the generation of reactive oxygen species, cell death, and energy production contributes to the importance of this organelle in the intracellular mechanism underlying the progression of the common sensory disorder of the elderly, presbycusis. Reduced mitochondrial DNA (mtDNA) gene expression and coding region variation have frequently been reported as being associated with the development of presbycusis. The mtDNA control region regulates gene expression and replication of the genome of this organelle. To comprehensively understand of the role of mitochondria in the progression of presbycusis, we compared variations in the mtDNA control region between subjects with presbycusis and controls. Methods A total of 58 presbycusis patients and 220 control subjects were enrolled in the study after examination by the otolaryngologist and audiology tests. Variations in the mtDNA control region were investigated by polymerase chain reaction and Sanger sequencing. Results A total of 113 sequence variants were observed in mtDNA, and variants were detected in 100% of patients, with 84% located in hypervariable regions. The frequencies of the variants, 16,223 C>T, 16,311 T>C, 16,249 T>C, and 15,954 A>C, were significantly different between presbycusis and control subjects. Conclusion The statistically significant difference in the frequencies of four nucleotide variants in the mtDNA control region of presbycusis patients and controls is in agreement with previous experimental evidence and supports the role of mitochondria in the intracellular mechanism underlying presbycusis development. Moreover, these variants have potential as diagnostic markers for individuals at a high risk of developing presbycusis. The data also suggest the possible presence of changes in the mtDNA control region in presbycusis, which could alter regulatory factor binding sites and influence mtDNA gene expression and copy number.
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Affiliation(s)
- Masoumeh Falah
- ENT and Head & Neck Research Center and Department, Iran University of Medical Sciences, Tehran, Iran
| | - Mohammad Farhadi
- ENT and Head & Neck Research Center and Department, Iran University of Medical Sciences, Tehran, Iran
| | - Seyed Kamran Kamrava
- ENT and Head & Neck Research Center and Department, Iran University of Medical Sciences, Tehran, Iran
| | - Saeid Mahmoudian
- ENT and Head & Neck Research Center and Department, Iran University of Medical Sciences, Tehran, Iran
| | - Ahmad Daneshi
- ENT and Head & Neck Research Center and Department, Iran University of Medical Sciences, Tehran, Iran
| | - Maryam Balali
- ENT and Head & Neck Research Center and Department, Iran University of Medical Sciences, Tehran, Iran
| | - Alimohamad Asghari
- Skull Base Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Massoud Houshmand
- ENT and Head & Neck Research Center and Department, Iran University of Medical Sciences, Tehran, Iran.,Department of Medical Genetics, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran
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Mishra M, Kowluru RA. Retinal mitochondrial DNA mismatch repair in the development of diabetic retinopathy, and its continued progression after termination of hyperglycemia. Invest Ophthalmol Vis Sci 2014; 55:6960-7. [PMID: 25249609 DOI: 10.1167/iovs.14-15020] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Mitochondrial DNA (mtDNA) is damaged in the retina in diabetes, and mitochondria copy numbers are decreased. The displacement-loop (D-loop) of the mtDNA, the region with transcription/replication elements, experiences more damage than other regions of mtDNA. Our aim was to examine the role of DNA mismatch repair (MMR) in mitochondria homeostasis in diabetic retinopathy, and in its continued progression after cessation of hyperglycemia. METHODS Effect of hyperglycemia on sequence variants in the D-loop region was investigated in retinal endothelial cells and in the retina from streptozotocin-induced diabetic rats using mismatch-specific surveyor nuclease. The role of MMR machinery in mtDNA damage and mitochondrial respiration was investigated in retinal endothelial cells overexpressing Mlh1, an MMR enzyme mainly associated with mtDNA polymerase gamma, or Msh2 (associated with nuclear polymerase beta). RESULTS Hyperglycemia increased sequence variants in the D-loop region. While overexpression of Mlh1 in endothelial cells ameliorated glucose-induced increase in D-loop sequence variants, decrease in respiration rate and increase in apoptosis, overexpression of Msh2 did not protect the mitochondria damage. Termination of hyperglycemia failed to reverse decrease in MMR enzymes and increase in D-loop sequence variants. CONCLUSIONS Due to a compromised MMR system, the sequence variants in the D-loop region were not repaired, and that resulted in impaired mtDNA transcription. Mitochondria become dysfunctional, and they continued to be dysfunctional even after hyperglycemia was terminated, contributing to the development, and progression of diabetic retinopathy. Thus, strategies targeting mitochondrial MMR machinery could help maintain mitochondria homeostasis, and inhibit the development of diabetic retinopathy and its continued progression.
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Affiliation(s)
- Manish Mishra
- Kresge Eye Institute, Wayne State University, Detroit, Michigan, United States
| | - Renu A Kowluru
- Kresge Eye Institute, Wayne State University, Detroit, Michigan, United States
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