1
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Jiao Y, Yan Z, Yang A. Mitochondria in innate immunity signaling and its therapeutic implications in autoimmune diseases. Front Immunol 2023; 14:1160035. [PMID: 37122709 PMCID: PMC10130412 DOI: 10.3389/fimmu.2023.1160035] [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: 02/06/2023] [Accepted: 03/28/2023] [Indexed: 05/02/2023] Open
Abstract
Autoimmune diseases are characterized by vast alterations in immune responses, but the pathogenesis remains sophisticated and yet to be fully elucidated. Multiple mechanisms regulating cell differentiation, maturation, and death are critical, among which mitochondria-related cellular organelle functions have recently gained accumulating attention. Mitochondria, as a highly preserved organelle in eukaryotes, have crucial roles in the cellular response to both exogenous and endogenous stress beyond their fundamental functions in chemical energy conversion. In this review, we aim to summarize recent findings on the function of mitochondria in the innate immune response and its aberrancy in autoimmune diseases such as rheumatoid arthritis, systemic lupus erythematosus, etc., mainly focusing on its direct impact on cellular metabolism and its machinery on regulating immune response signaling pathways. More importantly, we summarize the status quo of potential therapeutic targets found in the mitochondrial regulation in the setting of autoimmune diseases and wish to shed light on future studies.
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Affiliation(s)
- Yuhao Jiao
- Department of Gastroenterology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Zhiyu Yan
- Department of Gastroenterology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
- 4+4 Medical Doctor Program, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Aiming Yang
- Department of Gastroenterology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
- *Correspondence: Aiming Yang,
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2
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Long G, Gong R, Wang Q, Zhang D, Huang C. Role of released mitochondrial DNA in acute lung injury. Front Immunol 2022; 13:973089. [PMID: 36059472 PMCID: PMC9433898 DOI: 10.3389/fimmu.2022.973089] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Accepted: 08/01/2022] [Indexed: 12/02/2022] Open
Abstract
Acute lung injury(ALI)/acute respiratory distress syndrome(ARDS) is a form of acute-onset hypoxemic respiratory failure characterised by an acute, diffuse, inflammatory lung injury, and increased alveolar-capillary permeability, which is caused by a variety of pulmonary or nonpulmonary insults. Recently, aberrant mitochondria and mitochondrial DNA(mtDNA) level are associated with the development of ALI/ARDS, and plasma mtDNA level shows the potential to be a promising biomarker for clinical diagnosis and evaluation of lung injury severity. In mechanism, the mtDNA and its oxidised form, which are released from impaired mitochondria, play a crucial role in the inflammatory response and histopathological changes in the lung. In this review, we discuss mitochondrial outer membrane permeabilisation (MOMP), mitochondrial permeability transition pore(mPTP), extracellular vesicles (EVs), extracellular traps (ETs), and passive release as the principal mechanisms for the release of mitochondrial DNA into the cytoplasm and extracellular compartments respectively. Further, we explain how the released mtDNA and its oxidised form can induce inflammatory cytokine production and aggravate lung injury through the Toll-like receptor 9(TLR9) signalling, cytosolic cGAS-stimulator of interferon genes (STING) signalling (cGAS-STING) pathway, and inflammasomes activation. Additionally, we propose targeting mtDNA-mediated inflammatory pathways as a novel therapeutic approach for treating ALI/ARDS.
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Affiliation(s)
- Gangyu Long
- Wuhan Jinyintan Hospital, Tongji Medical College of Huazhong University of Science and Technology, Wuhan, China
| | - Rui Gong
- The First Affiliated Hospital of University of Science and Technology of China (USTC), Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Qian Wang
- Wuhan Jinyintan Hospital, Tongji Medical College of Huazhong University of Science and Technology, Wuhan, China
| | - Dingyu Zhang
- Wuhan Jinyintan Hospital, Tongji Medical College of Huazhong University of Science and Technology, Wuhan, China
- The First Affiliated Hospital of University of Science and Technology of China (USTC), Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
- Hubei Clinical Research Center for Infectious Diseases, Wuhan, China
- Wuhan Research Center for Communicable Disease Diagnosis and Treatment, Chinese Academy of Medical Sciences, Wuhan, China
- Joint Laboratory of Infectious Diseases and Health, Wuhan Institute of Virology and Wuhan Jinyintan Hospital, Chinese Academy of Sciences, Wuhan, China
- *Correspondence: Dingyu Zhang, ; Chaolin Huang,
| | - Chaolin Huang
- Wuhan Jinyintan Hospital, Tongji Medical College of Huazhong University of Science and Technology, Wuhan, China
- Hubei Clinical Research Center for Infectious Diseases, Wuhan, China
- Wuhan Research Center for Communicable Disease Diagnosis and Treatment, Chinese Academy of Medical Sciences, Wuhan, China
- Joint Laboratory of Infectious Diseases and Health, Wuhan Institute of Virology and Wuhan Jinyintan Hospital, Chinese Academy of Sciences, Wuhan, China
- *Correspondence: Dingyu Zhang, ; Chaolin Huang,
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3
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Anter A, Ahmed ASF, Hammad ASA, Almalki WH, Abdel Hafez SMN, Kasem AW, El-Moselhy MA, Alrabia MW, Ibrahim ARN, El-Daly M. The Severity of Acute Kidney and Lung Injuries Induced by Cecal Ligation and Puncture Is Attenuated by Menthol: Role of Proliferating Cell Nuclear Antigen and Apoptotic Markers. Front Med (Lausanne) 2022; 9:904286. [PMID: 35814769 PMCID: PMC9260148 DOI: 10.3389/fmed.2022.904286] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 05/16/2022] [Indexed: 11/24/2022] Open
Abstract
Objective Sepsis-induced acute lung injury (ALI) and acute kidney injury (AKI) are major causes of mortality. Menthol is a natural compound that has anti-inflammatory and antioxidative actions. Since exaggerated inflammatory and oxidative stress are characteristics of sepsis, the aim of this study was to evaluate the effect of menthol against sepsis-induced mortality, ALI, and AKI. Methods The cecal ligation and puncture (CLP) procedure was employed as a model of sepsis. Rats were grouped into sham, sham-Menthol, CLP, and CLP-Menthol (100 mg/kg, p.o). Key Findings A survival study showed that menthol enhanced the survival after sepsis from 0% in septic group to 30%. Septic rats developed histological evidence of ALI and AKI. Menthol markedly suppressed sepsis induced elevation of tissue TNF-a, ameliorated sepsis-induced cleavage of caspase-3 and restored the antiapoptotic marker Bcl2. Significance We introduced a role of the proliferating cell nuclear antigen (PCNA) in these tissues with a possible link to the damage induced by sepsis. PCNA level was markedly reduced in septic animals and menthol ameliorated this effect. Our data provide novel evidence that menthol protects against organ damage and decreases mortality in experimental sepsis.
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Affiliation(s)
- Aliaa Anter
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Minia University, Minya, Egypt
| | - Al-Shaimaa F. Ahmed
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Minia University, Minya, Egypt
- *Correspondence: Al-Shaimaa F. Ahmed,
| | - Asmaa S. A. Hammad
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Minia University, Minya, Egypt
| | - Waleed Hassan Almalki
- Department of Pharmacology and Toxicology, Umm Al-Qura University, Makkah, Saudi Arabia
| | | | - AlShaimaa W. Kasem
- Department of Pathology, Faculty of Medicine, Minia University, Minya, Egypt
| | - Mohamed A. El-Moselhy
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Minia University, Minya, Egypt
- Department of Clinical Pharmacy and Pharmacology, Ibn Sina National College for Medical Studies, Jeddah, Saudi Arabia
| | - Mohammad W. Alrabia
- Department of Microbiology and Medical Parasitology, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Ahmed R. N. Ibrahim
- Department of Clinical Pharmacy, College of Pharmacy, King Khalid University, Abha, Saudi Arabia
- Department of Biochemistry, Faculty of Pharmacy, Minia University, Minya, Egypt
| | - Mahmoud El-Daly
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Minia University, Minya, Egypt
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4
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Wen B, Njunge JM, Bourdon C, Gonzales GB, Gichuki BM, Lee D, Wishart DS, Ngari M, Chimwezi E, Thitiri J, Mwalekwa L, Voskuijl W, Berkley JA, Bandsma RHJ. Systemic inflammation and metabolic disturbances underlie inpatient mortality among ill children with severe malnutrition. SCIENCE ADVANCES 2022; 8:eabj6779. [PMID: 35171682 PMCID: PMC8849276 DOI: 10.1126/sciadv.abj6779] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 12/23/2021] [Indexed: 06/14/2023]
Abstract
Children admitted to hospital with an acute illness and concurrent severe malnutrition [complicated severe malnutrition (CSM)] have a high risk of dying. The biological processes underlying their mortality are poorly understood. In this case-control study nested within a multicenter randomized controlled trial among children with CSM in Kenya and Malawi, we found that blood metabolomic and proteomic profiles robustly differentiated children who died (n = 92) from those who survived (n = 92). Fatalities were characterized by increased energetic substrates (tricarboxylic acid cycle metabolites), microbial metabolites (e.g., propionate and isobutyrate), acute phase proteins (e.g., calprotectin and C-reactive protein), and inflammatory markers (e.g., interleukin-8 and tumor necrosis factor-α). These perturbations indicated disruptions in mitochondria-related bioenergetic pathways and sepsis-like responses. This study identified specific biomolecular disturbances associated with CSM mortality, revealing that systemic inflammation and bioenergetic deficits are targetable pathophysiological processes for improving survival of this vulnerable population.
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Affiliation(s)
- Bijun Wen
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Canada
- Department of Translational medicine, Hospital for Sick Children, Toronto, Canada
| | - James M. Njunge
- The Childhood Acute Illness & Nutrition Network, Nairobi, Kenya
- KEMRI/Wellcome Trust Research Programme, Kilifi, Kenya
| | - Celine Bourdon
- Department of Translational medicine, Hospital for Sick Children, Toronto, Canada
- The Childhood Acute Illness & Nutrition Network, Nairobi, Kenya
| | - Gerard Bryan Gonzales
- Nutrition, Metabolism and Genomics Group, Division of Human Nutrition and Health, Wageningen University & Research, Wageningen, Netherlands
| | - Bonface M. Gichuki
- The Childhood Acute Illness & Nutrition Network, Nairobi, Kenya
- KEMRI/Wellcome Trust Research Programme, Kilifi, Kenya
| | - Dorothy Lee
- Department of Translational medicine, Hospital for Sick Children, Toronto, Canada
| | | | - Moses Ngari
- The Childhood Acute Illness & Nutrition Network, Nairobi, Kenya
- KEMRI/Wellcome Trust Research Programme, Kilifi, Kenya
| | | | - Johnstone Thitiri
- The Childhood Acute Illness & Nutrition Network, Nairobi, Kenya
- KEMRI/Wellcome Trust Research Programme, Kilifi, Kenya
| | - Laura Mwalekwa
- KEMRI/Wellcome Trust Research Programme, Kilifi, Kenya
- Department of Paediatrics, Coast General Hospital, Mombasa, Kenya
| | - Wieger Voskuijl
- The Childhood Acute Illness & Nutrition Network, Nairobi, Kenya
- Department of Global Health, Amsterdam Institute for Global Health and Development, Amsterdam University Medical Centres, Amsterdam, Netherlands
- Department of Pediatrics, the College of Medicine, University of Malawi, Blantyre, Malawi
| | - James A. Berkley
- The Childhood Acute Illness & Nutrition Network, Nairobi, Kenya
- KEMRI/Wellcome Trust Research Programme, Kilifi, Kenya
- Centre for Tropical Medicine & Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Robert HJ Bandsma
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Canada
- Department of Translational medicine, Hospital for Sick Children, Toronto, Canada
- The Childhood Acute Illness & Nutrition Network, Nairobi, Kenya
- Department of Pediatrics, the College of Medicine, University of Malawi, Blantyre, Malawi
- Department of Biomedical Sciences, the College of Medicine, University of Malawi, Blantyre, Malawi
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5
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Mun Y, Hwang JS, Shin YJ. Role of Neutrophils on the Ocular Surface. Int J Mol Sci 2021; 22:10386. [PMID: 34638724 PMCID: PMC8508808 DOI: 10.3390/ijms221910386] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 09/16/2021] [Accepted: 09/23/2021] [Indexed: 02/07/2023] Open
Abstract
The ocular surface is a gateway that contacts the outside and receives stimulation from the outside. The corneal innate immune system is composed of many types of cells, including epithelial cells, fibroblasts, natural killer cells, macrophages, neutrophils, dendritic cells, mast cells, basophils, eosinophils, mucin, and lysozyme. Neutrophil infiltration and degranulation occur on the ocular surface. Degranulation, neutrophil extracellular traps formation, called NETosis, and autophagy in neutrophils are involved in the pathogenesis of ocular surface diseases. It is necessary to understand the role of neutrophils on the ocular surface. Furthermore, there is a need for research on therapeutic agents targeting neutrophils and neutrophil extracellular trap formation for ocular surface diseases.
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Affiliation(s)
- Yongseok Mun
- Department of Ophthalmology, Hallym University Medical Center, Hallym University College of Medicine, Seoul 07442, Korea; (Y.M.); (J.S.H.)
- Hallym BioEyeTech Research Center, Hallym University College of Medicine, Seoul 07442, Korea
| | - Jin Sun Hwang
- Department of Ophthalmology, Hallym University Medical Center, Hallym University College of Medicine, Seoul 07442, Korea; (Y.M.); (J.S.H.)
- Hallym BioEyeTech Research Center, Hallym University College of Medicine, Seoul 07442, Korea
| | - Young Joo Shin
- Department of Ophthalmology, Hallym University Medical Center, Hallym University College of Medicine, Seoul 07442, Korea; (Y.M.); (J.S.H.)
- Hallym BioEyeTech Research Center, Hallym University College of Medicine, Seoul 07442, Korea
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6
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Hernández-Beeftink T, Guillen-Guio B, Rodríguez-Pérez H, Marcelino-Rodríguez I, Lorenzo-Salazar JM, Corrales A, Prieto-González M, Rodríguez-Pérez A, Carriedo D, Blanco J, Ambrós A, González-Higueras E, Casanova NG, González-Garay M, Espinosa E, Muriel A, Domínguez D, de Lorenzo AG, Añón JM, Soro M, Belda J, Garcia JGN, Villar J, Flores C. Whole-Blood Mitochondrial DNA Copies Are Associated With the Prognosis of Acute Respiratory Distress Syndrome After Sepsis. Front Immunol 2021; 12:737369. [PMID: 34557198 PMCID: PMC8453061 DOI: 10.3389/fimmu.2021.737369] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 08/16/2021] [Indexed: 01/22/2023] Open
Abstract
Acute respiratory distress syndrome (ARDS) is an inflammatory process of the lungs that develops primarily in response to pulmonary or systemic sepsis, resulting in a disproportionate death toll in intensive care units (ICUs). Given its role as a critical activator of the inflammatory and innate immune responses, previous studies have reported that an increase of circulating cell-free mitochondrial DNA (mtDNA) is a biomarker for fatal outcome in the ICU. Here we analyzed the association of whole-blood mtDNA (wb-mtDNA) copies with 28-day survival from sepsis and sepsis-associated ARDS. We analyzed mtDNA data from 687 peripheral whole-blood samples within 24 h of sepsis diagnosis from unrelated Spanish patients with sepsis (264 with ARDS) included in the GEN-SEP study. The wb-mtDNA copies were obtained from the array intensities of selected probes, with 100% identity with mtDNA and with the largest number of mismatches with the nuclear sequences, and normalized across the individual-probe intensities. We used Cox regression models for testing the association with 28-day survival. We observed that wb-mtDNA copies were significantly associated with 28-day survival in ARDS patients (hazard ratio = 3.65, 95% confidence interval = 1.39–9.59, p = 0.009) but not in non-ARDS patients. Our findings support that wb-mtDNA copies at sepsis diagnosis could be considered an early prognostic biomarker in sepsis-associated ARDS patients. Future studies will be needed to evaluate the mechanistic links of this observation with the pathogenesis of ARDS.
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Affiliation(s)
- Tamara Hernández-Beeftink
- Research Unit, Hospital Universitario N.S. de Candelaria, Universidad de La Laguna, Santa Cruz de Tenerife, Spain.,Research Unit, Hospital Universitario Dr. Negrin, Las Palmas de Gran Canaria, Spain
| | - Beatriz Guillen-Guio
- Research Unit, Hospital Universitario N.S. de Candelaria, Universidad de La Laguna, Santa Cruz de Tenerife, Spain
| | - Héctor Rodríguez-Pérez
- Research Unit, Hospital Universitario N.S. de Candelaria, Universidad de La Laguna, Santa Cruz de Tenerife, Spain
| | - Itahisa Marcelino-Rodríguez
- Research Unit, Hospital Universitario N.S. de Candelaria, Universidad de La Laguna, Santa Cruz de Tenerife, Spain
| | - Jose M Lorenzo-Salazar
- Genomics Division, Instituto Tecnológico y de Energías Renovables (ITER), Tenerife, Spain
| | - Almudena Corrales
- Research Unit, Hospital Universitario N.S. de Candelaria, Universidad de La Laguna, Santa Cruz de Tenerife, Spain.,CIBER de Enfermedades Respiratorias, Instituto de Salud Carlos III, Madrid, Spain
| | | | - Aurelio Rodríguez-Pérez
- Department of Anesthesiology, Hospital Universitario de Gran Canaria Dr. Negrín, Las Palmas de Gran Canaria, Spain.,Department of Medical and Surgical Sciences, University of Las Palmas de Gran Canaria, Gran Canaria, Spain
| | - Demetrio Carriedo
- Intensive Care Unit, Complejo Hospitalario Universitario de León, León, Spain
| | - Jesús Blanco
- CIBER de Enfermedades Respiratorias, Instituto de Salud Carlos III, Madrid, Spain.,Intensive Care Unit, Hospital Universitario Rio Hortega, Valladolid, Spain
| | - Alfonso Ambrós
- Intensive Care Unit, Hospital General de Ciudad Real, Ciudad Real, Spain
| | | | - Nancy G Casanova
- Department of Medicine, The University of Arizona, Tucson, AZ, United States
| | | | - Elena Espinosa
- Department of Anesthesiology, Hospital Universitario N.S. de Candelaria, Santa Cruz de Tenerife, Spain
| | - Arturo Muriel
- Intensive Care Unit, Hospital Universitario Rio Hortega, Valladolid, Spain
| | - David Domínguez
- Department of Anesthesiology, Hospital Universitario N.S. de Candelaria, Santa Cruz de Tenerife, Spain
| | | | - José M Añón
- CIBER de Enfermedades Respiratorias, Instituto de Salud Carlos III, Madrid, Spain.,Intensive Care Unit, Hospital Universitario La Paz, IdiPAZ, Madrid, Spain
| | - Marina Soro
- Anesthesiology and Critical Care Department, Hospital Clinico Universitario of Valencia, Valencia, Spain
| | - Javier Belda
- Anesthesiology and Critical Care Department, Hospital Clinico Universitario of Valencia, Valencia, Spain
| | - Joe G N Garcia
- Department of Medicine, The University of Arizona, Tucson, AZ, United States
| | - Jesús Villar
- Research Unit, Hospital Universitario Dr. Negrin, Las Palmas de Gran Canaria, Spain.,CIBER de Enfermedades Respiratorias, Instituto de Salud Carlos III, Madrid, Spain
| | - Carlos Flores
- Research Unit, Hospital Universitario N.S. de Candelaria, Universidad de La Laguna, Santa Cruz de Tenerife, Spain.,Genomics Division, Instituto Tecnológico y de Energías Renovables (ITER), Tenerife, Spain.,CIBER de Enfermedades Respiratorias, Instituto de Salud Carlos III, Madrid, Spain
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7
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Qiu Y, Yu Y, Qin XM, Jiang T, Tan YF, Ouyang WX, Xiao ZH, Li SJ. CircTLK1 modulates sepsis-induced cardiomyocyte apoptosis via enhancing PARP1/HMGB1 axis-mediated mitochondrial DNA damage by sponging miR-17-5p. J Cell Mol Med 2021; 25:8244-8260. [PMID: 34410682 PMCID: PMC8419196 DOI: 10.1111/jcmm.16738] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 05/10/2021] [Accepted: 06/05/2021] [Indexed: 02/06/2023] Open
Abstract
Introduction Septic cardiomyopathy is a common complication of sepsis with high morbidity and mortality, but lacks specific therapy. This study aimed to reveal the role of circTLK1 and its potential mechanisms in septic cardiomyopathy. Materials and Methods The in vitro and in vivo models of septic cardiomyopathy were established. Cell viability and apoptosis were detected by CCK8, TUNEL and flow cytometry, respectively. LDH, CK, SOD, MDA, ATP, 8‐OHdG, NAD+/NADH ratio, ROS level, mitochondrial membrane potential and cytochrome C distribution were evaluated using commercial kits. qRT‐PCR and western blotting were performed to detect RNA and protein levels. Mitochondrial DNA (mtDNA) copy number and transcription were assessed by quantitative PCR. Dual‐luciferase assay, RNA immunoprecipitation and co‐immunoprecipitation were performed to verify the interaction between circTLK1/PARP1 and miR‐17‐5p. Results CircTLK1, PARP1 and HMGB1 were up‐regulated in the in vitro and in vivo models of septic cardiomyopathy. CircTLK1 inhibition restrained LPS‐induced up‐regulation of PARP1 and HMGB1. Moreover, circTLK1 knockdown repressed sepsis‐induced mtDNA oxidative damage, mitochondrial dysfunction and consequent cardiomyocyte apoptosis by inhibiting PARP1/HMGB1 axis in vitro and in vivo. In addition, circTLK1 enhanced PARP1 expression via sponging miR‐17‐5p. Inhibition of miR‐17‐5p abolished the protective effects of circTLK1 silencing on oxidative mtDNA damage and cardiomyocyte apoptosis. Conclusion CircTLK1 sponged miR‐17‐5p to aggravate mtDNA oxidative damage, mitochondrial dysfunction and cardiomyocyte apoptosis via activating PARP1/HMGB1 axis during sepsis, indicating that circTLK1 may be a putative therapeutic target for septic cardiomyopathy.
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Affiliation(s)
- Yu Qiu
- Emergency Center, Hunan Children's Hospital, Changsha, China
| | - Ying Yu
- Department of Hepatopathy, Hunan Children's Hospital, Changsha, China
| | - Xiao-Mei Qin
- Department of Hepatopathy, Hunan Children's Hospital, Changsha, China
| | - Tao Jiang
- Department of Hepatopathy, Hunan Children's Hospital, Changsha, China
| | - Yan-Fang Tan
- Department of Hepatopathy, Hunan Children's Hospital, Changsha, China
| | - Wen-Xian Ouyang
- Department of Hepatopathy, Hunan Children's Hospital, Changsha, China
| | - Zheng-Hui Xiao
- Emergency Center, Hunan Children's Hospital, Changsha, China
| | - Shuang-Jie Li
- Department of Hepatopathy, Hunan Children's Hospital, Changsha, China
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8
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Larson-Casey JL, He C, Carter AB. Mitochondrial quality control in pulmonary fibrosis. Redox Biol 2020; 33:101426. [PMID: 31928788 PMCID: PMC7251238 DOI: 10.1016/j.redox.2020.101426] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 12/19/2019] [Accepted: 01/03/2020] [Indexed: 12/11/2022] Open
Abstract
Mechanisms underlying the pathogenesis of pulmonary fibrosis remain incompletely understood. Emerging evidence suggests changes in mitochondrial quality control are a critical determinant in many lung diseases, including chronic obstructive pulmonary disease, asthma, pulmonary hypertension, acute lung injury, lung cancer, and in the susceptibility to pulmonary fibrosis. Once thought of as the kidney-bean shaped powerhouses of the cell, mitochondria are now known to form interconnected networks that rapidly and continuously change their size to meet cellular metabolic demands. Mitochondrial quality control modulates cell fate and homeostasis, and diminished mitochondrial quality control results in mitochondrial dysfunction, increased reactive oxygen species (ROS) production, reduced ATP production, and often induces intrinsic apoptosis. Here, we review the role of the mitochondria in alveolar epithelial cells, lung macrophages, and fibroblasts within the context of pulmonary fibrosis.
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Affiliation(s)
- Jennifer L Larson-Casey
- Department of Medicine, Division of Pulmonary, Allergy and Critical Care Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, United States
| | - Chao He
- Department of Medicine, Division of Pulmonary, Allergy and Critical Care Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, United States
| | - A Brent Carter
- Department of Medicine, Division of Pulmonary, Allergy and Critical Care Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, United States; Birmingham VAMC, Birmingham, AL, 35294, United States.
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9
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Tan Y, Chen S, Zhong J, Ren J, Dong M. Mitochondrial Injury and Targeted Intervention in Septic Cardiomyopathy. Curr Pharm Des 2019; 25:2060-2070. [PMID: 31284854 DOI: 10.2174/1381612825666190708155400] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 06/20/2019] [Indexed: 12/31/2022]
Abstract
Background:
Sepsis and septic shock are known to prompt multiple organ failure including cardiac
contractile dysfunction, which is typically referred to as septic cardiomyopathy. Among various theories postulated
for the etiology of septic cardiomyopathy, mitochondrial injury (both morphology and function) in the heart
is perceived as the main culprit for reduced myocardial performance and ultimately heart failure in the face of
sepsis.
Methods:
Over the past decades, ample of experimental and clinical work have appeared, focusing on myocardial
mitochondrial changes and related interventions in septic cardiomyopathy.
Results and Conclusion:
Here we will briefly summarize the recent experimental and clinical progress on myocardial
mitochondrial morphology and function in sepsis, and discuss possible underlying mechanisms, as well as
the contemporary interventional options.
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Affiliation(s)
- Ying Tan
- Department of Emergency Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
| | - Sainan Chen
- Department of Emergency Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
| | - Jiankai Zhong
- Department of Cardiology, Shunde Hospital, Southern Medical University, Foshan, 528300, Guangdong, China
| | - Jun Ren
- Department of Cardiology, Shanghai Institute of Cardiovascular Disease, Zhongshan Hospital Fudan University, Shanghai, 200032, China
| | - Maolong Dong
- Department of Emergency Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
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10
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Abstract
Mitochondria are functionally versatile organelles. In addition to their conventional role of meeting the cell's energy requirements, mitochondria also actively regulate innate immune responses against infectious and sterile insults. Components of mitochondria, when released or exposed in response to dysfunction or damage, can be directly recognized by receptors of the innate immune system and trigger an immune response. In addition, despite initiation that may be independent from mitochondria, numerous innate immune responses are still subject to mitochondrial regulation as discrete steps of their signaling cascades occur on mitochondria or require mitochondrial components. Finally, mitochondrial metabolites and the metabolic state of the mitochondria within an innate immune cell modulate the precise immune response and shape the direction and character of that cell's response to stimuli. Together, these pathways result in a nuanced and very specific regulation of innate immune responses by mitochondria.
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Key Words
- ASC, Apoptosis Associated Speck like protein containing CARD
- ASK1, apoptosis signal-regulating kinase 1
- ATP, adenosine tri-phosphate
- CAPS, cryopyrin associated periodic syndromes
- CARD, caspase activation and recruitment domain
- CL, cardiolipin
- CLR, C-type lectin receptor
- CREB, cAMP response element binding protein
- Cgas, cyclic GMP-AMP synthase
- DAMP, damage associated molecular pattern
- ESCIT, evolutionarily conserved signaling intermediate in the toll pathway
- ETC, electron transport chain
- FPR, formyl peptide receptor
- HIF, hypoxia-inducible factor
- HMGB1, high mobility group box protein 1
- IFN, interferon
- IL, interleukin
- IRF, interferon regulatory factor
- JNK, cJUN NH2-terminal kinase
- LPS, lipopolysaccharide
- LRR, leucine rich repeat
- MAPK, mitogen-activated protein kinase
- MARCH5, membrane-associated ring finger (C3HC4) 5
- MAVS, mitochondrial antiviral signaling
- MAVS, mitochondrial antiviral signaling protein
- MFN1/2, mitofusin
- MOMP, mitochondrial outer membrane permeabilization
- MPT, mitochondrial permeability transition
- MyD88, myeloid differentiation primary response 88
- NADH, nicotinamide adenine dinucleotide
- NBD, nucleotide binding domain
- NFκB, Nuclear factor κ B
- NLR, NOD like receptor
- NOD, nucleotide-binding oligomerization domain
- NRF2, nuclear factor erythroid 2-related factor 2
- PAMP, pathogen associated molecular pattern
- PPAR, peroxisome proliferator-accelerated receptor
- PRRs, pathogen recognition receptors
- RIG-I, retinoic acid inducible gene I
- RLR, retinoic acid inducible gene like receptor
- ROS, reactive oxygen species
- STING, stimulator of interferon gene
- TAK1, transforming growth factor-β-activated kinase 1
- TANK, TRAF family member-associated NFκB activator
- TBK1, TANK Binding Kinase 1
- TCA, Tri-carboxylic acid
- TFAM, mitochondrial transcription factor A
- TLR, Toll Like Receptor
- TRAF6, tumor necrosis factor receptor-associated factor 6
- TRIF, TIR-domain-containing adapter-inducing interferon β
- TUFM, Tu translation elongation factor.
- fMet, N-formylated methionine
- mROS, mitochondrial ROS
- mtDNA, mitochondrial DNA
- n-fp, n-formyl peptides
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Genetic variants of the MAVS, MITA and MFN2 genes are not associated with leprosy in Han Chinese from Southwest China. INFECTION GENETICS AND EVOLUTION 2016; 45:105-110. [DOI: 10.1016/j.meegid.2016.08.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 08/19/2016] [Accepted: 08/19/2016] [Indexed: 01/04/2023]
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12
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Gilkerson R. Commentary: Mitochondrial DNA damage and loss in diabetes. Diabetes Metab Res Rev 2016; 32:672-674. [PMID: 27253402 PMCID: PMC5248653 DOI: 10.1002/dmrr.2833] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 05/27/2016] [Indexed: 12/18/2022]
Abstract
This commentary discusses damage and loss of mitochondrial DNA (mtDNA) in type 2 diabetes mellitus from both the clinical and experimental perspectives. Increasingly, an array of studies in experimental models and patients suggests that the cellular stresses of insulin resistance in type 2 diabetes damage mtDNA, leading to loss of mitochondrial genetic content. As such, mtDNA is emerging as both a valuable monitoring tool and translational preventive target for metabolic disease. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Robert Gilkerson
- Departments of Biology, The University of Texas Rio Grande Valley, Edinburg, TX, USA.
- Clinical Laboratory Sciences, The University of Texas Rio Grande Valley, Edinburg, TX, USA.
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The role of myeloid differentiation factor 88 on mitochondrial dysfunction of peritoneal leukocytes during polymicrobial sepsis. Cent Eur J Immunol 2016; 41:153-8. [PMID: 27536200 PMCID: PMC4967649 DOI: 10.5114/ceji.2016.60989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 01/13/2016] [Indexed: 11/17/2022] Open
Abstract
OBJECTIVE To investigate the role of myeloid differentiation factor 88 (MyD88) on mitochondrial dysfunction of peritoneal leukocytes during polymicrobial sepsis. MATERIAL AND METHODS Polymicrobial peritonitis, a clinically relevant mouse model of sepsis, was generated by cecum ligation and puncture (CLP) in both male C57BL/6J wild-type (WT) and MyD88 knockout (MyD88(-/-)) mice. Twenty-four hours after surgeries, peritoneal leukocytes were collected and four parameters of mitochondrial function, including total intracellular and mitochondrial ROS burst, mitochondrial membrane depolarization and ATP depletion, were measured by flow cytometry or ATP assay, and then compared. RESULTS Polymicrobial sepsis led to a marked mitochondrial dysfunction of peritoneal leukocytes with total intracellular and mitochondrial ROS overproduction, decreased mitochondrial membrane potential and reduced intracellular ATP production. In comparison, there was no significant difference in the extent of mitochondrial dysfunction of peritoneal leukocytes between WT and MyD88(-/-) septic mice. CONCLUSIONS MyD88 may be not sufficient to regulate mitochondrial dysfunction of peritoneal leukocytes during polymicrobial sepsis.
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Lewis AJ, Billiar TR, Rosengart MR. Biology and Metabolism of Sepsis: Innate Immunity, Bioenergetics, and Autophagy. Surg Infect (Larchmt) 2016; 17:286-93. [PMID: 27093228 DOI: 10.1089/sur.2015.262] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Sepsis is a complex, heterogeneous physiologic condition that represents a significant public health concern. While many insights into the pathophysiology of sepsis have been elucidated over the past decades of research, important questions remain. This article serves as a review of several important areas in sepsis research. Understanding the innate immune response has been at the forefront as of late, especially in the context of cytokine-directed therapeutic trials. Cellular bioenergetic changes provide insight into the development of organ dysfunction in sepsis. Autophagy and mitophagy perform crucial cell housekeeping and stress response functions. Finally, age-related changes and their potential impact on the septic response are reviewed.
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Affiliation(s)
- Anthony J Lewis
- Department of Surgery, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Timothy R Billiar
- Department of Surgery, University of Pittsburgh , Pittsburgh, Pennsylvania
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15
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Abstract
In addition to oxidative phosphorylation (OXPHOS), mitochondria perform other functions such as heme biosynthesis and oxygen sensing and mediate calcium homeostasis, cell growth, and cell death. They participate in cell communication and regulation of inflammation and are important considerations in aging, drug toxicity, and pathogenesis. The cell's capacity to maintain its mitochondria involves intramitochondrial processes, such as heme and protein turnover, and those involving entire organelles, such as fusion, fission, selective mitochondrial macroautophagy (mitophagy), and mitochondrial biogenesis. The integration of these processes exemplifies mitochondrial quality control (QC), which is also important in cellular disorders ranging from primary mitochondrial genetic diseases to those that involve mitochondria secondarily, such as neurodegenerative, cardiovascular, inflammatory, and metabolic syndromes. Consequently, mitochondrial biology represents a potentially useful, but relatively unexploited area of therapeutic innovation. In patients with genetic OXPHOS disorders, the largest group of inborn errors of metabolism, effective therapies, apart from symptomatic and nutritional measures, are largely lacking. Moreover, the genetic and biochemical heterogeneity of these states is remarkably similar to those of certain acquired diseases characterized by metabolic and oxidative stress and displaying wide variability. This biologic variability reflects cell-specific and repair processes that complicate rational pharmacological approaches to both primary and secondary mitochondrial disorders. However, emerging concepts of mitochondrial turnover and dynamics along with new mitochondrial disease models are providing opportunities to develop and evaluate mitochondrial QC-based therapies. The goals of such therapies extend beyond amelioration of energy insufficiency and tissue loss and entail cell repair, cell replacement, and the prevention of fibrosis. This review summarizes current concepts of mitochondria as disease elements and outlines novel strategies to address mitochondrial dysfunction through the stimulation of mitochondrial biogenesis and quality control.
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Affiliation(s)
- Hagir B Suliman
- Departments of Medicine (C.A.P.), Anesthesiology (H.B.S.), Duke Cancer Institute (H.B.S.), and Pathology (C.A.P.), Duke University Medical Center, Durham North Carolina
| | - Claude A Piantadosi
- Departments of Medicine (C.A.P.), Anesthesiology (H.B.S.), Duke Cancer Institute (H.B.S.), and Pathology (C.A.P.), Duke University Medical Center, Durham North Carolina
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Mitochondrial ROS Induces Cardiac Inflammation via a Pathway through mtDNA Damage in a Pneumonia-Related Sepsis Model. PLoS One 2015; 10:e0139416. [PMID: 26448624 PMCID: PMC4598156 DOI: 10.1371/journal.pone.0139416] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Accepted: 09/14/2015] [Indexed: 12/21/2022] Open
Abstract
We have previously shown that mitochondria-targeted vitamin E (Mito-Vit-E), a mtROS specific antioxidant, improves cardiac performance and attenuates inflammation in a pneumonia-related sepsis model. In this study, we applied the same approaches to decipher the signaling pathway(s) of mtROS-dependent cardiac inflammation after sepsis. Sepsis was induced in Sprague Dawley rats by intratracheal injection of S. pneumoniae. Mito-Vit-E, vitamin E or vehicle was administered 30 minutes later. In myocardium 24 hours post-inoculation, Mito-Vit-E, but not vitamin E, significantly protected mtDNA integrity and decreased mtDNA damage. Mito-Vit-E alleviated sepsis-induced reduction in mitochondria-localized DNA repair enzymes including DNA polymerase γ, AP endonuclease, 8-oxoguanine glycosylase, and uracil-DNA glycosylase. Mito-Vit-E dramatically improved metabolism and membrane integrity in mitochondria, suppressed leakage of mtDNA into the cytoplasm, inhibited up-regulation of Toll-like receptor 9 (TLR9) pathway factors MYD88 and RAGE, and limited RAGE interaction with its ligand TFAM in septic hearts. Mito-Vit-E also deactivated NF-κB and caspase 1, reduced expression of the essential inflammasome component ASC, and decreased inflammatory cytokine IL–1β. In vitro, both Mito-Vit-E and TLR9 inhibitor OND-I suppressed LPS-induced up-regulation in MYD88, RAGE, ASC, active caspase 1, and IL–1β in cardiomyocytes. Since free mtDNA escaped from damaged mitochondria function as a type of DAMPs to stimulate inflammation through TLR9, these data together suggest that sepsis-induced cardiac inflammation is mediated, at least partially, through mtDNA-TLR9-RAGE. At last, Mito-Vit-E reduced the circulation of myocardial injury marker troponin-I, diminished apoptosis and amended morphology in septic hearts, suggesting that mitochondria-targeted antioxidants are a potential cardioprotective approach for sepsis.
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Mitochondrial Mechanisms in Septic Cardiomyopathy. Int J Mol Sci 2015; 16:17763-78. [PMID: 26247933 PMCID: PMC4581220 DOI: 10.3390/ijms160817763] [Citation(s) in RCA: 98] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Revised: 07/01/2015] [Accepted: 07/23/2015] [Indexed: 12/31/2022] Open
Abstract
Sepsis is the manifestation of the immune and inflammatory response to infection that may ultimately result in multi organ failure. Despite the therapeutic strategies that have been used up to now, sepsis and septic shock remain a leading cause of death in critically ill patients. Myocardial dysfunction is a well-described complication of severe sepsis, also referred to as septic cardiomyopathy, which may progress to right and left ventricular pump failure. Many substances and mechanisms seem to be involved in myocardial dysfunction in sepsis, including toxins, cytokines, nitric oxide, complement activation, apoptosis and energy metabolic derangements. Nevertheless, the precise underlying molecular mechanisms as well as their significance in the pathogenesis of septic cardiomyopathy remain incompletely understood. A well-investigated abnormality in septic cardiomyopathy is mitochondrial dysfunction, which likely contributes to cardiac dysfunction by causing myocardial energy depletion. A number of mechanisms have been proposed to cause mitochondrial dysfunction in septic cardiomyopathy, although it remains controversially discussed whether some mechanisms impair mitochondrial function or serve to restore mitochondrial function. The purpose of this review is to discuss mitochondrial mechanisms that may causally contribute to mitochondrial dysfunction and/or may represent adaptive responses to mitochondrial dysfunction in septic cardiomyopathy.
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Involvement of Visceral Adipose Tissue in Immunological Modulation of Inflammatory Cascade in Preeclampsia. Mediators Inflamm 2015; 2015:325932. [PMID: 26089598 PMCID: PMC4458290 DOI: 10.1155/2015/325932] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 04/04/2015] [Indexed: 01/12/2023] Open
Abstract
Objectives. The pathophysiology of preeclampsia is characterized by abnormal placentation, an exaggerated inflammatory response, and generalized dysfunction of the maternal endothelium. We investigated the effects of preeclampsia serum on the expression of inflammation-related genes by adipose tissue. Materials and Methods. Visceral adipose tissue was obtained from the omentum of patients with early ovarian cancer without metastasis. Adipose tissue was incubated with sera obtained from either five women affected with severe preeclampsia or five women from control pregnant women at 37°C in a humidified incubator at 5% CO2 for 24 hours. 370 genes in total mRNA were analyzed with quantitative RT-PCR (Inflammatory Response & Autoimmunity gene set). Results. Gene expression analysis revealed changes in the expression levels of 30 genes in adipose tissue treated with preeclampsia sera. Some genes are related to immune response, oxidative stress, insulin resistance, and adipogenesis, which plays a central role in excessive systemic inflammatory response of preeclampsia. In contrast, other genes have shown beneficial effects in the regulation of Th2 predominance, antioxidative stress, and insulin sensitivity. Conclusion. In conclusion, visceral adipose tissue offers protection against inflammation, oxidative insults, and other forms of cellular stress that are central to the pathogenesis of preeclampsia.
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Lobet E, Letesson JJ, Arnould T. Mitochondria: a target for bacteria. Biochem Pharmacol 2015; 94:173-85. [PMID: 25707982 DOI: 10.1016/j.bcp.2015.02.007] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 02/12/2015] [Accepted: 02/12/2015] [Indexed: 01/12/2023]
Abstract
Eukaryotic cells developed strategies to detect and eradicate infections. The innate immune system, which is the first line of defence against invading pathogens, relies on the recognition of molecular patterns conserved among pathogens. Pathogen associated molecular pattern binding to pattern recognition receptor triggers the activation of several signalling pathways leading to the establishment of a pro-inflammatory state required to control the infection. In addition, pathogens evolved to subvert those responses (with passive and active strategies) allowing their entry and persistence in the host cells and tissues. Indeed, several bacteria actively manipulate immune system or interfere with the cell fate for their own benefit. One can imagine that bacterial effectors can potentially manipulate every single organelle in the cell. However, the multiple functions fulfilled by mitochondria especially their involvement in the regulation of innate immune response, make mitochondria a target of choice for bacterial pathogens as they are not only a key component of the central metabolism through ATP production and synthesis of various biomolecules but they also take part to cell signalling through ROS production and control of calcium homeostasis as well as the control of cell survival/programmed cell death. Furthermore, considering that mitochondria derived from an ancestral bacterial endosymbiosis, it is not surprising that a special connection does exist between this organelle and bacteria. In this review, we will discuss different mitochondrial functions that are affected during bacterial infection as well as different strategies developed by bacterial pathogens to subvert functions related to calcium homeostasis, maintenance of redox status and mitochondrial morphology.
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Affiliation(s)
- Elodie Lobet
- Laboratory of Biochemistry and Cellular Biology (URBC), NAmur Research Institute for LIfe Science (NARILIS), University of Namur, 61 Rue de Bruxelles, 5000 Namur, Belgium.
| | - Jean-Jacques Letesson
- Research Unit in Microorganisms Biology, University of Namur, 61 Rue de Bruxelles, 5000 Namur, Belgium.
| | - Thierry Arnould
- Laboratory of Biochemistry and Cellular Biology (URBC), NAmur Research Institute for LIfe Science (NARILIS), University of Namur, 61 Rue de Bruxelles, 5000 Namur, Belgium.
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20
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Importance of Toll-like receptor 2 in mitochondrial dysfunction during polymicrobial sepsis. Anesthesiology 2015; 121:1236-47. [PMID: 25272245 DOI: 10.1097/aln.0000000000000470] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
BACKGROUND Toll-like receptor 2 (TLR2) contributes to sepsis pathogenesis such as deleterious systemic inflammation, cardiac dysfunction, and high mortality in animal studies. Mitochondrial dysfunction is a key molecular event that is associated with organ injury in sepsis. The role of TLR2 in sepsis-induced mitochondrial dysfunction remains unclear. METHODS Intracellular hydrogen peroxide (H2O2), mitochondrial superoxide (O2), mitochondrial membrane potential (ΔΨm), and intracellular adenosine triphosphate (ATP) were measured in peritoneal leukocytes. A mouse model of polymicrobial sepsis was generated by cecum ligation and puncture (CLP). Wild-type and TLR2-deficient (TLR2) mice were subjected to sham or CLP. Mitochondrial functions including reactive oxygen species (ROS), ΔΨm, intracellular ATP, and complex III activity were measured. RESULTS TLR2/1 activation by Pam3Cys enhanced intracellular H2O2 and mitochondrial O2 production in leukocytes, but had no effect on mitochondrial ΔΨm and ATP production. The effect was specific for TLR2/1 as TLR3 or TLR9 ligands did not induce ROS production. Polymicrobial sepsis induced mitochondrial dysfunction in leukocytes, as demonstrated by increased H2O2 and mitochondrial O2- production (CLP vs. sham; H2O2: 3,173±498, n=5 vs. 557±38, n=4; O2-: 707±66, n=35 vs. 485±35, n=17, mean fluorescence intensity, mean±SEM), attenuated complex III activity (13±2, n=16 vs. 30±3, n=7, millioptical densities/min), loss of mitochondrial ΔΨm, and depletion of intracellular ATP (33±6, n=11 vs. 296±29, n=4, nmol/mg protein). In comparison, there was significant improvement in mitochondrial function in septic TLR2-/- mice as evidenced by attenuated mitochondrial ROS production, better-maintained mitochondrial ΔΨm, and higher cellular ATP production. CONCLUSIONS TLR2 signaling plays a critical role in mediating mitochondrial dysfunction in peritoneal leukocytes during polymicrobial sepsis.
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21
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Liu TF, Vachharajani V, Millet P, Bharadwaj MS, Molina AJ, McCall CE. Sequential actions of SIRT1-RELB-SIRT3 coordinate nuclear-mitochondrial communication during immunometabolic adaptation to acute inflammation and sepsis. J Biol Chem 2014; 290:396-408. [PMID: 25404738 DOI: 10.1074/jbc.m114.566349] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
We reported that NAD(+)-dependent SIRT1, RELB, and SIRT6 nuclear proteins in monocytes regulate a switch from the glycolysis-dependent acute inflammatory response to fatty acid oxidation-dependent sepsis adaptation. We also found that disrupting SIRT1 activity during adaptation restores immunometabolic homeostasis and rescues septic mice from death. Here, we show that nuclear SIRT1 guides RELB to differentially induce SIRT3 expression and also increases mitochondrial biogenesis, which alters bioenergetics during sepsis adaptation. We constructed this concept using TLR4-stimulated THP1 human promonocytes, a model that mimics the initiation and adaptation stages of sepsis. Following increased expression, mitochondrial SIRT3 deacetylase activates the rate-limiting tricarboxylic acid cycle (TCA) isocitrate dehydrogenase 2 and superoxide dismutase 2, concomitant with increases in citrate synthase activity. Mitochondrial oxygen consumption rate increases early and decreases during adaptation, parallel with modifications to membrane depolarization, ATP generation, and production of mitochondrial superoxide and whole cell hydrogen peroxide. Evidence of SIRT1-RELB induction of mitochondrial biogenesis included increases in mitochondrial mass, mitochondrial-to-nuclear DNA ratios, and both nuclear and mitochondrial encoded proteins. We confirmed the SIRT-RELB-SIRT3 adaptation link to mitochondrial bioenergetics in both TLR4-stimulated normal and sepsis-adapted human blood monocytes and mouse splenocytes. We also found that SIRT1 inhibition ex vivo reversed the sepsis-induced changes in bioenergetics.
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Affiliation(s)
| | - Vidula Vachharajani
- From the Section of Molecular Medicine, the Department of Anesthesiology, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157
| | | | - Manish S Bharadwaj
- Section of Gerontology and Geriatric Medicine, Department of Internal Medicine, and
| | - Anthony J Molina
- Section of Gerontology and Geriatric Medicine, Department of Internal Medicine, and
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22
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Napoli E, Wong S, Hertz-Picciotto I, Giulivi C. Deficits in bioenergetics and impaired immune response in granulocytes from children with autism. Pediatrics 2014; 133:e1405-10. [PMID: 24753527 PMCID: PMC4006429 DOI: 10.1542/peds.2013-1545] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Despite the emerging role of mitochondria in immunity, a link between bioenergetics and the immune response in autism has not been explored. Mitochondrial outcomes and phorbol 12-myristate 13-acetate (PMA)-induced oxidative burst were evaluated in granulocytes from age-, race-, and gender-matched children with autism with severity scores of ≥7 (n = 10) and in typically developing (TD) children (n = 10). The oxidative phosphorylation capacity of granulocytes was 3-fold lower in children with autism than in TD children, with multiple deficits encompassing ≥1 Complexes. Higher oxidative stress in cells of children with autism was evidenced by higher rates of mitochondrial reactive oxygen species production (1.6-fold), higher mitochondrial DNA copy number per cell (1.5-fold), and increased deletions. Mitochondrial dysfunction in children with autism was accompanied by a lower (26% of TD children) oxidative burst by PMA-stimulated reduced nicotinamide-adenine dinucleotide phosphate (NADPH) oxidase and by a lower gene expression (45% of TD children's mean values) of the nuclear factor erythroid 2-related factor 2 transcription factor involved in the antioxidant response. Given that the majority of granulocytes of children with autism exhibited defects in oxidative phosphorylation, immune response, and antioxidant defense, our results support the concept that immunity and response to oxidative stress may be regulated by basic mitochondrial functions as part of an integrated metabolic network.
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Affiliation(s)
- Eleonora Napoli
- Department of Molecular Biosciences, School of Veterinary Medicine
| | - Sarah Wong
- Department of Molecular Biosciences, School of Veterinary Medicine
| | - Irva Hertz-Picciotto
- Department of Public Health Sciences, School of Medicine, and,Medical Investigations of Neurodevelopmental Disorders (M. I. N. D.) Institute, University of California, Davis, Davis California
| | - Cecilia Giulivi
- Department of Molecular Biosciences, School of Veterinary Medicine, Medical Investigations of Neurodevelopmental Disorders (M. I. N. D.) Institute, University of California, Davis, Davis California
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Schumacker PT, Gillespie MN, Nakahira K, Choi AMK, Crouser ED, Piantadosi CA, Bhattacharya J. Mitochondria in lung biology and pathology: more than just a powerhouse. Am J Physiol Lung Cell Mol Physiol 2014; 306:L962-74. [PMID: 24748601 DOI: 10.1152/ajplung.00073.2014] [Citation(s) in RCA: 144] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
An explosion of new information about mitochondria reveals that their importance extends well beyond their time-honored function as the "powerhouse of the cell." In this Perspectives article, we summarize new evidence showing that mitochondria are at the center of a reactive oxygen species (ROS)-dependent pathway governing the response to hypoxia and to mitochondrial quality control. The potential role of the mitochondrial genome as a sentinel molecule governing cytotoxic responses of lung cells to ROS stress also is highlighted. Additional attention is devoted to the fate of damaged mitochondrial DNA relative to its involvement as a damage-associated molecular pattern driving adverse lung and systemic cell responses in severe illness or trauma. Finally, emerging strategies for replenishing normal populations of mitochondria after damage, either through promotion of mitochondrial biogenesis or via mitochondrial transfer, are discussed.
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Affiliation(s)
- Paul T Schumacker
- Northwestern University Feinberg School of Medicine, Department of Pediatrics, Chicago, Illinois
| | - Mark N Gillespie
- University of South Alabama College of Medicine, Department of Pharmacology, Mobile, Alabama;
| | - Kiichi Nakahira
- Weill Cornell Medical College, Department of Medicine, New York, New York
| | - Augustine M K Choi
- Weill Cornell Medical College, Department of Medicine, New York, New York
| | - Elliott D Crouser
- The Ohio State University College of Medicine, Department of Internal Medicine, Columbus, Ohio
| | - Claude A Piantadosi
- Duke University School of Medicine, Department of Medicine, Durham, North Carolina, and
| | - Jahar Bhattacharya
- Columbia University Medical Center, Department of Physiology and Cellular Biophysics, New York, New York
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Patil NK, Parajuli N, MacMillan-Crow LA, Mayeux PR. Inactivation of renal mitochondrial respiratory complexes and manganese superoxide dismutase during sepsis: mitochondria-targeted antioxidant mitigates injury. Am J Physiol Renal Physiol 2014; 306:F734-43. [PMID: 24500690 DOI: 10.1152/ajprenal.00643.2013] [Citation(s) in RCA: 132] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Acute kidney injury (AKI) is a complication of sepsis and leads to a high mortality rate. Human and animal studies suggest that mitochondrial dysfunction plays an important role in sepsis-induced multi-organ failure; however, the specific mitochondrial targets damaged during sepsis remain elusive. We used a clinically relevant cecal ligation and puncture (CLP) murine model of sepsis and assessed renal mitochondrial function using high-resolution respirometry, renal microcirculation using intravital microscopy, and renal function. CLP caused a time-dependent decrease in mitochondrial complex I and II/III respiration and reduced ATP. By 4 h after CLP, activity of manganese superoxide dismutase (MnSOD) was decreased by 50% and inhibition was sustained through 36 h. These events were associated with increased mitochondrial superoxide generation. We then evaluated whether the mitochondria-targeted antioxidant Mito-TEMPO could reverse renal mitochondrial dysfunction and attenuate sepsis-induced AKI. Mito-TEMPO (10 mg/kg) given at 6 h post-CLP decreased mitochondrial superoxide levels, protected complex I and II/III respiration, and restored MnSOD activity by 18 h. Mito-TEMPO also improved renal microcirculation and glomerular filtration rate. Importantly, even delayed therapy with a single dose of Mito-TEMPO significantly increased 96-h survival rate from 40% in untreated septic mice to 80%. Thus, sepsis causes sustained inactivation of three mitochondrial targets that can lead to increased mitochondrial superoxide. Importantly, even delayed therapy with Mito-TEMPO alleviated kidney injury, suggesting that it may be a promising approach to treat septic AKI.
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Affiliation(s)
- Naeem K Patil
- Dept. of Pharmacology and Toxicology, Univ. of Arkansas for Medical Sciences, 325 Jack Stephens Dr., Biomedical Bldg. I, 323D, Little Rock, AR 72205.
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Nakahira K, Kyung SY, Rogers AJ, Gazourian L, Youn S, Massaro AF, Quintana C, Osorio JC, Wang Z, Zhao Y, Lawler LA, Christie JD, Meyer NJ, Causland FRM, Waikar SS, Waxman AB, Chung RT, Bueno R, Rosas IO, Fredenburgh LE, Baron RM, Christiani DC, Hunninghake GM, Choi AMK. Circulating mitochondrial DNA in patients in the ICU as a marker of mortality: derivation and validation. PLoS Med 2013; 10:e1001577; discussion e1001577. [PMID: 24391478 PMCID: PMC3876981 DOI: 10.1371/journal.pmed.1001577] [Citation(s) in RCA: 308] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Accepted: 11/07/2013] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Mitochondrial DNA (mtDNA) is a critical activator of inflammation and the innate immune system. However, mtDNA level has not been tested for its role as a biomarker in the intensive care unit (ICU). We hypothesized that circulating cell-free mtDNA levels would be associated with mortality and improve risk prediction in ICU patients. METHODS AND FINDINGS Analyses of mtDNA levels were performed on blood samples obtained from two prospective observational cohort studies of ICU patients (the Brigham and Women's Hospital Registry of Critical Illness [BWH RoCI, n = 200] and Molecular Epidemiology of Acute Respiratory Distress Syndrome [ME ARDS, n = 243]). mtDNA levels in plasma were assessed by measuring the copy number of the NADH dehydrogenase 1 gene using quantitative real-time PCR. Medical ICU patients with an elevated mtDNA level (≥3,200 copies/µl plasma) had increased odds of dying within 28 d of ICU admission in both the BWH RoCI (odds ratio [OR] 7.5, 95% CI 3.6-15.8, p = 1×10(-7)) and ME ARDS (OR 8.4, 95% CI 2.9-24.2, p = 9×10(-5)) cohorts, while no evidence for association was noted in non-medical ICU patients. The addition of an elevated mtDNA level improved the net reclassification index (NRI) of 28-d mortality among medical ICU patients when added to clinical models in both the BWH RoCI (NRI 79%, standard error 14%, p<1×10(-4)) and ME ARDS (NRI 55%, standard error 20%, p = 0.007) cohorts. In the BWH RoCI cohort, those with an elevated mtDNA level had an increased risk of death, even in analyses limited to patients with sepsis or acute respiratory distress syndrome. Study limitations include the lack of data elucidating the concise pathological roles of mtDNA in the patients, and the limited numbers of measurements for some of biomarkers. CONCLUSIONS Increased mtDNA levels are associated with ICU mortality, and inclusion of mtDNA level improves risk prediction in medical ICU patients. Our data suggest that mtDNA could serve as a viable plasma biomarker in medical ICU patients.
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Affiliation(s)
- Kiichi Nakahira
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Medicine, Weill Cornell Medical College, New York, New York, United States of America
| | - Sun-Young Kyung
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Internal Medicine, Gachon University Gil Hospital, Incheon, South Korea
| | - Angela J. Rogers
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- Channing Division of Network Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Stanford University, Stanford, California, United States of America
| | - Lee Gazourian
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Sojung Youn
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Anthony F. Massaro
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Carolina Quintana
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Juan C. Osorio
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Zhaoxi Wang
- Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, United States of America
| | - Yang Zhao
- Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, United States of America
| | - Laurie A. Lawler
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Jason D. Christie
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Nuala J. Meyer
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Finnian R. Mc. Causland
- Renal Division, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, United States of America
| | - Sushrut S. Waikar
- Renal Division, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, United States of America
| | - Aaron B. Waxman
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Raymond T. Chung
- Division of Gastroenterology, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Raphael Bueno
- Division of Thoracic Surgery, Department of Surgery, Brigham and Women's Hospital, Boston, Massachusetts, United States of America
| | - Ivan O. Rosas
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Laura E. Fredenburgh
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Rebecca M. Baron
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - David C. Christiani
- Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, United States of America
- Pulmonary and Critical Care Unit, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Gary M. Hunninghake
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Augustine M. K. Choi
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Medicine, Weill Cornell Medical College, New York, New York, United States of America
- Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
- * E-mail:
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Cherry AD, Suliman HB, Bartz RR, Piantadosi CA. Peroxisome proliferator-activated receptor γ co-activator 1-α as a critical co-activator of the murine hepatic oxidative stress response and mitochondrial biogenesis in Staphylococcus aureus sepsis. J Biol Chem 2013; 289:41-52. [PMID: 24253037 DOI: 10.1074/jbc.m113.512483] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
A key transcriptional regulator of cell metabolism, the peroxisome proliferator-activated receptor γ co-activator 1-α (PPARGC-1-α or PGC-1α), also regulates mitochondrial biogenesis, but its role in antioxidant gene regulation is not well understood. Here, we asked whether genetic heterozygosity of PGC-1α modulates gene expression for the mitochondrial antioxidant enzyme SOD-2 during hepatic inflammatory stress. Using Staphylococcus aureus peritonitis in mice, we found significant Sod2 gene induction in WT mice, whereas PGC-1α heterozygotes (PGC-1α(+/-)) failed to augment Sod2 mRNA and protein levels. Impaired Sod2 regulation in PGC-1α(+/-) mice was accompanied by oxidative stress shown by elevated mitochondrial GSSG/GSH and protein carbonyls. In silico analysis of the mouse proximal Sod2 promoter region revealed consensus binding sites for the Nfe2l2 (Nrf2) transcription factor. Chromatin immunoprecipitation demonstrated diminished Nfe2l2 protein binding to the antioxidant response element promoter site proximal to the Sod2 start site in PGC-1α heterozygous mice, implicating PGC-1α in facilitation of Nfe2l2 DNA binding. Nuclear protein co-immunoprecipitation demonstrated an interaction between hepatic Nfe2l2 and PGC-1α in WT mice that was greatly reduced in PGC-1α(+/-) mice. The data indicate that PGC-1α promotes mitochondrial antioxidant enzyme expression through Nfe2l2-mediated SOD-2 expression in sepsis. The presence of this new PGC-1α-dependent signaling axis indicates that PGC-1α opposes mitochondrial oxidative stress by means of selective induction of one or more antioxidant response element-driven genes. By implication, exploitation of this axis could lead to new pharmacological interventions to improve the antioxidant defenses during oxidative stress-induced mitochondrial damage.
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Affiliation(s)
- Anne D Cherry
- From the Departments of Anesthesiology, Medicine and Pathology, Duke University Medical Center, Durham, North Carolina 27710
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27
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Dugan LL, You YH, Ali SS, Diamond-Stanic M, Miyamoto S, DeCleves AE, Andreyev A, Quach T, Ly S, Shekhtman G, Nguyen W, Chepetan A, Le TP, Wang L, Xu M, Paik KP, Fogo A, Viollet B, Murphy A, Brosius F, Naviaux RK, Sharma K. AMPK dysregulation promotes diabetes-related reduction of superoxide and mitochondrial function. J Clin Invest 2013; 123:4888-99. [PMID: 24135141 DOI: 10.1172/jci66218] [Citation(s) in RCA: 354] [Impact Index Per Article: 32.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2012] [Accepted: 08/08/2013] [Indexed: 12/27/2022] Open
Abstract
Diabetic microvascular complications have been considered to be mediated by a glucose-driven increase in mitochondrial superoxide anion production. Here, we report that superoxide production was reduced in the kidneys of a steptozotocin-induced mouse model of type 1 diabetes, as assessed by in vivo real-time transcutaneous fluorescence, confocal microscopy, and electron paramagnetic resonance analysis. Reduction of mitochondrial biogenesis and phosphorylation of pyruvate dehydrogenase (PDH) were observed in kidneys from diabetic mice. These observations were consistent with an overall reduction of mitochondrial glucose oxidation. Activity of AMPK, the major energy-sensing enzyme, was reduced in kidneys from both diabetic mice and humans. Mitochondrial biogenesis, PDH activity, and mitochondrial complex activity were rescued by treatment with the AMPK activator 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside (AICAR). AICAR treatment induced superoxide production and was linked with glomerular matrix and albuminuria reduction in the diabetic kidney. Furthermore, diabetic heterozygous superoxide dismutase 2 (Sod2(+/-)) mice had no evidence of increased renal disease, and Ampka2(-/-) mice had increased albuminuria that was not reduced with AICAR treatment. Reduction of mitochondrial superoxide production with rotenone was sufficient to reduce AMPK phosphorylation in mouse kidneys. Taken together, these results demonstrate that diabetic kidneys have reduced superoxide and mitochondrial biogenesis and activation of AMPK enhances superoxide production and mitochondrial function while reducing disease activity.
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Gestational exposure to a viral mimetic poly(i:C) results in long-lasting changes in mitochondrial function by leucocytes in the adult offspring. Mediators Inflamm 2013; 2013:609602. [PMID: 24174710 PMCID: PMC3793312 DOI: 10.1155/2013/609602] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Accepted: 08/16/2013] [Indexed: 12/25/2022] Open
Abstract
Maternal immune activation (MIA) is a potential risk factor for autism spectrum disorder (ASD) and schizophrenia (SZ). In rodents, MIA results in changes in cytokine profiles and abnormal behaviors in the offspring that model these neuropsychiatric conditions. Given the central role that mitochondria have in immunity and other metabolic pathways, we hypothesized that MIA will result in a fetal imprinting that leads to postnatal deficits in the bioenergetics of immune cells. To this end, splenocytes from adult offspring exposed gestationally to the viral mimic poly(I:C) were evaluated for mitochondrial outcomes. A significant decrease in mitochondrial ATP production was observed in poly(I:C)-treated mice (45% of controls) mainly attributed to a lower complex I activity. No differences were observed between the two groups in the coupling of electron transport to ATP synthesis, or the oxygen uptake under uncoupling conditions. Concanavalin A- (ConA-) stimulated splenocytes from poly(I:C) animals showed no statistically significant changes in cytokine levels compared to controls. The present study reports for the first time that MIA activation by poly(I:C) at early gestation, which can lead to behavioral impairments in the offspring similar to SZ and ASD, leads to long-lasting effects in the bioenergetics of splenocytes of adult offspring.
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Langley RJ, Tsalik EL, van Velkinburgh JC, Glickman SW, Rice BJ, Wang C, Chen B, Carin L, Suarez A, Mohney RP, Freeman DH, Wang M, You J, Wulff J, Thompson JW, Moseley MA, Reisinger S, Edmonds BT, Grinnell B, Nelson DR, Dinwiddie DL, Miller NA, Saunders CJ, Soden SS, Rogers AJ, Gazourian L, Fredenburgh LE, Massaro AF, Baron RM, Choi AMK, Corey GR, Ginsburg GS, Cairns CB, Otero RM, Fowler VG, Rivers EP, Woods CW, Kingsmore SF. An integrated clinico-metabolomic model improves prediction of death in sepsis. Sci Transl Med 2013; 5:195ra95. [PMID: 23884467 DOI: 10.1126/scitranslmed.3005893] [Citation(s) in RCA: 329] [Impact Index Per Article: 29.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Sepsis is a common cause of death, but outcomes in individual patients are difficult to predict. Elucidating the molecular processes that differ between sepsis patients who survive and those who die may permit more appropriate treatments to be deployed. We examined the clinical features and the plasma metabolome and proteome of patients with and without community-acquired sepsis, upon their arrival at hospital emergency departments and 24 hours later. The metabolomes and proteomes of patients at hospital admittance who would ultimately die differed markedly from those of patients who would survive. The different profiles of proteins and metabolites clustered into the following groups: fatty acid transport and β-oxidation, gluconeogenesis, and the citric acid cycle. They differed consistently among several sets of patients, and diverged more as death approached. In contrast, the metabolomes and proteomes of surviving patients with mild sepsis did not differ from survivors with severe sepsis or septic shock. An algorithm derived from clinical features together with measurements of five metabolites predicted patient survival. This algorithm may help to guide the treatment of individual patients with sepsis.
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Meyer JN, Leung MCK, Rooney JP, Sendoel A, Hengartner MO, Kisby GE, Bess AS. Mitochondria as a target of environmental toxicants. Toxicol Sci 2013; 134:1-17. [PMID: 23629515 PMCID: PMC3693132 DOI: 10.1093/toxsci/kft102] [Citation(s) in RCA: 350] [Impact Index Per Article: 31.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Enormous strides have recently been made in our understanding of the biology and pathobiology of mitochondria. Many diseases have been identified as caused by mitochondrial dysfunction, and many pharmaceuticals have been identified as previously unrecognized mitochondrial toxicants. A much smaller but growing literature indicates that mitochondria are also targeted by environmental pollutants. We briefly review the importance of mitochondrial function and maintenance for health based on the genetics of mitochondrial diseases and the toxicities resulting from pharmaceutical exposure. We then discuss how the principles of mitochondrial vulnerability illustrated by those fields might apply to environmental contaminants, with particular attention to factors that may modulate vulnerability including genetic differences, epigenetic interactions, tissue characteristics, and developmental stage. Finally, we review the literature related to environmental mitochondrial toxicants, with a particular focus on those toxicants that target mitochondrial DNA. We conclude that the fields of environmental toxicology and environmental health should focus more strongly on mitochondria.
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Affiliation(s)
- Joel N Meyer
- Nicholas School of the Environment, Duke University, Durham, NC, USA.
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31
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Abstract
Recognition of microorganisms by pattern-recognition receptors (PRRs) is the primary component of innate immunity that is responsible for the maintenance of host-microbial interactions in intestinal mucosa. Dysregulation in host-commensal interactions has been implicated as the central pathogenesis of inflammatory bowel disease (IBD), which predisposes to developing colorectal cancer. Recent animal studies have begun to outline some unique physiology and pathology involving each PRR signaling in the intestine. The major roles played by PRRs in the gut appear to be the regulation of the number and the composition of commensal bacteria, epithelial proliferation, and mucosal permeability in response to epithelial injury. In addition, PRR signaling in lamina propria immune cells may be involved in induction of inflammation in response to invasion of pathogens. Because some PRR-deficient mice have shown variable susceptibility to colitis, the outcome of intestinal inflammation may be modified depending on PRR signaling in epithelial cells, immune cells, and the composition of commensal flora. Through recent findings in animal models of IBD, this review will discuss how abnormal PRR signaling may contribute to the pathogenesis of inflammation and inflammation-associated tumorigenesis in the intestine.
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Piantadosi CA, Suliman HB. Redox regulation of mitochondrial biogenesis. Free Radic Biol Med 2012; 53:2043-53. [PMID: 23000245 PMCID: PMC3604744 DOI: 10.1016/j.freeradbiomed.2012.09.014] [Citation(s) in RCA: 116] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Revised: 09/07/2012] [Accepted: 09/11/2012] [Indexed: 12/21/2022]
Abstract
The cell renews, adapts, or expands its mitochondrial population during episodes of cell damage or periods of intensified energy demand by the induction of mitochondrial biogenesis. This bigenomic program is modulated by redox-sensitive signals that respond to physiological nitric oxide (NO), carbon monoxide (CO), and mitochondrial reactive oxygen species production. This review summarizes our current ideas about the pathways involved in the activation of mitochondrial biogenesis by the physiological gases leading to changes in the redox milieu of the cell, with an emphasis on the responses to oxidative stress and inflammation. The cell's energy supply is protected from conditions that damage mitochondria by an inducible transcriptional program of mitochondrial biogenesis that operates in large part through redox signals involving the nitric oxide synthase and the heme oxygenase-1/CO systems. These redox events stimulate the coordinated activities of several multifunctional transcription factors and coactivators also involved in the elimination of defective mitochondria and the expression of counterinflammatory and antioxidant genes, such as IL10 and SOD2, as part of a unified damage-control network. The redox-regulated mechanisms of mitochondrial biogenesis schematically outlined in the graphical abstract link mitochondrial quality control to an enhanced capacity to support the cell's metabolic needs while improving its resistance to metabolic failure and avoidance of cell death during periods of oxidative stress.
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Affiliation(s)
- Claude A Piantadosi
- Department of Medicine, Duke University Medical Center and the Durham VA Medical Center, Durham, NC 27710, USA.
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33
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Kunz A, von Wurmb-Schwark N, Sewangi J, Ziske J, Lau I, Mbezi P, Theuring S, Hauser A, Dugange F, Katerna A, Harms G. Zidovudine exposure in HIV-1 infected Tanzanian women increases mitochondrial DNA levels in placenta and umbilical cords. PLoS One 2012; 7:e41637. [PMID: 22848552 PMCID: PMC3407225 DOI: 10.1371/journal.pone.0041637] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Accepted: 06/22/2012] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND Zidovudine (AZT) constitutes part of the recommended regimens for prevention and treatment of HIV-1 infection. At the same time, AZT as well as HIV-1 infection itself may induce mitochondrial damage. In this study, we analyzed the impact of prenatal AZT-exposure on mitochondrial alterations in HIV-infected women and their infants. METHODS Mitochondrial DNA (mtDNA) levels in placentas of HIV-1 infected Tanzanian women with and without prenatal AZT exposure, and in the umbilical cords of their AZT-exposed/unexposed infants were quantified using real-time PCR. Furthermore, we checked for the most common mitochondrial deletion in humans, the 4977 base pair deletion (dmtDNA4977) as a marker for mitochondrial stress. RESULTS 83 women fulfilled the inclusion criteria. 30 women had been treated with AZT (median duration 56 days; IQR 43-70 days) while 53 women had not taken AZT during pregnancy. Baseline maternal characteristics in the two groups were similar. The median mtDNA levels in placentas and umbilical cords of women (311 copies/cell) and infants (190 copies/cell) exposed to AZT were significantly higher than in AZT-unexposed women (187 copies/cell; p = 0.021) and infants (127 copies/cell; p = 0.037). The dmtDNA4977 was found in placentas of one woman of each group and in 3 umbilical cords of AZT-unexposed infants but not in umbilical cords of AZT-exposed infants. CONCLUSIONS Antenatal AZT intake did not increase the risk for the common mitochondrial deletion dmtDNA4977. Our data suggests that AZT exposure elevates mtDNA levels in placentas and umbilical cords possibly by positively influencing the course of maternal HIV-1 infection.
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Affiliation(s)
- Andrea Kunz
- Institute of Tropical Medicine and International Health, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | | | - Julius Sewangi
- Regional AIDS Control Program Mbeya Region, Ministry of Health and Social Welfare, Mbeya, Tanzania
| | - Judith Ziske
- Institute of Tropical Medicine and International Health, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Inga Lau
- Institute of Tropical Medicine and International Health, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Paulina Mbezi
- PMTCT Program Mbeya Region, Ministry of Health and Social Welfare, Mbeya, Tanzania
| | - Stefanie Theuring
- Institute of Tropical Medicine and International Health, Charité-Universitätsmedizin Berlin, Berlin, Germany
- * E-mail:
| | - Andrea Hauser
- Institute of Tropical Medicine and International Health, Charité-Universitätsmedizin Berlin, Berlin, Germany
- Center for HIV and Retrovirology, Robert Koch Institut, Berlin, Germany
| | - Festo Dugange
- Kyela District Hospital, Ministry of Health and Social Welfare, Kyela District, Tanzania
| | - Angela Katerna
- Institute of Legal Medicine, Christian-Albrechts-Universität Kiel, Kiel, Germany
| | - Gundel Harms
- Institute of Tropical Medicine and International Health, Charité-Universitätsmedizin Berlin, Berlin, Germany
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Traore K, Zirkin B, Thimmulappa RK, Biswal S, Trush MA. Upregulation of TLR1, TLR2, TLR4, and IRAK-2 Expression During ML-1 Cell Differentiation to Macrophages: Role in the Potentiation of Cellular Responses to LPS and LTA. ISRN ONCOLOGY 2012; 2012:641246. [PMID: 22685674 PMCID: PMC3364600 DOI: 10.5402/2012/641246] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Accepted: 03/06/2012] [Indexed: 12/27/2022]
Abstract
12-O-tetradecanoylphorbol 13-acetate (TPA) induces the differentiation of human myeloid ML-1 cells to macrophages. In the current study, the expression, responsiveness, and regulation of toll-like receptors (TLRs) in TPA-induced ML-1-derived macrophages were investigated. We have found that TPA-induced differentiation of ML-1 cells was accompanied by the upregulation of TLR1, TLR2, TLR4, and CD14 expression at both the mRNA and protein levels. Interestingly, TLR1 and TLR4 protein expression on ML-1 cells could be blocked by pretreatment with U0126, suggesting the role of an Erk1/2-induced differentiation signal in this process. In addition, the expression of IRAK-2, a key member of the TLR/IRAK-2/NF-κB-dependent signaling cascade was also induced in response to TPA. Accordingly, we demonstrated an increased cellular release of inflammatory cytokines (TNF-α and various interleukins) upon stimulation with LPS and LTA ligands for TLR4 and TLR2, respectively. Furthermore, using luminol-dependent chemiluminescence, addition of LPS and LTA induces a sustained DPI-inhibitable generation of reactive oxygen species (ROS) by the differentiated ML-1 cells. Together, these data suggest that the increase in the responsiveness of TPA-treated ML-1 cells to LPS and LTA occurs in response to the upregulation of their respective receptors as well as an induction of the IRAK-2 gene expression.
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Affiliation(s)
- Kassim Traore
- Department of Chemistry Geology & Physics, Elizabeth City State University, Elizabeth City, NC 27909, USA
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Liu TF, Brown CM, El Gazzar M, McPhail L, Millet P, Rao A, Vachharajani VT, Yoza BK, McCall CE. Fueling the flame: bioenergy couples metabolism and inflammation. J Leukoc Biol 2012; 92:499-507. [PMID: 22571857 DOI: 10.1189/jlb.0212078] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
We review the emerging concept that changes in cellular bioenergetics concomitantly reprogram inflammatory and metabolic responses. The molecular pathways of this integrative process modify innate and adaptive immune reactions associated with inflammation, as well as influencing the physiology of adjacent tissue and organs. The initiating proinflammatory phase of inflammation is anabolic and requires glucose as the primary fuel, whereas the opposing adaptation phase is catabolic and requires fatty acid oxidation. The fuel switch to fatty acid oxidation depends on the sensing of AMP and NAD(+) by AMPK and the SirT family of deacetylases (e.g., SirT1, -6, and -3), respectively, which couple inflammation and metabolism by chromatin and protein reprogramming. The AMP-AMPK/NAD(+)-SirT axis proceeds sequentially during acute systemic inflammation associated with sepsis but ceases during chronic inflammation associated with diabetes, obesity, and atherosclerosis. Rebalancing bioenergetics resolves inflammation. Manipulating cellular bioenergetics is identifying new ways to treat inflammatory and immune diseases.
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Affiliation(s)
- Tie Fu Liu
- Section of Molecular Medicine, Department of Internal Medicine, Wake Forest University School of Medicine, Winston-Salem, NC, USA.
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36
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Rao NA, Saraswathy S, Pararajasegaram G, Bhat SP. Small heat shock protein αA-crystallin prevents photoreceptor degeneration in experimental autoimmune uveitis. PLoS One 2012; 7:e33582. [PMID: 22479415 PMCID: PMC3316578 DOI: 10.1371/journal.pone.0033582] [Citation(s) in RCA: 27] [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: 09/23/2011] [Accepted: 02/15/2012] [Indexed: 12/26/2022] Open
Abstract
The small heat shock protein, αA-crystallin null (αA−/−) mice are known to be more prone to retinal degeneration than the wild type mice in Experimental Autoimmune Uveoretinitis (EAU). In this report we demonstrate that intravenous administration of αA preserves retinal architecture and prevents photoreceptor damage in EAU. Interestingly, only αA and not αB-crystallin (αB), a closely related small heat shock protein works, pointing to molecular specificity in the observed retinal protection. The possible involvement of αA in retinal protection through immune modulation is corroborated by adaptive transfer experiments, (employing αA−/− and wild type mice with EAU as donors and Rag2−/− as the recipient mice), which indicate that αA protects against the autoimmune challenge by modulating the systemic B and T cell immunity. We show that αA administration causes marked reduction in Th1 cytokines (TNF-α, IL-12 and IFN-γ), both in the retina and in the spleen; notably, IL-17 was only reduced in the retina suggesting local intervention. Importantly, expression of Toll-like receptors and their associated adaptors is also inhibited suggesting that αA protection, against photoreceptor loss in EAU, is associated with systemic suppression of both the adaptive and innate immune responses.
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Affiliation(s)
- Narsing A Rao
- Doheny Eye Institute, University of Southern California, Los Angeles, California, United States of America.
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37
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MacGarvey NC, Suliman HB, Bartz RR, Fu P, Withers CM, Welty-Wolf KE, Piantadosi CA. Activation of mitochondrial biogenesis by heme oxygenase-1-mediated NF-E2-related factor-2 induction rescues mice from lethal Staphylococcus aureus sepsis. Am J Respir Crit Care Med 2012; 185:851-61. [PMID: 22312014 DOI: 10.1164/rccm.201106-1152oc] [Citation(s) in RCA: 140] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
RATIONALE Mitochondrial damage is an important component of multiple organ failure syndrome, a highly lethal complication of severe sepsis that lacks specific therapy. Mitochondrial quality control is regulated in part by the heme oxygenase-1 (HO-1; Hmox1) system through the redox-regulated NF-E2-related factor-2 (Nrf2) transcription factor, but its role in mitochondrial biogenesis in Staphylococcus aureus sepsis is unknown. OBJECTIVES To test the hypothesis that Nrf2-dependent up-regulation of the HO-1/carbon monoxide (CO) system would preserve mitochondrial biogenesis and rescue mice from lethal S. aureus sepsis. METHODS A controlled murine S. aureus peritonitis model with and without inhaled CO was examined for HO-1 and Nrf2 regulation of mitochondrial biogenesis and the resolution of hepatic mitochondrial damage. MEASUREMENTS AND MAIN RESULTS Sepsis survival was significantly enhanced using inhaled CO (250 ppm once-daily for 1 h), and linked mechanistically to Hmox1 induction and mitochondrial HO activity through Nrf2 transcriptional and Akt kinase activity. HO-1/CO stimulated Nrf2-dependent gene expression and nuclear accumulation of nuclear respiratory factor-1, -2α (Gabpa), and peroxisome proliferator-activated receptor gamma coactivator-1α; increased mitochondrial transcription factor-A and citrate synthase protein levels; and augmented mtDNA copy number. CO enhanced antiinflammatory IL-10 and reduced proinflammatory tumor necrosis factor-α production. By contrast, Nrf2(-/-) and Akt1(-/-) mice lacked CO induction of Hmox1 and mitochondrial biogenesis, and CO rescued neither strain from S. aureus sepsis. CONCLUSIONS We identify an inducible Nrf2/HO-1 regulatory cycle for mitochondrial biogenesis that is prosurvival and counter-inflammatory in sepsis, and describe targeted induction of mitochondrial biogenesis as a potential multiple organ failure therapy.
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Piantadosi CA, Suliman HB. Transcriptional control of mitochondrial biogenesis and its interface with inflammatory processes. Biochim Biophys Acta Gen Subj 2012; 1820:532-41. [PMID: 22265687 DOI: 10.1016/j.bbagen.2012.01.003] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Revised: 12/23/2011] [Accepted: 01/07/2012] [Indexed: 12/28/2022]
Abstract
BACKGROUND Cells avoid major mitochondrial damage and energy failure during systemic inflammatory states, such as severe acute infections, by specific targeting of the inflammatory response and by inducing anti-inflammatory and anti-oxidant defenses. Recent evidence indicates that these cell defenses also include mitochondrial biogenesis and the clearance of damaged mitochondria through autophagy. SCOPE OF REVIEW This review addresses a group of transcriptional signaling mechanisms that engage mitochondrial biogenesis, including energy-sensing and redox-regulated transcription factors and co-activators, after major inflammatory events. MAJOR CONCLUSIONS Stimulation of the innate immune system by activation of toll-like receptors (TLR) generates pro-inflammatory mediators, such as tumor necrosis factor-α (TNF-α)and interleukin-1β (IL-1β), necessary for optimal host defense, but which also contribute to mitochondrial damage through oxidative stress and other mechanisms. To protect its energy supply, host cells sense mitochondrial damage and initiate mitochondrial biogenesis under the control of an inducible transcriptional program that also activates anti-oxidant and anti-inflammatory gene expression. This multifunctional network not only increases cellular resistance to metabolic failure, oxidative stress, and cell death, but promotes immune tolerance as shown in the graphical abstract. GENERAL SIGNIFICANCE The post-inflammatory induction of mitochondrial biogenesis supports metabolic function and cell viability while helping to control inflammation. In clinical settings, patients recovering from severe systemic infections may develop transient immune suppression, placing them at risk for recurrent infection, but there may be therapeutic opportunities to enhance mitochondrial quality control that would improve the resolution of life-threatening host responses to such infections.
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Affiliation(s)
- Claude A Piantadosi
- Department of Medicine, Duke University Medical Center, and Durham VA Medical Center, Durham, NC 27710, USA.
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Choumar A, Tarhuni A, Lettéron P, Reyl-Desmars F, Dauhoo N, Damasse J, Vadrot N, Nahon P, Moreau R, Pessayre D, Mansouri A. Lipopolysaccharide-induced mitochondrial DNA depletion. Antioxid Redox Signal 2011; 15:2837-54. [PMID: 21767162 DOI: 10.1089/ars.2010.3713] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Hepatic energy depletion has been described in severe sepsis, and lipopolysaccharide (LPS) has been shown to cause mitochondrial DNA (mtDNA) damage. To clarify the mechanisms of LPS-induced mtDNA damage and mitochondrial alterations, we treated wild-type (WT) or transgenic manganese superoxide dismutase-overerexpressing (MnSOD(+++)) mice with a single dose of LPS (5 mg/kg). In WT mice, LPS increased mitochondrial reactive oxygen species formation, hepatic inducible nitric oxide synthase (NOS) mRNA and protein, tumor necrosis factor-alpha, interleukin-1 beta, and high-mobility group protein B1 concentrations. Six to 48 h after LPS administration (5 mg/kg), liver mtDNA levels, respiratory complex I activity, and adenosine triphosphate (ATP) contents were decreased. In addition, LPS increased interferon-β concentration and decreased mitochondrial transcription factor A (Tfam) mRNA, Tfam protein, and mtDNA-encoded mRNAs. Morphological studies showed mild hepatic inflammation. The LPS (5 mg/kg)-induced mtDNA depletion, complex I inactivation, ATP depletion, and alanine aminotransferase increase were prevented in MnSOD(+++) mice or in WT mice cotreated with 1400W (a NOS inhibitor), (2-(2,2,6,6-tetramethylpiperidin-1-oxyl-4-ylamino)-2-oxoethyl)triphenylphosphonium chloride, monohydrate (a superoxide scavenger) or uric acid (a peroxynitrite scavenger). The MnSOD overexpression delayed death in mice challenged by a higher, lethal dose of LPS (25 mg/kg). In conclusion, LPS administration damages mtDNA and alters mitochondrial function. The protective effects of MnSOD, NOS inhibitors, and superoxide or peroxynitrite scavengers point out a role of the superoxide anion reacting with NO to form mtDNA- and protein-damaging peroxynitrite. In addition to the acute damage caused by reactive species, decreased levels of mitochondrial transcripts contribute to mitochondrial dysfunction.
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Affiliation(s)
- Amal Choumar
- INSERM, U773, Centre de Recherche Biomédicale Bichat Beaujon CRB3, Paris, France
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Kozlov AV, Bahrami S, Calzia E, Dungel P, Gille L, Kuznetsov AV, Troppmair J. Mitochondrial dysfunction and biogenesis: do ICU patients die from mitochondrial failure? Ann Intensive Care 2011; 1:41. [PMID: 21942988 PMCID: PMC3224479 DOI: 10.1186/2110-5820-1-41] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Accepted: 09/26/2011] [Indexed: 12/17/2022] Open
Abstract
Mitochondrial functions include production of energy, activation of programmed cell death, and a number of cell specific tasks, e.g., cell signaling, control of Ca2+ metabolism, and synthesis of a number of important biomolecules. As proper mitochondrial function is critical for normal performance and survival of cells, mitochondrial dysfunction often leads to pathological conditions resulting in various human diseases. Recently mitochondrial dysfunction has been linked to multiple organ failure (MOF) often leading to the death of critical care patients. However, there are two main reasons why this insight did not generate an adequate resonance in clinical settings. First, most data regarding mitochondrial dysfunction in organs susceptible to failure in critical care diseases (liver, kidney, heart, lung, intestine, brain) were collected using animal models. Second, there is no clear therapeutic strategy how acquired mitochondrial dysfunction can be improved. Only the benefit of such therapies will confirm the critical role of mitochondrial dysfunction in clinical settings. Here we summarized data on mitochondrial dysfunction obtained in diverse experimental systems, which are related to conditions seen in intensive care unit (ICU) patients. Particular attention is given to mechanisms that cause cell death and organ dysfunction and to prospective therapeutic strategies, directed to recover mitochondrial function. Collectively the data discussed in this review suggest that appropriate diagnosis and specific treatment of mitochondrial dysfunction in ICU patients may significantly improve the clinical outcome.
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Affiliation(s)
- Andrey V Kozlov
- Ludwig Boltzmann Institute for Experimental and Clinical Traumatology, AUVA Research Center, A-1200 Vienna, Austria.
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Sweeney TE, Suliman HB, Hollingsworth JW, Welty-Wolf KE, Piantadosi CA. A toll-like receptor 2 pathway regulates the Ppargc1a/b metabolic co-activators in mice with Staphylococcal aureus sepsis. PLoS One 2011; 6:e25249. [PMID: 21966468 PMCID: PMC3180377 DOI: 10.1371/journal.pone.0025249] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Accepted: 08/30/2011] [Indexed: 01/07/2023] Open
Abstract
Activation of the host antibacterial defenses by the toll-like receptors (TLR) also selectively activates energy-sensing and metabolic pathways, but the mechanisms are poorly understood. This includes the metabolic and mitochondrial biogenesis master co-activators, Ppargc1a (PGC-1α) and Ppargc1b (PGC-1β) in Staphylococcus aureus (S. aureus) sepsis. The expression of these genes in the liver is markedly attenuated inTLR2−/− mice and markedly accentuated in TLR4−/− mice compared with wild type (WT) mice. We sought to explain this difference by using specific TLR-pathway knockout mice to test the hypothesis that these co-activator genes are directly regulated through TLR2 signaling. By comparing their responses to S. aureus with WT mice, we found that MyD88-deficient and MAL-deficient mice expressed hepatic Ppargc1a and Ppargc1b normally, but that neither gene was activated in TRAM-deficient mice. Ppargc1a/b activation did not require NF-kβ, but did require an interferon response factor (IRF), because neither gene was activated in IRF-3/7 double-knockout mice in sepsis, but both were activated normally in Unc93b1-deficient (3d) mice. Nuclear IRF-7 levels in TLR2−/− and TLR4−/− mice decreased and increased respectively post-inoculation and IRF-7 DNA-binding at the Ppargc1a promoter was demonstrated by chromatin immunoprecipitation. Also, a TLR2-TLR4-TRAM native hepatic protein complex was detected by immunoprecipitation within 6 h of S. aureus inoculation that could support MyD88-independent signaling to Ppargc1a/b. Overall, these findings disclose a novel MyD88-independent pathway in S. aureus sepsis that links TLR2 and TLR4 signaling in innate immunity to Ppargc1a/b gene regulation in a critical metabolic organ, the liver, by means of TRAM, TRIF, and IRF-7.
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Affiliation(s)
- Timothy E Sweeney
- Department of Pathology, Duke University Medical Center, Durham, North Carolina, United States of America
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Abstract
OBJECTIVE The cytopathic hypoxia theory proposes that there is an impaired cellular oxygen utilization during sepsis. Respiratory complex IV, or cytochrome c oxidase, was only previously studied in muscle biopsies of 16 surviving and 12 nonsurviving septic patients. We hypothesized that higher activities and quantities of this enzyme complex could be associated with septic patient survival. The objective was to evaluate the relationship between cytochrome c oxidase activities and quantities and 6-month survival in a larger series of septic patients using a less invasive method (circulating platelets). DESIGN Prospective, multicenter, observational study. SETTING The study was carried out in six Spanish intensive care units. PATIENTS We included 96 septic patients. INTERVENTIONS We determined the cytochrome c oxidase activity per citrate synthase activity ratio and cytochrome c oxidase quantity per citrate synthase activity ratio in circulating platelets at the time of diagnosis and related them to 6-month survival. The written informed consent from the family members was obtained. MEASUREMENTS AND MAIN RESULTS Survivor patients (n = 54) showed higher cytochrome c oxidase activity per citrate synthase activity ratio (p = .04) and cytochrome c oxidase quantity per citrate synthase activity ratio (p = .006) than nonsurvivors (n = 42). Logistic regression analyses confirmed that the cytochrome c oxidase activity per citrate synthase activity ratio (p = .04) and cytochrome c oxidase quantity per citrate synthase activity ratio (p = .02) were independent predictors of 6-month survival. The area under the curve to predict 6-month survival was 0.62 (95% confidence interval 0.51-0.74; p = .04) for the cytochrome c oxidase activity per citrate synthase activity ratio and 0.67 (95% confidence interval 0.56-0.76; p = .003) for the cytochrome c oxidase quantity per citrate synthase activity ratio. A negative correlation was found between the cytochrome c oxidase quantity per citrate synthase activity ratio and Sepsis-Related Organ Failure Assessment score (p = .04). CONCLUSIONS Platelet cytochrome c oxidase activity and quantity were independent predictors of 6-month survival and could be used as biomarkers of sepsis mortality. This is a rapid, easy, and less invasive protocol to assess mitochondrial function. Patients with lower cytochrome c oxidase activity and quantity could benefit from drugs that improve mitochondrial function.
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Ko MK, Saraswathy S, Parikh JG, Rao NA. The role of TLR4 activation in photoreceptor mitochondrial oxidative stress. Invest Ophthalmol Vis Sci 2011; 52:5824-35. [PMID: 21666244 DOI: 10.1167/iovs.10-6357] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
PURPOSE Herein the authors investigated whether the activation of Toll-like receptors (TLRs) in the innate immune response causes retinal photoreceptor oxidative stress and mitochondrial DNA (mtDNA) damage. METHODS On day 5 after injection of complete Freund's adjuvant containing heat-killed Mycobacterium tuberculosis (CFA), retinas were submitted to polymerase chain reaction (PCR) array focused on the TLR signaling, or apoptosis, pathway. CFA-mediated TLR4 activation, oxidative stress, and mtDNA damage were determined in B10.RIII and knockout (KO) mice (recombination activation gene [Rag] 1(KO), TLR4(KO), myeloid differentiation primary response gene 88 [MyD88](KO), tumor necrosis factor [TNF]-α(KO), or caspase 7(KO) mice) using quantitative real-time PCR, enzyme-linked immunosorbent assay, Western blot analysis, and immunohistochemistry. The mycobacterial DNA load on the retina, brain, liver, and spleen was determined by real-time PCR after intracardiac perfusion. RESULTS PCR array demonstrated the upregulation of TLRs and their signaling molecules in retinas of CFA-injected mice compared with those of control animals without inflammatory cell infiltration in the retina and uvea. Mycobacterial DNA was detected in the retinas of CFA-injected mice. Retinas of CFA-injected animals showed oxidative stress and mtDNA damage, primarily in the photoreceptor inner segments. Upregulated TLR4 was localized with CD11b(+)MHCII(+) cells but not with GFAP(+) astrocytes. This oxidative stress/damage was similar in CFA-injected Rag1(KO) mice compared with wild-type controls. Such damage was absent in the retinas of CFA-injected TLR4(KO), MyD88(KO), and TNF-α(KO) mice. CFA-mediated inducible nitric oxide synthase expression in the retina was significantly decreased in TNF-α(KO) mice. CONCLUSIONS Retinal photoreceptors are susceptible to mitochondrial oxidative stress/mtDNA damage in robust TLR4-mediated innate immune response.
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Affiliation(s)
- MinHee K Ko
- Doheny Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, California 90033, USA
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Escames G, López LC, García JA, García-Corzo L, Ortiz F, Acuña-Castroviejo D. Mitochondrial DNA and inflammatory diseases. Hum Genet 2011; 131:161-73. [DOI: 10.1007/s00439-011-1057-y] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2011] [Accepted: 06/26/2011] [Indexed: 12/21/2022]
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McCall CE, El Gazzar M, Liu T, Vachharajani V, Yoza B. Epigenetics, bioenergetics, and microRNA coordinate gene-specific reprogramming during acute systemic inflammation. J Leukoc Biol 2011; 90:439-46. [PMID: 21610199 DOI: 10.1189/jlb.0211075] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Acute systemic inflammation from infectious and noninfectious etiologies has stereotypic features that progress through an initiation (proinflammatory) phase, an adaptive (anti-inflammatory) phase, and a resolution (restoration of homeostasis) phase. These phase-shifts are accompanied by profound and predictable changes in gene expression and metabolism. Here, we review the emerging concept that the temporal phases of acute systemic inflammation are controlled by an integrated bioenergy and epigenetic bridge that guides the timing of transcriptional and post-transcriptional processes of specific gene sets. This unifying connection depends, at least in part, on redox sensor NAD(+)-dependent deacetylase, Sirt1, and a NF-κB-dependent p65 and RelB feed-forward and gene-specific pathway that generates silent facultative heterochromatin and active euchromatin. An additional level of regulation for gene-specific reprogramming is generated by differential expression of miRNA that directly and indirectly disrupts translation of inflammatory genes. These molecular reprogramming circuits generate a dynamic chromatin landscape that temporally defines the course of acute inflammation.
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Affiliation(s)
- Charles E McCall
- Wake Forest University Medical Center, Winston Salem, NC 27157, USA.
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Piantadosi CA, Withers CM, Bartz RR, MacGarvey NC, Fu P, Sweeney TE, Welty-Wolf KE, Suliman HB. Heme oxygenase-1 couples activation of mitochondrial biogenesis to anti-inflammatory cytokine expression. J Biol Chem 2011; 286:16374-85. [PMID: 21454555 PMCID: PMC3091243 DOI: 10.1074/jbc.m110.207738] [Citation(s) in RCA: 207] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Revised: 03/16/2011] [Indexed: 12/20/2022] Open
Abstract
The induction of heme oxygenase-1 (HO-1; Hmox1) by inflammation, for instance in sepsis, is associated both with an anti-inflammatory response and with mitochondrial biogenesis. Here, we tested the idea that HO-1, acting through the Nfe2l2 (Nrf2) transcription factor, links anti-inflammatory cytokine expression to activation of mitochondrial biogenesis. HO-1 induction after LPS stimulated anti-inflammatory IL-10 and IL-1 receptor antagonist (IL-1Ra) expression in mouse liver, human HepG2 cells, and mouse J774.1 macrophages but blunted tumor necrosis factor-α expression. This was accompanied by nuclear Nfe2l2 accumulation and led us to identify abundant Nfe2l2 and other mitochondrial biogenesis transcription factor binding sites in the promoter regions of IL10 and IL1Ra compared with pro-inflammatory genes regulated by NF-κΒ. Mechanistically, HO-1, through its CO product, enabled these transcription factors to bind the core IL10 and IL1Ra promoters, which for IL10 included Nfe2l2, nuclear respiratory factor (NRF)-2 (Gabpa), and MEF2, and for IL1Ra, included NRF-1 and MEF2. In cells, Hmox1 or Nfe2l2 RNA silencing prevented IL-10 and IL-1Ra up-regulation, and HO-1 induction failed post-LPS in Nfe2l2-silenced cells and post-sepsis in Nfe2l2(-/-) mice. Nfe2l2(-/-) mice compared with WT mice, showed more liver damage, higher mortality, and ineffective CO rescue in sepsis. Nfe2l2(-/-) mice in sepsis also generated higher hepatic TNF-α mRNA levels, lower NRF-1 and PGC-1α mRNA levels, and no enhancement of anti-inflammatory Il10, Socs3, or bcl-x(L) gene expression. These findings disclose a highly structured transcriptional network that couples mitochondrial biogenesis to counter-inflammation with major implications for immune suppression in sepsis.
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Affiliation(s)
- Claude A Piantadosi
- Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710, USA.
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Liu TF, Yoza BK, El Gazzar M, Vachharajani VT, McCall CE. NAD+-dependent SIRT1 deacetylase participates in epigenetic reprogramming during endotoxin tolerance. J Biol Chem 2011; 286:9856-64. [PMID: 21245135 DOI: 10.1074/jbc.m110.196790] [Citation(s) in RCA: 189] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Gene-selective epigenetic reprogramming and shifts in cellular bioenergetics develop when Toll-like receptors (TLR) recognize and respond to systemic life-threatening infections. Using a human monocyte cell model of endotoxin tolerance and human leukocytes from acute systemic inflammation with sepsis, we report that energy sensor sirtuin 1 (SIRT1) coordinates the epigenetic and bioenergy shifts. After TLR4 signaling, SIRT1 rapidly accumulated at the promoters of TNF-α and IL-1β, but not IκBα; SIRT1 promoter binding was dependent on its co-factor, NAD(+). During this initial process, SIRT1 deacetylated RelA/p65 lysine 310 and nucleosomal histone H4 lysine 16 to promote termination of NFκB-dependent transcription. SIRT1 then remained promoter bound and recruited de novo induced RelB, which directed assembly of the mature transcription repressor complex that generates endotoxin tolerance. SIRT1 also promoted de novo expression of RelB. During sustained endotoxin tolerance, nicotinamide phosphoribosyltransferase (Nampt), the rate-limiting enzyme for endogenous production of NAD(+), and SIRT1 expression increased. The elevation of SIRT1 required protein stabilization and enhanced translation. To support the coordination of bioenergetics in human sepsis, we observed elevated NAD(+) levels concomitant with SIRT1 and RelB accumulation at the TNF-α promoter of endotoxin tolerant sepsis blood leukocytes. We conclude that TLR4 stimulation and human sepsis activate pathways that couple NAD(+) and its sensor SIRT1 with epigenetic reprogramming.
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Affiliation(s)
- Tie Fu Liu
- Department of Internal Medicine, Section of Molecular Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157, USA.
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Abstract
OBJECTIVE Obesity in pregnancy significantly increases the risk of the offspring developing obesity after birth. The aims of this study were to test the hypothesis that maternal obesity increases oxidative stress during fetal development, and to determine whether administration of an antioxidant supplement to pregnant Western diet-fed rats would prevent the development of adiposity in the offspring. RESEARCH DESIGN AND METHODS Female Sprague Dawley rats were started on the designated diet at 4 weeks of age. Four groups of animals were studied: control chow (control); control + antioxidants (control+Aox); Western diet (Western); and Western diet + antioxidants (Western+Aox). The rats were mated at 12 to 14 weeks of age, and all pups were weaned onto control diet. RESULTS Offspring from dams fed the Western diet had significantly increased adiposity as early as 2 weeks of age as well as impaired glucose tolerance compared with offspring of dams fed a control diet. Inflammation and oxidative stress were increased in preimplantation embryos, fetuses, and newborns of Western diet-fed rats. Gene expression of proadipogenic and lipogenic genes was altered in fat tissue of rats at 2 weeks and 2 months of age. The addition of an antioxidant supplement decreased adiposity and normalized glucose tolerance. CONCLUSIONS; Inflammation and oxidative stress appear to play a key role in the development of increased adiposity in the offspring of Western diet-fed pregnant dams. Restoration of the antioxidant balance during pregnancy in the Western diet-fed dam is associated with decreased adiposity in offspring.
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Affiliation(s)
- Sarbattama Sen
- Department of Pediatrics, The Children's Hospital of Philadelphia, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania
- Division of Newborn Medicine, Tufts Medical Center, Boston, Massachusetts
| | - Rebecca A. Simmons
- Department of Pediatrics, The Children's Hospital of Philadelphia, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania
- Corresponding author: Rebecca A. Simmons,
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Oxidative photoreceptor cell damage in autoimmune uveitis. J Ophthalmic Inflamm Infect 2010; 1:7-13. [PMID: 21475655 PMCID: PMC3062768 DOI: 10.1007/s12348-010-0007-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Accepted: 09/16/2010] [Indexed: 11/04/2022] Open
Abstract
Uveitis comprises an extensive array of intraocular inflammatory diseases and often results in irreversible visual loss. Experimental autoimmune uveitis (EAU) is an animal model used to study human uveitis. Both innate and adaptive immune responses are known to mediate retinal damage in EAU. The innate immune response occurs first with activation of toll-like receptors which upregulate inflammatory cytokines, leading to oxidative stress; subsequently, the adaptive immune response results in inflammatory cytokine upregulation and mitochondrial oxidative stress. In early EAU, mitochondrial DNA is damaged before inflammatory cellular infiltration and alters mitochondrial protein levels and the functions of mitochondria in AU. Our recent study confirms the importance of TLR4 in the generation of inflammatory cytokines, initiation of oxidative DNA damage, and induction of mitochondrial oxidative stress. Like EAU, sympathetic ophthalmia also results in photoreceptor mitochondrial oxidative damage. Agents that prevent mitochondrial oxidative stress and photoreceptor apoptosis may help prevent retinal damage and preserve vision in uveitis.
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