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Gugliucci A. The chylomicron saga: time to focus on postprandial metabolism. Front Endocrinol (Lausanne) 2024; 14:1322869. [PMID: 38303975 PMCID: PMC10830840 DOI: 10.3389/fendo.2023.1322869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 12/28/2023] [Indexed: 02/03/2024] Open
Abstract
Since statins have had such tremendous therapeutic success over the last three decades, the field of atherosclerosis has become somewhat LDL-centric, dismissing the relevance of triglycerides (TG), particularly chylomicrons, in atherogenesis. Nonetheless, 50% of patients who take statins are at risk of developing atherosclerotic cardiovascular disease (ASCVD) and are unable to achieve their goal LDL-C levels. This residual risk is mediated, in part by triglyceride rich lipoproteins (TRL) and their remnants. Following his seminal investigation on the subject, Zilversmit proposed that atherosclerosis is a postprandial event in 1979 (1-4). In essence, the concept suggests that remnant cholesterol-rich chylomicron (CM) and very-low density lipoprotein (VLDL) particles play a role in atherogenesis. Given the foregoing, this narrative review addresses the most recent improvements in our understanding of postprandial dyslipidemia. The primary metabolic pathways of chylomicrons are discussed, emphasizing the critical physiological role of lipoprotein lipase and apoCIII, the importance of these particles' fluxes in the postprandial period, their catabolic rate, the complexities of testing postprandial metabolism, and the role of angiopoietin-like proteins in the partition of CM during the fed cycle. The narrative is rounded out by the dysregulation of postprandial lipid metabolism in insulin resistance states and consequent CVD risk, the clinical evaluation of postprandial dyslipidemia, current research limits, and potential future study directions.
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Affiliation(s)
- Alejandro Gugliucci
- Glycation, Oxidation and Disease Laboratory, Department of Research, Touro University California, Vallejo, CA, United States
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2
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Guo CG, Sun R, Wang X, Yuan Y, Xu Y, Li S, Sun X, Wang J, Hu X, Guo T, Chen XW, Xiao RP, Zhang X. Intestinal SURF4 is essential for apolipoprotein transport and lipoprotein secretion. Mol Metab 2024; 79:101847. [PMID: 38042368 PMCID: PMC10755498 DOI: 10.1016/j.molmet.2023.101847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 11/20/2023] [Accepted: 11/27/2023] [Indexed: 12/04/2023] Open
Abstract
OBJECTIVE Lipoprotein assembly and secretion in the small intestine are critical for dietary fat absorption. Surfeit locus protein 4 (SURF4) serves as a cargo receptor, facilitating the cellular transport of multiple proteins and mediating hepatic lipid secretion in vivo. However, its involvement in intestinal lipid secretion is not fully understood. In this study, we investigated the role of SURF4 in intestinal lipid absorption. METHODS We generated intestine-specific Surf4 knockout mice and characterized the phenotypes. Additionally, we investigated the underlying mechanisms of SURF4 in intestinal lipid secretion using proteomics and cellular models. RESULTS We unveiled that SURF4 is indispensable for apolipoprotein transport and lipoprotein secretion. Intestine-specific Surf4 knockout mice exhibited ectopic lipid deposition in the small intestine and hypolipidemia. Deletion of SURF4 impeded the transport of apolipoprotein A1 (ApoA1), proline-rich acidic protein 1 (PRAP1), and apolipoprotein B48 (ApoB48) and hindered the assembly and secretion of chylomicrons and high-density lipoproteins. CONCLUSIONS SURF4 emerges as a pivotal regulator of intestinal lipid absorption via mediating the secretion of ApoA1, PRAP1 and ApoB48.
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Affiliation(s)
- Chun-Guang Guo
- Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing 100871, China; Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, Beijing 100871, China
| | - Rui Sun
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou 310024, China; Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou 310024, China
| | - Xiao Wang
- Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing 100871, China; Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, Beijing 100871, China
| | - Ye Yuan
- Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing 100871, China; Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, Beijing 100871, China
| | - Yan Xu
- Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing 100871, China; Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, Beijing 100871, China
| | - Shihan Li
- Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing 100871, China; Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, Beijing 100871, China
| | - Xueting Sun
- Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing 100871, China; Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, Beijing 100871, China
| | - Jue Wang
- Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing 100871, China; Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, Beijing 100871, China
| | - Xinli Hu
- Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing 100871, China; Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, Beijing 100871, China
| | - Tiannan Guo
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou 310024, China; Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou 310024, China
| | - Xiao-Wei Chen
- Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing 100871, China; Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, Beijing 100871, China; Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China.
| | - Rui-Ping Xiao
- Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing 100871, China; Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, Beijing 100871, China; Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China.
| | - Xiuqin Zhang
- Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing 100871, China; Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, Beijing 100871, China.
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Mukherjee K, Wang R, Xiao C. Release of Lipids Stored in the Intestine by Glucagon-Like Peptide-2 Involves a Gut-Brain Neural Pathway. Arterioscler Thromb Vasc Biol 2024; 44:192-201. [PMID: 37970717 DOI: 10.1161/atvbaha.123.320032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2023] [Accepted: 11/07/2023] [Indexed: 11/17/2023]
Abstract
BACKGROUND The gut hormone GLP-2 (glucagon-like peptide-2) plays important roles in lipid handling in the intestine. During postabsorptive stage, it releases preformed chylomicrons stored in the intestine, the underlying mechanisms of which are not well understood. Previous studies implicate the involvement of neural pathways in GLP-2's actions on lipid absorption in the intestine, but the role of such mechanisms in releasing postabsorptive lipid storage has not been established. METHODS Here, in mesenteric lymph duct cannulated rats, we directly tested whether gut-brain neural communication mediates GLP-2's effects on postabsorptive lipid mobilization in the intestine. We performed total subdiaphragmatic vagotomy to disrupt the gut-brain neural communication and analyzed lipid output 5 hours after a lipid load in response to intraperitoneal GLP-2 or saline. RESULTS Peripheral GLP-2 administration led to increased lymph lipid output and activation of proopiomelanocortin neurons in the arcuate nucleus of hypothalamus. Disruption of gut-brain neural communication via vagotomy blunted GLP-2's effects on promoting lipid release in the intestine. CONCLUSIONS These results, for the first time, demonstrate a novel mechanism in which postabsorptive mobilization of intestinal lipid storage by GLP-2 enlists a gut-brain neural pathway.
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Affiliation(s)
- Kundanika Mukherjee
- Department of Anatomy, Physiology and Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Rita Wang
- Department of Anatomy, Physiology and Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Changting Xiao
- Department of Anatomy, Physiology and Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada
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4
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Moschandrea C, Kondylis V, Evangelakos I, Herholz M, Schneider F, Schmidt C, Yang M, Ehret S, Heine M, Jaeckstein MY, Szczepanowska K, Schwarzer R, Baumann L, Bock T, Nikitopoulou E, Brodesser S, Krüger M, Frezza C, Heeren J, Trifunovic A, Pasparakis M. Mitochondrial dysfunction abrogates dietary lipid processing in enterocytes. Nature 2024; 625:385-392. [PMID: 38123683 PMCID: PMC10781618 DOI: 10.1038/s41586-023-06857-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 11/10/2023] [Indexed: 12/23/2023]
Abstract
Digested dietary fats are taken up by enterocytes where they are assembled into pre-chylomicrons in the endoplasmic reticulum followed by transport to the Golgi for maturation and subsequent secretion to the circulation1. The role of mitochondria in dietary lipid processing is unclear. Here we show that mitochondrial dysfunction in enterocytes inhibits chylomicron production and the transport of dietary lipids to peripheral organs. Mice with specific ablation of the mitochondrial aspartyl-tRNA synthetase DARS2 (ref. 2), the respiratory chain subunit SDHA3 or the assembly factor COX10 (ref. 4) in intestinal epithelial cells showed accumulation of large lipid droplets (LDs) in enterocytes of the proximal small intestine and failed to thrive. Feeding a fat-free diet suppressed the build-up of LDs in DARS2-deficient enterocytes, which shows that the accumulating lipids derive mostly from digested fat. Furthermore, metabolic tracing studies revealed an impaired transport of dietary lipids to peripheral organs in mice lacking DARS2 in intestinal epithelial cells. DARS2 deficiency caused a distinct lack of mature chylomicrons concomitant with a progressive dispersal of the Golgi apparatus in proximal enterocytes. This finding suggests that mitochondrial dysfunction results in impaired trafficking of chylomicrons from the endoplasmic reticulum to the Golgi, which in turn leads to storage of dietary lipids in large cytoplasmic LDs. Taken together, these results reveal a role for mitochondria in dietary lipid transport in enterocytes, which might be relevant for understanding the intestinal defects observed in patients with mitochondrial disorders5.
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Affiliation(s)
- Chrysanthi Moschandrea
- Institute for Genetics, University of Cologne, Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Vangelis Kondylis
- Institute for Pathology, Medical Faculty and University Hospital of Cologne, University of Cologne, Cologne, Germany
- Center for Molecular Medicine (CMMC), University of Cologne, Cologne, Germany
| | - Ioannis Evangelakos
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Marija Herholz
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
- Institute for Mitochondrial Diseases and Aging, Medical Faculty, University of Cologne, Cologne, Germany
| | - Farina Schneider
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
- Medical Faculty and University Hospital of Cologne, University of Cologne, Cologne, Germany
| | - Christina Schmidt
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
- Medical Faculty and University Hospital of Cologne, University of Cologne, Cologne, Germany
- MRC Cancer Unit, University of Cambridge, Hutchison/MRC Research Centre, Cambridge Biomedical Campus, Cambridge, UK
| | - Ming Yang
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
- Medical Faculty and University Hospital of Cologne, University of Cologne, Cologne, Germany
- MRC Cancer Unit, University of Cambridge, Hutchison/MRC Research Centre, Cambridge Biomedical Campus, Cambridge, UK
| | - Sandra Ehret
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Markus Heine
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Michelle Y Jaeckstein
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Karolina Szczepanowska
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
- Institute for Mitochondrial Diseases and Aging, Medical Faculty, University of Cologne, Cologne, Germany
| | - Robin Schwarzer
- Institute for Genetics, University of Cologne, Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Linda Baumann
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
- Institute for Mitochondrial Diseases and Aging, Medical Faculty, University of Cologne, Cologne, Germany
| | - Theresa Bock
- Institute for Genetics, University of Cologne, Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Efterpi Nikitopoulou
- MRC Cancer Unit, University of Cambridge, Hutchison/MRC Research Centre, Cambridge Biomedical Campus, Cambridge, UK
| | - Susanne Brodesser
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Marcus Krüger
- Institute for Genetics, University of Cologne, Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Christian Frezza
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
- Medical Faculty and University Hospital of Cologne, University of Cologne, Cologne, Germany
- MRC Cancer Unit, University of Cambridge, Hutchison/MRC Research Centre, Cambridge Biomedical Campus, Cambridge, UK
| | - Joerg Heeren
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Aleksandra Trifunovic
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany.
- Center for Molecular Medicine (CMMC), University of Cologne, Cologne, Germany.
- Institute for Mitochondrial Diseases and Aging, Medical Faculty, University of Cologne, Cologne, Germany.
| | - Manolis Pasparakis
- Institute for Genetics, University of Cologne, Cologne, Germany.
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany.
- Center for Molecular Medicine (CMMC), University of Cologne, Cologne, Germany.
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Anithasri A. An ode on the odyssey of lipids. Biochem Mol Biol Educ 2024; 52:127-128. [PMID: 37905739 DOI: 10.1002/bmb.21798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 09/30/2023] [Accepted: 10/18/2023] [Indexed: 11/02/2023]
Abstract
The poem Ode on the Odyssey of lipoproteins describes the structure, functions and metabolism of lipoproteins namely Chylomicrons, LDL, VLDL and HDL. This poem is a triolet with eight lines in each stanza. Odyssey is the travel experience of an adventurous journey when someone travels far and wide. This poem describes the transport adventures of Lipids when they travel in the form of lipoproteins. The poetic form of describing the metabolism of lipoproteins was intended to kindle the interest of the learners and to gain an imaginary experience in the metabolism of lipoproteins.
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Affiliation(s)
- Anbalagan Anithasri
- Department of Biochemistry, Government Villupuram Medical College, Villupuram, India
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6
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Wong A, Chu Y, Chen H, Feng W, Ji L, Qin C, Stocks MJ, Marlow M, Gershkovich P. Distribution of lamivudine into lymph node HIV reservoir. Int J Pharm 2023; 648:123574. [PMID: 37935311 DOI: 10.1016/j.ijpharm.2023.123574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 11/01/2023] [Accepted: 11/02/2023] [Indexed: 11/09/2023]
Abstract
Efficient delivery of antiretroviral agents to lymph nodes is important to decrease the size of the HIV reservoir within the lymphatic system. Lamivudine (3TC) is used in first-line regimens for the treatment of HIV. As a highly hydrophilic small molecule, 3TC is not predicted to associate with chylomicrons and therefore should have negligible uptake into intestinal lymphatics following oral administration. Similarly, negligible amounts of 3TC are predicted to be transported into peripheral lymphatics following subcutaneous (SC) injection due to the faster flow rate of blood in comparison to lymph. In this work, we performed pharmacokinetic and biodistribution studies of 3TC in rats following oral lipid-based, oral lipid-free, SC, and intravenous (IV) administrations. In the oral administration studies, mesenteric lymph nodes (MLNs) had significantly higher 3TC concentrations compared to other lymph nodes, with mean tissue:serum ratios ranging from 1.4 to 2.9. However, cells and chylomicrons found in mesenteric lymph showed low-to-undetectable concentrations. In SC studies, administration-side (right) draining inguinal and popliteal lymph nodes had significantly higher concentrations (tissue:serum ratios as high as 3.2) than corresponding left-side nodes. In IV studies, lymph nodes had lower mean tissue:serum ratios ranging from 0.9 to 1.4. We hypothesize that following oral or SC administration, slower permeation of this hydrophilic molecule into blood capillaries may result in considerable passive 3TC penetration into lymphatic vessels. Further studies will be needed to clarify the mechanism of delivery of 3TC and similar antiretroviral drugs into the lymph nodes.
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Affiliation(s)
- Abigail Wong
- School of Pharmacy, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Yenju Chu
- School of Pharmacy, University of Nottingham, University Park, Nottingham NG7 2RD, UK; Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Haojie Chen
- School of Pharmacy, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Wanshan Feng
- School of Pharmacy, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Liuhang Ji
- School of Pharmacy, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Chaolong Qin
- School of Pharmacy, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Michael J Stocks
- School of Pharmacy, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Maria Marlow
- School of Pharmacy, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Pavel Gershkovich
- School of Pharmacy, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
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Auclair N, Sané AT, Ahmarani L, Ould-Chikh NEH, Patey N, Beaulieu JF, Delvin E, Spahis S, Levy E. High-fat diet reveals the impact of Sar1b defects on lipid and lipoprotein profile and cholesterol metabolism. J Lipid Res 2023; 64:100423. [PMID: 37558128 PMCID: PMC10518719 DOI: 10.1016/j.jlr.2023.100423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 07/26/2023] [Accepted: 07/28/2023] [Indexed: 08/11/2023] Open
Abstract
Biallelic pathogenic variants of the Sar1b gene cause chylomicron retention disease (CRD) whose central phenotype is the inability to secrete chylomicrons. Patients with CRD experience numerous clinical symptoms such as gastrointestinal, hepatic, neuromuscular, ophthalmic, and cardiological abnormalities. Recently, the production of mice expressing either a targeted deletion or mutation of Sar1b recapitulated biochemical and gastrointestinal defects associated with CRD. The present study was conducted to better understand little-known aspects of Sar1b mutations, including mouse embryonic development, lipid profile, and lipoprotein composition in response to high-fat diet, gut and liver cholesterol metabolism, sex-specific effects, and genotype-phenotype differences. Sar1b deletion and mutation produce a lethal phenotype in homozygous mice, which display intestinal lipid accumulation without any gross morphological abnormalities. On high-fat diet, mutant mice exhibit more marked abnormalities in body composition, adipose tissue and liver weight, plasma cholesterol, non-HDL cholesterol and polyunsaturated fatty acids than those on the regular Chow diet. Divergences were also noted in lipoprotein lipid composition, lipid ratios (serving as indices of particle size) and lipoprotein-apolipoprotein distribution. Sar1b defects significantly reduce gut cholesterol accumulation while altering key players in cholesterol metabolism. Noteworthy, variations were observed between males and females, and between Sar1b deletion and mutation phenotypes. Overall, mutant animal findings reveal the importance of Sar1b in several biochemical, metabolic and developmental processes.
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Affiliation(s)
- Nickolas Auclair
- Research Center, CHU Sainte-Justine, Université de Montréal, Montreal, Quebec, Canada; Department of Pharmacology & Physiology, Université de Montréal, Montreal, Quebec, Canada
| | - Alain T Sané
- Research Center, CHU Sainte-Justine, Université de Montréal, Montreal, Quebec, Canada
| | - Léna Ahmarani
- Research Center, CHU Sainte-Justine, Université de Montréal, Montreal, Quebec, Canada
| | | | - Nathalie Patey
- Research Center, CHU Sainte-Justine, Université de Montréal, Montreal, Quebec, Canada
| | - Jean-François Beaulieu
- Laboratory of Intestinal Physiopathology, Department of Immunology and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Edgard Delvin
- Research Center, CHU Sainte-Justine, Université de Montréal, Montreal, Quebec, Canada
| | - Schohraya Spahis
- Research Center, CHU Sainte-Justine, Université de Montréal, Montreal, Quebec, Canada; Department of Nutrition, Université de Montréal, Montreal, Quebec, Canada
| | - Emile Levy
- Research Center, CHU Sainte-Justine, Université de Montréal, Montreal, Quebec, Canada; Department of Pharmacology & Physiology, Université de Montréal, Montreal, Quebec, Canada; Department of Nutrition, Université de Montréal, Montreal, Quebec, Canada.
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8
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Zarkada G, Chen X, Zhou X, Lange M, Zeng L, Lv W, Zhang X, Li Y, Zhou W, Liu K, Chen D, Ricard N, Liao JK, Kim YB, Benedito R, Claesson-Welsh L, Alitalo K, Simons M, Ju R, Li X, Eichmann A, Zhang F. Chylomicrons Regulate Lacteal Permeability and Intestinal Lipid Absorption. Circ Res 2023; 133:333-349. [PMID: 37462027 PMCID: PMC10530007 DOI: 10.1161/circresaha.123.322607] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 07/06/2023] [Indexed: 08/05/2023]
Abstract
BACKGROUND Lymphatic vessels are responsible for tissue drainage, and their malfunction is associated with chronic diseases. Lymph uptake occurs via specialized open cell-cell junctions between capillary lymphatic endothelial cells (LECs), whereas closed junctions in collecting LECs prevent lymph leakage. LEC junctions are known to dynamically remodel in development and disease, but how lymphatic permeability is regulated remains poorly understood. METHODS We used various genetically engineered mouse models in combination with cellular, biochemical, and molecular biology approaches to elucidate the signaling pathways regulating junction morphology and function in lymphatic capillaries. RESULTS By studying the permeability of intestinal lacteal capillaries to lipoprotein particles known as chylomicrons, we show that ROCK (Rho-associated kinase)-dependent cytoskeletal contractility is a fundamental mechanism of LEC permeability regulation. We show that chylomicron-derived lipids trigger neonatal lacteal junction opening via ROCK-dependent contraction of junction-anchored stress fibers. LEC-specific ROCK deletion abolished junction opening and plasma lipid uptake. Chylomicrons additionally inhibited VEGF (vascular endothelial growth factor)-A signaling. We show that VEGF-A antagonizes LEC junction opening via VEGFR (VEGF receptor) 2 and VEGFR3-dependent PI3K (phosphatidylinositol 3-kinase)/AKT (protein kinase B) activation of the small GTPase RAC1 (Rac family small GTPase 1), thereby restricting RhoA (Ras homolog family member A)/ROCK-mediated cytoskeleton contraction. CONCLUSIONS Our results reveal that antagonistic inputs into ROCK-dependent cytoskeleton contractions regulate the interconversion of lymphatic junctions in the intestine and in other tissues, providing a tunable mechanism to control the lymphatic barrier.
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Affiliation(s)
- Georgia Zarkada
- Cardiovascular Research Center and Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06510-3221, USA
| | - Xun Chen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China
| | - Xuetong Zhou
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China
| | - Martin Lange
- Cardiovascular Research Center and Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06510-3221, USA
| | - Lei Zeng
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China
| | - Wenyu Lv
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China
| | - Xuan Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China
| | - Yunhua Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China
| | - Weibin Zhou
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China
| | - Keli Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China
| | - Dongying Chen
- Cardiovascular Research Center and Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06510-3221, USA
| | - Nicolas Ricard
- Cardiovascular Research Center and Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06510-3221, USA
| | - James K. Liao
- University of Arizona, College of Medicine, Banner University Medical Center, Tucson, AZ, 85724, USA
| | - Young-Bum Kim
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts
| | - Rui Benedito
- Molecular Genetics of Angiogenesis Group, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid E28029, Spain
| | - Lena Claesson-Welsh
- Uppsala University, Rudbeck, SciLifeLab and Beijer Laboratories, Department of Immunology, Genetics and Pathology, 751 85 Uppsala, Sweden
| | - Kari Alitalo
- Wihuri Research Institute and Translational Cancer Medicine Program, Biomedicum, University of Helsinki, Finland
| | - Michael Simons
- Cardiovascular Research Center and Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06510-3221, USA
| | - Rong Ju
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China
| | - Xuri Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China
| | - Anne Eichmann
- Cardiovascular Research Center and Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06510-3221, USA
- INSERM U970, Paris Cardiovascular Research Center, 75015 Paris, France
| | - Feng Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China
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9
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Shi R, Lu W, Tian Y, Wang B. Intestinal SEC16B modulates obesity by regulating chylomicron metabolism. Mol Metab 2023; 70:101693. [PMID: 36796587 PMCID: PMC9976576 DOI: 10.1016/j.molmet.2023.101693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 01/30/2023] [Accepted: 02/08/2023] [Indexed: 02/16/2023] Open
Abstract
OBJECTIVE Genome-wide association studies (GWAS) have identified genetic variants in SEC16 homolog B (SEC16B) locus to be associated with obesity and body mass index (BMI) in various populations. SEC16B encodes a scaffold protein located at endoplasmic reticulum (ER) exit sites that is implicated to participate in the trafficking of COPII vesicles in mammalian cells. However, the function of SEC16B in vivo, especially in lipid metabolism, has not been investigated. METHODS We generated Sec16b intestinal knockout (IKO) mice and assessed the impact of its deficiency on high-fat diet (HFD) induced obesity and lipid absorption in both male and female mice. We examined lipid absorption in vivo by acute oil challenge and fasting/HFD refeeding. Biochemical analyses and imaging studies were performed to understand the underlying mechanisms. RESULTS Our results showed that Sec16b intestinal knockout (IKO) mice, especially female mice, were protected from HFD-induced obesity. Loss of Sec16b in intestine dramatically reduced postprandial serum triglyceride output upon intragastric lipid load or during overnight fasting and HFD refeeding. Further studies showed that intestinal Sec16b deficiency impaired apoB lipidation and chylomicron secretion. CONCLUSIONS Our studies demonstrated that intestinal SEC16B is required for dietary lipid absorption in mice. These results revealed that SEC16B plays important roles in chylomicron metabolism, which may shed light on the association between variants in SEC16B and obesity in human.
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Affiliation(s)
- Ruicheng Shi
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Wei Lu
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Ye Tian
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Bo Wang
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Division of Nutritional Sciences, College of Agricultural, Consumer and Environmental Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Cancer Center at Illinois, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
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10
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Dedousis NL, Teng L, Kohan AB. The Isolation of Flowing Mesenteric Lymph in Mice to Quantify In Vivo Kinetics of Dietary Lipid Absorption and Chylomicron Secretion. J Vis Exp 2022. [PMID: 36533833 DOI: 10.3791/64338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
Intestinal lipoproteins, especially triglyceride-rich chylomicrons, are a major driver of metabolism, inflammation, and cardiovascular diseases. However, isolating intestinal lipoproteins is very difficult in vivo because they are first secreted from the small intestine into the mesenteric lymphatics. Chylomicron-containing lymph then empties into the subclavian vein from the thoracic duct to deliver components of the meal to the heart, lungs, and, ultimately, whole-body circulation. Isolating naïve chylomicrons is impossible from blood since chylomicron triglyceride undergoes hydrolysis immediately upon interaction with lipoprotein lipase and other lipoprotein receptors in circulation. Therefore, the original 2-day lymph fistula procedure, described by Bollman et al. in rats, has historically been used to isolate fresh mesenteric lymph before its entry into the thoracic vein. That protocol has been improved upon and professionalized by the laboratory of Patrick Tso for the last 45 years, allowing for the analysis of these critical lipoproteins and secretions from the gut. The Tso lymph fistula procedure has now been updated and is presented here visually for the first time. This revised procedure is a single-day surgical technique for installing a duodenal feeding tube, cannulating the mesenteric lymph duct, and collecting lymph after a meal in conscious mice. The major benefits of these new techniques include the ability to reproducibly collect lymph from mice (which harnesses the power of genetic mouse models); the reduced anesthesia time for mice during the implantation of the duodenal infusion tube and the lymph cannula; the ability to continuously sample lymph throughout the feeding and post-prandial period; the ability to quantitatively measure hormones and cytokines before their dilution and enzymatic hydrolysis in blood; and the ability to collect large quantities of lymph for isolating intestinal lipoproteins. This technique is a powerful tool for directly and quantitatively measuring dietary nutrient absorption, intestinal lipoprotein synthesis, and chylomicron secretion.
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Affiliation(s)
- Nikolaos L Dedousis
- Division of Endocrinology and Metabolism, Department of Medicine, School of Medicine, University of Pittsburgh
| | - Lihong Teng
- Division of Endocrinology and Metabolism, Department of Medicine, School of Medicine, University of Pittsburgh
| | - Alison B Kohan
- Division of Endocrinology and Metabolism, Department of Medicine, School of Medicine, University of Pittsburgh;
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11
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Dedousis N, Teng L, Kanshana JS, Kohan AB. A single-day mouse mesenteric lymph surgery in mice: an updated approach to study dietary lipid absorption, chylomicron secretion, and lymphocyte dynamics. J Lipid Res 2022; 63:100284. [PMID: 36152881 PMCID: PMC9646667 DOI: 10.1016/j.jlr.2022.100284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 09/15/2022] [Accepted: 09/16/2022] [Indexed: 02/04/2023] Open
Abstract
The intestine plays a crucial role in regulating whole-body lipid metabolism through its unique function of absorbing dietary fat. In the small intestine, absorptive epithelial cells emulsify hydrophobic dietary triglycerides (TAGs) prior to secreting them into mesenteric lymphatic vessels as chylomicrons. Except for short- and medium-chain fatty acids, which are directly absorbed from the intestinal lumen into portal vasculature, the only way for an animal to absorb dietary TAG is through the chylomicron/mesenteric lymphatic pathway. Isolating intestinal lipoproteins, including chylomicrons, is extremely difficult in vivo because of the dilution of postprandial lymph in the peripheral blood. In addition, once postprandial lymph enters the circulation, chylomicron TAGs are rapidly hydrolyzed. To enhance isolation of large quantities of pure postprandial chylomicrons, we have modified the Tso group's highly reproducible gold-standard double-cannulation technique in rats to enable single-day surgery and lymph collection in mice. Our technique has a significantly higher survival rate than the traditional 2-day surgical model and allows for the collection of greater than 400 μl of chylous lymph with high postprandial TAG concentrations. Using this approach, we show that after an intraduodenal lipid bolus, the mesenteric lymph contains naïve CD4+ T-cell populations that can be quantified by flow cytometry. In conclusion, this experimental approach represents a quantitative tool for determining dietary lipid absorption, intestinal lipoprotein dynamics, and mesenteric immunity. Our model may also be a powerful tool for studies of antigens, the microbiome, pharmacokinetics, and dietary compound absorption.
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Affiliation(s)
- Nikolaos Dedousis
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, School of Medicine, Pittsburgh, PA, USA
| | - Lihong Teng
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, School of Medicine, Pittsburgh, PA, USA
| | - Jitendra S Kanshana
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, School of Medicine, Pittsburgh, PA, USA
| | - Alison B Kohan
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, School of Medicine, Pittsburgh, PA, USA.
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12
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Vergès B. Intestinal lipid absorption and transport in type 2 diabetes. Diabetologia 2022; 65:1587-1600. [PMID: 35908083 DOI: 10.1007/s00125-022-05765-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 06/14/2022] [Indexed: 11/03/2022]
Abstract
Postprandial hyperlipidaemia is an important feature of diabetic dyslipidaemia and plays an important role in the development of cardiovascular disease in individuals with type 2 diabetes. Postprandial hyperlipidaemia in type 2 diabetes is secondary to increased chylomicron production by the enterocytes and delayed catabolism of chylomicrons and chylomicron remnants. Insulin and some intestinal hormones (e.g. glucagon-like peptide-1 [GLP-1]) influence intestinal lipid metabolism. In individuals with type 2 diabetes, insulin resistance and possibly reduced GLP-1 secretion are involved in the pathophysiology of postprandial hyperlipidaemia. Several factors are involved in the overproduction of chylomicrons: (1) increased expression of microsomal triglyceride transfer protein, which is a key enzyme in chylomicron synthesis; (2) higher stability and availability of apolipoprotein B-48; and (3) increased de novo lipogenesis. Individuals with type 2 diabetes present with disorders of cholesterol metabolism in the enterocytes with reduced absorption and increased synthesis. The increased production of chylomicrons in type 2 diabetes is also associated with a reduction in their catabolism, mostly because of a reduction in activity of lipoprotein lipase. Modification of the microbiota, which is observed in type 2 diabetes, may also generate disorders of intestinal lipid metabolism, but human data remain limited. Some glucose-lowering treatments significantly influence intestinal lipid absorption and transport. Postprandial hyperlipidaemia is reduced by metformin, pioglitazone, alpha-glucosidase inhibitors, dipeptidyl peptidase 4 inhibitors and GLP-1 agonists. The most pronounced effect is observed with GLP-1 agonists, which reduce chylomicron production significantly in individuals with type 2 diabetes and have a direct effect on the intestine by reducing the expression of genes involved in intestinal lipoprotein metabolism. The effect of sodium-glucose cotransporter 2 inhibitors on intestinal lipid metabolism needs to be clarified.
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Affiliation(s)
- Bruno Vergès
- Endocrinology-Diabetology Department, University-Hospital, Dijon, France.
- Inserm UMR 1231, Medical School, University of Burgundy-Franche Comté, Dijon, France.
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13
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Hoffman S, Alvares D, Adeli K. GLP-1 attenuates intestinal fat absorption and chylomicron production via vagal afferent nerves originating in the portal vein. Mol Metab 2022; 65:101590. [PMID: 36067913 PMCID: PMC9486018 DOI: 10.1016/j.molmet.2022.101590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 08/22/2022] [Accepted: 09/01/2022] [Indexed: 12/04/2022] Open
Abstract
Background/Objective GLP-1R agonists have been shown to reduce fasting and postprandial plasma lipids, both of which are independent risk factors for the development of cardiovascular disease. However, how endogenous GLP-1 – which is rapidly degraded – modulates intestinal and hepatic lipid metabolism is less clear. A vagal gut-brain-axis originating in the portal vein has been proposed as a possible mechanism for GLP-1’s anti-lipemic effects. Here we sought to examine the relationship between vagal GLP-1 signalling and intestinal lipid absorption and lipoprotein production. Methods Syrian golden hamsters or C57BL/6 mice received portal vein injections of GLP-1(7-36), and postprandial and fasting plasma TG, TRL TG, or VLDL TG were examined. These experiments were repeated during sympathetic blockade, and under a variety of pharmacological or surgical deafferentation techniques. In addition, hamsters received nodose ganglia injections of a GLP-1R agonist or antagonist to further probe the vagal pathway. Peripheral studies were repeated in a novel GLP-1R KO hamster model and in our diet-induced hamster models of insulin resistance. Results GLP-1(7-36) site-specifically reduced postprandial and fasting plasma lipids in both hamsters and mice. These inhibitory effects of GLP-1 were investigated via pharmacological and surgical denervation experiments and found to be dependent on intact afferent vagal signalling cascades and efferent changes in sympathetic tone. Furthermore, GLP-1R agonism in the nodose ganglia resulted in markedly reduced postprandial plasma TG and TRL TG, and fasting VLDL TG and this nodose GLP-1R activity was essential for portal GLP-1s effect. Notably, portal and nodose ganglia GLP-1 effects were lost in GLP-1R KO hamsters and following diet-induced insulin resistance. Conclusion Our data demonstrates for the first time that portal GLP-1 modulates postprandial and fasting lipids via a complex vagal gut–brain–liver axis. Importantly, loss or interference with this signalling axis via surgical, pharmacological, or dietary intervention resulted in the loss of portal GLP-1s anti-lipemic effects. This supports emerging evidence that native GLP-1 works primarily through a vagal neuroendocrine mechanism.
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Affiliation(s)
- Simon Hoffman
- Molecular Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, M5G 1X8, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, M5S 1A8, Canada.
| | - Danielle Alvares
- Molecular Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, M5G 1X8, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, M5S 1A8, Canada.
| | - Khosrow Adeli
- Molecular Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, M5G 1X8, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, M5S 1A8, Canada.
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14
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Grande EM, Raka F, Hoffman S, Adeli K. GLP-2 Regulation of Dietary Fat Absorption and Intestinal Chylomicron Production via Neuronal Nitric Oxide Synthase (nNOS) Signaling. Diabetes 2022; 71:1388-1399. [PMID: 35476805 DOI: 10.2337/db21-1053] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 04/17/2022] [Indexed: 11/13/2022]
Abstract
Postprandial dyslipidemia is a metabolic condition commonly associated with insulin-resistant states, such as obesity and type 2 diabetes. It is characterized by the overproduction of intestinal chylomicron particles and excess atherogenic chylomicron remnants in circulation. We have previously shown that glucagon-like peptide 2 (GLP-2) augments dietary fat uptake and chylomicron production in insulin-resistant states; however, the underlying mechanisms remain unclear. Previous studies have implicated nitric oxide (NO) in the absorptive actions of GLP-2. In this study, we report a novel role for neuronal NO synthase (nNOS)-mediated NO generation in lipid uptake and chylomicron formation based on studies in C57BL/6J mice, nNOS-/- mice, and Syrian golden hamsters after intraduodenal and oral fat administration. GLP-2 treatment in wild-type (WT) mice significantly increased postprandial lipid accumulation and circulating apolipoprotein B48 protein levels, while these effects were abolished in nNOS-/- mice. nNOS inhibition in Syrian golden hamsters and protein kinase G (PKG) inhibition in WT mice also abrogated the effect of GLP-2 on postprandial lipid accumulation. These studies demonstrate a novel mechanism in which nNOS-generated NO is crucial for GLP-2-mediated lipid absorption and chylomicron production in both mouse and hamster models. Overall, our data implicate an nNOS-PKG-mediated pathway in GLP-2-mediated stimulation of dietary fat absorption and intestinal chylomicron production.
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Affiliation(s)
- Elisabeth M Grande
- Molecular Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Fitore Raka
- Molecular Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Simon Hoffman
- Molecular Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Khosrow Adeli
- Molecular Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
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15
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Abstract
PURPOSE OF REVIEW Lymphatics are known to have active, regulated pumping by smooth muscle cells that enhance lymph flow, but whether active regulation of lymphatic pumping contributes significantly to the rate of appearance of chylomicrons (CMs) in the blood circulation (i.e., CM production rate) is not currently known. In this review, we highlight some of the potential mechanisms by which lymphatics may regulate CM production. RECENT FINDINGS Recent data from our lab and others are beginning to provide clues that suggest a more active role of lymphatics in regulating CM appearance in the circulation through various mechanisms. Potential contributors include apolipoproteins, glucose, glucagon-like peptide-2, and vascular endothelial growth factor-C, but there are likely to be many more. SUMMARY The digested products of dietary fats absorbed by the small intestine are re-esterified and packaged by enterocytes into large, triglyceride-rich CM particles or stored temporarily in intracellular cytoplasmic lipid droplets. Secreted CMs traverse the lamina propria and are transported via lymphatics and then the blood circulation to liver and extrahepatic tissues, where they are stored or metabolized as a rich energy source. Although indirect data suggest a relationship between lymphatic pumping and CM production, this concept requires more experimental evidence before we can be sure that lymphatic pumping contributes significantly to the rate of CM appearance in the blood circulation.
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Affiliation(s)
- Majid M Syed-Abdul
- Departments of Medicine and Physiology and Banting and Best Diabetes Centre, University of Toronto, Toronto, Ontario, Canada
| | - Lili Tian
- Departments of Medicine and Physiology and Banting and Best Diabetes Centre, University of Toronto, Toronto, Ontario, Canada
| | - Changting Xiao
- Department of Anatomy, Physiology and Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Gary F Lewis
- Departments of Medicine and Physiology and Banting and Best Diabetes Centre, University of Toronto, Toronto, Ontario, Canada
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16
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Taskinen MR, Matikainen N, Björnson E, Söderlund S, Ainola M, Hakkarainen A, Lundbom N, Sihlbom C, Thorsell A, Andersson L, Adiels M, Hartmann B, Deacon CF, Holst JJ, Packard CJ, Borén J. Role of endogenous incretins in the regulation of postprandial lipoprotein metabolism. Eur J Endocrinol 2022; 187:75-84. [PMID: 35521766 DOI: 10.1530/eje-21-1187] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 04/22/2022] [Indexed: 11/08/2022]
Abstract
OBJECTIVE Incretins are known to influence lipid metabolism in the intestine when administered as pharmacologic agents. The aggregate influence of endogenous incretins on chylomicron production and clearance is less clear, particularly in light of opposing effects of co-secreted hormones. Here, we tested the hypothesis that physiological levels of incretins may impact on production or clearances rates of chylomicrons and VLDL. DESIGN AND METHODS A group of 22 overweight/obese men was studied to determine associations between plasma levels of glucagon-like peptides 1 and 2 (GLP-1 and GLP-2) and glucose-dependent insulinotropic polypeptide (GIP) after a fat-rich meal and the production and clearance rates of apoB48- and apoB100-containing triglyceride-rich lipoproteins. Subjects were stratified by above- and below-median incretin response (area under the curve). RESULTS Stratification yielded subgroups that differed about two-fold in incretin response. There were neither differences in apoB48 production rates in chylomicrons or VLDL fractions nor in apoB100 or triglyceride kinetics in VLDL between men with above- vs below-median incretin responses. The men with above-median GLP-1 and GLP-2 responses exhibited higher postprandial plasma and chylomicron triglyceride levels, but this could not be related to altered kinetic parameters. No differences were found between incretin response subgroups and particle clearance rates. CONCLUSION We found no evidence for a regulatory effect of endogenous incretins on contemporaneous chylomicron or VLDL metabolism following a standardised fat-rich meal. The actions of incretins at pharmacological doses may not be reflected at physiological levels of these hormones.
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Affiliation(s)
- Marja-Riitta Taskinen
- Research Programs Unit, Clinical and Molecular Metabolism, University of Helsinki, Helsinki, Finland
| | - Niina Matikainen
- Research Programs Unit, Clinical and Molecular Metabolism, University of Helsinki, Helsinki, Finland
- Endocrinology, Abdominal Center, Helsinki University Hospital, Helsinki, Finland
| | - Elias Björnson
- Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Sanni Söderlund
- Research Programs Unit, Clinical and Molecular Metabolism, University of Helsinki, Helsinki, Finland
- Endocrinology, Abdominal Center, Helsinki University Hospital, Helsinki, Finland
| | - Mari Ainola
- Research Programs Unit, Clinical and Molecular Metabolism, University of Helsinki, Helsinki, Finland
| | - Antti Hakkarainen
- HUS Medical Imaging Center, Radiology, Helsinki University Hospital, University of Helsinki, Helsinki, Finland
| | - Nina Lundbom
- HUS Medical Imaging Center, Radiology, Helsinki University Hospital, University of Helsinki, Helsinki, Finland
| | - Carina Sihlbom
- Proteomics Facility, University of Gothenburg, Gothenburg, Sweden
| | - Annika Thorsell
- Proteomics Facility, University of Gothenburg, Gothenburg, Sweden
| | - Linda Andersson
- Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Martin Adiels
- Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Bolette Hartmann
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Carolyn F Deacon
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- School of Biomedical Sciences, Ulster University, Coleraine, UK
| | - Jens J Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Chris J Packard
- Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, UK
| | - Jan Borén
- Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
- Wallenberg Laboratory, Sahlgrenska University Hospital, Gothenburg, Sweden
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17
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Zhu Q, Yang Q, Shen L, Qu J, Xu M, Wang DQH, Tso P, Liu M. Impact of Sequential Lipid Meals on Lymphatic Lipid Absorption and Transport in Rats. Genes (Basel) 2022; 13:277. [PMID: 35205322 PMCID: PMC8871868 DOI: 10.3390/genes13020277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 01/26/2022] [Accepted: 01/28/2022] [Indexed: 01/05/2023] Open
Abstract
The sequential meal pattern has recently received more attention because it reflects a phycological diet style for human beings. The present study investigated the effects of the second lipid meal on lymphatic lipid absorption and transport in adult rats following a previous lipid meal. Using the well-established lymph fistula model, we found that the second lipid meal significantly increased the lymphatic output of triglycerides, cholesterol, phospholipids, and non-esterified fatty acids compared with a single lipid meal. Besides that, the time reaching the peak of each lipid output was significantly faster compared with the first lipid meal. Additionally, the second lipid meal significantly increased the lymphatic output of apolipoprotein A-IV (ApoA-IV), but not apolipoprotein B-48 (ApoB-48) or apolipoprotein A-I (ApoA-I). Interestingly, the triglyceride/apoB-48 ratio was significantly increased after the second lipid meal, indicating the increased chylomicron size in the lymph. Finally, the second lipid meal increased the lymphatic output of rat mucosal mast cell protease II (RMCPII). No change was found in the expression of genes related to the permeability of lymphatic lacteals, including vascular endothelial growth factor-A (Vegfa), vascular endothelial growth factor receptor 1 (Flt1), and Neuropilin1 (Nrp1). Collectively, the second lipid meal led to the rapid appearance of bigger-sized chylomicrons in the lymph. It also increased the lymphatic output of various lipids and apoA-IV, and mucosal mast cell activity in the intestine.
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Affiliation(s)
- Qi Zhu
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45237, USA; (Q.Z.); (Q.Y.); (L.S.); (J.Q.); (M.X.); (P.T.)
| | - Qing Yang
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45237, USA; (Q.Z.); (Q.Y.); (L.S.); (J.Q.); (M.X.); (P.T.)
| | - Ling Shen
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45237, USA; (Q.Z.); (Q.Y.); (L.S.); (J.Q.); (M.X.); (P.T.)
| | - Jie Qu
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45237, USA; (Q.Z.); (Q.Y.); (L.S.); (J.Q.); (M.X.); (P.T.)
| | - Meifeng Xu
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45237, USA; (Q.Z.); (Q.Y.); (L.S.); (J.Q.); (M.X.); (P.T.)
| | - David Q.-H. Wang
- Department of Medicine and Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA;
| | - Patrick Tso
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45237, USA; (Q.Z.); (Q.Y.); (L.S.); (J.Q.); (M.X.); (P.T.)
| | - Min Liu
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45237, USA; (Q.Z.); (Q.Y.); (L.S.); (J.Q.); (M.X.); (P.T.)
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18
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Nahmias A, Stahel P, Tian L, Xiao C, Lewis GF. GLP-1 (Glucagon-Like Peptide-1) Is Physiologically Relevant for Chylomicron Secretion Beyond Its Known Pharmacological Role. Arterioscler Thromb Vasc Biol 2021; 41:1893-1900. [PMID: 33951941 DOI: 10.1161/atvbaha.121.316311] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Avital Nahmias
- Division of Endocrinology, Department of Medicine and Banting and Best Diabetes Centre, University of Toronto, Ontario, Canada (A.N., P.S., L.T., G.F.L.)
| | - Priska Stahel
- Division of Endocrinology, Department of Medicine and Banting and Best Diabetes Centre, University of Toronto, Ontario, Canada (A.N., P.S., L.T., G.F.L.)
| | - Lili Tian
- Division of Endocrinology, Department of Medicine and Banting and Best Diabetes Centre, University of Toronto, Ontario, Canada (A.N., P.S., L.T., G.F.L.)
| | - Changting Xiao
- Department of Anatomy, Physiology and Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, Canada (C.X.)
| | - Gary F Lewis
- Division of Endocrinology, Department of Medicine and Banting and Best Diabetes Centre, University of Toronto, Ontario, Canada (A.N., P.S., L.T., G.F.L.)
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19
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Trujillo‐Viera J, El‐Merahbi R, Schmidt V, Karwen T, Loza‐Valdes A, Strohmeyer A, Reuter S, Noh M, Wit M, Hawro I, Mocek S, Fey C, Mayer AE, Löffler MC, Wilhelmi I, Metzger M, Ishikawa E, Yamasaki S, Rau M, Geier A, Hankir M, Seyfried F, Klingenspor M, Sumara G. Protein Kinase D2 drives chylomicron-mediated lipid transport in the intestine and promotes obesity. EMBO Mol Med 2021; 13:e13548. [PMID: 33949105 PMCID: PMC8103097 DOI: 10.15252/emmm.202013548] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 03/16/2021] [Accepted: 03/17/2021] [Indexed: 12/12/2022] Open
Abstract
Lipids are the most energy-dense components of the diet, and their overconsumption promotes obesity and diabetes. Dietary fat content has been linked to the lipid processing activity by the intestine and its overall capacity to absorb triglycerides (TG). However, the signaling cascades driving intestinal lipid absorption in response to elevated dietary fat are largely unknown. Here, we describe an unexpected role of the protein kinase D2 (PKD2) in lipid homeostasis. We demonstrate that PKD2 activity promotes chylomicron-mediated TG transfer in enterocytes. PKD2 increases chylomicron size to enhance the TG secretion on the basolateral side of the mouse and human enterocytes, which is associated with decreased abundance of APOA4. PKD2 activation in intestine also correlates positively with circulating TG in obese human patients. Importantly, deletion, inactivation, or inhibition of PKD2 ameliorates high-fat diet-induced obesity and diabetes and improves gut microbiota profile in mice. Taken together, our findings suggest that PKD2 represents a key signaling node promoting dietary fat absorption and may serve as an attractive target for the treatment of obesity.
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Affiliation(s)
- Jonathan Trujillo‐Viera
- Rudolf‐Virchow‐ZentrumCenter for Integrative and Translational BioimagingUniversity of WürzburgWürzburgGermany
| | - Rabih El‐Merahbi
- Rudolf‐Virchow‐ZentrumCenter for Integrative and Translational BioimagingUniversity of WürzburgWürzburgGermany
| | - Vanessa Schmidt
- Rudolf‐Virchow‐ZentrumCenter for Integrative and Translational BioimagingUniversity of WürzburgWürzburgGermany
| | - Till Karwen
- Rudolf‐Virchow‐ZentrumCenter for Integrative and Translational BioimagingUniversity of WürzburgWürzburgGermany
| | - Angel Loza‐Valdes
- Nencki Institute of Experimental BiologyPolish Academy of SciencesWarszawaPoland
| | - Akim Strohmeyer
- Chair for Molecular Nutritional MedicineTechnical University of MunichTUM School of Life Sciences WeihenstephanFreisingGermany
- EKFZ ‐ Else Kröner‐Fresenius‐Center for Nutritional MedicineTechnical University of MunichMunichGermany
- ZIEL ‐ Institute for Food & HealthTechnical University of MunichFreisingGermany
| | - Saskia Reuter
- Rudolf‐Virchow‐ZentrumCenter for Integrative and Translational BioimagingUniversity of WürzburgWürzburgGermany
| | - Minhee Noh
- Rudolf‐Virchow‐ZentrumCenter for Integrative and Translational BioimagingUniversity of WürzburgWürzburgGermany
| | - Magdalena Wit
- Nencki Institute of Experimental BiologyPolish Academy of SciencesWarszawaPoland
| | - Izabela Hawro
- Nencki Institute of Experimental BiologyPolish Academy of SciencesWarszawaPoland
| | - Sabine Mocek
- Chair for Molecular Nutritional MedicineTechnical University of MunichTUM School of Life Sciences WeihenstephanFreisingGermany
- EKFZ ‐ Else Kröner‐Fresenius‐Center for Nutritional MedicineTechnical University of MunichMunichGermany
- ZIEL ‐ Institute for Food & HealthTechnical University of MunichFreisingGermany
| | - Christina Fey
- Fraunhofer Institute for Silicate Research (ISC)Translational Center Regenerative Therapies (TLC‐RT)WürzburgGermany
| | - Alexander E Mayer
- Rudolf‐Virchow‐ZentrumCenter for Integrative and Translational BioimagingUniversity of WürzburgWürzburgGermany
| | - Mona C Löffler
- Rudolf‐Virchow‐ZentrumCenter for Integrative and Translational BioimagingUniversity of WürzburgWürzburgGermany
| | - Ilka Wilhelmi
- Department of Experimental DiabetologyGerman Institute of Human Nutrition Potsdam‐RehbrueckeNuthetalGermany
- German Center for Diabetes Research (DZD)München‐NeuherbergGermany
| | - Marco Metzger
- Fraunhofer Institute for Silicate Research (ISC)Translational Center Regenerative Therapies (TLC‐RT)WürzburgGermany
| | - Eri Ishikawa
- Molecular ImmunologyResearch Institute for Microbial Diseases (RIMD)Osaka UniversitySuitaJapan
- Molecular ImmunologyImmunology Frontier Research Center (IFReC)Osaka UniversitySuitaJapan
| | - Sho Yamasaki
- Molecular ImmunologyResearch Institute for Microbial Diseases (RIMD)Osaka UniversitySuitaJapan
- Molecular ImmunologyImmunology Frontier Research Center (IFReC)Osaka UniversitySuitaJapan
| | - Monika Rau
- Division of HepatologyUniversity Hospital WürzburgWürzburgGermany
| | - Andreas Geier
- Division of HepatologyUniversity Hospital WürzburgWürzburgGermany
| | - Mohammed Hankir
- Department of General, Visceral, Transplant, Vascular and Pediatric SurgeryUniversity Hospital WürzburgWürzburgGermany
| | - Florian Seyfried
- Department of General, Visceral, Transplant, Vascular and Pediatric SurgeryUniversity Hospital WürzburgWürzburgGermany
| | - Martin Klingenspor
- Chair for Molecular Nutritional MedicineTechnical University of MunichTUM School of Life Sciences WeihenstephanFreisingGermany
- EKFZ ‐ Else Kröner‐Fresenius‐Center for Nutritional MedicineTechnical University of MunichMunichGermany
- ZIEL ‐ Institute for Food & HealthTechnical University of MunichFreisingGermany
| | - Grzegorz Sumara
- Rudolf‐Virchow‐ZentrumCenter for Integrative and Translational BioimagingUniversity of WürzburgWürzburgGermany
- Nencki Institute of Experimental BiologyPolish Academy of SciencesWarszawaPoland
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20
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Real JT, Ascaso JF. Lipid metabolism and classification of hyperlipaemias. Clin Investig Arterioscler 2021; 33 Suppl 1:3-9. [PMID: 33966810 DOI: 10.1016/j.arteri.2020.12.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 12/29/2020] [Indexed: 06/12/2023]
Abstract
This chapter summarises, and updates, lipid metabolism. Both pathways, exogenous metabolisms route via the chylomicrons, and the endogenous pathway of very low-density lipoproteins (VLDL) and low-density lipoproteins (LDL). The reverse cholesterol metabolism will also be mentioned. It also includes the current classification of hyperlipidaemias or hyperlipoproteinaemias, with a reminder of the phenotype classification, and further developments of the aetiological classification. Both parts have updated references, with which knowledge of this vast subject can be expanded.
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Affiliation(s)
- José T Real
- Unidad de Lípidos y Prevención Cardiovascular, Servicio de Endocrinología y Nutrición, Hospital Clínico Universitario de Valencia, Valencia, España; Departamento de Medicina, Universitat de València, Valencia, España; Instituto de Investigación Sanitaria INCLIVA, Valencia, España; CIBER de Diabetes y Enfermedades Metabólicas Asociadas - CIBERDEM, ISCIII, Madrid, España
| | - Juan F Ascaso
- Departamento de Medicina, Universitat de València, Valencia, España; Instituto de Investigación Sanitaria INCLIVA, Valencia, España; CIBER de Diabetes y Enfermedades Metabólicas Asociadas - CIBERDEM, ISCIII, Madrid, España.
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21
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Abstract
Chylomicrons and very-low-density lipoproteins (VLDLs) are large, complex cargos that may require specific chaperones for efficient transport from the ER to Golgi. In this issue of Cell Metabolism, Wang et al. (2020) identify SURF4, in coordination with SAR1B, as an essential player in COPII transport of VLDLs from ER to Golgi, suggesting that SURF4 may be a target for approaches aimed at reducing secretion of triglyceride-rich, atherogenic lipoproteins from the liver.
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Affiliation(s)
- Henry N Ginsberg
- Department of Medicine, Vagelos College of Physicians and Surgeons of Columbia University, New York, NY, USA.
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22
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Abstract
This study aimed to compare the distribution of vitamin E analogs, particularly α-tocopherol and δ-tocopherol, in mice fed with a normal diet and a high-fat and high-sucrose diet separately. We used male C57BL/6JJcl strain mice, which were divided into six groups (control [C], Cα, Cδ, high-fat and high-sucrose [H], Hα, and Hδ groups) and bred for 4 weeks. The additional quantity of α-tocopherol or E-mix D (containing 86.7% δ-tocopherol) into diet was 800 mg/kg diet. The final body weight was significantly higher in the H group than in the C group. However, the effects of vitamin E analog intake had no significant difference, with no synergy between vitamin E and diet. Similar results were obtained in epididymal fat weight. Moreover, α-tocopherol was mainly distributed in the liver in both the Cα group and Hα group, whereas δ-tocopherol mostly accumulated in the epididymal fat, in both the Cδ group and Hδ group. Also, δ-tocopherol was detected in all tissues in both groups. Both the α-tocopherol and δ-tocopherol levels in the epididymal fat were significantly lower in the H group than in the C group. In conclusion, our results suggest that a portion of δ-tocopherol was incorporated into the adipose tissue by chylomicron before arriving at the liver, and then it is metabolized in the liver.
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Affiliation(s)
- Chikako Kiyose
- Department of Nutrition and Life Science, Kanagawa Institute of Technology
| | - Hiroaki Nishikawa
- Department of Nutrition and Life Science, Kanagawa Institute of Technology
| | - Mana Nagase
- Department of Nutrition and Life Science, Kanagawa Institute of Technology
| | - Rieko Tanaka-Yachi
- Department of Pharmacology, National Center for Child Health and Development
| | - Chie Takahashi-Muto
- Department of Clinical Nutrition, Kitasato Junior College of Health and Hygienic Sciences
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23
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Lambadiari V, Korakas E, Tsimihodimos V. The Impact of Dietary Glycemic Index and Glycemic Load on Postprandial Lipid Kinetics, Dyslipidemia and Cardiovascular Risk. Nutrients 2020; 12:E2204. [PMID: 32722053 PMCID: PMC7468809 DOI: 10.3390/nu12082204] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 07/20/2020] [Accepted: 07/23/2020] [Indexed: 02/07/2023] Open
Abstract
Many recent studies have acknowledged postprandial hypetriglyceridemia as a distinct risk factor for cardiovascular disease. This dysmetabolic state is the result of the hepatic overproduction of very low-density lipoproteins (VLDLs) and intestinal secretion of chylomicrons (CMs), which leads to highly atherogenic particles and endothelial inflammation. Postprandial lipid metabolism does not only depend on consumed fat but also on the other classes of nutrients that a meal contains. Various mechanisms through which carbohydrates exacerbate lipidemia have been identified, especially for fructose, which stimulates de novo lipogenesis. Glycemic index and glycemic load, despite their intrinsic limitations, have been used as markers of the postprandial glucose and insulin response, and their association with metabolic health and cardiovascular events has been extensively studied with contradictory results. This review aims to discuss the importance and pathogenesis of postprandial hypertriglyceridemia and its association with cardiovascular disease. Then, we describe the mechanisms through which carbohydrates influence lipidemia and, through a brief presentation of the available clinical studies on glycemic index/glycemic load, we discuss the association of these indices with atherogenic dyslipidemia and address possible concerns and implications for everyday practice.
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Affiliation(s)
- Vaia Lambadiari
- Second Department of Internal Medicine and Research Institute, University General Hospital Attikon, 124 62 Haidari, Greece;
| | - Emmanouil Korakas
- Second Department of Internal Medicine and Research Institute, University General Hospital Attikon, 124 62 Haidari, Greece;
| | - Vasilios Tsimihodimos
- Department of Internal Medicine, School of Medicine, University of Ioannina, 451 10 Ioannina, Greece;
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24
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Chait A, Ginsberg HN, Vaisar T, Heinecke JW, Goldberg IJ, Bornfeldt KE. Remnants of the Triglyceride-Rich Lipoproteins, Diabetes, and Cardiovascular Disease. Diabetes 2020; 69:508-516. [PMID: 32198194 PMCID: PMC7085249 DOI: 10.2337/dbi19-0007] [Citation(s) in RCA: 108] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Accepted: 01/16/2020] [Indexed: 01/05/2023]
Abstract
Diabetes is now a pandemic disease. Moreover, a large number of people with prediabetes are at risk for developing frank diabetes worldwide. Both type 1 and type 2 diabetes increase the risk of atherosclerotic cardiovascular disease (CVD). Even with statin treatment to lower LDL cholesterol, patients with diabetes have a high residual CVD risk. Factors mediating the residual risk are incompletely characterized. An attractive hypothesis is that remnant lipoprotein particles (RLPs), derived by lipolysis from VLDL and chylomicrons, contribute to this residual risk. RLPs constitute a heterogeneous population of lipoprotein particles, varying markedly in size and composition. Although a universally accepted definition is lacking, for the purpose of this review we define RLPs as postlipolytic partially triglyceride-depleted particles derived from chylomicrons and VLDL that are relatively enriched in cholesteryl esters and apolipoprotein (apo)E. RLPs derived from chylomicrons contain apoB48, while those derived from VLDL contain apoB100. Clarity as to the role of RLPs in CVD risk is hampered by lack of a widely accepted definition and a paucity of adequate methods for their accurate and precise quantification. New specific methods for RLP quantification would greatly improve our understanding of their biology and role in promoting atherosclerosis in diabetes and other disorders.
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Affiliation(s)
- Alan Chait
- Department of Medicine, University of Washington Medicine Diabetes Institute, University of Washington, Seattle, WA
| | - Henry N Ginsberg
- Division of Preventive Medicine and Nutrition, Department of Medicine, Columbia University, New York, NY
| | - Tomas Vaisar
- Department of Medicine, University of Washington Medicine Diabetes Institute, University of Washington, Seattle, WA
| | - Jay W Heinecke
- Department of Medicine, University of Washington Medicine Diabetes Institute, University of Washington, Seattle, WA
| | - Ira J Goldberg
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, New York University, New York, NY
| | - Karin E Bornfeldt
- Department of Medicine, University of Washington Medicine Diabetes Institute, University of Washington, Seattle, WA
- Department of Pathology, University of Washington Medicine Diabetes Institute, University of Washington, Seattle, WA
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25
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Bittel AJ, Bittel DC, Mittendorfer B, Patterson BW, Okunade AL, Yoshino J, Porter LC, Abumrad NA, Reeds DN, Cade WT. A single bout of resistance exercise improves postprandial lipid metabolism in overweight/obese men with prediabetes. Diabetologia 2020; 63:611-623. [PMID: 31873788 PMCID: PMC7002271 DOI: 10.1007/s00125-019-05070-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Accepted: 11/06/2019] [Indexed: 12/21/2022]
Abstract
AIMS/HYPOTHESIS Prediabetes is associated with postprandial hypertriacylglycerolaemia. Resistance exercise acutely lowers postprandial plasma triacylglycerol (TG); however, the changes in lipid metabolism that mediate this reduction are poorly understood. The aim of this study was to identify the constitutive metabolic mechanisms underlying the changes in postprandial lipid metabolism after resistance exercise in obese men with prediabetes. METHODS We evaluated the effect of a single bout of whole-body resistance exercise (seven exercises, three sets, 10-12 repetitions at 80% of one-repetition maximum) on postprandial lipid metabolism in ten middle-aged (50 ± 9 years), overweight/obese (BMI: 33 ± 3 kg/m2), sedentary men with prediabetes (HbA1c >38 but <48 mmol/mol [>5.7% but <6.5%]), or fasting plasma glucose >5.6 mmol/l but <7.0 mmol/l or 2 h OGTT glucose >7.8 mmol/l but <11.1 mmol/l). We used a randomised, crossover design with a triple-tracer mixed meal test (ingested [(13C4)3]tripalmitin, i.v. [U-13C16]palmitate and [2H5]glycerol) to evaluate chylomicron-TG and total triacylglycerol-rich lipoprotein (TRL)-TG kinetics. We used adipose tissue and skeletal muscle biopsies to evaluate the expression of genes regulating lipolysis and lipid oxidation, skeletal muscle respirometry to evaluate oxidative capacity, and indirect calorimetry to assess whole-body lipid oxidation. RESULTS The single bout of resistance exercise reduced the lipaemic response to a mixed meal in obese men with prediabetes without changing chylomicron-TG or TRL-TG fractional clearance rates. However, resistance exercise reduced endogenous and meal-derived fatty acid incorporation into chylomicron-TG and TRL-TG. Resistance exercise also increased whole-body lipid oxidation, skeletal muscle mitochondrial respiration, oxidative gene expression in skeletal muscle, and the expression of key lipolysis genes in adipose tissue. CONCLUSIONS/INTERPRETATION A single bout of resistance exercise improves postprandial lipid metabolism in obese men with prediabetes, which may mitigate the risk for cardiovascular disease and type 2 diabetes.
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Affiliation(s)
- Adam J Bittel
- Program in Physical Therapy, Washington University, St Louis, Campus Box 8502, 4444 Forest Park Ave., St Louis, MO, 63110, USA.
| | - Daniel C Bittel
- Program in Physical Therapy, Washington University, St Louis, Campus Box 8502, 4444 Forest Park Ave., St Louis, MO, 63110, USA
| | - Bettina Mittendorfer
- Center for Human Nutrition, Washington University School of Medicine, St Louis, MO, USA
| | - Bruce W Patterson
- Center for Human Nutrition, Washington University School of Medicine, St Louis, MO, USA
| | - Adewole L Okunade
- Center for Human Nutrition, Washington University School of Medicine, St Louis, MO, USA
| | - Jun Yoshino
- Center for Human Nutrition, Washington University School of Medicine, St Louis, MO, USA
| | - Lane C Porter
- Center for Human Nutrition, Washington University School of Medicine, St Louis, MO, USA
| | - Nada A Abumrad
- Center for Human Nutrition, Washington University School of Medicine, St Louis, MO, USA
| | - Dominic N Reeds
- Center for Human Nutrition, Washington University School of Medicine, St Louis, MO, USA
| | - W Todd Cade
- Program in Physical Therapy, Washington University, St Louis, Campus Box 8502, 4444 Forest Park Ave., St Louis, MO, 63110, USA
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26
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Takanashi M, Kimura T, Li C, Tanaka M, Matsuhashi A, Yoshida H, Noda A, Xu P, Takase S, Okazaki S, Iizuka Y, Kumagai H, Ikeda Y, Gotoda T, Takahashi M, Yagyu H, Ishibashi S, Yamauchi T, Kadowaki T, Liang G, Okazaki H. Critical Role of SREBP-1c Large-VLDL Pathway in Environment-Induced Hypertriglyceridemia of Apo AV Deficiency. Arterioscler Thromb Vasc Biol 2020; 39:373-386. [PMID: 30700132 DOI: 10.1161/atvbaha.118.311931] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Objective- APOA5 variants are strongly associated with hypertriglyceridemia, as well as increased risks of cardiovascular disease and acute pancreatitis. Hypertriglyceridemia in apo AV dysfunction often aggravates by environmental factors such as high-carbohydrate diets or aging. To date, the molecular mechanisms by which these environmental factors induce hypertriglyceridemia are poorly defined, leaving the high-risk hypertriglyceridemia condition undertreated. Previously, we reported that LXR (liver X receptor)-SREBP (sterol regulatory element-binding protein)-1c pathway regulates large-VLDL (very low-density lipoprotein) production induced by LXR agonist. However, the pathophysiological relevance of the finding remains unknown. Approach and Results- Here, we reconstitute the environment-induced hypertriglyceridemia phenotype of human APOA5 deficiency in Apoa5-/- mice and delineate the role of SREBP-1c in vivo by generating Apoa5-/- ;Srebp-1c-/- mice. The Apoa5-/- mice, which showed moderate hypertriglyceridemia on a chow diet, developed severe hypertriglyceridemia on high-carbohydrate feeding or aging as seen in patients with human apo AV deficiency. These responses were nearly completely abolished in the Apoa5-/- ;Srebp-1c-/- mice. Further mechanistic studies revealed that in response to these environmental factors, SREBP-1c was activated to increase triglyceride synthesis and to permit the incorporation of triglyceride into abnormally large-VLDL particles, which require apo AV for efficient clearance. Conclusions- Severe hypertriglyceridemia develops only when genetic factors (apo AV deficiency) and environmental effects (SREBP-1c activation) coexist. We demonstrate that the regulated production of large-sized VLDL particles via SREBP-1c determines plasma triglyceride levels in apo AV deficiency. Our findings explain the long-standing enigma of the late-onset hypertriglyceridemia phenotype of apo AV deficiency and suggest a new approach to treat hypertriglyceridemia by targeting genes that mediate environmental effects.
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Affiliation(s)
- Mikio Takanashi
- From the Department of Diabetes and Metabolic Diseases (Mikio Takanashi, T. Kimura, C.L., M. Tanaka, A.M., H. Yoshida, A.N., P.X., S.T., S.O., Y. Iizuka, T.G., T.Y., T. Kadowaki, H.O.)
| | - Takeshi Kimura
- From the Department of Diabetes and Metabolic Diseases (Mikio Takanashi, T. Kimura, C.L., M. Tanaka, A.M., H. Yoshida, A.N., P.X., S.T., S.O., Y. Iizuka, T.G., T.Y., T. Kadowaki, H.O.)
| | - Chengcheng Li
- From the Department of Diabetes and Metabolic Diseases (Mikio Takanashi, T. Kimura, C.L., M. Tanaka, A.M., H. Yoshida, A.N., P.X., S.T., S.O., Y. Iizuka, T.G., T.Y., T. Kadowaki, H.O.)
| | - Masaki Tanaka
- From the Department of Diabetes and Metabolic Diseases (Mikio Takanashi, T. Kimura, C.L., M. Tanaka, A.M., H. Yoshida, A.N., P.X., S.T., S.O., Y. Iizuka, T.G., T.Y., T. Kadowaki, H.O.)
| | - Ako Matsuhashi
- From the Department of Diabetes and Metabolic Diseases (Mikio Takanashi, T. Kimura, C.L., M. Tanaka, A.M., H. Yoshida, A.N., P.X., S.T., S.O., Y. Iizuka, T.G., T.Y., T. Kadowaki, H.O.)
| | - Hiroki Yoshida
- From the Department of Diabetes and Metabolic Diseases (Mikio Takanashi, T. Kimura, C.L., M. Tanaka, A.M., H. Yoshida, A.N., P.X., S.T., S.O., Y. Iizuka, T.G., T.Y., T. Kadowaki, H.O.)
| | - Akari Noda
- From the Department of Diabetes and Metabolic Diseases (Mikio Takanashi, T. Kimura, C.L., M. Tanaka, A.M., H. Yoshida, A.N., P.X., S.T., S.O., Y. Iizuka, T.G., T.Y., T. Kadowaki, H.O.)
| | - Pengfei Xu
- From the Department of Diabetes and Metabolic Diseases (Mikio Takanashi, T. Kimura, C.L., M. Tanaka, A.M., H. Yoshida, A.N., P.X., S.T., S.O., Y. Iizuka, T.G., T.Y., T. Kadowaki, H.O.)
| | - Satoru Takase
- From the Department of Diabetes and Metabolic Diseases (Mikio Takanashi, T. Kimura, C.L., M. Tanaka, A.M., H. Yoshida, A.N., P.X., S.T., S.O., Y. Iizuka, T.G., T.Y., T. Kadowaki, H.O.)
| | - Sachiko Okazaki
- From the Department of Diabetes and Metabolic Diseases (Mikio Takanashi, T. Kimura, C.L., M. Tanaka, A.M., H. Yoshida, A.N., P.X., S.T., S.O., Y. Iizuka, T.G., T.Y., T. Kadowaki, H.O.)
| | - Yoko Iizuka
- From the Department of Diabetes and Metabolic Diseases (Mikio Takanashi, T. Kimura, C.L., M. Tanaka, A.M., H. Yoshida, A.N., P.X., S.T., S.O., Y. Iizuka, T.G., T.Y., T. Kadowaki, H.O.)
| | - Hidetoshi Kumagai
- Department of Cardiovascular Medicine (H.K., Y. Ikeda), Graduate School of Medicine, the University of Tokyo, Bunkyo-ku, Japan
| | - Yuichi Ikeda
- Department of Cardiovascular Medicine (H.K., Y. Ikeda), Graduate School of Medicine, the University of Tokyo, Bunkyo-ku, Japan
| | - Takanari Gotoda
- From the Department of Diabetes and Metabolic Diseases (Mikio Takanashi, T. Kimura, C.L., M. Tanaka, A.M., H. Yoshida, A.N., P.X., S.T., S.O., Y. Iizuka, T.G., T.Y., T. Kadowaki, H.O.)
| | - Manabu Takahashi
- Division of Endocrinology and Metabolism, School of Medicine, Jichi Medical University, Shimotsuke, Tochigi, Japan (Manabu Takahashi, S.I.)
| | - Hiroaki Yagyu
- Department of Endocrinology and Metabolism, Mito Medical Center, Tsukuba University Hospital, Mito, Ibaraki, Japan (H. Yagyu)
| | - Shun Ishibashi
- Division of Endocrinology and Metabolism, School of Medicine, Jichi Medical University, Shimotsuke, Tochigi, Japan (Manabu Takahashi, S.I.)
| | - Toshimasa Yamauchi
- From the Department of Diabetes and Metabolic Diseases (Mikio Takanashi, T. Kimura, C.L., M. Tanaka, A.M., H. Yoshida, A.N., P.X., S.T., S.O., Y. Iizuka, T.G., T.Y., T. Kadowaki, H.O.)
| | - Takashi Kadowaki
- From the Department of Diabetes and Metabolic Diseases (Mikio Takanashi, T. Kimura, C.L., M. Tanaka, A.M., H. Yoshida, A.N., P.X., S.T., S.O., Y. Iizuka, T.G., T.Y., T. Kadowaki, H.O.)
| | - Guosheng Liang
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX (G.L., H.O.)
| | - Hiroaki Okazaki
- From the Department of Diabetes and Metabolic Diseases (Mikio Takanashi, T. Kimura, C.L., M. Tanaka, A.M., H. Yoshida, A.N., P.X., S.T., S.O., Y. Iizuka, T.G., T.Y., T. Kadowaki, H.O.)
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX (G.L., H.O.)
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Xiao C, Stahel P, Morgantini C, Nahmias A, Dash S, Lewis GF. Glucagon-like peptide-2 mobilizes lipids from the intestine by a systemic nitric oxide-independent mechanism. Diabetes Obes Metab 2019; 21:2535-2541. [PMID: 31364232 DOI: 10.1111/dom.13839] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 07/09/2019] [Accepted: 07/25/2019] [Indexed: 12/20/2022]
Abstract
AIM To test the hypothesis that gut hormone glucagon-like peptide-2 (GLP-2) mobilizes intestinal triglyceride (TG) stores and stimulates chylomicron secretion by a nitric oxide (NO)-dependent mechanism in humans. METHODS In a randomized, single-blind, cross-over study, 10 healthy male volunteers ingested a high-fat formula followed, 7 hours later, by one of three treatments: NO synthase inhibitor L-NG -monomethyl arginine acetate (L-NMMA) + GLP-2 analogue teduglutide, normal saline + teduglutide, or L-NMMA + placebo. TG in plasma and lipoprotein fractions were measured, along with measurement of blood flow in superior mesenteric and coeliac arteries using Doppler ultrasound in six participants. RESULTS Teduglutide rapidly increased mesenteric blood flow and TG concentrations in plasma, in TG-rich lipoproteins, and most robustly in chylomicrons. L-NMMA significantly attenuated teduglutide-induced enhancement of mesenteric blood flow but not TG mobilization and chylomicron secretion. CONCLUSIONS GLP-2 mobilization of TG stores and stimulation of chylomicron secretion from the small intestine appears to be independent of systemic NO in humans.
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Affiliation(s)
- Changting Xiao
- Department of Medicine and Department of Physiology, Division of Endocrinology and Metabolism, Banting and Best Diabetes Centre, University of Toronto, Toronto, Canada
| | - Priska Stahel
- Department of Medicine and Department of Physiology, Division of Endocrinology and Metabolism, Banting and Best Diabetes Centre, University of Toronto, Toronto, Canada
| | - Cecilia Morgantini
- Department of Medicine and Department of Physiology, Division of Endocrinology and Metabolism, Banting and Best Diabetes Centre, University of Toronto, Toronto, Canada
| | - Avital Nahmias
- Department of Medicine and Department of Physiology, Division of Endocrinology and Metabolism, Banting and Best Diabetes Centre, University of Toronto, Toronto, Canada
| | - Satya Dash
- Department of Medicine and Department of Physiology, Division of Endocrinology and Metabolism, Banting and Best Diabetes Centre, University of Toronto, Toronto, Canada
| | - Gary F Lewis
- Department of Medicine and Department of Physiology, Division of Endocrinology and Metabolism, Banting and Best Diabetes Centre, University of Toronto, Toronto, Canada
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Abstract
PURPOSE OF REVIEW In this review, we describe novel findings related to intestinal lipid transport in lymphatic vessels. RECENT FINDINGS Studies have shown that chylomicron entry to lacteals and lymph movement in intestinal lymphatic capillaries is an active process. Regulators of this intestinal chylomicron transport include among others the autonomous nervous system, transcription factors like PLAGL2, and molecular regulators, such as VEGF-A/Nrp1/VEGFR1, VEGF-C/VEGFR3, DLL4, CALCRL and GLP-2. Chylomicron transport in intestinal lymphatics is now emerging not only as an option for drug delivery but also as a new candidate for drug targeting in lipid-related disorders. SUMMARY Dysfunctions of lymphatic lipid transport can result in conditions such as dyslipidaemia. Intestinal lymphatics also provide several potential therapeutic possibilities: molecular regulation of lacteal cell-to-cell junctioning and lymph flow could provide new ways of treating conditions like hyperlipidaemia and associated diseases, such as atherosclerosis and other cardiovascular diseases, obesity, diabetes and fatty-liver disease. The intestinal lymphatic system can also be employed to deliver lipid nanoparticles as drug carriers to the venous circulation for improved treatment outcome. These findings highlight the importance and need for research on the different players of intestinal lymphatics in dietary lipid handling and therapeutic applications.
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Affiliation(s)
- Krista Hokkanen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland
| | - Annakaisa Tirronen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland
| | - Seppo Ylä-Herttuala
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland
- Heart Center and Gene Therapy Unit, Kuopio University Hospital, Kuopio, Finland
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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30
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Abstract
PURPOSE OF REVIEW To review recent evidence for the role of carbohydrates in the promotion of de novo lipogenesis and lipoprotein secretion from the intestine. RECENT FINDINGS The consumption of diets rich in carbohydrates have been shown to promote elevations in circulating lipids. In particular, the consumption of monosaccharides, such as glucose and fructose, have been shown to induce increases in intestinal de novo lipogenesis, as well as be used as a substrate for the synthesis of triglycerides and lipoprotein export in the form of chylomicrons. Recently, various systematic reviews have analyzed the relative contribution of dietary fructose to intestinal lipogenesis. Although, there remains controversy within the literature, the body of evidence supports lipogenic effects of high fructose diets. In addition, alterations in markers of de novo lipogenesis within the jejunum of patients with insulin resistance may explain the alterations in their postprandial lipid profile. SUMMARY Recent evidence supports the contribution of dietary carbohydrates to intestinal lipogenesis and lipoprotein secretion; however, further research is required to fully understand the mechanisms underlying this complex process.
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Affiliation(s)
- Simon Hoffman
- Molecular Medicine, Research Institute, The Hospital for Sick Children
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Danielle Alvares
- Molecular Medicine, Research Institute, The Hospital for Sick Children
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Khosrow Adeli
- Molecular Medicine, Research Institute, The Hospital for Sick Children
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
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31
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Abstract
PURPOSE OF REVIEW Chylomicron retention disease (CRD) is an autosomic recessive disorder, in which intestinal fat malabsorption is the main cause of diverse severe manifestations. The specific molecular defect was identified in 2003 and consists of mutations in the SAR1B or SARA2 gene encoding for intracellular SAR1B GTPase protein. The aim of this review is first to provide an update of the recent biochemical, genetic and clinical findings, and second to discuss novel mechanisms related to hallmark symptoms. RECENT FINDINGS CRD patients present with SAR1B mutations, which disable the formation of coat protein complex II and thus blocks the transport of chylomicron cargo from the endoplasmic reticulum to the Golgi. Consequently, there is a total absence of chylomicron and apolipoprotein B-48 in the blood circulation following a fat meal, accompanied by a deficiency in liposoluble vitamins and essential fatty acids. The recent discovery of Transport and Golgi organization and Transport and Golgi organization-like proteins may explain the intriguing export of large chylomicron, exceeding coat protein complex II size. Hypocholesterolemia could be accounted for by a decrease in HDL cholesterol, likely a reflection of limited production of intestinal HDL in view of reduced ATP-binding cassette family A protein 1 and apolipoprotein A-I protein. In experimental studies, the paralog SAR1A compensates for the lack of the SAR1B GTPase protein. SUMMARY Molecular testing for CRD is recommended to distinguish the disease from other congenital fat malabsorptions, and to early define molecular aberrations, accelerate treatment, and prevent complications.
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Affiliation(s)
- Emile Levy
- Research Centre
- Gastroenterology, Hepatology and Nutrition Unit, CHU Ste-Justine
- Department of Nutrition, Université de Montréal, Montreal, Quebec, Canada
| | - Pierre Poinsot
- Gastroenterology, Hepatology and Nutrition Unit, CHU Ste-Justine
| | - Schohraya Spahis
- Research Centre
- Department of Nutrition, Université de Montréal, Montreal, Quebec, Canada
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32
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Whyte MB, Shojaee-Moradie F, Sharaf SE, Jackson NC, Fielding B, Hovorka R, Mendis J, Russell-Jones D, Umpleby AM. Lixisenatide Reduces Chylomicron Triacylglycerol by Increased Clearance. J Clin Endocrinol Metab 2019; 104:359-368. [PMID: 30215735 PMCID: PMC6300412 DOI: 10.1210/jc.2018-01176] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 09/06/2018] [Indexed: 12/17/2022]
Abstract
CONTEXT Glucagon-like peptide-1 (GLP-1) agonists control postprandial glucose and lipid excursion in type 2 diabetes; however, the mechanisms are unclear. OBJECTIVE To determine the mechanisms of postprandial lipid and glucose control with lixisenatide (GLP-1 analog) in type 2 diabetes. DESIGN Randomized, double-blind, cross-over study. SETTING Centre for Diabetes, Endocrinology, and Research, Royal Surrey County Hospital, Guildford, United Kingdom. PATIENTS Eight obese men with type 2 diabetes [age, 57.3 ± 1.9 years; body mass index, 30.3 ± 1.0 kg/m2; glycosylated hemoglobin, 66.5 ± 2.6 mmol/mol (8.2% ± 0.3%)]. INTERVENTIONS Two metabolic studies, 4 weeks after lixisenatide or placebo, with cross-over and repetition of studies. MAIN OUTCOME MEASURES Study one: very-low-density lipoprotein (VLDL) and chylomicron (CM) triacylglycerol (TAG) kinetics were measured with an IV bolus of [2H5]glycerol in a 12-hour study, with hourly feeding. Oral [13C]triolein, in a single meal, labeled enterally derived TAG. Study two: glucose kinetics were measured with [U-13C]glucose in a mixed-meal (plus acetaminophen to measure gastric emptying) and variable IV [6,6-2H2]glucose infusion. RESULTS Study one: CM-TAG (but not VLDL-TAG) pool-size was lower with lixisenatide (P = 0.046). Lixisenatide reduced CM [13C]oleate area under the curve (AUC)60-480min concentration (P = 0.048) and increased CM-TAG clearance, with no effect on CM-TAG production rate. Study two: postprandial glucose and insulin AUC0-240min were reduced with lixisenatide (P = 0.0051; P < 0.05). Total glucose production (P = 0.015), rate of glucose appearance from the meal (P = 0.0098), and acetaminophen AUC0-360min (P = 0.006) were lower with lixisenatide than with placebo. CONCLUSIONS Lixisenatide reduced [13C]oleate concentrations, derived from a single meal in CM-TAG and glucose rate of appearance from the meal through delayed gastric emptying. However, day-long CM production, measured with repeated meal feeding, was not reduced by lixisenatide and decreased CM-TAG concentration resulted from increased CM-TAG clearance.
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Affiliation(s)
- Martin B Whyte
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
- Correspondence and Reprint Requests: Martin B. Whyte, PhD, FRCP, Faculty of Health and Medical Sciences, University of Surrey, Leggett Building, Daphne Jackson Road, Guildford GU2 7WG, United Kingdom. E-mail:
| | | | - Sharaf E Sharaf
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Nicola C Jackson
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Barbara Fielding
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Roman Hovorka
- Diabetes Modelling Group, Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom
| | - Jeewaka Mendis
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - David Russell-Jones
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - A Margot Umpleby
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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34
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Leohr J, Heathman M, Kjellsson MC. Semi-physiological model of postprandial triglyceride response in lean, obese and very obese individuals after a high-fat meal. Diabetes Obes Metab 2018; 20:660-666. [PMID: 29072819 DOI: 10.1111/dom.13138] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 10/01/2017] [Accepted: 10/20/2017] [Indexed: 11/28/2022]
Abstract
AIMS To quantify the postprandial triglyceride (TG) response of chylomicrons and very-low-density lipoprotein-V6 (VLDL-V6) after a high-fat meal in lean, obese and very obese healthy individuals, using a mechanistic population lipokinetic modelling approach. METHODS Healthy individuals from three body mass index population categories: lean (18.5-24.9 kg/m2 ), obese (30-33 kg/m2 ), and very obese (34-40 kg/m2 ) were enrolled in a clinical study to assess the TG response after a high-fat meal, containing 60% fat. Non-linear mixed-effect modelling was used to analyse the TG concentrations of chylomicrons and large VLDL-V6 particles. RESULTS The TGs in chylomicrons and VLDL-V6 particles had a prominent postprandial peak and represented the majority of the postprandial response; only the VLDL-V6 showed a difference across the populations. A turn-over model successfully described the TG concentration-time profiles of both chylomicrons and large VLDL-V6 particles after the high-fat meal. This model consisted of four compartments: two transit compartments for the lag between meal consumption and appearance of TGs in the blood, and one compartment each for the chylomicrons and large VLDL-V6 particles. The rate constants for the production of chylomicrons and elimination of large VLDL-V6 particles, along with the conversion rate of chylomicrons to large VLDL-V6 particles were well defined. CONCLUSIONS This is the first lipokinetic model to describe the absorption of TGs from dietary fats into the blood stream and compares the dynamics of TGs in chylomicrons and large VLDL-V6 particles among lean, obese and very obese people. Such a model can be used to identify where pharmacological therapies act, thereby improving the determination of efficacy, and identifying complementary mechanisms for combinational drug therapies.
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Affiliation(s)
- Jennifer Leohr
- Eli Lilly and Company, Lilly Corporate Center, Indianapolis, Indiana
| | - Michael Heathman
- Eli Lilly and Company, Lilly Corporate Center, Indianapolis, Indiana
| | - Maria C Kjellsson
- Department of Pharmaceutical Biosciences, Pharmacometrics Research Group, Uppsala University, Uppsala, Sweden
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35
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Piché ME, Parry SA, Karpe F, Hodson L. Chylomicron-Derived Fatty Acid Spillover in Adipose Tissue: A Signature of Metabolic Health? J Clin Endocrinol Metab 2018; 103:25-34. [PMID: 29099975 PMCID: PMC5761493 DOI: 10.1210/jc.2017-01517] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 10/27/2017] [Indexed: 12/29/2022]
Abstract
Context and Objectives Spillover of fatty acids (FAs) into the plasma nonesterified fatty acid (NEFA) pool, because of an inability of adipose tissue (AT) to accommodate sufficient fat uptake, has been suggested to contribute to obesity-related insulin resistance. Using specific labeling techniques, we compared the proportion of spillover-derived NEFA across a range of adiposity. Participants and Methods Seventy-one healthy men and women were fed a mixed meal (40 g fat) containing [U13C]palmitate to assess the contribution of chylomicron-derived spillover FAs. To investigate subcutaneous abdominal-specific spillover, arteriovenous difference and stable-isotope methodologies were used in substudy (six men, six women). Results Chylomicron-derived FA spillover was higher in individuals with a BMI <25 kg/m2 (n = 18) compared with those with a BMI ≥25 kg/m2 (n = 53) (22.2 ± 1.6% vs 18.6 ± 0.7%, P = 0.02). Women had higher chylomicron-derived FA spillover than age- and BMI-matched men (21.9 ± 1.1% vs 15.0 ± 1.6%, P = 0.001). Assessing spillover across subcutaneous abdominal AT showed higher proportions in women than in men (28.5 ± 6.1% vs 9.9 ± 1.3%, P = 0.01). Conclusion There is a considerable degree of spillover FA into the systemic NEFA pool in the postprandial state; this process is greater and more dynamic in lean individuals and women. Contrary to general perception, spillover of chylomicron-derived FA into systemic circulation is a physiologically normal feature most easily observed in people with a higher capacity for clearance of plasma triglycerides, but does not appear to be a pathway providing excess NEFA in obesity.
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Affiliation(s)
- Marie-Eve Piché
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford OX3 7LE, United Kingdom
- Quebec Heart and Lung Institute, Laval University, Quebec G1V 4G5, Canada
| | - Siôn A. Parry
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford OX3 7LE, United Kingdom
| | - Fredrik Karpe
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford OX3 7LE, United Kingdom
- National Institute for Health Research Oxford Biomedical Research Centre, Oxford University Hospital Trusts, Oxford OX3 9DU, United Kingdom
| | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford OX3 7LE, United Kingdom
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36
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Closs CI, Ruiz Diaz MA, Cafferata AM, Becú-Villalobos D, Nogueira JP. [Role of the enterocyte in type 2 diabetes mellitus associated dyslipidemia]. Medicina (B Aires) 2018; 78:91-98. [PMID: 29659358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023] Open
Abstract
In type 2 diabetes mellitus there is an overproduction of chylomicron in the postprandial state that is associated with increased cardiovascular risk. Current evidence points out a leading role of enterocyte in dyslipidemia of type 2 diabetes mellitus, since it increases the production of apolipoprotein B-48 in response to a raise in plasma free fatty acids and glucose. The chylomicron metabolism is regulated by many factors apart from ingested fat, including hormonal and metabolic elements. More recently, studies about the role of gut hormones, have demonstrated that glucagon-like peptide-1 decreases the production of apolipoprotein B-48 and glucagon-like peptide-2 enhances it. Insulin acutely inhibits intestinal chylomicron production in healthy humans, whereas this acute inhibitory effect on apolipoprotein B-48 production is blunted in type 2 diabetes mellitus. Understanding these emerging regulators of intestinal chylomicron secretion may offer new mechanisms of control for its metabolism and provide novel therapeutic strategies focalized in type 2 diabetes mellitus postprandial hyperlipidemia with the reduction of cardiovascular disease risk.
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Affiliation(s)
- Cecilia I Closs
- Asociación Formoseña de Endocrinología y Metabolismo, Argentina
- Centro de Investigación en Endocrinología, Nutrición y Metabolismo (CIENM), Facultad de Ciencias de la Salud, Universidad Nacional de Formosa, Argentina
| | - Martín A Ruiz Diaz
- Centro de Investigación en Endocrinología, Nutrición y Metabolismo (CIENM), Facultad de Ciencias de la Salud, Universidad Nacional de Formosa, Argentina
| | - Alberto M Cafferata
- Prevención Cardiovascular, Sanatorio Finochietto, Argentina
- Facultad de Medicina, Instituto Universitario de Ciencias de la Salud, Fundación H.A. Barceló, Argentina
| | - Damasia Becú-Villalobos
- Instituto de Biología y Medicina Experimental (IBYME-CONICET-FIBYME),Buenos Aires, Argentina
| | - Juan P Nogueira
- Centro de Investigación en Endocrinología, Nutrición y Metabolismo (CIENM), Facultad de Ciencias de la Salud, Universidad Nacional de Formosa, Argentina. E-mail:
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Simionescu N, Simionescu M. Cellular interactions of lipoproteins with the vascular endothelium: endocytosis and transcytosis. Targeted Diagn Ther 2017; 5:45-95. [PMID: 1797171 DOI: 10.1201/9780203748831-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- N Simionescu
- Institute of Cellular Biology and Pathology, Bucharest, Romania
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38
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Hung YH, Carreiro AL, Buhman KK. Dgat1 and Dgat2 regulate enterocyte triacylglycerol distribution and alter proteins associated with cytoplasmic lipid droplets in response to dietary fat. Biochim Biophys Acta Mol Cell Biol Lipids 2017; 1862:600-614. [PMID: 28249764 PMCID: PMC5503214 DOI: 10.1016/j.bbalip.2017.02.014] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 01/31/2017] [Accepted: 02/24/2017] [Indexed: 12/16/2022]
Abstract
Enterocytes, the absorptive cells of the small intestine, mediate efficient absorption of dietary fat (triacylglycerol, TAG). The digestive products of dietary fat are taken up by enterocytes, re-esterified into TAG, and packaged on chylomicrons (CMs) for secretion into blood or temporarily stored within cytoplasmic lipid droplets (CLDs). Altered enterocyte TAG distribution impacts susceptibility to high fat diet associated diseases, but molecular mechanisms directing TAG toward these fates are unclear. Two enzymes, acyl CoA: diacylglycerol acyltransferase 1 (Dgat1) and Dgat2, catalyze the final, committed step of TAG synthesis within enterocytes. Mice with intestine-specific overexpression of Dgat1 (Dgat1Int) or Dgat2 (Dgat2Int), or lack of Dgat1 (Dgat1-/-), were previously found to have altered intestinal TAG secretion and storage. We hypothesized that varying intestinal Dgat1 and Dgat2 levels alters TAG distribution in subcellular pools for CM synthesis as well as the morphology and proteome of CLDs. To test this we used ultrastructural and proteomic methods to investigate intracellular TAG distribution and CLD-associated proteins in enterocytes from Dgat1Int, Dgat2Int, and Dgat1-/- mice 2h after a 200μl oral olive oil gavage. We found that varying levels of intestinal Dgat1 and Dgat2 altered TAG pools involved in CM assembly and secretion, the number or size of CLDs present in enterocytes, and the enterocyte CLD proteome. Overall, these results support a model where Dgat1 and Dgat2 function coordinately to regulate the process of dietary fat absorption by preferentially synthesizing TAG for incorporation into distinct subcellular TAG pools in enterocytes.
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Affiliation(s)
- Yu-Han Hung
- Department of Nutrition Science, Purdue University, West Lafayette, IN 47907, USA
| | - 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.
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Steenson S, Umpleby AM, Lovegrove JA, Jackson KG, Fielding BA. Role of the Enterocyte in Fructose-Induced Hypertriglyceridaemia. Nutrients 2017; 9:nu9040349. [PMID: 28368310 PMCID: PMC5409688 DOI: 10.3390/nu9040349] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 03/21/2017] [Accepted: 03/31/2017] [Indexed: 01/12/2023] Open
Abstract
Dietary fructose has been linked to an increased post-prandial triglyceride (TG) level; which is an established independent risk factor for cardiovascular disease. Although much research has focused on the effects of fructose consumption on liver-derived very-low density lipoprotein (VLDL); emerging evidence also suggests that fructose may raise post-prandial TG levels by affecting the metabolism of enterocytes of the small intestine. Enterocytes have become well recognised for their ability to transiently store lipids following a meal and to thus control post-prandial TG levels according to the rate of chylomicron (CM) lipoprotein synthesis and secretion. The influence of fructose consumption on several aspects of enterocyte lipid metabolism are discussed; including de novo lipogenesis; apolipoprotein B48 and CM-TG production; based on the findings of animal and human isotopic tracer studies. Methodological issues affecting the interpretation of fructose studies conducted to date are highlighted; including the accurate separation of CM and VLDL. Although the available evidence to date is limited; disruption of enterocyte lipid metabolism may make a meaningful contribution to the hypertriglyceridaemia often associated with fructose consumption.
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Affiliation(s)
- Simon Steenson
- Department of Nutritional Sciences, Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7WG, UK.
- Department of Food & Nutritional Sciences and Institute for Cardiovascular and Metabolic Research (ICMR), University of Reading, Reading RG6 6AP, UK.
| | - A Margot Umpleby
- Department of Nutritional Sciences, Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7WG, UK.
| | - Julie A Lovegrove
- Department of Food & Nutritional Sciences and Institute for Cardiovascular and Metabolic Research (ICMR), University of Reading, Reading RG6 6AP, UK.
| | - Kim G Jackson
- Department of Food & Nutritional Sciences and Institute for Cardiovascular and Metabolic Research (ICMR), University of Reading, Reading RG6 6AP, UK.
| | - Barbara A Fielding
- Department of Nutritional Sciences, Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7WG, UK.
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Titov VN. [The fatty acids, triglycerides, chylomicrons, endoplasmic net, paracrine regulated cells' cenosises and becoming of lymph flow system in phylogenesis]. Klin Lab Diagn 2016; 61:324-334. [PMID: 30601622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
According phylogenetic theory of general pathology, necessity in supply of cells in vivo with exogenous fatty acids-substrates for gaining energy and physical-chemical parameters of fatty acids resulted in development (initially in single paracrine regulated cenosis of cells) of system of fatty acids transfer through hydrophilic inter-cellular medium in form of triglycerides in composition of hydrophobic chylomicrons -from enterocytes where they were developed to cells into which they were deposited. It is assumed that system of transfer of hydrophobic chylomicrons through aqueous inter-cellular medium was developed by anatomic combination of tubules of endoplasmic reticulum of enterocytes and the same tubules of cells of areolar tissue in paracrine regulated cenosis of cells of enterocytes with development of the most early in phylogenesis system of directed transfer, lymph flow. This occurrence became a prototype of lymphatic system; its first biological predestination is transferring of fatty acids to all cells escaping hydrophilic inter-cellular medium. With time, the lymphatic system all paracrin regulated cenosis of cells in vivo united in single system and became the foundation of development of organs and systems. The unification of epithelial and connective tissue cells of areolar tissue in single structure turned out to become the basis that at later stages of phylogenesis the lymphatic system began, under expressed convolution of its structure (development of lymphatic nodes), to combine: a) implementation ofprimary biological function of trophology (function of nutrition) with biological function of adaptation; b) later biological reactions of inherited and acquired immune defense at stages of phylogenesis and, probably, c) participation in hydrodynamics of distal sections of closed systemic blood circulation. The mechanisms of osmotic “pushing" of lymph have a lot of common with initiation of stream of cerebrospinal fluid of central nervous system and flow of primary urine in tubules of nephron.
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van der Kolk BW, Goossens GH, Jocken JW, Kersten S, Blaak EE. Angiopoietin-Like Protein 4 and Postprandial Skeletal Muscle Lipid Metabolism in Overweight and Obese Prediabetics. J Clin Endocrinol Metab 2016; 101:2332-9. [PMID: 27011113 DOI: 10.1210/jc.2015-4285] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Angiopoietin-like protein 4 (ANGPTL4) decreases plasma triacylglycerol (TAG) clearance by inhibiting lipoprotein lipase (LPL) and may contribute to impairments in lipid metabolism under compromised metabolic conditions. OBJECTIVES To investigate the effects of a high-saturated fatty acid (SFA) mixed meal on plasma ANGPTL4 concentrations in relation to in vivo muscle LPL activity, to study the effects of dietary fat quality, and to examine skeletal muscle ANGPTL4 release. Design, Participants, Setting, and Interventions: We used a dual stable-isotope tracer technique in combination with measurements of arteriovenous concentration differences across forearm muscle to investigate muscle ANGPTL4 secretion and fatty acid handling under fasting conditions and after a high-SFA mixed meal in 73 overweight and obese humans at the Metabolic Research Unit of Maastricht University. The effect of dietary fat quality manipulation on plasma ANGPTL4 was investigated in 10 obese insulin-resistant participants. RESULTS The high-SFA meal decreased circulating ANGPTL4 concentrations (fasting, 5.2 ng/mL; vs 4 hours postprandial, 4.0 ng/mL; P < .001). Furthermore, skeletal muscle ANGPTL4 secretion into the circulation was observed (AUC0-4 h, P = .048). However, no association was observed between plasma ANGPTL4 and skeletal muscle very low-density lipoprotein or dietary (chylomicron) TAG extraction (AUC0-4 h, P = .372 and P = .139, respectively). In contrast to a high-SFA or high-monounsaturated fat meal, plasma ANGPTL4 remained unchanged after a high-polyunsaturated fat meal. CONCLUSIONS ANGPTL4 is secreted by human forearm muscle in postprandial conditions after a high-SFA meal. Plasma ANGPTL4 concentrations were not associated with in vivo skeletal muscle LPL activity after a high-SFA meal. Dietary fat quality affects plasma ANGPTL4, but it remains to be elucidated whether this influences short-term skeletal muscle lipid handling.
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Affiliation(s)
- Birgitta W van der Kolk
- Department of Human Biology (B.W.v.d.K., G.H.G., J.W.J., E.E.B.), NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, 6200 MD Maastricht, The Netherlands; and Nutrition, Metabolism, and Genomics Group (S.K.), Division of Human Nutrition, Wageningen University, 6700 HB Wageningen, The Netherlands
| | - Gijs H Goossens
- Department of Human Biology (B.W.v.d.K., G.H.G., J.W.J., E.E.B.), NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, 6200 MD Maastricht, The Netherlands; and Nutrition, Metabolism, and Genomics Group (S.K.), Division of Human Nutrition, Wageningen University, 6700 HB Wageningen, The Netherlands
| | - Johan W Jocken
- Department of Human Biology (B.W.v.d.K., G.H.G., J.W.J., E.E.B.), NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, 6200 MD Maastricht, The Netherlands; and Nutrition, Metabolism, and Genomics Group (S.K.), Division of Human Nutrition, Wageningen University, 6700 HB Wageningen, The Netherlands
| | - Sander Kersten
- Department of Human Biology (B.W.v.d.K., G.H.G., J.W.J., E.E.B.), NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, 6200 MD Maastricht, The Netherlands; and Nutrition, Metabolism, and Genomics Group (S.K.), Division of Human Nutrition, Wageningen University, 6700 HB Wageningen, The Netherlands
| | - Ellen E Blaak
- Department of Human Biology (B.W.v.d.K., G.H.G., J.W.J., E.E.B.), NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, 6200 MD Maastricht, The Netherlands; and Nutrition, Metabolism, and Genomics Group (S.K.), Division of Human Nutrition, Wageningen University, 6700 HB Wageningen, The Netherlands
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Abstract
CONTEXT Chronic sex steroid deficiency has effects on adipose fatty acid (FA) storage mechanisms and fat oxidation, but the chronology of events are not well understood. OBJECTIVE The objective of the study was to examine the acute effects of female sex steroid suppression on cellular mechanisms affecting abdominal and femoral subcutaneous adipose tissue FA storage. DESIGN This study had a randomized, longitudinal, parallel study design. SETTING The study was conducted at the Mayo Clinic Clinical Research Unit. PARTICIPANTS Thirty-eight nonsmoking premenopausal women aged 18-50 years participated in the study. INTERVENTION The intervention included randomization to receive one of the following: 1) no treatment (control), 2) 3.75 mg of Lupron, or 3) 3.75 mg of Lupron and estrogen, but not progesterone, replacement for 49 days, resulting in at least 4 weeks of sex steroid suppression. MAIN OUTCOME MEASURES Body composition, fat cell size, postprandial chylomicron and nonchylomicron triglyceride concentrations, adipose tissue meal FA storage, direct free fatty acid storage, lipoprotein lipase, acyl CoA synthetase, and diacylglycerol acyltransferase activities, and CD36 content were measured. RESULTS Compared with the control group, the fed state femoral lipoprotein lipase activity was reduced in women taking Lupron and those taking Lupron and estrogen replacement. In addition, we observed significantly greater postprandial chylomicronemia in the Lupron group than in the other two groups. There were no differences in overall fat storage and oxidation. Depending on the mode of data expression (per unit lipid vs per 1000 adipocytes), there were modest changes in acyl CoA synthetase, diacylglycerol acyltransferase, and CD36 in response to acute sex hormone suppression. CONCLUSIONS Our results suggest estrogen and progesterone may have different effects on the regulation of FA metabolism and that acute sex steroid deficiency in women does not alter fat storage and oxidation.
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Affiliation(s)
- Sylvia Santosa
- Endocrine Research Unit (S.S., M.D.J.), and Department of General Internal Medicine (S.L.B.), Mayo Clinic, Rochester, Minnesota 55905; and Department of Exercise Science (S.S.), and PERFORM Centre (S.S.) Concordia University, Montréal, Québec, Canada H4B 1R6
| | - Sara L Bonnes
- Endocrine Research Unit (S.S., M.D.J.), and Department of General Internal Medicine (S.L.B.), Mayo Clinic, Rochester, Minnesota 55905; and Department of Exercise Science (S.S.), and PERFORM Centre (S.S.) Concordia University, Montréal, Québec, Canada H4B 1R6
| | - Michael D Jensen
- Endocrine Research Unit (S.S., M.D.J.), and Department of General Internal Medicine (S.L.B.), Mayo Clinic, Rochester, Minnesota 55905; and Department of Exercise Science (S.S.), and PERFORM Centre (S.S.) Concordia University, Montréal, Québec, Canada H4B 1R6
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Kroiss M, Plonné D, Kendl S, Schirmer D, Ronchi CL, Schirbel A, Zink M, Lapa C, Klinker H, Fassnacht M, Heinz W, Sbiera S. Association of mitotane with chylomicrons and serum lipoproteins: practical implications for treatment of adrenocortical carcinoma. Eur J Endocrinol 2016; 174:343-53. [PMID: 26671975 DOI: 10.1530/eje-15-0946] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 12/15/2015] [Indexed: 12/19/2022]
Abstract
OBJECTIVE Oral mitotane (o,p'-DDD) is a cornerstone of medical treatment for adrenocortical carcinoma (ACC). AIM Serum mitotane concentrations >14 mg/l are targeted for improved efficacy but not achieved in about half of patients. Here we aimed at a better understanding of intestinal absorption and lipoprotein association of mitotane and metabolites o,p'-dichlorodiphenylacetic acid (o,p'-DDA) and o,p'-dichlorodiphenyldichloroethane (o,p'-DDE). DESIGN Lipoproteins were isolated by ultracentrifugation from the chyle of a 29-year-old patient and serum from additional 14 ACC patients treated with mitotane. HPLC was applied for quantification of mitotane and metabolites. We assessed NCI-H295 cell viability, cortisol production, and expression of endoplasmic reticulum (ER) stress marker genes to study the functional consequences of mitotane binding to lipoproteins. RESULTS Chyle of the index patient contained 197 mg/ml mitotane, 53 mg/ml o,p'-DDA, and 51 mg/l o,p'-DDE. Of the total mitotane in serum, lipoprotein fractions contained 21.7±21.4% (VLDL), 1.9±0.8% (IDL), 8.9±5.5% (LDL1), 18.9±9.6% (LDL2), 10.1±4.0% (LDL3), and 26.3±13.0% (HDL2). Only 12.3±5.5% were in the lipoprotein-depleted fraction. DISCUSSION Mitotane content of lipoproteins directly correlated with their triglyceride and cholesterol content. O,p'-DDE was similarly distributed, but 87.9±4.2% of o,p'-DDA found in the HDL2 and lipoprotein-depleted fractions. Binding of mitotane to human lipoproteins blunted its anti-proliferative and anti-hormonal effects on NCI-H295 cells and reduced ER stress marker gene expression. CONCLUSION Mitotane absorption involves chylomicron binding. High concentrations of o,p'-DDA and o,p'-DDE in chyle suggest intestinal mitotane metabolism. In serum, the majority of mitotane is bound to lipoproteins. In vitro, lipoprotein binding inhibits activity of mitotane suggesting that lipoprotein-free mitotane is the therapeutically active fraction.
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Affiliation(s)
- Matthias Kroiss
- Endocrine and Diabetes UnitDepartment of Internal Medicine IInfectiology UnitDepartment of Internal Medicine II, University Hospital Würzburg, Oberdürrbacher Street 6, 97080 Würzburg, GermanyComprehensive Cancer Center MainfrankenUniversity of Würzburg, Würzburg, GermanyDivision of Laboratory MedicineMedical Care Centre of Human Genetics Ulm, Ulm, GermanyDepartment of Nuclear MedicineUniversity Hospital Würzburg, Würzburg, GermanyClinical Chemistry and Laboratory MedicineUniversity Hospital Würzburg, Würzburg, Germany Endocrine and Diabetes UnitDepartment of Internal Medicine IInfectiology UnitDepartment of Internal Medicine II, University Hospital Würzburg, Oberdürrbacher Street 6, 97080 Würzburg, GermanyComprehensive Cancer Center MainfrankenUniversity of Würzburg, Würzburg, GermanyDivision of Laboratory MedicineMedical Care Centre of Human Genetics Ulm, Ulm, GermanyDepartment of Nuclear MedicineUniversity Hospital Würzburg, Würzburg, GermanyClinical Chemistry and Laboratory MedicineUniversity Hospital Würzburg, Würzburg, Germany
| | - Dietmar Plonné
- Endocrine and Diabetes UnitDepartment of Internal Medicine IInfectiology UnitDepartment of Internal Medicine II, University Hospital Würzburg, Oberdürrbacher Street 6, 97080 Würzburg, GermanyComprehensive Cancer Center MainfrankenUniversity of Würzburg, Würzburg, GermanyDivision of Laboratory MedicineMedical Care Centre of Human Genetics Ulm, Ulm, GermanyDepartment of Nuclear MedicineUniversity Hospital Würzburg, Würzburg, GermanyClinical Chemistry and Laboratory MedicineUniversity Hospital Würzburg, Würzburg, Germany
| | - Sabine Kendl
- Endocrine and Diabetes UnitDepartment of Internal Medicine IInfectiology UnitDepartment of Internal Medicine II, University Hospital Würzburg, Oberdürrbacher Street 6, 97080 Würzburg, GermanyComprehensive Cancer Center MainfrankenUniversity of Würzburg, Würzburg, GermanyDivision of Laboratory MedicineMedical Care Centre of Human Genetics Ulm, Ulm, GermanyDepartment of Nuclear MedicineUniversity Hospital Würzburg, Würzburg, GermanyClinical Chemistry and Laboratory MedicineUniversity Hospital Würzburg, Würzburg, Germany
| | - Diana Schirmer
- Endocrine and Diabetes UnitDepartment of Internal Medicine IInfectiology UnitDepartment of Internal Medicine II, University Hospital Würzburg, Oberdürrbacher Street 6, 97080 Würzburg, GermanyComprehensive Cancer Center MainfrankenUniversity of Würzburg, Würzburg, GermanyDivision of Laboratory MedicineMedical Care Centre of Human Genetics Ulm, Ulm, GermanyDepartment of Nuclear MedicineUniversity Hospital Würzburg, Würzburg, GermanyClinical Chemistry and Laboratory MedicineUniversity Hospital Würzburg, Würzburg, Germany
| | - Cristina L Ronchi
- Endocrine and Diabetes UnitDepartment of Internal Medicine IInfectiology UnitDepartment of Internal Medicine II, University Hospital Würzburg, Oberdürrbacher Street 6, 97080 Würzburg, GermanyComprehensive Cancer Center MainfrankenUniversity of Würzburg, Würzburg, GermanyDivision of Laboratory MedicineMedical Care Centre of Human Genetics Ulm, Ulm, GermanyDepartment of Nuclear MedicineUniversity Hospital Würzburg, Würzburg, GermanyClinical Chemistry and Laboratory MedicineUniversity Hospital Würzburg, Würzburg, Germany
| | - Andreas Schirbel
- Endocrine and Diabetes UnitDepartment of Internal Medicine IInfectiology UnitDepartment of Internal Medicine II, University Hospital Würzburg, Oberdürrbacher Street 6, 97080 Würzburg, GermanyComprehensive Cancer Center MainfrankenUniversity of Würzburg, Würzburg, GermanyDivision of Laboratory MedicineMedical Care Centre of Human Genetics Ulm, Ulm, GermanyDepartment of Nuclear MedicineUniversity Hospital Würzburg, Würzburg, GermanyClinical Chemistry and Laboratory MedicineUniversity Hospital Würzburg, Würzburg, Germany
| | - Martina Zink
- Endocrine and Diabetes UnitDepartment of Internal Medicine IInfectiology UnitDepartment of Internal Medicine II, University Hospital Würzburg, Oberdürrbacher Street 6, 97080 Würzburg, GermanyComprehensive Cancer Center MainfrankenUniversity of Würzburg, Würzburg, GermanyDivision of Laboratory MedicineMedical Care Centre of Human Genetics Ulm, Ulm, GermanyDepartment of Nuclear MedicineUniversity Hospital Würzburg, Würzburg, GermanyClinical Chemistry and Laboratory MedicineUniversity Hospital Würzburg, Würzburg, Germany
| | - Constantin Lapa
- Endocrine and Diabetes UnitDepartment of Internal Medicine IInfectiology UnitDepartment of Internal Medicine II, University Hospital Würzburg, Oberdürrbacher Street 6, 97080 Würzburg, GermanyComprehensive Cancer Center MainfrankenUniversity of Würzburg, Würzburg, GermanyDivision of Laboratory MedicineMedical Care Centre of Human Genetics Ulm, Ulm, GermanyDepartment of Nuclear MedicineUniversity Hospital Würzburg, Würzburg, GermanyClinical Chemistry and Laboratory MedicineUniversity Hospital Würzburg, Würzburg, Germany
| | - Hartwig Klinker
- Endocrine and Diabetes UnitDepartment of Internal Medicine IInfectiology UnitDepartment of Internal Medicine II, University Hospital Würzburg, Oberdürrbacher Street 6, 97080 Würzburg, GermanyComprehensive Cancer Center MainfrankenUniversity of Würzburg, Würzburg, GermanyDivision of Laboratory MedicineMedical Care Centre of Human Genetics Ulm, Ulm, GermanyDepartment of Nuclear MedicineUniversity Hospital Würzburg, Würzburg, GermanyClinical Chemistry and Laboratory MedicineUniversity Hospital Würzburg, Würzburg, Germany
| | - Martin Fassnacht
- Endocrine and Diabetes UnitDepartment of Internal Medicine IInfectiology UnitDepartment of Internal Medicine II, University Hospital Würzburg, Oberdürrbacher Street 6, 97080 Würzburg, GermanyComprehensive Cancer Center MainfrankenUniversity of Würzburg, Würzburg, GermanyDivision of Laboratory MedicineMedical Care Centre of Human Genetics Ulm, Ulm, GermanyDepartment of Nuclear MedicineUniversity Hospital Würzburg, Würzburg, GermanyClinical Chemistry and Laboratory MedicineUniversity Hospital Würzburg, Würzburg, Germany Endocrine and Diabetes UnitDepartment of Internal Medicine IInfectiology UnitDepartment of Internal Medicine II, University Hospital Würzburg, Oberdürrbacher Street 6, 97080 Würzburg, GermanyComprehensive Cancer Center MainfrankenUniversity of Würzburg, Würzburg, GermanyDivision of Laboratory MedicineMedical Care Centre of Human Genetics Ulm, Ulm, GermanyDepartment of Nuclear MedicineUniversity Hospital Würzburg, Würzburg, GermanyClinical Chemistry and Laboratory MedicineUniversity Hospital Würzburg, Würzburg, Germany Endocrine and Diabetes UnitDepartment of Internal Medicine IInfectiology UnitDepartment of Internal Medicine II, University Hospital Würzburg, Oberdürrbacher Street 6, 97080 Würzburg, GermanyComprehensive Cancer Center MainfrankenUniversity of Würzburg, Würzburg, GermanyDivision of Laboratory MedicineMedical Care Centre of Human Genetics Ulm, Ulm, GermanyDepartment of Nuclear MedicineUniversity Hospital Würzburg, Würzburg, GermanyClinical Chemistry and Laboratory MedicineUniversity Hospital Würzburg, Würzburg, Germany
| | - Werner Heinz
- Endocrine and Diabetes UnitDepartment of Internal Medicine IInfectiology UnitDepartment of Internal Medicine II, University Hospital Würzburg, Oberdürrbacher Street 6, 97080 Würzburg, GermanyComprehensive Cancer Center MainfrankenUniversity of Würzburg, Würzburg, GermanyDivision of Laboratory MedicineMedical Care Centre of Human Genetics Ulm, Ulm, GermanyDepartment of Nuclear MedicineUniversity Hospital Würzburg, Würzburg, GermanyClinical Chemistry and Laboratory MedicineUniversity Hospital Würzburg, Würzburg, Germany
| | - Silviu Sbiera
- Endocrine and Diabetes UnitDepartment of Internal Medicine IInfectiology UnitDepartment of Internal Medicine II, University Hospital Würzburg, Oberdürrbacher Street 6, 97080 Würzburg, GermanyComprehensive Cancer Center MainfrankenUniversity of Würzburg, Würzburg, GermanyDivision of Laboratory MedicineMedical Care Centre of Human Genetics Ulm, Ulm, GermanyDepartment of Nuclear MedicineUniversity Hospital Würzburg, Würzburg, GermanyClinical Chemistry and Laboratory MedicineUniversity Hospital Würzburg, Würzburg, Germany
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Hsieh J, Trajcevski KE, Farr SL, Baker CL, Lake EJ, Taher J, Iqbal J, Hussain MM, Adeli K. Glucagon-Like Peptide 2 (GLP-2) Stimulates Postprandial Chylomicron Production and Postabsorptive Release of Intestinal Triglyceride Storage Pools via Induction of Nitric Oxide Signaling in Male Hamsters and Mice. Endocrinology 2015; 156:3538-47. [PMID: 26132919 DOI: 10.1210/en.2015-1110] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The intestinal overproduction of apolipoprotein B48 (apoB48)-containing chylomicron particles is a common feature of diabetic dyslipidemia and contributes to cardiovascular risk in insulin resistant states. We previously reported that glucagon-like peptide-2 (GLP-2) is a key endocrine stimulator of enterocyte fat absorption and chylomicron output in the postprandial state. GLP-2's stimulatory effect on chylomicron production in the postabsorptive state has been confirmed in human studies. The mechanism by which GLP-2 regulates chylomicron production is unclear, because its receptor is not expressed on enterocytes. We provide evidence for a key role of nitric oxide (NO) in mediating the stimulatory effects of GLP-2 during the postprandial and postabsorptive periods. Intestinal chylomicron production was assessed in GLP-2-treated hamsters administered the pan-specific NO synthase (NOS) inhibitor L-N(G)-nitroarginine methyl ester (L-NAME), and in GLP-2-treated endothelial NOS knockout mice. L-NAME blocked GLP-2-stimulated apoB48 secretion and reduced triglycerides (TGs) in the TG-rich lipoprotein (TRL) fraction of the plasma in the postprandial state. Endothelial NOS-deficient mice were resistant to GLP-2 stimulation and secreted fewer large apoB48-particles. When TG storage pools were allowed to accumulate, L-NAME mitigated the GLP-2-mediated increase in TRL-TG, suggesting that NO is required for early mobilization and secretion of stored TG and preformed chylomicrons. Importantly, the NO donor S-nitroso-L-glutathione was able to elicit an increase in TRL-TG in vivo and stimulate chylomicron release in vitro in primary enterocytes. We describe a novel role for GLP-2-mediated NO-signaling as a critical regulator of intestinal lipid handling and a potential contributor to postprandial dyslipidemia.
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Affiliation(s)
- Joanne Hsieh
- Molecular Structure and Function (J.H., K.E.T., S.L.F., C.L.B., E.J.L., J.T., K.A.), Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada, M5G 1X8; Departments of Biochemistry (J.H., K.E.T., K.A.) and Laboratory Medicine and Pathobiology (S.L.F., J.T., K.A.), University of Toronto, Toronto, Ontario, Canada, M5S 1A8; and State University of New York Downstate Medical Center (J.I., M.H.H.), Brooklyn, New York 11203
| | - Karin E Trajcevski
- Molecular Structure and Function (J.H., K.E.T., S.L.F., C.L.B., E.J.L., J.T., K.A.), Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada, M5G 1X8; Departments of Biochemistry (J.H., K.E.T., K.A.) and Laboratory Medicine and Pathobiology (S.L.F., J.T., K.A.), University of Toronto, Toronto, Ontario, Canada, M5S 1A8; and State University of New York Downstate Medical Center (J.I., M.H.H.), Brooklyn, New York 11203
| | - Sarah L Farr
- Molecular Structure and Function (J.H., K.E.T., S.L.F., C.L.B., E.J.L., J.T., K.A.), Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada, M5G 1X8; Departments of Biochemistry (J.H., K.E.T., K.A.) and Laboratory Medicine and Pathobiology (S.L.F., J.T., K.A.), University of Toronto, Toronto, Ontario, Canada, M5S 1A8; and State University of New York Downstate Medical Center (J.I., M.H.H.), Brooklyn, New York 11203
| | - Christopher L Baker
- Molecular Structure and Function (J.H., K.E.T., S.L.F., C.L.B., E.J.L., J.T., K.A.), Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada, M5G 1X8; Departments of Biochemistry (J.H., K.E.T., K.A.) and Laboratory Medicine and Pathobiology (S.L.F., J.T., K.A.), University of Toronto, Toronto, Ontario, Canada, M5S 1A8; and State University of New York Downstate Medical Center (J.I., M.H.H.), Brooklyn, New York 11203
| | - Elizabeth J Lake
- Molecular Structure and Function (J.H., K.E.T., S.L.F., C.L.B., E.J.L., J.T., K.A.), Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada, M5G 1X8; Departments of Biochemistry (J.H., K.E.T., K.A.) and Laboratory Medicine and Pathobiology (S.L.F., J.T., K.A.), University of Toronto, Toronto, Ontario, Canada, M5S 1A8; and State University of New York Downstate Medical Center (J.I., M.H.H.), Brooklyn, New York 11203
| | - Jennifer Taher
- Molecular Structure and Function (J.H., K.E.T., S.L.F., C.L.B., E.J.L., J.T., K.A.), Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada, M5G 1X8; Departments of Biochemistry (J.H., K.E.T., K.A.) and Laboratory Medicine and Pathobiology (S.L.F., J.T., K.A.), University of Toronto, Toronto, Ontario, Canada, M5S 1A8; and State University of New York Downstate Medical Center (J.I., M.H.H.), Brooklyn, New York 11203
| | - Jahangir Iqbal
- Molecular Structure and Function (J.H., K.E.T., S.L.F., C.L.B., E.J.L., J.T., K.A.), Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada, M5G 1X8; Departments of Biochemistry (J.H., K.E.T., K.A.) and Laboratory Medicine and Pathobiology (S.L.F., J.T., K.A.), University of Toronto, Toronto, Ontario, Canada, M5S 1A8; and State University of New York Downstate Medical Center (J.I., M.H.H.), Brooklyn, New York 11203
| | - Mahmood M Hussain
- Molecular Structure and Function (J.H., K.E.T., S.L.F., C.L.B., E.J.L., J.T., K.A.), Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada, M5G 1X8; Departments of Biochemistry (J.H., K.E.T., K.A.) and Laboratory Medicine and Pathobiology (S.L.F., J.T., K.A.), University of Toronto, Toronto, Ontario, Canada, M5S 1A8; and State University of New York Downstate Medical Center (J.I., M.H.H.), Brooklyn, New York 11203
| | - Khosrow Adeli
- Molecular Structure and Function (J.H., K.E.T., S.L.F., C.L.B., E.J.L., J.T., K.A.), Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada, M5G 1X8; Departments of Biochemistry (J.H., K.E.T., K.A.) and Laboratory Medicine and Pathobiology (S.L.F., J.T., K.A.), University of Toronto, Toronto, Ontario, Canada, M5S 1A8; and State University of New York Downstate Medical Center (J.I., M.H.H.), Brooklyn, New York 11203
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Titov VN. [THE FATTY CELL. THE VISCERAL FATTY TISSUE, EFFECT OF HUMORAL MEDIATOR LEPTIN IN AUTOCRINE WAY AND IN PARACRIN CENOSISES OF CELLS. TWO PHYLOGENETICALLY, FUNCTIONALLY AND REGULATORY DIFFERENT POOLS OF FATTY TISSUE IN VIVO]. Klin Lab Diagn 2015; 60:4-13. [PMID: 26596040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Every cell reserves fatty acids in cytozol in drops of lipids in the form of non-polar triglycerides for itself andfor oxidation in mitochondria. The specialized visceral fatty cells ofomentum and adipocytes ofsubcutaneous fat are the cells absorbing saturated and mono unsaturated fatty acids in form of triglycerides in apoB-48 chylomicrons, apoB-100 lipoproteins of low and very low density. They deposit their physiological time and liberate fatty acids in intercellular medium in the form ofpolar unesterified fatty acids bound by albumin. According phylogenetic theory of general pathology, in biological function of trophology (nutrition) fatty cells sequentially implement biological reaction of exotrophy (external nutrition), deposition and endotrophy (internal nutrition). The humoral regulator offeedback in visceral fatty cells is leptin acting in autocrine way, in paracrin cenosises of cells and on the level of organism. The biological role of leptin is in preventing a) deposition of surplus amount of non-polar triglycerides in fatty cells; b) formation of endoplasmic "stress"; c) death of fatty cells in apoptosis way, formation of corpuscles of apoptosis and failure of biological function of endoecology; d) formation of biological reaction of inflammation in visceral fatty tissue; e) high level of unsaturated fatty acids in intercellular medium and f) development of metabolic syndrome. The leptin prevents aphysiological deposit ofnon-polar triglycerides in insulin-dependent cells that are not intended to deposit non-polar triglycerides and also in β-cells of islands. The main cause of high level ofleptin in blood plasma is overeating offood physiological by content of nutrients.
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Abstract
Research into lipoprotein metabolism has developed because understanding lipoprotein metabolism has important clinical indications. Lipoproteins are risk factors for cardiovascular disease. Recent advances include the identification of factors in the synthesis and secretion of triglyceride rich lipoproteins, chylomicrons (CM) and very low density lipoproteins (VLDL). These included the identification of microsomal transfer protein, the cotranslational targeting of apoproteinB (apoB) for degradation regulated by the availability of lipids, and the characterization of transport vesicles transporting primordial apoB containing particles to the Golgi. The lipase maturation factor 1, glycosylphosphatidylinositol-anchored high density lipoprotein binding protein 1 and an angiopoietin-like protein play a role in lipoprotein lipase (LPL)-mediated hydrolysis of secreted CMs and VLDL so that the right amount of fatty acid is delivered to the right tissue at the right time. Expression of the low density lipoprotein (LDL) receptor is regulated at both transcriptional and post-transcriptional level. Proprotein convertase subtilisin/kexin type 9 (PCSK9) has a pivotal role in the degradation of LDL receptor. Plasma remnant lipoproteins bind to specific receptors in the liver, the LDL receptor, VLDL receptor and LDL receptor-like proteins prior to removal from the plasma. Reverse cholesterol transport occurs when lipid free apoAI recruits cholesterol and phospholipid to assemble high density lipoprotein (HDL) particles. The discovery of ABC transporters (ABCA1 and ABCG1) and scavenger receptor class B type I (SR-BI) provided further information on the biogenesis of HDL. In humans HDL-cholesterol can be returned to the liver either by direct uptake by SR-BI or through cholesteryl ester transfer protein exchange of cholesteryl ester for triglycerides in apoB lipoproteins, followed by hepatic uptake of apoB containing particles. Cholesterol content in cells is regulated by several transcription factors, including the liver X receptor and sterol regulatory element binding protein. This review summarizes recent advances in knowledge of the molecular mechanisms regulating lipoprotein metabolism.
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Elmore BO, Triplett KD, Hall PR. Apolipoprotein B48, the Structural Component of Chylomicrons, Is Sufficient to Antagonize Staphylococcus aureus Quorum-Sensing. PLoS One 2015; 10:e0125027. [PMID: 25942561 PMCID: PMC4420250 DOI: 10.1371/journal.pone.0125027] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 03/19/2015] [Indexed: 01/09/2023] Open
Abstract
Serum lipoproteins (LP) are increasingly being recognized as dual purpose molecules that contribute to both cholesterol homeostasis and host innate defense. In fact, very low LP levels are associated with increased risk of bacterial infection in critically ill patients. In this respect, we reported that apolipoprotein B100 (apoB100), the 4536 amino acid structural protein of very low density lipoprotein (VLDL) produced by the liver, limits Staphylococcus aureus pathogenesis. S. aureus uses quorum-sensing (QS) via the accessory gene regulator (agr) operon and an autoinducing peptide (AIP) to coordinate expression of over 200 virulence genes. ApoB100 prevents agr activation by binding and sequestering secreted AIP. Importantly, human serum LP are produced not only by the liver, but are also produced by enterocytes, in the form of chylomicrons, during uptake of dietary lipids. In contrast to apoB100 in VLDL, human enterocytes use apoB48, the N-terminal 2152 amino acids (48%) of apoB100, as the structural component of chylomicrons. Interestingly, enteral feeding of critically ill patients has been associated with decreased risk of infectious complications, suggesting chylomicrons could contribute to host innate defense in critically ill patients when serum LP production by the liver is limited during the acute phase response. Therefore, we hypothesized that apoB48 would be sufficient to antagonize S. aureus QS. As expected, isolated apoB48-LP bound immobilized AIP and antagonized agr-signaling. ApoB48- and apoB100-LP inhibited agr activation with IC50s of 3.5 and 2.3 nM, respectively, demonstrating a conserved AIP binding site. Importantly, apoB48-LP antagonized QS, limited morbidity and promoted bacterial clearance in a mouse model of S. aureus infection. This work demonstrates that both naturally occurring forms of apolipoprotein B can antagonize S. aureus QS, and may suggest a previously unrecognized role for chylomicrons and enterocytes in host innate defense against S. aureus QS-mediated pathogenesis.
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Affiliation(s)
- Bradley O. Elmore
- Department of Pharmaceutical Sciences, University of New Mexico College of Pharmacy, Albuquerque, New Mexico, United States of America
| | - Kathleen D. Triplett
- Department of Pharmaceutical Sciences, University of New Mexico College of Pharmacy, Albuquerque, New Mexico, United States of America
| | - Pamela R. Hall
- Department of Pharmaceutical Sciences, University of New Mexico College of Pharmacy, Albuquerque, New Mexico, United States of America
- * E-mail:
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Affiliation(s)
- T A Sanders
- Department of Food and Nutrition Sciences, King's College London, University of London, UK
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Affiliation(s)
- W S Harris
- Department of Medicine, University of Kansas Medical Center, Kansas City
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