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Yang Z, Huang G, Zhou P, Zhang Y, Ding J, Sun Q, Hua T. Exercise ameliorates high-fat diet-induced insulin resistance accompanied by changes in protein levels of hepatic ATF3-related signaling in rats. Physiol Behav 2022; 249:113766. [PMID: 35240124 DOI: 10.1016/j.physbeh.2022.113766] [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: 10/14/2021] [Revised: 02/20/2022] [Accepted: 02/26/2022] [Indexed: 11/30/2022]
Abstract
PURPOSE Exercise is an effective way to alleviate insulin resistance (IR). However, the underlying mechanisms remain to be elucidated. Previous studies demonstrated that cardiolipin synthase 1 (CRLS1)/interferon-regulatory factor-2 binding protein 2 (IRF2bp2)-activating transcription factor 3 (ATF3)-adiponectin receptor 2 (AdipoR2)-adaptor protein containing pH domain, PTB domain and leucine zipper motif 1 (APPL1)-protein kinase B (AKT/PKB)-related signaling was closely associated with obesity-induced IR-related diseases, but the correlation between exercise training alleviating obesity-induced IR and the protein levels of hepatic CRLS1/IRF2bp2-ATF3-AdipoR2-APPL1-AKT-related signaling in rats is unknown. Therefore, We want to investigate the effect of exercise training on IR and the protein levels of hepatic CRLS1/IRF2bp2-ATF3-AdipoR2-APPL1-AKT-related signaling in rat. METHODS The male healthy Sprague-Dawley rats were divided into four groups: normal control group (NCG, n = 10), diet-induced obesity-sedentary group (DIO-SG, n = 10), diet-induced obesity-chronic exercise group (DIOCEG, n = 10) received chronic swim exercise training and diet-induced obesity-acute exercise group (DIO-AEG, n = 10) received acute swim exercise training. We measured the levels of IR-related indicators and the protein levels of hepatic CRLS1/IRF2bp2-ATF3-AdipoR2-APPL1-AKT-related signaling in NCG, DIO-SG, DIOCEG and DIO-AEG. RESULTS We found that high-fat diet (HFD)-induced obesity decreased insulin sensitivity in rats accompanied by decreased protein levels of hepatic CRLS1, IRF2bp2, AdipoR2, APPL1, p-AKT and increased protein level of hepatic ATF3. The acute exercise and the chronic exercise both increased insulin sensitivity in rats. The chronic exercise decreased hepatic ATF3 protein level and increased CRLS1, IRF2bp2, AdipoR2, APPL1, p-AKT protein levels in HFD-fed rats. The acute exercise decreased hepatic ATF3 protein level and increased hepatic IRF2bp2, APPL1 and p-AKT protein levels in HFD-fed rats. The acute exercise had no significant effect on hepatic CRLS1 and AdipoR2 protein levels in HFD-fed rats. CONCLUSION Our current findings indicated that exercise alleviated obesity-induced IR accompanied by changes in protein levels of hepatic ATF3-related signaling in rats. Our results are meaningful for exploring the molecular mechanism of exercise alleviating IR symptoms.
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Affiliation(s)
- Zhiwei Yang
- Physiology laboratory of College of Life Sciences, Anhui Normal University, Wuhu, China
| | - Guangyu Huang
- Physiology laboratory of College of Life Sciences, Anhui Normal University, Wuhu, China
| | - Puqing Zhou
- Physiology laboratory of College of Life Sciences, Anhui Normal University, Wuhu, China
| | - Yong Zhang
- Physiology laboratory of College of Life Sciences, Anhui Normal University, Wuhu, China
| | - Jing Ding
- Physiology laboratory of College of Life Sciences, Anhui Normal University, Wuhu, China
| | - Qingyan Sun
- Physiology laboratory of College of Life Sciences, Anhui Normal University, Wuhu, China.
| | - Tianmiao Hua
- Neurobiology laboratory of College of Life Sciences, Anhui Normal University, Wuhu, China
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Zheng YT, Xiao TM, Wu CX, Cheng JY, Li LY. Correlation of Adiponectin Gene Polymorphisms rs266729 and rs3774261 With Risk of Nonalcoholic Fatty Liver Disease: A Systematic Review and Meta-Analysis. Front Endocrinol (Lausanne) 2022; 13:798417. [PMID: 35399941 PMCID: PMC8983824 DOI: 10.3389/fendo.2022.798417] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 02/22/2022] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND Increasing evidence has suggested an association of adiponectin gene polymorphisms rs1501299, rs2241766, rs266729 and rs3774261 with risk of nonalcoholic fatty liver disease (NAFLD). This correlation has been extensively meta-analyzed for the first two polymorphisms, but not the second two. METHODS The PubMed, EMBASE, Google Scholar, and China National Knowledge Infrastructure databases were searched for relevant literature. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. RESULTS A total of 10 case-control studies on rs266729 (2,619 cases and 1,962 controls) and 3 case-control studies on rs3774261 (562 cases and 793 controls) were included. Meta-analysis showed that rs266729 was associated with significantly higher NAFLD risk based on the following five models: allelic, OR 1.72, 95% CI 1.34-2.21, P < 0.001; recessive, OR 2.35, 95% CI 1.86-2.95, P < 0.001; dominant, OR 1.84, 95% CI 1.34-2.53, P < 0.001; homozygous, OR 2.69, 95% CI 1.84-3.92, P < 0.001; and heterozygous, OR 1.72, 95% CI 1.28-2.32, P < 0.001. This association between rs266729 and NAFLD risk remained significant for all five models among studies with Asian, Chinese and Caucasian samples. The rs2241766 polymorphism was associated with significantly higher NAFLD risk according to the recessive model (OR 1.87, 95% CI 1.15-3.04, P = 0.01). CONCLUSION Polymorphisms rs266729 and rs3774261 in the adiponectin gene may be risk factors for NAFLD. These findings may pave the way for novel therapeutic strategies, but they should be verified in large, well-designed studies.
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Main Risk Factors of Type 2 Diabetes Mellitus with Nonalcoholic Fatty Liver Disease and Hepatocellular Carcinoma. JOURNAL OF ONCOLOGY 2021; 2021:7764817. [PMID: 34691178 PMCID: PMC8528616 DOI: 10.1155/2021/7764817] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 09/15/2021] [Indexed: 02/06/2023]
Abstract
Type 2 diabetes mellitus (T2DM) with nonalcoholic fatty liver disease (NAFLD) is a pathological metabolic disease characterized by high ketone lipid based on abnormal lipid metabolism. Compared with patients with single T2DM or NAFLD, T2DM complicated with NAFLD has more complicated pathogenic factors and pathological processes. Hepatocellular carcinoma (HCC), the leading malignancy arising from cirrhosis, is the second most lethal cancer globally. The purpose of this study was to clarify the main risk factors of T2DM with NAFLD and HCC. There are many challenges in the diagnosis and treatment of T2DM patients with NAFLD and HCC. The current gold standard is to adjust treatment strategy, optimize metabolic control, and improve liver phenotype. It is necessary to identify further the risk factors driving the progression of T2DM with NAFLD and HCC and evaluate new therapeutic targets, in addition to exploring the syndromic forms of T2DM combined with NAFLD and providing a theoretical basis for early prevention, diagnosis, and treatment of the disease using traditional Chinese medicine (TCM).
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Zhang Y, Yang Z, Xu Z, Wan J, Hua T, Sun Q. Exercise ameliorates insulin resistance and improves SIRT6-mediated insulin signaling transduction in liver of obese rats. Can J Physiol Pharmacol 2021; 99:506-511. [PMID: 32970960 DOI: 10.1139/cjpp-2020-0083] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Physical exercise is essential for the amelioration of insulin resistance (IR). The mechanisms in charge of improved IR, regulated by exercise, are insufficiently studied. Previous research revealed that Sirtuin 6 (SIRT6) - mediated insulin signaling acts a crucial element in hepatic IR. The objective of our research was to determine the effects of exercise on SIRT6-mediated insulin signaling in liver of IR rats. Forty male Sprague Dawley rats were randomly assigned to four groups (n = 10 rats each): control rats fed with standard chow (Lean group); sedentary rats fed with a high-fat diet (HFD-SED); rats fed with HFD and submitted to 8 week chronic swimming exercise training (HFD-CE); and rats fed HFD and submitted to one acute swimming exercise training (HFD-AE). HFD feeding lead to increased body weight, accumulation of hepatic triglyceride and serum free fatty acids, and enhanced gluconeogenesis. Besides, HFD feeding decreased body insulin sensitivity. Hepatic USP10 and SIRT6 protein levels decreased under obese status. Both chronic and acute exercise intervention alleviated physiological and metabolic status, increased hepatic USP10 and SIRT6 levels, improved insulin signaling transduction, and inhibited gluconeogenesis. These results showed that exercise intervention regulated SIRT6-mediated insulin signaling, which contributes to our understanding of the molecular mechanisms behind IR, in that a regular exercise can mitigate the effects of IR.
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Affiliation(s)
- Yong Zhang
- Physiology laboratory of College of Life Sciences, Anhui Normal University, Wuhu, China
| | - Zhiwei Yang
- Physiology laboratory of College of Life Sciences, Anhui Normal University, Wuhu, China
| | - Zhen Xu
- The State Key Laboratory of Pharmaceutical Biotechnology, Division of Immunology, Medical School, Nanjing University, Nanjing, China
| | - Jianyong Wan
- Physiology laboratory of College of Life Sciences, Anhui Normal University, Wuhu, China
| | - Tianmiao Hua
- Neurobiology laboratory of College of Life Sciences, Anhui Normal University, Wuhu, China
| | - Qingyan Sun
- Physiology laboratory of College of Life Sciences, Anhui Normal University, Wuhu, China
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Mahmoud AA, Moghazy HM, Yousef LM, Mohammad AN. Adiponectin rs2241766 and rs266729 gene polymorphisms in non-alcoholic fatty liver disease. GENE REPORTS 2019. [DOI: 10.1016/j.genrep.2019.100381] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Liu M, Liu S, Shang M, Liu X, Wang Y, Li Q, Mambiya M, Yang L, Zhang Q, Zhang K, Nie F, Zeng F, Liu W. Association between ADIPOQ G276T and C11377G polymorphisms and the risk of non-alcoholic fatty liver disease: An updated meta-analysis. Mol Genet Genomic Med 2019; 7:e624. [PMID: 30838812 PMCID: PMC6503060 DOI: 10.1002/mgg3.624] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 01/13/2019] [Accepted: 02/10/2019] [Indexed: 12/31/2022] Open
Abstract
Background Nonalcoholic fatty liver disease (NAFLD) is a significant contributor to global hepatic disorders. ADIPOQ gene single‐nucleotide polymorphisms have been associated with NAFLD susceptibility, but with inconsistent results across the studies. This study aimed to investigate the association between ADIPOQ polymorphisms (+276G>T, rs1501299 and −11377C>G, rs266729) and the risk of NAFLD. Methods PubMed, Embase, Wanfang, Web of Science, and China National Knowledge Infrastructure databases were used to identify the relevant published literature. Statistical analyses were calculated with STATA 11.0 software and RevMan 5.2. Summary odds ratios (OR) and 95% confidence intervals (CIs) were generated to assess the strength of the associations. Results Eleven relevant articles with a total of 3,644 participants (1,847 cases/1,797 controls) were included. Our meta‐analysis results revealed that ADIPOQ gene +276G>T polymorphism was not associated with NAFLD under various genetic models (allele model: OR = 0.99, 95% CI [0.69, 1.41]; dominant model: OR = 1.06, 95% CI [0.71, 1.58]; recessive model: OR = 0.83, 95% CI [0.42, 1.65]; homozygous model: OR = 0.86, 95% CI [0.38, 1.95]; heterozygous model: OR = 1.10, 95% CI [0.80, 1.53]; respectively). Moreover, no statistical significant association was found between +276G>T and NAFLD risk in the subgroups. ADIPOQ gene −11377C>G polymorphism significantly increased the risk of NAFLD (allele model: OR = 1.49, 95% CI [1.28, 1.75]; dominant model: OR = 1.64, 95% CI [1.35, 1.99]; recessive model: OR = 1.77, 95% CI [1.16, 2.70]; homozygous model: OR = 2.13, 95% CI [1.38, 3.28]; heterozygous model: OR = 1.58, 95% CI [1.29, 1.93]; respectively). Conclusion ADIPOQ gene −11377C>G may be a risk factor for NAFLD, while there was no association between ADIPOQ gene +276G>T polymorphism and the risk of NAFLD. Further studies are needed to detect the relationship between these ADIPOQ polymorphisms and NAFLD.
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Affiliation(s)
- Mengwei Liu
- Department of Nutrition and Food Hygiene, School of Public Health, China Medical University, Shenyang, P.R. China
| | - Shan Liu
- Department of Nutrition and Food Hygiene, School of Public Health, China Medical University, Shenyang, P.R. China
| | - Mengke Shang
- Department of Nutrition and Food Hygiene, School of Public Health, China Medical University, Shenyang, P.R. China
| | - Xiuping Liu
- Department of Nutrition and Food Hygiene, School of Public Health, China Medical University, Shenyang, P.R. China
| | - Yue Wang
- Department of Nutrition and Food Hygiene, School of Public Health, China Medical University, Shenyang, P.R. China
| | - Qian Li
- Department of Nutrition and Food Hygiene, School of Public Health, China Medical University, Shenyang, P.R. China
| | - Michael Mambiya
- Department of Nutrition and Food Hygiene, School of Public Health, China Medical University, Shenyang, P.R. China
| | - Luping Yang
- Department of Nutrition and Food Hygiene, School of Public Health, China Medical University, Shenyang, P.R. China
| | - Qian Zhang
- Department of Nutrition and Food Hygiene, School of Public Health, China Medical University, Shenyang, P.R. China
| | - Kaili Zhang
- Department of Nutrition and Food Hygiene, School of Public Health, China Medical University, Shenyang, P.R. China
| | - Fangfang Nie
- Department of Nutrition and Food Hygiene, School of Public Health, China Medical University, Shenyang, P.R. China
| | - Fanxin Zeng
- Department of Nutrition and Food Hygiene, School of Public Health, China Medical University, Shenyang, P.R. China
| | - Wanyang Liu
- Department of Nutrition and Food Hygiene, School of Public Health, China Medical University, Shenyang, P.R. China
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Liu J, Xing J, Wang B, Wei C, Yang R, Zhu Y, Qiu H. Correlation Between Adiponectin Gene rs1501299 Polymorphism and Nonalcoholic Fatty Liver Disease Susceptibility: A Systematic Review and Meta-Analysis. Med Sci Monit 2019; 25:1078-1086. [PMID: 30735485 PMCID: PMC6376635 DOI: 10.12659/msm.912737] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Background Metabolic related nonalcoholic fatty liver disease (NAFLD) is one of the most prevalent chronic liver diseases around the world. A single nucleotide polymorphism (SNP) rs1501299 (+276G>T) in the adiponectin gene has been recently revealed to be responsible for susceptibility to NAFLD. This meta-analysis intended to assess the association risk of NAFLD and rs1501299 polymorphism. Material/Methods We conducted a literature search on PubMed, Embase, and Cochrane Library databases. All involved studies were selected based on our search criteria. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to quantify the strength of the association. Subgroup analysis considered the effects of ethnicity, subject scope, and source of control. Publication bias was assessed by Begg’s tests. Results Eight qualified case-control studies with 1639 patients and 1426 controls demonstrated a significant correlation between rs1501299 polymorphism in adiponectin and NAFLD under the dominant model (OR=1.18, 95% CI=1.02–1.36), allelic contrast (OR=1.21, 95% CI=1.09–1.36), homozygote comparison (OR=1.63, 95% CI=1.26–2.01) and the recessive allele model (OR=1.58, 95% CI=1.23–2.02) with evident heterogeneity. No association was observed between the risk of NAFLD and the genotypic variants in heterozygote comparison (OR=1.11, 95% CI=0.95–1.29) without heterogeneity. Subgroup analysis suggested that the sample size could be the potential source of heterogeneity. Source of control was not the reason for between-study heterogeneity and further sensitivity analysis and publication bias revealed good consistency and symmetry in the pooling studies. Conclusions Results from our current meta-analysis gave insight into the correlation between rs1501299 polymorphism and the risk of NAFLD, indicating the variant of rs1501299 might be related to increased NAFLD susceptibility.
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Affiliation(s)
- Jiaxing Liu
- Bayi College of People's Liberation Army (PLA), Anhui Medical University, Nanjing, Jiangsu, China (mainland)
| | - Jicheng Xing
- Department of Clinical Laboratory, The 81st Hospital of People's Liberation Army (PLA), Nanjing, Jiangsu, China (mainland)
| | - Bing Wang
- Department of Clinical Laboratory, The 81st Hospital of People's Liberation Army (PLA), Nanjing, Jiangsu, China (mainland)
| | - Changyong Wei
- Department of Hematology and Medical Oncology, School of Medicine, Emory University, Atlanta, GA, USA
| | - Ruining Yang
- Department of Clinical Laboratory, The 81st Hospital of People's Liberation Army (PLA), Nanjing, Jiangsu, China (mainland)
| | - Yuerong Zhu
- Department of Clinical Laboratory, The 81st Hospital of People's Liberation Army (PLA), Nanjing, Jiangsu, China (mainland)
| | - Hong Qiu
- Department of Clinical Laboratory, The 81st Hospital of People's Liberation Army (PLA), Nanjing, Jiangsu, China (mainland)
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Zhang Y, Wan J, Xu Z, Hua T, Sun Q. Exercise ameliorates insulin resistance via regulating TGFβ-activated kinase 1 (TAK1)-mediated insulin signaling in liver of high-fat diet-induced obese rats. J Cell Physiol 2018; 234:7467-7474. [PMID: 30367484 DOI: 10.1002/jcp.27508] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 09/10/2018] [Indexed: 12/16/2022]
Abstract
Exercise is an effective therapy for insulin resistance. However, the underlying mechanism remains to be elucidated. Previous research demonstrated that TGFβ-activated kinase 1 (TAK1)-dependent signaling plays a crucial character in hepatic insulin resistance. Hepatic ubiquitin specific protease 4 (USP4), USP18, and dual-specificity phosphatases 14 (DUSP14) can suppress TAK1 phosphorylation, besides tumor necrosis factor receptor-associated factor 3 (TRAF3) and tripartite motif 8 (TRIM8) promote its phosphorylation. In this study, we tried to verify our hypothesis that exercise improves insulin resistance in high-fat diet (HFD)-induced obese (DIO) rats via regulating the TAK1 dependent signaling and TAK1 regulators in liver. Forty male Sprague-Dawley rats were randomized into four groups (n = 10): standard diet and sedentary as normal control; fed on HFD and DIO-sedentary; fed on HFD and DIO-chronic exercise; and fed on HFD and DIO-acute exercise. HFD feeding resulted in increased body weight, visceral fat mass, serum FFAs and hepatic lipid deposition, but decreased hepatic glycogen content and insulin sensitivity. Moreover, hepatic TRAF3 and TRIM8 protein levels increased, whereas USP4, USP18, and DUSP14 protein levels were decreased under obese status, which resulted in enhanced TAK1 phosphorylation and impaired insulin signaling. Exercise training, containing chronic and acute mode, both ameliorated insulin resistance. Meanwhile, decreased TAK1, c-Jun N-terminal kinase 1 (JNK1), and insulin receptor substrate 1 (IRS1) phosphorylation enhanced Akt phosphorylation in liver. Moreover, exercise enhanced USP4 and DUSP14 protein levels, whereas decreased TRIM8 protein levels in obese rats' liver. These results showed that exercise triggered a crucial modulation in TAK1-dependent signaling and its regulators in obese rats' liver, and distinct improvement in insulin sensitivity, which provide new insights into the mechanism by which physical exercise improves insulin resistance.
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Affiliation(s)
- Yong Zhang
- Division of Physiology, Physiology Laboratory of College of Life Sciences, Anhui Normal University, Wuhu, China
| | - Jianyong Wan
- Division of Physiology, Physiology Laboratory of College of Life Sciences, Anhui Normal University, Wuhu, China
| | - Zhen Xu
- Division of Immunology, The State Key Laboratory of Pharmaceutical Biotechnology, Medical School, Nanjing University, Nanjing, China
| | - Tianmiao Hua
- Division of Neurobiology, Neurobiology Laboratory of College of Life Sciences, Anhui Normal University, Wuhu, China
| | - Qingyan Sun
- Division of Physiology, Physiology Laboratory of College of Life Sciences, Anhui Normal University, Wuhu, China
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Hussain MK, Deli FA, Algenabi AHA, Abdul-Rudha KH. Adiponectin gene polymorphisms as a predictor for development of type 2 diabetes mellitus in Iraqi population. Gene 2018; 662:118-122. [DOI: 10.1016/j.gene.2018.03.087] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2017] [Revised: 03/23/2018] [Accepted: 03/28/2018] [Indexed: 12/18/2022]
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Zhang Y, Wan J, Liu S, Hua T, Sun Q. Exercise induced improvements in insulin sensitivity are concurrent with reduced NFE2/miR-432-5p and increased FAM3A. Life Sci 2018; 207:23-29. [PMID: 29802941 DOI: 10.1016/j.lfs.2018.05.040] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2018] [Revised: 05/14/2018] [Accepted: 05/22/2018] [Indexed: 10/16/2022]
Abstract
AIMS Little is known regarding whether the NFE2/miR-423-5p and FAM3A-ATP-Akt pathway in liver mediates exercise allured alleviation of insulin resistance connected with diet-induced obesity. This research inquired the influence of exercise on liver insulin sensitivity and whole body insulin resistance in high-fat diet fed rats. MATERIALS AND METHODS Forty male Sprague-Dawley rats at seven-week-old were assigned to four groups at random: standard diet as normal control group (NC, n = 10), high-fat diet group (HFD, n = 10), high-fat diet with chronic exercise intervention group (HFD-CE, n = 10) and high-fat diet with acute exercise intervention group (HFD-AE, n = 10). KEY FINDINGS Compared with rats fed with a standard diet, eight-week high-fat diet feeding lead to elevated body weight, visceral fat content and serum FFAs, and decreased insulin sensitivity index. Moreover, high-fat diet enhanced NFE2 protein expression and miR-423-5p level, decreased FAM3A mRNA and protein expression, ATP level and Akt phosphorylation in liver. In contrast, physical exercise, both chronic and acute exercise alleviated whole body insulin resistance, reduced hepatic NFE2 and miR-423-5p expression, and serum FFAs level, meanwhile enhanced FAM3A mRNA and protein expression, ATP level and Akt phosphorylation in liver. The current findings indicated that exercise in diet-induced obesity, both chronic and acute, induce a momentous regulation in NFE2/miR-423-5p and FAM3A-ATP-Akt pathway in liver, and improve hepatic insulin sensitivity and whole body insulin resistance. SIGNIFICANCE All these results supply crucial evidence in our comprehending of the molecular mechanism that connected exercise to an alleviation of insulin resistance.
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Affiliation(s)
- Yong Zhang
- Physiology Laboratory of College of Life Sciences, Anhui Normal University, Wuhu, China
| | - Jianyong Wan
- Physiology Laboratory of College of Life Sciences, Anhui Normal University, Wuhu, China
| | - Shiqiang Liu
- Physiology Laboratory of College of Life Sciences, Anhui Normal University, Wuhu, China
| | - Tianmiao Hua
- Neurobiology Laboratory of College of Life Sciences, Anhui Normal University, Wuhu, China
| | - Qingyan Sun
- Physiology Laboratory of College of Life Sciences, Anhui Normal University, Wuhu, China.
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Umano GR, Martino M, Santoro N. The Association between Pediatric NAFLD and Common Genetic Variants. CHILDREN-BASEL 2017. [PMID: 28629152 PMCID: PMC5483624 DOI: 10.3390/children4060049] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Non-alcoholic fatty liver disease (NAFLD) is one of the most common complications of obesity. Several studies have shown that genetic predisposition probably plays an important role in its pathogenesis. In fact, in the last few years a large number of genetic studies have provided compelling evidence that some gene variants, especially those in genes encoding proteins regulating lipid metabolism, are associated with intra-hepatic fat accumulation. Here we provide a comprehensive review of the gene variants that have affected the natural history of the disease.
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Affiliation(s)
- Giuseppina Rosaria Umano
- Department of Pediatrics, Yale University, 06520, New Haven, CT, USA.
- Dipartimento della Donna, del Bambino, di Vhirurgia Generale e Specialistica, Universita' della Campania Luigi Vanvitelli, 80138, Napoli, Italy.
| | - Mariangela Martino
- Department of Pediatrics, Yale University, 06520, New Haven, CT, USA.
- Dipartimento di Medicina V. Tiberio, Universita' del Molise, 86100, Campobasso, Italy.
| | - Nicola Santoro
- Department of Pediatrics, Yale University, 06520, New Haven, CT, USA.
- Dipartimento di Medicina V. Tiberio, Universita' del Molise, 86100, Campobasso, Italy.
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Du SX, Lu LL, Liu Y, Dong QJ, Xuan SY, Xin YN. Association of Adiponectin Gene Polymorphisms With the Risk of Coronary Artery Disease in Patients With Nonalcoholic Fatty Liver Disease in a Chinese Han Population. HEPATITIS MONTHLY 2016; 16:e37388. [PMID: 27642347 PMCID: PMC5018350 DOI: 10.5812/hepatmon.37388] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 05/11/2016] [Accepted: 05/31/2016] [Indexed: 12/11/2022]
Abstract
BACKGROUND Cardiovascular events are an independent risk factor for nonalcoholic fatty liver disease (NAFLD), which is the leading cause of mortality in NAFLD patients. Several recent studies demonstrated that adiponectin (Ad) polymorphisms were involved in the progression of NAFLD and coronary artery disease (CAD). However, reports on the association between Ad polymorphisms and the risk of developing CAD in NAFLD patients are lacking in a Northern Han Chinese population. OBJECTIVES The present study was designed to evaluate the association between Ad gene polymorphisms (rs266729 and rs2241766) and the risk of developing CAD in Northern Han Chinese patients with NAFLD. MATERIALS AND METHODS In this case-control study, using the polymerase chain reaction (PCR), Adrs266729 and rs2241766 gene polymorphisms were genotyped in B-type ultrasonography-proven NAFLD patients, with (n = 246) or without (n = 247) CAD and in healthy controls (n = 304). Serum lipid profiles were determined using biochemical methods. Statistical analyses were performed using SPSS 17.0 statistical software. RESULTS There were significant differences in the Adrs266729 G allele between the NAFLD patients with and without CAD (P < 0.05). In addition, there was a significant difference in the Adrs2241766 G allele of the NAFLD patients compared with that of the controls (P < 0.05). In the NAFLD CAD population, carriers of the G allele of Adrs266729 had higher serum triglycerides (TG), total cholesterol (TC), fasting plasma glucose (FPG), and low-density lipoprotein (LDL) levels and a lower Ad level than their noncarrier counterparts (P = 0.031, P = 0.034, P = 0.007, P < 0.001, and P < 0.001, respectively). NAFLD patients without CAD had higher TG and serum FPG values and a lower Ad level than their noncarrier counterparts (P = 0.014, P = 0.038, and P < 0.001, respectively). In the NAFLD patients with/without CAD, the carriers of the G allele of Adrs2241766 had higher TG levels (P = 0.039 and P = 0.042, respectively) than those of their noncarrier counterparts. CONCLUSIONS In this Northern Chinese Han population, the Adrs266729 and rs2241766 G alleles were closely associated with the occurrence of NAFLD. However, only NAFLD patients who carried the Adrs266729 G allele had an increased risk of developing CAD.
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Affiliation(s)
- Shui-Xian Du
- Medical College of Qingdao University, Qingdao, China
- Department of Gastroenterology, Qingdao Municipal Hospital, Qingdao, China
| | - Lin-Lin Lu
- Digestive Disease Key Laboratory of Qingdao, Qingdao, China
- Central Laboratories, Qingdao Municipal Hospital, Qingdao, China
| | - Yang Liu
- Medical College of Qingdao University, Qingdao, China
- Department of Gastroenterology, Qingdao Municipal Hospital, Qingdao, China
| | - Quan-Jiang Dong
- Department of Gastroenterology, Qingdao Municipal Hospital, Qingdao, China
- Digestive Disease Key Laboratory of Qingdao, Qingdao, China
| | - Shi-Ying Xuan
- Medical College of Qingdao University, Qingdao, China
- Department of Gastroenterology, Qingdao Municipal Hospital, Qingdao, China
- Digestive Disease Key Laboratory of Qingdao, Qingdao, China
- Corresponding Authors: Yong-Ning Xin, Medical College of Qingdao University, Qingdao, China. Tel: 86-53282789463, Fax: 86-53285968434, E-mail: ; Shi-Ying Xuan, Medical College of Qingdao University, Qingdao, China. Tel: +86-53288905508, Fax: +86-53288905293, E-mail:
| | - Yong-Ning Xin
- Medical College of Qingdao University, Qingdao, China
- Department of Gastroenterology, Qingdao Municipal Hospital, Qingdao, China
- Digestive Disease Key Laboratory of Qingdao, Qingdao, China
- Corresponding Authors: Yong-Ning Xin, Medical College of Qingdao University, Qingdao, China. Tel: 86-53282789463, Fax: 86-53285968434, E-mail: ; Shi-Ying Xuan, Medical College of Qingdao University, Qingdao, China. Tel: +86-53288905508, Fax: +86-53288905293, E-mail:
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Macaluso FS, Maida M, Petta S. Genetic background in nonalcoholic fatty liver disease: A comprehensive review. World J Gastroenterol 2015; 21:11088-11111. [PMID: 26494964 PMCID: PMC4607907 DOI: 10.3748/wjg.v21.i39.11088] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Revised: 06/11/2015] [Accepted: 09/02/2015] [Indexed: 02/06/2023] Open
Abstract
In the Western world, nonalcoholic fatty liver disease (NAFLD) is considered as one of the most significant liver diseases of the twenty-first century. Its development is certainly driven by environmental factors, but it is also regulated by genetic background. The role of heritability has been widely demonstrated by several epidemiological, familial, and twin studies and case series, and likely reflects the wide inter-individual and inter-ethnic genetic variability in systemic metabolism and wound healing response processes. Consistent with this idea, genome-wide association studies have clearly identified Patatin-like phosholipase domain-containing 3 gene variant I148M as a major player in the development and progression of NAFLD. More recently, the transmembrane 6 superfamily member 2 E167K variant emerged as a relevant contributor in both NAFLD pathogenesis and cardiovascular outcomes. Furthermore, numerous case-control studies have been performed to elucidate the potential role of candidate genes in the pathogenesis and progression of fatty liver, although findings are sometimes contradictory. Accordingly, we performed a comprehensive literature search and review on the role of genetics in NAFLD. We emphasize the strengths and weaknesses of the available literature and outline the putative role of each genetic variant in influencing susceptibility and/or progression of the disease.
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Zhou YJ, Zhang ZS, Nie YQ, Cao J, Cao CY, Li YY. Association of adiponectin gene variation with progression of nonalcoholic fatty liver disease: A 4-year follow-up survey. J Dig Dis 2015; 16:601-9. [PMID: 26334200 DOI: 10.1111/1751-2980.12288] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Revised: 08/17/2015] [Accepted: 09/01/2015] [Indexed: 12/11/2022]
Abstract
OBJECTIVE To explore the role of tagging single nucleotide polymorphisms (tagSNPs) in the adiponectin gene in the natural course of nonalcoholic fatty liver disease (NAFLD). METHODS The participants were chosen from our previous survey containing 3543 individuals. Finally, a total of 696 participants who had been followed up for a median of 4 years were included. Each participant was administered with an interview, physical examination, blood tests and ultrasonic examination at both baseline and end-point. Polymerase chain reaction-restriction fragment length polymorphism was applied to determine seven tagSNPs in the adiponectin gene, namely, rs182052, rs16861205, rs822396, rs7627128, rs1501299, rs2241767 and rs3774261. Ordinal logistic regression was used to screen risk factors of NAFLD progression as well as the susceptibility to the disease. Haplotypes analyses were performed to confirm the results. RESULTS After adjusting for age and gender, rs1501299 (G276T), rs2241767 (A45G) and rs3774261 (A712G) were found to be risk factors of both susceptibility (OR 5.040, 7.471 and 3.546, respectively) and progression (OR 3.83, 3.51 and 3.30, respectively) to NAFLD. Nevertheless, rs182052, rs16861205, rs822396 and rs7627128 had no impact on them. These findings were confirmed by haplotype analysis. CONCLUSION The tagSNPs rs2241767, rs1501299 and rs3774261 in the adiponectin gene are risk factors for the individuals' susceptibility to and progression of NAFLD.
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Affiliation(s)
- Yong Jian Zhou
- Department of Gastroenterology and Hepatology, Guangzhou Digestive Diseases Center, Guangzhou First People's Hospital, Guangzhou Medical University, Guangdong, China
| | - Zong Sheng Zhang
- Department of Gastroenterology and Hepatology, Guangzhou Digestive Diseases Center, Guangzhou First People's Hospital, Guangzhou Medical University, Guangdong, China
| | - Yu Qiang Nie
- Department of Gastroenterology and Hepatology, Guangzhou Digestive Diseases Center, Guangzhou First People's Hospital, Guangzhou Medical University, Guangdong, China
| | - Jie Cao
- Department of Gastroenterology and Hepatology, Guangzhou Digestive Diseases Center, Guangzhou First People's Hospital, Guangzhou Medical University, Guangdong, China
| | - Chuang Yu Cao
- Department of Gastroenterology and Hepatology, Guangzhou Digestive Diseases Center, Guangzhou First People's Hospital, Guangzhou Medical University, Guangdong, China
| | - Yu Yuan Li
- Department of Gastroenterology and Hepatology, Guangzhou Digestive Diseases Center, Guangzhou First People's Hospital, Guangzhou Medical University, Guangdong, China
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Association of adiponectin gene polymorphism with nonalcoholic fatty liver disease in Taiwanese patients with type 2 diabetes. PLoS One 2015; 10:e0127521. [PMID: 26042596 PMCID: PMC4456357 DOI: 10.1371/journal.pone.0127521] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 04/15/2015] [Indexed: 12/25/2022] Open
Abstract
Objective Patients with type 2 diabetes and nonalcoholic fatty liver disease (NAFLD) have a higher prevalence of cardiovascular diseases. In this study we investigated the frequency of single nucleotide polymorphisms (SNPs) of several candidate genes associated with NAFLD in Taiwanese patients with type 2 diabetes mellitus (DM) and NAFLD and in those with DM but without fatty liver disease. Methods We enrolled 350 patients with type 2 DM and NAFLD and 209 patients with DM but without NAFLD. Body mass index (BMI), % body fat (% BF), glycated hemoglobin (HbA1c), high molecular weight (HMW) isoform of adiponectin, aspartate aminotransferase (AST), alanine aminotransferase (ALT), total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein (HDL), and triglyceride (TG) levels were measured. Thirteen SNPs in 5 genes (adiponectin, leptin, peroxisome proliferator-activated receptor alpha, adiponutrin/patatin-like phospholipase domain-containing protein 3 and peroxisome proliferator-activated receptor γ co-activator 1α ) were measured. Results Only adiponectin rs266729 polymorphism was associated with susceptibility to NAFLD (p = 0.001). Subgroup analysis revealed that the proportion of subjects with homozygous genotype GG was higher in patients with NAFLD (31%) than in controls (11%) and that the proportions of heterozygous CG and homozygous CC were higher in controls (37% and 52%, respectively) than in patients with NAFLD (33% and 36%, respectively). Patients with NAFLD carrying the GG genotype of rs266729 showed significantly lower serum HMW adiponectin levels than patients carrying the GC or CC genotype (3.75±0.37 vs. 3.99±0.66 vs. 4.79±0.58 μg/ml, p< 0.001). Body fat and serum HMW adiponectin levels were the strongest predictors of developing NAFLD (p < 0.001 and 0.004, respectively). Conclusions In patients with type 2 diabetes gene polymorphism of adiponectin rs266729 is associated with risk of NAFLD. G allele of rs266729 is associated with hypoadiponectinemia. Low serum adiponectin level may precipitate liver steatosis in patients with type 2 diabetes.
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Wang BF, Wang Y, Ao R, Tong J, Wang BY. AdipoQ T45 G and G276 T Polymorphisms and Susceptibility to Nonalcoholic Fatty Liver Disease Among Asian Populations: A Meta-Analysis and Meta-Regression. J Clin Lab Anal 2014; 30:47-57. [PMID: 25385252 DOI: 10.1002/jcla.21814] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Revised: 08/08/2014] [Accepted: 08/25/2014] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Adiponectin (AdipoQ) is an adipose-derived plasma protein that plays an important role in hepatic lipoprotein-lipid metabolism. Emerging evidence have shown that two common polymorphisms (T45 G and G276 T) in the AdipoQ gene may contribute to increasing susceptibility to nonalcoholic fatty liver disease (NAFLD); however individually published studies show inconclusive results. This meta-analysis aimed to derive a more precise estimation of the association of AdipoQ T45 G (rs2241766 T>G) and G276 T (rs1501299 G>T) polymorphisms with NAFLD risk. METHOD Potential relevant studies were identified covering the following databases: PubMed, Embase, Web of Science, the Cochrane Library, Chinese National Knowledge Infrastructure (CNKI), Chinese Bio-medicine Database (CBM), and Chinese Sci-tech Journals databases. Statistical analyses were calculated using the version 12.0 STATA software (Stata Corp, College Station, TX, USA). Odds ratios (ORs) and its corresponding 95% confidence interval (CI) were calculated. RESULT Ten case-control studies were included with a total of 2,672 subjects, of these 1,117 being NAFLD patients and 1,555 being healthy controls. Our meta-analysis results revealed that the T variant of AdipoQ rs2241766 T>G polymorphism may be associated with an increased risk of NAFLD. There was also a significant association between the G variant of AdipoQ rs1501299 G>T polymorphism and an increased risk of NAFLD. Country-stratified analysis indicated that a higher AdipoQ rs2241766 T>G polymorphism was closely related with an increased risk of NAFLD in Chinese and Indian populations (all Ps < 0.05); a similar result was observed in Chinese populations between AdipoQ rs2241766 T>G polymorphism and an increased risk of NAFLD (P < 0.05). CONCLUSION In conclusion, the current meta-analysis indicates that AdipoQ rs2241766 T>G and rs1501299 G>T polymorphisms may contribute to an increasing susceptibility to NAFLD. Moreover, this meta-analysis also suggests for future larger studies with stratified case-control population, and greater focus on the gene-environment interactions regarding NAFLD susceptibility for valid studies.
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Affiliation(s)
- Bai-Fang Wang
- Department of Elderly Gastroenterology, First Affiliated Hospital of China Medical University, Shenyang, P. R. China
| | - Ying Wang
- Department of Elderly Gastroenterology, First Affiliated Hospital of China Medical University, Shenyang, P. R. China
| | - Ran Ao
- Department of Elderly Gastroenterology, First Affiliated Hospital of China Medical University, Shenyang, P. R. China
| | - Jing Tong
- Department of Elderly Gastroenterology, First Affiliated Hospital of China Medical University, Shenyang, P. R. China
| | - Bing-Yuan Wang
- Department of Elderly Gastroenterology, First Affiliated Hospital of China Medical University, Shenyang, P. R. China
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Banerjee M, Saxena M. Genetic polymorphisms of cytokine genes in type 2 diabetes mellitus. World J Diabetes 2014; 5:493-504. [PMID: 25126395 PMCID: PMC4127584 DOI: 10.4239/wjd.v5.i4.493] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Revised: 04/11/2014] [Accepted: 06/16/2014] [Indexed: 02/05/2023] Open
Abstract
Diabetes mellitus is a combined metabolic disorder which includes hyperglycemia, dyslipidemia, stroke and several other complications. Various groups all over the world are relentlessly working out the possible role of a vast number of genes associated with type 2 diabetes (T2DM). Inflammation is an important outcome of any kind of imbalance in the body and is therefore an indicator of several diseases, including T2DM. Various ethnic populations around the world show different levels of variations in single nucleotide polymorphisms (SNPs). The present review was undertaken to explore the association of cytokine gene polymorphisms with T2DM in populations of different ethnicities. This will lead to the understanding of the role of cytokine genes in T2DM risk and development. Association studies of genotypes of SNPs present in cytokine genes will help to identify risk haplotype(s) for disease susceptibility by developing prognostic markers and alter treatment strategies for T2DM and related complications. This will enable individuals at risk to take prior precautionary measures and avoid or delay the onset of the disease. Future challenges will be to understand the genotypic interactions between SNPs in one cytokine gene or several genes at different loci and study their association with T2DM.
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Wang J, Guo XF, Yu SJ, Song J, Zhang JX, Cao Z, Wang J, Ji MY, Dong WG. Adiponectin polymorphisms and non-alcoholic fatty liver disease risk: a meta-analysis. J Gastroenterol Hepatol 2014; 29:1396-405. [PMID: 24548122 DOI: 10.1111/jgh.12562] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/30/2014] [Indexed: 02/06/2023]
Abstract
BACKGROUND AND AIM The adiponectin polymorphism has been implicated in susceptibility to non-alcoholic fatty liver disease (NAFLD), but the results remain inconclusive. The aim of this meta-analysis is to investigate the association between adiponectin polymorphisms and NAFLD risk. METHODS All eligible case-control studies published up to September 2013 were identified by searching PubMed, Web of Science, and CNKI. Effect sizes of odds ratio (OR) and 95% confidence interval (95% CI) were calculated by using a fixed- or random-effect model. RESULTS A total of 10 case-control studies were included; of those, there were nine studies (1223 cases and 1580 controls) for +45T>G polymorphism, seven studies (876 cases and 989 controls) for +276G>T polymorphism, and three studies (299 cases and 383 controls) for -11337C>G polymorphism. Overall, a significantly increased risk was found for +45T>G and -11377C>G polymorphism (+45T>G: OR = 1.45, 95% CI: 1.06-2.00 for recessive model, OR = 1.48, 95% CI: 1.07-2.06 for GG vs TT; -11377C>G: OR = 1.52, 95% CI: 1.10-2.09 for dominant model, OR = 3.88, 95% CI: 1.29-11.68 for GG vs CC), while for +276G>T polymorphism, we found a significantly decreased risk between them (OR = 0.65, 95% CI: 0.45-0.94 for recessive model, OR = 0.58, 95% CI: 0.40-0.84 for TT vs GG). In subgroup analysis by ethnicity, significant association was detected among Asians for +276G>T polymorphism, but not for +45T>G polymorphism. Besides, none of the three adiponectin polymorphisms was associated with the serum adiponectin levels. CONCLUSION This meta-analysis suggests that adiponectin +45T>G and -11377C>G polymorphisms might be a risk factor for NAFLD, while +276G>T polymorphism may be a protective factor for NAFLD among Asians.
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Affiliation(s)
- Jun Wang
- Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan, Hubei Province, China
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Song A, Wang C, Ren L, Zhao J. Swimming improves high-fat induced insulin resistance by regulating lipid and energy metabolism and the insulin pathway in rats. Int J Mol Med 2014; 33:1671-9. [PMID: 24715199 DOI: 10.3892/ijmm.2014.1738] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2014] [Accepted: 04/02/2014] [Indexed: 11/06/2022] Open
Abstract
In this study, we aimed to determine the preventive and therapeutic effects of swimming on insulin resistance in high-fat-fed rats. Sprague-Dawley rats were divided into 4 groups and fed for 8 weeks as follows: i) the control (Con) group fed a control diet; ii) the high-fat (HF) group fed a high-fat diet; iii) the treatment (ST) group fed a high-fat diet and trained with swimming from the 4th week; and iv) the prevention (SP) group fed a high-fat diet and trained with swimming from the 1st week of the experiment. A hyperinsulinemic-euglycemic clamp was used to evaluate the insulin sensitivity of the rats. The ultrastructure of the liver cells was observed by electron microscopy. Hepatic lipid accumulation was observed by Oil Red O staining. Quantitative RT-PCR and western blot analysis were performed to detect the expression of proteins related to lipid metabolism, energy metabolism and insulin signaling transduction. After 8 weeks of feeding, compared with the Con group, the glucose infusion rate (GIR) was significantly decreased; a significant lipid accumulation was observed in the liver, while the ultrastructure of the liver cells was damaged in the HF group. Proteins related to lipid metabolism in the liver and skeletal muscle, including FAT and FABP were upregulated, while CPT1 and PPAR levels were downregulated in the HF group. The levels of the energy-metabolism-related molecules, AMPKα2, PGC1α, PGC1β and MFN2 were downregulated in skeletal muscle in the HF group. The expression levels of insulin signaling transduction molecules, INSR, IRS1, PI3K/p85, AKT2 and GLUT4, as well as the phosphorylation levels of INSR, IRS1, PI3K/p85 and AKT2 were lower in skeletal muscles in the HF rats. Compared with HF group, the GIR levels were significantly increased in the ST and SP groups. Lipid accumulation and damage to the ultrastructure of the liver cells were improved in both groups. The expression of molecules related to lipid metabolism in the liver and skeletal muscle, energy metabolism in skeletal muscle and insulin signaling transduction were all markedly upregulated. In conclusion, swimming can effectively improve insulin sensitivity and even prevent insulin resistance by affecting the expression of proteins related to lipid metabolism, energy metabolism and insulin signaling transduction in rats fed a high-fat diet.
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Affiliation(s)
- An Song
- Department of Endocrinology, Shandong Provincial Hospital, Shandong University, Jinan, Shandong 250021, P.R. China
| | - Chao Wang
- Department of Endocrinology, General Hospital of Hebei, Shijiazhuang, Hebei 050051, P.R. China
| | - Luping Ren
- Department of Endocrinology, General Hospital of Hebei, Shijiazhuang, Hebei 050051, P.R. China
| | - Jiajun Zhao
- Department of Endocrinology, Shandong Provincial Hospital, Shandong University, Jinan, Shandong 250021, P.R. China
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Dongiovanni P, Anstee QM, Valenti L. Genetic predisposition in NAFLD and NASH: impact on severity of liver disease and response to treatment. Curr Pharm Des 2014; 19:5219-38. [PMID: 23394097 PMCID: PMC3850262 DOI: 10.2174/13816128113199990381] [Citation(s) in RCA: 150] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Accepted: 02/01/2013] [Indexed: 02/07/2023]
Abstract
Liver fat deposition related to systemic insulin resistance defines non-alcoholic fatty liver disease (NAFLD) which, when associated with oxidative hepatocellular damage, inflammation, and activation of fibrogenesis, i.e. non-alcoholic steatohepatitis (NASH), can progress towards cirrhosis and hepatocellular carcinoma. Due to the epidemic of obesity, NAFLD is now the most frequent liver disease and the leading cause of altered liver enzymes in Western countries. Epidemiological, familial, and twin studies provide evidence for an element of heritability of NAFLD. Genetic modifiers of disease severity and progression have been identified through genome-wide association studies. These include the Patatin-like phosholipase domain-containing 3 (PNPLA3) gene variant I148M as a major determinant of inter-individual and ethnicity-related differences in hepatic fat content independent of insulin resistance and serum lipid concentration. Association studies confirm that the I148M polymorphism is also a strong modifier of NASH and progressive hepatic injury. Furthermore, a few large multicentre case-control studies have demonstrated a role for genetic variants implicated in insulin signalling, oxidative stress, and fibrogenesis in the progression of NAFLD towards fibrosing NASH, and confirm that hepatocellular fat accumulation and insulin resistance are key operative mechanisms closely involved in the progression of liver damage. It is now important to explore the molecular mechanisms underlying these associations between gene variants and progressive liver disease, and to evaluate their impact on the response to available therapies. It is hoped that this knowledge will offer further insights into pathogenesis, suggest novel therapeutic targets, and could help guide physicians towards individualised therapy that improves clinical outcome.
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Affiliation(s)
- Paola Dongiovanni
- Department of Pathophysiology and Transplantation, section Internal Medicine, Università degli Studi Milano, UO Medicina Interna1B, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy
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Mehta R, Birerdinc A, Younossi ZM. Host genetic variants in obesity-related nonalcoholic fatty liver disease. Clin Liver Dis 2014; 18:249-67. [PMID: 24274878 DOI: 10.1016/j.cld.2013.09.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is a complex disease. The considerable variability in the natural history of the disease suggests an important role for genetic variants in the disease development and progression. There is evidence based on genome-wide association studies and/or candidate gene studies that genetic polymorphisms underlying insulin signaling, lipid metabolism, oxidative stress, fibrogenesis, and inflammation can predispose individuals to NAFLD. This review highlights some of the genetic variants in NAFLD.
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Affiliation(s)
- Rohini Mehta
- Betty and Guy Beatty Center for Integrated Research, Center for Liver Disease, Inova Health System, Claude Moore Building, 3300 Gallows Road, Falls Church, VA 22042, USA
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Fan JG. Epidemiology of alcoholic and nonalcoholic fatty liver disease in China. J Gastroenterol Hepatol 2013; 28 Suppl 1:11-7. [PMID: 23855290 DOI: 10.1111/jgh.12036] [Citation(s) in RCA: 202] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/20/2013] [Indexed: 12/12/2022]
Abstract
The prevalence of patients presenting with fatty liver disease (FLD) in China has approximately doubled over the past two decades. At present, FLD, which is typically diagnosed by imaging, is highly prevalent (≈ 27% urban population) in China and is mainly related to obesity and metabolic syndrome (MetS). However, the percentage of alcoholic liver disease (ALD) among patients with chronic liver diseases in clinic is increasing as well, and a synergetic effect exists between heavy alcohol drinking and obesity in ALD. Prevalence figures reveal regional variations, with a median prevalence of ALD and nonalcoholic FLD (NAFLD) of 4.5% and 15.0%, respectively. The prevalence of NAFLD in children is 2.1%, although the prevalence increases to 68.2% among obese children. With the increasing pandemic of obesity and MetS in the general population, China is likely to harbor an increasing reservoir of patients with FLD. The risk factors for FLD resemble to those of Caucasian counterparts, but the ethnic-specific definitions of obesity and MetS are more useful in assessment of Chinese people. Therefore, FLD/NAFLD has become a most common chronic liver disease in China. Public health interventions are needed to halt the worldwide trend of obesity and alcohol abuse to ameliorate liver injury and to improve metabolic health.
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Affiliation(s)
- Jian-Gao Fan
- Department of Gastroenterology, Shanghai Key Laboratory of Children's Digestion and Nutrition, Xin-Hua Hospital Affiliated to Shanghai Jiao-Tong University School of Medicine, Shanghai, China.
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Saxena M, Srivastava N, Banerjee M. Genetic association of adiponectin gene polymorphisms (+45T/G and +10211T/G) with type 2 diabetes in North Indians. Diabetes Metab Syndr 2012; 6:65-69. [PMID: 23153972 DOI: 10.1016/j.dsx.2012.08.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Adiponectin (ADIPOQ) is an abundant protein hormone which belongs to a family of so-called adipokines. It is expressed mostly by adipocytes and is an important regulator of lipid and glucose metabolism. It was shown that decreased serum adiponectin concentration indicated insulin resistance and type 2 diabetes (T2DM) with the risk of cardiovascular complications. The fact that adiponectin is an insulin-sensitizing hormone with anti-diabetic, anti-inflammatory and anti-atherogenic properties, we proposed to study the association of ADIPOQ gene polymorphisms in subjects with T2DM. DNA was isolated from venous blood samples, quantified and subjected to Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) using suitable primers and restriction endonucleases. Adiponectin levels were measured in serum using ELISA. The genotypic, allelic and carriage rate frequencies distribution in patients and controls were analyzed by PSAW software (ver. 17.0). Odd ratios (OR) with 95% confidence interval (CI) were determined to describe the strength of association by logistic regression model. Out of the two polymorphisms studied, +10211T/G showed significant association (P=0.042), the 'G' allele association being highly significant (P=0.022). Further analysis showed that individuals with 'GG' haplotype were at increased risk of T2DM up to 15.5 times [P=0.015, OR (95% CI); 15.558 (1.690-143.174)]. The present study showed that the 'G' allele of ADIPOQ gene (+10211T/G) plays a prominent role with respect to T2DM susceptibility in North-Indian population.
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Affiliation(s)
- Madhukar Saxena
- Molecular & Human Genetics Laboratory, Department of Zoology, University of Lucknow, Lucknow, India.
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Hernaez R. Genetic factors associated with the presence and progression of nonalcoholic fatty liver disease: a narrative review. GASTROENTEROLOGIA Y HEPATOLOGIA 2011; 35:32-41. [PMID: 22093607 DOI: 10.1016/j.gastrohep.2011.08.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2011] [Accepted: 08/04/2011] [Indexed: 12/25/2022]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in the world. Whereas insulin resistance and obesity are considered major risk factors for the development and progression of NAFLD, the genetic underpinnings are unclear. Before 2008, candidate gene studies based on prior knowledge of pathophysiology of fatty liver yielded conflicting results. In 2008, Romeo et al. published the first genome wide association study and reported the strongest genetic signal for the presence of fatty liver (PNPLA3, patatin-like phospholipase domain containing 3; rs738409). Since then, two additional genome wide scans were published and identified 9 additional genetic variants. Whereas these results shed light into the understanding of the genetics of NAFLD, most of associations have not been replicated in independent samples and, therefore, remain undetermined the significance of these findings. This review aims to summarize the understanding of genetic epidemiology of NAFLD and highlights the gaps in knowledge.
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Affiliation(s)
- Ruben Hernaez
- Department of Medicine, The Johns Hopkins School of Medicine, Baltimore, MD 21287, USA.
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Abstract
Several candidate gene studies on the metabolic syndrome (MetS) have been conducted. However, for most single nucleotide polymorphisms (SNPs) no systematic review on their association with MetS exists. A systematic electronic literature search was conducted until the 2nd of June 2010, using HuGE Navigator. English language articles were selected. Only genes of which at least one SNP-MetS association was studied in an accumulative total population ≥ 4000 subjects were included. Meta-analyses were conducted on SNPs with three or more studies available in a generally healthy population. In total 88 studies on 25 genes were reviewed. Additionally, for nine SNPs in seven genes (GNB3, PPARG, TCF7L2, APOA5, APOC3, APOE, CETP) a meta-analysis was conducted. The minor allele of rs9939609 (FTO), rs7903146 (TCF7L2), C56G (APOA5), T1131C (APOA5), C482T (APOC3), C455T (APOC3) and 174G>C (IL6) were more prevalent in subjects with MetS, whereas the minor allele of Taq-1B (CETP) was less prevalent in subjects with the MetS. After having systematically reviewed the most studied SNP-MetS associations, we found evidence for an association with the MetS for eight SNPs, mostly located in genes involved in lipid metabolism.
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Affiliation(s)
- C M Povel
- National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands.
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Di Rosa M, Malaguarnera L. Genetic variants in candidate genes influencing NAFLD progression. J Mol Med (Berl) 2011; 90:105-18. [PMID: 21894552 DOI: 10.1007/s00109-011-0803-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2011] [Revised: 08/08/2011] [Accepted: 08/08/2011] [Indexed: 12/17/2022]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is a metabolic disorder including simple steatosis and nonalcoholic steatohepatitis (NASH). Advanced stages of NASH result ultimately in fibrosis, cirrhosis, and hepatocarcinoma. A diagnosis of NASH entails an increased risk of both liver-related and cardiovascular mortality as worsening of the metabolic syndrome. Because of its escalation, many investigations have been performed to elucidate the pathophysiologic origins of the disease progression. Human epidemiologic studies describing polymorphisms in a number of genes involved in metabolic dysfunctions have contributed to clarify the causes leading to the disease evolution. In this review, we attempt to outline critically the most recently identified genetic variants in NAFLD patients to identify possible risk factors promoting the progression of the disease. The evaluation of altered genotypes together with other clinical variables may facilitate the clinical management of these patients.
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Affiliation(s)
- Michelino Di Rosa
- Department of Biomedical Sciences, University of Catania, Via Androne, 83, 95124 Catania, Italy
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Namvaran F, Rahimi-Moghaddam P, Azarpira N, Nikeghbalian S. The association between adiponectin (+45T/G) and adiponectin receptor-2 (+795G/A) single nucleotide polymorphisms with cirrhosis in Iranian population. Mol Biol Rep 2011; 39:3219-23. [PMID: 21706165 DOI: 10.1007/s11033-011-1089-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2011] [Accepted: 06/11/2011] [Indexed: 01/07/2023]
Abstract
Adiponectin which possesses anti-inflammatory and insulin-sensitizing properties is elevated in blood circulation of liver cirrhosis patients. The genetic variations in the adiponectin gene can affect the circulating adiponectin level and stimulation of adiponectin receptor that may affect the activity of adiponectin. We investigated the effect of adiponectin single nucleotide polymorphisms (SNP) 45 T/G and adiponectin receptor-2 gene SNP 795G/A in cirrhotic Iranian population. A total of 97 cirrhotic patients and 128 healthy controls from Iranian population were genotyped for the adiponectin and adiponectin receptor 2 gene (+45T>G and 795G/A) by polymerase chain reaction-restriction fragment length polymorphism. G frequency was 21.1% versus 12.89% (P = 0.001) for SNP45, and G frequency was 75.8% versus 76.2% (P = 0.526) for SNP795G/A in the patients and control group, respectively. Based on our findings, the expression of the G allele at SNP45 is higher in the patient group compared with healthy subjects, suggesting that it may affect liver injury through changes in the plasma adiponectin level.
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Affiliation(s)
- Fatemeh Namvaran
- Department of Pharmacology, College of Medicine, Iran University of Medical Sciences, Tehran, Iran
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Buechler C, Wanninger J, Neumeier M. Adiponectin, a key adipokine in obesity related liver diseases. World J Gastroenterol 2011; 17:2801-11. [PMID: 21734787 PMCID: PMC3120939 DOI: 10.3748/wjg.v17.i23.2801] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Revised: 11/17/2010] [Accepted: 11/24/2010] [Indexed: 02/06/2023] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) comprising hepatic steatosis, non-alcoholic steatohepatitis (NASH), and progressive liver fibrosis is considered the most common liver disease in western countries. Fatty liver is more prevalent in overweight than normal-weight people and liver fat positively correlates with hepatic insulin resistance. Hepatic steatosis is regarded as a benign stage of NAFLD but may progress to NASH in a subgroup of patients. Besides liver biopsy no diagnostic tools to identify patients with NASH are available, and no effective treatment has been established. Visceral obesity is a main risk factor for NAFLD and inappropriate storage of triglycerides in adipocytes and higher concentrations of free fatty acids may add to increased hepatic lipid storage, insulin resistance, and progressive liver damage. Most of the adipose tissue-derived proteins are elevated in obesity and may contribute to systemic inflammation and liver damage. Adiponectin is highly abundant in human serum but its levels are reduced in obesity and are even lower in patients with hepatic steatosis or NASH. Adiponectin antagonizes excess lipid storage in the liver and protects from inflammation and fibrosis. This review aims to give a short survey on NAFLD and the hepatoprotective effects of adiponectin.
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Abstract
OBJECTIVE Results from the published studies on the association of adiponectin gene (ADIPOQ) polymorphisms with blood lipids and blood pressure are conflicting. We investigated the association of three ADIPOQ polymorphisms, +45 T > G (rs2241766), +276 G > T (rs1501299) and -11377 C > G (rs266729), with these traits in this meta-analysis. RESEARCH DESIGN AND METHODS We included 35 studies in this meta-analysis. Dominant models were used for this meta-analysis. RESULTS We did not detect a significant association of the -11377 C > G polymorphism with blood lipids or blood pressure (P > 0·05). The association of the +45 T > G polymorphism with blood lipids and blood pressure was, similarly, not significant (P > 0·05). The meta-analysis suggested a significant overall association of the +276 G > T polymorphism with lower levels of total cholesterol: weighted mean difference (WMD) = -0·10, 95% confidence interval (CI, -0·17, -0·03), P = 0·005, P(heterogeneity) = 0·04. This association was marginally significant in East Asians and East Asians with type 2 diabetes: WMD = -0·10, 95% CI (-0·20, 0·00), P = 0·05, P(heterogeneity) = 0·002, and WMD = -0·09, 95% CI (-0·18, -0·00), P = 0·05, P(heterogeneity) = 0·80, respectively. After exclusion of a study that was the source of heterogeneity, the association was significant in overall populations and marginally significant in East Asians: WMD= -0·06, 95% CI (-0·11, -0·01), P = 0·01, P(heterogeneity) = 0·98, and WMD = -0·06, 95% CI (-0·12, 0·00), P = 0·07, P(heterogeneity) = 0·83, respectively. However, none of these associations were significant after Bonferroni correction (significant threshold: P < 0·003). CONCLUSIONS Our meta-analysis does not suggest any association of the three ADIPOQ polymorphisms with blood lipids and blood pressure.
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Affiliation(s)
- Tongfeng Zhao
- Department of Geriatrics, the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
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Hooper AJ, Adams LA, Burnett JR. Genetic determinants of hepatic steatosis in man. J Lipid Res 2011; 52:593-617. [PMID: 21245030 DOI: 10.1194/jlr.r008896] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Hepatic steatosis is one of the most common liver disorders in the general population. The main cause of hepatic steatosis is nonalcoholic fatty liver disease (NAFLD), representing the hepatic component of the metabolic syndrome, which is characterized by type 2 diabetes, obesity, and dyslipidemia. Insulin resistance and excess adiposity are considered to play key roles in the pathogenesis of NAFLD. Although the risk factors for NAFLD are well established, the genetic basis of hepatic steatosis is largely unknown. Here we review recent progress on genomic variants and their association with hepatic steatosis and discuss the potential impact of these genetic studies on clinical practice. Identifying the genetic determinants of hepatic steatosis will lead to a better understanding of the pathogenesis and progression of NAFLD.
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Affiliation(s)
- Amanda J Hooper
- Department of Core Clinical Pathology and Biochemistry, Royal Perth Hospital, Perth, Australia
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Enns JE, Taylor CG, Zahradka P. Variations in Adipokine Genes AdipoQ, Lep, and LepR are Associated with Risk for Obesity-Related Metabolic Disease: The Modulatory Role of Gene-Nutrient Interactions. J Obes 2011; 2011:168659. [PMID: 21773001 PMCID: PMC3136149 DOI: 10.1155/2011/168659] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2011] [Accepted: 03/10/2011] [Indexed: 02/08/2023] Open
Abstract
Obesity rates are rapidly increasing worldwide and facilitate the development of many related disease states, such as cardiovascular disease, the metabolic syndrome, type 2 diabetes mellitus, and various types of cancer. Variation in metabolically important genes can have a great impact on a population's susceptibility to becoming obese and/or developing related complications. The adipokines adiponectin and leptin, as well as the leptin receptor, are major players in the regulation of body energy homeostasis and fat storage. This paper summarizes the findings of single nucleotide polymorphisms in these three genes and their effect on obesity and metabolic disease risk. Additionally, studies of gene-nutrient interactions involving adiponectin, leptin, and the leptin receptor are highlighted to emphasize the critical role of diet in susceptible populations.
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Affiliation(s)
- Jennifer Emily Enns
- Department of Physiology, University of Manitoba and Canadian Centre for Agri-Food Research in Health and Medicine, St. Boniface Hospital Research Centre, 351 Tache Ave, Winnipeg, Manitoba, Canada R2H 2A6
| | - Carla G. Taylor
- Departments of Human Nutritional Sciences and Physiology, University of Manitoba, 351 Tache Ave, Winnipeg, Manitoba, Canada R2H 2A6
| | - Peter Zahradka
- Departments of Physiology and Human Nutritional Sciences, University of Manitoba and Canadian Centre for Agri-Food Research in Health and Medicine, St. Boniface Hospital Research Centre, 351 Tache Ave, Winnipeg, Manitoba, Canada R2H 2A6
- *Peter Zahradka:
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Tilg H, Moschen A. Update on nonalcoholic fatty liver disease: genes involved in nonalcoholic fatty liver disease and associated inflammation. Curr Opin Clin Nutr Metab Care 2010; 13:391-6. [PMID: 20473151 DOI: 10.1097/mco.0b013e32833a87cc] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
PURPOSE OF REVIEW Nonalcoholic fatty liver disease (NAFLD) is one of the most prevalent liver diseases worldwide. Advanced age, extensive overweight and a number of features of the metabolic syndrome are associated with NAFLD severity. The cause of NAFLD is considered multifactorial with a substantial genetic component. RECENT FINDINGS Family members of children with NAFLD demonstrate a higher risk for NAFLD. Whereas such an association only suggests that familial factors are major determinants of whether or not an individual will develop NAFLD, recent genome-wide association studies were able to identify first candidate genes. An allele in patatin-like phospholipase 3, encoding a protein of unknown function with homology to lipid acyl hydrolases, is strongly associated with increased hepatic fat and inflammation. Apolipoprotein C3 gene variants are also associated with NAFLD and insulin resistance. Several other genetic variants have been identified, although with less convincing evidence. These genetic variants involve molecules regulating insulin signaling, lipid metabolism, oxidative stress or fibrogenesis. Furthermore, genetic variants of several cytokines and adipocytokines have been associated with NAFLD. SUMMARY Several genetic factors such as patatin-like phospholipase 3 or apolipoprotein C3 have been recently characterized in NAFLD. Further studies to identify their interaction with environmental factors are eagerly warranted.
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Affiliation(s)
- Herbert Tilg
- Christian Doppler Research Laboratory for Gut Inflammation, Innsbruck Medical University, Innsbruck, Austria.
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Polyzos SA, Kountouras J, Zavos C, Tsiaousi E. The role of adiponectin in the pathogenesis and treatment of non-alcoholic fatty liver disease. Diabetes Obes Metab 2010; 12:365-83. [PMID: 20415685 DOI: 10.1111/j.1463-1326.2009.01176.x] [Citation(s) in RCA: 177] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Non-alcoholic fatty liver disease (NAFLD) is recognized as the most common type of chronic liver disease in Western countries and the leading cause of cryptogenic cirrhosis. Insulin resistance (IR) is a key factor in the pathogenesis of NAFLD, the latter being considered as the hepatic component of IR or metabolic syndrome (MetS). Although the pathogenesis of NAFLD is not fully elucidated, a complex interaction between adipokines and cytokines produced by adipocytes and/or inflammatory cells infiltrating adipose tissue appears to play a crucial role in MetS and NAFLD. Adiponectin is the most abundant and adipose-specific adipokine. In the liver, adiponectin acts through the activation of 5-AMP-activated protein kinase and peroxisome proliferator-activated receptor-alpha pathways and inhibition of toll-like receptor-4 mediated signalling. There is an evidence that adiponectin decreases hepatic and systematic IR and attenuates liver inflammation and fibrosis. Adiponectin generally predicts steatosis grade and severity of NAFLD, but it remains to be addressed to what extent this is a direct effect or related to the presence of more severe IR. Although there is no proven pharmacotherapy for the treatment of NAFLD, recent therapeutic strategies have focused on the indirect upregulation of adiponectin through the administration of various therapeutic agents and/or lifestyle modifications. Weight loss, through diet, lifestyle changes and/or medications including orlistat, sibutramine, rimonabant or bariatric surgery, increase adiponectin and may improve liver histology. Insulin sensitizers, including pioglitazone and rosiglitazone, and lipid-lowering agents, including statins and fibrates, also upregulate adiponectin and ameliorate liver histology. The wider use of new treatment approaches appears to signal the dawn of a new era in the management of NAFLD. In this adiponectin-focused review, the pathogenetic role and the potential therapeutic benefits of adiponectin in NAFLD are systematically analysed.
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Affiliation(s)
- Stergios A Polyzos
- Second Medical Clinic, Medical School, Aristotle University of Thessaloniki, Ippokration Hospital, Thessaloniki, Greece.
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Abstract
Fifty years of the Gastroenterological Society of Australia have witnessed the changing appearance of Australians. Asian immigration has transformed the dominant urban culture from European to Eurasian, with some unique Australian attributes. Meanwhile, global conditions have altered body shape, and our sports-proud country is now fat! Thus, as in North America, Europe, China, and affluent Asia-Pacific countries, prosperity and lifestyle, cheap processed foods coupled with reduced physical activity have created an epidemic of over-nutrition resulting in overweight/obesity. Additional genetic factors are at the core of the apple shape (central obesity) that typifies over-nourished persons with metabolic syndrome. Indigenous Australians, once the leanest and fittest humans, now have exceedingly high rates of obesity and type 2 diabetes, contributing to shorter life expectancy; Asian Australians are also at higher risk. Like non-steroidal anti-inflammatory drugs (NSAIDs) and cigarette smoking, obesity now contributes much to gastrointestinal morbidity and mortality (gastroesophageal reflux disease, cancers, gallstones, endoscopy complications). This review focuses on Australian research about fatty liver, particularly roles of central obesity/insulin resistance in non-alcoholic fatty liver disease/steatohepatitis (NAFLD/NASH). The outputs include many highly cited original articles and reviews and the first book on NAFLD. Studies have identified community prevalence, clinical outcomes, association with insulin resistance, metabolic syndrome and hypoadiponectinemia, developed and explored animal models for mechanisms of inflammation and fibrosis, conceptualized etiopathogenesis, and demonstrated that NASH can be reversed by lowering body weight and increasing physical activity. The findings have led to development of regional guidelines on NAFLD, the first internationally, and should now inform daily practice of gastroenterologists.
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