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Bianco V, Svecla M, Vingiani GB, Kolb D, Schwarz B, Buerger M, Beretta G, Norata GD, Kratky D. Regional Differences in the Small Intestinal Proteome of Control Mice and of Mice Lacking Lysosomal Acid Lipase. J Proteome Res 2024; 23:1506-1518. [PMID: 38422518 PMCID: PMC7615810 DOI: 10.1021/acs.jproteome.4c00082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Accepted: 02/16/2024] [Indexed: 03/02/2024]
Abstract
The metabolic contribution of the small intestine (SI) is still unclear despite recent studies investigating the involvement of single cells in regional differences. Using untargeted proteomics, we identified regional characteristics of the three intestinal tracts of C57BL/6J mice and found that proteins abundant in the mouse ileum correlated with the high ileal expression of the corresponding genes in humans. In the SI of C57BL/6J mice, we also detected an increasing abundance of lysosomal acid lipase (LAL), which is responsible for degrading triacylglycerols and cholesteryl esters within the lysosome. LAL deficiency in patients and mice leads to lipid accumulation, gastrointestinal disturbances, and malabsorption. We previously demonstrated that macrophages massively infiltrated the SI of Lal-deficient (KO) mice, especially in the duodenum. Using untargeted proteomics (ProteomeXchange repository, data identifier PXD048378), we revealed a general inflammatory response and a common lipid-associated macrophage phenotype in all three intestinal segments of Lal KO mice, accompanied by a higher expression of GPNMB and concentrations of circulating sTREM2. However, only duodenal macrophages activated a metabolic switch from lipids to other pathways, which were downregulated in the jejunum and ileum of Lal KO mice. Our results provide new insights into the process of absorption in control mice and possible novel markers of LAL-D and/or systemic inflammation in LAL-D.
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Affiliation(s)
- Valentina Bianco
- Gottfried
Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstrasse 6/4, 8010 Graz, Austria
| | - Monika Svecla
- Department
of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Via Balzaretti 9, 20133 Milan, Italy
| | - Giovanni Battista Vingiani
- Department
of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Via Balzaretti 9, 20133 Milan, Italy
| | - Dagmar Kolb
- Core
Facility Ultrastructural Analysis, Medical
University of Graz, 8010 Graz, Austria
- BioTechMed-Graz, 8010 Graz, Austria
- Gottfried
Schatz Research Center, Cell Biology, Histology and Embryology, Medical University of Graz, 8010 Graz, Austria
| | - Birgit Schwarz
- Gottfried
Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstrasse 6/4, 8010 Graz, Austria
| | - Martin Buerger
- Gottfried
Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstrasse 6/4, 8010 Graz, Austria
| | - Giangiacomo Beretta
- Department
of Environmental Science and Policy, Università
degli Studi di Milano, 20133 Milan, Italy
| | - Giuseppe Danilo Norata
- Department
of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Via Balzaretti 9, 20133 Milan, Italy
- Centro
SISA per lo studio dell’Aterosclerosi, Ospedale Bassini, 20092 Cinisello Balsamo, Italy
| | - Dagmar Kratky
- Gottfried
Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstrasse 6/4, 8010 Graz, Austria
- BioTechMed-Graz, 8010 Graz, Austria
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Datta R, Gholampour MA, Yang CD, Volk R, Lin S, Podolsky MJ, Arnold T, Rieder F, Zaro BW, Verzi M, Lehner R, Abumrad N, Lizama CO, Atabai K. MFGE8 links absorption of dietary fatty acids with catabolism of enterocyte lipid stores through HNF4γ-dependent transcription of CES enzymes. Cell Rep 2023; 42:112249. [PMID: 36924494 PMCID: PMC10138282 DOI: 10.1016/j.celrep.2023.112249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 12/21/2022] [Accepted: 02/25/2023] [Indexed: 03/17/2023] Open
Abstract
Enterocytes modulate the extent of postprandial lipemia by storing dietary fats in cytoplasmic lipid droplets (cLDs). We have previously shown that the integrin ligand MFGE8 links absorption of dietary fats with activation of triglyceride (TG) hydrolases that catabolize cLDs for chylomicron production. Here, we identify CES1D as the key hydrolase downstream of the MFGE8-αvβ5 integrin pathway that regulates catabolism of diet-derived cLDs. Mfge8 knockout (KO) enterocytes have reduced CES1D transcript and protein levels and reduced protein levels of the transcription factor HNF4γ. Both Ces1d and Hnf4γ KO mice have decreased enterocyte TG hydrolase activity coupled with retention of TG in cLDs. Mechanistically, MFGE8-dependent fatty acid uptake through CD36 stabilizes HNF4γ protein level; HNF4γ then increases Ces1d transcription. Our work identifies a regulatory network that regulates the severity of postprandial lipemia by linking dietary fat absorption with protein stabilization of a transcription factor that increases expression of hydrolases responsible for catabolizing diet-derived cLDs.
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Affiliation(s)
- Ritwik Datta
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Mohammad A Gholampour
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Christopher D Yang
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Regan Volk
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Sinan Lin
- Department of Gastroenterology, Hepatology and Nutrition, Digestive Diseases and Surgery Institute, Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44106, USA
| | - Michael J Podolsky
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Thomas Arnold
- Department of Pediatrics, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Florian Rieder
- Department of Gastroenterology, Hepatology and Nutrition, Digestive Diseases and Surgery Institute, Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44106, USA
| | - Balyn W Zaro
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | | | - Richard Lehner
- Department of Pediatrics, University of Alberta, Edmonton, AB T6G 1C9, Canada
| | - Nada Abumrad
- Washington University School of Medicine in St. Louis, St. Louis, MO 63110, USA
| | - Carlos O Lizama
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Kamran Atabai
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158, USA; Lung Biology Center, University of California, San Francisco, San Francisco, CA 94143, USA.
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Honeder SE, Tomin T, Schinagl M, Pfleger R, Hoehlschen J, Darnhofer B, Schittmayer M, Birner‐Gruenberger R. Research Advances Through Activity‐Based Lipid Hydrolase Profiling. Isr J Chem 2023. [DOI: 10.1002/ijch.202200078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Sophie Elisabeth Honeder
- Research and Diagnostic Institute of Pathology Medical University of Graz Stiftingtalstraße 6 8036 Graz Austria
| | - Tamara Tomin
- Institute of Chemical Technologies and Analytics University of Technology Vienna Getreidemarkt 9 1060 Wien Austria
| | - Maximilian Schinagl
- Institute of Chemical Technologies and Analytics University of Technology Vienna Getreidemarkt 9 1060 Wien Austria
| | - Raphael Pfleger
- Institute of Chemical Technologies and Analytics University of Technology Vienna Getreidemarkt 9 1060 Wien Austria
| | - Julia Hoehlschen
- Institute of Chemical Technologies and Analytics University of Technology Vienna Getreidemarkt 9 1060 Wien Austria
| | - Barbara Darnhofer
- Core Facility Mass Spectrometry Center for Medical Research Medical University of Graz Neue Stiftingtalstraße 24 8036 Graz Austria
| | - Matthias Schittmayer
- Institute of Chemical Technologies and Analytics University of Technology Vienna Getreidemarkt 9 1060 Wien Austria
| | - Ruth Birner‐Gruenberger
- Research and Diagnostic Institute of Pathology Medical University of Graz Stiftingtalstraße 6 8036 Graz Austria
- Institute of Chemical Technologies and Analytics University of Technology Vienna Getreidemarkt 9 1060 Wien Austria
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Ghanem M, Lewis GF, Xiao C. Recent advances in cytoplasmic lipid droplet metabolism in intestinal enterocyte. Biochim Biophys Acta Mol Cell Biol Lipids 2022; 1867:159197. [PMID: 35820577 DOI: 10.1016/j.bbalip.2022.159197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 06/03/2022] [Accepted: 06/14/2022] [Indexed: 11/30/2022]
Abstract
Processing of dietary fats in the intestine is a highly regulated process that influences whole-body energy homeostasis and multiple physiological functions. Dysregulated lipid handling in the intestine leads to dyslipidemia and atherosclerotic cardiovascular disease. In intestinal enterocytes, lipids are incorporated into lipoproteins and cytoplasmic lipid droplets (CLDs). Lipoprotein synthesis and CLD metabolism are inter-connected pathways with multiple points of regulation. This review aims to highlight recent advances in the regulatory mechanisms of lipid processing in the enterocyte, with particular focus on CLDs. In-depth understanding of the regulation of lipid metabolism in the enterocyte may help identify therapeutic targets for the treatment and prevention of metabolic disorders.
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Affiliation(s)
- Murooj Ghanem
- Department of Anatomy, Physiology and Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Gary F Lewis
- Departments of Medicine and Physiology, University of Toronto, and University Health Network, Toronto, ON, Canada
| | - Changting Xiao
- Department of Anatomy, Physiology and Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada.
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Bradić I, Kuentzel KB, Honeder S, Grabner GF, Vujić N, Zimmermann R, Birner-Gruenberger R, Kratky D. Off-target effects of the lysosomal acid lipase inhibitors Lalistat-1 and Lalistat-2 on neutral lipid hydrolases. Mol Metab 2022; 61:101510. [PMID: 35504532 PMCID: PMC9118473 DOI: 10.1016/j.molmet.2022.101510] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 03/11/2022] [Accepted: 04/27/2022] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVES Lysosomal acid lipase (LAL) is the key enzyme, which degrades neutral lipids at an acidic pH in lysosomes. The role of LAL in various cellular processes has mostly been studied in LAL-knockout mice, which share phenotypical characteristics with humans suffering from LAL deficiency. In vitro, the cell-specific functions of LAL have been commonly investigated by using the LAL inhibitors Lalistat-1 and Lalistat-2. METHODS We performed lipid hydrolase activity assays and serine hydrolase-specific activity-based labeling combined with quantitative proteomics to investigate potential off-target effects of Lalistat-1 and -2. RESULTS Pharmacological LAL inhibition but not genetic loss of LAL impairs isoproterenol-stimulated lipolysis as well as neutral triglyceride and cholesteryl ester hydrolase activities. Apart from LAL, Lalistat-1 and -2 also inhibit major cytosolic lipid hydrolases responsible for lipid degradation in primary cells at neutral pH through off-target effects. Their binding to the active center of the enzymes leads to a decrease in neutral lipid hydrolase activities in cells overexpressing the respective enzymes. CONCLUSIONS Our findings are critically important since they demonstrate that commonly used concentrations of these inhibitors are not suitable to investigate the role of LAL-specific lipolysis in lysosomal function, signaling pathways, and autophagy. The interpretation of their effects on lipid metabolism should be taken with caution and the applied inhibitor concentrations in cell culture studies should not exceed 1 μM.
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Affiliation(s)
- Ivan Bradić
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Katharina B Kuentzel
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Sophie Honeder
- Diagnostic and Research Institute of Pathology, Medical University Graz, Graz, Austria
| | - Gernot F Grabner
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Nemanja Vujić
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Robert Zimmermann
- Institute of Molecular Biosciences, University of Graz, Graz, Austria; BioTechMed Graz, Graz, Austria
| | - Ruth Birner-Gruenberger
- Diagnostic and Research Institute of Pathology, Medical University Graz, Graz, Austria; BioTechMed Graz, Graz, Austria; Institute of Chemical Technologies and Analytics, TU Wien, Vienna, Austria
| | - Dagmar Kratky
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria; BioTechMed Graz, Graz, Austria.
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Zembroski AS, Xiao C, Buhman KK. The Roles of Cytoplasmic Lipid Droplets in Modulating Intestinal Uptake of Dietary Fat. Annu Rev Nutr 2021; 41:79-104. [PMID: 34283920 DOI: 10.1146/annurev-nutr-110320-013657] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Dietary fat absorption is required for health but also contributes to hyperlipidemia and metabolic disease when dysregulated. One step in the process of dietary fat absorption is the formation of cytoplasmic lipid droplets (CLDs) in small intestinal enterocytes; these CLDs serve as dynamic triacylglycerol storage organelles that influence the rate at which dietary fat is absorbed. Recent studies have uncovered novel factors regulating enterocyte CLD metabolism that in turn influence the absorption of dietary fat. These include peroxisome proliferator-activated receptor α activation, compartmentalization of different lipid pools, the gut microbiome, liver X receptor and farnesoid X receptor activation, obesity, and physiological factors stimulating CLD mobilization. Understanding how enterocyte CLD metabolism is regulated is key in modulating the absorption of dietary fat in the prevention of hyperlipidemia and its associated metabolic disorders. Expected final online publication date for the Annual Review of Nutrition, Volume 41 is September 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Alyssa S Zembroski
- Department of Nutrition Science, Purdue University, West Lafayette, Indiana 47907, USA;
| | - Changting Xiao
- Department of Anatomy, Physiology and Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada
| | - Kimberly K Buhman
- Department of Nutrition Science, Purdue University, West Lafayette, Indiana 47907, USA;
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Zembroski AS, D’Aquila T, Buhman KK. Characterization of cytoplasmic lipid droplets in each region of the small intestine of lean and diet-induced obese mice in response to dietary fat. Am J Physiol Gastrointest Liver Physiol 2021; 321:G75-G86. [PMID: 34009042 PMCID: PMC8321799 DOI: 10.1152/ajpgi.00084.2021] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The absorptive cells of the small intestine, namely, enterocytes, contribute to postprandial blood lipid levels by secreting dietary triacylglycerol in chylomicrons. The rate and amount of dietary triacylglycerol absorbed vary along the length of the small intestine. Excess dietary triacylglycerol not immediately secreted in chylomicrons can be temporarily stored in cytoplasmic lipid droplets (CLDs) and repackaged in chylomicrons at later times. The characteristics of CLDs, including their size, number per cell, and associated proteins, may influence CLD metabolism and reflect differences in lipid processing or storage in each intestinal region. However, it is unknown whether the characteristics or proteomes of CLDs differ in enterocytes of each intestine region in response to dietary fat. Furthermore, it is unclear if obesity influences the characteristics or proteomes of CLDs in each intestine region. To address this, we used transmission electron microscopy and shotgun liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis to assess the characteristics and proteome of CLDs in the proximal, middle, and distal regions of the small intestine of lean and diet-induced obese (DIO) mice 2 h after an oil gavage. We identified differences in lipid storage along the length of the small intestine and between lean and DIO mice, as well as distinct CLD proteomes reflecting potentially unique roles of CLDs in each region. This study reveals differences in lipid processing along the length of the small intestine in response to dietary fat in lean and DIO mice and reflects distinct features of the proximal, middle, distal region of the small intestine.NEW & NOTEWORTHY This study reflects the dynamics of fat absorption along the length of the small intestine in lean and obese mice in the physiological response to dietary fat. We identified unique features of cytoplasmic lipid droplets (CLDs) in the proximal, middle, and distal regions of the small intestine of lean and obese mice that may contribute to regional differences in dietary fat processing, absorption, or CLD metabolism.
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Affiliation(s)
| | - Theresa D’Aquila
- Department of Nutrition Science, Purdue University, West Lafayette, Indiana
| | - Kimberly K. Buhman
- Department of Nutrition Science, Purdue University, West Lafayette, Indiana
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