1
|
Ruan K, Bai G, Fang Y, Li D, Li T, Liu X, Lu B, Lu Q, Songyang Z, Sun S, Wang Z, Zhang X, Zhou W, Zhang H. Biomolecular condensates and disease pathogenesis. SCIENCE CHINA. LIFE SCIENCES 2024; 67:1792-1832. [PMID: 39037698 DOI: 10.1007/s11427-024-2661-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Accepted: 06/21/2024] [Indexed: 07/23/2024]
Abstract
Biomolecular condensates or membraneless organelles (MLOs) formed by liquid-liquid phase separation (LLPS) divide intracellular spaces into discrete compartments for specific functions. Dysregulation of LLPS or aberrant phase transition that disturbs the formation or material states of MLOs is closely correlated with neurodegeneration, tumorigenesis, and many other pathological processes. Herein, we summarize the recent progress in development of methods to monitor phase separation and we discuss the biogenesis and function of MLOs formed through phase separation. We then present emerging proof-of-concept examples regarding the disruption of phase separation homeostasis in a diverse array of clinical conditions including neurodegenerative disorders, hearing loss, cancers, and immunological diseases. Finally, we describe the emerging discovery of chemical modulators of phase separation.
Collapse
Affiliation(s)
- Ke Ruan
- The First Affiliated Hospital & School of Life Sciences, Ministry of Education Key Laboratory for Membrane-less Organelles & Cellular Dynamics, Hefei National Research Center for Interdisciplinary Sciences at the Microscale, Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230027, China.
| | - Ge Bai
- Nanhu Brain-computer Interface Institute, Hangzhou, 311100, China.
- Department of Neurology of Second Affiliated Hospital and School of Brain Science and Brain Medicine, Zhejiang University School of Medicine, Hangzhou, 310058, China.
| | - Yanshan Fang
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 201210, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Dan Li
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, 200030, China.
| | - Tingting Li
- Department of Biomedical Informatics, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China.
| | - Xingguo Liu
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China.
- Joint School of Life Sciences, Guangzhou Medical University, Guangzhou, 510000, China.
| | - Boxun Lu
- Neurology Department at Huashan Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, School of Life Sciences, Fudan University, Shanghai, 200433, China.
| | - Qing Lu
- Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Bio-X Institutes, Shanghai Jiao Tong University, Shanghai, 200030, China.
| | - Zhou Songyang
- State Key Laboratory of Biocontrol, MOE Key Laboratory of Gene Function and Regulation and Guangzhou Key Laboratory of Healthy Aging Research, School of Life Sciences, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, 510275, China.
| | - Shuguo Sun
- Department of Human Anatomy, Histology and Embryology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
| | - Zheng Wang
- The Second Affiliated Hospital, School of Basic Medical Sciences, Institute of Biomedical Innovation, Jiangxi Medical College, Nanchang University, Nanchang, 330031, China.
| | - Xin Zhang
- Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, 310024, China.
| | - Wen Zhou
- Department of Immunology and Microbiology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China.
| | - Hong Zhang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.
| |
Collapse
|
2
|
Ceylan D, Arat-Çelik HE, Aksahin IC. Integrating mitoepigenetics into research in mood disorders: a state-of-the-art review. Front Physiol 2024; 15:1338544. [PMID: 38410811 PMCID: PMC10895490 DOI: 10.3389/fphys.2024.1338544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Accepted: 01/24/2024] [Indexed: 02/28/2024] Open
Abstract
Mood disorders, including major depressive disorder and bipolar disorder, are highly prevalent and stand among the leading causes of disability. Despite the largely elusive nature of the molecular mechanisms underpinning these disorders, two pivotal contributors-mitochondrial dysfunctions and epigenetic alterations-have emerged as significant players in their pathogenesis. This state-of-the-art review aims to present existing data on epigenetic alterations in the mitochondrial genome in mood disorders, laying the groundwork for future research into their pathogenesis. Associations between abnormalities in mitochondrial function and mood disorders have been observed, with evidence pointing to notable changes in mitochondrial DNA (mtDNA). These changes encompass variations in copy number and oxidative damage. However, information on additional epigenetic alterations in the mitochondrial genome remains limited. Recent studies have delved into alterations in mtDNA and regulations in the mitochondrial genome, giving rise to the burgeoning field of mitochondrial epigenetics. Mitochondrial epigenetics encompasses three main categories of modifications: mtDNA methylation/hydroxymethylation, modifications of mitochondrial nucleoids, and mitochondrial RNA alterations. The epigenetic modulation of mitochondrial nucleoids, lacking histones, may impact mtDNA function. Additionally, mitochondrial RNAs, including non-coding RNAs, present a complex landscape influencing interactions between the mitochondria and the nucleus. The exploration of mitochondrial epigenetics offers valuable perspectives on how these alterations impact neurodegenerative diseases, presenting an intriguing avenue for research on mood disorders. Investigations into post-translational modifications and the role of mitochondrial non-coding RNAs hold promise to unravel the dynamics of mitoepigenetics in mood disorders, providing crucial insights for future therapeutic interventions.
Collapse
Affiliation(s)
- Deniz Ceylan
- Department of Psychiatry, School of Medicine, Koç University, Istanbul, Türkiye
- Koç University Research Center for Translational Medicine (KUTTAM), Affective Laboratory, Istanbul, Türkiye
| | | | - Izel Cemre Aksahin
- Koç University Research Center for Translational Medicine (KUTTAM), Affective Laboratory, Istanbul, Türkiye
- Graduate School of Health Sciences, Koç University, Istanbul, Türkiye
| |
Collapse
|
3
|
Targeted Mitochondrial Epigenetics: A New Direction in Alzheimer’s Disease Treatment. Int J Mol Sci 2022; 23:ijms23179703. [PMID: 36077101 PMCID: PMC9456144 DOI: 10.3390/ijms23179703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 08/19/2022] [Accepted: 08/25/2022] [Indexed: 11/23/2022] Open
Abstract
Mitochondrial epigenetic alterations are closely related to Alzheimer’s disease (AD), which is described in this review. Reports of the alteration of mitochondrial DNA (mtDNA) methylation in AD demonstrate that the disruption of the dynamic balance of mtDNA methylation and demethylation leads to damage to the mitochondrial electron transport chain and the obstruction of mitochondrial biogenesis, which is the most studied mitochondrial epigenetic change. Mitochondrial noncoding RNA modifications and the post-translational modification of mitochondrial nucleoproteins have been observed in neurodegenerative diseases and related diseases that increase the risk of AD. Although there are still relatively few mitochondrial noncoding RNA modifications and mitochondrial nuclear protein post-translational modifications reported in AD, we have reason to believe that these mitochondrial epigenetic modifications also play an important role in the AD process. This review provides a new research direction for the AD mechanism, starting from mitochondrial epigenetics. Further, this review summarizes therapeutic approaches to targeted mitochondrial epigenetics, which is the first systematic summary of therapeutic approaches in the field, including folic acid supplementation, mitochondrial-targeting antioxidants, and targeted ubiquitin-specific proteases, providing a reference for therapeutic targets for AD.
Collapse
|
4
|
Chen K, Lu P, Beeraka NM, Sukocheva OA, Madhunapantula SV, Liu J, Sinelnikov MY, Nikolenko VN, Bulygin KV, Mikhaleva LM, Reshetov IV, Gu Y, Zhang J, Cao Y, Somasundaram SG, Kirkland CE, Fan R, Aliev G. Mitochondrial mutations and mitoepigenetics: Focus on regulation of oxidative stress-induced responses in breast cancers. Semin Cancer Biol 2022; 83:556-569. [PMID: 33035656 DOI: 10.1016/j.semcancer.2020.09.012] [Citation(s) in RCA: 123] [Impact Index Per Article: 61.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Revised: 09/28/2020] [Accepted: 09/28/2020] [Indexed: 02/08/2023]
Abstract
Epigenetic regulation of mitochondrial DNA (mtDNA) is an emerging and fast-developing field of research. Compared to regulation of nucler DNA, mechanisms of mtDNA epigenetic regulation (mitoepigenetics) remain less investigated. However, mitochondrial signaling directs various vital intracellular processes including aerobic respiration, apoptosis, cell proliferation and survival, nucleic acid synthesis, and oxidative stress. The later process and associated mismanagement of reactive oxygen species (ROS) cascade were associated with cancer progression. It has been demonstrated that cancer cells contain ROS/oxidative stress-mediated defects in mtDNA repair system and mitochondrial nucleoid protection. Furthermore, mtDNA is vulnerable to damage caused by somatic mutations, resulting in the dysfunction of the mitochondrial respiratory chain and energy production, which fosters further generation of ROS and promotes oncogenicity. Mitochondrial proteins are encoded by the collective mitochondrial genome that comprises both nuclear and mitochondrial genomes coupled by crosstalk. Recent reports determined the defects in the collective mitochondrial genome that are conducive to breast cancer initiation and progression. Mutational damage to mtDNA, as well as its overproliferation and deletions, were reported to alter the nuclear epigenetic landscape. Unbalanced mitoepigenetics and adverse regulation of oxidative phosphorylation (OXPHOS) can efficiently facilitate cancer cell survival. Accordingly, several mitochondria-targeting therapeutic agents (biguanides, OXPHOS inhibitors, vitamin-E analogues, and antibiotic bedaquiline) were suggested for future clinical trials in breast cancer patients. However, crosstalk mechanisms between altered mitoepigenetics and cancer-associated mtDNA mutations remain largely unclear. Hence, mtDNA mutations and epigenetic modifications could be considered as potential molecular markers for early diagnosis and targeted therapy of breast cancer. This review discusses the role of mitoepigenetic regulation in cancer cells and potential employment of mtDNA modifications as novel anti-cancer targets.
Collapse
Affiliation(s)
- Kuo Chen
- The First Affiliated Hospital of Zhengzhou University, 1 Jianshedong Street, Zhengzhou, 450052, China; Institue for Regenerative Medicine, I.M. Sechenov First Moscow State Medical University (Sechenov University), 8/2 Trubetskaya Street, Moscow, 119991, Russia
| | - Pengwei Lu
- The First Affiliated Hospital of Zhengzhou University, 1 Jianshedong Street, Zhengzhou, 450052, China
| | - Narasimha M Beeraka
- Center of Excellence in Regenerative Medicine and Molecular Biology (CEMR), Department of Biochemistry, JSS Academy of Higher Education and Research (JSS AHER), Mysuru, Karnataka, India
| | - Olga A Sukocheva
- Discipline of Health Sciences, College of Nursing and Health Sciences, Flinders University, Bedford Park, South Australia, 5042, Australia
| | - SubbaRao V Madhunapantula
- Center of Excellence in Regenerative Medicine and Molecular Biology (CEMR), Department of Biochemistry, JSS Academy of Higher Education and Research (JSS AHER), Mysuru, Karnataka, India
| | - Junqi Liu
- Cancer Center, The First Affiliated Hospital of Zhengzhou University, 1 Jianshedong Str., Zhengzhou, 450052, China
| | - Mikhail Y Sinelnikov
- Institue for Regenerative Medicine, I.M. Sechenov First Moscow State Medical University (Sechenov University), 8/2 Trubetskaya Street, Moscow, 119991, Russia
| | - Vladimir N Nikolenko
- I.M. Sechenov First Moscow State Medical University of the Ministry of Health of the Russian Federation (Sechenov University), 8/2 Trubetskaya Street, Moscow, 119991, Russia; Department of Normal and Topographic Anatomy, Faculty of Fundamental Medicine, M.V. Lomonosov Moscow State University (MSU), 31-5 Lomonosovsky Prospect, 117192, Moscow, Russia
| | - Kirill V Bulygin
- I.M. Sechenov First Moscow State Medical University of the Ministry of Health of the Russian Federation (Sechenov University), 8/2 Trubetskaya Street, Moscow, 119991, Russia; Department of Normal and Topographic Anatomy, Faculty of Fundamental Medicine, M.V. Lomonosov Moscow State University (MSU), 31-5 Lomonosovsky Prospect, 117192, Moscow, Russia
| | - Liudmila M Mikhaleva
- Research Institute of Human Morphology, 3 Tsyurupy Street, Moscow, 117418, Russian Federation
| | - Igor V Reshetov
- I.M. Sechenov First Moscow State Medical University of the Ministry of Health of the Russian Federation (Sechenov University), 8/2 Trubetskaya Street, Moscow, 119991, Russia
| | - Yuanting Gu
- The First Affiliated Hospital of Zhengzhou University, 1 Jianshedong Street, Zhengzhou, 450052, China
| | - Jin Zhang
- I.M. Sechenov First Moscow State Medical University of the Ministry of Health of the Russian Federation (Sechenov University), 8/2 Trubetskaya Street, Moscow, 119991, Russia
| | - Yu Cao
- I.M. Sechenov First Moscow State Medical University of the Ministry of Health of the Russian Federation (Sechenov University), 8/2 Trubetskaya Street, Moscow, 119991, Russia
| | - Siva G Somasundaram
- Department of Biological Sciences, Salem University, 223 West Main Street Salem, WV, 26426, USA
| | - Cecil E Kirkland
- Department of Biological Sciences, Salem University, 223 West Main Street Salem, WV, 26426, USA
| | - Ruitai Fan
- The First Affiliated Hospital of Zhengzhou University, 1 Jianshedong Street, Zhengzhou, 450052, China.
| | - Gjumrakch Aliev
- I.M. Sechenov First Moscow State Medical University of the Ministry of Health of the Russian Federation (Sechenov University), 8/2 Trubetskaya Street, Moscow, 119991, Russia; Research Institute of Human Morphology, 3 Tsyurupy Street, Moscow, 117418, Russian Federation; Institute of Physiologically Active Compounds of Russian Academy of Sciences, Severny pr. 1, Chernogolovka, Moscow Region, 142432, Russia; GALLY International Research Institute, 7733 Louis Pasteur Drive, #330, San Antonio, TX, 78229, USA
| |
Collapse
|
5
|
Chatterjee D, Das P, Chakrabarti O. Mitochondrial Epigenetics Regulating Inflammation in Cancer and Aging. Front Cell Dev Biol 2022; 10:929708. [PMID: 35903542 PMCID: PMC9314556 DOI: 10.3389/fcell.2022.929708] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 06/09/2022] [Indexed: 12/14/2022] Open
Abstract
Inflammation is a defining factor in disease progression; epigenetic modifications of this first line of defence pathway can affect many physiological and pathological conditions, like aging and tumorigenesis. Inflammageing, one of the hallmarks of aging, represents a chronic, low key but a persistent inflammatory state. Oxidative stress, alterations in mitochondrial DNA (mtDNA) copy number and mis-localized extra-mitochondrial mtDNA are suggested to directly induce various immune response pathways. This could ultimately perturb cellular homeostasis and lead to pathological consequences. Epigenetic remodelling of mtDNA by DNA methylation, post-translational modifications of mtDNA binding proteins and regulation of mitochondrial gene expression by nuclear DNA or mtDNA encoded non-coding RNAs, are suggested to directly correlate with the onset and progression of various types of cancer. Mitochondria are also capable of regulating immune response to various infections and tissue damage by producing pro- or anti-inflammatory signals. This occurs by altering the levels of mitochondrial metabolites and reactive oxygen species (ROS) levels. Since mitochondria are known as the guardians of the inflammatory response, it is plausible that mitochondrial epigenetics might play a pivotal role in inflammation. Hence, this review focuses on the intricate dynamics of epigenetic alterations of inflammation, with emphasis on mitochondria in cancer and aging.
Collapse
Affiliation(s)
- Debmita Chatterjee
- Biophysics and Structural Genomics Division, Saha Institute of Nuclear Physics, Kolkata, India
- *Correspondence: Oishee Chakrabarti, ; Debmita Chatterjee, ; Palamou Das,
| | - Palamou Das
- Biophysics and Structural Genomics Division, Saha Institute of Nuclear Physics, Kolkata, India
- Homi Bhabha National Institute, Mumbai, India
- *Correspondence: Oishee Chakrabarti, ; Debmita Chatterjee, ; Palamou Das,
| | - Oishee Chakrabarti
- Biophysics and Structural Genomics Division, Saha Institute of Nuclear Physics, Kolkata, India
- Homi Bhabha National Institute, Mumbai, India
- *Correspondence: Oishee Chakrabarti, ; Debmita Chatterjee, ; Palamou Das,
| |
Collapse
|
6
|
Patel N, Yaqoob MM, Aksentijevic D. Cardiac metabolic remodelling in chronic kidney disease. Nat Rev Nephrol 2022; 18:524-537. [DOI: 10.1038/s41581-022-00576-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/14/2022] [Indexed: 11/09/2022]
|
7
|
Nusier M, Shah AK, Dhalla NS. Structure-Function Relationships and Modifications of Cardiac Sarcoplasmic Reticulum Ca2+-Transport. Physiol Res 2022; 70:S443-S470. [DOI: 10.33549/physiolres.934805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Sarcoplasmic reticulum (SR) is a specialized tubular network, which not only maintains the intracellular concentration of Ca2+ at a low level but is also known to release and accumulate Ca2+ for the occurrence of cardiac contraction and relaxation, respectively. This subcellular organelle is composed of several phospholipids and different Ca2+-cycling, Ca2+-binding and regulatory proteins, which work in a coordinated manner to determine its function in cardiomyocytes. Some of the major proteins in the cardiac SR membrane include Ca2+-pump ATPase (SERCA2), Ca2+-release protein (ryanodine receptor), calsequestrin (Ca2+-binding protein) and phospholamban (regulatory protein). The phosphorylation of SR Ca2+-cycling proteins by protein kinase A or Ca2+-calmodulin kinase (directly or indirectly) has been demonstrated to augment SR Ca2+-release and Ca2+-uptake activities and promote cardiac contraction and relaxation functions. The activation of phospholipases and proteases as well as changes in different gene expressions under different pathological conditions have been shown to alter the SR composition and produce Ca2+-handling abnormalities in cardiomyocytes for the development of cardiac dysfunction. The post-translational modifications of SR Ca2+ cycling proteins by processes such as oxidation, nitrosylation, glycosylation, lipidation, acetylation, sumoylation, and O GlcNacylation have also been reported to affect the SR Ca2+ release and uptake activities as well as cardiac contractile activity. The SR function in the heart is also influenced in association with changes in cardiac performance by several hormones including thyroid hormones and adiponectin as well as by exercise-training. On the basis of such observations, it is suggested that both Ca2+-cycling and regulatory proteins in the SR membranes are intimately involved in determining the status of cardiac function and are thus excellent targets for drug development for the treatment of heart disease.
Collapse
Affiliation(s)
| | | | - NS Dhalla
- Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen, Research Centre, 351 Tache Avenue, Winnipeg, MB, R2H 2A6 Canada.
| |
Collapse
|
8
|
Mohan R, Jo S, Lockridge A, Ferrington DA, Murray K, Eschenlauer A, Bernal-Mizrachi E, Fujitani Y, Alejandro EU. OGT Regulates Mitochondrial Biogenesis and Function via Diabetes Susceptibility Gene Pdx1. Diabetes 2021; 70:2608-2625. [PMID: 34462257 PMCID: PMC8564412 DOI: 10.2337/db21-0468] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 08/19/2021] [Indexed: 12/26/2022]
Abstract
O-GlcNAc transferase (OGT), a nutrient sensor sensitive to glucose flux, is highly expressed in the pancreas. However, the role of OGT in the mitochondria of β-cells is unexplored. In this study, we identified the role of OGT in mitochondrial function in β-cells. Constitutive deletion of OGT (βOGTKO) or inducible ablation in mature β-cells (iβOGTKO) causes distinct effects on mitochondrial morphology and function. Islets from βOGTKO, but not iβOGTKO, mice display swollen mitochondria, reduced glucose-stimulated oxygen consumption rate, ATP production, and glycolysis. Alleviating endoplasmic reticulum stress by genetic deletion of Chop did not rescue the mitochondrial dysfunction in βOGTKO mice. We identified altered islet proteome between βOGTKO and iβOGTKO mice. Pancreatic and duodenal homeobox 1 (Pdx1) was reduced in in βOGTKO islets. Pdx1 overexpression increased insulin content and improved mitochondrial morphology and function in βOGTKO islets. These data underscore the essential role of OGT in regulating β-cell mitochondrial morphology and bioenergetics. In conclusion, OGT couples nutrient signal and mitochondrial function to promote normal β-cell physiology.
Collapse
Affiliation(s)
- Ramkumar Mohan
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN
| | - Seokwon Jo
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN
| | - Amber Lockridge
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN
| | - Deborah A Ferrington
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota Medical School, Minneapolis, MN
| | - Kevin Murray
- University of Minnesota Informatics Institute, University of Minnesota Medical School, Minneapolis, MN
| | - Arthur Eschenlauer
- University of Minnesota Informatics Institute, University of Minnesota Medical School, Minneapolis, MN
| | - Ernesto Bernal-Mizrachi
- Miami VA Healthcare System, Miami, FL
- Division of Endocrinology, Diabetes and Metabolism, University of Miami, Miami, FL
| | - Yoshio Fujitani
- Institute for Molecular and Cellular Regulation, Gunma University, Gunma, Japan
| | - Emilyn U Alejandro
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN
| |
Collapse
|
9
|
El Hayek MS, Ernande L, Benitah JP, Gomez AM, Pereira L. The role of hyperglycaemia in the development of diabetic cardiomyopathy. Arch Cardiovasc Dis 2021; 114:748-760. [PMID: 34627704 DOI: 10.1016/j.acvd.2021.08.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 08/02/2021] [Accepted: 08/04/2021] [Indexed: 01/08/2023]
Abstract
Diabetes mellitus is a metabolic disorder with a chronic hyperglycaemic state. Cardiovascular diseases are the primary cause of mortality in patients with diabetes. Increasing evidence supports the existence of diabetic cardiomyopathy, a cardiac dysfunction with impaired cardiac contraction and relaxation, independent of coronary and/or valvular complications. Diabetic cardiomyopathy can lead to heart failure. Several preclinical and clinical studies have aimed to decipher the underlying mechanisms of diabetic cardiomyopathy. Among all the co-factors, hyperglycaemia seems to play an important role in this pathology. Hyperglycaemia has been shown to alter cardiac metabolism and function through several deleterious mechanisms, such as oxidative stress, inflammation, accumulation of advanced glycated end-products and upregulation of the hexosamine biosynthesis pathway. These mechanisms are responsible for the activation of hypertrophic pathways, epigenetic modifications, mitochondrial dysfunction, cell apoptosis, fibrosis and calcium mishandling, leading to cardiac stiffness, as well as contractile and relaxation dysfunction. This review aims to describe the hyperglycaemic-induced alterations that participate in diabetic cardiomyopathy, and their correlation with the severity of the disease and patient mortality, and to provide an overview of cardiac outcomes of glucose-lowering therapy.
Collapse
Affiliation(s)
| | - Laura Ernande
- INSERM U955, Université Paris-Est Créteil (UPEC), 94010 Créteil, France; Department of Cardiology, Institut Mondor de Recherche Biomédicale, INSERM U955-Équipe 8, Faculté de Médecine de Créteil, 94010 Créteil, France
| | | | - Ana-Maria Gomez
- Université Paris-Saclay, INSERM, UMR-S 1180, 92296 Châtenay-Malabry, France
| | - Laetitia Pereira
- Université Paris-Saclay, INSERM, UMR-S 1180, 92296 Châtenay-Malabry, France.
| |
Collapse
|
10
|
Sammy MJ, Connelly AW, Brown JA, Holleman C, Habegger KM, Ballinger SW. Mito-Mendelian interactions alter in vivo glucose metabolism and insulin sensitivity in healthy mice. Am J Physiol Endocrinol Metab 2021; 321:E521-E529. [PMID: 34370595 PMCID: PMC8560378 DOI: 10.1152/ajpendo.00069.2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The regulation of euglycemia is essential for human health with both chronic hypoglycemia and hyperglycemia having detrimental effects. It is well documented that the incidence of type 2 diabetes increases with age and exhibits racial disparity. Interestingly, mitochondrial DNA (mtDNA) damage also accumulates with age and its sequence varies with geographic maternal origins (maternal race). From these two observations, we hypothesized that mtDNA background may contribute to glucose metabolism and insulin sensitivity. Pronuclear transfer was used to generate mitochondrial-nuclear eXchange (MNX) mice to directly test this hypothesis, by assessing physiologic parameters of glucose metabolism in nuclear isogenic C57BL/6J mice harboring either a C57BL/6J (C57n:C57mt wild type-control) or C3H/HeN mtDNA (C57n:C3Hmt-MNX). All mice were fed normal chow diets. MNX mice were significantly leaner, had lower leptin levels, and were more insulin sensitive, with lower modified Homeostatic Model Assessment of Insulin Resistance (mHOMA-IR) values and enhanced insulin action when compared with their control counterparts. Further interrogation of muscle insulin signaling revealed higher phosphorylated Akt/total Akt ratios in MNX animals relative to control, consistent with greater insulin sensitivity. Overall, these results are consistent with the hypothesis that different mtDNA combinations on the same nuclear DNA (nDNA) background can significantly impact glucose metabolism and insulin sensitivity in healthy mice.NEW & NOTEWORTHY Different mitochondrial DNAs on the same nuclear genetic background can significantly impact body composition, glucose metabolism, and insulin sensitivity in healthy mice.
Collapse
Affiliation(s)
- Melissa J Sammy
- Division of Molecular and Cellular Pathology, Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama
- Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Ashley W Connelly
- Division of Molecular and Cellular Pathology, Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Jamelle A Brown
- Division of Molecular and Cellular Pathology, Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama
- Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Cassie Holleman
- Division of Endocrinology, Diabetes & Metabolism, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Kirk M Habegger
- Division of Endocrinology, Diabetes & Metabolism, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Scott W Ballinger
- Division of Molecular and Cellular Pathology, Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama
- Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, Alabama
| |
Collapse
|
11
|
Federico M, De la Fuente S, Palomeque J, Sheu SS. The role of mitochondria in metabolic disease: a special emphasis on heart dysfunction. J Physiol 2021; 599:3477-3493. [PMID: 33932959 PMCID: PMC8424986 DOI: 10.1113/jp279376] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Accepted: 03/18/2021] [Indexed: 01/10/2023] Open
Abstract
Metabolic diseases (MetDs) embrace a series of pathologies characterized by abnormal body glucose usage. The known diseases included in this group are metabolic syndrome, prediabetes and diabetes mellitus types 1 and 2. All of them are chronic pathologies that present metabolic disturbances and are classified as multi-organ diseases. Cardiomyopathy has been extensively described in diabetic patients without overt macrovascular complications. The heart is severely damaged during the progression of the disease; in fact, diabetic cardiomyopathies are the main cause of death in MetDs. Insulin resistance, hyperglycaemia and increased free fatty acid metabolism promote cardiac damage through mitochondria. These organelles supply most of the energy that the heart needs to beat and to control essential cellular functions, including Ca2+ signalling modulation, reactive oxygen species production and apoptotic cell death regulation. Several aspects of common mitochondrial functions have been described as being altered in diabetic cardiomyopathies, including impaired energy metabolism, compromised mitochondrial dynamics, deficiencies in Ca2+ handling, increases in reactive oxygen species production, and a higher probability of mitochondrial permeability transition pore opening. Therefore, the mitochondrial role in MetD-mediated heart dysfunction has been studied extensively to identify potential therapeutic targets for improving cardiac performance. Herein we review the cardiac pathology in metabolic syndrome, prediabetes and diabetes mellitus, focusing on the role of mitochondrial dysfunctions.
Collapse
Affiliation(s)
- Marilen Federico
- Centro de Investigaciones Cardiovasculares, CCT-La Plata-CONICET, Facultad de Cs. Medicas, UNLP, La Plata, Argentina
| | - Sergio De la Fuente
- Center for Translational Medicine, Department of Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107 USA
| | - Julieta Palomeque
- Centro de Investigaciones Cardiovasculares, CCT-La Plata-CONICET, Facultad de Cs. Medicas, UNLP, La Plata, Argentina
- Centro de Altos Estudios en Ciencias Humanas y de la Salud, Universidad Abierta Interamericana, CABA, Argentina
| | - Shey-Shing Sheu
- Center for Translational Medicine, Department of Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107 USA
| |
Collapse
|
12
|
Diaz-Juarez J, Suarez JA, Dillmann WH, Suarez J. Mitochondrial calcium handling and heart disease in diabetes mellitus. Biochim Biophys Acta Mol Basis Dis 2020; 1867:165984. [PMID: 33002576 DOI: 10.1016/j.bbadis.2020.165984] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 09/22/2020] [Accepted: 09/23/2020] [Indexed: 01/23/2023]
Abstract
Diabetes mellitus-induced heart disease, including diabetic cardiomyopathy, is an important medical problem and is difficult to treat. Diabetes mellitus increases the risk for heart failure and decreases cardiac myocyte function, which are linked to changes in cardiac mitochondrial energy metabolism. The free mitochondrial calcium concentration ([Ca2+]m) is fundamental in activating the mitochondrial respiratory chain complexes and ATP production and is also known to regulate the activity of key mitochondrial dehydrogenases. The mitochondrial calcium uniporter complex (MCUC) plays a major role in mediating mitochondrial Ca2+ import, and its expression and function therefore may have a marked impact on cardiac myocyte metabolism and function. Here, we summarize the pathophysiological role of [Ca2+]m handling and MCUC in the diabetic heart. In addition, we evaluate potential therapeutic targets, directed to the machinery that regulates mitochondrial calcium handling, to alleviate diabetes-related cardiac disease.
Collapse
Affiliation(s)
- Julieta Diaz-Juarez
- Department of Pharmacology, Instituto Nacional de Cardiología, Juan Badiano No. 1, Col. Seccion XVI, 14080 Tlalpan, Ciudad de Mexico, Mexico
| | - Jorge A Suarez
- Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Wolfgang H Dillmann
- Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Jorge Suarez
- Department of Medicine, University of California, San Diego, La Jolla, CA, USA.
| |
Collapse
|
13
|
Brown JA, Sammy MJ, Ballinger SW. An evolutionary, or "Mitocentric" perspective on cellular function and disease. Redox Biol 2020; 36:101568. [PMID: 32512469 PMCID: PMC7281786 DOI: 10.1016/j.redox.2020.101568] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 05/01/2020] [Accepted: 05/05/2020] [Indexed: 12/11/2022] Open
Abstract
The incidence of common, metabolic diseases (e.g. obesity, cardiovascular disease, diabetes) with complex genetic etiology has been steadily increasing nationally and globally. While identification of a genetic model that explains susceptibility and risk for these diseases has been pursued over several decades, no clear paradigm has yet been found to disentangle the genetic basis of polygenic/complex disease development. Since the evolution of the eukaryotic cell involved a symbiotic interaction between the antecedents of the mitochondrion and nucleus (which itself is a genetic hybrid), we suggest that this history provides a rational basis for investigating whether genetic interaction and co-evolution of these genomes still exists. We propose that both mitochondrial and Mendelian, or "mito-Mendelian" genetics play a significant role in cell function, and thus disease risk. This paradigm contemplates the natural variation and co-evolution of both mitochondrial and nuclear DNA backgrounds on multiple mitochondrial functions that are discussed herein, including energy production, cell signaling and immune response, which collectively can influence disease development. At the nexus of these processes is the economy of mitochondrial metabolism, programmed by both mitochondrial and nuclear genomes.
Collapse
Affiliation(s)
- Jamelle A Brown
- Department of Pathology, Division of Molecular and Cellular Pathology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Melissa J Sammy
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Scott W Ballinger
- Department of Pathology, Division of Molecular and Cellular Pathology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA.
| |
Collapse
|
14
|
Vozáriková V, Kunová N, Bauer JA, Frankovský J, Kotrasová V, Procházková K, Džugasová V, Kutejová E, Pevala V, Nosek J, Tomáška Ľ. Mitochondrial HMG-Box Containing Proteins: From Biochemical Properties to the Roles in Human Diseases. Biomolecules 2020; 10:biom10081193. [PMID: 32824374 PMCID: PMC7463775 DOI: 10.3390/biom10081193] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Revised: 08/11/2020] [Accepted: 08/13/2020] [Indexed: 12/14/2022] Open
Abstract
Mitochondrial DNA (mtDNA) molecules are packaged into compact nucleo-protein structures called mitochondrial nucleoids (mt-nucleoids). Their compaction is mediated in part by high-mobility group (HMG)-box containing proteins (mtHMG proteins), whose additional roles include the protection of mtDNA against damage, the regulation of gene expression and the segregation of mtDNA into daughter organelles. The molecular mechanisms underlying these functions have been identified through extensive biochemical, genetic, and structural studies, particularly on yeast (Abf2) and mammalian mitochondrial transcription factor A (TFAM) mtHMG proteins. The aim of this paper is to provide a comprehensive overview of the biochemical properties of mtHMG proteins, the structural basis of their interaction with DNA, their roles in various mtDNA transactions, and the evolutionary trajectories leading to their rapid diversification. We also describe how defects in the maintenance of mtDNA in cells with dysfunctional mtHMG proteins lead to different pathologies at the cellular and organismal level.
Collapse
Affiliation(s)
- Veronika Vozáriková
- Department of Genetics, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovičova 6, Mlynská dolina B-1, 842 15 Bratislava, Slovakia; (V.V.); (J.F.); (K.P.); (V.D.)
| | - Nina Kunová
- Institute of Molecular Biology, Slovak Academy of Sciences, Dúbravská cesta 21, 845 51 Bratislava, Slovakia; (N.K.); (J.A.B.); (V.K.); (E.K.); (V.P.)
| | - Jacob A. Bauer
- Institute of Molecular Biology, Slovak Academy of Sciences, Dúbravská cesta 21, 845 51 Bratislava, Slovakia; (N.K.); (J.A.B.); (V.K.); (E.K.); (V.P.)
| | - Ján Frankovský
- Department of Genetics, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovičova 6, Mlynská dolina B-1, 842 15 Bratislava, Slovakia; (V.V.); (J.F.); (K.P.); (V.D.)
| | - Veronika Kotrasová
- Institute of Molecular Biology, Slovak Academy of Sciences, Dúbravská cesta 21, 845 51 Bratislava, Slovakia; (N.K.); (J.A.B.); (V.K.); (E.K.); (V.P.)
| | - Katarína Procházková
- Department of Genetics, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovičova 6, Mlynská dolina B-1, 842 15 Bratislava, Slovakia; (V.V.); (J.F.); (K.P.); (V.D.)
| | - Vladimíra Džugasová
- Department of Genetics, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovičova 6, Mlynská dolina B-1, 842 15 Bratislava, Slovakia; (V.V.); (J.F.); (K.P.); (V.D.)
| | - Eva Kutejová
- Institute of Molecular Biology, Slovak Academy of Sciences, Dúbravská cesta 21, 845 51 Bratislava, Slovakia; (N.K.); (J.A.B.); (V.K.); (E.K.); (V.P.)
| | - Vladimír Pevala
- Institute of Molecular Biology, Slovak Academy of Sciences, Dúbravská cesta 21, 845 51 Bratislava, Slovakia; (N.K.); (J.A.B.); (V.K.); (E.K.); (V.P.)
| | - Jozef Nosek
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovičova 6, Mlynská dolina CH-1, 842 15 Bratislava, Slovakia;
| | - Ľubomír Tomáška
- Department of Genetics, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovičova 6, Mlynská dolina B-1, 842 15 Bratislava, Slovakia; (V.V.); (J.F.); (K.P.); (V.D.)
- Correspondence: ; Tel.: +421-2-90149-433
| |
Collapse
|
15
|
Fang Y, Akimoto M, Mayanagi K, Hatano A, Matsumoto M, Matsuda S, Yasukawa T, Kang D. Chemical acetylation of mitochondrial transcription factor A occurs on specific lysine residues and affects its ability to change global DNA topology. Mitochondrion 2020; 53:99-108. [PMID: 32439622 DOI: 10.1016/j.mito.2020.05.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 05/08/2020] [Accepted: 05/14/2020] [Indexed: 12/20/2022]
Abstract
Chemical acetylation is postulated to occur in mitochondria. Mitochondrial transcription factor A (TFAM or mtTFA), a mitochondrial transcription initiation factor as well as the major mitochondrial nucleoid protein coating the entire mitochondrial genome, is proposed to be acetylated in animals and cultured cells. This study investigated the properties of human TFAM, in conjunction with the mechanism and effects of TFAM acetylation in vitro. Using highly purified recombinant human TFAM and 3 kb circular DNA as a downsized mtDNA model, we studied how the global TFAM-DNA interaction is affected/regulated by the quantitative TFAM-DNA relationship and TFAM acetylation. Results showed that the TFAM-DNA ratio strictly affects the TFAM property to unwind circular DNA in the presence of topoisomerase I. Mass spectrometry analysis showed that in vitro chemical acetylation of TFAM with acetyl-coenzyme A occurs preferentially on specific lysine residues, including those reported to be acetylated in exogenously expressed TFAM in cultured human cells, indicating that chemical acetylation plays a crucial role in TFAM acetylation in mitochondria. Intriguingly, the modification significantly decreased TFAM's DNA-unwinding ability, while its DNA-binding ability was largely unaffected. Altogether, we propose TFAM is chemically acetylated in vivo, which could change mitochondrial DNA topology, leading to copy number and gene expression modulation.
Collapse
Affiliation(s)
- Yuan Fang
- Department of Clinical Chemistry and Laboratory Medicine, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka-shi, Fukuoka 812-8582, Japan
| | - Masaru Akimoto
- Department of Clinical Chemistry and Laboratory Medicine, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka-shi, Fukuoka 812-8582, Japan; Department of Clinical Chemistry and Laboratory Medicine, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka-shi, Fukuoka 812-8582, Japan
| | - Kouta Mayanagi
- Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka-shi, Fukuoka 812-8582, Japan
| | - Atsushi Hatano
- Department of Omics and Systems Biology, Graduate School of Medical and Dental Sciences, Niigata University, 757 Ichibancho, Asahimachi-dori, Chuo-ku, Niigata-shi, Niigata 951-8510, Japan
| | - Masaki Matsumoto
- Department of Omics and Systems Biology, Graduate School of Medical and Dental Sciences, Niigata University, 757 Ichibancho, Asahimachi-dori, Chuo-ku, Niigata-shi, Niigata 951-8510, Japan
| | - Shigeru Matsuda
- Department of Clinical Chemistry and Laboratory Medicine, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka-shi, Fukuoka 812-8582, Japan
| | - Takehiro Yasukawa
- Department of Clinical Chemistry and Laboratory Medicine, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka-shi, Fukuoka 812-8582, Japan.
| | - Dongchon Kang
- Department of Clinical Chemistry and Laboratory Medicine, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka-shi, Fukuoka 812-8582, Japan
| |
Collapse
|
16
|
Aspirin Improves Nonalcoholic Fatty Liver Disease and Atherosclerosis through Regulation of the PPAR δ-AMPK-PGC-1 α Pathway in Dyslipidemic Conditions. BIOMED RESEARCH INTERNATIONAL 2020; 2020:7806860. [PMID: 32258142 PMCID: PMC7106881 DOI: 10.1155/2020/7806860] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Revised: 02/10/2020] [Accepted: 02/24/2020] [Indexed: 02/08/2023]
Abstract
This study is aimed at elucidating how aspirin could systemically and simultaneously normalize nonalcoholic fatty liver disease (NAFLD) and atherosclerosis through both in vitro and in vivo studies in hyperlipidemic conditions. We evaluated the effects and mechanism of aspirin on the levels of various biomarkers related to NAFLD, atherosclerosis, and oxidative phosphorylation in cells and animals of hyperlipidemic conditions. The protein levels of biomarkers (PPARδ, AMPK, and PGC-1α) involved in oxidative phosphorylation in both the vascular endothelial and liver cells were elevated by the aspirin in hyperlipidemic condition. Also in the stimulation pathway of oxidative phosphorylation by aspirin, PPARδ was a superior regulator than AMPK and PGC-1α in HepG2 cells. In the vascular endothelial cells, the phosphorylated endothelial nitric oxide synthase level was increased by the treatment. The protein levels of biomarkers related to lipid synthesis were decreased by the treatment in the liver cells. In rabbits administered with cholesterol diet, the levels of triglyceride, HDL-cholesterol, and alanine amino transferase in serums were ameliorated by the aspirin treatment, the levels of ATP and TNFα were increased or decreased, respectively, by the aspirin in liver and aorta tissues, and mannose receptor and C-C chemokine receptor type 2 levels were increased or decreased by the aspirin in spleen, respectively. The elevated levels of macrophage antigen, angiotensin II type1 receptor, and lipid accumulation were decreased in both the liver and aorta tissues in the aspirin-treated group. In conclusion, aspirin can systemically and simultaneously ameliorate NAFLD and atherosclerosis by inhibiting lipid biosynthesis and inflammation and by elevating catabolic metabolism through the activation of the PPARδ-AMPK-PGC-1α pathway. Furthermore, aspirin may normalize atherosclerosis and NAFLD by modulating the mannose receptor and CCR2 in macrophages.
Collapse
|
17
|
Esch N, Jo S, Moore M, Alejandro EU. Nutrient Sensor mTOR and OGT: Orchestrators of Organelle Homeostasis in Pancreatic β-Cells. J Diabetes Res 2020; 2020:8872639. [PMID: 33457426 PMCID: PMC7787834 DOI: 10.1155/2020/8872639] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 11/06/2020] [Accepted: 11/24/2020] [Indexed: 02/08/2023] Open
Abstract
The purpose of this review is to integrate the role of nutrient-sensing pathways into β-cell organelle dysfunction prompted by nutrient excess during type 2 diabetes (T2D). T2D encompasses chronic hyperglycemia, hyperlipidemia, and inflammation, which each contribute to β-cell failure. These factors can disrupt the function of critical β-cell organelles, namely, the ER, mitochondria, lysosomes, and autophagosomes. Dysfunctional organelles cause defects in insulin synthesis and secretion and activate apoptotic pathways if homeostasis is not restored. In this review, we will focus on mTORC1 and OGT, two major anabolic nutrient sensors with important roles in β-cell physiology. Though acute stimulation of these sensors frequently improves β-cell function and promotes adaptation to cell stress, chronic and sustained activity disturbs organelle homeostasis. mTORC1 and OGT regulate organelle function by influencing the expression and activities of key proteins, enzymes, and transcription factors, as well as by modulating autophagy to influence clearance of defective organelles. In addition, mTORC1 and OGT activity influence islet inflammation during T2D, which can further disrupt organelle and β-cell function. Therapies for T2D that fine-tune the activity of these nutrient sensors have yet to be developed, but the important role of mTORC1 and OGT in organelle homeostasis makes them promising targets to improve β-cell function and survival.
Collapse
Affiliation(s)
- Nicholas Esch
- Department of Integrative Biology & Physiology, University of Minnesota Medical School, University of Minnesota, Minneapolis, Minnesota, USA
| | - Seokwon Jo
- Department of Integrative Biology & Physiology, University of Minnesota Medical School, University of Minnesota, Minneapolis, Minnesota, USA
| | - Mackenzie Moore
- Department of Integrative Biology & Physiology, University of Minnesota Medical School, University of Minnesota, Minneapolis, Minnesota, USA
- Department of Surgery, University of Minnesota Medical School, University of Minnesota, Minneapolis, Minnesota, USA
| | - Emilyn U. Alejandro
- Department of Integrative Biology & Physiology, University of Minnesota Medical School, University of Minnesota, Minneapolis, Minnesota, USA
| |
Collapse
|
18
|
Sharma N, Pasala MS, Prakash A. Mitochondrial DNA: Epigenetics and environment. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2019; 60:668-682. [PMID: 31335990 PMCID: PMC6941438 DOI: 10.1002/em.22319] [Citation(s) in RCA: 98] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 07/08/2019] [Accepted: 07/11/2019] [Indexed: 05/22/2023]
Abstract
Maintenance of the mitochondrial genome is essential for proper cellular function. For this purpose, mitochondrial DNA (mtDNA) needs to be faithfully replicated, transcribed, translated, and repaired in the face of constant onslaught from endogenous and environmental agents. Although only 13 polypeptides are encoded within mtDNA, the mitochondrial proteome comprises over 1500 proteins that are encoded by nuclear genes and translocated to the mitochondria for the purpose of maintaining mitochondrial function. Regulation of mtDNA and mitochondrial proteins by epigenetic changes and post-translational modifications facilitate crosstalk between the nucleus and the mitochondria and ultimately lead to the maintenance of cellular health and homeostasis. DNA methyl transferases have been identified in the mitochondria implicating that methylation occurs within this organelle; however, the extent to which mtDNA is methylated has been debated for many years. Mechanisms of demethylation within this organelle have also been postulated, but the exact mechanisms and their outcomes is still an active area of research. Mitochondrial dysfunction in the form of altered gene expression and ATP production, resulting from epigenetic changes, can lead to various conditions including aging-related neurodegenerative disorders, altered metabolism, changes in circadian rhythm, and cancer. Here, we provide an overview of the epigenetic regulation of mtDNA via methylation, long and short noncoding RNAs, and post-translational modifications of nucleoid proteins (as mitochondria lack histones). We also highlight the influence of xenobiotics such as airborne environmental pollutants, contamination from heavy metals, and therapeutic drugs on mtDNA methylation. Environ. Mol. Mutagen., 60:668-682, 2019. © 2019 Wiley Periodicals, Inc.
Collapse
|
19
|
Dai XG, Li T, Huang WB, Zeng ZH, Li Q, Yang Y, Duan ZP, Wang YJ, Ai YH. Upregulation of Mitochondrial Transcription Factor A Promotes the Repairment of Renal Tubular Epithelial Cells in Sepsis by Inhibiting Reactive Oxygen Species-Mediated Toll-Like Receptor 4/p38MAPK Signaling. Pathobiology 2019; 86:263-273. [PMID: 31430762 DOI: 10.1159/000501789] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Accepted: 06/09/2019] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Mitochondrial transcription factor A (TFAM) plays multiple pathophysiologic roles in mitochondrial DNA (mtDNA) maintenance. However, the role of TFAM in sepsis-induced acute kidney injury (AKI) remains largely unknown. METHODS Lipopolysaccharide (LPS) treatment of HK-2 cells mimics the in vitro model of AKI inflammation. pcDNA3.1 plasmid was used to construct pcDNA3.1-TFAM. sh-TFAM-543, sh-TFAM-717, sh-TFAM-765, sh-TFAM-904 and pcDNA3.1-TFAM were transfected into HK-2 cells using Lipofectamine 2000. MtDNA transcriptional levels were detected by quantitative real-time polymerase chain reaction (qRT-PCR). 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di-phenytetrazoliumromide (MTT) assay was performed to assess the cell viability. Changes in reactive oxygen species (ROS) and mitochondrial membrane potential in HK-2 cells were detected using the corresponding kits. Immunofluorescence experiment was used to investigate the displacement of TFAM. mRNA and protein expression levels of TFAM and its related genes were measured by qRT-PCR and western blot respectively. Mice in sepsis were administered cecal ligation and puncture surgery. RESULTS LPS treatment was a non-lethal influencing factor, leading to the upregulation of ROS levels and downregulation of mtDNA copy number and NADH dehydrogenase subunit-1 (ND1) expression, and caused damage to the mitochondria. As the LPS treatment time increased, TFAM was displaced from the periphery of the nucleus to cytoplasm. TFAM reduced ROS and P38MAPK levels by inhibiting toll-like receptor 4 (TLR4) expression, ultimately inhibiting inflammation and repairing mtDNA. CONCLUSIONS Our results indicate that TFAM repairs mtDNA by blocking the TLR4/ROS/P38MAPK signaling pathway in inflammatory cells, thereby repairing septic tubular epithelial cells, and TFAM may serve as a new target for sepsis therapy.
Collapse
Affiliation(s)
- Xin-Gui Dai
- Department of Intensive Care Unit, Xiangya Hospital, Central South University, Changsha, China.,Department of Critical Care Medicine, the First People's Hospital of Chenzhou, Chenzhou, China
| | - Tao Li
- Department of Critical Care Medicine, the First People's Hospital of Chenzhou, Chenzhou, China
| | - Wei-Bo Huang
- Department of Urology, Huashan Hospital, Fudan University, Shanghai, China
| | - Zhen-Hua Zeng
- Department of Critical Care Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Qiong Li
- Department of Critical Care Medicine, the First People's Hospital of Chenzhou, Chenzhou, China
| | - Yang Yang
- Department of Critical Care Medicine, the First People's Hospital of Chenzhou, Chenzhou, China
| | - Ze-Peng Duan
- Department of Critical Care Medicine, the First People's Hospital of Chenzhou, Chenzhou, China
| | - Yu-Jing Wang
- Department of Critical Care Medicine, the First People's Hospital of Chenzhou, Chenzhou, China
| | - Yu-Hang Ai
- Department of Intensive Care Unit, Xiangya Hospital, Central South University, Changsha, China,
| |
Collapse
|
20
|
Chang JYA, Yu F, Shi L, Ko ML, Ko GYP. Melatonin Affects Mitochondrial Fission/Fusion Dynamics in the Diabetic Retina. J Diabetes Res 2019; 2019:8463125. [PMID: 31098384 PMCID: PMC6487082 DOI: 10.1155/2019/8463125] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 01/14/2019] [Accepted: 02/10/2019] [Indexed: 02/07/2023] Open
Abstract
Mitochondrial fission and fusion are dependent on cellular nutritional states, and maintaining this dynamics is critical for the health of cells. Starvation triggers mitochondrial fusion to maintain bioenergetic efficiency, but during nutrient overloads (as with hyperglycemic conditions), fragmenting mitochondria is a way to store nutrients to avoid waste of energy. In addition to ATP production, mitochondria play an important role in buffering intracellular calcium (Ca2+). We found that in cultured 661W cells, a photoreceptor-derived cell line, hyperglycemic conditions triggered an increase of the expression of dynamin-related protein 1 (DRP1), a protein marker of mitochondrial fission, and a decrease of mitofusin 2 (MFN2), a protein for mitochondrial fusion. Further, these hyperglycemic cells also had decreased mitochondrial Ca2+ but increased cytosolic Ca2+. Treating these hyperglycemic cells with melatonin, a multifaceted antioxidant, averted hyperglycemia-altered mitochondrial fission-and-fusion dynamics and mitochondrial Ca2+ levels. To mimic how people most commonly take melatonin supplements, we gave melatonin to streptozotocin- (STZ-) induced type 1 diabetic mice by daily oral gavage and determined the effects of melatonin on diabetic eyes. We found that melatonin was not able to reverse the STZ-induced systemic hyperglycemic condition, but it prevented STZ-induced damage to the neural retina and retinal microvasculature. The beneficial effects of melatonin in the neural retina in part were through alleviating STZ-caused changes in mitochondrial dynamics and Ca2+ buffering.
Collapse
Affiliation(s)
- Janet Ya-An Chang
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, USA
- Interdisciplinary Toxicology Program, Texas A&M University, College Station, Texas, USA
| | - Fei Yu
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, USA
| | - Liheng Shi
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, USA
| | - Michael L. Ko
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, USA
| | - Gladys Y.-P. Ko
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, USA
- Interdisciplinary Toxicology Program, Texas A&M University, College Station, Texas, USA
- Texas A&M Institute of Neuroscience, Texas A&M University, College Station, Texas, USA
| |
Collapse
|
21
|
Mitochondrial - nuclear genetic interaction modulates whole body metabolism, adiposity and gene expression in vivo. EBioMedicine 2018; 36:316-328. [PMID: 30232024 PMCID: PMC6197375 DOI: 10.1016/j.ebiom.2018.08.036] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 08/14/2018] [Accepted: 08/15/2018] [Indexed: 01/16/2023] Open
Abstract
We hypothesized that changes in the mitochondrial DNA (mtDNA) would significantly influence whole body metabolism, adiposity and gene expression in response to diet. Because it is not feasible to directly test these predictions in humans we used Mitochondrial-Nuclear eXchange mice, which have reciprocally exchanged nuclear and mitochondrial genomes between different Mus musculus strains. Results demonstrate that nuclear-mitochondrial genetic background combination significantly alters metabolic efficiency and body composition. Comparative RNA sequencing analysis in adipose tissues also showed a clear influence of the mtDNA on regulating nuclear gene expression on the same nuclear background (up to a 10-fold change in the number of differentially expressed genes), revealing that neither Mendelian nor mitochondrial genetics unilaterally control gene expression. Additional analyses indicate that nuclear-mitochondrial genome combination modulates gene expression in a manner heretofore not described. These findings provide a new framework for understanding complex genetic disease susceptibility.
Collapse
|
22
|
Panahi G, Pasalar P, Zare M, Rizzuto R, Meshkani R. MCU-knockdown attenuates high glucose-induced inflammation through regulating MAPKs/NF-κB pathways and ROS production in HepG2 cells. PLoS One 2018; 13:e0196580. [PMID: 29709004 PMCID: PMC5927441 DOI: 10.1371/journal.pone.0196580] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 04/16/2018] [Indexed: 01/25/2023] Open
Abstract
Mitochondrial Ca2+ is a key regulator of organelle physiology and the excessive increase in mitochondrial calcium is associated with the oxidative stress. In the present study, we investigated the molecular mechanisms linking mitochondrial calcium to inflammatory and coagulative responses in hepatocytes exposed to high glucose (HG) (33mM glucose). Treatment of HepG2 cells with HG for 24 h induced insulin resistance, as demonstrated by an impairment of insulin-stimulated Akt phosphorylation. HepG2 treatment with HG led to an increase in mitochondrial Ca2+ uptake, while cytosolic calcium remained unchanged. Inhibition of MCU by lentiviral-mediated shRNA prevented mitochondrial calcium uptake and downregulated the inflammatory (TNF-α, IL-6) and coagulative (PAI-1 and FGA) mRNA expression in HepG2 cells exposed to HG. The protection from HG-induced inflammation by MCU inhibition was accompanied by a decrease in the generation of reactive oxygen species (ROS). Importantly, MCU inhibition in HepG2 cells abrogated the phosphorylation of p38, JNK and IKKα/IKKβ in HG treated cells. Taken together, these data suggest that MCU inhibition may represent a promising therapy for prevention of deleterious effects of obesity and metabolic diseases.
Collapse
Affiliation(s)
- Ghodratollah Panahi
- Department of Biochemistry, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, I.R Iran
| | - Parvin Pasalar
- Department of Biochemistry, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, I.R Iran
| | - Mina Zare
- Recombinant Protein Laboratory, Department of Biochemistry, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Rosario Rizzuto
- Department of Biomedical Sciences, University of Padova, Padua, Italy
| | - Reza Meshkani
- Department of Biochemistry, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, I.R Iran
- * E-mail:
| |
Collapse
|
23
|
King GA, Hashemi Shabestari M, Taris KKH, Pandey AK, Venkatesh S, Thilagavathi J, Singh K, Krishna Koppisetti R, Temiakov D, Roos WH, Suzuki CK, Wuite GJL. Acetylation and phosphorylation of human TFAM regulate TFAM-DNA interactions via contrasting mechanisms. Nucleic Acids Res 2018; 46:3633-3642. [PMID: 29897602 PMCID: PMC5909435 DOI: 10.1093/nar/gky204] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 03/05/2018] [Accepted: 03/08/2018] [Indexed: 01/13/2023] Open
Abstract
Mitochondrial transcription factor A (TFAM) is essential for the maintenance, expression and transmission of mitochondrial DNA (mtDNA). However, mechanisms for the post-translational regulation of TFAM are poorly understood. Here, we show that TFAM is lysine acetylated within its high-mobility-group box 1, a domain that can also be serine phosphorylated. Using bulk and single-molecule methods, we demonstrate that site-specific phosphoserine and acetyl-lysine mimics of human TFAM regulate its interaction with non-specific DNA through distinct kinetic pathways. We show that higher protein concentrations of both TFAM mimics are required to compact DNA to a similar extent as the wild-type. Compaction is thought to be crucial for regulating mtDNA segregation and expression. Moreover, we reveal that the reduced DNA binding affinity of the acetyl-lysine mimic arises from a lower on-rate, whereas the phosphoserine mimic displays both a decreased on-rate and an increased off-rate. Strikingly, the increased off-rate of the phosphoserine mimic is coupled to a significantly faster diffusion of TFAM on DNA. These findings indicate that acetylation and phosphorylation of TFAM can fine-tune TFAM-DNA binding affinity, to permit the discrete regulation of mtDNA dynamics. Furthermore, our results suggest that phosphorylation could additionally regulate transcription by altering the ability of TFAM to locate promoter sites.
Collapse
Affiliation(s)
- Graeme A King
- Department of Physics and Astronomy and LaserLaB, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Maryam Hashemi Shabestari
- Department of Physics and Astronomy and LaserLaB, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Kees-Karel H Taris
- Department of Physics and Astronomy and LaserLaB, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Ashutosh K Pandey
- Department of Microbiology, Biochemistry and Molecular Genetics, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
| | - Sundararajan Venkatesh
- Department of Microbiology, Biochemistry and Molecular Genetics, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
| | - Jayapalraja Thilagavathi
- Department of Microbiology, Biochemistry and Molecular Genetics, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
| | - Kamalendra Singh
- Department of Microbiology, Biochemistry and Molecular Genetics, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
- Department of Molecular Microbiology and Immunology, Christopher Bond Life Sciences Center, University of Missouri School of Medicine, Columbia, MO 65211, USA
- Department of Laboratory Medicine, Division of Clinical Microbiology, Karolinska Institutet, 171 77 Solna, Sweden
| | - Rama Krishna Koppisetti
- Department of Molecular Microbiology and Immunology, Christopher Bond Life Sciences Center, University of Missouri School of Medicine, Columbia, MO 65211, USA
| | - Dmitry Temiakov
- Department of Cell Biology, Rowan University, School of Osteopathic Medicine, Stratford, NJ 08084, USA
| | - Wouter H Roos
- Department of Molecular Biophysics, Zernike Instituut, Rijksuniversiteit Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Carolyn K Suzuki
- Department of Microbiology, Biochemistry and Molecular Genetics, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
| | - Gijs J L Wuite
- Department of Physics and Astronomy and LaserLaB, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| |
Collapse
|
24
|
Kang I, Chu CT, Kaufman BA. The mitochondrial transcription factor TFAM in neurodegeneration: emerging evidence and mechanisms. FEBS Lett 2018; 592:793-811. [PMID: 29364506 PMCID: PMC5851836 DOI: 10.1002/1873-3468.12989] [Citation(s) in RCA: 177] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 01/18/2018] [Accepted: 01/19/2018] [Indexed: 12/30/2022]
Abstract
The mitochondrial transcription factor A, or TFAM, is a mitochondrial DNA (mtDNA)-binding protein essential for genome maintenance. TFAM functions in determining the abundance of the mitochondrial genome by regulating packaging, stability, and replication. More recently, TFAM has been shown to play a central role in the mtDNA stress-mediated inflammatory response. Emerging evidence indicates that decreased mtDNA copy number is associated with several aging-related pathologies; however, little is known about the association of TFAM abundance and disease. In this Review, we evaluate the potential associations of altered TFAM levels or mtDNA copy number with neurodegeneration. We also describe potential mechanisms by which mtDNA replication, transcription initiation, and TFAM-mediated endogenous danger signals may impact mitochondrial homeostasis in Alzheimer, Huntington, Parkinson, and other neurodegenerative diseases.
Collapse
Affiliation(s)
- Inhae Kang
- Department of Food Science and Nutrition, Jeju National University, Jeju, Korea
- Division of Cardiology, Vascular Medicine Institute, Department of Medicine Center for Metabolic and Mitochondrial Medicine (C3M), University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Charleen T. Chu
- Department of Pathology, Center for Neuroscience, Pittsburgh Institute for Neurodegenerative Diseases, Conformational Protein Diseases Center, and the McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Brett A. Kaufman
- Division of Cardiology, Vascular Medicine Institute, Department of Medicine Center for Metabolic and Mitochondrial Medicine (C3M), University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| |
Collapse
|
25
|
Lambert M, Bastide B, Cieniewski-Bernard C. Involvement of O-GlcNAcylation in the Skeletal Muscle Physiology and Physiopathology: Focus on Muscle Metabolism. Front Endocrinol (Lausanne) 2018; 9:578. [PMID: 30459708 PMCID: PMC6232757 DOI: 10.3389/fendo.2018.00578] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Accepted: 09/11/2018] [Indexed: 12/13/2022] Open
Abstract
Skeletal muscle represents around 40% of whole body mass. The principal function of skeletal muscle is the conversion of chemical energy toward mechanic energy to ensure the development of force, provide movement and locomotion, and maintain posture. This crucial energy dependence is maintained by the faculty of the skeletal muscle for being a central place as a "reservoir" of amino acids and carbohydrates in the whole body. A fundamental post-translational modification, named O-GlcNAcylation, depends, inter alia, on these nutrients; it consists to the transfer or the removal of a unique monosaccharide (N-acetyl-D-glucosamine) to a serine or threonine hydroxyl group of nucleocytoplasmic and mitochondrial proteins in a dynamic process by the O-GlcNAc Transferase (OGT) and the O-GlcNAcase (OGA), respectively. O-GlcNAcylation has been shown to be strongly involved in crucial intracellular mechanisms through the modulation of signaling pathways, gene expression, or cytoskeletal functions in various organs and tissues, such as the brain, liver, kidney or pancreas, and linked to the etiology of associated diseases. In recent years, several studies were also focused on the role of O-GlcNAcylation in the physiology and the physiopathology of skeletal muscle. These studies were mostly interested in O-GlcNAcylation during muscle exercise or muscle-wasting conditions. Major findings pointed out a different "O-GlcNAc signature" depending on muscle type metabolism at resting, wasting and exercise conditions, as well as depending on acute or long-term exhausting exercise protocol. First insights showed some differential OGT/OGA expression and/or activity associated with some differential stress cellular responses through Reactive Oxygen Species and/or Heat-Shock Proteins. Robust data displayed that these O-GlcNAc changes could lead to (i) a differential modulation of the carbohydrates metabolism, since the majority of enzymes are known to be O-GlcNAcylated, and to (ii) a differential modulation of the protein synthesis/degradation balance since O-GlcNAcylation regulates some key signaling pathways such as Akt/GSK3β, Akt/mTOR, Myogenin/Atrogin-1, Myogenin/Mef2D, Mrf4 and PGC-1α in the skeletal muscle. Finally, such involvement of O-GlcNAcylation in some metabolic processes of the skeletal muscle might be linked to some associated diseases such as type 2 diabetes or neuromuscular diseases showing a critical increase of the global O-GlcNAcylation level.
Collapse
|
26
|
High leukocyte mtDNA content contributes to poor prognosis through ROS-mediated immunosuppression in hepatocellular carcinoma patients. Oncotarget 2017; 7:22834-45. [PMID: 26985767 PMCID: PMC5008404 DOI: 10.18632/oncotarget.8071] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 02/23/2016] [Indexed: 02/06/2023] Open
Abstract
Compelling epidemiological evidences indicate a significant association between leukocyte mitochondrial DNA (mtDNA) content and incidence risk of several malignancies, including hepatocellular carcinoma (HCC). However, whether leukocyte mtDNA content affect prognosis of HCC patients and underlying mechanism has never been explored. In our study, leukocyte mtDNA content was measured in 618 HCC patients and its prognostic value was analyzed. Moreover, we detected the immunophenotypes of peripheral blood mononuclear cells (PBMCs) and plasma concentrations of several cytokines in 40 HCC patients and assessed the modulating effects of mtDNA content on immunosuppression in cell models. Our results showed that HCC patients with high leukocyte mtDNA content exhibited a significantly worse recurrence-free survival (RFS) and overall survival (OS) than those with low leukocyte mtDNA content. Leukocyte mtDNA content and TNM stage exhibited a notable joint effect in prognosis prediction. Furthermore, we found that patients with high leukocyte mtDNA content exhibited a higher frequency of CD4+CD25+FOXP3+ regulatory T (Treg) cells and lower frequency of NK cells in PBMCs and had higher TGF-β1 and lower TNF-α and IFN-γ plasma concentration when compared with those with low leukocyte mtDNA content, which suggests an immunosuppressive status. High leukocyte mtDNA content significantly enhanced the ROS-mediated secretion of TGF-β1, which accounted for higher Treg and lower NK frequency in PBMCs. In a conclusion, our study for the first time demonstrates that leukocyte mtDNA content is an independent prognostic marker complementing TNM stage and associated with an ROS-mediated immunosuppressive phenotype in HCC patients.
Collapse
|
27
|
Singh RM, Waqar T, Howarth FC, Adeghate E, Bidasee K, Singh J. Hyperglycemia-induced cardiac contractile dysfunction in the diabetic heart. Heart Fail Rev 2017; 23:37-54. [DOI: 10.1007/s10741-017-9663-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
28
|
Wang CH, Wei YH. Role of mitochondrial dysfunction and dysregulation of Ca 2+ homeostasis in the pathophysiology of insulin resistance and type 2 diabetes. J Biomed Sci 2017; 24:70. [PMID: 28882140 PMCID: PMC5588717 DOI: 10.1186/s12929-017-0375-3] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 08/29/2017] [Indexed: 12/29/2022] Open
Abstract
Metabolic diseases such as obesity, type 2 diabetes (T2D) and insulin resistance have attracted great attention from biomedical researchers and clinicians because of the astonishing increase in its prevalence. Decrease in the capacity of oxidative metabolism and mitochondrial dysfunction are a major contributor to the development of these metabolic disorders. Recent studies indicate that alteration of intracellular Ca2+ levels and downstream Ca2+-dependent signaling pathways appear to modulate gene transcription and the activities of many enzymes involved in cellular metabolism. Ca2+ uptake into mitochondria modulates a number of Ca2+-dependent proteins and enzymes participating in fatty acids metabolism, tricarboxylic acid cycle, oxidative phosphorylation and apoptosis in response to physiological and pathophysiological conditions. Mitochondrial calcium uniporter (MCU) complex has been identified as a major channel located on the inner membrane to regulate Ca2+ transport into mitochondria. Recent studies of MCU complex have increased our understanding of the modulation of mitochondrial function and retrograde signaling to the nucleus via regulation of the mitochondrial Ca2+ level. Mitochondria couple cellular metabolic state by regulating not only their own Ca2+ levels, but also influence the entire network of cellular Ca2+ signaling. The mitochondria-associated ER membranes (MAMs), which are specialized structures between ER and mitochondria, are responsible for efficient communication between these organelles. Defects in the function or structure of MAMs have been observed in affected tissue cells in metabolic disease or neurodegenerative disorders. We demonstrated that dysregulation of intracellular Ca2+ homeostasis due to mitochondrial dysfunction or defects in the function of MAMs are involved in the pathogenesis of insulin insensitivity and T2D. These observations suggest that mitochondrial dysfunction and disturbance of Ca2+ homeostasis warrant further studies to assist the development of therapeutics for prevention and medication of insulin resistance and T2D.
Collapse
Affiliation(s)
- Chih-Hao Wang
- Center for Mitochondrial Medicine and Free Radical Research, Changhua Christian Hospital, No. 176, 6th Floor, Zhonghua Rd, Changhua City, 500, Taiwan.,Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Shih-Pai, Taipei, 112, Taiwan
| | - Yau-Huei Wei
- Center for Mitochondrial Medicine and Free Radical Research, Changhua Christian Hospital, No. 176, 6th Floor, Zhonghua Rd, Changhua City, 500, Taiwan. .,Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Shih-Pai, Taipei, 112, Taiwan. .,Institute of Biomedical Sciences, Mackay Medical College, Sanzhi, New Taipei City, 252, Taiwan.
| |
Collapse
|
29
|
Guo J, Zhao MH, Shin KT, Niu YJ, Ahn YD, Kim NH, Cui XS. The possible molecular mechanisms of bisphenol A action on porcine early embryonic development. Sci Rep 2017; 7:8632. [PMID: 28819136 PMCID: PMC5561233 DOI: 10.1038/s41598-017-09282-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 07/14/2017] [Indexed: 02/04/2023] Open
Abstract
Bisphenol A (BPA) is an environmental contaminant widely used in the plastic industry. BPA has been demonstrated to be an endocrine disruptor and has an adverse effect on the embryonic development of mammals. However, the mechanism of action of BPA is limited. In this study, we investigated the role and mechanism of BPA in porcine embryonic development. First, the parthenotes were treated with different concentrations of BPA. We found that blastocyst formation was impaired and the parthenotes were arrested at the 4-cell stage after treatment with 100 μm BPA. Second, ROS increased following the addition of BPA, which further caused mitochondrial damage, and cytochrome c was released from the mitochondria to induce apoptosis. The adaptive response was demonstrated through LC3 immunofluorescence staining and by assessing autophagy-related gene expression. In addition, BPA caused DNA damage through the p53-p21 signaling pathway. Thus, our results indicate that BPA displays an adverse effect on porcine early embryonic development through mitochondrial and DNA damage.
Collapse
Affiliation(s)
- Jing Guo
- Department of Animal Sciences, Chungbuk National University, Cheongju, Chungbuk, 361-763, Republic of Korea.,State Key Laboratory of Veterinary Biotechnology, Heilongjiang Provincial Key Laboratory of Laboratory Animal and Comparative Medicine, Harbin Veterinary Research Insititute of Chinese Academy of Agricultural Sciences, Harbin, 150069, China
| | - Ming-Hui Zhao
- Department of Animal Sciences, Chungbuk National University, Cheongju, Chungbuk, 361-763, Republic of Korea
| | - Kyung-Tae Shin
- Department of Animal Sciences, Chungbuk National University, Cheongju, Chungbuk, 361-763, Republic of Korea
| | - Ying-Jie Niu
- Department of Animal Sciences, Chungbuk National University, Cheongju, Chungbuk, 361-763, Republic of Korea
| | - Yong-Dae Ahn
- Cheongwon Natural Island, 203, Urongni, Seowongu, Cheongju, Chungbuk, 362-823, Republic of Korea
| | - Nam-Hyung Kim
- Department of Animal Sciences, Chungbuk National University, Cheongju, Chungbuk, 361-763, Republic of Korea.
| | - Xiang-Shun Cui
- Department of Animal Sciences, Chungbuk National University, Cheongju, Chungbuk, 361-763, Republic of Korea.
| |
Collapse
|
30
|
DeBalsi KL, Hoff KE, Copeland WC. Role of the mitochondrial DNA replication machinery in mitochondrial DNA mutagenesis, aging and age-related diseases. Ageing Res Rev 2017; 33:89-104. [PMID: 27143693 DOI: 10.1016/j.arr.2016.04.006] [Citation(s) in RCA: 117] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 04/19/2016] [Accepted: 04/19/2016] [Indexed: 12/19/2022]
Abstract
As regulators of bioenergetics in the cell and the primary source of endogenous reactive oxygen species (ROS), dysfunctional mitochondria have been implicated for decades in the process of aging and age-related diseases. Mitochondrial DNA (mtDNA) is replicated and repaired by nuclear-encoded mtDNA polymerase γ (Pol γ) and several other associated proteins, which compose the mtDNA replication machinery. Here, we review evidence that errors caused by this replication machinery and failure to repair these mtDNA errors results in mtDNA mutations. Clonal expansion of mtDNA mutations results in mitochondrial dysfunction, such as decreased electron transport chain (ETC) enzyme activity and impaired cellular respiration. We address the literature that mitochondrial dysfunction, in conjunction with altered mitochondrial dynamics, is a major driving force behind aging and age-related diseases. Additionally, interventions to improve mitochondrial function and attenuate the symptoms of aging are examined.
Collapse
Affiliation(s)
- Karen L DeBalsi
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Kirsten E Hoff
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - William C Copeland
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA.
| |
Collapse
|
31
|
Guo J, Lu WF, Liang S, Choi JW, Kim NH, Cui XS. Peroxisome proliferator-activated receptor δ improves porcine blastocyst hatching via the regulation of fatty acid oxidation. Theriogenology 2016; 90:266-275. [PMID: 28166979 DOI: 10.1016/j.theriogenology.2016.11.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 11/07/2016] [Accepted: 11/19/2016] [Indexed: 02/07/2023]
Abstract
Peroxisome proliferator-activated receptor δ (Pparδ) is a nuclear receptor that plays critical roles in lipid metabolism, glucose metabolism, and cell growth and differentiation. Several recent studies have shown that Pparδ promotes blastocyst hatching in vitro. However, the mechanism by which it promotes preimplantation embryonic development in vitro remains unclear. In this study, oocytes and parthenotes were treated with a specific agonist of PPARδ, GW501516. The activation of PPARδ had no effect on oocyte maturation for 1 μM and 10 μM GW501516 compared with the control group. Additionally, the PPARδ agonist did not affect blastocyst formation (77.79 ± 3.59% [10 μM], 79.00 ± 5.53% [50 μM], and 79.64 ± 6.00% [100 μM] vs. 81.69 ± 2.61% [control]). However, the blastocyst hatching rate was significantly greater for parthenotes treated with 10 and 50 μM agonist, and did not differ between those treated with 100 μM agonist and the control group (61.80 ± 3.03% [10 μM], 65.10 ± 5.25% [50 μM], and 38.85 ± 7.45% [100 μM] vs. 41.77 ± 10.88% [0 μM]). Activation of PPARδ also increased blastocyst quality and cell number, as well as ATP production. There were no clear differences in mitochondrial membrane potential, mitochondrion copy number, or glucose consumption between the treatment and control groups. However, PPARδ activation enhanced lipid accumulation via Fabp3 and Fabp5. Fatty acid oxidation also increased in response to treatment with the agonist via the rate-limiting gene Cpt2. Reactive oxygen species were modified and REDOX maintenance-related gene expression increased significantly in GW501516-exposed blastocysts. In addition, the activation of PPARδ resulted in changes in miRNA content. After treatment with the PPARδ agonist, miR-99 increased and miR-32 decreased. These data showed that PPARδ has a positive impact on blastocyst hatching via the regulation of lipid metabolism.
Collapse
Affiliation(s)
- Jing Guo
- Department of Animal Sciences, Chungbuk National University, Chungbuk, Cheongju, 361-763, Republic of Korea
| | - Wen-Fa Lu
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, 130118, China
| | - Shuang Liang
- Department of Animal Sciences, Chungbuk National University, Chungbuk, Cheongju, 361-763, Republic of Korea
| | - Jeong-Woo Choi
- Department of Animal Sciences, Chungbuk National University, Chungbuk, Cheongju, 361-763, Republic of Korea
| | - Nam-Hyung Kim
- Department of Animal Sciences, Chungbuk National University, Chungbuk, Cheongju, 361-763, Republic of Korea.
| | - Xiang-Shun Cui
- Department of Animal Sciences, Chungbuk National University, Chungbuk, Cheongju, 361-763, Republic of Korea.
| |
Collapse
|
32
|
Diaz-Juarez J, Suarez J, Cividini F, Scott BT, Diemer T, Dai A, Dillmann WH. Expression of the mitochondrial calcium uniporter in cardiac myocytes improves impaired mitochondrial calcium handling and metabolism in simulated hyperglycemia. Am J Physiol Cell Physiol 2016; 311:C1005-C1013. [PMID: 27681178 DOI: 10.1152/ajpcell.00236.2016] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 09/23/2016] [Indexed: 12/21/2022]
Abstract
Diabetic cardiomyopathy is associated with metabolic changes, including decreased glucose oxidation (Gox) and increased fatty acid oxidation (FAox), which result in cardiac energetic deficiency. Diabetic hyperglycemia is a pathophysiological mechanism that triggers multiple maladaptive phenomena. The mitochondrial Ca2+ uniporter (MCU) is the channel responsible for Ca2+ uptake in mitochondria, and free mitochondrial Ca2+ concentration ([Ca2+]m) regulates mitochondrial metabolism. Experiments with cardiac myocytes (CM) exposed to simulated hyperglycemia revealed reduced [Ca2+]m and MCU protein levels. Therefore, we investigated whether returning [Ca2+]m to normal levels in CM by MCU expression could lead to normalization of Gox and FAox with no detrimental effects. Mouse neonatal CM were exposed for 72 h to normal glucose [5.5 mM glucose + 19.5 mM mannitol (NG)], high glucose [25 mM glucose (HG)], or HG + adenoviral MCU expression. Gox and FAox, [Ca2+]m, MCU levels, pyruvate dehydrogenase (PDH) activity, oxidative stress, mitochondrial membrane potential, and apoptosis were assessed. [Ca2+]m and MCU protein levels were reduced after 72 h of HG. Gox was decreased and FAox was increased in HG, PDH activity was decreased, phosphorylated PDH levels were increased, and mitochondrial membrane potential was reduced. MCU expression returned these parameters toward NG levels. Moreover, increased oxidative stress and apoptosis were reduced in HG by MCU expression. We also observed reduced MCU protein levels and [Ca2+]m in hearts from type 1 diabetic mice. Thus we conclude that HG-induced metabolic alterations can be reversed by restoration of MCU levels, resulting in return of [Ca2+]m to normal levels.
Collapse
Affiliation(s)
- Julieta Diaz-Juarez
- Department of Medicine, University of California, San Diego, La Jolla, California; and.,Department of Pharmacology, Instituto Nacional de Cardiología Ignacio Chávez, Tlalpan, México, Mexico
| | - Jorge Suarez
- Department of Medicine, University of California, San Diego, La Jolla, California; and
| | - Federico Cividini
- Department of Medicine, University of California, San Diego, La Jolla, California; and
| | - Brian T Scott
- Department of Medicine, University of California, San Diego, La Jolla, California; and
| | - Tanja Diemer
- Department of Medicine, University of California, San Diego, La Jolla, California; and
| | - Anzhi Dai
- Department of Medicine, University of California, San Diego, La Jolla, California; and
| | - Wolfgang H Dillmann
- Department of Medicine, University of California, San Diego, La Jolla, California; and
| |
Collapse
|
33
|
Abstract
The heart is adapted to utilize all classes of substrates to meet the high-energy demand, and it tightly regulates its substrate utilization in response to environmental changes. Although fatty acids are known as the predominant fuel for the adult heart at resting stage, the heart switches its substrate preference toward glucose during stress conditions such as ischemia and pathological hypertrophy. Notably, increasing evidence suggests that the loss of metabolic flexibility associated with increased reliance on glucose utilization contribute to the development of cardiac dysfunction. The changes in glucose metabolism in hypertrophied hearts include altered glucose transport and increased glycolysis. Despite the role of glucose as an energy source, changes in other nonenergy producing pathways related to glucose metabolism, such as hexosamine biosynthetic pathway and pentose phosphate pathway, are also observed in the diseased hearts. This article summarizes the current knowledge regarding the regulation of glucose transporter expression and translocation in the heart during physiological and pathological conditions. It also discusses the signaling mechanisms governing glucose uptake in cardiomyocytes, as well as the changes of cardiac glucose metabolism under disease conditions.
Collapse
Affiliation(s)
- Dan Shao
- Mitochondria and Metabolism Center, University of Washington, Seattle, Washington, USA
| | - Rong Tian
- Mitochondria and Metabolism Center, University of Washington, Seattle, Washington, USA
| |
Collapse
|
34
|
Cai N, Li Y, Chang S, Liang J, Lin C, Zhang X, Liang L, Hu J, Chan W, Kendler KS, Malinauskas T, Huang GJ, Li Q, Mott R, Flint J. Genetic Control over mtDNA and Its Relationship to Major Depressive Disorder. Curr Biol 2015; 25:3170-7. [PMID: 26687620 PMCID: PMC4691240 DOI: 10.1016/j.cub.2015.10.065] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Revised: 10/07/2015] [Accepted: 10/28/2015] [Indexed: 12/25/2022]
Abstract
Control over the number of mtDNA molecules per cell appears to be tightly regulated, but the mechanisms involved are largely unknown. Reversible alterations in the amount of mtDNA occur in response to stress suggesting that control over the amount of mtDNA is involved in stress-related diseases including major depressive disorder (MDD). Using low-coverage sequence data from 10,442 Chinese women to compute the normalized numbers of reads mapping to the mitochondrial genome as a proxy for the amount of mtDNA, we identified two loci that contribute to mtDNA levels: one within the TFAM gene on chromosome 10 (rs11006126, p value = 8.73 × 10(-28), variance explained = 1.90%) and one over the CDK6 gene on chromosome 7 (rs445, p value = 6.03 × 10(-16), variance explained = 0.50%). Both loci replicated in an independent cohort. CDK6 is thus a new molecule involved in the control of mtDNA. We identify increased rates of heteroplasmy in women with MDD, and show from an experimental paradigm using mice that the increase is likely due to stress. Furthermore, at least one heteroplasmic variant is significantly associated with changes in the amount of mtDNA (position 513, p value = 3.27 × 10(-9), variance explained = 0.48%) suggesting site-specific heteroplasmy as a possible link between stress and increase in amount of mtDNA. These findings indicate the involvement of mitochondrial genome copy number and sequence in an organism's response to stress.
Collapse
Affiliation(s)
- Na Cai
- Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, Oxfordshire OX3 7BN, UK
| | - Yihan Li
- Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, Oxfordshire OX3 7BN, UK
| | - Simon Chang
- Department and Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan 33302, Taiwan
| | - Jieqin Liang
- BGI-Shenzhen, Floor 9 Complex Building, Beishan Industrial Zone, Yantian District, Shenzhen, Guangdong 518083, China
| | - Chongyun Lin
- BGI-Shenzhen, Floor 9 Complex Building, Beishan Industrial Zone, Yantian District, Shenzhen, Guangdong 518083, China
| | - Xiufei Zhang
- BGI-Shenzhen, Floor 9 Complex Building, Beishan Industrial Zone, Yantian District, Shenzhen, Guangdong 518083, China
| | - Lu Liang
- BGI-Shenzhen, Floor 9 Complex Building, Beishan Industrial Zone, Yantian District, Shenzhen, Guangdong 518083, China
| | - Jingchu Hu
- BGI-Shenzhen, Floor 9 Complex Building, Beishan Industrial Zone, Yantian District, Shenzhen, Guangdong 518083, China
| | - Wharton Chan
- Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, Oxfordshire OX3 7BN, UK
| | - Kenneth S Kendler
- Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Tomas Malinauskas
- Cold Spring Harbor Laboratory, Beckman Building, One Bungtown Road, Cold Spring Harbor, NY 11724, USA
| | - Guo-Jen Huang
- Department and Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan 33302, Taiwan
| | - Qibin Li
- BGI-Shenzhen, Floor 9 Complex Building, Beishan Industrial Zone, Yantian District, Shenzhen, Guangdong 518083, China
| | - Richard Mott
- Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, Oxfordshire OX3 7BN, UK
| | - Jonathan Flint
- Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, Oxfordshire OX3 7BN, UK.
| |
Collapse
|
35
|
Sung MM, Hamza SM, Dyck JRB. Myocardial metabolism in diabetic cardiomyopathy: potential therapeutic targets. Antioxid Redox Signal 2015; 22:1606-30. [PMID: 25808033 DOI: 10.1089/ars.2015.6305] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
SIGNIFICANCE Cardiovascular complications in diabetes are particularly serious and represent the primary cause of morbidity and mortality in diabetic patients. Despite early observations of cardiac dysfunction in diabetic humans, cardiomyopathy unique to diabetes has only recently been recognized. RECENT ADVANCES Research has focused on understanding the pathogenic mechanisms underlying the initiation and development of diabetic cardiomyopathy. Emerging data highlight the importance of altered mitochondrial function as a major contributor to cardiac dysfunction in diabetes. Mitochondrial dysfunction occurs by several mechanisms involving altered cardiac substrate metabolism, lipotoxicity, impaired cardiac insulin and glucose homeostasis, impaired cellular and mitochondrial calcium handling, oxidative stress, and mitochondrial uncoupling. CRITICAL ISSUES Currently, treatment is not specifically tailored for diabetic patients with cardiac dysfunction. Given the multifactorial development and progression of diabetic cardiomyopathy, traditional treatments such as anti-diabetic agents, as well as cellular and mitochondrial fatty acid uptake inhibitors aimed at shifting the balance of cardiac metabolism from utilizing fat to glucose may not adequately target all aspects of this condition. Thus, an alternative treatment such as resveratrol, which targets multiple facets of diabetes, may represent a safe and promising supplement to currently recommended clinical therapy and lifestyle changes. FUTURE DIRECTIONS Elucidation of the mechanisms underlying the initiation and progression of diabetic cardiomyopathy is essential for development of effective and targeted treatment strategies. Of particular interest is the investigation of alternative therapies such as resveratrol, which can function as both preventative and mitigating agents in the management of diabetic cardiomyopathy.
Collapse
Affiliation(s)
- Miranda M Sung
- Department of Pediatrics, Cardiovascular Research Centre, University of Alberta, Edmonton, Canada
| | - Shereen M Hamza
- Department of Pediatrics, Cardiovascular Research Centre, University of Alberta, Edmonton, Canada
| | - Jason R B Dyck
- Department of Pediatrics, Cardiovascular Research Centre, University of Alberta, Edmonton, Canada
| |
Collapse
|
36
|
Diabetes-associated dysregulation of O-GlcNAcylation in rat cardiac mitochondria. Proc Natl Acad Sci U S A 2015; 112:6050-5. [PMID: 25918408 DOI: 10.1073/pnas.1424017112] [Citation(s) in RCA: 153] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Elevated mitochondrial O-GlcNAcylation caused by hyperglycemia, as occurs in diabetes, significantly contributes to mitochondrial dysfunction and to diabetic cardiomyopathy. However, little is known about the enzymology of mitochondrial O-GlcNAcylation. Herein, we investigated the enzymes responsible for cycling O-GlcNAc on mitochondrial proteins and studied the mitochondrial transport of UDP-GlcNAc. Analyses of purified rat heart mitochondria from normal and streptozocin-treated diabetic rats show increased mitochondrial O-GlcNAc transferase (OGT) and a concomitant decrease in the mito-specific O-GlcNAcase (OGA). Strikingly, OGT is mislocalized in cardiac mitochondria from diabetic rats. Interaction of OGT and complex IV observed in normal rat heart mitochondria is visibly reduced in diabetic samples, where OGT is mislocalized to the matrix. Live cell OGA activity assays establish the presence of O-GlcNAcase within the mitochondria. Furthermore, we establish that the inner mitochondrial membrane transporter, pyrimidine nucleotide carrier, transports UDP-GlcNAc from the cytosol to the inside of the mitochondria. Knockdown of this transporter substantially lowers mitochondrial O-GlcNAcylation. Inhibition of OGT or OGA activity within neonatal rat cardiomyocytes significantly affects energy production, mitochondrial membrane potential, and mitochondrial oxygen consumption. These data suggest that cardiac mitochondria not only have robust O-GlcNAc cycling, but also that dysregulation of O-GlcNAcylation likely plays a key role in mitochondrial dysfunction associated with diabetes.
Collapse
|
37
|
Lai NC, Gao MH, Giamouridis D, Suarez J, Miyanohara A, Parikh J, Hightower S, Guo T, Dillmann W, Kim YC, Diaz-Juarez J, Hammond HK. Intravenous AAV8 Encoding Urocortin-2 Increases Function of the Failing Heart in Mice. Hum Gene Ther 2015; 26:347-56. [PMID: 25760560 PMCID: PMC4492611 DOI: 10.1089/hum.2014.157] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Urocortin-2 (UCn2) peptide infusion increases cardiac function in patients with heart failure, but chronic peptide infusion is cumbersome, is costly, and provides only short-term benefits. Gene transfer would circumvent these shortcomings. We previously showed that a single intravenous (IV) injection of AAV8.UCn2 increases plasma UCn2 and left ventricular (LV) systolic and diastolic function for at least 7 months in normal mice. Here we test the hypothesis that IV delivery of AAV8.UCn2 increases function of the failing heart. Myocardial infarction (MI, by coronary ligation) was used to induce heart failure, which was assessed by echocardiography 3 weeks after MI. Mice with LV ejection fraction (EF) <25% received IV delivery of AAV8.UCn2 (5×1011 gc) or saline, and 5 weeks later echocardiography showed increased LV EF in mice that received UCn2 gene transfer (p=0.01). In vivo physiological studies showed a 2-fold increase in peak rate of LV pressure development (LV +dP/dt; p<0.0001) and a 1.6-fold increase in peak rate of LV pressure decay (LV −dP/dt; p=0.0007), indicating increased LV systolic and diastolic function in treated mice. UCn2 gene transfer was associated with increased peak systolic Ca2+ transient amplitude and rate of Ca2+ decline and increased SERCA2a expression. In addition, UCn2 gene transfer reduced Thr286 phosphorylation of Cam kinase II, and increased expression of cardiac myosin light chain kinase, findings that would be anticipated to increase function of the failing heart. We conclude that a single IV injection of AAV8.UCn2 increases function of the failing heart. The simplicity of IV injection of a vector encoding a gene with beneficial paracrine effects to increase cardiac function is an attractive potential clinical strategy.
Collapse
Affiliation(s)
- N Chin Lai
- 1 VA San Diego Healthcare System , San Diego, CA 92161.,2 Department of Medicine, University of California-San Diego , San Diego, CA 92161
| | - Mei Hua Gao
- 1 VA San Diego Healthcare System , San Diego, CA 92161.,2 Department of Medicine, University of California-San Diego , San Diego, CA 92161
| | - Dimosthenis Giamouridis
- 1 VA San Diego Healthcare System , San Diego, CA 92161.,2 Department of Medicine, University of California-San Diego , San Diego, CA 92161
| | - Jorge Suarez
- 2 Department of Medicine, University of California-San Diego , San Diego, CA 92161
| | - Atsushi Miyanohara
- 2 Department of Medicine, University of California-San Diego , San Diego, CA 92161
| | - Jay Parikh
- 1 VA San Diego Healthcare System , San Diego, CA 92161.,2 Department of Medicine, University of California-San Diego , San Diego, CA 92161
| | - Stephen Hightower
- 1 VA San Diego Healthcare System , San Diego, CA 92161.,2 Department of Medicine, University of California-San Diego , San Diego, CA 92161
| | - Tracy Guo
- 2 Department of Medicine, University of California-San Diego , San Diego, CA 92161
| | - Wolfgang Dillmann
- 2 Department of Medicine, University of California-San Diego , San Diego, CA 92161
| | - Young-Chul Kim
- 2 Department of Medicine, University of California-San Diego , San Diego, CA 92161
| | - Julieta Diaz-Juarez
- 2 Department of Medicine, University of California-San Diego , San Diego, CA 92161
| | - H Kirk Hammond
- 1 VA San Diego Healthcare System , San Diego, CA 92161.,2 Department of Medicine, University of California-San Diego , San Diego, CA 92161
| |
Collapse
|
38
|
Gohbara M, Iwahashi N, Kataoka S, Hayakawa Y, Sakamaki K, Akiyama E, Maejima N, Tsukahara K, Hibi K, Kosuge M, Ebina T, Umemura S, Kimura K. Glycemic Variability Determined by Continuous Glucose Monitoring System Predicts Left Ventricular Remodeling in Patients With a First ST-Segment Elevation Myocardial Infarction. Circ J 2015; 79:1092-9. [PMID: 25739857 DOI: 10.1253/circj.cj-14-1226] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Impaired glucose metabolism plays an important role in patients with acute myocardial infarction, but the clinical significance of glycemic variability (GV) early after the onset of ST-segment elevation myocardial infarction (STEMI) remains to be fully elucidated. METHODS AND RESULTS We prospectively investigated the clinical impact of GV, as determined by a continuous glucose monitoring system (CGMS), on left ventricular remodeling (LVR) assessed by cardiac magnetic resonance imaging (CMR) in 69 patients (63±13 years, 59 men) with a first reperfused STEMI within 12 h of onset. All patients were equipped with a CGMS when in a stable phase after admission and underwent repeat CMR at baseline and 7 months follow-up. Patients were divided into 2 groups according to the mean amplitude of glycemic excursions (MAGE). Patients in the upper tertile of MAGE were categorized as group High (H) and the other two-thirds as group Low (L). LVR was defined as an absolute increase in left ventricular end-diastolic volume index of ≥20%. LVR more frequently occurred in group H than in group L (56% vs. 11%, P<0.001). Multivariate analysis showed the higher MAGE group was an independent predictor of LVR in the chronic phase (odds ratio, 13.999; 95% confidence interval, 3.059 to 64.056; P=0.001). CONCLUSIONS MAGE early after the onset of STEMI identified patients with LVR in the chronic phase.
Collapse
Affiliation(s)
- Masaomi Gohbara
- Division of Cardiology, Yokohama City University Medical Center
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Stammers AN, Susser SE, Hamm NC, Hlynsky MW, Kimber DE, Kehler DS, Duhamel TA. The regulation of sarco(endo)plasmic reticulum calcium-ATPases (SERCA). Can J Physiol Pharmacol 2015; 93:843-54. [PMID: 25730320 DOI: 10.1139/cjpp-2014-0463] [Citation(s) in RCA: 99] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The sarco(endo)plasmic reticulum calcium ATPase (SERCA) is responsible for transporting calcium (Ca(2+)) from the cytosol into the lumen of the sarcoplasmic reticulum (SR) following muscular contraction. The Ca(2+) sequestering activity of SERCA facilitates muscular relaxation in both cardiac and skeletal muscle. There are more than 10 distinct isoforms of SERCA expressed in different tissues. SERCA2a is the primary isoform expressed in cardiac tissue, whereas SERCA1a is the predominant isoform expressed in fast-twitch skeletal muscle. The Ca(2+) sequestering activity of SERCA is regulated at the level of protein content and is further modified by the endogenous proteins phospholamban (PLN) and sarcolipin (SLN). Additionally, several novel mechanisms, including post-translational modifications and microRNAs (miRNAs) are emerging as integral regulators of Ca(2+) transport activity. These regulatory mechanisms are clinically relevant, as dysregulated SERCA function has been implicated in the pathology of several disease states, including heart failure. Currently, several clinical trials are underway that utilize novel therapeutic approaches to restore SERCA2a activity in humans. The purpose of this review is to examine the regulatory mechanisms of the SERCA pump, with a particular emphasis on the influence of exercise in preventing the pathological conditions associated with impaired SERCA function.
Collapse
Affiliation(s)
- Andrew N Stammers
- a Health, Leisure & Human Performance Research Institute, Faculty of Kinesiology & Recreation Management, University of Manitoba.,b Institute of Cardiovascular Sciences, St. Boniface Hospital Research Centre
| | - Shanel E Susser
- b Institute of Cardiovascular Sciences, St. Boniface Hospital Research Centre.,c Department of Physiology, Faculty of Health Sciences, University of Manitoba
| | - Naomi C Hamm
- a Health, Leisure & Human Performance Research Institute, Faculty of Kinesiology & Recreation Management, University of Manitoba.,b Institute of Cardiovascular Sciences, St. Boniface Hospital Research Centre
| | - Michael W Hlynsky
- a Health, Leisure & Human Performance Research Institute, Faculty of Kinesiology & Recreation Management, University of Manitoba.,b Institute of Cardiovascular Sciences, St. Boniface Hospital Research Centre
| | - Dustin E Kimber
- a Health, Leisure & Human Performance Research Institute, Faculty of Kinesiology & Recreation Management, University of Manitoba.,b Institute of Cardiovascular Sciences, St. Boniface Hospital Research Centre
| | - D Scott Kehler
- a Health, Leisure & Human Performance Research Institute, Faculty of Kinesiology & Recreation Management, University of Manitoba.,b Institute of Cardiovascular Sciences, St. Boniface Hospital Research Centre
| | - Todd A Duhamel
- a Health, Leisure & Human Performance Research Institute, Faculty of Kinesiology & Recreation Management, University of Manitoba.,b Institute of Cardiovascular Sciences, St. Boniface Hospital Research Centre.,c Department of Physiology, Faculty of Health Sciences, University of Manitoba
| |
Collapse
|
40
|
Abstract
Diabetic cardiomyopathy (DCM) is defined as cardiac disease independent of vascular complications during diabetes. The number of new cases of DCM is rising at epidemic rates in proportion to newly diagnosed cases of diabetes mellitus (DM) throughout the world. DCM is a heart failure syndrome found in diabetic patients that is characterized by left ventricular hypertrophy and reduced diastolic function, with or without concurrent systolic dysfunction, occurring in the absence of hypertension and coronary artery disease. DCM and other diabetic complications are caused in part by elevations in blood glucose and lipids, characteristic of DM. Although there are pathological consequences to hyperglycemia and hyperlipidemia, the combination of the two metabolic abnormalities potentiates the severity of diabetic complications. A natural competition exists between glucose and fatty acid metabolism in the heart that is regulated by allosteric and feedback control and transcriptional modulation of key limiting enzymes. Inhibition of these glycolytic enzymes not only controls flux of substrate through the glycolytic pathway, but also leads to the diversion of glycolytic intermediate substrate through pathological pathways, which mediate the onset of diabetic complications. The present review describes the limiting steps involved in the development of these pathological pathways and the factors involved in the regulation of these limiting steps. Additionally, therapeutic options with demonstrated or postulated effects on DCM are described.
Collapse
Affiliation(s)
- Michael Isfort
- The Ohio State University College of Medicine, Columbus, OH, USA
| | | | | | | | | |
Collapse
|
41
|
Tan EP, Villar MT, E L, Lu J, Selfridge JE, Artigues A, Swerdlow RH, Slawson C. Altering O-linked β-N-acetylglucosamine cycling disrupts mitochondrial function. J Biol Chem 2014; 289:14719-30. [PMID: 24713701 DOI: 10.1074/jbc.m113.525790] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Mitochondrial impairment is commonly found in many diseases such as diabetes, cancer, and Alzheimer disease. We demonstrate that the enzymes responsible for the addition or removal of the O-GlcNAc modification, O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA), respectively, are critical regulators of mitochondrial function. Using a SILAC (stable isotope labeling of amino acids in cell culture)-based proteomics screen, we quantified the changes in mitochondrial protein expression in OGT- and OGA-overexpressing cells. Strikingly, overexpression of OGT or OGA showed significant decreases in mitochondria-localized proteins involved in the respiratory chain and the tricarboxylic acid cycle. Furthermore, mitochondrial morphology was altered in these cells. Both cellular respiration and glycolysis were reduced in OGT/OGA-overexpressing cells. These data demonstrate that alterations in O-GlcNAc cycling profoundly affect energy and metabolite production.
Collapse
Affiliation(s)
- Ee Phie Tan
- From the Department of Biochemistry and Molecular Biology
| | - Maria T Villar
- From the Department of Biochemistry and Molecular Biology
| | - Lezi E
- Department of Neurology, and
| | | | | | | | - Russell H Swerdlow
- From the Department of Biochemistry and Molecular Biology, Department of Neurology, and University of Kansas Alzheimer's Disease Center, University of Kansas Medical Center, Kansas City, Kansas 64108
| | - Chad Slawson
- From the Department of Biochemistry and Molecular Biology, University of Kansas Alzheimer's Disease Center, University of Kansas Medical Center, Kansas City, Kansas 64108 University of Kansas Cancer Center,
| |
Collapse
|
42
|
Gao MH, Lai NC, Miyanohara A, Schilling JM, Suarez J, Tang T, Guo T, Tang R, Parikh J, Giamouridis D, Dillmann WH, Patel HH, Roth DM, Dalton ND, Hammond HK. Intravenous adeno-associated virus serotype 8 encoding urocortin-2 provides sustained augmentation of left ventricular function in mice. Hum Gene Ther 2014; 24:777-85. [PMID: 23931341 DOI: 10.1089/hum.2013.088] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Urocortin-2 (UCn2) peptide infusion increases cardiac function in patients with heart failure, but chronic peptide infusion is cumbersome, costly, and provides only short-term benefits. Gene transfer would circumvent these shortcomings. Here we ask whether a single intravenous injection of adeno-associated virus type 8 encoding murine urocortin-2 (AAV8.UCn2) could provide long-term elevation in plasma UCn2 levels and increased left ventricular (LV) function. Normal mice received AAV8.UCn2 (5×10¹¹ genome copies, intravenous). Plasma UCn2 increased 15-fold 6 weeks and >11-fold 7 months after delivery. AAV8 DNA and UCn2 mRNA expression was persistent in LV and liver up to 7 months after a single intravenous injection of AAV8.UCn2. Physiological studies conducted both in situ and ex vivo showed increases in LV +dP/dt and in LV -dP/dt, findings that endured unchanged for 7 months. SERCA2a mRNA and protein expression was increased in LV samples and Ca²⁺ transient studies showed an increased rate of Ca²⁺ decline in cardiac myocytes from mice that had received UCn2 gene transfer. We conclude that a single intravenous injection of AAV8.UCn2 increases plasma UCn2 and increases LV systolic and diastolic function for at least 7 months. The simplicity of intravenous injection of a long-term expression vector encoding a gene with paracrine activity to increase cardiac function is a potentially attractive strategy in clinical settings. Future studies will determine the usefulness of this approach in the treatment of heart failure.
Collapse
Affiliation(s)
- Mei Hua Gao
- VA San Diego Healthcare System, San Diego, CA 92161, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
43
|
Santos JM, Mishra M, Kowluru RA. Posttranslational modification of mitochondrial transcription factor A in impaired mitochondria biogenesis: implications in diabetic retinopathy and metabolic memory phenomenon. Exp Eye Res 2014; 121:168-77. [PMID: 24607487 DOI: 10.1016/j.exer.2014.02.010] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Revised: 01/17/2014] [Accepted: 02/07/2014] [Indexed: 10/25/2022]
Abstract
Mitochondrial transcription factor A (TFAM) is one of the key regulators of the transcription of mtDNA. In diabetes, despite increase in gene transcripts of TFAM, its protein levels in the mitochondria are decreased and mitochondria copy numbers become subnormal. The aim of this study is to investigate the mechanism(s) responsible for decreased mitochondrial TFAM in diabetes. Using retinal endothelial cells, we have investigated the effect of overexpression of cytosolic chaperone, Hsp70, and TFAM on glucose-induced decrease in mitochondrial TFAM levels, and the transcription of mtDNA-encoded genes, NADH dehydrogenase subunit 6 (ND6) and cytochrome b (Cytb). To investigate the role of posttranslational modifications in subnormal mitochondrial TFAM, ubiquitination of TFAM was assessed, and the results were confirmed in the retina from streptozotocin-induced diabetic rats. While overexpression of Hsp70 failed to prevent glucose-induced decrease in mitochondrial TFAM and transcripts of ND6 and Cytb, overexpression of TFAM ameliorated decrease in its mitochondrial protein levels and transcriptional activity. TFAM was ubiquitinated by high glucose, and PYR-41, an inhibitor of ubiquitination, prevented TFAM ubiquitination and restored the transcriptional activity. Similarly, TFAM was ubiquitinated in the retina from diabetic rats, and it continued to be modified after reinstitution of normal glycemia. Our results clearly imply that the ubiquitination of TFAM impedes its transport to the mitochondria resulting in subnormal mtDNA transcription and mitochondria dysfunction, and inhibition of ubiquitination restores mitochondrial homeostasis. Reversal of hyperglycemia does not provide any benefit to TFAM ubiquitination. Thus, strategies targeting posttranslational modification could provide an avenue to preserve mitochondrial homeostasis, and inhibit the development/progression of diabetic retinopathy.
Collapse
Affiliation(s)
- Julia M Santos
- Kresge Eye Institute, Wayne State University, 4717 St. Antoine, Detroit, MI 48201, USA
| | - Manish Mishra
- Kresge Eye Institute, Wayne State University, 4717 St. Antoine, Detroit, MI 48201, USA
| | - Renu A Kowluru
- Kresge Eye Institute, Wayne State University, 4717 St. Antoine, Detroit, MI 48201, USA.
| |
Collapse
|
44
|
|
45
|
Kolwicz SC, Purohit S, Tian R. Cardiac metabolism and its interactions with contraction, growth, and survival of cardiomyocytes. Circ Res 2013; 113:603-16. [PMID: 23948585 DOI: 10.1161/circresaha.113.302095] [Citation(s) in RCA: 532] [Impact Index Per Article: 48.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The network for cardiac fuel metabolism contains intricate sets of interacting pathways that result in both ATP-producing and non-ATP-producing end points for each class of energy substrates. The most salient feature of the network is the metabolic flexibility demonstrated in response to various stimuli, including developmental changes and nutritional status. The heart is also capable of remodeling the metabolic pathways in chronic pathophysiological conditions, which results in modulations of myocardial energetics and contractile function. In a quest to understand the complexity of the cardiac metabolic network, pharmacological and genetic tools have been engaged to manipulate cardiac metabolism in a variety of research models. In concert, a host of therapeutic interventions have been tested clinically to target substrate preference, insulin sensitivity, and mitochondrial function. In addition, the contribution of cellular metabolism to growth, survival, and other signaling pathways through the production of metabolic intermediates has been increasingly noted. In this review, we provide an overview of the cardiac metabolic network and highlight alterations observed in cardiac pathologies as well as strategies used as metabolic therapies in heart failure. Lastly, the ability of metabolic derivatives to intersect growth and survival are also discussed.
Collapse
Affiliation(s)
- Stephen C Kolwicz
- Mitochondria and Metabolism Center, Department of Anesthesiology and Pain Medicine, University of Washington School of Medicine, Seattle, WA 98109, USA
| | | | | |
Collapse
|
46
|
Wang YE, Marinov GK, Wold BJ, Chan DC. Genome-wide analysis reveals coating of the mitochondrial genome by TFAM. PLoS One 2013; 8:e74513. [PMID: 23991223 PMCID: PMC3753274 DOI: 10.1371/journal.pone.0074513] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Accepted: 08/05/2013] [Indexed: 12/21/2022] Open
Abstract
Mitochondria contain a 16.6 kb circular genome encoding 13 proteins as well as mitochondrial tRNAs and rRNAs. Copies of the genome are organized into nucleoids containing both DNA and proteins, including the machinery required for mtDNA replication and transcription. The transcription factor TFAM is critical for initiation of transcription and replication of the genome, and is also thought to perform a packaging function. Although specific binding sites required for initiation of transcription have been identified in the D-loop, little is known about the characteristics of TFAM binding in its nonspecific packaging state. In addition, it is unclear whether TFAM also plays a role in the regulation of nuclear gene expression. Here we investigate these questions by using ChIP-seq to directly localize TFAM binding to DNA in human cells. Our results demonstrate that TFAM uniformly coats the whole mitochondrial genome, with no evidence of robust TFAM binding to the nuclear genome. Our study represents the first high-resolution assessment of TFAM binding on a genome-wide scale in human cells.
Collapse
Affiliation(s)
- Yun E. Wang
- Division of Biology, California Institute of Technology, Pasadena, California, United States of America
| | - Georgi K. Marinov
- Division of Biology, California Institute of Technology, Pasadena, California, United States of America
| | - Barbara J. Wold
- Division of Biology, California Institute of Technology, Pasadena, California, United States of America
| | - David C. Chan
- Division of Biology, California Institute of Technology, Pasadena, California, United States of America
- Howard Hughes Medical Institute, California Institute of Technology, Pasadena, California, United States of America
- * E-mail:
| |
Collapse
|
47
|
Santiago C, Garatachea N, Yvert T, Rodríguez-Romo G, Santos-Lozano A, Fiuza-Luces C, Lucia A. Mitochondriogenesis genes and extreme longevity. Rejuvenation Res 2013. [PMID: 23186209 DOI: 10.1089/rej.2012.1382] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Genes of the proliferator-activated receptor delta (PPARD)-peroxisome proliferator-activated receptor γ coactivator 1α (PPARGC1A, also termed PGC1-α)-nuclear respiratory factor (NRF)-mitochondrial transcription Factor A (TFAM) mitochondriogenesis pathway can influence health/disease phenotypes, yet their association with extreme longevity is not known. We studied the association of five common polymorphisms in genes of this pathway (rs2267668, rs8192678, rs6949152, rs12594956, rs1937) and extreme longevity using a case (107 centenarians)-control (284 young adults) design. We found no between-group differences in allele/genotype frequencies, except for CC genotype in rs1937 (p=0.003), with no representation in controls (0%), versus 2.8% in centenarians (2 men, 1 woman). In summary, the studied genetic variants of the PPARD-PPARGC1A-NRF-TFAM pathway were not associated with extreme longevity, yet a marginal association could exist for rs1937.
Collapse
|
48
|
Santos JM, Kowluru RA. Impaired transport of mitochondrial transcription factor A (TFAM) and the metabolic memory phenomenon associated with the progression of diabetic retinopathy. Diabetes Metab Res Rev 2013; 29:204-13. [PMID: 23255365 PMCID: PMC3596457 DOI: 10.1002/dmrr.2384] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Revised: 10/18/2012] [Accepted: 12/07/2012] [Indexed: 12/25/2022]
Abstract
BACKGROUND Diabetes damages retinal mitochondrial DNA (mtDNA) and compromises the mtDNA transcription. In the transcription and replication of mtDNA, nuclear-encoded mitochondrial transcription factor A (TFAM) is considered a key activator. We have shown that in diabetes, although retinal TFAM gene expression is increased, its mitochondrial levels are decreased. This study investigates the role of mitochondrial outer and inner membrane transport systems in the transfer of TFAM into the mitochondria in diabetes and how reversal of hyperglycaemia affects the ability of TFAM to reach the mitochondria. METHODS Components of the membrane transport system, Tom70, Tom40, Tim23, and Tim44, were analysed in the retina from streptozotocin-induced diabetic rats maintained in poor control or in good control for 8 months, or in poor control for 4 months followed by in good control for 4 months. The binding of TFAM with Tom70 and Tim44 was determined by co-immunoprecipitation and that with mtDNA by chromatin immunoprecipitation. RESULTS Retinal expressions of Tom70, Tom40, and Tim44 were significantly decreased in diabetes, and the binding of TFAM with Tom70, Tim44, and mtDNA was impaired. Reversal of hyperglycaemia had no beneficial effect on the decreased binding of TFAM to Tom proteins and mtDNA. CONCLUSIONS Thus, subnormal membrane transport to systems in diabetes impair the transfer of TFAM into the mitochondria, and decreased TFAM-mtDNA binding that results in subnormal mitochondria transcription. These processes continue to be dysfunctional even after the hyperglycaemic insult is terminated. Strategies targeting mitochondrial membrane transport proteins could have the potential of improving mitochondrial biogenesis and slowing or halting the progression of diabetic retinopathy.
Collapse
Affiliation(s)
- Julia M Santos
- Kresge Eye Institute, Wayne State University, Detroit, MI 48201, USA
| | | |
Collapse
|
49
|
Van Hoeck V, Leroy JLMR, Arias Alvarez M, Rizos D, Gutierrez-Adan A, Schnorbusch K, Bols PEJ, Leese HJ, Sturmey RG. Oocyte developmental failure in response to elevated nonesterified fatty acid concentrations: mechanistic insights. Reproduction 2013; 145:33-44. [PMID: 23108110 DOI: 10.1530/rep-12-0174] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Elevated plasma nonesterified fatty acid (NEFA) concentrations are associated with negative energy balance and metabolic disorders such as obesity and type II diabetes. Such increased plasma NEFA concentrations induce changes in the microenvironment of the ovarian follicle, which can compromise oocyte competence. Exposing oocytes to elevated NEFA concentrations during maturation affects the gene expression and phenotype of the subsequent embryo, notably prompting a disrupted oxidative metabolism. We hypothesized that these changes in the embryo are a consequence of modified energy metabolism in the oocyte. To investigate this, bovine cumulus oocyte complexes were matured under elevated NEFA conditions, and energy metabolism-related gene expression, mitochondrial function, and ultrastructure evaluated. It was found that expression of genes related to REDOX maintenance was modified in NEFA-exposed oocytes, cumulus cells, and resultant blastocysts. Moreover, the expression of genes related to fatty acid synthesis in embryos that developed from NEFA-exposed oocytes was upregulated. From a functional perspective, inhibition of fatty acid β-oxidation in maturing oocytes exposed to elevated NEFA concentrations restored developmental competence. There were no clear differences in mitochondrial morphology or oxygen consumption between treatments, although there was a trend for a higher mitochondrial membrane potential in zygotes derived from NEFA-exposed oocytes. These data show that the degree of mitochondrial fatty acid β-oxidation has a decisive impact on the development of NEFA-exposed oocytes. Furthermore, the gene expression data suggest that the resulting embryos adapt through altered metabolic strategies, which might explain the aberrant energy metabolism previously observed in these embryos originating from NEFA-exposed maturing oocytes.
Collapse
Affiliation(s)
- V Van Hoeck
- Veterinary Physiology and Biochemistry, Department of Veterinary Sciences, Faculty of Biomedical, Pharmaceutical and Veterinary Sciences, Gamete Research Center, University of Antwerp, Universiteitsplein 1-Gebouw U, B-2610 Wilrijk, Belgium.
| | | | | | | | | | | | | | | | | |
Collapse
|
50
|
Sai Y, Zou Z, Peng K, Dong Z. The Parkinson's disease-related genes act in mitochondrial homeostasis. Neurosci Biobehav Rev 2012; 36:2034-43. [DOI: 10.1016/j.neubiorev.2012.06.007] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Revised: 05/09/2012] [Accepted: 06/12/2012] [Indexed: 11/16/2022]
|