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Teng L, Dedousis N, Adeshirlarijaney A, Kanshana JS, Liu M, Hodges CA, Kohan AB. Impaired intestinal free fatty acid transport followed by chylomicron malformation, not pancreatic insufficiency, cause metabolic defects in cystic fibrosis. J Lipid Res 2024; 65:100551. [PMID: 39002195 DOI: 10.1016/j.jlr.2024.100551] [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: 12/06/2023] [Revised: 04/03/2024] [Accepted: 04/29/2024] [Indexed: 07/15/2024] Open
Abstract
Intestinal disease is one of the earliest manifestations of cystic fibrosis (CF) in children and is closely tied to deficits in growth and nutrition, both of which are directly linked to future mortality. Patients are treated aggressively with pancreatic enzyme replacement therapy and a high-fat diet to circumvent fat malabsorption, but this does not reverse growth and nutritional defects. We hypothesized that defects in chylomicron production could explain why CF body weights and nutrition are so resistant to clinical treatments. We used gold standard intestinal lipid absorption and metabolism approaches, including mouse mesenteric lymph cannulation, in vivo chylomicron secretion kinetics, transmission electron microscopy, small intestinal organoids, and chylomicron metabolism assays to test this hypothesis. In mice expressing the G542X mutation in cystic fibrosis transmembrane conductance regulator (CFTR-/- mice), we find that defective FFA trafficking across the epithelium into enterocytes drives a chylomicron formation defect. Furthermore, G542X mice secrete small, triglyceride-poor chylomicrons into the lymph and blood. These defective chylomicrons are cleared into extraintestinal tissues at ∼10-fold faster than WT chylomicrons. This defect in FFA absorption resulting in dysfunctional chylomicrons cannot be explained by steatorrhea or pancreatic insufficiency and is maintained in primary small intestinal organoids treated with micellar lipids. These studies suggest that the ultrahigh-fat diet that most people with CF are counselled to follow may instead make steatorrhea and malabsorption defects worse by overloading the absorptive capacity of the CF small intestine.
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Affiliation(s)
- Lihong Teng
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA; Department of Immunology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Nikolaos Dedousis
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA; Department of Immunology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Aneseh Adeshirlarijaney
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA; Department of Immunology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jitendra S Kanshana
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA; Department of Immunology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Min Liu
- Department of Pathology and Laboratory Medicine, University of Cincinnati, Cincinnati, OH, USA
| | - Craig A Hodges
- Department of Genetics and Genome Sciences and Department of Pediatrics, Case Western Reserve University, Cleveland, OH, USA
| | - Alison B Kohan
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA; Department of Immunology, University of Pittsburgh, Pittsburgh, PA, USA.
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2
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Ramos-León J, Valencia C, Gutiérrez-Mariscal M, Rivera-Miranda DA, García-Meléndrez C, Covarrubias L. The loss of antioxidant activities impairs intestinal epithelium homeostasis by altering lipid metabolism. Exp Cell Res 2024; 437:113965. [PMID: 38378126 DOI: 10.1016/j.yexcr.2024.113965] [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: 09/01/2023] [Revised: 02/02/2024] [Accepted: 02/08/2024] [Indexed: 02/22/2024]
Abstract
Reactive oxygens species (ROS) are common byproducts of metabolic reactions and could be at the origin of many diseases of the elderly. Here we investigated the role of ROS in the renewal of the intestinal epithelium in mice lacking catalase (CAT) and/or nicotinamide nucleotide transhydrogenase (NNT) activities. Cat-/- mice have delayed intestinal epithelium renewal and were prone to develop necrotizing enterocolitis upon starvation. Interestingly, crypts lacking CAT showed fewer intestinal stem cells (ISC) and lower stem cell activity than wild-type. In contrast, crypts lacking NNT showed a similar number of ISCs as wild-type but increased stem cell activity, which was also impaired by the loss of CAT. No alteration in the number of Paneth cells (PCs) was observed in crypts of either Cat-/- or Nnt-/- mice, but they showed an evident decline in the amount of lysozyme. Cat deficiency caused fat accumulation in crypts, and a fall in the remarkable high amount of adipose triglyceride lipase (ATGL) in PCs. Notably, the low levels of ATGL in the intestine of Cat -/- mice increased after a treatment with the antioxidant N-acetyl-L-cysteine. Supporting a role of ATGL in the regulation of ISC activity, its inhibition halt intestinal organoid development. These data suggest that the reduction in the renewal capacity of intestine originates from fatty acid metabolic alterations caused by peroxisomal ROS.
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Affiliation(s)
- Javier Ramos-León
- Departamento de Genética Del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mor., Mexico
| | - Concepción Valencia
- Departamento de Genética Del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mor., Mexico
| | - Mariana Gutiérrez-Mariscal
- Departamento de Genética Del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mor., Mexico
| | - David-Alejandro Rivera-Miranda
- Departamento de Genética Del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mor., Mexico
| | - Celina García-Meléndrez
- Departamento de Genética Del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mor., Mexico
| | - Luis Covarrubias
- Departamento de Genética Del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mor., Mexico.
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3
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Gaudino SJ, Singh A, Huang H, Padiadpu J, Jean-Pierre M, Kempen C, Bahadur T, Shiomitsu K, Blumberg R, Shroyer KR, Beyaz S, Shulzhenko N, Morgun A, Kumar P. Intestinal IL-22RA1 signaling regulates intrinsic and systemic lipid and glucose metabolism to alleviate obesity-associated disorders. Nat Commun 2024; 15:1597. [PMID: 38383607 PMCID: PMC10881576 DOI: 10.1038/s41467-024-45568-6] [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: 04/28/2022] [Accepted: 01/26/2024] [Indexed: 02/23/2024] Open
Abstract
IL-22 is critical for ameliorating obesity-induced metabolic disorders. However, it is unknown where IL-22 acts to mediate these outcomes. Here we examine the importance of tissue-specific IL-22RA1 signaling in mediating long-term high fat diet (HFD) driven metabolic disorders. To do so, we generated intestinal epithelium-, liver-, and white adipose tissue (WAT)-specific Il22ra1 knockout and littermate control mice. Intestinal epithelium- and liver-specific IL-22RA1 signaling upregulated systemic glucose metabolism. Intestinal IL-22RA1 signaling also mediated liver and WAT metabolism in a microbiota-dependent manner. We identified an association between Oscillibacter and elevated WAT inflammation, likely induced by Mmp12 expressing macrophages. Mechanistically, transcription of intestinal lipid metabolism genes is regulated by IL-22 and potentially IL-22-induced IL-18. Lastly, we show that Paneth cell-specific IL-22RA1 signaling, in part, mediates systemic glucose metabolism after HFD. Overall, these results elucidate a key role of intestinal epithelium-specific IL-22RA1 signaling in regulating intestinal metabolism and alleviating systemic obesity-associated disorders.
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Affiliation(s)
- Stephen J Gaudino
- Department of Microbiology and Immunology, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY, USA
| | - Ankita Singh
- Department of Microbiology and Immunology, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY, USA
| | - Huakang Huang
- Department of Microbiology and Immunology, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY, USA
| | - Jyothi Padiadpu
- College of Pharmacy, Oregon State University, Corvallis, OR, USA
| | - Makheni Jean-Pierre
- Department of Microbiology and Immunology, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY, USA
| | - Cody Kempen
- Department of Microbiology and Immunology, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY, USA
| | - Tej Bahadur
- Department of Microbiology and Immunology, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY, USA
| | - Kiyoshi Shiomitsu
- Department of Microbiology and Immunology, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY, USA
| | - Richard Blumberg
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Kenneth R Shroyer
- Department of Pathology, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY, USA
| | - Semir Beyaz
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, 11724, USA
| | - Natalia Shulzhenko
- Carlson College of Veterinary Medicine, Oregon State University, Corvallis, OR, USA
| | - Andrey Morgun
- College of Pharmacy, Oregon State University, Corvallis, OR, USA
| | - Pawan Kumar
- Department of Microbiology and Immunology, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY, USA.
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4
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Nazeer B, Khawar MB, Khalid MU, Hamid SE, Rafiq M, Abbasi MH, Sheikh N, Ali A, Fatima H, Ahmad S. Emerging role of lipophagy in liver disorders. Mol Cell Biochem 2024; 479:1-11. [PMID: 36943663 DOI: 10.1007/s11010-023-04707-1] [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: 02/13/2022] [Accepted: 03/10/2023] [Indexed: 03/23/2023]
Abstract
Lipophagy is a selective degradation of lipids by a lysosomal-mediated pathway, and dysregulation of lipophagy is linked with the pathological hallmark of many liver diseases. Downregulation of lipophagy in liver cells results in abnormal accumulation of LDs (Lipid droplets) in hepatocytes which is a characteristic feature of several liver pathologies such as nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH). Contrarily, upregulation of lipophagy in activated hepatic stellate cells (HSCs) is associated with hepatic fibrosis and cirrhosis. Lipid metabolism reprogramming in violent cancer cells contributes to the progression of liver cancer. In this review, we have summarized the recent studies focusing on various components of the lipophagic machinery that can be modulated for their potential role as therapeutic agents against a wide range of liver diseases.
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Affiliation(s)
- Bismillah Nazeer
- Molecular Medicine and Cancer Therapeutics Lab, Department of Zoology, Faculty of Sciences, University of Central Punjab, Lahore, Pakistan
| | - Muhammad Babar Khawar
- Applied Molecular Biology and Biomedicine Lab, Department of Zoology, University of Narowal, Narowal, Pakistan.
| | - Muhammad Usman Khalid
- Molecular Medicine and Cancer Therapeutics Lab, Department of Zoology, Faculty of Sciences, University of Central Punjab, Lahore, Pakistan
| | - Syeda Eisha Hamid
- Molecular Medicine and Cancer Therapeutics Lab, Department of Zoology, Faculty of Sciences, University of Central Punjab, Lahore, Pakistan
| | - Mussarat Rafiq
- Cell and Molecular Biology Lab, Institute of Zoology, University of the Punjab, Lahore, Pakistan
| | | | - Nadeem Sheikh
- Cell and Molecular Biology Lab, Institute of Zoology, University of the Punjab, Lahore, Pakistan.
| | - Ahmad Ali
- Molecular Medicine and Cancer Therapeutics Lab, Department of Zoology, Faculty of Sciences, University of Central Punjab, Lahore, Pakistan
| | - Hooriya Fatima
- Molecular Medicine and Cancer Therapeutics Lab, Department of Zoology, Faculty of Sciences, University of Central Punjab, Lahore, Pakistan
| | - Sadia Ahmad
- Molecular Medicine and Cancer Therapeutics Lab, Department of Zoology, Faculty of Sciences, University of Central Punjab, Lahore, Pakistan
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5
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Li J, Wang Y, Yang P, Han H, Zhang G, Xu H, Quan K. Overexpression of ATGL impairs lipid droplet accumulation by accelerating lipolysis in goat mammary epithelial cells. Anim Biotechnol 2023; 34:3126-3134. [PMID: 36306180 DOI: 10.1080/10495398.2022.2136678] [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] [Indexed: 11/01/2022]
Abstract
Adipose triglyceride lipase (ATGL) is the key enzyme for the degradation of triacylglycerols (TAGs). It functions in concert with other enzymes to mobilize TAG and supply fatty acids (FAs) for energy production. Dysregulated lipolysis leads to excess concentrations of circulating FAs, which may lead to destructive and lipotoxic effects to the organism. To understand the role of ATGL in mammary lipid metabolism, ATGL was overexpressed in goat mammary epithelial cells (GMECs) by using a recombinant adenovirus system. ATGL overexpression decreased lipid droplet (LD) accumulation and cellular TG content (p < 0.05) along with a decrease in the expression of the key enzyme that catalyzes the final step of TG synthesis (DGAT). Significant increases were observed in the expression of genes related to lipolysis (hormone-sensitive lipase [HSL]) and FA desaturation (SCD) by ATGL overexpression. Genes responsible for FA oxidation (PPARα), LD formation and secretion (ADRP and BTN1A1), and long-chain FA uptake (CD36) were all decreased by ATGL overexpression (p < 0.05). The primary products of TAG lipolysis, free FAs (FFAs), were notably increased in the ATGL-overexpressing cells. Taken together, our results demonstrated that ATGL activation impairs lipid formation partially through accelerating lipolysis in GMECs.
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Affiliation(s)
- Jun Li
- College of Animal Science and Technology, Henan University of Animal Husbandry and Economy, Zhengzhou, PR China
| | - Yaling Wang
- College of Animal Science and Technology, Henan Agricultural University, Zhengzhou, PR China
| | - Pengkun Yang
- College of Animal Science and Technology, Henan University of Animal Husbandry and Economy, Zhengzhou, PR China
| | - Haoyuan Han
- College of Animal Science and Technology, Henan University of Animal Husbandry and Economy, Zhengzhou, PR China
| | - Guizhi Zhang
- College of Animal Science and Technology, Henan University of Animal Husbandry and Economy, Zhengzhou, PR China
| | - Huifen Xu
- College of Animal Science and Technology, Henan Agricultural University, Zhengzhou, PR China
| | - Kai Quan
- College of Animal Science and Technology, Henan University of Animal Husbandry and Economy, Zhengzhou, PR China
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6
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Hofer P, Grabner GF, König M, Xie H, Bulfon D, Ludwig AE, Wolinski H, Zimmermann R, Zechner R, Heier C. Cooperative lipolytic control of neuronal triacylglycerol by spastic paraplegia-associated enzyme DDHD2 and ATGL. J Lipid Res 2023; 64:100457. [PMID: 37832604 PMCID: PMC10665947 DOI: 10.1016/j.jlr.2023.100457] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 10/01/2023] [Accepted: 10/04/2023] [Indexed: 10/15/2023] Open
Abstract
Intracellular lipolysis-the enzymatic breakdown of lipid droplet-associated triacylglycerol (TAG)-depends on the cooperative action of several hydrolytic enzymes and regulatory proteins, together designated as lipolysome. Adipose triglyceride lipase (ATGL) acts as a major cellular TAG hydrolase and core effector of the lipolysome in many peripheral tissues. Neurons initiate lipolysis independently of ATGL via DDHD domain-containing 2 (DDHD2), a multifunctional lipid hydrolase whose dysfunction causes neuronal TAG deposition and hereditary spastic paraplegia. Whether and how DDHD2 cooperates with other lipolytic enzymes is currently unknown. In this study, we further investigated the enzymatic properties and functions of DDHD2 in neuroblastoma cells and primary neurons. We found that DDHD2 hydrolyzes multiple acylglycerols in vitro and substantially contributes to neutral lipid hydrolase activities of neuroblastoma cells and brain tissue. Substrate promiscuity of DDHD2 allowed its engagement at different steps of the lipolytic cascade: In neuroblastoma cells, DDHD2 functioned exclusively downstream of ATGL in the hydrolysis of sn-1,3-diacylglycerol (DAG) isomers but was dispensable for TAG hydrolysis and lipid droplet homeostasis. In primary cortical neurons, DDHD2 exhibited lipolytic control over both, DAG and TAG, and complemented ATGL-dependent TAG hydrolysis. We conclude that neuronal cells use noncanonical configurations of the lipolysome and engage DDHD2 as dual TAG/DAG hydrolase in cooperation with ATGL.
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Affiliation(s)
- Peter Hofer
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Gernot F Grabner
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Mario König
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Hao Xie
- Institute of Molecular Biosciences, University of Graz, Graz, Austria; State Key Laboratory of Natural Medicines, Key Laboratory of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University, Nanjing, China
| | - Dominik Bulfon
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Anton E Ludwig
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Heimo Wolinski
- Institute of Molecular Biosciences, University of Graz, Graz, Austria; BioHealth Field of Excellence, University of Graz, Graz, Austria
| | - Robert Zimmermann
- Institute of Molecular Biosciences, University of Graz, Graz, Austria; BioHealth Field of Excellence, University of Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria
| | - Rudolf Zechner
- Institute of Molecular Biosciences, University of Graz, Graz, Austria; BioHealth Field of Excellence, University of Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria
| | - Christoph Heier
- Institute of Molecular Biosciences, University of Graz, Graz, Austria; BioHealth Field of Excellence, University of Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria.
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7
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Ge W, Sun Q, Yang Y, Ding Z, Liu J, Zhang J. Circadian PER1 controls daily fat absorption with the regulation of PER1-PKA on phosphorylation of bile acid synthetase. J Lipid Res 2023; 64:100390. [PMID: 37209828 PMCID: PMC10276160 DOI: 10.1016/j.jlr.2023.100390] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 05/10/2023] [Accepted: 05/11/2023] [Indexed: 05/22/2023] Open
Abstract
Several epidemiological studies suggest a correlation between eating time and obesity. Night eating syndrome characterized by a time-delayed eating pattern is positively associated with obesity in humans as well as in experimental animals. Here, we show that oil intake at night significantly makes more fat than that at day in wild-type mice, and circadian Period 1 (Per1) contributes to this day-night difference. Per1-knockout mice are protected from high-fat diet-induced obesity, which is accompanied by a reduction in the size of the bile acid pool, and the oral administration of bile acids restores fat absorption and accumulation. We identify that PER1 directly binds to the major hepatic enzymes involved in bile acid synthesis such as cholesterol 7alpha-hydroxylase and sterol 12alpha-hydroxylase. A biosynthesis rhythm of bile acids is accompanied by the activity and instability of bile acid synthases with PER1/PKA-mediated phosphorylation pathways. Both fasting and high fat stress enhance Per1 expression, increasing the fat absorption and accumulation. Our findings reveal that Per1 is an energy regulator and controls daily fat absorption and accumulation. Circadian Per1 controls daily fat absorption and accumulation, suggesting Per1 is a potential candidate of a key regulator in stress response and the relevant obesity risk.
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Affiliation(s)
- Wenhao Ge
- Center for Molecular Metabolism, Nanjing University of Science & Technology, Nanjing, China
| | - Qi Sun
- Key Laboratory of Cardiovascular and Cerebrovascular Diseases, Bengbu Medical College, Bengbu, China
| | - Yunxia Yang
- Center for Molecular Metabolism, Nanjing University of Science & Technology, Nanjing, China
| | - Zhao Ding
- Center for Molecular Metabolism, Nanjing University of Science & Technology, Nanjing, China
| | - Junhao Liu
- Center for Molecular Metabolism, Nanjing University of Science & Technology, Nanjing, China
| | - Jianfa Zhang
- Center for Molecular Metabolism, Nanjing University of Science & Technology, Nanjing, China.
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8
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Han J, Dong L, Wu M, Ma F. Dynamic polarization of tumor-associated macrophages and their interaction with intratumoral T cells in an inflamed tumor microenvironment: from mechanistic insights to therapeutic opportunities. Front Immunol 2023; 14:1160340. [PMID: 37251409 PMCID: PMC10219223 DOI: 10.3389/fimmu.2023.1160340] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 04/20/2023] [Indexed: 05/31/2023] Open
Abstract
Immunotherapy has brought a paradigm shift in the treatment of tumors in recent decades. However, a significant proportion of patients remain unresponsive, largely due to the immunosuppressive tumor microenvironment (TME). Tumor-associated macrophages (TAMs) play crucial roles in shaping the TME by exhibiting dual identities as both mediators and responders of inflammation. TAMs closely interact with intratumoral T cells, regulating their infiltration, activation, expansion, effector function, and exhaustion through multiple secretory and surface factors. Nevertheless, the heterogeneous and plastic nature of TAMs renders the targeting of any of these factors alone inadequate and poses significant challenges for mechanistic studies and clinical translation of corresponding therapies. In this review, we present a comprehensive summary of the mechanisms by which TAMs dynamically polarize to influence intratumoral T cells, with a focus on their interaction with other TME cells and metabolic competition. For each mechanism, we also discuss relevant therapeutic opportunities, including non-specific and targeted approaches in combination with checkpoint inhibitors and cellular therapies. Our ultimate goal is to develop macrophage-centered therapies that can fine-tune tumor inflammation and empower immunotherapy.
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Affiliation(s)
- Jiashu Han
- 4+4 Medical Doctor Program, Chinese Academy of Medical Sciences and Peking Union Medical College, Dongcheng, Beijing, China
| | - Luochu Dong
- 4+4 Medical Doctor Program, Chinese Academy of Medical Sciences and Peking Union Medical College, Dongcheng, Beijing, China
| | - Mengwei Wu
- Department of General Surgery, Peking Union Medical College Hospital (CAMS), Beijing, China
| | - Fei Ma
- Center for National Cancer, Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
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9
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Adam AH, Verdegem M, Soliman AA, Zaki M, Khalil RH, Nour AEM, Khaled AA, El Basuini MF, Khalil HS. Effect of dietary bile acids: Growth performance, immune response, genes expression of fatty acid metabolism, intestinal, and liver morphology of striped catfish (Pangasianodon hypophthalmus). AQUACULTURE REPORTS 2023; 29:101510. [DOI: 10.1016/j.aqrep.2023.101510] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
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10
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Li X, Liu Q, Pan Y, Chen S, Zhao Y, Hu Y. New insights into the role of dietary triglyceride absorption in obesity and metabolic diseases. Front Pharmacol 2023; 14:1097835. [PMID: 36817150 PMCID: PMC9932209 DOI: 10.3389/fphar.2023.1097835] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 01/20/2023] [Indexed: 02/05/2023] Open
Abstract
The incidence of obesity and associated metabolic diseases is increasing globally, adversely affecting human health. Dietary fats, especially triglycerides, are an important source of energy for the body, and the intestine absorbs lipids through a series of orderly and complex steps. A long-term high-fat diet leads to intestinal dysfunction, inducing obesity and metabolic disorders. Therefore, regulating dietary triglycerides absorption is a promising therapeutic strategy. In this review, we will discuss diverse aspects of the dietary triglycerides hydrolysis, fatty acid uptake, triglycerides resynthesis, chylomicron assembly, trafficking, and secretion processes in intestinal epithelial cells, as well as potential targets in this process that may influence dietary fat-induced obesity and metabolic diseases. We also mention the possible shortcomings and deficiencies in modulating dietary lipid absorption targets to provide a better understanding of their administrability as drugs in obesity and related metabolic disorders.
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Affiliation(s)
- Xiaojing Li
- Key Laboratory of Liver and Kidney Diseases (Ministry of Education), Institute of Liver Diseases, Shanghai Key Laboratory of Traditional Chinese Clinical Medicine, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Qiaohong Liu
- Institute of Clinical Pharmacology, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Yuqing Pan
- Key Laboratory of Liver and Kidney Diseases (Ministry of Education), Institute of Liver Diseases, Shanghai Key Laboratory of Traditional Chinese Clinical Medicine, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Si Chen
- Key Laboratory of Liver and Kidney Diseases (Ministry of Education), Institute of Liver Diseases, Shanghai Key Laboratory of Traditional Chinese Clinical Medicine, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Yu Zhao
- Key Laboratory of Liver and Kidney Diseases (Ministry of Education), Institute of Liver Diseases, Shanghai Key Laboratory of Traditional Chinese Clinical Medicine, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China,*Correspondence: Yu Zhao, ; Yiyang Hu,
| | - Yiyang Hu
- Key Laboratory of Liver and Kidney Diseases (Ministry of Education), Institute of Liver Diseases, Shanghai Key Laboratory of Traditional Chinese Clinical Medicine, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China,Institute of Clinical Pharmacology, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China,*Correspondence: Yu Zhao, ; Yiyang Hu,
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11
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He Q, Gao L, Zhang F, Yao W, Wu J, Song N, Luo J, Zhang Y. The FoxO1-ATGL axis alters milk lipolysis homeostasis through PI3K/AKT signaling pathway in dairy goat mammary epithelial cells. J Anim Sci 2023; 101:skad286. [PMID: 37638641 PMCID: PMC10699848 DOI: 10.1093/jas/skad286] [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: 04/10/2023] [Accepted: 08/25/2023] [Indexed: 08/29/2023] Open
Abstract
Goat milk is enriched in fatty acids which are beneficial to human health. Previous research has revealed that 98% of milk fat is composed of triglycerides. However, the mechanisms regulating milk fat composition remain unclear. Forkhead box protein O1 (FoxO1) is a crucial regulatory factor involved in lipid metabolism across various cell types. Chromatin immunoprecipitation sequencing (ChIP)-seq data) and RNA sequencing (RNA-seq) data revealed that have indicated a close association between FoxO1 was closely related to lipid metabolism during lactation in dairy goats. The objective of this study was to investigate the mechanisms by which FoxO1 regulates lipid metabolism in goat mammary epithelial cells (GMECs). FoxO1 knockdown significantly downregulated the expression of adipose triglyceride lipase (ATGL) and suppressed the activity of the ATGL promoter. Consistently, the number of lipid droplets decreased significantly in FoxO1-overexpressing cells and increased in ATGL-knockdown cells. To further verify the effect of FoxO1 on ATGL promoter activity, cells were transfected with four promoter fragments of different lengths. We found that the core region of the ATGL promoter was located between -882 bp and -524 bp, encompassing two FoxO1 binding sites (FKH1 and FKH2). Mutations in the FoxO1 binding sites significantly downregulated ATGL promoter activity in GMECs. Luciferase reporter assays demonstrated that FoxO1 overexpression markedly enhanced ATGL promoter activity. Furthermore, site-directed mutation confirmed that FKH1 and FKH2 sites were simultaneously mutated significantly attenuated the stimulatory effect of FoxO1 on ATGL promoter activities simultaneous mutation of FKH1 and FKH2 sites significantly attenuated the stimulatory effect of FoxO1 on ATGL promoter activity. ChIP assays showed that FoxO1 directly binds to the FKH2 element located in the ATGL promoter in vivo. Finally, immunofluorescence staining revealed that insulin promotes the translocation of FoxO1 from the nucleus to the cytoplasm, thereby attenuating the FoxO1-induced activation of the ATGL promoter. Collectively, these findings uncover a novel pathway where by FoxO1 may regulate lipid metabolism in GMECs specifically by modulating the transcriptional activity of ATGL.
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Affiliation(s)
- Qiuya He
- Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling 712100, China
| | - Liangjiahui Gao
- Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling 712100, China
| | - Fuhong Zhang
- Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling 712100, China
| | - Weiwei Yao
- Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling 712100, China
| | - Jiao Wu
- Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling 712100, China
| | - Ning Song
- College of Animal Science and Technology, Anhui Province Key Laboratory of Local Livestock and Poultry Genetic Resource Conservation and Bio-breeding, Anhui Agricultural University, Hefei 230036, China
| | - Jun Luo
- Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling 712100, China
| | - Yong Zhang
- Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling 712100, China
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12
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Yang Z, Lian W, Waiho K, Zhu L, Chen A, Cheng Y, Wang Y. Effects of copper exposure on lipid metabolism and SREBP pathway in the Chinese mitten crab Eriocheir sinensis. CHEMOSPHERE 2022; 308:136556. [PMID: 36155024 DOI: 10.1016/j.chemosphere.2022.136556] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 09/16/2022] [Accepted: 09/17/2022] [Indexed: 06/16/2023]
Abstract
Copper (Cu) is not only a common metal pollutant in the aquatic environment but also an essential trace element for aquatic organisms such as the Chinese mitten crab (Eriocheir sinensis). Cu is known to regulate lipid metabolism yet exert toxic effects if ingested in excess. However, the molecular regulatory roles of Cu in the lipid metabolism of crabs remains unclear. Thus, this study investigated the potential regulatory mechanism of Cu onto lipid metabolism of E. sinensis following acute Cu exposure. Crabs were exposed to environmental concentration of Cu (50 μg/L) for 96 h, and the expression of sterol regulatory element binding protein (SREBP) was knocked down by RNA interference (RNAi) to test its effect on Cu exposure. The results showed that RNAi significantly attenuated the Cu exposure-induced increase in lipid synthesis and triglycerides (TG) hydrolysis, while significantly inhibited the Cu exposure-induced decrease in fatty acid β-oxidation, suggesting that SREBP is involved in Cu-induced lipid metabolism. Subsequent analyses of the transcriptome results further revealed potential responsive genes of SREBP that were linked to lipid metabolism and immune regulation. Moreover, Cu may affect lipid metabolism through the TOR-SREBP pathway in E. sinensis. This work provides a reference for exploring the effects of Cu on lipid metabolism disorders in crustaceans.
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Affiliation(s)
- Zhigang Yang
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture, Shanghai Ocean University, Shanghai, 201306, China; Centre for Research on Environmental Ecology and Fish Nutrition (CREEFFN) of the Ministry of Agriculture, Shanghai Ocean University, Shanghai, 201306, China
| | - Wan Lian
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture, Shanghai Ocean University, Shanghai, 201306, China; Centre for Research on Environmental Ecology and Fish Nutrition (CREEFFN) of the Ministry of Agriculture, Shanghai Ocean University, Shanghai, 201306, China
| | - Khor Waiho
- Higher Institution Centre of Excellence (HICoE), Institute of Tropical Aquaculture and Fisheries, Universiti Malaysia Terengganu, Terengganu, Malaysia
| | - Liangliang Zhu
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture, Shanghai Ocean University, Shanghai, 201306, China; Centre for Research on Environmental Ecology and Fish Nutrition (CREEFFN) of the Ministry of Agriculture, Shanghai Ocean University, Shanghai, 201306, China
| | - Aqin Chen
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture, Shanghai Ocean University, Shanghai, 201306, China; Centre for Research on Environmental Ecology and Fish Nutrition (CREEFFN) of the Ministry of Agriculture, Shanghai Ocean University, Shanghai, 201306, China
| | - Yongxu Cheng
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture, Shanghai Ocean University, Shanghai, 201306, China; Centre for Research on Environmental Ecology and Fish Nutrition (CREEFFN) of the Ministry of Agriculture, Shanghai Ocean University, Shanghai, 201306, China
| | - Youji Wang
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture, Shanghai Ocean University, Shanghai, 201306, China; Centre for Research on Environmental Ecology and Fish Nutrition (CREEFFN) of the Ministry of Agriculture, Shanghai Ocean University, Shanghai, 201306, China; International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai, China.
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13
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Approaches to Measuring the Activity of Major Lipolytic and Lipogenic Enzymes In Vitro and Ex Vivo. Int J Mol Sci 2022; 23:ijms231911093. [PMID: 36232405 PMCID: PMC9570359 DOI: 10.3390/ijms231911093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 09/14/2022] [Accepted: 09/16/2022] [Indexed: 11/17/2022] Open
Abstract
Since the 1950s, one of the goals of adipose tissue research has been to determine lipolytic and lipogenic activity as the primary metabolic pathways affecting adipocyte health and size and thus representing potential therapeutic targets for the treatment of obesity and associated diseases. Nowadays, there is a relatively large number of methods to measure the activity of these pathways and involved enzymes, but their applicability to different biological samples is variable. Here, we review the characteristics of mean lipogenic and lipolytic enzymes, their inhibitors, and available methodologies for assessing their activity, and comment on the advantages and disadvantages of these methodologies and their applicability in vivo, ex vivo, and in vitro, i.e., in cells, organs and their respective extracts, with the emphasis on adipocytes and adipose tissue.
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14
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Ghanem M, Lewis GF, Xiao C. Recent advances in cytoplasmic lipid droplet metabolism in intestinal enterocyte. Biochim Biophys Acta Mol Cell Biol Lipids 2022; 1867:159197. [PMID: 35820577 DOI: 10.1016/j.bbalip.2022.159197] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 06/03/2022] [Accepted: 06/14/2022] [Indexed: 11/30/2022]
Abstract
Processing of dietary fats in the intestine is a highly regulated process that influences whole-body energy homeostasis and multiple physiological functions. Dysregulated lipid handling in the intestine leads to dyslipidemia and atherosclerotic cardiovascular disease. In intestinal enterocytes, lipids are incorporated into lipoproteins and cytoplasmic lipid droplets (CLDs). Lipoprotein synthesis and CLD metabolism are inter-connected pathways with multiple points of regulation. This review aims to highlight recent advances in the regulatory mechanisms of lipid processing in the enterocyte, with particular focus on CLDs. In-depth understanding of the regulation of lipid metabolism in the enterocyte may help identify therapeutic targets for the treatment and prevention of metabolic disorders.
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Affiliation(s)
- Murooj Ghanem
- Department of Anatomy, Physiology and Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Gary F Lewis
- Departments of Medicine and Physiology, University of Toronto, and University Health Network, Toronto, ON, Canada
| | - Changting Xiao
- Department of Anatomy, Physiology and Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada.
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15
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Wit M, Trujillo-Viera J, Strohmeyer A, Klingenspor M, Hankir M, Sumara G. When fat meets the gut-focus on intestinal lipid handling in metabolic health and disease. EMBO Mol Med 2022; 14:e14742. [PMID: 35437952 PMCID: PMC9081902 DOI: 10.15252/emmm.202114742] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 02/10/2022] [Accepted: 02/11/2022] [Indexed: 12/12/2022] Open
Abstract
The regular overconsumption of energy‐dense foods (rich in lipids and sugars) results in elevated intestinal nutrient absorption and consequently excessive accumulation of lipids in the liver, adipose tissue, skeletal muscles, and other organs. This can eventually lead to obesity and obesity‐associated diseases such as type 2 diabetes (T2D), non‐alcoholic fatty liver disease (NAFLD), cardiovascular disease, and certain types of cancer, as well as aggravate inflammatory bowel disease (IBD). Therefore, targeting the pathways that regulate intestinal nutrient absorption holds significant therapeutic potential. In this review, we discuss the molecular and cellular mechanisms controlling intestinal lipid handling, their relevance to the development of metabolic diseases, and emerging therapeutic strategies.
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Affiliation(s)
- Magdalena Wit
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warszawa, Poland
| | - Jonathan Trujillo-Viera
- Rudolf-Virchow-Zentrum, Center for Integrative and Translational Bioimaging, University of Würzburg, Würzburg, Germany
| | - Akim Strohmeyer
- Chair for Molecular Nutritional Medicine, Technical University of Munich, TUM School of Life Sciences Weihenstephan, Freising, Germany.,EKFZ - Else Kröner-Fresenius-Center for Nutritional Medicine, Technical University of Munich, Munich, Germany.,ZIEL - Institute for Food & Health, Technical University of Munich, Freising, Germany
| | - Martin Klingenspor
- Chair for Molecular Nutritional Medicine, Technical University of Munich, TUM School of Life Sciences Weihenstephan, Freising, Germany.,EKFZ - Else Kröner-Fresenius-Center for Nutritional Medicine, Technical University of Munich, Munich, Germany.,ZIEL - Institute for Food & Health, Technical University of Munich, Freising, Germany
| | - Mohammed Hankir
- Department of General, Visceral, Transplant, Vascular and Pediatric Surgery, University Hospital Wuerzburg, Wuerzburg, Germany
| | - Grzegorz Sumara
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warszawa, Poland
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16
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Pressly JD, Gurumani MZ, Varona Santos JT, Fornoni A, Merscher S, Al-Ali H. Adaptive and maladaptive roles of lipid droplets in health and disease. Am J Physiol Cell Physiol 2022; 322:C468-C481. [PMID: 35108119 PMCID: PMC8917915 DOI: 10.1152/ajpcell.00239.2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Advances in the understanding of lipid droplet biology have revealed essential roles for these organelles in mediating proper cellular homeostasis and stress response. Lipid droplets were initially thought to play a passive role in energy storage. However, recent studies demonstrate that they have substantially broader functions, including protection from reactive oxygen species, endoplasmic reticulum stress, and lipotoxicity. Dysregulation of lipid droplet homeostasis is associated with various pathologies spanning neurological, metabolic, cardiovascular, oncological, and renal diseases. This review provides an overview of the current understanding of lipid droplet biology in both health and disease.
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Affiliation(s)
- Jeffrey D. Pressly
- 1Katz Division of Nephrology and Hypertension and Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, Florida,2Department of Medicine, University of Miami, Miller School of Medicine, Miami, Florida
| | - Margaret Z. Gurumani
- 1Katz Division of Nephrology and Hypertension and Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, Florida,2Department of Medicine, University of Miami, Miller School of Medicine, Miami, Florida
| | - Javier T. Varona Santos
- 1Katz Division of Nephrology and Hypertension and Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, Florida,2Department of Medicine, University of Miami, Miller School of Medicine, Miami, Florida
| | - Alessia Fornoni
- 1Katz Division of Nephrology and Hypertension and Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, Florida,2Department of Medicine, University of Miami, Miller School of Medicine, Miami, Florida
| | - Sandra Merscher
- 1Katz Division of Nephrology and Hypertension and Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, Florida,2Department of Medicine, University of Miami, Miller School of Medicine, Miami, Florida
| | - Hassan Al-Ali
- 1Katz Division of Nephrology and Hypertension and Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, Florida,2Department of Medicine, University of Miami, Miller School of Medicine, Miami, Florida,3Department of Neurological Surgery, University of Miami, Miller School of Medicine, Miami, Florida,4The Miami Project to Cure Paralysis, University of Miami, Miller School of Medicine, Miami, Florida,5Sylvester Comprehensive Cancer Center, University of Miami, Miller School of Medicine, Miami, Florida
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17
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Enterocyte-specific ATGL overexpression affects intestinal and systemic cholesterol homeostasis. Biochim Biophys Acta Mol Cell Biol Lipids 2022; 1867:159121. [PMID: 35150895 DOI: 10.1016/j.bbalip.2022.159121] [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: 11/30/2021] [Revised: 01/19/2022] [Accepted: 02/01/2022] [Indexed: 11/24/2022]
Abstract
Enterocytes of the small intestine (SI) play an important role in maintaining systemic lipid levels by regulating dietary lipid absorption and postprandial lipoprotein secretion. An excessive amount of dietary-derived triglycerides (TGs) taken up by the apical side of enterocytes or basolaterally internalized lipoprotein remnants can be transiently stored in cytosolic lipid droplets (cLDs). As mice lacking adipose TG lipase (ATGL) in the SI display massive accumulation of cLDs but also delayed cholesterol absorption, we hypothesized that SI-specific overexpression of ATGL (Atgl iTg) might have beneficial effects on lipid homeostasis in the gut and possibly throughout the body. Here, we demonstrate that Atgl iTg mice had only modestly increased enzymatic activity despite drastically elevated Atgl mRNA levels (up to 120-fold) on chow diet, and was highly induced upon high-fat/high-cholesterol diet (HF/HCD) feeding. Atgl iTg mice showed markedly reduced intestinal TG concentrations after acute and chronic lipid challenge without affecting chylomicron TG secretion. Circulating plasma cholesterol levels were significantly lower in Atgl iTg mice under different feeding conditions, contrasting the accelerated uptake of dietary cholesterol into the circulation after HF/HCD feeding. In the fasted state, gene expression analysis revealed modulation of PPARα and liver X receptor (LXR) target genes by an increased fatty acid release, whereas the decreased plasma cholesterol concentrations in refed mice were more likely due to changes in HDL synthesis and secretion. We conclude that ATGL, in addition to its role in TG catabolism, plays a critical role in whole-body cholesterol homeostasis by modulating PPARα and LXR signaling in intestinal enterocytes.
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18
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Bai J, Zhu Y, He L, Zhang J, Li J, Pan R, Zhang J, Zhao Y, Cui L, Lu H, Jiang Y, Xiao X. Saponins from bitter melon reduce lipid accumulation via induction of autophagy in C. elegans and HepG2 cell line. Curr Res Food Sci 2022; 5:1167-1175. [PMID: 35936825 PMCID: PMC9352806 DOI: 10.1016/j.crfs.2022.06.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 06/22/2022] [Accepted: 06/27/2022] [Indexed: 11/03/2022] Open
Abstract
Saponins from bitter melon (BMS) are well-known to have various biological activities, especially in the field of fat-lowering. However, many gaps remain in our knowledge of BMS-induced fat reduction and health benefits. Here, we aimed to investigate the precise mechanism of BMS in alleviating fat accumulation in C. elegans and HepG2 cell line. Results indicated that BMS showed strong fat-lowering and lifespan-extension properties. Lipidomic analysis illustrated that BMS could alter the lipid profile, especially represented by phosphatidylethanolamine (PE) increase, which plays an essential role in autophagy. Furthermore, we applied gene-deficient mutants and RNAi technology to confirm that BMS largely depended on daf-16/FoxO1 and hlh-30/TFEB mediated lipophagy to reduce fat deposition. In addition, BMS could ameliorate oil acid (OA)-induced fat accumulation in HepG2 cells by induction of autophagy-related proteins, such as the phosphorylated AMPK and LC3B. In conclusion, our results elucidated the underlying mechanism of bitter melon saponins interfering with lipid metabolism from the autophagy point of view, which provide new insights into a nutraceutical to mitigate obesity. Bitter melon saponin (BMS) could inhibit fat accumulation and extended the lifespan of C. elegans. Lipidomics analysis predicted autophagy may be a key pathway involved in the fat-lowering effects of BMS. BMS induced daf-16/hlh-30 mediated lipophagy to confer fat-lowering benefit. BMS regulated autophagy via activating AMPK phosphorylation and LC3B expressions in HepG2 cells.
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19
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Sachdev V, Duta-Mare M, Korbelius M, Vujić N, Leopold C, Freark de Boer J, Rainer S, Fickert P, Kolb D, Kuipers F, Radovic B, Gorkiewicz G, Kratky D. Impaired Bile Acid Metabolism and Gut Dysbiosis in Mice Lacking Lysosomal Acid Lipase. Cells 2021; 10:2619. [PMID: 34685599 PMCID: PMC8533808 DOI: 10.3390/cells10102619] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 09/26/2021] [Accepted: 09/27/2021] [Indexed: 12/12/2022] Open
Abstract
Lysosomal acid lipase (LAL) is the sole enzyme known to be responsible for the hydrolysis of cholesteryl esters and triglycerides at an acidic pH in lysosomes, resulting in the release of unesterified cholesterol and free fatty acids. However, the role of LAL in diet-induced adaptations is largely unexplored. In this study, we demonstrate that feeding a Western-type diet to Lal-deficient (LAL-KO) mice triggers metabolic reprogramming that modulates gut-liver cholesterol homeostasis. Induction of ileal fibroblast growth factor 15 (three-fold), absence of hepatic cholesterol 7α-hydroxylase expression, and activation of the ERK phosphorylation cascade results in altered bile acid composition, substantial changes in the gut microbiome, reduced nutrient absorption by 40%, and two-fold increased fecal lipid excretion in LAL-KO mice. These metabolic adaptations lead to impaired bile acid synthesis, lipoprotein uptake, and cholesterol absorption and ultimately to the resistance of LAL-KO mice to diet-induced obesity. Our results indicate that LAL-derived lipolytic products might be important metabolic effectors in the maintenance of whole-body lipid homeostasis.
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Affiliation(s)
- Vinay Sachdev
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria; (V.S.); (M.D.-M.); (M.K.); (N.V.); (C.L.); (S.R.); (B.R.)
| | - Madalina Duta-Mare
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria; (V.S.); (M.D.-M.); (M.K.); (N.V.); (C.L.); (S.R.); (B.R.)
| | - Melanie Korbelius
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria; (V.S.); (M.D.-M.); (M.K.); (N.V.); (C.L.); (S.R.); (B.R.)
| | - Nemanja Vujić
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria; (V.S.); (M.D.-M.); (M.K.); (N.V.); (C.L.); (S.R.); (B.R.)
| | - Christina Leopold
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria; (V.S.); (M.D.-M.); (M.K.); (N.V.); (C.L.); (S.R.); (B.R.)
| | - Jan Freark de Boer
- Department of Pediatrics, University Medical Center Groningen, 9713 Groningen, The Netherlands; (J.F.d.B.); (F.K.)
- Department of Laboratory Medicine, University Medical Center Groningen, 9713 Groningen, The Netherlands
| | - Silvia Rainer
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria; (V.S.); (M.D.-M.); (M.K.); (N.V.); (C.L.); (S.R.); (B.R.)
| | - Peter Fickert
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Medical University of Graz, 8010 Graz, Austria;
| | - Dagmar Kolb
- Cell Biology, Histology and Embryology, Gottfried Schatz Research Center, 8010 Graz, Austria;
- Center for Medical Research Medical University of Graz, 8010 Graz, Austria
| | - Folkert Kuipers
- Department of Pediatrics, University Medical Center Groningen, 9713 Groningen, The Netherlands; (J.F.d.B.); (F.K.)
- Department of Laboratory Medicine, University Medical Center Groningen, 9713 Groningen, The Netherlands
| | - Branislav Radovic
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria; (V.S.); (M.D.-M.); (M.K.); (N.V.); (C.L.); (S.R.); (B.R.)
| | - Gregor Gorkiewicz
- Diagnostic and Research Institute of Pathology, Medical University of Graz, 8010 Graz, Austria;
| | - Dagmar Kratky
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria; (V.S.); (M.D.-M.); (M.K.); (N.V.); (C.L.); (S.R.); (B.R.)
- BioTechMed-Graz, 8010 Graz, Austria
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20
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Zhou N, Du S, Dai Y, Yang F, Li X. ω3PUFAs improve hepatic steatosis in postnatal overfed rats and HepG2 cells by inhibiting acetyl-CoA carboxylase. Food Sci Nutr 2021; 9:5153-5165. [PMID: 34532024 PMCID: PMC8441356 DOI: 10.1002/fsn3.2482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 06/14/2021] [Accepted: 07/07/2021] [Indexed: 11/18/2022] Open
Abstract
Postnatal overfeeding can lead to persistent increases in hepatic lipid synthesis and the risk of nonalcoholic fatty liver disease (NAFLD) in adulthood. The ω3 polyunsaturated fatty acids (ω3PUFAs) exhibit beneficial effects on NAFLD. Here, we employed a rat model and an in vitro HepG2 cell model to investigate whether fish oil (FO) affects hepatic lipid synthesis due to postnatal overfeeding. Male Sprague-Dawley were divided into litter sizes of three (small litters, SLs) or 10 (normal litters, NLs) on postnatal day 3 and were fed standard chow or FO diet beginning on postnatal week 3 to generate NL, SL, NL-FO, and SL-FO groups. The results indicated that the FO diet reduced the postnatal overfeeding-induced body weight gain and NAFLD characteristics (such as serum and liver triglyceride (TG) and hepatic steatosis). In addition, FO restored the expression of hepatic lipid metabolism-related genes (including SCD1, FASN, CPT1, LPL, ACC, and SREBP-1c) in SL-FO rats. Specifically, the activity and expression pattern of ACC were consistent with SREBP-1c. Furthermore, HepG2 cells were treated with oleic acid (OA), followed by eicosapentenoic acid (EPA), with or without SREBP-1c siRNA. The cellular lipid droplets, TG content, and the expression of ACC (by 75%) and SREBP-1c (by 45%) were increased by OA stimulation (p < .05), which was inhibited by EPA treatment. However, the effect of EPA treatment was abolished when SREBP-1c was silenced. In conclusion, ω3PUFAs-rich diet may be an effective way to reverse the developmental programming of hepatic lipid synthesis, at least partially, by inhibiting ACC through modulating SREBP-1c.
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Affiliation(s)
- Nan Zhou
- Department of Child Health CareChildren’s Hospital of Nanjing Medical UniversityNanjingChina
| | - Susu Du
- Department of Child Health CareChildren’s Hospital of Nanjing Medical UniversityNanjingChina
| | - Yanyan Dai
- Department of Child Health CareChildren’s Hospital of Nanjing Medical UniversityNanjingChina
| | - Fan Yang
- Department of Child Health CareChildren’s Hospital of Nanjing Medical UniversityNanjingChina
| | - Xiaonan Li
- Department of Child Health CareChildren’s Hospital of Nanjing Medical UniversityNanjingChina
- Institute of Pediatric ResearchNanjing Medical UniversityNanjingChina
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21
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Zembroski AS, Xiao C, Buhman KK. The Roles of Cytoplasmic Lipid Droplets in Modulating Intestinal Uptake of Dietary Fat. Annu Rev Nutr 2021; 41:79-104. [PMID: 34283920 DOI: 10.1146/annurev-nutr-110320-013657] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Dietary fat absorption is required for health but also contributes to hyperlipidemia and metabolic disease when dysregulated. One step in the process of dietary fat absorption is the formation of cytoplasmic lipid droplets (CLDs) in small intestinal enterocytes; these CLDs serve as dynamic triacylglycerol storage organelles that influence the rate at which dietary fat is absorbed. Recent studies have uncovered novel factors regulating enterocyte CLD metabolism that in turn influence the absorption of dietary fat. These include peroxisome proliferator-activated receptor α activation, compartmentalization of different lipid pools, the gut microbiome, liver X receptor and farnesoid X receptor activation, obesity, and physiological factors stimulating CLD mobilization. Understanding how enterocyte CLD metabolism is regulated is key in modulating the absorption of dietary fat in the prevention of hyperlipidemia and its associated metabolic disorders. Expected final online publication date for the Annual Review of Nutrition, Volume 41 is September 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Alyssa S Zembroski
- Department of Nutrition Science, Purdue University, West Lafayette, Indiana 47907, USA;
| | - Changting Xiao
- Department of Anatomy, Physiology and Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada
| | - Kimberly K Buhman
- Department of Nutrition Science, Purdue University, West Lafayette, Indiana 47907, USA;
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22
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Han SL, Qian YC, Limbu SM, Wang J, Chen LQ, Zhang ML, Du ZY. Lipolysis and lipophagy play individual and interactive roles in regulating triacylglycerol and cholesterol homeostasis and mitochondrial form in zebrafish. Biochim Biophys Acta Mol Cell Biol Lipids 2021; 1866:158988. [PMID: 34111526 DOI: 10.1016/j.bbalip.2021.158988] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 05/29/2021] [Accepted: 06/03/2021] [Indexed: 12/26/2022]
Abstract
Neutral lipases-mediated lipolysis and acid lipases-moderated lipophagy are two main processes for degradation of lipid droplets (LDs). However, the individual and interactive roles of these metabolic pathways are not well known across vertebrates. This study explored the roles of lipolysis and lipophagy from the aspect of neutral and acid lipases in zebrafish. We established zebrafish strains deficient in either adipose triglyceride lipase (atgl-/-; AKO fish) or lysosomal acid lipase (lal-/-; LKO fish) respectively, and then inhibited lipolysis in the LKO fish and lipophagy in the AKO fish by feeding diets supplemented with the corresponding inhibitors Atglistatin and 3-Methyladenine, respectively. Both the AKO and LKO fish showed reduced growth, swimming activity, and oxygen consumption. The AKO fish did not show phenotypes in adipose tissue, but mainly accumulated triacylglycerol (TAG) in liver, also, they had large LDs in the hepatocytes, and did not stimulate lipophagy as a compensation response but maintained basal lipophagy. The LKO fish reduced total lipid accumulation in the body but had high cholesterol content in liver; also, they accumulated small LDs in the hepatocytes, and showed increased lipolysis, especially Atgl expression, as a compensatory mechanism. Simultaneous inhibition of lipolysis and lipophagy in zebrafish resulted in severe liver damage, with the potential to trigger mitophagy. Overall, our study illustrates that lipolysis and lipophagy perform individual and interactive roles in maintaining homeostasis of TAG and cholesterol metabolism. Furthermore, the interactive roles of lipolysis and lipophagy may be essential in regulating the functions and form of mitochondria.
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Affiliation(s)
- Si-Lan Han
- LANEH, School of Life Sciences, East China Normal University, Shanghai, China
| | - Yu-Cheng Qian
- LANEH, School of Life Sciences, East China Normal University, Shanghai, China
| | | | - Jing Wang
- LANEH, School of Life Sciences, East China Normal University, Shanghai, China
| | - Li-Qiao Chen
- LANEH, School of Life Sciences, East China Normal University, Shanghai, China
| | - Mei-Ling Zhang
- LANEH, School of Life Sciences, East China Normal University, Shanghai, China
| | - Zhen-Yu Du
- LANEH, School of Life Sciences, East China Normal University, Shanghai, China.
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23
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Kim YS, Nam HJ, Han CY, Joo MS, Jang K, Jun DW, Kim SG. Liver X Receptor Alpha Activation Inhibits Autophagy and Lipophagy in Hepatocytes by Dysregulating Autophagy-Related 4B Cysteine Peptidase and Rab-8B, Reducing Mitochondrial Fuel Oxidation. Hepatology 2021; 73:1307-1326. [PMID: 32557804 DOI: 10.1002/hep.31423] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 05/20/2020] [Accepted: 05/21/2020] [Indexed: 12/12/2022]
Abstract
BACKGROUND AND AIMS Fat accumulation results from increased fat absorption and/or defective fat metabolism. Currently, the lipid-sensing nuclear receptor that controls fat utilization in hepatocytes is elusive. Liver X receptor alpha (LXRα) promotes accumulation of lipids through the induction of several lipogenic genes. However, its effect on lipid degradation is open for study. Here, we investigated the inhibitory role of LXRα in autophagy/lipophagy in hepatocytes and the underlying basis. APPROACH AND RESULTS In LXRα knockout mice fed a high-fat diet, or cell models, LXRα activation suppressed the function of mitochondria by inhibiting autophagy/lipophagy and induced hepatic steatosis. Gene sets associated with "autophagy" were enriched in hepatic transcriptome data. Autophagy flux was markedly augmented in the LXRα knockout mouse liver and primary hepatocytes. Mechanistically, LXRα suppressed autophagy-related 4B cysteine peptidase (ATG4B) and Rab-8B, responsible for autophagosome and -lysosome formation, by inducing let-7a and microRNA (miR)-34a. Chromatin immunoprecipitation assay enabled us to find LXRα as a transcription factor of let-7a and miR-34a. Moreover, 3' untranslated region luciferase assay substantiated the direct inhibitory effects of let-7a and miR-34a on ATG4B and Rab-8B. Consistently, either LXRα activation or the let-7a/miR-34a transfection lowered mitochondrial oxygen consumption rate and mitochondrial transmembrane potential and increased fat levels. In obese animals or nonalcoholic fatty liver disease (NAFLD) patients, let-7a and miR-34a levels were elevated with simultaneous decreases in ATG4B and Rab-8B levels. CONCLUSIONS LXRα inhibits autophagy in hepatocytes through down-regulating ATG4B and Rab-8B by transcriptionally activating microRNA let-7a-2 and microRNA 34a genes and suppresses mitochondrial biogenesis and fuel consumption. This highlights a function of LXRα that culminates in the progression of liver steatosis and steatohepatitis, and the identified targets may be applied for a therapeutic strategy in the treatment of NAFLD.
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Affiliation(s)
- Yun Seok Kim
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, Korea
| | - Hyeon Joo Nam
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, Korea
| | - Chang Yeob Han
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, Korea.,School of Pharmacy, Jeonbuk National University, Jeonju-si, Jeonbuk, Korea
| | - Min Sung Joo
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, Korea
| | - Kiseok Jang
- Department of Pathology, Hanyang University School of Medicine, Seoul, Korea
| | - Dae Won Jun
- Internal Medicine, Hanyang University School of Medicine, Seoul, Korea
| | - Sang Geon Kim
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, Korea
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24
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Han SL, Liu Y, Limbu SM, Chen LQ, Zhang ML, Du ZY. The reduction of lipid-sourced energy production caused by ATGL inhibition cannot be compensated by activation of HSL, autophagy, and utilization of other nutrients in fish. FISH PHYSIOLOGY AND BIOCHEMISTRY 2021; 47:173-188. [PMID: 33245450 DOI: 10.1007/s10695-020-00904-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 11/18/2020] [Indexed: 06/11/2023]
Abstract
The adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL)-mediated lipolysis play important roles in lipid catabolism. ATGL is considered the central rate-limiting enzyme in the mobilization of fatty acids in mammals. Currently, severe fat accumulation has been commonly detected in farmed fish globally. However, the ATGL-mediated lipolysis and the potential synergy among ATGL, HSL, and autophagy, which is another way for lipid breakdown, have not been intensively understood in fish. In the present study, we added Atglistatin as an ATGL-specific inhibitor into the zebrafish diet and fed to the fish for 5 weeks. The results showed that the Atglistatin-treated fish exhibited severe fat deposition, reduced oxygen consumption, and fatty acid β-oxidation, accompanied with increased oxidative stress and inflammation. Furthermore, the Atglistatin-treated fish elevated total and phosphorylation protein expressions of HSL. However, the free fatty acids and lipase activities in organs were still systemically reduced in the Atglistatin-treated fish, and the autophagy marker LC3 was also decreased in the liver. On the other hand, glycogenolysis was stimulated but blood glucose was higher in the Atglistatin-treated fish. The transcriptomic analysis also provided the hint that the protein turnover efficiency in Atglistatin-treated fish was likely to be accelerated, but the protein content in whole fish was not affected. Taken together, ATGL plays crucial roles in energy homeostasis such that its inhibition causes loss of lipid-sourced energy production, which cannot be compensated by activation of HSL, autophagy, and utilization of other nutrients.
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Affiliation(s)
- Si-Lan Han
- LANEH, School of Life Sciences, East China Normal University, Shanghai, China
| | - Yan Liu
- LANEH, School of Life Sciences, East China Normal University, Shanghai, China
| | - Samwel M Limbu
- LANEH, School of Life Sciences, East China Normal University, Shanghai, China
- Department of Aquatic Sciences and Fisheries Technology, University of Dar es Salaam, P.O. Box 35064, Dar es Salaam, Tanzania
- ECNU-UDSM Joint Research Center for Aquaculture and Fish Biology (JRCAFB), Dar es Salaam, Tanzania
| | - Li-Qiao Chen
- LANEH, School of Life Sciences, East China Normal University, Shanghai, China
| | - Mei-Ling Zhang
- LANEH, School of Life Sciences, East China Normal University, Shanghai, China
| | - Zhen-Yu Du
- LANEH, School of Life Sciences, East China Normal University, Shanghai, China.
- ECNU-UDSM Joint Research Center for Aquaculture and Fish Biology (JRCAFB), Shanghai, China.
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25
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Sistilli G, Kalendova V, Cajka T, Irodenko I, Bardova K, Oseeva M, Zacek P, Kroupova P, Horakova O, Lackner K, Gastaldelli A, Kuda O, Kopecky J, Rossmeisl M. Krill Oil Supplementation Reduces Exacerbated Hepatic Steatosis Induced by Thermoneutral Housing in Mice with Diet-Induced Obesity. Nutrients 2021; 13:437. [PMID: 33572810 PMCID: PMC7912192 DOI: 10.3390/nu13020437] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 01/19/2021] [Accepted: 01/26/2021] [Indexed: 02/07/2023] Open
Abstract
Preclinical evidence suggests that n-3 fatty acids EPA and DHA (Omega-3) supplemented as phospholipids (PLs) may be more effective than triacylglycerols (TAGs) in reducing hepatic steatosis. To further test the ability of Omega-3 PLs to alleviate liver steatosis, we used a model of exacerbated non-alcoholic fatty liver disease based on high-fat feeding at thermoneutral temperature. Male C57BL/6N mice were fed for 24 weeks a lard-based diet given either alone (LHF) or supplemented with Omega-3 (30 mg/g diet) as PLs (krill oil; ω3PL) or TAGs (Epax 3000TG concentrate; ω3TG), which had a similar total content of EPA and DHA and their ratio. Substantial levels of TAG accumulation (~250 mg/g) but relatively low inflammation/fibrosis levels were achieved in the livers of control LHF mice. Liver steatosis was reduced by >40% in the ω3PL but not ω3TG group, and plasma ALT levels were markedly reduced (by 68%) in ω3PL mice as well. Krill oil administration also improved hepatic insulin sensitivity, and its effects were associated with high plasma adiponectin levels (150% of LHF mice) along with superior bioavailability of EPA, increased content of alkaloids stachydrine and trigonelline, suppression of lipogenic gene expression, and decreased diacylglycerol levels in the liver. This study reveals that in addition to Omega-3 PLs, other constituents of krill oil, such as alkaloids, may contribute to its strong antisteatotic effects in the liver.
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Affiliation(s)
- Gabriella Sistilli
- Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14220 Prague 4, Czech Republic; (G.S.); (V.K.); (T.C.); (I.I.); (K.B.); (M.O.); (P.K.); (O.H.); (O.K.); (J.K.)
- Department of Physiology, Faculty of Science, Charles University, Vinicna 7, 12844 Prague 2, Czech Republic
| | - Veronika Kalendova
- Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14220 Prague 4, Czech Republic; (G.S.); (V.K.); (T.C.); (I.I.); (K.B.); (M.O.); (P.K.); (O.H.); (O.K.); (J.K.)
- Department of Physiology, Faculty of Science, Charles University, Vinicna 7, 12844 Prague 2, Czech Republic
| | - Tomas Cajka
- Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14220 Prague 4, Czech Republic; (G.S.); (V.K.); (T.C.); (I.I.); (K.B.); (M.O.); (P.K.); (O.H.); (O.K.); (J.K.)
| | - Illaria Irodenko
- Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14220 Prague 4, Czech Republic; (G.S.); (V.K.); (T.C.); (I.I.); (K.B.); (M.O.); (P.K.); (O.H.); (O.K.); (J.K.)
- Department of Physiology, Faculty of Science, Charles University, Vinicna 7, 12844 Prague 2, Czech Republic
| | - Kristina Bardova
- Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14220 Prague 4, Czech Republic; (G.S.); (V.K.); (T.C.); (I.I.); (K.B.); (M.O.); (P.K.); (O.H.); (O.K.); (J.K.)
| | - Marina Oseeva
- Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14220 Prague 4, Czech Republic; (G.S.); (V.K.); (T.C.); (I.I.); (K.B.); (M.O.); (P.K.); (O.H.); (O.K.); (J.K.)
- Department of Physiology, Faculty of Science, Charles University, Vinicna 7, 12844 Prague 2, Czech Republic
| | - Petr Zacek
- Proteomics Core Facility, Faculty of Science, Charles University, Division BIOCEV, Prumyslova 595, 25250 Vestec, Czech Republic;
| | - Petra Kroupova
- Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14220 Prague 4, Czech Republic; (G.S.); (V.K.); (T.C.); (I.I.); (K.B.); (M.O.); (P.K.); (O.H.); (O.K.); (J.K.)
| | - Olga Horakova
- Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14220 Prague 4, Czech Republic; (G.S.); (V.K.); (T.C.); (I.I.); (K.B.); (M.O.); (P.K.); (O.H.); (O.K.); (J.K.)
| | - Karoline Lackner
- Institute of Pathology, Medical University of Graz, Neue Stiftingtalstraße 6, 8010 Graz, Austria;
| | - Amalia Gastaldelli
- Cardiometabolic Risk Unit, Institute of Clinical Physiology, National Research Council, Via Moruzzi 1, 56100 Pisa, Italy;
| | - Ondrej Kuda
- Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14220 Prague 4, Czech Republic; (G.S.); (V.K.); (T.C.); (I.I.); (K.B.); (M.O.); (P.K.); (O.H.); (O.K.); (J.K.)
| | - Jan Kopecky
- Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14220 Prague 4, Czech Republic; (G.S.); (V.K.); (T.C.); (I.I.); (K.B.); (M.O.); (P.K.); (O.H.); (O.K.); (J.K.)
| | - Martin Rossmeisl
- Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14220 Prague 4, Czech Republic; (G.S.); (V.K.); (T.C.); (I.I.); (K.B.); (M.O.); (P.K.); (O.H.); (O.K.); (J.K.)
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26
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Schittmayer M, Vujic N, Darnhofer B, Korbelius M, Honeder S, Kratky D, Birner-Gruenberger R. Spatially Resolved Activity-based Proteomic Profiles of the Murine Small Intestinal Lipases. Mol Cell Proteomics 2020; 19:2104-2115. [PMID: 33023980 PMCID: PMC7710144 DOI: 10.1074/mcp.ra120.002171] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 09/28/2020] [Indexed: 01/05/2023] Open
Abstract
Despite the crucial function of the small intestine in nutrient uptake our understanding of the molecular events underlying the digestive function is still rudimentary. Recent studies demonstrated that enterocytes do not direct the entire dietary triacylglycerol toward immediate chylomicron synthesis. Especially after high-fat challenges, parts of the resynthesized triacylglycerol are packaged into cytosolic lipid droplets for transient storage in the endothelial layer of the small intestine. The reason for this temporary storage of triacylglycerol is not completely understood. To utilize lipids from cytosolic lipid droplets for chylomicron synthesis in the endoplasmic reticulum, stored triacylglycerol has to be hydrolyzed either by cytosolic lipolysis or lipophagy. Interestingly, triacylglycerol storage and chylomicron secretion rates are unevenly distributed along the small intestine, with the proximal jejunum exhibiting the highest intermittent storage capacity. We hypothesize that correlating hydrolytic enzyme activities with the reported distribution of triacylglycerol storage and chylomicron secretion in different sections of the small intestine is a promising strategy to determine key enzymes in triacylglycerol remobilization. We employed a serine hydrolase specific activity-based labeling approach in combination with quantitative proteomics to identify and rank hydrolases based on their relative activity in 11 sections of the small intestine. Moreover, we identified several clusters of enzymes showing similar activity distribution along the small intestine. Merging our activity-based results with substrate specificity and subcellular localization known from previous studies, carboxylesterase 2e and arylacetamide deacetylase emerge as promising candidates for triacylglycerol mobilization from cytosolic lipid droplets in enterocytes.
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Affiliation(s)
- Matthias Schittmayer
- Institute of Chemical Technologies and Analytics, Vienna University of Technology, Vienna, Austria; Diagnostic and Research Institute of Pathology, Medical University Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria.
| | - Nemanja Vujic
- Gottfried Schatz Research Center, Medical University Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria
| | - Barbara Darnhofer
- Diagnostic and Research Institute of Pathology, Medical University Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria
| | - Melanie Korbelius
- Gottfried Schatz Research Center, Medical University Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria
| | - Sophie Honeder
- Diagnostic and Research Institute of Pathology, Medical University Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria
| | - Dagmar Kratky
- Gottfried Schatz Research Center, Medical University Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria.
| | - Ruth Birner-Gruenberger
- Institute of Chemical Technologies and Analytics, Vienna University of Technology, Vienna, Austria; Diagnostic and Research Institute of Pathology, Medical University Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria.
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27
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Littlejohn NK, Seban N, Liu CC, Srinivasan S. A feedback loop governs the relationship between lipid metabolism and longevity. eLife 2020; 9:58815. [PMID: 33078707 PMCID: PMC7575325 DOI: 10.7554/elife.58815] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 09/25/2020] [Indexed: 12/16/2022] Open
Abstract
The relationship between lipid metabolism and longevity remains unclear. Although fat oxidation is essential for weight loss, whether it remains beneficial when sustained for long periods, and the extent to which it may attenuate or augment lifespan remain important unanswered questions. Here, we develop an experimental handle in the Caenorhabditis elegans model system, in which we uncover the mechanisms that connect long-term fat oxidation with longevity. We find that sustained β-oxidation via activation of the conserved triglyceride lipase ATGL-1, triggers a feedback transcriptional loop that involves the mito-nuclear transcription factor ATFS-1, and a previously unknown and highly conserved repressor of ATGL-1 called HLH-11/AP4. This feedback loop orchestrates the dual control of fat oxidation and lifespan, and shields the organism from life-shortening mitochondrial stress in the face of continuous fat oxidation. Thus, we uncover one mechanism by which fat oxidation can be sustained for long periods without deleterious effects on longevity.
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Affiliation(s)
- Nicole K Littlejohn
- Department of Neuroscience and The Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, United States
| | - Nicolas Seban
- Department of Neuroscience and The Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, United States
| | - Chung-Chih Liu
- Skaggs Graduate School of Chemical and Biological Sciences, The Scripps Research Institute, La Jolla, United States
| | - Supriya Srinivasan
- Department of Neuroscience and The Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, United States
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28
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Kim YS, Kim SG. Endoplasmic reticulum stress and autophagy dysregulation in alcoholic and non-alcoholic liver diseases. Clin Mol Hepatol 2020; 26:715-727. [PMID: 32951410 PMCID: PMC7641579 DOI: 10.3350/cmh.2020.0173] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 08/31/2020] [Indexed: 12/15/2022] Open
Abstract
Alcoholic and non-alcoholic liver diseases begin from an imbalance in lipid metabolism in hepatocytes as the earliest response. Both liver diseases share common disease features and stages (i.e., steatosis, hepatitis, cirrhosis, and hepatocellular carcinoma). However, the two diseases have differential pathogenesis and clinical symptoms. Studies have elucidated the molecular basis underlying similarities and differences in the pathogenesis of the diseases; the factors contributing to the progression of liver diseases include depletion of sulfhydryl pools, enhanced levels of reactive oxygen and nitrogen intermediates, increased sensitivity of hepatocytes to toxic cytokines, mitochondrial dysfunction, and insulin resistance. Endoplasmic reticulum (ER) stress, which is caused by the accumulation of misfolded proteins and calcium depletion, contributes to the pathogenesis, often causing catastrophic cell death. Several studies have demonstrated a mechanism by which ER stress triggers liver disease progression. Autophagy is an evolutionarily conserved process that regulates organelle turnover and cellular energy balance through decomposing damaged organelles including mitochondria, misfolded proteins, and lipid droplets. Autophagy dysregulation also exacerbates liver diseases. Thus, autophagy-related molecules can be potential therapeutic targets for liver diseases. Since ER stress and autophagy are closely linked to each other, an understanding of the molecules, gene clusters, and networks engaged in these processes would be of help to find new remedies for alcoholic and non-alcoholic liver diseases. In this review, we summarize the recent findings and perspectives in the context of the molecular pathogenesis of the liver diseases.
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Affiliation(s)
- Yun Seok Kim
- College of Pharmacy, Seoul National University, Seoul, Korea
| | - Sang Geon Kim
- College of Pharmacy, Seoul National University, Seoul, Korea.,College of Pharmacy, Dongguk University, Goyang, Korea
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29
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Korbelius M, Vujic N, Sachdev V, Obrowsky S, Rainer S, Gottschalk B, Graier WF, Kratky D. ATGL/CGI-58-Dependent Hydrolysis of a Lipid Storage Pool in Murine Enterocytes. Cell Rep 2020; 28:1923-1934.e4. [PMID: 31412256 PMCID: PMC6713565 DOI: 10.1016/j.celrep.2019.07.030] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 03/29/2019] [Accepted: 07/11/2019] [Indexed: 12/22/2022] Open
Abstract
As circulating lipid levels are balanced by the rate of lipoprotein release and clearance from the plasma, lipid absorption in the small intestine critically contributes to the maintenance of whole-body lipid homeostasis. Within enterocytes, excessive triglycerides are transiently stored as cytosolic lipid droplets (cLDs), and their mobilization sustains lipid supply during interprandial periods. Using mice lacking adipose triglyceride lipase (ATGL) and its coactivator comparative gene identification-58 (CGI-58) exclusively in the intestine (intestine-specific double KO [iDKO]), we show that ATGL/CGI-58 are not involved in providing substrates for chylomicron synthesis. Massive intestinal cLD accumulation in iDKO mice independent of dietary lipids together with inefficient lipid incorporation into cLDs in the early absorption phase demonstrate the existence of a secretion/re-uptake cycle, corroborating the availability of two diverse cLD pools. This study identified ATGL/CGI-58 as critical players in the catabolism of basolaterally (blood) derived lipids and highlights the necessity to modify the current model of intestinal lipid metabolism.
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Affiliation(s)
- Melanie Korbelius
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Styria, Austria
| | - Nemanja Vujic
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Styria, Austria
| | - Vinay Sachdev
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Styria, Austria
| | - Sascha Obrowsky
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Styria, Austria
| | - Silvia Rainer
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Styria, Austria
| | - Benjamin Gottschalk
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Styria, Austria
| | - Wolfgang F Graier
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Styria, Austria; BioTechMed-Graz, 8010 Graz, Styria, Austria
| | - Dagmar Kratky
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Styria, Austria; BioTechMed-Graz, 8010 Graz, Styria, Austria.
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30
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Grasp55 -/- mice display impaired fat absorption and resistance to high-fat diet-induced obesity. Nat Commun 2020; 11:1418. [PMID: 32184397 PMCID: PMC7078302 DOI: 10.1038/s41467-020-14912-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 01/31/2020] [Indexed: 12/27/2022] Open
Abstract
The Golgi apparatus plays a central role in the intracellular transport of macromolecules. However, molecular mechanisms of Golgi-mediated lipid transport remain poorly understood. Here, we show that genetic inactivation of the Golgi-resident protein GRASP55 in mice reduces whole-body fat mass via impaired intestinal fat absorption and evokes resistance to high-fat diet induced body weight gain. Mechanistic analyses reveal that GRASP55 participates in the Golgi-mediated lipid droplet (LD) targeting of some LD-associated lipases, such as ATGL and MGL, which is required for sustained lipid supply for chylomicron assembly and secretion. Consequently, GRASP55 deficiency leads to reduced chylomicron secretion and abnormally large LD formation in intestinal epithelial cells upon exogenous lipid challenge. Notably, deletion of dGrasp in Drosophila causes similar defects of lipid accumulation in the midgut. These results highlight the importance of the Golgi complex in cellular lipid regulation, which is evolutionary conserved, and uncover potential therapeutic targets for obesity-associated diseases. The physiological roles of the Golgi reassembly-stacking protein 55 (GRASP55/GORASP55) remain largely elusive. Here, the authors show that the Golgi-resident protein GRASP55 plays a crucial role in lipid homeostasis by regulating intestinal lipid uptake.
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31
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Regulation of intestinal lipid metabolism: current concepts and relevance to disease. Nat Rev Gastroenterol Hepatol 2020; 17:169-183. [PMID: 32015520 DOI: 10.1038/s41575-019-0250-7] [Citation(s) in RCA: 223] [Impact Index Per Article: 55.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/02/2019] [Indexed: 12/21/2022]
Abstract
Lipids entering the gastrointestinal tract include dietary lipids (triacylglycerols, cholesteryl esters and phospholipids) and endogenous lipids from bile (phospholipids and cholesterol) and from shed intestinal epithelial cells (enterocytes). Here, we comprehensively review the digestion, uptake and intracellular re-synthesis of intestinal lipids as well as their packaging into pre-chylomicrons in the endoplasmic reticulum, their modification in the Golgi apparatus and the exocytosis of the chylomicrons into the lamina propria and subsequently to lymph. We also discuss other fates of intestinal lipids, including intestinal HDL and VLDL secretion, cytosolic lipid droplets and fatty acid oxidation. In addition, we highlight the applicability of these findings to human disease and the development of therapeutics targeting lipid metabolism. Finally, we explore the emerging role of the gut microbiota in modulating intestinal lipid metabolism and outline key questions for future research.
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32
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Zhang YX, Jiang ZY, Han SL, Li LY, Qiao F, Zhang ML, Du ZY. Inhibition of intestinal lipases alleviates the adverse effects caused by high-fat diet in Nile tilapia. FISH PHYSIOLOGY AND BIOCHEMISTRY 2020; 46:111-123. [PMID: 31520202 DOI: 10.1007/s10695-019-00701-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 09/02/2019] [Indexed: 06/10/2023]
Abstract
Intestinal lipases are fat-digesting enzymes, which play vital roles in lipid absorption in the intestine. To study the regulation of intestinal lipase activity in systemic lipid metabolism in fish, especially in the metabolic diseases caused by high-fat diet (HFD) feeding, we inhibited intestinal lipases in Nile tilapia to investigate the physiological consequences. In the present study, Nile tilapia were firstly fed with HFD (12% fat) for 6 weeks to establish a fatty fish model. Afterwards, Orlistat as a potent intestinal lipase inhibitor was added into the HFD for the following 5-week feeding trial, with two dietary doses (Orlistat16 group, 16 mg/kg body weight; Orlistat32 group, 32 mg/kg body weight). After the trial, both doses of Orlistat treatment significantly reduced intestinal lipase activity, fat absorption, hepatic lipid accumulation, and gene expression of lipogenesis, whereas increased gene expression of lipid catabolism. Moreover, intestinal lipase inhibition increased immune enzyme activities, antioxidant capacity, and gene expression of anti-inflammatory cytokines, whereas lowered gene expression of pro-inflammatory cytokines. Besides, Orlistat could also improve the structure of the intestine and increase expression of intestinal tight-coupling protein. Taken together, intestinal lipase inhibition alleviated the adverse effects caused by HFD in Nile tilapia. Thus, intestinal lipases played key roles in absorbing dietary lipid and could be a promising target in regulating systemic lipid metabolism in fish.
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Affiliation(s)
- Yu-Xue Zhang
- Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, 200241, People's Republic of China
| | - Zhe-Yue Jiang
- Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, 200241, People's Republic of China
| | - Si-Lan Han
- Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, 200241, People's Republic of China
| | - Ling-Yu Li
- Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, 200241, People's Republic of China
| | - Fang Qiao
- Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, 200241, People's Republic of China
| | - Mei-Ling Zhang
- Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, 200241, People's Republic of China
| | - Zhen-Yu Du
- Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, 200241, People's Republic of China.
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Yu L, Li Y, Grisé A, Wang H. CGI-58: Versatile Regulator of Intracellular Lipid Droplet Homeostasis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1276:197-222. [PMID: 32705602 PMCID: PMC8063591 DOI: 10.1007/978-981-15-6082-8_13] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Comparative gene identification-58 (CGI-58), also known as α/β-hydrolase domain-containing 5 (ABHD5), is a member of a large family of proteins containing an α/β-hydrolase-fold. CGI-58 is well-known as the co-activator of adipose triglyceride lipase (ATGL), which is a key enzyme initiating cytosolic lipid droplet lipolysis. Mutations in either the human CGI-58 or ATGL gene cause an autosomal recessive neutral lipid storage disease, characterized by the excessive accumulation of triglyceride (TAG)-rich lipid droplets in the cytoplasm of almost all cell types. CGI-58, however, has ATGL-independent functions. Distinct phenotypes associated with CGI-58 deficiency commonly include ichthyosis (scaly dry skin), nonalcoholic steatohepatitis, and hepatic fibrosis. Through regulated interactions with multiple protein families, CGI-58 controls many metabolic and signaling pathways, such as lipid and glucose metabolism, energy balance, insulin signaling, inflammatory responses, and thermogenesis. Recent studies have shown that CGI-58 regulates the pathogenesis of common metabolic diseases in a tissue-specific manner. Future studies are needed to molecularly define ATGL-independent functions of CGI-58, including the newly identified serine protease activity of CGI-58. Elucidation of these versatile functions of CGI-58 may uncover fundamental cellular processes governing lipid and energy homeostasis, which may help develop novel approaches that counter against obesity and its associated metabolic sequelae.
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Affiliation(s)
- Liqing Yu
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA.
| | - Yi Li
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Alison Grisé
- College of Computer, Math, and Natural Sciences, College of Behavioral and Social Sciences, University of Maryland, College Park, MD, USA
| | - Huan Wang
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
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Kounakis K, Chaniotakis M, Markaki M, Tavernarakis N. Emerging Roles of Lipophagy in Health and Disease. Front Cell Dev Biol 2019; 7:185. [PMID: 31552248 PMCID: PMC6746960 DOI: 10.3389/fcell.2019.00185] [Citation(s) in RCA: 84] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Accepted: 08/21/2019] [Indexed: 12/12/2022] Open
Abstract
The term lipophagy is used to describe the autophagic degradation of lipid droplets, the main lipid storage organelles of eukaryotic cells. Ever since its discovery in 2009, lipophagy has emerged as a significant component of lipid metabolism with important implications for organismal health. This review aims to provide a brief summary of our current knowledge on the mechanisms that are responsible for regulating lipophagy and the impact the process has under physiological and pathological conditions.
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Affiliation(s)
- Konstantinos Kounakis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology - Hellas, Heraklion, Greece.,Department of Basic Sciences, Medical School, University of Crete, Heraklion, Greece
| | - Manos Chaniotakis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology - Hellas, Heraklion, Greece.,Department of Chemistry, University of Crete, Heraklion, Greece
| | - Maria Markaki
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology - Hellas, Heraklion, Greece
| | - Nektarios Tavernarakis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology - Hellas, Heraklion, Greece.,Department of Basic Sciences, Medical School, University of Crete, Heraklion, Greece
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Li D, Rodia CN, Johnson ZK, Bae M, Muter A, Heussinger AE, Tambini N, Longo AM, Dong H, Lee JY, Kohan AB. Intestinal basolateral lipid substrate transport is linked to chylomicron secretion and is regulated by apoC-III. J Lipid Res 2019; 60:1503-1515. [PMID: 31152000 PMCID: PMC6718441 DOI: 10.1194/jlr.m092460] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 05/31/2019] [Indexed: 01/26/2023] Open
Abstract
Chylomicron metabolism is critical for determining plasma levels of triacylglycerols (TAGs) and cholesterol, both of which are risk factors for CVD. The rates of chylomicron secretion and remnant clearance are controlled by intracellular and extracellular factors, including apoC-III. We have previously shown that human apoC-III overexpression in mice (apoC-IIITg mice) decreases the rate of chylomicron secretion into lymph, as well as the TAG composition in chylomicrons. We now find that this decrease in chylomicron secretion is not due to the intracellular effects of apoC-III, but instead that primary murine enteroids are capable of taking up TAG from TAG-rich lipoproteins (TRLs) on their basolateral surface; and via Seahorse analyses, we find that mitochondrial respiration is induced by basolateral TRLs. Furthermore, TAG uptake into the enterocyte is inhibited when excess apoC-III is present on TRLs. In vivo, we find that dietary TAG is diverted from the cytosolic lipid droplets and driven toward mitochondrial FA oxidation when plasma apoC-III is high (or when basolateral substrates are absent). We propose that this pathway of basolateral lipid substrate transport (BLST) plays a physiologically relevant role in the maintenance of dietary lipid absorption and chylomicron secretion. Further, when apoC-III is in excess, it inhibits BLST and chylomicron secretion.
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Affiliation(s)
- Diana Li
- Department of Nutritional Sciences, University of Connecticut, Storrs, CT
| | - Cayla N Rodia
- Department of Nutritional Sciences, University of Connecticut, Storrs, CT
| | - Zania K Johnson
- Department of Nutritional Sciences, University of Connecticut, Storrs, CT
| | - Minkyung Bae
- Department of Nutritional Sciences, University of Connecticut, Storrs, CT
| | - Angelika Muter
- Department of Nutritional Sciences, University of Connecticut, Storrs, CT
| | - Amy E Heussinger
- Department of Nutritional Sciences, University of Connecticut, Storrs, CT
| | - Nicholas Tambini
- Department of Nutritional Sciences, University of Connecticut, Storrs, CT
| | - Austin M Longo
- Department of Nutritional Sciences, University of Connecticut, Storrs, CT
| | - Hongli Dong
- Department of Nutritional Sciences, University of Connecticut, Storrs, CT
| | - Ji-Young Lee
- Department of Nutritional Sciences, University of Connecticut, Storrs, CT
| | - Alison B Kohan
- Department of Nutritional Sciences, University of Connecticut, Storrs, CT.
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Yu B, Peng XH, Wang LY, Wang AB, Su YY, Chen JH, Zhang XW, Zhao DZ, Wang H, Pang DX, Ouyang HS, Tang XC, Zhang MJ. Abnormality of intestinal cholesterol absorption in ApcMin/+ mice with colon cancer cachexia. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2019; 12:759-767. [PMID: 31933883 PMCID: PMC6945172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 12/30/2018] [Accepted: 01/24/2019] [Indexed: 06/10/2023]
Abstract
Colorectal cancer syndrome has been one of the greatest concerns in the world, particularly in developed countries. Several epidemiological studies have shown that dyslipidemia may be associated with the progression of intestinal cachexia, but there is little research on the function of the small intestine, which is involved in blood lipid metabolism, in dyslipidemia. In the present study, we aimed to explore the function of intestinal cholesterol absorption in the ApcMin/+ mouse model using an intestinal lipid absorption test. We found that both triglyceride (TG) and total cholesterol (TC) uptake were inhibited in the intestine of ApcMin/+ mice with age and the intestinal peroxisome proliferator-activated receptor α (PPARα) downregulated the processes of β-oxidation, oxidative stress response, and cholesterol absorption in APC-deficient mice. In addition, reduced expression levels of farnesoid X receptor (FXR) and apical sodium-dependent bile acid transporter (ASBT) indicated that bile acid metabolism might be associated with intestinal cholesterol absorption in ApcMin/+ mice. Thus, our data suggested that the intestine plays an essential role in cholesterol uptake and that bile acid metabolism seems to cause a decrease in intestinal cholesterol uptake in ApcMin/+ mice.
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Affiliation(s)
- Biao Yu
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University Changchun, Jilin Province, China
| | - Xiao-Huan Peng
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University Changchun, Jilin Province, China
| | - Ling-Yu Wang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University Changchun, Jilin Province, China
| | - An-Bei Wang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University Changchun, Jilin Province, China
| | - Yan-Yan Su
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University Changchun, Jilin Province, China
| | - Jia-Huan Chen
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University Changchun, Jilin Province, China
| | - Xin-Wei Zhang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University Changchun, Jilin Province, China
| | - Da-Zhong Zhao
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University Changchun, Jilin Province, China
| | - He Wang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University Changchun, Jilin Province, China
| | - Da-Xin Pang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University Changchun, Jilin Province, China
| | - Hong-Sheng Ouyang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University Changchun, Jilin Province, China
| | - Xiao-Chun Tang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University Changchun, Jilin Province, China
| | - Ming-Jun Zhang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University Changchun, Jilin Province, China
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Leopold C, Duta-Mare M, Sachdev V, Goeritzer M, Maresch LK, Kolb D, Reicher H, Wagner B, Stojakovic T, Ruelicke T, Haemmerle G, Hoefler G, Sattler W, Kratky D. Hepatocyte-specific lysosomal acid lipase deficiency protects mice from diet-induced obesity but promotes hepatic inflammation. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1864:500-511. [PMID: 30639734 PMCID: PMC6372077 DOI: 10.1016/j.bbalip.2019.01.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 12/20/2018] [Accepted: 01/06/2019] [Indexed: 12/21/2022]
Abstract
Lysosomal acid lipase (LAL) hydrolyzes cholesteryl esters (CE) and triglycerides (TG) to generate fatty acids (FA) and cholesterol. LAL deficiency (LAL-D) in both humans and mice leads to hepatomegaly, hypercholesterolemia, and shortened life span. Despite its essential role in lysosomal neutral lipid catabolism, the cell type-specific contribution of LAL to disease progression is still elusive. To investigate the role of LAL in the liver in more detail and to exclude the contribution of LAL in macrophages, we generated hepatocyte-specific LAL-deficient mice (Liv-Lipa−/−) and fed them either chow or high fat/high cholesterol diets (HF/HCD). Comparable to systemic LAL-D, Liv-Lipa−/− mice were resistant to diet-induced obesity independent of food intake, movement, and energy expenditure. Reduced body weight gain was mainly due to reduced white adipose tissue depots. Furthermore, Liv-Lipa−/− mice exhibited improved glucose clearance during glucose and insulin tolerance tests compared to control mice. Analysis of hepatic lipid content revealed a massive reduction of TG, whereas CE concentrations were markedly increased, leading to CE crystal formation in the livers of Liv-Lipa−/− mice. Elevated plasma transaminase activities, increased pro-inflammatory cytokines and chemokines as well as hepatic macrophage infiltration indicated liver inflammation. Our data provide evidence that hepatocyte-specific LAL deficiency is sufficient to alter whole-body lipid and energy homeostasis in mice. We conclude that hepatic LAL plays a pivotal role by preventing liver damage and maintaining lipid and energy homeostasis, especially during high lipid availability.
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Affiliation(s)
- Christina Leopold
- Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Madalina Duta-Mare
- Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Vinay Sachdev
- Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | | | | | - Dagmar Kolb
- Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria; Center for Medical Research, Medical University of Graz, Graz, Austria
| | - Helga Reicher
- Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Bettina Wagner
- Institute of Laboratory Animal Science, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Tatjana Stojakovic
- Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Graz, Austria
| | - Thomas Ruelicke
- Institute of Laboratory Animal Science, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Guenter Haemmerle
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Gerald Hoefler
- Diagnostic and Research Institute of Pathology, Medical University of Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria
| | - Wolfgang Sattler
- Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria
| | - Dagmar Kratky
- Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria.
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38
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Han B, Yu B, Liu L, Xiu Y, Wang H. Experimental investigation of the strong stability, antibacterial and anti-inflammatory effect and high bioabsorbability of a perilla oil or linseed oil nanoemulsion system. RSC Adv 2019; 9:25739-25749. [PMID: 35530056 PMCID: PMC9070085 DOI: 10.1039/c9ra03595h] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 08/12/2019] [Indexed: 12/03/2022] Open
Abstract
Perilla oil (PO) and linseed oil (LO) are very rich in nutrients and have great potential market value. Using the Cremophor RH40-Span80 preparation system to make a perilla oil nanoemulsion (PON) or linseed oil nanoemulsion (LON) can improve the bioavailability and stability of these oils. The effect of different reaction conditions on the stability of the emulsion was investigated. The results showed that the PON and LON have good stability at pH ≥ 7, different storage temperatures (4 °C, 25 °C, 37 °C and 55 °C) and different NaCl concentrations (0, 2, 4, 6, 8 M). Meanwhile, it was found that the content of the lipid peroxidation product malondialdehyde (MDA) in the nanoemulsion did not change significantly over 7 days, further demonstrating the stability of the nanoemulsion. Through anti-inflammatory and antibacterial tests, it was found that the PON and LON have an effective inhibitory effect on inflammation; moreover, the PON inhibits the growth of Escherichia coli, Salmonella enteritidis and Pseudomonas tolaasii, and the LON has an inhibitory effect on Staphylococcus aureus and Pseudomonas tolaasii (inhibition zone > 10 mm). In addition, we found that there were no pathological differences in the heart, liver, spleen and kidney of Kunming mice between the PO and PON groups and the LO and LON groups. Furthermore, after intraperitoneal injection of P 407 into mice, the comparison between PON and PO and between LON and LO showed that the blood lipid levels of the mice in the PON and LON treatment groups increased, indicating that the absorption capacity of the small intestine of the mice for the PON and LON was enhanced. Therefore, the preparation of the PON and LON has good development prospects and opens up opportunities in the development of the food industry. Strong stability, antibacterial, anti-inflammatory effect and high bioabsorbability of a perilla oil or linseed oil nanoemulsion system.![]()
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Affiliation(s)
- Baoqing Han
- College of Food Sciences and Engineering
- Jilin University
- Changchun 130062
- China
| | - Biao Yu
- Jilin Provincial Key Laboratory of Animal Embryo Engineering
- College of Animal Sciences
- Jilin University
- Changchun 130062
- China
| | - Lu Liu
- College of Food Sciences and Engineering
- Jilin University
- Changchun 130062
- China
| | - Yi Xiu
- College of Food Sciences and Engineering
- Jilin University
- Changchun 130062
- China
| | - Hongsu Wang
- College of Food Sciences and Engineering
- Jilin University
- Changchun 130062
- China
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Yang P, Zhang H, Wan J, Hu J, Liu J, Wang J, Zhang Y, Yu LL. Dietary sn-2 palmitic triacylglycerols reduced faecal lipids, calcium contents and altered lipid metabolism in Sprague-Dawley rats. Int J Food Sci Nutr 2018; 70:474-483. [PMID: 30569770 DOI: 10.1080/09637486.2018.1541968] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
In this study, the impact of dietary sn-2 palmitic triacylglycerol (sn-2 PTAG) on faecal lipids, calcium excretion and lipid metabolic alternation was investigated in Sprague-Dawley (SD) rats fed with high-fat diet containing either palm olein (PO, sn-2 palmitic acid (PA) of 14.8%), sn-2 PTAG50 (sn-2 PA of 56.4%) or sn-2 PTAG70 (sn-2 PA of 72.4%), respectively. After 4-week feeding period, SD rats fed with sn-2 PTAGs showed reduced faecal soap fatty acids, neutral lipid and calcium excretion compared to those of PO-fed rats, whereas a significant difference was only observed for the sn-2 PTAG70-fed rats (p < .05). Moreover, dietary sn-2 PTAG70 also showed a significant effect on decreasing serum triacylglycerol (TAG) level, reducing perirenal adipocyte size and regulating lipid metabolism in small intestine and perirenal adipose tissue of SD rats. Significantly increased mRNA levels of genes involved in intestinal lipid anabolism as well as lipid catabolism were both observed in the sn-2 PTAG70-fed rats (p < .05). Meanwhile, dietary sn-2 PTAG70 also significantly up-regulated lipolysis, mitochondrial fatty acid oxidation and thermogenesis-related gene and protein levels in perirenal adipose tissue, which might be correlated with the reduced perirenal adipocyte size. Taken together, our findings indicated that sn-2 PTAG70 may have some beneficial effects on intestinal lipid utilisation and lipid metabolic activity for energy supply in visceral adipose tissue.
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Affiliation(s)
- Puyu Yang
- a Institute of Food and Nutraceutical Science, School of Agriculture and Biology , Shanghai Jiao Tong University , Shanghai , China
| | - Hong Zhang
- b Wilmar (Shanghai) Biotechnology Research & Development Center Co. Ltd , Shanghai , China
| | - Jianchun Wan
- b Wilmar (Shanghai) Biotechnology Research & Development Center Co. Ltd , Shanghai , China
| | - Jinyu Hu
- a Institute of Food and Nutraceutical Science, School of Agriculture and Biology , Shanghai Jiao Tong University , Shanghai , China
| | - Junchen Liu
- a Institute of Food and Nutraceutical Science, School of Agriculture and Biology , Shanghai Jiao Tong University , Shanghai , China
| | - Jing Wang
- c Beijing Advanced Innovation Center for Food Nutrition and Human Health , Beijing Technology & Business University (BTBU) , Beijing , China
| | - Yaqiong Zhang
- a Institute of Food and Nutraceutical Science, School of Agriculture and Biology , Shanghai Jiao Tong University , Shanghai , China
| | - Liangli Lucy Yu
- d Department of Nutrition and Food Science , University of Maryland , College Park , ML , USA
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Xiao C, Stahel P, Lewis GF. Regulation of Chylomicron Secretion: Focus on Post-Assembly Mechanisms. Cell Mol Gastroenterol Hepatol 2018; 7:487-501. [PMID: 30819663 PMCID: PMC6396431 DOI: 10.1016/j.jcmgh.2018.10.015] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 10/23/2018] [Accepted: 10/25/2018] [Indexed: 02/06/2023]
Abstract
Rapid and efficient digestion and absorption of dietary triglycerides and other lipids by the intestine, the packaging of those lipids into lipoprotein chylomicron (CM) particles, and their secretion via the lymphatic duct into the blood circulation are essential in maintaining whole-body lipid and energy homeostasis. Biosynthesis and assembly of CMs in enterocytes is a complex multistep process that is subject to regulation by intracellular signaling pathways as well as by hormones, nutrients, and neural factors extrinsic to the enterocyte. Dysregulation of this process has implications for health and disease, contributing to dyslipidemia and a potentially increased risk of atherosclerotic cardiovascular disease. There is increasing recognition that, besides intracellular regulation of CM assembly and secretion, regulation of postassembly pathways also plays important roles in CM secretion. This review examines recent advances in our understanding of the regulation of CM secretion in relation to mobilization of intestinal lipid stores, drawing particular attention to post-assembly regulatory mechanisms, including intracellular trafficking of triglycerides in enterocytes, CM mobilization from the lamina propria, and regulated transport of CM by intestinal lymphatics.
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Affiliation(s)
- Changting Xiao
- Changting Xiao, PhD, Princess Margaret Cancer Research Tower 10-203, Medical and Related Science Centre, 101 College Street, Toronto, Ontario M5G 1L7, Canada. fax: (416) 581-7487.
| | | | - Gary F. Lewis
- Correspondence Address correspondence to: Gary F. Lewis, MD, FRCPC, Toronto General Hospital, 200 Elizabeth Street, EN12-218, Toronto, Ontario M5G 2C4, Canada. fax: (416) 340-3314.
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Of mice and men: The physiological role of adipose triglyceride lipase (ATGL). Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1864:880-899. [PMID: 30367950 PMCID: PMC6439276 DOI: 10.1016/j.bbalip.2018.10.008] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 10/18/2018] [Accepted: 10/19/2018] [Indexed: 12/12/2022]
Abstract
Adipose triglyceride lipase (ATGL) has been discovered 14 years ago and revised our view on intracellular triglyceride (TG) mobilization – a process termed lipolysis. ATGL initiates the hydrolysis of TGs to release fatty acids (FAs) that are crucial energy substrates, precursors for the synthesis of membrane lipids, and ligands of nuclear receptors. Thus, ATGL is a key enzyme in whole-body energy homeostasis. In this review, we give an update on how ATGL is regulated on the transcriptional and post-transcriptional level and how this affects the enzymes' activity in the context of neutral lipid catabolism. In depth, we highlight and discuss the numerous physiological functions of ATGL in lipid and energy metabolism. Over more than a decade, different genetic mouse models lacking or overexpressing ATGL in a cell- or tissue-specific manner have been generated and characterized. Moreover, pharmacological studies became available due to the development of a specific murine ATGL inhibitor (Atglistatin®). The identification of patients with mutations in the human gene encoding ATGL and their disease spectrum has underpinned the importance of ATGL in humans. Together, mouse models and human data have advanced our understanding of the physiological role of ATGL in lipid and energy metabolism in adipose and non-adipose tissues, and of the pathophysiological consequences of ATGL dysfunction in mice and men. Summary of mouse models with genetic or pharmacological manipulation of ATGL. Summary of patients with mutations in the human gene encoding ATGL. In depth discussion of the role of ATGL in numerous physiological processes in mice and men.
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Werno MW, Wilhelmi I, Kuropka B, Ebert F, Freund C, Schürmann A. The GTPase ARFRP1 affects lipid droplet protein composition and triglyceride release from intracellular storage of intestinal Caco-2 cells. Biochem Biophys Res Commun 2018; 506:259-265. [PMID: 30348522 DOI: 10.1016/j.bbrc.2018.10.092] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 10/15/2018] [Indexed: 11/17/2022]
Abstract
Intestinal release of dietary triglycerides via chylomicrons is the major contributor to elevated postprandial triglyceride levels. Dietary lipids can be transiently stored in cytosolic lipid droplets (LDs) located in intestinal enterocytes for later release. ADP ribosylation factor-related protein 1 (ARFRP1) participates in processes of LD growth in adipocytes and in lipidation of lipoproteins in liver and intestine. This study aims to explore the impact of ARFRP1 on LD organization and its interplay with chylomicron-mediated triglyceride release in intestinal-like Caco-2 cells. Suppression of Arfrp1 reduced release of intracellularly derived triglycerides (0.69-fold) and increased the abundance of transitional endoplasmic reticulum ATPase TERA/VCP, fatty acid synthase-associated factor 2 (FAF2) and perilipin 2 (Plin2) at the LD surface. Furthermore, TERA/VCP and FAF2 co-occurred more frequently with ATGL at LDs, suggesting a reduced adipocyte triglyceride lipase (ATGL)-mediated lipolysis. Accordingly, inhibition of lipolysis reduced lipid release from intracellular storage pools by the same magnitude as Arfrp1 depletion. Thus, the lack of Arfrp1 increases the abundance of lipolysis-modulating enzymes TERA/VCP, FAF2 and Plin2 at LDs, which might decrease lipolysis and reduce availability of fatty acids for triglyceride synthesis and their release via chylomicrons.
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Affiliation(s)
- Martin Witold Werno
- Department of Experimental Diabetology, German Institute of Human Nutrition Potsdam-Rehbruecke (DIfE), 14558 Nuthetal, Germany; German Center for Diabetes Research, München-Neuherberg, 85764 Neuherberg, Germany
| | - Ilka Wilhelmi
- Department of Experimental Diabetology, German Institute of Human Nutrition Potsdam-Rehbruecke (DIfE), 14558 Nuthetal, Germany; German Center for Diabetes Research, München-Neuherberg, 85764 Neuherberg, Germany
| | - Benno Kuropka
- Laboratory of Protein Biochemistry, Institute of Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany
| | - Franziska Ebert
- Department of Food Chemistry, Institute of Nutritional Science, University of Potsdam, Arthur-Scheunert-Allee 114-116, Nuthetal 14558, Germany
| | - Christian Freund
- Laboratory of Protein Biochemistry, Institute of Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany
| | - Annette Schürmann
- Department of Experimental Diabetology, German Institute of Human Nutrition Potsdam-Rehbruecke (DIfE), 14558 Nuthetal, Germany; German Center for Diabetes Research, München-Neuherberg, 85764 Neuherberg, Germany.
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43
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Hung YH, Buhman KK. DGAT1 deficiency disrupts lysosome function in enterocytes during dietary fat absorption. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1864:587-595. [PMID: 30342099 DOI: 10.1016/j.bbalip.2018.10.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 09/27/2018] [Accepted: 10/13/2018] [Indexed: 11/25/2022]
Abstract
Enterocytes, the absorptive cells of the small intestine, mediate the process of dietary fat absorption by secreting triacylglycerol (TAG) into circulation. When levels of dietary fat are high, TAG is stored in cytoplasmic lipid droplets (CLDs) and sequentially hydrolyzed for ultimate secretion. Mice with deficiency in acyl CoA: diacylglycerol acyltransferase 1 (Dgat1-/- mice) were previously reported to have a reduced rate of intestinal TAG secretion and abnormal TAG accumulation in enterocyte CLDs. This unique intestinal phenotype is critical to their resistance to diet-induced obesity; however, the underlying mechanism remains unclear. Emerging evidence shows that lysosomal TAG hydrolysis contributes to autophagy-mediated CLD mobilization termed lipophagy, and when disrupted results in CLD accumulation. In order to study how lipophagy contributes to the unique intestinal phenotype of Dgat1-/- mice, enterocytes from wild-type (WT) and Dgat1-/- mice were examined at 2 and 6 h after oral oil gavage. Through ultrastructural analysis we observed TAG present within autophagic vesicles (AVs) in mouse enterocytes, suggesting the role of lipophagy in intestinal CLD mobilization during dietary fat absorption. Furthermore, we found that Dgat1-/- mice had abnormal TAG accumulation within AVs and less acidic lysosomes compared to WT mice. Together these findings suggest that the delayed dietary fat absorption seen in Dgat1-/- mice is, in part, due to the dysregulated flux of autophagy-mediated CLD mobilization and impairment of lysosomal acidification in enterocytes. The present study highlights the critical role of lysosome in enterocyte CLD mobilization for proper dietary fat absorption.
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Affiliation(s)
- Yu-Han Hung
- Department of Nutrition Science, Purdue University, West Lafayette, IN, United States of America
| | - Kimberly K Buhman
- Department of Nutrition Science, Purdue University, West Lafayette, IN, United States of America.
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Zhou L, Yu M, Arshad M, Wang W, Lu Y, Gong J, Gu Y, Li P, Xu L. Coordination Among Lipid Droplets, Peroxisomes, and Mitochondria Regulates Energy Expenditure Through the CIDE-ATGL-PPARα Pathway in Adipocytes. Diabetes 2018; 67:1935-1948. [PMID: 29986925 DOI: 10.2337/db17-1452] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 06/29/2018] [Indexed: 11/13/2022]
Abstract
Metabolic homeostasis is maintained by an interplay among tissues, organs, intracellular organelles, and molecules. Cidea and Cidec are lipid droplet (LD)-associated proteins that promote lipid storage in brown adipose tissue (BAT) and white adipose tissue (WAT). Using ob/ob/Cidea-/- , ob/ob/Cidec-/- , and ob/ob/Cidea-/-/Cidec-/- mouse models and CIDE-deficient cells, we studied metabolic regulation during severe obesity to identify ways to maintain metabolic homeostasis and promote antiobesity effects. The phenotype of ob/ob/Cidea-/- mice was similar to that of ob/ob mice in terms of serum parameters, adipose tissues, lipid storage, and gene expression. Typical lipodystrophy accompanied by insulin resistance occurred in ob/ob/Cidec-/- mice, with ectopic storage of lipids in the BAT and liver. Interestingly, double deficiency of Cidea and Cidec activated both WAT and BAT to consume more energy and to increase insulin sensitivity compared with their behavior in the other three mouse models. Increased lipolysis, which occurred on the LD surfaces and released fatty acids, led to activated β-oxidation and oxidative phosphorylation in peroxisomes and mitochondria in CIDE-deficient adipocytes. The coordination among LDs, peroxisomes, and mitochondria was regulated by adipocyte triglyceride lipase (ATGL)-peroxisome proliferator-activated receptor α (PPARα). Double deficiency of Cidea and Cidec activated energy consumption in both WAT and BAT, which provided new insights into therapeutic approaches for obesity and diabetes.
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Affiliation(s)
- Linkang Zhou
- State Key Laboratory of Membrane Biology and Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, People's Republic of China
| | - Miao Yu
- State Key Laboratory of Membrane Biology and Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, People's Republic of China
| | - Muhammad Arshad
- Department of Bioinformatics and Biotechnology, International Islamic University, Islamabad, Pakistan
| | - Wenmin Wang
- State Key Laboratory of Membrane Biology and Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, People's Republic of China
| | - Ye Lu
- State Key Laboratory of Membrane Biology and Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, People's Republic of China
| | - Jingyi Gong
- State Key Laboratory of Membrane Biology and Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, People's Republic of China
| | - Yangnan Gu
- Center for Plant Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, People's Republic of China
| | - Peng Li
- State Key Laboratory of Membrane Biology and Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, People's Republic of China
| | - Li Xu
- State Key Laboratory of Membrane Biology and Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, People's Republic of China
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45
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Cifarelli V, Abumrad NA. Intestinal CD36 and Other Key Proteins of Lipid Utilization: Role in Absorption and Gut Homeostasis. Compr Physiol 2018; 8:493-507. [PMID: 29687890 PMCID: PMC6247794 DOI: 10.1002/cphy.c170026] [Citation(s) in RCA: 92] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Several proteins have been implicated in fatty acid (FA) transport by enterocytes including the scavenger receptor CD36 (SR-B2), the scavenger receptor B1 (SR-B1) a member of the CD36 family and the FA transport protein 4 (FATP4). Here, we review the regulation of enterocyte FA uptake and its function in lipid absorption including prechylomicron formation, assembly and transport. Emphasis is given to CD36, which is abundantly expressed along the digestive tract of rodents and humans and has been the most studied. We also address the pleiotropic functions of CD36 that go beyond lipid absorption and metabolism to include recent evidence of its impact on intestinal homeostasis and barrier maintenance. Areas of progress involving contribution of membrane phospholipid remodeling and of cytosolic FA-binding proteins, FABP1 and FABP2 to fat absorption will be covered. © 2018 American Physiological Society. Compr Physiol 8:493-507, 2018.
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Affiliation(s)
- Vincenza Cifarelli
- Department of Internal Medicine, Center for Human Nutrition, Washington University School of Medicine, St Louis, Missouri, USA
| | - Nada A. Abumrad
- Department of Internal Medicine, Center for Human Nutrition, Washington University School of Medicine, St Louis, Missouri, USA
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46
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Vujic N, Korbelius M, Leopold C, Duta-Mare M, Rainer S, Schlager S, Goeritzer M, Kolb D, Eichmann TO, Diwoky C, Zimmer A, Zimmermann R, Lass A, Radovic B, Kratky D. Monoglyceride lipase deficiency affects hepatic cholesterol metabolism and lipid-dependent gut transit in ApoE-/- mice. Oncotarget 2018; 8:33122-33136. [PMID: 28380440 PMCID: PMC5464855 DOI: 10.18632/oncotarget.16529] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Accepted: 03/14/2017] [Indexed: 11/25/2022] Open
Abstract
Monoglyceride lipase (MGL) hydrolyzes monoglycerides (MGs) to glycerol and fatty acids. Among various MG species MGL also degrades 2-arachidonoylglycerol (2-AG), the most abundant endocannabinoid and potent activator of cannabinoid receptors (CBR) 1 and 2. MGL-knockout (-/-) mice exhibit pronounced 2-AG accumulation, but lack central cannabimimetic effects due to CB1R desensitization. We have previously shown that MGL affects plaque stability in apolipoprotein E (ApoE)-/- mice, an established animal model for dyslipidemia and atherosclerosis. In the current study, we investigated functional consequences of MGL deficiency on lipid and energy metabolism in ApoE/MGL double knockout (DKO) mice. MGL deficiency affected hepatic cholesterol metabolism by causing increased cholesterol elimination via the biliary pathway. Moreover, DKO mice exhibit lipid-triggered delay in gastric emptying without major effects on overall triglyceride and cholesterol absorption. The observed phenotype of DKO mice is likely not a consequence of potentiated CB1R signaling but rather dependent on the activation of alternative signaling pathways. We conclude that MGL deficiency causes complex metabolic changes including cholesterol metabolism and regulation of gut transit independent of the endocannabinoid system.
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Affiliation(s)
- Nemanja Vujic
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Melanie Korbelius
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Christina Leopold
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Madalina Duta-Mare
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Silvia Rainer
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Stefanie Schlager
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Madeleine Goeritzer
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Dagmar Kolb
- Center for Medical Research, Institute of Cell Biology, Histology and Embryology, Medical University of Graz, Austria
| | - Thomas O Eichmann
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Clemens Diwoky
- Institute of Biomedical Engineering, Graz University of Technology, Graz, Austria.,Current address: Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Andreas Zimmer
- Institute of Pharmaceutical Sciences, University of Graz, Graz, Austria.,BioTechMed, Graz, Austria
| | - Robert Zimmermann
- Institute of Molecular Biosciences, University of Graz, Graz, Austria.,BioTechMed, Graz, Austria
| | - Achim Lass
- Institute of Molecular Biosciences, University of Graz, Graz, Austria.,BioTechMed, Graz, Austria
| | - Branislav Radovic
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria.,BioTechMed, Graz, Austria
| | - Dagmar Kratky
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria.,BioTechMed, Graz, Austria
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Xiao C, Stahel P, Carreiro AL, Buhman KK, Lewis GF. Recent Advances in Triacylglycerol Mobilization by the Gut. Trends Endocrinol Metab 2018; 29:151-163. [PMID: 29306629 DOI: 10.1016/j.tem.2017.12.001] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 11/30/2017] [Accepted: 12/04/2017] [Indexed: 11/26/2022]
Abstract
Dietary lipid absorption and lipoprotein secretion by the gut are important in maintaining whole-body energy homeostasis and have significant implications for health and disease. The processing of dietary lipids, including storage within and subsequent mobilization and transport from enterocyte cytoplasmic lipid droplets or other intestinal lipid storage pools (including the secretary pathway, lamina propria and lymphatics) and secretion of chylomicrons, involves coordinated steps that are subject to various controls. This review summarizes recent advances in our understanding of the mechanisms that underlie lipid storage and mobilization by small intestinal enterocytes and the intestinal lymphatic vasculature. Therapeutic targeting of lipid processing by the gut may provide opportunities for the treatment and prevention of dyslipidemia, and for improving health status.
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Affiliation(s)
- Changting Xiao
- Departments of Medicine and Physiology, Division of Endocrinology and Metabolism, Banting and Best Diabetes Centre, University of Toronto, Toronto, ON, Canada
| | - Priska Stahel
- Departments of Medicine and Physiology, Division of Endocrinology and Metabolism, Banting and Best Diabetes Centre, University of Toronto, Toronto, ON, Canada
| | - Alicia L Carreiro
- Department of Nutrition Science, Purdue University, West Lafayette, IN 47907, USA
| | - Kimberly K Buhman
- Department of Nutrition Science, Purdue University, West Lafayette, IN 47907, USA
| | - Gary F Lewis
- Departments of Medicine and Physiology, Division of Endocrinology and Metabolism, Banting and Best Diabetes Centre, University of Toronto, Toronto, ON, Canada.
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48
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Hints on ATGL implications in cancer: beyond bioenergetic clues. Cell Death Dis 2018; 9:316. [PMID: 29472527 PMCID: PMC5833653 DOI: 10.1038/s41419-018-0345-z] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 01/22/2018] [Accepted: 01/23/2018] [Indexed: 12/21/2022]
Abstract
Among metabolic rearrangements occurring in cancer cells, lipid metabolism alteration has become a hallmark, aimed at sustaining accelerated proliferation. In particular, fatty acids (FAs) are dramatically required by cancer cells as signalling molecules and membrane building blocks, beyond bioenergetics. Along with de novo biosynthesis, free FAs derive from dietary sources or from intracellular lipid droplets, which represent the storage of triacylglycerols (TAGs). Adipose triglyceride lipase (ATGL) is the rate-limiting enzyme of lipolysis, catalysing the first step of intracellular TAGs hydrolysis in several tissues. However, the roles of ATGL in cancer are still neglected though a putative tumour suppressor function of ATGL has been envisaged, as its expression is frequently reduced in different human cancers (e.g., lung, muscle, and pancreas). In this review, we will introduce lipid metabolism focusing on ATGL functions and regulation in normal cell physiology providing also speculative perspectives on potential non-energetic functions of ATGL in cancer. In particular, we will discuss how ATGL is implicated, mainly through the peroxisome proliferator-activated receptor-α (PPAR-α) signalling, in inflammation, redox homoeostasis and autophagy, which are well-known processes deregulated during cancer formation and/or progression.
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Auclair N, Melbouci L, St-Pierre D, Levy E. Gastrointestinal factors regulating lipid droplet formation in the intestine. Exp Cell Res 2018; 363:1-14. [PMID: 29305172 DOI: 10.1016/j.yexcr.2017.12.031] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 12/28/2017] [Accepted: 12/29/2017] [Indexed: 12/22/2022]
Abstract
Cytoplasmic lipid droplets (CLD) are considered as neutral lipid reservoirs, which protect cells from lipotoxicity. It became clear that these fascinating dynamic organelles play a role not only in energy storage and metabolism, but also in cellular lipid and protein handling, inter-organelle communication, and signaling among diverse functions. Their dysregulation is associated with multiple disorders, including obesity, liver steatosis and cardiovascular diseases. The central aim of this review is to highlight the link between intra-enterocyte CLD dynamics and the formation of chylomicrons, the main intestinal dietary lipid vehicle, after overviewing the morphology, molecular composition, biogenesis and functions of CLD.
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Affiliation(s)
- N Auclair
- Research Centre, CHU Sainte-Justine and Department of Montreal, Quebec, Canada H3T 1C5; Nutrition, Université de Montréal, Montreal, Quebec, Canada H3T 1C5
| | - L Melbouci
- Research Centre, CHU Sainte-Justine and Department of Montreal, Quebec, Canada H3T 1C5; Department of Sciences and Physical Activities, UQAM, Quebec, Canada H2X 1Y4
| | - D St-Pierre
- Research Centre, CHU Sainte-Justine and Department of Montreal, Quebec, Canada H3T 1C5; Department of Sciences and Physical Activities, UQAM, Quebec, Canada H2X 1Y4
| | - E Levy
- Research Centre, CHU Sainte-Justine and Department of Montreal, Quebec, Canada H3T 1C5; Nutrition, Université de Montréal, Montreal, Quebec, Canada H3T 1C5; Institute of Nutrition and Functional Foods (INAF), Université Laval, Quebec, Quebec, Canada G1V 0A6.
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50
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Zechner R, Madeo F, Kratky D. Cytosolic lipolysis and lipophagy: two sides of the same coin. Nat Rev Mol Cell Biol 2017; 18:671-684. [DOI: 10.1038/nrm.2017.76] [Citation(s) in RCA: 258] [Impact Index Per Article: 36.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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