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Zhang L, Yao Z, Ji G. Herbal Extracts and Natural Products in Alleviating Non-alcoholic Fatty Liver Disease via Activating Autophagy. Front Pharmacol 2018; 9:1459. [PMID: 30618753 PMCID: PMC6297257 DOI: 10.3389/fphar.2018.01459] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 11/29/2018] [Indexed: 12/14/2022] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is the most common form of chronic liver disease world-wide, and currently therapeutic options for NAFLD are limited. Herbal medicine (HM) may offer an attractive alternative for the treatment of NAFLD. Recent years have witnessed a growing interest in the autophagy-inducing agents, and autophagy activation has been recognized as an efficient strategy in managing NAFLD and related complications. Pharmacological studies have demonstrated certain potential of HM extracts and natural products in inducing autophagy, which might contribute to the efficacy of HM in preventing and treating NAFLD. This review aims to summarize current understanding of mechanisms of HM extracts and natural products in preventing and treating NAFLD. Specially, we focused on mechanisms by which autophagy can target the main pathogenesis events associated with NAFLD, including hepatic steatosis, inflammation, oxidative stress, and apoptosis. It is hoped that this brief review can provide a general understanding of HM extracts and natural products in treating NAFLD, and raise awareness of potential clinical application of HM in general.
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Affiliation(s)
- Li Zhang
- Institute of Digestive Diseases, China-Canada Center of Research for Digestive Diseases, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Zemin Yao
- Department of Biochemistry, Microbiology and Immunology, Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON, Canada
| | - Guang Ji
- Institute of Digestive Diseases, China-Canada Center of Research for Digestive Diseases, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
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Niture S, Gyamfi MA, Kedir H, Arthur E, Ressom H, Deep G, Kumar D. Serotonin induced hepatic steatosis is associated with modulation of autophagy and notch signaling pathway. Cell Commun Signal 2018; 16:78. [PMID: 30409162 PMCID: PMC6225666 DOI: 10.1186/s12964-018-0282-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 10/09/2018] [Indexed: 01/08/2023] Open
Abstract
Background Besides its neurotransmitter and vasoconstriction functions, serotonin is an important mediator of numerous biological processes in peripheral tissues including cell proliferation, steatosis, and fibrogenesis. Recent reports indicate that serotonin may promote tumor growth in liver cancer, however, the molecular mechanisms remain elusive. n this study, we investigated the role and molecular signaling mechanisms mediated by serotonin in liver cancer cell survival, drug resistance, and steatosis. Methods Effect of serotonin on modulation of cell survival/proliferation was determined by MTT/WST1 assay. Effect of serotonin on the regulation of autophagy biomarkers and lipid/fatty acid proteins expression, AKT/mTOR and Notch signaling was evaluated by immunoblotting. The role of serotonin in normal human hepatocytes and liver cancer cell steatosis was analyzed by Oil Red O staining. The mRNA expression levels of lipid/fatty acid proteins and serotonin receptors were validated by qRT-PCR. The important roles of autophagy, Notch signaling, serotonin receptors and serotonin re-uptake proteins on serotonin-mediated cell steatosis were investigated by using selective inhibitors or antagonists. The association of peripheral serotonin, autophagy, and hepatic steatosis was also investigated using chronic EtOH fed mouse model. Results Exposure of liver cancer cells to serotonin induced Notch signaling and autophagy, independent of AKT/mTOR pathway. Also, serotonin enhanced cancer cell proliferation/survival and drug resistance. Furthermore, serotonin treatment up-regulated the expression of lipogenic proteins and increased steatosis in liver cancer cells. Inhibition of autophagy or Notch signaling reduced serotonin-mediated cell steatosis. Treatment with serotonin receptor antagonists 5-HTr1B and 5-HTr2B reduced serotonin-mediated cell steatosis; in contrast, treatment with selective serotonin reuptake inhibitors (SSRIs) increased steatosis. In addition, mice fed with chronic EtOH resulted in increased serum serotonin levels which were associated with the induction of hepatic steatosis and autophagy. Conclusions Serotonin regulates liver cancer cell steatosis, cells survival, and may promote liver carcinogenesis by activation of Notch signaling and autophagy. Electronic supplementary material The online version of this article (10.1186/s12964-018-0282-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Suryakant Niture
- Julius L. Chambers Biomedical Biotechnology Research Institute, North Carolina Central University Durham, 1801 Fayetteville St, Durham, NC, 27707, USA
| | - Maxwell A Gyamfi
- Julius L. Chambers Biomedical Biotechnology Research Institute, North Carolina Central University Durham, 1801 Fayetteville St, Durham, NC, 27707, USA
| | - Habib Kedir
- Julius L. Chambers Biomedical Biotechnology Research Institute, North Carolina Central University Durham, 1801 Fayetteville St, Durham, NC, 27707, USA
| | - Elena Arthur
- Julius L. Chambers Biomedical Biotechnology Research Institute, North Carolina Central University Durham, 1801 Fayetteville St, Durham, NC, 27707, USA
| | - Habtom Ressom
- Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC, 20008, USA
| | - Gagan Deep
- Wake Forest Baptist Comprehensive Cancer Center, Wake Forest School of Medicine, Winston-Salem, NC, 27109, USA
| | - Deepak Kumar
- Julius L. Chambers Biomedical Biotechnology Research Institute, North Carolina Central University Durham, 1801 Fayetteville St, Durham, NC, 27707, USA. .,Department of Pharmaceutical Sciences, North Carolina Central University, Durham, NC, 27707, USA. .,Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC, 20008, USA.
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Bessone F, Dirchwolf M, Rodil MA, Razori MV, Roma MG. Review article: drug-induced liver injury in the context of nonalcoholic fatty liver disease - a physiopathological and clinical integrated view. Aliment Pharmacol Ther 2018; 48:892-913. [PMID: 30194708 DOI: 10.1111/apt.14952] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 03/25/2018] [Accepted: 07/30/2018] [Indexed: 12/15/2022]
Abstract
BACKGROUND Nonalcoholic fatty disease (NAFLD) is the most common liver disease, since it is strongly associated with obesity and metabolic syndrome pandemics. NAFLD may affect drug disposal and has common pathophysiological mechanisms with drug-induced liver injury (DILI); this may predispose to hepatoxicity induced by certain drugs that share these pathophysiological mechanisms. In addition, drugs may trigger fatty liver and inflammation per se by mimicking NAFLD pathophysiological mechanisms. AIMS To provide a comprehensive update on (a) potential mechanisms whereby certain drugs can be more hepatotoxic in NAFLD patients, (b) the steatogenic effects of drugs, and (c) the mechanism involved in drug-induced steatohepatitis (DISH). METHODS A language- and date-unrestricted Medline literature search was conducted to identify pertinent basic and clinical studies on the topic. RESULTS Drugs can induce macrovesicular steatosis by mimicking NAFLD pathogenic factors, including insulin resistance and imbalance between fat gain and loss. Other forms of hepatic fat accumulation exist, such as microvesicular steatosis and phospholipidosis, and are mostly associated with acute mitochondrial dysfunction and defective lipophagy, respectively. Drug-induced mitochondrial dysfunction is also commonly involved in DISH. Patients with pre-existing NAFLD may be at higher risk of DILI induced by certain drugs, and polypharmacy in obese individuals to treat their comorbidities may be a contributing factor. CONCLUSIONS The relationship between DILI and NAFLD may be reciprocal: drugs can cause NAFLD by acting as steatogenic factors, and pre-existing NAFLD could be a predisposing condition for certain drugs to cause DILI. Polypharmacy associated with obesity might potentiate the association between this condition and DILI.
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Affiliation(s)
- Fernando Bessone
- Hospital Provincial del Centenario, Facultad de Ciencias Médicas, Servicio de Gastroenterología y Hepatología, Universidad Nacional de Rosario, Rosario, Argentina
| | - Melisa Dirchwolf
- Unidad de Transplante Hepático, Servicio de Hepatología, Hospital Privado de Rosario, Rosario, Argentina
| | - María Agustina Rodil
- Hospital Provincial del Centenario, Facultad de Ciencias Médicas, Servicio de Gastroenterología y Hepatología, Universidad Nacional de Rosario, Rosario, Argentina
| | - María Valeria Razori
- Instituto de Fisiología Experimental (IFISE-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Marcelo G Roma
- Instituto de Fisiología Experimental (IFISE-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
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Miranda DA, Krause WC, Cazenave-Gassiot A, Suzawa M, Escusa H, Foo JC, Shihadih DS, Stahl A, Fitch M, Nyangau E, Hellerstein M, Wenk MR, Silver DL, Ingraham HA. LRH-1 regulates hepatic lipid homeostasis and maintains arachidonoyl phospholipid pools critical for phospholipid diversity. JCI Insight 2018. [PMID: 29515023 DOI: 10.1172/jci.insight.96151] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Excess lipid accumulation is an early signature of nonalcoholic fatty liver disease (NAFLD). Although liver receptor homolog 1 (LRH-1) (encoded by NR5A2) is suppressed in human NAFLD, evidence linking this phospholipid-bound nuclear receptor to hepatic lipid metabolism is lacking. Here, we report an essential role for LRH-1 in hepatic lipid storage and phospholipid composition based on an acute hepatic KO of LRH-1 in adult mice (LRH-1AAV8-Cre mice). Indeed, LRH-1-deficient hepatocytes exhibited large cytosolic lipid droplets and increased triglycerides (TGs). LRH-1-deficient mice fed high-fat diet displayed macrovesicular steatosis, liver injury, and glucose intolerance, all of which were reversed or improved by expressing wild-type human LRH-1. While hepatic lipid synthesis decreased and lipid export remained unchanged in mutants, elevated circulating free fatty acid helped explain the lipid imbalance in LRH-1AAV8-Cre mice. Lipidomic and genomic analyses revealed that loss of LRH-1 disrupts hepatic phospholipid composition, leading to lowered arachidonoyl (AA) phospholipids due to repression of Elovl5 and Fads2, two critical genes in AA biosynthesis. Our findings reveal a role for the phospholipid sensor LRH-1 in maintaining adequate pools of hepatic AA phospholipids, further supporting the idea that phospholipid diversity is an important contributor to healthy hepatic lipid storage.
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Affiliation(s)
- Diego A Miranda
- Department of Cellular and Molecular Pharmacology, UCSF, San Francisco, California, USA
| | - William C Krause
- Department of Cellular and Molecular Pharmacology, UCSF, San Francisco, California, USA
| | - Amaury Cazenave-Gassiot
- Department of Biochemistry, Yong Loo Lin School of Medicine and Singapore Lipidomics Incubator, Life Sciences Institute, National University of Singapore, Singapore
| | - Miyuki Suzawa
- Department of Cellular and Molecular Pharmacology, UCSF, San Francisco, California, USA
| | - Hazel Escusa
- Department of Cellular and Molecular Pharmacology, UCSF, San Francisco, California, USA
| | - Juat Chin Foo
- Department of Biochemistry, Yong Loo Lin School of Medicine and Singapore Lipidomics Incubator, Life Sciences Institute, National University of Singapore, Singapore
| | - Diyala S Shihadih
- Department of Nutritional Sciences and Toxicology, University of California Berkeley, Berkeley, California, USA
| | - Andreas Stahl
- Department of Nutritional Sciences and Toxicology, University of California Berkeley, Berkeley, California, USA
| | - Mark Fitch
- Department of Nutritional Sciences and Toxicology, University of California Berkeley, Berkeley, California, USA
| | - Edna Nyangau
- Department of Nutritional Sciences and Toxicology, University of California Berkeley, Berkeley, California, USA
| | - Marc Hellerstein
- Department of Nutritional Sciences and Toxicology, University of California Berkeley, Berkeley, California, USA
| | - Markus R Wenk
- Department of Biochemistry, Yong Loo Lin School of Medicine and Singapore Lipidomics Incubator, Life Sciences Institute, National University of Singapore, Singapore
| | - David L Silver
- Signature Research Program in Cardiovascular and Metabolic Diseases, Duke-National University of Singapore, Singapore
| | - Holly A Ingraham
- Department of Cellular and Molecular Pharmacology, UCSF, San Francisco, California, USA
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Abdel-Mohsen MA, El-Braky AAA, Ghazal AAER, Shamseya MM. Autophagy, apoptosis, vitamin D, and vitamin D receptor in hepatocellular carcinoma associated with hepatitis C virus. Medicine (Baltimore) 2018; 97:e0172. [PMID: 29561429 PMCID: PMC5895342 DOI: 10.1097/md.0000000000010172] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The aims of this study were to investigate the interplay between autophagy and apoptosis and to investigate the association between both of autophagy and apoptosis and vitamin D and its receptor in hepatitis C virus (HCV) viral infection and its implication in the progression into hepatocellular carcinoma (HCC).A cross-sectional study where serum levels of microtubule-associated protein 1A/1B-light chain 3 (LC3); marker of autophagy, caspase-3; marker of apoptosis, vitamin D3 and vitamin D receptor (VDR) were measured in healthy subjects as well as HCV and HCV-HCC patients using enzyme-linked immunosorbent assay technique.Collectively, the liver profile revealed hepatic dysfunctions in HCV patients with or without HCC. A significant reduction in the serum concentration levels LC3 and caspase-3 were observed referring to the down regulation of autophagy and host-mediated apoptosis in HCV patients with or without HCC. Deficiency of vitamin D and decreased levels of its receptor were observed in HCV and HCV-HCC patients.The perturbation in vitamin D/VDR axis, which modulates both of autophagy and apoptosis in HCV infection, may point out to its involvement and implication in the pathogenesis of HCV infection and the development of HCV-related HCC. Therefore, supplementation with vitamin D may not be the only solution to restore the vital biological functions of vitamin D but VDR-targeted therapy may be of great importance in this respect.
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Affiliation(s)
| | | | | | - Mohammed Mohammed Shamseya
- Department of Clinical and Experimental Internal Medicine, Medical Research Institute, Alexandria University, Alexandria, Egypt
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Ali MA, Matboli M, El-Khazragy N, Saber O, El-Nakeep S, Abdelzaher HM, Shafei AES, Mostafa R. Investigating miRNA-661 and ATG4-B mRNA expression as potential biomarkers for hepatocellular carcinoma. Biomark Med 2018; 12:245-256. [PMID: 29441798 DOI: 10.2217/bmm-2017-0273] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
AIM We aimed to examine the statistical association between serum expression of miRNA 661 (miR-661) and ATG-4B mRNA and hepatocellular carcinoma (HCC) based on in silico data analysis followed by clinical validation. PATIENTS & METHODS Quantitative reverse-transcriptase real-time PCR was used to examine the expression of miR-661 and ATG-4B mRNA in the sera of HCC patients versus control. RESULTS The expression of miR-661 and ATG-4B mRNA was positive in 97.14 and 77.14%, respectively, in HCC patients. The survival analysis showed that ATG-4B mRNA was an independent prognostic factor. CONCLUSION Our data are the first report of its kind regarding the considerable clinical significance of miR-661 and ATG-4B mRNA in HCC patients.
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Affiliation(s)
- Mahmoud A Ali
- Department of Biomedical Research, Armed Forces College of Medicine (AFCM), Cairo, 11774, Egypt
| | - Marwa Matboli
- Department of Medical Biochemistry & Molecular Biology, Ain Shams Faculty of Medicine Research Center (Masri), 11778, Eygpt
| | - Nashwa El-Khazragy
- Department of Clinical Pathology, Oncology Diagnostic Unit, Faculty of Medicine, Ain Shams University, Cairo, 11778, Egypt
| | - Osama Saber
- Armed Forces College of Medicine (AFCM), Cairo, 11774, Egypt
| | - Sarah El-Nakeep
- Hepatology & Gastroenterology Unit, Internal Medicine Department, Faculty of Medicine, Ain Shams University, Cairo, 11778, Egypt
| | - Hana M Abdelzaher
- Faculty of Biotechnology, October University for Modern Sciences & Arts, Cairo, 12585, Egypt
| | - Ayman El-Sayed Shafei
- Department of Biomedical Research, Armed Forces College of Medicine (AFCM), Cairo, 11774, Egypt
| | - Randa Mostafa
- Department of Biomedical Research, Armed Forces College of Medicine (AFCM), Cairo, 11774, Egypt
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Zhang Z, Yao Z, Chen Y, Qian L, Jiang S, Zhou J, Shao J, Chen A, Zhang F, Zheng S. Lipophagy and liver disease: New perspectives to better understanding and therapy. Biomed Pharmacother 2017; 97:339-348. [PMID: 29091883 DOI: 10.1016/j.biopha.2017.07.168] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 07/10/2017] [Accepted: 07/30/2017] [Indexed: 02/07/2023] Open
Abstract
Intracellular lipid droplets (LDs) are remarkably dynamic and complex organelles that enact regulated storage and release of lipids to fulfil their fundamental roles in energy metabolism, membrane synthesis and provision of lipid-derived signaling molecules. The recent finding that LDs can be selectively degraded by the lysosomal pathway of autophagy through a process termed lipophagy has opened up a new understanding of how lipid metabolism regulates cellular physiology and pathophysiology. Many new functions for autophagic lipid metabolism have now been defined in various diseases including liver disease. Lipophagy was originally described in hepatocytes, where it is critical for maintaining cellular energy homeostasis in obesity and metabolic syndrome. In vitro and in vivo studies have demonstrated the selective uptake of LDs by autophagosomes, and inhibition of autophagy has been shown to reduce the β-oxidation of free fatty acids due to the increased accumulation of lipids and LDs. The identification of lipophagy as a new process dedicated to cellular lipid removal has mapped autophagy as an emerging player in cellular lipid metabolism. Pharmacological or genetic modulation of lipophagy might point to possible therapeutic strategies for combating a broad range of liver diseases. This review summarizes recent work focusing on lipophagy and liver disease as well as highlighting challenges and future directions of research. On the other hand, it also offers a glimpse into different strategies that have been used in experimental models to counteract excessive pathological lipophagy in the prevention and treatment of liver disease.
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Affiliation(s)
- Zili Zhang
- Department of Pharmacology, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210023, China
| | - Zhen Yao
- Department of Pharmacology, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210023, China
| | - Yifan Chen
- Department of Pharmacology, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210023, China
| | - Lei Qian
- Department of Pharmacology, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210023, China
| | - Shuoyi Jiang
- Department of Pharmacology, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210023, China
| | - Jingyi Zhou
- Department of Pharmacology, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210023, China
| | - Jiangjuan Shao
- Department of Pharmacology, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210023, China
| | - Anping Chen
- Department of Pathology, School of Medicine, Saint Louis University, St Louis, MO 63104, USA
| | - Feng Zhang
- Department of Pharmacology, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210023, China; Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing 210023, China; Jiangsu Key Laboratory of Therapeutic Material of Chinese Medicine, Nanjing University of Chinese Medicine, Nanjing 210023, China
| | - Shizhong Zheng
- Department of Pharmacology, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210023, China; Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing 210023, China; Jiangsu Key Laboratory of Therapeutic Material of Chinese Medicine, Nanjing University of Chinese Medicine, Nanjing 210023, China.
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Combination of ULK1 and LC3B improve prognosis assessment of hepatocellular carcinoma. Biomed Pharmacother 2017; 97:195-202. [PMID: 29091866 DOI: 10.1016/j.biopha.2017.10.025] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 09/30/2017] [Accepted: 10/03/2017] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Autophagy involves in both prevention and promotion in cancer, and its role probably changed during tumor development. Defined the dynamic function of autophagy in cancer may advance precision diagnostics, treatment, and guide drug design. Autophagy related protein ULK1 is key regulator of autophagy, and its role in hepatocellular carcinoma (HCC) was still unclear. This study aims to investigate ULK1's capacity along with other autophagic markers in predicting prognosis of HCC and explore position of these biomarkers in dynamic function of autophagy during HCC progression. METHODS The expression of ULK1 and other autophagic marker (LC3B) were test by Tissue microarray-based immunohistochemistry in 156 operable HCC patients. Survival analysis and correlation analysis were used to analysis influence of ULK1 and combined biomarker on clinical characteristics and prognosis. RESULTS The expression level of ULK1 was not related to all clinicopathological features, however, high expression of the ULK1 as well as LC3B overexpression suggested large tumor size (P=0.035), high levels of serum AFP (P=0.049), more frequency of node metastasis (P=0.015), later TNM stage (P=0.009). Survival analysis showed that ULK1 expression were negatively correlated with PFS rather than OS in HCC patients (P=0.021), while LC3B were suggested to be negatively related with patients' PFS, However, Simultaneous high expression of ULK1 and LC3B had a poorer 5-year overall survival (OS) rate (P=0.002) and shorter 5-year progression free survival (PFS)(P=0.003), Further multivariate analysis revealed that the two combined biomarkers were independent factors to predict the prognosis of OS and PFS in all patients, while ULK1 alone or LC3B alone were only an independent predict factor for OS or PFS respectively. CONCLUSION ULK1 were demonstrated to be an important prognostic factor for HCC patient, and it combined LC3B would improve prognosis assessment of the patients. Combined autophagic biomarkers would better represent dynamic stage of autophagy and It might provide a potential therapeutic way that how to interfere autophagy in HCC.
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Schulze RJ, Sathyanarayan A, Mashek DG. Breaking fat: The regulation and mechanisms of lipophagy. Biochim Biophys Acta Mol Cell Biol Lipids 2017. [PMID: 28642194 DOI: 10.1016/j.bbalip.2017.06.008] [Citation(s) in RCA: 151] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Lipophagy is defined as the autophagic degradation of intracellular lipid droplets (LDs). While the field of lipophagy research is relatively young, an expansion of research in this area over the past several years has greatly advanced our understanding of lipophagy. Since its original characterization in fasted liver, the contribution of lipophagy is now recognized in various organisms, cell types, metabolic states and disease models. Moreover, recent studies provide exciting new insights into the underlying mechanisms of lipophagy induction as well as the consequences of lipophagy on cell metabolism and signaling. This review summarizes recent work focusing on LDs and lipophagy as well as highlighting challenges and future directions of research as our understanding of lipophagy continues to grow and evolve. This article is part of a Special Issue entitled: Recent Advances in Lipid Droplet Biology edited by Rosalind Coleman and Matthijs Hesselink.
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Affiliation(s)
- Ryan J Schulze
- Department of Biochemistry and Molecular Biology and the Center for Digestive Diseases, Mayo Clinic, Rochester, MN, United States
| | - Aishwarya Sathyanarayan
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, United States
| | - Douglas G Mashek
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, United States; Department of Medicine, Division of Diabetes, Endocrinology and Metabolism, University of Minnesota, Minneapolis, MN, United States.
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Tsai TH, Chen E, Li L, Saha P, Lee HJ, Huang LS, Shelness GS, Chan L, Chang BHJ. The constitutive lipid droplet protein PLIN2 regulates autophagy in liver. Autophagy 2017; 13:1130-1144. [PMID: 28548876 DOI: 10.1080/15548627.2017.1319544] [Citation(s) in RCA: 129] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Excess triglyceride (TG) accumulation in the liver underlies fatty liver disease, a highly prevalent ailment. TG occurs in the liver sequestered in lipid droplets, the major lipid storage organelle. Lipid droplets are home to the lipid droplet proteins, the most abundant of which are the perilipins (PLINs), encoded by 5 different genes, Plin1 to Plin5. Of the corresponding gene products, PLIN2 is the only constitutive and ubiquitously expressed lipid droplet protein that has been used as a protein marker for lipid droplets. We and others reported that plin2-/- mice have an ∼60% reduction in TG content, and are protected against fatty liver disease. Here we show that PLIN2 overexpression protects lipid droplets against macroautophagy/autophagy, whereas PLIN2 deficiency enhances autophagy and depletes hepatic TG. The enhanced autophagy in plin2-/- mice protects against severe ER stress-induced hepatosteatosis and hepatocyte apoptosis. In contrast, hepatic TG depletion resulting from other genetic and pharmacological manipulations has no effect on autophagy. Importantly, PLIN2 deficiency lowers cellular TG content in wild-type mouse embryonic fibroblasts (MEFs) via enhanced autophagy, but does not affect cellular TG content in atg7-/- MEFs that are devoid of autophagic function. Conversely, adenovirus-shAtg7-mediated hepatic Atg7 knockdown per se does not alter the hepatic TG level, suggesting a more complex regulation in vivo. In sum, PLIN2 guards its own house, the lipid droplet. PLIN2 overexpression protects against autophagy, and its downregulation stimulates TG catabolism via autophagy.
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Affiliation(s)
- Tsung-Huang Tsai
- a Departments of Medicine, Baylor College of Medicine , Houston , TX , USA
| | - Elaine Chen
- b Molecular and Cellular Biology , Baylor College of Medicine , Houston , TX , USA
| | - Lan Li
- a Departments of Medicine, Baylor College of Medicine , Houston , TX , USA
| | - Pradip Saha
- a Departments of Medicine, Baylor College of Medicine , Houston , TX , USA.,b Molecular and Cellular Biology , Baylor College of Medicine , Houston , TX , USA
| | - Hsiao-Ju Lee
- a Departments of Medicine, Baylor College of Medicine , Houston , TX , USA
| | - Li-Shin Huang
- c Department of Medicine , Columbia University , New York , NY , USA
| | - Gregory S Shelness
- d Department of Internal Medicine , Section on Molecular Medicine, Wake Forest School of Medicine , Winston-Salem , NC , USA
| | - Lawrence Chan
- a Departments of Medicine, Baylor College of Medicine , Houston , TX , USA.,b Molecular and Cellular Biology , Baylor College of Medicine , Houston , TX , USA
| | - Benny Hung-Junn Chang
- a Departments of Medicine, Baylor College of Medicine , Houston , TX , USA.,b Molecular and Cellular Biology , Baylor College of Medicine , Houston , TX , USA
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Liu C, Liao JZ, Li PY. Traditional Chinese herbal extracts inducing autophagy as a novel approach in therapy of nonalcoholic fatty liver disease. World J Gastroenterol 2017; 23:1964-1973. [PMID: 28373762 PMCID: PMC5360637 DOI: 10.3748/wjg.v23.i11.1964] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 12/23/2016] [Accepted: 01/18/2017] [Indexed: 02/07/2023] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is one of the leading causes of chronic liver diseases around the world due to the modern sedentary and food-abundant lifestyle, which is characterized by excessive fat accumulation in the liver related with causes other than alcohol abuse. It is widely acknowledged that insulin resistance, dysfunctional lipid metabolism, endoplasmic reticulum stress, oxidative stress, inflammation, and apoptosis/necrosis may all contribute to NAFLD. Autophagy is a protective self-digestion of intracellular organelles, including lipid droplets (lipophagy), in response to stress to maintain homeostasis. Lipophagy is another pathway for lipid degradation besides lipolysis. It is reported that impaired autophagy also contributes to NAFLD. Some studies have suggested that the histological characteristics of NAFLD (steatosis, lobular inflammation, and peri-sinusoid fibrosis) might be improved by treatment with traditional Chinese herbal extracts, while autophagy may be induced. This review will provide insights into the characteristics of autophagy in NAFLD and the related role/mechanisms of autophagy induced by traditional Chinese herbal extracts such as resveratrol, Lycium barbarum polysaccharides, dioscin, bergamot polyphenol fraction, capsaicin, and garlic-derived S-allylmercaptocysteine, which may inhibit the progression of NAFLD. Regulation of autophagy/lipophagy with traditional Chinese herbal extracts may be a novel approach for treating NAFLD, and the molecular mechanisms should be elucidated further in the near future.
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Rosa-Caldwell ME, Lee DE, Brown JL, Brown LA, Perry RA, Greene ES, Carvallo Chaigneau FR, Washington TA, Greene NP. Moderate physical activity promotes basal hepatic autophagy in diet-induced obese mice. Appl Physiol Nutr Metab 2017; 42:148-156. [DOI: 10.1139/apnm-2016-0280] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Obesity is a known risk factor for the development of hepatic disease; obesity-induced fatty liver can lead to inflammation, steatosis, and cirrhosis and is associated with degeneration of the mitochondria. Lifestyle interventions such as physical activity may ameliorate this condition. The purpose of this study was to investigate regulation of mitochondrial and autophagy quality control in liver following Western diet-induced obesity and voluntary physical activity. Eight-week-old C57BL/6J mice were fed a Western diet (WD) or normal chow (NC, control) for 4 weeks; afterwards, groups were divided into voluntary wheel running (VWR) or sedentary (SED) conditions for an additional 4 weeks. WD-SED animals had a median histology score of 2, whereas WD-VWR was not different from NC groups (median score 1). There was no difference in mRNA of inflammatory markers Il6 and Tnfa in WD animals. WD animals had 50% lower mitochondrial content (COX IV and Cytochrome C proteins), 50% lower Pgc1a mRNA content, and reduced content of mitochondrial fusion and fission markers. Markers of autophagy were increased in VWR animals, regardless of obesity, as measured by 50% greater LC3-II/I ratio and 40% lower p62 protein content. BNIP3 protein content was 30% less in WD animals compared with NC animals, regardless of physical activity. Diet-induced obesity results in derangements in mitochondrial quality control that appear to occur prior to the onset of hepatic inflammation. Moderate physical activity appears to enhance basal autophagy in the liver; increased autophagy may provide protection from hepatic fat accumulation.
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Affiliation(s)
- Megan E. Rosa-Caldwell
- Integrative Muscle Metabolism Laboratory, Human Performance Laboratory, Department of Health, Human Performance and Recreation, University of Arkansas, Fayetteville, AR 72701, USA
| | - David E. Lee
- Integrative Muscle Metabolism Laboratory, Human Performance Laboratory, Department of Health, Human Performance and Recreation, University of Arkansas, Fayetteville, AR 72701, USA
| | - Jacob L. Brown
- Integrative Muscle Metabolism Laboratory, Human Performance Laboratory, Department of Health, Human Performance and Recreation, University of Arkansas, Fayetteville, AR 72701, USA
| | - Lemuel A. Brown
- Exercise Muscle Biology Laboratory, Human Performance Laboratory, Department of Health, Human Performance and Recreation, University of Arkansas, Fayetteville, AR 72701, USA
| | - Richard A. Perry
- Exercise Muscle Biology Laboratory, Human Performance Laboratory, Department of Health, Human Performance and Recreation, University of Arkansas, Fayetteville, AR 72701, USA
| | - Elizabeth S. Greene
- Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA
| | - Francisco R. Carvallo Chaigneau
- California Animal Health and Food Safety Laboratory, University of California-Davis School of Veterinary Medicine, Davis, CA 95616, USA
| | - Tyrone A. Washington
- Exercise Muscle Biology Laboratory, Human Performance Laboratory, Department of Health, Human Performance and Recreation, University of Arkansas, Fayetteville, AR 72701, USA
| | - Nicholas P. Greene
- Integrative Muscle Metabolism Laboratory, Human Performance Laboratory, Department of Health, Human Performance and Recreation, University of Arkansas, Fayetteville, AR 72701, USA
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Liu TY, Xiong XQ, Ren XS, Zhao MX, Shi CX, Wang JJ, Zhou YB, Zhang F, Han Y, Gao XY, Chen Q, Li YH, Kang YM, Zhu GQ. FNDC5 Alleviates Hepatosteatosis by Restoring AMPK/mTOR-Mediated Autophagy, Fatty Acid Oxidation, and Lipogenesis in Mice. Diabetes 2016; 65:3262-3275. [PMID: 27504012 DOI: 10.2337/db16-0356] [Citation(s) in RCA: 103] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Accepted: 07/21/2016] [Indexed: 11/13/2022]
Abstract
Fibronectin type III domain-containing 5 (FNDC5) protein induces browning of subcutaneous fat and mediates the beneficial effects of exercise on metabolism. However, whether FNDC5 is associated with hepatic steatosis, autophagy, fatty acid oxidation (FAO), and lipogenesis remains unknown. Herein, we show the roles and mechanisms of FNDC5 in hepatic steatosis, autophagy, and lipid metabolism. Fasted FNDC5-/- mice exhibited severe steatosis, reduced autophagy, and FAO, and enhanced lipogenesis in the liver compared with wild-type mice. Energy deprivation-induced autophagy, FAO, and AMPK activity were attenuated in FNDC5-/- hepatocytes, which were restored by activating AMPK with 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR). Inhibition of mammalian target of rapamycin (mTOR) complex 1 with rapamycin enhanced autophagy and FAO and attenuated lipogenesis and steatosis in FNDC5-/- livers. FNDC5 deficiency exacerbated hyperlipemia, hepatic FAO and autophagy impairment, hepatic lipogenesis, and lipid accumulation in obese mice. Exogenous FNDC5 stimulated autophagy and FAO gene expression in hepatocytes and repaired the attenuated autophagy and palmitate-induced steatosis in FNDC5-/- hepatocytes. FNDC5 overexpression prevented hyperlipemia, hepatic FAO and autophagy impairment, hepatic lipogenesis, and lipid accumulation in obese mice. These results indicate that FNDC5 deficiency impairs autophagy and FAO and enhances lipogenesis via the AMPK/mTOR pathway. FNDC5 deficiency aggravates whereas FNDC5 overexpression prevents the HFD-induced hyperlipemia, hepatic lipid accumulation, and impaired FAO and autophagy in the liver.
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Affiliation(s)
- Tong-Yan Liu
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Xiao-Qing Xiong
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Xing-Sheng Ren
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Ming-Xia Zhao
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Chang-Xiang Shi
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Jue-Jin Wang
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Ye-Bo Zhou
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Feng Zhang
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Ying Han
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Xing-Ya Gao
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Qi Chen
- Department of Pathophysiology, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Yue-Hua Li
- Department of Pathophysiology, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Yu-Ming Kang
- Department of Physiology and Pathophysiology, Cardiovascular Research Center, Xi'an Jiaotong University School of Medicine, Xi'an, Shaanxi, China
| | - Guo-Qing Zhu
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu, China
- Department of Pathophysiology, Nanjing Medical University, Nanjing, Jiangsu, China
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Kwanten WJ, Vandewynckel YP, Martinet W, De Winter BY, Michielsen PP, Van Hoof VO, Driessen A, Timmermans JP, Bedossa P, Van Vlierberghe H, Francque SM. Hepatocellular autophagy modulates the unfolded protein response and fasting-induced steatosis in mice. Am J Physiol Gastrointest Liver Physiol 2016; 311:G599-G609. [PMID: 27514483 PMCID: PMC5142201 DOI: 10.1152/ajpgi.00418.2015] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 08/05/2016] [Indexed: 01/31/2023]
Abstract
Autophagy and the unfolded protein response (UPR) are key cellular homeostatic mechanisms and are both involved in liver diseases, including nonalcoholic fatty liver disease (NAFLD). Although increasing but conflicting results link these mechanisms to lipid metabolism, their role and potential cross talk herein have been poorly investigated. Therefore, we assessed the effects of hepatocyte-specific autophagy deficiency on liver parenchyma, the UPR, and lipid metabolism. Adult hepatocellular-specific autophagy-deficient mice (Atg7F/FAlb-Cre+) were compared with their autophagy-competent littermates (Atg7+/+Alb-Cre+). Livers were analyzed by electron microscopy, histology, real-time qPCR, and Western blotting. Atg7F/FAlb-Cre+ mice developed hepatomegaly with significant parenchymal injury, as shown by inflammatory infiltrates, hepatocellular apoptosis, pericellular fibrosis, and a pronounced ductular reaction. Surprisingly, the UPR exhibited a pathway-selective pattern upon autophagy deficiency. The activity of the adaptive activating transcription factor 6 (ATF6) pathway was abolished, whereas the proapoptotic protein kinase RNA-like ER kinase pathway was increased compared with Atg7+/+Alb-Cre+ mice. The inositol-requiring enzyme-1α signal was unaltered. Fasting-induced steatosis was absent in Atg7F/FAlb-Cre+ mice. Remarkably, some isolated islands of fat-containing and autophagy-competent cells were observed in these livers. Hepatocellular autophagy is essential for parenchymal integrity in mice. Moreover, in the case of autophagy deficiency, the three different UPR branches are pathway selectively modulated. Attenuation of the ATF6 pathway might explain the observed impairment of fasting-induced steatosis. Finally, autophagy and lipid droplets are directly linked to each other.
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Affiliation(s)
- Wilhelmus J. Kwanten
- 1Laboratory of Experimental Medicine and Pediatrics (LEMP), University of Antwerp, Antwerp, Belgium;
| | | | - Wim Martinet
- 3Laboratory of Physiopharmacology, University of Antwerp, Antwerp, Belgium;
| | - Benedicte Y. De Winter
- 1Laboratory of Experimental Medicine and Pediatrics (LEMP), University of Antwerp, Antwerp, Belgium;
| | - Peter P. Michielsen
- 1Laboratory of Experimental Medicine and Pediatrics (LEMP), University of Antwerp, Antwerp, Belgium; ,4Department of Gastroenterology and Hepatology, Antwerp University Hospital, Edegem (Antwerp), Belgium;
| | - Viviane O. Van Hoof
- 5Department of Clinical Chemistry, Antwerp University Hospital, Edegem (Antwerp), Belgium;
| | - Ann Driessen
- 6Department of Pathology, Antwerp University Hospital/University of Antwerp, Edegem (Antwerp), Belgium;
| | | | - Pierre Bedossa
- 8Department of Pathology, Beaujon Hospital, Assistance Publique-Hôpitaux de Paris, Paris University-Denis Diderot, Clichy, France
| | - Hans Van Vlierberghe
- 2Department of Hepatology and Gastroenterology, Ghent University, Ghent, Belgium;
| | - Sven M. Francque
- 1Laboratory of Experimental Medicine and Pediatrics (LEMP), University of Antwerp, Antwerp, Belgium; ,4Department of Gastroenterology and Hepatology, Antwerp University Hospital, Edegem (Antwerp), Belgium;
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65
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Gong LL, Li GR, Zhang W, Liu H, Lv YL, Han FF, Wan ZR, Shi MB, Liu LH. Akebia Saponin D Decreases Hepatic Steatosis through Autophagy Modulation. J Pharmacol Exp Ther 2016; 359:392-400. [DOI: 10.1124/jpet.116.236562] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 09/20/2016] [Indexed: 01/01/2023] Open
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Taniguchi K, Yamachika S, He F, Karin M. p62/SQSTM1-Dr. Jekyll and Mr. Hyde that prevents oxidative stress but promotes liver cancer. FEBS Lett 2016; 590:2375-97. [PMID: 27404485 DOI: 10.1002/1873-3468.12301] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 07/08/2016] [Accepted: 07/09/2016] [Indexed: 12/17/2022]
Abstract
p62/SQSTM1 is a multifunctional signaling hub and autophagy adaptor with many binding partners, which allow it to activate mTORC1-dependent nutrient sensing, NF-κB-mediated inflammatory responses, and the NRF2-activated antioxidant defense. p62 recognizes polyubiquitin chains via its C-terminal domain and binds to LC3 via its LIR motif, thereby promoting the autophagic degradation of ubiquitinated cargos. p62 accumulates in many human liver diseases, including nonalcoholic steatohepatitis (NASH) and hepatocellular carcinoma (HCC), where it is a component of Mallory-Denk bodies and intracellular hyaline bodies. Chronic p62 elevation contributes to HCC development by preventing oncogene-induced senescence and death of cancer-initiating cells and enhancing their proliferation. In this review, we discuss p62-mediated signaling pathways and their roles in liver pathophysiology, especially NASH and HCC.
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Affiliation(s)
- Koji Taniguchi
- Laboratory of Gene Regulation and Signal Transduction, Departments of Pharmacology and Pathology, University of California San Diego, La Jolla, CA, USA.,Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.,Department of Microbiology and Immunology, Keio University School of Medicine, Tokyo, Japan
| | - Shinichiro Yamachika
- Laboratory of Gene Regulation and Signal Transduction, Departments of Pharmacology and Pathology, University of California San Diego, La Jolla, CA, USA
| | - Feng He
- Laboratory of Gene Regulation and Signal Transduction, Departments of Pharmacology and Pathology, University of California San Diego, La Jolla, CA, USA
| | - Michael Karin
- Laboratory of Gene Regulation and Signal Transduction, Departments of Pharmacology and Pathology, University of California San Diego, La Jolla, CA, USA
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67
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Xu YJ, Lin J, Lu Y, Zhong SL, Wang L, Dong L, Wu YD, Peng J, Zhang L, Pan XF, Zhou W, Zhao Y, Wen LP, Yu SH. Lanthanide co-doped paramagnetic spindle-like mesocrystals for imaging and autophagy induction. NANOSCALE 2016; 8:13399-13406. [PMID: 27346838 DOI: 10.1039/c6nr03171d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We synthesized two novel lanthanide doped spindle-like mesocrystals, YF3:Ce,Eu,Gd and YF3:Ce,Tb,Gd (abbreviated as YEG and YTG mesospindles, respectively). Both of them possess paramagnetic and fluorescent properties, and their excellent cyto-compatibility and low haemolysis are further confirmed. Therefore, they could act as dual mode contrast agents for magnetic resonance imaging (MRI) and fluorescence imaging. Furthermore, YEG and YTG mesospindles induce dose and time dependent autophagy by activating the PI3K signaling pathway. The autophagy induced by YEG and YTG mesocrystals is confirmed by enhanced autophagosome formation, normal cargo degradation, and no disruption of lysosomal function. This work is important to illustrate how rare-earth mesocrystals affect the autophagic pathway, indicating the potential of the YEG and YTG mesospindles in diagnosis and therapy.
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Affiliation(s)
- Yun-Jun Xu
- Division of Nanomaterials & Chemistry, Hefei National Laboratory for Physical Sciences at the Microscale, Collaborative Innovation Center of Suzhou Nano Science and Technology, Department of Chemistry, University of Science and Technology of China, Hefei 230026, P. R. China.
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68
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Liu W, Baker RD, Bhatia T, Zhu L, Baker SS. Pathogenesis of nonalcoholic steatohepatitis. Cell Mol Life Sci 2016; 73:1969-87. [PMID: 26894897 PMCID: PMC11108381 DOI: 10.1007/s00018-016-2161-x] [Citation(s) in RCA: 106] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 01/19/2016] [Accepted: 02/09/2016] [Indexed: 02/06/2023]
Abstract
Nonalcoholic steatohepatitis (NASH) is a severe form of nonalcoholic fatty liver disease and a risk factor for cirrhosis and hepatocellular carcinoma. The pathological features of NASH include steatosis, hepatocyte injury, inflammation, and various degrees of fibrosis. Steatosis reflects disordered lipid metabolism. Insulin resistance and excessive fatty acid influx to the liver are two important contributing factors. Steatosis is also likely associated with lipotoxicity and cellular stresses such as oxidative stress and endoplasmic reticulum stress, which result in hepatocyte injury. Inflammation and fibrosis are frequently triggered by various signals such as proinflammatory cytokines and chemokines, released by injuried hepatocytes and activated Kupffer cells. Although much progress has been made, the pathogenesis of NASH is not fully elucidated. The purpose of this review is to discuss the current understanding of NASH pathogenesis, mainly focusing on factors contributing to steatosis, hepatocyte injury, inflammation, and fibrosis.
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Affiliation(s)
- Wensheng Liu
- Department of Pediatrics, Digestive Diseases and Nutrition Center, Women and Children's Hospital of Buffalo, The State University of New York at Buffalo (SUNY Buffalo), 3435 Main Street, 422 BRB, Buffalo, NY, 14214, USA.
| | - Robert D Baker
- Department of Pediatrics, Digestive Diseases and Nutrition Center, Women and Children's Hospital of Buffalo, The State University of New York at Buffalo (SUNY Buffalo), 3435 Main Street, 422 BRB, Buffalo, NY, 14214, USA
| | - Tavleen Bhatia
- Department of Pediatrics, Digestive Diseases and Nutrition Center, Women and Children's Hospital of Buffalo, The State University of New York at Buffalo (SUNY Buffalo), 3435 Main Street, 422 BRB, Buffalo, NY, 14214, USA
| | - Lixin Zhu
- Department of Pediatrics, Digestive Diseases and Nutrition Center, Women and Children's Hospital of Buffalo, The State University of New York at Buffalo (SUNY Buffalo), 3435 Main Street, 422 BRB, Buffalo, NY, 14214, USA
| | - Susan S Baker
- Department of Pediatrics, Digestive Diseases and Nutrition Center, Women and Children's Hospital of Buffalo, The State University of New York at Buffalo (SUNY Buffalo), 3435 Main Street, 422 BRB, Buffalo, NY, 14214, USA.
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Blocking Nuclear Factor-Kappa B Protects against Diet-Induced Hepatic Steatosis and Insulin Resistance in Mice. PLoS One 2016; 11:e0149677. [PMID: 26930600 PMCID: PMC4773172 DOI: 10.1371/journal.pone.0149677] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 02/02/2016] [Indexed: 02/06/2023] Open
Abstract
Inflammation critically contributes to the development of various metabolic diseases. However, the effects of inhibiting inflammatory signaling on hepatic steatosis and insulin resistance, as well as the underlying mechanisms remain obscure. In the current study, male C57BL/6J mice were fed a chow diet or high-fat diet (HFD) for 8 weeks. HFD-fed mice were respectively treated with p65 siRNA, non-silence control siRNA or vehicle every 4th day for the last 4 weeks. Vehicle-treated (HF) and non-silence siRNA-treated (HFNS) mice displayed overt inflammation, hepatic steatosis and insulin resistance compared with chow-diet-fed (NC) mice. Upon treatment with NF-κB p65 siRNA, HFD-fed (HFPS) mice were protected from hepatic steatosis and insulin resistance. Furthermore, Atg7 and Beclin1 expressions and p-AMPK were increased while p-mTOR was decreased in livers of HFPS mice in relative to HF and HFNS mice. These results suggest a crosslink between NF-κB signaling pathway and liver AMPK/mTOR/autophagy axis in the context of hepatic steatosis and insulin resistance.
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70
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Jin Y, Bai Y, Ni H, Qiang L, Ye L, Shan Y, Zhou M. Activation of autophagy through calcium-dependent AMPK/mTOR and PKCθ pathway causes activation of rat hepatic stellate cells under hypoxic stress. FEBS Lett 2016; 590:672-82. [PMID: 26848942 DOI: 10.1002/1873-3468.12090] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Revised: 01/15/2016] [Accepted: 01/29/2016] [Indexed: 12/15/2022]
Affiliation(s)
- Yuepeng Jin
- Department of Surgery; The First Affiliated Hospital; Wenzhou Medical University; China
| | | | - Haizhen Ni
- Department of Surgery; The First Affiliated Hospital; Wenzhou Medical University; China
| | - Li Qiang
- Wenzhou Medical University; China
| | - Lechi Ye
- Department of Oncological Surgery; The First Affiliated Hospital; Wenzhou Medical University; China
| | - Yunfeng Shan
- Department of Surgery; The First Affiliated Hospital; Wenzhou Medical University; China
| | - Mengtao Zhou
- Department of Surgery; The First Affiliated Hospital; Wenzhou Medical University; China
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Li J, Chen K, Li S, Feng J, Liu T, Wang F, Zhang R, Xu S, Zhou Y, Zhou S, Xia Y, Lu J, Zhou Y, Guo C. Protective effect of fucoidan from Fucus vesiculosus on liver fibrosis via the TGF-β1/Smad pathway-mediated inhibition of extracellular matrix and autophagy. Drug Des Devel Ther 2016; 10:619-30. [PMID: 26929597 PMCID: PMC4758785 DOI: 10.2147/dddt.s98740] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Liver fibrosis is a dynamic reversible pathological process in the development of chronic liver disease to cirrhosis. However, the current treatments are not administered for a long term due to their various side effects. Autophagy is initiated to decompose damaged or excess organelles, which had been found to alter the progression of liver fibrosis. In this article, we hypothesized that fucoidan from Fucus vesiculosus may attenuate liver fibrosis in mice by inhibition of the extracellular matrix and autophagy in carbon tetrachloride- and bile duct ligation-induced animal models of liver fibrosis. The results were determined using enzyme-linked immunosorbent assay, quantitative real-time polymerase chain reaction, Western blotting, and immunohistochemical staining. Fucoidan from F. vesiculosus could inhibit the activation of hepatic stellate cells and the formation of extracellular matrix and autophagosomes, and its effect may be associated with the downregulation of transforming growth factor beta 1/Smads pathways. Fucoidan, as an autophagy and transforming growth factor beta 1 inhibitor, could be a promising potential therapeutic agent for liver fibrosis.
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Affiliation(s)
- Jingjing Li
- Department of Gastroenterology, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai, People’s Republic of China
| | - Kan Chen
- Department of Gastroenterology, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai, People’s Republic of China
| | - Sainan Li
- Department of Gastroenterology, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai, People’s Republic of China
| | - Jiao Feng
- Department of Gastroenterology, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai, People’s Republic of China
| | - Tong Liu
- Department of Gastroenterology, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai, People’s Republic of China
| | - Fan Wang
- Department of Gastroenterology, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai, People’s Republic of China
| | - Rong Zhang
- Department of Gastroenterology, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai, People’s Republic of China
- The First Clinical Medical College of Nanjing Medical University, Nanjing, People’s Republic of China
| | - Shizan Xu
- Department of Gastroenterology, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai, People’s Republic of China
- The First Clinical Medical College of Nanjing Medical University, Nanjing, People’s Republic of China
| | - Yuqing Zhou
- Department of Gastroenterology, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai, People’s Republic of China
- Department of Gastroenterology, The First Affiliated Hospital of Soochow University, Suzhou, People’s Republic of China
| | - Shunfeng Zhou
- Department of Gastroenterology, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai, People’s Republic of China
- Department of Gastroenterology, The First Affiliated Hospital of Soochow University, Suzhou, People’s Republic of China
| | - Yujing Xia
- Department of Gastroenterology, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai, People’s Republic of China
| | - Jie Lu
- Department of Gastroenterology, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai, People’s Republic of China
| | - Yingqun Zhou
- Department of Gastroenterology, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai, People’s Republic of China
| | - Chuanyong Guo
- Department of Gastroenterology, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai, People’s Republic of China
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Quercetin Alleviates High-Fat Diet-Induced Oxidized Low-Density Lipoprotein Accumulation in the Liver: Implication for Autophagy Regulation. BIOMED RESEARCH INTERNATIONAL 2015; 2015:607531. [PMID: 26697490 PMCID: PMC4678061 DOI: 10.1155/2015/607531] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 10/23/2015] [Accepted: 11/04/2015] [Indexed: 12/16/2022]
Abstract
A growing body of evidence has indicated that high-fat diet-induced nonalcoholic fatty liver disease is usually accompanied by oxidized low-density lipoprotein (ox-LDL) deposited in the liver. The current study aimed to investigate the effect of quercetin on high-fat diet-induced ox-LDL accumulation in the liver and to explore the potential underlying mechanisms. The results demonstrate that quercetin supplementation for 24 weeks significantly alleviated high-fat diet-induced liver damage and reduced hepatic cholesterol and ox-LDL level. Quercetin notably inhibited both mRNA and protein expression of CD36 (reduced by 53% and 71%, resp.) and MSR1 (reduced by 25% and 45%, resp.), which were upregulated by high-fat diet. The expression of LC3II was upregulated by 2.4 times whereas that of p62 and mTOR was downregulated by 57% and 63% by quercetin treatment. Therefore, the significantly improved autophagy lysosomal degradation capacity for ox-LDL may be implicated in the hepatoprotective effect of quercetin; scavenger receptors mediated ox-LDL uptake might also be involved.
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Lee YJ, Jang BK. The Role of Autophagy in Hepatocellular Carcinoma. Int J Mol Sci 2015; 16:26629-43. [PMID: 26561802 PMCID: PMC4661843 DOI: 10.3390/ijms161125984] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 10/26/2015] [Accepted: 10/30/2015] [Indexed: 12/23/2022] Open
Abstract
Autophagy is a catabolic process involved in cellular homeostasis under basal and stressed conditions. Autophagy is crucial for normal liver physiology and the pathogenesis of liver diseases. During the last decade, the function of autophagy in hepatocellular carcinoma (HCC) has been evaluated extensively. Currently, autophagy is thought to play a dual role in HCC, i.e., autophagy is involved in tumorigenesis and tumor suppression. Recent investigations of autophagy have suggested that autophagy biomarkers can facilitate HCC prognosis and the establishment of therapeutic approaches. In this review, we briefly summarize the current understanding of autophagy and discuss recent evidence for its role in HCC.
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MESH Headings
- AMP-Activated Protein Kinases/genetics
- AMP-Activated Protein Kinases/metabolism
- Animals
- Apoptosis Regulatory Proteins/genetics
- Apoptosis Regulatory Proteins/metabolism
- Autophagy/genetics
- Autophagy-Related Protein-1 Homolog
- Beclin-1
- Biomarkers, Tumor/genetics
- Biomarkers, Tumor/metabolism
- Carcinoma, Hepatocellular/diagnosis
- Carcinoma, Hepatocellular/genetics
- Carcinoma, Hepatocellular/metabolism
- Carcinoma, Hepatocellular/pathology
- Cell Transformation, Neoplastic/genetics
- Cell Transformation, Neoplastic/metabolism
- Cell Transformation, Neoplastic/pathology
- Gene Expression Regulation, Neoplastic
- Humans
- Intracellular Signaling Peptides and Proteins/genetics
- Intracellular Signaling Peptides and Proteins/metabolism
- Liver Neoplasms/diagnosis
- Liver Neoplasms/genetics
- Liver Neoplasms/metabolism
- Liver Neoplasms/pathology
- Mechanistic Target of Rapamycin Complex 1
- Mice
- Multiprotein Complexes/genetics
- Multiprotein Complexes/metabolism
- Prognosis
- Protein Serine-Threonine Kinases/genetics
- Protein Serine-Threonine Kinases/metabolism
- Signal Transduction
- TOR Serine-Threonine Kinases/genetics
- TOR Serine-Threonine Kinases/metabolism
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Affiliation(s)
- Yoo Jin Lee
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Keimyung University School of Medicine, Daegu 700-712, Korea.
| | - Byoung Kuk Jang
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Keimyung University School of Medicine, Daegu 700-712, Korea.
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74
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Li SJ, Ding ST, Mersmann HJ, Chu CH, Hsu CD, Chen CY. A nutritional nonalcoholic steatohepatitis minipig model. J Nutr Biochem 2015; 28:51-60. [PMID: 26878782 DOI: 10.1016/j.jnutbio.2015.09.029] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 09/26/2015] [Accepted: 09/30/2015] [Indexed: 02/07/2023]
Abstract
BACKGROUND AND AIMS The objective of this study was to elucidate whether a Western diet was associated with nonalcoholic steatohepatitis (NASH), and the relationship between NASH, autophagy and endoplasmic reticulum (ER) stress. METHODS Four-month-old Lee-Sung minipigs were randomly assigned to two groups: control diet (C) and Western diet (W), for a 5-month experimental period. RESULTS Feeding a Western diet produced a body composition with more fat, less lean and a greater liver weight. Compared with C pigs, W pigs also exhibited an elevated level of plasma insulin and free fatty acid. The W pigs displayed glucose intolerance, lower circulation antioxidant capacity and greater hepatic oxidative stress. Furthermore, pig fed the W diets had increased collagen accumulation in the liver and elevated systemic inflammation [tumor necrosis factor α and interleukin (IL)-6]. Compared with C pigs, W pigs had higher hepatic ER stress-related protein expression of GRP94, CHOP and caspase-12. The W pigs also had greater hepatic autophagy-related protein expression of p62 and LC3II. In an obesity antibody array analysis, W pigs had higher type 2 diabetes mellitus- (insulin-like growth factor 1, osteoprotegerin and resistin), atherosclerosis- (vascular endothelial growth factor, platelet-derived growth factor-AA and plasminogen activator inhibitor-I) and inflammation- [IL-1, macrophage-stimulating protein alpha, X-linked ectodermal dysplasia receptor and serum amyloid A (SAA)] related protein expressions. In addition, W pigs had greater plasma SAA concentration than C pigs and plasma SAA level was highly associated with IL-6. CONCLUSIONS We successfully established a NASH pig model, and our findings suggested an association of NASH with ER stress and autophagy. The SAA has potential as a novel plasma biomarker for nonalcoholic fatty liver disease pigs.
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Affiliation(s)
- Sin-Jin Li
- Department of Animal Science and Technology, National Taiwan University, No. 50, Lane 155, Sec 3, Keelung Rd, Taipei 10672, Taiwan
| | - Shih-Torng Ding
- Department of Animal Science and Technology, National Taiwan University, No. 50, Lane 155, Sec 3, Keelung Rd, Taipei 10672, Taiwan
| | - Harry J Mersmann
- Department of Animal Science and Technology, National Taiwan University, No. 50, Lane 155, Sec 3, Keelung Rd, Taipei 10672, Taiwan
| | - Chun-Han Chu
- Department of Animal Science and Technology, National Taiwan University, No. 50, Lane 155, Sec 3, Keelung Rd, Taipei 10672, Taiwan
| | - Chia-Da Hsu
- School of Veterinary Medicine, National Taiwan University, No. 1, Sec 4, Roosevelt Rd, Taipei 106, Taiwan
| | - Ching-Yi Chen
- Department of Animal Science and Technology, National Taiwan University, No. 50, Lane 155, Sec 3, Keelung Rd, Taipei 10672, Taiwan.
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75
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Abstract
Associated with the obesity epidemic, non-alcoholic fatty liver disease (NAFLD) has become the leading liver disease in North America. Approximately 30 % of patients with NAFLD may develop non-alcoholic steatohepatitis (NASH) that can lead to cirrhosis and hepatocellular carcinoma (HCC). Frequently animal models are used to help identify underlying factors contributing to NAFLD including insulin resistance, dysregulated lipid metabolism and mitochondrial stress. However, studying the inflammatory, progressive nature of NASH in the context of obesity has proven to be a challenge in mice. Although the development of effective treatment strategies for NAFLD and NASH is gaining momentum, the field is hindered by a lack of a concise animal model that reflects the development of liver disease during obesity and the metabolic syndrome. Therefore, selecting an animal model to study NAFLD or NASH must be done carefully to ensure the optimal application. The most widely used animal models have been reviewed highlighting their advantages and disadvantages to studying NAFLD and NASH specifically in the context of obesity.
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76
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Mashek DG, Khan SA, Sathyanarayan A, Ploeger JM, Franklin MP. Hepatic lipid droplet biology: Getting to the root of fatty liver. Hepatology 2015; 62:964-7. [PMID: 25854913 PMCID: PMC4549163 DOI: 10.1002/hep.27839] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 04/04/2015] [Indexed: 12/22/2022]
Abstract
Hepatic steatosis is defined by the accumulation of lipid droplets (LDs). Once thought to be only inert energy storage depots, LDs are increasingly recognized as organelles that have important functions in hepatocytes beyond lipid storage. The lipid and protein composition of LDs is highly dynamic and influences their intrinsic metabolism and signaling properties, which ultimately links them to the changes in hepatic function. This concise review highlights recent discoveries in LD biology and unique aspects of hepatic LDs and their role in liver disease.
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Affiliation(s)
- Douglas G Mashek
- Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN
| | - Salmaan A Khan
- Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN
| | | | - Jonathan M Ploeger
- Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN
| | - Mallory P Franklin
- Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN
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77
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Calvo N, Beltrán-Debón R, Rodríguez-Gallego E, Hernández-Aguilera A, Guirro M, Mariné-Casadó R, Millá L, Alegret JM, Sabench F, del Castillo D, Vinaixa M, Rodríguez M&A, Correig X, García-Álvarez R, Menendez JA, Camps J, Joven J. Liver fat deposition and mitochondrial dysfunction in morbid obesity: An approach combining metabolomics with liver imaging and histology. World J Gastroenterol 2015; 21:7529-7544. [PMID: 26140000 PMCID: PMC4481449 DOI: 10.3748/wjg.v21.i24.7529] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 02/13/2015] [Indexed: 02/06/2023] Open
Abstract
AIM: To explore the usefulness of magnetic resonance imaging (MRI) and spectroscopy (MRS) for assessment of non-alcoholic fat liver disease (NAFLD) as compared with liver histological and metabolomics findings.
METHODS: Patients undergoing bariatric surgery following procedures involved in laparoscopic sleeve gastrectomy were recruited as a model of obesity-induced NAFLD in an observational, prospective, single-site, cross-sectional study with a pre-set duration of 1 year. Relevant data were obtained prospectively and surrogates for inflammation, oxidative stress and lipid and glucose metabolism were obtained through standard laboratory measurements. To provide reliable data from MRI and MRS, novel procedures were designed to limit sampling variability and other sources of error using a 1.5T Signa HDx scanner and protocols acquired from the 3D or 2D Fat SAT FIESTA prescription manager. We used our previously described 1H NMR-based metabolomics assays. Data were obtained immediately before surgery and after a 12-mo period including histology of the liver and measurement of metabolites. Values from 1H NMR spectra obtained after surgery were omitted due to technical limitations.
RESULTS: MRI data showed excellent correlation with the concentration of liver triglycerides, other hepatic lipid components and the histological assessment, which excluded the presence of non-alcoholic steatohepatitis (NASH). MRI was sufficient to follow up NAFLD in obese patients undergoing bariatric surgery and data suggest usefulness in other clinical situations. The information provided by MRS replicated that obtained by MRI using the -CH3 peak (0.9 ppm), the -CH2- peak (1.3 ppm, mostly triglyceride) and the
-CH=CH- peak (2.2 ppm). No patient depicted NASH. After surgery all patients significantly decreased their body weight and steatosis was virtually absent even in patients with previous severe disease. Improvement was also observed in the serum concentrations of selected variables. The most relevant findings using metabolomics indicate increased levels of triglyceride and monounsaturated fatty acids in severe steatosis but those results were accompanied by a significant depletion of diglycerides, polyunsaturated fatty acids, glucose-6-phosphate and the ATP/AMP ratio. Combined data indicated the coordinated action on mitochondrial fat oxidation and glucose transport activity and may support the consideration of NAFLD as a likely mitochondrial disease. This concept may help to explain the dissociation between excess lipid storage in adipose tissue and NAFLD and may direct the search for plasma biomarkers and novel therapeutic strategies. A limitation of our study is that data were obtained in a relatively low number of patients.
CONCLUSION: MRI is sufficient to stage NAFLD in obese patients and to assess the improvement after bariatric surgery. Other data were superfluous for this purpose.
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78
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79
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Acid sphingomyelinase-ceramide system in steatohepatitis: a novel target regulating multiple pathways. J Hepatol 2015; 62:219-33. [PMID: 25281863 DOI: 10.1016/j.jhep.2014.09.023] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Revised: 09/13/2014] [Accepted: 09/24/2014] [Indexed: 02/07/2023]
Abstract
Steatohepatitis (SH) is an intermediate stage of fatty liver disease and is one of the most common causes of chronic liver disease worldwide that may progress to cirrhosis and liver cancer. SH encompasses alcoholic and non-alcoholic steatohepatitis, the latter being of particular concern as it is associated with obesity and insulin resistance and has become a major cause of liver transplantation. The molecular mechanisms governing the transition from steatosis to SH are not fully understood. Here we discuss emerging data indicating that the acid sphingomyelinase (ASMase), a specific mechanism of ceramide generation, is required for the activation of key pathways that regulate steatosis, fibrosis and lipotoxicity, including endoplasmic reticulum stress, autophagy and lysosomal membrane permeabilization. Moreover, ASMase modulates alterations of the methionine cycle and phosphatidylcholine homeostasis, two crucial events involved in SH that regulate methylation reactions, antioxidant defence and membrane integrity. These new findings suggest that targeting ASMase in combination with restoring methionine metabolism and phosphatidylcholine levels may be of utility in the treatment of SH.
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80
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Hauff P, Gottwald U, Ocker M. Early to Phase II drugs currently under investigation for the treatment of liver fibrosis. Expert Opin Investig Drugs 2014; 24:309-27. [PMID: 25547844 DOI: 10.1517/13543784.2015.997874] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
INTRODUCTION Chronic liver diseases represent a high unmet medical need and are characterized by persistent inflammation, parenchymal damage and fibrotic remodeling, leading eventually to cirrhosis and hepatic failure. Besides the persisting high prevalence of chronic viral hepatitis B and C, the dramatic increase in nonalcoholic steatohepatitis is now considered to be a major pathophysiologic driver for fibrosis development and subsequently cirrhosis. Increasing evidence suggests that also liver cirrhosis can regress when treated adequately. AREAS COVERED Herein, the authors review the underlying pathophysiologic mechanisms leading to fibrotic remodeling in the liver. They also highlight the options for novel treatment strategies by using molecular targeted agents. EXPERT OPINION New in vitro and preclinical animal models, and the careful selection of patients with high disease dynamics for clinical studies, provide a sound basis for the clinical development of antifibrotic agents in humans. Surrogate parameters of liver function, inflammation, tissue remodeling and damage, as well as noninvasive imaging techniques, can be applied in clinical trials to provide fast readouts and novel and reliable endpoints for trial design, and provide an attractive regulatory environment for this emerging disease area.
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