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Atarashi N, Morishita M, Matsuda S. Activation of innate immune receptor TLR9 by mitochondrial DNA plays essential roles in the chemical long-term depression of hippocampal neurons. J Biol Chem 2024; 300:105744. [PMID: 38354781 PMCID: PMC10943477 DOI: 10.1016/j.jbc.2024.105744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 01/11/2024] [Accepted: 02/04/2024] [Indexed: 02/16/2024] Open
Abstract
Synaptic plasticity is believed to be the cellular basis for experience-dependent learning and memory. Although long-term depression (LTD), a form of synaptic plasticity, is caused by the activity-dependent reduction of cell surface α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA)-type glutamate receptors (AMPA receptors) at postsynaptic sites, its regulation by neuronal activity is not completely understood. In this study, we showed that the inhibition of toll-like receptor-9 (TLR9), an innate immune receptor, suppresses N-methyl-d-aspartate (NMDA)-induced reduction of cell surface AMPA receptors in cultured hippocampal neurons. We found that inhibition of TLR9 also blocked NMDA-induced activation of caspase-3, which plays an essential role in the induction of LTD. siRNA-based knockdown of TLR9 also suppressed the NMDA-induced reduction of cell surface AMPA receptors, although the scrambled RNA had no effect on the NMDA-induced trafficking of AMPA receptors. Overexpression of the siRNA-resistant form of TLR9 rescued the AMPA receptor trafficking abolished by siRNA. Furthermore, NMDA stimulation induced rapid mitochondrial morphological changes, mitophagy, and the binding of mitochondrial DNA (mtDNA) to TLR9. Treatment with dideoxycytidine and mitochondrial division inhibitor-1, which block mtDNA replication and mitophagy, respectively, inhibited NMDA-dependent AMPA receptor internalization. These results suggest that mitophagy induced by NMDA receptor activation releases mtDNA and activates TLR9, which plays an essential role in the trafficking of AMPA receptors during the induction of LTD.
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Affiliation(s)
- Naoya Atarashi
- Department of Engineering Science, Graduate School of Informatics and Engineering, The University of Electro-Communications, Tokyo, Japan
| | - Misaki Morishita
- Department of Engineering Science, Graduate School of Informatics and Engineering, The University of Electro-Communications, Tokyo, Japan
| | - Shinji Matsuda
- Department of Engineering Science, Graduate School of Informatics and Engineering, The University of Electro-Communications, Tokyo, Japan; Center for Neuroscience and Biomedical Engineering (CNBE), The University of Electro-Communications, Tokyo, Japan.
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Yin L, Yuan L, Tang Y, Luo Z, Lin X, Wang S, Liang P, Jiang B. NUCLEOLIN PROMOTES AUTOPHAGY THROUGH PGC-1Α IN LPS-INDUCED MYOCARDIAL INJURY. Shock 2023; 60:227-237. [PMID: 37249064 DOI: 10.1097/shk.0000000000002152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
ABSTRACT As a multifunctional protein, nucleolin can participate in a variety of cellular processes. Nucleolin also has multiple protective effects on heart disease. Previous studies have shown that nucleolin could not only resist oxidative stress damage and inflammatory damage, but also regulate autophagy to play a protective role in cardiac ischemia. However, the specific mechanism has not been fully elucidated in LPS-induced myocardial injury. Therefore, the aim of this study is to explore the underlying mechanism by which nucleolin regulates autophagy to protect against LPS-induced myocardial injury in vivo and in vitro . In our study, we found that nucleolin could bind to PGC-1α, and we predicted that this interaction could promote autophagy and played a role in inhibiting cardiomyocyte apoptosis. Downregulation of nucleolin in H9C2 cells resulted in decreased autophagy and increased cell apoptosis during LPS-induced myocardial injury, while upregulation of PGC-1α had the opposite protective effect. Upregulation of nucleolin expression in cardiomyocytes could increase the level of autophagy during LPS-induced myocardial injury. In contrast, interference with PGC-1α expression resulted in a decrease in the protective effect of nucleolin, leading to reduced autophagy and thus increasing apoptosis. By using tandem fluorescent-tagged LC3 autophagic flux detection system, we observed autophagic flux and determined that PGC-1α interference could block autophagic lysosomal progression. We further tested our hypothesis in the nucleolin cardiac-specific knockout mice. Finally, we also found that inhibition of autophagy can reduce mitochondrial biogenesis as well as increase apoptosis, which demonstrated the importance of autophagy. Therefore, we can speculate that nucleolin can protect LPS-induced myocardial injury by regulating autophagy, and this protective effect may be mediated by the interaction with PGC-1α, which can positively regulate the ULK1, an autophagy-related protein. Our study provides a new clue for the cardioprotective effect of nucleolin, and may provide new evidence for the treatment of LPS-induced myocardial injury through the regulation of autophagy.
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Affiliation(s)
| | | | | | | | | | | | - Pengfei Liang
- Department of Burns and Plastic Surgery, Xiangya Hospital, Central South University, Changsha, Hunan, China
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Zhang G, Dong D, Wan X, Zhang Y. Cardiomyocyte death in sepsis: Mechanisms and regulation (Review). Mol Med Rep 2022; 26:257. [PMID: 35703348 PMCID: PMC9218731 DOI: 10.3892/mmr.2022.12773] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Accepted: 05/20/2022] [Indexed: 11/06/2022] Open
Abstract
Sepsis‑induced cardiac dysfunction is one of the most common types of organ dysfunction in sepsis; its pathogenesis is highly complex and not yet fully understood. Cardiomyocytes serve a key role in the pathophysiology of cardiac function; due to the limited ability of cardiomyocytes to regenerate, their loss contributes to decreased cardiac function. The activation of inflammatory signalling pathways affects cardiomyocyte function and modes of cardiomyocyte death in sepsis. Prevention of cardiomyocyte death is an important therapeutic strategy for sepsis‑induced cardiac dysfunction. Thus, understanding the signalling pathways that activate cardiomyocyte death and cross‑regulation between death modes are key to finding therapeutic targets. The present review focused on advances in understanding of sepsis‑induced cardiomyocyte death pathways, including apoptosis, necroptosis, mitochondria‑mediated necrosis, pyroptosis, ferroptosis and autophagy. The present review summarizes the effect of inflammatory activation on cardiomyocyte death mechanisms, the diversity of regulatory mechanisms and cross‑regulation between death modes and the effect on cardiac function in sepsis to provide a theoretical basis for treatment of sepsis‑induced cardiac dysfunction.
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Affiliation(s)
- Geping Zhang
- Department of Critical Care Medicine, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116011, P.R. China
| | - Dan Dong
- Department of Critical Care Medicine, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116011, P.R. China
| | - Xianyao Wan
- Department of Critical Care Medicine, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116011, P.R. China
| | - Yongli Zhang
- Department of Critical Care Medicine, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116011, P.R. China
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4
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Regulation of Oxidative Phosphorylation of Liver Mitochondria in Sepsis. Cells 2022; 11:cells11101598. [PMID: 35626633 PMCID: PMC9139457 DOI: 10.3390/cells11101598] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 04/25/2022] [Accepted: 05/09/2022] [Indexed: 11/26/2022] Open
Abstract
The link between liver dysfunction and decreased mitochondrial oxidative phosphorylation in sepsis has been clearly established in experimental models. Energy transduction is plastic: the efficiency of mitochondrial coupling collapses in the early stage of sepsis but is expected to increase during the recovery phases of sepsis. Among the mechanisms regulating the coupling efficiency of hepatic mitochondria, the slipping reactions at the cytochrome oxidase and ATP synthase seem to be a determining element, whereas other regulatory mechanisms such as those involving proton leakage across the mitochondrial membrane have not yet been formally proven in the context of sepsis. If the dysfunction of hepatic mitochondria is related to impaired cytochrome c oxidase and ATP synthase functions, we need to consider therapeutic avenues to restore their activities for recovery from sepsis. In this review, we discussed previous findings regarding the regulatory mechanism involved in changes in the oxidative phosphorylation of liver mitochondria in sepsis, and propose therapeutic avenues to improve the functions of cytochrome c oxidase and ATP synthase in sepsis.
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PI3K/mTOR inhibition prevents anal cancer in mice with established low-grade anal dysplasia. Exp Mol Pathol 2022; 125:104752. [PMID: 35183509 PMCID: PMC9018484 DOI: 10.1016/j.yexmp.2022.104752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 02/14/2022] [Accepted: 02/15/2022] [Indexed: 11/20/2022]
Abstract
Low-grade anal dysplasia is a disease that can progress to high-grade anal dysplasia and eventually anal cancer if left untreated. Research has shown that low-grade anal dysplasia is marked by significant autophagic dysfunction. We hypothesized that systemic induction of autophagy, via phosphoinositide 3-kinase/mammalian target of rapamycin (PI3K/mTOR) inhibition, would be effective in preventing anal cancer development in human papillomavirus (HPV) mice (K14E6/E7) with established low-grade anal dysplasia. Mice began treatment at 15 weeks of age, when 75% of mice spontaneously develop low-grade anal dysplasia, and were divided into the following groups: no treatment, systemic LY3023414 (4.5 mg/kg, dual PI3K/mTOR inhibitor) alone, topical 7,12 dimethylbenz[a]anthracene (DMBA) alone, or systemic LY3023414 and topical DMBA. Groups were compared for final histology, PI3K activity, mTOR activity, autophagic induction (light chain 3B (LC3β)), autophagic function (p62 protein), and tumor-free survival. Untreated mice or mice treated with LY3023414 alone did not progress to cancer. There was a statistically significant decrease in the number of mice that developed histologic evidence of cancer when comparing mice that received systemic LY3203414 with topical DMBA versus those that received topical DMBA alone (p = 0.0003). PI3K and mTOR activity decreased in groups treated with systemic LY3023414 and topical DMBA as compared with those treated with topical DMBA alone (p = 0.0005 and p = 0.0271, respectively). LC3β and p62 expression was not statistically altered with systemic LY3023414 treatment. Mice developed less overt tumors and had increased tumor-free survival when treated with systemic LY3023414 in the presence of topical DMBA compared to topical DMBA alone (p = 0.0016 and p < 0.001, respectively). Systemic LY3023414 treatment is effective in anal cancer prevention in the setting of established low-grade anal dysplasia in an HPV-associated mouse model of anal cancer.
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Lu J, Lu J, Bu X, Li Y, Ge G, Guan S. Ginsenoside Rb1 alleviates liver injury induced by 3-chloro-1,2-propanediol by stimulating autophagic flux. J Food Sci 2021; 86:5503-5515. [PMID: 34812491 DOI: 10.1111/1750-3841.15968] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 10/11/2021] [Accepted: 10/15/2021] [Indexed: 11/30/2022]
Abstract
In recent years, foodborne pollutants have become a hot issue in the field of food safety. 3-chloro-1,2-propanediol (3-MCPD) is a widely existing food contaminant. In our previous study, it was confirmed that 3-MCPD can block autophagic flux by inhibiting lysosomal function, thus causing liver injury. Ginseng is a traditional Chinese herbal medicine that contains a variety of bioactive ingredients, among which ginsenoside Rb1 (Gs-Rb1) is the most abundant. In this study, we aim to use Gs-Rb1 to improve 3-MCPD-induced autophagic flux blockage to alleviate liver injury. First, a nontoxic dose of Gs-Rb1 was identified by screening with the MTT method in which Gs-Rb1was added to HepG2 cells and co-treated with 3-MCPD. We found that Gs-Rb1 effectively enhanced the cell activity inhibited by 3-MCPD. Meanwhile, apoptosis data showed that Gs-Rb1 significantly alleviated the apoptosis of HepG2 cells induced by 3-MCPD. Subsequently, we found that Gs-Rb1 could alleviate autophagic flux blockage caused by 3-MCPD in a dose-dependent manner by detecting autophagy-related protein levels and transfecting mRFP-GFP-LC3 adenovirus. On this basis, we used Western blotting and qPCR to explore whether miR-128 was involved in the alleviation effect of Gs-Rb1 on autophagic flux blockade induced by 3-MCPD. The results showed that Gs-Rb1 inhibited the expression of miR-128 and promoted the nuclear expression and target gene transcription of TFEB. Finally, the findings were confirmed by using a hsa-miR-128 inhibitor and mimic. We found that hsa-miR-128 inhibitor alleviated the autophagic flux blockage and apoptosis caused by 3-MCPD and Gs-Rb1 also had a certain alleviation effect on the autophagic flux blockage and apoptosis caused by hsa-miR-128 mimic. This study elaborated the mechanism by which Gs-Rb1 alleviates hepatotoxicity induced by foodborne 3-MCPD by stimulating autophagic flux via miR-128-targeted TFEB, which provides a reliable theoretical basis and target for the use of natural substances to reduce the harm of food processing pollutants on the human body. PRACTICAL APPLICATION: We found that natural ginsenoside Rb1 can alleviate liver injury induced by 3-MCPD(a toxic substance found in foods such as refined vegetable oil, soy sauce, and baby milk powder), which is conducive to the development and utilization of ginseng and has practical significance for the prevention of foodborne liver injury.
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Affiliation(s)
- Jianing Lu
- College of Food Science and Engineering, Jilin University, Changchun, Jilin, People's Republic of China
| | - Jing Lu
- College of Food Science and Engineering, Jilin University, Changchun, Jilin, People's Republic of China.,Key Laboratory of Zoonosis, Ministry of Education College of Veterinary Medicine, Jilin University, Changchun, Jilin, People's Republic of China
| | - Xiujuan Bu
- College of Food Science and Engineering, Jilin University, Changchun, Jilin, People's Republic of China
| | - Yazhuo Li
- College of Food Science and Engineering, Jilin University, Changchun, Jilin, People's Republic of China
| | - Guangcai Ge
- College of Food Science and Engineering, Jilin University, Changchun, Jilin, People's Republic of China
| | - Shuang Guan
- College of Food Science and Engineering, Jilin University, Changchun, Jilin, People's Republic of China.,Key Laboratory of Zoonosis, Ministry of Education College of Veterinary Medicine, Jilin University, Changchun, Jilin, People's Republic of China
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Abstract
Mitochondria have been studied for decades from the standpoint of metabolism and ATP generation. However, in recent years mitochondrial dynamics and its influence on bioenergetics and cellular homeostasis is also being appreciated. Mitochondria undergo regular cycles of fusion and fission regulated by various cues including cellular energy requirements and pathophysiological stimuli, and the network of critical proteins and membrane lipids involved in mitochondrial dynamics is being revealed. Hepatocytes are highly metabolic cells which have abundant mitochondria suggesting a biologically relevant role for mitochondrial dynamics in hepatocyte injury and recovery. Here we review information on molecular mediators of mitochondrial dynamics and their alteration in drug-induced liver injury. Based on current information, it is evident that changes in mitochondrial fusion and fission are hallmarks of liver pathophysiology ranging from acetaminophen-induced or cholestatic liver injury to chronic liver diseases. These alterations in mitochondrial dynamics influence multiple related mitochondrial responses such as mitophagy and mitochondrial biogenesis, which are important adaptive responses facilitating liver recovery in several contexts, including drug-induced liver injury. The current focus on characterization of molecular mechanisms of mitochondrial dynamics is of immense relevance to liver pathophysiology and have the potential to provide significant insight into mechanisms of liver recovery and regeneration after injury.
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Wang R, Xu Y, Fang Y, Wang C, Xue Y, Wang F, Cheng J, Ren H, Wang J, Guo W, Liu L, Zhang M. Pathogenetic mechanisms of septic cardiomyopathy. J Cell Physiol 2021; 237:49-58. [PMID: 34278573 DOI: 10.1002/jcp.30527] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 06/17/2021] [Accepted: 07/06/2021] [Indexed: 12/29/2022]
Abstract
Sepsis is a serious complication after infection, whose further development may lead to multiple organ dysfunction syndrome and so on. It is an important cause of death in critically ill patients who suffered an infection. Sepsis cardiomyopathy is a common complication that exacerbates the prognosis of patients. At present, though the pathogenesis of sepsis cardiomyopathy is not completely clear, in-depth study of the pathogenesis of sepsis cardiomyopathy and the discovery of its potential therapeutic targets may decrease the mortality of sepsis patients and bring clinical benefits. This article reviews mitochondrial dysfunction, mitophagy, oxidation stress, and other mechanisms in sepsis cardiomyopathy.
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Affiliation(s)
- Runze Wang
- Department of Cardiology, Tangdu Hospital, The Fourth Military Medical University, Xi'an, Shaanxi, China.,Department of Hematology, Tangdu Hospital, The Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Yuerong Xu
- Department of Orthodontics, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Yexian Fang
- Department of Cardiology, Tangdu Hospital, The Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Chiyao Wang
- Department of Cardiology, Tangdu Hospital, The Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Yugang Xue
- Department of Cardiology, Tangdu Hospital, The Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Fangfang Wang
- Department of Cardiology, Tangdu Hospital, The Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Jin Cheng
- Department of Cardiology, Tangdu Hospital, The Fourth Military Medical University, Xi'an, Shaanxi, China
| | - He Ren
- Department of Cardiology, Tangdu Hospital, The Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Jie Wang
- Department of Cardiology, Tangdu Hospital, The Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Wangang Guo
- Department of Cardiology, Tangdu Hospital, The Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Li Liu
- Department of Hematology, Tangdu Hospital, The Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Mingming Zhang
- Department of Cardiology, Tangdu Hospital, The Fourth Military Medical University, Xi'an, Shaanxi, China
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Zhu CL, Yao RQ, Li LX, Li P, Xie J, Wang JF, Deng XM. Mechanism of Mitophagy and Its Role in Sepsis Induced Organ Dysfunction: A Review. Front Cell Dev Biol 2021; 9:664896. [PMID: 34164394 PMCID: PMC8215549 DOI: 10.1164/rccm.202111-2484oc+10.3389/fcell.2021.664896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 05/18/2021] [Indexed: 01/17/2024] Open
Abstract
Autophagy, an evolutionarily conserved process, plays an important role in maintaining cellular homeostasis under physiological and pathophysiological conditions. It is widely believed that mitochondria influence the development of disease by regulating cellular metabolism. When challenged by different stimuli, mitochondria may experience morphological disorders and functional abnormalities, leading to a selective form of autophagy-mitophagy, which can clear damaged mitochondria to promote mitochondrial quality control. Sepsis is a complex global problem with multiple organ dysfunction, often accompanied by manifold mitochondrial damage. Recent studies have shown that autophagy can regulate both innate and acquired immune processes to protect against organ dysfunction in sepsis. Sepsis-induced mitochondrial dysfunction may play a pathophysiological role in the initiation and progression of sepsis-induced organ failure. Mitophagy is reported to be beneficial for sepsis by eliminating disabled mitochondria and maintaining homeostasis to protect against organ failure. In this review, we summarize the recent findings and mechanisms of mitophagy and its involvement in septic organ dysfunction as a potential therapeutic target.
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Affiliation(s)
- Cheng-long Zhu
- Department of Anesthesiology and Intensive Care, Changhai Hospital, The Naval Medical University, Shanghai, China
| | - Ren-qi Yao
- Trauma Research Center, Fourth Medical Center of the Chinese PLA General Hospital, Beijing, China
- Department of Burn Surgery, Changhai Hospital, The Naval Medical University, Shanghai, China
| | - Lu-xi Li
- Department of Anesthesiology and Intensive Care, Changhai Hospital, The Naval Medical University, Shanghai, China
| | - Peng Li
- Department of Anesthesiology and Intensive Care, Changhai Hospital, The Naval Medical University, Shanghai, China
| | - Jian Xie
- Department of Anesthesiology and Intensive Care, Changhai Hospital, The Naval Medical University, Shanghai, China
| | - Jia-feng Wang
- Department of Anesthesiology and Intensive Care, Changhai Hospital, The Naval Medical University, Shanghai, China
| | - Xiao-ming Deng
- Department of Anesthesiology and Intensive Care, Changhai Hospital, The Naval Medical University, Shanghai, China
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10
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Zhu CL, Yao RQ, Li LX, Li P, Xie J, Wang JF, Deng XM. Mechanism of Mitophagy and Its Role in Sepsis Induced Organ Dysfunction: A Review. Front Cell Dev Biol 2021; 9:664896. [PMID: 34164394 PMCID: PMC8215549 DOI: 10.1164/rccm.202111-2484oc 10.3389/fcell.2021.664896] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Autophagy, an evolutionarily conserved process, plays an important role in maintaining cellular homeostasis under physiological and pathophysiological conditions. It is widely believed that mitochondria influence the development of disease by regulating cellular metabolism. When challenged by different stimuli, mitochondria may experience morphological disorders and functional abnormalities, leading to a selective form of autophagy-mitophagy, which can clear damaged mitochondria to promote mitochondrial quality control. Sepsis is a complex global problem with multiple organ dysfunction, often accompanied by manifold mitochondrial damage. Recent studies have shown that autophagy can regulate both innate and acquired immune processes to protect against organ dysfunction in sepsis. Sepsis-induced mitochondrial dysfunction may play a pathophysiological role in the initiation and progression of sepsis-induced organ failure. Mitophagy is reported to be beneficial for sepsis by eliminating disabled mitochondria and maintaining homeostasis to protect against organ failure. In this review, we summarize the recent findings and mechanisms of mitophagy and its involvement in septic organ dysfunction as a potential therapeutic target.
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Affiliation(s)
- Cheng-long Zhu
- Department of Anesthesiology and Intensive Care, Changhai Hospital, The Naval Medical University, Shanghai, China
| | - Ren-qi Yao
- Trauma Research Center, Fourth Medical Center of the Chinese PLA General Hospital, Beijing, China,Department of Burn Surgery, Changhai Hospital, The Naval Medical University, Shanghai, China
| | - Lu-xi Li
- Department of Anesthesiology and Intensive Care, Changhai Hospital, The Naval Medical University, Shanghai, China
| | - Peng Li
- Department of Anesthesiology and Intensive Care, Changhai Hospital, The Naval Medical University, Shanghai, China
| | - Jian Xie
- Department of Anesthesiology and Intensive Care, Changhai Hospital, The Naval Medical University, Shanghai, China
| | - Jia-feng Wang
- Department of Anesthesiology and Intensive Care, Changhai Hospital, The Naval Medical University, Shanghai, China,*Correspondence: Jia-feng Wang,
| | - Xiao-ming Deng
- Department of Anesthesiology and Intensive Care, Changhai Hospital, The Naval Medical University, Shanghai, China,Xiao-ming Deng,
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Zhu CL, Yao RQ, Li LX, Li P, Xie J, Wang JF, Deng XM. Mechanism of Mitophagy and Its Role in Sepsis Induced Organ Dysfunction: A Review. Front Cell Dev Biol 2021; 9:664896. [PMID: 34164394 PMCID: PMC8215549 DOI: 10.3389/fcell.2021.664896] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 05/18/2021] [Indexed: 12/14/2022] Open
Abstract
Autophagy, an evolutionarily conserved process, plays an important role in maintaining cellular homeostasis under physiological and pathophysiological conditions. It is widely believed that mitochondria influence the development of disease by regulating cellular metabolism. When challenged by different stimuli, mitochondria may experience morphological disorders and functional abnormalities, leading to a selective form of autophagy-mitophagy, which can clear damaged mitochondria to promote mitochondrial quality control. Sepsis is a complex global problem with multiple organ dysfunction, often accompanied by manifold mitochondrial damage. Recent studies have shown that autophagy can regulate both innate and acquired immune processes to protect against organ dysfunction in sepsis. Sepsis-induced mitochondrial dysfunction may play a pathophysiological role in the initiation and progression of sepsis-induced organ failure. Mitophagy is reported to be beneficial for sepsis by eliminating disabled mitochondria and maintaining homeostasis to protect against organ failure. In this review, we summarize the recent findings and mechanisms of mitophagy and its involvement in septic organ dysfunction as a potential therapeutic target.
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Affiliation(s)
- Cheng-Long Zhu
- Department of Anesthesiology and Intensive Care, Changhai Hospital, The Naval Medical University, Shanghai, China
| | - Ren-Qi Yao
- Trauma Research Center, Fourth Medical Center of the Chinese PLA General Hospital, Beijing, China.,Department of Burn Surgery, Changhai Hospital, The Naval Medical University, Shanghai, China
| | - Lu-Xi Li
- Department of Anesthesiology and Intensive Care, Changhai Hospital, The Naval Medical University, Shanghai, China
| | - Peng Li
- Department of Anesthesiology and Intensive Care, Changhai Hospital, The Naval Medical University, Shanghai, China
| | - Jian Xie
- Department of Anesthesiology and Intensive Care, Changhai Hospital, The Naval Medical University, Shanghai, China
| | - Jia-Feng Wang
- Department of Anesthesiology and Intensive Care, Changhai Hospital, The Naval Medical University, Shanghai, China
| | - Xiao-Ming Deng
- Department of Anesthesiology and Intensive Care, Changhai Hospital, The Naval Medical University, Shanghai, China
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Lian N, Shen M, Zhang K, Pan J, Jiang Y, Yu Y, Yu Y. Drinking Hydrogen-Rich Water Alleviates Chemotherapy-Induced Neuropathic Pain Through the Regulation of Gut Microbiota. J Pain Res 2021; 14:681-691. [PMID: 33732014 PMCID: PMC7956896 DOI: 10.2147/jpr.s288289] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 02/18/2021] [Indexed: 12/20/2022] Open
Abstract
Introduction Chemotherapy-induced neuropathic pain (CINP) is one of the most common complications of chemotherapeutic drugs which limits the dose and duration of potentially life-saving anticancer treatment and compromises the quality of life of patients. Our previous studies have reported that molecular hydrogen (H2) can be used to prevent and treat various diseases. But the underlying mechanism remains unclear. The aim of the present study was to explore the effects of hydrogen-rich water on gut microbiota in CINP. Methods All C57BL/6J mice were divided into 4 groups: The group fed with normal drinking water and injected with saline (H2O + Saline), the group fed with normal drinking water and injected with oxaliplatin (H2O + OXA), the group fed with hydrogen-rich water and injected with saline (HW + Saline), and the group fed with hydrogen-rich water and injected with oxaliplatin (HW + OXA). The mechanical paw withdrawal threshold of the mice was tested on days 0, 5, 10, 15 and 20 after hydrogen-rich water treatment. On day 20, feces of mice from different groups were collected for microbial community diversity and structure analysis. The levels of inflammatory cytokines (TNF-α and IL-6), oxidative stress factors (OH- and ONOO-), lipopolysaccharide (LPS) and Toll-like receptor 4 (TLR4) were detected in dorsal root ganglia (DRG), L4-6 spinal cord segments and serum by enzyme-linked immunosorbent assay. The expression of TLR4 in DRG and spinal cords was determined by Western blot. Results The results illustrated that hydrogen-rich water could alleviate oxaliplatin-induced hyperalgesia, reduce the microbial diversity and alter the structure of gut microbiota, reverse the imbalance of inflammatory cytokines and oxidative stress, and decrease the expression of LPS and TLR4. Conclusion Hydrogen-rich water may alleviate CINP by affecting the diversity and structure of the gut microbiota, and then the LPS-TLR4 pathway, which provides a direction for further research.
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Affiliation(s)
- Naqi Lian
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, 300052, People's Republic of China.,Tianjin Institute of Anesthesiology, Tianjin, People's Republic of China
| | - Mengxi Shen
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, 300052, People's Republic of China.,Tianjin Institute of Anesthesiology, Tianjin, People's Republic of China
| | - Kai Zhang
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, 300052, People's Republic of China.,Tianjin Institute of Anesthesiology, Tianjin, People's Republic of China
| | - Jiacheng Pan
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, 300052, People's Republic of China.,Tianjin Institute of Anesthesiology, Tianjin, People's Republic of China
| | - Yi Jiang
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, 300052, People's Republic of China.,Tianjin Institute of Anesthesiology, Tianjin, People's Republic of China
| | - Yang Yu
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, 300052, People's Republic of China.,Tianjin Institute of Anesthesiology, Tianjin, People's Republic of China
| | - Yonghao Yu
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, 300052, People's Republic of China.,Tianjin Institute of Anesthesiology, Tianjin, People's Republic of China
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13
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Patoli D, Mignotte F, Deckert V, Dusuel A, Dumont A, Rieu A, Jalil A, Van Dongen K, Bourgeois T, Gautier T, Magnani C, Le Guern N, Mandard S, Bastin J, Djouadi F, Schaeffer C, Guillaumot N, Narce M, Nguyen M, Guy J, Dargent A, Quenot JP, Rialland M, Masson D, Auwerx J, Lagrost L, Thomas C. Inhibition of mitophagy drives macrophage activation and antibacterial defense during sepsis. J Clin Invest 2021; 130:5858-5874. [PMID: 32759503 DOI: 10.1172/jci130996] [Citation(s) in RCA: 89] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 07/29/2020] [Indexed: 12/26/2022] Open
Abstract
Mitochondria have emerged as key actors of innate and adaptive immunity. Mitophagy has a pivotal role in cell homeostasis, but its contribution to macrophage functions and host defense remains to be delineated. Here, we showed that lipopolysaccharide (LPS) in combination with IFN-γ inhibited PINK1-dependent mitophagy in macrophages through a STAT1-dependent activation of the inflammatory caspases 1 and 11. In addition, we demonstrated that the inhibition of mitophagy triggered classical macrophage activation in a mitochondrial ROS-dependent manner. In a murine model of polymicrobial infection (cecal ligature and puncture), adoptive transfer of Pink1-deficient bone marrow or pharmacological inhibition of mitophagy promoted macrophage activation, which favored bactericidal clearance and led to a better survival rate. Reciprocally, mitochondrial uncouplers that promote mitophagy reversed LPS/IFN-γ-mediated activation of macrophages and led to immunoparalysis with impaired bacterial clearance and lowered survival. In critically ill patients, we showed that mitophagy was inhibited in blood monocytes of patients with sepsis as compared with nonseptic patients. Overall, this work demonstrates that the inhibition of mitophagy is a physiological mechanism that contributes to the activation of myeloid cells and improves the outcome of sepsis.
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Affiliation(s)
- Danish Patoli
- Université de Bourgogne Franche-Comté (UBFC), UMR 1231, INSERM/AgroSup Dijon/Université de Bourgogne, Dijon, France.,LipSTIC LabEx, Dijon, France
| | - Franck Mignotte
- Université de Bourgogne Franche-Comté (UBFC), UMR 1231, INSERM/AgroSup Dijon/Université de Bourgogne, Dijon, France.,LipSTIC LabEx, Dijon, France
| | - Valérie Deckert
- Université de Bourgogne Franche-Comté (UBFC), UMR 1231, INSERM/AgroSup Dijon/Université de Bourgogne, Dijon, France.,LipSTIC LabEx, Dijon, France
| | - Alois Dusuel
- Université de Bourgogne Franche-Comté (UBFC), UMR 1231, INSERM/AgroSup Dijon/Université de Bourgogne, Dijon, France.,LipSTIC LabEx, Dijon, France
| | - Adélie Dumont
- Université de Bourgogne Franche-Comté (UBFC), UMR 1231, INSERM/AgroSup Dijon/Université de Bourgogne, Dijon, France.,LipSTIC LabEx, Dijon, France
| | - Aurélie Rieu
- UBFC, UMR PAM A 02.102, AgroSup Dijon/ Université de Bourgogne, Dijon, France
| | - Antoine Jalil
- Université de Bourgogne Franche-Comté (UBFC), UMR 1231, INSERM/AgroSup Dijon/Université de Bourgogne, Dijon, France.,LipSTIC LabEx, Dijon, France
| | - Kevin Van Dongen
- Université de Bourgogne Franche-Comté (UBFC), UMR 1231, INSERM/AgroSup Dijon/Université de Bourgogne, Dijon, France.,LipSTIC LabEx, Dijon, France
| | - Thibaut Bourgeois
- Université de Bourgogne Franche-Comté (UBFC), UMR 1231, INSERM/AgroSup Dijon/Université de Bourgogne, Dijon, France.,LipSTIC LabEx, Dijon, France
| | - Thomas Gautier
- Université de Bourgogne Franche-Comté (UBFC), UMR 1231, INSERM/AgroSup Dijon/Université de Bourgogne, Dijon, France.,LipSTIC LabEx, Dijon, France
| | - Charlène Magnani
- Université de Bourgogne Franche-Comté (UBFC), UMR 1231, INSERM/AgroSup Dijon/Université de Bourgogne, Dijon, France.,LipSTIC LabEx, Dijon, France
| | - Naig Le Guern
- Université de Bourgogne Franche-Comté (UBFC), UMR 1231, INSERM/AgroSup Dijon/Université de Bourgogne, Dijon, France.,LipSTIC LabEx, Dijon, France
| | - Stéphane Mandard
- Université de Bourgogne Franche-Comté (UBFC), UMR 1231, INSERM/AgroSup Dijon/Université de Bourgogne, Dijon, France.,LipSTIC LabEx, Dijon, France
| | - Jean Bastin
- Centre de Recherche des Cordeliers, INSERM, Université Sorbonne-Paris-Cité, Paris, France
| | - Fatima Djouadi
- Centre de Recherche des Cordeliers, INSERM, Université Sorbonne-Paris-Cité, Paris, France
| | | | - Nina Guillaumot
- Université de Strasbourg, CNRS, UMR 7178, LSMBO, Strasbourg, France
| | - Michel Narce
- Université de Bourgogne Franche-Comté (UBFC), UMR 1231, INSERM/AgroSup Dijon/Université de Bourgogne, Dijon, France.,LipSTIC LabEx, Dijon, France
| | - Maxime Nguyen
- Université de Bourgogne Franche-Comté (UBFC), UMR 1231, INSERM/AgroSup Dijon/Université de Bourgogne, Dijon, France.,LipSTIC LabEx, Dijon, France.,Department of Anesthesiology and Intensive Care
| | | | - Auguste Dargent
- Université de Bourgogne Franche-Comté (UBFC), UMR 1231, INSERM/AgroSup Dijon/Université de Bourgogne, Dijon, France.,LipSTIC LabEx, Dijon, France.,Department of Intensive Care, University Hospital François Mitterrand, Dijon, France
| | - Jean-Pierre Quenot
- Université de Bourgogne Franche-Comté (UBFC), UMR 1231, INSERM/AgroSup Dijon/Université de Bourgogne, Dijon, France.,LipSTIC LabEx, Dijon, France.,Department of Intensive Care, University Hospital François Mitterrand, Dijon, France.,Clinical Epidemiology, INSERM CIC 1432 and University of Burgundy, Dijon, France
| | - Mickaël Rialland
- Université de Bourgogne Franche-Comté (UBFC), UMR 1231, INSERM/AgroSup Dijon/Université de Bourgogne, Dijon, France.,LipSTIC LabEx, Dijon, France
| | - David Masson
- Université de Bourgogne Franche-Comté (UBFC), UMR 1231, INSERM/AgroSup Dijon/Université de Bourgogne, Dijon, France.,LipSTIC LabEx, Dijon, France.,Clinical Biochemistry Department, University Hospital François Mitterrand, Dijon, France
| | - Johan Auwerx
- Laboratory for Integrative Systems Physiology, Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Laurent Lagrost
- Université de Bourgogne Franche-Comté (UBFC), UMR 1231, INSERM/AgroSup Dijon/Université de Bourgogne, Dijon, France.,LipSTIC LabEx, Dijon, France.,Clinical Biochemistry Department, University Hospital François Mitterrand, Dijon, France
| | - Charles Thomas
- Université de Bourgogne Franche-Comté (UBFC), UMR 1231, INSERM/AgroSup Dijon/Université de Bourgogne, Dijon, France.,LipSTIC LabEx, Dijon, France
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14
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Zhang X, Griepentrog JE, Zou B, Xu L, Cyr AR, Chambers LM, Zuckerbraun BS, Shiva S, Rosengart MR. CaMKIV regulates mitochondrial dynamics during sepsis. Cell Calcium 2020; 92:102286. [PMID: 32932146 DOI: 10.1016/j.ceca.2020.102286] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 08/28/2020] [Indexed: 12/12/2022]
Abstract
Sepsis and shock states impose mitochondrial stress, and in response, adaptive mechanisms such as fission, fusion and mitophagy are induced to eliminate damaged portions of or entire dysfunctional mitochondria. The mechanisms underlying these events are being elucidated; yet a direct link between loss of mitochondrial membrane potential ΔΨm and the initiation of fission, fusion and mitophagy remains to be well characterized. The direct association between the magnitude of the ΔΨm and the capacity for mitochondria to buffer Ca2+ renders Ca2+ uniquely suited as the signal engaging these mechanisms in circumstances of mitochondrial stress that lower the ΔΨm. Herein, we show that the calcium/calmodulin-dependent protein kinase (CaMK) IV mediates an adaptive slowing in oxidative respiration that minimizes oxidative stress in the kidneys of mice subjected to either cecal ligation and puncture (CLP) sepsis or endotoxemia. CaMKIV shifts the balance towards mitochondrial fission and away from fusion by 1) directly phosphorylating an activating Serine616 on the fission protein DRP1 and 2) reducing the expression of the fusion proteins Mfn1/2 and OPA-1. CaMKIV, through its function as a direct PINK1 kinase and regulator of Parkin expression, also enables mitophagy. These data support that CaMKIV serves as a keystone linking mitochondrial stress with the adaptive mechanisms of mitochondrial fission, fusion and mitophagy that mitigate oxidative stress in the kidneys of mice responding to sepsis.
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Affiliation(s)
- Xianghong Zhang
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA, United States
| | - John E Griepentrog
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA, United States
| | - Baobo Zou
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA, United States
| | - Li Xu
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA, United States; Department of Emergency, Union Hospital, Tongji Medical College, Hua Zhong University of Science and Technology, Wuhan, China
| | - Anthony R Cyr
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA, United States
| | - Lauran M Chambers
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA, United States
| | - Brian S Zuckerbraun
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA, United States
| | - Sruti Shiva
- Department of Pharmacology & Chemical Biology, Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, United States
| | - Matthew R Rosengart
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA, United States.
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15
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Liu G, Liu W, Guo J. Clinical significance of miR-181a in patients with neonatal sepsis and its regulatory role in the lipopolysaccharide-induced inflammatory response. Exp Ther Med 2020; 19:1977-1983. [PMID: 32104257 DOI: 10.3892/etm.2020.8408] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 10/30/2019] [Indexed: 12/16/2022] Open
Abstract
Neonatal sepsis (NS) poses a serious threat to the health of neonates worldwide. The present study aimed to investigate the diagnostic value of microRNA (miR)-181a in patients with NS and the regulatory role of miR-181a in lipopolysaccharide (LPS)-induced inflammation. A total of 102 neonates with NS and 50 neonates without sepsis were enrolled in the present study. The serum levels of miR-181a were estimated using reverse transcription-quantitative PCR. Receiver operating characteristic (ROC) analysis was performed to evaluate the diagnostic value of miR-181a for NS. The effect of miR-181a on the expression of Toll-like receptor (TLR)4 was assessed after modification of the expression of miR-181a in monocytes isolated from the blood of neonates in vitro. An ELISA was used to measure the concentration of inflammatory cytokines tumor necrosis factor (TNF)-α and interleukin (IL)-8 in the supernatant of monocytes. The serum levels of miR-181a were decreased in patients with NS compared with those in the controls. The area under the ROC curve of miR-181a was 0.893 with a sensitivity of 83.3% and a specificity of 84.0%. LPS stimulation in monocytes also led to a decrease in the expression of miR-181a. TLR4 was proven to be a direct target gene of miR-181a, according to the results of a luciferase reporter assay, and overexpression of miR-181a suppressed TLR4 expression in monocytes. Regarding LPS-induced inflammation, it was revealed that the upregulated levels of TNF-α and IL-8 induced by LPS were reduced by overexpression of miR-181a in monocytes. In conclusion, decreased serum levels of miR-181a may serve as a diagnostic biomarker in patients with NS and overexpression of miR-181a inhibits the LPS-induced inflammatory response at least partially by targeting TLR4. Aberrant miR-181a may be a non-invasive biomarker for NS patients, and provide a novel insight into the pathologic mechanisms of action behind the development of NS.
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Affiliation(s)
- Guozhi Liu
- Department of Neonatology, Yidu Central Hospital of Weifang, Weifang, Shandong 262500, P.R. China
| | - Wei Liu
- Department of Neonatology, Yidu Central Hospital of Weifang, Weifang, Shandong 262500, P.R. China
| | - Jie Guo
- Department of Neonatology, Yidu Central Hospital of Weifang, Weifang, Shandong 262500, P.R. China
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16
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Hydrogen alleviated organ injury and dysfunction in sepsis: The role of cross-talk between autophagy and endoplasmic reticulum stress: Experimental research. Int Immunopharmacol 2020; 78:106049. [DOI: 10.1016/j.intimp.2019.106049] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 11/10/2019] [Accepted: 11/11/2019] [Indexed: 01/26/2023]
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17
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The Pathogenesis of Sepsis and Potential Therapeutic Targets. Int J Mol Sci 2019; 20:ijms20215376. [PMID: 31671729 PMCID: PMC6862039 DOI: 10.3390/ijms20215376] [Citation(s) in RCA: 327] [Impact Index Per Article: 65.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 10/05/2019] [Accepted: 10/25/2019] [Indexed: 02/06/2023] Open
Abstract
Sepsis is defined as “a life-threatening organ dysfunction caused by a host’s dysfunctional response to infection”. Although the treatment of sepsis has developed rapidly in the past few years, sepsis incidence and mortality in clinical treatment is still climbing. Moreover, because of the diverse manifestations of sepsis, clinicians continue to face severe challenges in the diagnosis, treatment, and management of patients with sepsis. Here, we review the recent development in our understanding regarding the cellular pathogenesis and the target of clinical diagnosis of sepsis, with the goal of enhancing the current understanding of sepsis. The present state of research on targeted therapeutic drugs is also elaborated upon to provide information for the treatment of sepsis.
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18
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Endotoxin Engages Mitochondrial Quality Control via an iNOS-Reactive Oxygen Species Signaling Pathway in Hepatocytes. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:4745067. [PMID: 31772705 PMCID: PMC6854992 DOI: 10.1155/2019/4745067] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 08/15/2019] [Accepted: 09/12/2019] [Indexed: 12/22/2022]
Abstract
Background Organ injury and dysfunction in sepsis accounts for significant morbidity and mortality. Adaptive cellular responses in the setting of sepsis prevent injury and allow for organ recovery. We and others have shown that part of the adaptive response includes regulation of cellular respiration and maintenance of a healthy mitochondrial population. Herein, we hypothesized that endotoxin-induced changes in hepatocyte mitochondrial respiration and homeostasis are regulated by an inducible nitric oxide synthase/nitric oxide (iNOS/NO)-mitochondrial reactive oxygen species (mtROS) signaling axis, involving activation of the NRF2 signaling pathway. Methods Wild-type (C57Bl/6) or iNos−/− male mice were subjected to intraperitoneal lipopolysaccharide (LPS) injections to simulate endotoxemia. Individual mice were randomized to treatment with NO-releasing agent DPTA-NONOate, mtROS scavenger MitoTEMPO, or vehicle controls. Other mice were treated with scramble or Nrf2-specific siRNA via tail vein injection. Primary murine hepatocytes were utilized for in vitro studies with or without LPS stimulation. Oxygen consumption rates were measured to establish mitochondrial respiratory parameters. Western blotting, confocal microscopy with immunocytochemistry, and rtPCR were performed for analysis of iNOS as well as markers of both autophagy and mitochondrial biogenesis. Results LPS treatment inhibited aerobic respiration in vitro in wild-type but not iNos−/− cells. Experimental endotoxemia in vivo or in vitro induced iNOS protein and mtROS production. However, induction of mtROS was dependent on iNOS expression. Furthermore, LPS-induced hepatic autophagy/mitophagy and mitochondrial biogenesis were significantly attenuated in iNos−/− mice or cells with NO or mtROS scavenging. These responses were rescued in iNos−/− mice via delivery of NO both in vivo and in vitro. Conclusions. These data suggest that regulation of mitochondrial quality control following hepatocyte LPS exposure is dependent at least in part on a NO-mtROS signaling network. Further investigation to identify specific agents that modulate this process may facilitate the prevention of organ injury in sepsis.
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19
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Tan Y, Chen S, Zhong J, Ren J, Dong M. Mitochondrial Injury and Targeted Intervention in Septic Cardiomyopathy. Curr Pharm Des 2019; 25:2060-2070. [PMID: 31284854 DOI: 10.2174/1381612825666190708155400] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 06/20/2019] [Indexed: 12/31/2022]
Abstract
Background:
Sepsis and septic shock are known to prompt multiple organ failure including cardiac
contractile dysfunction, which is typically referred to as septic cardiomyopathy. Among various theories postulated
for the etiology of septic cardiomyopathy, mitochondrial injury (both morphology and function) in the heart
is perceived as the main culprit for reduced myocardial performance and ultimately heart failure in the face of
sepsis.
Methods:
Over the past decades, ample of experimental and clinical work have appeared, focusing on myocardial
mitochondrial changes and related interventions in septic cardiomyopathy.
Results and Conclusion:
Here we will briefly summarize the recent experimental and clinical progress on myocardial
mitochondrial morphology and function in sepsis, and discuss possible underlying mechanisms, as well as
the contemporary interventional options.
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Affiliation(s)
- Ying Tan
- Department of Emergency Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
| | - Sainan Chen
- Department of Emergency Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
| | - Jiankai Zhong
- Department of Cardiology, Shunde Hospital, Southern Medical University, Foshan, 528300, Guangdong, China
| | - Jun Ren
- Department of Cardiology, Shanghai Institute of Cardiovascular Disease, Zhongshan Hospital Fudan University, Shanghai, 200032, China
| | - Maolong Dong
- Department of Emergency Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
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20
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Maurice NM, Bedi B, Yuan Z, Goldberg JB, Koval M, Hart CM, Sadikot RT. Pseudomonas aeruginosa Induced Host Epithelial Cell Mitochondrial Dysfunction. Sci Rep 2019; 9:11929. [PMID: 31417101 PMCID: PMC6695387 DOI: 10.1038/s41598-019-47457-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 07/07/2019] [Indexed: 02/06/2023] Open
Abstract
The pathogenicity of P. aeruginosa is dependent on quorum sensing (QS), an inter-bacterial communication system that can also modulate host biology. The innate immune function of the lung mucosal barrier is dependent on proper mitochondrial function. The purpose of this study was to define the mechanism by which bacterial factors modulate host lung epithelial cell mitochondrial function and to investigate novel therapies that ameliorate this effect. 3-oxo-C12-HSL disrupts mitochondrial morphology, attenuates mitochondrial bioenergetics, and induces mitochondrial DNA oxidative injury. Mechanistically, we show that 3-oxo-C12-HSL attenuates expression of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), a master regulator of mitochondrial biogenesis, antioxidant defense, and cellular respiration, and its downstream effectors in both BEAS-2B and primary lung epithelial cells. Overexpression of PGC-1α attenuates the inhibition in cellular respiration caused by 3-oxo-C12-HSL. Pharmacologic activation of PGC-1α restores barrier integrity in cells treated with 3-oxo-C12-HSL. These data demonstrate that the P. aeruginosa QS molecule, 3-oxo-C12-HSL, alters mitochondrial pathways critical for lung mucosal immunity. Genetic and pharmacologic strategies that activate the PGC-1α pathway enhance host epithelial cell mitochondrial function and improve the epithelial innate response to P. aeruginosa. Therapies that rescue PGC-1α function may provide a complementary approach in the treatment of P. aeruginosa infection.
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Affiliation(s)
- Nicholas M Maurice
- Department of Medicine, Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Emory University School of Medicine, Atlanta, GA, 30322, USA.,Atlanta Veterans Affairs Health Care System, Decatur, GA, 30033, USA
| | - Brahmchetna Bedi
- Department of Medicine, Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Emory University School of Medicine, Atlanta, GA, 30322, USA.,Atlanta Veterans Affairs Health Care System, Decatur, GA, 30033, USA
| | - Zhihong Yuan
- Department of Medicine, Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Emory University School of Medicine, Atlanta, GA, 30322, USA.,Atlanta Veterans Affairs Health Care System, Decatur, GA, 30033, USA
| | - Joanna B Goldberg
- Department of Pediatrics, Division of Pulmonology, Allergy/Immunology, Cystic Fibrosis, and Sleep, Emory University, Atlanta, GA, 30322, USA.,Children's Healthcare of Atlanta, Center for CF and Airways Disease Research Atlanta, Atlanta, GA, USA
| | - Michael Koval
- Department of Medicine, Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Emory University School of Medicine, Atlanta, GA, 30322, USA.,Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - C Michael Hart
- Department of Medicine, Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Emory University School of Medicine, Atlanta, GA, 30322, USA.,Atlanta Veterans Affairs Health Care System, Decatur, GA, 30033, USA
| | - Ruxana T Sadikot
- Department of Medicine, Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Emory University School of Medicine, Atlanta, GA, 30322, USA. .,Atlanta Veterans Affairs Health Care System, Decatur, GA, 30033, USA.
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21
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Wang F, Lei X, Zhao Y, Yu Q, Li Q, Zhao H, Pei Z. Protective role of thymoquinone in sepsis-induced liver injury in BALB/c mice. Exp Ther Med 2019; 18:1985-1992. [PMID: 31410159 PMCID: PMC6676142 DOI: 10.3892/etm.2019.7779] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2018] [Accepted: 06/06/2019] [Indexed: 02/07/2023] Open
Abstract
Sepsis increases the risk of developing liver injury. Previous studies have demonstrated that thymoquinone (TQ) exhibits hepatoprotective properties in vivo as well as in vitro. The present study aimed to investigate the underlying mechanisms of the protective effects of TQ against liver injury in septic BALB/c mice. Male BALB/c mice (age, 8 weeks) were randomly divided into four groups, namely, the control, TQ (50 mg/kg/day) treatment, cecal ligation and puncture (CLP), and TQ + CLP groups. CLP was performed following gavage of TQ for 2 weeks. At 48 h post-CLP, the histopathological alterations in the liver tissue (LT) and plasma levels of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) were assessed. The present study evaluated microtubule-associated protein light chain 3 (LC3), sequestosome-1 (p62) and beclin 1 protein expression by western blotting and immunostaining, as well as interleukin (IL)-6, IL-1β, IL-10, monocyte chemoattractant protein-1 (MCP-1) and tumor necrosis factor-α (TNF-α) mRNA expression by RT-qPCR. The results of the present study indicated that administration of TQ to mice reduced the histological alterations caused by CLP in LT. TQ inhibited the plasma levels of ALT, AST and ALP in the CLP group. TQ significantly inhibited the elevation of p62, IL-1β, IL-6, MCP-1 and TNF-α levels as well as increased the LC3, beclin 1 and IL-10 levels in LT. PI3K expression in the TQ + CLP group was significantly decreased compared with that in the CLP group. TQ treatment effectively modulated the expression levels of p62, LC3, beclin 1, PI3K and proinflammatory cytokines, and may be an important agent for the treatment of sepsis-induced liver injury.
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Affiliation(s)
- Fei Wang
- Department of Gastroenterology, Affiliated Zhongshan Hospital of Dalian University, Dalian, Liaoning 116001, P.R. China
| | - Xiong Lei
- Graduate School of Dalian Medical University, The First Clinical College, Dalian, Liaoning 116044, P.R. China
| | - Yue Zhao
- Graduate School of Dalian Medical University, The First Clinical College, Dalian, Liaoning 116044, P.R. China
| | - Qinggong Yu
- Department of Gastroenterology, Affiliated Zhongshan Hospital of Dalian University, Dalian, Liaoning 116001, P.R. China
| | - Qianwei Li
- Department of Gastroenterology, Affiliated Zhongshan Hospital of Dalian University, Dalian, Liaoning 116001, P.R. China
| | - Hui Zhao
- Department of Vascular Surgery, Affiliated Zhongshan Hospital of Dalian University, Dalian, Liaoning 116001, P.R. China
| | - Zuowei Pei
- Department of Cardiology, Affiliated Zhongshan Hospital of Dalian University, Dalian, Liaoning 116001, P.R. China
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22
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Yan M, Yu Y, Mao X, Feng J, Wang Y, Chen H, Xie K, Yu Y. Hydrogen gas inhalation attenuates sepsis-induced liver injury in a FUNDC1-dependent manner. Int Immunopharmacol 2019; 71:61-67. [DOI: 10.1016/j.intimp.2019.03.021] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 03/08/2019] [Accepted: 03/08/2019] [Indexed: 01/08/2023]
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23
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Wu Y, Yao YM, Lu ZQ. Mitochondrial quality control mechanisms as potential therapeutic targets in sepsis-induced multiple organ failure. J Mol Med (Berl) 2019; 97:451-462. [PMID: 30788535 DOI: 10.1007/s00109-019-01756-2] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 12/24/2018] [Accepted: 02/06/2019] [Indexed: 02/07/2023]
Abstract
Sepsis is a dysregulated response to severe infection characterized by life-threatening organ failure and is the leading cause of mortality worldwide. Multiple organ failure is the central characteristic of sepsis and is associated with poor outcome of septic patients. Ultrastructural damage to the mitochondria and mitochondrial dysfunction are reported in sepsis. Mitochondrial dysfunction with subsequent ATP deficiency, excessive reactive oxygen species (ROS) release, and cytochrome c release are all considered to contribute to organ failure. Consistent mitochondrial dysfunction leads to reduced mitochondrial quality control capacity, which eliminates dysfunctional and superfluous mitochondria to maintain mitochondrial homeostasis. Mitochondrial quality is controlled through a series of processes including mitochondrial biogenesis, mitochondrial dynamics, mitophagy, and transport processes. Several studies have indicated that multiple organ failure is ameliorated by restoring mitochondrial quality control mechanisms and is further amplified by defective quality control mechanisms. This review will focus on advances concerning potential mechanisms in regulating mitochondrial quality control and impacts of mitochondrial quality control on the progression of sepsis.
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Affiliation(s)
- You Wu
- Emergency Department, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, People's Republic of China.,Wenzhou Municipal Key Laboratory of Emergency, Critical Care and Disaster Medicine, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, People's Republic of China
| | - Yong-Ming Yao
- Emergency Department, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, People's Republic of China. .,Trauma Research Center, First Hospital Affiliated to the Chinese PLA General Hospital, Beijing, People's Republic of China.
| | - Zhong-Qiu Lu
- Emergency Department, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, People's Republic of China. .,Wenzhou Municipal Key Laboratory of Emergency, Critical Care and Disaster Medicine, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, People's Republic of China. .,College of Nursing, Wenzhou Medical University, Wenzhou, People's Republic of China.
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24
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Zhang Y, Wang L, Meng L, Cao G, Wu Y. Sirtuin 6 overexpression relieves sepsis-induced acute kidney injury by promoting autophagy. Cell Cycle 2019; 18:425-436. [PMID: 30700227 DOI: 10.1080/15384101.2019.1568746] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Sirtuin 6 (SIRT6) has the function of regulating autophagy. The aim of this study was to investigate the mechanism through which SIRT6 relieved acute kidney injury (AKI) caused by sepsis. The AKI model was established with lipopolysaccharides (LPS) using mice. Hematoxylin-eosin (HE) staining and streptavidin-perosidase (SP) staining was used to observe kidney tissue and test SIRT6 and LC3B proteins in kidney. Enzyme-linked immunosorbent assay (ELISA) was performed to detected the tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) concentrations. Cell counting kit-8 (CCK-8) assay and flow cytometry were carried out to test the cell viability and apoptosis rate respectively. Protein and mRNA were determined by Western blot and quantitative real-time polymerase chain reaction (qRT-PCR). AKI induced by LPS had self-repairing ability. At 12 h after modeling, the expression levels of TNF-α, IL-6, SIRT6 and LC3B-II/LC3B-I were first significantly increased and were then significantly decreased at 48 h after modeling. LPS inhibited the growth of HK-2 cells and promoted the expressions of TNF-α, IL-6, SIRT6 and LC3B. Overexpression of SIRT6 down-regulated the secretion of TNF-α and IL-6 induced by LPS. SIRT6 overexpression inhibited apoptosis induced by LPS and promoted autophagy in HK-2 cells. Silencing of the SIRT6 gene not only promoted the secretion of TNF-α and IL-6 by HK-2 cells, but also promoted apoptosis and reduced autophagy. LPS up-regulated the expression of SIRT6 gene in HK-2 cells. Overexpression of the SIRT6 gene could inhibit apoptosis and induce autophagy, which might be involved in repairing kidney damage caused by LPS.
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Affiliation(s)
- Yang Zhang
- a College of Anesthesia , Xuzhou Medical University , Xuzhou , China
| | - Ling Wang
- b Department of Nephrology , Xuzhou No.1 People's Hospital , Xuzhou , China
| | - Lei Meng
- c Department of Intensive Care Unit , The Affiliated Hospital of Xuzhou Medical University , Xuzhou , China
| | - Guangke Cao
- d Department of Intensive Care Unit , Xuzhou No.1 People's Hospital , Xuzhou , China
| | - Yu Wu
- b Department of Nephrology , Xuzhou No.1 People's Hospital , Xuzhou , China
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25
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Ma WQ, Sun XJ, Wang Y, Zhu Y, Han XQ, Liu NF. Restoring mitochondrial biogenesis with metformin attenuates β-GP-induced phenotypic transformation of VSMCs into an osteogenic phenotype via inhibition of PDK4/oxidative stress-mediated apoptosis. Mol Cell Endocrinol 2019; 479:39-53. [PMID: 30170182 DOI: 10.1016/j.mce.2018.08.012] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 08/27/2018] [Accepted: 08/27/2018] [Indexed: 12/19/2022]
Abstract
Mitochondrial abnormalities have long been observed in the development of vascular calcification. Metformin, a member of the biguanide class of antidiabetic drugs, has recently received attention owing to new findings regarding its protective role in cardiovascular disease. Since the precise control of mitochondrial quantity and quality is critical for the survival and function of vascular smooth muscle cells (VSMCs), maintaining mitochondrial homeostasis may be a potential protective factor for VSMCs against osteoblast-like phenotypic transition. However, limited studies have been reported in this area. Here, we investigated the role of metformin in the phenotypic transformation of VSMCs, as well as its intracellular signal transduction pathways. We demonstrated that supplementation with metformin restored the β-glycerophosphate (β-GP)-mediated impairment of mitochondrial biogenesis in VSMCs, as evidenced by an increased mitochondrial DNA copy number, a restored mitochondrial membrane potential (MMP), and upregulated mitochondrial biogenesis-related gene expression, whereas the AMP-activated protein kinase (AMPK) inhibitor compound C suppressed these effects. We also observed that overexpression of pyruvate dehydrogenase kinase 4 (PDK4), an important mitochondrial matrix enzyme in cellular energy metabolism, exacerbated β-GP-induced oxidative stress and subsequent apoptosis in VSMCs but that these effects were suppressed by dichloroacetate, a widely reported PDK4 inhibitor. More importantly, enhanced mitochondrial biogenesis attenuated the β-GP-induced phenotypic transformation of VSMCs into an osteogenic phenotype through inhibition of the PDK4/oxidative stress-mediated apoptosis pathway, whereas disruption of mitochondrial biogenesis by zidovudine aggravated β-GP-induced apoptosis in VSMCs. In addition, inhibition of autophagy by small interfering RNA targeting Atg5 reduced mitochondrial biogenesis in VSMCs. In summary, we uncovered a novel mechanism by which metformin attenuates the phenotypic transformation of VSMCs into an osteogenic phenotype via inhibition of the PDK4/oxidative stress-mediated apoptosis pathway, and mitochondrial homeostasis is involved in this process.
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Affiliation(s)
- Wen-Qi Ma
- Department of Cardiology, Zhongda Hospital, School of Medicine, Southeast University, 87 Dingjiaqiao, Nanjing 210009, PR China
| | - Xue-Jiao Sun
- Department of Cardiology, Zhongda Hospital, School of Medicine, Southeast University, 87 Dingjiaqiao, Nanjing 210009, PR China
| | - Ying Wang
- Department of Cardiology, Zhongda Hospital, School of Medicine, Southeast University, 87 Dingjiaqiao, Nanjing 210009, PR China
| | - Yi Zhu
- Department of Cardiology, Zhongda Hospital, School of Medicine, Southeast University, 87 Dingjiaqiao, Nanjing 210009, PR China
| | - Xi-Qiong Han
- Department of Cardiology, Zhongda Hospital, School of Medicine, Southeast University, 87 Dingjiaqiao, Nanjing 210009, PR China
| | - Nai-Feng Liu
- Department of Cardiology, Zhongda Hospital, School of Medicine, Southeast University, 87 Dingjiaqiao, Nanjing 210009, PR China.
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26
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Widdrington JD, Gomez-Duran A, Pyle A, Ruchaud-Sparagano MH, Scott J, Baudouin SV, Rostron AJ, Lovat PE, Chinnery PF, Simpson AJ. Exposure of Monocytic Cells to Lipopolysaccharide Induces Coordinated Endotoxin Tolerance, Mitochondrial Biogenesis, Mitophagy, and Antioxidant Defenses. Front Immunol 2018; 9:2217. [PMID: 30319656 PMCID: PMC6170658 DOI: 10.3389/fimmu.2018.02217] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 09/06/2018] [Indexed: 12/21/2022] Open
Abstract
In order to limit the adverse effects of excessive inflammation, anti-inflammatory responses are stimulated at an early stage of an infection, but during sepsis these can lead to deactivation of immune cells including monocytes. In addition, there is emerging evidence that the up-regulation of mitochondrial quality control mechanisms, including mitochondrial biogenesis and mitophagy, is important during the recovery from sepsis and inflammation. We aimed to describe the relationship between the compensatory immune and mitochondrial responses that are triggered following exposure to an inflammatory stimulus in human monocytic cells. Incubation with lipopolysaccharide resulted in a change in the immune phenotype of THP-1 cells consistent with the induction of endotoxin tolerance, similar to that seen in deactivated septic monocytes. After exposure to LPS there was also early evidence of oxidative stress, which resolved in association with the induction of antioxidant defenses and the stimulation of mitochondrial degradation through mitophagy. This was compensated by a parallel up-regulation of mitochondrial biogenesis that resulted in an overall increase in mitochondrial respiratory activity. These observations improve our understanding of the normal homeostatic responses that limit the adverse cellular effects of unregulated inflammation, and which may become ineffective when an infection causes sepsis.
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Affiliation(s)
- John D Widdrington
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom.,Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Aurora Gomez-Duran
- Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom.,MRC Mitochondrial Biology Unit, Cambridge Biomedical Campus, Cambridge, United Kingdom.,Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | - Angela Pyle
- Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom
| | | | - Jonathan Scott
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Simon V Baudouin
- Department of Anaesthesia, Royal Victoria Infirmary, Newcastle upon Tyne, United Kingdom
| | - Anthony J Rostron
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Penny E Lovat
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Patrick F Chinnery
- Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom.,MRC Mitochondrial Biology Unit, Cambridge Biomedical Campus, Cambridge, United Kingdom.,Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | - A John Simpson
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom
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27
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Abstract
PURPOSE OF REVIEW Sepsis is a common and frequently fatal condition in which mortality has been consistently linked to increasing organ dysfunction. For example, acute kidney injury (AKI) occurs in 40-50% of septic patients and increases mortality six to eight-fold. However, the mechanisms by which sepsis causes organ dysfunction are not well understood and hence current therapy remains reactive and nonspecific. RECENT FINDINGS Recent studies have challenged the previous notion that organ dysfunction is solely secondary to hypoperfusion, by showing, for example, that AKI occurs in the setting of normal or increased renal blood flow; and that it is characterized not by acute tubular necrosis or apoptosis, but rather by heterogeneous areas of colocalized sluggish peritubular blood flow and tubular epithelial cell oxidative stress. Evidence has also shown that microvascular dysfunction, inflammation, and the metabolic response to inflammatory injury are fundamental pathophysiologic mechanisms that may explain the development of sepsis-induced AKI. SUMMARY The implications of these findings are significant because in the context of decades of negative clinical trials in the field, the recognition that other mechanisms are at play opens the possibility to better understand the processes of injury and repair, and provides an invaluable opportunity to design mechanism-targeted therapeutic interventions.
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28
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Ren C, Zhang H, Wu TT, Yao YM. Autophagy: A Potential Therapeutic Target for Reversing Sepsis-Induced Immunosuppression. Front Immunol 2017; 8:1832. [PMID: 29326712 PMCID: PMC5741675 DOI: 10.3389/fimmu.2017.01832] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2017] [Accepted: 12/04/2017] [Indexed: 01/17/2023] Open
Abstract
Sepsis remains the leading cause of mortality in intensive care units and an intractable condition due to uncontrolled inflammation together with immune suppression. Dysfunction of immune cells is considered as a major cause for poor outcome of septic patients but with little specific treatments. Currently, autophagy that is recognized as an important self-protective mechanism for cellular survival exhibits great potential for maintaining immune homeostasis and alleviating multiple organ failure, which further improves survival of septic animals. The protective effect of autophagy on immune cells covers both innate and adaptive immune responses and refers to various cellular receptors and intracellular signaling. Multiple drugs and measures are reportedly beneficial for septic challenge by inducing autophagy process. Therefore, autophagy might be an effective target for reversing immunosuppression compromised by sepsis.
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Affiliation(s)
- Chao Ren
- Trauma Research Center, First Hospital Affiliated to the Chinese PLA General Hospital, Beijing, China.,School of Medicine, Nankai University, Tianjin, China
| | - Hui Zhang
- Trauma Research Center, First Hospital Affiliated to the Chinese PLA General Hospital, Beijing, China
| | - Tian-Tian Wu
- Trauma Research Center, First Hospital Affiliated to the Chinese PLA General Hospital, Beijing, China
| | - Yong-Ming Yao
- Trauma Research Center, First Hospital Affiliated to the Chinese PLA General Hospital, Beijing, China.,School of Medicine, Nankai University, Tianjin, China.,State Key Laboratory of Kidney Disease, The Chinese PLA General Hospital, Beijing, China
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29
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Thiessen SE, Derese I, Derde S, Dufour T, Pauwels L, Bekhuis Y, Pintelon I, Martinet W, Van den Berghe G, Vanhorebeek I. The Role of Autophagy in Critical Illness-induced Liver Damage. Sci Rep 2017; 7:14150. [PMID: 29074879 PMCID: PMC5658339 DOI: 10.1038/s41598-017-14405-w] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Accepted: 10/02/2017] [Indexed: 12/14/2022] Open
Abstract
Mitochondrial dysfunction and endoplasmic reticulum (ER) stress, which activates the unfolded protein response (UPR), mediate critical illness-induced organ failure, often affecting the liver. Autophagy is known to alleviate both and suppressed or insufficiently activated autophagy in prolonged illness has shown to associate with organ failure. Whether insufficient autophagy contributes to organ failure during critical illness by affecting these underlying mechanisms is incompletely understood. In this study, we investigated whether the inability to acutely activate hepatic autophagy during critical illness aggravates liver damage by increasing hepatic mitochondrial dysfunction and affecting the UPR. In a mouse model of critical illness, induced by surgery and sepsis, we investigated the impact of inactivating hepatic autophagy on markers of hepatic mitochondrial function, the UPR and liver damage in acute (1 day) and prolonged (3 days) critical illness. Hepatic autophagy inactivation during critical illness acutely worsened mitochondrial dysfunction and time-dependently modulated the hepatic UPR. Furthermore, autophagy inactivation aggravated markers of liver damage on both time points. In conclusion, the inability to acutely activate autophagy in liver during critical illness worsened hepatic mitochondrial damage and dysfunction, partially prohibited acute UPR activation and aggravated liver damage, indicating that autophagy is crucial in alleviating critical illness-induced organ failure.
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Affiliation(s)
- Steven E Thiessen
- Clinical Division and Laboratory of Intensive Care Medicine, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, 3000, Belgium
| | - Inge Derese
- Clinical Division and Laboratory of Intensive Care Medicine, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, 3000, Belgium
| | - Sarah Derde
- Clinical Division and Laboratory of Intensive Care Medicine, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, 3000, Belgium
| | - Thomas Dufour
- Clinical Division and Laboratory of Intensive Care Medicine, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, 3000, Belgium
| | - Lies Pauwels
- Clinical Division and Laboratory of Intensive Care Medicine, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, 3000, Belgium
| | - Youri Bekhuis
- Clinical Division and Laboratory of Intensive Care Medicine, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, 3000, Belgium
| | - Isabel Pintelon
- Laboratory of Cell Biology and Histology, University of Antwerp, Antwerp, 2610, Belgium
| | - Wim Martinet
- Laboratory of Physiopharmacology, University of Antwerp, Antwerp, 2610, Belgium
| | - Greet Van den Berghe
- Clinical Division and Laboratory of Intensive Care Medicine, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, 3000, Belgium
| | - Ilse Vanhorebeek
- Clinical Division and Laboratory of Intensive Care Medicine, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, 3000, Belgium.
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30
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Abstract
Sepsis-associated organ dysfunction involves multiple responses to inflammation, including endothelial and microvascular dysfunction, immune and autonomic dysregulation, and cellular metabolic reprogramming. The effect of targeting these mechanistic pathways on short- and long-term outcomes depends highly on the timing of therapeutic intervention. Furthermore, there is a need to understand the adaptive or maladaptive character of these mechanisms, to discover phase-specific biomarkers to guide therapy, and to conceptualize these mechanisms in terms of resistance and tolerance.
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Affiliation(s)
- Rachel Pool
- Department of Anesthesiology, University of Pittsburgh Medical Center, 200 Lothrop Street, Pittsburgh, PA 15213, USA
| | - Hernando Gomez
- Center for Critical Care Nephrology, The CRISMA (Clinical Research, Investigation, and Systems Modeling of Acute Illness) Center, Department of Critical Care Medicine, University of Pittsburgh, 3347 Forbes Avenue, Suite 220, Pittsburgh, PA 15213, USA.
| | - John A Kellum
- Center for Critical Care Nephrology, The CRISMA (Clinical Research, Investigation, and Systems Modeling of Acute Illness) Center, Department of Critical Care Medicine, University of Pittsburgh, 3347 Forbes Avenue, Suite 220, Pittsburgh, PA 15213, USA
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31
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Ginsenoside Rg3 attenuates sepsis-induced injury and mitochondrial dysfunction in liver via AMPK-mediated autophagy flux. Biosci Rep 2017; 37:BSR20170934. [PMID: 28779013 PMCID: PMC5577177 DOI: 10.1042/bsr20170934] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 08/04/2017] [Accepted: 08/04/2017] [Indexed: 12/13/2022] Open
Abstract
Sepsis-led mitochondrial dysfunction has become a critical pathophysiological procedure in sepsis. Since ginsenosides have been applied in the treatment of mitochondrial dysfunction, ginsenoside Rg3 was employed to study its effects on the mitochondrial dysfunction induced by sepsis. The apoptosis rate, oxygen consumption rate (OCR), reactive oxygen species (ROS), antioxidant glutathione (GSH) pools, and mitochondrial transmembrane potential (MTP) were determined in LPS-induced sepsis hepatocytes treated with different concentrations of Rg3. Then, the protein expression levels of mitochondrial biogenesis related transcription factors, autophagy-related proteins, and AMP-activated protein kinase (AMPK) signal pathway related proteins were determined by Western blotting in both in vitro and in vivo sepsis models. Rg3 shows functions of promotion of OCR, attenuation of ROS, and maintenance of GSH pools, and its conjugating activity in the in vitro sepsis models. Rg3-treated cells were observed to have a higher MTP value compared with the LPS only induced cells. Moreover, Rg3 treatment can inhibit mitochondrial dysfunction via increasing the protein expression levels of mitochondrial biogenesis related transcription factors. Rg3 treatment has the function of inhibitor of apoptosis of human primary hepatocytes, and Rg3 can up-regulate the autophagy-related proteins and activate AMPK signal pathway in sepsis models. Meanwhile, the mitochondrial protective function exerted by Rg3 decreased after the autophagy inhibitors or AMPK inhibitor treatment in LPS-induced human primary hepatocytes. Rg3 can improve mitochondrial dysfunction by regulating autophagy in mitochondria via activating the AMPK signal pathway, thus protecting cell and organ injuries caused by sepsis.
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32
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Abstract
Bile acids are synthesized in the liver and are the major component in bile. Impaired bile flow leads to cholestasis that is characterized by elevated levels of bile acid in the liver and serum, followed by hepatocyte and biliary injury. Although the causes of cholestasis have been extensively studied, the molecular mechanisms as to how bile acids initiate liver injury remain controversial. In this chapter, we summarize recent advances in the pathogenesis of bile acid induced liver injury. These include bile acid signaling pathways in hepatocytes as well as the response of cholangiocytes and innate immune cells in the liver in both patients with cholestasis and cholestatic animal models. We focus on how bile acids trigger the production of molecular mediators of neutrophil recruitment and the role of the inflammatory response in this pathological process. These advances point to a number of novel targets where drugs might be judged to be effective therapies for cholestatic liver injury.
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Affiliation(s)
- Man Li
- The Liver Center, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Shi-Ying Cai
- The Liver Center, Yale University School of Medicine, New Haven, CT 06510, USA
| | - James L Boyer
- The Liver Center, Yale University School of Medicine, New Haven, CT 06510, USA.
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33
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Li M, Cai SY, Boyer JL. Mechanisms of bile acid mediated inflammation in the liver. Mol Aspects Med 2017; 56:45-53. [PMID: 28606651 DOI: 10.1016/j.mam.2017.06.001] [Citation(s) in RCA: 147] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 05/26/2017] [Accepted: 06/07/2017] [Indexed: 02/07/2023]
Abstract
Bile acids are synthesized in the liver and are the major component in bile. Impaired bile flow leads to cholestasis that is characterized by elevated levels of bile acid in the liver and serum, followed by hepatocyte and biliary injury. Although the causes of cholestasis have been extensively studied, the molecular mechanisms as to how bile acids initiate liver injury remain controversial. In this chapter, we summarize recent advances in the pathogenesis of bile acid induced liver injury. These include bile acid signaling pathways in hepatocytes as well as the response of cholangiocytes and innate immune cells in the liver in both patients with cholestasis and cholestatic animal models. We focus on how bile acids trigger the production of molecular mediators of neutrophil recruitment and the role of the inflammatory response in this pathological process. These advances point to a number of novel targets where drugs might be judged to be effective therapies for cholestatic liver injury.
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Affiliation(s)
- Man Li
- The Liver Center, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Shi-Ying Cai
- The Liver Center, Yale University School of Medicine, New Haven, CT 06510, USA
| | - James L Boyer
- The Liver Center, Yale University School of Medicine, New Haven, CT 06510, USA.
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34
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Tohme S, Yazdani HO, Liu Y, Loughran P, van der Windt DJ, Huang H, Simmons RL, Shiva S, Tai S, Tsung A. Hypoxia mediates mitochondrial biogenesis in hepatocellular carcinoma to promote tumor growth through HMGB1 and TLR9 interaction. Hepatology 2017; 66:182-197. [PMID: 28370295 PMCID: PMC5481489 DOI: 10.1002/hep.29184] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 02/26/2017] [Accepted: 03/23/2017] [Indexed: 12/12/2022]
Abstract
UNLABELLED The ability of cancer cells to survive and grow under hypoxic conditions has been known for decades, but the mechanisms remain poorly understood. Under certain conditions, cancer cells undergo changes in their bioenergetic profile to favor mitochondrial respiration by activating the peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α) and up-regulating mitochondrial biogenesis. In this study, we hypothesized that augmented mitochondrial biogenesis plays a critical role for cancer cells to survive hypoxia. Consistent with this hypothesis, both hypoxic human hepatocellular carcinoma (HCC) tumors and HCC cell lines subjected to hypoxia increase mitochondrial biogenesis. Silencing of PGC-1α in hypoxic HCC cell lines halts their proliferation. Mechanistic investigations in vitro indicated that intracellular high mobility group box 1 (HMGB1) protein, a nuclear protein overexpressed in HCC, is essential for the process. Silencing of HMGB1 in hypoxic HCC cell lines resulted in a significant decrease in PGC-1α activation and mitochondrial biogenesis. Without HMGB1, hypoxic HCC cells had significantly reduced adenosine triphosphate production, decreased cellular proliferation, and increased apoptosis. In a diethylnitrosamine-induced murine model of HCC, genetic blocking of HMGB1 in hypoxic tumors resulted in a significant decrease in tumor growth. Tumors lacking HMGB1 had a significant reduction in mitochondrial biogenesis and a significant increase in mitochondrial dysfunction. Further in vitro mechanistic experiments indicated that during hypoxia HMGB1 translocates from the nucleus to the cytoplasm and binds to cytoplasmic Toll-like receptor-9. This binding leads to activation of p38 and subsequent phosphorylation of PGC-1α, with resultant up-regulation of mitochondrial biogenesis. CONCLUSION Taken together, our findings suggest that during hypoxia HMGB1 up-regulates mitochondrial biogenesis in HCC cancer cells, promoting tumor survival and proliferation. (Hepatology 2017;66:182-197).
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Affiliation(s)
- Samer Tohme
- Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA
| | - Hamza O Yazdani
- Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA
| | - Yao Liu
- Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA
| | - Patricia Loughran
- Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA,Center for Biologic Imaging, Department of Cell Biology, University of Pittsburgh Medical Center, Pittsburgh, PA
| | | | - Hai Huang
- Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA
| | - Richard L Simmons
- Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA
| | - Sruti Shiva
- Department of Pharmacology and Chemical Biology, Vascular Medicine Institute, Center for Metabolism and Mitochondrial Medicine, University of Pittsburgh, Pittsburgh, PA
| | - Sheng Tai
- Department of General Surgery, the Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang. China
| | - Allan Tsung
- Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA
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35
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Zhang X, Yuan D, Sun Q, Xu L, Lee E, Lewis AJ, Zuckerbraun BS, Rosengart MR. Calcium/calmodulin-dependent protein kinase regulates the PINK1/Parkin and DJ-1 pathways of mitophagy during sepsis. FASEB J 2017; 31:4382-4395. [PMID: 28615325 DOI: 10.1096/fj.201601096rrr] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 06/06/2017] [Indexed: 11/11/2022]
Abstract
During sepsis and shock states, mitochondrial dysfunction occurs. Consequently, adaptive mechanisms, such as fission, fusion, and mitophagy, are induced to eliminate damaged portions or entire dysfunctional mitochondria. The regulatory PINK1/Parkin and DJ-1 pathways are strongly induced by mitochondrial depolarization, although a direct link between loss of mitochondrial membrane potential (ΔΨ) and mitophagy has not been identified. Mitochondria also buffer Ca2+, and their buffering capacity is dependent on ΔΨ Here, we characterize a role for calcium/calmodulin-dependent protein kinase (CaMK) I in the regulation of these mechanisms. Loss of ΔΨ with either pharmacologic depolarization or LPS leads to Ca2+-dependent mitochondrial recruitment and activation of CaMKI that precedes the colocalization of PINK1/Parkin and DJ-1. CaMKI is required and serves as both a PINK1 and Parkin kinase. The mechanisms operate in both immune and nonimmune cells and are induced in in vivo models of endotoxemia, sepsis, and hemorrhagic shock. These data support the idea that CaMKI links mitochondrial stress with the PINK1/Parkin and DJ-1 mechanisms of mitophagy.-Zhang, X., Yuan, D., Sun, Q., Xu, L., Lee, E., Lewis, A. J., Zuckerbraun, B. S., Rosengart, M. R. Calcium/calmodulin-dependent protein kinase regulates the PINK1/Parkin and DJ-1 pathways of mitophagy during sepsis.
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Affiliation(s)
- Xianghong Zhang
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Du Yuan
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.,Department of Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Qian Sun
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Li Xu
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.,Department of Emergency Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Emma Lee
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Anthony J Lewis
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Brian S Zuckerbraun
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Matthew R Rosengart
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA;
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36
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Chung KW, Kim KM, Choi YJ, An HJ, Lee B, Kim DH, Lee EK, Im E, Lee J, Im DS, Yu BP, Chung HY. The critical role played by endotoxin-induced liver autophagy in the maintenance of lipid metabolism during sepsis. Autophagy 2017; 13:1113-1129. [PMID: 28575583 DOI: 10.1080/15548627.2017.1319040] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Macroautophagy/autophagy is a central mechanism by which cells maintain integrity and homeostasis, and endotoxin-induced autophagy plays important roles in innate immunity. Although TLR4 stimulation mediated by lipopolysaccharide (LPS) also upregulates autophagy in hepatocytes and liver, its physiological role remains elusive. The objective of this study was to determine the role of LPS-induced autophagy in the regulation of liver lipid metabolism. LPS treatment (5 mg/kg) increased autophagy, as detected by LC3 conversion and transmission electron microscopy (TEM) analysis in C57BL6 mouse livers. AC2F hepatocytes also showed increased autophagic flux after LPS treatment (1 μg/ml). To investigate the role of LPS-induced autophagy further, liver lipid metabolism changes in LPS-treated mice and fasted controls were compared. Interestingly, LPS-treated mice showed less lipid accumulation in liver than fasted mice despite increased fatty acid uptake and lipid synthesis-associated genes. In vitro analysis using AC2F hepatocytes demonstrated LPS-induced autophagy influenced the degradation of lipid droplets. Inhibition of LPS-induced autophagy using bafilomycin A1 or Atg7 knockdown significantly increased lipid accumulation in AC2F hepatocytes. In addition, pretreatment with chloroquine aggravated LPS-induced lipid accumulation and inflammation in C57BL6 mouse livers. The physiological importance of autophagy was verified in LPS-treated young and aged rats. Autophagic response was diminished in LPS-treated aged rats and lipid metabolism was impaired during sepsis, indicating autophagy response is important for regulating lipid metabolism after endotoxin challenge. Our findings demonstrate endotoxin-induced autophagy is important for the regulation of lipid metabolism, and suggest that autophagy helps maintain lipid metabolism homeostasis during sepsis.
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Affiliation(s)
- Ki Wung Chung
- a Molecular Inflammation Research Center for Aging Intervention (MRCA) , College of Pharmacy, Pusan National University , Busan , South Korea
| | - Kyung Mok Kim
- a Molecular Inflammation Research Center for Aging Intervention (MRCA) , College of Pharmacy, Pusan National University , Busan , South Korea
| | - Yeon Ja Choi
- a Molecular Inflammation Research Center for Aging Intervention (MRCA) , College of Pharmacy, Pusan National University , Busan , South Korea
| | - Hye Jin An
- a Molecular Inflammation Research Center for Aging Intervention (MRCA) , College of Pharmacy, Pusan National University , Busan , South Korea
| | - Bonggi Lee
- a Molecular Inflammation Research Center for Aging Intervention (MRCA) , College of Pharmacy, Pusan National University , Busan , South Korea.,b Korean Medicine (KM)-Application Center , Korea Institute of Oriental Medicine (KIOM) , Daegu , South Korea
| | - Dae Hyun Kim
- a Molecular Inflammation Research Center for Aging Intervention (MRCA) , College of Pharmacy, Pusan National University , Busan , South Korea
| | - Eun Kyeong Lee
- a Molecular Inflammation Research Center for Aging Intervention (MRCA) , College of Pharmacy, Pusan National University , Busan , South Korea
| | - Eunok Im
- a Molecular Inflammation Research Center for Aging Intervention (MRCA) , College of Pharmacy, Pusan National University , Busan , South Korea
| | - Jaewon Lee
- a Molecular Inflammation Research Center for Aging Intervention (MRCA) , College of Pharmacy, Pusan National University , Busan , South Korea
| | - Dong Soon Im
- a Molecular Inflammation Research Center for Aging Intervention (MRCA) , College of Pharmacy, Pusan National University , Busan , South Korea
| | - Byung Pal Yu
- c Department of Physiology , University of Texas Health Science Center at San Antonio , San Antonio , TX , USA
| | - Hae Young Chung
- a Molecular Inflammation Research Center for Aging Intervention (MRCA) , College of Pharmacy, Pusan National University , Busan , South Korea
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Cai SY, Ouyang X, Chen Y, Soroka CJ, Wang J, Mennone A, Wang Y, Mehal WZ, Jain D, Boyer JL. Bile acids initiate cholestatic liver injury by triggering a hepatocyte-specific inflammatory response. JCI Insight 2017; 2:e90780. [PMID: 28289714 DOI: 10.1172/jci.insight.90780] [Citation(s) in RCA: 167] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Mechanisms of bile acid-induced (BA-induced) liver injury in cholestasis are controversial, limiting development of new therapies. We examined how BAs initiate liver injury using isolated liver cells from humans and mice and in-vivo mouse models. At pathophysiologic concentrations, BAs induced proinflammatory cytokine expression in mouse and human hepatocytes, but not in nonparenchymal cells or cholangiocytes. These hepatocyte-specific cytokines stimulated neutrophil chemotaxis. Inflammatory injury was mitigated in Ccl2-/- mice treated with BA or after bile duct ligation, where less hepatic infiltration of neutrophils was detected. Neutrophils in periportal areas of livers from cholestatic patients also correlated with elevations in their serum aminotransferases. This liver-specific inflammatory response required BA entry into hepatocytes via basolateral transporter Ntcp. Pathophysiologic levels of BAs induced markers of ER stress and mitochondrial damage in mouse hepatocytes. Chemokine induction by BAs was reduced in hepatocytes from Tlr9-/- mice, while liver injury was diminished both in conventional and hepatocyte-specific Tlr9-/- mice, confirming a role for Tlr9 in BA-induced liver injury. These findings reveal potentially novel mechanisms whereby BAs elicit a hepatocyte-specific cytokine-induced inflammatory liver injury that involves innate immunity and point to likely novel pathways for treating cholestatic liver disease.
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Affiliation(s)
- Shi-Ying Cai
- Department of Internal Medicine and Yale Liver Center, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Xinshou Ouyang
- Department of Internal Medicine and Yale Liver Center, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Yonglin Chen
- Department of Internal Medicine and Yale Liver Center, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Carol J Soroka
- Department of Internal Medicine and Yale Liver Center, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Juxian Wang
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Albert Mennone
- Department of Internal Medicine and Yale Liver Center, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Yucheng Wang
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Wajahat Z Mehal
- Department of Internal Medicine and Yale Liver Center, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Dhanpat Jain
- Department of Internal Medicine and Yale Liver Center, Yale University School of Medicine, New Haven, Connecticut, USA
| | - James L Boyer
- Department of Internal Medicine and Yale Liver Center, Yale University School of Medicine, New Haven, Connecticut, USA
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El-Tanbouly GS, El-Awady MS, Megahed NA, Salem HA, El-Kashef HA. The NF-κB inhibitor celastrol attenuates acute hepatic dysfunction induced by cecal ligation and puncture in rats. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2017; 50:175-182. [PMID: 28189063 DOI: 10.1016/j.etap.2017.02.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 01/12/2017] [Accepted: 02/03/2017] [Indexed: 06/06/2023]
Abstract
Acute hepatic dysfunction associating sepsis is mediated mainly by toll-like receptor-4 (TLR-4)/nuclear factor kappa-B (NF-κB) inflammatory pathway. This study explores potential hepatoprotective effect of the NF-κB inhibitor celastrol in cecal ligation and puncture (CLP) model in rats. Protective effect of celastrol (1mg/kg, i.p., 1h before CLP) was illustrated after 24h by preventing CLP-induced hepatic histopathological changes and elevation in serum hepatic biomarkers [alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TB) and gamma aminotransferase (γ-GT)] without affecting mortality. Celastrol anti-inflammatory effect was illustrated by inhibiting increased serum and hepatic mRNA expression of interleukin-6 (IL-6) without affecting IL-10 elevation. Furthermore, celastrol inhibited CLP-induced elevations in hepatic mRNA expression of nuclear factor inhibitory protein kappa-B alpha (NFκBia), TLR-4, 5-lipoxygenase (5-LOX) and prevented NF-κB/p65 nuclear translocation and activation. In conclusion, celastrol prevented CLP-induced acute hepatic dysfunction through its anti-inflammatory effect by attenuating NF-κB activation, TLR-4 and 5-LOX expression with subsequent reduction in pro-inflammatory IL-6.
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Affiliation(s)
- Ghada S El-Tanbouly
- Department of Pharmacology and Biochemistry, Faculty of Pharmacy, Delta University for science and technology, Gamasa, Egypt
| | - Mohammed S El-Awady
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt.
| | - Nermeen A Megahed
- Department of Pathology, Faculty of Medicine, Mansoura University, Mansoura, Egypt
| | - Hatem A Salem
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt
| | - Hassan A El-Kashef
- Department of Pharmacology and Biochemistry, Faculty of Pharmacy, Delta University for science and technology, Gamasa, Egypt; Department of Pharmacology and Toxicology, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt
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Abstract
The host defence against infection is an adaptive response in which several mechanisms are deployed to decrease the pathogen load, limit tissue injury and restore homeostasis. In the past few years new evidence has suggested that the ability of the immune system to limit the microbial burden - termed resistance - might not be the only defence mechanism. In fact, the capacity of the host to decrease its own susceptibility to inflammation- induced tissue damage - termed tolerance - might be as important as resistance in determining the outcome of the infection. Metabolic adaptations are central to the function of the cellular immune response. Coordinated reprogramming of metabolic signalling enables cells to execute resistance and tolerance pathways, withstand injury, steer tissue repair and promote organ recovery. During sepsis-induced acute kidney injury, early reprogramming of metabolism can determine the extent of organ dysfunction, progression to fibrosis, and the development of chronic kidney disease. Here we discuss the mechanisms of tolerance that act in the kidney during sepsis, with particular attention to the role of metabolic responses in coordinating these adaptive strategies. We suggest a novel conceptual model of the cellular and organic response to sepsis that might lead to new avenues for targeted, organ-protective therapies.
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Lee SB, Kang JW, Kim SJ, Ahn J, Kim J, Lee SM. Afzelin ameliorates D-galactosamine and lipopolysaccharide-induced fulminant hepatic failure by modulating mitochondrial quality control and dynamics. Br J Pharmacol 2016; 174:195-209. [PMID: 27861739 DOI: 10.1111/bph.13669] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Revised: 11/01/2016] [Accepted: 11/08/2016] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND AND PURPOSE Fulminant hepatic failure (FHF) is a fatal clinical syndrome that results in excessive inflammation and hepatocyte death. Mitochondrial dysfunction is considered to be a possible mechanism of FHF. Afzelin, a flavonol glycoside found in Houttuynia cordata Thunberg, has anti-inflammatory and antioxidant properties. The present study elucidated the cytoprotective mechanisms of afzelin against D-galactosamine (GalN)/LPS induced FHF, particularly focusing on mitochondrial quality control and dynamics. EXPERIMENTAL APPROACH Mice were administered afzelin i.p. 1 h before receiving GalN (800 mg·kg-1 )/LPS (40 μg·kg-1 ), and they were then killed 5 h after GalN/LPS treatment. KEY RESULTS Afzelin improved the survival rate and reduced the serum levels of alanine aminotransferase and pro-inflammatory cytokines in GalN/LPS-treated mice. Afzelin attenuated the mitochondrial damage, as indicated by diminished mitochondrial swelling and mitochondrial glutamate dehydrogenase activity in GalN/LPS-treated mice. Afzelin enhanced mitochondrial biogenesis, as indicated by increased levels of PPAR-γ coactivator 1α, nuclear respiratory factor 1 and mitochondrial transcription factor A. Afzelin also decreased the level of mitophagy-related proteins, parkin and PTEN-induced putative kinase 1. Furthermore, while GalN/LPS significantly increased the level of fission-related protein, dynamin-related protein 1, and decreased the level of fusion-related protein, mitofusin 2; these effects were attenuated by afzelin. CONCLUSIONS AND IMPLICATIONS Our findings demonstrated that afzelin protects against GalN/LPS-induced liver injury by enhancing mitochondrial biogenesis, suppressing excessive mitophagy and balancing mitochondrial dynamics.
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Affiliation(s)
- Sang-Bin Lee
- School of Pharmacy, Sungkyunkwan University, Suwon, South Korea
| | - Jung-Woo Kang
- School of Pharmacy, Sungkyunkwan University, Suwon, South Korea
| | - So-Jin Kim
- School of Pharmacy, Sungkyunkwan University, Suwon, South Korea
| | - Jongmin Ahn
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, South Korea
| | - Jinwoong Kim
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, South Korea
| | - Sun-Mee Lee
- School of Pharmacy, Sungkyunkwan University, Suwon, South Korea
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Lim JS, Kim HS, Nguyen KCT, Cho KA. The role of TLR9 in stress-dependent autophagy formation. Biochem Biophys Res Commun 2016; 481:219-226. [PMID: 27793667 DOI: 10.1016/j.bbrc.2016.10.105] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 10/25/2016] [Indexed: 02/05/2023]
Abstract
Autophagy is a self-degradation process that is important for balancing energy sources at critical times in development and in response to nutrient stress. Recently, it was report that autophagy is controlled by recognizing conserved pattern recognition receptors (PRRs), including toll-like receptors (TLRs). However, the molecular mechanism of TLRs in autophagy is not well understood. In this study, we found that serum starvation-dependent autophagy was associated with TLR9 activation in the absence of CpG-ODN, which is a specific TLR9 ligand. TLR9 was not only elevated but also colocalized with LC3 during autophagy by serum starvation or CPG-ODN treatment; however, these events did not occur simultaneously during autophagosome accumulation. Autophagy was even induced upon TLR9 activation after inhibiting recruitment of initial autophagy components by 3-MA, a specific inhibitor of class III PI3-kinase. Our data suggested that TLR9 may be promptly induced and recruit autophagy components from the endosome to autophagosome in response to stress.
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Affiliation(s)
- Jae Sung Lim
- Department of Biochemistry, Chonnam National University Medical School, Gwangju 501-746, South Korea; Center for Creative Biomedical Scientists, Chonnam National University Medical School, Gwangju 501-746, South Korea
| | - Hyeon Sik Kim
- Department of Nuclear Medicine, Chonnam National University Hwasun Hospital, 160 Ilsim-Ri, Hwasun-gun, Jeonnam 519-809, South Korea
| | - Kim Cuc Thi Nguyen
- Department of Biochemistry, Chonnam National University Medical School, Gwangju 501-746, South Korea; Center for Creative Biomedical Scientists, Chonnam National University Medical School, Gwangju 501-746, South Korea
| | - Kyung A Cho
- Department of Biochemistry, Chonnam National University Medical School, Gwangju 501-746, South Korea; Center for Creative Biomedical Scientists, Chonnam National University Medical School, Gwangju 501-746, South Korea; Research Institute of Medical Sciences, Chonnam National University Medical School, Gwangju 501-746, South Korea.
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Autophagosome-lysosome fusion triggers a lysosomal response mediated by TLR9 and controlled by OCRL. Nat Cell Biol 2016; 18:839-850. [PMID: 27398910 PMCID: PMC5040511 DOI: 10.1038/ncb3386] [Citation(s) in RCA: 122] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2015] [Accepted: 06/09/2016] [Indexed: 12/14/2022]
Abstract
Phosphoinositides (PtdIns) control fundamental cell processes, and inherited defects of PtdIns kinases or phosphatases cause severe human diseases, including Lowe syndrome due to mutations in OCRL, which encodes a PtdIns(4,5)P2 5-phosphatase. Here we unveil a lysosomal response to the arrival of autophagosomal cargo in which OCRL plays a key part. We identify mitochondrial DNA and TLR9 as the cargo and the receptor that triggers and mediates, respectively, this response. This lysosome-cargo response is required to sustain the autophagic flux and involves a local increase in PtdIns(4,5)P2 that is confined in space and time by OCRL. Depleting or inhibiting OCRL leads to an accumulation of lysosomal PtdIns(4,5)P2, an inhibitor of the calcium channel mucolipin-1 that controls autophagosome-lysosome fusion. Hence, autophagosomes accumulate in OCRL-depleted cells and in the kidneys of Lowe syndrome patients. Importantly, boosting the activity of mucolipin-1 with selective agonists restores the autophagic flux in cells from Lowe syndrome patients.
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Sinha RA, Singh BK, Zhou J, Wu Y, Farah BL, Ohba K, Lesmana R, Gooding J, Bay BH, Yen PM. Thyroid hormone induction of mitochondrial activity is coupled to mitophagy via ROS-AMPK-ULK1 signaling. Autophagy 2016; 11:1341-57. [PMID: 26103054 DOI: 10.1080/15548627.2015.1061849] [Citation(s) in RCA: 132] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Currently, there is limited understanding about hormonal regulation of mitochondrial turnover. Thyroid hormone (T3) increases oxidative phosphorylation (OXPHOS), which generates reactive oxygen species (ROS) that damage mitochondria. However, the mechanism for maintenance of mitochondrial activity and quality control by this hormone is not known. Here, we used both in vitro and in vivo hepatic cell models to demonstrate that induction of mitophagy by T3 is coupled to oxidative phosphorylation and ROS production. We show that T3 induction of ROS activates CAMKK2 (calcium/calmodulin-dependent protein kinase kinase 2, β) mediated phosphorylation of PRKAA1/AMPK (5' AMP-activated protein kinase), which in turn phosphorylates ULK1 (unc-51 like autophagy activating kinase 1) leading to its mitochondrial recruitment and initiation of mitophagy. Furthermore, loss of ULK1 in T3-treated cells impairs both mitophagy as well as OXPHOS without affecting T3 induced general autophagy/lipophagy. These findings demonstrate a novel ROS-AMPK-ULK1 mechanism that couples T3-induced mitochondrial turnover with activity, wherein mitophagy is necessary not only for removing damaged mitochondria but also for sustaining efficient OXPHOS.
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Affiliation(s)
- Rohit A Sinha
- a Program of Cardiovascular and Metabolic Disorders; Duke-NUS Graduate Medical School ; Singapore
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44
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Ho J, Yu J, Wong SH, Zhang L, Liu X, Wong WT, Leung CCH, Choi G, Wang MHT, Gin T, Chan MTV, Wu WKK. Autophagy in sepsis: Degradation into exhaustion? Autophagy 2016; 12:1073-82. [PMID: 27172163 DOI: 10.1080/15548627.2016.1179410] [Citation(s) in RCA: 105] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Autophagy is one of the innate immune defense mechanisms against microbial challenges. Previous in vitro and in vivo models of sepsis demonstrated that autophagy was activated initially in sepsis, followed by a subsequent phase of impairment. Autophagy modulation appears to be protective against multiple organ injuries in these murine sepsis models. This is achieved in part by preventing apoptosis, maintaining a balance between the productions of pro- and anti-inflammatory cytokines, and preserving mitochondrial functions. This article aims to discuss the role of autophagy in sepsis and the therapeutic potential of autophagy enhancers.
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Affiliation(s)
- Jeffery Ho
- a Department of Anesthesia and Intensive Care , The Chinese University of Hong Kong, Hong Kong Special Administrative Region , China
| | - Jun Yu
- b State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Sciences and Department of Medicine and Therapeutics , The Chinese University of Hong Kong, Hong Kong Special Administrative Region , China
| | - Sunny H Wong
- b State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Sciences and Department of Medicine and Therapeutics , The Chinese University of Hong Kong, Hong Kong Special Administrative Region , China
| | - Lin Zhang
- c School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region , China
| | - Xiaodong Liu
- a Department of Anesthesia and Intensive Care , The Chinese University of Hong Kong, Hong Kong Special Administrative Region , China
| | - Wai T Wong
- a Department of Anesthesia and Intensive Care , The Chinese University of Hong Kong, Hong Kong Special Administrative Region , China
| | - Czarina C H Leung
- a Department of Anesthesia and Intensive Care , The Chinese University of Hong Kong, Hong Kong Special Administrative Region , China
| | - Gordon Choi
- a Department of Anesthesia and Intensive Care , The Chinese University of Hong Kong, Hong Kong Special Administrative Region , China
| | - Maggie H T Wang
- d The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong Special Administrative Region , China
| | - Tony Gin
- a Department of Anesthesia and Intensive Care , The Chinese University of Hong Kong, Hong Kong Special Administrative Region , China
| | - Matthew T V Chan
- a Department of Anesthesia and Intensive Care , The Chinese University of Hong Kong, Hong Kong Special Administrative Region , China
| | - William K K Wu
- a Department of Anesthesia and Intensive Care , The Chinese University of Hong Kong, Hong Kong Special Administrative Region , China.,b State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Sciences and Department of Medicine and Therapeutics , The Chinese University of Hong Kong, Hong Kong Special Administrative Region , China
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45
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Lewis AJ, Billiar TR, Rosengart MR. Biology and Metabolism of Sepsis: Innate Immunity, Bioenergetics, and Autophagy. Surg Infect (Larchmt) 2016; 17:286-93. [PMID: 27093228 DOI: 10.1089/sur.2015.262] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Sepsis is a complex, heterogeneous physiologic condition that represents a significant public health concern. While many insights into the pathophysiology of sepsis have been elucidated over the past decades of research, important questions remain. This article serves as a review of several important areas in sepsis research. Understanding the innate immune response has been at the forefront as of late, especially in the context of cytokine-directed therapeutic trials. Cellular bioenergetic changes provide insight into the development of organ dysfunction in sepsis. Autophagy and mitophagy perform crucial cell housekeeping and stress response functions. Finally, age-related changes and their potential impact on the septic response are reviewed.
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Affiliation(s)
- Anthony J Lewis
- Department of Surgery, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Timothy R Billiar
- Department of Surgery, University of Pittsburgh , Pittsburgh, Pennsylvania
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46
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Arulkumaran N, Deutschman CS, Pinsky MR, Zuckerbraun B, Schumacker PT, Gomez H, Gomez A, Murray P, Kellum JA. MITOCHONDRIAL FUNCTION IN SEPSIS. Shock 2016; 45:271-81. [PMID: 26871665 PMCID: PMC4755359 DOI: 10.1097/shk.0000000000000463] [Citation(s) in RCA: 128] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Mitochondria are an essential part of the cellular infrastructure, being the primary site for high-energy adenosine triphosphate production through oxidative phosphorylation. Clearly, in severe systemic inflammatory states, like sepsis, cellular metabolism is usually altered, and end organ dysfunction is not only common, but also predictive of long-term morbidity and mortality. Clearly, interest is mitochondrial function both as a target for intracellular injury and response to extrinsic stress have been a major focus of basic science and clinical research into the pathophysiology of acute illness. However, mitochondria have multiple metabolic and signaling functions that may be central in both the expression of sepsis and its ultimate outcome. In this review, the authors address five primary questions centered on the role of mitochondria in sepsis. This review should be used both as a summary source in placing mitochondrial physiology within the context of acute illness and as a focal point for addressing new research into diagnostic and treatment opportunities these insights provide.
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Affiliation(s)
| | - Clifford S. Deutschman
- Department of Pediatrics and Molecular Medicine, Hofstra-North Shore-Long Island Jewish School of Medicine
| | - Michael R. Pinsky
- Department of Critical Care Medicine, University of Pittsburgh School of Medicine
| | | | - Paul T. Schumacker
- Departments of Pediatrics-Neonatology, Cell and Molecular Biology and Medicine, Northwestern University Feinberg School of Medicine
| | - Hernando Gomez
- Department of Critical Care Medicine, University of Pittsburgh School of Medicine
- Center for Critical Care Nephrology, University of Pittsburgh, Pittsburgh PA
| | - Alonso Gomez
- Academia Colombiana de Medicina Critica (ACOMEC)
- Division of Critical Care Medicine, Clínica Palermo, Bogotá, Colombia
| | | | - John A. Kellum
- Department of Critical Care Medicine, University of Pittsburgh School of Medicine
- Center for Critical Care Nephrology, University of Pittsburgh, Pittsburgh PA
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47
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Rasid O, Cavaillon JM. Recent developments in severe sepsis research: from bench to bedside and back. Future Microbiol 2016; 11:293-314. [PMID: 26849633 DOI: 10.2217/fmb.15.133] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Severe sepsis remains a worldwide threat, not only in industrialized countries, due to their aging population, but also in developing countries where there still are numerous cases of neonatal and puerperal sepsis. Tools for early diagnosis, a prerequisite for rapid and appropriate antibiotic therapy, are still required. In this review, we highlight some recent developments in our understanding of the associated systemic inflammatory response that help deciphering pathophysiology (e.g., epigenetic, miRNA, regulatory loops, compartmentalization, apoptosis and synergy) and discuss some of the consequences of sepsis (e.g., immune status, neurological and muscular alterations). We also emphasize the challenge to better define animal models and discuss past failures in clinical investigations in order to define new efficient therapies.
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Affiliation(s)
- Orhan Rasid
- Unit Cytokines & Inflammation, Institut Pasteur, 28 rue Dr. Roux, Paris, France
| | - Jean-Marc Cavaillon
- Unit Cytokines & Inflammation, Institut Pasteur, 28 rue Dr. Roux, Paris, France
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48
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Kang JW, Kim SJ, Cho HI, Lee SM. DAMPs activating innate immune responses in sepsis. Ageing Res Rev 2015; 24:54-65. [PMID: 25816752 DOI: 10.1016/j.arr.2015.03.003] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 03/09/2015] [Accepted: 03/13/2015] [Indexed: 12/11/2022]
Abstract
Sepsis refers to the deleterious and non-resolving systemic inflammatory response of the host to microbial infection and is the leading cause of death in intensive care units. The pathogenesis of sepsis is highly complex. It is principally attributable to dysregulation of the innate immune system. Damage-associated molecular patterns (DAMPs) are actively secreted by innate immune cells and/or released passively by injured or damaged cells in response to infection or injury. In the present review, we highlight emerging evidence that supports the notion that extracellular DAMPs act as crucial proinflammatory danger signals. Furthermore, we discuss the potential of a wide array of DAMPs as therapeutic targets in sepsis.
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Affiliation(s)
- Jung-Woo Kang
- School of Pharmacy, Sungkyunkwan University, Seobu-ro 2066, Jangan-gu, Suwon, Gyeonggi-do, 440-746 South Korea
| | - So-Jin Kim
- School of Pharmacy, Sungkyunkwan University, Seobu-ro 2066, Jangan-gu, Suwon, Gyeonggi-do, 440-746 South Korea
| | - Hong-Ik Cho
- School of Pharmacy, Sungkyunkwan University, Seobu-ro 2066, Jangan-gu, Suwon, Gyeonggi-do, 440-746 South Korea
| | - Sun-Mee Lee
- School of Pharmacy, Sungkyunkwan University, Seobu-ro 2066, Jangan-gu, Suwon, Gyeonggi-do, 440-746 South Korea.
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49
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Sarkaki A, Farbood Y, Badavi M, Khalaj L, Khodagholi F, Ashabi G. Metformin improves anxiety-like behaviors through AMPK-dependent regulation of autophagy following transient forebrain ischemia. Metab Brain Dis 2015; 30:1139-50. [PMID: 25936719 DOI: 10.1007/s11011-015-9677-x] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2015] [Accepted: 04/23/2015] [Indexed: 12/18/2022]
Abstract
Stroke is one of the main threats to the public health worldwide. Metformin, an anti-diabetic drug, is an activator of AMP-activated protein kinase (AMPK). Metformin plays an important role on improving behavior in neurodegenerative diseases through diverse pathways. In the current study we aimed to investigate the probable effects of metformin on anxiety and autophagy pathway in global cerebral ischemia. Rats were divided into seven groups; Sham, ischemia (I/R), metformin (met), compound c (CC), CC+ischemia, met+ischemia, met+CC+ischemia. Metformin was pretreated for 2 weeks and CC administrated half an hour before global cerebral ischemia. Blood glucose, body weight, sensorimotor scores, elevated plus maze and open field test were evaluated after ischemia. Autophagy related factors were measured by Western blot and immunofluorescent assay in hippocampus of rats. Based on our results, pretreatment of rats by metformin improved sensory motor signs, anxiolytic behavior and locomotion in ischemic rats. CC injection in I/R rats attenuated the therapeutic effects of metformin. Autophagy factors such as light chain 3B, Atg7, Atg5-12 and beclin-1 decreased in ischemic rats compared to the sham group (P < 0.001 in all proteins). Level of autophagic factors increased in metformin pretreated rats compared to global cerebral ischemia (P < 0.001 in all proteins). These data indicated that the beneficial role of metformin in behavior and autophagy flux mediates via AMPK. Our results recommended that metformin therapy could improve psychological disorders and movement disability following I/R and profound understanding of AMPK-dependent autophagy would enhance its development as a promising target for intracellular pathway.
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Affiliation(s)
- Alireza Sarkaki
- Department of Physiology, Faculty of Medicine, Jundishapur University of Medical Sciences, P.O.box: 61357-19754, Ahvaz, Iran
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50
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Mitochondrial Mechanisms in Septic Cardiomyopathy. Int J Mol Sci 2015; 16:17763-78. [PMID: 26247933 PMCID: PMC4581220 DOI: 10.3390/ijms160817763] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Revised: 07/01/2015] [Accepted: 07/23/2015] [Indexed: 12/31/2022] Open
Abstract
Sepsis is the manifestation of the immune and inflammatory response to infection that may ultimately result in multi organ failure. Despite the therapeutic strategies that have been used up to now, sepsis and septic shock remain a leading cause of death in critically ill patients. Myocardial dysfunction is a well-described complication of severe sepsis, also referred to as septic cardiomyopathy, which may progress to right and left ventricular pump failure. Many substances and mechanisms seem to be involved in myocardial dysfunction in sepsis, including toxins, cytokines, nitric oxide, complement activation, apoptosis and energy metabolic derangements. Nevertheless, the precise underlying molecular mechanisms as well as their significance in the pathogenesis of septic cardiomyopathy remain incompletely understood. A well-investigated abnormality in septic cardiomyopathy is mitochondrial dysfunction, which likely contributes to cardiac dysfunction by causing myocardial energy depletion. A number of mechanisms have been proposed to cause mitochondrial dysfunction in septic cardiomyopathy, although it remains controversially discussed whether some mechanisms impair mitochondrial function or serve to restore mitochondrial function. The purpose of this review is to discuss mitochondrial mechanisms that may causally contribute to mitochondrial dysfunction and/or may represent adaptive responses to mitochondrial dysfunction in septic cardiomyopathy.
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