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Pateras IS, Igea A, Nikas IP, Leventakou D, Koufopoulos NI, Ieronimaki AI, Bergonzini A, Ryu HS, Chatzigeorgiou A, Frisan T, Kittas C, Panayiotides IG. Diagnostic Challenges during Inflammation and Cancer: Current Biomarkers and Future Perspectives in Navigating through the Minefield of Reactive versus Dysplastic and Cancerous Lesions in the Digestive System. Int J Mol Sci 2024; 25:1251. [PMID: 38279253 PMCID: PMC10816510 DOI: 10.3390/ijms25021251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 01/12/2024] [Accepted: 01/16/2024] [Indexed: 01/28/2024] Open
Abstract
In the setting of pronounced inflammation, changes in the epithelium may overlap with neoplasia, often rendering it impossible to establish a diagnosis with certainty in daily clinical practice. Here, we discuss the underlying molecular mechanisms driving tissue response during persistent inflammatory signaling along with the potential association with cancer in the gastrointestinal tract, pancreas, extrahepatic bile ducts, and liver. We highlight the histopathological challenges encountered in the diagnosis of chronic inflammation in routine practice and pinpoint tissue-based biomarkers that could complement morphology to differentiate reactive from dysplastic or cancerous lesions. We refer to the advantages and limitations of existing biomarkers employing immunohistochemistry and point to promising new markers, including the generation of novel antibodies targeting mutant proteins, miRNAs, and array assays. Advancements in experimental models, including mouse and 3D models, have improved our understanding of tissue response. The integration of digital pathology along with artificial intelligence may also complement routine visual inspections. Navigating through tissue responses in various chronic inflammatory contexts will help us develop novel and reliable biomarkers that will improve diagnostic decisions and ultimately patient treatment.
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Affiliation(s)
- Ioannis S. Pateras
- 2nd Department of Pathology, “Attikon” University Hospital, Medical School, National and Kapodistrian University of Athens, 124 62 Athens, Greece; (D.L.); (N.I.K.); (A.I.I.); (I.G.P.)
| | - Ana Igea
- Instituto de Investigación Sanitaria de Santiago de Compostela (IDIS), 15706 Santiago de Compostela, Spain;
- Mobile Genomes, Centre for Research in Molecular Medicine and Chronic Diseases (CiMUS), University of Santiago de Compostela (USC), 15706 Santiago de Compostela, Spain
| | - Ilias P. Nikas
- Medical School, University of Cyprus, 2029 Nicosia, Cyprus
| | - Danai Leventakou
- 2nd Department of Pathology, “Attikon” University Hospital, Medical School, National and Kapodistrian University of Athens, 124 62 Athens, Greece; (D.L.); (N.I.K.); (A.I.I.); (I.G.P.)
| | - Nektarios I. Koufopoulos
- 2nd Department of Pathology, “Attikon” University Hospital, Medical School, National and Kapodistrian University of Athens, 124 62 Athens, Greece; (D.L.); (N.I.K.); (A.I.I.); (I.G.P.)
| | - Argyro Ioanna Ieronimaki
- 2nd Department of Pathology, “Attikon” University Hospital, Medical School, National and Kapodistrian University of Athens, 124 62 Athens, Greece; (D.L.); (N.I.K.); (A.I.I.); (I.G.P.)
| | - Anna Bergonzini
- Center for Infectious Medicine, Department of Medicine Huddinge, Karolinska Institutet, Karolinska University Hospital, Alfred Nobels Allé 8, 141 52 Stockholm, Sweden;
- Department of Molecular Biology and Umeå Centre for Microbial Research (UCMR), Umeå University, 901 87 Umeå, Sweden;
| | - Han Suk Ryu
- Department of Pathology, Seoul National University Hospital, Seoul 03080, Republic of Korea;
| | - Antonios Chatzigeorgiou
- Department of Physiology, Medical School, National and Kapodistrian University of Athens, 115 27 Athens, Greece;
| | - Teresa Frisan
- Department of Molecular Biology and Umeå Centre for Microbial Research (UCMR), Umeå University, 901 87 Umeå, Sweden;
| | - Christos Kittas
- Department of Histopathology, Biomedicine Group of Health Company, 156 26 Athens, Greece;
| | - Ioannis G. Panayiotides
- 2nd Department of Pathology, “Attikon” University Hospital, Medical School, National and Kapodistrian University of Athens, 124 62 Athens, Greece; (D.L.); (N.I.K.); (A.I.I.); (I.G.P.)
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Alim Al-Bari A, Ito Y, Thomes PG, Menon MB, García-Macia M, Fadel R, Stadlin A, Peake N, Faris ME, Eid N, Klionsky DJ. Emerging mechanistic insights of selective autophagy in hepatic diseases. Front Pharmacol 2023; 14:1149809. [PMID: 37007026 PMCID: PMC10060854 DOI: 10.3389/fphar.2023.1149809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 02/23/2023] [Indexed: 03/18/2023] Open
Abstract
Macroautophagy (hereafter referred to as autophagy), a highly conserved metabolic process, regulates cellular homeostasis by degrading dysfunctional cytosolic constituents and invading pathogens via the lysosomal system. In addition, autophagy selectively recycles specific organelles such as damaged mitochondria (via mitophagy), and lipid droplets (LDs; via lipophagy) or eliminates specialized intracellular pathogenic microorganisms such as hepatitis B virus (HBV) and coronaviruses (via virophagy). Selective autophagy, particularly mitophagy, plays a key role in the preservation of healthy liver physiology, and its dysfunction is connected to the pathogenesis of a wide variety of liver diseases. For example, lipophagy has emerged as a defensive mechanism against chronic liver diseases. There is a prominent role for mitophagy and lipophagy in hepatic pathologies including non-alcoholic fatty liver disease (NAFLD), hepatocellular carcinoma (HCC), and drug-induced liver injury. Moreover, these selective autophagy pathways including virophagy are being investigated in the context of viral hepatitis and, more recently, the coronavirus disease 2019 (COVID-19)-associated hepatic pathologies. The interplay between diverse types of selective autophagy and its impact on liver diseases is briefly addressed. Thus, modulating selective autophagy (e.g., mitophagy) would seem to be effective in improving liver diseases. Considering the prominence of selective autophagy in liver physiology, this review summarizes the current understanding of the molecular mechanisms and functions of selective autophagy (mainly mitophagy and lipophagy) in liver physiology and pathophysiology. This may help in finding therapeutic interventions targeting hepatic diseases via manipulation of selective autophagy.
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Affiliation(s)
- Abdul Alim Al-Bari
- Department of Pharmacy, Faculty of Science, University of Rajshahi, Rajshahi, Bangladesh
| | - Yuko Ito
- Department of General and Gastroenterological Surgery, Osaka Medical and Pharmaceutical University, Osaka, Japan
| | - Paul G. Thomes
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, United States
| | - Manoj B. Menon
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, New Delhi, India
| | - Marina García-Macia
- Institute of Functional Biology and Genomics (IBFG), Universidad de Salamanca-CSIC, Institute of Biomedical Research of Salamanca (IBSAL), Hospital Universitario de Salamanca, Salamanca, Spain
| | - Raouf Fadel
- Department of Anatomy, College of Medicine and Medical Sciences, Arabian Gulf University, Al Manama, Bahrain
| | - Alfreda Stadlin
- Basic Medical Sciences Department, College of Medicine, Ajman university, Ajman, United Arab Emirates
| | - Nicholas Peake
- Biomolecular Sciences Research Centre, Sheffield Hallam University, Sheffield, United Kingdom
| | - MoezAlIslam Ezzat Faris
- Department of Clinical Nutrition and Dietetics, College of Health Sciences, University of Sharjah, United Arab Emirates
| | - Nabil Eid
- Department of Anatomy, Division of Human Biology, School of Medicine, International Medical University, Kuala Lumpur, Malaysia
- *Correspondence: Nabil Eid,
| | - Daniel J. Klionsky
- Life Sciences Institute and Department of Molecular, Cellular and Developmental Biology, University of MI, Ann Arbor, MI, United States
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Kim DK, Han D, Bae J, Kim H, Lee S, Kim JS, Jeong YG, Shin J, Park HW. Verapamil-loaded supramolecular hydrogel patch attenuates metabolic dysfunction-associated fatty liver disease via restoration of autophagic clearance of aggregated proteins and inhibition of NLRP3. Biomater Res 2023; 27:4. [PMID: 36670488 PMCID: PMC9854054 DOI: 10.1186/s40824-023-00342-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 01/15/2023] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Obesity, a serious threat to public health, is linked to chronic metabolic complications including insulin resistance, type-2 diabetes, and metabolic dysfunction-associated fatty liver disease (MAFLD). Current obesity medications are challenged by poor effectiveness, poor patient compliance, and potential side effects. Verapamil is an inhibitor of L-type calcium channels, FDA-approved for the treatment of hypertension. We previously investigated the effect of verapamil on modulating autophagy to treat obesity-associated lipotoxicity. This study aims to develop a verapamil transdermal patch and to evaluate its anti-obesity effects. METHODS Verapamil is loaded in biomimetic vascular bundle-like carboxymethyl pullulan-based supramolecular hydrogel patches cross-linked with citric acid and glycerol linkages (CLCMP). The investigation was then carried out to determine the therapeutic effect of verapamil-loaded CLCMP (Vera@CLCMP) on diet-induced obese mice. RESULTS Vera@CLCMP hydrogel patches with hierarchically organized and anisotropic pore structures not only improved verapamil bioavailability without modifying its chemical structure but also enhanced verapamil release through the stratum corneum barrier. Vera@CLCMP patches exhibit low toxicity and high effectiveness at delivering verapamil into the systemic circulation through the dermis in a sustained manner. Specifically, transdermal administration of this patch into diet-induced obese mice drastically improved glucose tolerance and insulin sensitivity and alleviated metabolic derangements associated with MAFLD. Furthermore, we uncovered a distinct molecular mechanism underlying the anti-obesity effects associated with the hepatic NLR family pyrin domain-containing 3 (NLRP3) inflammasome and autophagic clearance by the vera@CLCMP hydrogel patches. CONCLUSION The current study provides promising drug delivery platforms for long-term family treatment of chronic diseases, including obesity and metabolic dysfunctions.
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Affiliation(s)
- Do Kyung Kim
- grid.411143.20000 0000 8674 9741Department of Anatomy, Konyang University College of Medicine, Daejeon, 35365 Republic of Korea
| | - Daewon Han
- grid.411143.20000 0000 8674 9741Department of Cell Biology, Konyang University College of Medicine, Daejeon, 35365 Republic of Korea
| | - Jeongyun Bae
- grid.411143.20000 0000 8674 9741Department of Cell Biology, Konyang University College of Medicine, Daejeon, 35365 Republic of Korea
| | - Haeil Kim
- grid.411143.20000 0000 8674 9741Department of Cell Biology, Konyang University College of Medicine, Daejeon, 35365 Republic of Korea
| | - Solji Lee
- grid.411143.20000 0000 8674 9741Department of Cell Biology, Konyang University College of Medicine, Daejeon, 35365 Republic of Korea
| | - Jong-Seok Kim
- grid.411143.20000 0000 8674 9741Myunggok Medical Research Institute, Konyang University College of Medicine, Daejeon, 35365 Republic of Korea
| | - Young-Gil Jeong
- grid.411143.20000 0000 8674 9741Department of Anatomy, Konyang University College of Medicine, Daejeon, 35365 Republic of Korea
| | - Jongdae Shin
- grid.411143.20000 0000 8674 9741Department of Cell Biology, Konyang University College of Medicine, Daejeon, 35365 Republic of Korea ,grid.411143.20000 0000 8674 9741Myunggok Medical Research Institute, Konyang University College of Medicine, Daejeon, 35365 Republic of Korea
| | - Hwan-Woo Park
- grid.411143.20000 0000 8674 9741Department of Cell Biology, Konyang University College of Medicine, Daejeon, 35365 Republic of Korea ,grid.411143.20000 0000 8674 9741Myunggok Medical Research Institute, Konyang University College of Medicine, Daejeon, 35365 Republic of Korea
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Barrientos-Riosalido A, Real M, Bertran L, Aguilar C, Martínez S, Parada D, Vives M, Sabench F, Riesco D, Castillo DD, Richart C, Auguet T. Increased Hepatic ATG7 mRNA and ATG7 Protein Expression in Nonalcoholic Steatohepatitis Associated with Obesity. Int J Mol Sci 2023; 24:ijms24021324. [PMID: 36674839 PMCID: PMC9867349 DOI: 10.3390/ijms24021324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Revised: 01/05/2023] [Accepted: 01/06/2023] [Indexed: 01/11/2023] Open
Abstract
The autophagy gene ATG7 has been shown to be essential for the induction of autophagy, a process that used to be suppressed in nonalcoholic fatty liver disease (NAFLD). However, the specific role of ATG7 in NAFLD remains unclear. The aim of this study was to analyze hepatic ATG7 mRNA and ATG7 protein expression regarding obesity-associated NAFLD. Patients included women classified into normal weight (NW, n = 6) and morbid obesity (MO, n = 72). The second group was subclassified into normal liver (NL, n = 11), simple steatosis (SS, n= 29), and nonalcoholic steatohepatitis (NASH, n = 32). mRNA expression was analyzed by RT-qPCR and protein expression was evaluated by Western blotting. Our results showed that NASH patients presented higher ATG7 mRNA and ATG7 protein levels. ATG7 mRNA expression was increased in NASH compared with SS, while ATG7 protein abundance was enhanced in NASH compared with NL. ATG7 mRNA correlated negatively with the expression of some hepatic lipid metabolism-related genes and positively with endocannabinoid receptors, adiponectin hepatic expression, and omentin levels. These results suggest that ATG7-mediated autophagy may play an important role in the pathogenesis of NAFLD, especially in NASH, perhaps playing a possible protective role. However, this is a preliminary study that needs to be further studied.
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Affiliation(s)
- Andrea Barrientos-Riosalido
- Grup de Recerca GEMMAIR (AGAUR)-Medicina Aplicada (URV), Departament de Medicina i Cirurgia, Universitat Rovira i Virgili (URV), Institut d’Investigació Sanitària Pere Virgili (IISPV), 43007 Tarragona, Spain
| | - Monica Real
- Servei Medicina Interna, Hospital Universitari Joan XXIII Tarragona, Mallafré Guasch, 4, 43007 Tarragona, Spain
| | - Laia Bertran
- Grup de Recerca GEMMAIR (AGAUR)-Medicina Aplicada (URV), Departament de Medicina i Cirurgia, Universitat Rovira i Virgili (URV), Institut d’Investigació Sanitària Pere Virgili (IISPV), 43007 Tarragona, Spain
| | - Carmen Aguilar
- Grup de Recerca GEMMAIR (AGAUR)-Medicina Aplicada (URV), Departament de Medicina i Cirurgia, Universitat Rovira i Virgili (URV), Institut d’Investigació Sanitària Pere Virgili (IISPV), 43007 Tarragona, Spain
| | - Salomé Martínez
- Servei Anatomia Patològica, Hospital Universitari Joan XXIII Tarragona, Mallafré Guasch, 4, 43007 Tarragona, Spain
| | - David Parada
- Servei Anatomia Patològica, Hospital Universitari Sant Joan de Reus, Avinguda Doctor Josep Laporte, 2, 43204 Reus, Spain
| | - Margarita Vives
- Servei de Cirurgia, Hospital Sant Joan de Reus, Departament de Medicina i Cirurgia, URV, IISPV, Avinguda Doctor Josep Laporte, 2, 43204 Reus, Spain
| | - Fàtima Sabench
- Servei de Cirurgia, Hospital Sant Joan de Reus, Departament de Medicina i Cirurgia, URV, IISPV, Avinguda Doctor Josep Laporte, 2, 43204 Reus, Spain
| | - David Riesco
- Servei Medicina Interna, Hospital Universitari Joan XXIII Tarragona, Mallafré Guasch, 4, 43007 Tarragona, Spain
| | - Daniel Del Castillo
- Servei de Cirurgia, Hospital Sant Joan de Reus, Departament de Medicina i Cirurgia, URV, IISPV, Avinguda Doctor Josep Laporte, 2, 43204 Reus, Spain
| | - Cristóbal Richart
- Grup de Recerca GEMMAIR (AGAUR)-Medicina Aplicada (URV), Departament de Medicina i Cirurgia, Universitat Rovira i Virgili (URV), Institut d’Investigació Sanitària Pere Virgili (IISPV), 43007 Tarragona, Spain
| | - Teresa Auguet
- Grup de Recerca GEMMAIR (AGAUR)-Medicina Aplicada (URV), Departament de Medicina i Cirurgia, Universitat Rovira i Virgili (URV), Institut d’Investigació Sanitària Pere Virgili (IISPV), 43007 Tarragona, Spain
- Servei Medicina Interna, Hospital Universitari Joan XXIII Tarragona, Mallafré Guasch, 4, 43007 Tarragona, Spain
- Correspondence: ; Tel.: +34-977-29-58-33
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Fu R, Jiang X, Yang Y, Wang C, Zhang Y, Zhu Y, Zhang H. Bidirectional regulation of structural damage on autophagy in the C. elegans epidermis. Autophagy 2022; 18:2731-2745. [PMID: 35311461 PMCID: PMC9629849 DOI: 10.1080/15548627.2022.2047345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 02/21/2022] [Accepted: 02/23/2022] [Indexed: 12/15/2022] Open
Abstract
A variety of disturbances such as starvation, organelle damage, heat stress, hypoxia and pathogen infection can influence the autophagic process. However, how the macroautophagy/autophagy machinery is regulated intrinsically by structural damage of the cell remains largely unknown. In this work, we utilized the C. elegans epidermis as the model to address this question. Our results showed that structural damage by mechanical wounding exerted proximal inhibitory effect and distant promotional effect on autophagy within the same epidermal cell. By disrupting individual mechanical supporting structures, we found that only damage of the basal extracellular matrix or the underlying muscle cells activated a distinct autophagic response in the epidermis. On the contrary, structural disruption of the epidermal cells at the apical side inhibited autophagy activation caused by different stress factors. Mechanistic studies showed that the basal promotional effect of structural damage on epidermal autophagy was mediated by a mechanotransduction pathway going through the basal hemidesmosome receptor and LET-363/MTOR, while the apical inhibitory effect was mostly carried out by activation of calcium signaling. Elevated autophagy in the epidermis played a detrimental rather than a beneficial role on cell survival against structural damage. The results obtained from these studies will not only help us better understand the pathogenesis of structural damage- and autophagy-related diseases, but also provide insight into more generic rules of autophagy regulation by the structural and mechanical properties of cells across species.Abbreviations : ATG: autophagy related; BLI-1: BLIstered cuticle 1; CeHDs: C. elegans hemidesmosomes; COL-19: COLlagen 19; DPY-7: DumPY 7; ECM: extracellular matrix; EPG-5: ectopic PGL granules 5; GFP: green fluorescent protein; GIT-1: GIT1 (mammalian G protein-coupled receptor kinase InTeractor 1) homolog; GTL-2: Gon-Two Like 2 (TRP subfamily); HIS-58, HIStone 58; IFB-1: Intermediate Filament, B 1; LET: LEThal; LGG-1: LC3, GABARAP and GATE-16 family 1; MTOR: mechanistic target of rapamycin; MTORC1: MTOR complex 1; MUP-4: MUscle Positioning 4; NLP-29: Neuropeptide-Like Protein 29; PAT: Paralyzed Arrest at Two-fold; PIX-1: PIX (PAK (p21-activated kinase) Interacting eXchange factor) homolog 1; RFP: red fluorescent protein; RNAi: RNA interference; SQST-1: SeQueSTosome related 1; UNC: UNCoordinated; UV: ultraviolet; VAB-10: variable ABnormal morphology 10; WT: wild type.
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Affiliation(s)
- Rong Fu
- Jiangsu Key Laboratory of Infection and Immunity, Institute of Biology and Medical Sciences, Soochow University, Suzhou, China
| | - Xiaowan Jiang
- Jiangsu Key Laboratory of Infection and Immunity, Institute of Biology and Medical Sciences, Soochow University, Suzhou, China
| | - Yuyan Yang
- Jiangsu Key Laboratory of Infection and Immunity, Institute of Biology and Medical Sciences, Soochow University, Suzhou, China
| | - Chunxia Wang
- Jiangsu Key Laboratory of Infection and Immunity, Institute of Biology and Medical Sciences, Soochow University, Suzhou, China
| | - Yun Zhang
- Jiangsu Key Laboratory of Infection and Immunity, Institute of Biology and Medical Sciences, Soochow University, Suzhou, China
| | - Yi Zhu
- Jiangsu Key Laboratory of Infection and Immunity, Institute of Biology and Medical Sciences, Soochow University, Suzhou, China
| | - Huimin Zhang
- Jiangsu Key Laboratory of Infection and Immunity, Institute of Biology and Medical Sciences, Soochow University, Suzhou, China
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Autophagy in Hematological Malignancies. Cancers (Basel) 2022; 14:cancers14205072. [PMID: 36291856 PMCID: PMC9600546 DOI: 10.3390/cancers14205072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Revised: 10/10/2022] [Accepted: 10/13/2022] [Indexed: 11/29/2022] Open
Abstract
Simple Summary Autophagy is a dynamic and tightly regulated process that seems to have dual effects in cancer. In some contexts, it can induce carcinogenesis and promote cancer cell survival, whereas in others, it acts preventing tumor cell growth and tumor progression. Thus, autophagy functions seem to strictly depend on cancer ontogenesis, progression, and type. Here, we will dive into the current knowledge of autophagy in hematological malignancies and will highlight the main genetic components involved in each cancer type. Abstract Autophagy is a highly conserved metabolic pathway via which unwanted intracellular materials, such as unfolded proteins or damaged organelles, are digested. It is activated in response to conditions of oxidative stress or starvation, and is essential for the maintenance of cellular homeostasis and other vital functions, such as differentiation, cell death, and the cell cycle. Therefore, autophagy plays an important role in the initiation and progression of tumors, including hematological malignancies, where damaged autophagy during hematopoiesis can cause malignant transformation and increase cell proliferation. Over the last decade, the importance of autophagy in response to standard pharmacological treatment of hematological tumors has been observed, revealing completely opposite roles depending on the tumor type and stage. Thus, autophagy can promote tumor survival by attenuating the cellular damage caused by drugs and/or stabilizing oncogenic proteins, but can also have an antitumoral effect due to autophagic cell death. Therefore, autophagy-based strategies must depend on the context to create specific and safe combination therapies that could contribute to improved clinical outcomes. In this review, we describe the process of autophagy and its role on hematopoiesis, and we highlight recent research investigating its role as a potential therapeutic target in hematological malignancies. The findings suggest that genetic variants within autophagy-related genes modulate the risk of developing hemopathies, as well as patient survival.
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Morishita H, Komatsu M. Role of autophagy in liver diseases. CURRENT OPINION IN PHYSIOLOGY 2022. [DOI: 10.1016/j.cophys.2022.100594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Takanezawa Y, Harada R, Shibagaki Y, Kashiwano Y, Nakamura R, Ohshiro Y, Uraguchi S, Kiyono M. Protective function of the SQSTM1/p62-NEDD4 complex against methylmercury toxicity. Biochem Biophys Res Commun 2022; 609:134-140. [PMID: 35452957 DOI: 10.1016/j.bbrc.2022.04.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 04/06/2022] [Indexed: 11/02/2022]
Abstract
SQSTM1/p62, hereinafter referred to as p62, is a stress-induced cellular protein that interacts with various signaling proteins as well as ubiquitinated proteins to regulate a variety of cellular functions and cell survival. Methylmercury (MeHg) exposure increases the levels of p62, the latter playing a protective role in MeHg-induced toxicity. However, the underlying mechanism by which p62 alleviates MeHg toxicity remains poorly understood. Herein, we report the interaction of p62 with neural precursor cell expressed developmentally down-regulated protein 4 (NEDD4), a HECT E3 ubiquitin ligase. The region of p62 where NEDD4 binds is located at the proline- and arginine (PR)-rich region (amino acids: 102-119), C-terminal extension of the Phox and Bem1 (PB1) domain. To evaluate the importance of the p62-NEDD4 complex, we examined the compensation of deletion mutant (GFP-Δ102-119 p62) for the lack of endogenous p62 in MEFs. GFP-p62/p62KO cells exhibited significantly higher cell viability than GFP-Δ102-119 p62/p62KO cells after treatment with MeHg. Our findings suggest novel mechanisms to alleviate MeHg toxicity through p62-NEDD4 complex formation.
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Affiliation(s)
- Yasukazu Takanezawa
- Department of Public Health, School of Pharmacy, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641, Japan.
| | - Ryohei Harada
- Department of Public Health, School of Pharmacy, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641, Japan
| | - Yoshio Shibagaki
- Division of Biochemistry, School of Pharmacy, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641, Japan
| | - Yui Kashiwano
- Department of Public Health, School of Pharmacy, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641, Japan
| | - Ryosuke Nakamura
- Department of Public Health, School of Pharmacy, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641, Japan
| | - Yuka Ohshiro
- Department of Public Health, School of Pharmacy, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641, Japan
| | - Shimpei Uraguchi
- Department of Public Health, School of Pharmacy, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641, Japan
| | - Masako Kiyono
- Department of Public Health, School of Pharmacy, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641, Japan
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In vitro ballooned hepatocytes can be produced by primary human hepatocytes and hepatic stellate cell sheets. Sci Rep 2022; 12:5341. [PMID: 35351975 PMCID: PMC8964766 DOI: 10.1038/s41598-022-09428-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 03/17/2022] [Indexed: 11/17/2022] Open
Abstract
Despite the increasing prevalence of Nonalcoholic steatohepatitis (NASH) worldwide, there is no effective treatment available for this disease. “Ballooned hepatocyte” is a characteristic finding in NASH and is correlated with disease prognosis, but their mechanisms of action are poorly understood; furthermore, neither animal nor in vitro models of NASH have been able to adequately represent ballooned hepatocytes. Herein, we engineered cell sheets to develop a new in vitro model of ballooned hepatocytes. Primary human hepatocytes (PHH) and Hepatic stellate cells (HSC) were co-cultured to produce cell sheets, which were cultured in glucose and lipid containing medium, following which histological and functional analyses were performed. Histological findings showed hepatocyte ballooning, accumulation of fat droplets, abnormal cytokeratin arrangement, and the presence of Mallory–Denk bodies and abnormal organelles. These findings are similar to those of ballooned hepatocytes in human NASH. Functional analysis showed elevated levels of TGFβ-1, SHH, and p62, but not TNF-α, IL-8. Exposure of PHH/HSC sheets to a glucolipotoxicity environment induces ballooned hepatocyte without inflammation. Moreover, fibrosis is an important mechanism underlying ballooned hepatocytes and could be the basis for the development of a new in vitro NASH model with ballooned hepatocytes.
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Xia F, Fu Y, Xie H, Chen Y, Fang D, Zhang W, Liu P, Li M. Suppression of ATG4B by copper inhibits autophagy and involves in Mallory body formation. Redox Biol 2022; 52:102284. [PMID: 35349929 PMCID: PMC8965161 DOI: 10.1016/j.redox.2022.102284] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 03/01/2022] [Accepted: 03/10/2022] [Indexed: 12/19/2022] Open
Abstract
Autophagy is an evolutionarily conserved self-protecting mechanism implicated in cellular homeostasis. ATG4B plays a vital role in autophagy process via undertaking priming and delipidation of LC3. Chemical inhibitors and regulative modifications such as oxidation of ATG4B have been demonstrated to modulate autophagy function. Whether and how ATG4B could be regulated by metal ions is largely unknown. Copper is an essential trace metal served as static co-factors in redox reactions in physiology process. Excessive accumulation of copper in ATP7B mutant cells leads to pathology progression such as insoluble Mallory body (MB) in Wilson disease (WD). The clearance of MB via autophagy pathway was thought as a promising strategy for WD. Here, we discovered that copper ion instead of other ions could inhibit the activity of ATG4B followed by autophagy suppression. In addition, copper could induce ATG4B oligomers depending on cysteine oxidation which could be abolished in reduced condition. Copper also promotes the formation of insoluble ATG4B aggregates, as well as p62-and ubiquitin-positive aggregates, which is consistent with the components of MB caused by copper overload in WD cell model. Importantly, overexpression of ATG4B could partially reduce the formation of MB and rescue impaired autophagy. Taken together, our results uncovered for the first time a new damage mechanism mediated by copper and implied new insights of the crosstalk between the toxicity of copper and autophagy in the pathogenesis of WD.
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Affiliation(s)
- Fan Xia
- School of Pharmaceutical Sciences, Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, National and Local Joint Engineering Laboratory of Druggability and New Drugs Evaluation, Guangdong Engineering Laboratory of Druggability and New Drugs Evaluation, Sun Yat-Sen University, Guangzhou, 510006, China
| | - Yuanyuan Fu
- School of Pharmaceutical Sciences, Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, National and Local Joint Engineering Laboratory of Druggability and New Drugs Evaluation, Guangdong Engineering Laboratory of Druggability and New Drugs Evaluation, Sun Yat-Sen University, Guangzhou, 510006, China
| | - Huazhong Xie
- School of Pharmaceutical Sciences, Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, National and Local Joint Engineering Laboratory of Druggability and New Drugs Evaluation, Guangdong Engineering Laboratory of Druggability and New Drugs Evaluation, Sun Yat-Sen University, Guangzhou, 510006, China
| | - Yuxin Chen
- School of Pharmaceutical Sciences, Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, National and Local Joint Engineering Laboratory of Druggability and New Drugs Evaluation, Guangdong Engineering Laboratory of Druggability and New Drugs Evaluation, Sun Yat-Sen University, Guangzhou, 510006, China
| | - Dongmei Fang
- School of Pharmaceutical Sciences, Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, National and Local Joint Engineering Laboratory of Druggability and New Drugs Evaluation, Guangdong Engineering Laboratory of Druggability and New Drugs Evaluation, Sun Yat-Sen University, Guangzhou, 510006, China
| | - Wei Zhang
- Laboratory Animal Center, Sun Yat-Sen University, Guangzhou, 510006, China
| | - Peiqing Liu
- School of Pharmaceutical Sciences, Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, National and Local Joint Engineering Laboratory of Druggability and New Drugs Evaluation, Guangdong Engineering Laboratory of Druggability and New Drugs Evaluation, Sun Yat-Sen University, Guangzhou, 510006, China
| | - Min Li
- School of Pharmaceutical Sciences, Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, National and Local Joint Engineering Laboratory of Druggability and New Drugs Evaluation, Guangdong Engineering Laboratory of Druggability and New Drugs Evaluation, Sun Yat-Sen University, Guangzhou, 510006, China.
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11
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Son S, Baek A, Lee JH, Kim DE. Autophagosome-lysosome fusion is facilitated by plectin-stabilized actin and keratin 8 during macroautophagic process. Cell Mol Life Sci 2022; 79:95. [PMID: 35080691 PMCID: PMC11072119 DOI: 10.1007/s00018-022-04144-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 12/22/2021] [Accepted: 01/10/2022] [Indexed: 12/19/2022]
Abstract
Autophagy is a lysosome-mediated degradative process that removes damaged proteins and organelles, during which autophagosome-lysosome fusion is a key step of the autophagic flux. Based on our observation that intermediate cytofilament keratin 8 (KRT8) enhances autophagic clearance in cells under oxidative stress condition, we investigated whether KRT8 supports the cytoplasmic architectural networks to facilitate the vesicular fusion entailing trafficking onto filamentous tracks. We found that KRT8 interacts with actin filaments via the cytolinker, plectin (PLEC) during trafficking of autophagosome. When PLEC was knocked down or KRT8 structure was collapsed by phosphorylation, autophagosome-lysosome fusion was attenuated. Inhibition of actin polymerization resulted in accumulation of autophagosomes owing to a decrease in autophagosome and lysosome fusion. Furthermore, myosin motor protein was found to be responsible for vesicular trafficking along the actin filaments to entail autolysosome formation. Thus, the autophagosome-lysosome fusion is aided by PLEC-stabilized actin filaments as well as intermediate cytofilament KRT8 that supports the structural integrity of actin filaments during macroautophagic process under oxidative stress condition.
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Affiliation(s)
- Sumin Son
- Department of Bioscience and Biotechnology, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, 05029, Republic of Korea
| | - Ahruem Baek
- Safety Measurement Institute, Korea Research Institute of Standards and Science, 267 Gajeong-Ro, Yuseong-Gu, Daejeon, 34113, Republic of Korea
| | - Jong Hun Lee
- Department of Food Science and Biotechnology, College of BioNano Technology, Gachon University, Seongnam, 13120, Republic of Korea
| | - Dong-Eun Kim
- Department of Bioscience and Biotechnology, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, 05029, Republic of Korea.
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12
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Waite KA, Burris A, Vontz G, Lang A, Roelofs J. Proteaphagy is specifically regulated and requires factors dispensable for general autophagy. J Biol Chem 2022; 298:101494. [PMID: 34919962 PMCID: PMC8732087 DOI: 10.1016/j.jbc.2021.101494] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 12/07/2021] [Indexed: 12/27/2022] Open
Abstract
Changing physiological conditions can increase the need for protein degradative capacity in eukaryotic cells. Both the ubiquitin-proteasome system and autophagy contribute to protein degradation. However, these processes can be differently regulated depending on the physiological conditions. Strikingly, proteasomes themselves can be a substrate for autophagy. The signals and molecular mechanisms that govern proteasome autophagy (proteaphagy) are only partly understood. Here, we used immunoblots, native gel analyses, and fluorescent microscopy to understand the regulation of proteaphagy in response to genetic and small molecule-induced perturbations. Our data indicate that chemical inhibition of the master nutrient sensor TORC1 (inhibition of which induces general autophagy) with rapamycin induces a bi-phasic response where proteasome levels are upregulated after an autophagy-dependent reduction. Surprisingly, several conditions that result in inhibited TORC1, such as caffeinine treatment or nitrogen starvation, only induced proteaphagy (i.e., without any proteasome upregulation), suggesting a convergence of signals upstream of proteaphagy under different physiological conditions. Indeed, we found that several conditions that activated general autophagy did not induce proteaphagy, further distinguishing proteaphagy from general autophagy. Consistent with this, we show that Atg11, a selective autophagy receptor, as well as the MAP kinases Mpk1, Mkk1, and Mkk2 all play a role in autophagy of proteasomes, although they are dispensable for general autophagy. Taken together, our data provide new insights into the molecular regulation of proteaphagy by demonstrating that degradation of proteasome complexes is specifically regulated under different autophagy-inducing conditions.
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Affiliation(s)
- Kenrick A Waite
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Alicia Burris
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, Kansas, USA; Molecular, Cellular, and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, Kansas, USA; Biology & Environmental Health, Missouri Southern State University, Joplin, Missouri, USA
| | - Gabrielle Vontz
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Angelica Lang
- Molecular, Cellular, and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, Kansas, USA
| | - Jeroen Roelofs
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, Kansas, USA.
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13
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Yang SC. A New Perspective on Fish Oil: The Prevention of Alcoholic Liver Disease. J Oleo Sci 2021; 70:1531-1538. [PMID: 34732632 DOI: 10.5650/jos.ess21216] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The mechanisms of alcoholic liver diseases (ALD) are very complex and interrelated, including abnormal lipid metabolism, oxidative stress, and gut-derived endotoxin pathway. On the other hand, fish oil is rich in n-3 polyunsaturated fatty acids (PUFAs), such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which decrease blood triglyceride concentration in hypertriglycemia patients and show protective effects against fatty liver. However, there is limited evidence from studies of the relationship between fish oil and ALD based on the viewpoint of the intestinal integrity and microflora. Therefore, this review discusses the mechanism of amelioration for ALD by fish oil. Based on our previous studies, partial replacement of olive oil by fish oil in alcohol-containing liquid diet ameliorated the liver damage including fatty liver and inflammation in rats. Based on these results, the mechanisms of hepatoprotective effects due to fish oil substitution were discussed in three parts, such as regulating lipid metabolism, decreasing oxidative stress and maintaining intestinal health. First of all, we found that fish oil substitution increased plasma adiponectin levels, and then increasing MCAD and CPT-1 mRNA levels to accelerate fatty acid oxidation in liver, then further prevent ethanol-induced hepatosteatosis in rats with chronic alcohol-feeding. Fish oil replacement also enhanced hepatic autophagy flux, which enhanced lipid degradation, then inhibited lipid accumulation in liver. Secondly, the appreciable proportion of fish oil decreased lipid peroxidation by reducing the protein expression of cytochrome p450 2E1 in chronic alcohol-feeding rats. We also speculated that the appropriate proportion of n-6 and n-3 PUFAs is very important for preventing alcoholic liver disease. At last, substituting fish oil for olive oil normalized the intestinal permeability and fecal microbiota composition, thus providing a low plasma endotoxin level and inflammatory responses, which exert ameliorative effects on ethanol-induced liver injuries in rats.
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Affiliation(s)
- Suh-Ching Yang
- School of Nutrition and Health Sciences, Taipei Medical University.,Research Center of Geriatric Nutrition, College of Nutrition, Taipei Medical University.,Graduate Institute of Metabolism and Obesity Sciences, Taipei Medical University.,School of Gerontology Health Management, College of Nursing, Taipei Medical University.,Nutrition Research Center, Taipei Medical University Hospital
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14
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Involvement of Autophagy in Ageing and Chronic Cholestatic Diseases. Cells 2021; 10:cells10102772. [PMID: 34685751 PMCID: PMC8534511 DOI: 10.3390/cells10102772] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 10/05/2021] [Accepted: 10/13/2021] [Indexed: 01/18/2023] Open
Abstract
Autophagy is a “housekeeping” lysosomal degradation process involved in numerous physiological and pathological processes in all eukaryotic cells. The dysregulation of hepatic autophagy has been described in several conditions, from obesity to diabetes and cholestatic disease. We review the role of autophagy, focusing on age-related cholestatic diseases, and discuss its therapeutic potential and the molecular targets identified to date. The accumulation of toxic BAs is the main cause of cell damage in cholestasis patients. BAs and their receptor, FXR, have been implicated in the regulation of hepatic autophagy. The mechanisms by which cholestasis induces liver damage include mitochondrial dysfunction, oxidative stress and ER stress, which lead to cell death and ultimately to liver fibrosis as a compensatory mechanism to reduce the damage. The stimulation of autophagy seems to ameliorate the liver damage. Autophagic activity decreases with age in several species, whereas its basic extends lifespan in animals, suggesting that it is one of the convergent mechanisms of several longevity pathways. No strategies aimed at inducing autophagy have yet been tested in cholestasis patients. However, its stimulation can be viewed as a novel therapeutic strategy that may reduce ageing-dependent liver deterioration and also mitigate hepatic steatosis.
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15
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Ma M, Xie W, Li X. Identification of Autophagy-Related Genes in the Progression from Non-Alcoholic Fatty Liver to Non-Alcoholic Steatohepatitis. Int J Gen Med 2021; 14:3163-3176. [PMID: 34262330 PMCID: PMC8275104 DOI: 10.2147/ijgm.s317785] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 06/18/2021] [Indexed: 12/30/2022] Open
Abstract
Background Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide. Autophagy plays a vital role in NAFLD development and progression. We aimed to establish a novel autophagy-related gene (ARG) signature as a therapeutic target in NAFLD patients based on high-throughput sequencing data. Methods ARGs obtained from the HAMdb and high-sequencing data obtained from the Gene Expression Omnibus (GEO) database were analyzed to identify differentially expressed ARGs (DEARGs) between normal and NASH tissues. Then, gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were performed to explore potential biological and pathological functions of DEARGs. The protein-protein interaction (PPI) network of the DEARGs was established through the STRING website, and visualized by Cytoscape. In addition, hub genes were validated by an independent dataset GSE89632. Finally, we performed Gene Set Variation Analysis (GSVA) pathway-related analysis to identify the pivotal signaling pathways and genes for the progression of non-alcoholic fatty liver (NAFL) to non-alcoholic steatohepatitis (NASH). Results A total of 76 DEARGs were identified in the GSE126848 dataset, of which 45 genes were upregulated and 31 genes were downregulated. GO analysis showed that the biological functions of DEARGs focused primarily on autophagy, cellular response to external stimulus, fibroblast proliferation, late endosome, and ubiquitin protein ligase binding. KEGG pathway analysis showed that these DEARGs were mainly involved in the apoptosis, PI3K-Akt signaling pathway, and estrogen signaling pathway. Among DEGs, 9 most closely related genes were identified from the PPI network. Furthermore, NOS3, IGF1, VAMP8, FOS, and HMOX1 were verified in the GSE89632 dataset. At last, the MAPK signal pathway was identified as important pathway, and JUN was identified as a key gene involved in the progression from NAFL to NASH. Conclusion This study may provide credible molecular biomarkers in terms of screening and diagnosis for NAFLD. Meanwhile, it also serves as a basis for exploring the molecular mechanisms underlying the progression of NAFL to NASH.
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Affiliation(s)
- Mengyao Ma
- Department of Laboratory Medicine, Biology Science Institutes, Chongqing Medical University, Chongqing, 400032, People's Republic of China
| | - Wenhua Xie
- Department of Laboratory Medicine, Biology Science Institutes, Chongqing Medical University, Chongqing, 400032, People's Republic of China
| | - Xi Li
- Department of Laboratory Medicine, Biology Science Institutes, Chongqing Medical University, Chongqing, 400032, People's Republic of China
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16
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Biglycan: A regulator of hepatorenal inflammation and autophagy. Matrix Biol 2021; 100-101:150-161. [DOI: 10.1016/j.matbio.2021.06.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 06/03/2021] [Accepted: 06/04/2021] [Indexed: 02/07/2023]
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17
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Niture S, Lin M, Rios-Colon L, Qi Q, Moore JT, Kumar D. Emerging Roles of Impaired Autophagy in Fatty Liver Disease and Hepatocellular Carcinoma. Int J Hepatol 2021; 2021:6675762. [PMID: 33976943 PMCID: PMC8083829 DOI: 10.1155/2021/6675762] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 03/16/2021] [Accepted: 04/06/2021] [Indexed: 02/07/2023] Open
Abstract
Autophagy is a conserved catabolic process that eliminates dysfunctional cytosolic biomolecules through vacuole-mediated sequestration and lysosomal degradation. Although the molecular mechanisms that regulate autophagy are not fully understood, recent work indicates that dysfunctional/impaired autophagic functions are associated with the development and progression of nonalcoholic fatty liver disease (NAFLD), alcoholic fatty liver disease (AFLD), and hepatocellular carcinoma (HCC). Autophagy prevents NAFLD and AFLD progression through enhanced lipid catabolism and decreasing hepatic steatosis, which is characterized by the accumulation of triglycerides and increased inflammation. However, as both diseases progress, autophagy can become impaired leading to exacerbation of both pathological conditions and progression into HCC. Due to the significance of impaired autophagy in these diseases, there is increased interest in studying pathways and targets involved in maintaining efficient autophagic functions as potential therapeutic targets. In this review, we summarize how impaired autophagy affects liver function and contributes to NAFLD, AFLD, and HCC progression. We will also explore how recent discoveries could provide novel therapeutic opportunities to effectively treat these diseases.
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Affiliation(s)
- Suryakant Niture
- Julius L. Chambers Biomedical Biotechnology Research Institute, North Carolina Central University Durham, NC 27707, USA
| | - Minghui Lin
- The Fourth People's Hospital of Ningxia Hui Autonomous Region, Yinchuan, China 750021
| | - Leslimar Rios-Colon
- Julius L. Chambers Biomedical Biotechnology Research Institute, North Carolina Central University Durham, NC 27707, USA
| | - Qi Qi
- Julius L. Chambers Biomedical Biotechnology Research Institute, North Carolina Central University Durham, NC 27707, USA
| | - John T. Moore
- Julius L. Chambers Biomedical Biotechnology Research Institute, North Carolina Central University Durham, NC 27707, USA
| | - Deepak Kumar
- Julius L. Chambers Biomedical Biotechnology Research Institute, North Carolina Central University Durham, NC 27707, USA
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18
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Kouroumalis E, Voumvouraki A, Augoustaki A, Samonakis DN. Autophagy in liver diseases. World J Hepatol 2021; 13:6-65. [PMID: 33584986 PMCID: PMC7856864 DOI: 10.4254/wjh.v13.i1.6] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 12/10/2020] [Accepted: 12/26/2020] [Indexed: 02/06/2023] Open
Abstract
Autophagy is the liver cell energy recycling system regulating a variety of homeostatic mechanisms. Damaged organelles, lipids and proteins are degraded in the lysosomes and their elements are re-used by the cell. Investigations on autophagy have led to the award of two Nobel Prizes and a health of important reports. In this review we describe the fundamental functions of autophagy in the liver including new data on the regulation of autophagy. Moreover we emphasize the fact that autophagy acts like a two edge sword in many occasions with the most prominent paradigm being its involvement in the initiation and progress of hepatocellular carcinoma. We also focused to the implication of autophagy and its specialized forms of lipophagy and mitophagy in the pathogenesis of various liver diseases. We analyzed autophagy not only in well studied diseases, like alcoholic and nonalcoholic fatty liver and liver fibrosis but also in viral hepatitis, biliary diseases, autoimmune hepatitis and rare diseases including inherited metabolic diseases and also acetaminophene hepatotoxicity. We also stressed the different consequences that activation or impairment of autophagy may have in hepatocytes as opposed to Kupffer cells, sinusoidal endothelial cells or hepatic stellate cells. Finally, we analyzed the limited clinical data compared to the extensive experimental evidence and the possible future therapeutic interventions based on autophagy manipulation.
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Affiliation(s)
- Elias Kouroumalis
- Liver Research Laboratory, University of Crete Medical School, Heraklion 71110, Greece
| | - Argryro Voumvouraki
- 1 Department of Internal Medicine, AHEPA University Hospital, Thessaloniki 54636, Greece
| | - Aikaterini Augoustaki
- Department of Gastroenterology and Hepatology, University Hospital of Crete, Heraklion 71110, Greece
| | - Dimitrios N Samonakis
- Department of Gastroenterology and Hepatology, University Hospital of Crete, Heraklion 71110, Greece.
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19
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Honma Y, Miyagawa K, Hara Y, Hayashi T, Kusanaga M, Ogino N, Minami S, Oe S, Ikeda M, Hino K, Harada M. Correlation of hepatitis C virus-mediated endoplasmic reticulum stress with autophagic flux impairment and hepatocarcinogenesis. Med Mol Morphol 2021; 54:108-121. [PMID: 33386512 DOI: 10.1007/s00795-020-00271-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 11/13/2020] [Indexed: 12/29/2022]
Abstract
Hepatitis C virus (HCV) infection has been known to use autophagy for its replication. However, the mechanisms by which HCV modulates autophagy remain controversial. We used HCV-Japanese fulminant hepatitis-1-infected Huh7 cells. HCV infection induced the accumulation of autophagosomes. Morphological analyses of monomeric red fluorescent protein (mRFP)-green fluorescent protein (GFP) tandem fluorescent-tagged LC3 transfection showed HCV infection impaired autophagic flux. Autophagosome-lysosome fusion assessed by transfection of mRFP- or GFP-LC3 and immunostaining of lysosomal-associated membrane protein 1 was inhibited by HCV infection. Decrease of HCV-induced endoplasmic reticulum (ER) stress by 4-phenylbutyric acid, a chemical chaperone, improved the HCV-mediated autophagic flux impairment. HCV infection-induced oxidative stress and subsequently DNA damage, but not apoptosis. Furthermore, HCV induced cytoprotective effects against the cellular stress by facilitating the formation of cytoplasmic inclusion bodies as shown by p62 expression and by modulating keratin protein expression and activated nuclear factor erythroid 2-related factor 2. HCV eradication by direct-acting antivirals improved autophagic flux, but DNA damage persisted. In conclusion, HCV-induced ER stress correlates with autophagic flux impairment. Decrease of ER stress is considered to be a promising therapeutic strategy for HCV-related chronic liver diseases. However, we should be aware that the risk of hepatocarcinogenesis remains even after HCV eradication.
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Affiliation(s)
- Yuichi Honma
- Third Department of Internal Medicine, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, 807-8555, Japan.
| | - Koichiro Miyagawa
- Third Department of Internal Medicine, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, 807-8555, Japan
| | - Yuichi Hara
- Department of Hepatology and Pancreatology, Kawasaki Medical School, Kurashiki, Japan
| | - Tsuguru Hayashi
- Third Department of Internal Medicine, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, 807-8555, Japan
| | - Masashi Kusanaga
- Third Department of Internal Medicine, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, 807-8555, Japan
| | - Noriyoshi Ogino
- Third Department of Internal Medicine, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, 807-8555, Japan
| | - Sota Minami
- Third Department of Internal Medicine, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, 807-8555, Japan
| | - Shinji Oe
- Third Department of Internal Medicine, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, 807-8555, Japan
| | - Masanori Ikeda
- Department of Persistent and Oncogenic Viruses, Center for Chronic Viral Diseases, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Keisuke Hino
- Department of Hepatology and Pancreatology, Kawasaki Medical School, Kurashiki, Japan
| | - Masaru Harada
- Third Department of Internal Medicine, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, 807-8555, Japan.
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Panzitt K, Fickert P, Wagner M. Regulation of autophagy by bile acids and in cholestasis - CholestoPHAGY or CholeSTOPagy. Biochim Biophys Acta Mol Basis Dis 2020; 1867:166017. [PMID: 33242590 DOI: 10.1016/j.bbadis.2020.166017] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 10/13/2020] [Accepted: 11/17/2020] [Indexed: 12/15/2022]
Abstract
Autophagy is a lysosomal degradation pathway in which the cell self-digests its own components to provide nutrients in harsh environmental conditions. It also represents an opportunity to rid the cell of superfluous and damaged organelles, misfolded proteins or invaded microorganisms. Liver autophagy contributes to basic hepatic functions such as lipid, glycogen and protein turnover. Deregulated hepatic autophagy has been linked to many liver diseases including alpha-1-antitrypsin deficiency, alcoholic and non-alcoholic fatty liver diseases, hepatitis B and C infections, liver fibrosis as well as liver cancer. Recently, bile acids and the bile acid receptor FXR have been implicated in the regulation of hepatic autophagy, which implies a role of autophagy also for cholestatic liver diseases. This review summarizes the current evidence of bile acid mediated effects on autophagy and how this affects cholestatic liver diseases. Although detailed studies are lacking, we suggest a concept that the activity of autophagy in cholestasis depends on the disease stage, where autophagy may be induced at early stages ("cholestophagy") but may be impaired in prolonged cholestatic states ("cholestopagy").
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Affiliation(s)
- Katrin Panzitt
- Research Unit for Translational Nuclear Receptor Research, Division of Gastroenterology and Hepatology, Medical University of Graz, Graz, Austria
| | - Peter Fickert
- Laboratory of Experimental and Molecular Hepatology, Division of Gastroenterology and Hepatology, Medical University of Graz, Graz, Austria
| | - Martin Wagner
- Research Unit for Translational Nuclear Receptor Research, Division of Gastroenterology and Hepatology, Medical University of Graz, Graz, Austria.
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Park HS, Song JW, Park JH, Lim BK, Moon OS, Son HY, Lee JH, Gao B, Won YS, Kwon HJ. TXNIP/VDUP1 attenuates steatohepatitis via autophagy and fatty acid oxidation. Autophagy 2020; 17:2549-2564. [PMID: 33190588 DOI: 10.1080/15548627.2020.1834711] [Citation(s) in RCA: 85] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Impaired macroautophagy/autophagy has been implicated in experimental and human nonalcoholic steatohepatitis (NASH). However, the mechanism underlying autophagy dysregulation in NASH is largely unknown. Here, we investigated the role and mechanism of TXNIP/VDUP1 (thioredoxin interacting protein), a key mediator of cellular stress responses, in the pathogenesis of NASH. Hepatic TXNIP expression was upregulated in nonalcoholic fatty liver disease (NAFLD) patients and in methionine choline-deficient (MCD) diet-fed mice, as well as in palmitic acid (PA)-treated hepatocytes. Upregulation of hepatic TXNIP was positively correlated with impaired autophagy, as evidenced by a decreased number of MAP1LC3B/LC3B (microtubule-associated protein 1 light chain 3 beta) puncta and increased SQSTM1/p62 (sequestosome 1) expression. Deletion of the Txnip gene enhanced hepatic steatosis, inflammation, and fibrosis, accompanied by impaired autophagy and fatty acid oxidation (FAO) in MCD diet-fed mice. Mechanistically, TXNIP directly interacted with and positively regulated p-PRKAA, leading to inactivation of MTOR (mechanistic target of rapamycin kinase) complex 1 (MTORC1) and nuclear translocation of TFEB (transcription factor EB), which in turn promoted autophagy. Inhibition of MTORC1 by rapamycin induced autophagy and increased the expression levels of FAO-related genes and concomitantly attenuated lipid accumulation in PA-treated txnip-knockout (KO) hepatocytes, which was further abolished by silencing of Atg7. Rapamycin treatment also attenuated MCD diet-induced steatosis, inflammation, and fibrosis with increased TFEB nuclear translocation and restored FAO in txnip-KO mice. Our findings suggest that elevated TXNIP ameliorates steatohepatitis by interacting with PRKAA and thereby inducing autophagy and FAO. Targeting TXNIP may be a potential therapeutic approach for NASH.Abbreviations: ACOX1: acyl-Coenzyme A oxidase 1, palmitoyl; ACSL1: acyl-CoA synthetase long-chain family member 1; ACTA2/α-SMA: actin, alpha 2, smooth muscle, aorta; ACTB: actin beta; ADGRE1/F4/80: adhesion G protein-coupled receptor E1; AMPK: AMP-activated protein kinase; ATG: autophagy-related; BafA1: bafilomycin A1; COL1A1/Col1α1: collagen, type I, alpha 1; CPT1A: carnitine palmitoyltransferase 1a, liver; CQ: chloroquine; DGAT1: diacylglycerol O-acyltransferase 1; DGAT2: diacylglycerol O-acyltransferase 2; ECI2/Peci: enoyl-Coenzyme A isomerase 2; EHHADH: enoyl-Coenzyme A, hydratase/3-hydroxyacyl Coenzyme A dehydrogenase; FAO: fatty acid oxidation; FASN: fatty acid synthase; FFA: free fatty acids; GFP: green fluorescent protein; GK/GYK: glycerol kinase; GOT1/AST: glutamic-oxaloacetic transaminase 1, soluble; GPAM: glycerol-3-phosphate acyltransferase, mitochondrial; GPT/ALT: glutamic pyruvic transaminase, soluble; H&E: hematoxylin and eosin; IL1B/IL-1β: interleukin 1 beta; IL6: interleukin 6; IOD: integral optical density; KO: knockout; Leu: leupeptin; LPIN1: lipin 1; MAP1LC3B/LC3B: microtubule-associated protein 1 light chain 3 beta; MCD: methionine choline-deficient; MMP9: matrix metallopeptidase 9; mRNA: messenger RNA; MTORC1: mechanistic target of rapamycin kinase complex 1; NAFLD: nonalcoholic fatty liver diseases; NASH: nonalcoholic steatohepatitis; PA: palmitic acid; PPARA/PPARα: peroxisome proliferator activated receptor alpha; PPARG/PPARγ: peroxisome proliferator activated receptor gamma; qRT-PCR: quantitative real-time PCR; RPS6KB1/p70S6K1: ribosomal protein S6 kinase, polypeptide 1; RPTOR: regulatory associated protein of MTOR complex 1; SCD1: stearoyl-Coenzyme A desaturase 1; SEM: standard error of the mean; siRNA: small interfering RNA; SQSTM1/p62: sequestosome 1; TFEB: transcription factor EB; TG: triglyceride; TGFB/TGF-β: transforming growth factor, beta; TIMP1: tissue inhibitor of metalloproteinase 1; TNF/TNF-α: tumor necrosis factor; TXNIP/VDUP1: thioredoxin interacting protein; WT: wild-type.
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Affiliation(s)
- Hee-Seon Park
- Department of Veterinary Pathology, College of Veterinary Medicine, Chungnam National University, Daejeon, Korea
| | - Ji-Won Song
- Department of Veterinary Pathology, College of Veterinary Medicine, Chungnam National University, Daejeon, Korea
| | - Jin-Ho Park
- Department of Biomedical Science, Jungwon University, Chungbuk, Korea
| | - Byung-Kwan Lim
- Department of Biomedical Science, Jungwon University, Chungbuk, Korea
| | - Og-Sung Moon
- Laboratory Animal Resource Center, Korea Research Institute of Bioscience and Biotechnology, Chungbuk, Korea
| | - Hwa-Young Son
- Department of Veterinary Pathology, College of Veterinary Medicine, Chungnam National University, Daejeon, Korea
| | - Jae-Hyuk Lee
- Department of Pathology, Chonnam National University Medical School, Gwangju, Korea
| | - Bin Gao
- Laboratory of Liver Diseases, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA
| | - Young-Suk Won
- Laboratory Animal Resource Center, Korea Research Institute of Bioscience and Biotechnology, Chungbuk, Korea
| | - Hyo-Jung Kwon
- Department of Veterinary Pathology, College of Veterinary Medicine, Chungnam National University, Daejeon, Korea
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Type 4B hereditary hemochromatosis due to heterozygous p.D157A mutation in SLC40A1 complicated with hypopituitarism. Med Mol Morphol 2020; 54:60-67. [PMID: 32607777 DOI: 10.1007/s00795-020-00259-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 06/13/2020] [Indexed: 10/24/2022]
Abstract
Hemochromatosis is a clinical syndrome characterized by iron overload in various organs. We present here a case of type 4 hereditary hemochromatosis due to heterozygous mutation in SLC40A1 gene (p.D157A). SLC40A1 encodes ferroportin, a macromolecule only known as iron exporter from mammalian cells. He first presented symptoms correlated with hypopituitarism. Furthermore, marked hyperferritinemia and high transferrin saturation were revealed in combination with the findings of iron overload in the liver, spleen and pituitary gland by computed tomography and magnetic resonance imaging. Liver biopsy revealed iron deposition in both hepatocytes and Kupffer cells. SLC40A1 mutations are considered to cause wide heterogeneity by various ferroportin mutations. Thus, clinicopathological examinations seem to be very important for diagnosing phenotype of type 4 hemochromatosis in addition to the gene analysis. We diagnosed him as type 4B hereditary hemochromatosis (ferroportin-associated hemochromatosis) by the findings of high transferrin saturation and iron deposition in hepatocytes, and then started iron chelating treatment. We should suspect the possibility of hereditary hemochromatosis even in Japanese with severe iron overload. Although the same mutation in SLC40A1 gene (p.D157A) had been reported to cause "loss of function" phenotype, we considered that the mutation of our case caused "gain of function" phenotype.
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Honma Y, Sato-Morita M, Katsuki Y, Mihara H, Baba R, Hino K, Kawashima A, Ariyasu T, Harada M. Trehalose alleviates oxidative stress-mediated liver injury and Mallor-Denk body formation via activating autophagy in mice. Med Mol Morphol 2020; 54:41-51. [PMID: 32588144 DOI: 10.1007/s00795-020-00258-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 06/16/2020] [Indexed: 02/06/2023]
Abstract
Autophagy is a degradation pathway for long-lived cytoplasmic proteins or damaged organelles and also for many aggregate-prone and disease-causing proteins. Endoplasmic reticulum (ER) stress and oxidative stress are associated with the pathophysiology of various liver diseases. These stresses induce the accumulation of abnormal proteins, Mallory-Denk body (MDB) formation and apoptosis in hepatocytes. A disaccharide trehalose had been reported to induce autophagy and decrease aggregate-prone proteins and cytotoxicity in neurodegenerative disease models. But the effects of trehalose in hepatocytes have not been fully understood. We examined the effect of trehalose on autophagy, ER stress and oxidative stress-mediated cytotoxicity and MDB formation in hepatocytes using mice model with 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) treatment for 3 months. We administered trehalose by intraperitoneal injection of water containing 10% trehalose (0.02 mg/g body weight) every other day for 3 months. Our results demonstrated that trehalose induced autophagy and reduced ER stress, oxidative stress, MDB formation and apoptosis in hepatocytes of DDC-fed mice by Western blotting and immunostaining analyses. Electron microscopy revealed that trehalose induced autolysosome formation, which located is close to the MDBs. Thus, our findings suggest that trehalose can become a therapeutic agent for oxidative stress-related liver diseases via activating autophagy.
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Affiliation(s)
- Yuichi Honma
- Third Department of Internal Medicine, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, 807-8555, Japan.
| | - Miyuki Sato-Morita
- Third Department of Internal Medicine, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, 807-8555, Japan
| | - Yuka Katsuki
- Third Department of Internal Medicine, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, 807-8555, Japan
| | - Hitomi Mihara
- Third Department of Internal Medicine, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, 807-8555, Japan
| | - Ryoko Baba
- Department of Anatomy, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Katsuhiko Hino
- Core Technology Division, R&D Center, Hayashibara Co., Ltd., Okayama, Japan
| | - Akira Kawashima
- Applied Technology Division, R&D Center, Hayashibara Co., Ltd., Okayama, Japan
| | - Toshio Ariyasu
- Applied Technology Division, R&D Center, Hayashibara Co., Ltd., Okayama, Japan
| | - Masaru Harada
- Third Department of Internal Medicine, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, 807-8555, Japan
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Shin WH, Park JH, Chung KC. The central regulator p62 between ubiquitin proteasome system and autophagy and its role in the mitophagy and Parkinson's disease. BMB Rep 2020. [PMID: 31818366 PMCID: PMC6999829 DOI: 10.5483/bmbrep.2020.53.1.283] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The ubiquitin-proteasome system (UPS) and autophagy are two major degradative pathways of proteins in eukaryotic cells. As about 30% of newly synthesized proteins are known to be misfolded under normal cell conditions, the precise and timely operation of the UPS and autophagy to remove them as well as their tightly controlled regulation, is so important for proper cell function and survival. In the UPS, target proteins are labeled by small proteins called ubiquitin, which are then transported to the proteasome complex for degradation. Alternatively, many greatly damaged proteins are believed to be delivered to the lysosome for autophagic degradation. Although these autophagy and UPS pathways have not been considered to be directly related, many recent studies proposed their close link and dynamic interconversion. In this review, we’ll focus on the several regulatory molecules that function in both UPS and autophagy and their crosstalk. Among the proposed multiple modulators, we will take a closer look at the so-called main connector of UPS-autophagy regulation, p62. Last, the functional role of p62 in the mitophagy and its implication for the pathogenesis of Parkinson’s disease, one of the major neurodegenerative diseases, will be briefly reviewed.
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Affiliation(s)
- Woo Hyun Shin
- Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, Korea
| | - Joon Hyung Park
- Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, Korea
| | - Kwang Chul Chung
- Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, Korea
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Homma T, Fujii J. Emerging connections between oxidative stress, defective proteolysis, and metabolic diseases. Free Radic Res 2020; 54:931-946. [DOI: 10.1080/10715762.2020.1734588] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Takujiro Homma
- Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Yamagata University, Yamagata, Japan
| | - Junichi Fujii
- Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Yamagata University, Yamagata, Japan
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Ke PY. Mitophagy in the Pathogenesis of Liver Diseases. Cells 2020; 9:cells9040831. [PMID: 32235615 PMCID: PMC7226805 DOI: 10.3390/cells9040831] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 03/25/2020] [Accepted: 03/27/2020] [Indexed: 02/07/2023] Open
Abstract
Autophagy is a catabolic process involving vacuolar sequestration of intracellular components and their targeting to lysosomes for degradation, thus supporting nutrient recycling and energy regeneration. Accumulating evidence indicates that in addition to being a bulk, nonselective degradation mechanism, autophagy may selectively eliminate damaged mitochondria to promote mitochondrial turnover, a process termed “mitophagy”. Mitophagy sequesters dysfunctional mitochondria via ubiquitination and cargo receptor recognition and has emerged as an important event in the regulation of liver physiology. Recent studies have shown that mitophagy may participate in the pathogenesis of various liver diseases, such as liver injury, liver steatosis/fatty liver disease, hepatocellular carcinoma, viral hepatitis, and hepatic fibrosis. This review summarizes the current knowledge on the molecular regulations and functions of mitophagy in liver physiology and the roles of mitophagy in the development of liver-related diseases. Furthermore, the therapeutic implications of targeting hepatic mitophagy to design a new strategy to cure liver diseases are discussed.
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Affiliation(s)
- Po-Yuan Ke
- Department of Biochemistry & Molecular Biology and Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan; ; Tel.: +886-3-211-8800 (ext. 5115); Fax: +886-3-211-8700
- Liver Research Center, Chang Gung Memorial Hospital, Taoyuan 33305, Taiwan
- Division of Allergy, Immunology, and Rheumatology, Chang Gung Memorial Hospital, Taoyuan 33305, Taiwan
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Hepatocyte Injury and Hepatic Stem Cell Niche in the Progression of Non-Alcoholic Steatohepatitis. Cells 2020; 9:cells9030590. [PMID: 32131439 PMCID: PMC7140508 DOI: 10.3390/cells9030590] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 02/21/2020] [Accepted: 02/27/2020] [Indexed: 02/07/2023] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is a chronic liver disease characterized by lipid accumulation in hepatocytes in the absence of excessive alcohol consumption. The global prevalence of NAFLD is constantly increasing. NAFLD is a disease spectrum comprising distinct stages with different prognoses. Non-alcoholic steatohepatitis (NASH) is a progressive condition, characterized by liver inflammation and hepatocyte ballooning, with or without fibrosis. The natural history of NAFLD is negatively influenced by NASH onset and by the progression towards advanced fibrosis. Pathogenetic mechanisms and cellular interactions leading to NASH and fibrosis involve hepatocytes, liver macrophages, myofibroblast cell subpopulations, and the resident progenitor cell niche. These cells are implied in the regenerative trajectories following liver injury, and impairment or perturbation of these mechanisms could lead to NASH and fibrosis. Recent evidence underlines the contribution of extra-hepatic organs/tissues (e.g., gut, adipose tissue) in influencing NASH development by interacting with hepatic cells through various molecular pathways. The present review aims to summarize the role of hepatic parenchymal and non-parenchymal cells, their mutual influence, and the possible interactions with extra-hepatic tissues and organs in the pathogenesis of NAFLD.
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Fish oil up-regulates hepatic autophagy in rats with chronic ethanol consumption. J Nutr Biochem 2019; 77:108314. [PMID: 31884243 DOI: 10.1016/j.jnutbio.2019.108314] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 11/12/2019] [Accepted: 11/27/2019] [Indexed: 12/12/2022]
Abstract
In this study, we examined the regulation of autophagy by fish oil in rats under ethanol-containing diets. Thirty male Wistar rats (8-week-old) were divided into six groups and fed a control diet or an ethanol-containing diet, which was adjusted with fish oil to replace 25% or 57% of the olive oil. After 8 weeks, rats in the E (ethanol diet) group showed the significantly higher plasma aspartate transaminase (AST) and alanine transaminase (ALT) activities, protein expression of cytochrome P450 2E1 (CYP2E1), and levels of hepatic inflammatory cytokines. However, all of those items had significantly decreased in the EF25 (ethanol with 25% fish oil) and EF57 (ethanol with 57% fish oil) groups. As to autophagic indicators, protein expressions of mammalian target of rapamycin (mTOR), Unc-51-like autophagy activating kinase 1 (ULK1) and p62 were significantly increased in the E group. Conversely, the protein expressions of light chain 3II (LC3II)/LC3I and Beclin1 were significantly decreased in the E group. On the other hand, protein expressions of phosphorylated Akt, mTOR, ULK1, and p62 were down-regulated, protein expressions of LC3II/LC3I and Beclin1 were conversely up-regulated in the EF25 and EF57 groups. Fish oil activated hepatic autophagy via inhibiting the Akt signaling pathway, which exerted protective effects against ethanol-induced liver injury in rats.
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D'Eletto M, Rossin F, Fedorova O, Farrace MG, Piacentini M. Transglutaminase type 2 in the regulation of proteostasis. Biol Chem 2019; 400:125-140. [PMID: 29908126 DOI: 10.1515/hsz-2018-0217] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 05/15/2018] [Indexed: 12/21/2022]
Abstract
The maintenance of protein homeostasis (proteostasis) is a fundamental aspect of cell physiology that is essential for the survival of organisms under a variety of environmental and/or intracellular stress conditions. Acute and/or persistent stress exceeding the capacity of the intracellular homeostatic systems results in protein aggregation and/or damaged organelles that leads to pathological cellular states often resulting in cell death. These events are continuously suppressed by a complex macromolecular machinery that uses different intracellular pathways to maintain the proteome integrity in the various subcellular compartments ensuring a healthy cellular life span. Recent findings have highlighted the role of the multifunctional enzyme type 2 transglutaminase (TG2) as a key player in the regulation of intracellular pathways, such as autophagy/mitophagy, exosomes formation and chaperones function, which form the basis of proteostasis regulation under conditions of cellular stress. Here, we review the role of TG2 in these stress response pathways and how its various enzymatic activities might contributes to the proteostasis control.
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Affiliation(s)
- Manuela D'Eletto
- Department of Biology, University of Rome 'Tor Vergata', Via della Ricerca Scientifica, I-00133 Rome, Italy
| | - Federica Rossin
- Department of Biology, University of Rome 'Tor Vergata', Via della Ricerca Scientifica, I-00133 Rome, Italy
| | - Olga Fedorova
- Institute of Cytology, 194064 Saint-Petersburg, Russia
| | - Maria Grazia Farrace
- Department of Biology, University of Rome 'Tor Vergata', Via della Ricerca Scientifica, I-00133 Rome, Italy
| | - Mauro Piacentini
- Department of Biology, University of Rome 'Tor Vergata', Via della Ricerca Scientifica, I-00133 Rome, Italy.,National Institute for Infectious Diseases I.R.C.C.S. 'Lazzaro Spallanzani', I-00149 Rome, Italy
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Ogino N, Miyagawa K, Kusanaga M, Hayashi T, Minami S, Oe S, Honma Y, Harada M. Involvement of sarco/endoplasmic reticulum calcium ATPase-mediated calcium flux in the protective effect of oleic acid against lipotoxicity in hepatocytes. Exp Cell Res 2019; 385:111651. [PMID: 31568762 DOI: 10.1016/j.yexcr.2019.111651] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 09/22/2019] [Accepted: 09/26/2019] [Indexed: 12/14/2022]
Abstract
Elevated free fatty acids, particularly saturated ones such as palmitic acid, may play an important role in the lipotoxic mechanism of nonalcoholic fatty liver disease (NAFLD). Saturated fatty acids induce autophagy dysfunction and endoplasmic reticulum (ER) stress leading to apoptosis in hepatocytes. However, unsaturated fatty acids, such as oleic acid, are nontoxic and can even prevent saturated fatty acid-induced toxicity in vitro. Although emerging evidence has suggested that ER calcium flux disruption in hepatocytes is involved in NAFLD pathogenesis, the roles of fatty acids in autophagy and ER calcium flux still remain unclear. We demonstrated that oleic acid ameliorated palmitic acid-induced autophagy arrest and ER stress in parallel with ER calcium depletion in hepatocytes. Moreover, we found that the effect of oleic acid against autophagy arrest was reversed by the pharmacological inhibition of sarcoplasmic reticulum Ca2+-ATPase (SERCA), which influxes calcium to ER. These data suggest that SERCA-mediated ER calcium flux is greatly involved in fatty acid-induced lipotoxicity in hepatocytes, and the prevention of ER calcium depletion may restore saturated fatty acid-induced autophagy arrest in hepatocytes.
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Affiliation(s)
- Noriyoshi Ogino
- Third Department of Internal Medicine, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
| | - Koichiro Miyagawa
- Third Department of Internal Medicine, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Masashi Kusanaga
- Third Department of Internal Medicine, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Tsuguru Hayashi
- Third Department of Internal Medicine, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Sota Minami
- Third Department of Internal Medicine, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Shinji Oe
- Third Department of Internal Medicine, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Yuichi Honma
- Third Department of Internal Medicine, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Masaru Harada
- Third Department of Internal Medicine, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
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High-fat and high-cholesterol diet decreases phosphorylated inositol-requiring kinase-1 and inhibits autophagy process in rat liver. Sci Rep 2019; 9:12514. [PMID: 31467308 PMCID: PMC6715744 DOI: 10.1038/s41598-019-48973-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 08/14/2019] [Indexed: 12/19/2022] Open
Abstract
Precise molecular pathways involved in the progression of non-alcoholic steatohepatitis (NASH) remain to be elucidated. As Mallory–Denk bodies were occasionally observed in the enlarged hepatocytes in NASH model rat (SHRSP5/Dmcr) fed high-fat and high-cholesterol (HFC) diet, we aimed to clarify the roles of autophagy and endoplasmic reticulum (ER) stress in NASH progression. Male SHRSP5/Dmcr were randomly divided into 4 groups. Two groups were fed a control diet; the other two groups were fed a HFC diet for 2 and 8 weeks, respectively. The HFC diet increased the autophagy-related proteins levels and microtubule-associated protein 1 light chain 3-II/I ratio after 2 and 8 weeks, respectively. However, regarding ER stress-related proteins, the HFC diet decreased the levels of phosphorylated (p-) inositol-requiring kinase-1 (p-IRE-1) and p-protein kinase RNA-like ER kinase after 2 weeks. Additionally, the HFC diet increased anti-ubiquitin-positive cells and the level of the autophagy substrate p62, suggesting that the HFC diet induced dysfunction in ubiquitin-dependent protein degradation pathways. In conclusion, the HFC diet arrested the autophagy process in the liver; this was particularly associated with decreases in p-IRE-1 expression.
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Maitra D, Carter EL, Richardson R, Rittié L, Basrur V, Zhang H, Nesvizhskii AI, Osawa Y, Wolf MW, Ragsdale SW, Lehnert N, Herrmann H, Omary MB. Oxygen and Conformation Dependent Protein Oxidation and Aggregation by Porphyrins in Hepatocytes and Light-Exposed Cells. Cell Mol Gastroenterol Hepatol 2019; 8:659-682.e1. [PMID: 31173894 PMCID: PMC6889786 DOI: 10.1016/j.jcmgh.2019.05.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 05/28/2019] [Accepted: 05/28/2019] [Indexed: 02/06/2023]
Abstract
BACKGROUND & AIMS Porphyrias are caused by porphyrin accumulation resulting from defects in the heme biosynthetic pathway that typically lead to photosensitivity and possible end-stage liver disease with an increased risk of hepatocellular carcinoma. Our aims were to study the mechanism of porphyrin-induced cell damage and protein aggregation, including liver injury, where light exposure is absent. METHODS Porphyria was induced in vivo in mice using 3,5-diethoxycarbonyl-1,4-dihydrocollidine or in vitro by exposing human liver Huh7 cells and keratinocytes, or their lysates, to protoporphyrin-IX, other porphyrins, or to δ-aminolevulinic acid plus deferoxamine. The livers, cultured cells, or porphyrin exposed purified proteins were analyzed for protein aggregation and oxidation using immunoblotting, mass spectrometry, and electron paramagnetic resonance spectroscopy. Consequences on cell-cycle progression were assessed. RESULTS Porphyrin-mediated protein aggregation required porphyrin-photosensitized singlet oxygen and porphyrin carboxylate side-chain deprotonation, and occurred with site-selective native protein methionine oxidation. Noncovalent interaction of protoporphyrin-IX with oxidized proteins led to protein aggregation that was reversed by incubation with acidified n-butanol or high-salt buffer. Phototoxicity and the ensuing proteotoxicity, mimicking porphyria photosensitivity conditions, were validated in cultured keratinocytes. Protoporphyrin-IX inhibited proteasome function by aggregating several proteasomal subunits, and caused cell growth arrest and aggregation of key cell proliferation proteins. Light-independent synergy of protein aggregation was observed when porphyrin was applied together with glucose oxidase as a secondary peroxide source. CONCLUSIONS Photo-excitable porphyrins with deprotonated carboxylates mediate protein aggregation. Porphyrin-mediated proteotoxicity in the absence of light, as in the liver, requires porphyrin accumulation coupled with a second tissue oxidative injury. These findings provide a potential mechanism for internal organ damage and photosensitivity in porphyrias.
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Affiliation(s)
- Dhiman Maitra
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan.
| | - Eric L Carter
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan
| | - Rani Richardson
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan
| | - Laure Rittié
- Department of Dermatology, University of Michigan, Ann Arbor, Michigan
| | - Venkatesha Basrur
- Department of Pathology, University of Michigan, Ann Arbor, Michigan
| | - Haoming Zhang
- Department of Pharmacology, University of Michigan, Ann Arbor, Michigan
| | | | - Yoichi Osawa
- Department of Pharmacology, University of Michigan, Ann Arbor, Michigan
| | - Matthew W Wolf
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan
| | - Stephen W Ragsdale
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan
| | - Nicolai Lehnert
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan; Department of Biophysics, University of Michigan, Ann Arbor, Michigan
| | - Harald Herrmann
- Institute of Neuropathology, University Hospital Erlangen, Erlangen, Germany; Division of Molecular Genetics, German Cancer Research Center, Heidelberg, Germany
| | - M Bishr Omary
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan; Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan; Cell Biology, Faculty of Science and Technology, Åbo Akademi University, Turku, Finland
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Response to the letter by Sumida et al. regarding our manuscript "Evaluation of ballooned hepatocytes as a risk factor for future progression of fibrosis in patients with non-alcoholic fatty liver disease". J Gastroenterol 2019; 54:476-477. [PMID: 30915534 DOI: 10.1007/s00535-019-01574-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 03/15/2019] [Indexed: 02/04/2023]
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Denk H, Stumptner C, Abuja PM, Zatloukal K. Sequestosome 1/p62-related pathways as therapeutic targets in hepatocellular carcinoma. Expert Opin Ther Targets 2019; 23:393-406. [PMID: 30987486 DOI: 10.1080/14728222.2019.1601703] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
INTRODUCTION Protein sequestosome 1/p62 (p62) plays a crucial role in vital complex and interacting signaling pathways in normal and neoplastic cells. P62 is involved in autophagy, defense against oxidative stress via activation of the Keap1/Nrf2 system, in protein aggregation and sequestration, and in apoptosis. Autophagy contributes to cell survival and proliferation by eliminating damaged organelles, potentially toxic protein aggregates and invading microorganisms, and by providing nutrients under starvation conditions. The same holds true for oxidative stress defense, which may prevent genomic alterations and tumor initiation but also protect established tumor cells and promote tumor progression. Cross-talk between autophagy and apoptosis is regulated by a signaling network with the involvement of p62. Areas covered: The review deals with structure, function, and regulation of p62 and its role in liver carcinogenesis. Emphasis is placed on mechanisms leading to overexpression of p62 and its accumulation as inclusion bodies in HCC and on the impact of p62-dependent signaling pathways in tumor cells with the aim to explore the possible role of p62 as the therapeutic target. Expert opinion: Depending on the context, targeting p62 or interference with related pathways, such as autophagy, is a potential therapeutic strategy in HCC. However, the heterogeneity of this tumor entity and the complexity and mutual interactions of the p62-dependent pathways involved are challenges for a targeted therapy since interference with p62-mediated regulatory processes could result likewise in inhibition of tumorigenesis and in its promotion and thus provoke harmful side effects. Therapy-related patient stratification based on reliable markers to better define pathogenic principles of the tumor is a necessity when this type of treatment is considered.
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Affiliation(s)
- Helmut Denk
- a Institute of Pathology , Medical University of Graz , Graz , Austria
| | - Conny Stumptner
- a Institute of Pathology , Medical University of Graz , Graz , Austria
| | - Peter M Abuja
- a Institute of Pathology , Medical University of Graz , Graz , Austria
| | - Kurt Zatloukal
- a Institute of Pathology , Medical University of Graz , Graz , Austria
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Khambu B, Wang L, Zhang H, Yin XM. The Activation and Function of Autophagy in Alcoholic Liver Disease. Curr Mol Pharmacol 2019; 10:165-171. [PMID: 26278385 DOI: 10.2174/1874467208666150817112654] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Revised: 07/29/2015] [Accepted: 08/07/2015] [Indexed: 02/07/2023]
Abstract
Autophagy is an important lysosome-mediated intracellular degradation pathway required for tissue homeostasis. Dysregulation of liver autophagy is closely associated with different liver diseases including alcoholic liver disease. Studies now indicate that autophagy may be induced or suppressed depending on the amount and the duration of ethanol treatment. Autophagy induced by ethanol serves as a protective mechanism, probably by selective degradation of the damaged mitochondria (mitophagy) and excess lipid droplets (lipophagy) and in turn attenuates alcohol-induced steatosis and liver injury. However, the detailed molecular mechanism of selective targeting of mitochondria and lipid is still unclear. Autophagy may possess other functions that protect hepatocytes from ethanol. Understanding these molecular entities would be essential in order to therapeutically module autophagy for treatment of alcoholic liver disease.
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Affiliation(s)
- Bilon Khambu
- Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN 46202. United States
| | - Lin Wang
- Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN 46202. United States
| | - Hao Zhang
- Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN 46202. United States
| | - Xiao-Ming Yin
- Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN 46202. United States
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Chao X, Ding WX. Role and mechanisms of autophagy in alcohol-induced liver injury. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2019; 85:109-131. [PMID: 31307584 PMCID: PMC7141786 DOI: 10.1016/bs.apha.2019.01.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Alcoholic liver disease (ALD) is one of the major causes of chronic liver disease worldwide. Currently, no successful treatments are available for ALD. The pathogenesis of ALD is characterized as simple steatosis, fibrosis, cirrhosis, alcoholic hepatitis (AH), and eventually hepatocellular carcinoma (HCC). Autophagy is a highly conserved intracellular catabolic process, which aims at recycling cellular components and removing damaged organelles in response to starvation and stresses. Therefore, autophagy is considered as an important cellular adaptive and survival mechanism under various pathophysiological conditions. Recent studies from our lab and others suggest that chronic alcohol consumption may impair autophagy and contribute to the pathogenesis of ALD. In this chapter, we summarize recent progress on the role and mechanisms of autophagy in the development of ALD. Understanding the roles of autophagy in ALD may offer novel therapeutic avenues against ALD by targeting these pathways.
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Affiliation(s)
- Xiaojuan Chao
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS, United States
| | - Wen-Xing Ding
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS, United States.
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Ke PY. Diverse Functions of Autophagy in Liver Physiology and Liver Diseases. Int J Mol Sci 2019; 20:E300. [PMID: 30642133 PMCID: PMC6358975 DOI: 10.3390/ijms20020300] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Revised: 01/05/2019] [Accepted: 01/08/2019] [Indexed: 01/09/2023] Open
Abstract
Autophagy is a catabolic process by which eukaryotic cells eliminate cytosolic materials through vacuole-mediated sequestration and subsequent delivery to lysosomes for degradation, thus maintaining cellular homeostasis and the integrity of organelles. Autophagy has emerged as playing a critical role in the regulation of liver physiology and the balancing of liver metabolism. Conversely, numerous recent studies have indicated that autophagy may disease-dependently participate in the pathogenesis of liver diseases, such as liver hepatitis, steatosis, fibrosis, cirrhosis, and hepatocellular carcinoma. This review summarizes the current knowledge on the functions of autophagy in hepatic metabolism and the contribution of autophagy to the pathophysiology of liver-related diseases. Moreover, the impacts of autophagy modulation on the amelioration of the development and progression of liver diseases are also discussed.
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Affiliation(s)
- Po-Yuan Ke
- Department of Biochemistry & Molecular Biology and Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan.
- Liver Research Center, Chang Gung Memorial Hospital, Taoyuan 33305, Taiwan.
- Division of Allergy, Immunology, and Rheumatology, Chang Gung Memorial Hospital, Taoyuan 33305, Taiwan.
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Saggi H, Maitra D, Jiang A, Zhang R, Wang P, Cornuet P, Singh S, Locker J, Ma X, Dailey H, Abrams M, Omary MB, Monga SP, Nejak-Bowen K. Loss of hepatocyte β-catenin protects mice from experimental porphyria-associated liver injury. J Hepatol 2019; 70:108-117. [PMID: 30287339 PMCID: PMC6459193 DOI: 10.1016/j.jhep.2018.09.023] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 08/30/2018] [Accepted: 09/18/2018] [Indexed: 12/12/2022]
Abstract
BACKGROUND & AIMS Porphyrias result from anomalies of heme biosynthetic enzymes and can lead to cirrhosis and hepatocellular cancer. In mice, these diseases can be modeled by administration of a diet containing 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC), which causes accumulation of porphyrin intermediates, resulting in hepatobiliary injury. Wnt/β-catenin signaling has been shown to be a modulatable target in models of biliary injury; thus, we investigated its role in DDC-driven injury. METHODS β-Catenin (Ctnnb1) knockout (KO) mice, Wnt co-receptor KO mice, and littermate controls were fed a DDC diet for 2 weeks. β-Catenin was exogenously inhibited in hepatocytes by administering β-catenin dicer-substrate RNA (DsiRNA), conjugated to a lipid nanoparticle, to mice after DDC diet and then weekly for 4 weeks. In all experiments, serum and livers were collected; livers were analyzed by histology, western blotting, and real-time PCR. Porphyrin was measured by fluorescence, quantification of polarized light images, and liquid chromatography-mass spectrometry. RESULTS DDC-fed mice lacking β-catenin or Wnt signaling had decreased liver injury compared to controls. Exogenous mice that underwent β-catenin suppression by DsiRNA during DDC feeding also showed less injury compared to control mice receiving lipid nanoparticles. Control livers contained extensive porphyrin deposits which were largely absent in mice lacking β-catenin signaling. Notably, we identified a network of key heme biosynthesis enzymes that are suppressed in the absence of β-catenin, preventing accumulation of toxic protoporphyrins. Additionally, mice lacking β-catenin exhibited fewer protein aggregates, improved proteasomal activity, and reduced induction of autophagy, all contributing to protection from injury. CONCLUSIONS β-Catenin inhibition, through its pleiotropic effects on metabolism, cell stress, and autophagy, represents a novel therapeutic approach for patients with porphyria. LAY SUMMARY Porphyrias are disorders resulting from abnormalities in the steps that lead to heme production, which cause build-up of toxic by-products called porphyrins. Liver is commonly either a source or a target of excess porphyrins, and complications can range from minor abnormalities to liver failure. In this report, we inhibited Wnt/β-catenin signaling in an experimental model of porphyria, which resulted in decreased liver injury. Targeting β-catenin affected multiple components of the heme biosynthesis pathway, thus preventing build-up of porphyrin intermediates. Our study suggests that drugs inhibiting β-catenin activity could reduce the amount of porphyrin accumulation and help alleviate symptoms in patients with porphyria.
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Affiliation(s)
- Harvinder Saggi
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA, United States
| | - Dhiman Maitra
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, United States
| | - An Jiang
- 2nd Affilitated Hospital, Xi’an Jiaotong University, Xi’an, Chin
| | - Rong Zhang
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA, United States
| | - Pengcheng Wang
- School of Pharmacy, University of Pittsburgh, Pittsburgh, PA, United States
| | - Pamela Cornuet
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA, United States
| | - Sucha Singh
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA, United States
| | - Joseph Locker
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA, United States,Pittsburgh Liver Research Center, Pittsburgh, PA, United States
| | - Xiaochao Ma
- School of Pharmacy, University of Pittsburgh, Pittsburgh, PA, United States
| | - Harry Dailey
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, United States
| | - Marc Abrams
- Dicerna Pharmaceuticals, Inc, Cambridge, MA, United States
| | - M. Bishr Omary
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, United States
| | - Satdarshan P. Monga
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA, United States,Pittsburgh Liver Research Center, Pittsburgh, PA, United States
| | - Kari Nejak-Bowen
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA, United States; Pittsburgh Liver Research Center, Pittsburgh, PA, United States.
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Khambu B, Yan S, Huda N, Liu G, Yin XM. Autophagy in non-alcoholic fatty liver disease and alcoholic liver disease. LIVER RESEARCH 2018; 2:112-119. [PMID: 31123622 PMCID: PMC6528826 DOI: 10.1016/j.livres.2018.09.004] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Autophagy is an evolutionarily conserved intracellular degradative function that is important for liver homeostasis. Accumulating evidence suggests that autophagy is deregulated during the progression and development of alcoholic and non-alcoholic liver diseases. Impaired autophagy prevents the clearance of excessive lipid droplets (LDs), damaged mitochondria, and toxic protein aggregates, which can be generated during the progression of various liver diseases, thus contributing to the development of steatosis, injury, steatohepatitis, fibrosis, and tumors. In this review, we look at the status of hepatic autophagy during the pathogenesis of alcoholic and non-alcoholic liver diseases. We also examine the mechanisms of defects in autophagy, and the hepato-protective roles of autophagy in non-alcoholic fatty liver disease (NAFLD) and alcoholic liver disease (ALD), focusing mainly on steatosis and liver injury. Finally, we discuss the therapeutic potential of autophagy modulating agents for the treatment of these two common liver diseases.
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40
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Basisty NB, Liu Y, Reynolds J, Karunadharma PP, Dai DF, Fredrickson J, Beyer RP, MacCoss MJ, Rabinovitch PS. Stable Isotope Labeling Reveals Novel Insights Into Ubiquitin-Mediated Protein Aggregation With Age, Calorie Restriction, and Rapamycin Treatment. J Gerontol A Biol Sci Med Sci 2018; 73:561-570. [PMID: 28958078 PMCID: PMC6380815 DOI: 10.1093/gerona/glx047] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 08/16/2017] [Indexed: 12/30/2022] Open
Abstract
Accumulation of protein aggregates with age was first described in aged human tissue over 150 years ago and has since been described in virtually every human tissue. Ubiquitin modifications are a canonical marker of insoluble protein aggregates; however, the composition of most age-related inclusions remains relatively unknown. To examine the landscape of age-related protein aggregation in vivo, we performed an antibody-based pulldown of ubiquitinated proteins coupled with metabolic labeling and mass spectrometry on young and old mice on calorie restriction (CR), rapamycin (RP)-supplemented, and control diets. We show increased abundance of many ubiquitinated proteins in old mice and greater retention of preexisting (unlabeled) ubiquitinated proteins relative to their unmodified counterparts-fitting the expected profile of age-increased accumulation of long-lived aggregating proteins. Both CR and RP profoundly affected ubiquitinome composition, half-live, and the insolubility of proteins, consistent with their ability to mobilize these age-associated accumulations. Finally, confocal microscopy confirmed the aggregation of two of the top predicted aggregating proteins, keratins 8/18 and catalase, as well as their attenuation by CR and RP. Stable-isotope labeling is a powerful tool to gain novel insights into proteostasis mechanisms, including protein aggregation, and could be used to identify novel therapeutic targets in aging and protein aggregation diseases.
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Affiliation(s)
- Nathan B Basisty
- Department of Pathology, University of Washington, Seattle
- Buck Institute for Research on Aging, Novato, California
| | - Yuxin Liu
- Department of Medicine, SUNY Upstate Medical University, Syracuse, New York
| | - Jason Reynolds
- Department of Medicine, University of Washington, Seattle
| | | | - Dao-Fu Dai
- Department of Pathology, University of Washington, Seattle
- Department of Pathology, University of Iowa Carver College of Medicine, Iowa City
| | | | - Richard P Beyer
- Department of Environmental Health, University of Washington, Seattle
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Sha Z, Schnell HM, Ruoff K, Goldberg A. Rapid induction of p62 and GABARAPL1 upon proteasome inhibition promotes survival before autophagy activation. J Cell Biol 2018. [PMID: 29535191 PMCID: PMC5940303 DOI: 10.1083/jcb.201708168] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Cells are thought to adapt to proteasome inhibition by using alternative pathways for degradation such as autophagy. Sha et al. now report that cells rapidly induce GABARAPL1 and p62 upon proteasome inhibition, but this promotes cell survival by sequestering ubiquitinated and sumoylated proteins long before the cells induce other Atg genes and activate autophagy. Proteasome inhibitors are used as research tools and to treat multiple myeloma, and proteasome activity is diminished in several neurodegenerative diseases. We therefore studied how cells compensate for proteasome inhibition. In 4 h, proteasome inhibitor treatment caused dramatic and selective induction of GABARAPL1 (but not other autophagy genes) and p62, which binds ubiquitinated proteins and GABARAPL1 on autophagosomes. Knockdown of p62 or GABARAPL1 reduced cell survival upon proteasome inhibition. p62 induction requires the transcription factor nuclear factor (erythroid-derived 2)-like 1 (Nrf1), which simultaneously induces proteasome genes. After 20-h exposure to proteasome inhibitors, cells activated autophagy and expression of most autophagy genes by an Nrf1-independent mechanism. Although p62 facilitates the association of ubiquitinated proteins with autophagosomes, its knockdown in neuroblastoma cells blocked the buildup of ubiquitin conjugates in perinuclear aggresomes and of sumoylated proteins in nuclear inclusions but did not reduce the degradation of ubiquitinated proteins. Thus, upon proteasome inhibition, cells rapidly induce p62 expression, which enhances survival primarily by sequestering ubiquitinated proteins in inclusions.
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Affiliation(s)
- Zhe Sha
- Harvard Medical School, Boston, MA
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Honma Y, Sato-Morita M, Katsuki Y, Mihara H, Baba R, Harada M. Trehalose activates autophagy and decreases proteasome inhibitor-induced endoplasmic reticulum stress and oxidative stress-mediated cytotoxicity in hepatocytes. Hepatol Res 2018; 48:94-105. [PMID: 28295916 DOI: 10.1111/hepr.12892] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 02/23/2017] [Accepted: 03/08/2017] [Indexed: 02/08/2023]
Abstract
AIM Endoplasmic reticulum stress is associated with the pathophysiology of various liver diseases. Endoplasmic reticulum stress mediates the accumulation of abnormal proteins and leads to oxidative stress, cytoplasmic inclusion body formation, and apoptosis in hepatocytes. Autophagy is a bulk degradation pathway for long-lived cytoplasmic proteins or damaged organelles and is also a major degradation pathway for many aggregate-prone and disease-causing proteins. We previously reported that rapamycin, a mammalian target of rapamycin inhibitor, activated autophagy and decreased proteasome inhibitor-mediated ubiquitinated protein accumulation, cytoplasmic inclusion body formation, and apoptosis in hepatocytes. Trehalose is a non-reducing disaccharide that has been shown to activate autophagy. It has been reported to decrease aggregate-prone proteins and ameliorate cytotoxicity in neurodegenerative disease models. However, the effects of trehalose in hepatocytes are unclear. METHODS We show here that trehalose activated autophagy and reduced endoplasmic reticulum stress, cytoplasmic inclusion body formation, and apoptosis in proteasome inhibitor-treated liver-derived cultured cells. CONCLUSION To our knowledge, this is the first report showing that trehalose activates autophagy and has cytoprotective effects in hepatocytes. Our findings suggest that trehalose can become a therapeutic agent for endoplasmic reticulum stress-related liver diseases.
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Affiliation(s)
- Yuichi Honma
- Third Department of Internal Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Miyuki Sato-Morita
- Third Department of Internal Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Yuka Katsuki
- Third Department of Internal Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Hitomi Mihara
- Third Department of Internal Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Ryoko Baba
- Department of Anatomy, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Masaru Harada
- Third Department of Internal Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
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Multifaceted Roles of GSK-3 in Cancer and Autophagy-Related Diseases. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:4629495. [PMID: 29379583 PMCID: PMC5742885 DOI: 10.1155/2017/4629495] [Citation(s) in RCA: 156] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 10/07/2017] [Accepted: 10/23/2017] [Indexed: 02/07/2023]
Abstract
GSK-3 is a ubiquitously expressed serine/threonine kinase existing as GSK-3α and GSK-3β isoforms, both active under basal conditions and inactivated upon phosphorylation by different upstream kinases. Initially discovered as a regulator of glycogen synthesis, GSK-3 is also involved in several signaling pathways controlling many different key functions. Here, we discuss recent advances regarding (i) GSK-3 structure, function, regulation, and involvement in several cancers, including hepatocarcinoma, cholangiocarcinoma, breast cancer, prostate cancer, leukemia, and melanoma (active GSK-3 has been shown to induce apoptosis in some cases or inhibit apoptosis in other cases and to induce cancer progression or inhibit tumor cell proliferation, suggesting that different GSK-3 modulators may address different specific targets); (ii) GSK-3 involvement in autophagy modulation, reviewing signaling pathways involved in neurodegenerative and liver diseases; (iii) GSK-3 role in oxidative stress and autophagic cell death, focusing on liver injury; (iv) GSK-3 as a possible therapeutic target of natural substances and synthetic inhibitors in many diseases; and (v) GSK-3 role as modulator of mammalian aging, related to metabolic alterations characterizing senescent cells and age-related diseases. Studies summarized here underline the GSK-3 multifaceted role and indicate such kinase as a molecular target in different pathologies, including diseases associated with autophagy dysregulation.
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Wang L, Zhou J, Yan S, Lei G, Lee CH, Yin XM. Ethanol-triggered Lipophagy Requires SQSTM1 in AML12 Hepatic Cells. Sci Rep 2017; 7:12307. [PMID: 28951592 PMCID: PMC5614958 DOI: 10.1038/s41598-017-12485-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 09/05/2017] [Indexed: 12/14/2022] Open
Abstract
Ethanol-induced hepatic lipophagy plays an important cytoprotective role against liver injury, but its mechanism is not fully determined. In the present study, ethanol-induced lipophagy was studied in an immortalized mouse hepatocyte line, AML12. We found that ethanol treatment elevated lipid content in these cells, which could be regulated by autophagy. To determine the potential mechanism, we investigated the role of a key adaptor molecule SQSTM1/p62. SQSTM1 can bind to LC3 on autophagosomes and ubiquitinated molecules on cargos, thus facilitating the autophagic engulfment of the cargo. We found that both LC3 and SQSTM1 could colocalize with lipid droplets (LDs) following ethanol treatment. Colocalization of LC3 with LDs was significantly inhibited by SQSTM1 knockdown, which also reduced ethanol-induced lipid elevation. In addition, increased ubiquitin signals were found to colocalize with SQSTM1 on LDs in response to ethanol. Moreover, the SQSTM1 signal was colocalized with that of perilipin1, a major protein on LDs. Finally, perilipin1 knockdown significantly altered ethanol-induced lipophagy. Taken together, these data support a model in which autophagosomes were directed to the LDs via SQSTM1, which bound to ubiquitinated proteins, possibly including perilipin 1, on LDs. This study provides a potential mechanistic explanation to how ethanol induces lipophagy in hepatocytes.
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Affiliation(s)
- Lin Wang
- Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.,College of Animal Science and Veterinary Medicine, Shandong Agricultural University, 61 Daizong Street, Tai'an City, Shandong Province, 271018, China.,Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, 61 Daizong Street, Tai'an City, Shandong Province, 271018, China.,Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention, Shandong Agricultural University, 61 Daizong Street, Tai'an City, Shandong Province, 271018, China
| | - Jun Zhou
- Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.,Center of Minimally Invasive Surgery, Xiangya 2nd Hospital, Central South University, Changsha, Hunan, 410011, China
| | - Shengmin Yan
- Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Guangsheng Lei
- Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Chao-Hung Lee
- Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Xiao-Ming Yin
- Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.
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Ji CH, Kwon YT. Crosstalk and Interplay between the Ubiquitin-Proteasome System and Autophagy. Mol Cells 2017; 40:441-449. [PMID: 28743182 PMCID: PMC5547213 DOI: 10.14348/molcells.2017.0115] [Citation(s) in RCA: 143] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Accepted: 07/12/2017] [Indexed: 12/21/2022] Open
Abstract
Proteolysis in eukaryotic cells is mainly mediated by the ubiquitin (Ub)-proteasome system (UPS) and the autophagylysosome system (hereafter autophagy). The UPS is a selective proteolytic system in which substrates are recognized and tagged with ubiquitin for processive degradation by the proteasome. Autophagy is a bulk degradative system that uses lysosomal hydrolases to degrade proteins as well as various other cellular constituents. Since the inception of their discoveries, the UPS and autophagy were thought to be independent of each other in components, action mechanisms, and substrate selectivity. Recent studies suggest that cells operate a single proteolytic network comprising of the UPS and autophagy that share notable similarity in many aspects and functionally cooperate with each other to maintain proteostasis. In this review, we discuss the mechanisms underlying the crosstalk and interplay between the UPS and autophagy, with an emphasis on substrate selectivity and compensatory regulation under cellular stresses.
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Affiliation(s)
- Chang Hoon Ji
- Protein Metabolism Medical Research Center and Department of Biomedical Sciences, Seoul National University, Seoul 03080,
Korea
| | - Yong Tae Kwon
- Protein Metabolism Medical Research Center and Department of Biomedical Sciences, Seoul National University, Seoul 03080,
Korea
- Ischemic/Hypoxic Disease Institute, College of Medicine, Seoul National University, Seoul 03080,
Korea
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46
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Yan S, Huda N, Khambu B, Yin XM. Relevance of autophagy to fatty liver diseases and potential therapeutic applications. Amino Acids 2017; 49:1965-1979. [PMID: 28478585 DOI: 10.1007/s00726-017-2429-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 04/21/2017] [Indexed: 12/19/2022]
Abstract
Autophagy is an evolutionarily conserved lysosome-mediated cellular degradation program. Accumulating evidence shows that autophagy is important to the maintenance of liver homeostasis. Autophagy involves recycling of cellular nutrients recycling as well as quality control of subcellular organelles. Autophagy deficiency in the liver causes various liver pathologies. Fatty liver disease (FLD) is characterized by the accumulation of lipids in hepatocytes and the dysfunction in energy metabolism. Autophagy is negatively affected by the pathogenesis of FLD and the activation of autophagy could ameliorate steatosis, which suggests a potential therapeutic approach to FLD. In this review, we will discuss autophagy and its relevance to liver diseases, especially FLD. In addition, we will discuss recent findings on potential therapeutic applications of autophagy modulators for FLD.
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Affiliation(s)
- Shengmin Yan
- Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Nazmul Huda
- Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Bilon Khambu
- Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Xiao-Ming Yin
- Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.
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Abstract
The concept of macroautophagy was established in 1963, soon after the discovery of lysosomes in rat liver. Over the 50 years since, studies of liver autophagy have produced many important findings. The liver is rich in lysosomes and possesses high levels of metabolic-stress-induced autophagy, which is precisely regulated by concentrations of hormones and amino acids. Liver autophagy provides starved cells with amino acids, glucose and free fatty acids for use in energy production and synthesis of new macromolecules, and also controls the quality and quantity of organelles such as mitochondria. Although the efforts of early investigators contributed markedly to our current knowledge of autophagy, the identification of autophagy-related genes represented a revolutionary breakthrough in our understanding of the physiological roles of autophagy in the liver. A growing body of evidence has shown that liver autophagy contributes to basic hepatic functions, including glycogenolysis, gluconeogenesis and β-oxidation, through selective turnover of specific cargos controlled by a series of transcription factors. In this Review, we outline the history of liver autophagy study, and then describe the roles of autophagy in hepatic metabolism under healthy and disease conditions, including the involvement of autophagy in α1-antitrypsin deficiency, NAFLD, hepatocellular carcinoma and viral hepatitis.
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Affiliation(s)
- Takashi Ueno
- Laboratory of Proteomics and Biomolecular Science, Research Support Center, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Masaaki Komatsu
- Department of Biochemistry, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata 951-8510, Japan
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48
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Baek A, Yoon S, Kim J, Baek YM, Park H, Lim D, Chung H, Kim DE. Autophagy and KRT8/keratin 8 protect degeneration of retinal pigment epithelium under oxidative stress. Autophagy 2017; 13:248-263. [PMID: 28045574 DOI: 10.1080/15548627.2016.1256932] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Contribution of autophagy and regulation of related proteins to the degeneration of retinal pigment epithelium (RPE) in age-related macular degeneration (AMD) remain unknown. We report that upregulation of KRT8 (keratin 8) as well as its phosphorylation are accompanied with autophagy and attenuated with the inhibition of autophagy in RPE cells under oxidative stress. KRT8 appears to have a dual role in RPE pathophysiology. While increased expression of KRT8 following autophagy provides a cytoprotective role in RPE, phosphorylation of KRT8 induces pathologic epithelial-mesenchymal transition (EMT) of RPE cells under oxidative stress, which is mediated by MAPK1/ERK2 (mitogen-activated protein kinase 1) and MAPK3/ERK1. Inhibition of autophagy further promotes EMT, which can be reversed by inhibition of MAPK. Thus, regulated enhancement of autophagy with concurrent increased expression of KRT8 and the inhibition of KRT8 phosphorylation serve to inhibit oxidative stress-induced EMT of RPE cells as well as to prevent cell death, suggesting that pharmacological manipulation of KRT8 upregulation through autophagy with combined inhibition of the MAPK1/3 pathway may be attractive therapeutic strategies for the treatment of AMD.
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Affiliation(s)
- Ahruem Baek
- a Department of Bioscience and Biotechnology , Konkuk University , Gwangjin-gu , Seoul , Korea
| | - Soojin Yoon
- a Department of Bioscience and Biotechnology , Konkuk University , Gwangjin-gu , Seoul , Korea
| | - Jean Kim
- b Department of Ophthalmology , Konkuk University School of Medicine , Gwangjin-gu , Seoul , Korea
| | - Yu Mi Baek
- a Department of Bioscience and Biotechnology , Konkuk University , Gwangjin-gu , Seoul , Korea
| | - Hanna Park
- a Department of Bioscience and Biotechnology , Konkuk University , Gwangjin-gu , Seoul , Korea
| | - Daehan Lim
- b Department of Ophthalmology , Konkuk University School of Medicine , Gwangjin-gu , Seoul , Korea
| | - Hyewon Chung
- b Department of Ophthalmology , Konkuk University School of Medicine , Gwangjin-gu , Seoul , Korea
| | - Dong-Eun Kim
- a Department of Bioscience and Biotechnology , Konkuk University , Gwangjin-gu , Seoul , Korea
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Bettermann K, Mehta AK, Hofer EM, Wohlrab C, Golob-Schwarzl N, Svendova V, Schimek MG, Stumptner C, Thüringer A, Speicher MR, Lackner C, Zatloukal K, Denk H, Haybaeck J. Keratin 18-deficiency results in steatohepatitis and liver tumors in old mice: A model of steatohepatitis-associated liver carcinogenesis. Oncotarget 2016; 7:73309-73322. [PMID: 27689336 PMCID: PMC5341981 DOI: 10.18632/oncotarget.12325] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 09/19/2016] [Indexed: 02/06/2023] Open
Abstract
Backround: Steatohepatitis (SH)-associated liver carcinogenesis is an increasingly important issue in clinical medicine. SH is morphologically characterized by steatosis, hepatocyte injury, ballooning, hepatocytic cytoplasmic inclusions termed Mallory-Denk bodies (MDBs), inflammation and fibrosis. RESULTS 17-20-months-old Krt18-/- and Krt18+/- mice in contrast to wt mice spontaneously developed liver lesions closely resembling the morphological spectrum of human SH as well as liver tumors. The pathologic alterations were more pronounced in Krt18-/- than in Krt18+/- mice. The frequency of liver tumors with male predominance was significantly higher in Krt18-/- compared to age-matched Krt18+/- and wt mice. Krt18-deficient tumors in contrast to wt animals displayed SH features and often pleomorphic morphology. aCGH analysis of tumors revealed chromosomal aberrations in Krt18-/- liver tumors, affecting loci of oncogenes and tumor suppressor genes. MATERIALS AND METHODS Livers of 3-, 6-, 12- and 17-20-months-old aged wild type (wt), Krt18+/- and Krt18-/- (129P2/OlaHsd background) mice were analyzed by light and immunofluorescence microscopy as well as immunohistochemistry. Liver tumors arising in aged mice were analyzed by array comparative genomic hybridization (aCGH). CONCLUSIONS Our findings show that K18 deficiency of hepatocytes leads to steatosis, increasing with age, and finally to SH. K18 deficiency and age promote liver tumor development in mice, frequently on the basis of chromosomal instability, resembling human HCC with stemness features.
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Affiliation(s)
- Kira Bettermann
- Institute of Pathology, Medical University of Graz, Graz 8036, Austria
| | | | - Eva M. Hofer
- Institute of Pathology, Medical University of Graz, Graz 8036, Austria
| | - Christina Wohlrab
- Institute of Pathology, Medical University of Graz, Graz 8036, Austria
| | | | - Vendula Svendova
- Institute for Medical Informatics, Statistics and Documentation, Medical University of Graz, Graz 8036, Austria
| | - Michael G. Schimek
- Institute for Medical Informatics, Statistics and Documentation, Medical University of Graz, Graz 8036, Austria
| | | | - Andrea Thüringer
- Institute of Pathology, Medical University of Graz, Graz 8036, Austria
| | | | - Carolin Lackner
- Institute of Pathology, Medical University of Graz, Graz 8036, Austria
| | - Kurt Zatloukal
- Institute of Pathology, Medical University of Graz, Graz 8036, Austria
| | - Helmut Denk
- Institute of Pathology, Medical University of Graz, Graz 8036, Austria
| | - Johannes Haybaeck
- Institute of Pathology, Medical University of Graz, Graz 8036, Austria
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50
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Lahiri P, Schmidt V, Smole C, Kufferath I, Denk H, Strnad P, Rülicke T, Fröhlich LF, Zatloukal K. p62/Sequestosome-1 Is Indispensable for Maturation and Stabilization of Mallory-Denk Bodies. PLoS One 2016; 11:e0161083. [PMID: 27526095 PMCID: PMC4985067 DOI: 10.1371/journal.pone.0161083] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 07/31/2016] [Indexed: 11/19/2022] Open
Abstract
Mallory-Denk bodies (MDBs) are hepatocytic protein aggregates found in steatohepatitis and several other chronic liver diseases as well as hepatocellular carcinoma. MDBs are mainly composed of phosphorylated keratins and stress protein p62/Sequestosome-1 (p62), which is a common component of cytoplasmic aggregates in a variety of protein aggregation diseases. In contrast to the well-established role of keratins, the role of p62 in MDB pathogenesis is still elusive. We have generated total and hepatocyte-specific p62 knockout mice, fed them with 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) to induce MDBs and allowed the mice to recover from DDC intoxication on a standard diet to investigate the role of p62 in MDB formation and elimination. In the absence of p62, smaller, granular and less distinct MDBs appeared, which failed to mature to larger and compact inclusions. Moreover, p62 deficiency impaired the binding of other proteins such as NBR1 and Hsp25 to MDBs and altered the cellular defense mechanism by downregulation of Nrf2 target genes. Upon recovery from DDC intoxication on a standard diet, there was an enhanced reduction of p62-deficient MDBs, which was accompanied by a pronounced decrease in ubiquitinated proteins. Our data provide strong evidence that keratin aggregation is the initial step in MDB formation in steatohepatitis-related mouse models. Interaction of p62 with keratin aggregates then leads to maturation i.e., enlargement and stabilization of the MDBs as well as recruitment of other MDB-associated proteins.
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Affiliation(s)
- Pooja Lahiri
- Institute of Pathology, Medical University of Graz, Graz, Austria
| | - Volker Schmidt
- Institute of Laboratory Animal Science, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Claudia Smole
- Institute of Pathology, Medical University of Graz, Graz, Austria
| | - Iris Kufferath
- Institute of Pathology, Medical University of Graz, Graz, Austria
| | - Helmut Denk
- Institute of Pathology, Medical University of Graz, Graz, Austria
| | - Pavel Strnad
- IZKF and Department of Internal Medicine III, Aachen, Germany
| | - Thomas Rülicke
- Institute of Laboratory Animal Science, University of Veterinary Medicine Vienna, Vienna, Austria
| | | | - Kurt Zatloukal
- Institute of Pathology, Medical University of Graz, Graz, Austria
- * E-mail:
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