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Habib S. Team players in the pathogenesis of metabolic dysfunctions-associated steatotic liver disease: The basis of development of pharmacotherapy. World J Gastrointest Pathophysiol 2024; 15:93606. [PMID: 39220834 PMCID: PMC11362842 DOI: 10.4291/wjgp.v15.i4.93606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Revised: 05/14/2024] [Accepted: 07/23/2024] [Indexed: 08/22/2024] Open
Abstract
Nutrient metabolism is regulated by several factors. Social determinants of health with or without genetics are the primary regulator of metabolism, and an unhealthy lifestyle affects all modulators and mediators, leading to the adaptation and finally to the exhaustion of cellular functions. Hepatic steatosis is defined by presence of fat in more than 5% of hepatocytes. In hepatocytes, fat is stored as triglycerides in lipid droplet. Hepatic steatosis results from a combination of multiple intracellular processes. In a healthy individual nutrient metabolism is regulated at several steps. It ranges from the selection of nutrients in a grocery store to the last step of consumption of ATP as an energy or as a building block of a cell as structural component. Several hormones, peptides, and genes have been described that participate in nutrient metabolism. Several enzymes participate in each nutrient metabolism as described above from ingestion to generation of ATP. As of now several publications have revealed very intricate regulation of nutrient metabolism, where most of the regulatory factors are tied to each other bidirectionally, making it difficult to comprehend chronological sequence of events. Insulin hormone is the primary regulator of all nutrients' metabolism both in prandial and fasting states. Insulin exerts its effects directly and indirectly on enzymes involved in the three main cellular function processes; metabolic, inflammation and repair, and cell growth and regeneration. Final regulators that control the enzymatic functions through stimulation or suppression of a cell are nuclear receptors in especially farnesoid X receptor and peroxisome proliferator-activated receptor/RXR ligands, adiponectin, leptin, and adiponutrin. Insulin hormone has direct effect on these final modulators. Whereas blood glucose level, serum lipids, incretin hormones, bile acids in conjunction with microbiota are intermediary modulators which are controlled by lifestyle. The purpose of this review is to overview the key players in the pathogenesis of metabolic dysfunction-associated steatotic liver disease (MASLD) that help us understand the disease natural course, risk stratification, role of lifestyle and pharmacotherapy in each individual patient with MASLD to achieve personalized care and target the practice of precision medicine. PubMed and Google Scholar databases were used to identify publication related to metabolism of carbohydrate and fat in states of health and disease states; MASLD, cardiovascular disease and cancer. More than 1000 publications including original research and review papers were reviewed.
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Affiliation(s)
- Shahid Habib
- Department of Hepatology, Liver Institute PLLC, Tucson, AZ 85712, United States
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Lulić AM, Katalinić M. The PNPLA family of enzymes: characterisation and biological role. Arh Hig Rada Toksikol 2023; 74:75-89. [PMID: 37357879 PMCID: PMC10291501 DOI: 10.2478/aiht-2023-74-3723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 02/01/2023] [Accepted: 05/01/2023] [Indexed: 06/27/2023] Open
Abstract
This paper brings a brief review of the human patatin-like phospholipase domain-containing protein (PNPLA) family. Even though it consists of only nine members, their physiological roles and mechanisms of their catalytic activity are not fully understood. However, the results of a number of knock-out and gain- or loss-of-function research models suggest that these enzymes have an important role in maintaining the homeostasis and integrity of organelle membranes, in cell growth, signalling, cell death, and the metabolism of lipids such as triacylglycerol, phospholipids, ceramides, and retinyl esters. Research has also revealed a connection between PNPLA family member mutations or irregular catalytic activity and the development of various diseases. Here we summarise important findings published so far and discuss their structure, localisation in the cell, distribution in the tissues, specificity for substrates, and their potential physiological role, especially in view of their potential as drug targets.
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Affiliation(s)
- Ana-Marija Lulić
- Institute for Medical Research and Occupational Health, Biochemistry and Organic Analytical Chemistry Unit, Zagreb, Croatia
| | - Maja Katalinić
- Institute for Medical Research and Occupational Health, Biochemistry and Organic Analytical Chemistry Unit, Zagreb, Croatia
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3
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Yoshimura SM, Duarte SMB, Stefano JT, Mazo DFDC, Pinho JRR, Oliveira CP. PNPLA3 GENE POLYMORPHISM AND RED MEAT CONSUMPTION INCREASED FIBROSIS RISK IN NASH BIOPSY-PROVEN PATIENTS UNDER MEDICAL FOLLOW-UP IN A TERTIARY CENTER IN SOUTHWEST BRAZIL. ARQUIVOS DE GASTROENTEROLOGIA 2023; 60:98-105. [PMID: 37194786 DOI: 10.1590/s0004-2803.202301000-13] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 01/24/2023] [Indexed: 05/18/2023]
Abstract
BACKGROUND Recent studies show an increase in nonalcoholic fatty liver disease (NAFLD) in populations with higher consumption of red meat, processed and cooked at high temperatures. On the other hand, the single nucleotide polymorphism rs738409 in the Patatin-like phospholipase domain containing 3 (PNPLA3) gene has been implicated in susceptibility to NAFLD and liver fibrosis. However, the synergistic effect between red meat consumption and the PNPLA3 gene polymorphism in NAFLD has not yet been evaluated. OBJECTIVE To evaluate the association between the presence of the polymorphism in the PNPLA3 gene and the consumption of macronutrients, including meat consumption and its cooking method among NAFLD patients. METHODS This was a cross-sectional study with 91 patients diagnosed with NAFLD by liver biopsy with genotyping for the polymorphism in the PNPLA3 gene were included. The consumption of calories and macronutrients was verified using the semi-quantitative food frequency questionnaire and the specific questionnaire on meat consumption. PNPLA3 gene polymorphism was analyzed by real-time polymerase chain reaction (RT-PCR) and anthropometric evaluation was realized. RESULTS The mean BMI was 32.38±4.58 kg/m² and the waist circumference was 107±10 cm. On liver biopsy, 42% of patients had significant fibrosis (F≥2). The odds ratio of F≥2 was 2.12 for the GG group and 1.54 for the CG group, compared to the CC group. The mean caloric intake was 1170±463.20 kcal/d. The odds ratio in the CC group concerning high red meat consumption in comparison to low consumption was 1.33. For white meat, the odds ratio was 0.8 when comparing high and low intake, also in the CC group. CONCLUSION High red meat intake and PNPLA3 gene polymorphism seem to synergistically affect NAFLD and liver fibrosis, requiring confirmation in a larger number of patients and in different populations.
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Affiliation(s)
- Silvia Massami Yoshimura
- Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Departamento de Gastroenterologia e Hepatologia, Laboratório de Gastroenterologia Clínica e Experimental (LIM-07), São Paulo, SP, Brasil
| | - Sebastião Mauro Bezerra Duarte
- Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Departamento de Gastroenterologia e Hepatologia, Laboratório de Gastroenterologia Clínica e Experimental (LIM-07), São Paulo, SP, Brasil
| | - José Tadeu Stefano
- Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Departamento de Gastroenterologia e Hepatologia, Laboratório de Gastroenterologia Clínica e Experimental (LIM-07), São Paulo, SP, Brasil
| | - Daniel Ferraz de Campos Mazo
- Faculdade de Medicina da Universidade de São Paulo, Departamento de Gastroenterologia, Divisão de Gastroenterologia Clínica e Hepatologia, São Paulo, SP, Brasil
| | - João Renato Rebello Pinho
- Faculdade de Medicina da Universidade de São Paulo, Instituto de Medicina Tropical (LIM-07), São Paulo, SP, Brasil
| | - Claudia P Oliveira
- Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Departamento de Gastroenterologia e Hepatologia, Laboratório de Gastroenterologia Clínica e Experimental (LIM-07), São Paulo, SP, Brasil
- Faculdade de Medicina da Universidade de São Paulo, Departamento de Gastroenterologia, Divisão de Gastroenterologia Clínica e Hepatologia, São Paulo, SP, Brasil
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NAFLD: genetics and its clinical implications. Clin Res Hepatol Gastroenterol 2022; 46:102003. [PMID: 35963605 DOI: 10.1016/j.clinre.2022.102003] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 07/28/2022] [Accepted: 08/09/2022] [Indexed: 02/04/2023]
Abstract
Worldwide non-alcoholic fatty liver disease (NAFLD) is recognized as the most common type of liver disease and its burden increasing at an alarming rate. NAFLD entails steatosis, fibrosis, cirrhosis, and, finally, hepatocellular carcinoma (HCC). The substantial inter-patient variation during disease progression is the hallmark of individuals with NAFLD. The variability of NAFLD development and related complications among individuals is determined by genetic and environmental factors. Genome-wide association studies (GWAS) have discovered reproducible and robust associations between gene variants such as PNPLA3, TM6SF2, HSD17B13, MBOAT7, GCKR and NAFLD. Evidences have provided the new insights into the NAFLD biology and underlined potential pharmaceutical targets. Ideally, the candidate genes associated with the hereditability of NAFLD are mainly involved in assembly of lipid droplets, lipid remodeling, lipoprotein packing and secretion, redox status mitochondria, and de novo lipogenesis. In recent years, the ability to translate genetics into a clinical context has emerged substantially by combining genetic variants primarily associated with NAFLD into polygenic risk scores (PRS). These score in combination with metabolic factors could be utilized to identify the severe liver diseases in patients with the gene regulatory networks (GRNs). Hereby, we even have highlighted the current understanding related to the schedule therapeutic approach of an individual based on microbial colonization and dysbiosis reversal as a therapy for NAFLD. The premise of this review is to concentrate on the potential of genetic factors and their translation into the design of novel therapeutics, as well as their implications for future research into personalized medications using microbiota.
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Aly O, Zaki HH, Herzalla MR, Fathy A, Raafat N, Hafez MM. Gene polymorphisms of Patatin-like phospholipase domain containing 3 (PNPLA3), adiponectin, leptin in diabetic obese patients. PLoS One 2020; 15:e0234465. [PMID: 32544194 PMCID: PMC7297308 DOI: 10.1371/journal.pone.0234465] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Accepted: 05/13/2020] [Indexed: 12/20/2022] Open
Abstract
Obesity leads a crucial importance in metabolic disorders, as well as type 2 diabetes mellitus. Our present study was designed to assess the potential role of irisin, adiponectin, leptin and gene polymorphism of PNPLA3, leptin and adiponectin as predictive markers of diabetes associated with obesity. One hundred eighty subjects were distributed to three groups including; healthy non-diabetic non obese volunteers as a control group, diabetic non obese group, and diabetic obese group (n = 60 for each group). Fasting blood samples of all groups were collected to determine fasting blood glucose, insulin levels, insulin resistance, total cholesterol, high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), triacylglycerol, irisin, adiponectin, leptin; as well as, polymorphism of PNPLA3, adiponectin and leptin. The results showed that glucose, insulin resistance, total cholesterol, irisin, leptin, LDL-C, triacylglycerol concentrations were significantly increased, however, insulin, HDL-C, adiponectin were significantly decreased in diabetic obese patients in relation to diabetic non-obese patients as well as in healthy volunteers. The polymorphism of PNPLA3 rs738409 was linearly related to irisin and leptin but was not related with circulating concentrations of adiponectin. We concluded that increased irisin and leptin levels can predict the insulin resistance in obese patients. Moreover, patients who have mutant genotype of PNPLA3 I148 gene (rs738409) C>G, ADIPOQ gene (rs266729) G>C and LEP gene (rs2167270) G>A showed a significant higher susceptibility rate for DM in obese people than those with wild type. This could be considered as an adjustable retort to counter the impact of obesity on glucose homeostasis.
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Affiliation(s)
- Omnia Aly
- Department of Medical Biochemistry, National Research Centre, Cairo, Egypt
| | - Hanan Hassan Zaki
- Department of Medical Biochemistry, National Research Centre, Cairo, Egypt
| | - Mohamed R. Herzalla
- Department of Internal Medicine, Faculty of Medicine, Zagazig University, Zagazig, Egypt
| | - Ahmed Fathy
- Department of Internal Medicine, Faculty of Medicine, Zagazig University, Zagazig, Egypt
| | - Nermin Raafat
- Medical Biochemistry Department, Faculty of Medicine, Zagazig University, Zagazig, Egypt
| | - Mohamed M. Hafez
- Biochemistry Department, Faculty of Pharmacy, Ahram Canadian University, 6th of October City, Egypt
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Duarte CRA, Farmer C, Palin MF. Body condition of late pregnant gilts affects the expression of selected adipokines and their receptors in mammary fat and backfat tissues. J Anim Sci 2019; 97:220-230. [PMID: 30321363 DOI: 10.1093/jas/sky391] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 10/11/2018] [Indexed: 12/26/2022] Open
Abstract
The impact of body condition in late gestating gilts on gene expression of selected adipokines and their receptors in backfat and mammary fat tissues was studied. The presence of associations between mammary gland composition variables and the mRNA abundance of selected genes and serum concentrations of adiponectin and leptin was also investigated. A total of 45 gilts were selected at mating based on their backfat depth and were allocated to three groups: (1) low backfat (LBF; 12-15 mm; n = 14), (2) medium backfat (MBF; 17-19 mm; n = 15), and (3) high backfat (HBF; 22-26 mm; n = 16). Gilts were fed different amounts of a conventional diet to maintain differences in backfat depth throughout the gestation period. Blood samples were collected at day 109 of gestation to measure adiponectin and leptin serum concentrations. Gilts were slaughtered on day 110 of gestation, and mammary glands were collected to determine mammary composition. Mammary fat and backfat tissues were also sampled to measure the mRNA abundance of selected genes. In mammary fat tissue, there was an effect of body condition on the prolactin (PRL; P = 0.01), adiponutrin (PNPLA3; P < 0.10), and prolactin receptor long form (PRLR-LF; P < 0.10) genes. There was a greater PRL mRNA abundance in mammary fat tissue from HBF than LBF or MBF gilts (P < 0.05). The PNPLA3 mRNA abundance was lower in HBF than in MBF gilts (P < 0.05), and that of PRLR-LF was lower in LBF than in HBF gilts (P < 0.05). In backfat, body condition affected the mRNA abundance of leptin (P < 0.05) and PNPLA3 (P < 0.01), with the greatest expression levels being observed in HBF gilts for both genes. Association analyses suggest a detrimental effect of high circulating leptin concentrations on gilts mammary development, as reflected by the negative correlations between serum leptin and protein percent (r = -0.66, P < 0.01), and concentrations of DNA (r = -0.62, P < 0.01) and RNA (r = -0.60, P < 0.01) in mammary parenchyma. Current results show that body condition of gilts at the end of gestation can affect the expression of adipokines in mammary fat and backfat tissues, with a different regulation of transcript abundance being observed in these two fat depots. Results also suggest that circulating leptin is strongly associated with mammary gland composition of late pregnant gilts, whereas locally synthesized leptin from mammary fat tissue is not.
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Affiliation(s)
- Cristiane R A Duarte
- Faculdade de Ciências Agrárias, Biológicas e da Saúde, Universidade do Estado de Mato Grosso, Tangará da Serra, MT, Brazil
| | - Chantal Farmer
- Agriculture and Agri-Food Canada, Sherbrooke R & D Centre, Sherbrooke, QC , Canada
| | - Marie-France Palin
- Agriculture and Agri-Food Canada, Sherbrooke R & D Centre, Sherbrooke, QC , Canada
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Abstract
PURPOSE OF REVIEW The liver is the central hub of lipoprotein metabolism. A complex relationship exists between dyslipidemia and chronic liver diseases (CLDs). Recent advances in the genetics of nonalcoholic fatty liver disease (NAFLD) and alcoholic liver disease (ALD) exemplify the pivotal role of lipoprotein metabolism in the pathogenesis of CLD. We review these relationships in four quintessential forms of CLD: NAFLD, ALD, cholestatic liver disease and cirrhosis, with a focus on recent discoveries. RECENT FINDINGS An I148 M variant in patatin-like phospholipase domain-containing protein 3 (PNPLA3) and an E167K variant in transmembrane 6 superfamily 2 (TM6SF2) are major genetic risk factors for the development and progression of NAFLD. These genetic variants also increase the risk of ALD. Both PNPLA3 and TM6SF2 are involved in the hepatic assembly of very low-density lipoprotein. The discovery of these two genetic variants highlights the risk of CLD when environmental factors are combined with functional modifications in the lipoprotein metabolism pathway. SUMMARY The relationship between CLD and lipoprotein metabolism is reciprocal. On the one hand, the progression of CLD impairs lipoprotein metabolism; on the other hand, modifications in lipoprotein metabolism can substantially increase the risk of CLD. These relationships are at play among the most common forms of CLD affecting a significant proportion of the population.
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Affiliation(s)
- Maria Camila Perez-Matos
- Division of Gastroenterology and Hepatology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Bynvant Sandhu
- Department of Surgery and Cancer, Imperial College London, London, UK
| | - Alan Bonder
- Division of Gastroenterology and Hepatology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Zhenghui Gordon Jiang
- Division of Gastroenterology and Hepatology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
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Negoita F, Blomdahl J, Wasserstrom S, Winberg ME, Osmark P, Larsson S, Stenkula KG, Ekstedt M, Kechagias S, Holm C, Jones HA. PNPLA3 variant M148 causes resistance to starvation-mediated lipid droplet autophagy in human hepatocytes. J Cell Biochem 2019; 120:343-356. [PMID: 30171718 DOI: 10.1002/jcb.27378] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2018] [Accepted: 07/02/2018] [Indexed: 12/30/2022]
Abstract
The mechanism of how patatin-like phospholipase domain-containing protein 3 (PNPLA3) variant M148 is associated with increased risk of development of hepatic steatosis is still debated. Here, we propose a novel role of PNPLA3 as a key player during autophagosome formation in the process of lipophagy. A human hepatocyte cell line, HepG2 cells, expressing recombinant I148 or 148M, was used to study lipophagy under energy deprived conditions, and lipid droplet morphology was investigated using florescence microscopy, image analysis and biochemical assays. Autophagic flux was studied using the golden-standard of LC3-II turnover in combination with the well characterized GFP-RFP-LC3 vector. To discriminate between, perturbed autophagic initiation and lysosome functionality, lysosomes were characterized by Lysotracker staining and LAMP1 protein levels as well as activity and activation of cathepsin B. For validation, human liver biopsies genotyped for I148 and 148M were analyzed for the presence of LC3-II and PNPLA3 on lipid droplets. We show that the M148-PNPLA3 variant is associated with lipid droplets that are resistant to starvation-mediated degradation. M148 expressing hepatocytes reveal decreased autophagic flux and reduced lipophagy. Both I148-PNPLA3 and M148-PNPLA3 colocalize and interact with LC3-II, but the M148-PNPLA3 variant has lower ability to bind LC3-II. Together, our data indicate that PNPLA3 might play an essential role in lipophagy in hepatocytes and furthermore that the M148-PNPLA3 variant appears to display a loss in this activity, leading to decreased lipophagy.
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Affiliation(s)
- Florentina Negoita
- Department of Experimental Medical Science, Faculty of Medicine, Lund University, Lund, Sweden
| | - Julia Blomdahl
- Department of Gastroenterology and Hepatology, Linköping University, Linköping, Sweden
- Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
| | - Sebastian Wasserstrom
- Department of Experimental Medical Science, Faculty of Medicine, Lund University, Lund, Sweden
| | - Martin E Winberg
- Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
| | - Peter Osmark
- Department of Experimental Medical Science, Faculty of Medicine, Lund University, Lund, Sweden
| | - Sara Larsson
- Department of Experimental Medical Science, Faculty of Medicine, Lund University, Lund, Sweden
| | - Karin G Stenkula
- Department of Experimental Medical Science, Faculty of Medicine, Lund University, Lund, Sweden
| | - Mattias Ekstedt
- Department of Gastroenterology and Hepatology, Linköping University, Linköping, Sweden
- Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
| | - Stergios Kechagias
- Department of Gastroenterology and Hepatology, Linköping University, Linköping, Sweden
- Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
| | - Cecilia Holm
- Department of Experimental Medical Science, Faculty of Medicine, Lund University, Lund, Sweden
| | - Helena A Jones
- Department of Experimental Medical Science, Faculty of Medicine, Lund University, Lund, Sweden
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Rüschenbaum S, Schwarzkopf K, Friedrich-Rust M, Seeger F, Schoelzel F, Martinez Y, Zeuzem S, Bojunga J, Lange CM. Patatin-like phospholipase domain containing 3 variants differentially impact metabolic traits in individuals at high risk for cardiovascular events. Hepatol Commun 2018; 2:798-806. [PMID: 30027138 PMCID: PMC6049070 DOI: 10.1002/hep4.1183] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 03/14/2018] [Accepted: 03/17/2018] [Indexed: 12/16/2022] Open
Abstract
Single nucleotide polymorphism (SNP) rs738409 C>G in the patatin‐like phospholipase domain containing 3 (PNPLA3) gene results in an amino acid exchange from isoleucin to methionine at position I148M of PNPLA3. The expression of this loss‐of‐function mutation leads to impaired hepatocellular triglyceride hydrolysis and is associated with the development of liver steatosis, fibrosis, and hepatocellular carcinoma. In contrast to these well‐established associations, the relationship of the PNPLA3 rs738409 variant with other metabolic traits is incompletely understood. We therefore assessed the association of the PNPLA3 rs738409 genotype with relevant metabolic traits in a prospective study of patients at high risk for cardiovascular events, i.e., patients undergoing coronary angiography. In a total of 270 patients, known associations of the PNPLA3 rs738409 GG genotype with nonalcoholic steatohepatitis and liver fibrosis were confirmed. In addition, we found an association of the PNPLA3 rs738409 G allele with the presence of diabetes (22% versus 28% versus 58% for CC versus CG versus GG genotype, respectively; P = 0.02). In contrast to its association with nonalcoholic fatty liver disease, liver fibrosis, and diabetes, the minor G allele of PNPLA3 rs738409 was inversely associated with total serum cholesterol and low‐density lipoprotein serum levels (P = 0.003 and P = 0.02, respectively). Finally, there was a trend toward an inverse association between the presence of the PNPLA3 rs738409 G allele and significant coronary heart disease. Comparable trends were observed for the transmembrane 6 superfamily member 2 (TM6SF2) 167 K variant, but the sample size was too small to evaluate this rarer variant. Conclusion: The PNPLA3 rs738409 G allele is associated with liver disease but also with a relatively benign cardiovascular risk profile. (Hepatology Communications 2018;2:798‐806)
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Affiliation(s)
- Sabrina Rüschenbaum
- Department of Internal Medicine 1 J.W. Goethe-University Hospital Frankfurt Germany
| | | | | | - Florian Seeger
- Department of Cardiology St. Elisabeth Hospital Ravensburg Germany
| | - Fabian Schoelzel
- Department of Internal Medicine 1 J.W. Goethe-University Hospital Frankfurt Germany
| | - Yolanda Martinez
- Department of Internal Medicine 1 J.W. Goethe-University Hospital Frankfurt Germany
| | - Stefan Zeuzem
- Department of Internal Medicine 1 J.W. Goethe-University Hospital Frankfurt Germany
| | - Jörg Bojunga
- Department of Internal Medicine 1 J.W. Goethe-University Hospital Frankfurt Germany
| | - Christian M Lange
- Department of Internal Medicine 1 J.W. Goethe-University Hospital Frankfurt Germany
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Genetic and Epigenetic Regulation in Nonalcoholic Fatty Liver Disease (NAFLD). Int J Mol Sci 2018; 19:ijms19030911. [PMID: 29562725 PMCID: PMC5877772 DOI: 10.3390/ijms19030911] [Citation(s) in RCA: 101] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 03/14/2018] [Accepted: 03/15/2018] [Indexed: 12/12/2022] Open
Abstract
Genetics and epigenetics play a key role in the development of several diseases, including nonalcoholic fatty liver disease (NAFLD). Family studies demonstrate that first degree relatives of patients with NAFLD are at a much higher risk of the disease than the general population. The development of the Genome Wide Association Study (GWAS) technology has allowed the identification of numerous genetic polymorphisms involved in the evolution of diseases (e.g., PNPLA3, MBOAT7). On the other hand, epigenetic changes interact with inherited risk factors to determine an individual’s susceptibility to NAFLD. Modifications of the histones amino-terminal ends are key factors in the maintenance of chromatin structure and gene expression (cAMP-responsive element binding protein H (CREBH) or SIRT1). Activation of SIRT1 showed potential against the physiological mechanisms related to NAFLD. Abnormal DNA methylation represents a starting point for cancer development in NAFLD patients. Besides, the evaluation of circulating miRNA profiles represents a promising approach to assess and non-invasively monitor liver disease severity. To date, there is no approved pharmacologic therapy for NAFLD and the current treatment remains weight loss with lifestyle modification and exercise. In this review, the status of research into relevant genetic and epigenetic modifiers of NAFLD progression will be discussed.
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Dutta AK. Adiponutrin (PNPLA3) in liver fibrogenesis: Is unaltered HepG2 cell line a better model system compared to murine models? Med Hypotheses 2015; 85:736-9. [PMID: 26519102 DOI: 10.1016/j.mehy.2015.10.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2015] [Revised: 10/09/2015] [Accepted: 10/18/2015] [Indexed: 01/04/2023]
Abstract
Alcoholic liver disease is a major source of morbidity and mortality worldwide. Twin studies had demonstrated heritability of alcoholic liver disease. Although to date only Adiponutrin (PNPLA3) rs738409 polymorphism (I148M) had been unequivocally proved to be associated with increased risk of alcoholic liver disease across different ethnicities. This protein was previously thought to have a predominant lipolytic role. However, recent investigations have provided evidence of lipogenic activity of this protein. The current hypothesis paper is summarizing the recent evidences gleaned in biological role of Adiponutrin and bioinformatic pointers towards a role in lipid trafficking. A critical appraisal of the utility of murine models and cell based systems in investigating Adiponutrin is also presented. As the HepG2 cell line harbors the I148M mutation in homozygous state it is hypothesized that this should represent an ideal model system for PNPLA3 biology. Thus, as Adiponutrin is proposed as having both lipolytic and lipogenic/lipid trafficking roles it is termed as a Yin-Yang protein in analogy to ancient Chinese wisdom.
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Affiliation(s)
- Atanu Kumar Dutta
- Department of Biochemistry, IPGMER and SSKM Hospital, Kolkata, India.
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