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Shi X, Zhang Q, Chang M, Zhang Y, Zhao M, Yang B, Li P, Zhang Y. Ferroptosis is involved in passive Heymann nephritis in rats. Heliyon 2023; 9:e21050. [PMID: 37886789 PMCID: PMC10597846 DOI: 10.1016/j.heliyon.2023.e21050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Revised: 10/04/2023] [Accepted: 10/13/2023] [Indexed: 10/28/2023] Open
Abstract
Ferroptosis is found to be involved in some experimental models of kidney diseases, but its role in membrane nephropathy (MN) is still unclear. The purpose of this study is to explore whether ferroptosis occurred in MN, and the role of ferritinophagy. In this study, passive Heymann nephritis (PHN) rats were induced by single tail vein injection of anti-Fx1A serum, and normal rats were used as control. The changes of 24 h urinary protein, serum biochemical parameters, renal pathological damage, iron content, lipid peroxidation parameters, ferroptosis markers, and ferritinophagy markers were evaluated in the two groups. Compared with the control group, PHN rats showed obvious proteinuria, hypoproteinemia, and hyperlipidemia. Besides, more severe renal pathological damage and higher Fe2+ levels were observed in PHN rats, and the levels of malondialdehyde (MDA) increased significantly, while the levels of superoxide Dismutase (SOD) and glutathione (GSH) decreased. In addition, the expression of glutathione peroxidase 4 (GPX4) in renal tissues of PHN rats decreased significantly, while the expression of transferrin receptor (TFR) and acyl-CoA synthetase long-chain family member 4 (ACSL4) increased. The expression of microtubule associated protein 1 light chain 3 (LC3) II/LC3I and nuclear receptor coactivator 4 (NCOA4) increased significantly. Therefore, our study shows that ferroptosis is involved in the pathological damage of MN, and companied by activation of ferritinophagy.
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Affiliation(s)
- Xiujie Shi
- Department of Nephrology, Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, 100091, China
| | - Qi Zhang
- Department of Nephrology, Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, 100091, China
| | - Meiying Chang
- Department of Nephrology, Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, 100091, China
| | - Yifan Zhang
- Department of Nephrology, Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, 100091, China
- Beijing University of Chinese Medicine, Beijing, 100029, China
| | - MingMing Zhao
- Department of Nephrology, Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, 100091, China
| | - Bin Yang
- Department of Pathology, Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, 100091, China
| | - Peng Li
- Experimental Research Center, Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, 100091, China
| | - Yu Zhang
- Department of Nephrology, Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, 100091, China
- Xin-Huangpu Joint Innovation Institute of Chinese Medicine, Guangzhou, 510535, China
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2
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Homma T, Fujii J. Emerging connections between oxidative stress, defective proteolysis, and metabolic diseases. Free Radic Res 2020; 54:931-946. [DOI: 10.1080/10715762.2020.1734588] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Takujiro Homma
- Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Yamagata University, Yamagata, Japan
| | - Junichi Fujii
- Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Yamagata University, Yamagata, Japan
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3
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Cao P, Zhang Y, Huang Z, Sullivan MA, He Z, Wang J, Chen Z, Hu H, Wang K. The Preventative Effects of Procyanidin on Binge Ethanol-Induced Lipid Accumulation and ROS Overproduction via the Promotion of Hepatic Autophagy. Mol Nutr Food Res 2019; 63:e1801255. [PMID: 31336037 DOI: 10.1002/mnfr.201801255] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2018] [Revised: 07/08/2019] [Indexed: 11/11/2022]
Abstract
SCOPE Autophagy plays an important role in alleviating alcoholic liver disease (ALD). In this study, it is discovered that a dimer procyanidin (DPC) significantly prevented ALD by promoting hepatic autophagy. METHODS AND RESULTS Both cell and animal disease models stimulated by excessive ethanol are employed to evaluate the protective actions of DPC. Specifically, in vitro, DPC significantly decreased intracellular lipid deposition, diminished reactive oxygen species (ROS) formation, and elevated the level of mitochondrial membrane potential. These beneficial effects can be remarkably blocked by 3-methyladenine, a potent autophagy inhibitor, suggesting the autophagy-dependent protective role of DPC. In vivo, DPC pretreatment can also significantly reduce lipid accumulation, ROS overproduction, and elevated GSH content in the liver. Similarly, these protective effects of DPC can be partially reversed by chloroquine, a lysosomal inhibitor used to block the late-stage autophagy flux. Moreover, the determinations of LC3 and p62 protein expressions, autophagic flux assessments, and transmission electron microscopy observation further demonstrate the pro-autophagic effect of DPC. CONCLUSIONS DPC may activate hepatic autophagy to eliminate lipid droplets and damaged mitochondria, thereby reducing hepatic lipid disposition and ROS overproduction. This study demonstrates that DPC is a protective reagent on ALD, providing a novel strategy of fighting ALD.
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Affiliation(s)
- Peng Cao
- Department of Pharmacy, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Yu Zhang
- Department of Pharmacy, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Zi Huang
- School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Mitchell A Sullivan
- Glycation and Diabetes, Mater Research Institute-The University of Queensland, The Translational Institute, Brisbane, QLD, 4102, Australia
| | - Zihao He
- Department of Pharmacy, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Jinglin Wang
- Department of Pharmacy, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Zehong Chen
- Department of Pharmacy, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Huiping Hu
- School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Kaiping Wang
- School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
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4
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Kivinen N. The role of autophagy in age-related macular degeneration. Acta Ophthalmol 2018; 96 Suppl A110:1-50. [PMID: 29633521 DOI: 10.1111/aos.13753] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Niko Kivinen
- Department of Ophthalmology; University of Eastern Finland; Kuopio Finland
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5
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Xiao Y, Chen X, Huang S, Li G, Mo M, Zhang L, Chen C, Guo W, Zhou M, Wu Z, Cen L, Long S, Li S, Yang X, Qu S, Pei Z, Xu P. Iron promotes α-synuclein aggregation and transmission by inhibiting TFEB-mediated autophagosome-lysosome fusion. J Neurochem 2018; 145:34-50. [PMID: 29364516 DOI: 10.1111/jnc.14312] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 01/15/2018] [Accepted: 01/17/2018] [Indexed: 12/21/2022]
Affiliation(s)
- Yousheng Xiao
- Department of Neurology; The First Affiliated Hospital of Guangxi Medical University; Nanning China
- Department of Neurology; National Key Clinical; Department and Key Discipline of Neurology; The First Affiliated Hospital of Sun Yat-sen University; Guangzhou China
| | - Xiang Chen
- Department of Neurology; National Key Clinical; Department and Key Discipline of Neurology; The First Affiliated Hospital of Sun Yat-sen University; Guangzhou China
| | - Shuxuan Huang
- Department of Neurology; The First Affiliated Hospital of Guangzhou Medical University; Guangzhou China
| | - Guihua Li
- Department of Neurology; The First Affiliated Hospital of Guangzhou Medical University; Guangzhou China
| | - Mingshu Mo
- Department of Neurology; The First Affiliated Hospital of Guangzhou Medical University; Guangzhou China
| | - Li Zhang
- Geriatric Neurology Department; Nanjing Brain Hospital; Nanjing Medical University; Nanjing China
| | - Chaojun Chen
- Department of Neurology; Guangzhou Chinese Medical Integrated Hospital (Huadu); Guangzhou China
| | - Wenyuan Guo
- Department of Neurology; The First Affiliated Hospital of Guangzhou Medical University; Guangzhou China
| | - Miaomiao Zhou
- Department of Neurology; The First Affiliated Hospital of Guangzhou Medical University; Guangzhou China
| | - Zhuohua Wu
- Department of Neurology; The First Affiliated Hospital of Guangzhou Medical University; Guangzhou China
| | - Luan Cen
- Department of Neurology; The First Affiliated Hospital of Guangxi Medical University; Nanning China
| | - Simei Long
- Department of Neurology; National Key Clinical; Department and Key Discipline of Neurology; The First Affiliated Hospital of Sun Yat-sen University; Guangzhou China
| | - Shaomin Li
- Ann Romney Center for Neurologic Disease; Brigham and Women's Hospital; Harvard Medical School; Boston MA USA
| | - Xinling Yang
- Department of Neurology; The Second Affiliated Hospital of Xinjiang Medical University; Urumqi China
| | - Shaogang Qu
- Clinical Medicine Research Center; Shunde Hospital; Southern Medical University; Foshan China
| | - Zhong Pei
- Department of Neurology; National Key Clinical; Department and Key Discipline of Neurology; The First Affiliated Hospital of Sun Yat-sen University; Guangzhou China
| | - Pingyi Xu
- Department of Neurology; The First Affiliated Hospital of Guangzhou Medical University; Guangzhou China
- Key Laboratory of Respiratory Disease; The First Affiliated Hospital of Guangzhou Medical University; Guangzhou China
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6
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Alegre F, Moragrega ÁB, Polo M, Marti‐Rodrigo A, Esplugues JV, Blas‐Garcia A, Apostolova N. Role of p62/SQSTM1 beyond autophagy: a lesson learned from drug-induced toxicity in vitro. Br J Pharmacol 2018; 175:440-455. [PMID: 29148034 PMCID: PMC5773949 DOI: 10.1111/bph.14093] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2017] [Revised: 10/02/2017] [Accepted: 11/07/2017] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND AND PURPOSE SQSTM1/p62 is a multifunctional, stress-induced, scaffold protein involved in multiple cellular processes including autophagic clearance, regulation of inflammatory responses and redox homeostasis. Its altered function has been associated with different human pathologies, such as neurodegenerative, metabolic and bone diseases (down-regulation), and cancerogenesis (up-regulation). However, its role in the off-target effects of clinically used drugs is still not understood. EXPERIMENTAL APPROACH We evaluated the expression of p62 in cultured Hep3B cells and their derived ρ° cells (lacking mitochondria), along with markers of autophagy and mitochondrial dysfunction. The effects of efavirenz were compared with those of known pharmacological stressors, rotenone, thapsigargin and CCCP, and we also used transient silencing with siRNA and p62 overexpression. Western blotting, quantRT-PCR and fluorescence microscopy were used to assay these effects and their underlying mechanisms. KEY RESULTS In Hep3B cells, efavirenz augmented p62 protein content, an effect not observed in the corresponding ρ° cells. p62 up-regulation followed enhanced SQSTM1 expression mediated through the transcription factor CHOP/DDIT3, while other well-known regulators (NF-kB and Nrf2) were not involved. Inhibition of autophagy with 3MA or with transient silencing of Atg5 did not affect SQSTM1 expression in efavirenz-treated cells while p62 overexpression ameliorated the deleterious effect of efavirenz on cell viability. CONCLUSION AND IMPLICATIONS In our model, p62 exerted a specific, autophagy-independent role and protected against efavirenz-induced mitochondrial ROS generation and activation of the NLRP3 inflammasome. These findings add to the multifunctional nature of p62 and may help to understand the off-target effects of clinically useful drugs.
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Affiliation(s)
- Fernando Alegre
- Departamento de Farmacología, Facultad de MedicinaUniversidad de ValenciaValenciaSpain
- FISABIO–Hospital Universitario Dr. PesetValenciaSpain
| | - Ángela B Moragrega
- Departamento de Farmacología, Facultad de MedicinaUniversidad de ValenciaValenciaSpain
| | - Miriam Polo
- Departamento de Farmacología, Facultad de MedicinaUniversidad de ValenciaValenciaSpain
- FISABIO–Hospital Universitario Dr. PesetValenciaSpain
| | - Alberto Marti‐Rodrigo
- Departamento de Farmacología, Facultad de MedicinaUniversidad de ValenciaValenciaSpain
| | - Juan V Esplugues
- Departamento de Farmacología, Facultad de MedicinaUniversidad de ValenciaValenciaSpain
- FISABIO–Hospital Universitario Dr. PesetValenciaSpain
- CIBERehdValenciaSpain
| | - Ana Blas‐Garcia
- Departamento de Farmacología, Facultad de MedicinaUniversidad de ValenciaValenciaSpain
- CIBERehdValenciaSpain
| | - Nadezda Apostolova
- Departamento de Farmacología, Facultad de MedicinaUniversidad de ValenciaValenciaSpain
- CIBERehdValenciaSpain
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7
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Sequestosome1/p62 protects mouse embryonic fibroblasts against low-dose methylercury-induced cytotoxicity and is involved in clearance of ubiquitinated proteins. Sci Rep 2017; 7:16735. [PMID: 29196648 PMCID: PMC5711938 DOI: 10.1038/s41598-017-17112-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 11/22/2017] [Indexed: 01/07/2023] Open
Abstract
Methylmercury (MeHg) is a widely distributed environmental pollutant that causes a series of cytotoxic effects. However, molecular mechanisms underlying MeHg toxicity are not fully understood. Here, we report that sequestosome1/p62 protects mouse embryonic fibroblasts (MEFs) against low-dose MeHg cytotoxicity via clearance of MeHg-induced ubiquitinated proteins. p62 mRNA and protein expression in MEFs were temporally induced by MeHg exposure p62-deficient MEFs exhibited higher sensitivity to MeHg exposure compared to their wild-type (WT) counterparts. An earlier and higher level of accumulation of ubiquitinated proteins was detected in p62-deficient cells compared with WT MEFs. Confocal microscopy revealed that p62 and ubiquitinated proteins co-localized in the perinuclear region of MEFs following MeHg treatment. Further analysis of MEFs revealed that ubiquitinated proteins co-localized with LC3-positive puncta upon co-treatment with MeHg and chloroquine, an autophagy inhibitor. In contrast, there was minimal co-localization in p62-deficient MEFs. The present study, for the first time, examined the expression and distribution of p62 and ubiquitinated proteins in cells exposed to low-dose MeHg. Our findings suggest that p62 is crucial for cytoprotection against MeHg-induced toxicity and is required for MeHg-induced ubiquitinated protein clearance.
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8
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Mizunoe Y, Kobayashi M, Sudo Y, Watanabe S, Yasukawa H, Natori D, Hoshino A, Negishi A, Okita N, Komatsu M, Higami Y. Trehalose protects against oxidative stress by regulating the Keap1-Nrf2 and autophagy pathways. Redox Biol 2017; 15:115-124. [PMID: 29241092 PMCID: PMC5730428 DOI: 10.1016/j.redox.2017.09.007] [Citation(s) in RCA: 141] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 09/09/2017] [Accepted: 09/13/2017] [Indexed: 12/19/2022] Open
Abstract
Dysfunction of autophagy, which regulates cellular homeostasis by degrading organelles and proteins, is associated with pathogenesis of various diseases such as cancer, neurodegeneration and metabolic disease. Trehalose, a naturally occurring nontoxic disaccharide found in plants, insects, microorganisms and invertebrates, but not in mammals, was reported to function as a mechanistic target of the rapamycin (mTOR)-independent inducer of autophagy. In addition, trehalose functions as an antioxidant though its underlying molecular mechanisms remain unclear. In this study, we showed that trehalose not only promoted autophagy, but also increased p62 protein expression, in an autophagy-independent manner. In addition, trehalose increased nuclear translocation of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) in a p62-dependent manner and enhance expression of its downstream antioxidant factors, heme oxygenase-1 (Ho-1) and nicotinamide adenine dinucleotide phosphate quinone dehydrogenase 1 (Nqo1). Moreover, treatment with trehalose significantly reduced amount of reactive oxygen species. Collectively, these results suggested that trehalose can function as a novel activator of the p62-Keap1/Nrf2 pathway, in addition to inducing autophagy. Therefore, trehalose may be useful to treat many chronic diseases involving oxidative stress and dysfunction of autophagy.
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Affiliation(s)
- Yuhei Mizunoe
- Laboratory of Molecular Pathology and Metabolic Disease, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Noda, Chiba 278-8510, Japan; Translational Research Center, Research Institute of Science and Technology, Tokyo University of Science, Noda 278-8510, Japan
| | - Masaki Kobayashi
- Laboratory of Molecular Pathology and Metabolic Disease, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Noda, Chiba 278-8510, Japan; Translational Research Center, Research Institute of Science and Technology, Tokyo University of Science, Noda 278-8510, Japan
| | - Yuka Sudo
- Laboratory of Molecular Pathology and Metabolic Disease, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Noda, Chiba 278-8510, Japan; Translational Research Center, Research Institute of Science and Technology, Tokyo University of Science, Noda 278-8510, Japan
| | - Shukoh Watanabe
- Laboratory of Molecular Pathology and Metabolic Disease, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Noda, Chiba 278-8510, Japan
| | - Hiromine Yasukawa
- Laboratory of Molecular Pathology and Metabolic Disease, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Noda, Chiba 278-8510, Japan
| | - Daiki Natori
- Laboratory of Molecular Pathology and Metabolic Disease, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Noda, Chiba 278-8510, Japan
| | - Ayana Hoshino
- Laboratory of Molecular Pathology and Metabolic Disease, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Noda, Chiba 278-8510, Japan
| | - Arisa Negishi
- Laboratory of Molecular Pathology and Metabolic Disease, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Noda, Chiba 278-8510, Japan
| | - Naoyuki Okita
- Translational Research Center, Research Institute of Science and Technology, Tokyo University of Science, Noda 278-8510, Japan; Department of Internal Medicine Research, Sasaki Institute, Sasaki Foundation, Tokyo 101-0062, Japan
| | - Masaaki Komatsu
- Department of Biochemistry, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951-8510, Japan
| | - Yoshikazu Higami
- Laboratory of Molecular Pathology and Metabolic Disease, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Noda, Chiba 278-8510, Japan; Translational Research Center, Research Institute of Science and Technology, Tokyo University of Science, Noda 278-8510, Japan.
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9
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Mildenberger J, Johansson I, Sergin I, Kjøbli E, Damås JK, Razani B, Flo TH, Bjørkøy G. N-3 PUFAs induce inflammatory tolerance by formation of KEAP1-containing SQSTM1/p62-bodies and activation of NFE2L2. Autophagy 2017; 13:1664-1678. [PMID: 28820283 PMCID: PMC5640206 DOI: 10.1080/15548627.2017.1345411] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Inflammation is crucial in the defense against infections but must be tightly controlled to limit detrimental hyperactivation. Our diet influences inflammatory processes and omega-3 polyunsaturated fatty acids (n-3 PUFAs) have known anti-inflammatory effects. The balance of pro- and anti-inflammatory processes is coordinated by macrophages and macroautophagy/autophagy has recently emerged as a cellular process that dampens inflammation. Here we report that the n-3 PUFA docosahexaenoic acid (DHA) transiently induces cytosolic speckles of the autophagic receptor SQSTM1/p62 (sequestosome 1) (described as SQSTM1/p62-bodies) in macrophages. We suggest that the formation of SQSTM1/p62-bodies represents a fast mechanism of NFE2L2/Nrf2 (nuclear factor, erythroid 2 like 2) activation by recruitment of KEAP1 (kelch like ECH associated protein 1). Further, the autophagy receptor TAX1BP1 (Tax1 binding protein 1) and ubiquitin-editing enzyme TNFAIP3/A20 (TNF α induced protein 3) could be identified in DHA-induced SQSTM1/p62-bodies. Simultaneously, DHA strongly dampened the induction of pro-inflammatory genes including CXCL10 (C-X-C motif chemokine ligand 10) and we suggest that formation of SQSTM1/p62-bodies and activation of NFE2L2 leads to tolerance towards selective inflammatory stimuli. Finally, reduced CXCL10 levels were related to the improved clinical outcome in n-3 PUFA-supplemented heart-transplant patients and we propose CXCL10 as a robust marker for the clinical benefits mobilized by n-3 PUFA supplementation.
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Affiliation(s)
- Jennifer Mildenberger
- a Centre of Molecular Inflammation Research and Department of Cancer Research and Molecular Medicine, Faculty of Medicine and Health Sciences , Norwegian University of Science and Technology , Trondheim , Norway.,b Department of Biomedical Laboratory Science, Faculty of Natural Sciences , Norwegian University of Science and Technology , Trondheim , Norway
| | - Ida Johansson
- a Centre of Molecular Inflammation Research and Department of Cancer Research and Molecular Medicine, Faculty of Medicine and Health Sciences , Norwegian University of Science and Technology , Trondheim , Norway
| | - Ismail Sergin
- d Department of Medicine, Cardiovascular Division , Washington University School of Medicine , St. Louis , MO , USA
| | - Eli Kjøbli
- b Department of Biomedical Laboratory Science, Faculty of Natural Sciences , Norwegian University of Science and Technology , Trondheim , Norway
| | - Jan Kristian Damås
- a Centre of Molecular Inflammation Research and Department of Cancer Research and Molecular Medicine, Faculty of Medicine and Health Sciences , Norwegian University of Science and Technology , Trondheim , Norway.,c Department of Infectious Diseases , St Olav University Hospital , Trondheim , Norway
| | - Babak Razani
- d Department of Medicine, Cardiovascular Division , Washington University School of Medicine , St. Louis , MO , USA.,e Department of Pathology & Immunology , Washington University School of Medicine , St. Louis , MO , USA
| | - Trude Helen Flo
- a Centre of Molecular Inflammation Research and Department of Cancer Research and Molecular Medicine, Faculty of Medicine and Health Sciences , Norwegian University of Science and Technology , Trondheim , Norway
| | - Geir Bjørkøy
- a Centre of Molecular Inflammation Research and Department of Cancer Research and Molecular Medicine, Faculty of Medicine and Health Sciences , Norwegian University of Science and Technology , Trondheim , Norway.,b Department of Biomedical Laboratory Science, Faculty of Natural Sciences , Norwegian University of Science and Technology , Trondheim , Norway
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10
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Liebl MP, Hoppe T. It's all about talking: two-way communication between proteasomal and lysosomal degradation pathways via ubiquitin. Am J Physiol Cell Physiol 2016; 311:C166-78. [PMID: 27225656 DOI: 10.1152/ajpcell.00074.2016] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Selective degradation of proteins requires a fine-tuned coordination of the two major proteolytic pathways, the ubiquitin-proteasome system (UPS) and autophagy. Substrate selection and proteolytic activity are defined by a plethora of regulatory cofactors influencing each other. Both proteolytic pathways are initiated by ubiquitylation to mark substrate proteins for degradation, although the size and/or topology of the modification are different. In this context E3 ubiquitin ligases, ensuring the covalent attachment of activated ubiquitin to the substrate, are of special importance. The regulation of E3 ligase activity, competition between different E3 ligases for binding E2 conjugation enzymes and substrates, as well as their interplay with deubiquitylating enzymes (DUBs) represent key events in the cross talk between the UPS and autophagy. The coordination between both degradation routes is further influenced by heat shock factors and ubiquitin-binding proteins (UBPs) such as p97, p62, or optineurin. Mutations in enzymes and ubiquitin-binding proteins or a general decline of both proteolytic systems during aging result in accumulation of damaged and aggregated proteins. Thus further mechanistic understanding of how UPS and autophagy communicate might allow therapeutic intervention especially against age-related diseases.
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Affiliation(s)
- Martina P Liebl
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Thorsten Hoppe
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
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11
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Yazdani M, Andresen AMS, Gjøen T. Short-term effect of bisphenol-a on oxidative stress responses in Atlantic salmon kidney cell line: a transcriptional study. Toxicol Mech Methods 2016; 26:295-300. [PMID: 27117342 DOI: 10.1080/15376516.2016.1177864] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Bisphenol A (BPA) is regularly detected in aquatic ecosystems due to increased use of products based on polycarbonate plastics and epoxy resins. It migrates from these products directly into rivers and marine waters or indirectly through effluents from wastewater treatment plants and landfilled sites. BPA can affect aquatic organisms both chronically and acutely at sensitive live stages. Despite reports indicating harmful effects of BPA, little is known about its role in oxidative stress responses in fish. In this study, we investigated the transcriptional effect of BPA (0, 1, 10, 100 μM) on an Atlantic salmon kidney (ASK) cell line for 6 h and 24 h by monitoring expression of 11 genes: elongation factor 1-alpha (ef1a), 18S ribosomal RNA (18s), gluthation (gsh), superoxide dismutase (sod), thioredoxin (txd), Salmo salar oxidative stress-responsive serine-rich 1 (oxr), glucose-regulated protein 78 (grp78), heat shock protein 70 (hsp70), sequestosome1 (p62), interleukin-1 beta (il-1beta) and toll-like receptor 8 (tlr8). In general, only the 100 μM concentration treatment altered the mRNA expression. BPA down-regulated the expression of gsh and sod genes for both exposure-times while txd gene was the only down-regulated after 6-h exposure. The up-regulation of genes in the ASK cell line exposed for 6 h was only observed in il-1beta, while the 24-h exposure resulted in the up-regulation of oxr, tlr8, hsp70, p62 and il-1beta genes. The last three genes increased several fold compared to the others. The results showed that BPA exposure at 100 μM imposed oxidative stress on the ASK cell line and longer exposure time involved transcriptional responses of immune-related genes. This may indicate the possible role of BPA-associated oxidative stress in induction of inflammatory response in this macrophage-like cell type.
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Affiliation(s)
- Mazyar Yazdani
- a Department of Biosciences , University of Oslo , Oslo , Norway ;,b Department of Pharmaceutical Biosciences, School of Pharmacy , University of Oslo , Norway
| | | | - Tor Gjøen
- b Department of Pharmaceutical Biosciences, School of Pharmacy , University of Oslo , Norway
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12
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Upadhyay A, Amanullah A, Chhangani D, Mishra R, Prasad A, Mishra A. Mahogunin Ring Finger-1 (MGRN1), a Multifaceted Ubiquitin Ligase: Recent Unraveling of Neurobiological Mechanisms. Mol Neurobiol 2015; 53:4484-96. [PMID: 26255182 DOI: 10.1007/s12035-015-9379-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Accepted: 07/27/2015] [Indexed: 11/29/2022]
Abstract
In healthy cell, inappropriate accumulation of poor or damaged proteins is prevented by cellular quality control system. Autophagy and ubiquitin proteasome system (UPS) provides regular cytoprotection against proteotoxicity induced by abnormal or disruptive proteins. E3 ubiquitin ligases are crucial components in this defense mechanism. Mahogunin Ring Finger-1 (MGRN1), an E3 ubiquitin ligase of the Really Interesting New Gene (RING) finger family, plays a pivotal role in many biological and cellular mechanisms. Previous findings indicate that lack of functions of MGRN1 can cause spongiform neurodegeneration, congenital heart defects, abnormal left-right patterning, and mitochondrial dysfunctions in mice brains. However, the detailed molecular pathomechanism of MGRN1 in cellular functions and diseases is not well known. This article comprehensively represents the molecular nature, characterization, and functions of MGRN1; we also summarize possible beneficiary aspects of this novel E3 ubiquitin ligase. Here, we review recent literature on the role of MGRN1 in the neuro-pathobiological mechanisms, with precise focus on the processes of neurodegeneration, and thereby propose new lines of potential targets for therapeutic intervention.
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Affiliation(s)
- Arun Upadhyay
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Jodhpur, Rajasthan, 342011, India
| | - Ayeman Amanullah
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Jodhpur, Rajasthan, 342011, India
| | - Deepak Chhangani
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Jodhpur, Rajasthan, 342011, India
| | - Ribhav Mishra
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Jodhpur, Rajasthan, 342011, India
| | - Amit Prasad
- School of Basic Sciences, Indian Institute of Technology Mandi, Mandi, Himachal Pradesh, 175005, India
| | - Amit Mishra
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Jodhpur, Rajasthan, 342011, India.
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Jain A, Rusten TE, Katheder N, Elvenes J, Bruun JA, Sjøttem E, Lamark T, Johansen T. p62/Sequestosome-1, Autophagy-related Gene 8, and Autophagy in Drosophila Are Regulated by Nuclear Factor Erythroid 2-related Factor 2 (NRF2), Independent of Transcription Factor TFEB. J Biol Chem 2015; 290:14945-62. [PMID: 25931115 DOI: 10.1074/jbc.m115.656116] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Indexed: 12/30/2022] Open
Abstract
The selective autophagy receptor p62/sequestosome 1 (SQSTM1) interacts directly with LC3 and is involved in oxidative stress signaling in two ways in mammals. First, p62 is transcriptionally induced upon oxidative stress by the NF-E2-related factor 2 (NRF2) by direct binding to an antioxidant response element in the p62 promoter. Second, p62 accumulation, occurring when autophagy is impaired, leads to increased p62 binding to the NRF2 inhibitor KEAP1, resulting in reduced proteasomal turnover of NRF2. This gives chronic oxidative stress signaling through a feed forward loop. Here, we show that the Drosophila p62/SQSTM1 orthologue, Ref(2)P, interacts directly with DmAtg8a via an LC3-interacting region motif, supporting a role for Ref(2)P in selective autophagy. The ref(2)P promoter also contains a functional antioxidant response element that is directly bound by the NRF2 orthologue, CncC, which can induce ref(2)P expression along with the oxidative stress-associated gene gstD1. However, distinct from the situation in mammals, Ref(2)P does not interact directly with DmKeap1 via a KEAP1-interacting region motif; nor does ectopically expressed Ref(2)P or autophagy deficiency activate the oxidative stress response. Instead, DmAtg8a interacts directly with DmKeap1, and DmKeap1 is removed upon programmed autophagy in Drosophila gut cells. Strikingly, CncC induced increased Atg8a levels and autophagy independent of TFEB/MitF in fat body and larval gut tissues. Thus, these results extend the intimate relationship between oxidative stress-sensing NRF2/CncC transcription factors and autophagy and suggest that NRF2/CncC may regulate autophagic activity in other organisms too.
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Affiliation(s)
- Ashish Jain
- From the Molecular Cancer Research Group, Institute of Medical Biology, University of Tromsø, 9037 Tromsø, Norway and
| | - Tor Erik Rusten
- the Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Centre for Cancer Biomedicine, University of Oslo, 0379 Oslo, Norway
| | - Nadja Katheder
- the Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Centre for Cancer Biomedicine, University of Oslo, 0379 Oslo, Norway
| | - Julianne Elvenes
- From the Molecular Cancer Research Group, Institute of Medical Biology, University of Tromsø, 9037 Tromsø, Norway and
| | - Jack-Ansgar Bruun
- From the Molecular Cancer Research Group, Institute of Medical Biology, University of Tromsø, 9037 Tromsø, Norway and
| | - Eva Sjøttem
- From the Molecular Cancer Research Group, Institute of Medical Biology, University of Tromsø, 9037 Tromsø, Norway and
| | - Trond Lamark
- From the Molecular Cancer Research Group, Institute of Medical Biology, University of Tromsø, 9037 Tromsø, Norway and
| | - Terje Johansen
- From the Molecular Cancer Research Group, Institute of Medical Biology, University of Tromsø, 9037 Tromsø, Norway and
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del Caño-Espinel M, Acebes JR, Sanchez D, Ganfornina MD. Lazarillo-related Lipocalins confer long-term protection against type I Spinocerebellar Ataxia degeneration contributing to optimize selective autophagy. Mol Neurodegener 2015; 10:11. [PMID: 25888134 PMCID: PMC4374295 DOI: 10.1186/s13024-015-0009-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2014] [Accepted: 03/02/2015] [Indexed: 12/22/2022] Open
Abstract
Background A diverse set of neurodegenerative disorders are caused by abnormal extensions of polyglutamine (poly-Q) stretches in various, functionally unrelated proteins. A common feature of these diseases is altered proteostasis. Autophagy induction is part of the endogenous response to poly-Q protein expression. However, if autophagy is not resolved properly, clearance of toxic proteins or aggregates cannot occur effectively. Likewise, excessive autophagy induction can cause autophagic stress and neurodegeneration. The Lipocalins ApoD, Glial Lazarillo (GLaz) and Neural Lazarillo (NLaz) are neuroprotectors upon oxidative stress or aging. In this work we test whether these Lipocalins also protect against poly-Q-triggered deterioration of protein quality control systems. Results Using a Drosophila retinal degeneration model of Type-1 Spinocerebellar Ataxia (SCA1) combined with genetic manipulation of NLaz and GLaz expression, we demonstrate that both Lipocalins protect against SCA1 neurodegeneration. They are part of the endogenous transcriptional response to SCA1, and their effect is non-additive, suggesting participation in a similar mechanism. GLaz beneficial effects persist throughout aging, and appears when expressed by degenerating neurons or by retinal support and glial cells. GLaz gain-of-function reduces cell death and the extent of ubiquitinated proteins accumulation, and decreases the expression of Atg8a/LC3, p62 mRNA and protein levels, and GstS1 induction. Over-expression of GLaz is able to reduce p62 and ubiquitinated proteins levels when rapamycin-dependent and SCA1-dependent inductions of autophagy are combined. In the absence of neurodegeneration, GLaz loss-of-function increases Atg8a/LC3 mRNA and p62 protein levels without altering p62 mRNA levels. Knocking-down autophagy, by interfering with Atg8a or p62 expression or by expressing dominant-negative Atg1/ULK1 or Atg4a transgenes, rescues SCA1-dependent neurodegeneration in a similar extent to the protective effect of GLaz. Further GLaz-dependent improvement is concealed. Conclusions This work shows for the first time that a Lipocalin rescues neurons from pathogenic SCA1 degeneration by optimizing clearance of aggregation-prone proteins. GLaz modulates key autophagy genes and lipid-peroxide clearance responsive genes. Down-regulation of selective autophagy causes similar and non-additive rescuing effects. These data suggest that SCA1 neurodegeneration concurs with autophagic stress, and places Lazarillo-related Lipocalins as valuable players in the endogenous protection against the two major contributors to aging and neurodegeneration: ROS-dependent damage and proteostasis deterioration. Electronic supplementary material The online version of this article (doi:10.1186/s13024-015-0009-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Manuela del Caño-Espinel
- Instituto de Biología y Genética Molecular-Departamento de Bioquímica y Biología Molecular y Fisiología, Universidad de Valladolid-CSIC, c/ Sanz y Forés 3, 47003, Valladolid, Spain.
| | - Judith R Acebes
- Instituto de Biología y Genética Molecular-Departamento de Bioquímica y Biología Molecular y Fisiología, Universidad de Valladolid-CSIC, c/ Sanz y Forés 3, 47003, Valladolid, Spain.
| | - Diego Sanchez
- Instituto de Biología y Genética Molecular-Departamento de Bioquímica y Biología Molecular y Fisiología, Universidad de Valladolid-CSIC, c/ Sanz y Forés 3, 47003, Valladolid, Spain.
| | - Maria D Ganfornina
- Instituto de Biología y Genética Molecular-Departamento de Bioquímica y Biología Molecular y Fisiología, Universidad de Valladolid-CSIC, c/ Sanz y Forés 3, 47003, Valladolid, Spain.
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15
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Son YO, Pratheeshkumar P, Roy RV, Hitron JA, Wang L, Zhang Z, Shi X. Nrf2/p62 signaling in apoptosis resistance and its role in cadmium-induced carcinogenesis. J Biol Chem 2014; 289:28660-75. [PMID: 25157103 DOI: 10.1074/jbc.m114.595496] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The cadmium-transformed human lung bronchial epithelial BEAS-2B cells exhibit a property of apoptosis resistance as compared with normal non-transformed BEAS-2B cells. The level of basal reactive oxygen species (ROS) is extremely low in transformed cells in correlation with elevated expressions of both antioxidant enzymes (catalase, SOD1, and SOD2) and antiapoptotic proteins (Bcl-2/Bcl-xL). Moreover, Nrf2 and p62 are highly expressed in these transformed cells. The knockdown of Nrf2 or p62 by siRNA enhances ROS levels and cadmium-induced apoptosis. The binding activities of Nrf2 on the antioxidant response element promoter regions of p62/Bcl-2/Bcl-xL were dramatically increased in the cadmium-exposed transformed cells. Cadmium exposure increased the formation of LC3-II and the frequency of GFP-LC3 punctal cells in non-transformed BEAS-2B cells, whereas these increases are not shown in transformed cells, an indication of autophagy deficiency of transformed cells. Furthermore, the expression levels of Nrf2 and p62 are dramatically increased during chronic long term exposure to cadmium in the BEAS-2B cells as well as antiapoptotic proteins and antioxidant enzymes. These proteins are overexpressed in the tumor tissues derived from xenograft mouse models. Moreover, the colony growth is significantly attenuated in the transformed cells by siRNA transfection specific for Nrf2 or p62. Taken together, this study demonstrates that cadmium-transformed cells have acquired autophagy deficiency, leading to constitutive p62 and Nrf2 overexpression. These overexpressions up-regulate the antioxidant proteins catalase and SOD and the antiapoptotic proteins Bcl-2 and Bcl-xL. The final consequences are decrease in ROS generation, apoptotic resistance, and increased cell survival, proliferation, and tumorigenesis.
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Affiliation(s)
- Young-Ok Son
- From the Center for Research on Environmental Disease and the Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, Kentucky 40536-0305
| | - Poyil Pratheeshkumar
- From the Center for Research on Environmental Disease and the Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, Kentucky 40536-0305
| | - Ram Vinod Roy
- From the Center for Research on Environmental Disease and the Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, Kentucky 40536-0305
| | - John Andrew Hitron
- the Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, Kentucky 40536-0305
| | - Lei Wang
- From the Center for Research on Environmental Disease and the Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, Kentucky 40536-0305
| | - Zhuo Zhang
- the Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, Kentucky 40536-0305
| | - Xianglin Shi
- From the Center for Research on Environmental Disease and the Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, Kentucky 40536-0305
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16
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Homma T, Ishibashi D, Nakagaki T, Satoh K, Sano K, Atarashi R, Nishida N. Increased expression of p62/SQSTM1 in prion diseases and its association with pathogenic prion protein. Sci Rep 2014; 4:4504. [PMID: 24675871 PMCID: PMC3968452 DOI: 10.1038/srep04504] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Accepted: 03/04/2014] [Indexed: 11/30/2022] Open
Abstract
Prion diseases are neurodegenerative disorders characterized by the aggregation of abnormally folded prion protein (PrPSc). In this study, we focused on the mechanism of clearance of PrPSc, which remains unclear. p62 is a cytosolic protein known to mediate both the formation and degradation of aggregates of abnormal proteins. The levels of p62 protein increased in prion-infected brains and persistently infected cell cultures. Upon proteasome inhibition, p62 co-localized with PrPSc, forming a large aggregate in the perinuclear region, hereafter referred to as PrPSc-aggresome. These aggregates were surrounded with autophagosome marker LC3 and lysosomes in prion-infected cells. Moreover, transient expression of the phosphomimic form of p62, which has enhanced ubiquitin-binding activity, reduced the amount of PrPSc in prion-infected cells, indicating that the activation of p62 could accelerate the clearance of PrPSc. Our findings would thus suggest that p62 could be a target for the therapeutic control of prion diseases.
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Affiliation(s)
- Takujiro Homma
- Department of Molecular Microbiology and immunology, Graduate School of Biomedical sciences, Nagasaki University, Nagasaki 852-8523, Japan
| | - Daisuke Ishibashi
- Department of Molecular Microbiology and immunology, Graduate School of Biomedical sciences, Nagasaki University, Nagasaki 852-8523, Japan
| | - Takehiro Nakagaki
- Department of Molecular Microbiology and immunology, Graduate School of Biomedical sciences, Nagasaki University, Nagasaki 852-8523, Japan
| | - Katsuya Satoh
- Department of Molecular Microbiology and immunology, Graduate School of Biomedical sciences, Nagasaki University, Nagasaki 852-8523, Japan
| | - Kazunori Sano
- Department of Molecular Microbiology and immunology, Graduate School of Biomedical sciences, Nagasaki University, Nagasaki 852-8523, Japan
| | - Ryuichiro Atarashi
- 1] Department of Molecular Microbiology and immunology, Graduate School of Biomedical sciences, Nagasaki University, Nagasaki 852-8523, Japan [2] Nagasaki University Research Centre for Genomic Instability and Carcinogenesis, Nagasaki 852-8523, Japan
| | - Noriyuki Nishida
- Department of Molecular Microbiology and immunology, Graduate School of Biomedical sciences, Nagasaki University, Nagasaki 852-8523, Japan
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17
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Ishii T, Warabi E, Siow RCM, Mann GE. Sequestosome1/p62: a regulator of redox-sensitive voltage-activated potassium channels, arterial remodeling, inflammation, and neurite outgrowth. Free Radic Biol Med 2013; 65:102-116. [PMID: 23792273 DOI: 10.1016/j.freeradbiomed.2013.06.019] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Revised: 06/06/2013] [Accepted: 06/07/2013] [Indexed: 12/14/2022]
Abstract
Sequestosome1/p62 (SQSTM1) is an oxidative stress-inducible protein regulated by the redox-sensitive transcription factor Nrf2. It is not an antioxidant but known as a multifunctional regulator of cell signaling with an ability to modulate targeted or selective degradation of proteins through autophagy. SQSTM1 implements these functions through physical interactions with different types of proteins including atypical PKCs, nonreceptor-type tyrosine kinase p56(Lck) (Lck), polyubiquitin, and autophagosomal factor LC3. One of the notable physiological functions of SQSTM1 is the regulation of redox-sensitive voltage-gated potassium (Kv) channels which are composed of α and β subunits: (Kvα)4 (Kvβ)4. Previous studies have established that SQSTM1 scaffolds PKCζ, enhancing phosphorylation of Kvβ which induces inhibition of pulmonary arterial Kv1.5 channels under acute hypoxia. Recent studies reveal that Lck indirectly interacts with Kv1.3 α subunits and plays a key role in acute hypoxia-induced Kv1.3 channel inhibition in T lymphocytes. Kv1.3 channels provide a signaling platform to modulate the migration and proliferation of arterial smooth muscle cells and activation of T lymphocytes, and hence have been recognized as a therapeutic target for treatment of restenosis and autoimmune diseases. In this review, we focus on the functional interactions of SQSTM1 with Kv channels through two key partners aPKCs and Lck. Furthermore, we provide molecular insights into the functions of SQSTM1 in suppression of proliferation of arterial smooth muscle cells and neointimal hyperplasia following carotid artery ligation, in T lymphocyte differentiation and activation, and in NGF-induced neurite outgrowth in PC12 cells.
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Affiliation(s)
- Tetsuro Ishii
- School of Medicine, University of Tsukuba, Tennoudai 1-1-1, Tsukuba, Ibaraki, 305-8575, Japan.
| | - Eiji Warabi
- School of Medicine, University of Tsukuba, Tennoudai 1-1-1, Tsukuba, Ibaraki, 305-8575, Japan
| | - Richard C M Siow
- Cardiovascular Division, British Heart Foundation Centre of Research Excellence, School of Medicine, King's College London, London SE1 9NH, UK
| | - Giovanni E Mann
- Cardiovascular Division, British Heart Foundation Centre of Research Excellence, School of Medicine, King's College London, London SE1 9NH, UK
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18
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Manley S, Williams JA, Ding WX. Role of p62/SQSTM1 in liver physiology and pathogenesis. Exp Biol Med (Maywood) 2013; 238:525-38. [PMID: 23856904 DOI: 10.1177/1535370213489446] [Citation(s) in RCA: 103] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
p62/sequestosome-1/A170/ZIP (hereafter referred to as p62) is a scaffold protein that has multiple functions, such as signal transduction, cell proliferation, cell survival, cell death, inflammation, tumourigenesis and oxidative stress response. While p62 is an autophagy substrate and is degraded by autophagy, p62 serves as an autophagy receptor for selective autophagic clearance of protein aggregates and organelles. Moreover, p62 functions as a signalling hub for various signalling pathways, including NF-κB, Nrf2 and mTOR. In this review, we discuss the pathophysiological role of p62 in the liver, including formation of hepatic inclusion bodies, cholestasis, obesity, insulin resistance, liver cell death and tumourigenesis.
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Affiliation(s)
- Sharon Manley
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, USA
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19
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Viiri J, Amadio M, Marchesi N, Hyttinen JMT, Kivinen N, Sironen R, Rilla K, Akhtar S, Provenzani A, D'Agostino VG, Govoni S, Pascale A, Agostini H, Petrovski G, Salminen A, Kaarniranta K. Autophagy activation clears ELAVL1/HuR-mediated accumulation of SQSTM1/p62 during proteasomal inhibition in human retinal pigment epithelial cells. PLoS One 2013; 8:e69563. [PMID: 23922739 PMCID: PMC3726683 DOI: 10.1371/journal.pone.0069563] [Citation(s) in RCA: 126] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Accepted: 06/10/2013] [Indexed: 12/21/2022] Open
Abstract
Age-related macular degeneration (AMD) is the most common reason of visual impairment in the elderly in the Western countries. The degeneration of retinal pigment epithelial cells (RPE) causes secondarily adverse effects on neural retina leading to visual loss. The aging characteristics of the RPE involve lysosomal accumulation of lipofuscin and extracellular protein aggregates called “drusen”. Molecular mechanisms behind protein aggregations are weakly understood. There is intriguing evidence suggesting that protein SQSTM1/p62, together with autophagy, has a role in the pathology of different degenerative diseases. It appears that SQSTM1/p62 is a connecting link between autophagy and proteasome mediated proteolysis, and expressed strongly under the exposure to various oxidative stimuli and proteasomal inhibition. ELAVL1/HuR protein is a post-transcriptional factor, which acts mainly as a positive regulator of gene expression by binding to specific mRNAs whose corresponding proteins are fundamental for key cellular functions. We here show that, under proteasomal inhibitor MG-132, ELAVL1/HuR is up-regulated at both mRNA and protein levels, and that this protein binds and post-transcriptionally regulates SQSTM1/p62 mRNA in ARPE-19 cell line. Furthermore, we observed that proteasomal inhibition caused accumulation of SQSTM1/p62 bound irreversibly to perinuclear protein aggregates. The addition of the AMPK activator AICAR was pro-survival and promoted cleansing by autophagy of the former complex, but not of the ELAVL1/HuR accumulation, indeed suggesting that SQSTM1/p62 is decreased through autophagy-mediated degradation, while ELAVL1/HuR through the proteasomal pathway. Interestingly, when compared to human controls, AMD donor samples show strong SQSTM1/p62 rather than ELAVL1/HuR accumulation in the drusen rich macular area suggesting impaired autophagy in the pathology of AMD.
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Affiliation(s)
- Johanna Viiri
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland
| | - Marialaura Amadio
- Department of Drug Sciences, Pharmacology Section, University of Pavia, Pavia, Italy
| | - Nicoletta Marchesi
- Department of Drug Sciences, Pharmacology Section, University of Pavia, Pavia, Italy
| | - Juha M. T. Hyttinen
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland
| | - Niko Kivinen
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland
| | - Reijo Sironen
- Institute of Clinical Medicine, Pathology and Forensic Medicine, University of Eastern Finland, Kuopio, Finland
- Department of Clinical Pathology, Kuopio University Hospital, Kuopio, Finland
- Biocenter Kuopio and Cancer Center of Eastern Finland, University of Eastern Finland, Kuopio, Finland
| | - Kirsi Rilla
- Department of Anatomy, School of Medicine, Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland
| | - Saeed Akhtar
- Department of Optometry and Vision Sciences College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Alessandro Provenzani
- Laboratory of Genomic Screening, Centre for Integrative Biology, University of Trento, Trento, Italy
| | - Vito Giuseppe D'Agostino
- Laboratory of Genomic Screening, Centre for Integrative Biology, University of Trento, Trento, Italy
| | - Stefano Govoni
- Department of Drug Sciences, Pharmacology Section, University of Pavia, Pavia, Italy
| | - Alessia Pascale
- Department of Drug Sciences, Pharmacology Section, University of Pavia, Pavia, Italy
| | - Hansjurgen Agostini
- Department of Ophthalmology, University Eye Hospital, Albert-Ludwigs University of Freiburg, Freiburg im Breisgau, Germany
| | - Goran Petrovski
- Department of Ophthalmology, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary
- Stem Cells and Eye Research Laboratory, Department of Biochemistry and Molecular Biology, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary
| | - Antero Salminen
- Department of Neurology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland
- Department of Neurology, Kuopio University Hospital, Kuopio, Finland
| | - Kai Kaarniranta
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland
- Department of Ophthalmology, Kuopio University Hospital, Kuopio, Finland
- * E-mail:
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20
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Chiba Y, Takei S, Kawamura N, Kawaguchi Y, Sasaki K, Hasegawa-Ishii S, Furukawa A, Hosokawa M, Shimada A. Immunohistochemical localization of aggresomal proteins in glial cytoplasmic inclusions in multiple system atrophy. Neuropathol Appl Neurobiol 2013; 38:559-71. [PMID: 22013984 DOI: 10.1111/j.1365-2990.2011.01229.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
AIMS Multiple system atrophy (MSA) is pathologically characterized by the formation of α-synuclein-containing glial cytoplasmic inclusions (GCIs) in oligodendrocytes. However, the mechanisms of GCI formation are not fully understood. Cellular machinery for the formation of aggresomes has been linked to the biogenesis of the Lewy body, a characteristic α-synuclein-containing inclusion of Parkinson's disease and dementia with Lewy bodies. Here, we examined whether GCIs contain the components of aggresomes by immunohistochemistry. METHODS Sections from five patients with MSA were stained immunohistochemically with antibodies against aggresome-related proteins and analysed in comparison with sections from five patients with no neurological disease. We evaluated the presence or absence of aggresome-related proteins in GCIs by double immunofluorescence and immunoelectron microscopy. RESULTS GCIs were clearly immunolabelled with antibodies against aggresome-related proteins, such as γ-tubulin, histone deacetylase 6 (HDAC6) and 20S proteasome subunits. Neuronal cytoplasmic inclusions (NCIs) were also immunopositive for these aggresome-related proteins. Double immunofluorescence staining and quantitative analysis demonstrated that the majority of GCIs contained these proteins, as well as other aggresome-related proteins, such as Hsp70, Hsp90 and 62-kDa protein/sequestosome 1 (p62/SQSTM1). Immunoelectron microscopy demonstrated immunoreactivities for γ-tubulin and HDAC6 along the fibrils comprising GCIs. CONCLUSIONS Our results indicate that GCIs, and probably NCIs, share at least some characteristics with aggresomes in terms of their protein components. Therefore, GCIs and NCIs may be another manifestation of aggresome-related inclusion bodies observed in neurodegenerative diseases.
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Affiliation(s)
- Y Chiba
- Department of Pathology, Institute for Developmental Research, Aichi Human Service Center, Kasugai, Aichi, Japan
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Tanabe F, Yone K, Kawabata N, Sakakima H, Matsuda F, Ishidou Y, Maeda S, Abematsu M, Komiya S, Setoguchi T. Accumulation of p62 in degenerated spinal cord under chronic mechanical compression: functional analysis of p62 and autophagy in hypoxic neuronal cells. Autophagy 2012; 7:1462-71. [PMID: 22082874 DOI: 10.4161/auto.7.12.17892] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Intracellular accumulation of altered proteins, including p62 and ubiquitinated proteins, is the basis of most neurodegenerative disorders. The relationship among the accumulation of altered proteins, autophagy, and spinal cord dysfunction by cervical spondylotic myelopathy has not been clarified. We examined the expression of p62 and autophagy markers in the chronically compressed spinal cord of tiptoe-walking Yoshimura mice. In addition, we examined the expression and roles of p62 and autophagy in hypoxic neuronal cells. Western blot analysis showed the accumulation of p62, ubiquitinated proteins, and microtubule-associated protein 1 light chain 3 (LC3), an autophagic marker, in the compressed spinal cord. Immunohistochemical examinations showed that p62 accumulated in neurons, axons, astrocytes, and oligodendrocytes. Electron microscopy showed the expression of autophagy markers, including autolysosomes and autophagic vesicles, in the compressed spinal cord. These findings suggest the presence of p62 and autophagy in the degenerated compressed spinal cord. Hypoxic stress increased the expression of p62, ubiquitinated proteins, and LC3-II in neuronal cells. In addition, LC3 turnover assay and GFP-LC3 cleavage assay showed that hypoxic stress increased autophagy flux in neuronal cells. These findings suggest that hypoxic stress induces accumulation of p62 and autophagy in neuronal cells. The forced expression of p62 decreased the number of neuronal cells under hypoxic stress. These findings suggest that p62 accumulation under hypoxic stress promotes neuronal cell death. Treatment with 3-methyladenine, an autophagy inhibitor decreased the number of neuronal cells, whereas lithium chloride, an autophagy inducer increased the number of cells under hypoxic stress. These findings suggest that autophagy promotes neuronal cell survival under hypoxic stress. Our findings suggest that pharmacological inducers of autophagy may be useful for treating cervical spondylotic myelopathy patients.
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Affiliation(s)
- Fumito Tanabe
- Department of Orthopaedic Surgery, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Kagoshima Prefecture, Japan
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22
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Abstract
Mounting evidence suggests that autophagy is a more selective process than originally anticipated. The discovery and characterization of autophagic adapters, like p62 and NBR1, has provided mechanistic insight into this process. p62 and NBR1 are both selectively degraded by autophagy and able to act as cargo receptors for degradation of ubiquitinated substrates. A direct interaction between these autophagic adapters and the autophagosomal marker protein LC3, mediated by a so-called LIR (LC3-interacting region) motif, their inherent ability to polymerize or aggregate as well as their ability to specifically recognize substrates are required for efficient selective autophagy. These three required features of autophagic cargo receptors are evolutionarily conserved and also employed in the yeast cytoplasm-to-vacuole targeting (Cvt) pathway and in the degradation of P granules in C. elegans. Here, we review the mechanistic basis of selective autophagy in mammalian cells discussing the degradation of misfolded proteins, p62 bodies, aggresomes, mitochondria and invading bacteria. The emerging picture of selective autophagy affecting the regulation of cell signaling with consequences for oxidative stress responses, tumorigenesis and innate immunity is also addressed.
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Affiliation(s)
- Terje Johansen
- Molecular Cancer Research Group, Institute of Medical Biology, University of Tromsø, Tromsø, Norway.
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Park B, Oh CK, Choi WS, Chung IK, Youdim MBH, Oh YJ. Microarray expression profiling in 6-hydroxydopamine-induced dopaminergic neuronal cell death. J Neural Transm (Vienna) 2011; 118:1585-98. [PMID: 21904894 DOI: 10.1007/s00702-011-0710-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Accepted: 08/20/2011] [Indexed: 11/24/2022]
Abstract
Parkinson's disease (PD) is the second most common neurodegenerative disorder and is characterized by a loss of dopaminergic neurons in the substantia nigra pars compacta. To discover potential key molecules in this process, we utilized cDNA microarray technology to obtain an expression profile of transcripts in MN9D dopaminergic neuronal cells treated with 6-hydroxydopamine. Using a self-organizing map algorithm, data mining and clustering were combined to identify distinct functional subgroups of genes. We identified alterations in the expression of 81 genes in eight clusters. Among these genes, we verified protein expression patterns of MAP kinase phosphatase 1 and sequestosome 1 using both cell culture and rat brain models of PD. Immunological analyses revealed increased expression levels as well as aggregated distribution patterns of these gene products in 6-hydroxydopamine-treated dopaminergic neurons. In addition to the identification of other proteins that are known to be associated with protein aggregation, our results raise the possibility that a more widespread set of proteins may be associated with the generation of protein aggregates in dying neurons. Further research to determine the functional roles of other altered gene products within the same cluster as well as the seven remaining clusters may provide new insights into the neurodegeneration that underlies PD pathogenesis.
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Affiliation(s)
- Bokyung Park
- Department of Biology, Yonsei University College of Life Science and Biotechnology, 134 Shinchon-Dong, Seodaemoon-Gu, Seoul, Korea
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24
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Yamamoto A, Simonsen A. The elimination of accumulated and aggregated proteins: a role for aggrephagy in neurodegeneration. Neurobiol Dis 2010; 43:17-28. [PMID: 20732422 DOI: 10.1016/j.nbd.2010.08.015] [Citation(s) in RCA: 124] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2010] [Revised: 08/11/2010] [Accepted: 08/16/2010] [Indexed: 12/21/2022] Open
Abstract
The presence of ubiquitinated protein inclusions is a hallmark of most adult onset neurodegenerative disorders. Although the toxicity of these structures remains controversial, their prolonged presence in neurons is indicative of some failure in fundamental cellular processes. It therefore may be possible that driving the elimination of inclusions can help re-establish normal cellular function. There is growing evidence that macroautophagy has two roles; first, as a non-selective degradative response to cellular stress such as starvation, and the other as a highly selective quality control mechanism whose basal levels are important to maintain cellular health. One particular form of macroautophagy, aggrephagy, may have particular relevance in neurodegeneration, as it is responsible for the selective elimination of accumulated and aggregated ubiquitinated proteins. In this review, we will discuss the molecular mechanisms and role of protein aggregation in neurodegeneration, as well as the molecular mechanism of aggrephagy and how it may impact disease. This article is part of a Special Issue entitled "Autophagy and protein degradation in neurological diseases."
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Affiliation(s)
- Ai Yamamoto
- Dept of Neurology, Columbia University, New York, NY 10032, USA.
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25
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Swearingen KE, Loomis WP, Zheng M, Cookson BT, Dovichi NJ. Proteomic profiling of lipopolysaccharide-activated macrophages by isotope coded affinity tagging. J Proteome Res 2010; 9:2412-21. [PMID: 20199111 DOI: 10.1021/pr901124u] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Lipopolysaccharide (LPS), a glycolipid component of the outer membranes of Gram-negative bacteria, initiates proinflammatory, proapoptotic, and antiapoptotic pathways upon binding to macrophage TLR4. Macrophages that are exposed to LPS become activated and exhibit altered morphology and response to infection. We performed isotope coded affinity tagging (ICAT), multidimensional liquid chromatography, and mass spectrometry to identify proteins that are differently expressed between naive and LPS-activated macrophages. We performed replicate ICAT analyses on RAW 264.7 cultured mouse macrophages as well as C57BL/6 bone marrow derived mouse macrophages. We identified and obtained relative abundances for 1064 proteins, of which we identified 36 as having significantly different expression levels upon activation by LPS. We also compared our results with a two color microarray gene expression assay performed by the Institute for Systems Biology and observed approximately 75% agreement between mRNA transcription and protein expression regarding up- or down-regulation of gene products. We used Western blot analysis to confirm the findings of ICAT and mRNA for one protein, sequestosome 1, the cellular concentration of which was observed to increase upon activation by LPS.
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Affiliation(s)
- Kristian E Swearingen
- Department of Chemistry, University of Washington, P.O. Box 351700, Seattle, Washington 98195-1700, USA
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26
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Jain A, Lamark T, Sjøttem E, Larsen KB, Awuh JA, Øvervatn A, McMahon M, Hayes JD, Johansen T. p62/SQSTM1 is a target gene for transcription factor NRF2 and creates a positive feedback loop by inducing antioxidant response element-driven gene transcription. J Biol Chem 2010; 285:22576-91. [PMID: 20452972 DOI: 10.1074/jbc.m110.118976] [Citation(s) in RCA: 1099] [Impact Index Per Article: 78.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The p62/SQSTM1 (sequestosome 1) protein, which acts as a cargo receptor for autophagic degradation of ubiquitinated targets, is up-regulated by various stressors. Induction of the p62 gene by oxidative stress is mediated by NF-E2-related factor 2 (NRF2) and, at the same time, p62 protein contributes to the activation of NRF2, but hitherto the mechanisms involved were not known. Herein, we have mapped an antioxidant response element (ARE) in the p62 promoter that is responsible for its induction by oxidative stress via NRF2. Chromatin immunoprecipitation and gel mobility-shift assays verified that NRF2 binds to this cis-element in vivo and in vitro. Also, p62 docks directly onto the Kelch-repeat domain of Kelch-like ECH-associated protein 1 (KEAP1), via a motif designated the KEAP1 interacting region (KIR), thereby blocking binding between KEAP1 and NRF2 that leads to ubiquitylation and degradation of the transcription factor. The KIR motif in p62 is located immediately C-terminal to the LC3-interacting region (LIR) and resembles the ETGE motif utilized by NRF2 for its interaction with KEAP1. KIR is required for p62 to stabilize NRF2, and inhibition of KEAP1 by p62 occurs from a cytoplasmic location within the cell. The LIR and KIR motifs cannot be engaged simultaneously by LC3 and KEAP1, but because p62 is polymeric the interaction between KEAP1 and p62 leads to accumulation of KEAP1 in p62 bodies, which is followed by autophagic degradation of KEAP1. Our data explain how p62 contributes to activation of NRF2 target genes in response to oxidative stress through creating a positive feedback loop.
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Affiliation(s)
- Ashish Jain
- Molecular Cancer Research Group, Institute of Medical Biology, University of Tromsø, 9037 Tromsø, Norway
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27
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Pankiv S, Lamark T, Bruun JA, Øvervatn A, Bjørkøy G, Johansen T. Nucleocytoplasmic shuttling of p62/SQSTM1 and its role in recruitment of nuclear polyubiquitinated proteins to promyelocytic leukemia bodies. J Biol Chem 2009; 285:5941-53. [PMID: 20018885 DOI: 10.1074/jbc.m109.039925] [Citation(s) in RCA: 184] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
p62, also known as sequestosome1 (SQSTM1), A170, or ZIP, is a multifunctional protein implicated in several signal transduction pathways. p62 is induced by various forms of cellular stress, is degraded by autophagy, and acts as a cargo receptor for autophagic degradation of ubiquitinated targets. It is also suggested to shuttle ubiquitinated proteins for proteasomal degradation. p62 is commonly found in cytosolic protein inclusions in patients with protein aggregopathies, it is up-regulated in several forms of human tumors, and mutations in the gene are linked to classical adult onset Paget disease of the bone. To this end, p62 has generally been considered to be a cytosolic protein, and little attention has been paid to possible nuclear roles of this protein. Here, we present evidence that p62 shuttles continuously between nuclear and cytosolic compartments at a high rate. The protein is also found in nuclear promyelocytic leukemia bodies. We show that p62 contains two nuclear localization signals and a nuclear export signal. Our data suggest that the nucleocytoplasmic shuttling of p62 is modulated by phosphorylations at or near the most important nuclear localization signal, NLS2. The aggregation of p62 in cytosolic bodies also regulates the transport of p62 between the compartments. We found p62 to be essential for accumulation of polyubiquitinated proteins in promyelocytic leukemia bodies upon inhibition of nuclear protein export. Furthermore, p62 contributed to the assembly of proteasome-containing degradative compartments in the vicinity of nuclear aggregates containing polyglutamine-expanded Ataxin1Q84 and to the degradation of Ataxin1Q84.
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Affiliation(s)
- Serhiy Pankiv
- Molecular Cancer Research Group, Institute of Medical Biology, University of Tromsø, 9037 Tromsø, Norway
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28
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Lamark T, Johansen T. Autophagy: links with the proteasome. Curr Opin Cell Biol 2009; 22:192-8. [PMID: 19962293 DOI: 10.1016/j.ceb.2009.11.002] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2009] [Accepted: 11/05/2009] [Indexed: 10/20/2022]
Abstract
The two main protein degradation systems of eukaryotic cells, the ubiquitin-proteasome system and autophagy, have been thought of as quite separate systems. However, recent findings strongly suggest that there is crosstalk and even cooperation between these two degradation pathways. Ubiquitination and degradation of misfolded proteins by the ubiquitin-proteasome system have been investigated for some time, but much less is known about autophagic degradation of misfolded proteins. We will here discuss recent findings that shed some light on the cellular processes deciding when and how misfolded proteins are specifically selected for autophagic degradation in favor of proteasomal degradation.
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Affiliation(s)
- Trond Lamark
- Molecular Cancer Research Group, Institute of Medical Biology, University of Tromsø, 9037 Tromsø, Norway
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29
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Nogalska A, Terracciano C, D’Agostino C, King Engel W, Askanas V. p62/SQSTM1 is overexpressed and prominently accumulated in inclusions of sporadic inclusion-body myositis muscle fibers, and can help differentiating it from polymyositis and dermatomyositis. Acta Neuropathol 2009; 118:407-13. [PMID: 19557423 DOI: 10.1007/s00401-009-0564-6] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2009] [Revised: 06/17/2009] [Accepted: 06/17/2009] [Indexed: 10/20/2022]
Abstract
p62, also known as sequestosome1, is a shuttle protein transporting polyubiquitinated proteins for both the proteasomal and lysosomal degradation. p62 is an integral component of inclusions in brains of various neurodegenerative disorders, including Alzheimer disease (AD) neurofibrillary tangles (NFTs) and Lewy bodies in Parkinson disease. In AD brain, the p62 localized in NFTs is associated with phosphorylated tau (p-tau). Sporadic inclusion-body myositis (s-IBM) is the most common progressive muscle disease associated with aging, and its muscle tissue has several phenotypic similarities to AD brain. Abnormal accumulation of intracellular multiprotein inclusions, containing p-tau in the form of paired helical filaments, amyloid-beta, and several other "Alzheimer-characteristic proteins", is a characteristic feature of the s-IBM muscle fiber phenotype. Diminished proteasomal and lysosomal protein degradation appear to play an important role in the formation of intra-muscle-fiber inclusions. We now report that: (1) in s-IBM muscle fibers, p62 protein is increased on both the protein and the mRNA levels, and it is strongly accumulated within, and as a dense peripheral shell surrounding, p-tau containing inclusions, by both the light- and electron-microscopy. Accordingly, our studies provide a new, reliable, and simple molecular marker of p-tau inclusions in s-IBM muscle fibers. The prominent p62 immunohistochemical positivity and pattern diagnostically distinguish s-IBM from polymyositis and dermatomyositis. (2) In normal cultured human muscle fibers, experimental inhibition of either proteasomal or lysosomal protein degradation caused substantial increase of p62, suggesting that similar in vivo mechanisms might contribute to the p62 increase in s-IBM muscle fibers.
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30
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Du Y, Wooten MC, Gearing M, Wooten MW. Age-associated oxidative damage to the p62 promoter: implications for Alzheimer disease. Free Radic Biol Med 2009; 46:492-501. [PMID: 19071211 PMCID: PMC2684672 DOI: 10.1016/j.freeradbiomed.2008.11.003] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2008] [Revised: 10/27/2008] [Accepted: 11/03/2008] [Indexed: 11/25/2022]
Abstract
The absence of the p62 gene in mouse brain leads to biochemical and cognitive deficits that resemble Alzheimer disease (AD). In this context, the objective of this study was to examine the relationship between age-induced oxidative damage to the p62 promoter and AD. Increased 8-OHdG staining, a marker of oxidative stress, was observed in brain sections from mice deficient in the p62 gene compared to control. Treatment of MEF cells deficient in p62 with H(2)O(2) resulted in decreased cell survival and an absence of Nrf2 nuclear translocation. The mouse p62 promoter exhibited elevated oxidative damage with increasing age, and the degree of p62 promoter damage was also age-correlated in human brain samples. In human subjects, the expression of p62 was decreased in AD brain relative to age-matched controls, and likewise decreased p62 expression correlated with oxidative damage to the promoter. Treatment of HEK cells with H(2)O(2) resulted in decreased p62 expression concomitant with increased promoter damage. Consistent with these findings, a transgenic AD mouse model also exhibited increased p62 promoter damage and reduced p62 levels in brain. Altogether, our results reveal that oxidative damage to the p62 promoter correlates with decreased expression of p62 and may contribute to age-associated neurodegenerative disease such as AD and others.
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Affiliation(s)
- Yifeng Du
- Department of Biological Sciences, Cellular and Molecular Biosciences Program, Auburn University, AL 38849, U.S.A
| | - Michael C. Wooten
- Department of Biological Sciences, Cellular and Molecular Biosciences Program, Auburn University, AL 38849, U.S.A
| | - Marla Gearing
- Pathology & Laboratory Medicine, Emory University, Atlanta, GA 30322, U.S.A
| | - Marie W. Wooten
- Department of Biological Sciences, Cellular and Molecular Biosciences Program, Auburn University, AL 38849, U.S.A
- Corresponding author. Send correspondence to Marie W. Wooten, 331 Funchess Hall, Department of Biological Sciences, Auburn University, AL 38849, Tel: (334) 844-9226, Fax: (334) 844-5255, E-mail address:
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31
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Alirezaei M, Kiosses WB, Flynn CT, Brady NR, Fox HS. Disruption of neuronal autophagy by infected microglia results in neurodegeneration. PLoS One 2008; 3:e2906. [PMID: 18682838 PMCID: PMC2483417 DOI: 10.1371/journal.pone.0002906] [Citation(s) in RCA: 125] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2008] [Accepted: 07/15/2008] [Indexed: 12/14/2022] Open
Abstract
There is compelling evidence to support the idea that autophagy has a protective function in neurons and its disruption results in neurodegenerative disorders. Neuronal damage is well-documented in the brains of HIV-infected individuals, and evidence of inflammation, oxidative stress, damage to synaptic and dendritic structures, and neuronal loss are present in the brains of those with HIV-associated dementia. We investigated the role of autophagy in microglia-induced neurotoxicity in primary rodent neurons, primate and human models. We demonstrate here that products of simian immunodeficiency virus (SIV)-infected microglia inhibit neuronal autophagy, resulting in decreased neuronal survival. Quantitative analysis of autophagy vacuole numbers in rat primary neurons revealed a striking loss from the processes. Assessment of multiple biochemical markers of autophagic activity confirmed the inhibition of autophagy in neurons. Importantly, autophagy could be induced in neurons through rapamycin treatment, and such treatment conferred significant protection to neurons. Two major mediators of HIV-induced neurotoxicity, tumor necrosis factor-alpha and glutamate, had similar effects on reducing autophagy in neurons. The mRNA level of p62 was increased in the brain in SIV encephalitis and as well as in brains from individuals with HIV dementia, and abnormal neuronal p62 dot structures immunoreactivity was present and had a similar pattern with abnormal ubiquitinylated proteins. Taken together, these results identify that induction of deficits in autophagy is a significant mechanism for neurodegenerative processes that arise from glial, as opposed to neuronal, sources, and that the maintenance of autophagy may have a pivotal role in neuroprotection in the setting of HIV infection.
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Affiliation(s)
- Mehrdad Alirezaei
- Molecular and Integrative Neurosciences Department, The Scripps Research Institute, La Jolla, California, United States of America
| | - William B. Kiosses
- Core Microscopy Facility, The Scripps Research Institute, La Jolla, California, United States of America
| | - Claudia T. Flynn
- Molecular and Integrative Neurosciences Department, The Scripps Research Institute, La Jolla, California, United States of America
| | - Nathan R. Brady
- Deutsches Krebsforschungszentrum and BIOQUANT, Heidelberg, Germany
| | - Howard S. Fox
- Molecular and Integrative Neurosciences Department, The Scripps Research Institute, La Jolla, California, United States of America
- * E-mail:
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32
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Pankiv S, Clausen TH, Lamark T, Brech A, Bruun JA, Outzen H, Øvervatn A, Bjørkøy G, Johansen T. p62/SQSTM1 binds directly to Atg8/LC3 to facilitate degradation of ubiquitinated protein aggregates by autophagy. J Biol Chem 2007; 282:24131-45. [PMID: 17580304 DOI: 10.1074/jbc.m702824200] [Citation(s) in RCA: 3401] [Impact Index Per Article: 200.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Protein degradation by basal constitutive autophagy is important to avoid accumulation of polyubiquitinated protein aggregates and development of neurodegenerative diseases. The polyubiquitin-binding protein p62/SQSTM1 is degraded by autophagy. It is found in cellular inclusion bodies together with polyubiquitinated proteins and in cytosolic protein aggregates that accumulate in various chronic, toxic, and degenerative diseases. Here we show for the first time a direct interaction between p62 and the autophagic effector proteins LC3A and -B and the related gamma-aminobutyrate receptor-associated protein and gamma-aminobutyrate receptor-associated-like proteins. The binding is mediated by a 22-residue sequence of p62 containing an evolutionarily conserved motif. To monitor the autophagic sequestration of p62- and LC3-positive bodies, we developed a novel pH-sensitive fluorescent tag consisting of a tandem fusion of the red, acid-insensitive mCherry and the acid-sensitive green fluorescent proteins. This approach revealed that p62- and LC3-positive bodies are degraded in autolysosomes. Strikingly, even rather large p62-positive inclusion bodies (2 microm diameter) become degraded by autophagy. The specific interaction between p62 and LC3, requiring the motif we have mapped, is instrumental in mediating autophagic degradation of the p62-positive bodies. We also demonstrate that the previously reported aggresome-like induced structures containing ubiquitinated proteins in cytosolic bodies are dependent on p62 for their formation. In fact, p62 bodies and these structures are indistinguishable. Taken together, our results clearly suggest that p62 is required both for the formation and the degradation of polyubiquitin-containing bodies by autophagy.
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Affiliation(s)
- Serhiy Pankiv
- Biochemistry Department, Institute of Medical Biology, University of Tromsø, 9037 Tromsø, Norway
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33
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Gal J, Ström AL, Kilty R, Zhang F, Zhu H. p62 Accumulates and Enhances Aggregate Formation in Model Systems of Familial Amyotrophic Lateral Sclerosis. J Biol Chem 2007; 282:11068-77. [PMID: 17296612 DOI: 10.1074/jbc.m608787200] [Citation(s) in RCA: 132] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a progressive neurode-generative disease characterized by motor neuron death. A hallmark of the disease is the appearance of protein aggregates in the affected motor neurons. We have found that p62, a protein implicated in protein aggregate formation, accumulated progressively in the G93A mouse spinal cord. The accumulation of p62 was in parallel to the increase of polyubiquitinated proteins and mutant SOD1 aggregates. Immunostaining studies showed that p62, ubiquitin, and mutant SOD1 co-localized in the protein aggregates in affected cells in G93A mouse spinal cord. The p62 protein selectively interacted with familial ALS mutants, but not WT SOD1. When p62 was co-expressed with SOD1 in NSC34 cells, it greatly enhanced the formation of aggregates of the ALS-linked SOD1 mutants, but not wild-type SOD1. Cell viability was measured in the presence and absence of overexpressed p62, and the results suggest that the large aggregates facilitated by p62 were not directly toxic to cells under the conditions in this study. Deletion of the ubiquitin-association (UBA) domain of p62 significantly decreased the p62-facilitated aggregate formation, but did not completely inhibit it. Further protein interaction experiments also showed that the truncated p62 with the UBA domain deletion remained capable of interacting with mutant SOD1. The findings of this study show that p62 plays a critical role in forming protein aggregates in familial ALS, likely by linking misfolded mutant SOD1 molecules and other cellular proteins together.
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Affiliation(s)
- Jozsef Gal
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington 40536, USA
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34
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Bjørkøy G, Lamark T, Brech A, Outzen H, Perander M, Overvatn A, Stenmark H, Johansen T. p62/SQSTM1 forms protein aggregates degraded by autophagy and has a protective effect on huntingtin-induced cell death. ACTA ACUST UNITED AC 2005; 171:603-14. [PMID: 16286508 PMCID: PMC2171557 DOI: 10.1083/jcb.200507002] [Citation(s) in RCA: 2512] [Impact Index Per Article: 132.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Autophagic degradation of ubiquitinated protein aggregates is important for cell survival, but it is not known how the autophagic machinery recognizes such aggregates. In this study, we report that polymerization of the polyubiquitin-binding protein p62/SQSTM1 yields protein bodies that either reside free in the cytosol and nucleus or occur within autophagosomes and lysosomal structures. Inhibition of autophagy led to an increase in the size and number of p62 bodies and p62 protein levels. The autophagic marker light chain 3 (LC3) colocalized with p62 bodies and co-immunoprecipitated with p62, suggesting that these two proteins participate in the same complexes. The depletion of p62 inhibited recruitment of LC3 to autophagosomes under starvation conditions. Strikingly, p62 and LC3 formed a shell surrounding aggregates of mutant huntingtin. Reduction of p62 protein levels or interference with p62 function significantly increased cell death that was induced by the expression of mutant huntingtin. We suggest that p62 may, via LC3, be involved in linking polyubiquitinated protein aggregates to the autophagy machinery.
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Affiliation(s)
- Geir Bjørkøy
- Biochemistry Department, Institute of Medical Biology, University of Tromsø, 9037 Tromsø, Norway
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35
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Kim Y, Uhm DY, Shin J, Chung S. Modulation of delayed rectifier potassium channel by protein kinase C zeta-containing signaling complex in pheochromocytoma cells. Neuroscience 2004; 125:359-68. [PMID: 15062979 DOI: 10.1016/j.neuroscience.2003.08.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/04/2003] [Indexed: 10/26/2022]
Abstract
Voltage-dependent delayed rectifier K(+) (Kv) channels are fundamental components in the regulation of neuronal excitability. We found that nerve growth factor (NGF) treatment of PC12 cells induced a hyperpolarizing shift of the Kv current activation curve by about 15 mV. This effect was similar to the effect of the modulatory subunit, Kv beta, on the cloned Kv channel, and required the activity of protein kinase C (PKC)zeta. Since NGF treatment of PC12 cells is known to increase the expression of p62 protein, which binds both to Kv beta and to PKC zeta, our results are consistent with the model in which p62 functions as a physical link in the assembly of signaling complex, PKC zeta-p62-Kv channel. In agreement with this model, the transient expression of p62 induced the same change in the Kv current activation curve as NGF, and the suppression of p62 expression inhibited the effect of NGF. The amount of bound Kv beta to p62 was increased by NGF treatment. These results suggest that the increased p62 protein induces the formation of the signaling complexes, enabling PKC zeta to modulate Kv channels. Thus, this may constitute a new way of modulating Kv channel activities.
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Affiliation(s)
- Y Kim
- Department of Physiology, Sungkyunkwan University School of Medicine, Suwon 440-746, South Korea
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36
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Nakaso K, Yoshimoto Y, Nakano T, Takeshima T, Fukuhara Y, Yasui K, Araga S, Yanagawa T, Ishii T, Nakashima K. Transcriptional activation of p62/A170/ZIP during the formation of the aggregates: possible mechanisms and the role in Lewy body formation in Parkinson's disease. Brain Res 2004; 1012:42-51. [PMID: 15158159 DOI: 10.1016/j.brainres.2004.03.029] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/23/2004] [Indexed: 12/31/2022]
Abstract
Formation of intracellular inclusion bodies due to defects in the protein degradation machinery is associated with the pathogenesis of neurodegenerative diseases. Sequestosomal protein p62/A170/ZIP, which is an oxidative stress-related protein and a ubiquitin-binding protein, is a component protein of Lewy bodies that are observed in patients with Parkinson's disease. The association of p62 with poly-ubiquitinated proteins may be an important step in the formation of intracellular protein aggregates like Lewy bodies. To study the role of p62 in the formation of protein aggregates in PC12 cells, we monitored the intracellular localizations of p62 and ubiquitinated proteins and the levels of both components during treatment with MG132, a proteasome inhibitor. In the early stage of aggregate formation, p62 did not always co-localize with ubiquitin. In contrast, these proteins were always co-localized in later stages. After the treatment of the cells with MG132, we found that the expression level of p62 increased due to the transcriptional activation of the gene and that higher molecular sizes of p62, corresponding to mono- and di-ubiquitinated formes, were also formed. Both the transcriptional inhibitor actinomycin D and an antisense oligonucleotide of p62 inhibited the MG132-mediated increase of p62, the sequestration of ubiquitinated proteins, and the enlargement of the aggregates. Furthermore, p62-positive aggregates were observed primarily in surviving cells. Together, these results suggest that p62 plays an important role in the protection of cells from the toxicity of misfolded proteins by enhancing aggregate formation especially in the later stages.
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Affiliation(s)
- Kazuhiro Nakaso
- Department of Neurology, Institute of Neurological Sciences, Faculty of Medicine, Tottori University, 36-1, Nishimachi, Yonago, 683-8504, Japan.
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37
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Youdim MB, Grünblatt E, Levites Y, Maor G, Mandel S. Early and late molecular events in neurodegeneration and neuroprotection in Parkinson's disease MPTP model as assessed by cDNA microarray; the role of iron. Neurotox Res 2002; 4:679-689. [PMID: 12709306 DOI: 10.1080/1029842021000045507] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Possible cell death mechanisms for pars compacta nigro-striatal dopamine neurons in Parkinson's disease include oxidative stress, inflammatory processes, nitric oxide iron accumulation, glutamate toxicity and diminished neurotrophic factor responses. There is a notion that Parkinson's disease is not a single disorder but a syndrome that can be initiated by several factors. Because of limitations of biochemical methods in the global analysis of neuronal death, a full picture of events has not been established. However, recently developed cDNA microarray or microchips, in which the global expression of thousands of genes can be assessed simultaneously, is changing the prospect for understanding the disease process, its progression, response to drugs, etc. The neurotoxin N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is considered the most valid model of Parkinson's disease. We employed the technique of cDNA microarray gene expression to determine the mechanism of action of MPTP in mouse substantia nigra. Also, we studied neuroprotective processes induced by several compounds, including R-apomorphine and the green tea polyphenol epigallo-catechin-3-gallate (EGCG). This was done in two ways: (1) the time-dependent acute effect of MPTP, for determining which of the initial genes might lead to dopamine neuron death and (2) gene expression at the time of MPTP-induced dopamine neuron death. We observed that early (acute MPTP) gene expression differs from effects seen at the time of death (chronic MPTP), and that early gene changes are crucial for setting into action genes that eventually cause dopamine neuron death. Furthermore, this process is a cascade of "domino" effects, some of which were previously established by biochemical means. However, our findings show an additional large number of events previously unknown. The neuroprotective drugs reversed some but not all of the gene expression, suggesting involvement of these genes in the neurodegenerative process. Because of the profound complexity of "domino" effect it is now reasonable to understand why a single neuroprotective drug has not shown clinical neuroprotective efficacy. Future multi neuroprotective drugs may be necessary for treatment of not only Parkinson's disease, but other neurodegenerative diseases (e.g. Alzheimer's disease) and detrimental states (e.g. ischaemia).
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Affiliation(s)
- Moussa B.H. Youdim
- Department of Pharmacology, Technion-Faculty of Medicine, Eve Topf and US National Parkinson's Foundation Centers for Neurodegenerative Diseases, P.O.B. 9697, Efron St., Haifa, 31096, Israel
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38
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Mandel S, Grünblatt E, Maor G, Youdim MBH. Early and late gene changes in MPTP mice model of Parkinson's disease employing cDNA microarray. Neurochem Res 2002; 27:1231-43. [PMID: 12462421 DOI: 10.1023/a:1020989812576] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Recently, we reported specific brain gene expression changes in the chronic MPTP model inthe late stage of degeneration, employing cDNA expression array, which indicate a "domino" cascade of events involved in neuronal cell death. In an attempt to elucidate early gene expression profile in the region of the substantia nigra (SN) and the striatum of acute MPTP-treated mice (3-24 h), we elected a restricted number of genes affected by the long-term MPTP treatment, and their expression was examined. Specifically, we detected alterations in the expression of genes implicated in oxidative-stress, inflammatory processes, signal transduction and glutamate toxicity. These pro-toxic genes appear to be compensated by the elevated expression in trophic factors and antioxidant defenses, which are also activated by short exposure to MPTP. The time course of these gene expression changes indicates the importance of investigating the early gene cascade of events occurring prior to late nigrostriatal dopamine neuronal cell death.
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Affiliation(s)
- Silvia Mandel
- Eye Topf and U.S. National Parkinson's Foundation Centers of Excellence for Neurodegenerative Diseases, Bruce Rappaport Family Research Institute and Department of Pharmacology, Haifa, Israel
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Stumptner C, Fuchsbichler A, Heid H, Zatloukal K, Denk H. Mallory body--a disease-associated type of sequestosome. Hepatology 2002; 35:1053-62. [PMID: 11981755 DOI: 10.1053/jhep.2002.32674] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
Abstract
Mallory bodies (MBs) consist of abnormal keratins, ubiquitin, heat shock proteins, and the protein p62. p62 is encoded by an immediate-early response gene that rapidly responds to a variety of extracellular signals involved in cell proliferation, differentiation, and particularly oxidative stress. It acts as an adapter in signal transduction and binds noncovalently to ubiquitin, possibly being involved in the regulation of the fate of ubiquitinated proteins by segregation (i.e., sequestosome or aggresome formation). The presence of p62 together with ubiquitinated abnormal keratins in the MB characterizes MBs as a disease-associated type of sequestosome. A detailed study on the expression of p62 and its relationship to MB formation in the 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC)-treated mouse liver is reported based on immunohistochemical, immunoblot, and Northern blot analyses. The results indicate that p62 is rapidly induced in hepatocytes of intoxicated animals preceding MB formation. As suggested by experiments with short-term DDC-treated naive mice and mice refed DDC after recovery from long-term DDC treatment (primed mice), p62 does not exert an initiating effect on MB formation but the appearance of MBs requires the presence of abnormal keratins, which associate with p62 after ubiquitination. The rapid induction of p62 and its association with MBs further support the role of oxidative stress in MB formation. In conclusion, the constant presence of p62 in MBs suggests that binding of p62 to abnormal keratins may allow hepatocytes to dispose potentially harmful proteins in a biologically inert manner.
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Affiliation(s)
- Cornelia Stumptner
- Department of Pathology, School of Medicine, University of Graz, Graz, Austria
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40
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Abstract
Several highly conserved p62 homologs have recently been isolated, e.g. the rat atypical protein kinase C-interacting protein (ZIP), the murine A170/signal transduction and adapter protein, and the human p62, a protein that binds the Src homology 2 domain of p56(lck). These proteins share striking similarity in amino acid sequence and structural motifs, thereby suggesting conserved functional properties. ZIP/p62 has been shown to play an important role as a scaffold leading to the activation of the transcription factor nuclear factor kappaB. In addition, a nuclear form of p62 has been characterized that can serve as a transcriptional co-activator. Moreover, p62 is capable of binding ubiquitin (Ub) non-covalently through its Ub-associated domain. In this review, we will focus on the structure and function of ZIP/p62.
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Affiliation(s)
- Thangiah Geetha
- Department of Biological Sciences, Program in Cellular and Molecular Biosciences, 331 Funchess Hall, Auburn University, Auburn, AL 36849, USA
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41
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Zatloukal K, Stumptner C, Fuchsbichler A, Heid H, Schnoelzer M, Kenner L, Kleinert R, Prinz M, Aguzzi A, Denk H. p62 Is a common component of cytoplasmic inclusions in protein aggregation diseases. THE AMERICAN JOURNAL OF PATHOLOGY 2002; 160:255-63. [PMID: 11786419 PMCID: PMC1867135 DOI: 10.1016/s0002-9440(10)64369-6] [Citation(s) in RCA: 468] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Exposure of cells to stress, particularly oxidative stress, leads to misfolding of proteins and, if they are not refolded or degraded, to cytoplasmic protein aggregates. Protein aggregates are characteristic features of a variety of chronic toxic and degenerative diseases, such as Mallory bodies (MBs) in hepatocytes in alcoholic and non-alcoholic steatohepatitis, neurofibrillary tangles in neurons in Alzheimer's, and Lewy bodies in Parkinson's disease. Using 2D gel electrophoresis and mass spectrometry, we identified p62 as a novel MB component. p62 and cytokeratins (CKs) are major MB constituents; HSP 70, HSP 25, and ubiquitinated CKs are also present. These proteins characterize MBs as a prototype of disease-associated cytoplasmic inclusions generated by stress-induced protein misfolding. As revealed by transfection of tissue culture cells overexpressed p62 did not induce aggregation of regular CK filaments but selectively bound to misfolded and ubiquitinated CKs. The general role of p62 in the cellular response to misfolded proteins was substantiated by detection of p62 in other cytoplasmic inclusions, such as neurofibrillary tangles, Lewy bodies, Rosenthal fibers, intracytoplasmic hyaline bodies in hepatocellular carcinoma, and alpha1-antitrypsin aggregates. The presence of p62 along with other stress proteins and ubiquitin in cytoplasmic inclusions indicates deposition as aggregates as a third line of defense against misfolded proteins in addition to refolding and degradation.
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Affiliation(s)
- Kurt Zatloukal
- Department of Pathology, Karl-Franzens University, Graz, Austria.
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Grünblatt E, Mandel S, Maor G, Youdim MB. Gene expression analysis in N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine mice model of Parkinson's disease using cDNA microarray: effect of R-apomorphine. J Neurochem 2001; 78:1-12. [PMID: 11432968 DOI: 10.1046/j.1471-4159.2001.00397.x] [Citation(s) in RCA: 135] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
To establish the possible roles of oxidative stress, inflammatory processes and other unknown mechanisms in neurodegeneration, we investigated brain gene alterations in N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mice model of Parkinson's disease using Atlas mouse cDNA expression array membrane. The expression of 51 different genes involved in oxidative stress, inflammation, glutamate and neurotrophic factors pathways as well as in still undefined processes, such as cell cycle regulators and signal transduction molecules, was differentially affected by the treatment. The present study indicates the involvement of an additional cascade of events that might act in parallel to oxidative stress and inflammation to converge eventually into a common pathway leading to neurodegeneration. The attenuation of these gene changes by R-apomorphine, an iron chelator-radical scavenger drug, supports our previous findings in vivo where R-apomorphine was neuroprotective.
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Affiliation(s)
- E Grünblatt
- Technion Faculty of Medicine, Eve Topf and US National Parkinson's Foundation Centers for Neurodegenerative Diseases, Department of Pharmacology, Haifa, Israel
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43
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Abstract
Reactive oxygen species are produced by all aerobic cells and are widely believed to play a pivotal role in aging as well as a number of degenerative diseases. The consequences of the generation of oxidants in cells does not appear to be limited to promotion of deleterious effects. Alterations in oxidative metabolism have long been known to occur during differentiation and development. Experimental perturbations in cellular redox state have been shown to exert a strong impact on these processes. The discovery of specific genes and pathways affected by oxidants led to the hypothesis that reactive oxygen species serve as subcellular messengers in gene regulatory and signal transduction pathways. Additionally, antioxidants can activate numerous genes and pathways. The burgeoning growth in the number of pathways shown to be dependent on oxidation or antioxidation has accelerated during the last decade. In the discussion presented here, we provide a tabular summary of many of the redox effects on gene expression and signaling pathways that are currently known to exist.
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Affiliation(s)
- R G Allen
- Lankenau Medical Research Center, Thomas Jefferson University, Wynnewood, PA 19106, USA
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44
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Abstract
Macrophages produce reactive oxygen species such as O2-, H2O2 and *OH that contribute to the pathogenesis of diseases such as inflammation and atherosclerosis. The cells have multiple defense systems against those reactive oxygen species, and we describe here such an oxidative stress-inducible defense system. Upon exposure to reactive oxygen species and electrophilic agents, murine peritoneal macrophages induce stress proteins to protect themselves. Using differential screening, we cloned two novel proteins designated MSP23 and A170 that are induced in the cells by low levels of reactive oxygen species, electrophilic agents and other oxidative stress agents. MSP23 is murine peroxiredoxin I having a thioredoxin peroxidase activity and A170 is known as an ubiquitin- and PKC xi-binding protein. In addition to these two proteins, heme oxygenase-1 (HO-1) and cystine transport activity are also induced in the cells under oxidative stress conditions. Using nrf2-deficient macrophages, we found that transcription factor Nrf2, which is known to interact with antioxidant responsive elements (AREs) in the regulatory sequences of the genes, plays an important role in the oxidative stress-inducible response in the cells.
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Affiliation(s)
- T Ishii
- Department of Biochemistry, Institute of Basic Medical Sciences, University of Tsukuba, Ibaraki, Japan.
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Rachubinski RA, Marcus SL, Capone JP. The p56(lck)-interacting protein p62 stimulates transcription via the SV40 enhancer. J Biol Chem 1999; 274:18278-84. [PMID: 10373430 DOI: 10.1074/jbc.274.26.18278] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
p62 is a recently identified ubiquitin-binding, cytosolic phosphoprotein that interacts with several signal transduction molecules including the tyrosine kinase p56(lck) and the protein kinase C-zeta. p62 is therefore suggested to serve an important role in signal transduction in the cell, although the physiological function of p62 remains undefined. Here we demonstrate by transient transfection assays that p62 stimulates the transcription of reporter genes linked to the simian virus 40 (SV40) enhancer. A putative p62-responsive element was localized to the B domain of the distal 72-base pair repeat of the SV40 enhancer. p62 was unable to bind this element in vitro, nor was it able to activate transcription when directly tethered to a promoter, suggesting that p62 stimulates transcription via an indirect mechanism. Stimulation of transcription mediated by p62 was dependent on its amino-terminal region, which is also necessary for interaction with cell surface signaling molecules. These findings indicate that p62 may link extracellular signals directly to transcriptional responses, and identify the SV40 enhancer as a downstream target for signal transduction pathways in which p62 participates.
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Affiliation(s)
- R A Rachubinski
- Department of Cell Biology, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
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Nakaso K, Kitayama M, Ishii T, Bannai S, Yanagawa T, Kimura K, Nakashima K, Ohama E, Yamada K. Effects of kainate-mediated excitotoxicity on the expression of rat counterparts of A170 and MSP23 stress proteins in the brain. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 1999; 69:155-63. [PMID: 10366737 DOI: 10.1016/s0169-328x(99)00093-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Stress proteins play important roles in the protective mechanisms under critical conditions for cell survival. We report here the expression of A170 and MSP23, oxidative stress-inducible proteins, under kainate-mediated excitotoxicity in the rat brain. A170 mRNA was significantly induced in the brain 5-8 h after i.p. kainate administration. MSP23 mRNA was observed at quite a low level in the rat brain, and the induction of MSP23 mRNA was not observed during the period 24 h after kainate administration. Immunoblot analysis demonstrated that the maximal expression level of A170 protein occurred 8 h after treatment in each part of the brain. MSP23 protein was constitutively expressed in the brain and the level of this protein was significantly decreased during the period 24 h after kainate administration. In situ hybridization and immunohistochemical studies showed that A170 was expressed predominantly in neurons, especially in pyramidal neurons of the cerebrum and cerebellar Purkinje cells, while MSP23 was expressed in oligodendrocytes. The induction of A170 was observed in the regions which are affected by excitotoxicity and this induction was observed in the earlier phase than cell death. Also, the region which shows high vulnerability to excitotoxicity such as pyramidal cell layer in the hippocampus, showed lower A170 expression than that which shows resistance to excitotoxicity, such as the dentate gyrus in the hippocampus. These results suggest that A170 may play a protective role in the brain under kainate-mediated excitotoxicity.
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Affiliation(s)
- K Nakaso
- Department of Biochemistry, Faculty of Medicine, Tottori University, Yonago, Japan.
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47
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Nakaso K, Kitayama M, Kimura K, Yanagawa T, Ohama E, Nakashima K, Ishii T, Yamada K. Induction of heme oxygenase-1 in the rat brain by kainic acid-mediated excitotoxicity: the dissociation of mRNA and protein expression in hippocampus. Biochem Biophys Res Commun 1999; 259:91-6. [PMID: 10334921 DOI: 10.1006/bbrc.1999.0724] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Heme oxygenase-1 (HO-1) is induced under various stresses. Here we report the induction and localization of HO-1 in the rat brain by intraperitoneal administration of kainic acid (KA). Both mRNA and protein of HO-1 were markedly induced by KA treatment, and each maximal induction was observed 24 h after KA administration. In situ hybridization analysis showed that HO-1 mRNA appeared predominantly in glial cells, and confined neurons were positive in the cerebral cortex, basal ganglia, and hippocampal pyramidal cell layer. Immunohistochemical analysis showed that the positive cells in the cerebral cortex and hippocampus were mainly astrocytes and microglia, whereas neurons in the basal ganglia showed intense immunoreactivity. We also demonstrate the dissociation between HO-1 mRNA and protein level in the hippocampal pyramidal neurons, which is known to be vulnerable against excitotoxicity, and discuss the correlation between this dissociation and the vulnerability of hippocampal pyramidal neurons.
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Affiliation(s)
- K Nakaso
- Faculty of Medicine, Tottori University, Yonago, Japan
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48
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Allen RG. Oxidative stress and superoxide dismutase in development, aging and gene regulation. AGE 1998; 21:47-76. [PMID: 23604352 PMCID: PMC3455717 DOI: 10.1007/s11357-998-0007-7] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Free radicals and other reactive oxygen species are produced in the metabolic pathways of aerobic cells and affect a number of biological processes. Oxidation reactions have been postulated to play a role in aging, a number of degenerative diseases, differentiation and development as well as serving as subcellular messengers in gene regulatory and signal transduction pathways. The discovery of the activity of superoxide dismutase is a seminal work in free radical biology, because it established that free radicals were generated by cells and because it made removal of a specific free radical substance possible for the first time, which greatly accelerated research in this area. In this review, the role of reactive oxygen in aging, amyotrophic lateral sclerosis (a neurodegenerative disease), development, differentiation, and signal transduction are discussed. Emphasis is also given to the role of superoxide dismutases in these phenomena.
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Yanagawa T, Yuki K, Yoshida H, Bannai S, Ishii T. Phosphorylation of A170 stress protein by casein kinase II-like activity in macrophages. Biochem Biophys Res Commun 1997; 241:157-63. [PMID: 9405250 DOI: 10.1006/bbrc.1997.7783] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A170 is an oxidative stress-inducible protein having a Zinc finger domain, two PEST sequences, and many potential phosphorylation sites for serine/threonine kinases. These structural features suggest that the phosphorylation of A170 affects its function and degradation. We have found that A170 is phosphorylated in cultured murine peritoneal macrophages. In addition, using recombinant A170 proteins, we found two proteins of 40 and 44 kDa with kinase activity in cell extracts using an in-gel kinase assay. We compared the properties of the intrinsic A170 kinases with those of mitogen-activated protein kinase (ERK 2), protein kinase A (PKA), casein kinase II (CK II), and protein kinase C, since their catalytic subunits have molecular masses similar to A170 kinases. ERK 2, CK II, and PKA phosphorylated recombinant A170 as a substrate. The 40 and 44 kDa kinases present in the macrophage extract were similar to alpha and alpha' subunits of CK II in respect to substrate specificity, pharmacological properties, immuno-reactivities, and ubiquitous expression in tissues.
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Affiliation(s)
- T Yanagawa
- Institute of Basic Medical Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305, Japan
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