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The KEAP1-NRF2 System and Esophageal Cancer. Cancers (Basel) 2022; 14:cancers14194702. [PMID: 36230622 PMCID: PMC9564177 DOI: 10.3390/cancers14194702] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 09/24/2022] [Accepted: 09/24/2022] [Indexed: 12/18/2022] Open
Abstract
NRF2 (nuclear factor erythroid 2-related factor 2) is a transcription factor that regulates the expression of many cytoprotective genes. NRF2 activation is mainly regulated by KEAP1 (kelch-like ECH-associated protein 1) through ubiquitination and proteasome degradation. Esophageal cancer is classified histologically into two major types: esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC). ESCC harbors more genetic alterations in the KEAP-NRF2 system than EAC does, which results in NRF2 activation in these cancers. NRF2-addicted ESCC exhibits increased malignancy and acquisition of resistance to chemoradiotherapy. Therefore, it has been recognized that the development of drugs targeting the KEAP1-NRF2 system based on the molecular dissection of NRF2 function is important and urgent for the treatment of ESCC, along with efficient clinical screening for NRF2-addicted ESCC patients. Recently, the fate of NRF2-activated cells in esophageal tissues, which was under the influence of strong cell competition, and its relationship to the pathogenesis of ESCC, was clarified. In this review, we will summarize the current knowledge of the KEAP1-NRF2 system and the treatment of ESCC. We propose three main strategies for the treatment of NRF2-addicted cancer: (1) NRF2 inhibitors, (2) synthetic lethal drugs for NRF2-addicted cancers, and (3) NRF2 inducers of the host defense system.
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Watahiki T, Okada K, Warabi E, Nagaoka T, Suzuki H, Ishige K, Yanagawa T, Takahashi S, Mizokami Y, Tokushige K, Ariizumi SI, Yamamoto M, Shoda J. Gender difference in development of steatohepatitis in p62/Sqstm1 and Nrf2 double-knockout mice. Exp Anim 2020; 69:395-406. [PMID: 32493884 PMCID: PMC7677087 DOI: 10.1538/expanim.20-0028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 05/10/2020] [Indexed: 12/23/2022] Open
Abstract
Gender and menopause influence the severity and development manner of nonalcoholic steatohepatitis (NASH). Male p62/Sqstm1 and nuclear factor E2-related factor-2 (p62 and Nrf2) double-knockout (DKO) mice exhibit severe steatohepatitis caused by hyperphagia-induced obesity, overload of lipopolysaccharide (LPS) into the liver, and potentiation of the inflammatory response in Kupffer cells. However, the pathogenetic phenotype of steatohepatitis in female DKO mice remains unknown. Phenotypic changes of steatohepatitis in DKO mice were compared in terms of gender differences. Compared with DKO male mice, DKO female mice exhibited later onset of steatohepatitis with obesity after 30 weeks of age, as well as milder severity of hepatic inflammation and fibrosis. Serum estradiol was higher in female than male mice, with levels increasing up to 30 weeks of age before decreasing until 50 weeks of age (corresponding to the post-menopausal period). Fecal and serum LPS were lower in female mice than male mice, and inflammatory signaling in the liver was attenuated in female compared with male mice. Correlating with LPS levels, the composition of intestinal microbiota in female mice was different from male mice. Gender differences were observed for the development of steatohepatitis in DKO mice. Low-grade inflammatory hit in the liver under in vivo conditions of high estradiol may be attributable to the milder pathological features of steatohepatitis in female mice.
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Affiliation(s)
- Takahisa Watahiki
- Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba-shi, Ibaraki 305-8575, Japan
| | - Kosuke Okada
- Tsukuba Preventive Medicine Research Center, University of Tsukuba Hospital, 1-1-1 Tennodai, Tsukuba-shi, Ibaraki 305-8575, Japan
- Department of Gastroenterology, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba-shi, Ibaraki 305-8575, Japan
| | - Eiji Warabi
- Division of Biomedical Sciences, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba-shi, Ibaraki 305-8575, Japan
| | - Tsugumi Nagaoka
- Division of Medical Sciences, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba-shi, Ibaraki 305-8575, Japan
| | - Hideo Suzuki
- Tsukuba Preventive Medicine Research Center, University of Tsukuba Hospital, 1-1-1 Tennodai, Tsukuba-shi, Ibaraki 305-8575, Japan
- Department of Gastroenterology, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba-shi, Ibaraki 305-8575, Japan
| | - Kazunori Ishige
- Department of Gastroenterology, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba-shi, Ibaraki 305-8575, Japan
| | - Toru Yanagawa
- Department of Oral and Maxillofacial Surgery, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba-shi, Ibaraki 305-8575, Japan
| | - Satoru Takahashi
- Division of Biomedical Sciences, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba-shi, Ibaraki 305-8575, Japan
| | - Yuji Mizokami
- Department of Gastroenterology, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba-shi, Ibaraki 305-8575, Japan
| | - Katsutoshi Tokushige
- Institute of Gastroenterology and Internal Medicine, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan
| | - Shun-Ichi Ariizumi
- Department of Surgery, Institute of Gastroenterology, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan
| | - Masakazu Yamamoto
- Department of Surgery, Institute of Gastroenterology, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan
| | - Junichi Shoda
- Division of Medical Sciences, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba-shi, Ibaraki 305-8575, Japan
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Chen Y, Li Q, Li Q, Xing S, Liu Y, Liu Y, Chen Y, Liu W, Feng F, Sun H. p62/SQSTM1, a Central but Unexploited Target: Advances in Its Physiological/Pathogenic Functions and Small Molecular Modulators. J Med Chem 2020; 63:10135-10157. [DOI: 10.1021/acs.jmedchem.9b02038] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Ying Chen
- Department of Natural Medicinal Chemistry, China Pharmaceutical University, Nanjing 211198, People’s Republic of China
| | - Qi Li
- School of Pharmacy, China Pharmaceutical University, Nanjing 211198, People’s Republic of China
| | - Qihang Li
- School of Pharmacy, China Pharmaceutical University, Nanjing 211198, People’s Republic of China
| | - Shuaishuai Xing
- School of Pharmacy, China Pharmaceutical University, Nanjing 211198, People’s Republic of China
| | - Yang Liu
- School of Pharmacy, China Pharmaceutical University, Nanjing 211198, People’s Republic of China
| | - Yijun Liu
- School of Pharmacy, China Pharmaceutical University, Nanjing 211198, People’s Republic of China
| | - Yao Chen
- School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210023, People’s Republic of China
| | - Wenyuan Liu
- School of Pharmacy, China Pharmaceutical University, Nanjing 211198, People’s Republic of China
| | - Feng Feng
- Department of Natural Medicinal Chemistry, China Pharmaceutical University, Nanjing 211198, People’s Republic of China
- Jiangsu Food and Pharmaceuticals Science College, Institute of Food and Pharmaceuticals Research, Huaian 223005, People’s Republic of China
| | - Haopeng Sun
- School of Pharmacy, China Pharmaceutical University, Nanjing 211198, People’s Republic of China
- Jiangsu Food and Pharmaceuticals Science College, Institute of Food and Pharmaceuticals Research, Huaian 223005, People’s Republic of China
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Kirkin V. History of the Selective Autophagy Research: How Did It Begin and Where Does It Stand Today? J Mol Biol 2020; 432:3-27. [PMID: 31082435 PMCID: PMC6971693 DOI: 10.1016/j.jmb.2019.05.010] [Citation(s) in RCA: 84] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 05/03/2019] [Accepted: 05/06/2019] [Indexed: 02/07/2023]
Abstract
Autophagy, self-eating, is a pivotal catabolic mechanism that ensures homeostasis and survival of the cell in the face of stressors as different as starvation, infection, or protein misfolding. The importance of the research in this field was recognized by the general public after the Nobel Prize for Physiology or Medicine was awarded in 2016 to Yoshinori Ohsumi for discoveries of the mechanisms of autophagy using yeast as a model organism. One of the seminal findings of Ohsumi was on the role ubiquitin-like proteins (UBLs)-Atg5, Atg12, and Atg8-play in the formation of the double-membrane vesicle autophagosome, which is the functional unit of autophagy. Subsequent work by several groups demonstrated that, like the founding member of the UBL family ubiquitin, these small but versatile protein and lipid modifiers interact with a plethora of proteins, which either directly regulate autophagosome formation, for example, components of the Atg1/ULK1 complex, or are involved in cargo recognition, for example, Atg19 and p62/SQSTM1. By tethering the cargo to the UBLs present on the forming autophagosome, the latter proteins were proposed to effectively act as selective autophagy receptors. The discovery of the selective autophagy receptors brought a breakthrough in the autophagy field, supplying the mechanistic underpinning for the formation of an autophagosome selectively around the cytosolic cargo, that is, a protein aggregate, a mitochondrion, or a cytosolic bacterium. In this historical overview, I highlight key steps that the research into selective autophagy has been taking over the past 20 years. I comment on their significance and discuss current challenges in developing more detailed knowledge of the mechanisms of selective autophagy. I will conclude by introducing the new directions that this dynamic research field is taking into its third decade.
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Affiliation(s)
- Vladimir Kirkin
- Cancer Research UK Cancer Therapeutics Unit, The Institute of Cancer Research, London SM2 5NG, UK.
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Albanese F, Novello S, Morari M. Autophagy and LRRK2 in the Aging Brain. Front Neurosci 2019; 13:1352. [PMID: 31920513 PMCID: PMC6928047 DOI: 10.3389/fnins.2019.01352] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 12/02/2019] [Indexed: 12/20/2022] Open
Abstract
Autophagy is a highly conserved process by which long-lived macromolecules, protein aggregates and dysfunctional/damaged organelles are delivered to lysosomes for degradation. Autophagy plays a crucial role in regulating protein quality control and cell homeostasis in response to energetic needs and environmental challenges. Indeed, activation of autophagy increases the life-span of living organisms, and impairment of autophagy is associated with several human disorders, among which neurodegenerative disorders of aging, such as Parkinson’s disease. These disorders are characterized by the accumulation of aggregates of aberrant or misfolded proteins that are toxic for neurons. Since aging is associated with impaired autophagy, autophagy inducers have been viewed as a strategy to counteract the age-related physiological decline in brain functions and emergence of neurodegenerative disorders. Parkinson’s disease is a hypokinetic, multisystemic disorder characterized by age-related, progressive degeneration of central and peripheral neuronal populations, associated with intraneuronal accumulation of proteinaceous aggregates mainly composed by the presynaptic protein α-synuclein. α-synuclein is a substrate of macroautophagy and chaperone-mediated autophagy (two major forms of autophagy), thus impairment of its clearance might favor the process of α-synuclein seeding and spreading that trigger and sustain the progression of this disorder. Genetic factors causing Parkinson’s disease have been identified, among which mutations in the LRRK2 gene, which encodes for a multidomain protein encompassing central GTPase and kinase domains, surrounded by protein-protein interaction domains. Six LRRK2 mutations have been pathogenically linked to Parkinson’s disease, the most frequent being the G2019S in the kinase domain. LRRK2-associated Parkinson’s disease is clinically and neuropathologically similar to idiopathic Parkinson’s disease, also showing age-dependency and incomplete penetrance. Several mechanisms have been proposed through which LRRK2 mutations can lead to Parkinson’s disease. The present article will focus on the evidence that LRRK2 and its mutants are associated with autophagy dysregulation. Studies in cell lines and neurons in vitro and in LRRK2 knock-out, knock-in, kinase-dead and transgenic animals in vivo will be reviewed. The role of aging in LRRK2-induced synucleinopathy will be discussed. Possible mechanisms underlying the LRRK2-mediated control over autophagy will be analyzed, and the contribution of autophagy dysregulation to the neurotoxic actions of LRRK2 will be examined.
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Affiliation(s)
- Federica Albanese
- Section of Pharmacology, Department of Medical Sciences, University of Ferrara, Ferrara, Italy
| | - Salvatore Novello
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Michele Morari
- Section of Pharmacology, Department of Medical Sciences, University of Ferrara, Ferrara, Italy
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Yoshida T, Terabe T, Nagai H, Uchida F, Hasegawa S, Nagao T, Miyabe S, Ishibashi‐Kanno N, Yamagata K, Warabi E, Gosho M, Yanagawa T, Bukawa H. Association between p62 expression and clinicopathological characteristics in oral leukoplakia. Clin Exp Dent Res 2019; 5:389-397. [PMID: 31452949 PMCID: PMC6704027 DOI: 10.1002/cre2.193] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 04/30/2019] [Accepted: 04/30/2019] [Indexed: 12/31/2022] Open
Abstract
Objective Oral leukoplakia is keratinized lesions in the buccal mucosa, tongue, and gingiva. It is the most common oral precancerous lesion; oxidative stresses and irrelevant autophagy have been reported to be the cause of oncogenesis. p62, a cytoplasmic protein induced by oxidative stress, is an adaptor protein involved in the formation of protein aggregates and induction and inhibition of autophagy. The inhibition of autophagy induces p62 overexpression and promotes oncogenesis via the oncogenic signaling pathway. The aim of the present study was to elucidate the involvement of intracellular expression of p62 in oral leukoplakia and to address its potential clinical implementation as a biomarker to predict malignant transformation. Material and Methods Fifty samples from subjects with confirmed oral leukoplakia were evaluated by immunohistochemical staining for the expression of p62, 8-hydroxy-2'-deoxyguanosine (8-OHdG), Ki67, and p53. Univariate and multivariate logistic regression analyses were performed to evaluate the association between p62, 8-OHdG, Ki67, and p53 and clinical characteristics, including epithelial dysplasia. Results Significant associations were observed between p62 expression in the nucleus, p62 aggregation, and epithelial dysplasia (adjusted odds ratio [OR] = 5.75; 95% confidence interval [CI]: [1.28, 26.2]; .024 and OR = 6.16; 95% CI: [1.01, 37.4]; .048, respectively). The expression of p62 in the cytoplasm and the levels of 8-OHdG, Ki67, and p53 were not significantly associated with epithelial dysplasia. A significant relationship was found between p62 expression in the nucleus and p53 expression (OR = 3.94; 95% CI: [1.14, 13.6]; .031). Conclusions The results suggested that p62 expression in the nucleus and p62 aggregation can be potential markers to predict the malignant transformation of oral leukoplakia.
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Affiliation(s)
- Toshio Yoshida
- Oral and Maxillofacial Surgery, Clinical Sciences, Graduate School of Comprehensive Human ScienceUniversity of TsukubaTsukubaJapan
- Yoshida Dental OfficeMedical Cooperation TokuekaiIshiokaJapan
| | - Takehito Terabe
- Department of Oral and Maxillofacial Surgery, Association for Development of Community MedicineIshioka Daiichi HospitalIshiokaJapan
| | - Hiroki Nagai
- Department of Oral and Maxillofacial Surgery, Faculty of MedicineUniversity of TsukubaTsukubaJapan
| | - Fumihiko Uchida
- Department of Oral and Maxillofacial Surgery, Faculty of MedicineUniversity of TsukubaTsukubaJapan
| | - Shogo Hasegawa
- Department of Maxillofacial Surgery, School of DentistryAichi‐Gakuen UniversityNagoyaJapan
- Department of Oral and Maxillofacial SurgeryToyota Wakatake HospitalToyotaJapan
| | - Toru Nagao
- Department of Maxillofacial Surgery, School of DentistryAichi‐Gakuen UniversityNagoyaJapan
| | - Satoru Miyabe
- Department of Maxillofacial Surgery, School of DentistryAichi‐Gakuen UniversityNagoyaJapan
| | - Naomi Ishibashi‐Kanno
- Department of Oral and Maxillofacial Surgery, Faculty of MedicineUniversity of TsukubaTsukubaJapan
| | - Kenji Yamagata
- Department of Oral and Maxillofacial Surgery, Faculty of MedicineUniversity of TsukubaTsukubaJapan
| | - Eiji Warabi
- Department of Anatomy and Embryology, Faculty of MedicineUniversity of TsukubaTsukubaJapan
| | - Masahiko Gosho
- Department of Biostatistics, Faculty of MedicineUniversity of TsukubaTsukubaJapan
| | - Toru Yanagawa
- Department of Oral and Maxillofacial Surgery, Faculty of MedicineUniversity of TsukubaTsukubaJapan
| | - Hiroki Bukawa
- Department of Oral and Maxillofacial Surgery, Faculty of MedicineUniversity of TsukubaTsukubaJapan
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7
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Serum starvation raises turnover of phosphorylated p62/SQSTM1 (Serine 349), reveals expression of proteasome and N-glycanase1 interactive protein RAD23B and sensitizes human synovial fibroblasts to BAY 11-7085-induced cell death. Oncotarget 2018; 9:35830-35843. [PMID: 30533198 PMCID: PMC6254681 DOI: 10.18632/oncotarget.26295] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 10/24/2018] [Indexed: 02/06/2023] Open
Abstract
Phosphorylation of p62/SQSTM1 (p62) on Serine 349 (P-Ser349 p62) as well as proteasome dysfunction have been shown to activate the cell protective Keap1/Nrf2 pathway. We showed previously that BAY 11-7085-induced human synovial fibroblast cell death includes autophagy and p62 downregulation. In this work, we have studied expression of P-Ser349 p62 in human synovial fibroblasts. Results showed that P-Ser349 p62 was not detected in synovial cell extracts unless cells were cultured in the presence of proteasome inhibitor (MG132). MG132 revealed P-Ser349 p62 turnover, that was further increased by concomitant autophagy inhibition and markedly enhanced in serum starved cells. Starvation sensitized synovial fibroblasts to BAY 11-7085 while MG132 protected both non-starved and starved cells from BAY 11-7085-induced cell death. Lentivirus mediated overexpression of phosphorylation-mimetic p62 mutant S349E markedly protected synovial fibroblasts from BAY 11-7085. Inhibitor of Keap1-P-S349 p62 interaction, K67, had synergistic effect with MG132. Starvation increased p62 molecular weight, that was reversed by serum and bovine serum albumin re-feeding. Furthermore, starvation markedly induced RAD23B. Increased endo-β-N-acetylglucosaminidase (ENGase) turnover was detected in starved synovial fibroblasts. PNGase F treatment produced faster migration p62 form in human synovial tissue extracts but starvation-like p62 form of higher molecular weight in synovial cell extracts. Co-transfection of NGLY1, with p62 or p62 mutants S349A and S349E markedly stabilized p62 expressions in HEK293 cells. Tunicamycin upregulated p62 and protected synovial fibroblasts from BAY 11-7085-induced cell death. These results showed that P-Ser349 p62 has pro-survival role in human synovial fibroblasts and that de-glycosylation events are involved in p62 turnover.
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8
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Thomas RE, Vincow ES, Merrihew GE, MacCoss MJ, Davis MY, Pallanck LJ. Glucocerebrosidase deficiency promotes protein aggregation through dysregulation of extracellular vesicles. PLoS Genet 2018; 14:e1007694. [PMID: 30256786 PMCID: PMC6175534 DOI: 10.1371/journal.pgen.1007694] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 10/08/2018] [Accepted: 09/13/2018] [Indexed: 12/21/2022] Open
Abstract
Mutations in the glucosylceramidase beta (GBA) gene are strongly associated with neurodegenerative diseases marked by protein aggregation. GBA encodes the lysosomal enzyme glucocerebrosidase, which breaks down glucosylceramide. A common explanation for the link between GBA mutations and protein aggregation is that lysosomal accumulation of glucosylceramide causes impaired autophagy. We tested this hypothesis directly by measuring protein turnover and abundance in Drosophila mutants with deletions in the GBA ortholog Gba1b. Proteomic analyses revealed that known autophagy substrates, which had severely impaired turnover in autophagy-deficient Atg7 mutants, showed little to no overall slowing of turnover or increase in abundance in Gba1b mutants. Likewise, Gba1b mutants did not have the marked impairment of mitochondrial protein turnover seen in mitophagy-deficient parkin mutants. Proteasome activity, microautophagy, and endocytic degradation also appeared unaffected in Gba1b mutants. However, we found striking changes in the turnover and abundance of proteins associated with extracellular vesicles (EVs), which have been proposed as vehicles for the spread of protein aggregates in neurodegenerative disease. These changes were specific to Gba1b mutants and did not represent an acceleration of normal aging. Western blotting of isolated EVs confirmed the increased abundance of EV proteins in Gba1b mutants, and nanoparticle tracking analysis revealed that Gba1b mutants had six times as many EVs as controls. Genetic perturbations of EV production in Gba1b mutants suppressed protein aggregation, demonstrating that the increase in EV abundance contributed to the accumulation of protein aggregates. Together, our findings indicate that glucocerebrosidase deficiency causes pathogenic changes in EV metabolism and may promote the spread of protein aggregates through extracellular vesicles.
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Affiliation(s)
- Ruth E. Thomas
- Department of Genome Sciences, University of Washington, Seattle, WA, United States of America
| | - Evelyn S. Vincow
- Department of Genome Sciences, University of Washington, Seattle, WA, United States of America
| | - Gennifer E. Merrihew
- Department of Genome Sciences, University of Washington, Seattle, WA, United States of America
| | - Michael J. MacCoss
- Department of Genome Sciences, University of Washington, Seattle, WA, United States of America
| | - Marie Y. Davis
- Department of Neurology, University of Washington, Seattle, WA, United States of America
- Department of Neurology, Veterans Affairs Puget Sound Health Care System, Seattle, WA, United States of America
| | - Leo J. Pallanck
- Department of Genome Sciences, University of Washington, Seattle, WA, United States of America
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Akiyama K, Warabi E, Okada K, Yanagawa T, Ishii T, Kose K, Tokushige K, Ishige K, Mizokami Y, Yamagata K, Onizawa K, Ariizumi SI, Yamamoto M, Shoda J. Deletion of both p62 and Nrf2 spontaneously results in the development of nonalcoholic steatohepatitis. Exp Anim 2017; 67:201-218. [PMID: 29276215 PMCID: PMC5955752 DOI: 10.1538/expanim.17-0112] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Nonalcoholic steatohepatitis (NASH) is one of the leading causes of chronic liver disease
worldwide. However, details of pathogenetic mechanisms remain unknown. Deletion of both
p62/Sqstm1 and Nrf2 genes spontaneously led to the
development of NASH in mice fed a normal chow and was associated with liver tumorigenesis.
The pathogenetic mechanism (s) underlying the NASH development was investigated in
p62:Nrf2 double-knockout (DKO) mice. DKO mice showed massive
hepatomegaly and steatohepatitis with fat accumulation and had hyperphagia-induced obesity
coupled with insulin resistance and adipokine imbalance. They also showed dysbiosis
associated with an increased proportion of gram-negative bacteria species and an increased
lipopolysaccharide (LPS) level in feces. Intestinal permeability was elevated in
association with both epithelial damage and decreased expression levels of tight junction
protein zona occludens-1, and thereby LPS levels were increased in serum. For Kupffer
cells, the foreign body phagocytic capacity was decreased in magnetic resonance imaging,
and the proportion of M1 cells was increased in DKO mice. In vitro
experiments showed that the inflammatory response was accelerated in the
p62:Nrf2 double-deficient Kupffer cells when
challenged with a low dose of LPS. Diet restriction improved the hepatic conditions of
NASH in association with improved dysbiosis and decreased LPS levels. The results suggest
that in DKO mice, activation of innate immunity by excessive LPS flux from the intestines,
occurring both within and outside the liver, is central to the development of hepatic
damage in the form of NASH.
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Affiliation(s)
- Kentaro Akiyama
- Doctoral Programs in Medical Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba-shi, Ibaraki 305-8575, Japan.,Japan Society for the Promotion of Science, 5-3-1 Kojimachi, Chiyoda-ku, Tokyo 102-0083, Japan
| | - Eiji Warabi
- Division of Biomedical Science, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba-shi, Ibaraki 305-8575, Japan
| | - Kosuke Okada
- Division of Gastroenterology, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba-shi, Ibaraki 305-8575, Japan
| | - Toru Yanagawa
- Division of Oral and Maxillofacial Surgery, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba-shi, Ibaraki 305-8575, Japan
| | - Tetsuro Ishii
- Division of Biomedical Science, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba-shi, Ibaraki 305-8575, Japan
| | - Katsumi Kose
- Institute of Applied Physics, University of Tsukuba, 1-1-1 Tennodai, Tsukuba-shi, Ibaraki 305-8573, Japan
| | - Katsutoshi Tokushige
- Institute of Gastroenterology Internal Medicine, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan
| | - Kazunori Ishige
- Division of Gastroenterology, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba-shi, Ibaraki 305-8575, Japan
| | - Yuji Mizokami
- Division of Gastroenterology, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba-shi, Ibaraki 305-8575, Japan
| | - Kenji Yamagata
- Division of Oral and Maxillofacial Surgery, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba-shi, Ibaraki 305-8575, Japan
| | - Kojiro Onizawa
- Division of Oral and Maxillofacial Surgery, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba-shi, Ibaraki 305-8575, Japan
| | - Shun-Ichi Ariizumi
- Institute of Gastroenterology Surgery, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan
| | - Masakazu Yamamoto
- Institute of Gastroenterology Surgery, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan
| | - Junichi Shoda
- Medical Sciences, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba-shi, Ibaraki 305-8575, Japan
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10
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Taniguchi K, Yamachika S, He F, Karin M. p62/SQSTM1-Dr. Jekyll and Mr. Hyde that prevents oxidative stress but promotes liver cancer. FEBS Lett 2016; 590:2375-97. [PMID: 27404485 DOI: 10.1002/1873-3468.12301] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 07/08/2016] [Accepted: 07/09/2016] [Indexed: 12/17/2022]
Abstract
p62/SQSTM1 is a multifunctional signaling hub and autophagy adaptor with many binding partners, which allow it to activate mTORC1-dependent nutrient sensing, NF-κB-mediated inflammatory responses, and the NRF2-activated antioxidant defense. p62 recognizes polyubiquitin chains via its C-terminal domain and binds to LC3 via its LIR motif, thereby promoting the autophagic degradation of ubiquitinated cargos. p62 accumulates in many human liver diseases, including nonalcoholic steatohepatitis (NASH) and hepatocellular carcinoma (HCC), where it is a component of Mallory-Denk bodies and intracellular hyaline bodies. Chronic p62 elevation contributes to HCC development by preventing oncogene-induced senescence and death of cancer-initiating cells and enhancing their proliferation. In this review, we discuss p62-mediated signaling pathways and their roles in liver pathophysiology, especially NASH and HCC.
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Affiliation(s)
- Koji Taniguchi
- Laboratory of Gene Regulation and Signal Transduction, Departments of Pharmacology and Pathology, University of California San Diego, La Jolla, CA, USA.,Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.,Department of Microbiology and Immunology, Keio University School of Medicine, Tokyo, Japan
| | - Shinichiro Yamachika
- Laboratory of Gene Regulation and Signal Transduction, Departments of Pharmacology and Pathology, University of California San Diego, La Jolla, CA, USA
| | - Feng He
- Laboratory of Gene Regulation and Signal Transduction, Departments of Pharmacology and Pathology, University of California San Diego, La Jolla, CA, USA
| | - Michael Karin
- Laboratory of Gene Regulation and Signal Transduction, Departments of Pharmacology and Pathology, University of California San Diego, La Jolla, CA, USA
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11
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p62 modulates the intrinsic signaling of UVB-induced apoptosis. J Dermatol Sci 2016; 83:226-33. [PMID: 27368125 DOI: 10.1016/j.jdermsci.2016.05.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 05/09/2016] [Accepted: 05/10/2016] [Indexed: 12/13/2022]
Abstract
BACKGROUND UVB radiation is the main source of sunburn and skin cancers. Apoptosis eliminates photodamaged cells, and is thus important for preventing epidermal carcinogenesis. The cytoplasmic regulatory protein p62/A170/sequestosome 1 (p62) molecule is involved in a variety of cellular and signaling pathways. p62 is known to be and important in autophagy, but its role in UVB-induced apoptosis remains to be clarified. OBJECTIVE To investigate the role of p62 against UVB-induced apoptotic changes, using mouse embryonic fibroblasts (MEFs) derived from p62 homozygous knockout (p62(-/-)) mice. METHODS p62(-/-) and wild-type (p62(+/+)) mice and MEFs were subjected to UVB irradiation, and the resultant apoptosis was analyzed using flow cytometry, quantitative real-time PCR, and western blots. RESULTS Apoptosis was decreased in the p62(-/-) MEFs compared to p62(+/+) MEFs in response to UVB treatment. Compared with p62(+/+) MEFs, p62(-/-) MEFs expressed significantly more Bcl-2 and less Bax, and showed increased Src and Stat3 phosphorylation. Our results show that p62 regulates apoptotic pathways by modifying critical signaling intermediates such as Src and Stat3. CONCLUSION p62 deficiency [corrected] reduces UVB-induced apoptosis by modulating intrinsic apoptotic signaling through Src phosphorylation.
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12
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Pan JA, Sun Y, Jiang YP, Bott AJ, Jaber N, Dou Z, Yang B, Chen JS, Catanzaro JM, Du C, Ding WX, Diaz-Meco MT, Moscat J, Ozato K, Lin RZ, Zong WX. TRIM21 Ubiquitylates SQSTM1/p62 and Suppresses Protein Sequestration to Regulate Redox Homeostasis. Mol Cell 2016; 61:720-733. [PMID: 26942676 PMCID: PMC4779181 DOI: 10.1016/j.molcel.2016.02.007] [Citation(s) in RCA: 128] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 01/13/2016] [Accepted: 02/05/2016] [Indexed: 12/27/2022]
Abstract
TRIM21 is a RING finger domain-containing ubiquitin E3 ligase whose expression is elevated in autoimmune disease. While TRIM21 plays an important role in immune activation during pathogen infection, little is known about its inherent cellular function. Here we show that TRIM21 plays an essential role in redox regulation by directly interacting with SQSTM1/p62 and ubiquitylating p62 at lysine 7 (K7) via K63-linkage. As p62 oligomerizes and sequesters client proteins in inclusions, the TRIM21-mediated p62 ubiquitylation abrogates p62 oligomerization and sequestration of proteins including Keap1, a negative regulator of antioxidant response. TRIM21-deficient cells display an enhanced antioxidant response and reduced cell death in response to oxidative stress. Genetic ablation of TRIM21 in mice confers protection from oxidative damages caused by arsenic-induced liver insult and pressure overload heart injury. Therefore, TRIM21 plays an essential role in p62-regulated redox homeostasis and may be a viable target for treating pathological conditions resulting from oxidative damage.
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Affiliation(s)
- Ji-An Pan
- Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers University, 164 Frelinghuysen Road, Piscataway, NJ 08854, USA; Rutgers Cancer Institute of New Jersey, 195 Little Albany Street, New Brunswick, NJ 08903, USA; Department of Molecular Genetics & Microbiology, Stony Brook University, Stony Brook, NY 11794, USA.
| | - Yu Sun
- Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers University, 164 Frelinghuysen Road, Piscataway, NJ 08854, USA; Rutgers Cancer Institute of New Jersey, 195 Little Albany Street, New Brunswick, NJ 08903, USA; Department of Molecular Genetics & Microbiology, Stony Brook University, Stony Brook, NY 11794, USA
| | - Ya-Ping Jiang
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, NY 11794, USA
| | - Alex J Bott
- Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers University, 164 Frelinghuysen Road, Piscataway, NJ 08854, USA; Rutgers Cancer Institute of New Jersey, 195 Little Albany Street, New Brunswick, NJ 08903, USA; Department of Molecular Genetics & Microbiology, Stony Brook University, Stony Brook, NY 11794, USA
| | - Nadia Jaber
- Department of Molecular Genetics & Microbiology, Stony Brook University, Stony Brook, NY 11794, USA
| | - Zhixun Dou
- Department of Molecular Genetics & Microbiology, Stony Brook University, Stony Brook, NY 11794, USA
| | - Bin Yang
- Key Laboratory of Artificial Cells, Tianjin Third Central Hospital, Tianjin 300170, China
| | - Juei-Suei Chen
- Department of Molecular Genetics & Microbiology, Stony Brook University, Stony Brook, NY 11794, USA
| | - Joseph M Catanzaro
- Department of Molecular Genetics & Microbiology, Stony Brook University, Stony Brook, NY 11794, USA
| | - Chunying Du
- Department of Cancer Biology, University of Cincinnati, Cincinnati, OH 45267, USA
| | - Wen-Xing Ding
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Maria T Diaz-Meco
- Cancer Metabolism and Signaling Networks Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Jorge Moscat
- Cancer Metabolism and Signaling Networks Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Keiko Ozato
- Division of Developmental Biology, NICHD, National Institutes of Health, Bethesda, MD 20892, USA
| | - Richard Z Lin
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, NY 11794, USA; Department of Veterans Affairs Medical Center, Northport, NY 11768, USA
| | - Wei-Xing Zong
- Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers University, 164 Frelinghuysen Road, Piscataway, NJ 08854, USA; Rutgers Cancer Institute of New Jersey, 195 Little Albany Street, New Brunswick, NJ 08903, USA; Department of Molecular Genetics & Microbiology, Stony Brook University, Stony Brook, NY 11794, USA.
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Itoh K, Ye P, Matsumiya T, Tanji K, Ozaki T. Emerging functional cross-talk between the Keap1-Nrf2 system and mitochondria. J Clin Biochem Nutr 2015; 56:91-7. [PMID: 25759513 PMCID: PMC4345178 DOI: 10.3164/jcbn.14-134] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 12/01/2014] [Indexed: 12/30/2022] Open
Abstract
Nuclear factor erythroid-derived 2-related factor 2 (Nrf2) was originally identified as a positive regulator of drug detoxifying enzyme gene expression during exposure to environmental electrophiles. Currently, Nrf2 is known to regulate the expression of hundreds of cytoprotective genes to counteract endogenously or exogenously generated oxidative stress. Furthermore, when activated in human tumors by somatic mutations, Nrf2 confers growth advantages and chemoresistance by regulating genes involved in various processes such as the pentose phosphate pathway and nucleotide synthesis in addition to antioxidant proteins. Interestingly, increasing evidence shows that Nrf2 is associated with mitochondrial biogenesis during environmental stresses in certain tissues such as the heart. Furthermore, SKN-1, a functional homolog of Nrf2 in C. elegans, is activated by mitochondrial reactive oxygen species and extends life span by promoting mitochondrial homeostasis (i.e., mitohormesis). Similarly, Nrf2 activation was recently observed in the heart of surfeit locus protein 1 (Surf1) -/- mice in which cellular respiration was decreased due to cytochrome c oxidase defects. In this review, we critically examine the relationship between Nrf2 and mitochondria and argue that the Nrf2 stress pathway intimately communicates with mitochondria to maintain cellular homeostasis during oxidative stress.
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Affiliation(s)
- Ken Itoh
- Department of Stress Response Science, Center for Advanced Medical Research, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562, Japan
| | - Peng Ye
- Department of Stress Response Science, Center for Advanced Medical Research, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562, Japan
| | - Tomoh Matsumiya
- Department of Vascular Biology, Institute of Brain Science, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562, Japan
| | - Kunikazu Tanji
- Department of Neuropathology, Institute of Brain Science, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562, Japan
| | - Taku Ozaki
- Research Center for Child Mental Development, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562, Japan
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14
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Tanji K, Miki Y, Ozaki T, Maruyama A, Yoshida H, Mimura J, Matsumiya T, Mori F, Imaizumi T, Itoh K, Kakita A, Takahashi H, Wakabayashi K. Phosphorylation of serine 349 of p62 in Alzheimer's disease brain. Acta Neuropathol Commun 2014; 2:50. [PMID: 24886973 PMCID: PMC4035093 DOI: 10.1186/2051-5960-2-50] [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: 02/27/2014] [Accepted: 04/22/2014] [Indexed: 12/30/2022] Open
Abstract
Background Extensive research on p62 has established its role in oxidative stress, protein degradation and in several diseases such as Paget’s disease of the bone, frontotemporal lobar degeneration and amyotrophic lateral sclerosis. Importantly, previous studies showed that p62 binds directly to Keap1, which is a ubiquitin E3 ligase responsible for degrading Nrf2. Indeed, colocalisation of p62 and Keap1 occurs in tumorigenesis and neurodegeneration. A serine (S) residue in the Keap1-interacting region of p62 is phosphorylated in hepatocellular carcinoma, and this phosphorylation contributes to tumour growth through the higher affinity of p62 to Keap1. However, it remains largely unknown whether p62 is phosphorylated in the Keap1-interacting region under neurodegenerative conditions. Results To answer this question, we generated an antibody against phosphorylated S349 (P-S349) of p62 and showed that S349 is phosphorylated following disruption of protein degradation. In particular, the ratio of P-S349 to total p62 levels was significantly increased in the brains with Alzheimer’s disease (AD) compared with controls. We also compared the reactivity of the P-S349 antibody with P-S403 of p62 and showed that these two phosphorylated sites on p62 cause different responses with proteasome inhibition and show distinct localisation patterns in AD brains. In addition to disruption of protein degradation systems, activation of oxidative stress can induce P-S349. Conclusion These results support the hypothesis that disruption of protein degradation systems and sustained activation of the Keap1-Nrf2 system occur in the brains with AD. Electronic supplementary material The online version of this article (doi:10.1186/2051-5960-2-50) contains supplementary material, which is available to authorized users.
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15
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Deficiency of p62/Sequestosome 1 causes hyperphagia due to leptin resistance in the brain. J Neurosci 2013; 33:14767-77. [PMID: 24027277 DOI: 10.1523/jneurosci.2954-12.2013] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The cytoplasmic regulatory protein p62 (Sequestosome 1/A170) is known to modulate various receptor-mediated intracellular signaling pathways. p62 deficiency was shown to result in mature-onset obesity in mice, but the mechanisms underlying this abnormality remained unclear. Here we report that hyperphagia due to central leptin resistance is the cause of obesity in p62(-/-) mice. We found that these mice show hyperphagia. Restriction of food to the amount eaten by wild-type mice prevented excess body weight gain and fat accumulation, suggesting that overfeeding is the primary cause of obesity in p62(-/-) mice. Brain-specific p62 deficiency caused mature-onset obesity to the same extent as in p62(-/-) mice, further supporting a neuronal mechanism as the major cause of obesity in these mice. Immunohistochemical analysis revealed that p62 is highly expressed in hypothalamic neurons, including POMC neurons in the arcuate nucleus. Central leptin resistance was observed even in young preobese p62(-/-) mice. We found a defect in intracellular distribution of the transcription factor Stat3, which is essential for the action of leptin, in p62(-/-) mice. These results indicate that brain p62 plays an important role in bodyweight control by modulating the central leptin-signaling pathway and that lack of p62 in the brain causes leptin resistance, leading to hyperphagia. Thus, p62 could be a clinical target for treating obesity and metabolic syndrome.
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16
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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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17
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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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18
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Rué L, López-Soop G, Gelpi E, Martínez-Vicente M, Alberch J, Pérez-Navarro E. Brain region- and age-dependent dysregulation of p62 and NBR1 in a mouse model of Huntington's disease. Neurobiol Dis 2013; 52:219-28. [PMID: 23295856 DOI: 10.1016/j.nbd.2012.12.008] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2012] [Revised: 11/12/2012] [Accepted: 12/21/2012] [Indexed: 10/27/2022] Open
Abstract
Huntington's disease is characterized by the formation of protein aggregates, which can be degraded by macroautophagy. Here, we studied protein levels and intracellular distribution of p62 and NBR1, two macroautophagy cargo receptors, during disease progression. In R6/1 mice, p62 and NBR1 protein levels were decreased in all brain regions analyzed early in the disease, whereas at late stages they accumulated in the striatum and hippocampus, but not in the cortex. The accumulation of p62, but not NBR1, occurred in neuronal nuclei, where it co-localized with mutant huntingtin inclusions, both in R6/1 and Huntington's disease patients. Moreover, exportin-1 was selectively decreased in old R6/1 mice brain, and could worsen p62 nuclear accumulation. In conclusion, p62 interacts with mutant huntingtin and is retained in the nucleus along the progression of the disease, mostly in striatal and hippocampal neurons. Thus, cytoplasmic NBR1 might be important to maintain basal levels of selective macroautophagy in these neurons.
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Affiliation(s)
- Laura Rué
- Departament de Biologia Cel·lular, Immunologia i Neurociències, Facultat de Medicina, Universitat de Barcelona, 08036 Barcelona, Spain
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Gu J, Chi M, Sun X, Wang G, Li M, Liu L, Li X. Propofol-induced protection of SH-SY5Y cells against hydrogen peroxide is associated with the HO-1 via the ERK pathway. Int J Med Sci 2013; 10:599-606. [PMID: 23569422 PMCID: PMC3619098 DOI: 10.7150/ijms.5151] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2012] [Accepted: 03/07/2013] [Indexed: 11/25/2022] Open
Abstract
Propofol (2, 6-diisopropylphenol), is an anesthetic and routinely used for the humans sedation during surgery. The potent inducers of phase II detoxifying and antioxidant stress responsive to propofol were investigated. First, a dose of 25-100 µM propofol showed no significant cytotoxicity on SH-SY5Y cells and pre-treatment of SH-SY5Y cells with propofol (25-100 μM) for 8h prevented cell death and maintained cell integrity following exposure to 1 mM hydrogen peroxide by MTT assays. Then, an increase in the generation of ROS following hydrogen peroxide treatment was significantly attenuated by 8 h pre-treatment with propofol. Additionally, the potential roles of ERK, p 38 MAPK and JNK in the regulation of propofol-induced endogenous HO-1 expression in SH-SY5Y cells were estimated by Western blotting assays. Results showed that propofol significantly increased the phosphorylation levels of ERK, p 38 MAPK and JNK and antioxidant stress responsive to propofol was attenuated by the inhibition of ERK signaling biochemical inhibitors. These results suggest that the ERK pathway plays an important role in the regulation of propofol-mediated antioxidant effects in SH-SY5Y cells.
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Affiliation(s)
- Jing Gu
- Department of Anesthesiology, Third Affiliated Hospital of Harbin Medical University, No. 6 Baojian Rd., Nangang District, Harbin 150081, China
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Liu X, Gal J, Zhu H. Sequestosome 1/p62: a multi-domain protein with multi-faceted functions. ACTA ACUST UNITED AC 2012. [DOI: 10.1007/s11515-012-1217-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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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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22
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Abstract
The accumulation of protein aggregates in neurons appears to be a basic feature of neurodegenerative disease. In Huntington's Disease (HD), a progressive and ultimately fatal neurodegenerative disorder caused by an expansion of the polyglutamine repeat within the protein Huntingtin (Htt), the immediate proximal cause of disease is well understood. However, the cellular mechanisms which modulate the rate at which fragments of Htt containing polyglutamine accumulate in neurons is a central issue in the development of approaches to modulate the rate and extent of neuronal loss in this disease. We have recently found that Htt is phosphorylated by the kinase IKK on serine (S) 13, activating its phosphorylation on S16 and its acetylation and poly-SUMOylation, modifications that modulate its clearance by the proteasome and lysosome in cells. In the discussion here I suggest that Htt may have a normal function in the lysosomal mechanism of selective macroautophagy involved in its own degradation which may share some similarity with the yeast cytoplasm to vacuole targeting (Cvt) pathway. Pharmacologic activation of this pathway may be useful early in disease progression to treat HD and other neurodegenerative diseases characterized by the accumulation of disease proteins.
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Affiliation(s)
- Joan S Steffan
- Department of Psychiatry and Human Behavior, University of California, Irvine, CA, USA.
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Huang C, Yitzhaki S, Perry CN, Liu W, Giricz Z, Mentzer RM, Gottlieb RA. Autophagy induced by ischemic preconditioning is essential for cardioprotection. J Cardiovasc Transl Res 2010; 3:365-73. [PMID: 20559777 PMCID: PMC2899015 DOI: 10.1007/s12265-010-9189-3] [Citation(s) in RCA: 138] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2010] [Accepted: 04/22/2010] [Indexed: 12/11/2022]
Abstract
Based on growing evidence linking autophagy to preconditioning, we tested the hypothesis that autophagy is necessary for cardioprotection conferred by ischemic preconditioning (IPC). We induced IPC with three cycles of 5 min regional ischemia alternating with 5 min reperfusion and assessed the induction of autophagy in mCherry-LC3 transgenic mice by imaging of fluorescent autophagosomes in cryosections. We found a rapid and significant increase in the number of autophagosomes in the risk zone of the preconditioned hearts. In Langendorff-perfused hearts subjected to an IPC protocol of 3 x 5 min ischemia, we also observed an increase in autophagy within 10 min, as assessed by Western blotting for p62 and cadaverine dye binding. To establish the role of autophagy in IPC cardioprotection, we inhibited autophagy with Tat-ATG5(K130R), a dominant negative mutation of the autophagy protein Atg5. Cardioprotection by IPC was reduced in rat hearts perfused with recombinant Tat-ATG5(K130R). To extend the potential significance of autophagy in cardioprotection, we also assessed three structurally unrelated cardioprotective agents--UTP, diazoxide, and ranolazine--for their ability to induce autophagy in HL-1 cells. We found that all three agents induced autophagy; inhibition of autophagy abolished their protective effect. Taken together, these findings establish autophagy as an end-effector in ischemic and pharmacologic preconditioning.
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Affiliation(s)
- Chengqun Huang
- BioScience Center, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182-4650 USA
| | - Smadar Yitzhaki
- BioScience Center, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182-4650 USA
| | - Cynthia N. Perry
- BioScience Center, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182-4650 USA
- Molecular Pathology Graduate Program, University of California San Diego, San Diego, CA USA
| | - Wayne Liu
- BioScience Center, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182-4650 USA
| | - Zoltan Giricz
- BioScience Center, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182-4650 USA
| | - Robert M. Mentzer
- BioScience Center, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182-4650 USA
- Cardiovascular Research Institute, Wayne State University School of Medicine, Detroit, MI USA
| | - Roberta A. Gottlieb
- BioScience Center, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182-4650 USA
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Affiliation(s)
- G David Roodman
- University of Pittsburgh, School of Medicine/Hematology-Oncology, Pittsburgh, PA, USA.
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25
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Susaki E, Kaneko-Oshikawa C, Miyata K, Tabata M, Yamada T, Oike Y, Katagiri H, Nakayama KI. Increased E4 activity in mice leads to ubiquitin-containing aggregates and degeneration of hypothalamic neurons resulting in obesity. J Biol Chem 2010; 285:15538-15547. [PMID: 20190229 DOI: 10.1074/jbc.m110.105841] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Obesity has become a serious worldwide public health problem. Although neural degeneration in specific brain regions has been suggested to contribute to obesity phenotype in humans, a causal relationship between these two conditions has not been demonstrated experimentally. We now show that E4B (also known as UFD2a), a mammalian ubiquitin chain elongation factor (E4), induces the formation of intracellular aggregates positive for ubiquitin and the adaptor protein p62 when overexpressed in cultured cells or the brain. Mice transgenic for E4B manifested neural degeneration in association with aggregate formation, and they exhibited functional impairment specifically in a subset of hypothalamic neurons that regulate food intake and energy expenditure, resulting in development of hyperphagic obesity and related metabolic abnormalities. The neural pathology of E4B transgenic mice was similar to that of human neurodegenerative diseases associated with the formation of intracellular ubiquitin-positive deposits, indicating the existence of a link between such diseases and obesity and related metabolic disorders. Our findings thus provide experimental evidence for a role of hypothalamic neurodegeneration in obesity, and the E4B transgenic mouse should prove to be a useful animal model for studies of the relationship between neurodegenerative diseases and obesity.
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Affiliation(s)
- Etsuo Susaki
- Department of Molecular and Cellular Biology, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Fukuoka 812-8582; Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012
| | - Chie Kaneko-Oshikawa
- Department of Molecular and Cellular Biology, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Fukuoka 812-8582; Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012
| | - Keishi Miyata
- Department of Molecular Genetics, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto 860-8556
| | - Mitsuhisa Tabata
- Department of Molecular Genetics, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto 860-8556
| | - Tetsuya Yamada
- Division of Advanced Therapeutics for Metabolic Diseases, Center for Translational and Advanced Animal Research, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan
| | - Yuichi Oike
- Department of Molecular Genetics, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto 860-8556
| | - Hideki Katagiri
- Division of Advanced Therapeutics for Metabolic Diseases, Center for Translational and Advanced Animal Research, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan
| | - Keiichi I Nakayama
- Department of Molecular and Cellular Biology, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Fukuoka 812-8582; Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012.
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Tabuchi K, Oikawa K, Hoshino T, Nishimura B, Hayashi K, Yanagawa T, Warabi E, Ishii T, Tanaka S, Hara A. Cochlear protection from acoustic injury by inhibitors of p38 mitogen-activated protein kinase and sequestosome 1 stress protein. Neuroscience 2009; 166:665-70. [PMID: 20036720 DOI: 10.1016/j.neuroscience.2009.12.038] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2009] [Revised: 12/13/2009] [Accepted: 12/14/2009] [Indexed: 11/27/2022]
Abstract
This study evaluated the protective role of p38 mitogen-activated protein kinase (p38 MAPK) inhibitors and sequestosome 1 (Sqstm1/A170/p62), a stress-induced signal modulator, in acoustic injury of the cochlea in mice. Two weeks after the exposure of mice to acoustic stress, threshold shifts of the auditory brainstem response (ABR) from the pre-exposure level and hair cell loss were evaluated. The activation of p38 MAPK was observed in cochlea by immunostaining 4 h after acoustic stress. To examine the role of p38 MAPK in tissue injury, its inhibitors were i.p. injected into male wild-type C57BL mice before the acoustic overexposure. The inhibitors SB202190 and SB203580 but not the inactive analogue SB202474 dose-dependently decreased the auditory threshold shift and outer hair cell loss induced by acoustic overexposure, suggesting the involvement of p38 MAPK in ototoxicity. We found that acoustic overexposure induced the up-regulation of Sqstm1 mRNA expression in the cochlea of wild-type mice and that SQSTM1-deficient mice exhibited an enhanced ABR threshold shift and hair cell loss, suggesting a role of SQSTM1 in the protection of tissue from acoustic stress.
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Affiliation(s)
- K Tabuchi
- Department of Otolaryngology, Head and Neck Surgery, Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8575, Japan.
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Sugimoto R, Warabi E, Katayanagi S, Sakai S, Uwayama J, Yanagawa T, Watanabe A, Harada H, Kitamura K, Noguchi N, Yoshida H, Siow RCM, Mann GE, Ishii T. Enhanced neointimal hyperplasia and carotid artery remodelling in sequestosome 1 deficient mice. J Cell Mol Med 2009; 14:1546-54. [PMID: 19780870 PMCID: PMC3829020 DOI: 10.1111/j.1582-4934.2009.00914.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Deficiency in the signal adaptor protein sequestosome 1 (SQSTM1/A170/p62) in mice is associated with mature-onset obesity, accompanied by insulin and leptin resistance. We previously established that redox sensitive transcription factor Nrf2 up-regulates SQSTM1 expression in response to atherogenic stimuli or laminar shear stress in vascular cells, and here examine the role of SQSTM1 in neointimal hyperplasia and vascular remodelling in vivo following carotid artery ligation. Neointimal hyperplasia was markedly enhanced at ligation sites after 3 weeks in SQSTM1(-/-) compared with wild-type (WT) mice. The intimal area and stenotic ratio were, respectively, 2.1- and 1.7-fold higher in SQSTM1(-/-) mice, indicating enhanced proliferation of vascular smooth muscle cells (SMCs). When aortic SMCs were isolated from WT and SQSTM1(-/-) mice and cultured in vitro, we found that SQSTM1(-/-) SMCs proliferated more rapidly in response to foetal calf serum (FCS) and attained 2-3-fold higher cell densities compared to WT SMCs. Moreover, migration of SQSTM1(-/-) SMCs was enhanced compared to WT SMCs. Early and late phases of p38(MAPK) activation in response to FCS stimulation were also more enhanced in SQSTM1(-/-) SMCs, and inhibitors of p38 and ERK1/2 signalling pathways significantly attenuated SMC proliferation. In summary, SQSTM1(-/-) mice exhibit enhanced neointimal hyperplasia and vascular remodelling following arterial ligation in vivo. The enhanced proliferation of SQSTM1(-/-) aortic SMCs in vitro highlights a novel role for SQSTM1 in suppressing smooth muscle proliferation following vascular injury.
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Affiliation(s)
- Rika Sugimoto
- Majors of Medical Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
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Du Y, Wooten MC, Wooten MW. Oxidative damage to the promoter region of SQSTM1/p62 is common to neurodegenerative disease. Neurobiol Dis 2009; 35:302-10. [PMID: 19481605 DOI: 10.1016/j.nbd.2009.05.015] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2009] [Revised: 05/11/2009] [Accepted: 05/17/2009] [Indexed: 01/21/2023] Open
Abstract
Recently we reported that declined SQSTM1/p62 expression in Alzheimer disease brain was age-correlated with oxidative damage to the p62 promoter. The objective of this study was to examine whether oxidative damage to the p62 promoter is common to DNA recovered from brain of individuals with neurodegenerative disease. Increased 8-OHdG staining was observed in brain sections from Alzheimer's disease (AD), Parkinson disease (PD), Huntington disease (HD), Frontotemporal dementia (FTD), and Pick's disease compared to control subjects. In parallel, the p62 promoter exhibited elevated oxidative damage in samples from various diseases compared to normal brain, and damage was negatively correlated with p62 expression in FTD samples. Oxidative damage to the p62 promoter induced by H2O2 treatment decreased its transcriptional activity. In keeping with this observation, the transcriptional activity of a Sp-1 element deletion mutant displayed reduced stimulus-induced activity. These findings reveal that oxidative damage to the p62 promoter decreased its transcriptional activity and might therefore account for decreased expression of p62. Altogether these results suggest that pharmacological means to increase p62 expression may be beneficial in delaying the onset of neurodegeneration.
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Affiliation(s)
- Yifeng Du
- Department of Biological Sciences, Cellular and Molecular Biosciences Program, 331 Funchess Hall, Auburn University, AL 38849, USA
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Okada K, Yanagawa T, Warabi E, Yamastu K, Uwayama J, Takeda K, Utsunomiya H, Yoshida H, Shoda J, Ishii T. The alpha-glucosidase inhibitor acarbose prevents obesity and simple steatosis in sequestosome 1/A170/p62 deficient mice. Hepatol Res 2009; 39:490-500. [PMID: 19207582 DOI: 10.1111/j.1872-034x.2008.00478.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
AIM Sequestosome 1 (SQSTM1)/A170/p62 plays an important role in membrane-receptor mediated signal transduction and autophagic protein degradation. Although the mechanism involved is not clear, sqstm1 gene knockout (KO) mice develop mature-onset obesity and insulin resistance, leading to type II diabetes. KO mice show accumulation of fat in white adipose tissue and the liver when fed a standard diet. Acarbose is an alpha-glucosidase inhibitor that improves insulin sensitivity and decreases postprandial hyperglycemia, and it is used to treat type 2 diabetes. We examined whether or not dietary acarbose prevented obesity and simple steatosis in KO mice. METHODS Wild-type (WT) and KO mice were fed a standard diet with or without acarbose (0.8% w/w) from 15-25 weeks of age. The body weight and the fat content of adipose tissue and the liver were measured, and changes of lipid metabolism in these tissues were assessed from gene expression. RESULTS Acarbose treatment suppressed weight gain and the development of hepatic steatosis in KO mice. Acarbose treatment up-regulated hepatic expression of the pparalpha, ucp-2, and abca1 genes, as well as srebp1c, pparalpha, and ppargamma in adipose tissue. In WT mice, however, acarbose treatment had little influence on weight gain and gene expression. CONCLUSIONS The results of this study suggest that long-term administration of acarbose is effective for prevention of obesity and simple steatosis in SQSTM1-KO mice.
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Affiliation(s)
- Kosuke Okada
- Department of Gastroenterology, University of Tsukuba, Tsukuba, Japan
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30
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Heo SR, Han AM, Kwon YK, Joung I. p62 protects SH-SY5Y neuroblastoma cells against H2O2-induced injury through the PDK1/Akt pathway. Neurosci Lett 2009; 450:45-50. [DOI: 10.1016/j.neulet.2008.11.011] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2008] [Revised: 10/29/2008] [Accepted: 11/06/2008] [Indexed: 01/29/2023]
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31
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Waguri S, Komatsu M. Chapter 9 Biochemical and Morphological Detection of Inclusion Bodies in Autophagy‐Deficient Mice. Methods Enzymol 2009; 453:181-96. [DOI: 10.1016/s0076-6879(08)04009-3] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Kim OJ, Ariano MA, Namkung Y, Marinec P, Kim E, Han J, Sibley DR. D2 dopamine receptor expression and trafficking is regulated through direct interactions with ZIP. J Neurochem 2008; 106:83-95. [PMID: 18346199 DOI: 10.1111/j.1471-4159.2008.05348.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We have used the yeast two-hybrid system to identify protein kinase C-zeta interacting protein (ZIP) as a novel interacting protein for the D(2) dopamine receptor (DAR). This interaction was identified by screening a rat brain cDNA library using the third intracellular loop of the D(2) DAR as bait. A partial-length cDNA encoding ZIP was isolated and characterized as specifically interacting with the third intracellular loop of the D(2) DAR, but not with the third intracellular loops of other DAR subtypes. Biochemical confirmation of the ZIP-D(2) DAR interaction was obtained by expressing the full-length ZIP and D(2) DAR proteins in mammalian cells and demonstrating that they could be co-immunoprecipitated. We further showed that ZIP and the D(2) DAR could be co-immunoprecipitated from endogenous brain tissues. Immunohistochemical analyses further revealed that ZIP and the D(2) DAR were extensively co-localized within numerous neurons in various brain regions. ZIP exists as three protein isoforms of varying length, which are derived from alternative RNA splicing. All three isoforms were found to interact with the D(2) DAR, which allowed for the delineation of the receptor interacting domain to within 38 residues of ZIP. Functionally, over-expression of ZIP was found to result in decreased expression of the D(2) DAR with a corresponding decrease in receptor modulation of cAMP accumulation. Confocal microscopy revealed that ZIP over-expression also lead to an intracellular accumulation of D(2) DAR protein in lysosome compartments. These results suggest that ZIP can physically interact with the D(2) DAR leading to increased intracellular trafficking to lysosomes with subsequent down-regulation of receptor expression and function.
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Affiliation(s)
- Ok-Jin Kim
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, Kansas 66045-7582, USA.
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Komatsu M, Waguri S, Koike M, Sou YS, Ueno T, Hara T, Mizushima N, Iwata JI, Ezaki J, Murata S, Hamazaki J, Nishito Y, Iemura SI, Natsume T, Yanagawa T, Uwayama J, Warabi E, Yoshida H, Ishii T, Kobayashi A, Yamamoto M, Yue Z, Uchiyama Y, Kominami E, Tanaka K. Homeostatic levels of p62 control cytoplasmic inclusion body formation in autophagy-deficient mice. Cell 2008; 131:1149-63. [PMID: 18083104 DOI: 10.1016/j.cell.2007.10.035] [Citation(s) in RCA: 1662] [Impact Index Per Article: 103.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2007] [Revised: 06/26/2007] [Accepted: 10/09/2007] [Indexed: 02/06/2023]
Abstract
Inactivation of constitutive autophagy results in formation of cytoplasmic protein inclusions and leads to liver injury and neurodegeneration, but the details of abnormalities related to impaired autophagy are largely unknown. Here we used mouse genetic analyses to define the roles of autophagy in the aforementioned events. We report that the ubiquitin- and LC3-binding protein "p62" regulates the formation of protein aggregates and is removed by autophagy. Thus, genetic ablation of p62 suppressed the appearance of ubiquitin-positive protein aggregates in hepatocytes and neurons, indicating that p62 plays an important role in inclusion body formation. Moreover, loss of p62 markedly attenuated liver injury caused by autophagy deficiency, whereas it had little effect on neuronal degeneration. Our findings highlight the unexpected role of homeostatic level of p62, which is regulated by autophagy, in controlling intracellular inclusion body formation, and indicate that the pathologic process associated with autophagic deficiency is cell-type specific.
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Affiliation(s)
- Masaaki Komatsu
- Laboratory of Frontier Science, Tokyo Metropolitan Institute of Medical Science, Bunkyo-ku, Tokyo 113-8613, Japan
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Abstract
Autophagy is a process of cellular "self-eating" in which portions of cytoplasm are sequestered within double-membrane cytosolic vesicles termed autophagosomes. The autophagosome cargo is delivered to the lysosome, broken down, and the resulting amino acids recycled after release back into the cytosol. Autophagy occurs in all eukaryotes and can be up-regulated in response to various nutrient limitations. Under these conditions, autophagy may become essential for viability. In addition, autophagy plays a role in certain diseases, acting to prevent some types of neurodegeneration and cancer, and in the elimination of invading pathogens. We review the current information on the mechanism of autophagy, with a focus on its role in protein metabolism and intracellular homeostasis.
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Affiliation(s)
- Noboru Mizushima
- Department of Physiology and Cell Biology, Tokyo Medical and Dental University, Tokyo 113-8519, Japan.
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Sumimoto H, Kamakura S, Ito T. Structure and Function of the PB1 Domain, a Protein Interaction Module Conserved in Animals, Fungi, Amoebas, and Plants. ACTA ACUST UNITED AC 2007; 2007:re6. [PMID: 17726178 DOI: 10.1126/stke.4012007re6] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Proteins containing the PB1 domain, a protein interaction module conserved in animals, fungi, amoebas, and plants, participate in diverse biological processes. The PB1 domains adopt a ubiquitin-like beta-grasp fold, containing two alpha helices and a mixed five-stranded beta sheet, and are classified into groups harboring an acidic OPCA motif (type I), the invariant lysine residue on the first beta strand (type II), or both (type I/II). The OPCA motif of a type I PB1 domain forms salt bridges with basic residues, especially the conserved lysine, of a type II PB1 domain, thereby mediating a specific PB1-PB1 heterodimerization, whereas additional contacts contribute to high affinity and specificity of the modular interaction. The canonical PB1 dimerization is required for the formation of complexes between p40(phox) and p67(phox) (for activation of the NADPH oxidase crucial for mammalian host defense), between the scaffold Bem1 and the guanine nucleotide exchange factor Cdc24 (for polarity establishment in yeasts), and between the polarity protein Par6 and atypical protein kinase C (for cell polarization in animal cells), as well as for the interaction between the mitogen-activated protein kinase kinase kinases MEKK2 or MEKK3 and the downstream target mitogen-activated protein kinase kinase MEK5 (for early cardiovascular development in mammals). PB1 domains can also mediate interactions with other protein domains. For example, an intramolecular interaction between the PB1 and PX domains of p40(phox) regulates phagosomal targeting of the microbicidal NADPH oxidase; the PB1 domain of MEK5 is likely responsible for binding to the downstream kinase ERK5, which lacks a PB1 domain; and the scaffold protein Nbr1 associates through a PB1-containing region with titin, a sarcomere protein without a PB1 domain. This Review describes various aspects of PB1 domains at the molecular and cellular levels.
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Affiliation(s)
- Hideki Sumimoto
- Medical Institute of Bioregulation, Kyushu University, Maidashi, Higashi-ku, Fukuoka, Japan.
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36
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Pastila R, Leszczynski D. Ultraviolet-A radiation induces changes in cyclin G gene expression in mouse melanoma B16-F1 cells. Cancer Cell Int 2007; 7:7. [PMID: 17474990 PMCID: PMC1871570 DOI: 10.1186/1475-2867-7-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2006] [Accepted: 05/02/2007] [Indexed: 11/30/2022] Open
Abstract
Background We have previously shown that ultraviolet-A (UVA) radiation enhances metastatic lung colonization capacity of B16-F1 melanoma cells. The aim of this study was to examine changes in expression profile of genes in mouse melanoma B16-F1 cells exposed to UVA radiation. Results B16-F1 melanoma cells were exposed to a single UVA radiation dose of 8 J/cm2 and mRNA was isolated 4 h after the end of UVA exposure. Atlas™ Mouse Cancer 1.2 cDNA expression arrays were used for the large-scale screening to identify the genes involved in the regulation of carcinogenesis, tumor progression and metastasis. Physiologically relevant UVA dose induced differential expression in 9 genes in the UVA exposed melanoma cells as compared to the unexposed control cells. The expression of seven genes out of nine was upregulated (HSC70, HSP86, α-B-crystallin, GST mu2, Oxidative stress induced protein OSI, VEGF, cyclin G), whereas the expression of two genes was down-regulated (G-actin, non-muscle cofilin). The gene expression of cyclin G was mostly affected by UVA radiation, increasing by 4.85-folds 4 hour after exposure. The analysis of cyclin G protein expression revealed 1.36-fold increase at the 6 hour time point after UVA exposure. Cell cycle arrest in G2/M phase, which is known to be regulated by cyclin G, occurred at 4-h hour time-point, peaking 8 hours after the end of UVA irradiation, suggesting that cyclin G might play a role in the cell cycle arrest. Conclusion Our results suggest that UVA radiation-induces changes in the expression of several genes. Some of these changes, e.g. in expression of cyclin G, possibly might affect cell physiology (cell cycle arrest).
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Affiliation(s)
- Riikka Pastila
- Non-ionizing Radiation Laboratory; STUK-Radiation and Nuclear Safety Authority, Helsinki, Finland
| | - Dariusz Leszczynski
- Radiation Biology Laboratory; Department of Research and Environmental Surveillance, STUK-Radiation and Nuclear Safety Authority, Helsinki, Finland
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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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Joung I, Kim HJ, Kwon YK. p62 modulates Akt activity via association with PKCzeta in neuronal survival and differentiation. Biochem Biophys Res Commun 2005; 334:654-60. [PMID: 16011831 DOI: 10.1016/j.bbrc.2005.06.138] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2005] [Accepted: 06/22/2005] [Indexed: 11/17/2022]
Abstract
p62 is a ubiquitously expressed phosphoprotein that interacts with a number of signaling molecules and a major component of neurofibrillary tangles in the brain of Alzheimer's disease patients. It has been implicated in important cellular functions such as cell proliferation and anti-apoptotic pathways. In this study, we have addressed the potential role of p62 during neuronal differentiation and survival using HiB5, a rat neuronal progenitor cell. We generated a recombinant adenovirus encoding T7-epitope tagged p62 to reliably transfer p62 cDNA into the neuronal cells. The results show that an overexpression of p62 led not only to neuronal differentiation, but also to decreased cell death induced by serum withdrawal in HiB5 cells. In this process p62-dependent Akt phosphorylation occurred via the release of Akt from PKCzeta by association of p62 and PKCzeta, which is known as a negative regulator of Akt activation. These findings indicate that p62 facilitates cell survival through novel signaling cascades that result in Akt activation. Furthermore, we found that p62 expression was induced during neuronal differentiation. Taken together, the data suggest p62 is a regulator of neuronal cell survival and differentiation.
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Affiliation(s)
- Insil Joung
- Department of Biology, Hanseo University, Seosan, Chungnam 352-820, Korea.
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Lackner C, Dlaska D, Fuchsbichler A, Stumptner C, Gogg-Kamerer M, Zatloukal K, Denk H. p62 protein is expressed in pancreatic beta cells. J Pathol 2005; 206:402-8. [PMID: 15926199 DOI: 10.1002/path.1786] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
p62 is a cellular protein that plays an adapter role in signal transduction pathways involved in such diverse biological functions as proliferation, differentiation, reaction to oxidative stress and immune response. Furthermore, p62 has recently been detected as a component of intracytoplasmic protein aggregates (inclusion bodies), which are hallmarks of a variety of chronic degenerative disorders, such as Parkinson's disease and Alzheimer's disease, but also of steatohepatitis. Here we report that p62 and insulin are co-expressed in a diffuse fashion in beta cells in normal human pancreas as well as in primary chronic pancreatitis and in normal pancreas from mouse and swine. In contrast, p62 protein is absent from, or only focally and very weakly expressed in, insulinomas, glucagonomas or non-functioning pancreatic neuroendocrine tumours or carcinomas that express insulin or other pancreatic as well as extrapancreatic hormones. Although the biological function of p62 in beta cells is unknown, the co-expression of p62 and insulin in non-neoplastic beta cells suggests that, in the beta cell, p62 may play a role in specific insulin-related signalling. Since p62 may also be involved in pro-apototic signal transduction, the loss of p62 expression in neuroendocrine neoplasms of the pancreas may render the tumour cells less sensitive to pro-apototic signals. Further research is necessary to elucidate the role of p62 in beta cell-specific signal transduction.
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Affiliation(s)
- Carolin Lackner
- Institute of Pathology, Medical University of Graz, Austria.
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Schroth W, Ender A, Schierwater B. Molecular biomarkers and adaptation to environmental stress in moon jelly (Aurelia spp.). MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2005; 7:449-61. [PMID: 15976937 DOI: 10.1007/s10126-004-4095-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2004] [Accepted: 11/12/2004] [Indexed: 05/03/2023]
Abstract
We describe a strategy that identifies molecular biomarkers and links the study of abiotic stress to evolutionary history. By utilizing the moon jellyfish Aurelia spp. as a model, we identified genes differentially regulated in response to the chemical stressor tributyltin by means of complementary DNA subtraction analyses. Expression of 3 out of 25 identified candidate genes, one oxidative stress gene, one heat shock (hsp70) gene, and one GTP-binding gene, was quantified under laboratory conditions and in field tests using semiquantitative reverse transcriptase polymerase chain reaction. Differential expression patterns were found following exposure to tributyltin and temperature treatments. The findings suggest that the identified genes are involved in response to chemical as well as heat- induced stress and may serve as biomarkers for monitoring marine habitats. Gene regulatory patterns combined with phylogenetic inferences of the hsp70 gene support a possible role of ecologically driven divergence within the genus Aurelia. We show that added information on genetic variability can raise the predictive power of molecular biomarkers in studies of individual stress response.
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Affiliation(s)
- Werner Schroth
- Ecology & Evolution, ITZ, TiHo Hannover, Bünteweg 17d, D-30559, Hannover, Germany.
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Nan L, Wu Y, Bardag-Gorce F, Li J, French BA, Fu AN, Francis T, Vu J, French SW. p62 is involved in the mechanism of Mallory body formation. Exp Mol Pathol 2004; 77:168-75. [PMID: 15507232 DOI: 10.1016/j.yexmp.2004.06.003] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2004] [Accepted: 06/17/2004] [Indexed: 11/16/2022]
Abstract
p62 is a scaffolding protein that binds to polyubiquitin. It is involved in the degradation of proteins by the proteasome. To determine if p62 is critical in the development of Mallory bodies (MBs), primary culture hepatocytes from drug-primed mice were studied and the results were compared with normal hepatocytes. Gene-specific gripNA (gp62) was added to the medium of the primary cultures of the hepatocytes to inhibit the expression of p62. Overexpression of p62 was achieved by transfecting the hepatocytes with a plasmid containing green fluorescent protein (GFP) fused p62 (p62-GFP). Gp62 dramatically inhibited MB formation by 94% in drug-primed hepatocytes. The cells transfected with gp62 had decreased protein levels of p62, ubiquitin (Ub), and cytokeratin 8 (CK8). Overexpression of p62 accelerated and enhanced MB formation by 339% in drug-primed hepatocytes. Overexpression of p62 in normal mouse hepatocytes induced MB-like aggresomes that were stained by Ub but not by CK8. The results indicate that p62 is involved in the mechanism of MB formation.
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Affiliation(s)
- Li Nan
- Department of Pathology, Harbor-UCLA Medical Center, Torrance, CA 90502, USA
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42
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Kzhyshkowska J, Gratchev A, Martens JH, Pervushina O, Mamidi S, Johansson S, Schledzewski K, Hansen B, He X, Tang J, Nakayama K, Goerdt S. Stabilin-1 localizes to endosomes and the trans-Golgi network in human macrophages and interacts with GGA adaptors. J Leukoc Biol 2004; 76:1151-61. [PMID: 15345724 DOI: 10.1189/jlb.0504300] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Stabilin-1 and stabilin-2 constitute a novel family of fasciclin domain-containing hyaluronan receptor homologues recently described by us. Whereas stabilin-1 is expressed in sinusoidal endothelial cells and in macrophages in vivo, stabilin-2 is absent from the latter. In the present study, we analyzed the subcellular distribution of stabilin-1 in primary human macrophages. Using flow cytometry, expression of stabilin-1 was demonstrated on the surface of interleukin-4/dexamethasone-stimulated macrophages (MPhi2). By immunofluorescence and confocal microscopy, we established that stabilin-1 is preferentially localized in early endosome antigen-1-positive early/sorting endosomes and in recycling endosomes identified by transferrin endocytosis. Association of stabilin-1 was infrequently seen with p62 lck ligand-positive late endosomes and with CD63-positive lysosomes but not in lysosome-associated membrane protein-1-positive lysosomes. Stabilin-1 was also found in the trans-Golgi network (TGN) but not in Golgi stack structures. Glutathione S-transferase pull-down assay revealed that the cytoplasmic tail of stabilin-1 but not stabilin-2 binds to recently discovered Golgi-localized, gamma-ear-containing, adenosine 5'-diphosphate-ribosylation factor-binding (GGA) adaptors GGA1, GGA2, and GGA3 long, mediating traffic between Golgi and endosomal/lysosomal compartments. Stabilin-1 did not bind to GGA3 short, which lacks a part of the Vps27p/Hrs/STAM domain. Deletion of DDSLL and LL amino acid motifs resulted in decreased binding of stabilin-1 with GGAs. A small portion of stabilin-1 colocalized with GGA2 and GGA3 in the TGN in MPhi2. Treatment with brefeldin A resulted in accumulation of stabilin-1 in the TGN. Our results suggest that stabilin-1 is involved in the GGA-mediated sorting processes at the interface of the biosynthetic and endosomal pathways; similarly to other GGA-interacting proteins, stabilin-1 may thus function in endocytic and secretory processes of human macrophages.
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Affiliation(s)
- Julia Kzhyshkowska
- Department of Dermatology, University Medical Centre Mannheim, University of Heidelberg, Theodor-Kutzer Ufer 1-3, 68167 Mannheim, Germany.
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43
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Tamasi V, Jeffries JM, Arteel GE, Falkner KC. Ebselen augments its peroxidase activity by inducing nrf-2-dependent transcription. Arch Biochem Biophys 2004; 431:161-8. [PMID: 15488464 DOI: 10.1016/j.abb.2004.07.030] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2004] [Revised: 07/12/2004] [Indexed: 02/01/2023]
Abstract
Ebselen is an organoselenium compound that acts as a glutathione peroxidase mimic. Since ebselen is a hydrophobic, thio-reactive compound capable of interacting with Keap-1, we tested its ability to activate nrf-2-dependent responses in the human hepatocarcinoma derived cell line, HepG2. Ebselen (25 microM) increased expression of an nrf-2 response element reporter in transient transfection experiments by 4-fold. Although, the induction was lower than that observed with classic nrf-2 inducer, sulforaphane (10 microL; 7-fold), ebselen also induced expression of native NAD(P)H:quinone oxidoreductase (1.6-fold) activity; induction of this protein is known to be dependent on nrf-2 action. Treatment of HepG2 cells with ebselen increased glutathione levels after 12 (1.5-fold) or 24 (1.9-fold)h of treatment. Treatment of the cells with either sulforaphane or ebselen 24 h prior to treatment with varying concentrations of t-butyl hydroperoxide increased the half maximal lethal dose from 28 to 42 microM and 58 microM for sulforaphane and ebselen, respectively. The protective effects of ebselen treatment were greater with pretreatment (IC50=58 microM) than simultaneous addition (IC50=45 microM). The protein synthesis inhibitor cycloheximide blocked increases in intracellular glutathione synthesis and partially blocked the protective effects of this regimen on increasing cell survival following t-butyl hydroperoxide treatment. Likewise co-treatment with the MEK 1 inhibitor, PD98059, which has been shown to inhibit nrf-2-dependent gene activation, partially inhibited the ebselen-dependent increases in IC50 while not affecting the control cells. We conclude that nrf-2 activation augments the role of ebselen as an antioxidant or by indirect induction of cellular antioxidant defences.
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Affiliation(s)
- Viola Tamasi
- Department of Biochemistry and Molecular Biology, University of Louisville School of Medicine, Louisville, KY 40292, USA
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44
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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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45
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Müller T, Langner C, Fuchsbichler A, Heinz-Erian P, Ellemunter H, Schlenck B, Bavdekar AR, Pradhan AM, Pandit A, Müller-Höcker J, Melter M, Kobayashi K, Nagasaka H, Kikuta H, Müller W, Tanner MS, Sternlieb I, Zatloukal K, Denk H. Immunohistochemical analysis of Mallory bodies in Wilsonian and non-Wilsonian hepatic copper toxicosis. Hepatology 2004; 39:963-9. [PMID: 15057900 DOI: 10.1002/hep.20108] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Patients with Wilson's disease (WD), Indian childhood cirrhosis (ICC), and idiopathic copper toxicosis (ICT) develop severe liver disease morphologically characterized by ballooning of hepatocytes, inflammation, cytoskeletal alterations, and Mallory body (MB) formation, finally leading to mostly micronodular cirrhosis. The pathogenesis of MBs in copper toxicosis is still unresolved. Immunohistochemical analysis of MBs in different types of copper intoxication revealed that keratin, p62, and ubiquitin are integral components. Thus MBs associated with copper intoxication resemble those present in alcoholic steatohepatitis (ASH) and nonalcoholic steatohepatitis (NASH). p62 is a multifunctional immediate early gene product that, on the one hand, is involved in stress-induced cell signaling (particularly that of oxidative stress) by acting as an adapter protein linking receptor-interacting protein (RIP) with the atypical protein kinase C. On the other hand, p62 binds with high affinity to polyubiquitin and ubiquitinated proteins. In conclusion, p62 accumulation in WD, ICC, and ICT and deposition in MBs indicates a central role of protein misfolding induced by oxidative stress in copper-induced liver toxicity. By sequestering potentially harmful misfolded ubiquitinated proteins as inert cytoplasmic inclusion bodies (e.g., as MBs), p62 may be a major player in an important cellular rescue mechanism in oxidative hepatocyte injury.
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Affiliation(s)
- Thomas Müller
- Department of Pediatrics, University of Innsbruck, Innsbruck, Austria
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Zatloukal K, Stumptner C, Fuchsbichler A, Janig E, Denk H. Intermediate Filament Protein Inclusions. Methods Cell Biol 2004; 78:205-28. [PMID: 15646620 DOI: 10.1016/s0091-679x(04)78008-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Kurt Zatloukal
- Institute of Pathology, Medical University of Graz, A-8036 Graz, Austria
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47
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Aono J, Yanagawa T, Itoh K, Li B, Yoshida H, Kumagai Y, Yamamoto M, Ishii T. Activation of Nrf2 and accumulation of ubiquitinated A170 by arsenic in osteoblasts. Biochem Biophys Res Commun 2003; 305:271-7. [PMID: 12745069 DOI: 10.1016/s0006-291x(03)00728-9] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Sub-lethal levels of arsenic induce upregulation of stress proteins. We here report for the first time that inorganic arsenic activates the transcription factor Nrf2, which controls the expression of oxidative stress-induced proteins. Treatment of cultured MC3T3-E1 osteoblasts with arsenite or arsenate induced increase of Nrf2, followed by transcriptional activation of target genes encoding HO-1, Prx I, and A170. We found that arsenate (200-800 micro M) only slightly increased the normal 60kDa A170 protein but markedly increased higher molecular mass forms of A170 (HMM-A170) that appeared as smeared bands. Arsenate also markedly increased ubiquitin-conjugated cellular proteins, suggesting that HMM-A170 was one of the poly-ubiquitinated proteins. Arsenite (50-100 micro M) also induced accumulation of HMM-A170 and ubiquitin-conjugated proteins. These results provide the first direct evidence that toxic arsenics impair the normal function of A170. Our findings provide a potential diagnostic tool for monitoring biotoxicity in cells and tissues in response to arsenic compounds.
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Affiliation(s)
- Junko Aono
- Institute of Clinical Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
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48
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Ji C, Kaplowitz N. Betaine decreases hyperhomocysteinemia, endoplasmic reticulum stress, and liver injury in alcohol-fed mice. Gastroenterology 2003; 124:1488-99. [PMID: 12730887 DOI: 10.1016/s0016-5085(03)00276-2] [Citation(s) in RCA: 424] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
BACKGROUND & AIMS Alcohol-induced hyperhomocysteinemia has been reported in rats and humans. Hyperhomocysteinemia has been associated with endoplasmic reticulum (ER) stress leading to the activation of ER-dependent apoptosis or up-regulation of lipid synthesis. This novel ER stress mechanism of alcoholic liver injury was studied in the model of intragastric alcohol-fed mice. METHODS Effects of alcohol on gene expression were analyzed using cDNA microarrays, RT-PCR, and Western blots over a period of 6 weeks. Liver injury was examined by histologic staining and TUNEL. RESULTS We observed fatty liver, increased hepatic necroinflammation and apoptosis, and hyperhomocysteinemia. Of 1176 toxicology-related genes, glucose-regulated proteins (GRP-78 and -94), growth arrest/DNA damage-inducible protein 153 (CHOP/GADD153), and caspase-12 indicative of an ER stress response were among the alcohol-responsive genes. Sterol regulatory element binding protein (SREBP-1) and HMG-CoA reductase also were enhanced with alcohol administration. RT-PCR and selective Western blots confirmed the alcohol-induced expression of ER stress-related apoptosis and lipid synthesis genes. Addition of 0.5% and maximal 1.5% betaine to the alcohol diet reduced the elevated level of plasma homocysteine by 54% and more than 80% accompanied by a decrease in hepatic lipids and ER stress response. Betaine did not attenuate the ethanol-induced increase in tumor necrosis factor alpha or CD14 mRNA. CONCLUSIONS The results strongly suggest that alcohol may modulate both apoptotic and fat synthetic gene expression through homocysteine-induced ER stress in chronic alcoholic mouse liver and that correction of hyperhomocysteinemia by betaine or other approaches may be useful to prevent alcoholic liver disease.
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Affiliation(s)
- Cheng Ji
- USC/UCLA Research Center for Alcoholic Liver and Pancreatic Diseases, Research Center for Liver Disease and Department of Medicine, Keck School of Medicine, University of Southern California, Los Angeles, 90033, USA.
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Harding HP, Zhang Y, Zeng H, Novoa I, Lu PD, Calfon M, Sadri N, Yun C, Popko B, Paules R, Stojdl DF, Bell JC, Hettmann T, Leiden JM, Ron D. An integrated stress response regulates amino acid metabolism and resistance to oxidative stress. Mol Cell 2003; 11:619-33. [PMID: 12667446 DOI: 10.1016/s1097-2765(03)00105-9] [Citation(s) in RCA: 2425] [Impact Index Per Article: 115.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Eukaryotic cells respond to unfolded proteins in their endoplasmic reticulum (ER stress), amino acid starvation, or oxidants by phosphorylating the alpha subunit of translation initiation factor 2 (eIF2alpha). This adaptation inhibits general protein synthesis while promoting translation and expression of the transcription factor ATF4. Atf4(-/-) cells are impaired in expressing genes involved in amino acid import, glutathione biosynthesis, and resistance to oxidative stress. Perk(-/-) cells, lacking an upstream ER stress-activated eIF2alpha kinase that activates Atf4, accumulate endogenous peroxides during ER stress, whereas interference with the ER oxidase ERO1 abrogates such accumulation. A signaling pathway initiated by eIF2alpha phosphorylation protects cells against metabolic consequences of ER oxidation by promoting the linked processes of amino acid sufficiency and resistance to oxidative stress.
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Affiliation(s)
- Heather P Harding
- Skirball Institute, New York University School of Medicine, New York, NY 10016, USA
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Tabuchi Y, Zhao QL, Kondo T. DNA microarray analysis of differentially expressed genes responsive to bisphenol A, an alkylphenol derivative, in an in vitro mouse Sertoli cell model. JAPANESE JOURNAL OF PHARMACOLOGY 2002; 89:413-6. [PMID: 12233820 DOI: 10.1254/jjp.89.413] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
To identify genes elicited by bisphenol A (BPA) in Sertoli cells, we carried out a microarray analysis of TTE3 cells (a mouse Sertoli cell line) treated with BPA. BPA (100, 200 and 400 microM) induced cell death concentration-dependently, with levels being 25%, 33% and 96%, respectively. Of the 1,081 genes analyzed, 3 genes showed decreased levels of expression while the remaining 10 genes showed increased levels in the cells treated with a subtoxic dose of BPA (200 microM). The expressions of six genes were confirmed by the TaqMan assay. These findings suggest that DNA microarray analysis is a useful tool for investigating the molecular mechanisms of the toxic effects of BPA in testicular cells.
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Affiliation(s)
- Yoshiaki Tabuchi
- Molecular Genetics Research Center, Faculty of Medicine, Toyama Medical and Pharmaceutical University, Sugitani, Japan.
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