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Liu Y, Zhang J. Saturated hydrogen saline ameliorates lipopolysaccharide-induced acute lung injury by reducing excessive autophagy. Exp Ther Med 2017; 13:2609-2615. [PMID: 28596808 PMCID: PMC5460057 DOI: 10.3892/etm.2017.4353] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 02/07/2017] [Indexed: 12/20/2022] Open
Abstract
The pathogenesis of acute lung injury (ALI) induced by lipopolysaccharide (LPS) involves excessive pulmonary inflammation and oxidative stress. In turn, autophagy is associated with inflammatory diseases and organ dysfunction, and studies have demonstrated that LPS treatment may trigger autophagy. Thus, excessive autophagy may stimulate the strong inflammatory response observed in the development of LPS-induced ALI. Saturated hydrogen saline may alleviate LPS-induced ALI by inhibiting autophagy, however its underlying mechanisms of action remain unknown. It has been suggested that saturated hydrogen saline may downregulate expression of nuclear factor (NF)-κB, leading to a decrease in Beclin-1 transcription and inhibition of autophagy. Inhibition of autophagy also occurs via the phosphorylation of Unc-51-like autophagy activating kinase 1 and autophagy-related protein-13 by mechanistic target of rapamycin, which in turn may be upregulated by saturated hydrogen saline. In addition, signaling pathways involving heme oxygenase-1 and p38 mitogen-activated protein kinase are associated with the alleviative effects of saturated hydrogen saline on LPS-induced autophagy. The present review focuses on potential molecular mechanisms regarding the effects of saturated hydrogen saline in the reduction of autophagy during LPS-induced ALI.
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Affiliation(s)
- Yiming Liu
- Department of Anesthesiology, Affiliated Shengjing Hospital, China Medical University, Shenyang, Liaoning 110004, P.R. China
| | - Jin Zhang
- Department of Anesthesiology, Affiliated Shengjing Hospital, China Medical University, Shenyang, Liaoning 110004, P.R. China
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102
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Verma N, Manna SK. Advanced glycation end products (AGE) potentiates cell death in p53 negative cells via upregulaion of NF-kappa B and impairment of autophagy. J Cell Physiol 2017; 232:3598-3610. [DOI: 10.1002/jcp.25828] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Accepted: 01/25/2017] [Indexed: 12/28/2022]
Affiliation(s)
- Neeharika Verma
- Laboratory of Immunology; Centre for DNA Fingerprinting and Diagnostics; Hyderabad Telangana India
- Graduate Studies; Manipal University; Manipal Karnataka India
| | - Sunil K. Manna
- Laboratory of Immunology; Centre for DNA Fingerprinting and Diagnostics; Hyderabad Telangana India
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103
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TNF-α stimulates endothelial palmitic acid transcytosis and promotes insulin resistance. Sci Rep 2017; 7:44659. [PMID: 28304381 PMCID: PMC5356338 DOI: 10.1038/srep44659] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 02/13/2017] [Indexed: 01/15/2023] Open
Abstract
Persistent elevation of plasma TNF-α is a marker of low grade systemic inflammation. Palmitic acid (PA) is the most abundant type of saturated fatty acid in human body. PA is bound with albumin in plasma and could not pass through endothelial barrier freely. Albumin-bound PA has to be transported across monolayer endothelial cells through intracellular transcytosis, but not intercellular diffusion. In the present study, we discovered that TNF-α might stimulate PA transcytosis across cardiac microvascular endothelial cells, which further impaired the insulin-stimulated glucose uptake by cardiomyocytes and promoted insulin resistance. In this process, TNF-α-stimulated endothelial autophagy and NF-κB signaling crosstalk with each other and orchestrate the whole event, ultimately result in increased expression of fatty acid transporter protein 4 (FATP4) in endothelial cells and mediate the increased PA transcytosis across microvascular endothelial cells. Hopefully the present study discovered a novel missing link between low grade systemic inflammation and insulin resistance.
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104
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Inhibiting ROS-NF-κB-dependent autophagy enhanced brazilin-induced apoptosis in head and neck squamous cell carcinoma. Food Chem Toxicol 2017; 101:55-66. [DOI: 10.1016/j.fct.2017.01.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 12/19/2016] [Accepted: 01/03/2017] [Indexed: 02/07/2023]
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105
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Chinchwadkar S, Padmanabhan S, Mishra P, Singh S, Suresh SN, Vats S, Barve G, Ammanathan V, Manjithaya R. Multifaceted Housekeeping Functions of Autophagy. J Indian Inst Sci 2017. [DOI: 10.1007/s41745-016-0015-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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106
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Inhibiting reactive oxygen species-dependent autophagy enhanced baicalein-induced apoptosis in oral squamous cell carcinoma. J Nat Med 2017; 71:433-441. [PMID: 28176233 DOI: 10.1007/s11418-017-1076-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 01/24/2017] [Indexed: 02/07/2023]
Abstract
Autophagy modulation has been considered a potential therapeutic strategy for oral squamous cell carcinoma (OSCC). A previous study confirmed that baicalein might possess significant anti-carcinogenic activity. However, whether baicalein induces autophagy and its role in cell death in OSCC are still unclear. The aim of this study was to investigate the anticancer activity and molecular targets of baicalein in OSCC in vitro. In this study, we found that baicalein induced significant apoptosis in OSCC cells Cal27. In addition to showing apoptosis induction, we also demonstrated baicalein-induced autophagic response in Cal27 cells. Moreover, pharmacologically or genetically blocking autophagy enhanced baicalein-induced apoptosis, indicating the cytoprotective role of autophagy in baicalein-treated Cal27 cells. Importantly, we found that baicalein triggered reactive oxygen species (ROS) generation in Cal27 cells. Furthermore, N-acetyl-cysteine, a ROS scavenger, abrogated the effects of baicalein on ROS-dependent autophagy. Therefore, we found that baicalein increased autophagy through the promotion of ROS signaling pathways in OSCC. These data also suggest that a strategy of blocking ROS-dependent autophagy to enhance the activity of baicalein warrants further attention for the treatment of OSCC.
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107
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Goldberg AA, Nkengfac B, Sanchez AMJ, Moroz N, Qureshi ST, Koromilas AE, Wang S, Burelle Y, Hussain SN, Kristof AS. Regulation of ULK1 Expression and Autophagy by STAT1. J Biol Chem 2016; 292:1899-1909. [PMID: 28011640 DOI: 10.1074/jbc.m116.771584] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Indexed: 02/02/2023] Open
Abstract
Autophagy involves the lysosomal degradation of cytoplasmic contents for regeneration of anabolic substrates during nutritional or inflammatory stress. Its initiation occurs rapidly after inactivation of the protein kinase mammalian target of rapamycin (mTOR) (or mechanistic target of rapamycin), leading to dephosphorylation of Unc-51-like kinase 1 (ULK1) and autophagosome formation. Recent studies indicate that mTOR can, in parallel, regulate the activity of stress transcription factors, including signal transducer and activator of transcription-1 (STAT1). The current study addresses the role of STAT1 as a transcriptional suppressor of autophagy genes and autophagic activity. We show that STAT1-deficient human fibrosarcoma cells exhibited enhanced autophagic flux as well as its induction by pharmacological inhibition of mTOR. Consistent with enhanced autophagy initiation, ULK1 mRNA and protein levels were increased in STAT1-deficient cells. By chromatin immunoprecipitation, STAT1 bound a putative regulatory sequence in the ULK1 5'-flanking region, the mutation of which increased ULK1 promoter activity, and rendered it unresponsive to mTOR inhibition. Consistent with an anti-apoptotic effect of autophagy, rapamycin-induced apoptosis and cytotoxicity were blocked in STAT1-deficient cells but restored in cells simultaneously exposed to the autophagy inhibitor ammonium chloride. In vivo, skeletal muscle ULK1 mRNA and protein levels as well as autophagic flux were significantly enhanced in STAT1-deficient mice. These results demonstrate a novel mechanism by which STAT1 negatively regulates ULK1 expression and autophagy.
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Affiliation(s)
- Alexander A Goldberg
- From the Departments of Critical Care and Medicine, McGill University Health Centre and Meakins-Christie Laboratories, McGill University, Montreal, Quebec H4A 3J1, Canada
| | - Bernard Nkengfac
- From the Departments of Critical Care and Medicine, McGill University Health Centre and Meakins-Christie Laboratories, McGill University, Montreal, Quebec H4A 3J1, Canada
| | - Anthony M J Sanchez
- From the Departments of Critical Care and Medicine, McGill University Health Centre and Meakins-Christie Laboratories, McGill University, Montreal, Quebec H4A 3J1, Canada
| | - Nikolay Moroz
- From the Departments of Critical Care and Medicine, McGill University Health Centre and Meakins-Christie Laboratories, McGill University, Montreal, Quebec H4A 3J1, Canada
| | - Salman T Qureshi
- From the Departments of Critical Care and Medicine, McGill University Health Centre and Meakins-Christie Laboratories, McGill University, Montreal, Quebec H4A 3J1, Canada
| | - Antonis E Koromilas
- the Lady Davis Institute for Medical Research, McGill University, Sir Mortimer B. Davis-Jewish General Hospital, Montreal, Quebec H3T 1E2, Canada
| | - Shuo Wang
- the Lady Davis Institute for Medical Research, McGill University, Sir Mortimer B. Davis-Jewish General Hospital, Montreal, Quebec H3T 1E2, Canada
| | - Yan Burelle
- Faculty of Pharmacy, Université de Montréal, Montréal, Québec H3T 1J4, Canada
| | - Sabah N Hussain
- From the Departments of Critical Care and Medicine, McGill University Health Centre and Meakins-Christie Laboratories, McGill University, Montreal, Quebec H4A 3J1, Canada
| | - Arnold S Kristof
- From the Departments of Critical Care and Medicine, McGill University Health Centre and Meakins-Christie Laboratories, McGill University, Montreal, Quebec H4A 3J1, Canada.
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108
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Downregulation of ASPP2 improves hepatocellular carcinoma cells survival via promoting BECN1-dependent autophagy initiation. Cell Death Dis 2016; 7:e2512. [PMID: 27929538 PMCID: PMC5260975 DOI: 10.1038/cddis.2016.407] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 10/01/2016] [Accepted: 10/18/2016] [Indexed: 01/01/2023]
Abstract
Autophagy is an important catabolic process, which sustains intracellular homeostasis and lengthens cell survival under stress. Here we identify the ankyrin-repeat-containing, SH3-domain-containing, and proline-rich region-containing protein 2 (ASPP2), a haploinsufficient tumor suppressor, as a molecular regulator of starvation-induced autophagy in hepatocellular carcinoma (HCC). ASPP2 expression is associated with an autophagic response upon nutrient deprivation and downregulation of ASPP2 facilitates autophagic flux, whereas overexpression of ASPP2 blocks this starvation-induced autophagy in HCC cells. Mechanistically, ASPP2 inhibits autophagy through regulating BECN1 transcription and formation of phosphatidylinositol 3-kinase catalytic subunit type 3 (PIK3C3) complex. Firstly, ASPP2 inhibits p65/RelA-induced transcription of BECN1, directly by an ASPP2-p65/RelA-IκBα complex which inhibits phosphorylation of IκBα and the translocation of p65/RelA into the nucleus. Secondly, ASPP2 binds to BECN1, leading to decreased binding of PIK3C3 and UV radiation resistance-associated gene (UVRAG), and increased binding of Rubicon in PIK3C3 complex. Downregulation of ASPP2 enhances the pro-survival and chemoresistant property via autophagy in HCC cells in vitro and in vivo. Decreased ASPP2 expression was associated with increased BECN1 and poor survival in HCC patients. Therefore, ASPP2 is a key regulator of BECN1-dependent autophagy, and decreased ASPP2 may contribute to tumor progression and chemoresistance via promoting autophagy.
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109
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Vlahakis A, Debnath J. The Interconnections between Autophagy and Integrin-Mediated Cell Adhesion. J Mol Biol 2016; 429:515-530. [PMID: 27932295 DOI: 10.1016/j.jmb.2016.11.027] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2016] [Revised: 11/27/2016] [Accepted: 11/29/2016] [Indexed: 12/25/2022]
Abstract
Autophagy is a cellular degradation process integral for promoting cellular adaptation during metabolic stress while also functioning as a cellular homeostatic mechanism. Mounting evidence also demonstrates that autophagy is induced upon loss of integrin-mediated cell attachments to the surrounding extracellular matrix (ECM). Analogous to its established cytoprotective role during nutrient starvation, autophagy protects cells from detachment-induced cell death, termed anoikis. Here, we review the significance of autophagy as an anoikis resistance pathway, focusing on the intracellular signals associated with integrins that modulate the autophagy response and dictate the balance between cell death and survival following loss of cell-matrix contact. In addition, we highlight recent studies demonstrating that autophagy functions in the upstream regulation of integrin-mediated cell adhesion via the control of focal adhesion remodeling, and discuss how these emerging interconnections between integrin-mediated adhesion pathways and autophagy influence cancer progression and metastasis.
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Affiliation(s)
- Ariadne Vlahakis
- Department of Pathology and Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Jayanta Debnath
- Department of Pathology and Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA 94143, USA.
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110
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Eliopoulos AG, Havaki S, Gorgoulis VG. DNA Damage Response and Autophagy: A Meaningful Partnership. Front Genet 2016; 7:204. [PMID: 27917193 PMCID: PMC5116470 DOI: 10.3389/fgene.2016.00204] [Citation(s) in RCA: 124] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 11/02/2016] [Indexed: 01/07/2023] Open
Abstract
Autophagy and the DNA damage response (DDR) are biological processes essential for cellular and organismal homeostasis. Herein, we summarize and discuss emerging evidence linking DDR to autophagy. We highlight published data suggesting that autophagy is activated by DNA damage and is required for several functional outcomes of DDR signaling, including repair of DNA lesions, senescence, cell death, and cytokine secretion. Uncovering the mechanisms by which autophagy and DDR are intertwined provides novel insight into the pathobiology of conditions associated with accumulation of DNA damage, including cancer and aging, and novel concepts for the development of improved therapeutic strategies against these pathologies.
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Affiliation(s)
- Aristides G Eliopoulos
- Molecular and Cellular Biology Laboratory, Division of Basic Sciences, Medical School, University of CreteHeraklion, Greece; Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology HellasHeraklion, Greece
| | - Sophia Havaki
- Molecular Carcinogenesis Group, Department of Histology and Embryology, Medical School, National and Kapodistrian University of Athens Athens, Greece
| | - Vassilis G Gorgoulis
- Molecular Carcinogenesis Group, Department of Histology and Embryology, Medical School, National and Kapodistrian University of AthensAthens, Greece; Faculty Institute of Cancer Sciences, Manchester Academic Health Sciences Centre, University of ManchesterManchester, UK; Biomedical Research Foundation of the Academy of AthensAthens, Greece
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111
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Wei FZ, Cao Z, Wang X, Wang H, Cai MY, Li T, Hattori N, Wang D, Du Y, Song B, Cao LL, Shen C, Wang L, Wang H, Yang Y, Xie D, Wang F, Ushijima T, Zhao Y, Zhu WG. Epigenetic regulation of autophagy by the methyltransferase EZH2 through an MTOR-dependent pathway. Autophagy 2016; 11:2309-22. [PMID: 26735435 DOI: 10.1080/15548627.2015.1117734] [Citation(s) in RCA: 117] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
Macroautophagy is an evolutionarily conserved cellular process involved in the clearance of proteins and organelles. Although the autophagy regulation machinery has been widely studied, the key epigenetic control of autophagy process still remains unknown. Here we report that the methyltransferase EZH2 (enhancer of zeste 2 polycomb repressive complex 2 subunit) epigenetically represses several negative regulators of the MTOR (mechanistic target of rapamycin [serine/threonine kinase]) pathway, such as TSC2, RHOA, DEPTOR, FKBP11, RGS16 and GPI. EZH2 was recruited to these genes promoters via MTA2 (metastasis associated 1 family, member 2), a component of the nucleosome remodeling and histone deacetylase (NuRD) complex. MTA2 was identified as a new chromatin binding protein whose association with chromatin facilitated the subsequent recruitment of EZH2 to silenced targeted genes, especially TSC2. Downregulation of TSC2 (tuberous sclerosis 2) by EZH2 elicited MTOR activation, which in turn modulated subsequent MTOR pathway-related events, including inhibition of autophagy. In human colorectal carcinoma (CRC) tissues, the expression of MTA2 and EZH2 correlated negatively with expression of TSC2, which reveals a novel link among epigenetic regulation, the MTOR pathway, autophagy induction, and tumorigenesis.
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Affiliation(s)
- Fu-Zheng Wei
- a Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education); State Key Laboratory of Natural and Biomimetic Drugs; Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function; Department of Biochemistry and Molecular Biology; Peking University Health Science Center ; Beijing , China
| | - Ziyang Cao
- a Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education); State Key Laboratory of Natural and Biomimetic Drugs; Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function; Department of Biochemistry and Molecular Biology; Peking University Health Science Center ; Beijing , China
| | - Xi Wang
- a Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education); State Key Laboratory of Natural and Biomimetic Drugs; Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function; Department of Biochemistry and Molecular Biology; Peking University Health Science Center ; Beijing , China
| | - Hui Wang
- a Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education); State Key Laboratory of Natural and Biomimetic Drugs; Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function; Department of Biochemistry and Molecular Biology; Peking University Health Science Center ; Beijing , China
| | - Mu-Yan Cai
- b State Key Laboratory of Oncology in South China; Sun Yat-Sen University Cancer Center ; Guangzhou , China
| | - Tingting Li
- c Department of Biomedical Informatics ; School of Basic Medical Sciences; Peking University Health Science Center ; Beijing , China
| | - Naoko Hattori
- d Division of Epigenomics; National Cancer Center Research Institute ; Tokyo , Japan
| | - Donglai Wang
- a Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education); State Key Laboratory of Natural and Biomimetic Drugs; Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function; Department of Biochemistry and Molecular Biology; Peking University Health Science Center ; Beijing , China
| | - Yipeng Du
- a Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education); State Key Laboratory of Natural and Biomimetic Drugs; Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function; Department of Biochemistry and Molecular Biology; Peking University Health Science Center ; Beijing , China
| | - Boyan Song
- a Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education); State Key Laboratory of Natural and Biomimetic Drugs; Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function; Department of Biochemistry and Molecular Biology; Peking University Health Science Center ; Beijing , China
| | - Lin-Lin Cao
- a Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education); State Key Laboratory of Natural and Biomimetic Drugs; Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function; Department of Biochemistry and Molecular Biology; Peking University Health Science Center ; Beijing , China
| | - Changchun Shen
- a Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education); State Key Laboratory of Natural and Biomimetic Drugs; Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function; Department of Biochemistry and Molecular Biology; Peking University Health Science Center ; Beijing , China
| | - Lina Wang
- a Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education); State Key Laboratory of Natural and Biomimetic Drugs; Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function; Department of Biochemistry and Molecular Biology; Peking University Health Science Center ; Beijing , China
| | - Haiying Wang
- a Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education); State Key Laboratory of Natural and Biomimetic Drugs; Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function; Department of Biochemistry and Molecular Biology; Peking University Health Science Center ; Beijing , China
| | - Yang Yang
- a Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education); State Key Laboratory of Natural and Biomimetic Drugs; Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function; Department of Biochemistry and Molecular Biology; Peking University Health Science Center ; Beijing , China
| | - Dan Xie
- b State Key Laboratory of Oncology in South China; Sun Yat-Sen University Cancer Center ; Guangzhou , China
| | - Fan Wang
- e Department of Radiation Medicine; School of Basic Medical Sciences ; Peking University ; Beijing , People's Republic of China
| | - Toshikazu Ushijima
- d Division of Epigenomics; National Cancer Center Research Institute ; Tokyo , Japan
| | - Ying Zhao
- a Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education); State Key Laboratory of Natural and Biomimetic Drugs; Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function; Department of Biochemistry and Molecular Biology; Peking University Health Science Center ; Beijing , China
| | - Wei-Guo Zhu
- a Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education); State Key Laboratory of Natural and Biomimetic Drugs; Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function; Department of Biochemistry and Molecular Biology; Peking University Health Science Center ; Beijing , China.,f Peking University-Tsinghua University Center for Life Sciences ; Beijing , China.,g School of Medicine; Shenzhen University ; Shenzhen , China
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112
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Gao S, Sun D, Wang G, Zhang J, Jiang Y, Li G, Zhang K, Wang L, Huang J, Chen L. Growth inhibitory effect of paratocarpin E, a prenylated chalcone isolated from Euphorbia humifusa Wild., by induction of autophagy and apoptosis in human breast cancer cells. Bioorg Chem 2016; 69:121-128. [PMID: 27814565 DOI: 10.1016/j.bioorg.2016.10.005] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 10/18/2016] [Accepted: 10/24/2016] [Indexed: 01/08/2023]
Abstract
Five flavones, including four flavonoids and one prenylated chalcone (paratocarpin E), were isolated from E. humifusa. and their chemical structures were established by spectroscopic analyses. We assessed the efficacy of these compounds against the growth of human breast cancer, leukemic, kidney cancer cell lines. Among them, paratocarpin E showed significant cytotoxicity against these cancer cell lines with an IC50 of 19.6μM on the growth of MCF-7 cells. Paratocarpin E treatment of MCF-7 cells resulted in typical apoptotic features via increasing expression of activated caspase-8 and -9 and PARP cleavage. Moreover, paratocarpin E altered the expression of Bax and Bcl-2, leading to the release of cytochrome c from the mitochondria into the cytosol, suggesting that the mitochondria-mediated apoptosis was initiated. In addition, paratocarpin E increased the MDC-positive autophagic vacuoles, the ratio of LC3-II/LC3-I protein levels of Beclin-1, but decreased p62 expression, indicating the potent pro-autophagic effects of paratocarpin E in MCF-7 cells. Mechanistically, cell death induced by paratocarpin E is able to induce apoptosis of MCF-7 cells by activating p38 and JNK signaling pathway while inhibiting Erk pathway. Furthermore, paratocarpin E promotes the activation and nuclear translocation of NF-κB, which plays an important role in balancing paratocarpin E-mediated apoptosis and autophagy. The molecular docking study also revealed that paratocarpin E bound to Fas and NF-κB complex. These findings provide initial evidences that paratocarpin E can be used as a potential anti-cancer drug in future for breast cancer therapy.
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Affiliation(s)
- Suyu Gao
- Department of Natural Products Chemistry, School of Traditional Chinese Materia Medica, Key Laboratory of Structure-Based Drug Design & Discovery, Ministry of Education, Shenyang Pharmaceutical University, Shenyang 110016, People's Republic of China
| | - Dejuan Sun
- Department of Natural Products Chemistry, School of Traditional Chinese Materia Medica, Key Laboratory of Structure-Based Drug Design & Discovery, Ministry of Education, Shenyang Pharmaceutical University, Shenyang 110016, People's Republic of China
| | - Guan Wang
- Department of Natural Products Chemistry, School of Traditional Chinese Materia Medica, Key Laboratory of Structure-Based Drug Design & Discovery, Ministry of Education, Shenyang Pharmaceutical University, Shenyang 110016, People's Republic of China
| | - Jin Zhang
- Department of Natural Products Chemistry, School of Traditional Chinese Materia Medica, Key Laboratory of Structure-Based Drug Design & Discovery, Ministry of Education, Shenyang Pharmaceutical University, Shenyang 110016, People's Republic of China
| | - Yingnan Jiang
- Department of Natural Products Chemistry, School of Traditional Chinese Materia Medica, Key Laboratory of Structure-Based Drug Design & Discovery, Ministry of Education, Shenyang Pharmaceutical University, Shenyang 110016, People's Republic of China
| | - Guoyu Li
- School of Pharmacy, Shihezi University, Shihezi 832023, People's Republic of China
| | - Ke Zhang
- School of Pharmacy, Shihezi University, Shihezi 832023, People's Republic of China
| | - Lei Wang
- Department of Natural Products Chemistry, School of Traditional Chinese Materia Medica, Key Laboratory of Structure-Based Drug Design & Discovery, Ministry of Education, Shenyang Pharmaceutical University, Shenyang 110016, People's Republic of China
| | - Jian Huang
- Department of Natural Products Chemistry, School of Traditional Chinese Materia Medica, Key Laboratory of Structure-Based Drug Design & Discovery, Ministry of Education, Shenyang Pharmaceutical University, Shenyang 110016, People's Republic of China
| | - Lixia Chen
- Department of Natural Products Chemistry, School of Traditional Chinese Materia Medica, Key Laboratory of Structure-Based Drug Design & Discovery, Ministry of Education, Shenyang Pharmaceutical University, Shenyang 110016, People's Republic of China.
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113
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Kunanopparat A, Kimkong I, Palaga T, Tangkijvanich P, Sirichindakul B, Hirankarn N. Increased ATG5-ATG12 in hepatitis B virus-associated hepatocellular carcinoma and their role in apoptosis. World J Gastroenterol 2016; 22:8361-8374. [PMID: 27729742 PMCID: PMC5055866 DOI: 10.3748/wjg.v22.i37.8361] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2016] [Revised: 07/04/2016] [Accepted: 08/01/2016] [Indexed: 02/06/2023] Open
Abstract
AIM To investigate autophagy-related genes, particularly ATG12, in apoptosis and cell cycle in hepatitis B virus (HBV)-associated hepatocellular carcinoma (HCC) and non-HBV-HCC cell lines.
METHODS The expression of autophagy-related genes in HBV-associated hepatocellular carcinoma and non-HBV-HCC cell lines and human liver tissues was examined by quantitative real-time reverse transcriptase-polymerase chain reaction (qRT-PCR) and western blotting. The silencing of target genes was used to examine the function of various genes in apoptosis and cell cycle progression.
RESULTS The expression of autophagy related genes ATG5, ATG12, ATG9A and ATG4B expression was analyzed in HepG2.2.15 cells and compared with HepG2 and THLE cells. We found that ATG5 and ATG12 mRNA expression was significantly increased in HepG2.2.15 cells compared to HepG2 cells (P < 0.005). Moreover, ATG5-ATG12 protein levels were increased in tumor liver tissues compared to adjacent non-tumor tissues mainly from HCC patients with HBV infection. We also analyzed the function of ATG12 in cell apoptosis and cell cycle progression. The percentage of apoptotic cells increased by 11.4% in ATG12-silenced HepG2.2.15 cells (P < 0.005) but did not change in ATG12-silenced HepG2 cells under starvation with Earle’s balanced salt solution. However, the combination blockade of Notch signaling and ATG12 decreased the apoptotic rate of HepG2.2.15 cells from 55.6% to 50.4% (P < 0.05).
CONCLUSION ATG12 is important for HBV-associated apoptosis and a potential drug target for HBV-HCC. Combination inhibition of ATG12/Notch signaling had no additional effect on HepG2.2.15 apoptosis.
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114
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Phycocyanin Inhibits Tumorigenic Potential of Pancreatic Cancer Cells: Role of Apoptosis and Autophagy. Sci Rep 2016; 6:34564. [PMID: 27694919 PMCID: PMC5046139 DOI: 10.1038/srep34564] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 09/13/2016] [Indexed: 12/17/2022] Open
Abstract
Pancreatic adenocarcinoma (PDA) is one of the most lethal human malignancies, and unresponsive to current chemotherapies. Here we investigate the therapeutic potential of phycocyanin as an anti-PDA agent in vivo and in vitro. Phycocyanin, a natural product purified from Spirulina, effectively inhibits the pancreatic cancer cell proliferation in vitro and xenograft tumor growth in vivo. Phycocyanin induces G2/M cell cycle arrest, apoptotic and autophagic cell death in PANC-1 cells. Inhibition of autophagy by targeting Beclin 1 using siRNA significantly suppresses cell growth inhibition and death induced by phycocyanin, whereas inhibition of both autophagy and apoptosis rescues phycocyanin-mediated cell death. Mechanistically, cell death induced by phycocyanin is the result of cross-talk among the MAPK, Akt/mTOR/p70S6K and NF-κB pathways. Phycocyanin is able to induce apoptosis of PANC-1 cell by activating p38 and JNK signaling pathways while inhibiting Erk pathway. On the other hand, phycocyanin promotes autophagic cell death by inhibiting PI3/Akt/mTOR signaling pathways. Furthermore, phycocyanin promotes the activation and nuclear translocation of NF-κB, which plays an important role in balancing phycocyanin-mediated apoptosis and autosis. In conclusion, our studies demonstrate that phycocyanin exerts anti-pancreatic cancer activity by inducing apoptotic and autophagic cell death, thereby identifying phycocyanin as a promising anti-pancreatic cancer agent.
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115
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Fekadu J, Rami A. Beclin-1 Deficiency Alters Autophagosome Formation, Lysosome Biogenesis and Enhances Neuronal Vulnerability of HT22 Hippocampal Cells. Mol Neurobiol 2016; 53:5500-9. [PMID: 26456737 DOI: 10.1007/s12035-015-9453-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 09/25/2015] [Indexed: 12/31/2022]
Abstract
Beclin-1 is assumed to be a critical component participating in autophagosome formation in mammals; however, the exact role of Beclin-1 in autophagy remains controversial. Here (1) we created a HT22-Beclin-1-knockdown cell line using the Q-techBECN1 technique, (2) examined the potential role of Beclin-1 in an autophagic response in hippocampal HT22 neurons challenged with rapamycin, (3) investigated the expression of several gene products involved in the autophagic pathway, and (4) checked the effects of Beclin-1 knockdown on neuronal death induced by AAS. Rapamycin induced and altered the expression of autophagy signature proteins in wild-type cultures as well as in HT22-Beclin-1-knockdown cells. However, among the examined markers, only two factors exhibited dramatic changes when comparing controls to HT22-Beclin-1-knockdown cells. The amount of LC3, an important protein for the initiation of autophagosome formation and LAMP-1, a major constituent of the lysosomal membrane, underwent a dramatic and highly significant increase in control cultures challenged with rapamycin. In contrast, rapamycin was not able to induce any significant changes in LC3 and LAMP-1 levels in HT22-Beclin-1-knockdown cells. In addition, the knockdown of Beclin-1 enhanced neuronal susceptibility to death signals induced by AAS. Our data demonstrate the essential role of Beclin-1 in the formation of autophagosomes and lysosome biogenesis and underline that deletion of this key system is deleterious for cell viability.
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Affiliation(s)
- J Fekadu
- Institut für Zelluläre und Molekulare Anatomie (Anatomie III), Klinikum der Johann Wolfgang von Goethe-Universität, Theodor-Stern-Kai 7, 60590, Frankfurt/Main, Germany
| | - A Rami
- Institut für Zelluläre und Molekulare Anatomie (Anatomie III), Klinikum der Johann Wolfgang von Goethe-Universität, Theodor-Stern-Kai 7, 60590, Frankfurt/Main, Germany.
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RelA-Mediated BECN1 Expression Is Required for Reactive Oxygen Species-Induced Autophagy in Oral Cancer Cells Exposed to Low-Power Laser Irradiation. PLoS One 2016; 11:e0160586. [PMID: 27632526 PMCID: PMC5025201 DOI: 10.1371/journal.pone.0160586] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 07/21/2016] [Indexed: 12/22/2022] Open
Abstract
Low-power laser irradiation (LPLI) is a non-invasive and safe method for cancer treatment that alters a variety of physiological processes in the cells. Autophagy can play either a cytoprotective role or a detrimental role in cancer cells exposed to stress. The detailed mechanisms of autophagy and its role on cytotoxicity in oral cancer cells exposed to LPLI remain unclear. In this study, we showed that LPLI at 810 nm with energy density 60 J/cm2 increased the number of microtubule associated protein 1 light chain 3 (MAP1LC3) puncta and increased autophagic flux in oral cancer cells. Moreover, reactive oxygen species (ROS) production was induced, which increased RelA transcriptional activity and beclin 1 (BECN1) expression in oral cancer cells irradiated with LPLI. Furthermore, ROS scavenger or knockdown of RelA diminished LPLI-induced BECN1 expression and MAP1LC3-II conversion. In addition, pharmacological and genetic ablation of autophagy significantly enhanced the effects of LPLI-induced apoptosis in oral cancer cells. These results suggest that autophagy may be a resistant mechanism for LPLI-induced apoptosis in oral cancer cells.
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Qin Y, Liu Y, Hao W, Decker Y, Tomic I, Menger MD, Liu C, Fassbender K. Stimulation of TLR4 Attenuates Alzheimer’s Disease–Related Symptoms and Pathology in Tau-Transgenic Mice. THE JOURNAL OF IMMUNOLOGY 2016; 197:3281-3292. [DOI: 10.4049/jimmunol.1600873] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 08/14/2016] [Indexed: 01/09/2023]
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Choudhury KR, Bucha S, Baksi S, Mukhopadhyay D, Bhattacharyya NP. Chaperone-like protein HYPK and its interacting partners augment autophagy. Eur J Cell Biol 2016; 95:182-94. [PMID: 27067261 DOI: 10.1016/j.ejcb.2016.03.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Revised: 03/24/2016] [Accepted: 03/29/2016] [Indexed: 12/26/2022] Open
Abstract
To decipher the function(s) of HYPK, a huntingtin (HTT)-interacting protein with chaperone-like activity, we had previously identified 36 novel interacting partners of HYPK. Another 13 proteins were known earlier to be associated with HYPK. On the basis of analysis of the interacting partners of HYPK, it has been shown that HYPK may participate in diverse cellular functions relevant to Huntington's disease. In the present study, we identified additional 5 proteins by co-immunoprecipitation and co-localization. As of now we have 54 primary interactors of HYPK. From the database we collected 1026 unique proteins (secondary interactors) interacting with these 54 primary HYPK interacting partners. We observed that 10 primary and 91 secondary interacting proteins of HYPK are associated with two types of autophagy processes. We next tested the hypothesis that the hub, HYPK, might itself be involved in autophagy. Using mouse striatal STHdh(Q7)/Hdh(Q7) cell lines, we observed that over expression of HYPK significantly increased background cellular autophagy, while knock down of endogenous HYPK decreased the autophagy level as detected by altered LC3I conversion, BECN1 expression, cleavage of GFP from LC3-GFP, ATG5-ATG12 conjugate formation and expression of transcription factors like Tfeb, Srebp2 and Zkscan3. This result shows that HYPK, possibly with its interacting partners, induces autophagy. We further observed that N-terminal mutant HTT reduced the cellular levels of LC3II and BECN1, which could be recovered significantly upon over expression of HYPK in these cells. This result further confirms that HYPK could also be involved in clearing mutant HTT aggregates by augmenting autophagy pathway.
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Affiliation(s)
- Kamalika Roy Choudhury
- Crystallography and Molecular Biology Division, Saha Institute of Nuclear Physics, 1/AF, Bidhan Nagar, Kolkata 700 064, India.
| | - Sudha Bucha
- Crystallography and Molecular Biology Division, Saha Institute of Nuclear Physics, 1/AF, Bidhan Nagar, Kolkata 700 064, India.
| | - Shounak Baksi
- Crystallography and Molecular Biology Division, Saha Institute of Nuclear Physics, 1/AF, Bidhan Nagar, Kolkata 700 064, India.
| | - Debashis Mukhopadhyay
- Crystallography and Molecular Biology Division, Saha Institute of Nuclear Physics, 1/AF, Bidhan Nagar, Kolkata 700 064, India.
| | - Nitai P Bhattacharyya
- Crystallography and Molecular Biology Division, Saha Institute of Nuclear Physics, 1/AF, Bidhan Nagar, Kolkata 700 064, India.
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Gao H, Lin L, Haq IU, Zeng SM. Inhibition of NF-κB promotes autophagy via JNK signaling pathway in porcine granulosa cells. Biochem Biophys Res Commun 2016; 473:311-316. [PMID: 27016483 DOI: 10.1016/j.bbrc.2016.03.101] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 03/21/2016] [Indexed: 12/15/2022]
Abstract
The transcription factor nuclear factor-κB (NF-κB) plays an important role in diverse processes, including cell proliferation and differentiation, apoptosis and inflammation. However, the role of NF-κB in porcine follicle development is not clearly elucidated. In this study, we demonstrated that follicle stimulating hormone (FSH) increased the level of inhibitor of NF-κB (IκB) protein and promoted the cytoplasmic localization of p65, indicating that FSH inhibits the activation of NF-κB in porcine granulosa cells. Moreover, inhibition of NF-κB by FSH or another specific inhibitor of NF-κB, pyrrolidine dithiocarbamate (PDTC), could activate JNK signaling and enhance autophagic activity in porcine granulosa cells. Knockdown of RelA (p65) Subunit of NF-κB by RNA interference abrogated the activation of JNK signaling pathway and the increase of autophagic protein expression by FSH. Meanwhile, the functional significance of FSH or PDTC-mediated autophagy were further investigated. Our results demonstrated that the increased autophagy promoted progesterone secretion in porcine granulosa cells. Blockage of autophagy by chloroquine obviated the FSH or PDTC-induced progesterone production. Taken together, these results indicate that inhibition of NF-κB increased autophagy via JNK signaling, and promote steroidogenesis in porcine granulosa cells. Our results provide new insights into the regulation and function of autophagy in mammalian follicle development.
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Affiliation(s)
- Hui Gao
- Laboratory of Animal Embryonic Biotechnology, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China
| | - Lu Lin
- Laboratory of Animal Embryonic Biotechnology, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China
| | - Ihtesham Ul Haq
- Laboratory of Animal Embryonic Biotechnology, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China
| | - Shen-Ming Zeng
- Laboratory of Animal Embryonic Biotechnology, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China.
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Li WL, Xiong LX, Shi XY, Xiao L, Qi GY, Meng C. IKKβ/NFκBp65 activated by interleukin-13 targets the autophagy-related genes LC3B and beclin 1 in fibroblasts co-cultured with breast cancer cells. Exp Ther Med 2016; 11:1259-1264. [PMID: 27073433 PMCID: PMC4812107 DOI: 10.3892/etm.2016.3054] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 01/19/2016] [Indexed: 12/11/2022] Open
Abstract
Interleukin-13 (IL-13), a Th2 cytokine, plays an important role in fibrosis, inflammation, tissue hyperresponsiveness and tumor development. Although studies have demonstrated that IL-13 exerts its roles through signal transducer and activator of transcription 6 (STAT6) signaling pathway, recent studies have revealed that I kappa B kinase (IKK)/nuclear factor kappa B (NFκB) pathway may also be involved in. The aim of this study was to investigate whether IL-13 delivers signals to IKKβ/NFκBp65 and whether autophagy genes are IL-13-induced the activation of NFκBp65 transcriptional targets in fibroblasts of breast tumor stroma. We examined the phosphorylation of IKKβ, the activation of NFκBp65 and NFκBp65-targeted autophagy genes in fibroblasts co-cultured with breast cancer cells under the condition of IL-13 stimulation. Results of this study showed that IL-13 induced IKKβ phosphorylation in the fibroblast line ESF co-cultured with breast cancer cell line BT474, and subsequently NFκBp65 was activated and aimed at beclin 1 and microtubule-associated protein 1 light chain 3 B (MAP1LC3B or LC3B) in these ESF cells. BMS345541, an inhibitor of IKK/NFκB pathway, significantly inhibited the IL-13-induced the activation of NFκB and also inhibited NFκB-targeted beclin 1 and LC3B expression. Our results suggest that IL-13 regulates beclin 1 and LC3B expression through IKKβ/NFκBp65 in fibroblasts co-cultured with breast cancer cells, and IL-13 plays role in activating IKKβ/NFκBp65.
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Affiliation(s)
- Wen-Lin Li
- Key Laboratory of Medical Biology, Nanchang University, Nanchang, Jiangxi 330006, P.R. China
| | - Li-Xia Xiong
- Department of Pathophysiology, Medical College, Nanchang University, Nanchang, Jiangxi 330006, P.R. China
| | - Xiao-Yu Shi
- Key Laboratory of Medical Biology, Nanchang University, Nanchang, Jiangxi 330006, P.R. China
| | - Liang Xiao
- Molecular Laboratory, Jiangxi University of Traditional Chinese Medicine, Nanchang, Jiangxi 330006, P.R. China
| | - Guan-Yun Qi
- Key Laboratory of Medical Biology, Nanchang University, Nanchang, Jiangxi 330006, P.R. China
| | - Chuang Meng
- Key Laboratory of Medical Biology, Nanchang University, Nanchang, Jiangxi 330006, P.R. China
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121
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Zhang SF, Wang XY, Fu ZQ, Peng QH, Zhang JY, Ye F, Fu YF, Zhou CY, Lu WG, Cheng XD, Xie X. TXNDC17 promotes paclitaxel resistance via inducing autophagy in ovarian cancer. Autophagy 2016; 11:225-38. [PMID: 25607466 DOI: 10.1080/15548627.2014.998931] [Citation(s) in RCA: 125] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Paclitaxel is recommended as a first-line chemotherapeutic agent against ovarian cancer, but drug resistance becomes a major limitation of its success clinically. The key molecule or mechanism associated with paclitaxel resistance in ovarian cancer still remains unclear. Here, we showed that TXNDC17 screened from 356 differentially expressed proteins by LC-MS/MS label-free quantitative proteomics was more highly expressed in paclitaxel-resistant ovarian cancer cells and tissues, and the high expression of TXNDC17 was associated with poorer prognostic factors and exhibited shortened survival in 157 ovarian cancer patients. Moreover, paclitaxel exposure induced upregulation of TXNDC17 and BECN1 expression, increase of autophagosome formation, and autophagic flux that conferred cytoprotection for ovarian cancer cells from paclitaxel. TXNDC17 inhibition by siRNA or enforced overexpression by a pcDNA3.1(+)-TXNDC17 plasmid correspondingly decreased or increased the autophagy response and paclitaxel resistance. Additionally, the downregulation of BECN1 by siRNA attenuated the activation of autophagy and cytoprotection from paclitaxel induced by TXNDC17 overexpression in ovarian cancer cells. Thus, our findings suggest that TXNDC17, through participation of BECN1, induces autophagy and consequently results in paclitaxel resistance in ovarian cancer. TXNDC17 may be a potential predictor or target in ovarian cancer therapeutics.
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Key Words
- 95% CI, 95% confidence interval
- ALDOC, aldolase C, fructose-bisphosphate
- ATG5, autophagy-related 5
- BECN1
- BECN1, Beclin 1, autophagy-related
- BafA1, bafilomycin A1
- CNN3, calponin 3, acidic
- DAPI, 4', 6-diamidino-2-phenylindole
- FLNA, filamin A, α
- GO, gene ontology
- GenMAPP, gene microarray pathway profiler
- HBSS, Hank's balanced salt solution
- HR, hazard ratio
- KEGG, Kyoto encyclopedia of genes and genome
- LC-MS/MS, liquid chromatography-mass spectrometry/ mass spectrometry
- MAP1LC3B/LC3B, microtubule-associated protein 1 light chain 3 β
- OS, overall survival
- PFS, progression-free survival
- PGAM1, phosphoglycerate mutase 1 (brain)
- SQSTM1, sequestosome 1
- TNF, tumor necrosis factor
- TXN, thioredoxin
- TXNDC17
- TXNDC17, thioredoxin domain containing 17
- UTP23, small subunit (SSU) processome component, homolog (yeast)
- autophagy
- ovarian cancer
- paclitaxel resistance
- siRNA, short interfering RNA
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Affiliation(s)
- Song-Fa Zhang
- a Women's Reproductive Health Laboratory of Zhejiang Province; Women's Hospital; School of Medicine ; Zhejiang University ; Hangzhou , China
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Tommasino C, Marconi M, Ciarlo L, Matarrese P, Malorni W. Autophagic flux and autophagosome morphogenesis require the participation of sphingolipids. Apoptosis 2015; 20:645-57. [PMID: 25697338 DOI: 10.1007/s10495-015-1102-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Apoptosis and autophagy are two evolutionary conserved processes that exert a critical role in the maintenance of tissue homeostasis. While apoptosis is a tightly regulated cell program implicated in the removal of damaged or unwanted cells, autophagy is a cellular catabolic pathway that is involved in the lysosomal degradation and recycling of proteins and organelles, and is thereby considered an important cytoprotection mechanism. Sphingolipids (SLs), which are ubiquitous membrane lipids in eukaryotes, participate in the generation of various membrane structures, including lipid rafts and caveolae, and contribute to a number of cellular functions such as cell proliferation, apoptosis and, as suggested more recently, autophagy. For instance, SLs are hypothesized to be involved in several intracellular processes, including organelle membrane scrambling, whilst at the plasma membrane lipid rafts, acting as catalytic domains, strongly contribute to the ignition of critical signaling pathways determining cell fate. In particular, by targeting several shared regulators, ceramide, sphingosine-1-phosphate, dihydroceramide, sphingomyelin and gangliosides seem able to differentially regulate the autophagic pathway and/or contribute to the autophagosome formation. This review illustrates recent studies on this matter, particularly lipid rafts, briefly underscoring the possible implication of SLs and their alterations in the autophagy disturbances and in the pathogenesis of some human diseases.
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Affiliation(s)
- Chiara Tommasino
- Section of Cell Aging and Degeneration, Department of Therapeutic Research and Medicine Evaluation, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161, Rome, Italy
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Bowie M, Pilie P, Wulfkuhle J, Lem S, Hoffman A, Desai S, Petricoin E, Carter A, Ambrose A, Seewaldt V, Yu D, Ibarra Drendall C. Fluoxetine induces cytotoxic endoplasmic reticulum stress and autophagy in triple negative breast cancer. World J Clin Oncol 2015; 6:299-311. [PMID: 26677444 PMCID: PMC4675916 DOI: 10.5306/wjco.v6.i6.299] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Revised: 09/08/2015] [Accepted: 10/27/2015] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the mechanism of action of lipophilic antidepressant fluoxetine (FLX) in representative molecular subtypes of breast cancer.
METHODS: The anti-proliferative effects and mechanistic action of FLX in triple-negative (SUM149PT) and luminal (T47D and Au565) cancer cells and non-transformed MCF10A were investigated. Reverse phase protein microarray (RPPM) was performed with and without 10 μmol/L FLX for 24 and 48 h to determine which proteins are significantly changed. Viability and cell cycle analysis were also performed to determine drug effects on cell growth. Western blotting was used to confirm the change in protein expression examined by RPPM or pursue other signaling proteins.
RESULTS: The FLX-induced cell growth inhibition in all cell lines was concentration- and time-dependent but less pronounced in early passage MCF10A. In comparison to the other lines, cell growth reduction in SUM149PT coincided with significant induction of endoplasmic reticulum (ER) stress and autophagy after 24 and 48 h of 10 μmol/L FLX, resulting in decreased translation of proteins along the receptor tyrosine kinase/Akt/mammalian target of rapamycin pathways. The increase in autophagy marker, cleaved microtubule-associated protein 1 light chain 3, in SUM149PT after 24 h of FLX was likely due to increased metabolic demands of rapidly dividing cells and ER stress. Consequently, the unfolded protein response mediated by double-stranded RNA-dependent protein kinase-like ER kinase resulted in inhibition of protein synthesis, growth arrest at the G1 phase, autophagy, and caspase-7-mediated cell death.
CONCLUSION: Our study suggests a new role for FLX as an inducer of ER stress and autophagy, resulting in death of aggressive triple negative breast cancer SUM149PT.
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Wang JD, Cao YL, Li Q, Yang YP, Jin M, Chen D, Wang F, Wang GH, Qin ZH, Hu LF, Liu CF. A pivotal role of FOS-mediated BECN1/Beclin 1 upregulation in dopamine D2 and D3 receptor agonist-induced autophagy activation. Autophagy 2015; 11:2057-2073. [PMID: 26649942 PMCID: PMC4824582 DOI: 10.1080/15548627.2015.1100930] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Autophagy dysfunction is implicated in the pathogenesis of Parkinson disease (PD). BECN1/Beclin 1 acts as a critical regulator of autophagy and other cellular processes; yet, little is known about the function and regulation of BECN1 in PD. In this study, we report that dopamine D2 and D3 receptor (DRD2 and DRD3) activation by pramipexole and quinpirole could enhance BECN1 transcription and promote autophagy activation in several cell lines, including PC12, MES23.5 and differentiated SH-SY5Y cells, and also in tyrosine hydroxylase positive primary midbrain neurons. Moreover, we identified a novel FOS (FBJ murine osteosarcoma viral oncogene homolog) binding sequence (5′-TGCCTCA-3′) in the rat and human Becn1/BECN1 promoter and uncovered an essential role of FOS binding in the enhancement of Becn1 transcription in PC12 cells in response to the dopamine agonist(s). In addition, we demonstrated a critical role of intracellular Ca2+ elevation, followed by the enhanced phosphorylation of CAMK4 (calcium/calmodulin-dependent protein kinase IV) and CREB (cAMP responsive element binding protein) in the increases of FOS expression and autophagy activity. More importantly, pramipexole treatment ameliorated the SNCA/α-synuclein accumulation in rotenone-treated PC12 cells that overexpress wild-type or A53T mutant SNCA by promoting autophagy flux. This effect was also demonstrated in the substantia nigra and the striatum of SNCAA53T transgenic mice. The inhibition of SNCA accumulation by pramipexole was attenuated by cotreatment with the DRD2 and DRD3 antagonists and Becn1 siRNAs. Thus, our findings suggest that DRD2 and DRD3 agonist(s) may induce autophagy activation via a BECN1-dependent pathway and have the potential to reduce SNCA accumulation in PD.
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Affiliation(s)
- Jian-Da Wang
- a Department of Neurology ; Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases; The Second Affiliated Hospital of Soochow University; Soochow University ; Suzhou , China.,b Institute of Neuroscience; Soochow University ; Suzhou , China.,c Department of Pediatrics ; Second Affiliated Hospital; School of Medicine, Zhejiang University ; Hangzhou, Zhejiang , China
| | - Yu-Lan Cao
- a Department of Neurology ; Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases; The Second Affiliated Hospital of Soochow University; Soochow University ; Suzhou , China.,b Institute of Neuroscience; Soochow University ; Suzhou , China
| | - Qian Li
- b Institute of Neuroscience; Soochow University ; Suzhou , China.,d Department of Pharmacology ; Soochow University; College of Pharmaceutical Sciences ; Suzhou , China
| | - Ya-Ping Yang
- a Department of Neurology ; Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases; The Second Affiliated Hospital of Soochow University; Soochow University ; Suzhou , China
| | - Mengmeng Jin
- a Department of Neurology ; Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases; The Second Affiliated Hospital of Soochow University; Soochow University ; Suzhou , China
| | - Dong Chen
- d Department of Pharmacology ; Soochow University; College of Pharmaceutical Sciences ; Suzhou , China
| | - Fen Wang
- b Institute of Neuroscience; Soochow University ; Suzhou , China
| | - Guang-Hui Wang
- d Department of Pharmacology ; Soochow University; College of Pharmaceutical Sciences ; Suzhou , China
| | - Zheng-Hong Qin
- d Department of Pharmacology ; Soochow University; College of Pharmaceutical Sciences ; Suzhou , China
| | - Li-Fang Hu
- b Institute of Neuroscience; Soochow University ; Suzhou , China.,d Department of Pharmacology ; Soochow University; College of Pharmaceutical Sciences ; Suzhou , China
| | - Chun-Feng Liu
- a Department of Neurology ; Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases; The Second Affiliated Hospital of Soochow University; Soochow University ; Suzhou , China.,b Institute of Neuroscience; Soochow University ; Suzhou , China
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Guo Y, Liu S, Zhang X, Wang L, Gao J, Han A, Hao A. G-CSF promotes autophagy and reduces neural tissue damage after spinal cord injury in mice. J Transl Med 2015; 95:1439-49. [PMID: 26524416 DOI: 10.1038/labinvest.2015.120] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 04/24/2015] [Accepted: 04/28/2015] [Indexed: 12/19/2022] Open
Abstract
Granulocyte colony-stimulating factor (G-CSF) was investigated for its capacity to induce autophagy and related neuroprotective mechanisms in an acute spinal cord injury model. To accomplish this goal, we established a mouse spinal cord hemisection model to test the effects of recombinant human G-CSF. The results showed that autophagy was activated after spinal cord injury and G-CSF appears to induce a more rapid activation of autophagy within injured spinal cords as compared with that of non-treated animals. Apoptosis as induced in mechanically injured neurons with G-CSF treatment was enhanced after inhibiting autophagy by 3-methyladenine (3-MA), which partially blocked the neuroprotective effect of autophagy as induced by G-CSF. In addition, G-CSF inhibited the activity of the NF-κB signal pathway in neurons after mechanical injury. We conclude that G-CSF promotes autophagy by inhibiting the NF-κB signal pathway and protects neuronal structure after spinal cord injury. We therefore suggest that G-CSF, which rapidly induces autophagy after spinal cord injury to inhibit neuronal apoptosis, may thus provide an effective auxiliary therapeutic intervention for spinal cord injury.
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Affiliation(s)
- Yuji Guo
- Key Laboratory of the Ministry of Education for Experimental Teratology, Department of Histology and Embryology, Shandong University School of Medicine, Jinan, China
| | - Shangming Liu
- Key Laboratory of the Ministry of Education for Experimental Teratology, Department of Histology and Embryology, Shandong University School of Medicine, Jinan, China
| | - Xianghong Zhang
- Key Laboratory of the Ministry of Education for Experimental Teratology, Department of Histology and Embryology, Shandong University School of Medicine, Jinan, China
| | - Liyan Wang
- Key Laboratory of the Ministry of Education for Experimental Teratology, Department of Histology and Embryology, Shandong University School of Medicine, Jinan, China
| | - Jiangang Gao
- Institute of Developmental Biology, College of Life Science, Shandong University, Jinan, China
| | - Aiqing Han
- Department of Obstetrics, Maternal and Children Health Hospital of Jinan City, Jinan, China
| | - Aijun Hao
- Key Laboratory of the Ministry of Education for Experimental Teratology, Department of Histology and Embryology, Shandong University School of Medicine, Jinan, China
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Verma N, Manna SK. Advanced Glycation End Products (AGE) Potently Induce Autophagy through Activation of RAF Protein Kinase and Nuclear Factor κB (NF-κB). J Biol Chem 2015; 291:1481-91. [PMID: 26586913 DOI: 10.1074/jbc.m115.667576] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Indexed: 11/06/2022] Open
Abstract
Advanced glycation end products (AGE) accumulate in diabetic patients and aging people because of high amounts of three- or four-carbon sugars derived from glucose, thereby causing multiple consequences, including inflammation, apoptosis, obesity, and age-related disorders. It is important to understand the mechanism of AGE-mediated signaling leading to the activation of autophagy (self-eating) that might result in obesity. We detected AGE as one of the potent inducers of autophagy compared with doxorubicin and TNF. AGE-mediated autophagy is inhibited by suppression of PI3K and potentiated by the autophagosome maturation blocker bafilomycin. It increases autophagy in different cell types, and that correlates with the expression of its receptor, receptor for AGE. LC3B, the marker for autophagosomes, is shown to increase upon AGE stimulation. AGE-mediated autophagy is partially suppressed by inhibitor of NF-κB, PKC, or ERK alone and significantly in combination. AGE increases sterol regulatory element binding protein activity, which leads to an increase in lipogenesis. Although AGE-mediated lipogenesis is affected by autophagy inhibitors, AGE-mediated autophagy is not influenced by lipogenesis inhibitors, suggesting that the turnover of lipid droplets overcomes the autophagic clearance. For the first time, we provide data showing that AGE induces several cell signaling cascades, like NF-κB, PKC, ERK, and MAPK, that are involved in autophagy and simultaneously help with the accumulation of lipid droplets that are not cleared effectively by autophagy, therefore causing obesity.
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Affiliation(s)
- Neeharika Verma
- From the Laboratory of Immunology, Centre for DNA Fingerprinting and Diagnostics, Nampally, Hyderabad 500001, India and Graduate Studies, Manipal University, Manipal, Karnataka 576104, India
| | - Sunil K Manna
- From the Laboratory of Immunology, Centre for DNA Fingerprinting and Diagnostics, Nampally, Hyderabad 500001, India and
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127
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SZC017, a novel oleanolic acid derivative, induces apoptosis and autophagy in human breast cancer cells. Apoptosis 2015; 20:1636-50. [DOI: 10.1007/s10495-015-1179-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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128
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Chen L, Liu D, Zhang Y, Zhang H, Cheng H. The autophagy molecule Beclin 1 maintains persistent activity of NF-κB and Stat3 in HTLV-1-transformed T lymphocytes. Biochem Biophys Res Commun 2015; 465:739-45. [PMID: 26319552 DOI: 10.1016/j.bbrc.2015.08.070] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 08/16/2015] [Indexed: 12/19/2022]
Abstract
The retroviral oncoprotein Tax from human T cell leukemia virus type 1 (HTLV-1) induces persistent activation of IκB kinase (IKK)/NF-κB signaling, an essential step for initiating HTLV-1 oncogenesis. The regulation of the IKK/NF-κB signaling in HTLV-1-transformed T cells remains incompletely understood. In the present study, we showed that the autophagy molecule Beclin1 not only executed a cytoprotective function through induction of autophagy but also played a pivotal role in maintaining Tax-induced activation of two key survival factors, NF-κB and Stat3. Silencing Beclin1 in HTLV-1-transformed T cells resulted in diminished activities of NF-κB and Stat3 as well as impaired growth. In Beclin1-depleted cells, Tax failed to activate NF-κB and Stat3 at its full capacity. In addition, we showed that Beclin1 interacted with the catalytic subunits of IKK. Further, we observed that selective inhibition of IKK repressed the activities of both NF-κB and Stat3 in the context of HTLV-1-transformation of T cells. Our data, therefore, unveiled a key role of Beclin1 in maintaining persistent activities of both NF-κB and Stat3 in the pathogenesis of HTLV-1-mediated oncogenesis.
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Affiliation(s)
- Li Chen
- Pharmacy College, Fujian University of Traditional Chinese Medicine, Fuzhou, China; Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Dan Liu
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Yang Zhang
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Huan Zhang
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Hua Cheng
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Marlene and Stewart Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
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129
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Liang K, Zhu L, Tan J, Shi W, He Q, Yu B. Identification of autophagy signaling network that contributes to stroke in the ischemic rodent brain via gene expression. Neurosci Bull 2015; 31:480-90. [PMID: 26254060 DOI: 10.1007/s12264-015-1547-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 07/09/2015] [Indexed: 11/24/2022] Open
Abstract
Autophagy plays a vital role in cerebral ischemia and may be a potential target for developing novel therapy for stroke. In this study, we constructed an autophagy-related pathway network by analyzing the genes related to autophagy and ischemic stroke, and the risk genes were screened. Two autophagy-related modules were significantly up-regulated and clustered to influence cerebral ischemia. Besides, three key modular genes (NFKB1, RELA, and STAT3) were revealed. With 5-fold cross validation, the ROC curves of NFKB1, RELA, and STAT3 were 0.8256, 0.8462, and 0.8923. They formed a complex module and competitively mediated the activation of autophagy in cerebral ischemia. In conclusion, a module containing NFKB1, RELA, and STAT3 mediates autophagy, serving as a potential biomarker for the diagnosis and therapy of ischemic stroke.
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Affiliation(s)
- Kun Liang
- Department of Vascular Surgery, Huashan Hospital, Fudan University, Shanghai, 200040, China
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130
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Xu K, Chen W, Wang X, Peng Y, Liang A, Huang D, Li C, Ye W. Autophagy attenuates the catabolic effect during inflammatory conditions in nucleus pulposus cells, as sustained by NF-κB and JNK inhibition. Int J Mol Med 2015; 36:661-8. [PMID: 26165348 PMCID: PMC4533778 DOI: 10.3892/ijmm.2015.2280] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2015] [Accepted: 06/24/2015] [Indexed: 11/17/2022] Open
Abstract
Proteoglycan degradation contributing to the pathogenesis of intervertebral disc (IVD) degeneration is induced by inflammatory cytokines, such as tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β). Cell autophagy exists in degenerative diseases, including osteoarthritis and inter-vertebral disc degeneration. However, the autophagy induced by TNF-α and IL-1β and the corresponding molecular mechanism appear to be cell-type dependent. The effect and mechanism of autophagy regulated by TNF-α and IL-1β in IVDs remains unclear. Additionally, the impact of autophagy on the catabolic effect in inflammatory conditions also remains elusive. In the present study, autophagy activator and inhibitor were used to demonstrate the impact of autophagy on the catabolic effect induced by TNF-α. A critical role of autophagy was identified in rat nucleus pulposus (NP) cells: Inhibition of autophagy suppresses, while activation of autophagy enhances, the catabolic effect of cytokines. Subsequently, the autophagy-related gene expression in rat NP cells following TNF-α and IL-1β treatment was observed using immunofluorescence, quantitative polymerase chain reaction and western blot analysis; however, no association was present. In addition, nuclear factor κB (NF-κB), c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinases and p38 mitogen-activated protein kinase inhibitors and TNF-α were used to determine the molecular mechanism of autophagy during the inflammatory conditions, and only the NF-κB and JNK inhibitor were found to enhance the autophagy of rat NP cells. Finally, IKKβ knockdown was used to further confirm the effect of the NF-κB signal on human NP cells autophagy, and the data showed that IKKβ knockdown upregulated the autophagy of NP cells during inflammatory conditions.
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Affiliation(s)
- Kang Xu
- Experimental Center of the Surgery, Sun Yat‑sen Memorial Hospital, Sun Yat‑sen University, Guangzhou, Guangdong 510120, P.R. China
| | - Weijian Chen
- Department of Orthopedics, The Second People's Hospital of Guangdong Province, Guangzhou, Guangdong 510080, P.R. China
| | - Xiaofei Wang
- Department of Spinal Surgery, Sun Yat‑sen Memorial Hospital, Sun Yat‑sen University, Guangzhou, Guangdong 510120, P.R. China
| | - Yan Peng
- Department of Spinal Surgery, Sun Yat‑sen Memorial Hospital, Sun Yat‑sen University, Guangzhou, Guangdong 510120, P.R. China
| | - Anjing Liang
- Department of Spinal Surgery, Sun Yat‑sen Memorial Hospital, Sun Yat‑sen University, Guangzhou, Guangdong 510120, P.R. China
| | - Dongsheng Huang
- Department of Spinal Surgery, Sun Yat‑sen Memorial Hospital, Sun Yat‑sen University, Guangzhou, Guangdong 510120, P.R. China
| | - Chunhai Li
- Department of Spinal Surgery, Sun Yat‑sen Memorial Hospital, Sun Yat‑sen University, Guangzhou, Guangdong 510120, P.R. China
| | - Wei Ye
- Department of Spinal Surgery, Sun Yat‑sen Memorial Hospital, Sun Yat‑sen University, Guangzhou, Guangdong 510120, P.R. China
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131
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Abstract
Autophagy is an intracellular catabolic pathway essential for the recycling of proteins and larger substrates such as aggregates, apoptotic corpses, or long-lived and superfluous organelles whose accumulation could be toxic for cells. Because of its unique feature to engulf part of cytoplasm in double-membrane cup-shaped structures, which further fuses with lysosomes, autophagy is also involved in the elimination of host cell invaders and takes an active part of the innate and adaptive immune response. Its pivotal role in maintenance of the inflammatory balance makes dysfunctions of the autophagy process having important pathological consequences. Indeed, defects in autophagy are associated with a wide range of human diseases including metabolic disorders (diabetes and obesity), inflammatory bowel disease (IBD), and cancer. In this review, we will focus on interrelations that exist between inflammation and autophagy. We will discuss in particular how mediators of inflammation can regulate autophagy activity and, conversely, how autophagy shapes the inflammatory response. Impact of genetic polymorphisms in autophagy-related gene on inflammatory bowel disease will be also discussed.
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132
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Xu DW, Zhang GQ, Wang ZW, Xu XY, Liu TX. Autophagy in Tumorigenesis and Cancer Treatment. Asian Pac J Cancer Prev 2015; 16:2167-75. [DOI: 10.7314/apjcp.2015.16.6.2167] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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133
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Song B, Bian Q, Shao CH, Li G, Liu AA, Jing W, Liu R, Zhang YJ, Zhou YQ, Hu XG, Jin G. Ulinastatin reduces the resistance of liver cancer cells to epirubicin by inhibiting autophagy. PLoS One 2015; 10:e0120694. [PMID: 25815885 PMCID: PMC4376693 DOI: 10.1371/journal.pone.0120694] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2014] [Accepted: 01/26/2015] [Indexed: 12/19/2022] Open
Abstract
During chemotherapy, drug resistance caused by autophagy remains a major challenge to successful treatment of cancer patients. The purpose of this study is to show that ulinastatin (UTI), a trypsin inhibitor, could reduce the resistance of liver cancer cells to chemotherapeutic agent epirubicin (EPI). We achieved this conclusion by analyzing the effect of EPI alone or UTI plus EPI on SMMC-7721 and MHCC-LM3 liver cancer cells. We also generated an EPI-resistant liver cancer cell line (MHCC-LM3er cells), and found that UTI could sensitize the LM3er cells to EPI. Autophagy usually functions to protect cancer cells during chemotherapy. Our study showed that UTI inhibited the autophagy induced by EPI in liver cancer cells, which promoted apoptosis, and therefore, reduced the resistance of the cancer cells to EPI. Further studies showed that the UTI-mediated inhibition on autophagy was achieved by inhibiting transcriptional factor nuclear factor-κB (NF-κB) signaling pathway. To verify our results in vivo, we injected MHCC-LM3 liver cancer cells or EPI-resistant LM3er cells into mice, and found that EPI could only effectively inhibit the growth of tumor in MHCC-LM3 cell-injected mice, but not in LM3er cell-injected mice. However, when UTI was also administered, the growth of tumor was inhibited in the MHCC-LM3er cell-injected mice as well. Our results suggest that UTI may be used in combination with anti-cancer drugs, such as EPI, to improve the outcome of cancer therapy.
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MESH Headings
- Animals
- Antibiotics, Antineoplastic/pharmacology
- Apoptosis/drug effects
- Autophagy/drug effects
- Biomarkers, Tumor/genetics
- Biomarkers, Tumor/metabolism
- Blotting, Western
- Carcinoma, Hepatocellular/drug therapy
- Carcinoma, Hepatocellular/metabolism
- Carcinoma, Hepatocellular/pathology
- Drug Resistance, Neoplasm/drug effects
- Epirubicin/pharmacology
- Glycoproteins/pharmacology
- Humans
- Liver Neoplasms/drug therapy
- Liver Neoplasms/metabolism
- Liver Neoplasms/pathology
- Male
- Mice
- Mice, Nude
- RNA, Messenger/genetics
- Real-Time Polymerase Chain Reaction
- Reverse Transcriptase Polymerase Chain Reaction
- Signal Transduction/drug effects
- Trypsin Inhibitors/pharmacology
- Tumor Cells, Cultured
- Xenograft Model Antitumor Assays
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Affiliation(s)
- Bin Song
- Department of General Surgery, Changhai Hospital, Second Military Medical University, Shanghai, 200438, China
| | - Qi Bian
- Department of Nephrology, Changhai Hospital, Second Military Medical University, Shanghai, 200438, China
| | - Cheng Hao Shao
- Department of General Surgery, Changhai Hospital, Second Military Medical University, Shanghai, 200438, China
| | - Gang Li
- Department of General Surgery, Changhai Hospital, Second Military Medical University, Shanghai, 200438, China
| | - An An Liu
- Department of General Surgery, Changhai Hospital, Second Military Medical University, Shanghai, 200438, China
| | - Wei Jing
- Department of General Surgery, Changhai Hospital, Second Military Medical University, Shanghai, 200438, China
| | - Rui Liu
- Department of General Surgery, Changhai Hospital, Second Military Medical University, Shanghai, 200438, China
| | - Yi-Jie Zhang
- Department of General Surgery, Changhai Hospital, Second Military Medical University, Shanghai, 200438, China
| | - Ying-Qi Zhou
- Department of General Surgery, Changhai Hospital, Second Military Medical University, Shanghai, 200438, China
| | - Xian-Gui Hu
- Department of General Surgery, Changhai Hospital, Second Military Medical University, Shanghai, 200438, China
- * E-mail: (GJ); (XGH)
| | - Gang Jin
- Department of General Surgery, Changhai Hospital, Second Military Medical University, Shanghai, 200438, China
- * E-mail: (GJ); (XGH)
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134
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Feng Y, Yao Z, Klionsky DJ. How to control self-digestion: transcriptional, post-transcriptional, and post-translational regulation of autophagy. Trends Cell Biol 2015; 25:354-63. [PMID: 25759175 DOI: 10.1016/j.tcb.2015.02.002] [Citation(s) in RCA: 252] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 02/04/2015] [Accepted: 02/05/2015] [Indexed: 01/23/2023]
Abstract
Macroautophagy (hereafter autophagy), literally defined as a type of self-eating, is a dynamic cellular process in which cytoplasm is sequestered within a unique compartment termed the phagophore. Upon completion, the phagophore matures into a double-membrane autophagosome that fuses with the lysosome or vacuole, allowing degradation of the cargo. Nonselective autophagy is primarily a cytoprotective response to various types of stress; however, the process can also be highly selective. Autophagy is involved in various aspects of cell physiology, and its dysregulation is associated with a range of diseases. The regulation of autophagy is complex, and the process must be properly modulated to maintain cellular homeostasis. In this review, we focus on the current state of knowledge concerning transcriptional, post-transcriptional, and post-translational regulation of autophagy in yeast and mammals.
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Affiliation(s)
- Yuchen Feng
- Life Sciences Institute and the Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Zhiyuan Yao
- Life Sciences Institute and the Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Daniel J Klionsky
- Life Sciences Institute and the Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USA.
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135
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Lin F, Ghislat G, Luo S, Renna M, Siddiqi F, Rubinsztein DC. XIAP and cIAP1 amplifications induce Beclin 1-dependent autophagy through NFκB activation. Hum Mol Genet 2015; 24:2899-913. [PMID: 25669656 PMCID: PMC4406300 DOI: 10.1093/hmg/ddv052] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Accepted: 02/06/2015] [Indexed: 12/31/2022] Open
Abstract
Perturbations in autophagy and apoptosis are associated with cancer development. XIAP and cIAP1 are two members of the inhibitors of apoptosis protein family whose expression is elevated in different cancers. Here we report that XIAP and cIAP1 induce autophagy by upregulating the transcription of Beclin 1, an essential autophagy gene. The E3 ubiquitin ligase activity of both proteins activates NFκB signalling, leading to the direct binding of p65 to the promoter of Beclin 1 and to its transcriptional activation. This mechanism may be relevant in cancer cells, since we found increased levels of autophagy in different B-cell lymphoma-derived cell lines where XIAP is overexpressed and pharmacological inhibition of XIAP in these cell lines reduced autophagosome biogenesis. Thus, the chemotherapy resistance associated with XIAP and cIAP1 overexpression observed in several human cancers may be, at least in part, due to the Beclin 1-dependent autophagy activation by IAPs described in this study. In this context, the disruption of this increased autophagy might represent a valuable pharmacological tool to be included in combined anti-neoplastic therapies.
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Affiliation(s)
- Fang Lin
- Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Wellcome/MRC Building, Addenbrooke's Hospital, Hills Road, Cambridge CB2 0XY, UK
| | - Ghita Ghislat
- Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Wellcome/MRC Building, Addenbrooke's Hospital, Hills Road, Cambridge CB2 0XY, UK
| | - Shouqing Luo
- Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Wellcome/MRC Building, Addenbrooke's Hospital, Hills Road, Cambridge CB2 0XY, UK
| | - Maurizio Renna
- Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Wellcome/MRC Building, Addenbrooke's Hospital, Hills Road, Cambridge CB2 0XY, UK
| | - Farah Siddiqi
- Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Wellcome/MRC Building, Addenbrooke's Hospital, Hills Road, Cambridge CB2 0XY, UK
| | - David C Rubinsztein
- Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Wellcome/MRC Building, Addenbrooke's Hospital, Hills Road, Cambridge CB2 0XY, UK
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136
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Chandra V, Bhagyaraj E, Parkesh R, Gupta P. Transcription factors and cognate signalling cascades in the regulation of autophagy. Biol Rev Camb Philos Soc 2015; 91:429-51. [PMID: 25651938 DOI: 10.1111/brv.12177] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Revised: 01/04/2015] [Accepted: 01/11/2015] [Indexed: 12/11/2022]
Abstract
Autophagy is a process that maintains the equilibrium between biosynthesis and the recycling of cellular constituents; it is critical for avoiding the pathophysiology that results from imbalance in cellular homeostasis. Recent reports indicate the need for the design of high-throughput screening assays to identify targets and small molecules for autophagy modulation. For such screening, however, a better understanding of the regulation of autophagy is essential. In addition to regulation by various signalling cascades, regulation of gene expression by transcription factors is also critical. This review focuses on the various transcription factors as well as the corresponding signalling molecules that act together to translate the stimuli to effector molecules that up- or downregulate autophagy. This review rationalizes the importance of these transcription factors functioning in tandem with cognate signalling molecules and their interfaces as possible therapeutic targets for more specific pharmacological interventions.
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Affiliation(s)
- Vemika Chandra
- CSIR-Institute of Microbial Technology, Sector 39-A, Chandigarh 160036, India
| | - Ella Bhagyaraj
- CSIR-Institute of Microbial Technology, Sector 39-A, Chandigarh 160036, India
| | - Raman Parkesh
- CSIR-Institute of Microbial Technology, Sector 39-A, Chandigarh 160036, India
| | - Pawan Gupta
- CSIR-Institute of Microbial Technology, Sector 39-A, Chandigarh 160036, India
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137
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Haar L, Ren X, Liu Y, Koch SE, Goines J, Tranter M, Engevik MA, Nieman M, Rubinstein J, Jones WK. Acute consumption of a high-fat diet prior to ischemia-reperfusion results in cardioprotection through NF-κB-dependent regulation of autophagic pathways. Am J Physiol Heart Circ Physiol 2014; 307:H1705-13. [PMID: 25239807 DOI: 10.1152/ajpheart.00271.2014] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Previous studies have demonstrated improvement of cardiac function occurs with acute consumption of a high-fat diet (HFD) after myocardial infarction (MI). However, no data exist addressing the effects of acute HFD upon the extent of injury after MI. This study investigates the hypothesis that short-term HFD, prior to infarction, protects the heart against ischemia-reperfusion (I/R) injury through NF-κB-dependent regulation of cell death pathways in the heart. Data show that an acute HFD initiates cardioprotection against MI (>50% reduction in infarct size normalized to risk region) after 24 h to 2 wk of HFD, but protection is completely absent after 6 wk of HFD, when mice are reported to develop pathophysiology related to the diet. Furthermore, cardioprotection after 24 h of HFD persists after an additional 24 h of normal chow feeding and was found to be dependent upon NF-κB activation in cardiomyocytes. This study also indicates that short-term HFD activates autophagic processes (beclin-1, LC-3) preischemia, as seen in other protective stimuli. Increases in beclin-1 and LC-3 were found to be NF-κB-dependent, and administration of chloroquine, an inhibitor of autophagy, abrogated cardioprotection. Our results support that acute high-fat feeding mediates cardioprotection against I/R injury associated with a NF-κB-dependent increase in autophagy and reduced apoptosis, as has been found for ischemic preconditioning.
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Affiliation(s)
- Lauren Haar
- Department of Systems Biology and Physiology, University of Cincinnati, Cincinnati, Ohio
| | - Xiaoping Ren
- Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati, Cincinnati, Ohio
| | - Yong Liu
- Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati, Cincinnati, Ohio
| | - Sheryl E Koch
- Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati, Cincinnati, Ohio
| | - Jillian Goines
- Department of Molecular Pharmacology and Therapeutics Loyola University Chicago, Maywood, Illinois; and Department of Pharmacology and Cell Biophysics, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Michael Tranter
- Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati, Cincinnati, Ohio
| | - Melinda A Engevik
- Department of Systems Biology and Physiology, University of Cincinnati, Cincinnati, Ohio
| | - Michelle Nieman
- Department of Systems Biology and Physiology, University of Cincinnati, Cincinnati, Ohio
| | - Jack Rubinstein
- Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati, Cincinnati, Ohio
| | - W Keith Jones
- Department of Molecular Pharmacology and Therapeutics Loyola University Chicago, Maywood, Illinois; and Department of Pharmacology and Cell Biophysics, University of Cincinnati College of Medicine, Cincinnati, Ohio
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138
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Chung YH, Jang Y, Choi B, Song DH, Lee EJ, Kim SM, Song Y, Kang SW, Yoon SY, Chang EJ. Beclin-1 Is Required for RANKL-Induced Osteoclast Differentiation. J Cell Physiol 2014; 229:1963-71. [DOI: 10.1002/jcp.24646] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2013] [Accepted: 04/11/2014] [Indexed: 12/31/2022]
Affiliation(s)
- Yeon-Ho Chung
- Department of Biomedical Sciences; University of Ulsan College of Medicine, Asan Medical Center; Seoul Korea
- Department of Anatomy and Cell Biology; Cell Dysfunction Research Center and BMIT, University of Ulsan College of Medicine; Seoul Korea
| | - Youngsaeng Jang
- Department of Biomedical Sciences; University of Ulsan College of Medicine, Asan Medical Center; Seoul Korea
- Department of Anatomy and Cell Biology; Cell Dysfunction Research Center and BMIT, University of Ulsan College of Medicine; Seoul Korea
| | - Bongkun Choi
- Department of Biomedical Sciences; University of Ulsan College of Medicine, Asan Medical Center; Seoul Korea
- Department of Anatomy and Cell Biology; Cell Dysfunction Research Center and BMIT, University of Ulsan College of Medicine; Seoul Korea
| | - Da-Hyun Song
- Department of Biomedical Sciences; University of Ulsan College of Medicine, Asan Medical Center; Seoul Korea
- Department of Anatomy and Cell Biology; Cell Dysfunction Research Center and BMIT, University of Ulsan College of Medicine; Seoul Korea
| | - Eun-Jin Lee
- Department of Biomedical Sciences; University of Ulsan College of Medicine, Asan Medical Center; Seoul Korea
- Department of Anatomy and Cell Biology; Cell Dysfunction Research Center and BMIT, University of Ulsan College of Medicine; Seoul Korea
| | - Sang-Min Kim
- Department of Biomedical Sciences; University of Ulsan College of Medicine, Asan Medical Center; Seoul Korea
- Department of Anatomy and Cell Biology; Cell Dysfunction Research Center and BMIT, University of Ulsan College of Medicine; Seoul Korea
| | - Youngsup Song
- Department of Biomedical Sciences; University of Ulsan College of Medicine, Asan Medical Center; Seoul Korea
- Department of Anatomy and Cell Biology; Cell Dysfunction Research Center and BMIT, University of Ulsan College of Medicine; Seoul Korea
| | - Sang-Wook Kang
- Department of Biomedical Sciences; University of Ulsan College of Medicine, Asan Medical Center; Seoul Korea
- Department of Anatomy and Cell Biology; Cell Dysfunction Research Center and BMIT, University of Ulsan College of Medicine; Seoul Korea
| | - Seung-Yong Yoon
- Department of Anatomy and Cell Biology; Cell Dysfunction Research Center and BMIT, University of Ulsan College of Medicine; Seoul Korea
| | - Eun-Ju Chang
- Department of Biomedical Sciences; University of Ulsan College of Medicine, Asan Medical Center; Seoul Korea
- Department of Anatomy and Cell Biology; Cell Dysfunction Research Center and BMIT, University of Ulsan College of Medicine; Seoul Korea
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139
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Labouba I, Poisson A, Lafontaine J, Delvoye N, Gannon PO, Le Page C, Saad F, Mes-Masson AM. The RelB alternative NF-kappaB subunit promotes autophagy in 22Rv1 prostate cancer cells in vitro and affects mouse xenograft tumor growth in vivo. Cancer Cell Int 2014; 14:67. [PMID: 25788857 PMCID: PMC4364035 DOI: 10.1186/1475-2867-14-67] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 05/15/2014] [Indexed: 11/17/2022] Open
Abstract
Background The involvement of NF-κB signaling in prostate cancer (PCa) has largely been established through the study of the classical p65 subunit. Nuclear localization of p65 in PCa patient tissues has been shown to correlate with biochemical recurrence, while in vitro studies have demonstrated that the classical NF-κB signaling pathway promotes PCa progression and metastatic potential. More recently, the nuclear location of RelB, a member of the alternative NF-κB signaling, has also been shown to correlate with the Gleason score. The current study aims to clarify the role of alternative NF-κB in PCa cells by exploring, in vitro and in vivo, the effects of RelB overexpression on PCa biology. Methods Using a lentivirus-expression system, we constitutively overexpressed RelB or control GFP into 22Rv1 cells and monitored alternative transcriptional NF-κB activity. In vivo, tumor growth was assessed after the injection of 22Rv1-derived cells into SCID mice. In vitro, the impact of RelB on 22Rv1 cell proliferation was evaluated in monolayer culture. The anchorage-independent cell growth of derived-22Rv1 cells was assessed by soft agar assay. Apoptosis and autophagy were evaluated by Western blot analysis in 22Rv1-derived cells cultured in suspension using poly-HEMA pre-coated dishes. Results The overexpression of RelB in 22Rv1 cells induced the constitutive activation of the alternative NF-κB pathway. In vivo, RelB expression caused a lag in the initiation of 22Rv1-induced tumors in SCID mice. In vitro, RelB stimulated the proliferation of 22Rv1 cells and reduced their ability to grow in soft agar. These observations may be reconciled by our findings that, when cultured in suspension on poly-HEMA pre-coated dishes, 22Rv1 cells expressing RelB were more susceptible to cell death, and more specifically to autophagy controlled death. Conclusions This study highlights a role of the alternative NF-κB pathway in proliferation and the controlled autophagy. Thus, the interplay of these properties may contribute to tumor survival in stress conditions while promoting PCa cells growth contributing to the overall tumorigenicity of these cells.
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Affiliation(s)
- Ingrid Labouba
- Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM)/Institut du cancer de Montréal, Montreal, Canada
| | - Alexis Poisson
- Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM)/Institut du cancer de Montréal, Montreal, Canada
| | - Julie Lafontaine
- Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM)/Institut du cancer de Montréal, Montreal, Canada
| | - Nathalie Delvoye
- Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM)/Institut du cancer de Montréal, Montreal, Canada
| | - Philippe O Gannon
- Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM)/Institut du cancer de Montréal, Montreal, Canada
| | - Cécile Le Page
- Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM)/Institut du cancer de Montréal, Montreal, Canada
| | - Fred Saad
- Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM)/Institut du cancer de Montréal, Montreal, Canada ; Division of Urology, CHUM, Université de Montréal, CHUM Notre-Dame, 1560 Sherbrooke east, Montreal, Quebec, Canada
| | - Anne-Marie Mes-Masson
- Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM)/Institut du cancer de Montréal, Montreal, Canada ; Department of Medicine, Université de Montréal, Montreal, Canada
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140
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Deng Y, Xu J, Zhang X, Yang J, Zhang D, Huang J, Lv P, Shen W, Yang Y. Berberine attenuates autophagy in adipocytes by targeting BECN1. Autophagy 2014; 10:1776-86. [PMID: 25126729 DOI: 10.4161/auto.29746] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The lysosomal degradation pathway, autophagy, is essential for the maintenance of cellular homeostasis. Recently, autophagy has been demonstrated to be required in the process of adipocyte conversion. However, its role in mature adipocytes under physiological and pathological conditions remains unclear. Here, we report a major function of BECN1 in the regulation of basal autophagy in mature adipocytes. We also show that berberine, a natural plant alkaloid, inhibits basal autophagy in adipocytes and adipose tissue of mice fed a high-fat diet via downregulation of BECN1 expression. We further demonstrate that berberine has a pronounced effect on the stability of Becn 1 mRNA through the Mir30 family. These findings explore the potential of BECN1 as a key molecule and a drug target for regulating autophagy in mature adipocytes.
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Affiliation(s)
- Yujie Deng
- Department of Endocrine and Metabolic Diseases; Institute of Endocrine and Metabolic Diseases; Ruijin Hospital; Shanghai Jiaotong University School of Medicine; Shanghai, China
| | - Jun Xu
- Department of Endocrine and Metabolic Diseases; Institute of Endocrine and Metabolic Diseases; Ruijin Hospital; Shanghai Jiaotong University School of Medicine; Shanghai, China
| | - Xiaoyan Zhang
- Department of Endocrine and Metabolic Diseases; Institute of Endocrine and Metabolic Diseases; Ruijin Hospital; Shanghai Jiaotong University School of Medicine; Shanghai, China
| | - Jian Yang
- Department of Endocrine and Metabolic Diseases; Institute of Endocrine and Metabolic Diseases; Ruijin Hospital; Shanghai Jiaotong University School of Medicine; Shanghai, China
| | - Di Zhang
- Department of Endocrine and Metabolic Diseases; Institute of Endocrine and Metabolic Diseases; Ruijin Hospital; Shanghai Jiaotong University School of Medicine; Shanghai, China
| | - Jian Huang
- Department of Endocrine and Metabolic Diseases; Institute of Endocrine and Metabolic Diseases; Ruijin Hospital; Shanghai Jiaotong University School of Medicine; Shanghai, China
| | - Pengfei Lv
- Department of Endocrine and Metabolic Diseases; Institute of Endocrine and Metabolic Diseases; Ruijin Hospital; Shanghai Jiaotong University School of Medicine; Shanghai, China
| | - Weili Shen
- Shanghai Key Laboratory of Vascular Biology; Department of Hypertension; Ruijin Hospital; Shanghai Jiaotong University School of Medicine; Shanghai, China
| | - Ying Yang
- Department of Endocrine and Metabolic Diseases; Institute of Endocrine and Metabolic Diseases; Ruijin Hospital; Shanghai Jiaotong University School of Medicine; Shanghai, China
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141
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Zhu W, Swaminathan G, Plowey ED. GA binding protein augments autophagy via transcriptional activation of BECN1-PIK3C3 complex genes. Autophagy 2014; 10:1622-36. [PMID: 25046113 DOI: 10.4161/auto.29454] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Macroautophagy is a vesicular catabolic trafficking pathway that is thought to protect cells from diverse stressors and to promote longevity. Recent studies have revealed that transcription factors play important roles in the regulation of autophagy. In this study, we have identified GA binding protein (GABP) as a transcriptional regulator of the combinatorial expression of BECN1-PIK3C3 complex genes involved in autophagosome initiation. We performed bioinformatics analyses that demonstrated highly conserved putative GABP sites in genes that encode BECN1/Beclin 1, several BECN1 interacting proteins, and downstream autophagy proteins including the ATG12-ATG5-ATG16L1 complex. We demonstrate that GABP binds to the promoter regions of BECN1-PIK3C3 complex genes and activates their transcriptional activities. Knockdown of GABP reduced BECN1-PIK3C3 complex transcripts, BECN1-PIK3C3 complex protein levels and autophagy in cultured cells. Conversely, overexpression of GABP increased autophagy. Nutrient starvation increased GABP-dependent transcriptional activity of BECN1-PIK3C3 complex gene promoters and increased the recruitment of GABP to the BECN1 promoter. Our data reveal a novel function of GABP in the regulation of autophagy via transcriptional activation of the BECN1-PIK3C3 complex.
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Affiliation(s)
- Wan Zhu
- Department of Pathology; Stanford University School of Medicine; Stanford, CA USA
| | - Gayathri Swaminathan
- Department of Pathology; Stanford University School of Medicine; Stanford, CA USA
| | - Edward D Plowey
- Department of Pathology; Stanford University School of Medicine; Stanford, CA USA
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142
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Abstract
SIGNIFICANCE Oxidative (reactive oxygen species [ROS]) and nitrosative (reactive nitrogen species [RNS]) stress affects many physiological processes, including survival and death. Although high levels of ROS/RNS mainly causes cell death, low levels of free radicals directly modulate the activities of transcriptional factors, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), p53, and nuclear factor (erythroid-derived) 2-like (Nrf2), and regulate numerous protein kinase cascades that participate in the regulation of the cross talk between autophagy and apoptosis. RECENT ADVANCES Low levels of ROS modify Atg4 and high mobility group box 1 (HMGB1) proteins, activate AMP-activated protein kinase (AMPK) and apoptosis signal-regulating kinase/c-Jun N-terminal kinase (JNK) pathways, or transactivate various proteins that could upregulate autophagy, leading to reductions in apoptosis. Transactivation of antioxidant genes blocks apoptosis and serves as a feedback loop to reduce autophagy. Free radicals could also activate protein kinase B (PKB, or Akt), preventing both autophagy and apoptosis. Stimulation of nitric oxide formation causes S-nitrosylation of several kinases, including JNK1 and IκB kinase β, which blocks autophagy and could promote apoptosis. However, S-nitrosylation of some proapoptotic proteins could block apoptosis. CRITICAL ISSUES Endoplasmic reticulum and mitochondria are the main sources of free radicals, which play an essential role in the regulation of apoptosis and autophagy. Oxidation of cardiolipin promotes cytochrome c release and apoptosis that potentially could be inhibited by autophagic clearance of damaged mitochondria. Elimination of damaged mitochondria reduces ROS accumulation, creating a feedback loop that causes inhibition of autophagy. Low levels of RNS could inhibit fission of mitochondria, which would block their degradation by autophagy and spare cells from apoptosis. FUTURE DIRECTIONS Understanding of mechanisms that regulate the cross talk between cell fates is essential for discovery of therapeutic tools in the strenuous fight against various disorders, including neurodegeneration and cancer.
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Affiliation(s)
- Vitaliy O Kaminskyy
- 1 Division of Toxicology, Institute of Environmental Medicine , Karolinska Institutet, Stockholm, Sweden
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143
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Jin M, Klionsky DJ. Regulation of autophagy: modulation of the size and number of autophagosomes. FEBS Lett 2014; 588:2457-63. [PMID: 24928445 DOI: 10.1016/j.febslet.2014.06.015] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 06/02/2014] [Accepted: 06/03/2014] [Indexed: 10/25/2022]
Abstract
Autophagy as a conserved degradation and recycling process in eukaryotic cells, occurs constitutively, but is induced by stress. A fine regulation of autophagy in space, time, and intensity is critical for maintaining normal energy homeostasis and metabolism, and to allow for its therapeutic modulation in various autophagy-related human diseases. Autophagy activity is regulated in both transcriptional and post-translational manners. In this review, we summarize the cytosolic regulation of autophagy via its molecular machinery, and nuclear regulation by transcription factors. Specifically, we consider Ume6-ATG8 and Pho23-ATG9 transcriptional regulation in detail, as examples of how nuclear transcription factors and cytosolic machinery cooperate to determine autophagosome size and number, which are the two main mechanistic factors through which autophagy activity is regulated.
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Affiliation(s)
- Meiyan Jin
- Life Sciences Institute, and the Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, United States
| | - Daniel J Klionsky
- Life Sciences Institute, and the Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, United States.
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144
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Kuse Y, Ogawa K, Tsuruma K, Shimazawa M, Hara H. Damage of photoreceptor-derived cells in culture induced by light emitting diode-derived blue light. Sci Rep 2014; 4:5223. [PMID: 24909301 PMCID: PMC4048889 DOI: 10.1038/srep05223] [Citation(s) in RCA: 153] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Accepted: 05/21/2014] [Indexed: 01/21/2023] Open
Abstract
Our eyes are increasingly exposed to light from the emitting diode (LED) light of video display terminals (VDT) which contain much blue light. VDTs are equipped with televisions, personal computers, and smart phones. The present study aims to clarify the mechanism underlying blue LED light-induced photoreceptor cell damage. Murine cone photoreceptor-derived cells (661 W) were exposed to blue, white, or green LED light (0.38 mW/cm2). In the present study, blue LED light increased reactive oxygen species (ROS) production, altered the protein expression level, induced the aggregation of short-wavelength opsins (S-opsin), resulting in severe cell damage. While, blue LED light damaged the primary retinal cells and the damage was photoreceptor specific. N-Acetylcysteine (NAC), an antioxidant, protected against the cellular damage induced by blue LED light. Overall, the LED light induced cell damage was wavelength-, but not energy-dependent and may cause more severe retinal photoreceptor cell damage than the other LED light.
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Affiliation(s)
- Yoshiki Kuse
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu 501-1196, Japan
| | - Kenjiro Ogawa
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu 501-1196, Japan
| | - Kazuhiro Tsuruma
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu 501-1196, Japan
| | - Masamitsu Shimazawa
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu 501-1196, Japan
| | - Hideaki Hara
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu 501-1196, Japan
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145
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Poluzzi C, Casulli J, Goyal A, Mercer TJ, Neill T, Iozzo RV. Endorepellin evokes autophagy in endothelial cells. J Biol Chem 2014; 289:16114-28. [PMID: 24737315 DOI: 10.1074/jbc.m114.556530] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Endorepellin, the C-terminal fragment of the heparan sulfate proteoglycan perlecan, possesses angiostatic activity via dual receptor antagonism, through concurrent binding to the α2β1 integrin and vascular endothelial growth factor receptor 2 (VEGFR2). Here, we discovered that soluble endorepellin induced autophagy in endothelial cells by modulating the expression of Beclin 1, LC3, and p62, three established autophagic markers. Moreover, endorepellin evoked expression of the imprinted tumor suppressor gene Peg3 and its co-localization with Beclin 1 and LC3 in autophagosomes, suggesting a major role for this gene in endothelial cell autophagy. Mechanistically, endorepellin induced autophagy by down-regulating VEGFR2 via the two LG1/2 domains, whereas the C-terminal LG3 domain, the portion responsible for binding the α2β1 integrin, was ineffective. Endorepellin also induced transcriptional activity of the BECN1 promoter in endothelial cells, and the VEGFR2-specific tyrosine kinase inhibitor, SU5416, blocked this effect. Finally, we found a correlation between endorepellin-evoked inhibition of capillary morphogenesis and enhanced autophagy. Thus, we have identified a new role for this endogenous angiostatic fragment in inducing autophagy through a VEGFR2-dependent but α2β1 integrin-independent pathway. This novel mechanism specifically targets endothelial cells and could represent a promising new strategy to potentiate the angiostatic effect of endorepellin and perhaps other angiostatic matrix proteins.
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Affiliation(s)
- Chiara Poluzzi
- From the Department of Pathology, Anatomy, and Cell Biology and the Cancer Cell Biology and Signaling Program, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Joshua Casulli
- From the Department of Pathology, Anatomy, and Cell Biology and the Cancer Cell Biology and Signaling Program, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Atul Goyal
- From the Department of Pathology, Anatomy, and Cell Biology and the Cancer Cell Biology and Signaling Program, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Thomas J Mercer
- From the Department of Pathology, Anatomy, and Cell Biology and the Cancer Cell Biology and Signaling Program, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Thomas Neill
- From the Department of Pathology, Anatomy, and Cell Biology and the Cancer Cell Biology and Signaling Program, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Renato V Iozzo
- From the Department of Pathology, Anatomy, and Cell Biology and the Cancer Cell Biology and Signaling Program, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
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146
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Tumor necrosis factor receptor-associated periodic syndrome as a model linking autophagy and inflammation in protein aggregation diseases. J Mol Med (Berl) 2014; 92:583-94. [PMID: 24706103 DOI: 10.1007/s00109-014-1150-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Revised: 03/21/2014] [Accepted: 03/27/2014] [Indexed: 01/09/2023]
Abstract
Autophagy prevents cellular damage by eliminating insoluble aggregates of mutant misfolded proteins, which accumulate under different pathological conditions. Downregulation of autophagy enhances the inflammatory response and thus represents a possible common pathogenic event underlying a number of autoinflammatory syndromes, such as tumor necrosis factor (TNF) receptor-associated periodic syndrome (TRAPS). The pathogenesis of other monogenic or complex disorders that display symptoms of excessive inflammation also involve the autophagy pathway. Studies have shown that TRAPS-associated TNFRSF1A mutations induce cytoplasmic retention of the TNFR1 receptor, defective TNF-induced apoptosis, and production of reactive oxygen species (ROS). Furthermore, autophagy impairment may account for the pathogenic effects of TNFRSF1A mutations, thus inducing inflammation in TRAPS. In this review, we summarize the molecular interactions and functional links between autophagy with regard to nuclear factor-kappa B activation, ROS production, and apoptosis. Furthermore, we propose a complex interplay of these pathways as a model to explain the relationship between mutant protein misfolding and inflammation in genetically determined and aggregation-prone diseases. Accordingly, autophagy function should be investigated in all diseases showing an inflammatory component, and for which the molecular pathogenesis is still unclear.
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147
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Yang CS, Kim JJ, Lee HM, Jin HS, Lee SH, Park JH, Kim SJ, Kim JM, Han YM, Lee MS, Kweon GR, Shong M, Jo EK. The AMPK-PPARGC1A pathway is required for antimicrobial host defense through activation of autophagy. Autophagy 2014; 10:785-802. [PMID: 24598403 DOI: 10.4161/auto.28072] [Citation(s) in RCA: 91] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
AMP-activated protein kinase (AMPK) is a crucial energy sensor and plays a key role in integration of cellular functions to maintain homeostasis. Despite this, it is largely unknown whether targeting the AMPK pathway can be used as a therapeutic strategy for infectious diseases. Herein, we show that AMPK activation robustly induces antibacterial autophagy, which contributes to antimicrobial defense against Mycobacterium tuberculosis (Mtb). AMPK activation led to inhibition of Mtb-induced phosphorylation of the mechanistic target of rapamycin (MTOR) in macrophages. In addition, AMPK activation increased the genes involved in oxidative phosphorylation, mitochondrial ATP production, and biogenesis in Mtb-infected macrophages. Notably, peroxisome proliferator-activated receptor-gamma, coactivator 1α (PPARGC1A) was required for AMPK-mediated antimicrobial activity, as well as enhancement of mitochondrial function and biogenesis, in macrophages. Further, the AMPK-PPARGC1A pathway was involved in the upregulation of multiple autophagy-related genes via CCAAT/enhancer binding protein (C/EBP), β (CEBPB). PPARGC1A knockdown inhibited the AMPK-mediated induction of autophagy and impaired the fusion of phagosomes with MAP1LC3B (LC3B) autophagosomes in Mtb-infected macrophages. The link between autophagy, mitochondrial function, and antimicrobial activity was further demonstrated by studying LysMCre-mediated knockout of atg7, demonstrating mitochondrial ultrastructural defects and dysfunction, as well as blockade of antimicrobial activity against mycobacteria. Collectively, our results identify the AMPK-PPARGC1A axis as contributing to autophagy activation leading to an antimicrobial response, as a novel host defense mechanism.
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Affiliation(s)
- Chul-Su Yang
- Department of Microbiology; Chungnam National University School of Medicine; Daejeon, Korea; Infection Signaling Network Research Center; Chungnam National University School of Medicine; Daejeon, Korea
| | - Jwa-Jin Kim
- Department of Microbiology; Chungnam National University School of Medicine; Daejeon, Korea; Infection Signaling Network Research Center; Chungnam National University School of Medicine; Daejeon, Korea
| | - Hye-Mi Lee
- Department of Microbiology; Chungnam National University School of Medicine; Daejeon, Korea; Infection Signaling Network Research Center; Chungnam National University School of Medicine; Daejeon, Korea
| | - Hyo Sun Jin
- Department of Microbiology; Chungnam National University School of Medicine; Daejeon, Korea; Infection Signaling Network Research Center; Chungnam National University School of Medicine; Daejeon, Korea
| | - Sang-Hee Lee
- BioMedical Research Center; Korea Advanced Institute of Science and Technology; Daejeon, Korea
| | - Ji-Hoon Park
- Infection Signaling Network Research Center; Chungnam National University School of Medicine; Daejeon, Korea; Department of Biochemistry; Chungnam National University School of Medicine; Daejeon, Korea
| | - Soung Jung Kim
- Department of Internal Medicine and Research Center for Endocrine and Metabolic Diseases; Chungnam National University School of Medicine; Daejeon, Korea
| | - Jin-Man Kim
- Infection Signaling Network Research Center; Chungnam National University School of Medicine; Daejeon, Korea; Department of Pathology; Chungnam National University School of Medicine; Daejeon, Korea
| | - Yong-Mahn Han
- Department of Biological Sciences and Center for Stem Cell Differentiation; Korea Advanced Institute of Science and Technology; Daejeon, Korea
| | - Myung-Shik Lee
- Department of Medicine; Samsung Medical Center; Sungkyunkwan University School of Medicine; Seoul, Korea
| | - Gi Ryang Kweon
- Infection Signaling Network Research Center; Chungnam National University School of Medicine; Daejeon, Korea; Department of Biochemistry; Chungnam National University School of Medicine; Daejeon, Korea
| | - Minho Shong
- Department of Internal Medicine and Research Center for Endocrine and Metabolic Diseases; Chungnam National University School of Medicine; Daejeon, Korea
| | - Eun-Kyeong Jo
- Department of Microbiology; Chungnam National University School of Medicine; Daejeon, Korea; Infection Signaling Network Research Center; Chungnam National University School of Medicine; Daejeon, Korea
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148
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Sinha B, Rubens M. Systemic immune activation in HIV and potential therapeutic options. Immunopharmacol Immunotoxicol 2014; 36:89-95. [PMID: 24552614 DOI: 10.3109/08923973.2014.890217] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
CONTEXT Advancement in HIV treatment has evolved over the last two decades with the discovery of new drugs and approaches. Studies have demonstrated that HIV-infected individuals have elevated immune activation even during effective antiretroviral therapy. Persistently elevated immune activation has been one of the main obstacles against developing an effective approach for curing HIV. OBJECTIVE This review examines the mechanism of microbial translocation in HIV-infected individuals and currently investigated potential therapeutic approaches. METHODS We searched PubMed and Medline for peer-reviwed articles and recent HIV/AIDS conference abstracts and papers. Narrative review method was used since the objectives of the study were mechanism of microbial translocation and mechanism of action of multiple drugs against it. RESULTS Microbial translocation occurs as a result of the disruption of epithelial barrier and immunological dysfunction within the intestinal tract due to defective tight junctions, loss of TH17 type CD4(+) T cells, impaired liver architecture, and depletion of intestinal myelomonocytic cells. Potent and effective way to intervene microbial translocation is to target the mechanism of actions involved in microbial translocation by restoration of beneficial microbiata with supplemental probiotics/prebiotics, increased clearance of microbial products from systemic circulation with targeted antibodies and restoration of intestinal integrity with antibiotics. CONCLUSIONS Number of promising drug molecules against microbial translocation are currently under various stages of trials and the results of these trials will hopefully contribute significantly toward effective therapeutic intervention. However, studies also need to explore the effect of combination drugs to abrogate microbial translocation.
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149
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Synergistic antitumor effect of Doxorubicin and tacrolimus (FK506) on hepatocellular carcinoma cell lines. ScientificWorldJournal 2014; 2014:450390. [PMID: 24701168 PMCID: PMC3951002 DOI: 10.1155/2014/450390] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Accepted: 12/24/2013] [Indexed: 01/24/2023] Open
Abstract
Hepatocellular carcinoma is the fifth most common cancer worldwide and shows a complex clinical course, poor response to pharmacological treatment, and a severe prognosis. Thus, the aim of this study was to investigate whether tacrolimus (FK506) has synergistic antitumor effects with doxorubicin on two human hepatocellular carcinoma cell lines, Huh7 and HepG2. Cell viability was analyzed by Sulforhodamine B assay and synergic effect was evaluated by the software CalcuSyn. Cell apoptosis was evaluated using Annexin V and Dead Cell assay. Apoptosis-related protein PARP-1 cleaved and autophagy-related protein expressions (Beclin-1 and LC3B) were measured by western blotting analysis. Cytokines concentration in cellular supernatants after treatments was studied by Bio-Plex assay. Interestingly the formulation with doxorubicin and tacrolimus induced higher cytotoxicity level on tumor cells than single treatment. Moreover, our results showed that the mechanisms involved were (i) a strong cell apoptosis induction, (ii) contemporaneous decrease of autophagy activation, understood as prosurvival process, and (iii) downregulation of proinflammatory cytokines. In conclusion, future studies could relate to the doxorubicin/tacrolimus combination effects in mice models bearing HCC in order to see if this formulation could be useful in HCC treatment.
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150
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Cycloheximide inhibits starvation-induced autophagy through mTORC1 activation. Biochem Biophys Res Commun 2014; 445:334-9. [PMID: 24525133 DOI: 10.1016/j.bbrc.2014.01.180] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Accepted: 01/29/2014] [Indexed: 11/23/2022]
Abstract
Protein synthesis inhibitors such as cycloheximide (CHX) are known to suppress protein degradation including autophagy. The fact that CHX inhibits autophagy has been generally interpreted to indicate that newly synthesized protein is indispensable for autophagy. However, CHX is also known to increase the intracellular level of amino acids and activate mTORC1 activity, a master negative regulator of autophagy. Accordingly, CHX can affect autophagic activity through inhibition of de novo protein synthesis and/or modulation of mTORC1 signaling. In this study, we investigated the effects of CHX on autophagy using specific autophagy markers. We found that CHX inhibited starvation-induced autophagy but not Torin1-induced autophagy. CHX also suppressed starvation-induced puncta formation of GFP-ULK1, an early-step marker of the autophagic process which is regulated by mTORC1. CHX activated mTORC1 even under autophagy-inducible starvation conditions. Finally, the inhibitory effect of CHX on starvation-induced autophagy was cancelled by the mTOR inhibitor Torin1. These results suggest that CHX inhibits starvation-induced autophagy through mTORC1 activation and also that autophagy does not require new protein synthesis at least in the acute phase of starvation.
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