151
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Wu T, Yoon H, Xiong Y, Dixon-Clarke SE, Nowak RP, Fischer ES. Targeted protein degradation as a powerful research tool in basic biology and drug target discovery. Nat Struct Mol Biol 2020; 27:605-614. [PMID: 32541897 PMCID: PMC7923177 DOI: 10.1038/s41594-020-0438-0] [Citation(s) in RCA: 99] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 04/23/2020] [Indexed: 12/16/2022]
Abstract
Controlled perturbation of protein activity is essential to study protein function in cells and living organisms. Small molecules that hijack the cellular protein ubiquitination machinery to selectively degrade proteins of interest, so-called degraders, have recently emerged as alternatives to selective chemical inhibitors, both as therapeutic modalities and as powerful research tools. These systems offer unprecedented temporal and spatial control over protein function. Here, we review recent developments in this field, with a particular focus on the use of degraders as research tools to interrogate complex biological problems.
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Affiliation(s)
- Tao Wu
- Department of Cancer Biology, Dana Farber Cancer Institute, Boston, MA, USA
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
| | - Hojong Yoon
- Department of Cancer Biology, Dana Farber Cancer Institute, Boston, MA, USA
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
| | - Yuan Xiong
- Department of Cancer Biology, Dana Farber Cancer Institute, Boston, MA, USA
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
| | - Sarah E Dixon-Clarke
- Department of Cancer Biology, Dana Farber Cancer Institute, Boston, MA, USA
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
| | - Radosław P Nowak
- Department of Cancer Biology, Dana Farber Cancer Institute, Boston, MA, USA
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
| | - Eric S Fischer
- Department of Cancer Biology, Dana Farber Cancer Institute, Boston, MA, USA.
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA.
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152
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Hoque KM, Dixon EE, Lewis RM, Allan J, Gamble GD, Phipps-Green AJ, Halperin Kuhns VL, Horne AM, Stamp LK, Merriman TR, Dalbeth N, Woodward OM. The ABCG2 Q141K hyperuricemia and gout associated variant illuminates the physiology of human urate excretion. Nat Commun 2020; 11:2767. [PMID: 32488095 PMCID: PMC7265540 DOI: 10.1038/s41467-020-16525-w] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 05/06/2020] [Indexed: 02/06/2023] Open
Abstract
The pathophysiological nature of the common ABCG2 gout and hyperuricemia associated variant Q141K (rs2231142) remains undefined. Here, we use a human interventional cohort study (ACTRN12615001302549) to understand the physiological role of ABCG2 and find that participants with the Q141K ABCG2 variant display elevated serum urate, unaltered FEUA, and significant evidence of reduced extra-renal urate excretion. We explore mechanisms by generating a mouse model of the orthologous Q140K Abcg2 variant and find male mice have significant hyperuricemia and metabolic alterations, but only subtle alterations of renal urate excretion and ABCG2 abundance. By contrast, these mice display a severe defect in ABCG2 abundance and function in the intestinal tract. These results suggest a tissue specific pathobiology of the Q141K variant, support an important role for ABCG2 in urate excretion in both the human kidney and intestinal tract, and provide insight into the importance of intestinal urate excretion for serum urate homeostasis. The common ABCG2 variant Q141K contributes to hyperuricemia and gout risk. Here, using a human interventional study and a new orthologous mouse model, the authors report a tissue specific pathobiology of the Q141K variant, and support a significant role for ABCG2 in urate excretion in both the kidney and intestine.
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Affiliation(s)
- Kazi Mirajul Hoque
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Eryn E Dixon
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Raychel M Lewis
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Jordyn Allan
- Department of Medicine, University of Auckland, Auckland, New Zealand
| | - Gregory D Gamble
- Department of Medicine, University of Auckland, Auckland, New Zealand
| | | | | | - Anne M Horne
- Department of Medicine, University of Auckland, Auckland, New Zealand
| | - Lisa K Stamp
- Department of Medicine, University of Otago, Christchurch, New Zealand
| | - Tony R Merriman
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | - Nicola Dalbeth
- Department of Medicine, University of Auckland, Auckland, New Zealand
| | - Owen M Woodward
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, USA.
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153
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Trépo E, Valenti L. Update on NAFLD genetics: From new variants to the clinic. J Hepatol 2020; 72:1196-1209. [PMID: 32145256 DOI: 10.1016/j.jhep.2020.02.020] [Citation(s) in RCA: 218] [Impact Index Per Article: 54.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 02/04/2020] [Accepted: 02/13/2020] [Indexed: 02/07/2023]
Abstract
Non-alcoholic fatty liver disease (NAFLD) is the leading cause of liver diseases in high-income countries and the burden of NAFLD is increasing at an alarming rate. The risk of developing NAFLD and related complications is highly variable among individuals and is determined by environmental and genetic factors. Genome-wide association studies have uncovered robust and reproducible associations between variations in genes such as PNPLA3, TM6SF2, MBOAT7, GCKR, HSD17B13 and the natural history of NAFLD. These findings have provided compelling new insights into the biology of NAFLD and highlighted potentially attractive pharmaceutical targets. More recently the development of polygenic risk scores, which have shown promising results for the clinical risk prediction of other complex traits (such as cardiovascular disease and breast cancer), have provided new impetus for the clinical validation of genetic variants in NAFLD risk stratification. Herein, we review current knowledge on the genetic architecture of NAFLD, including gene-environment interactions, and discuss the implications for disease pathobiology, drug discovery and risk prediction. We particularly focus on the potential clinical translation of recent genetic advances, discussing methodological hurdles that must be overcome before these discoveries can be implemented in everyday practice.
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Affiliation(s)
- Eric Trépo
- Department of Gastroenterology, Hepatopancreatology and Digestive Oncology, C.U.B. Hôpital Erasme, Université Libre de Bruxelles, Brussels, Belgium; Laboratory of Experimental Gastroenterology, Université Libre de Bruxelles, Brussels, Belgium.
| | - Luca Valenti
- Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Milan, Italy; Translational Medicine - Department of Transfusion Medicine and Hematology, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
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154
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Carlsson B, Lindén D, Brolén G, Liljeblad M, Bjursell M, Romeo S, Loomba R. Review article: the emerging role of genetics in precision medicine for patients with non-alcoholic steatohepatitis. Aliment Pharmacol Ther 2020; 51:1305-1320. [PMID: 32383295 PMCID: PMC7318322 DOI: 10.1111/apt.15738] [Citation(s) in RCA: 105] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 01/13/2020] [Accepted: 03/29/2020] [Indexed: 12/12/2022]
Abstract
BACKGROUND Non-alcoholic steatohepatitis (NASH) is a severe form of non-alcoholic fatty liver disease (NAFLD) characterised by liver fat accumulation, inflammation and progressive fibrosis. Emerging data indicate that genetic susceptibility increases risks of NAFLD, NASH and NASH-related cirrhosis. AIMS To review NASH genetics and discuss the potential for precision medicine approaches to treatment. METHOD PubMed search and inclusion of relevant literature. RESULTS Single-nucleotide polymorphisms in PNPLA3, TM6SF2, GCKR, MBOAT7 and HSD17B13 are clearly associated with NASH development or progression. These genetic variants are common and have moderate-to-large effect sizes for development of NAFLD, NASH and hepatocellular carcinoma (HCC). The genes play roles in lipid remodelling in lipid droplets, hepatic very low-density lipoprotein (VLDL) secretion and de novo lipogenesis. The PNPLA3 I148M variant (rs738409) has large effects, with approximately twofold increased odds of NAFLD and threefold increased odds of NASH and HCC per allele. Obesity interacts with PNPLA3 I148M to elevate liver fat content and increase rates of NASH. Although the isoleucine-to-methionine substitution at amino acid position 148 of the PNPLA3 enzyme inactivates its lipid remodelling activity, the effect of PNPLA3 I148M results from trans-repression of another lipase (ATGL/PNPLA2) by sequestration of a shared cofactor (CGI-58/ABHD5), leading to decreased hepatic lipolysis and VLDL secretion. In homozygous Pnpla3 I148M knock-in rodent models of NAFLD, targeted PNPLA3 mRNA knockdown reduces hepatic steatosis, inflammation and fibrosis. CONCLUSION The emerging genetic and molecular understanding of NASH paves the way for novel interventions, including precision medicines that can modulate the activity of specific genes associated with NASH.
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Affiliation(s)
- Björn Carlsson
- Research and Early DevelopmentCardiovascular, Renal and MetabolismBioPharmaceuticals R&DAstraZenecaGothenburgSweden
| | - Daniel Lindén
- Research and Early DevelopmentCardiovascular, Renal and MetabolismBioPharmaceuticals R&DAstraZenecaGothenburgSweden,Division of EndocrinologyDepartment of Neuroscience and PhysiologySahlgrenska AcademyUniversity of GothenburgGothenburgSweden
| | - Gabriella Brolén
- Precision MedicineCardiovascular, Renal and MetabolismR&DAstraZenecaGothenburgSweden
| | - Mathias Liljeblad
- Research and Early DevelopmentCardiovascular, Renal and MetabolismBioPharmaceuticals R&DAstraZenecaGothenburgSweden
| | - Mikael Bjursell
- Research and Early DevelopmentCardiovascular, Renal and MetabolismBioPharmaceuticals R&DAstraZenecaGothenburgSweden
| | - Stefano Romeo
- Department of Molecular and Clinical MedicineUniversity of GothenburgGothenburgSweden,Clinical Nutrition UnitDepartment of Medical and Surgical SciencesMagna Graecia UniversityCatanzaroItaly,Cardiology DepartmentSahlgrenska University HospitalGothenburgSweden
| | - Rohit Loomba
- NAFLD Research CenterDivision of GastroenterologyUniversity of California San DiegoSan DiegoCAUSA
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155
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Molecular Mechanisms Regulating Obesity-Associated Hepatocellular Carcinoma. Cancers (Basel) 2020; 12:cancers12051290. [PMID: 32443737 PMCID: PMC7281233 DOI: 10.3390/cancers12051290] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 05/14/2020] [Accepted: 05/17/2020] [Indexed: 02/07/2023] Open
Abstract
Obesity is a global, intractable issue, altering inflammatory and stress response pathways, and promoting tissue adiposity and tumorigenesis. Visceral fat accumulation is correlated with primary tumor recurrence, poor prognosis and chemotherapeutic resistance. Accumulating evidence highlights a close association between obesity and an increased incidence of hepatocellular carcinoma (HCC). Obesity drives HCC, and obesity-associated tumorigenesis develops via nonalcoholic fatty liver (NAFL), progressing to nonalcoholic steatohepatitis (NASH) and ultimately to HCC. The better molecular elucidation and proteogenomic characterization of obesity-associated HCC might eventually open up potential therapeutic avenues. The mechanisms relating obesity and HCC are correlated with adipose tissue remodeling, alteration in the gut microbiome, genetic factors, ER stress, oxidative stress and epigenetic changes. During obesity-related hepatocarcinogenesis, adipokine secretion is dysregulated and the nuclear factor erythroid 2 related factor 1 (Nrf-1), nuclear factor kappa B (NF-κB), mammalian target of rapamycin (mTOR), phosphatidylinositol-3-kinase (PI3K)/phosphatase and tensin homolog (PTEN)/Akt, and Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathways are activated. This review captures the present trends allied with the molecular mechanisms involved in obesity-associated hepatic tumorigenesis, showcasing next generation molecular therapeutic strategies and their mechanisms for the successful treatment of HCC.
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156
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Bruschi FV, Tardelli M, Herac M, Claudel T, Trauner M. Metabolic regulation of hepatic PNPLA3 expression and severity of liver fibrosis in patients with NASH. Liver Int 2020; 40:1098-1110. [PMID: 32043752 PMCID: PMC7318357 DOI: 10.1111/liv.14402] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Revised: 01/31/2020] [Accepted: 02/03/2020] [Indexed: 02/06/2023]
Abstract
BACKGROUND AND AIMS The genetic PNPLA3 polymorphism I148M has been extensively associated with higher risk for development and progression of NAFLD towards NASH. METHODS PNPLA3 and α-SMA expression were quantified in liver biopsies collected from NASH patients (n = 26) with different fibrosis stages and PNPLA3 genotypes. To study the potential mechanisms driving PNPLA3 expression during NASH progression towards fibrosis, hepatocytes and hepatic stellate cells (HSCs) were cultivated in low and high glucose medium. Moreover, hepatocytes were treated with increasing concentrations of palmitic acid alone or in combination with glucose. Conditioned media were collected from challenged hepatocytes to stimulate HSCs. RESULTS Tissue expression of PNPLA3 was significantly enhanced in biopsies of patients carrying the I148M polymorphism compared to wild type (WT). In NASH biopsies, PNPLA3 significantly correlated with fibrosis stage and α-SMA levels independently of PNPLA3 genotype. In line, PNPLA3 expression was higher in α-SMA positive cells. Low glucose increased PNPLA3 in HSCs, whereas high glucose induced PNPLA3 and de-novo lipogenesis-related genes expression in hepatocytes. Palmitic acid induced fat accumulation and cell stress markers in hepatocytes, which could be counteracted by oleic acid. Conditioned media collected from lipotoxic challenged hepatocytes markedly induced PNPLA3 mRNA and protein levels, fibrogenic and autophagic markers and promoted migration in HSCs. Notably, conditioned media collected from hepatocytes cultivated with both glucose and palmitic acid exacerbated HSCs migration, PNPLA3 and fibrogenic gene expression, promoting release of cytokines from HSCs. CONCLUSIONS Collectively, our observations uncover the diverse metabolic regulation of PNPLA3 among different hepatic cell populations and support its relation to fibrosis progression.
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Affiliation(s)
- Francesca V. Bruschi
- Hans Popper Laboratory of Molecular HepatologyDivision of Gastroenterology and HepatologyInternal Medicine IIIMedical University of ViennaViennaAustria
| | - Matteo Tardelli
- Hans Popper Laboratory of Molecular HepatologyDivision of Gastroenterology and HepatologyInternal Medicine IIIMedical University of ViennaViennaAustria,Division of Gastroenterology and HepatologyJoan and Sanford I. Weill Cornell Department of MedicineWeill Cornell Medical CollegeNew YorkNYUSA
| | - Merima Herac
- Clinical Institute of PathologyMedical University of ViennaViennaAustria
| | - Thierry Claudel
- Hans Popper Laboratory of Molecular HepatologyDivision of Gastroenterology and HepatologyInternal Medicine IIIMedical University of ViennaViennaAustria
| | - Michael Trauner
- Hans Popper Laboratory of Molecular HepatologyDivision of Gastroenterology and HepatologyInternal Medicine IIIMedical University of ViennaViennaAustria
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157
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Krawczyk M, Liebe R, Lammert F. Toward Genetic Prediction of Nonalcoholic Fatty Liver Disease Trajectories: PNPLA3 and Beyond. Gastroenterology 2020; 158:1865-1880.e1. [PMID: 32068025 DOI: 10.1053/j.gastro.2020.01.053] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 01/29/2020] [Accepted: 01/29/2020] [Indexed: 12/14/2022]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is on the verge of becoming the leading cause of liver disease. NAFLD develops at the interface between environmental factors and inherited predisposition. Genome-wide association studies, followed by exome-wide analyses, led to identification of genetic risk variants (eg, PNPLA3, TM6SF2, and SERPINA1) and key pathways involved in fatty liver disease pathobiology. Functional studies improved our understanding of these genetic factors and the molecular mechanisms underlying the trajectories from fat accumulation to fibrosis, cirrhosis, and cancer over time. Here, we summarize key NAFLD risk genes and illustrate their interactions in a 3-dimensional "risk space." Although NAFLD genomics sometimes appears to be "lost in translation," we envision clinical utility in trial design, outcome prediction, and NAFLD surveillance.
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Affiliation(s)
- Marcin Krawczyk
- Department of Medicine II (Gastroenterology and Endocrinology), Saarland University Medical Center, Saarland University, Homburg; Laboratory of Metabolic Liver Diseases, Center for Preclinical Research, Department of General, Transplant and Liver Surgery, Medical University of Warsaw, Warsaw, Poland
| | - Roman Liebe
- Department of Medicine II (Gastroenterology and Endocrinology), Saarland University Medical Center, Saarland University, Homburg; Department of Gastroenterology, Hepatology and Infectious Diseases, University Hospital Düsseldorf, Heinrich Heine University, Düsseldorf, Germany
| | - Frank Lammert
- Department of Medicine II (Gastroenterology and Endocrinology), Saarland University Medical Center, Saarland University, Homburg.
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158
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The landscape of gene mutations in cirrhosis and hepatocellular carcinoma. J Hepatol 2020; 72:990-1002. [PMID: 32044402 DOI: 10.1016/j.jhep.2020.01.019] [Citation(s) in RCA: 97] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 01/16/2020] [Accepted: 01/21/2020] [Indexed: 12/13/2022]
Abstract
Chronic liver disease and primary liver cancer are a massive global problem, with a future increase in incidences predicted. The most prevalent form of primary liver cancer, hepatocellular carcinoma, occurs after years of chronic liver disease. Mutations in the genome are a causative and defining feature of all cancers. Chronic liver disease, mostly at the cirrhotic stage, causes the accumulation of progressive mutations which can drive cancer development. Within the liver, a Darwinian process selects out dominant clones with selected driver mutations but also leaves a trail of passenger mutations which can be used to track the evolution of a tumour. Understanding what causes specific mutations and how they combine with one another to form cancer is a question at the heart of understanding, preventing and tackling liver cancer. Herein, we review the landscape of gene mutations in cirrhosis, especially those paving the way toward hepatocellular carcinoma development, that have been characterised by recent studies capitalising on technological advances in genomic sequencing. With these insights, we are beginning to understand how cancers form in the liver, particularly on the background of chronic liver disease. This knowledge may soon lead to breakthroughs in the way we detect, diagnose and treat this devastating disease.
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159
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Salvoza NC, Giraudi PJ, Tiribelli C, Rosso N. Sex differences in non-alcoholic fatty liver disease: hints for future management of the disease. EXPLORATION OF MEDICINE 2020. [DOI: 10.37349/emed.2020.00005] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) remains a major cause of chronic liver disease worldwide. Despite extensive studies, the heterogeneity of the risk factors as well as different disease mechanisms complicate the goals toward effective diagnosis and management. Recently, it has been shown that sex differences play a role in the prevalence and progression of NAFLD. In vitro, in vivo, and clinical studies revealed that the lower prevalence of NAFLD in premenopausal as compared to postmenopausal women and men is mainly due to the protective effects of estrogen and body fat distribution. It has been also described that males and females present differential pathogenic features in terms of biochemical profiles and histological characteristics. However, the exact molecular mechanisms for the gender differences that exist in the pathogenesis of NAFLD are still elusive. Lipogenesis, oxidative stress, and inflammation play a key role in the progression of NAFLD. For NAFLD, only a few studies characterized these mechanisms at the molecular level. Therefore, we aim to review the reported differential molecular mechanisms that trigger such different pathogenesis in both sexes. Differences in lipid metabolism, glucose homeostasis, oxidative stress, inflammation, and fibrosis were discussed based on the evidence reported in recent publications. In conclusion, with this review, we hope to provide a new perspective for the development of future practice guidelines as well as a new avenue for the management of the disease.
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Affiliation(s)
- Noel C. Salvoza
- Fondazione Italiana Fegato ONLUS, Area Science Park Basovizza SS14 km 163.5, 34149 Trieste, Italy; Philippine Council for Health Research and Development, DOST Compound, Bicutan Taguig City 1631, Philippines
| | - Pablo J. Giraudi
- Fondazione Italiana Fegato ONLUS, Area Science Park Basovizza SS14 km 163.5, 34149 Trieste, Italy
| | - Claudio Tiribelli
- Fondazione Italiana Fegato ONLUS, Area Science Park Basovizza SS14 km 163.5, 34149 Trieste, Italy
| | - Natalia Rosso
- Fondazione Italiana Fegato ONLUS, Area Science Park Basovizza SS14 km 163.5, 34149 Trieste, Italy
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160
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Burslem GM, Crews CM. Proteolysis-Targeting Chimeras as Therapeutics and Tools for Biological Discovery. Cell 2020; 181:102-114. [PMID: 31955850 PMCID: PMC7319047 DOI: 10.1016/j.cell.2019.11.031] [Citation(s) in RCA: 531] [Impact Index Per Article: 132.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 11/07/2019] [Accepted: 11/21/2019] [Indexed: 12/16/2022]
Abstract
New biological tools provide new techniques to probe fundamental biological processes. Here we describe the burgeoning field of proteolysis-targeting chimeras (PROTACs), which are capable of modulating protein concentrations at a post-translational level by co-opting the ubiquitin-proteasome system. We describe the PROTAC technology and its application to drug discovery and provide examples where PROTACs have enabled novel biological insights. Furthermore, we provide a workflow for PROTAC development and use and discuss the benefits and issues associated with PROTACs. Finally, we compare PROTAC-mediated protein-level modulation with other technologies, such as RNAi and genome editing.
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Affiliation(s)
- George M Burslem
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Craig M Crews
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA; Departments of Chemistry and Pharmacology, Yale University, New Haven, CT, USA.
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161
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Saki S, Saki N, Poustchi H, Malekzadeh R. Assessment of Genetic Aspects of Non-alcoholic Fatty Liver and Premature Cardiovascular Events. Middle East J Dig Dis 2020; 12:65-88. [PMID: 32626560 PMCID: PMC7320986 DOI: 10.34172/mejdd.2020.166] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 03/19/2019] [Indexed: 12/12/2022] Open
Abstract
Recent evidence has demonstrated a strong interplay and multifaceted relationship between non-alcoholic fatty liver disease (NAFLD) and cardiovascular disease (CVD). CVD is the major cause of death in patients with NAFLD. NAFLD also has strong associations with diabetes and metabolic syndrome. In this comprehensive review, we aimed to overview the primary environmental and genetic risk factors of NAFLD, and CVD and also focus on the genetic aspects of these two disorders. NAFLD and CVD are both heterogeneous diseases with common genetic and molecular pathways. We have searched for the latest published articles regarding this matter and tried to provide an overview of recent insights into the genetic aspects of NAFLD and CVD. The common genetic and molecular pathways involved in NAFLD and CVD are insulin resistance (IR), subclinical inflammation, oxidative stress, and atherogenic dyslipidemia. According to an investigation, the exact associations between genomic characteristics of NAFLD and CVD and casual relationships are not fully determined. Different gene polymorphisms have been identified as the genetic components of the NAFLDCVD association. Some of the most documented ones of these gene polymorphisms are patatin-like phospholipase domain-containing protein 3 (PNPLA3), transmembrane 6 superfamily member 2 (TM6SF2), hydroxysteroid 17-beta dehydrogenase 13 (HSD17B13), adiponectin-encoding gene (ADIPOQ), apolipoprotein C3 (APOC3), peroxisome proliferator-activated receptors (PPAR), leptin receptor (LEPR), sterol regulatory element-binding proteins (SREBP), tumor necrosis factor-alpha (TNF-α), microsomal triglyceride transfer protein (MTTP), manganese superoxide dismutase (MnSOD), membrane-bound O-acyltransferase domain-containing 7 (MBOAT7), and mutation in DYRK1B that substitutes cysteine for arginine at position 102 in kinase-like domain. Further cohort studies with a significant sample size using advanced genomic assessments and next-generation sequencing techniques are needed to shed more light on genetic associations between NAFLD and CVD.
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Affiliation(s)
- Sara Saki
- Tehran University of Medical Sciences, Tehran, Iran
| | - Nader Saki
- Hoveizeh Cohort Study, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Hossein Poustchi
- Digestive Disease Research Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Reza Malekzadeh
- Digestive Disease Research Institute, Tehran University of Medical Sciences, Tehran, Iran
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162
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Stender S, Romeo S. HSD17B13 as a promising therapeutic target against chronic liver disease. Liver Int 2020; 40:756-757. [PMID: 32255570 DOI: 10.1111/liv.14411] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Stefan Stender
- Department of Clinical Biochemistry, Rigshospitalet, Copenhagen University Hospital, Copenhagen.,Department of Clinical Biochemistry, Bispebjerg and Frederiksberg Hospital, Copenhagen University Hospital, Copenhagen
| | - Stefano Romeo
- Sahlgrenska Academy, Department of Clinical and Molecular Medicine, University of Gothenburg, Gothenburg.,Department of Cardiology, Sahlgrenska University Hospital, Gothenburg.,Clinical Nutrition Unit, Department of Medical and Surgical Sciences, University Magna Graecia, Catanzaro
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163
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Unalp-Arida A, Ruhl CE. Patatin-Like Phospholipase Domain-Containing Protein 3 I148M and Liver Fat and Fibrosis Scores Predict Liver Disease Mortality in the U.S. Population. Hepatology 2020; 71:820-834. [PMID: 31705824 DOI: 10.1002/hep.31032] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 11/03/2019] [Indexed: 12/11/2022]
Abstract
BACKGROUND AND AIMS Fatty liver causes premature death worldwide and requires long-term health care. We examined relationships of liver disease markers, including patatin-like phospholipase domain-containing protein 3 (PNPLA3) I148M, with mortality in the U.S. National Health and Nutrition Examination Survey, 1988-1994, with 27 years of linked mortality data. APPROACH AND RESULTS We studied 13,298 viral hepatitis negative adults who fasted at least 4 hours using the nonalcoholic fatty liver disease (NAFLD) liver fat score and NAFLD fibrosis score. PNPLA3 I148M was genotyped in a subgroup of participants from 1991 to 1994 (n = 5,640). Participants were passively followed for mortality, identified by death certificate underlying or contributing causes, by linkage to the National Death Index through 2015. During follow-up (median, 23.2 years), cumulative mortality was 33.2% overall and 1.1% with liver disease, including primary liver cancer. Increased liver disease mortality was associated with PNPLA3 I148M (hazard ratio [HR], 2.9; 95% confidence interval [CI], 0.9-9.8) and 148M genotypes (HR, 18.2; 95% CI, 3.5-93.8), an intermediate (HR, 3.8; 95% CI, 1.3-10.7) or high (HR, 12.6; 95% CI, 4.3-36.3) NAFLD liver fat score, and a high NAFLD fibrosis score (HR, 12.2; 95% CI, 1.9-80.6) adjusted for risk factors. Survival curves suggest that increased mortality risk with two 148M alleles was greatest beginning in the second decade of follow-up. Overall, but not cardiovascular disease, mortality was associated with the PNPLA3 148M allele, and both mortality outcomes were associated with higher fat and fibrosis scores. CONCLUSIONS In the U.S. population, PNPLA3 I148M and higher NAFLD liver fat and fibrosis scores were associated with increased liver disease mortality. Genetic variant PNPLA3 I148M may complement other liver disease markers for NAFLD surveillance.
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Affiliation(s)
- Aynur Unalp-Arida
- Department of Health and Human Services, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD
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164
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Abstract
Nonalcoholic fatty liver disease is strongly associated with obesity and the metabolic syndrome, but genetic factors also contribute to disease susceptibility. Human genetic studies have identified several common genetic variants contributing to nonalcoholic fatty liver disease initiation and progression. These findings have provided new insights into the pathogenesis of nonalcoholic fatty liver disease and opened up new avenues for the development of therapeutic interventions. In this review, we summarize the current state of knowledge about the genetic determinants of nonalcoholic fatty liver disease, focusing on the most robustly validated genetic risk factors and on recently discovered modifiers of disease progression.
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Affiliation(s)
- Julia Kozlitina
- Eugene McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-8591, USA.
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165
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Jeon S, Carr R. Alcohol effects on hepatic lipid metabolism. J Lipid Res 2020; 61:470-479. [PMID: 32029510 DOI: 10.1194/jlr.r119000547] [Citation(s) in RCA: 115] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 01/28/2020] [Indexed: 12/16/2022] Open
Abstract
Alcoholic liver disease (ALD) is the most prevalent type of chronic liver disease with significant morbidity and mortality worldwide. ALD begins with simple hepatic steatosis and progresses to alcoholic steatohepatitis, fibrosis, and cirrhosis. The severity of hepatic steatosis is highly associated with the development of later stages of ALD. This review explores the disturbances of alcohol-induced hepatic lipid metabolism through altered hepatic lipid uptake, de novo lipid synthesis, fatty acid oxidation, hepatic lipid export, and lipid droplet formation and catabolism. In addition, we review emerging data on the contributions of genetics and bioactive lipid metabolism in alcohol-induced hepatic lipid accumulation.
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Affiliation(s)
- Sookyoung Jeon
- Division of Gastroenterology, University of Pennsylvania, Philadelphia, PA
| | - Rotonya Carr
- Division of Gastroenterology, University of Pennsylvania, Philadelphia, PA
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166
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Verma R, Mohl D, Deshaies RJ. Harnessing the Power of Proteolysis for Targeted Protein Inactivation. Mol Cell 2020; 77:446-460. [PMID: 32004468 DOI: 10.1016/j.molcel.2020.01.010] [Citation(s) in RCA: 124] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 11/26/2019] [Accepted: 01/07/2020] [Indexed: 12/11/2022]
Abstract
Two decades into the twenty-first century, a confluence of breakthrough technologies wielded at the molecular level is presenting biologists with unique opportunities to unravel the complexities of the cellular world. CRISPR/Cas9 allows gene knock-outs, knock-ins, and single-base editing at chromosomal loci. RNA-based tools such as siRNA, antisense oligos, and morpholinos can be used to silence expression of specific genes. Meanwhile, protein knockdown tools that draw inspiration from natural regulatory mechanisms and facilitate elimination of native or degron-tagged proteins from cells are rapidly emerging. The acute and reversible reduction in protein levels enabled by these methods allows for precise determination of loss-of-function phenotypes free from secondary effects or compensatory adaptation that can confound nucleic-acid-based methods that involve slow depletion or permanent loss of a protein. In this Review, we summarize the ingenious ways biologists have exploited natural mechanisms for protein degradation to direct the elimination of specific proteins at will. This has led to advancements not only in basic research but also in the therapeutic space with the introduction of PROTACs into clinical trials for cancer patients.
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Affiliation(s)
- Rati Verma
- AMGEN Research, One Amgen Center Drive, Thousand Oaks, CA 91320, USA.
| | - Dane Mohl
- AMGEN Research, One Amgen Center Drive, Thousand Oaks, CA 91320, USA
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167
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Parthasarathy G, Revelo X, Malhi H. Pathogenesis of Nonalcoholic Steatohepatitis: An Overview. Hepatol Commun 2020; 4:478-492. [PMID: 32258944 PMCID: PMC7109346 DOI: 10.1002/hep4.1479] [Citation(s) in RCA: 227] [Impact Index Per Article: 56.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 12/21/2019] [Indexed: 12/11/2022] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) is a heterogeneous group of liver diseases characterized by the accumulation of fat in the liver. The heterogeneity of NAFLD is reflected in a clinical and histologic spectrum where some patients develop isolated steatosis of the liver, termed nonalcoholic fatty liver, whereas others develop hepatocyte injury, ballooning, inflammation, and consequent fibrosis, termed nonalcoholic steatohepatitis (NASH). Systemic insulin resistance is a major driver of hepatic steatosis in NAFLD. Lipotoxicity of accumulated lipids along with activation of the innate immune system are major drivers of NASH. Lipid‐induced sublethal and lethal stress culminates in the activation of inflammatory processes, such as the release of proinflammatory extracellular vesicles and cell death. Innate and adaptive immune mechanisms involving macrophages, dendritic cells, and lymphocytes are central drivers of inflammation that recognize damage‐ and pathogen‐associated molecular patterns and contribute to the progression of the inflammatory cascade. While the activation of the innate immune system and the recruitment of proinflammatory monocytes into the liver in NASH are well known, the exact signals that lead to this remain less well defined. Further, the contribution of other immune cell types, such as neutrophils and B cells, is an area of intense research. Many host factors, such as the microbiome and gut–liver axis, modify individual susceptibility to NASH. In this review, we discuss lipotoxicity, inflammation, and the contribution of interorgan crosstalk in NASH pathogenesis.
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Affiliation(s)
| | - Xavier Revelo
- Department of Integrative Biology and Physiology University of Minnesota Minneapolis MN
| | - Harmeet Malhi
- Division of Gastroenterology and Hepatology Mayo Clinic Rochester MN
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168
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Romeo S, Sanyal A, Valenti L. Leveraging Human Genetics to Identify Potential New Treatments for Fatty Liver Disease. Cell Metab 2020; 31:35-45. [PMID: 31914377 DOI: 10.1016/j.cmet.2019.12.002] [Citation(s) in RCA: 125] [Impact Index Per Article: 31.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 10/07/2019] [Accepted: 12/06/2019] [Indexed: 02/08/2023]
Abstract
Fatty liver disease (FLD), including its more severe pathologies, namely steatohepatitis, hepatocarcinoma, and cirrhosis, is the most common cause of chronic liver disease worldwide and is projected to become the leading cause of hepatocellular carcinoma and end-stage liver disease. FLD is heterogeneous with multiple etiologies and diverse histological phenotypes, so therapies will ultimately need to be individualized for relevant targets. Inherited factors contribute to FLD, and most of the genetic variation influencing liver disease development and progression is derived from genes involved in lipid biology, including PNPLA3, TM6SF2, GCKR, MBOAT7, and HSD17B13. From this point of view, we focus in this perspective on how human molecular genetics of FLD have highlighted defects in hepatic lipid handling as a major common mechanism of its pathology and how this insight could be leveraged to treat and prevent its more serious complications.
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Affiliation(s)
- Stefano Romeo
- Department of Molecular and Clinical Medicine, University of Gothenburg, Gothenburg, Sweden; Clinical Nutrition Unit, Department of Medical and Surgical Sciences, Magna Graecia University, Catanzaro, Italy; Cardiology Department, Sahlgrenska University Hospital, Gothenburg, Sweden.
| | - Arun Sanyal
- Division of Gastroenterology and Hepatology, Department of Medicine, Virginia Commonwealth University, Richmond, VA, USA.
| | - Luca Valenti
- Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Translational Medicine, Department of Transfusion Medicine and Hematology, Fondazione IRCCS Ca' Granda, Pad Marangoni, Milan, Italy.
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169
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Affiliation(s)
- Linshan Shang
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN
| | - Douglas G Mashek
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN.,Department of Medicine, Division of Diabetes, Endocrinology and Metabolism, University of Minnesota, Minneapolis, MN
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170
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Abstract
Nonalcoholic fatty liver disease (NAFLD) is considered the hepatic manifestation of the metabolic syndrome (MetS) and comprises one of the largest health threats of the twenty-first century. In this chapter, we review the current state of knowledge of NAFLD and underline the striking similarities with atherosclerosis. We first describe current epidemiological data showing the staggering increase of NAFLD numbers and its related clinical and economic costs. We then provide an overview of pathophysiological hepatic processes in NAFLD and highlight the systemic aspects of NAFLD that point toward metabolic crosstalk between organs as an important cause of metabolic disease. Finally, we end by highlighting the currently investigated therapeutic approaches for NAFLD, which also show strong similarities with a range of treatment options for atherosclerosis.
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171
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Yu L, Li Y, Grisé A, Wang H. CGI-58: Versatile Regulator of Intracellular Lipid Droplet Homeostasis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1276:197-222. [PMID: 32705602 PMCID: PMC8063591 DOI: 10.1007/978-981-15-6082-8_13] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Comparative gene identification-58 (CGI-58), also known as α/β-hydrolase domain-containing 5 (ABHD5), is a member of a large family of proteins containing an α/β-hydrolase-fold. CGI-58 is well-known as the co-activator of adipose triglyceride lipase (ATGL), which is a key enzyme initiating cytosolic lipid droplet lipolysis. Mutations in either the human CGI-58 or ATGL gene cause an autosomal recessive neutral lipid storage disease, characterized by the excessive accumulation of triglyceride (TAG)-rich lipid droplets in the cytoplasm of almost all cell types. CGI-58, however, has ATGL-independent functions. Distinct phenotypes associated with CGI-58 deficiency commonly include ichthyosis (scaly dry skin), nonalcoholic steatohepatitis, and hepatic fibrosis. Through regulated interactions with multiple protein families, CGI-58 controls many metabolic and signaling pathways, such as lipid and glucose metabolism, energy balance, insulin signaling, inflammatory responses, and thermogenesis. Recent studies have shown that CGI-58 regulates the pathogenesis of common metabolic diseases in a tissue-specific manner. Future studies are needed to molecularly define ATGL-independent functions of CGI-58, including the newly identified serine protease activity of CGI-58. Elucidation of these versatile functions of CGI-58 may uncover fundamental cellular processes governing lipid and energy homeostasis, which may help develop novel approaches that counter against obesity and its associated metabolic sequelae.
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Affiliation(s)
- Liqing Yu
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA.
| | - Yi Li
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Alison Grisé
- College of Computer, Math, and Natural Sciences, College of Behavioral and Social Sciences, University of Maryland, College Park, MD, USA
| | - Huan Wang
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
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172
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Dhar D, Baglieri J, Kisseleva T, Brenner DA. Mechanisms of liver fibrosis and its role in liver cancer. Exp Biol Med (Maywood) 2020; 245:96-108. [PMID: 31924111 PMCID: PMC7016420 DOI: 10.1177/1535370219898141] [Citation(s) in RCA: 179] [Impact Index Per Article: 44.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Hepatic fibrogenesis is a pathophysiological outcome of chronic liver injury hallmarked by excessive accumulation of extracellular matrix proteins. Fibrosis is a dynamic process that involves cross-talk between parenchymal cells (hepatocytes), hepatic stellate cells, sinusoidal endothelial cells and both resident and infiltrating immune cells. In this review, we focus on key cell-types that contribute to liver fibrosis, cytokines, and chemokines influencing this process and what it takes for fibrosis to regress. We discuss how mitochondria and metabolic changes in hepatic stellate cells modulate the fibrogenic process. We also briefly review how the presence of fibrosis affects development of hepatocellular carcinoma.
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Affiliation(s)
- Debanjan Dhar
- Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Jacopo Baglieri
- Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Tatiana Kisseleva
- Department of Surgery, University of California San Diego, La Jolla, CA 92093, USA
| | - David A Brenner
- Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA
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173
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Qureshi K, Neuschwander-Tetri BA. The molecular basis for current targets of NASH therapies. Expert Opin Investig Drugs 2019; 29:151-161. [PMID: 31847612 DOI: 10.1080/13543784.2020.1703949] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Introduction: Nonalcoholic steatohepatitis (NASH) is a leading cause of liver disease in children and adults, a major contributor to health-care expenditures, and now a leading reason for liver transplantation. Adopting lifestyle modifications with regular exercise and a focus on healthy eating habits is the primary recommendation. However, patients are often unable to achieve and sustain such changes for a variety of social, physical, psychological and genetic reasons. Thus, treatments that can prevent and reverse NASH and its associated fibrosis are a major focus of current drug development.Areas covered: This review covers the current understanding of lipotoxic liver injury in the pathogenesis of NASH and how lifestyle modification and the spectrum of drugs currently in clinical trials address the many pathways leading to the phenotype of NASH.Expert opinion: Contrary to the frequently expressed nihilistic view of our understanding of NASH and disappointment with clinical trial results, much is known about the pathogenesis of NASH and there is much reason to be optimistic that effective therapies will be identified in the next 5-10 years. Achieving this will require continued refinement of clinical trial endpoints, continued engagement of trial sponsors and regulatory authorities, and continued participation of dedicated patients in clinical trials.
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Affiliation(s)
- Kamran Qureshi
- Division of Gastroenterology and Hepatology, Saint Louis University, St. Louis, MO, USA
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174
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Dong XC. PNPLA3-A Potential Therapeutic Target for Personalized Treatment of Chronic Liver Disease. Front Med (Lausanne) 2019; 6:304. [PMID: 31921875 PMCID: PMC6927947 DOI: 10.3389/fmed.2019.00304] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 12/02/2019] [Indexed: 01/10/2023] Open
Abstract
Patatin-like phospholipase domain-containing protein 3 (PNPLA3) is a lipid droplet-associated protein that has been shown to have hydrolase activity toward triglycerides and retinyl esters. The first evidence of PNPLA3 being associated with fatty liver disease was revealed by a genome-wide association study (GWAS) of Hispanic, African American, and European American individuals in the Dallas Heart Study back in 2008. Since then, numerous GWAS reports have shown that PNPLA3 rs738409[G] (148M) variant is associated with hepatic triglyceride accumulation (steatosis), inflammation, fibrosis, cirrhosis, and even hepatocellular carcinoma regardless of etiologies including alcohol- or obesity-related and others. The frequency of PNPLA3(148M) variant ranges from 17% in African Americans, 23% in European Americans, to 49% in Hispanics in the Dallas Heart Study. Due to high prevalence of obesity and alcohol consumption in modern societies, the PNPLA3(148M) gene variant and environment interaction poses a serious concern for public health, especially chronic liver diseases including alcohol-related liver disease (ALD) and nonalcoholic fatty liver disease (NAFLD). Therefore, PNPLA3(148M) variant is a potential therapeutic target for chronic liver disease in the rs738409 allele carriers. Currently, there is no approved drug specifically targeting the PNPLA3(148M) variant yet. With additional mechanistic studies, novel therapeutic strategies are expected to be developed for the treatment of the PNPLA3(148M) variant-associated chronic liver diseases in the near future.
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Affiliation(s)
- Xiaocheng Charlie Dong
- Center for Diabetes and Metabolic Diseases, Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, United States
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175
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Abstract
The rising incidence of alcohol-related liver disease (ALD) demands making urgent progress in understanding the fundamental molecular basis of alcohol-related hepatocellular damage. One of the key early events accompanying chronic alcohol usage is the accumulation of lipid droplets (LDs) in the hepatocellular cytoplasm. LDs are far from inert sites of neutral lipid storage; rather, they represent key organelles that play vital roles in the metabolic state of the cell. In this review, we will examine the biology of these structures and outline recent efforts being made to understand the effects of alcohol exposure on the biogenesis, catabolism, and motility of LDs and how their dynamic nature is perturbed in the context of ALD.
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Affiliation(s)
- Ryan J. Schulze
- Department of Biochemistry and Molecular Biology and the Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN, USA,Corresponding author. Department of Biochemistry and Molecular Biology and the Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN, USA. (R.J. Schulze)
| | - Wen-Xing Ding
- Department of Pharmacology, Toxicology, and Therapeutics, The University of Kansas Medical Center, Kansas City, KS, USA
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176
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Lung T, Sakem B, Risch L, Würzner R, Colucci G, Cerny A, Nydegger U. The complement system in liver diseases: Evidence-based approach and therapeutic options. J Transl Autoimmun 2019; 2:100017. [PMID: 32743505 PMCID: PMC7388403 DOI: 10.1016/j.jtauto.2019.100017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Revised: 09/05/2019] [Accepted: 09/10/2019] [Indexed: 12/12/2022] Open
Abstract
Complement is usually seen to largely originate from the liver to accomplish its tasks systemically - its return to the production site has long been underestimated. Recent progress in genomics, therapeutic effects on complement, standardised possibilities in medical laboratory tests and involvement of complosome brings the complement system with its three major functions of opsonization, cytolysis and phagocytosis back to liver biology and pathology. The LOINC™ system features 20 entries for the C3 component of complement to anticipate the application of artificial intelligence data banks algorythms of which are fed with patient-specific data connected to standard lab assays for liver function. These advancements now lead to increased vigilance by clinicians. This reassessment article will further elucidate the distribution of synthesis sites to the three germ layer-derived cell systems and the role complement now known to play in embryogenesis, senescence, allotransplantation and autoimmune disease. This establishes the liver as part of the gastro-intestinal system in connection with nosological entities never thought of, such as the microbiota-liver-brain axis. In neurological disease etiology infectious and autoimmune hepatitis play an important role in the context of causative viz reactive complement activation. The mosaic of autoimmunity, i.e. multiple combinations of the many factors producing varying clinical pictures, leads to the manifold facets of liver autoimmunity.
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Affiliation(s)
- Thomas Lung
- Labormedizinisches Zentrum Dr. Risch, Lagerstrasse 30, CH-9470, Buchs, Switzerland
| | - Benjamin Sakem
- Labormedizinisches Zentrum Dr. Risch, Waldeggstrasse 37, CH-3097, Liebefeld bei Bern, Switzerland
| | - Lorenz Risch
- Labormedizinisches Zentrum Dr. Risch, Waldeggstrasse 37, CH-3097, Liebefeld bei Bern, Switzerland
| | - Reinhard Würzner
- Medical University Innsbruck, Division of Hygiene & Medical Microbiology, Department of Hygiene, Microbiology and Public Health, Schöpfstrasse 41, A-6020, Innsbruck, Austria
| | - Giuseppe Colucci
- Clinica Luganese Moncucco, Lugano, Via Moncucco, CH-6900, Lugano, Switzerland
- Faculty of Medicine, University of Basel, Basel, Switzerland
| | - Andreas Cerny
- Epatocentro Ticino, Via Soldino 5, CH-6900, Lugano, Switzerland
| | - Urs Nydegger
- Labormedizinisches Zentrum Dr. Risch, Waldeggstrasse 37, CH-3097, Liebefeld bei Bern, Switzerland
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177
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Abstract
Fatty liver disease (FLD) affects more than one-third of the population in the western world and an increasing number of children in the United States. It is a leading cause of obesity and liver transplantation. Mechanistic insights into the causes of FLD are urgently needed since no therapeutic intervention has proven to be effective. A sequence variation in patatin like phospholipase domain-containing protein 3 (PNPLA3), rs 738409, is strongly associated with the progression of fatty liver disease. The resulting mutant causes a substitution of isoleucine to methionine at position 148. The underlying mechanism of this disease remains unsolved although several studies have illuminated key insights into its pathogenesis. This review highlights the progress in our understanding of PNPLA3 function in lipid droplet dynamics and explores possible therapeutic interventions to ameliorate this human health hazard.
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Affiliation(s)
- Soumik Basu Ray
- Eugene McDermott Center for Human Growth and Development, Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX, USA
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178
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Nischalke HD, Lutz P, Bartok E, Krämer B, Langhans B, Frizler R, Berg T, Hampe J, Buch S, Datz C, Stickel F, Hartmann G, Strassburg CP, Nattermann J, Spengler U. The PNPLA3 I148M variant promotes lipid-induced hepatocyte secretion of CXC chemokines establishing a tumorigenic milieu. J Mol Med (Berl) 2019; 97:1589-1600. [PMID: 31637480 DOI: 10.1007/s00109-019-01836-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 09/05/2019] [Accepted: 09/20/2019] [Indexed: 02/07/2023]
Abstract
The I148M variant of the Patatin-like phospholipase domain-containing 3 (PNPLA3) protein is associated with an increased risk for liver inflammation and hepatocellular carcinoma (HCC), but the underlying mechanism is unknown. We hypothesized that enhanced CXC chemokine secretion mediates hepatic inflammation that accelerates development of HCC. Expandable primary human (upcyte®) hepatocytes and human PLC/PRF/5 hepatoma cells were lentivirally transduced with both PNPLA3 I148M variants and stimulated with lipids. Cytokine levels in culture supernatant and patient sera (n = 80) were analyzed by ELISA. Supernatants were assessed in transmigration experiments, tube formation, and proliferation assays. In vitro, lipid stimulation of transduced hepatocytes dose-dependently induced the production of interleukin-8 and CXCL1 in hepatocytes carrying the PNPLA3 148M variant. In line, sera from PNPLA3 148M-positive patients with alcoholic liver cirrhosis contained higher levels of interleukin-8 and CXCL1 than patients with wild-type PNPLA3. Supernatants from lipid-stimulated hepatocytes with the PNPLA3 148M variant induced enhanced migration of white blood cells, angiogenesis, and cell proliferation in comparison with supernatants from wild-type hepatocytes via CXC receptors 1 and 2. Increased production of interleukin-8 and CXCL1 by hepatocytes carrying the PNPLA3 148M variant contributes to a pro-inflammatory and tumorigenic milieu in patients with alcoholic liver disease. KEY MESSAGES: The PNPLA3 148M variant is associated with cirrhosis and hepatocellular carcinoma. Lipid stimulation of hepatocytes with this variant induces IL-8 and CXCL1. Supernatants from hepatocytes with this variant promote migration and angiogenesis. Sera from patients with this variant contained enhanced levels of IL-8 and CXCL1. The PNPLA3 148M variant contributes to a tumorigenic milieu via IL-8 and CXCL1.
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Affiliation(s)
- Hans Dieter Nischalke
- Department of Internal Medicine I, University Hospital, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany.
| | - Philipp Lutz
- Department of Internal Medicine I, University Hospital, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
| | - Eva Bartok
- Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital, University of Bonn, Bonn, Germany
| | - Benjamin Krämer
- Department of Internal Medicine I, University Hospital, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
| | - Bettina Langhans
- Department of Internal Medicine I, University Hospital, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
| | - Regina Frizler
- Department of Internal Medicine I, University Hospital, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
| | - Thomas Berg
- Department of Gastroenterology, University Hospital Leipzig, Leipzig, Germany
| | - Jochen Hampe
- Medical Department 1, University Hospital Dresden, TU Dresden, Dresden, Germany
| | - Stephan Buch
- Medical Department 1, University Hospital Dresden, TU Dresden, Dresden, Germany
| | - Christian Datz
- Department of Internal Medicine, Hospital Oberndorf, Teaching Hospital of the Paracelsus Private University of Salzburg, Salzburg, Austria
| | - Felix Stickel
- Department of Gastroenterology and Hepatology, University Hospital of Zürich, Zürich, Switzerland
| | - Gunther Hartmann
- Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital, University of Bonn, Bonn, Germany
| | - Christian P Strassburg
- Department of Internal Medicine I, University Hospital, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
| | - Jacob Nattermann
- Department of Internal Medicine I, University Hospital, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
| | - Ulrich Spengler
- Department of Internal Medicine I, University Hospital, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
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179
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Helsley RN, Varadharajan V, Brown AL, Gromovsky AD, Schugar RC, Ramachandiran I, Fung K, Kabbany MN, Banerjee R, Neumann CK, Finney C, Pathak P, Orabi D, Osborn LJ, Massey W, Zhang R, Kadam A, Sansbury BE, Pan C, Sacks J, Lee RG, Crooke RM, Graham MJ, Lemieux ME, Gogonea V, Kirwan JP, Allende DS, Civelek M, Fox PL, Rudel LL, Lusis AJ, Spite M, Brown JM. Obesity-linked suppression of membrane-bound O-acyltransferase 7 (MBOAT7) drives non-alcoholic fatty liver disease. eLife 2019; 8:e49882. [PMID: 31621579 PMCID: PMC6850774 DOI: 10.7554/elife.49882] [Citation(s) in RCA: 82] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 10/11/2019] [Indexed: 12/14/2022] Open
Abstract
Recent studies have identified a genetic variant rs641738 near two genes encoding membrane bound O-acyltransferase domain-containing 7 (MBOAT7) and transmembrane channel-like 4 (TMC4) that associate with increased risk of non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis (NASH), alcohol-related cirrhosis, and liver fibrosis in those infected with viral hepatitis (Buch et al., 2015; Mancina et al., 2016; Luukkonen et al., 2016; Thabet et al., 2016; Viitasalo et al., 2016; Krawczyk et al., 2017; Thabet et al., 2017). Based on hepatic expression quantitative trait loci analysis, it has been suggested that MBOAT7 loss of function promotes liver disease progression (Buch et al., 2015; Mancina et al., 2016; Luukkonen et al., 2016; Thabet et al., 2016; Viitasalo et al., 2016; Krawczyk et al., 2017; Thabet et al., 2017), but this has never been formally tested. Here we show that Mboat7 loss, but not Tmc4, in mice is sufficient to promote the progression of NAFLD in the setting of high fat diet. Mboat7 loss of function is associated with accumulation of its substrate lysophosphatidylinositol (LPI) lipids, and direct administration of LPI promotes hepatic inflammatory and fibrotic transcriptional changes in an Mboat7-dependent manner. These studies reveal a novel role for MBOAT7-driven acylation of LPI lipids in suppressing the progression of NAFLD.
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Affiliation(s)
- Robert N Helsley
- Department of Cardiovascular and Metabolic SciencesCleveland ClinicClevelandUnited States
- Department of Internal MedicineUniversity of CincinnatiCincinnatiUnited States
| | | | - Amanda L Brown
- Department of Cardiovascular and Metabolic SciencesCleveland ClinicClevelandUnited States
| | - Anthony D Gromovsky
- Department of Cardiovascular and Metabolic SciencesCleveland ClinicClevelandUnited States
| | - Rebecca C Schugar
- Department of Cardiovascular and Metabolic SciencesCleveland ClinicClevelandUnited States
| | - Iyappan Ramachandiran
- Department of Cardiovascular and Metabolic SciencesCleveland ClinicClevelandUnited States
| | - Kevin Fung
- Department of Cardiovascular and Metabolic SciencesCleveland ClinicClevelandUnited States
| | | | - Rakhee Banerjee
- Department of Cardiovascular and Metabolic SciencesCleveland ClinicClevelandUnited States
| | - Chase K Neumann
- Department of Cardiovascular and Metabolic SciencesCleveland ClinicClevelandUnited States
| | - Chelsea Finney
- Department of Cardiovascular and Metabolic SciencesCleveland ClinicClevelandUnited States
| | - Preeti Pathak
- Department of Cardiovascular and Metabolic SciencesCleveland ClinicClevelandUnited States
| | - Danny Orabi
- Department of Cardiovascular and Metabolic SciencesCleveland ClinicClevelandUnited States
| | - Lucas J Osborn
- Department of Cardiovascular and Metabolic SciencesCleveland ClinicClevelandUnited States
| | - William Massey
- Department of Cardiovascular and Metabolic SciencesCleveland ClinicClevelandUnited States
| | - Renliang Zhang
- Department of Cardiovascular and Metabolic SciencesCleveland ClinicClevelandUnited States
| | - Anagha Kadam
- Department of Cardiovascular and Metabolic SciencesCleveland ClinicClevelandUnited States
| | - Brian E Sansbury
- Center for Experimental Therapeutics & Reperfusion Injury, Department of Anesthesiology, Perioperative and Pain MedicineBrigham and Women’s Hospital, Harvard Medical SchoolBostonUnited States
| | - Calvin Pan
- Department of MedicineUniversity of California, Los AngelesLos AngelesUnited States
- Department of MicrobiologyUniversity of California, Los AngelesLos AngelesUnited States
- Department of Human GeneticsUniversity of California, Los AngelesLos AngelesUnited States
| | - Jessica Sacks
- Department of PathobiologyCleveland ClinicClevelandUnited States
| | - Richard G Lee
- Cardiovascular Group, Antisense Drug DiscoveryIonis Pharmaceuticals, IncCarlsbadUnited States
| | - Rosanne M Crooke
- Cardiovascular Group, Antisense Drug DiscoveryIonis Pharmaceuticals, IncCarlsbadUnited States
| | - Mark J Graham
- Cardiovascular Group, Antisense Drug DiscoveryIonis Pharmaceuticals, IncCarlsbadUnited States
| | | | - Valentin Gogonea
- Department of ChemistryCleveland State UniversityClevelandUnited States
| | - John P Kirwan
- Department of PathobiologyCleveland ClinicClevelandUnited States
| | - Daniela S Allende
- Department of Anatomical PathologyCleveland ClinicClevelandUnited States
| | - Mete Civelek
- Department of Biomedical EngineeringUniversity of VirginiaCharlottesvilleUnited States
| | - Paul L Fox
- Department of Cardiovascular and Metabolic SciencesCleveland ClinicClevelandUnited States
| | - Lawrence L Rudel
- Department of Pathology, Section on Lipid SciencesWake Forest University School of MedicineWinston-SalemUnited States
| | - Aldons J Lusis
- Department of MedicineUniversity of California, Los AngelesLos AngelesUnited States
- Department of MicrobiologyUniversity of California, Los AngelesLos AngelesUnited States
- Department of Human GeneticsUniversity of California, Los AngelesLos AngelesUnited States
| | - Matthew Spite
- Center for Experimental Therapeutics & Reperfusion Injury, Department of Anesthesiology, Perioperative and Pain MedicineBrigham and Women’s Hospital, Harvard Medical SchoolBostonUnited States
| | - J Mark Brown
- Department of Cardiovascular and Metabolic SciencesCleveland ClinicClevelandUnited States
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180
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Senkerikova R, Frankova S, Jirsa M, Kreidlova M, Merta D, Neroldova M, Chmelova K, Spicak J, Sperl J. PNPLA3 rs738409 G allele carriers with genotype 1b HCV cirrhosis have lower viral load but develop liver failure at younger age. PLoS One 2019; 14:e0222609. [PMID: 31527889 PMCID: PMC6748417 DOI: 10.1371/journal.pone.0222609] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2019] [Accepted: 09/03/2019] [Indexed: 12/19/2022] Open
Abstract
Background PNPLA3 rs738409 minor allele c.444G represents a risk factor for liver steatosis and fibrosis progression also in chronic hepatitis C (HCV). We investigated its impact on the timing of liver transplantation (LT) in patients with genotype 1b HCV cirrhosis. Methods We genotyped and evaluated 172 LT candidates with liver cirrhosis owing to chronic HCV infection, genotype 1b. One hundred patients needed LT for chronic liver failure (CLF) and 72 for a small hepatocellular carcinoma (HCC) in the cirrhotic liver without CLF. Population controls (n = 647) were selected from the Czech cross-sectional study MONICA. Results The CLF patients were younger (53.5 ± 7.2 vs. 59.6 ± 6.6, P < 0.001) with more advanced liver disease than HCC patients (Child-Pugh’s score 9.1 ± 1.8 vs. 7.1 ± 1.9, P < 0.001, MELD 14.1 ± 3.9 vs. 11.1 ± 3.7, P < 0.001). PNPLA3 G allele increased the risk of LT for CLF in both allelic and recessive models (CG + GG vs. CC: OR, 1.90; 95% CI, 1.017–3.472, P = 0.045 and GG vs. CC + CG: OR, 2.94; 95% CI, 1.032–7.513, P = 0.042). Multivariate analysis identified younger age (P < 0.001) and the G allele (P < 0.05) as risk factors for CLF. The genotype frequencies between the CLF group and MONICA study significantly differed in both, allelic and recessive model (P = 0.004, OR 1.87, 95% CI 1.222–2.875; P < 0.001, OR 3.33, 95% CI 1.824–6.084, respectively). The OR values almost doubled in the recessive model compared with the allelic model suggesting the additive effect of allele G. In contrast, genotype frequencies in the HCC group were similar to the MONICA study in both models. Pretransplant viral load was significantly lower in GG than in CC + CG genotypes (median, IQR; 162,500 (61,550–319,000) IU/ml vs. 570,000 (172,000–1,595,000) IU/ml, P < 0.0009). Conclusions Our results suggest that PNPLA3 rs738409 G allele carriage may be associated with a faster progression of HCV cirrhosis to chronic liver failure.
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Affiliation(s)
- Renata Senkerikova
- Department of Hepatogastroenterology, Transplant Centre, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
- Charles University, First Faculty of Medicine, Prague, Czech Republic
| | - Sona Frankova
- Department of Hepatogastroenterology, Transplant Centre, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - Milan Jirsa
- Charles University, First Faculty of Medicine, Prague, Czech Republic
- Laboratory of Experimental Hepatology, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - Miluse Kreidlova
- Institute of Medical Biochemistry and Laboratory Diagnostics First Faculty of Medicine Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Dusan Merta
- Anesthesiology, Resuscitation and Intensive Care Department, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - Magdalena Neroldova
- Charles University, First Faculty of Medicine, Prague, Czech Republic
- Laboratory of Experimental Hepatology, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - Klara Chmelova
- Department of Hepatogastroenterology, Transplant Centre, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
- Charles University, First Faculty of Medicine, Prague, Czech Republic
| | - Julius Spicak
- Department of Hepatogastroenterology, Transplant Centre, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - Jan Sperl
- Department of Hepatogastroenterology, Transplant Centre, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
- Charles University, First Faculty of Medicine, Prague, Czech Republic
- * E-mail:
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181
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Taliento AE, Dallio M, Federico A, Prati D, Valenti L. Novel Insights into the Genetic Landscape of Nonalcoholic Fatty Liver Disease. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:E2755. [PMID: 31375010 PMCID: PMC6695718 DOI: 10.3390/ijerph16152755] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 07/27/2019] [Accepted: 07/30/2019] [Indexed: 12/19/2022]
Abstract
Nonalcoholic fatty liver disease (NAFLD), the most common liver disorder worldwide, is epidemiologically associated with overweight, insulin resistance features and type 2 diabetes, and can progress to advanced liver fibrosis and hepatocellular carcinoma. Genetic factors play an important role in the development of NAFLD, which is a multifactorial disease. Several common naturally occurring variants modulating lipid and retinol metabolism in hepatocytes predispose to NAFLD development and progression, in particular those in PNPLA3, TM6SF2, MBOAT7, and HSD17B13. In addition, genetic variants that protect hepatic cells from oxidative stress modulate the susceptibility to progressive NAFLD. Although the molecular mechanisms linking these genetic variants with liver disease are not yet fully understood, hepatic fat has emerged as a major driver of the disease, while altered retinol metabolism and mitochondrial oxidative stress play a role in determining the development of advanced NAFLD.
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Affiliation(s)
- Alice Emma Taliento
- Translational Medicine, Department of Transfusion Medicine and Hematology, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico IRCCS, 20122 Milan, Italy
| | - Marcello Dallio
- Department of Precision Medicine, University of Campania "Luigi Vanvitelli", 80131 Naples, Italy.
| | - Alessandro Federico
- Department of Precision Medicine, University of Campania "Luigi Vanvitelli", 80131 Naples, Italy
| | - Daniele Prati
- Translational Medicine, Department of Transfusion Medicine and Hematology, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico IRCCS, 20122 Milan, Italy
| | - Luca Valenti
- Translational Medicine, Department of Transfusion Medicine and Hematology, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico IRCCS, 20122 Milan, Italy.
- Department of Pathophysiology and Transplantation, University of Milan, 20122 Milano, Italy.
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182
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Nunes Dos Santos K, Florentino RM, França A, Lima Filho ACM, Santos MLD, Missiaggia D, Fonseca MDC, Brasil Costa I, Vidigal PVT, Nathanson MH, Lemos FDO, Leite MF. Polymorphism in the Promoter Region of NFE2L2 Gene Is a Genetic Marker of Susceptibility to Cirrhosis Associated with Alcohol Abuse. Int J Mol Sci 2019; 20:E3589. [PMID: 31340446 PMCID: PMC6678089 DOI: 10.3390/ijms20143589] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 07/12/2019] [Accepted: 07/15/2019] [Indexed: 12/12/2022] Open
Abstract
Alcoholic liver disease (ALD) is a highly prevalent spectrum of pathologies caused by alcohol overconsumption. Morbidity and mortality related to ALD are increasing worldwide, thereby demanding strategies for early diagnosis and detection of ALD predisposition. A potential candidate as a marker for ALD susceptibility is the transcription factor nuclear factor erythroid-related factor 2 (Nrf2), codified by the nuclear factor erythroid 2-related factor 2 gene (NFE2L2). Nrf2 regulates expression of proteins that protect against oxidative stress and inflammation caused by alcohol overconsumption. Here, we assessed genetic variants of NFE2L2 for association with ALD. Specimens from patients diagnosed with cirrhosis caused by ALD were genotyped for three NFE2L2 single nucleotide polymorphisms (SNP) (SNPs: rs35652124, rs4893819, and rs6721961). Hematoxylin & eosin and immunohistochemistry were performed to determine the inflammatory score and Nrf2 expression, respectively. SNPs rs4893819 and rs6721961 were not specifically associated with ALD, but analysis of SNP rs35652124 suggested that this polymorphism predisposes to ALD. Furthermore, SNP rs35652124 was associated with a lower level of Nrf2 expression. Moreover, liver samples from ALD patients with this polymorphism displayed more severe inflammatory activity. Together, these findings provide evidence that the SNP rs35652124 variation in the Nrf2-encoding gene NFE2L2 is a potential genetic marker for susceptibility to ALD.
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Affiliation(s)
| | | | - Andressa França
- Universidade Federal de Minas Gerais, Belo Horizonte, MG 31270-901, Brazil
| | | | | | - Dabny Missiaggia
- Universidade Federal de Minas Gerais, Belo Horizonte, MG 31270-901, Brazil
| | - Matheus de Castro Fonseca
- Laboratório Nacional de Biociências (LNBio), Centro de Pesquisa em Energia e Materiais (CNPEM), Campinas, SP 13083-970, Brazil
| | - Igor Brasil Costa
- Instituto de Pesquisas Evandro Chagas - IEC, Ananindeua, PA 67030-000, Brazil
| | | | - Michael H Nathanson
- Section of Digestive Diseases, Yale University School of Medicine, New Haven, CT 06510, USA
| | | | - M Fatima Leite
- Universidade Federal de Minas Gerais, Belo Horizonte, MG 31270-901, Brazil
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183
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Schulze RJ, Schott MB, Casey CA, Tuma PL, McNiven MA. The cell biology of the hepatocyte: A membrane trafficking machine. J Cell Biol 2019; 218:2096-2112. [PMID: 31201265 PMCID: PMC6605791 DOI: 10.1083/jcb.201903090] [Citation(s) in RCA: 90] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 05/24/2019] [Accepted: 05/28/2019] [Indexed: 12/24/2022] Open
Abstract
The liver performs numerous vital functions, including the detoxification of blood before access to the brain while simultaneously secreting and internalizing scores of proteins and lipids to maintain appropriate blood chemistry. Furthermore, the liver also synthesizes and secretes bile to enable the digestion of food. These diverse attributes are all performed by hepatocytes, the parenchymal cells of the liver. As predicted, these cells possess a remarkably well-developed and complex membrane trafficking machinery that is dedicated to moving specific cargos to their correct cellular locations. Importantly, while most epithelial cells secrete nascent proteins directionally toward a single lumen, the hepatocyte secretes both proteins and bile concomitantly at its basolateral and apical domains, respectively. In this Beyond the Cell review, we will detail these central features of the hepatocyte and highlight how membrane transport processes play a key role in healthy liver function and how they are affected by disease.
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Affiliation(s)
- Ryan J Schulze
- Division of Gastroenterology and Hepatology, Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN
| | - Micah B Schott
- Division of Gastroenterology and Hepatology, Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN
| | - Carol A Casey
- Research Service, Department of Veterans Affairs, Nebraska-Western Iowa Health Care System, Omaha, NE
- Departments of Internal Medicine and Biochemistry & Molecular Biology, University of Nebraska Medical Center, Omaha, NE
| | | | - Mark A McNiven
- Division of Gastroenterology and Hepatology, Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN
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