1
|
Scorletti E, Saiman Y, Jeon S, Schneider CV, Buyco DG, Lin C, Himes BE, Mesaros CA, Vujkovic M, Creasy KT, Furth EE, Billheimer JT, Hand NJ, Kaplan DE, Chang KM, Tsao PS, Lynch JA, Dempsey JL, Harkin J, Bayen S, Conlon D, Guerraty M, Phillips MC, Rader DJ, Carr RM. A missense variant in human perilipin 2 ( PLIN2 Ser251Pro) reduces hepatic steatosis in mice. JHEP Rep 2024; 6:100902. [PMID: 38074507 PMCID: PMC10701134 DOI: 10.1016/j.jhepr.2023.100902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 08/01/2023] [Accepted: 08/24/2023] [Indexed: 01/23/2024] Open
Abstract
Background & Aims Non-alcoholic fatty liver disease (NAFLD) is characterised by the accumulation of lipid droplets (LDs) within hepatocytes. Perilipin 2 (PLIN2) is the most abundant protein in hepatic LDs and its expression correlates with intracellular lipid accumulation. A recently discovered PLIN2 coding variant, Ser251Pro (rs35568725), was found to promote the accumulation of small LDs in embryonic kidney cells. In this study, we investigate the role of PLIN2-Ser251Pro (PLIN2-Pro251) on hepatic LD metabolism in vivo and research the metabolic phenotypes associated with this variant in humans. Methods For our animal model, we used Plin2 knockout mice in which we expressed either human PLIN2-Pro251 (Pro251 mice) or wild-type human PLIN2-Ser251 (Ser251 mice) in a hepatocyte-specific manner. We fed both cohorts a lipogenic high-fat, high-cholesterol, high-fructose diet for 12 weeks. Results Pro251 mice were associated with reduced liver triglycerides (TGs) and had lower mRNA expression of fatty acid synthase and diacylglycerol O-acyltransferase-2 compared with Ser251 mice. Moreover, Pro251 mice had a reduction of polyunsaturated fatty acids-TGs and reduced expression of epoxygenase genes. For our human study, we analysed the Penn Medicine BioBank, the Million Veteran Program, and UK Biobank. Across these databases, the minor allele frequency of PLIN2-Pro251 was approximately 5%. There was no association with the clinical diagnosis of NAFLD, however, there was a trend toward reduced liver fat in PLIN2-Pro251 carriers by MRI-spectroscopy in UK Biobank subjects. Conclusions In mice lacking endogenous Plin2, expression of human PLIN2-Pro251 attenuated high-fat, high-fructose, high-cholesterol, diet-induced hepatic steatosis compared with human wild-type PLIN2-Ser251. Moreover, Pro251 mice had lower polyunsaturated fatty acids-TGs and epoxygenase genes expression, suggesting less liver oxidative stress. In humans, PLIN2-Pro251 is not associated with NAFLD. Impact and Implications Lipid droplet accumulation in hepatocytes is the distinctive characteristic of non-alcoholic fatty liver disease. Perilipin 2 (PLIN2) is the most abundant protein in hepatic lipid droplets; however, little is known on the role of a specific polymorphism PLIN2-Pro251 on hepatic lipid droplet metabolism. PLIN2-Pro251 attenuates liver triglycerides accumulation after a high-fat-high-glucose-diet. PLIN2-Pro251 may be a novel lipid droplet protein target for the treatment of liver steatosis.
Collapse
Affiliation(s)
- Eleonora Scorletti
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Division of Translational Medicine and Human Genetics, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Yedidya Saiman
- Department of Hepatology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Sookyoung Jeon
- Department of Food Science and Nutrition, Hallym University, Chuncheon, Gangwon-do, Republic of Korea
| | - Carolin V. Schneider
- Department of Medicine III, Gastroenterology, Metabolic Diseases and Intensive Care, University Hospital RWTH Aachen, Aachen, Germany
| | - Delfin G. Buyco
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA
| | - Chelsea Lin
- School of Medicine, Oregon Health & Science University, Portland, OR, USA
| | - Blanca E. Himes
- Department of Biostatistics, Epidemiology and Informatics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Clementina A. Mesaros
- Department of Systems Pharmacology and Translational Therapeutics (SPATT) University of Pennsylvania, Philadelphia, PA, USA
| | - Marijana Vujkovic
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Kate Townsend Creasy
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Emma E. Furth
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Jeffrey T. Billheimer
- Division of Translational Medicine and Human Genetics, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Nicholas J. Hand
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - David E. Kaplan
- Division of Gastroenterology and Hepatology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Kyong-Mi Chang
- Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA, USA
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Philip S. Tsao
- Precision Medicine, VA Palo Alto Health Care System, Palo Alto, CA, USA
| | - Julie A. Lynch
- VA Informatics & Computing Infrastructure, VA Salt Lake City Utah & University of Utah, School of Medicine, Salt Lake City, UT, USA
| | - Joseph L. Dempsey
- Division of Gastroenterology, Department of Medicine, School of Medicine, University of Washington, Seattle, WA, USA
| | - Julia Harkin
- Division of Gastroenterology, Department of Medicine, School of Medicine, University of Washington, Seattle, WA, USA
| | - Susovon Bayen
- Division of Gastroenterology, Department of Medicine, School of Medicine, University of Washington, Seattle, WA, USA
| | - Donna Conlon
- Division of Cardiovascular Medicine, Department of Medicine, University of Pennsylvania, PA, USA
| | - Marie Guerraty
- Division of Cardiovascular Medicine, Department of Medicine, University of Pennsylvania, PA, USA
| | - Michael C. Phillips
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Daniel J. Rader
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Division of Translational Medicine and Human Genetics, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Rotonya M. Carr
- Division of Gastroenterology, Department of Medicine, School of Medicine, University of Washington, Seattle, WA, USA
| |
Collapse
|
2
|
Shihana F, Cholan PM, Fraser S, Oehlers SH, Seth D. Investigating the role of lipid genes in liver disease using fatty liver models of alcohol and high fat in zebrafish (Danio rerio). Liver Int 2023; 43:2455-2468. [PMID: 37650211 DOI: 10.1111/liv.15716] [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: 04/26/2023] [Revised: 07/25/2023] [Accepted: 08/10/2023] [Indexed: 09/01/2023]
Abstract
BACKGROUND Accumulation of lipid in the liver is the first hallmark of both alcohol-related liver disease (ALD) and non-alcohol-related fatty liver disease (NAFLD). Recent studies indicate that specific mutations in lipid genes confer risk and might influence disease progression to irreversible liver cirrhosis. This study aimed to understand the function/s of lipid risk genes driving disease development in zebrafish genetic models of alcohol-related and non-alcohol-related fatty liver. METHODS We used zebrafish larvae to investigate the effect of alcohol and high fat to model fatty liver and tested the utility of this model to study lipid risk gene functions. CRISPR/Cas9 gene editing was used to create knockdowns in 5 days post-fertilisation zebrafish larvae for the available orthologs of human cirrhosis risk genes (pnpla3, faf2, tm6sf2). To establish fatty liver models, larvae were exposed to ethanol and a high-fat diet (HFD) consisting of chicken egg yolk. Changes in morphology (imaging), survival, liver injury (biochemical tests, histopathology), gene expression (qPCR) and lipid accumulation (dye-specific live imaging) were analysed across treatment groups to test the functions of these genes. RESULTS Exposure of 5-day post-fertilisation (dpf) WT larvae to 2% ethanol or HFD for 48 h developed measurable hepatic steatosis. CRISPR-Cas9 genome editing depleted pnpla3, faf2 and tm6sf2 gene expression in these CRISPR knockdown larvae (crispants). Depletion significantly increased the effects of ethanol and HFD toxicity by increasing hepatic steatosis and hepatic neutrophil recruitment ≥2-fold in all three crispants. Furthermore, ethanol or HFD exposure significantly altered the expression of genes associated with ethanol metabolism (cyp2y3) and lipid metabolism-related gene expression, including atgl (triglyceride hydrolysis), axox1, echs1 (fatty acid β-oxidation), fabp10a (transport), hmgcra (metabolism), notch1 (signalling) and srebp1 (lipid synthesis), in all three pnpla3, faf2 and tm6sf2 crispants. Nile Red staining in all three crispants revealed significantly increased lipid droplet size and triglyceride accumulation in the livers following exposure to ethanol or HFD. CONCLUSIONS We identified roles for pnpla3, faf2 and tm6sf2 genes in triglyceride accumulation and fatty acid oxidation pathways in a zebrafish larvae model of fatty liver.
Collapse
Affiliation(s)
- Fathima Shihana
- Centenary Institute of Cancer Medicine & Cell Biology, The University of Sydney, Camperdown, New South Wales, Australia
- Edith Collins Centre (Translational Research in Alcohol Drugs and Toxicology), Sydney Local Health District, Sydney, New South Wales, Australia
| | - Pradeep Manuneedhi Cholan
- Centenary Institute of Cancer Medicine & Cell Biology, The University of Sydney, Camperdown, New South Wales, Australia
| | - Stuart Fraser
- Centenary Institute of Cancer Medicine & Cell Biology, The University of Sydney, Camperdown, New South Wales, Australia
- School of Biomedical Engineering, Faculty of Engineering, University of Sydney, Camperdown, New South Wales, Australia
| | - Stefan H Oehlers
- Centenary Institute of Cancer Medicine & Cell Biology, The University of Sydney, Camperdown, New South Wales, Australia
- Sydney School of Medicine, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
| | - Devanshi Seth
- Centenary Institute of Cancer Medicine & Cell Biology, The University of Sydney, Camperdown, New South Wales, Australia
- Edith Collins Centre (Translational Research in Alcohol Drugs and Toxicology), Sydney Local Health District, Sydney, New South Wales, Australia
- Sydney School of Medicine, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
| |
Collapse
|