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Van Woerkom A, Harney DJ, Nagarajan SR, Hakeem-Sanni MF, Lin J, Hooke M, Pulpitel T, Cooney GJ, Larance M, Saunders DN, Brandon AE, Hoy AJ. Hepatic lipid droplet-associated proteome changes distinguish dietary-induced fatty liver from glucose tolerance in male mice. Am J Physiol Endocrinol Metab 2024; 326:E842-E855. [PMID: 38656127 DOI: 10.1152/ajpendo.00013.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 04/12/2024] [Accepted: 04/15/2024] [Indexed: 04/26/2024]
Abstract
Fatty liver is characterized by the expansion of lipid droplets (LDs) and is associated with the development of many metabolic diseases. We assessed the morphology of hepatic LDs and performed quantitative proteomics in lean, glucose-tolerant mice compared with high-fat diet (HFD) fed mice that displayed hepatic steatosis and glucose intolerance as well as high-starch diet (HStD) fed mice who exhibited similar levels of hepatic steatosis but remained glucose tolerant. Both HFD- and HStD-fed mice had more and larger LDs than Chow-fed animals. We observed striking differences in liver LD proteomes of HFD- and HStD-fed mice compared with Chow-fed mice, with fewer differences between HFD and HStD. Taking advantage of our diet strategy, we identified a fatty liver LD proteome consisting of proteins common in HFD- and HStD-fed mice, as well as a proteome associated with glucose tolerance that included proteins shared in Chow and HStD but not HFD-fed mice. Notably, glucose intolerance was associated with changes in the ratio of adipose triglyceride lipase to perilipin 5 in the LD proteome, suggesting dysregulation of neutral lipid homeostasis in glucose-intolerant fatty liver. We conclude that our novel dietary approach uncouples ectopic lipid burden from insulin resistance-associated changes in the hepatic lipid droplet proteome.NEW & NOTEWORTHY This study identified a fatty liver lipid droplet proteome and one associated with glucose tolerance. Notably, glucose intolerance was linked with changes in the ratio of adipose triglyceride lipase to perilipin 5 that is indicative of dysregulation of neutral lipid homeostasis.
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Affiliation(s)
- Andries Van Woerkom
- Faculty of Medicine and Health, School of Medical Sciences, Charles Perkins Centre, University of Sydney, Sydney, New South Wales, Australia
| | - Dylan J Harney
- Faculty of Medicine and Health, School of Medical Sciences, Charles Perkins Centre, University of Sydney, Sydney, New South Wales, Australia
- Faculty of Science, School of Life and Environmental Sciences, Charles Perkins Centre, The University of Sydney, Sydney, New South Wales, Australia
| | - Shilpa R Nagarajan
- Faculty of Medicine and Health, School of Medical Sciences, Charles Perkins Centre, University of Sydney, Sydney, New South Wales, Australia
| | - Mariam F Hakeem-Sanni
- Faculty of Medicine and Health, School of Medical Sciences, Charles Perkins Centre, University of Sydney, Sydney, New South Wales, Australia
| | - Jinfeng Lin
- Faculty of Medicine and Health, School of Medical Sciences, Charles Perkins Centre, University of Sydney, Sydney, New South Wales, Australia
| | - Matthew Hooke
- Faculty of Medicine and Health, School of Medical Sciences, Charles Perkins Centre, University of Sydney, Sydney, New South Wales, Australia
| | - Tamara Pulpitel
- Faculty of Science, School of Life and Environmental Sciences, Charles Perkins Centre, The University of Sydney, Sydney, New South Wales, Australia
| | - Gregory J Cooney
- Faculty of Medicine and Health, School of Medical Sciences, Charles Perkins Centre, University of Sydney, Sydney, New South Wales, Australia
| | - Mark Larance
- Faculty of Medicine and Health, School of Medical Sciences, Charles Perkins Centre, University of Sydney, Sydney, New South Wales, Australia
| | - Darren N Saunders
- Faculty of Medicine and Health, School of Medical Sciences, Charles Perkins Centre, University of Sydney, Sydney, New South Wales, Australia
| | - Amanda E Brandon
- Faculty of Medicine and Health, School of Medical Sciences, Charles Perkins Centre, University of Sydney, Sydney, New South Wales, Australia
- Faculty of Science, School of Life and Environmental Sciences, Charles Perkins Centre, The University of Sydney, Sydney, New South Wales, Australia
| | - Andrew J Hoy
- Faculty of Medicine and Health, School of Medical Sciences, Charles Perkins Centre, University of Sydney, Sydney, New South Wales, Australia
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Lundsgaard AM, Bojsen-Møller KN, Kiens B. Dietary Regulation of Hepatic Triacylglycerol Content-the Role of Eucaloric Carbohydrate Restriction with Fat or Protein Replacement. Adv Nutr 2023; 14:1359-1373. [PMID: 37591342 PMCID: PMC10721463 DOI: 10.1016/j.advnut.2023.08.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 07/21/2023] [Accepted: 08/07/2023] [Indexed: 08/19/2023] Open
Abstract
Accumulation of hepatic triacylglycerol (TG) is highly associated with impaired whole-body insulin-glucose homeostasis and dyslipidemia. The summarized findings from human intervention studies investigating the effect of reduced dietary carbohydrate and increased fat intake (and in studies also increased protein) while maintaining energy intake at eucaloric requirements reveal a beneficial effect of carbohydrate reduction on hepatic TG content in obese individuals with steatosis and indices of insulin resistance. Evidence suggests that the reduction of hepatic TG content after reduced intake of carbohydrates and increased fat/protein intake in humans, results from regulation of fatty acid (FA) metabolism within the liver, with an increase in hepatic FA oxidation and ketogenesis, together with a concomitant downregulation of FA synthesis from de novo lipogenesis. The adaptations in hepatic metabolism may result from reduced intrahepatic monosaccharide and insulin availability, reduced glycolysis and increased FA availability when carbohydrate intake is reduced.
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Affiliation(s)
- Anne-Marie Lundsgaard
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark.
| | | | - Bente Kiens
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
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Zhao Y, Zhao W, Ma J, Toshiyoshi M, Zhao Y. Patatin-like phospholipase domain-containing 3 gene (PNPLA3) polymorphic (rs738409) single nucleotide polymorphisms and susceptibility to nonalcoholic fatty liver disease: A meta-analysis of twenty studies. Medicine (Baltimore) 2023; 102:e33110. [PMID: 36897668 PMCID: PMC9997767 DOI: 10.1097/md.0000000000033110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 02/07/2023] [Indexed: 03/11/2023] Open
Abstract
BACKGROUND To investigate the correlation between rs738409 polymorphism of patatin-like phospholipase domain-containing protein 3 (PNPLA3) gene (encoding I148m) and genetic susceptibility to nonalcoholic fatty liver disease (NAFLD). METHODS Web of Science, Embase, PubMed, Cochrane Library, China National Knowledge Infrastructure, Wanfang Data Knowledge Service Platform databases were subjected to study retrieving, from the earliest records to November 2022. International databases were searched using the key words (PNPLA3 gene or PNPLA3 polymorphism or patatin-like phospholipase domain-containing pro-tein3) and (nonalcoholic fatty liver disease or NAFLD or nonalcoholic steatohepatitis) and their possible combination. There was no limitation to language. Ethnicity and country restrictions were not applied. Hardy-Weinberg equilibrium about the genotype frequencies of rs738,409 polymorphism in group of controls was assessed using a chi-square goodness-of-fit test (P > .05). A chi-square-based Q test was applied to assess heterogeneity among studies. The random-effect model (DerSimonian-Laird method) was used when a probability value of P < .10, I2 > 50%. If not, the fixed-effect model (Mantel-Haenszel method) was adopted. The current meta-analysis was done by using STATA 16.0. RESULTS Twenty studies are selected for this meta-analysis, which includes totally 3240 patients in the treatment group and 5210 patients in the control group. These studies demonstrated a significant increased association between rs738,409 and NAFLD under 5 models: allelic contrast (odds ratio [OR] = 1.98, 95% confidence interval [CI] = 1.65-2.37, Pheterogeneity = 0.000, Z = 7.346, P = .000), homozygote comparison (OR = 3.59, 95% CI = 2.56-5.04, Pheterogeneity = 0.000, Z = 7.416, P = .000), heterozygote comparison (OR = 1.93, 95% CI = 1.63-2.30, Pheterogeneity = 0.002, Z = 7.507, P = .000), the dominant allele model (OR = 2.33, 95% CI = 1.89-2.88, Pheterogeneity = 0.000, Z = 7.856, P = .000), and the recessive allele model (OR = 2.56, 95% CI = 1.96-3.35, Pheterogeneity = 0.000, Z = 6.850, P = .000). Subgroup analysis shows that the rs738,409 polymorphism of PNPLA3 gene in Caucasians and those with a sample size of < 300 is significantly associated with the susceptibility to nonalcoholic fatty liver. Sensitivity analysis shows that the results of meta-analysis are stable. CONCLUSION PNPLA3 rs738,409 may play a significant role in increasing risk of NAFLD.
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Affiliation(s)
- Yan Zhao
- Graduate school, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Wenli Zhao
- Department of Public Health, International College, Krirk University, Bangkok, Thailand
- Liver Center, Saga University Hospital, Saga University 849-8501, Saga City, Japan
| | - Jingchao Ma
- Department of Public Health, International College, Krirk University, Bangkok, Thailand
| | - Maeda Toshiyoshi
- International Education College, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Ye Zhao
- Department of Public Health, International College, Krirk University, Bangkok, Thailand
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A Comparison of Primary Human Hepatocytes and Hepatoma Cell Lines to Model the Effects of Fatty Acids, Fructose and Glucose on Liver Cell Lipid Accumulation. Nutrients 2022; 15:nu15010040. [PMID: 36615698 PMCID: PMC9824391 DOI: 10.3390/nu15010040] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 12/14/2022] [Accepted: 12/19/2022] [Indexed: 12/24/2022] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) begins with lipid accumulation within hepatocytes, but the relative contributions of different macronutrients is still unclear. We investigated the impact of fatty acids, glucose and fructose on lipid accumulation in primary human hepatocytes (PHH) and three different cell lines: HepG2 (human hepatoblastoma−derived cell line), Huh7 (human hepatocellular carcinoma cell line) and McA-RH7777 (McA, rat hepatocellular carcinoma cell line). Cells were treated for 48 h with fatty acids (0 or 200 μM), glucose (5 mM or 11 mM) and fructose (0 mM, 2 mM or 8 mM). Lipid accumulation was measured via Nile Red staining. All cell types accumulated lipid in response to fatty acids (p < 0.001). PHH and McA, but not HepG2 or Huh7 cells, accumulated more lipid with 11 mM glucose plus fatty acids (p = 0.004, fatty acid × glucose interaction, for both), but only PHH increased lipid accumulation in response to fructose (p < 0.001). Considerable variation was observed between PHH cells from different individuals. Lipid accumulation in PHH was increased by insulin (p = 0.003) with inter-individual variability. Similarly, insulin increased lipid accumulation in both HepG2 and McA cells, with a bigger response in McA in the presence of fatty acids (p < 0.001 for fatty acid × insulin). McA were more insulin sensitive than either HepG2 or Huh7 cells in terms of AKT phosphorylation (p < 0.001 insulin × cell type interaction). Hence, glucose and fructose can contribute to the accumulation of lipid in PHH with considerable inter-individual variation, but hepatoma cell lines are not good models of PHH.
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Ramos-Lopez O. Multi-Omics Nutritional Approaches Targeting Metabolic-Associated Fatty Liver Disease. Genes (Basel) 2022; 13:2142. [PMID: 36421817 PMCID: PMC9690481 DOI: 10.3390/genes13112142] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 11/15/2022] [Accepted: 11/16/2022] [Indexed: 10/29/2023] Open
Abstract
Currently, metabolic-associated fatty liver disease (MAFLD) is a leading global cause of chronic liver disease, and is expected to become one of the most common indications of liver transplantation. MAFLD is associated with obesity, involving multiple mechanisms such as alterations in lipid metabolism, insulin resistance, hyperinflammation, mitochondrial dysfunction, cell apoptosis, oxidative stress, and extracellular matrix formation. However, the onset and progression of MAFLD is variable among individuals, being influenced by intrinsic (personal) and external environmental factors. In this context, sequence structural variants across the human genome, epigenetic phenomena (i.e., DNA methylation, histone modifications, and long non-coding RNAs) affecting gene expression, gut microbiota dysbiosis, and metabolomics/lipidomic fingerprints may account for differences in MAFLD outcomes through interactions with nutritional features. This knowledge may contribute to gaining a deeper understanding of the molecular and physiological processes underlying MAFLD pathogenesis and phenotype heterogeneity, as well as facilitating the identification of biomarkers of disease progression and therapeutic targets for the implementation of tailored nutritional strategies. This comprehensive literature review highlights the potential of nutrigenetic, nutriepigenetic, nutrimetagenomic, nutritranscriptomics, and nutrimetabolomic approaches for the prevention and management of MAFLD in humans through the lens of precision nutrition.
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Affiliation(s)
- Omar Ramos-Lopez
- Medicine and Psychology School, Autonomous University of Baja California, Tijuana 22390, Mexico
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Galsgaard KD, Elmelund E, Johansen CD, Bomholt AB, Kizilkaya HS, Ceutz F, Hunt JE, Kissow H, Winther-Sørensen M, Sørensen CM, Kruse T, Lau JF, Rosenkilde MM, Ørskov C, Christoffersen C, Holst JJ, Wewer Albrechtsen NJ. Glucagon receptor antagonism impairs and glucagon receptor agonism enhances triglycerides metabolism in mice. Mol Metab 2022; 66:101639. [PMID: 36400402 PMCID: PMC9706156 DOI: 10.1016/j.molmet.2022.101639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 11/06/2022] [Accepted: 11/09/2022] [Indexed: 11/17/2022] Open
Abstract
OBJECTIVE Treatment with glucagon receptor antagonists (GRAs) reduces blood glucose but causes dyslipidemia and accumulation of fat in the liver. We investigated the acute and chronic effects of glucagon on lipid metabolism in mice. METHODS Chronic effects of glucagon receptor signaling on lipid metabolism were studied using oral lipid tolerance tests (OLTTs) in overnight fasted glucagon receptor knockout (Gcgr-/-) mice, and in C57Bl/6JRj mice treated with a glucagon receptor antibody (GCGR Ab) or a long-acting glucagon analogue (GCGA) for eight weeks. Following treatment, liver tissue was harvested for RNA-sequencing and triglyceride measurements. Acute effects were studied in C57Bl/6JRj mice treated with a GRA or GCGA 1 h or immediately before OLTTs, respectively. Direct effects of glucagon on hepatic lipolysis were studied using isolated perfused mouse liver preparations. To investigate potential effects of GCGA and GRA on gastric emptying, paracetamol was, in separate experiments, administered immediately before OLTTs. RESULTS Plasma triglyceride concentrations increased 2-fold in Gcgr-/- mice compared to their wild-type littermates during the OLTT (P = 0.001). Chronic treatment with GCGR Ab increased, whereas GCGA treatment decreased, plasma triglyceride concentrations during OLTTs (P < 0.05). Genes involved in lipid metabolism were upregulated upon GCGR Ab treatment while GCGA treatment had opposite effects. Acute GRA and GCGA treatment, respectively, increased (P = 0.02) and decreased (P = 0.003) plasma triglyceride concentrations during OLTTs. Glucagon stimulated hepatic lipolysis, evident by an increase in free fatty acid concentrations in the effluent from perfused mouse livers. In line with this, GCGR Ab treatment increased, while GCGA treatment decreased, liver triglyceride concentrations. The effects of glucagon appeared independent of changes in gastric emptying of paracetamol. CONCLUSIONS Glucagon receptor signaling regulates triglyceride metabolism, both chronically and acutely, in mice. These data expand glucagon´s biological role and implicate that intact glucagon signaling is important for lipid metabolism. Glucagon agonism may have beneficial effects on hepatic and peripheral triglyceride metabolism.
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Affiliation(s)
- Katrine D. Galsgaard
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark,Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Emilie Elmelund
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Christian D. Johansen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark,Novo Nordisk Foundation Center for Protein Research, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Anna B. Bomholt
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Hüsün S. Kizilkaya
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Frederik Ceutz
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jenna E. Hunt
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark,Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Hannelouise Kissow
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Marie Winther-Sørensen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark,Novo Nordisk Foundation Center for Protein Research, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Charlotte M. Sørensen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Thomas Kruse
- Novo Nordisk A/S, Research Chemistry, Novo Nordisk Park, DK-2760 Måløv, Denmark
| | - Jesper F. Lau
- Novo Nordisk A/S, Research Chemistry, Novo Nordisk Park, DK-2760 Måløv, Denmark
| | - Mette M. Rosenkilde
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Cathrine Ørskov
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Christina Christoffersen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark,Department of Clinical Biochemistry, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Jens J. Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark,Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Nicolai J. Wewer Albrechtsen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark,Novo Nordisk Foundation Center for Protein Research, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark,Department of Clinical Biochemistry, Bispebjerg & Frederiksberg Hospitals, University of Copenhagen, 2400 Bispebjerg, Denmark,Corresponding author. Department of Biomedical Sciences and Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, and Department of Clinical Biochemistry, Bispebjerg & Frederiksberg Hospitals, University of Copenhagen, 2400 Bispebjerg, Denmark.
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Progressive Liver Fibrosis in Non-Alcoholic Fatty Liver Disease. Cells 2021; 10:cells10123401. [PMID: 34943908 PMCID: PMC8699709 DOI: 10.3390/cells10123401] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 11/29/2021] [Accepted: 11/29/2021] [Indexed: 12/11/2022] Open
Abstract
Non-alcoholic steatohepatitis (NASH) is a chronic and progressive form of non-alcoholic fatty liver disease. Its global incidence is increasing and makes NASH an epidemic and a public health threat. Non-alcoholic fatty liver disease is associated with major morbidity and mortality, with a heavy burden on quality of life and liver transplant requirements. Due to repeated insults to the liver, patients are at risk for developing hepatocellular carcinoma. The progression of NASH was initially defined according to a two-hit model involving an initial development of steatosis, followed by a process of lipid peroxidation and inflammation. In contrast, current evidence proposes a “multi-hit” or “multi-parallel hit” model that includes multiple pathways promoting progressive fibrosis and oncogenesis. This model includes multiple cellular, genetic, immunological, metabolic, and endocrine pathways leading to hepatocellular carcinoma development, underscoring the complexity of this disease.
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Glucagon is associated with NAFLD inflammatory progression in type 2 diabetes, not with NAFLD fibrotic progression. Eur J Gastroenterol Hepatol 2021; 33:e818-e823. [PMID: 34402473 PMCID: PMC8734619 DOI: 10.1097/meg.0000000000002269] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVES Higher prevalence of progressive stages of nonalcoholic fatty liver disease (NAFLD) and hyperglucagonemia were observed in type 2 diabetes. We aim to investigate whether islet alpha cell dysfunction (evaluated by glucagon) associates with NAFLD progression in type 2 diabetic adults. METHODS A total of 4937 diabetic participants were enrolled from seven communities in Shanghai, China. Probable nonalcoholic steatohepatitis (NASH) was defined by the presence of NAFLD and metabolic syndrome. Probable NAFLD fibrosis score was used to identify patients with different risk stratification of bridging fibrosis (stage 3) or cirrhosis (stage 4). RESULTS After adjustment for age, sex, duration of diabetes, current smoking, waist circumference, C-peptide, HbA1c, dyslipidemia, hypertension and use of incretins and SGLT2 inhibitor, glucagon quartiles were negatively associated with probable NASH (Q4 vs. Q1 OR 0.71, 95% confidence interval, 0.53-0.96, P for trend=0.010), though they were not associated with simple NAFLD (P for trend=0.176). Furthermore, glucagon was not significantly associated with fibrotic progression of liver steatosis in diabetic patients with NAFLD (P for trend=0.889). CONCLUSIONS Significant associations were observed among glucagon and inflammatory progression of NAFLD, but not with fibrotic progression. Further understanding the association between islet alpha cell and liver may lead to development of treatment strategies for NAFLD patients with type 2 diabetes.
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Impact of the Association Between PNPLA3 Genetic Variation and Dietary Intake on the Risk of Significant Fibrosis in Patients With NAFLD. Am J Gastroenterol 2021; 116:994-1006. [PMID: 33306506 PMCID: PMC8087619 DOI: 10.14309/ajg.0000000000001072] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 10/23/2020] [Indexed: 12/11/2022]
Abstract
INTRODUCTION This study explored the relationship between patatin-like phospholipase domain-containing 3 gene (PNPLA3 rs738409), nutrient intake, and liver histology severity in patients with nonalcoholic fatty liver disease (NAFLD). METHODS PNPLA3-rs738409 variant was genotyped in 452 non-Hispanic whites with histologically confirmed NAFLD who completed Food Frequency Questionnaire within 6 months of their liver biopsy. The fibrosis severity on liver histology was the outcome of interest. RESULTS The distribution of PNPLA3 genotypes was CC: 28%, CG: 46%, and GG: 25%. High-carbohydrate (% of energy/d) intake was positively associated (adjusted [Adj] odds ratio [OR]: 1.03, P < 0.01), whereas higher n-3 polyunsaturated fatty acids (n-3 PUFAs) (g/d) (Adj. OR: 0.17, P < 0.01), isoflavones (mg/d) (Adj. OR: 0.74, P = 0.049), methionine (mg/d) (Adj. OR: 0.32, P < 0.01), and choline (mg/d) (Adj. OR: 0.32, P < 0.01) intakes were inversely associated with increased risk of significant fibrosis (stage of fibrosis ≥2). By using an additive model of inheritance, our moderation analysis showed that PNPLA3 rs738409 significantly modulates the relationship between carbohydrate (%), n-3 PUFAs, total isoflavones, methionine, and choline intakes and fibrosis severity in a dose-dependent, genotype manner. These dietary factors tended to have a larger and significant effect on fibrosis severity among rs738409 G-allele carriers. Associations between significant fibrosis and carbohydrates (Adj. OR: 1.04, P = 0.019), n-3 PUFAs (Adj. OR: 0.16, P < 0.01), isoflavones (Adj. OR: 0.65, P = 0.025), methionine (Adj. OR: 0.30, P < 0.01), and total choline (Adj. OR: 0.29, P < 0.01) intakes remained significant only among rs738409 G-allele carriers. DISCUSSION This gene-diet interaction study suggests that PNPLA3 rs738409 G-allele might modulate the effect of specific dietary nutrients on risk of fibrosis in patients with NAFLD.
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Cariello M, Piccinin E, Moschetta A. Transcriptional Regulation of Metabolic Pathways via Lipid-Sensing Nuclear Receptors PPARs, FXR, and LXR in NASH. Cell Mol Gastroenterol Hepatol 2021; 11:1519-1539. [PMID: 33545430 PMCID: PMC8042405 DOI: 10.1016/j.jcmgh.2021.01.012] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 01/19/2021] [Accepted: 01/19/2021] [Indexed: 02/07/2023]
Abstract
Nonalcoholic fatty liver disease comprises a wide spectrum of liver injuries from simple steatosis to steatohepatitis and cirrhosis. Nonalcoholic steatohepatitis (NASH) is defined when liver steatosis is associated with inflammation, hepatocyte damage, and fibrosis. A genetic predisposition and environmental insults (ie, dietary habits, obesity) are putatively responsible for NASH progression. Here, we present the impact of the lipid-sensing nuclear receptors in the pathogenesis and treatment of NASH. In detail, we discuss the pros and cons of the putative transcriptional action of the fatty acid sensors (peroxisome proliferator-activated receptors), the bile acid sensor (farnesoid X receptor), and the oxysterol sensor (liver X receptors) in the pathogenesis and bona fide treatment of NASH.
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Affiliation(s)
- Marica Cariello
- Department of Interdisciplinary Medicine, University of Bari "Aldo Moro," Bari, Italy
| | - Elena Piccinin
- Department of Basic Medical Sciences, Neurosciences and Sense Organs, University of Bari "Aldo Moro," Bari, Italy
| | - Antonio Moschetta
- Department of Interdisciplinary Medicine, University of Bari "Aldo Moro," Bari, Italy; National Institute for Biostructures and Biosystems (INBB), Rome, Italy; Scientific Institute for Research, Hospitalization and Healthcare (IRCCS) Istituto Tumori Giovanni Paolo II, Bari, Italy.
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Pralle RS, Erb SJ, Holdorf HT, White HM. Greater liver PNPLA3 protein abundance in vivo and in vitro supports lower triglyceride accumulation in dairy cows. Sci Rep 2021; 11:2839. [PMID: 33531537 PMCID: PMC7854614 DOI: 10.1038/s41598-021-82233-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 01/14/2021] [Indexed: 02/07/2023] Open
Abstract
Fatty liver syndrome is a prevalent metabolic disorder in peripartum dairy cows that unfavorably impacts lactation performance and health. Patatin-like phospholipase domain-containing protein 3 (PNPLA3) is a lipase that plays a central role in human non-alcoholic fatty liver disease etiology but has received limited attention in bovine fatty liver research. Thus, we investigated the relationship between tissue PNPLA3 expression and liver triglyceride accumulation in vivo via a ketosis induction protocol in multiparous dairy cows peripartum, as well as in vitro via small interfering RNA knockdown of PNPLA3 mRNA expression in bovine primary hepatocytes. Results demonstrated a negative association (P = 0.04) between liver PNPLA3 protein abundance and liver triglyceride content in peripartum dairy cows, while adipose PNPLA3 protein abundance was not associated with liver triglyceride content or blood fatty acid concentration. Knockdown of PNPLA3 mRNA resulted in reduced PNPLA3 protein abundance (P < 0.01) and greater liver triglyceride content (P < 0.01). Together, these results suggest greater liver PNPLA3 protein abundance may directly limit liver triglyceride accumulation peripartum, potentially preventing bovine fatty liver or accelerating recovery from fatty liver syndrome.
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Affiliation(s)
- Ryan S Pralle
- Department of Dairy Science, University of Wisconsin-Madison, Madison, 53706, USA
| | - Sophia J Erb
- Department of Dairy Science, University of Wisconsin-Madison, Madison, 53706, USA
| | - Henry T Holdorf
- Department of Dairy Science, University of Wisconsin-Madison, Madison, 53706, USA
| | - Heather M White
- Department of Dairy Science, University of Wisconsin-Madison, 1675 Observatory Drive, Rm 934B, Madison, WI, 53706, USA.
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Zhou B, Ho SS, Greer SU, Spies N, Bell JM, Zhang X, Zhu X, Arthur JG, Byeon S, Pattni R, Saha I, Huang Y, Song G, Perrin D, Wong WH, Ji HP, Abyzov A, Urban AE. Haplotype-resolved and integrated genome analysis of the cancer cell line HepG2. Nucleic Acids Res 2019; 47:3846-3861. [PMID: 30864654 PMCID: PMC6486628 DOI: 10.1093/nar/gkz169] [Citation(s) in RCA: 170] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 02/19/2019] [Accepted: 03/01/2019] [Indexed: 12/19/2022] Open
Abstract
HepG2 is one of the most widely used human cancer cell lines in biomedical research and one of the main cell lines of ENCODE. Although the functional genomic and epigenomic characteristics of HepG2 are extensively studied, its genome sequence has never been comprehensively analyzed and higher order genomic structural features are largely unknown. The high degree of aneuploidy in HepG2 renders traditional genome variant analysis methods challenging and partially ineffective. Correct and complete interpretation of the extensive functional genomics data from HepG2 requires an understanding of the cell line’s genome sequence and genome structure. Using a variety of sequencing and analysis methods, we identified a wide spectrum of genome characteristics in HepG2: copy numbers of chromosomal segments at high resolution, SNVs and Indels (corrected for aneuploidy), regions with loss of heterozygosity, phased haplotypes extending to entire chromosome arms, retrotransposon insertions and structural variants (SVs) including complex and somatic genomic rearrangements. A large number of SVs were phased, sequence assembled and experimentally validated. We re-analyzed published HepG2 datasets for allele-specific expression and DNA methylation and assembled an allele-specific CRISPR/Cas9 targeting map. We demonstrate how deeper insights into genomic regulatory complexity are gained by adopting a genome-integrated framework.
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Affiliation(s)
- Bo Zhou
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA.,Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Steve S Ho
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA.,Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Stephanie U Greer
- Division of Oncology, Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Noah Spies
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA.,Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA.,Genome-scale Measurements Group, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - John M Bell
- Stanford Genome Technology Center, Stanford University, Palo Alto, CA 94304, USA
| | - Xianglong Zhang
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA.,Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Xiaowei Zhu
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA.,Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Joseph G Arthur
- Department of Statistics, Stanford University, Stanford, CA 94305, USA
| | - Seunggyu Byeon
- School of Computer Science and Engineering, College of Engineering, Pusan National University, Busan 46241, South Korea
| | - Reenal Pattni
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA.,Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Ishan Saha
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Yiling Huang
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA.,Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Giltae Song
- School of Computer Science and Engineering, College of Engineering, Pusan National University, Busan 46241, South Korea
| | - Dimitri Perrin
- Science and Engineering Faculty, Queensland University of Technology, Brisbane, QLD 4001, Australia
| | - Wing H Wong
- Department of Statistics, Stanford University, Stanford, CA 94305, USA.,Department of Biomedical Data Science, Bio-X Program, Stanford University, Stanford, CA 94305, USA
| | - Hanlee P Ji
- Division of Oncology, Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA.,Stanford Genome Technology Center, Stanford University, Palo Alto, CA 94304, USA
| | - Alexej Abyzov
- Department of Health Sciences Research, Center for Individualized Medicine, Mayo Clinic, Rochester, MN 55905, USA
| | - Alexander E Urban
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA.,Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA.,Tashia and John Morgridge Faculty Scholar, Stanford Child Health Research Institute, Stanford, CA 94305, USA
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13
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The Chinese medicine Chai Hu Li Zhong Tang protects against non-alcoholic fatty liver disease by activating AMPKα. Biosci Rep 2018; 38:BSR20180644. [PMID: 30291215 PMCID: PMC6239269 DOI: 10.1042/bsr20180644] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 09/03/2018] [Accepted: 09/24/2018] [Indexed: 12/17/2022] Open
Abstract
An effective treatment for non-alcoholic fatty liver disease (NAFLD) is urgently needed. In the present study, we investigated whether the Chinese medicine Chai Hu Li Zhong Tang (CHLZT) could protect against the development of NAFLD. Rats in an animal model of NAFLD were treated with CHLZT, and their serum levels of cholesterol (TC), triglycerides (TG), high density lipoprotein-cholesterol (HDL-C), low density lipoprotein-cholesterol (LDL-C), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) were detected with an automatic biochemical analyzer. A cellular model of NAFLD was also established by culturing HepG2 cells in a medium that contained a long chain fat emulsion. Those cells were treated with CHLZT that contained serum from rats. After treatment, the levels of adenylate-activated protein kinase (AMPK) α (AMPKα), p-AMPKα, acetyl coenzyme A carboxylase (ACC) α (ACCα), pACCα, PPARγ, and SREBP-2 were detected. The AMPK agonist, acadesine (AICAR), was used as a positive control compound. Our results showed that CHLZT or AICAR significantly decreased the serum levels of TG, TC, LDL-C, AST, ALT, and insulin in NAFLD rats, and significantly increased their serum HDL-C levels. Treatments with CHLZT or AICAR significantly decreased the numbers of lipid droplets in NAFLD liver tissues and HepG2 cells. CHLZT and AICAR increased the levels of p-AMPKα and PPARγ in the NAFLD liver tissues and HepG2 cells, but decreased the levels of ACC-α, p-ACC-α, SREBP-2, and 3-hydroxyl-3-methylglutaryl-coenzyme A reductase (HMGR). CHLZT protects against NAFLD by activating AMPKα, and also by inhibiting ACC activity, down-regulating SREBP2 and HMGR, and up-regulating PPAR-γ. Our results suggest that CHLZT might be useful for treating NAFLD in the clinic.
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14
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Chen J, Montagner A, Tan NS, Wahli W. Insights into the Role of PPARβ/δ in NAFLD. Int J Mol Sci 2018; 19:ijms19071893. [PMID: 29954129 PMCID: PMC6073272 DOI: 10.3390/ijms19071893] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 06/13/2018] [Accepted: 06/23/2018] [Indexed: 12/14/2022] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is a major health issue in developed countries. Although usually associated with obesity, NAFLD is also diagnosed in individuals with low body mass index (BMI) values, especially in Asia. NAFLD can progress from steatosis to non-alcoholic steatohepatitis (NASH), which is characterized by liver damage and inflammation, leading to cirrhosis and hepatocellular carcinoma (HCC). NAFLD development can be induced by lipid metabolism alterations; imbalances of pro- and anti-inflammatory molecules; and changes in various other factors, such as gut nutrient-derived signals and adipokines. Obesity-related metabolic disorders may be improved by activation of the nuclear receptor peroxisome proliferator-activated receptor (PPAR)β/δ, which is involved in metabolic processes and other functions. This review is focused on research findings related to PPARβ/δ-mediated regulation of hepatic lipid and glucose metabolism and NAFLD development. It also discusses the potential use of pharmacological PPARβ/δ activation for NAFLD treatment.
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Affiliation(s)
- Jiapeng Chen
- Lee Kong Chian School of Medicine, Nanyang Technological University, 11 Mandalay Road, Singapore 308232, Singapore.
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore.
| | - Alexandra Montagner
- ToxAlim, Research Center in Food Toxicology, National Institute for Agricultural Research (INRA), 180 Chemin de Tournefeuille, 31300 Toulouse, France.
- Institut National de La Santé et de La Recherche Médicale (INSERM), UMR1048, Institute of Metabolic and Cardiovascular Diseases, 31027 Toulouse, France.
| | - Nguan Soon Tan
- Lee Kong Chian School of Medicine, Nanyang Technological University, 11 Mandalay Road, Singapore 308232, Singapore.
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore.
- KK Research Centre, KK Women's and Children Hospital, 100 Bukit Timah Road, Singapore 229899, Singapore.
- Institute of Molecular and Cell Biology, Agency for Science Technology & Research, 61 Biopolis Drive, Proteos, Singapore 138673, Singapore.
| | - Walter Wahli
- Lee Kong Chian School of Medicine, Nanyang Technological University, 11 Mandalay Road, Singapore 308232, Singapore.
- ToxAlim, Research Center in Food Toxicology, National Institute for Agricultural Research (INRA), 180 Chemin de Tournefeuille, 31300 Toulouse, France.
- Center for Integrative Genomics, University of Lausanne, Génopode, CH-1015 Lausanne, Switzerland.
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15
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Lim HW, Bernstein DE. Risk Factors for the Development of Nonalcoholic Fatty Liver Disease/Nonalcoholic Steatohepatitis, Including Genetics. Clin Liver Dis 2018; 22:39-57. [PMID: 29128060 DOI: 10.1016/j.cld.2017.08.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Nonalcoholic fatty liver disease is emerging as the most common cause of chronic liver disease worldwide. This trend is, in part, secondary, to the growing incidence of obesity, type 2 diabetes, and metabolic syndrome. Other risk factors include age, gender, race/ethnicity, genetic predisposition, and polycystic ovarian disease. With the introduction of genome-wide association studies, genetic mutations contributing to inherited susceptibility to steatosis have been identified, which hold keys to future improvement in diagnosis and management. This article expands on the aforementioned risk factors and summarizes the current available data on genetic and environmental factors associated with this common entity.
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Affiliation(s)
- Huei-Wen Lim
- Department of Internal Medicine, Northwell Health, 400 Community Drive, Manhasset, NY 11030, USA
| | - David E Bernstein
- Department of Gastroenterology and Hepatology, Northwell Health, Center for Liver Diseases, 400 Community Drive, Manhasset, NY 11030, USA.
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16
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Wattacheril J, Rose KL, Hill S, Lanciault C, Murray CR, Washington K, Williams B, English W, Spann M, Clements R, Abumrad N, Flynn CR. Non-alcoholic fatty liver disease phosphoproteomics: A functional piece of the precision puzzle. Hepatol Res 2017; 47:1469-1483. [PMID: 28258704 PMCID: PMC5583035 DOI: 10.1111/hepr.12885] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 01/27/2017] [Accepted: 02/28/2017] [Indexed: 12/24/2022]
Abstract
BACKGROUND Molecular signaling events associated with the necroinflammatory changes in nonalcoholic steatohepatitis (NASH) are not well understood. AIMS To understand the molecular basis of NASH, we evaluated reversible phosphorylation events in hepatic tissue derived from Class III obese subjects by phosphoproteomic means with the aim of highlighting key regulatory pathways that distinguish NASH from non-alcoholic fatty liver disease (also known as simple steatosis; SS). MATERIALS & METHODS Class III obese subjects undergoing bariatric surgery underwent liver biopsy (eight normal patients, eight with simple steatosis, and eight NASH patients). Our strategy was unbiased, comparing global differences in liver protein reversible phosphorylation events across the 24 subjects. RESULTS Of the 3078 phosphorylation sites assigned (2465 phosphoserine, 445 phosphothreonine, 165 phosphotyrosine), 53 were altered by a factor of 2 among cohorts, and of those, 12 were significantly increased or decreased by ANOVA (P < 0.05). DISCUSSION Statistical analyses of canonical signaling pathways identified carbohydrate metabolism and RNA post-transcriptional modification among the most over-represented networks. CONCLUSION Collectively, these results raise the possibility of abnormalities in carbohydrate metabolism as an important trigger for the development of NASH, in parallel with already established abnormalities in lipid metabolism.
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Affiliation(s)
- Julia Wattacheril
- Center for Liver Disease and Transplantation, College of Physicians and Surgeons, Columbia University Medical Center, New York, New York, United States of America
| | - Kristie L. Rose
- Mass Spectrometry Research Center, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Salisha Hill
- Mass Spectrometry Research Center, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Christian Lanciault
- Department of Pathology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Clark R. Murray
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Kay Washington
- Department of Pathology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Brandon Williams
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Wayne English
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Matthew Spann
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Ronald Clements
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Naji Abumrad
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Charles Robb Flynn
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America,Corresponding author: Charles Flynn, PhD, Assistant Professor, Department of Surgery, Vanderbilt University, MRBIV Room 8465A, 2213 Garland Ave, Nashville, TN 37232,
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17
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Kern L, Spreckels J, Nist A, Stiewe T, Skevaki C, Greene B, Mernberger M, Elsässer HP. Altered glycogen metabolism causes hepatomegaly following an Atg7 deletion. Cell Tissue Res 2016; 366:651-665. [PMID: 27553638 DOI: 10.1007/s00441-016-2477-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 07/12/2016] [Indexed: 01/21/2023]
Abstract
Autophagy is a lysosomal degradation process involved in the turnover of organelles or other cell constituents, in providing sources for energy production under starving conditions and in cell metabolism. A key protein in the macroautophagic machinery is the autophagy-related protein (Atg) 7. Constitutive deletion of Atg7 is lethal at birth. A conditional deletion of Atg7 in hepatocytes leads to hepatomegaly and in aged animals to liver tumors. With this study, we aim at analyzing the hepatomegaly development in more detail. The 3- to 4-fold enlargement of the liver takes place between days 25 and 35 after birth (P25-P35) and persists at least until P90. This is accompanied by a change in the expression of enzymes involved in the glycogen/glucose metabolism. While glycogen synthesis is inhibited, glucose is preferentially kept as glucose-6-phosphate inside the cells, inducing a swelling of the cells caused by hyperosmolarity. An increase of lipogenic enzymes suggests that glucose-6-phosphate is delivered to lipogenic pathways, which is supported by the occurrence of a steatosis around P30. The development of hepatomegaly is accompanied by a polyploidisation of hepatocytes, an enhanced expression of genes related to inflammatory processes and an infiltration of macrophages and granulocytes. Our data provide evidence that the attenuation of macroautophagy in hepatocytes leads to a glucose retention that causes cell swelling. The resulting hepatomegaly, which develops in a time interval of about 10 days, perturbs liver perfusion and induces an inflammatory reaction together with polyploidisation.
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Affiliation(s)
- Lara Kern
- Department of Cytobiology and Cytopathobiology, Philipps University, 35033, Marburg, Germany
| | - Johanne Spreckels
- Department of Cytobiology and Cytopathobiology, Philipps University, 35033, Marburg, Germany
| | - Andrea Nist
- Genomics Unit, Philipps University, 35043, Marburg, Germany
| | - Thorsten Stiewe
- Genomics Unit, Philipps University, 35043, Marburg, Germany.,Institute of Molecular Oncology, Philipps University, 35043, Marburg, Germany
| | - Chrysanthi Skevaki
- Institute of Laboratory Medicine, Pathobiochemistry and Molecular Diagnostics, Philipps University, 35043, Marburg, Germany
| | - Brandon Greene
- Institute of Medical Biometry and Epidemiology, Philipps University, 35037, Marburg, Germany
| | - Marco Mernberger
- Institute of Molecular Oncology, Philipps University, 35043, Marburg, Germany
| | - Hans-Peter Elsässer
- Department of Cytobiology and Cytopathobiology, Philipps University, 35033, Marburg, Germany.
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18
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Mahady SE, George J. Exercise and diet in the management of nonalcoholic fatty liver disease. Metabolism 2016; 65:1172-82. [PMID: 26805014 DOI: 10.1016/j.metabol.2015.10.032] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Revised: 10/27/2015] [Accepted: 10/31/2015] [Indexed: 02/08/2023]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver condition worldwide, and is projected to become the leading cause for liver transplantation in the United States as early as 2020. The mainstay of treatment remains lifestyle modification with diet and exercise recommendations, as although some pharmacological treatments such as glitazones and Vitamin E have shown benefit, there are concerns regarding long term safety. The evidence base for dietary interventions in NAFLD such as the Mediterranean diet, omega-3 polyunsaturated fatty acids and coffee is mainly derived from observational data with questionable validity. Where trials exist, they have shown benefit for surrogate outcomes such as hepatic steatosis and insulin resistance, but no trials have been conducted with salient clinical outcomes such as reduction in progression to chronic liver disease. Benefit in surrogate outcomes has also been seen for aerobic, anaerobic and combined modality exercise but it remains unclear if one type is superior. Furthermore, a reduction in sedentary time appears equally important. To provide a sound evidence base for lifestyle recommendations to people with NAFLD, longer duration trials of standardized dietary or exercise interventions, and testing various doses, types and with liver related outcomes, are essential.
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Affiliation(s)
- Suzanne E Mahady
- Storr Liver Centre, Westmead Millennium Institute for Medical Research and Westmead Hospital, the University of Sydney, NSW, Australia; Sydney School of Public Health, University of Sydney, NSW Australia.
| | - Jacob George
- Storr Liver Centre, Westmead Millennium Institute for Medical Research and Westmead Hospital, the University of Sydney, NSW, Australia
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19
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Polyzos SA, Mantzoros CS. Nonalcoholic fatty future disease. Metabolism 2016; 65:1007-16. [PMID: 26805015 DOI: 10.1016/j.metabol.2015.12.009] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 12/15/2015] [Accepted: 12/16/2015] [Indexed: 01/12/2023]
Affiliation(s)
- Stergios A Polyzos
- Second Medical Clinic, Aristotle University of Thessaloniki, Ippokration Hospital, Thessaloniki, Greece
| | - Christos S Mantzoros
- Division of Endocrinology, Diabetes and Metabolism, Department of Internal Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA; Boston VA Healthcare system and Division of Endocrinology, Diabetes and Metabolism, Department of Internal Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
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20
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Aragonès G, Auguet T, Armengol S, Berlanga A, Guiu-Jurado E, Aguilar C, Martínez S, Sabench F, Porras JA, Ruiz MD, Hernández M, Sirvent JJ, Del Castillo D, Richart C. PNPLA3 Expression Is Related to Liver Steatosis in Morbidly Obese Women with Non-Alcoholic Fatty Liver Disease. Int J Mol Sci 2016; 17:ijms17050630. [PMID: 27128907 PMCID: PMC4881456 DOI: 10.3390/ijms17050630] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 04/19/2016] [Accepted: 04/22/2016] [Indexed: 12/17/2022] Open
Abstract
Recent reports suggest a role for the Patatin-like phospholipase domain-containing protein 3 (PNPLA3) in the pathology of non-alcoholic fatty liver disease (NAFLD). Lipid deposition in the liver seems to be a critical process in the pathogenesis of NAFLD. The aim of the present work was to evaluate the association between the liver PNPLA3 expression, key genes of lipid metabolism, and the presence of NAFLD in morbidly obese women. We used real-time polymerase chain reaction (PCR) analysis to analyze the hepatic expression of PNPLA3 and lipid metabolism-related genes in 55 morbidly obese subjects with normal liver histology (NL, n = 18), simple steatosis (SS, n = 20), and non-alcoholic steatohepatitis (NASH, n = 17). Liver biopsies were collected during bariatric surgery. We observed that liver PNPLA3 expression was increased in NAFLD than in NL. It was also upregulated in SS than in NL. Interestingly, we found that the expression of PNPLA3 was significantly higher in severe than mild SS group. In addition, the expression of the transcription factors LXRα, PPARα, and SREBP2 was positively correlated with PNPLA3 liver expression. Regarding rs738409 polymorphism, GG genotype was positive correlated with the presence of NASH. In conclusion, our results show that PNPLA3 could be related to lipid accumulation in liver, mainly in the development and progression of simple steatosis.
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Affiliation(s)
- Gemma Aragonès
- Group de Recerca GEMMAIR (AGAUR)-Medicina Aplicada, Institut Investigació Sanitària Pere Virgili (IISPV), Departament de Medicina i Cirurgia, Universitat Rovira i Virgili (URV), 43007 Tarragona, Spain.
| | - Teresa Auguet
- Group de Recerca GEMMAIR (AGAUR)-Medicina Aplicada, Institut Investigació Sanitària Pere Virgili (IISPV), Departament de Medicina i Cirurgia, Universitat Rovira i Virgili (URV), 43007 Tarragona, Spain.
- Servei Medicina Interna, Hospital Universitari Joan XXIII Tarragona, Mallafré Guasch, 4, 43007 Tarragona, Spain.
| | - Sandra Armengol
- Group de Recerca GEMMAIR (AGAUR)-Medicina Aplicada, Institut Investigació Sanitària Pere Virgili (IISPV), Departament de Medicina i Cirurgia, Universitat Rovira i Virgili (URV), 43007 Tarragona, Spain.
| | - Alba Berlanga
- Group de Recerca GEMMAIR (AGAUR)-Medicina Aplicada, Institut Investigació Sanitària Pere Virgili (IISPV), Departament de Medicina i Cirurgia, Universitat Rovira i Virgili (URV), 43007 Tarragona, Spain.
| | - Esther Guiu-Jurado
- Group de Recerca GEMMAIR (AGAUR)-Medicina Aplicada, Institut Investigació Sanitària Pere Virgili (IISPV), Departament de Medicina i Cirurgia, Universitat Rovira i Virgili (URV), 43007 Tarragona, Spain.
| | - Carmen Aguilar
- Group de Recerca GEMMAIR (AGAUR)-Medicina Aplicada, Institut Investigació Sanitària Pere Virgili (IISPV), Departament de Medicina i Cirurgia, Universitat Rovira i Virgili (URV), 43007 Tarragona, Spain.
| | - Salomé Martínez
- Servei Anatomia Patològica, Hospital Universitari Joan XXIII Tarragona, Mallafré Guasch, 4, 43007 Tarragona, Spain.
| | - Fátima Sabench
- Servei de Cirurgia, Hospital Sant Joan de Reus, Departament de Medicina i Cirurgia, Universitat Rovira i Virgili (URV), IISPV, Avinguda Doctor Josep Laporte, 2, 43204 Tarragona, Spain.
| | - José Antonio Porras
- Servei Medicina Interna, Hospital Universitari Joan XXIII Tarragona, Mallafré Guasch, 4, 43007 Tarragona, Spain.
| | - Maikel Daniel Ruiz
- Servei Medicina Interna, Hospital Universitari Joan XXIII Tarragona, Mallafré Guasch, 4, 43007 Tarragona, Spain.
| | - Mercé Hernández
- Servei de Cirurgia, Hospital Sant Joan de Reus, Departament de Medicina i Cirurgia, Universitat Rovira i Virgili (URV), IISPV, Avinguda Doctor Josep Laporte, 2, 43204 Tarragona, Spain.
| | - Joan Josep Sirvent
- Servei Anatomia Patològica, Hospital Universitari Joan XXIII Tarragona, Mallafré Guasch, 4, 43007 Tarragona, Spain.
| | - Daniel Del Castillo
- Servei de Cirurgia, Hospital Sant Joan de Reus, Departament de Medicina i Cirurgia, Universitat Rovira i Virgili (URV), IISPV, Avinguda Doctor Josep Laporte, 2, 43204 Tarragona, Spain.
| | - Cristóbal Richart
- Group de Recerca GEMMAIR (AGAUR)-Medicina Aplicada, Institut Investigació Sanitària Pere Virgili (IISPV), Departament de Medicina i Cirurgia, Universitat Rovira i Virgili (URV), 43007 Tarragona, Spain.
- Servei Medicina Interna, Hospital Universitari Joan XXIII Tarragona, Mallafré Guasch, 4, 43007 Tarragona, Spain.
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21
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Hao L, Huang KH, Ito K, Sae-tan S, Lambert JD, Ross AC. Fibroblast Growth Factor 21 (Fgf21) Gene Expression Is Elevated in the Liver of Mice Fed a High-Carbohydrate Liquid Diet and Attenuated by a Lipid Emulsion but Is Not Upregulated in the Liver of Mice Fed a High-Fat Obesogenic Diet. J Nutr 2016; 146:184-90. [PMID: 26764334 PMCID: PMC4725428 DOI: 10.3945/jn.115.216572] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Accepted: 11/30/2015] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Fibroblast growth factor 21 (FGF21) is a regulator of carbohydrate and lipid metabolism; however, the regulation of Fgf21 gene expression by diet remains incompletely understood. OBJECTIVE We investigated the effect of a high-carbohydrate (HC) liquid diet, with and without supplementation with a lipid emulsion (LE), and of a high-fat diet (HFD) compared with a low-fat diet (LFD) on the regulation of Fgf21 gene expression in the liver of intact mice. METHODS C57BL/6 male mice were fed standard feed pellets (SFPs), a purified HC liquid diet (adequate in calories and protein), or an HC liquid diet containing an LE at either 4% or 13.5% of energy for 5 wk (Expt. 1) or 1 wk (Expt. 2). In Expt. 3, mice were fed a purified LFD (∼10% fat) or HFD (∼60% fat) or were fed an HFD and given access to a running wheel for voluntary exercise for 16 wk. RESULTS Fgf21 mRNA in liver and FGF21 protein in plasma were increased by 3.5- to 7-fold in HC mice compared with SFP mice (P < 0.001), whereas the LE dose-dependently attenuated the induction of Fgf21 expression (P < 0.05). After 16 wk, hepatic Fgf21 mRNA did not differ between LFD and HFD mice but was dramatically reduced in the HFD+exercise group to <20% of the level in the HFD group (P < 0.0001). CONCLUSIONS In mice, hepatic Fgf21 expression was upregulated by 1 and 5 wk of feeding a lipogenic HC diet but not by 16 wk of feeding an obesogenic HFD, whereas the addition of fat as an LE to the HC formula significantly reduced Fgf21 gene expression and the plasma FGF21 protein concentration. Our results support a strong and reversible response of hepatic Fgf21 expression to shifts in dietary glucose intake.
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Affiliation(s)
- Lei Hao
- Departments of Nutritional Sciences
| | | | | | | | | | - A Catharine Ross
- Departments of Nutritional Sciences, Center for Immunology and Infectious Disease, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA
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Mann JP, Semple RK, Armstrong MJ. How Useful Are Monogenic Rodent Models for the Study of Human Non-Alcoholic Fatty Liver Disease? Front Endocrinol (Lausanne) 2016; 7:145. [PMID: 27899914 PMCID: PMC5110950 DOI: 10.3389/fendo.2016.00145] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2016] [Accepted: 11/01/2016] [Indexed: 12/22/2022] Open
Abstract
Improving understanding of the genetic basis of human non-alcoholic fatty liver disease (NAFLD) has the potential to facilitate risk stratification of affected patients, permit personalized treatment, and inform development of new therapeutic strategies. Animal models have been widely used to interrogate the pathophysiology of, and genetic predisposition to, NAFLD. Nevertheless, considerable interspecies differences in intermediary metabolism potentially limit the extent to which results can be extrapolated to humans. For example, human genome-wide association studies have identified polymorphisms in PNPLA3 and TM6SF2 as the two most prevalent determinants of susceptibility to NAFLD and its inflammatory component (NASH), but animal models of these mutations have had only variable success in recapitulating this link. In this review, we critically appraise selected murine monogenic models of NAFLD, NASH, and hepatocellular carcinoma (HCC) with a focus on how closely they mirror human disease.
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Affiliation(s)
- Jake P. Mann
- Department of Paediatrics, University of Cambridge, Cambridge, UK
| | - Robert K. Semple
- The University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge, UK
- The National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge, UK
- *Correspondence: Robert K. Semple,
| | - Matthew J. Armstrong
- Centre for Liver Research, National Institute for Health Research (NIHR) Birmingham Liver Biomedical Research Unit, University of Birmingham, Birmingham, UK
- Liver Unit, Queen Elizabeth University Hospital Birmingham, Birmingham, UK
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