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Felipe Souza E Silva L, Siena Dos Santos A, Mayumi Yuzawa J, Luiz de Barros Torresi J, Ziroldo A, Rosado Rosenstock T. SIRTUINS MODULATORS COUNTERACT MITOCHONDRIAL DYSFUNCTION IN CELLULAR MODELS OF HYPOXIA: RELEVANCE TO SCHIZOPHRENIA. Neuroscience 2023:S0306-4522(23)00200-2. [PMID: 37169164 DOI: 10.1016/j.neuroscience.2023.04.027] [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: 10/24/2022] [Revised: 04/16/2023] [Accepted: 04/27/2023] [Indexed: 05/13/2023]
Abstract
Schizophrenia (SZ) is a neurodevelopmental-associated disorder strongly related to environmental factors, such as hypoxia. Because there is no cure for SZ or any pharmacological approach that could revert hypoxia-induced cellular damages, we evaluated whether modulators of sirtuins could abrogate hypoxia-induced mitochondrial deregulation as a neuroprotective strategy. Firstly, astrocytes from control (Wistar) and Spontaneously Hypertensive Rats (SHR), a model of both SZ and neonatal hypoxia, were submitted to chemical hypoxia. Then, cells were exposed to different concentrations of Nicotinamide (NAM), Resveratrol (Resv), and Sirtinol (Sir) for 48hrs. Our data indicate that sirtuins modulation reduces cell death increasing the acetylation of histone 3. This outcome is related to the rescue of loss of mitochondrial membrane potential, changes in mitochondrial calcium buffering capacity, decreased O2-• levels and increased expression of metabolic regulators (Nrf-1 and Nfe2l2) and mitochondrial content. Such findings are relevant not only for hypoxia-associated conditions, named pre-eclampsia but also for SZ since prenatal hypoxia is a relevant environmental factor related to this burdensome neuropsychiatric disorder.
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Affiliation(s)
- Luiz Felipe Souza E Silva
- Department of Pharmacology, Institute of Biomedical Science, University of São Paulo, São Paulo, Brazil
| | - Amanda Siena Dos Santos
- Department of Pharmacology, Institute of Biomedical Science, University of São Paulo, São Paulo, Brazil
| | - Jessica Mayumi Yuzawa
- Department of Physiological Science, Santa Casa de São Paulo School of Medical Science, São Paulo, Brazil
| | | | - Alan Ziroldo
- Department of Physiological Science, Santa Casa de São Paulo School of Medical Science, São Paulo, Brazil
| | - Tatiana Rosado Rosenstock
- Department of Pharmacology, Institute of Biomedical Science, University of São Paulo, São Paulo, Brazil; Dept. of Bioscience, In-vitro Neuroscience, Sygnature Discovery, Nottingham, United Kingdom.
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Guo J, Ye X, Zhao Y, Huang D, Wu Q, Ihsan A, Wang X. NRF-2α and mitophagy underlie enhanced mitochondrial functions and biogenesis induced by T-2 toxin in GH3 cells. Food Chem Toxicol 2023; 174:113687. [PMID: 36863559 DOI: 10.1016/j.fct.2023.113687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 02/16/2023] [Accepted: 02/20/2023] [Indexed: 03/04/2023]
Abstract
T-2 toxin is a natural contaminant in grain cereals produced by species of Fusarium. Studies indicate that T-2 toxin can positively affect mitochondrial function, but the underlying mechanism is unclear. In this study, we examined the role of nuclear respiratory factor 2α (NRF-2α) in T-2 toxin-activated mitochondrial biogenesis and the direct target genes of NRF-2α. Furthermore, we investigated T-2 toxin-induced autophagy and mitophagy, and the role of mitophagy in changes in mitochondrial function and apoptosis. It was found that T-2 toxin significantly increased NRF-2α levels and nuclear localization of NRF-2α was induced. NRF-2α deletion significantly increased the production of reactive oxygen species (ROS), abrogated T-2 toxin-induced increases in ATP and mitochondrial complex I activity, and inhibited the mitochondrial DNA copy number. Meanwhile, With chromatin immunoprecipitation sequencing (ChIP-Seq), various novel NRF-2α target genes were identified, such as mitochondrial iron-sulphur subunits (Ndufs 3,7) and mitochondrial transcription factors (Tfam, Tfb1m, and Tfb2m). Some target genes were also involved in mitochondrial fusion and fission (Drp1), mitochondrial translation (Yars2) and splicing (Ddx55), and mitophagy. Further studies showed that T-2 toxin induced Atg5 dependent autophagy and Atg5/PINK1-dependent mitophagy. In addition, mitophagy defects increase ROS production, inhibit ATP levels and the expression of genes related to mitochondrial dynamics, and promote apoptosis in the presence of T-2 toxins. Altogether, these results suggest that NRF-2α plays a critical role in promoting mitochondrial function and biogenesis through regulation of mitochondrial genes, and, interestingly, mitophagy caused by T-2 toxin positively affected mitochondrial function and protected cell survival against T-2 toxin.
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Affiliation(s)
- Jingchao Guo
- National Reference Laboratory of Veterinary Drug Residues (HZAU) and MAO Key Laboratory for Detection of Veterinary Drug Residues, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Xiaochun Ye
- National Reference Laboratory of Veterinary Drug Residues (HZAU) and MAO Key Laboratory for Detection of Veterinary Drug Residues, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Yongxia Zhao
- MOA Laboratory for Risk Assessment of Quality and Safety of Livestock and Poultry Products, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Deyu Huang
- MOA Laboratory for Risk Assessment of Quality and Safety of Livestock and Poultry Products, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Qinghua Wu
- College of Life Science, Institute of Biomedicine, Yangtze University, Jingzhou, 434025, China
| | - Awais Ihsan
- Department of Biosciences, COMSATS University Islamabad, Sahiwal campus, Pakistan
| | - Xu Wang
- National Reference Laboratory of Veterinary Drug Residues (HZAU) and MAO Key Laboratory for Detection of Veterinary Drug Residues, Huazhong Agricultural University, Wuhan, Hubei, 430070, China; MOA Laboratory for Risk Assessment of Quality and Safety of Livestock and Poultry Products, Huazhong Agricultural University, Wuhan, Hubei, 430070, China.
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Dasgupta D, Mahadev Bhat S, Price AL, Delmotte P, Sieck GC. Molecular Mechanisms Underlying TNFα-Induced Mitochondrial Biogenesis in Human Airway Smooth Muscle. Int J Mol Sci 2023; 24:5788. [PMID: 36982859 PMCID: PMC10055892 DOI: 10.3390/ijms24065788] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 03/10/2023] [Accepted: 03/15/2023] [Indexed: 03/22/2023] Open
Abstract
Proinflammatory cytokines such as TNFα mediate airway inflammation. Previously, we showed that TNFα increases mitochondrial biogenesis in human ASM (hASM) cells, which is associated with increased PGC1α expression. We hypothesized that TNFα induces CREB and ATF1 phosphorylation (pCREBS133 and pATF1S63), which transcriptionally co-activate PGC1α expression. Primary hASM cells were dissociated from bronchiolar tissue obtained from patients undergoing lung resection, cultured (one-three passages), and then differentiated by serum deprivation (48 h). hASM cells from the same patient were divided into two groups: TNFα (20 ng/mL) treated for 6 h and untreated controls. Mitochondria were labeled using MitoTracker green and imaged using 3D confocal microscopy to determine mitochondrial volume density. Mitochondrial biogenesis was assessed based on relative mitochondrial DNA (mtDNA) copy number determined by quantitative real-time PCR (qPCR). Gene and/or protein expression of pCREBS133, pATF1S63, PCG1α, and downstream signaling molecules (NRFs, TFAM) that regulate transcription and replication of the mitochondrial genome, were determined by qPCR and/or Western blot. TNFα increased mitochondrial volume density and mitochondrial biogenesis in hASM cells, which was associated with an increase in pCREBS133, pATF1S63 and PCG1α expression, with downstream transcriptional activation of NRF1, NRF2, and TFAM. We conclude that TNFα increases mitochondrial volume density in hASM cells via a pCREBS133/pATF1S63/PCG1α-mediated pathway.
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Affiliation(s)
| | | | | | | | - Gary C. Sieck
- Department of Physiology & Biomedical Engineering, Mayo Clinic, Rochester, MN 55905, USA
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Li D, Yuan X, Dong S, Al-Dhamin Z, Du J, Fu N, Nan Y. Heme oxygenase-1 prevents non-alcoholic steatohepatitis through modulating mitochondrial quality control. Acta Physiol (Oxf) 2023; 237:e13918. [PMID: 36602456 DOI: 10.1111/apha.13918] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 10/19/2022] [Accepted: 01/02/2023] [Indexed: 01/06/2023]
Abstract
AIM Nonalcoholic steatohepatitis (NASH) is a severe form of nonalcoholic fatty liver disease (NAFLD) and lacks effective treatment options. Heme oxygenase-1 (HO-1) is a critical defense against oxidative stress and inflammation in the liver injury. This study aims to investigate the protective role and underlying mechanisms of HO-1 in NASH pathogenesis. METHODS The hepatocyte-specific HO-1 knockout (HO-1HEPKO ) mice on a C57BL/6J background (HO-1fl/fl /Alb-Cre) were generated and fed a high-fat/western-style diet (HFD) or methionine-choline-deficient diet (MCD). Changes in mitochondrial ultrastructure were observed by transmission electron microscopy and confocal microscopy. A mitochondrial PCR array was used to identify the crucial genes associated with mitochondrial dysfunction. RESULTS Hepatocyte-specific HO-1HEPKO mice developed steatohepatitis with severe steatosis, ballooning, and necroinflammation. Dysregulated hepatic expression of mitochondria-related proteins, including DRP1, Tomm20, MFN1 and MFN2 were detected in NASH animals. Ultrastructural mitochondrial damage was observed in HO-1HEPKO mice. Mitochondrial dysfunction was recapitulated in HO-1-knockdown cells in vitro, as evidenced by decreased membrane potential, reduced ATP content, and mtDNA damage. Conversely, HO-1 overexpression restored these changes in vitro. Mechanistically, HO-1 deficiency reduced the inhibitory effect on Tomm20, leading to mitochondrial dysfunction, and thereby causing steatohepatitis. CONCLUSIONS HO-1 attenuates diet-induced steatohepatitis by preventing mitochondrial dysfunction, indicating that HO-1 may constitute a potential therapeutic target for NASH.
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Affiliation(s)
- Dongdong Li
- Department of Traditional and Western Medical Hepatology, Third Hospital of Hebei Medical University, Shijiazhuang, China
- Hebei Provincial Key Laboratory of Liver Fibrosis in Chronic Liver Diseases, Shijiazhuang, China
| | - Xiwei Yuan
- Department of Traditional and Western Medical Hepatology, Third Hospital of Hebei Medical University, Shijiazhuang, China
- Hebei Provincial Key Laboratory of Liver Fibrosis in Chronic Liver Diseases, Shijiazhuang, China
| | - Shiming Dong
- Department of Traditional and Western Medical Hepatology, Third Hospital of Hebei Medical University, Shijiazhuang, China
- Hebei Provincial Key Laboratory of Liver Fibrosis in Chronic Liver Diseases, Shijiazhuang, China
| | - Zaid Al-Dhamin
- Department of Traditional and Western Medical Hepatology, Third Hospital of Hebei Medical University, Shijiazhuang, China
- Hebei Provincial Key Laboratory of Liver Fibrosis in Chronic Liver Diseases, Shijiazhuang, China
| | - Jinghua Du
- Department of Traditional and Western Medical Hepatology, Third Hospital of Hebei Medical University, Shijiazhuang, China
- Hebei Provincial Key Laboratory of Liver Fibrosis in Chronic Liver Diseases, Shijiazhuang, China
| | - Na Fu
- Department of Traditional and Western Medical Hepatology, Third Hospital of Hebei Medical University, Shijiazhuang, China
- Hebei Provincial Key Laboratory of Liver Fibrosis in Chronic Liver Diseases, Shijiazhuang, China
| | - Yuemin Nan
- Department of Traditional and Western Medical Hepatology, Third Hospital of Hebei Medical University, Shijiazhuang, China
- Hebei Provincial Key Laboratory of Liver Fibrosis in Chronic Liver Diseases, Shijiazhuang, China
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Zhuang X, Ma J, Xu G, Sun Z. SHP-1 knockdown suppresses mitochondrial biogenesis and aggravates mitochondria-dependent apoptosis induced by all trans retinal through the STING/AMPK pathways. Mol Med 2022; 28:125. [PMID: 36273174 PMCID: PMC9588232 DOI: 10.1186/s10020-022-00554-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Accepted: 10/06/2022] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Oxidative stress-caused damage to the retinal pigment epithelium (RPE) underlies the onset and progression of age-related macular degeneration (AMD). Impaired mitochondrial biogenesis sensitizes RPE cells to mitochondrial dysfunction, energy insufficiency and death. Src-homology 2 domain-containing phosphatase (SHP)-1 is important in regulating immune responses and cell survival. However, its roles in cell survival are not always consistent. Until now, the effects of SHP-1 on RPE dysfunction, especially mitochondrial homeostasis, remain to be elucidated. We sought to clarify the effects of SHP-1 in RPE cells in response to atRAL-induced oxidative stress and determine the regulatory mechanisms involved. METHODS In the all trans retinal (atRAL)-induced oxidative stress model, we used the vector of lentivirus to knockdown the expression of SHP-1 in ARPE-19 cells. CCK-8 assay, Annexin V/PI staining and JC-1 staining were utilized to determine the cell viability, cell apoptosis and mitochondrial membrane potential. We also used immunoprecipitation to examine the ubiquitination modification of stimulator of interferon genes (STING) and its interaction with SHP-1. The expression levels of mitochondrial marker, proteins related to mitochondrial biogenesis, and signaling molecules involved were examined by western blotting analysis. RESULTS We found that SHP-1 knockdown predisposed RPE cells to apoptosis, aggravated mitochondrial damage, and repressed mitochondrial biogenesis after treatment with atRAL. Immunofluoresent staining and immunoprecipitation analysis confirmed that SHP-1 interacted with the endoplasmic reticulum-resident STING and suppressed K63-linked ubiquitination and activation of STING. Inhibition of STING with the specific antagonist H151 attenuated the effects of SHP-1 knockdown on mitochondrial biogenesis and oxidative damage. The adenosine monophosphate-activated protein kinase (AMPK) pathway acted as the crucial downstream target of STING and was involved in the regulatory processes. CONCLUSIONS These findings suggest that SHP-1 knockdown potentiates STING overactivation and represses mitochondrial biogenesis and cell survival, at least in part by blocking the AMPK pathway in RPE cells. Therefore, restoring mitochondrial health by regulating SHP-1 in RPE cells may be a potential therapeutic strategy for degenerative retinal diseases including AMD.
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Affiliation(s)
- Xiaonan Zhuang
- Department of Ophthalmology, Eye and ENT Hospital of Fudan University, 83 Fenyang Road, Shanghai, 200031, China
- Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia, Fudan University, Shanghai, China
| | - Jun Ma
- Eye Institute, Eye & ENT Hospital, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia, Fudan University, Shanghai, China
| | - Gezhi Xu
- Department of Ophthalmology, Eye and ENT Hospital of Fudan University, 83 Fenyang Road, Shanghai, 200031, China
- Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia, Fudan University, Shanghai, China
| | - Zhongcui Sun
- Department of Ophthalmology, Eye and ENT Hospital of Fudan University, 83 Fenyang Road, Shanghai, 200031, China.
- Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China.
- NHC Key Laboratory of Myopia, Fudan University, Shanghai, China.
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Lin YH, Lim SN, Chen CY, Chi HC, Yeh CT, Lin WR. Functional Role of Mitochondrial DNA in Cancer Progression. Int J Mol Sci 2022; 23:ijms23031659. [PMID: 35163579 PMCID: PMC8915179 DOI: 10.3390/ijms23031659] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 01/27/2022] [Accepted: 01/29/2022] [Indexed: 12/25/2022] Open
Abstract
Mitochondrial DNA (mtDNA) has been identified as a significant genetic biomarker in disease, cancer and evolution. Mitochondria function as modulators for regulating cellular metabolism. In the clinic, mtDNA variations (mutations/single nucleotide polymorphisms) and dysregulation of mitochondria-encoded genes are associated with survival outcomes among cancer patients. On the other hand, nuclear-encoded genes have been found to regulate mitochondria-encoded gene expression, in turn regulating mitochondrial homeostasis. These observations suggest that the crosstalk between the nuclear genome and mitochondrial genome is important for cellular function. Therefore, this review summarizes the significant mechanisms and functional roles of mtDNA variations (DNA level) and mtDNA-encoded genes (RNA and protein levels) in cancers and discusses new mechanisms of crosstalk between mtDNA and the nuclear genome.
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Affiliation(s)
- Yang-Hsiang Lin
- Liver Research Center, Linkou Chang Gung Memorial Hospital, Taoyuan 333, Taiwan;
| | - Siew-Na Lim
- Department of Neurology, Linkou Chang Gung Memorial Hospital, Taoyuan 333, Taiwan;
- College of Medicine, Chang Gung University, Taoyuan 333, Taiwan
| | - Cheng-Yi Chen
- Department of Cell Biology and Anatomy, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan;
| | - Hsiang-Cheng Chi
- Graduate Institute of Integrated Medicine, China Medical University, Taichung 404, Taiwan;
- Chinese Medicine Research Center, China Medical University, Taichung 404, Taiwan
| | - Chau-Ting Yeh
- Liver Research Center, Linkou Chang Gung Memorial Hospital, Taoyuan 333, Taiwan;
- College of Medicine, Chang Gung University, Taoyuan 333, Taiwan
- Department of Hepatology and Gastroenterology, Linkou Chang Gung Memorial Hospital, Taoyuan 333, Taiwan
- Molecular Medicine Research Center, Chang Gung University, Taoyuan 333, Taiwan
- Correspondence: (C.-T.Y.); (W.-R.L.); Tel./Fax: +886-3-3281200 (ext. 8102) (W.-R.L.)
| | - Wey-Ran Lin
- Liver Research Center, Linkou Chang Gung Memorial Hospital, Taoyuan 333, Taiwan;
- College of Medicine, Chang Gung University, Taoyuan 333, Taiwan
- Department of Hepatology and Gastroenterology, Linkou Chang Gung Memorial Hospital, Taoyuan 333, Taiwan
- Correspondence: (C.-T.Y.); (W.-R.L.); Tel./Fax: +886-3-3281200 (ext. 8102) (W.-R.L.)
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Kim JY, Zhou D, Cui XS. Bezafibrate prevents aging in in vitro-matured porcine oocytes. JOURNAL OF ANIMAL SCIENCE AND TECHNOLOGY 2021; 63:766-777. [PMID: 34447954 PMCID: PMC8367403 DOI: 10.5187/jast.2021.e64] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 03/24/2021] [Accepted: 04/07/2021] [Indexed: 01/09/2023]
Abstract
Bezafibrate, a fibrate drug used as a lipid-lowering agent to treat
hyperlipidemia, is a pan-agonist of peroxisome proliferator-activated receptor
alpha. It can enhance mitochondrial fatty acid oxidation, oxidative
phosphorylation, and mitochondrial biogenesis. After ovulation, oocytes may get
arrested at the metaphase II (MII) stage until fertilization beyond optimal
timing, which is termed as post-ovulatory aging. Post-ovulatory aging is a
disease that degrades DNA, mitochondria, and oxidative system, and has a
negative impact on embryo development and quality; however, the impact of
bezafibrate during post-ovulatory aging has not been fully defined. In the
present study, we assessed the ability of bezafibrate to prevent the progression
of aging in in vitro conditions as well as the underlying
mechanisms in pigs. An appropriate concentration of this drug (50 μM) was
added, and then oxidative stress, reactive oxygen species downstream,
mitochondrial biogenesis, and mitochondrial function were analyzed via
immunofluorescence staining and real-time polymerase chain reaction. Bezafibrate
significantly alleviated reactive oxygen species and ameliorated glutathione
production simultaneously in oocytes and embryos. Moreover, it diminished H2A.X
and attenuated CASPASE 3 expression produced by oxidative stress in oocytes and
embryos. Furthermore, bezafibrate remarkably improved the mitochondrial function
and blastocyst quality as well as markedly reduced the mitochondria/TOM20 ratio
and mtDNA copy number. The elevated PARKIN level indicated that mitophagy was
induced by bezafibrate treatment after post-ovulatory aging. Collectively, these
results suggest that bezafibrate beneficially affects against porcine
post-ovulatory oocyte aging in porcine by its antioxidant property and
mitochondrial protection.
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Affiliation(s)
- Ju-Yeon Kim
- Department of Animal Sciences, Chungbuk National University, Cheongju 28644, Korea
| | - Dongjie Zhou
- Department of Animal Sciences, Chungbuk National University, Cheongju 28644, Korea
| | - Xiang-Shun Cui
- Department of Animal Sciences, Chungbuk National University, Cheongju 28644, Korea
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8
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Polansky H, Lori G. How microcompetition with latent viruses can cause α synuclein aggregation, mitochondrial dysfunction, and eventually Parkinson's disease. J Neurovirol 2021; 27:52-57. [PMID: 33405201 DOI: 10.1007/s13365-020-00929-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: 03/18/2020] [Revised: 10/19/2020] [Accepted: 11/19/2020] [Indexed: 11/24/2022]
Abstract
The cause of most Parkinson's disease cases is unknown. However, it is well documented that mitochondrial dysfunction and misfolded α synuclein aggregation are important cellular abnormalities associated with the disease. In this paper, we use the microcompetition model to show how latent viruses, which infect the central and peripheral nervous systems, can cause the observed mitochondrial dysfunction and excess α synuclein aggregation, and eventually, Parkinson's disease.
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Affiliation(s)
- Hanan Polansky
- The Center for the Biology of Chronic Disease (CBCD), 3 Germay Dr, Wilmington, DE, 19804, USA.
| | - Gillad Lori
- The Center for the Biology of Chronic Disease (CBCD), 3 Germay Dr, Wilmington, DE, 19804, USA
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Krämer L, Groh C, Herrmann JM. The proteasome: friend and foe of mitochondrial biogenesis. FEBS Lett 2020; 595:1223-1238. [PMID: 33249599 DOI: 10.1002/1873-3468.14010] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 10/26/2020] [Accepted: 11/01/2020] [Indexed: 01/06/2023]
Abstract
Most mitochondrial proteins are synthesized in the cytosol and subsequently translocated as unfolded polypeptides into mitochondria. Cytosolic chaperones maintain precursor proteins in an import-competent state. This post-translational import reaction is under surveillance of the cytosolic ubiquitin-proteasome system, which carries out several distinguishable activities. On the one hand, the proteasome degrades nonproductive protein precursors from the cytosol and nucleus, import intermediates that are stuck in mitochondrial translocases, and misfolded or damaged proteins from the outer membrane and the intermembrane space. These surveillance activities of the proteasome are essential for mitochondrial functionality, as well as cellular fitness and survival. On the other hand, the proteasome competes with mitochondria for nonimported cytosolic precursor proteins, which can compromise mitochondrial biogenesis. In order to balance the positive and negative effects of the cytosolic protein quality control system on mitochondria, mitochondrial import efficiency directly regulates the capacity of the proteasome via transcription factor Rpn4 in yeast and nuclear respiratory factor (Nrf) 1 and 2 in animal cells. In this review, we provide a thorough overview of how the proteasome regulates mitochondrial biogenesis.
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Affiliation(s)
- Lena Krämer
- Cell Biology, University of Kaiserslautern, Germany
| | - Carina Groh
- Cell Biology, University of Kaiserslautern, Germany
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10
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Mitochondrial biogenesis in organismal senescence and neurodegeneration. Mech Ageing Dev 2020; 191:111345. [DOI: 10.1016/j.mad.2020.111345] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 08/17/2020] [Accepted: 08/27/2020] [Indexed: 12/19/2022]
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11
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Torma F, Gombos Z, Jokai M, Berkes I, Takeda M, Mimura T, Radak Z, Gyori F. The roles of microRNA in redox metabolism and exercise-mediated adaptation. JOURNAL OF SPORT AND HEALTH SCIENCE 2020; 9:405-414. [PMID: 32780693 PMCID: PMC7498669 DOI: 10.1016/j.jshs.2020.03.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2019] [Revised: 01/03/2020] [Accepted: 02/10/2020] [Indexed: 05/10/2023]
Abstract
MicroRNAs (miRs) are small regulatory RNA transcripts capable of post-transcriptional silencing of mRNA messages by entering a cellular bimolecular apparatus called RNA-induced silencing complex. miRs are involved in the regulation of cellular processes producing, eliminating or repairing the damage caused by reactive oxygen species, and they are active players in redox homeostasis. Increased mitochondrial biogenesis, function and hypertrophy of skeletal muscle are important adaptive responses to regular exercise. In the present review, we highlight some of the redox-sensitive regulatory roles of miRs.
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Affiliation(s)
- Ferenc Torma
- Research Center of Molecular Exercise Science, University of Physical Education, Budapest 1123, Hungary
| | - Zoltan Gombos
- Research Center of Molecular Exercise Science, University of Physical Education, Budapest 1123, Hungary
| | - Matyas Jokai
- Research Center of Molecular Exercise Science, University of Physical Education, Budapest 1123, Hungary
| | - Istvan Berkes
- Research Center of Molecular Exercise Science, University of Physical Education, Budapest 1123, Hungary
| | - Masaki Takeda
- Faculty of Health and Sports Science, Doshisha University, Kyotanabe 610-0394, Japan
| | - Tatsuya Mimura
- Faculty of Sport and Health Sciences, Osaka Sangyo University, Osaka 573-1004, Japan
| | - Zsolt Radak
- Research Center of Molecular Exercise Science, University of Physical Education, Budapest 1123, Hungary; Faculty of Sport Sciences, Waseda University, Tokorozawa, Saitama 359-1192, Japan; Institute of Physical Education and Sport Science, JGYPK, University of Szeged, Szeged 6726, Hungary.
| | - Ferenc Gyori
- Institute of Physical Education and Sport Science, JGYPK, University of Szeged, Szeged 6726, Hungary
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12
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Trcka F, Durech M, Vankova P, Vandova V, Simoncik O, Kavan D, Vojtesek B, Muller P, Man P. The interaction of the mitochondrial protein importer TOMM34 with HSP70 is regulated by TOMM34 phosphorylation and binding to 14-3-3 adaptors. J Biol Chem 2020; 295:8928-8944. [PMID: 32371396 PMCID: PMC7335785 DOI: 10.1074/jbc.ra120.012624] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2020] [Revised: 04/28/2020] [Indexed: 01/17/2023] Open
Abstract
Translocase of outer mitochondrial membrane 34 (TOMM34) orchestrates heat shock protein 70 (HSP70)/HSP90-mediated transport of mitochondrial precursor proteins. Here, using in vitro phosphorylation and refolding assays, analytical size-exclusion chromatography, and hydrogen/deuterium exchange MS, we found that TOMM34 associates with 14-3-3 proteins after its phosphorylation by protein kinase A (PKA). PKA preferentially targeted two serine residues in TOMM34: Ser93 and Ser160, located in the tetratricopeptide repeat 1 (TPR1) domain and the interdomain linker, respectively. Both of these residues were necessary for efficient 14-3-3 protein binding. We determined that phosphorylation-induced structural changes in TOMM34 are further augmented by binding to 14-3-3, leading to destabilization of TOMM34's secondary structure. We also observed that this interaction with 14-3-3 occludes the TOMM34 interaction interface with ATP-bound HSP70 dimers, which leaves them intact and thereby eliminates an inhibitory effect of TOMM34 on HSP70-mediated refolding in vitro In contrast, we noted that TOMM34 in complex with 14-3-3 could bind HSP90. Both TOMM34 and 14-3-3 participated in cytosolic precursor protein transport mediated by the coordinated activities of HSP70 and HSP90. Our results provide important insights into how PKA-mediated phosphorylation and 14-3-3 binding regulate the availability of TOMM34 for its interaction with HSP70.
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Affiliation(s)
- Filip Trcka
- Regional Centre for Applied Molecular Oncology, Masaryk Memorial Cancer Institute, Brno, Czech Republic
| | - Michal Durech
- Regional Centre for Applied Molecular Oncology, Masaryk Memorial Cancer Institute, Brno, Czech Republic
| | - Pavla Vankova
- BioCeV, Institute of Microbiology of the Czech Academy of Sciences, Vestec, Czech Republic; Department of Biochemistry, Faculty of Science, Charles University, Prague, Czech Republic
| | - Veronika Vandova
- Regional Centre for Applied Molecular Oncology, Masaryk Memorial Cancer Institute, Brno, Czech Republic
| | - Oliver Simoncik
- Regional Centre for Applied Molecular Oncology, Masaryk Memorial Cancer Institute, Brno, Czech Republic
| | - Daniel Kavan
- BioCeV, Institute of Microbiology of the Czech Academy of Sciences, Vestec, Czech Republic; Department of Biochemistry, Faculty of Science, Charles University, Prague, Czech Republic
| | - Borivoj Vojtesek
- Regional Centre for Applied Molecular Oncology, Masaryk Memorial Cancer Institute, Brno, Czech Republic
| | - Petr Muller
- Regional Centre for Applied Molecular Oncology, Masaryk Memorial Cancer Institute, Brno, Czech Republic.
| | - Petr Man
- BioCeV, Institute of Microbiology of the Czech Academy of Sciences, Vestec, Czech Republic.
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Yan X, Wang B, Hu Y, Wang S, Zhang X. Abnormal Mitochondrial Quality Control in Neurodegenerative Diseases. Front Cell Neurosci 2020; 14:138. [PMID: 32655368 PMCID: PMC7324542 DOI: 10.3389/fncel.2020.00138] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 04/22/2020] [Indexed: 12/12/2022] Open
Abstract
Neurodegenerative diseases, including Alzheimer’s, Parkinson’s, Huntington’s, and amyotrophic lateral sclerosis, are characterized by a progressive loss of selective neuron subtypes in the central nervous system (CNS). Although various factors account for the initiation and development of these diseases, accumulating evidence shows that impaired mitochondrial function is a prominent and common mechanism. Mitochondria play a critical role in neurons and are involved in energy production, cellular metabolism regulation, intracellular calcium homeostasis, immune responses, and cell fate. Thus, cells in the CNS heavily rely on mitochondrial integrity. Many aspects of mitochondrial dysfunction are manifested in neurodegenerative diseases, including aberrant mitochondrial quality control (mitoQC), mitochondrial-driven inflammation, and bioenergetic defects. Herein, we briefly summarize the molecular basis of mitoQC, including mitochondrial proteostasis, biogenesis, dynamics, and organelle degradation. We also focus on the research, to date, regarding aberrant mitoQC and mitochondrial-driven inflammation in several common neurodegenerative diseases. In addition, we outline novel therapeutic strategies that target aberrant mitoQC in neurodegenerative diseases.
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Affiliation(s)
- Xu Yan
- The VIP Department, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, China
| | - Biyao Wang
- The VIP Department, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, China
| | - Yue Hu
- The VIP Department, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, China
| | - Sijian Wang
- Center of Implant Dentistry, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, China
| | - Xinwen Zhang
- Center of Implant Dentistry, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, China
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Yan X, Wang B, Hu Y, Wang S, Zhang X. Abnormal Mitochondrial Quality Control in Neurodegenerative Diseases. Front Cell Neurosci 2020; 14:138. [PMID: 32655368 DOI: 10.3389/fncel.2020.00138/xml/nlm] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 04/22/2020] [Indexed: 05/25/2023] Open
Abstract
Neurodegenerative diseases, including Alzheimer's, Parkinson's, Huntington's, and amyotrophic lateral sclerosis, are characterized by a progressive loss of selective neuron subtypes in the central nervous system (CNS). Although various factors account for the initiation and development of these diseases, accumulating evidence shows that impaired mitochondrial function is a prominent and common mechanism. Mitochondria play a critical role in neurons and are involved in energy production, cellular metabolism regulation, intracellular calcium homeostasis, immune responses, and cell fate. Thus, cells in the CNS heavily rely on mitochondrial integrity. Many aspects of mitochondrial dysfunction are manifested in neurodegenerative diseases, including aberrant mitochondrial quality control (mitoQC), mitochondrial-driven inflammation, and bioenergetic defects. Herein, we briefly summarize the molecular basis of mitoQC, including mitochondrial proteostasis, biogenesis, dynamics, and organelle degradation. We also focus on the research, to date, regarding aberrant mitoQC and mitochondrial-driven inflammation in several common neurodegenerative diseases. In addition, we outline novel therapeutic strategies that target aberrant mitoQC in neurodegenerative diseases.
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Affiliation(s)
- Xu Yan
- The VIP Department, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, China
| | - Biyao Wang
- The VIP Department, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, China
| | - Yue Hu
- The VIP Department, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, China
| | - Sijian Wang
- Center of Implant Dentistry, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, China
| | - Xinwen Zhang
- Center of Implant Dentistry, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, China
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Pfannschmidt T, Terry MJ, Van Aken O, Quiros PM. Retrograde signals from endosymbiotic organelles: a common control principle in eukaryotic cells. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190396. [PMID: 32362267 DOI: 10.1098/rstb.2019.0396] [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: 12/23/2022] Open
Abstract
Endosymbiotic organelles of eukaryotic cells, the plastids, including chloroplasts and mitochondria, are highly integrated into cellular signalling networks. In both heterotrophic and autotrophic organisms, plastids and/or mitochondria require extensive organelle-to-nucleus communication in order to establish a coordinated expression of their own genomes with the nuclear genome, which encodes the majority of the components of these organelles. This goal is achieved by the use of a variety of signals that inform the cell nucleus about the number and developmental status of the organelles and their reaction to changing external environments. Such signals have been identified in both photosynthetic and non-photosynthetic eukaryotes (known as retrograde signalling and retrograde response, respectively) and, therefore, appear to be universal mechanisms acting in eukaryotes of all kingdoms. In particular, chloroplasts and mitochondria both harbour crucial redox reactions that are the basis of eukaryotic life and are, therefore, especially susceptible to stress from the environment, which they signal to the rest of the cell. These signals are crucial for cell survival, lifespan and environmental adjustment, and regulate quality control and targeted degradation of dysfunctional organelles, metabolic adjustments, and developmental signalling, as well as induction of apoptosis. The functional similarities between retrograde signalling pathways in autotrophic and non-autotrophic organisms are striking, suggesting the existence of common principles in signalling mechanisms or similarities in their evolution. Here, we provide a survey for the newcomers to this field of research and discuss the importance of retrograde signalling in the context of eukaryotic evolution. Furthermore, we discuss commonalities and differences in retrograde signalling mechanisms and propose retrograde signalling as a general signalling mechanism in eukaryotic cells that will be also of interest for the specialist. This article is part of the theme issue 'Retrograde signalling from endosymbiotic organelles'.
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Affiliation(s)
- Thomas Pfannschmidt
- Institute of Botany, Plant Physiology, Leibniz University Hannover, Herrenhäuser Straße 2, 30419 Hannover, Germany
| | - Matthew J Terry
- School of Biological Sciences, University of Southampton, Southampton SO17 1BJ, UK
| | - Olivier Van Aken
- Department of Biology, Lund University, Sölvegatan 35, 223 62 Lund, Sweden
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16
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Zilocchi M, Fasano M, Alberio T. Mitochondrial Proteins in the Development of Parkinson’s Disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1158:17-44. [DOI: 10.1007/978-981-13-8367-0_2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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17
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Prieto-Ruiz JA, Alis R, García-Benlloch S, Sáez-Atiénzar S, Ventura I, Hernández-Andreu JM, Hernández-Yago J, Blesa JR. Expression of the human TIMM23 and TIMM23B genes is regulated by the GABP transcription factor. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2018; 1861:80-94. [PMID: 29413900 DOI: 10.1016/j.bbagrm.2018.01.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2017] [Revised: 01/10/2018] [Accepted: 01/10/2018] [Indexed: 12/26/2022]
Abstract
The TIM23 protein is a key component of the mitochondrial import machinery in yeast and mammals. TIM23 is the channel-forming subunit of the translocase of the inner mitochondrial membrane (TIM23) complex, which mediates preprotein translocation across the mitochondrial inner membrane. In this paper, we aimed to characterize the promoter region of the highly similar human TIM23 orthologs: TIMM23 and TIMM23B. Bioinformatic analysis revealed putative sites for the GA-binding protein (GABP) and the recombination signal binding protein for immunoglobulin kappa J (RBPJ) transcription factors in both promoters. Luciferase reporter assays, electrophoretic mobility shift assays, and chromatin immunoprecipitation experiments showed three functional sites for GABP and one functional site for RBPJ in both promoters. Moreover, silencing of GABPA, the gene encoding the DNA-binding subunit of the GABP transcription factor, resulted in reduced expression of TIMM23 and TIMM23B. Our results show an essential role of GABP in activating TIMM23 expression. More broadly, they suggest that physiological signals involved in activating mitochondrial biogenesis and oxidative function also enhance the transcription but not the protein level of TIMM23, which is essential for maintaining mitochondrial function and homeostasis.
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Affiliation(s)
- Jesús A Prieto-Ruiz
- Facultad de Medicina, Universidad Católica de Valencia San Vicente Mártir, c/ Quevedo 2, 46001, Valencia, Spain; Instituto Universitario de Investigación Dr. Viña Giner, Universidad Católica de Valencia San Vicente Mártir, c/ Quevedo 2, 46001, Valencia, Spain.
| | - Rafael Alis
- Facultad de Medicina, Universidad Católica de Valencia San Vicente Mártir, c/ Quevedo 2, 46001, Valencia, Spain; Instituto Universitario de Investigación Dr. Viña Giner, Universidad Católica de Valencia San Vicente Mártir, c/ Quevedo 2, 46001, Valencia, Spain.
| | - Sandra García-Benlloch
- Facultad de Medicina, Universidad Católica de Valencia San Vicente Mártir, c/ Quevedo 2, 46001, Valencia, Spain; Instituto Universitario de Investigación Dr. Viña Giner, Universidad Católica de Valencia San Vicente Mártir, c/ Quevedo 2, 46001, Valencia, Spain.
| | - Sara Sáez-Atiénzar
- Facultad de Medicina, Universidad Católica de Valencia San Vicente Mártir, c/ Quevedo 2, 46001, Valencia, Spain; Instituto Universitario de Investigación Dr. Viña Giner, Universidad Católica de Valencia San Vicente Mártir, c/ Quevedo 2, 46001, Valencia, Spain.
| | - Ignacio Ventura
- Facultad de Medicina, Universidad Católica de Valencia San Vicente Mártir, c/ Quevedo 2, 46001, Valencia, Spain; Instituto Universitario de Investigación Dr. Viña Giner, Universidad Católica de Valencia San Vicente Mártir, c/ Quevedo 2, 46001, Valencia, Spain.
| | - José M Hernández-Andreu
- Facultad de Medicina, Universidad Católica de Valencia San Vicente Mártir, c/ Quevedo 2, 46001, Valencia, Spain; Instituto Universitario de Investigación Dr. Viña Giner, Universidad Católica de Valencia San Vicente Mártir, c/ Quevedo 2, 46001, Valencia, Spain.
| | - José Hernández-Yago
- Instituto Universitario de Investigación Dr. Viña Giner, Universidad Católica de Valencia San Vicente Mártir, c/ Quevedo 2, 46001, Valencia, Spain; Facultad de Veterinaria y Ciencias Experimentales, Universidad Católica de Valencia San Vicente Mártir, c/ Guillem de Castro 94, 46001, Valencia, Spain.
| | - José R Blesa
- Facultad de Medicina, Universidad Católica de Valencia San Vicente Mártir, c/ Quevedo 2, 46001, Valencia, Spain; Instituto Universitario de Investigación Dr. Viña Giner, Universidad Católica de Valencia San Vicente Mártir, c/ Quevedo 2, 46001, Valencia, Spain.
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Khalil B, Liévens JC. Mitochondrial quality control in amyotrophic lateral sclerosis: towards a common pathway? Neural Regen Res 2017; 12:1052-1061. [PMID: 28852382 PMCID: PMC5558479 DOI: 10.4103/1673-5374.211179] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/27/2017] [Indexed: 12/12/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disorder characterized by loss of upper and lower motor neurons. Different mechanisms contribute to the disease initiation and progression, including mitochondrial dysfunction which has been proposed to be a central determinant in ALS pathogenesis. Indeed, while mitochondrial defects have been mainly described in ALS-linked SOD1 mutants, it is now well established that mitochondria become also dysfunctional in other ALS conditions. In such context, the mitochondrial quality control system allows to restore normal functioning of mitochondria and to prevent cell death, by both eliminating and replacing damaged mitochondrial components or by degrading the entire organelle through mitophagy. Recent evidence shows that ALS-related genes interfere with the mitochondrial quality control system. This review highlights how ineffective mitochondrial quality control may render motor neurons defenseless towards the accumulating mitochondrial damage in ALS.
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Affiliation(s)
- Bilal Khalil
- Department of Neuroscience, Mayo Clinic Florida, Jacksonville, FL, USA
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Quirós PM, Mottis A, Auwerx J. Mitonuclear communication in homeostasis and stress. Nat Rev Mol Cell Biol 2016; 17:213-26. [PMID: 26956194 DOI: 10.1038/nrm.2016.23] [Citation(s) in RCA: 479] [Impact Index Per Article: 59.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Mitochondria participate in crucial cellular processes such as energy harvesting and intermediate metabolism. Although mitochondria possess their own genome--a vestige of their bacterial origins and endosymbiotic evolution--most mitochondrial proteins are encoded in the nucleus. The expression of the mitochondrial proteome hence requires tight coordination between the two genomes to adapt mitochondrial function to the ever-changing cellular milieu. In this Review, we focus on the pathways that coordinate the communication between mitochondria and the nucleus during homeostasis and mitochondrial stress. These pathways include nucleus-to-mitochondria (anterograde) and mitochondria-to-nucleus (retrograde) communication, mitonuclear feedback signalling and proteostasis regulation, the integrated stress response and non-cell-autonomous communication. We discuss how mitonuclear communication safeguards cellular and organismal fitness and regulates lifespan.
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Affiliation(s)
- Pedro M Quirós
- Laboratory for Integrative and Systems Physiology, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland
| | - Adrienne Mottis
- Laboratory for Integrative and Systems Physiology, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland
| | - Johan Auwerx
- Laboratory for Integrative and Systems Physiology, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland
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de Toro-Martín J, Guénard F, Tchernof A, Deshaies Y, Pérusse L, Hould FS, Lebel S, Marceau P, Vohl MC. Methylation quantitative trait loci within the TOMM20 gene are associated with metabolic syndrome-related lipid alterations in severely obese subjects. Diabetol Metab Syndr 2016; 8:55. [PMID: 27478511 PMCID: PMC4966599 DOI: 10.1186/s13098-016-0171-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 07/14/2016] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND The TOMM20 gene was previously identified as differentially expressed and methylated between severely obese subjects with and without metabolic syndrome (MS). Since metabolic complications do not affect all obese patients to the same extent, the aim of this study was to identify methylation quantitative trait loci (meQTL) potentially associated with MS-related complications within the TOMM20 locus. METHODS Methylation profiling, SNP genotyping and meQTL association tests (general linear models) were performed in a population of 48 severely obese subjects. Genotyping was extended to a larger population of 1720 severely obese subjects with or without MS, where genotype- and diplotype-based association tests were assessed by logistic regression. In silico analyses were performed using TRAP. RESULTS Four SNPs were identified as significant meQTLs for the differentially methylated site cg16490124. Individuals carrying rare alleles of rs4567344 (A > G) (P = 4.9 × 10(-2)) and rs11301 (T > C) (P = 5.9 × 10(-3)) showed decreased methylation levels at this site, whereas those carrying rare alleles of rs4551650 (T > C) (P = 3.5 × 10(-15)) and rs17523127 (C > G) (P = 3.5 × 10(-15)) exhibited a significant increase in methylation. rs4567344 and rs11301 were associated with increased susceptibility to exhibit high plasma triglycerides (TG ≥ 1.69 mmol/L), while rare alleles of rs4551650 and rs17523127 were significantly more represented in the low plasma total-C group (total-C ≤ 6.2 mmol/L). Haplotype reconstruction with the four meQTLs (rs4567344, rs11301, rs4551650, rs17523127) led to the identification of ten different diplotypes, with H1/H2 (GCGG/ACGG) exhibiting a nearly absence of methylation at cg16490124, and showing the highest risk of elevated plasma TG levels [OR = 2.03 (1.59-3.59)], a novel association with elevated LDL-cholesterol [OR = 1.86 (1.06-3.27)] and the complete inversion of the protective effect on total-C levels [OR = 2.03 (1.59-3.59)], especially in men. In silico analyses revealed that rs17523127 overlapped the CpG site cg16490124 and encompassed the core binding sites of the transcription factors Egr 1, 2 and 3, located within the TOMM20 promoter region. CONCLUSION This study demonstrates that TOMM20 SNPs associated with MS-related lipid alterations are meQTLs potentially exerting their action through a CpG methylation-dependent effect. The strength of the diplotype-based associations may denote a novel meQTL additive action and point to this locus as particularly relevant in the inter-individual variability observed in the metabolic profiles of obese subjects.
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Affiliation(s)
- Juan de Toro-Martín
- Institute of Nutrition and Functional Foods (INAF), Laval University, Québec, QC Canada
- School of Nutrition, Laval University, Québec, QC Canada
| | - Frédéric Guénard
- Institute of Nutrition and Functional Foods (INAF), Laval University, Québec, QC Canada
- School of Nutrition, Laval University, Québec, QC Canada
| | - André Tchernof
- School of Nutrition, Laval University, Québec, QC Canada
- Québec Heart and Lung Institute, Québec, QC Canada
| | - Yves Deshaies
- Québec Heart and Lung Institute, Québec, QC Canada
- Department of Medicine, Laval University, Québec, QC Canada
| | - Louis Pérusse
- Institute of Nutrition and Functional Foods (INAF), Laval University, Québec, QC Canada
- Department of Kinesiology, Laval University, Québec, QC Canada
| | | | - Stéfane Lebel
- Department of Surgery, Laval University, Québec, QC Canada
| | - Picard Marceau
- Department of Surgery, Laval University, Québec, QC Canada
| | - Marie-Claude Vohl
- Institute of Nutrition and Functional Foods (INAF), Laval University, Québec, QC Canada
- School of Nutrition, Laval University, Québec, QC Canada
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Bahat A, Perlberg S, Melamed-Book N, Isaac S, Eden A, Lauria I, Langer T, Orly J. Transcriptional activation of LON Gene by a new form of mitochondrial stress: A role for the nuclear respiratory factor 2 in StAR overload response (SOR). Mol Cell Endocrinol 2015; 408:62-72. [PMID: 25724481 DOI: 10.1016/j.mce.2015.02.022] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2014] [Revised: 02/19/2015] [Accepted: 02/19/2015] [Indexed: 01/19/2023]
Abstract
High output of steroid hormone synthesis in steroidogenic cells of the adrenal cortex and the gonads requires the expression of the steroidogenic acute regulatory protein (StAR) that facilitates cholesterol mobilization to the mitochondrial inner membrane where the CYP11A1/P450scc enzyme complex converts the sterol to the first steroid. Earlier studies have shown that StAR is active while pausing on the cytosolic face of the outer mitochondrial membrane while subsequent import of the protein into the matrix terminates the cholesterol mobilization activity. Consequently, during repeated activity cycles, high level of post-active StAR accumulates in the mitochondrial matrix. To prevent functional damage due to such protein overload effect, StAR is degraded by a sequence of three to four ATP-dependent proteases of the mitochondria protein quality control system, including LON and the m-AAA membranous proteases AFG3L2 and SPG7/paraplegin. Furthermore, StAR expression in both peri-ovulatory ovarian cells, or under ectopic expression in cell line models, results in up to 3-fold enrichment of the mitochondrial proteases and their transcripts. We named this novel form of mitochondrial stress as StAR overload response (SOR). To better understand the SOR mechanism at the transcriptional level we analyzed first the unexplored properties of the proximal promoter of the LON gene. Our findings suggest that the human nuclear respiratory factor 2 (NRF-2), also known as GA binding protein (GABP), is responsible for 88% of the proximal promoter activity, including the observed increase of transcription in the presence of StAR. Further studies are expected to reveal if common transcriptional determinants coordinate the SOR induced transcription of all the genes encoding the SOR proteases.
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Affiliation(s)
- Assaf Bahat
- Department of Biological Chemistry at the Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Shira Perlberg
- Department of Biological Chemistry at the Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Naomi Melamed-Book
- Bio-Imaging Unit at the Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Sara Isaac
- Department of Cell & Developmental Biology at the Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Amir Eden
- Department of Cell & Developmental Biology at the Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Ines Lauria
- CECAD Research Center, Institute for Genetics, University of Cologne, 50931 Cologne, Germany
| | - Thomas Langer
- CECAD Research Center, Institute for Genetics, University of Cologne, 50931 Cologne, Germany
| | - Joseph Orly
- Department of Biological Chemistry at the Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
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Hood DA, Uguccioni G, Vainshtein A, D'souza D. Mechanisms of exercise-induced mitochondrial biogenesis in skeletal muscle: implications for health and disease. Compr Physiol 2013; 1:1119-34. [PMID: 23733637 DOI: 10.1002/cphy.c100074] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Mitochondria have paradoxical functions within cells. Essential providers of energy for cellular survival, they are also harbingers of cell death (apoptosis). Mitochondria exhibit remarkable dynamics, undergoing fission, fusion, and reticular expansion. Both nuclear and mitochondrial DNA (mtDNA) encode vital sets of proteins which, when incorporated into the inner mitochondrial membrane, provide electron transport capacity for ATP production, and when mutated lead to a broad spectrum of diseases. Acute exercise can activate a set of signaling cascades in skeletal muscle, leading to the activation of the gene expression pathway, from transcription, to post-translational modifications. Research has begun to unravel the important signals and their protein targets that trigger the onset of mitochondrial adaptations to exercise. Exercise training leads to an accumulation of nuclear- and mtDNA-encoded proteins that assemble into functional complexes devoted to mitochondrial respiration, reactive oxygen species (ROS) production, the import of proteins and metabolites, or apoptosis. This process of biogenesis has important consequences for metabolic health, the oxidative capacity of muscle, and whole body fitness. In contrast, the chronic muscle disuse that accompanies aging or muscle wasting diseases provokes a decline in mitochondrial content and function, which elicits excessive ROS formation and apoptotic signaling. Research continues to seek the molecular underpinnings of how regular exercise can be used to attenuate these decrements in organelle function, maintain skeletal muscle health, and improve quality of life.
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Affiliation(s)
- David A Hood
- School of Kinesiology and Health Science, York University, Toronto, Ontario, Canada.
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Baldelli S, Aquilano K, Ciriolo MR. Punctum on two different transcription factors regulated by PGC-1α: Nuclear factor erythroid-derived 2-like 2 and nuclear respiratory factor 2. Biochim Biophys Acta Gen Subj 2013; 1830:4137-46. [DOI: 10.1016/j.bbagen.2013.04.006] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Revised: 03/21/2013] [Accepted: 04/02/2013] [Indexed: 12/30/2022]
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Dysregulation of mitochondrial quality control processes contribute to sarcopenia in a mouse model of premature aging. PLoS One 2013; 8:e69327. [PMID: 23935986 PMCID: PMC3720551 DOI: 10.1371/journal.pone.0069327] [Citation(s) in RCA: 123] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Accepted: 06/07/2013] [Indexed: 01/07/2023] Open
Abstract
Mitochondrial DNA (mtDNA) mutations lead to decrements in mitochondrial function and accelerated rates of these mutations has been linked to skeletal muscle loss (sarcopenia). The purpose of this study was to investigate the effect of mtDNA mutations on mitochondrial quality control processes in skeletal muscle from animals (young; 3–6 months and older; 8–15 months) expressing a proofreading-deficient version of mtDNA polymerase gamma (PolG). This progeroid aging model exhibits elevated mtDNA mutation rates, mitochondrial dysfunction, and a premature aging phenotype that includes sarcopenia. We found increased expression of the mitochondrial biogenesis regulator peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α) and its target proteins, nuclear respiratory factor 1 (NRF-1) and mitochondrial transcription factor A (Tfam) in PolG animals compared to wild-type (WT) (P<0.05). Muscle from older PolG animals displayed higher mitochondrial fission protein 1 (Fis1) concurrent with greater induction of autophagy, as indicated by changes in Atg5 and p62 protein content (P<0.05). Additionally, levels of the Tom22 import protein were higher in PolG animals when compared to WT (P<0.05). In contrast, muscle from normally-aged animals exhibited a distinctly different expression profile compared to PolG animals. Older WT animals appeared to have higher fusion (greater Mfn1/Mfn2, and lower Fis1) and lower autophagy (Beclin-1 and p62) compared to young WT suggesting that autophagy is impaired in aging muscle. In conclusion, muscle from mtDNA mutator mice display higher mitochondrial fission and autophagy levels that likely contribute to the sarcopenic phenotype observed in premature aging and this differs from the response observed in normally-aged muscle.
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Yang JJ, Tao H, Huang C, Li J. Nuclear erythroid 2-related factor 2: a novel potential therapeutic target for liver fibrosis. Food Chem Toxicol 2013; 59:421-7. [PMID: 23793039 DOI: 10.1016/j.fct.2013.06.018] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2013] [Revised: 06/10/2013] [Accepted: 06/12/2013] [Indexed: 12/30/2022]
Abstract
Hepatic stellate cells (HSC) are the key fibrogenic cells of the liver. HSC activation is a process of cellular transdifferentiation that occurs upon liver injury, but the mechanisms underlying liver fibrosis are unknown. Nuclear erythroid 2-related factor 2 (Nrf2) is an oxidative stress-mediated transcription factor with a variety of downstream targets aimed at cytoprotection. However, Nrf2 has recently been implicated as a new therapeutic target for the treatment of liver fibrosis. This review focuses on the transcriptional repressors that either control liver injury or regulate specific fibrogenic functions of liver fibrosis. We also show that Nrf2 may reveal significant gene expression changes, suggesting that Nrf2 activation may ameliorate liver fibrosis.
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Affiliation(s)
- Jing-Jing Yang
- School of Pharmacy, Anhui Medical University, Hefei 230032, China
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Piantadosi CA, Suliman HB. Redox regulation of mitochondrial biogenesis. Free Radic Biol Med 2012; 53:2043-53. [PMID: 23000245 PMCID: PMC3604744 DOI: 10.1016/j.freeradbiomed.2012.09.014] [Citation(s) in RCA: 116] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Revised: 09/07/2012] [Accepted: 09/11/2012] [Indexed: 12/21/2022]
Abstract
The cell renews, adapts, or expands its mitochondrial population during episodes of cell damage or periods of intensified energy demand by the induction of mitochondrial biogenesis. This bigenomic program is modulated by redox-sensitive signals that respond to physiological nitric oxide (NO), carbon monoxide (CO), and mitochondrial reactive oxygen species production. This review summarizes our current ideas about the pathways involved in the activation of mitochondrial biogenesis by the physiological gases leading to changes in the redox milieu of the cell, with an emphasis on the responses to oxidative stress and inflammation. The cell's energy supply is protected from conditions that damage mitochondria by an inducible transcriptional program of mitochondrial biogenesis that operates in large part through redox signals involving the nitric oxide synthase and the heme oxygenase-1/CO systems. These redox events stimulate the coordinated activities of several multifunctional transcription factors and coactivators also involved in the elimination of defective mitochondria and the expression of counterinflammatory and antioxidant genes, such as IL10 and SOD2, as part of a unified damage-control network. The redox-regulated mechanisms of mitochondrial biogenesis schematically outlined in the graphical abstract link mitochondrial quality control to an enhanced capacity to support the cell's metabolic needs while improving its resistance to metabolic failure and avoidance of cell death during periods of oxidative stress.
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Affiliation(s)
- Claude A Piantadosi
- Department of Medicine, Duke University Medical Center and the Durham VA Medical Center, Durham, NC 27710, USA.
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Wong-Riley MTT. Bigenomic regulation of cytochrome c oxidase in neurons and the tight coupling between neuronal activity and energy metabolism. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 748:283-304. [PMID: 22729863 DOI: 10.1007/978-1-4614-3573-0_12] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Cytochrome c oxidase is the terminal enzyme of the mitochondrial electron transport chain, without which oxidative metabolism cannot be carried to completion. It is one of only four unique, bigenomic proteins in mammalian cells. The holoenzyme is made up of three mitochondrial-encoded and ten nuclear-encoded subunits in a 1:1 stoichiometry. The ten nuclear subunit genes are located in nine different chromosomes. The coordinated regulation of such a multisubunit, multichromosomal, bigenomic enzyme poses a challenge. It is especially so for neurons, whose mitochondria are widely distributed in extensive dendritic and axonal processes, resulting in the separation of the mitochondrial from the nuclear genome by great distances. Neuronal activity dictates COX activity that reflects protein amount, which, in turn, is regulated at the transcriptional level. All 13 COX transcripts are up- and downregulated by neuronal activity. The ten nuclear COX transcripts and those for Tfam and Tfbms important for mitochondrial COX transcripts are transcribed in the same transcription factory. Bigenomic regulation of all 13 transcripts is mediated by nuclear respiratory factors 1 and 2 (NRF-1 and NRF-2). NRF-1, in addition, also regulates critical neurochemicals of glutamatergic synaptic transmission, thereby ensuring the tight coupling of energy metabolism and neuronal activity at the molecular level in neurons.
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Affiliation(s)
- Margaret T T Wong-Riley
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
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Li M, Vascotto C, Xu S, Dai N, Qing Y, Zhong Z, Tell G, Wang D. Human AP endonuclease/redox factor APE1/ref-1 modulates mitochondrial function after oxidative stress by regulating the transcriptional activity of NRF1. Free Radic Biol Med 2012; 53:237-48. [PMID: 22580151 DOI: 10.1016/j.freeradbiomed.2012.04.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2012] [Revised: 03/06/2012] [Accepted: 04/06/2012] [Indexed: 12/11/2022]
Abstract
Maintenance of mitochondrial functionality largely depends on nuclear transcription because most mitochondrial proteins are encoded by the nuclear genome and transported to the mitochondria. Nuclear respiration factor 1 (NRF1) plays a crucial role in regulating the expression of a broad range of mitochondrial genes in the nucleus in response to cellular oxidative stress. However, little is known about the redox regulatory mechanism of the transcriptional activity of NRF1. In this study, we show that the human apurinic/apyrimidinic endonuclease/redox factor (APE1/Ref-1) is involved in mitochondrial function regulation by modulating the DNA-binding activity of NRF1. Our results show that both APE1 expression level and its redox activity are essential for maintenance of the mitochondrial function after tert-butylhydroperoxide-induced oxidative stress. Upon knocking down or redox mutation of APE1, NRF1 DNA-binding activity was impaired and, consequently, the expression of its downstream genes, including Tfam, Cox6c, and Tomm22, was significantly reduced. NRF1 knockdown blocked the restoration of mitochondrial function by APE1 overexpression, which further suggests APE1 regulates mitochondrial function through an NRF1-dependent pathway. Taken together, our results reveal APE1 as a new coactivator of NRF1, which highlights an additional regulatory role of APE1 in maintenance of mitochondrial functionality.
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Affiliation(s)
- Mengxia Li
- Cancer Center and Department of Pathology, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing 400042, People's Republic of China
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Joseph AM, Hood DA. Plasticity of TOM complex assembly in skeletal muscle mitochondria in response to chronic contractile activity. Mitochondrion 2011; 12:305-12. [PMID: 22142511 DOI: 10.1016/j.mito.2011.11.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2011] [Revised: 11/10/2011] [Accepted: 11/17/2011] [Indexed: 10/15/2022]
Abstract
We investigated the assembly of the TOM complex within skeletal muscle under conditions of chronic contractile activity-induced mitochondrial biogenesis. Tom40 import into mitochondria was increased by chronic contractile activity, as was its time-dependent assembly into the TOM complex. These changes coincided with contractile activity-induced augmentations in the expression of key protein import machinery components Tim17, Tim23, and Tom22, as well as the cytosolic chaperone Hsp90. These data indicate the adaptability of the TOM protein import complex and suggest a regulatory role for the assembly of this complex in exercise-induced mitochondrial biogenesis.
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Affiliation(s)
- Anna-Maria Joseph
- Department of Biology, York University, Toronto, Ontario, Canada M3J 1P3
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Scarpulla RC. Nucleus-encoded regulators of mitochondrial function: integration of respiratory chain expression, nutrient sensing and metabolic stress. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2011; 1819:1088-97. [PMID: 22080153 DOI: 10.1016/j.bbagrm.2011.10.011] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Accepted: 10/28/2011] [Indexed: 12/23/2022]
Abstract
Nucleus-encoded regulatory factors are major contributors to mitochondrial biogenesis and function. Several act within the organelle to regulate mitochondrial transcription and translation while others direct the expression of nuclear genes encoding the respiratory chain and other oxidative functions. Loss-of-function studies for many of these factors reveal a wide spectrum of phenotypes. These range from embryonic lethality and severe respiratory chain deficiency to relatively mild mitochondrial defects seen only under conditions of physiological stress. The PGC-1 family of regulated coactivators (PGC-1α, PGC-1β and PRC) plays an important integrative role through their interactions with transcription factors (NRF-1, NRF-2, ERRα, CREB, YY1 and others) that control respiratory gene expression. In addition, recent evidence suggests that PGC-1 coactivators may balance the cellular response to oxidant stress by promoting a pro-oxidant environment or by orchestrating an inflammatory response to severe metabolic stress. These pathways may serve as essential links between the energy generating functions of mitochondria and the cellular REDOX environment associated with longevity, senescence and disease. This article is part of a Special Issue entitled: Mitochondrial Gene Expression.
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Affiliation(s)
- Richard C Scarpulla
- Department of Cell and Molecular Biology, Northwestern Medical School, Chicago, IL 60611, USA.
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PGC-1alpha downstream transcription factors NRF-1 and TFAM are genetic modifiers of Huntington disease. Mol Neurodegener 2011; 6:32. [PMID: 21595933 PMCID: PMC3117738 DOI: 10.1186/1750-1326-6-32] [Citation(s) in RCA: 96] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2010] [Accepted: 05/19/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Huntington disease (HD) is an inherited neurodegenerative disease caused by an abnormal expansion of a CAG repeat in the huntingtin HTT (HD) gene. The primary genetic determinant of the age at onset (AO) is the length of the HTT CAG repeat; however, the remaining genetic contribution to the AO of HD has largely not been elucidated. Recent studies showed that impaired functioning of the peroxisome proliferator-activated receptor gamma coactivator 1a (PGC-1alpha) contributes to mitochondrial dysfunction and appears to play an important role in HD pathogenesis. Further genetic evidence for involvement of PGC-1alpha in HD pathogenesis was generated by the findings that sequence variations in the PPARGC1A gene encoding PGC-1alpha exert modifying effects on the AO in HD. In this study, we hypothesised that polymorphisms in PGC-1alpha downstream targets might also contribute to the variation in the AO. RESULTS In over 400 German HD patients, polymorphisms in the nuclear respiratory factor 1 gene, NRF-1, and the mitochondrial transcription factor A, encoded by TFAM showed nominally significant association with AO of HD. When combining these results with the previously described modifiers rs7665116 in PPARGC1A and C7028T in the cytochrome c oxidase subunit I (CO1, mt haplogroup H) in a multivariable model, a substantial proportion of the variation in AO can be explained by the joint effect of significant modifiers and their interactions, respectively. CONCLUSIONS These results underscore that impairment of mitochondrial function plays a critical role in the pathogenesis of HD and that upstream transcriptional activators of PGC-1alpha may be useful targets in the treatment of HD.
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Pinti M, Gibellini L, De Biasi S, Nasi M, Roat E, O'Connor JE, Cossarizza A. Functional characterization of the promoter of the human Lon protease gene. Mitochondrion 2011; 11:200-6. [DOI: 10.1016/j.mito.2010.09.010] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2010] [Revised: 08/30/2010] [Accepted: 09/28/2010] [Indexed: 10/19/2022]
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Lee KJ, Lee KM, Jo S, Kang KW, Park CS. Induction of cereblon by NF-E2-related factor 2 in neuroblastoma cells exposed to hypoxia-reoxygenation. Biochem Biophys Res Commun 2010; 399:711-5. [DOI: 10.1016/j.bbrc.2010.08.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Accepted: 08/02/2010] [Indexed: 10/19/2022]
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Chang JC, Kou SJ, Lin WT, Liu CS. Regulatory role of mitochondria in oxidative stress and atherosclerosis. World J Cardiol 2010; 2:150-9. [PMID: 21160733 PMCID: PMC2999054 DOI: 10.4330/wjc.v2.i6.150] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Revised: 06/07/2010] [Accepted: 06/14/2010] [Indexed: 02/06/2023] Open
Abstract
Mitochondrial physiology and biogenesis play a crucial role in the initiation and progression of cardiovascular disease following oxidative stress-induced damage such as atherosclerosis (AST). Dysfunctional mitochondria caused by an increase in mitochondrial reactive oxygen species (ROS) production, accumulation of mitochondrial DNA damage, and respiratory chain deficiency induces death of endothelial/smooth muscle cells and favors plaque formation/rupture via the regulation of mitochondrial biogenesis-related genes such as peroxisome proliferator-activated receptor γ coactivator (PGC-1), although more detailed mechanisms still need further study. Based on the effect of healthy mitochondria produced by mitochondrial biogenesis on decreasing ROS-mediated cell death and the recent finding that the regulation of PGC-1 involves mitochondrial fusion-related protein (mitofusin), we thus infer the regulatory role of mitochondrial fusion/fission balance in AST pathophysiology. In this review, the first section discusses the possible association between AST-inducing factors and the molecular regulatory mechanisms of mitochondrial biogenesis and dynamics, and explains the role of mitochondria-dependent regulation in cell apoptosis during AST development. Furthermore, nitric oxide has the Janus-faced effect by protecting vascular damage caused by AST while being a reactive nitrogen species (RNS) which act together with ROS to damage cells. Therefore, in the second section we discuss mitochondrial ATP-sensitive K(+) channels, which regulate mitochondrial ion transport to maintain mitochondrial physiology, involved in the regulation of ROS/RNS production and their influence on AST/cardiovascular diseases (CVD). Through this review, we can further appreciate the multi-regulatory functions of the mitochondria involved in AST development. The understanding of these related mechanisms will benefit drug development in treating AST/CVD through targeted biofunctions of mitochondria.
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Affiliation(s)
- Jui-Chih Chang
- Jui-Chih Chang, Wei-Ting Lin, Chin-San Liu, Department of Neurology, Vascular and Genomic Center, Changhua Christian Hospital, Changhua 50094, Taiwan, China
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Bruni F, Polosa PL, Gadaleta MN, Cantatore P, Roberti M. Nuclear respiratory factor 2 induces the expression of many but not all human proteins acting in mitochondrial DNA transcription and replication. J Biol Chem 2009; 285:3939-3948. [PMID: 19951946 DOI: 10.1074/jbc.m109.044305] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
In mammals, NRF-2 (nuclear respiratory factor 2), also named GA-binding protein, is an Ets family transcription factor that controls many genes involved in cell cycle progression and protein synthesis as well as in mitochondrial biogenesis. In this paper, we analyzed the role of NRF-2 in the regulation of human genes involved in mitochondrial DNA transcription and replication. By a combination of bioinformatic and biochemical approaches, we found that the factor binds in vitro and in vivo to the proximal promoter region of the genes coding for the transcription termination factor mTERF, the RNA polymerase POLRMT, the B subunit of the DNA polymerase-gamma, the DNA helicase TWINKLE, and the single-stranded DNA-binding protein mtSSB. The role of NRF-2 in modulating the expression of those genes was further established by RNA interference and overexpression strategies. On the contrary, we found that NRF-2 does not control the genes for the subunit A of DNA polymerase-gamma and for the transcription repressor MTERF3; we suggest that these genes are under regulatory mechanisms that do not involve NRF proteins. Since NRFs are known to positively control the expression of transcription-activating proteins, the novelty emerging from our data is that proteins playing antithetical roles in mitochondrial DNA transcription, namely activators and repressors, are under different regulatory pathways. Finally, we developed a more stringent consensus with respect to the general consensus of NRF-2/GA-binding protein when searching for NRF-2 binding sites in the promoter of mitochondrial proteins.
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Affiliation(s)
- Francesco Bruni
- From the Department of Biochemistry and Molecular Biology "Ernesto Quagliariello," University of Bari, Via Orabona 4, 70125 Bari and
| | - Paola Loguercio Polosa
- From the Department of Biochemistry and Molecular Biology "Ernesto Quagliariello," University of Bari, Via Orabona 4, 70125 Bari and
| | - Maria Nicola Gadaleta
- From the Department of Biochemistry and Molecular Biology "Ernesto Quagliariello," University of Bari, Via Orabona 4, 70125 Bari and; the Institute of Biomembranes and Bioenergetics, Consiglio Nazionale delle Ricerche, Via Amendola 165/A, 70126 Bari, Italy
| | - Palmiro Cantatore
- From the Department of Biochemistry and Molecular Biology "Ernesto Quagliariello," University of Bari, Via Orabona 4, 70125 Bari and; the Institute of Biomembranes and Bioenergetics, Consiglio Nazionale delle Ricerche, Via Amendola 165/A, 70126 Bari, Italy
| | - Marina Roberti
- From the Department of Biochemistry and Molecular Biology "Ernesto Quagliariello," University of Bari, Via Orabona 4, 70125 Bari and.
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Baltzer C, Tiefenböck SK, Marti M, Frei C. Nutrition controls mitochondrial biogenesis in the Drosophila adipose tissue through Delg and cyclin D/Cdk4. PLoS One 2009; 4:e6935. [PMID: 19742324 PMCID: PMC2735006 DOI: 10.1371/journal.pone.0006935] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2009] [Accepted: 08/16/2009] [Indexed: 11/25/2022] Open
Abstract
Mitochondria are cellular organelles that perform critical metabolic functions: they generate energy from nutrients but also provide metabolites for de novo synthesis of fatty acids and several amino acids. Thus mitochondrial mass and activity must be coordinated with nutrient availability, yet this remains poorly understood. Here, we demonstrate that Drosophila larvae grown in low yeast food have strong defects in mitochondrial abundance and respiration activity in the larval fat body. This correlates with reduced expression of genes encoding mitochondrial proteins, particularly genes involved in oxidative phosphorylation. Second, genes involved in glutamine metabolism are also expressed in a nutrient-dependent manner, suggesting a coordination of amino acid synthesis with mitochondrial abundance and activity. Moreover, we show that Delg (CG6338), the Drosophila homologue to the alpha subunit of mammalian transcription factor NRF-2/GABP, is required for proper expression of most genes encoding mitochondrial proteins. Our data demonstrate that Delg is critical to adjust mitochondrial abundance in respect to Cyclin D/Cdk4, a growth-promoting complex and glutamine metabolism according to nutrient availability. However, in contrast to nutrients, Delg is not involved in the regulation of mitochondrial activity in the fat body. These findings are the first genetic evidence that the regulation of mitochondrial mass can be uncoupled from mitochondrial activity.
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Blesa JR, Prieto-Ruiz JA, Abraham BA, Harrison BL, Hegde AA, Hernández-Yago J. NRF-1 is the major transcription factor regulating the expression of the human TOMM34 gene. Biochem Cell Biol 2009; 86:46-56. [PMID: 18364745 DOI: 10.1139/o07-151] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The human TOMM34 gene encodes a cytosolic protein with chaperone-like activity that helps import some preproteins to the mitochondria by keeping them in an unfolded, import-compatible state. TOMM34 was found to be upregulated frequently in colorectal tumors, suggesting that it also has a role in the growth of cancer cells. In this context, TOMM34 is a potential target for novel anticancer drugs, and it might also be used in the diagnosis of colorectal cancer. Nuclear respiratory factors (NRFs) play an important role in governing the nuclear-mitochondrial interactions implicated in mitochondrial biogenesis. Our previous studies revealed that NRFs promote the expression of the major members of the mitochondrial transport machinery, TOMM70 and TOMM20. Here we report the existence of binding sites for NRF-1, Sp1, and NRF-2 in the 5' region of the human TOMM34 gene. We determined the effects of mutations at these sites on promoter activity in HeLa S3 and A204 cells, in conjunction with chromatin immunoprecipitation experiments, electrophoretic mobility shift assays, and in vivo methylation analysis of the promoter region. We conclude that NRF-1 is the main transcription factor regulating the expression of TOMM34. Sp1 interacts with NRF-1 to stimulate the promoter's full activity.
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Affiliation(s)
- José R Blesa
- Fundacion Centro de Investigacion Principe Felipe, Av. Autopista del Saler 16-3, Valencia, Spain.
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Fu J, Zhang J, Jin F, Patchefsky J, Braunewell KH, Klein-Szanto AJ. Promoter regulation of the visinin-like subfamily of neuronal calcium sensor proteins by nuclear respiratory factor-1. J Biol Chem 2009; 284:27577-86. [PMID: 19674972 DOI: 10.1074/jbc.m109.049361] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
VILIP-1 (gene name VSNL1), a member of the neuronal Ca(2+) sensor protein family, acts as a tumor suppressor gene by inhibiting cell proliferation, adhesion, and invasiveness. VILIP-1 expression is down-regulated in several types of human cancer. In human non-small cell lung cancer, we found that down-regulation was due to epigenetic changes. Consequently, in this study we analyzed the VSNL1 promoter and its regulation. Serial truncation of the proximal 2-kb VSNL1 promoter (VP-1998) from its 5' terminus disclosed that the last 3' terminal 100-bp promoter fragment maintained similar promoter activity as compared with VP-1998 and therefore was referred to as VSNL1 minimal promoter. When the 5' terminal 50 bp were deleted from the minimal promoter, the activity was dramatically decreased, suggesting that the deleted 50 bp contained a potential cis-acting element crucial for promoter activity. Deletion and site-directed mutagenesis combined with in silico transcription factor binding analysis of VSNL1 promoter identified nuclear respiratory factor (NRF)-1/alpha-PAL as a major player in regulating VSNL1 minimal promoter activity. The function of NRF-1 was further confirmed using dominant-negative NRF-1 overexpression and NRF-1 small interfering RNA knockdown. Electrophoretic mobility shift assay and chromatin immunoprecipitation provided evidence for direct NRF-1 binding to the VSNL1 promoter. Methylation of the NRF-1-binding site was found to be able to regulate VSNL1 promoter activity. Our results further indicated that NRF-1 could be a regulatory factor for gene expression of the other visinin-like subfamily members including HPCAL4, HPCAL1, HPCA, and NCALD.
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Affiliation(s)
- Jian Fu
- Department of Pathology, Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111, USA
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Transcriptional and post-transcriptional regulation of mitochondrial biogenesis in skeletal muscle: effects of exercise and aging. Biochim Biophys Acta Gen Subj 2009; 1800:223-34. [PMID: 19682549 DOI: 10.1016/j.bbagen.2009.07.031] [Citation(s) in RCA: 120] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2009] [Revised: 07/27/2009] [Accepted: 07/30/2009] [Indexed: 12/18/2022]
Abstract
Acute contractile activity of skeletal muscle initiates the activation of signaling kinases. This promotes the phosphorylation of transcription factors, leading to enhanced DNA binding and transcriptional activation and/or repression. The mRNA products of nuclear genes encoding mitochondrial proteins are translated in the cytosol and imported into pre-existing mitochondria. When contractile activity is repeated, the recapitulation of these cellular events progressively leads to an expansion of the mitochondrial reticulum within muscle. This has physiologically relevant health benefit, including enhanced lipid metabolism and reduced muscle fatigability. In aging skeletal muscle, the response to contractile activity appears to be attenuated, suggesting that a greater contractile stimulus is required to attain a similar phenotype adaptation. This review summarizes our current understanding of the effects of exercise on the gene expression pathway leading to organelle biogenesis in muscle.
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Huang CC, Chang WSW. Cooperation between NRF-2 and YY-1 transcription factors is essential for triggering the expression of the PREPL-C2ORF34 bidirectional gene pair. BMC Mol Biol 2009; 10:67. [PMID: 19575798 PMCID: PMC2713978 DOI: 10.1186/1471-2199-10-67] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2008] [Accepted: 07/03/2009] [Indexed: 11/11/2022] Open
Abstract
Background Many mammalian genes are organized as bidirectional (head-to-head) gene pairs with the two genes separated only by less than 1 kb. The transcriptional regulation of these bidirectional gene pairs remains largely unclear, but a few studies have suggested that the two closely adjacent genes in divergent orientation can be co-regulated by a single transcription factor binding to a specific regulatory fragment. Here we report an evolutionarily conserved bidirectional gene pair, known as the PREPL-C2ORF34 gene pair, whose transcription relies on the synergic cooperation of two transcription factors binding to an intergenic bidirectional minimal promoter. Results While PREPL is present primarily in brain and heart, C2ORF34 is ubiquitously and abundantly expressed in almost all tissues. Genomic analyses revealed that these two non-homologous genes are adjacent in a head-to-head configuration on human chromosome 2p21 and separated by only 405 bp. Within this short intergenic region, a 243-bp GC-rich segment was demonstrated to function as a bidirectional minimal promoter to initiate the transcription of both flanking genes. Two key transcription factors, NRF-2 and YY-1, were further identified to coordinately participate in driving both gene expressions in an additive manner. The functional cooperation between these two transcription factors, along with their genomic binding sites and some cis-acting repressive elements, are essential for the transcriptional activation and tissue distribution of the PREPL-C2ORF34 bidirectional gene pair. Conclusion This study provides new insights into the complex transcriptional mechanism of a mammalian head-to-head gene pair which requires cooperative binding of multiple transcription factors to a bidirectional minimal promoter of the shared intergenic region.
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Affiliation(s)
- Chien-Chang Huang
- 1Institute of Life Sciences, National Defense Medical Center, Taipei 114, Taiwan.
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41
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Chen JQ, Cammarata PR, Baines CP, Yager JD. Regulation of mitochondrial respiratory chain biogenesis by estrogens/estrogen receptors and physiological, pathological and pharmacological implications. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2009; 1793:1540-70. [PMID: 19559056 DOI: 10.1016/j.bbamcr.2009.06.001] [Citation(s) in RCA: 189] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2009] [Revised: 06/16/2009] [Accepted: 06/17/2009] [Indexed: 12/21/2022]
Abstract
There has been increasing evidence pointing to the mitochondrial respiratory chain (MRC) as a novel and important target for the actions of 17beta-estradiol (E(2)) and estrogen receptors (ER) in a number of cell types and tissues that have high demands for mitochondrial energy metabolism. This novel E(2)-mediated mitochondrial pathway involves the cooperation of both nuclear and mitochondrial ERalpha and ERbeta and their co-activators on the coordinate regulation of both nuclear DNA- and mitochondrial DNA-encoded genes for MRC proteins. In this paper, we have: 1) comprehensively reviewed studies that reveal a novel role of estrogens and ERs in the regulation of MRC biogenesis; 2) discussed their physiological, pathological and pharmacological implications in the control of cell proliferation and apoptosis in relation to estrogen-mediated carcinogenesis, anti-cancer drug resistance in human breast cancer cells, neuroprotection for Alzheimer's disease and Parkinson's disease in brain, cardiovascular protection in human heart and their beneficial effects in lens physiology related to cataract in the eye; and 3) pointed out new research directions to address the key questions in this important and newly emerging area. We also suggest a novel conceptual approach that will contribute to innovative regimens for the prevention or treatment of a wide variety of medical complications based on E(2)/ER-mediated MRC biogenesis pathway.
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Affiliation(s)
- Jin-Qiang Chen
- Breast Cancer Research Laboratory, Fox Chase Cancer Center, Philadelphia, PA 19111, USA.
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42
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Scarpulla RC. Nuclear control of respiratory chain expression by nuclear respiratory factors and PGC-1-related coactivator. Ann N Y Acad Sci 2009; 1147:321-34. [PMID: 19076454 DOI: 10.1196/annals.1427.006] [Citation(s) in RCA: 272] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Expression of the respiratory apparatus depends on both nuclear and mitochondrial genes. Although these genes are sequestered in distinct cellular organelles, their transcription relies on nucleus-encoded factors. Certain of these factors are directed to the mitochondria, where they sponsor the bi-directional transcription of mitochondrial DNA. Others act on nuclear genes that encode the majority of the respiratory subunits and many other gene products required for the assembly and function of the respiratory chain. The nuclear respiratory factors, NRF-1 and NRF-2, contribute to the expression of respiratory subunits and mitochondrial transcription factors and thus have been implicated in nucleo-mitochondrial interactions. In addition, coactivators of the PGC-1 family serve as mediators between the environment and the transcriptional machinery governing mitochondrial biogenesis. One family member, peroxisome proliferator-activated receptor gamma coactivator PGC-1-related coactivator (PRC), is an immediate early gene product that is rapidly induced by mitogenic signals in the absence of de novo protein synthesis. Like other PGC-1 family members, PRC binds NRF-1 and activates NRF-1 target genes. In addition, PRC complexes with NRF-2 and HCF-1 (host cell factor-1) in the activation of NRF-2-dependent promoters. HCF-1 functions in cell-cycle progression and has been identified as an NRF-2 coactivator. The association of these factors with PRC is suggestive of a role for the complex in cell growth. Finally, shRNA-mediated knock down of PRC expression results in a complex phenotype that includes the inhibition of respiratory growth on galactose and the loss of respiratory complexes. Thus, PRC may help integrate the expression of the respiratory apparatus with the cell proliferative program.
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Affiliation(s)
- Richard C Scarpulla
- Department of Cell and Molecular Biology, Northwestern Medical School, Chicago, IL 60611, USA.
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In vitro methylation of nuclear respiratory factor-2 binding sites suppresses the promoter activity of the human TOMM70 gene. Gene 2008; 427:58-64. [PMID: 18852034 DOI: 10.1016/j.gene.2008.09.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2008] [Revised: 09/04/2008] [Accepted: 09/17/2008] [Indexed: 11/28/2022]
Abstract
TOMM70 is a subunit of the outer mitochondrial membrane translocase that plays a major role as a receptor of hydrophobic preproteins targeted to mitochondria. We have previously reported that two binding sites for transcription factor NRF-2 in the promoter region of the human TOMM70 gene are essential in activating transcription (Blesa et al., Mitochondrion 2004; 3:251-59. Blesa et al., Biochem Cell Biol 2006; 84:813-22). This region contains thirteen CpG methylation sites, three of which occur in the sequence 5'-CCGG-3' that is specifically recognized by HpaII methylase which modifies the internal cytosine residue. Interestingly, each NRF-2 site contains one CCGG sequence, allowing specific methylation of the NRF-2 sites and, therefore, providing an ideal model to study how methylation of these sites affects promoter activity. In this paper we report that site-specific methylation of the NRF-2 binding sites in the TOMM70 promoter down-regulated expression of a luciferase reporter in HeLa S3 cells. Electrophoretic mobility shift assays confirmed abrogation of NRF-2 binding at the methylated sites. These results suggest that methylation of the TOMM70 promoter in mammalian cells may silence TOMM70 expression. However, studies of methylation degree on DNAs from different sources found no methylation in the promoter regions of TOMM70 and other TOMM/TIMM family genes. Thus, although in vitro methylation inactivates the expression of TOMM70, our results suggest that this is not the mechanism modulating its expression in vivo. Since a number of nuclear genes encoding mitochondrial translocases have NRF-2 binding sequences containing CpG methylation sites, a possible role of methylation as a regulatory mechanism of mitochondrial biogenesis can be ruled out.
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Scarpulla RC. Transcriptional paradigms in mammalian mitochondrial biogenesis and function. Physiol Rev 2008; 88:611-38. [PMID: 18391175 DOI: 10.1152/physrev.00025.2007] [Citation(s) in RCA: 1156] [Impact Index Per Article: 72.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Mitochondria contain their own genetic system and undergo a unique mode of cytoplasmic inheritance. Each organelle has multiple copies of a covalently closed circular DNA genome (mtDNA). The entire protein coding capacity of mtDNA is devoted to the synthesis of 13 essential subunits of the inner membrane complexes of the respiratory apparatus. Thus the majority of respiratory proteins and all of the other gene products necessary for the myriad mitochondrial functions are derived from nuclear genes. Transcription of mtDNA requires a small number of nucleus-encoded proteins including a single RNA polymerase (POLRMT), auxiliary factors necessary for promoter recognition (TFB1M, TFB2M) and activation (Tfam), and a termination factor (mTERF). This relatively simple system can account for the bidirectional transcription of mtDNA from divergent promoters and key termination events controlling the rRNA/mRNA ratio. Nucleomitochondrial interactions depend on the interplay between transcription factors (NRF-1, NRF-2, PPARalpha, ERRalpha, Sp1, and others) and members of the PGC-1 family of regulated coactivators (PGC-1alpha, PGC-1beta, and PRC). The transcription factors target genes that specify the respiratory chain, the mitochondrial transcription, translation and replication machinery, and protein import and assembly apparatus among others. These factors are in turn activated directly or indirectly by PGC-1 family coactivators whose differential expression is controlled by an array of environmental signals including temperature, energy deprivation, and availability of nutrients and growth factors. These transcriptional paradigms provide a basic framework for understanding the integration of mitochondrial biogenesis and function with signaling events that dictate cell- and tissue-specific energetic properties.
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Affiliation(s)
- Richard C Scarpulla
- Department of Cell and Molecular Biology, Northwestern Medical School, Chicago, Illinois 60611, USA
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