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Zhang M, Cheng Y, Zhai Y, Cui Y, Zhang W, Sun H, Xin W, Zhou L, Gao X, Li S, Sun H. Attenuated succinate accumulation relieves neuronal injury induced by hypoxia in neonatal mice. Cell Death Dis 2022; 8:138. [PMID: 35351859 PMCID: PMC8964675 DOI: 10.1038/s41420-022-00940-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 02/19/2022] [Accepted: 03/08/2022] [Indexed: 12/01/2022]
Abstract
Hypoxia causes neonatal neuronal damage. However, the underlying mechanism remains unclear. This study aimed to explore the changes in succinate levels and identify the mechanisms underlying their contribution to hypoxia-induced damage in newborn mice. The neonatal C57BL/6J mouse hypoxia model was used in our study. We evaluated the levels of succinate, iron, reactive oxygen species (ROS), and mitochondrial ROS, and assessed mitophagy, neuronal damage, and learning and memory function, after hypoxia treatment. The neonatal mice showed increased succinate levels in the early hypoxia stage, followed by increased levels of oxidative stress, iron stress, neuronal damage, and cognitive deficits. Succinate levels were significantly reduced following treatment with inhibitors of succinate dehydrogenase (SDH), purine nucleotide cycle (PNC), and malate/aspartate shuttle (MAS), with the corresponding attenuation of oxidative stress, iron stress, neuronal damage, and cognitive impairment. Reversal catalysis of SDH through fumarate from the PNC and MAS pathways might be involved in hypoxia-induced succinate accumulation. Succinate accumulation in the early period after hypoxia may crucially contribute to oxidative and iron stress. Relieving succinate accumulation at the early hypoxia stage could prevent neuronal damage and cognitive impairment in neonatal hypoxia. ![]()
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Wang Z, Chen L, Huang Y, Luo M, Wang H, Jiang Z, Zheng J, Yang Z, Chen Z, Zhang C, Long L, Wang Y, Li X, Liao F, Gan Y, Luo P, Liu Y, Wang Y, XuTan, Zhou Z, Zhang A, Shi C. Pharmaceutical targeting of succinate dehydrogenase in fibroblasts controls bleomycin-induced lung fibrosis. Redox Biol 2021; 46:102082. [PMID: 34343908 PMCID: PMC8342973 DOI: 10.1016/j.redox.2021.102082] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 07/23/2021] [Indexed: 12/20/2022] Open
Abstract
Idiopathic pulmonary fibrosis (IPF) is characterized by excessive deposition of extracellular matrix in the lung with fibroblast-to-myofibroblast transition, leading to chronically compromising lung function and death. However, very little is known about the metabolic alterations of fibroblasts in IPF, and there is still a lack of pharmaceutical agents to target the metabolic dysregulation. Here we show a glycolysis upregulation and fatty acid oxidation (FAO) downregulation in fibroblasts from fibrotic lung, and perturbation of glycolysis and FAO affects fibroblasts transdifferentiation. In addition, there is a significant accumulation of succinate both in fibrotic lung tissues and myofibroblasts, where succinate dehydrogenase (SDH) operates in reverse by reducing fumarate to succinate. Then succinate contributes to glycolysis upregulation and FAO downregulation by stabilizing HIF-1α, which promotes the development of lung fibrosis. In addition, we identify a near-infrared small molecule dye, IR-780, as a targeting agent which stimulates mild inhibition of succinate dehydrogenase subunit A (SDHA) in fibroblasts, and which inhibits TGF-β1 induced SDH and succinate elevation, then to prevent fibrosis formation and respiratory dysfunction. Further, enhanced cell retention of IR-780 is shown to promote severe inhibition of SDHA in myofibroblasts, which may contribute to excessive ROS generation and selectively induces myofibroblasts to apoptosis, and then therapeutically improves established lung fibrosis in vivo. These findings indicate that targeting metabolic dysregulation has significant implications for therapies aimed at lung fibrosis and succinate dehydrogenase is an exciting new therapeutic target to treat IPF. Glycolysis upregulation and fatty acid oxidation (FAO) downregulation in fibroblasts lead to lung fibrosis. Succinate contributes to metabolic dysregulation of fibroblasts by stabilizing HIF-1α. Succinate dehydrogenase is an exciting new therapeutic target to treat IPF. IR-780 can be a promising agent to control lung fibrosis by targeting succinate dehydrogenase.
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Affiliation(s)
- Ziwen Wang
- Institute of Rocket Force Medicine, State Key Laboratory of Trauma, Burns and Combined Injury, Third Military Medical University (Army Medical University), Chongqing, 400038, China; Department of Cardiology, Geriatric Cardiovascular Disease Research and Treatment Center, The 82nd Group Army Hospital of PLA (252 Hospital of PLA), Baoding, Hebei, 071000, China
| | - Long Chen
- Institute of Rocket Force Medicine, State Key Laboratory of Trauma, Burns and Combined Injury, Third Military Medical University (Army Medical University), Chongqing, 400038, China
| | - Yu Huang
- Institute of Rocket Force Medicine, State Key Laboratory of Trauma, Burns and Combined Injury, Third Military Medical University (Army Medical University), Chongqing, 400038, China; Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, Department of Toxicology, Guizhou Medical University, Guiyang, 550025, China
| | - Min Luo
- Institute of Rocket Force Medicine, State Key Laboratory of Trauma, Burns and Combined Injury, Third Military Medical University (Army Medical University), Chongqing, 400038, China; Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, Department of Toxicology, Guizhou Medical University, Guiyang, 550025, China
| | - Huilan Wang
- Institute of Rocket Force Medicine, State Key Laboratory of Trauma, Burns and Combined Injury, Third Military Medical University (Army Medical University), Chongqing, 400038, China; Institute of Clinical Medicine, Southwest Medical University, Luzhou, 646000, China
| | - Zhongyong Jiang
- Institute of Rocket Force Medicine, State Key Laboratory of Trauma, Burns and Combined Injury, Third Military Medical University (Army Medical University), Chongqing, 400038, China
| | - Jiancheng Zheng
- Institute of Rocket Force Medicine, State Key Laboratory of Trauma, Burns and Combined Injury, Third Military Medical University (Army Medical University), Chongqing, 400038, China
| | - Zeyu Yang
- Breast and Thyroid Surgical Department, Chongqing General Hospital, University of Chinese Academy of Sciences, Chongqing, 401147, China
| | - Zelin Chen
- Institute of Rocket Force Medicine, State Key Laboratory of Trauma, Burns and Combined Injury, Third Military Medical University (Army Medical University), Chongqing, 400038, China
| | - Chi Zhang
- Institute of Rocket Force Medicine, State Key Laboratory of Trauma, Burns and Combined Injury, Third Military Medical University (Army Medical University), Chongqing, 400038, China
| | - Lei Long
- Institute of Rocket Force Medicine, State Key Laboratory of Trauma, Burns and Combined Injury, Third Military Medical University (Army Medical University), Chongqing, 400038, China
| | - Yawei Wang
- Institute of Rocket Force Medicine, State Key Laboratory of Trauma, Burns and Combined Injury, Third Military Medical University (Army Medical University), Chongqing, 400038, China
| | - Xueru Li
- Department of Ophthalmology, Third Affiliated Hospital of Chongqing Medical University (Gener Hospital), Chongqing, 401120, China
| | - Fengying Liao
- Institute of Rocket Force Medicine, State Key Laboratory of Trauma, Burns and Combined Injury, Third Military Medical University (Army Medical University), Chongqing, 400038, China
| | - Yibo Gan
- Institute of Rocket Force Medicine, State Key Laboratory of Trauma, Burns and Combined Injury, Third Military Medical University (Army Medical University), Chongqing, 400038, China
| | - Peng Luo
- Institute of Rocket Force Medicine, State Key Laboratory of Trauma, Burns and Combined Injury, Third Military Medical University (Army Medical University), Chongqing, 400038, China
| | - Yunsheng Liu
- Institute of Rocket Force Medicine, State Key Laboratory of Trauma, Burns and Combined Injury, Third Military Medical University (Army Medical University), Chongqing, 400038, China
| | - Yu Wang
- Institute of Rocket Force Medicine, State Key Laboratory of Trauma, Burns and Combined Injury, Third Military Medical University (Army Medical University), Chongqing, 400038, China
| | - XuTan
- Institute of Rocket Force Medicine, State Key Laboratory of Trauma, Burns and Combined Injury, Third Military Medical University (Army Medical University), Chongqing, 400038, China
| | - Ziyuan Zhou
- Department of Environmental Health, College of Preventive Medicine, Third Military Medical University, Chongqing, 400038, China.
| | - Aihua Zhang
- Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, Department of Toxicology, Guizhou Medical University, Guiyang, 550025, China.
| | - Chunmeng Shi
- Institute of Rocket Force Medicine, State Key Laboratory of Trauma, Burns and Combined Injury, Third Military Medical University (Army Medical University), Chongqing, 400038, China.
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He J, Liu R, Zheng W, Guo H, Yang Y, Zhao R, Yao W. High ambient temperature exposure during late gestation disrupts glycolipid metabolism and hepatic mitochondrial function tightly related to gut microbial dysbiosis in pregnant mice. Microb Biotechnol 2021; 14:2116-2129. [PMID: 34272826 PMCID: PMC8449678 DOI: 10.1111/1751-7915.13893] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Accepted: 07/03/2021] [Indexed: 12/11/2022] Open
Abstract
As global warming intensifies, emerging evidence has demonstrated high ambient temperature during pregnancy negatively affects maternal physiology with compromised pregnant outcomes; however, little is known about the roles of gut microbiota and its underlying mechanisms in this process. Here, for the first time, we explored the potential mechanisms of gut microbiota involved in the disrupted glycolipid metabolism via hepatic mitochondrial function. Our results indicate heat stress (HS) reduces fat and protein contents and serum levels of insulin and triglyceride (TG), while increases that of non-esterified fatty acid (NEFA), β-hydroxybutyric acid (B-HBA), creatinine and blood urea nitrogen (BUN) (P < 0.05). Additionally, HS downregulates both mitochondrial genes (mtDNA) and nuclear encoding mitochondrial functional genes with increasing serum levels of malondialdehyde (MDA) and 8-hydroxydeoxyguanosine (8-OHdG) (P < 0.05). Regarding microbial response, HS boosts serum levels of lipopolysaccharide (LPS) (P < 0.05) and alters β-diversity (ANOSIM, P < 0.01), increasing the proportions of Escherichia-Shigella, Acinetobacter and Klebsiella (q < 0.05), while reducing that of Ruminiclostridium, Blautia, Lachnospiraceae_NK4A136_group, Clostridium VadinBB60 and Muribaculaceae (q < 0.05). PICRUSt analysis predicts that HS upregulates 11 KEGG pathways, mainly including bile secretion and bacterial invasion of epithelial cells. The collective results suggest that microbial dysbiosis due to late gestational HS has strong associations with damaged hepatic mitochondrial function and disrupted metabolic profiles.
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Affiliation(s)
- Jianwen He
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China.,Affiliated Hospital of Shaanxi University of Chinese Medicine, Shaanxi University of Chinese Medicine, Xianyang, 712000, China
| | - Riliang Liu
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Weijiang Zheng
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Huiduo Guo
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yunnan Yang
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Ruqian Zhao
- Key Lab of Animal Physiology and Biochemistry, Nanjing Agricultural University, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Nanjing, 210095, China
| | - Wen Yao
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China.,Key Lab of Animal Physiology and Biochemistry, Nanjing Agricultural University, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Nanjing, 210095, China
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Succinate accumulation contributes to oxidative stress and iron accumulation in pentylenetetrazol-induced epileptogenesis and kainic acid-induced seizure. Neurochem Int 2021; 149:105123. [PMID: 34224804 DOI: 10.1016/j.neuint.2021.105123] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 06/17/2021] [Accepted: 06/30/2021] [Indexed: 11/21/2022]
Abstract
This study explored the role of succinate accumulation in the oxidative stress and iron accumulation in both pentylenetetrazol (PTZ)-induced epileptogenesis and kainic acid (KA)-induced status epilepticus (SE). The levels of succinate, oxidative stress, iron content, iron-related protein expression, and the severity of neuronal injury and seizures were measured in both models. We found that increased concentrations of succinate were associated with increased levels of oxidative stress, iron content, iron regulator protein, and iron importer divalent metal transporter 1, as well as decreased levels of iron exporter ferropotin 1. Aggravated neuronal injury was observed in the hippocampi and cortices of both models. The cell-permeable molecule dimethyl malonate (DM), a competitive inhibitor of succinate dehydrogenase (SDH), significantly attenuated succinate accumulation, reduced the oxidative stress and iron levels, and mitigated the severity of the seizures and neuronal injury. Our results thus indicate that the accumulation of succinate due to the reverse catalysis of SDH may exacerbate oxidative stress and thus induce iron accumulation and neuronal injury in both models. Targeting succinate accumulation may achieve neuroprotective and anti-seizure effects.
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Kulkarni CA, Nadtochiy SM, Kennedy L, Zhang J, Chhim S, Alwaseem H, Murphy E, Fu D, Brookes PS. ALKBH7 mediates necrosis via rewiring of glyoxal metabolism. eLife 2020; 9:58573. [PMID: 32795389 PMCID: PMC7442491 DOI: 10.7554/elife.58573] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 08/13/2020] [Indexed: 02/06/2023] Open
Abstract
Alkb homolog 7 (ALKBH7) is a mitochondrial α-ketoglutarate dioxygenase required for DNA alkylation-induced necrosis, but its function and substrates remain unclear. Herein, we show ALKBH7 regulates dialdehyde metabolism, which impacts the cardiac response to ischemia-reperfusion (IR) injury. Using a multi-omics approach, we find no evidence ALKBH7 functions as a prolyl-hydroxylase, but we do find Alkbh7-/- mice have elevated glyoxalase I (GLO-1), a dialdehyde detoxifying enzyme. Metabolic pathways related to the glycolytic by-product methylglyoxal (MGO) are rewired in Alkbh7-/- mice, along with elevated levels of MGO protein adducts. Despite greater glycative stress, hearts from Alkbh7-/- mice are protected against IR injury, in a manner blocked by GLO-1 inhibition. Integrating these observations, we propose ALKBH7 regulates glyoxal metabolism, and that protection against necrosis and cardiac IR injury bought on by ALKBH7 deficiency originates from the signaling response to elevated MGO stress.
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Affiliation(s)
- Chaitanya A Kulkarni
- Department of Anesthesiology & Perioperative Medicine, University of Rochester Medical Center, Rochester, NY, United States
| | - Sergiy M Nadtochiy
- Department of Anesthesiology & Perioperative Medicine, University of Rochester Medical Center, Rochester, NY, United States
| | - Leslie Kennedy
- NHLBI Intramural Research Program, National Institutes of Health, Bethesda, United States
| | - Jimmy Zhang
- Department of Anesthesiology & Perioperative Medicine, University of Rochester Medical Center, Rochester, NY, United States
| | - Sophea Chhim
- Department of Biology, University of Rochester, Rochester, NY, United States
| | - Hanan Alwaseem
- Department of Chemistry, University of Rochester, Rochester, NY, United States
| | - Elizabeth Murphy
- NHLBI Intramural Research Program, National Institutes of Health, Bethesda, United States
| | - Dragony Fu
- Department of Biology, University of Rochester, Rochester, NY, United States
| | - Paul S Brookes
- Department of Anesthesiology & Perioperative Medicine, University of Rochester Medical Center, Rochester, NY, United States
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Fang P, Yu M, Shi M, Bo P, Gu X, Zhang Z. Baicalin and its aglycone: a novel approach for treatment of metabolic disorders. Pharmacol Rep 2020; 72:13-23. [PMID: 32016847 DOI: 10.1007/s43440-019-00024-x] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 07/27/2019] [Accepted: 08/25/2019] [Indexed: 12/18/2022]
Abstract
BACKGROUND The current strategies for prevention and treatment of insulin resistance and type 2 diabetes are not fully effective and frequently accompanied by many negative effects. Therefore, novel ways to prevent insulin resistance and type 2 diabetes are urgently needed. The roots of Scutellaria radix are commonly used in traditional Chinese medicines for prevention and treatment of type 2 diabetes, atherosclerosis, hypertension, hyperlipidemia, dysentery, and other respiratory disorders. Baicalin and baicalein are the major and active ingredient extracts from Scutellaria baicalensis. METHODS A comprehensive and systematic review of literature on baicalin and baicalein was carried out. RESULTS Emerging evidence indicated that baicalin and baicalein possessed hepatoprotective, anti-oxidative, anti-dyslipidemic, anti-lipogenic, anti-obese, anti-inflammatory, and anti-diabetic effects, being effective for treating obesity, insulin resistance, non-alcoholic fatty liver, and dyslipidemia. Besides, baicalin and baicalein are almost non-toxic to epithelial, peripheral, and myeloid cells. CONCLUSION The purpose of this study is to focus on the therapeutic applications and accompanying molecular mechanisms of baicalin and baicalein against hyperglycemia, insulin resistance, type 2 diabetes, hyperlipidemia, obesity, and non-alcoholic fatty liver, and trying to establish a novel anti-obese and anti-diabetic strategy.
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Affiliation(s)
- Penghua Fang
- Department of Physiology, Hanlin College, Nanjing University of Chinese Medicine, Taizhou, 225300, Jiangsu, China.,Jiangsu Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Treatment of Senile Diseases, Medical College, Yangzhou University, Yangzhou, 225001, China
| | - Mei Yu
- Department of Physiology, Hanlin College, Nanjing University of Chinese Medicine, Taizhou, 225300, Jiangsu, China
| | - Mingyi Shi
- Jiangsu Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Treatment of Senile Diseases, Medical College, Yangzhou University, Yangzhou, 225001, China
| | - Ping Bo
- Department of Endocrinology, Clinical Medical College, Yangzhou University, Yangzhou, 225001, Jiangsu, China.,Jiangsu Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Treatment of Senile Diseases, Medical College, Yangzhou University, Yangzhou, 225001, China
| | - Xuewen Gu
- Department of Pathology, Clinical Medical College, Yangzhou University, Yangzhou, 225001, Jiangsu, China
| | - Zhenwen Zhang
- Department of Endocrinology, Clinical Medical College, Yangzhou University, Yangzhou, 225001, Jiangsu, China.
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Zhang Y, Zhang M, Zhu W, Yu J, Wang Q, Zhang J, Cui Y, Pan X, Gao X, Sun H. Succinate accumulation induces mitochondrial reactive oxygen species generation and promotes status epilepticus in the kainic acid rat model. Redox Biol 2019; 28:101365. [PMID: 31707354 PMCID: PMC6854095 DOI: 10.1016/j.redox.2019.101365] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 10/15/2019] [Accepted: 10/28/2019] [Indexed: 11/29/2022] Open
Abstract
Though succinate accumulation is associated with reactive oxygen species (ROS) production and neuronal injury, which play critical roles in epilepsy, it is unclear whether succinate accumulation contributes to the onset of epilepsy or seizures. We sought to investigate changes in succinate, oxidative stress, and mito-SOX levels, as well as mitophagy and neuronal change, in different status epilepticus (SE) rat models. Our results demonstrate that KA-induced SE was accompanied by increased levels of succinate, oxidative stress, and mito-SOX, as well as mitophagy and neuronal degeneration. The similarly increased levels of succinate, oxidative stress, and mito-SOX were also found in pilocarpine-induced SE. Moreover, the reduction of succinate accumulation by the inhibition of succinate dehydrogenase (SDH), malate/aspartate shuttle (MAS), or purine nucleotide cycle (PNC) served to reduce succinate, oxidative stress, and mito-SOX levels, thereby preventing oxidative stress-related neuronal damage and lessening seizure severity. Interestingly, simulating succinate accumulation with succinic acid dimethyl ester may induce succinate accumulation and increased oxidative stress and mito-SOX levels, as well as behavior and seizures in electroencephalograms similar to those observed in rats exposed to KA. Our results indicate that succinate accumulation may contribute to the increased oxidative stress/mitochondrial ROS levels, neuronal degeneration, and SE induced by KA administration. Furthermore, we found that succinate accumulation was mainly due to the inverse catalysis of SDH from fumarate, which was supplemented by the MAS and PNC pathways. These results reveal new insights into the mechanisms underlying SE and that reducing succinate accumulation may be a clinically useful therapeutic target in SE. KA- or pilocarpine-induced SE was accompanied by succinate accumulation. Succinate accumulation caused elevated ROS/mito-ROS levels and neuronal injury. Inverse catalysis of SDH from fumarate mainly caused succinate accumulation. Inhibiting succinate accumulation relieved oxidative stress level, neuronal injury, and seizure. Simulating succinate accumulation induced elevated oxidative stress level and seizure.
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Affiliation(s)
- Yurong Zhang
- School of Pharmaceutical Sciences, Binzhou Medical University, Yantai, 264003, China
| | - Mengdi Zhang
- School of Pharmaceutical Sciences, Binzhou Medical University, Yantai, 264003, China
| | - Wei Zhu
- Institute of Radiation Medicine, Shandong Academy of Medical Sciences, Jinan, 250062, China
| | - Jie Yu
- School of Pharmaceutical Sciences, Binzhou Medical University, Yantai, 264003, China
| | - Qiaoyun Wang
- School of Pharmaceutical Sciences, Binzhou Medical University, Yantai, 264003, China
| | - Jinjin Zhang
- School of Pharmaceutical Sciences, Binzhou Medical University, Yantai, 264003, China
| | - Yaru Cui
- School of Pharmaceutical Sciences, Binzhou Medical University, Yantai, 264003, China
| | - Xiaohong Pan
- School of Pharmaceutical Sciences, Binzhou Medical University, Yantai, 264003, China
| | - Xue Gao
- School of Pharmaceutical Sciences, Binzhou Medical University, Yantai, 264003, China
| | - Hongliu Sun
- School of Pharmaceutical Sciences, Binzhou Medical University, Yantai, 264003, China.
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8
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García-Aguilar A, Martínez-Reyes I, Cuezva JM. Changes in the Turnover of the Cellular Proteome during Metabolic Reprogramming: A Role for mtROS in Proteostasis. J Proteome Res 2019; 18:3142-3155. [DOI: 10.1021/acs.jproteome.9b00239] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Ana García-Aguilar
- Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Centro de Investigación Biomédica en Red de Enfermedades Raras CIBERER-ISCIII, Instituto de Investigación Hospital 12 de Octubre (i+12), Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Inmaculada Martínez-Reyes
- Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Centro de Investigación Biomédica en Red de Enfermedades Raras CIBERER-ISCIII, Instituto de Investigación Hospital 12 de Octubre (i+12), Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - José M. Cuezva
- Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Centro de Investigación Biomédica en Red de Enfermedades Raras CIBERER-ISCIII, Instituto de Investigación Hospital 12 de Octubre (i+12), Universidad Autónoma de Madrid, 28049 Madrid, Spain
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Li S, Liu L, He G, Wu J. Molecular targets and mechanisms of bioactive peptides against metabolic syndromes. Food Funct 2018; 9:42-52. [PMID: 29188845 DOI: 10.1039/c7fo01323j] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Bioactive peptides are present in all living organisms and have critical roles ranging from protection against infection as the key element of innate immunity, regulating blood pressure and glucose levels, to reducing signs of ageing by killing senescent cells. Bioactive peptides are also encrypted within food protein sequences that can be released during proteolysis or food processing. These specific food protein fragments are reported to have potential for improving human health and preventing metabolic diseases through their impact on inflammation, blood pressure, obesity, and type-2 diabetes. This review mainly focuses on the molecular targets and the underlying mechanisms of bioactive peptides against various metabolic syndromes including inflammation, high blood pressure, obesity, and type-2 diabetes, to provide new insights and perspectives on the potential of bioactive peptides for management of metabolic syndromes.
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Affiliation(s)
- Shanshan Li
- College of Biosystems Engineering and Food Science, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
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10
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Zou R, Shi W, Tao J, Li H, Lin X, Yang S, Hua P. SIRT5 and post-translational protein modifications: A potential therapeutic target for myocardial ischemia-reperfusion injury with regard to mitochondrial dynamics and oxidative metabolism. Eur J Pharmacol 2018; 818:410-418. [DOI: 10.1016/j.ejphar.2017.11.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 10/23/2017] [Accepted: 11/01/2017] [Indexed: 11/27/2022]
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11
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Eyassu F, Angione C. Modelling pyruvate dehydrogenase under hypoxia and its role in cancer metabolism. ROYAL SOCIETY OPEN SCIENCE 2017; 4:170360. [PMID: 29134060 PMCID: PMC5666243 DOI: 10.1098/rsos.170360] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Accepted: 09/25/2017] [Indexed: 05/18/2023]
Abstract
Metabolism is the only biological system that can be fully modelled at genome scale. As a result, metabolic models have been increasingly used to study the molecular mechanisms of various diseases. Hypoxia, a low-oxygen tension, is a well-known characteristic of many cancer cells. Pyruvate dehydrogenase (PDH) controls the flux of metabolites between glycolysis and the tricarboxylic acid cycle and is a key enzyme in metabolic reprogramming in cancer metabolism. Here, we develop and manually curate a constraint-based metabolic model to investigate the mechanism of pyruvate dehydrogenase under hypoxia. Our results characterize the activity of pyruvate dehydrogenase and its decline during hypoxia. This results in lactate accumulation, consistent with recent hypoxia studies and a well-known feature in cancer metabolism. We apply machine-learning techniques on the flux datasets to identify reactions that drive these variations. We also identify distinct features on the structure of the variables and individual metabolic components in the switch from normoxia to hypoxia. Our results provide a framework for future studies by integrating multi-omics data to predict condition-specific metabolic phenotypes under hypoxia.
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12
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Microbe-mitochondrion crosstalk and health: An emerging paradigm. Mitochondrion 2017; 39:20-25. [PMID: 28838618 DOI: 10.1016/j.mito.2017.08.008] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 07/07/2017] [Accepted: 08/15/2017] [Indexed: 02/07/2023]
Abstract
Human mitochondria are descendants of microbes and altered mitochondrial function has been implicated in processes ranging from ageing to diabetes. Recent work has highlighted the importance of gut microbial communities in human health and disease. While the spotlight has been on the influence of such communities on the human immune system and the extraction of calories from otherwise indigestible food, an important but less investigated link between the microbes and mitochondria remains unexplored. Microbial metabolites including short chain fatty acids as well as other molecules such as pyrroloquinoline quinone, fermentation gases, and modified fatty acids influence mitochondrial function. This review focuses on the known direct and indirect effects of microbes upon mitochondria and speculates regarding additional links for which there is circumstantial evidence. Overall, while there is compelling evidence that a microbiota-mitochondria link exists, explicit and holistic mechanistic studies are warranted to advance this nascent field.
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13
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Di Meo S, Iossa S, Venditti P. Skeletal muscle insulin resistance: role of mitochondria and other ROS sources. J Endocrinol 2017; 233:R15-R42. [PMID: 28232636 DOI: 10.1530/joe-16-0598] [Citation(s) in RCA: 193] [Impact Index Per Article: 27.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 01/31/2017] [Indexed: 12/12/2022]
Abstract
At present, obesity is one of the most important public health problems in the world because it causes several diseases and reduces life expectancy. Although it is well known that insulin resistance plays a pivotal role in the development of type 2 diabetes mellitus (the more frequent disease in obese people) the link between obesity and insulin resistance is yet a matter of debate. One of the most deleterious effects of obesity is the deposition of lipids in non-adipose tissues when the capacity of adipose tissue is overwhelmed. During the last decade, reduced mitochondrial function has been considered as an important contributor to 'toxic' lipid metabolite accumulation and consequent insulin resistance. More recent reports suggest that mitochondrial dysfunction is not an early event in the development of insulin resistance, but rather a complication of the hyperlipidemia-induced reactive oxygen species (ROS) production in skeletal muscle, which might promote mitochondrial alterations, lipid accumulation and inhibition of insulin action. Here, we review the literature dealing with the mitochondria-centered mechanisms proposed to explain the onset of obesity-linked IR in skeletal muscle. We conclude that the different pathways leading to insulin resistance may act synergistically because ROS production by mitochondria and other sources can result in mitochondrial dysfunction, which in turn can further increase ROS production leading to the establishment of a harmful positive feedback loop.
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Affiliation(s)
- Sergio Di Meo
- Department of BiologyUniversity of Naples 'Federico II', Naples, Italy
| | - Susanna Iossa
- Department of BiologyUniversity of Naples 'Federico II', Naples, Italy
| | - Paola Venditti
- Department of BiologyUniversity of Naples 'Federico II', Naples, Italy
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14
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Prolyl hydroxylase domain enzymes and their role in cell signaling and cancer metabolism. Int J Biochem Cell Biol 2016; 80:71-80. [PMID: 27702652 DOI: 10.1016/j.biocel.2016.09.026] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 09/28/2016] [Accepted: 09/30/2016] [Indexed: 12/20/2022]
Abstract
The prolyl hydroxylase domain (PHD) enzymes regulate the stability of the hypoxia-inducible factor (HIF) in response to oxygen availability. During oxygen limitation, the inhibition of PHD permits the stabilization of HIF, allowing the cellular adaptation to hypoxia. This adaptation is especially important for solid tumors, which are often exposed to a hypoxic environment. However, and despite their original role as the oxygen sensors of the cell, PHD are currently known to display HIF-independent and hydroxylase-independent functions in the control of different cellular pathways, including mTOR pathway, NF-kB pathway, apoptosis and cellular metabolism. In this review, we summarize the recent advances in the regulation and functions of PHD in cancer signaling and cell metabolism.
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15
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McMurtrey RJ. Analytic Models of Oxygen and Nutrient Diffusion, Metabolism Dynamics, and Architecture Optimization in Three-Dimensional Tissue Constructs with Applications and Insights in Cerebral Organoids. Tissue Eng Part C Methods 2016; 22:221-49. [PMID: 26650970 PMCID: PMC5029285 DOI: 10.1089/ten.tec.2015.0375] [Citation(s) in RCA: 131] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 12/02/2015] [Indexed: 12/12/2022] Open
Abstract
Diffusion models are important in tissue engineering as they enable an understanding of gas, nutrient, and signaling molecule delivery to cells in cell cultures and tissue constructs. As three-dimensional (3D) tissue constructs become larger, more intricate, and more clinically applicable, it will be essential to understand internal dynamics and signaling molecule concentrations throughout the tissue and whether cells are receiving appropriate nutrient delivery. Diffusion characteristics present a significant limitation in many engineered tissues, particularly for avascular tissues and for cells whose viability, differentiation, or function are affected by concentrations of oxygen and nutrients. This article seeks to provide novel analytic solutions for certain cases of steady-state and nonsteady-state diffusion and metabolism in basic 3D construct designs (planar, cylindrical, and spherical forms), solutions that would otherwise require mathematical approximations achieved through numerical methods. This model is applied to cerebral organoids, where it is shown that limitations in diffusion and organoid size can be partially overcome by localizing metabolically active cells to an outer layer in a sphere, a regionalization process that is known to occur through neuroglial precursor migration both in organoids and in early brain development. The given prototypical solutions include a review of metabolic information for many cell types and can be broadly applied to many forms of tissue constructs. This work enables researchers to model oxygen and nutrient delivery to cells, predict cell viability, study dynamics of mass transport in 3D tissue constructs, design constructs with improved diffusion capabilities, and accurately control molecular concentrations in tissue constructs that may be used in studying models of development and disease or for conditioning cells to enhance survival after insults like ischemia or implantation into the body, thereby providing a framework for better understanding and exploring the characteristics and behaviors of engineered tissue constructs.
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Affiliation(s)
- Richard J. McMurtrey
- Institute of Neural Regeneration & Tissue Engineering, Highland, Utah, United States
- Department of Engineering Science, Institute of Biomedical Engineering, University of Oxford, Oxford, United Kingdom
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16
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Zhdanov AV, Okkelman IA, Collins FW, Melgar S, Papkovsky DB. A novel effect of DMOG on cell metabolism: direct inhibition of mitochondrial function precedes HIF target gene expression. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1847:1254-66. [DOI: 10.1016/j.bbabio.2015.06.016] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Revised: 06/11/2015] [Accepted: 06/30/2015] [Indexed: 12/17/2022]
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17
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Wu J, Bond C, Chen P, Chen M, Li Y, Shohet RV, Wright G. HIF-1α in the heart: remodeling nucleotide metabolism. J Mol Cell Cardiol 2015; 82:194-200. [PMID: 25681585 DOI: 10.1016/j.yjmcc.2015.01.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Revised: 01/09/2015] [Accepted: 01/12/2015] [Indexed: 01/06/2023]
Abstract
These studies have examined the effect of hypoxia inducible factor 1α (HIF-1α) on nucleotide metabolism in the ischemic heart using a genetic mouse model with heart-specific and regulated expression of a stable form of HIF-1α. We find that AMP deaminase (AMPD), the entry point of the purine nucleotide cycle (PNC), is induced by HIF-1α at the level of mRNA, protein, and activity. AMP that accumulates during ischemia can be metabolized to adenosine by 5'-nucleotidase or to IMP by AMPD. Consistent with the finding of AMPD induction, adenosine accumulation during ischemia was much attenuated in HIF-1α-expressing hearts. Further investigation of nucleotide salvage enzymes found that hypoxanthine phosphoribosyl transferase (HPRT) is also upregulated in HIF-1α-expressing hearts. Treatment of hearts with an inhibitor of the PNC, hadacidin, hastens the fall of the adenylate energy charge during ischemia and the accumulation of AMP. The results provide new insight into the role of the PNC in the heart, especially as it relates to ischemia, and indicate that HIF-1α regulates nucleotide metabolism as a compensatory response to hypoxia.
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Affiliation(s)
- Joe Wu
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, USA
| | - Cherie Bond
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, USA
| | - Ping Chen
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, USA
| | - Minghua Chen
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, USA
| | - Ying Li
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, USA
| | - Ralph V Shohet
- Department of Medicine, John Burns College of Medicine, University of Hawaii, Honolulu, HI, USA
| | - Gary Wright
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, USA.
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18
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Chouchani ET, Pell VR, Gaude E, Aksentijević D, Sundier SY, Robb EL, Logan A, Nadtochiy SM, Ord ENJ, Smith AC, Eyassu F, Shirley R, Hu CH, Dare AJ, James AM, Rogatti S, Hartley RC, Eaton S, Costa ASH, Brookes PS, Davidson SM, Duchen MR, Saeb-Parsy K, Shattock MJ, Robinson AJ, Work LM, Frezza C, Krieg T, Murphy MP. Ischaemic accumulation of succinate controls reperfusion injury through mitochondrial ROS. Nature 2014; 515:431-435. [PMID: 25383517 PMCID: PMC4255242 DOI: 10.1038/nature13909] [Citation(s) in RCA: 1893] [Impact Index Per Article: 189.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Accepted: 09/30/2014] [Indexed: 02/08/2023]
Abstract
Ischaemia-reperfusion injury occurs when the blood supply to an organ is disrupted and then restored, and underlies many disorders, notably heart attack and stroke. While reperfusion of ischaemic tissue is essential for survival, it also initiates oxidative damage, cell death and aberrant immune responses through the generation of mitochondrial reactive oxygen species (ROS). Although mitochondrial ROS production in ischaemia reperfusion is established, it has generally been considered a nonspecific response to reperfusion. Here we develop a comparative in vivo metabolomic analysis, and unexpectedly identify widely conserved metabolic pathways responsible for mitochondrial ROS production during ischaemia reperfusion. We show that selective accumulation of the citric acid cycle intermediate succinate is a universal metabolic signature of ischaemia in a range of tissues and is responsible for mitochondrial ROS production during reperfusion. Ischaemic succinate accumulation arises from reversal of succinate dehydrogenase, which in turn is driven by fumarate overflow from purine nucleotide breakdown and partial reversal of the malate/aspartate shuttle. After reperfusion, the accumulated succinate is rapidly re-oxidized by succinate dehydrogenase, driving extensive ROS generation by reverse electron transport at mitochondrial complex I. Decreasing ischaemic succinate accumulation by pharmacological inhibition is sufficient to ameliorate in vivo ischaemia-reperfusion injury in murine models of heart attack and stroke. Thus, we have identified a conserved metabolic response of tissues to ischaemia and reperfusion that unifies many hitherto unconnected aspects of ischaemia-reperfusion injury. Furthermore, these findings reveal a new pathway for metabolic control of ROS production in vivo, while demonstrating that inhibition of ischaemic succinate accumulation and its oxidation after subsequent reperfusion is a potential therapeutic target to decrease ischaemia-reperfusion injury in a range of pathologies.
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Affiliation(s)
- Edward T Chouchani
- MRC Mitochondrial Biology Unit, Hills Road, Cambridge CB2 0XY, UK
- Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK
| | - Victoria R Pell
- Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK
| | - Edoardo Gaude
- MRC Cancer Unit, University of Cambridge, Hutchison/MRC Research Centre, Box 197, Cambridge Biomedical Campus, Cambridge, CB2 0XZ, UK
| | - Dunja Aksentijević
- King's College London, British Heart Foundation Centre of Excellence, The Rayne Institute, St Thomas' Hospital, London SE1 7EH, UK
| | - Stephanie Y Sundier
- Department of Cell and Developmental Biology and UCL Consortium for Mitochondrial Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Ellen L Robb
- MRC Mitochondrial Biology Unit, Hills Road, Cambridge CB2 0XY, UK
| | - Angela Logan
- MRC Mitochondrial Biology Unit, Hills Road, Cambridge CB2 0XY, UK
| | - Sergiy M Nadtochiy
- Department of Anesthesiology, University of Rochester Medical Center, 601 Elmwood Avenue, Rochester, NY 14642, USA
| | - Emily N J Ord
- Institute of Cardiovascular & Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8TA, UK
| | - Anthony C Smith
- MRC Mitochondrial Biology Unit, Hills Road, Cambridge CB2 0XY, UK
| | - Filmon Eyassu
- MRC Mitochondrial Biology Unit, Hills Road, Cambridge CB2 0XY, UK
| | - Rachel Shirley
- Institute of Cardiovascular & Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8TA, UK
| | - Chou-Hui Hu
- Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK
| | - Anna J Dare
- MRC Mitochondrial Biology Unit, Hills Road, Cambridge CB2 0XY, UK
| | - Andrew M James
- MRC Mitochondrial Biology Unit, Hills Road, Cambridge CB2 0XY, UK
| | | | | | - Simon Eaton
- Unit of Paediatric Surgery, UCL Institute of Child Health, London, WC1N 1EH, UK
| | - Ana S H Costa
- MRC Cancer Unit, University of Cambridge, Hutchison/MRC Research Centre, Box 197, Cambridge Biomedical Campus, Cambridge, CB2 0XZ, UK
| | - Paul S Brookes
- Department of Anesthesiology, University of Rochester Medical Center, 601 Elmwood Avenue, Rochester, NY 14642, USA
| | - Sean M Davidson
- Hatter Cardiovascular Institute, University College London, 67 Chenies Mews, London, WC1E 6HX, UK
| | - Michael R Duchen
- Department of Cell and Developmental Biology and UCL Consortium for Mitochondrial Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Kourosh Saeb-Parsy
- University Department of Surgery and Cambridge NIHR Biomedical Research Centre, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK
| | - Michael J Shattock
- King's College London, British Heart Foundation Centre of Excellence, The Rayne Institute, St Thomas' Hospital, London SE1 7EH, UK
| | - Alan J Robinson
- MRC Mitochondrial Biology Unit, Hills Road, Cambridge CB2 0XY, UK
| | - Lorraine M Work
- Institute of Cardiovascular & Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8TA, UK
| | - Christian Frezza
- MRC Cancer Unit, University of Cambridge, Hutchison/MRC Research Centre, Box 197, Cambridge Biomedical Campus, Cambridge, CB2 0XZ, UK
| | - Thomas Krieg
- Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK
| | - Michael P Murphy
- MRC Mitochondrial Biology Unit, Hills Road, Cambridge CB2 0XY, UK
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19
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Ong SG, Lee WH, Theodorou L, Kodo K, Lim SY, Shukla DH, Briston T, Kiriakidis S, Ashcroft M, Davidson SM, Maxwell PH, Yellon DM, Hausenloy DJ. HIF-1 reduces ischaemia–reperfusion injury in the heart by targeting the mitochondrial permeability transition pore. Cardiovasc Res 2014; 104:24-36. [DOI: 10.1093/cvr/cvu172] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
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20
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Lee YS, Kim JW, Osborne O, Oh DY, Sasik R, Schenk S, Chen A, Chung H, Murphy A, Watkins SM, Quehenberger O, Johnson RS, Olefsky JM. Increased adipocyte O2 consumption triggers HIF-1α, causing inflammation and insulin resistance in obesity. Cell 2014; 157:1339-1352. [PMID: 24906151 PMCID: PMC4114226 DOI: 10.1016/j.cell.2014.05.012] [Citation(s) in RCA: 403] [Impact Index Per Article: 40.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Revised: 01/30/2014] [Accepted: 05/01/2014] [Indexed: 12/30/2022]
Abstract
Adipose tissue hypoxia and inflammation have been causally implicated in obesity-induced insulin resistance. Here, we report that, early in the course of high-fat diet (HFD) feeding and obesity, adipocyte respiration becomes uncoupled, leading to increased oxygen consumption and a state of relative adipocyte hypoxia. These events are sufficient to trigger HIF-1α induction, setting off the chronic adipose tissue inflammatory response characteristic of obesity. At the molecular level, these events involve saturated fatty acid stimulation of the adenine nucleotide translocase 2 (ANT2), an inner mitochondrial membrane protein, which leads to the uncoupled respiratory state. Genetic or pharmacologic inhibition of either ANT2 or HIF-1α can prevent or reverse these pathophysiologic events, restoring a state of insulin sensitivity and glucose tolerance. These results reveal the sequential series of events in obesity-induced inflammation and insulin resistance.
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Affiliation(s)
- Yun Sok Lee
- Department of Medicine, Division of Endocrinology and Metabolism, University of California, San Diego, La Jolla, CA 92093, USA
| | - Jung-Whan Kim
- Molecular Biology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Olivia Osborne
- Department of Medicine, Division of Endocrinology and Metabolism, University of California, San Diego, La Jolla, CA 92093, USA
| | - Da Young Oh
- Department of Medicine, Division of Endocrinology and Metabolism, University of California, San Diego, La Jolla, CA 92093, USA
| | - Roman Sasik
- Department of Medicine, Division of Endocrinology and Metabolism, University of California, San Diego, La Jolla, CA 92093, USA
| | - Simon Schenk
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CA 92093, USA
| | - Ai Chen
- Department of Medicine, Division of Endocrinology and Metabolism, University of California, San Diego, La Jolla, CA 92093, USA
| | - Heekyung Chung
- Department of Medicine, Division of Endocrinology and Metabolism, University of California, San Diego, La Jolla, CA 92093, USA
| | - Anne Murphy
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA
| | | | - Oswald Quehenberger
- Department of Medicine, Division of Endocrinology and Metabolism, University of California, San Diego, La Jolla, CA 92093, USA
| | - Randall S Johnson
- Molecular Biology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA; Department of Cell and Molecular Biology, Karolinska Institute, Stockholm, 171 77, Sweden; Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, CB2 3EG, UK.
| | - Jerrold M Olefsky
- Department of Medicine, Division of Endocrinology and Metabolism, University of California, San Diego, La Jolla, CA 92093, USA.
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21
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Lottes RG, Newton DA, Spyropoulos DD, Baatz JE. Alveolar type II cells maintain bioenergetic homeostasis in hypoxia through metabolic and molecular adaptation. Am J Physiol Lung Cell Mol Physiol 2014; 306:L947-55. [PMID: 24682450 DOI: 10.1152/ajplung.00298.2013] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Although many lung diseases are associated with hypoxia, alveolar type II epithelial (ATII) cell impairment, and pulmonary surfactant dysfunction, the effects of O(2) limitation on metabolic pathways necessary to maintain cellular energy in ATII cells have not been studied extensively. This report presents results of targeted assays aimed at identifying specific metabolic processes that contribute to energy homeostasis using primary ATII cells and a model ATII cell line, mouse lung epithelial 15 (MLE-15), cultured in normoxic and hypoxic conditions. MLEs cultured in normoxia demonstrated a robust O(2) consumption rate (OCR) coupled to ATP generation and limited extracellular lactate production, indicating reliance on oxidative phosphorylation for ATP production. Pharmacological uncoupling of respiration increased OCR in normoxic cultures to 175% of basal levels, indicating significant spare respiratory capacity. However, when exposed to hypoxia for 20 h, basal O(2) consumption fell to 60% of normoxic rates, and cells maintained only ∼50% of normoxic spare respiratory capacity, indicating suppression of mitochondrial function, although intracellular ATP levels remained at near normoxic levels. Moreover, while hypoxic exposure stimulated glycogen synthesis and storage in MLE-15, glycolytic rate (as measured by lactate generation) was not significantly increased in the cells, despite enhanced expression of several enzymes related to glycolysis. These results were largely recapitulated in murine primary ATII, demonstrating MLE-15 suitability for modeling ATII metabolism. The ability of ATII cells to maintain ATP levels in hypoxia without enhancing glycolysis suggests that these cells are exceptionally efficient at conserving ATP to maintain bioenergetic homeostasis under O(2) limitation.
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Affiliation(s)
- Robyn G Lottes
- Department of Pediatrics, Medical University of South Carolina, Charleston, South Carolia; and
| | - Danforth A Newton
- Department of Pediatrics, Medical University of South Carolina, Charleston, South Carolia; and
| | - Demetri D Spyropoulos
- Department of Pathology & Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolia
| | - John E Baatz
- Department of Pediatrics, Medical University of South Carolina, Charleston, South Carolia; and
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22
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Competitive HIF Prolyl Hydroxylase Inhibitors Show Protection against Oxidative Stress by a Mechanism Partially Dependent on Glycolysis. ISRN NEUROSCIENCE 2013; 2013:598587. [PMID: 25006572 PMCID: PMC4061615 DOI: 10.1155/2013/598587] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Accepted: 09/04/2012] [Indexed: 01/20/2023]
Abstract
The hypoxia inducible factor 1 (HIF-1) is a central transcription factor involved in the cellular and molecular adaptation to hypoxia and low glucose supply. The level of HIF-1 is to a large degree regulated by the HIF prolyl hydroxylase enzymes (HPHs) belonging to the Fe(II) and 2-oxoglutarate-dependent dioxygenase superfamily. In the present study, we compared competitive and noncompetitive HPH-inhibitor compounds in two different cell types (SH-SY5Y and PC12). Although the competitive HPH-inhibitor compounds were found to be pharmacologically more potent than the non-competitive compounds at inhibiting HPH2 and HPH1, this was not translated into the cellular effects of the compounds, where the non-competitive inhibitors were actually more potent than the competitive in stabilizing and translocatingHIF1αto the nucleus (quantified with Cellomics ArrayScan technology). This could be explained by the high cellular concentrations of the cofactor 2-oxoglutarate (2-OG) as the competitive inhibitors act by binding to the 2-OG site of the HPH enzymes. Both competitive and non-competitive HPH inhibitors protected the cells against 6-OHDA induced oxidative stress. In addition, the protective effect of a specific HPH inhibitor was partially preserved when the cells were serum starved and exposed to 2-deoxyglucose, an inhibitor of glycolysis, indicating that other processes than restoring energy supply could be important for the HIF-mediated cytoprotection.
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23
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Clanton TL, Hogan MC, Gladden LB. Regulation of cellular gas exchange, oxygen sensing, and metabolic control. Compr Physiol 2013; 3:1135-90. [PMID: 23897683 DOI: 10.1002/cphy.c120030] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cells must continuously monitor and couple their metabolic requirements for ATP utilization with their ability to take up O2 for mitochondrial respiration. When O2 uptake and delivery move out of homeostasis, cells have elaborate and diverse sensing and response systems to compensate. In this review, we explore the biophysics of O2 and gas diffusion in the cell, how intracellular O2 is regulated, how intracellular O2 levels are sensed and how sensing systems impact mitochondrial respiration and shifts in metabolic pathways. Particular attention is paid to how O2 affects the redox state of the cell, as well as the NO, H2S, and CO concentrations. We also explore how these agents can affect various aspects of gas exchange and activate acute signaling pathways that promote survival. Two kinds of challenges to gas exchange are also discussed in detail: when insufficient O2 is available for respiration (hypoxia) and when metabolic requirements test the limits of gas exchange (exercising skeletal muscle). This review also focuses on responses to acute hypoxia in the context of the original "unifying theory of hypoxia tolerance" as expressed by Hochachka and colleagues. It includes discourse on the regulation of mitochondrial electron transport, metabolic suppression, shifts in metabolic pathways, and recruitment of cell survival pathways preventing collapse of membrane potential and nuclear apoptosis. Regarding exercise, the issues discussed relate to the O2 sensitivity of metabolic rate, O2 kinetics in exercise, and influences of available O2 on glycolysis and lactate production.
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Affiliation(s)
- T L Clanton
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, USA.
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24
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Takahashi E, Sato M. Anaerobic respiration sustains mitochondrial membrane potential in a prolyl hydroxylase pathway-activated cancer cell line in a hypoxic microenvironment. Am J Physiol Cell Physiol 2013; 306:C334-42. [PMID: 24048731 DOI: 10.1152/ajpcell.00255.2013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
To elucidate how tumor cells produce energy in oxygen-depleted microenvironments, we studied the possibility of mitochondrial electron transport without oxygen. We produced well-controlled oxygen gradients (ΔO2) in monolayer-cultured cells. We then visualized oxygen levels and mitochondrial membrane potential (ΔΦm) in individual cells by using the red shift of green fluorescent protein (GFP) fluorescence and a cationic fluorescent dye, respectively. In this two-dimensional tissue model, ΔΦm was abolished in cells >500 μm from the oxygen source [the anoxic front (AF)], indicating limitations in diffusional oxygen delivery. This result perfectly matched GFP-determined ΔO2. In cells pretreated with dimethyloxaloylglycine (DMOG), a prolyl hydroxylase domain-containing protein (PHD) inhibitor, the AF was expanded to 1,500-2,000 μm from the source. In these cells, tissue ΔO2 was substantially decreased, indicating that PHD pathway activation suppressed mitochondrial respiration. The expansion of the AF and the reduction of ΔO2 were much more prominent in a cancer cell line (Hep3B) than in the equivalent fibroblast-like cell line (COS-7). Hence, the results indicate that PHD pathway-activated cells can sustain ΔΦm, despite significantly decreased electron flux to complex IV. Complex II inhibition abolished the effect of DMOG in expanding the AF, although tissue ΔO2 remained shallow. Separate experiments demonstrated that complex II plays a substantial role in sustaining ΔΦm in DMOG-pretreated Hep3B cells with complex III inhibition. From these results, we conclude that PHD pathway activation can sustain ΔΦm in an otherwise anoxic microenvironment by decreasing tissue ΔO2 while activating oxygen-independent electron transport in mitochondria.
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Affiliation(s)
- Eiji Takahashi
- Advanced Technology Fusion, Graduate School of Science and Engineering, Saga University, Saga, Japan; and
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Wu J, Chen P, Li Y, Ardell C, Der T, Shohet R, Chen M, Wright GL. HIF-1α in heart: protective mechanisms. Am J Physiol Heart Circ Physiol 2013; 305:H821-8. [PMID: 23873797 DOI: 10.1152/ajpheart.00140.2013] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Hypoxia-inducible factor-1α (HIF-1α) is a transcription factor that directs many of the cellular responses to hypoxia. In these studies, we have used a mouse model containing a cardiac-specific, oxygen-stabilized, doxycycline (Dox)-off regulated HIF-1α transgene to probe the role of HIF-1α in cardioprotection. Hearts used in these studies were derived from wild-type (WT), noninduced (Non-I), and 2 day (2D) and 6 day (6D) Dox-deprived mice. Whereas HIF-1α protein is undetectable in WT mice, it is present in heart tissue of "noninduced" transgenic mice, presumably because of leakiness of the promoter construct. In mice denied Dox for 2 or 6 days, HIF-1α is overexpressed to a much greater extent than Non-I or WT animals, as expected. WT and HIF-1α-expressing hearts (Non-I, 2D and 6D induced) were subjected to 30 min of ischemia, and functional recovery was measured upon reperfusion. Recovery of preischemic left ventricular developed pressure was 14% for WT, 67% for Non-I hearts, 64% for 2D-induced, and 62% for 6D-induced hearts. 6D-induced HIF hearts have increased preischemic glycogen reserves, higher glycogen synthase protein levels, and significantly higher lactic acid release during ischemia. 6D-induced HIF hearts were also better able to maintain ATP levels during ischemia compared with WT and Non-I hearts. Interestingly, Non-I hearts showed no significant increase in glycogen reserves, glycolytic flux, or greater ATP preservation during ischemia and yet were protected to a similar extent as the 6D-induced hearts. Finally, the mitochondrial membrane potential of isolated adult myocytes was monitored during anoxia or treatments with cyanide and 2-deoxyglucose. HIF-1α expression was shown to protect mitochondrial polarization during both stress treatments. Taken together these data indicate that, while HIF-1α expression in heart does induce increases in compensatory glycolytic capacity, these changes are not necessarily required for cardioprotection, at least in this model of ischemic stress.
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Affiliation(s)
- Joe Wu
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University; and
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Hill BG, Benavides GA, Lancaster JR, Ballinger S, Dell’Italia L, Zhang J, Darley-Usmar VM. Integration of cellular bioenergetics with mitochondrial quality control and autophagy. Biol Chem 2012; 393:1485-1512. [PMID: 23092819 PMCID: PMC3594552 DOI: 10.1515/hsz-2012-0198] [Citation(s) in RCA: 346] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2012] [Accepted: 06/22/2012] [Indexed: 02/06/2023]
Abstract
Bioenergetic dysfunction is emerging as a cornerstone for establishing a framework for understanding the pathophysiology of cardiovascular disease, diabetes,cancer and neurodegeneration. Recent advances in cellular bioenergetics have shown that many cells maintain a substantial bioenergetic reserve capacity, which is a prospective index of ‘ healthy ’ mitochondrial populations.The bioenergetics of the cell are likely regulated by energy requirements and substrate availability. Additionally,the overall quality of the mitochondrial population and the relative abundance of mitochondria in cells and tissues also impinge on overall bioenergetic capacity and resistance to stress. Because mitochondria are susceptible to damage mediated by reactive oxygen/nitrogen and lipid species, maintaining a ‘ healthy ’ population of mitochondria through quality control mechanisms appears to be essential for cell survival under conditions of pathological stress. Accumulating evidence suggest that mitophagy is particularly important for preventing amplification of initial oxidative insults, which otherwise would further impair the respiratory chain or promote mutations in mitochondrial DNA (mtDNA). The processes underlying the regulation of mitophagy depend on several factors, including the integrity of mtDNA, electron transport chain activity, and the interaction and regulation of the autophagic machinery. The integration and interpretation of cellular bioenergetics in the context of mitochondrial quality control and genetics is the theme of this review.
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Affiliation(s)
- Bradford G. Hill
- Diabetes and Obesity Center, Institute of Molecular Cardiology, and Department of Medicine, University of Louisville, Louisville, KY
- Departments of Biochemistry and Molecular Biology and Physiology and Biophysics, University of Louisville, Louisville, KY
| | - Gloria A. Benavides
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL 35294
- Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Jack R. Lancaster
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL 35294
- Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294
- Department of Anesthesiology, University of Alabama at Birmingham, Birmingham, AL 35294
- Department of Physiology and Biophysics, University of Alabama at Birmingham, Birmingham, AL 35294
- Department of Environmental Health Sciences, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Scott Ballinger
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL 35294
- Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294
- Department of Medicine, Center for Heart Failure Research, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Lou Dell’Italia
- Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294
- Department of Medicine, Center for Heart Failure Research, University of Alabama at Birmingham, Birmingham, AL 35294
- Department of Veteran Affairs Medical Center, Birmingham, AL 35294
| | - Jianhua Zhang
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL 35294
- Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294
- Department of Veteran Affairs Medical Center, Birmingham, AL 35294
| | - Victor M. Darley-Usmar
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL 35294
- Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294
- Department of Medicine, Center for Heart Failure Research, University of Alabama at Birmingham, Birmingham, AL 35294
- Department of Environmental Health Sciences, University of Alabama at Birmingham, Birmingham, AL 35294
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27
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Assessment of drug-induced mitochondrial dysfunction via altered cellular respiration and acidification measured in a 96-well platform. J Bioenerg Biomembr 2012; 44:421-37. [DOI: 10.1007/s10863-012-9446-z] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2012] [Accepted: 04/23/2012] [Indexed: 11/28/2022]
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Lee WH, Lin RJ, Lin SY, Chen YC, Lin HM, Liang YC. Osthole enhances glucose uptake through activation of AMP-activated protein kinase in skeletal muscle cells. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2011; 59:12874-12881. [PMID: 22098542 DOI: 10.1021/jf2036559] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
AMP-activated protein kinase (AMPK) is an energy sensor that regulates cellular metabolism. Activation of AMPK in skeletal muscles, the liver, and adipose tissues results in a favorable metabolic milieu for preventing and treating type 2 diabetes, i.e., decreased levels of circulating glucose, plasma lipids, and ectopic fat accumulation and enhanced insulin sensitivity. Osthole was extracted from a Chinese herbal medicine, and we found that it had glucose lowering activity in our previous study. However, the detailed glucose lowering mechanisms of osthole are still unclear. In this study, we used skeletal muscle cells to examine the underlying molecular mechanisms of osthole's glucose lowering activity. A Western blot analysis revealed that osthole significantly induced phosphorylation of AMPK and acetyl-CoA carboxylase (ACC). Next, we found that osthole significantly increased the level of translocation of glucose transporter 4 (GLUT4) to plasma membranes and glucose uptake in a dose-dependent manner. Osthole-induced glucose uptake was reversed by treatment with Compound C, an AMPK inhibitor, suggesting that osthole-induced glucose uptake was mediated in an AMPK-dependent manner. The increase in the AMP:ATP ratio was involved in osthole's activation of AMPK. Finally, we found that osthole counteracted hyperglycemia in mice with streptozotocin-induced diabetes. These results suggest that the increase in the AMP:ATP ratio by osthole triggered activation of the AMPK signaling pathway and led to increases in plasma membrane GLUT4 content and glucose uptake level. Therefore, osthole might have potential as an antidiabetic agent for treating diabetes.
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Affiliation(s)
- Wei-Hwa Lee
- Department of Pathology, Shuang Ho Hospital, Taipei Medical University, Taipei, Taiwan
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29
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Dranka BP, Benavides GA, Diers AR, Giordano S, Zelickson BR, Reily C, Zou L, Chatham JC, Hill BG, Zhang J, Landar A, Darley-Usmar VM. Assessing bioenergetic function in response to oxidative stress by metabolic profiling. Free Radic Biol Med 2011; 51:1621-35. [PMID: 21872656 PMCID: PMC3548422 DOI: 10.1016/j.freeradbiomed.2011.08.005] [Citation(s) in RCA: 344] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Revised: 08/08/2011] [Accepted: 08/09/2011] [Indexed: 12/22/2022]
Abstract
It is now clear that mitochondria are an important target for oxidative stress in a broad range of pathologies, including cardiovascular disease, diabetes, neurodegeneration, and cancer. Methods for assessing the impact of reactive species on isolated mitochondria are well established but constrained by the need for large amounts of material to prepare intact mitochondria for polarographic measurements. With the availability of high-resolution polarography and fluorescence techniques for the measurement of oxygen concentration in solution, measurements of mitochondrial function in intact cells can be made. Recently, the development of extracellular flux methods to monitor changes in oxygen concentration and pH in cultures of adherent cells in multiple-sample wells simultaneously has greatly enhanced the ability to measure bioenergetic function in response to oxidative stress. Here we describe these methods in detail using representative cell types from renal, cardiovascular, nervous, and tumorigenic model systems while illustrating the application of three protocols to analyze the bioenergetic response of cells to oxidative stress.
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Affiliation(s)
- Brian P. Dranka
- Department of Pathology and Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Gloria A. Benavides
- Department of Pathology and Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Anne R. Diers
- Department of Pathology and Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Samantha Giordano
- Department of Pathology and Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Blake R. Zelickson
- Department of Pathology and Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Colin Reily
- Department of Pathology and Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Luyun Zou
- Department of Pathology and Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - John C. Chatham
- Department of Pathology and Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Bradford G. Hill
- Department of Cardiovascular Medicine, University of Louisville, Louisville, KY 40202
| | - Jianhua Zhang
- Department of Pathology and Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Aimee Landar
- Department of Pathology and Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Victor M. Darley-Usmar
- Department of Pathology and Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294
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Takahashi E, Sato M. Impact of intracellular diffusion of oxygen in hypoxic sensing. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2011; 701:301-6. [PMID: 21445801 DOI: 10.1007/978-1-4419-7756-4_40] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
Hypoxia-inducible factor 1 (HIF-1) is the key to genetic adaptations to hypoxia in eukaryotes. In vivo, capillary pO(2) and extracellular- and intracellular- O(2) gradients define pO2 at the O(2) labile subunit HIF-1α.With a novel technique for subcellular imaging of O(2) heterogeneity using GFP, the present study was undertaken to examine the possibility that changes in mitochondrial respiration significantly affect intracellular O(2) gradients and thus, HIF-1 expression.We failed to demonstrate consistent changes in intracellular O(2) distributions in cultured cells with different metabolic and morphological properties (COS-7, Hep G2, and Hep3B cells) while mitochondrial O(2) consumption was widely changed at 1%O(2).Thus,we conclude that conductance for intracellular diffusion of O(2) is high in these cells and intracellular O(2) gradients might not be involved in the regulation of HIF-1 expression in vivo.
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Affiliation(s)
- Eiji Takahashi
- Department of Physiology, Yamagata University School of Medicine, Yamagata, Japan.
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31
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Wagner BA, Venkataraman S, Buettner GR. The rate of oxygen utilization by cells. Free Radic Biol Med 2011; 51:700-12. [PMID: 21664270 PMCID: PMC3147247 DOI: 10.1016/j.freeradbiomed.2011.05.024] [Citation(s) in RCA: 217] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2011] [Revised: 04/26/2011] [Accepted: 05/19/2011] [Indexed: 11/18/2022]
Abstract
The discovery of oxygen is considered by some to be the most important scientific discovery of all time--from both physical-chemical/astrophysics and biology/evolution viewpoints. One of the major developments during evolution is the ability to capture dioxygen in the environment and deliver it to each cell in the multicellular, complex mammalian body-on demand, i.e., just in time. Humans use oxygen to extract approximately 2550 calories (10.4 MJ) from food to meet daily energy requirements. This combustion requires about 22 mol of dioxygen per day, or 2.5×10(-4) mol s(-1). This is an average rate of oxygen utilization of 2.5×10(-18) mol cell(-1) s(-1), i.e., 2.5 amol cell(-1) s(-1). Cells have a wide range of oxygen utilization, depending on cell type, function, and biological status. Measured rates of oxygen utilization by mammalian cells in culture range from <1 to >350 amol cell(-1) s(-1). There is a loose positive linear correlation of the rate of oxygen consumption by mammalian cells in culture with cell volume and cell protein. The use of oxygen by cells and tissues is an essential aspect of the basic redox biology of cells and tissues. This type of quantitative information is fundamental to investigations in quantitative redox biology, especially redox systems biology.
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Affiliation(s)
- Brett A Wagner
- Free Radical and Radiation Biology Program and ESR Facility, The University of Iowa, Iowa City, IA 52242–1181, USA
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32
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Kurakin A. The self-organizing fractal theory as a universal discovery method: the phenomenon of life. Theor Biol Med Model 2011; 8:4. [PMID: 21447162 PMCID: PMC3080324 DOI: 10.1186/1742-4682-8-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2010] [Accepted: 03/29/2011] [Indexed: 12/15/2022] Open
Abstract
A universal discovery method potentially applicable to all disciplines studying organizational phenomena has been developed. This method takes advantage of a new form of global symmetry, namely, scale-invariance of self-organizational dynamics of energy/matter at all levels of organizational hierarchy, from elementary particles through cells and organisms to the Universe as a whole. The method is based on an alternative conceptualization of physical reality postulating that the energy/matter comprising the Universe is far from equilibrium, that it exists as a flow, and that it develops via self-organization in accordance with the empirical laws of nonequilibrium thermodynamics. It is postulated that the energy/matter flowing through and comprising the Universe evolves as a multiscale, self-similar structure-process, i.e., as a self-organizing fractal. This means that certain organizational structures and processes are scale-invariant and are reproduced at all levels of the organizational hierarchy. Being a form of symmetry, scale-invariance naturally lends itself to a new discovery method that allows for the deduction of missing information by comparing scale-invariant organizational patterns across different levels of the organizational hierarchy.An application of the new discovery method to life sciences reveals that moving electrons represent a keystone physical force (flux) that powers, animates, informs, and binds all living structures-processes into a planetary-wide, multiscale system of electron flow/circulation, and that all living organisms and their larger-scale organizations emerge to function as electron transport networks that are supported by and, at the same time, support the flow of electrons down the Earth's redox gradient maintained along the core-mantle-crust-ocean-atmosphere axis of the planet. The presented findings lead to a radically new perspective on the nature and origin of life, suggesting that living matter is an organizational state/phase of nonliving matter and a natural consequence of the evolution and self-organization of nonliving matter.The presented paradigm opens doors for explosive advances in many disciplines, by uniting them within a single conceptual framework and providing a discovery method that allows for the systematic generation of knowledge through comparison and complementation of empirical data across different sciences and disciplines.
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Affiliation(s)
- Alexei Kurakin
- Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA.
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Foley K, Boguslavsky S, Klip A. Endocytosis, recycling, and regulated exocytosis of glucose transporter 4. Biochemistry 2011; 50:3048-61. [PMID: 21405107 DOI: 10.1021/bi2000356] [Citation(s) in RCA: 122] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Glucose transporter 4 (GLUT4) is responsible for the uptake of glucose into muscle and adipose tissues. Under resting conditions, GLUT4 is dynamically retained through idle cycling among selective intracellular compartments, from whence it undergoes slow recycling to the plasma membrane (PM). This dynamic retention can be released by command from intracellular signals elicited by insulin and other stimuli, which result in 2-10-fold increases in the surface level of GLUT4. Insulin-derived signals promote translocation of GLUT4 to the PM from a specialized compartment termed GLUT4 storage vesicles (GSV). Much effort has been devoted to the characterization of the intracellular compartments and dynamics of GLUT4 cycling and to the signals by which GLUT4 is sorted into, and recruited from, GSV. This review summarizes our understanding of intracellular GLUT4 traffic during its internalization from the membrane, its slow, constitutive recycling, and its regulated exocytosis in response to insulin. In spite of specific differences in GLUT4 dynamic behavior in adipose and muscle cells, the generalities of its endocytic and exocytic itineraries are consistent and an array of regulatory proteins that regulate each vesicular traffic event emerges from these cell systems.
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Affiliation(s)
- Kevin Foley
- Cell Biology Program, The Hospital for Sick Children, Toronto, Ontario M4G 1X8, Canada
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34
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Takahashi E, Sato M. Imaging of oxygen gradients in monolayer cultured cells using green fluorescent protein. Am J Physiol Cell Physiol 2010; 299:C1318-23. [DOI: 10.1152/ajpcell.00254.2010] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Gradients of Po2 between capillary blood and mitochondria are the driving force for diffusional O2 delivery in tissues. Hypoxic microenvironments in tissues that result from diffusional O2 gradients are especially relevant in solid tumors because they have been related to a poor prognosis. To address the impact of tissue O2 gradients, we developed a novel technique that permits imaging of intracellular O2 levels in cultured cells at a subcellular spatial resolution. This was done, with the sensitivity to O2 ≤3%, by the O2-dependent red shift of green fluorescent protein (AcGFP1) fluorescence. Measurements were carried out in a confluent monolayer of Hep3B cells expressing AcGFP1 in the cytoplasm. To establish a two-dimensional O2 diffusion model, a thin quartz glass slip was placed onto the monolayer cells to prevent O2 diffusion from the top surface of the cell layer. The magnitude of the red shift progressively increased as the distance from the gas coverslip interface increased. It reached an anoxic level in cells located at ∼220 μm and ∼690 μm from the gas coverslip boundary at 1% and 3% gas phase O2, respectively. Thus the average O2 gradient was 0.03 mmHg/μm in the present tissue model. Abolition of mitochondrial respiration significantly dampened the gradients. Furthermore, intracellular gradients of the red shift in mitochondria-targeted AcGFP1 in single Hep3B cells suggest that the origin of tissue O2 gradients is intracellular. Findings in the present two-dimensional O2 diffusion model support the crucial role of tissue O2 diffusion in defining the O2 microenvironment in individual cells.
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Affiliation(s)
- Eiji Takahashi
- Biomedical Engineering Course, Advanced Technology Fusion, Graduate School of Science and Engineering, Saga University, Saga, Japan and
| | - Michihiko Sato
- CLRE, Yamagata University School of Medicine, Yamagata, Japan
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Kimata M, Matoba S, Iwai-Kanai E, Nakamura H, Hoshino A, Nakaoka M, Katamura M, Okawa Y, Mita Y, Okigaki M, Ikeda K, Tatsumi T, Matsubara H. p53 and TIGAR regulate cardiac myocyte energy homeostasis under hypoxic stress. Am J Physiol Heart Circ Physiol 2010; 299:H1908-16. [PMID: 20935145 DOI: 10.1152/ajpheart.00250.2010] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Bioenergetic homeostasis is altered in heart failure and may play an important role in pathogenesis. p53 has been implicated in heart failure, and although its role in regulating tumorigenesis is well characterized, its activities on cellular metabolism are just beginning to be understood. We investigated the role of p53 and its transcriptional target gene TP53-induced glycolysis and apoptosis regulator (TIGAR) in myocardial energy metabolism under conditions simulating ischemia that can lead to heart failure. Expression of p53 and TIGAR was markedly upregulated after myocardial infarction, and apoptotic myocytes were decreased by 42% in p53-deficient mouse hearts compared with those in wild-type mice. To examine the effect of p53 on energy metabolism, cardiac myocytes were exposed to hypoxia. Hypoxia induced p53 and TIGAR expression in a p53-dependent manner. Knockdown of p53 or TIGAR increased glycolysis with elevated fructose-2,6-bisphosphate levels and reduced myocyte apoptosis. Hypoxic stress decreased phosphocreatine content and the mitochondrial membrane potential of myocytes without changes in ATP content, the effects of which were prevented by the knockdown of TIGAR. Inhibition of glycolysis by 2-deoxyglucose blocked these bioenergetic effects and TIGAR siRNA-mediated prevention of apoptosis, and, in contrast, overexpression of TIGAR reduced glucose utilization and increased apoptosis. Our data demonstrate that p53 and TIGAR inhibit glycolysis in hypoxic myocytes and that inhibition of glycolysis is closely involved in apoptosis, suggesting that p53 and TIGAR are significant mediators of cellular energy homeostasis and cell death under ischemic stress.
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Affiliation(s)
- Masaki Kimata
- Department of Cardiovascular Medicine, Kyoto Prefectural University School of Medicine, Kyoto, Japan
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Abstract
The endothelium is vital to the proper functioning in the heart, in particular due to its production of nitric oxide (NO) which regulates vascular tone. Damage to the endothelium contributes to the development of atherosclerosis, and hence to possible myocardial infarction and subsequent heart failure. Like most cells, endothelial cells contain mitochondria, despite their having relatively little dependence on oxidative phosphorylation for ATP production. However, endothelial mitochondria are centrally involved in maintaining the fine regulatory balance between mitochondrial calcium concentration, reactive oxygen species (ROS) production, and NO. This raises the question of whether damage to endothelial mitochondria would have repercussions in terms of the development of heart disease. In fact, increasingly nuanced techniques enabling restricted transgenic expression of antioxidant proteins in mice has demonstrated that mitochondrial ROS do contribute to endothelial damage. New pharmaceutical approaches designed to target protective molecules such as ROS scavengers to the mitochondria promise to be effective in preventing heart disease. As well as protecting cardiomyocytes, these drugs may have the added benefit of preventing damage to the endothelial mitochondria. However, much remains to be done in understanding the contribution that mitochondria make to endothelial function.
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Affiliation(s)
- Sean Michael Davidson
- Department of Medicine, The Hatter Cardiovascular Institute, University College London Hospital, London WC1E 6HX, UK.
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Beeson CC, Beeson GC, Schnellmann RG. A high-throughput respirometric assay for mitochondrial biogenesis and toxicity. Anal Biochem 2010; 404:75-81. [PMID: 20465991 DOI: 10.1016/j.ab.2010.04.040] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2010] [Revised: 04/22/2010] [Accepted: 04/30/2010] [Indexed: 01/12/2023]
Abstract
Mitochondria are a common target of toxicity for drugs and other chemicals and result in decreased aerobic metabolism and cell death. In contrast, mitochondrial biogenesis restores cell vitality, and there is a need for new agents to induce biogenesis. Current cell-based models of mitochondrial biogenesis or toxicity are inadequate because cultured cell lines are highly glycolytic with minimal aerobic metabolism and altered mitochondrial physiology. In addition, there are no high-throughput real-time assays that assess mitochondrial function. We adapted primary cultures of renal proximal tubular cells (RPTCs) that exhibit in vivo levels of aerobic metabolism, are not glycolytic, and retain higher levels of differentiated functions and used the Seahorse Bioscience analyzer to measure mitochondrial function in real time in multiwell plates. Using uncoupled respiration as a marker of electron transport chain (ETC) integrity, the nephrotoxicants cisplatin, HgCl(2), and gentamicin exhibited mitochondrial toxicity prior to decreases in basal respiration and cell death. Conversely, using FCCP (carbonylcyanide p-trifluoromethoxyphenylhydrazone)-uncoupled respiration as a marker of maximal ETC activity, 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI), SRT1720, resveratrol, daidzein, and metformin produced mitochondrial biogenesis in RPTCs. The merger of the RPTC model and multiwell respirometry results in a single high-throughput assay to measure mitochondrial biogenesis and toxicity and nephrotoxic potential.
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Affiliation(s)
- Craig C Beeson
- Department of Pharmaceutical and Biomedical Sciences, Medical University of South Carolina, Charleston, 29425, USA
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Abe Y, Sakairi T, Kajiyama H, Shrivastav S, Beeson C, Kopp JB. Bioenergetic characterization of mouse podocytes. Am J Physiol Cell Physiol 2010; 299:C464-76. [PMID: 20445170 DOI: 10.1152/ajpcell.00563.2009] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Mitochondrial dysfunction contributes to podocyte injury, but normal podocyte bioenergetics have not been characterized. We measured oxygen consumption rates (OCR) and extracellular acidification rates (ECAR), using a transformed mouse podocyte cell line and the Seahorse Bioscience XF24 Extracellular Flux Analyzer. Basal OCR and ECAR were 55.2 +/- 9.9 pmol/min and 3.1 +/- 1.9 milli-pH units/min, respectively. The complex V inhibitor oligomycin reduced OCR to approximately 45% of baseline rates, indicating that approximately 55% of cellular oxygen consumption was coupled to ATP synthesis. Rotenone, a complex I inhibitor, reduced OCR to approximately 25% of the baseline rates, suggesting that mitochondrial respiration accounted for approximately 75% of the total cellular respiration. Thus approximately 75% of mitochondrial respiration was coupled to ATP synthesis and approximately 25% was accounted for by proton leak. Carbonyl cyanide p-trifluoromethoxyphenylhydrazone (FCCP), which uncouples electron transport from ATP generation, increased OCR and ECAR to approximately 360% and 840% of control levels. FCCP plus rotenone reduced ATP content by 60%, the glycolysis inhibitor 2-deoxyglucose reduced ATP by 35%, and 2-deoxyglucose in combination with FCCP or rotenone reduced ATP by >85%. The lactate dehydrogenase inhibitor oxamate and 2-deoxyglucose did not reduce ECAR, and 2-deoxyglucose had no effect on OCR, although 2-deoxyglucose reduced ATP content by 25%. Mitochondrial uncoupling induced by FCCP was associated with increased OCR with certain substrates, including lactate, glucose, pyruvate, and palmitate. Replication of these experiments in primary mouse podocytes yielded similar data. We conclude that mitochondria play the primary role in maintaining podocyte energy homeostasis, while glycolysis makes a lesser contribution.
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Affiliation(s)
- Yoshifusa Abe
- Kidney Disease Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-1268, USA
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Intracellular diffusion of oxygen and hypoxic sensing: role of mitochondrial respiration. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2010. [PMID: 20217352 DOI: 10.1007/978-1-4419-5692-7_43] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register]
Abstract
In vivo, diffusional O(2) gradients from the capillary blood to the intracellular space determine O(2) availability at the O(2) sensing molecules in the cell. With a novel technique for imaging intracellular O(2) levels using green fluorescent protein (GFP), we examined the possibility that diffusional O(2) concentration gradients might be involved in the cellular hypoxic sensing in cultured Hep3B cells. In the present study, we failed to demonstrate significant gradients of intracellular O(2) when mitochondrial respiration was maximally elevated by an uncoupler of oxidative phosphorylation. Thus, we conclude that intracellular O(2) gradients may be negligible at normal mitochondrial O(2) demand in these cells.
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Takeda K, Ichiki T, Narabayashi E, Inanaga K, Miyazaki R, Hashimoto T, Matsuura H, Ikeda J, Miyata T, Sunagawa K. Inhibition of Prolyl Hydroxylase Domain-Containing Protein Suppressed Lipopolysaccharide-Induced TNF-α Expression. Arterioscler Thromb Vasc Biol 2009; 29:2132-7. [DOI: 10.1161/atvbaha.109.196071] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Kotaro Takeda
- From the Departments of Advanced Therapeutics for Cardiovascular Diseases (K.T., T.I., K.S.) and Cardiovascular Medicine (E.N., K.I., R.M., T.H., H.M., J.I., K.S.), Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan; and the Center for Translational and Advanced Research (T.M.), Tohoku University Graduate School of Medicine, Miyagi, Japan
| | - Toshihiro Ichiki
- From the Departments of Advanced Therapeutics for Cardiovascular Diseases (K.T., T.I., K.S.) and Cardiovascular Medicine (E.N., K.I., R.M., T.H., H.M., J.I., K.S.), Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan; and the Center for Translational and Advanced Research (T.M.), Tohoku University Graduate School of Medicine, Miyagi, Japan
| | - Eriko Narabayashi
- From the Departments of Advanced Therapeutics for Cardiovascular Diseases (K.T., T.I., K.S.) and Cardiovascular Medicine (E.N., K.I., R.M., T.H., H.M., J.I., K.S.), Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan; and the Center for Translational and Advanced Research (T.M.), Tohoku University Graduate School of Medicine, Miyagi, Japan
| | - Keita Inanaga
- From the Departments of Advanced Therapeutics for Cardiovascular Diseases (K.T., T.I., K.S.) and Cardiovascular Medicine (E.N., K.I., R.M., T.H., H.M., J.I., K.S.), Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan; and the Center for Translational and Advanced Research (T.M.), Tohoku University Graduate School of Medicine, Miyagi, Japan
| | - Ryohei Miyazaki
- From the Departments of Advanced Therapeutics for Cardiovascular Diseases (K.T., T.I., K.S.) and Cardiovascular Medicine (E.N., K.I., R.M., T.H., H.M., J.I., K.S.), Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan; and the Center for Translational and Advanced Research (T.M.), Tohoku University Graduate School of Medicine, Miyagi, Japan
| | - Toru Hashimoto
- From the Departments of Advanced Therapeutics for Cardiovascular Diseases (K.T., T.I., K.S.) and Cardiovascular Medicine (E.N., K.I., R.M., T.H., H.M., J.I., K.S.), Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan; and the Center for Translational and Advanced Research (T.M.), Tohoku University Graduate School of Medicine, Miyagi, Japan
| | - Hirohide Matsuura
- From the Departments of Advanced Therapeutics for Cardiovascular Diseases (K.T., T.I., K.S.) and Cardiovascular Medicine (E.N., K.I., R.M., T.H., H.M., J.I., K.S.), Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan; and the Center for Translational and Advanced Research (T.M.), Tohoku University Graduate School of Medicine, Miyagi, Japan
| | - Jiro Ikeda
- From the Departments of Advanced Therapeutics for Cardiovascular Diseases (K.T., T.I., K.S.) and Cardiovascular Medicine (E.N., K.I., R.M., T.H., H.M., J.I., K.S.), Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan; and the Center for Translational and Advanced Research (T.M.), Tohoku University Graduate School of Medicine, Miyagi, Japan
| | - Toshio Miyata
- From the Departments of Advanced Therapeutics for Cardiovascular Diseases (K.T., T.I., K.S.) and Cardiovascular Medicine (E.N., K.I., R.M., T.H., H.M., J.I., K.S.), Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan; and the Center for Translational and Advanced Research (T.M.), Tohoku University Graduate School of Medicine, Miyagi, Japan
| | - Kenji Sunagawa
- From the Departments of Advanced Therapeutics for Cardiovascular Diseases (K.T., T.I., K.S.) and Cardiovascular Medicine (E.N., K.I., R.M., T.H., H.M., J.I., K.S.), Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan; and the Center for Translational and Advanced Research (T.M.), Tohoku University Graduate School of Medicine, Miyagi, Japan
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Ashrafian H, Neubauer S. Metabolomic profiling of cardiac substrate utilization: fanning the flames of systems biology? Circulation 2009; 119:1700-2. [PMID: 19349333 DOI: 10.1161/circulationaha.109.849919] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Shavell VI, Saed GM, Diamond MP. Review: cellular metabolism: contribution to postoperative adhesion development. Reprod Sci 2009; 16:627-34. [PMID: 19293132 DOI: 10.1177/1933719109332826] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Postoperative adhesions are a significant source of morbidity, including contributions to pelvic pain, bowel obstruction, and infertility. While the mechanisms of postoperative adhesion development are complex and incompletely understood, hypoxia appears to trigger a cascade of intracellular responses involving hypoxia-inducible factors, lactate, reactive oxygen species, reactive nitrogen species, and insulin-like growth factors that results in manifestation of the adhesion phenotype. Thus, substantial evidence exists to implicate the direct role of cellular metabolism in wound repair and adhesion development.
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Affiliation(s)
- Valerie I Shavell
- Department of Obstetrics and Gynecology, Division of Reproductive Endocrinology and Infertility, Wayne State University School of Medicine, Detroit, Michigan 48201, USA
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Aragonés J, Fraisl P, Baes M, Carmeliet P. Oxygen sensors at the crossroad of metabolism. Cell Metab 2009; 9:11-22. [PMID: 19117543 DOI: 10.1016/j.cmet.2008.10.001] [Citation(s) in RCA: 206] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2008] [Revised: 09/26/2008] [Accepted: 09/30/2008] [Indexed: 12/14/2022]
Abstract
Aerobic organisms developed mechanisms to protect themselves against a shortage of oxygen (O(2)). Recent studies reveal that O(2) sensors, belonging to the novel class of 2-oxoglutarate dependent iron(ii)-dioxygenases, have more important roles in metabolism than anticipated. Here, we provide a "metabolo-centric" overview of the role of the PHD/FIH members of this family in metabolism, in particular on how they regulate O(2) supply and consumption, energy compensation and conservation, O(2) conformance and hypoxia tolerance, redox and pH homeostasis, and other vital metabolic processes with implications in health and disease. These insights may offer novel opportunities for the treatment of ischemic diseases.
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Affiliation(s)
- Julián Aragonés
- Vesalius Research Center, K.U. Leuven, Leuven, B-3000, Belgium
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Green CJ, Göransson O, Kular GS, Leslie NR, Gray A, Alessi DR, Sakamoto K, Hundal HS. Use of Akt Inhibitor and a Drug-resistant Mutant Validates a Critical Role for Protein Kinase B/Akt in the Insulin-dependent Regulation of Glucose and System A Amino Acid Uptake. J Biol Chem 2008; 283:27653-27667. [DOI: 10.1074/jbc.m802623200] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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