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Yang Y, Konrad RJ, Ploug M, Young SG. APOA5 Deficiency Causes Hypertriglyceridemia by Reducing Amounts of Lipoprotein Lipase in Capillaries. J Lipid Res 2024:100578. [PMID: 38880127 DOI: 10.1016/j.jlr.2024.100578] [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: 05/29/2024] [Revised: 06/11/2024] [Accepted: 06/12/2024] [Indexed: 06/18/2024] Open
Abstract
Apolipoprotein AV (APOA5) deficiency causes hypertriglyceridemia in mice and humans. For years, the cause remained a mystery, but the mechanisms have now come into focus. Here, we review progress in defining APOA5's function in plasma triglyceride metabolism. Biochemical studies revealed that APOA5 binds to the angiopoietin-like protein 3/8 complex (ANGPTL3/8) and suppresses its ability to inhibit the activity of lipoprotein lipase (LPL). Thus, APOA5 deficiency is accompanied by increased ANGPTL3/8 activity and lower levels of LPL activity. APOA5 deficiency also reduces amounts of LPL in capillaries of oxidative tissues (e.g., heart, brown adipose tissue). Cell culture experiments revealed the likely explanation: ANGPTL3/8 detaches LPL from its binding sites on the surface of cells, and that effect is blocked by APOA5. Both the low intracapillary LPL levels and the high plasma triglyceride levels in Apoa5-/- mice are normalized by recombinant APOA5. Carboxyl-terminal sequences in APOA5 are crucial for its function; a mutant APOA5 lacking 40-carboxyl-terminal residues cannot bind to ANGPTL3/8 and lacks the ability to change intracapillary LPL levels or plasma triglyceride levels in Apoa5-/- mice. Also, an antibody against the last 26 amino acids of APOA5 reduces intracapillary LPL levels and increases plasma triglyceride levels in wild-type mice. An inhibitory ANGPTL3/8-specific antibody functions as an APOA5-mimetic reagent, increasing intracapillary LPL levels and lowering plasma triglyceride levels in both Apoa5-/- and wild-type mice. That antibody is a potentially attractive strategy for treating elevated plasma lipid levels in human patients.
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Affiliation(s)
- Ye Yang
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA, 90095 USA; Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA, 90095 USA
| | - Robert J Konrad
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana 46225 USA
| | - Michael Ploug
- Finsen Laboratory, Copenhagen University Hospital-Rigshospitalet, DK-2200 Copenhagen N, Denmark; Finsen Laboratory, Biotech Research and Innovation Centre, University of Copenhagen, DK-2200 Copenhagen N, Denmark
| | - Stephen G Young
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA, 90095 USA; Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA, 90095 USA.
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Johnson SM, Bao H, McMahon CE, Chen Y, Burr SD, Anderson AM, Madeyski-Bengtson K, Lindén D, Han X, Liu J. PNPLA3 is a triglyceride lipase that mobilizes polyunsaturated fatty acids to facilitate hepatic secretion of large-sized very low-density lipoprotein. Nat Commun 2024; 15:4847. [PMID: 38844467 PMCID: PMC11156938 DOI: 10.1038/s41467-024-49224-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 05/22/2024] [Indexed: 06/09/2024] Open
Abstract
The I148M variant of PNPLA3 is closely associated with hepatic steatosis. Recent evidence indicates that the I148M mutant functions as an inhibitor of PNPLA2/ATGL-mediated lipolysis, leaving the role of wild-type PNPLA3 undefined. Despite showing a triglyceride hydrolase activity in vitro, PNPLA3 has yet to be established as a lipase in vivo. Here, we show that PNPLA3 preferentially hydrolyzes polyunsaturated triglycerides, mobilizing polyunsaturated fatty acids for phospholipid desaturation and enhancing hepatic secretion of triglyceride-rich lipoproteins. Under lipogenic conditions, mice with liver-specific knockout or acute knockdown of PNPLA3 exhibit aggravated liver steatosis and reduced plasma VLDL-triglyceride levels. Similarly, I148M-knockin mice show decreased hepatic triglyceride secretion during lipogenic stimulation. Our results highlight a specific context whereby the wild-type PNPLA3 facilitates the balance between hepatic triglyceride storage and secretion, and suggest the potential contribution of a loss-of-function by the I148M variant to the development of fatty liver disease in humans.
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Affiliation(s)
- Scott M Johnson
- Department of Biochemistry and Molecular Biology; Mayo Clinic College of Medicine & Science, Rochester, MN, 55905, USA
- Mayo Clinic Graduate School of Biomedical Sciences; Mayo Clinic College of Medicine & Science, Rochester, MN, 55905, USA
- Department of Cell Biology; University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Hanmei Bao
- Barshop Institute for Longevity and Aging Studies and Department of Medicine, Division of Diabetes; University of Texas Health San Antonio, San Antonio, TX, 78229, USA
| | - Cailin E McMahon
- Molecular Biology and Genetics Department; Cornell College of Agriculture and Life Sciences, Ithaca, NY, 14853, USA
| | - Yongbin Chen
- Department of Biochemistry and Molecular Biology; Mayo Clinic College of Medicine & Science, Rochester, MN, 55905, USA
| | - Stephanie D Burr
- Department of Biochemistry and Molecular Biology; Mayo Clinic College of Medicine & Science, Rochester, MN, 55905, USA
| | - Aaron M Anderson
- Department of Developmental Biology; Washington University School of Medicine in St. Louis, St. Louis, MO, 63110, USA
| | - Katja Madeyski-Bengtson
- Translational Genomics, Discovery Sciences; BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Daniel Lindén
- Bioscience Metabolism, Research and Early Development Cardiovascular, Renal and Metabolism (CVRM); BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
- Division of Endocrinology, Department of Neuroscience and Physiology; Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Xianlin Han
- Barshop Institute for Longevity and Aging Studies and Department of Medicine, Division of Diabetes; University of Texas Health San Antonio, San Antonio, TX, 78229, USA
| | - Jun Liu
- Department of Biochemistry and Molecular Biology; Mayo Clinic College of Medicine & Science, Rochester, MN, 55905, USA.
- Division of Endocrinology, Diabetes, Metabolism and Nutrition; Mayo Clinic in Rochester, Rochester, MN, 55905, USA.
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Abulaiti D, Abudureyimu S, Li H, Cao Y, Gao Y. Nomogram developed with APOA5 genetic variant rs662799 and clinical characteristics predicting risk of essential hypertension in a Chinese population. Cardiovasc Diagn Ther 2024; 14:118-128. [PMID: 38434565 PMCID: PMC10904303 DOI: 10.21037/cdt-23-289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Accepted: 12/01/2023] [Indexed: 03/05/2024]
Abstract
Background The apolipoprotein A5 (APOA5) gene has been identified as a key regulatory factor in triglyceride (TG) metabolism and plasma lipid levels. Genetic polymorphisms of APOA5 have been linked to an elevated risk of atherosclerosis, metabolic syndrome, stroke, and coronary artery disease. The rs662799 variant is a single nucleotide polymorphism (SNP) that occurs at a specific position within the APOA5 gene. However, the association between rs662799 polymorphism and essential hypertension (EHT) remains unclear. The study aimed to comprehensively examine the potential correlation between the rs662799 polymorphism and the susceptibility to EHT in a Chinese population using a systematic analysis. Methods In a case study conducted at the First Affiliated Hospital of Xinjiang Medical University between Jan 2019 and Dec 2021, we examined a total of 700 cases of EHT along with 700 corresponding controls. The serum concentrations of various lipid parameters were measured by enzymatic method, while the genotyping of the SNP was performed using the improved multiplex ligation detection reaction (iMLDR) method. The independent risk factors of EHT were identified from multivariable logistic regression analysis. The nomogram prediction model that incorporated the APOA5 genetic variations and clinical variables was constructed. In addition, receiver operating characteristic (ROC) curve and Hosmer-Lemeshow test were conducted to determine the performance of the nomogram model. The optimal threshold was calculated based on Youden index. Results Our study revealed a higher prevalence of the G allele of the rs662799 variant in individuals diagnosed with EHT compared to the control group. Logistic regression analysis indicated that with the adjustment of other confounders, the observed difference between the two groups remained statistically significant [odds ratio (OR) =1.519; 95% confidence interval (CI): 1.203-1.917; P<0.001]. Based on 8 independent risk factors including APOA5 rs662799 G allele, age, body mass index (BMI), smoking, diabetes, education, low-density lipoprotein cholesterol (LDL-C), and TG, we constructed a novel risk evaluation nomogram of EHT. The area under the ROC curve of the nomogram was 0.722 (95% CI: 0.693-0.752; P<0.001) and 0.747 (95% CI: 0.690-0.804; P<0.001) for the training and validation set, respectively. Furthermore, the Hosmer-Lemeshow test indicated excellent calibration performance, yielding P values of 0.969 for the training set and 0.761 for the validation set. Conclusions In our study, the rs662799 variant of the APOA5 gene was significantly associated with susceptibility to EHT. A nomogram for the early prediction of EHT in in the Chinese population was successfully constructed and validated. The nomogram can provide a visual assessment of the risk of EHT for clinical consultation.
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Affiliation(s)
- Dilihumaer Abulaiti
- Department of Comprehensive Internal Medicine, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, China
| | - Shajidan Abudureyimu
- Department of Comprehensive Internal Medicine, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, China
| | - Hui Li
- Department of Comprehensive Internal Medicine, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, China
| | - Yan Cao
- Department of Hepatobiliary and Pancreatic Surgery, Affiliated Cancer Hospital of Xinjiang Medical University, Urumqi, China
| | - Ying Gao
- Department of Comprehensive Internal Medicine, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, China
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Yang Y, Beigneux AP, Song W, Nguyen LP, Jung H, Tu Y, Weston TA, Tran CM, Xie K, Yu RG, Tran AP, Miyashita K, Nakajima K, Murakami M, Chen YQ, Zhen EY, Kim JR, Kim PH, Birrane G, Tontonoz P, Ploug M, Konrad RJ, Fong LG, Young SG. Hypertriglyceridemia in Apoa5-/- mice results from reduced amounts of lipoprotein lipase in the capillary lumen. J Clin Invest 2023; 133:e172600. [PMID: 37824203 PMCID: PMC10688983 DOI: 10.1172/jci172600] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 10/05/2023] [Indexed: 10/14/2023] Open
Abstract
Why apolipoprotein AV (APOA5) deficiency causes hypertriglyceridemia has remained unclear, but we have suspected that the underlying cause is reduced amounts of lipoprotein lipase (LPL) in capillaries. By routine immunohistochemistry, we observed reduced LPL staining of heart and brown adipose tissue (BAT) capillaries in Apoa5-/- mice. Also, after an intravenous injection of LPL-, CD31-, and GPIHBP1-specific mAbs, the binding of LPL Abs to heart and BAT capillaries (relative to CD31 or GPIHBP1 Abs) was reduced in Apoa5-/- mice. LPL levels in the postheparin plasma were also lower in Apoa5-/- mice. We suspected that a recent biochemical observation - that APOA5 binds to the ANGPTL3/8 complex and suppresses its capacity to inhibit LPL catalytic activity - could be related to the low intracapillary LPL levels in Apoa5-/- mice. We showed that an ANGPTL3/8-specific mAb (IBA490) and APOA5 normalized plasma triglyceride (TG) levels and intracapillary LPL levels in Apoa5-/- mice. We also showed that ANGPTL3/8 detached LPL from heparan sulfate proteoglycans and GPIHBP1 on the surface of cells and that the LPL detachment was blocked by IBA490 and APOA5. Our studies explain the hypertriglyceridemia in Apoa5-/- mice and further illuminate the molecular mechanisms that regulate plasma TG metabolism.
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Affiliation(s)
- Ye Yang
- Department of Medicine and
- Human Genetics, David Geffen School of Medicine, UCLA, Los Angeles, California, USA
| | | | | | | | | | | | | | | | | | | | | | - Kazuya Miyashita
- Department of Clinical Laboratory Medicine, Gunma University, Graduate School of Medicine, Maebashi, Gunma, Japan
| | - Katsuyuki Nakajima
- Department of Clinical Laboratory Medicine, Gunma University, Graduate School of Medicine, Maebashi, Gunma, Japan
| | - Masami Murakami
- Department of Clinical Laboratory Medicine, Gunma University, Graduate School of Medicine, Maebashi, Gunma, Japan
| | - Yan Q. Chen
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana, USA
| | - Eugene Y. Zhen
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana, USA
| | | | | | - Gabriel Birrane
- Division of Experimental Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - Peter Tontonoz
- Department of Pathology and Laboratory Medicine, UCLA, Los Angeles, California, USA
| | - Michael Ploug
- Finsen Laboratory, Copenhagen University Hospital–Rigshospitalet, Copenhagen, Denmark
- Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark
| | - Robert J. Konrad
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana, USA
| | | | - Stephen G. Young
- Department of Medicine and
- Human Genetics, David Geffen School of Medicine, UCLA, Los Angeles, California, USA
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Guo J, Wang H, Li Y, Zhu S, Hu H, Gu Z. Nanotechnology in coronary heart disease. Acta Biomater 2023; 171:37-67. [PMID: 37714246 DOI: 10.1016/j.actbio.2023.09.011] [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: 05/22/2023] [Revised: 08/17/2023] [Accepted: 09/08/2023] [Indexed: 09/17/2023]
Abstract
Coronary heart disease (CHD) is one of the major causes of death and disability worldwide, especially in low- and middle-income countries and among older populations. Conventional diagnostic and therapeutic approaches have limitations such as low sensitivity, high cost and side effects. Nanotechnology offers promising alternative strategies for the diagnosis and treatment of CHD by exploiting the unique properties of nanomaterials. In this review, we use bibliometric analysis to identify research hotspots in the application of nanotechnology in CHD and provide a comprehensive overview of the current state of the art. Nanomaterials with enhanced imaging and biosensing capabilities can improve the early detection of CHD through advanced contrast agents and high-resolution imaging techniques. Moreover, nanomaterials can facilitate targeted drug delivery, tissue engineering and modulation of inflammation and oxidative stress, thus addressing multiple aspects of CHD pathophysiology. We discuss the application of nanotechnology in CHD diagnosis (imaging and sensors) and treatment (regulation of macrophages, cardiac repair, anti-oxidative stress), and provide insights into future research directions and clinical translation. This review serves as a valuable resource for researchers and clinicians seeking to harness the potential of nanotechnology in the management of CHD. STATEMENT OF SIGNIFICANCE: Coronary heart disease (CHD) is the one of leading cause of death and disability worldwide. Nanotechnology offers new strategies for diagnosing and treating CHD by exploiting the unique properties of nanomaterials. This review uses bibliometric analysis to uncover research trends in the use of nanotechnology for CHD. We discuss the potential of nanomaterials for early CHD detection through advanced imaging and biosensing, targeted drug delivery, tissue engineering, and modulation of inflammation and oxidative stress. We also offer insights into future research directions and potential clinical applications. This work aims to guide researchers and clinicians in leveraging nanotechnology to improve CHD patient outcomes and quality of life.
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Affiliation(s)
- Junsong Guo
- Academician Workstation, Affiliated Hospital of North Sichuan Medical College, Nanchong, Sichuan 637000, China; Department of Cardiology, Affiliated Hospital of North Sichuan Medical College, Nanchong, Sichuan 637000, China
| | - Hao Wang
- Academician Workstation, Affiliated Hospital of North Sichuan Medical College, Nanchong, Sichuan 637000, China; Department of Cardiology, Affiliated Hospital of North Sichuan Medical College, Nanchong, Sichuan 637000, China
| | - Ying Li
- Academician Workstation, Affiliated Hospital of North Sichuan Medical College, Nanchong, Sichuan 637000, China; Department of Cardiology, Affiliated Hospital of North Sichuan Medical College, Nanchong, Sichuan 637000, China
| | - Shuang Zhu
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nano-safety, Institute of High Energy Physics, Beijing 100049, China; CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology of China, Chinese Academy of Sciences, Beijing 100190, China; Center of Materials Science and Optoelectronics Engineering, College of Materials Science and Optoelectronic Technology, University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Houxiang Hu
- Academician Workstation, Affiliated Hospital of North Sichuan Medical College, Nanchong, Sichuan 637000, China; Department of Cardiology, Affiliated Hospital of North Sichuan Medical College, Nanchong, Sichuan 637000, China.
| | - Zhanjun Gu
- Academician Workstation, Affiliated Hospital of North Sichuan Medical College, Nanchong, Sichuan 637000, China; CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nano-safety, Institute of High Energy Physics, Beijing 100049, China; Center of Materials Science and Optoelectronics Engineering, College of Materials Science and Optoelectronic Technology, University of Chinese Academy of Sciences, Beijing 100049, China.
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Johnson S, Bao H, McMahon C, Chen Y, Burr S, Anderson A, Madeyski-Bengtson K, Lindén D, Han X, Liu J. Substrate-Specific Function of PNPLA3 Facilitates Hepatic VLDL-Triglyceride Secretion During Stimulated Lipogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.30.553213. [PMID: 37693552 PMCID: PMC10491159 DOI: 10.1101/2023.08.30.553213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
The I148M variant of PNPLA3 is strongly linked to hepatic steatosis. Evidence suggests a gain-of-function role for the I148M mutant as an ATGL inhibitor, leaving the physiological relevance of wild-type PNPLA3 undefined. Here we show that PNPLA3 selectively degrades triglycerides (TGs) enriched in polyunsaturated fatty acids (PUFAs) independently of ATGL in cultured cells and mice. Lipidomics and metabolite tracing analyses demonstrated that PNPLA3 mobilizes PUFAs from intracellular TGs for phospholipid desaturation, supporting hepatic secretion of TG-rich lipoproteins. Consequently, mice with liver-specific knockout or acute knockdown of PNPLA3 both exhibited aggravated liver steatosis and concomitant decreases in plasma VLDL-TG, phenotypes that manifest only under lipogenic conditions. I148M-knockin mice similarly displayed impaired hepatic TG secretion during lipogenic stimulation. Our results highlight a specific context whereby PNPLA3 facilitates the balance between hepatic TG storage and secretion and suggest the potential contributions of I148M variant loss-of-function to the development of hepatic steatosis in humans. Summary Statement We define the physiological role of wild type PNPLA3 in maintaining hepatic VLDL-TG secretion.
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Tanaka M, Takase S, Ishiura H, Yamauchi T, Okazaki S, Okazaki H. A novel homozygous nonsense variant of LMF1 in pregnancy-induced hypertriglyceridemia with acute pancreatitis. J Clin Lipidol 2023; 17:327-331. [PMID: 37005154 DOI: 10.1016/j.jacl.2023.03.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 03/05/2023] [Accepted: 03/14/2023] [Indexed: 03/29/2023]
Abstract
Hypertriglyceridemia (HTG)-induced pancreatitis during pregnancy could lead to maternal and fetal death. However, its genetic bases are not fully understood, and its treatment strategies are yet to be established. Here we report a case with a novel homozygous nonsense variant of LMF1 in pregnancy-associated HTG with acute pancreatitis. Our patient had childhood-onset severe HTG that had been well-controlled by dietary management in the non-pregnant period with plasma triglyceride (TG) levels at around 200 mg/dL. Milky plasma was noted at the first-trimester pregnancy checkup, followed by a severe increase in plasma TG (10,500 mg/dL) that resulted in pancreatitis in the last trimester. The implementation of strict dietary fat restriction (less than 4 grams per day) reduced plasma TG levels and led to successful delivery. Exome sequencing revealed a novel homozygous nonsense variant in LMF1 (c.697C>T, p.Arg233Ter). The activities of lipoprotein lipase (LPL) and hepatic lipase in post-heparin plasma were not abolished but reduced. The use of pemafibrate decreased plasma TG levels with a concomitant increase in LPL activity. HTG in childhood or early pregnancy is commonly assumed to be polygenic in origin but should be regarded as a feature suggestive of monogenic hyperchylomicronemia. Adequate TG monitoring and dietary fat restriction should be implemented to prevent potentially lethal events of pancreatitis.
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Affiliation(s)
- Masaki Tanaka
- The Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Satoru Takase
- The Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Hiroyuki Ishiura
- The Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Toshimasa Yamauchi
- The Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Sachiko Okazaki
- The Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan; The Division for Health Service Promotion, The University of Tokyo, Tokyo, Japan
| | - Hiroaki Okazaki
- The Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan; The Division of Endocrinology and Metabolism, Department of Internal Medicine, Jichi Medical University, Tochigi, Japan.
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Kozan DW, Derrick JT, Ludington WB, Farber SA. From worms to humans: Understanding intestinal lipid metabolism via model organisms. Biochim Biophys Acta Mol Cell Biol Lipids 2023; 1868:159290. [PMID: 36738984 PMCID: PMC9974936 DOI: 10.1016/j.bbalip.2023.159290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 01/10/2023] [Accepted: 01/19/2023] [Indexed: 02/05/2023]
Abstract
The intestine is responsible for efficient absorption and packaging of dietary lipids before they enter the circulatory system. This review provides a comprehensive overview of how intestinal enterocytes from diverse model organisms absorb dietary lipid and subsequently secrete the largest class of lipoproteins (chylomicrons) to meet the unique needs of each animal. We discuss the putative relationship between diet and metabolic disease progression, specifically Type 2 Diabetes Mellitus. Understanding the molecular response of intestinal cells to dietary lipid has the potential to undercover novel therapies to combat metabolic syndrome.
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Affiliation(s)
- Darby W Kozan
- Department of Biology, Johns Hopkins University, Baltimore, MD, United States; Department of Embryology, Carnegie Institute for Science, Baltimore, MD, United States
| | - Joshua T Derrick
- Department of Biology, Johns Hopkins University, Baltimore, MD, United States; Department of Embryology, Carnegie Institute for Science, Baltimore, MD, United States
| | - William B Ludington
- Department of Biology, Johns Hopkins University, Baltimore, MD, United States; Department of Embryology, Carnegie Institute for Science, Baltimore, MD, United States
| | - Steven A Farber
- Department of Biology, Johns Hopkins University, Baltimore, MD, United States; Department of Embryology, Carnegie Institute for Science, Baltimore, MD, United States.
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Ku T, Zhou M, Hou Y, Xie Y, Li G, Sang N. Tebuconazole induces liver injury coupled with ROS-mediated hepatic metabolism disorder. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 220:112309. [PMID: 34015629 DOI: 10.1016/j.ecoenv.2021.112309] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 04/28/2021] [Accepted: 05/01/2021] [Indexed: 06/12/2023]
Abstract
Tebuconazole, the most widely used fungicide, is reported to cause various environmental problems and have serious health risks in humans. Despite numerous advances in toxicity studies, its internal metabolic process and the underlying mechanisms have not been systemically studied. The present study administered low doses (0.02 g/kg bw and 0.06 g/kg bw) of tebuconazole to C57BL/6 mice in vivo. The high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was developed and validated to analyze the tebuconazole in different organs, and our data revealed that tebuconazole mainly accumulated in the liver and that histopathological damage were exhibited in this organ. Tebuconazole significantly dysregulated phase Ⅰ- and phase II-metabolizing enzymes, ATP-binding cassette (ABC) efflux transporters (Abcc2 and Abcc3) and fatty acid metabolism-related genes (Cdkn1a and Fasn), thereby directly causing liver hypertrophy and steatosis. Importantly, the excessive induction of reactive oxygen species (ROS) and oxidative stress partially accounted for the metabolic abnormalities mediated by tebuconazole. Moreover, these alterations were related to the abnormal transcriptional levels of peroxisome proliferator-activated receptor α (PPAR-α) and liver x receptor α (LXR-α), which were predicted to bind to tebuconazole via hydrogen bonding interactions. The current findings provide new insight into the molecular mechanisms of metabolic abnormalities induced by tebuconazole at low concentration, and are conducive to a better understanding of the environmental risk posed by this fungicide.
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Affiliation(s)
- Tingting Ku
- College of Environmental Science and Resources, Research Center of Environment and Health, Shanxi University, Taiyuan, Shanxi 030006, PR China
| | - Mengmeng Zhou
- College of Environmental Science and Resources, Research Center of Environment and Health, Shanxi University, Taiyuan, Shanxi 030006, PR China
| | - Yanwen Hou
- College of Environmental Science and Resources, Research Center of Environment and Health, Shanxi University, Taiyuan, Shanxi 030006, PR China
| | - Yuanyuan Xie
- College of Environmental Science and Resources, Research Center of Environment and Health, Shanxi University, Taiyuan, Shanxi 030006, PR China
| | - Guangke Li
- College of Environmental Science and Resources, Research Center of Environment and Health, Shanxi University, Taiyuan, Shanxi 030006, PR China
| | - Nan Sang
- College of Environmental Science and Resources, Research Center of Environment and Health, Shanxi University, Taiyuan, Shanxi 030006, PR China.
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Heeren J, Scheja L. Metabolic-associated fatty liver disease and lipoprotein metabolism. Mol Metab 2021; 50:101238. [PMID: 33892169 PMCID: PMC8324684 DOI: 10.1016/j.molmet.2021.101238] [Citation(s) in RCA: 191] [Impact Index Per Article: 63.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 04/01/2021] [Accepted: 04/15/2021] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Non-alcoholic fatty liver disease, or as recently proposed 'metabolic-associated fatty liver disease' (MAFLD), is characterized by pathological accumulation of triglycerides and other lipids in hepatocytes. This common disease can progress from simple steatosis to steatohepatitis, and eventually end-stage liver diseases. MAFLD is closely related to disturbances in systemic energy metabolism, including insulin resistance and atherogenic dyslipidemia. SCOPE OF REVIEW The liver is the central organ in lipid metabolism by secreting very low density lipoproteins (VLDL) and, on the other hand, by internalizing fatty acids and lipoproteins. This review article discusses recent research addressing hepatic lipid synthesis, VLDL production, and lipoprotein internalization as well as the lipid exchange between adipose tissue and the liver in the context of MAFLD. MAJOR CONCLUSIONS Liver steatosis in MAFLD is triggered by excessive hepatic triglyceride synthesis utilizing fatty acids derived from white adipose tissue (WAT), de novo lipogenesis (DNL) and endocytosed remnants of triglyceride-rich lipoproteins. In consequence of high hepatic lipid content, VLDL secretion is enhanced, which is the primary cause of complex dyslipidemia typical for subjects with MAFLD. Interventions reducing VLDL secretory capacity attenuate dyslipidemia while they exacerbate MAFLD, indicating that the balance of lipid storage versus secretion in hepatocytes is a critical parameter determining disease outcome. Proof of concept studies have shown that promoting lipid storage and energy combustion in adipose tissues reduces hepatic lipid load and thus ameliorates MAFLD. Moreover, hepatocellular triglyceride synthesis from DNL and WAT-derived fatty acids can be targeted to treat MAFLD. However, more research is needed to understand how individual transporters, enzymes, and their isoforms affect steatosis and dyslipidemia in vivo, and whether these two aspects of MAFLD can be selectively treated. Processing of cholesterol-enriched lipoproteins appears less important for steatosis. It may, however, modulate inflammation and consequently MAFLD progression.
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Affiliation(s)
- Joerg Heeren
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
| | - Ludger Scheja
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
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Muriel P, López-Sánchez P, Ramos-Tovar E. Fructose and the Liver. Int J Mol Sci 2021; 22:6969. [PMID: 34203484 PMCID: PMC8267750 DOI: 10.3390/ijms22136969] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 06/22/2021] [Accepted: 06/25/2021] [Indexed: 02/07/2023] Open
Abstract
Chronic diseases represent a major challenge in world health. Metabolic syndrome is a constellation of disturbances affecting several organs, and it has been proposed to be a liver-centered condition. Fructose overconsumption may result in insulin resistance, oxidative stress, inflammation, elevated uric acid levels, increased blood pressure, and increased triglyceride concentrations in both the blood and liver. Non-alcoholic fatty liver disease (NAFLD) is a term widely used to describe excessive fatty infiltration in the liver in the absence of alcohol, autoimmune disorders, or viral hepatitis; it is attributed to obesity, high sugar and fat consumption, and sedentarism. If untreated, NAFLD can progress to nonalcoholic steatohepatitis (NASH), characterized by inflammation and mild fibrosis in addition to fat infiltration and, eventually, advanced scar tissue deposition, cirrhosis, and finally liver cancer, which constitutes the culmination of the disease. Notably, fructose is recognized as a major mediator of NAFLD, as a significant correlation between fructose intake and the degree of inflammation and fibrosis has been found in preclinical and clinical studies. Moreover, fructose is a risk factor for liver cancer development. Interestingly, fructose induces a number of proinflammatory, fibrogenic, and oncogenic signaling pathways that explain its deleterious effects in the body, especially in the liver.
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Affiliation(s)
- Pablo Muriel
- Laboratory of Experimental Hepatology, Department of Pharmacology, Cinvestav-IPN, Apartado Postal 14-740, Mexico City 07300, Mexico;
| | - Pedro López-Sánchez
- Postgraduate Studies and Research Section, School of Higher Education in Medicine-IPN, Plan de San Luis y Díaz Mirón s/n, Casco de Santo Tomás, Mexico City 11340, Mexico;
| | - Erika Ramos-Tovar
- Postgraduate Studies and Research Section, School of Higher Education in Medicine-IPN, Plan de San Luis y Díaz Mirón s/n, Casco de Santo Tomás, Mexico City 11340, Mexico;
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Okazaki H, Gotoda T, Ogura M, Ishibashi S, Inagaki K, Daida H, Hayashi T, Hori M, Masuda D, Matsuki K, Yokoyama S, Harada-Shiba M. Current Diagnosis and Management of Primary Chylomicronemia. J Atheroscler Thromb 2021; 28:883-904. [PMID: 33980761 PMCID: PMC8532063 DOI: 10.5551/jat.rv17054] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Primary chylomicronemia (PCM) is a rare and intractable disease characterized by marked accumulation of chylomicrons in plasma. The levels of plasma triglycerides (TGs) typically range from 1,000 - 15,000 mg/dL or higher.
PCM is caused by defects in the lipoprotein lipase (LPL) pathway due to genetic mutations, autoantibodies, or unidentified causes. The monogenic type is typically inherited as an autosomal recessive trait with loss-of-function mutations in LPL pathway genes (
LPL
,
LMF1
,
GPIHBP1
,
APOC2
, and
APOA5
). Secondary/environmental factors (diabetes, alcohol intake, pregnancy, etc.) often exacerbate hypertriglyceridemia (HTG).
The signs, symptoms, and complications of chylomicronemia include eruptive xanthomas, lipemia retinalis, hepatosplenomegaly, and acute pancreatitis with onset as early as in infancy. Acute pancreatitis can be fatal and recurrent episodes of abdominal pain may lead to dietary fat intolerance and failure to thrive. The main goal of treatment is to prevent acute pancreatitis by reducing plasma TG levels to at least less than 500-1,000 mg/dL. However, current TG-lowering medications are generally ineffective for PCM. The only other treatment options are modulation of secondary/environmental factors. Most patients need strict dietary fat restriction, which is often difficult to maintain and likely affects their quality of life. Timely diagnosis is critical for the best prognosis with currently available management, but PCM is often misdiagnosed and undertreated. The aim of this review is firstly to summarize the pathogenesis, signs, symptoms, diagnosis, and management of PCM, and secondly to propose simple diagnostic criteria that can be readily translated into general clinical practice to improve the diagnostic rate of PCM. In fact, these criteria are currently used to define eligibility to receive social support from the Japanese government for PCM as a rare and intractable disease. Nevertheless, further research to unravel the molecular pathogenesis and develop effective therapeutic modalities is warranted. Nationwide registry research on PCM is currently ongoing in Japan with the aim of better understanding the disease burden as well as the unmet needs of this life-threatening disease with poor therapeutic options.
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Affiliation(s)
- Hiroaki Okazaki
- Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo
| | - Takanari Gotoda
- Department of Metabolic Biochemistry, Faculty of Medicine, Kyorin University
| | - Masatsune Ogura
- Department of Molecular Innovation in Lipidology, National Cerebral and Cardiovascular Center Research Institute
| | - Shun Ishibashi
- Division of Endocrinology and Metabolism, Department of Internal Medicine, School of Medicine, Jichi Medical University
| | - Kyoko Inagaki
- Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Nippon Medical School
| | - Hiroyuki Daida
- Faculty of Health Science, Juntendo University, Juntendo University Graduate School of Medicine
| | - Toshio Hayashi
- School of Health Sciences, Nagoya University Graduate School of Medicine
| | - Mika Hori
- Department of Endocrinology, Research Institute of Environmental Medicine, Nagoya University
| | - Daisaku Masuda
- Department of Cardiology, Health Care Center, Rinku Innovation Center for Wellness Care and Activities (RICWA), Rinku General Medical Center
| | - Kota Matsuki
- Department of Endocrinology and Metabolism, Hirosaki University Graduate School of Medicine
| | | | - Mariko Harada-Shiba
- Department of Molecular Pathogenesis, National Cerebral and Cardiovascular Center Research Institute
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