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Ellis JL, Evason KJ, Zhang C, Fourman MN, Liu J, Ninov N, Delous M, Vanhollebeke B, Fiddes I, Otis JP, Houvras Y, Farber SA, Xu X, Lin X, Stainier DYR, Yin C. A missense mutation in the proprotein convertase gene furinb causes hepatic cystogenesis during liver development in zebrafish. Hepatol Commun 2022; 6:3083-3097. [PMID: 36017776 PMCID: PMC9592797 DOI: 10.1002/hep4.2038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 05/28/2022] [Accepted: 06/17/2022] [Indexed: 12/14/2022] Open
Abstract
Hepatic cysts are fluid-filled lesions in the liver that are estimated to occur in 5% of the population. They may cause hepatomegaly and abdominal pain. Progression to secondary fibrosis, cirrhosis, or cholangiocarcinoma can lead to morbidity and mortality. Previous studies of patients and rodent models have associated hepatic cyst formation with increased proliferation and fluid secretion in cholangiocytes, which are partially due to impaired primary cilia. Congenital hepatic cysts are thought to originate from faulty bile duct development, but the underlying mechanisms are not fully understood. In a forward genetic screen, we identified a zebrafish mutant that developed hepatic cysts during larval stages. The cyst formation was not due to changes in biliary cell proliferation, bile secretion, or impairment of primary cilia. Instead, time-lapse live imaging data showed that the mutant biliary cells failed to form interconnecting bile ducts because of defects in motility and protrusive activity. Accordingly, immunostaining revealed a disorganized actin and microtubule cytoskeleton in the mutant biliary cells. By whole-genome sequencing, we determined that the cystic phenotype in the mutant was caused by a missense mutation in the furinb gene, which encodes a proprotein convertase. The mutation altered Furinb localization and caused endoplasmic reticulum (ER) stress. The cystic phenotype could be suppressed by treatment with the ER stress inhibitor 4-phenylbutyric acid and exacerbated by treatment with the ER stress inducer tunicamycin. The mutant liver also exhibited increased mammalian target of rapamycin (mTOR) signaling. Treatment with mTOR inhibitors halted cyst formation at least partially through reducing ER stress. Conclusion: Our study has established a vertebrate model for studying hepatic cystogenesis and illustrated the contribution of ER stress in the disease pathogenesis.
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Affiliation(s)
- Jillian L. Ellis
- Division of Gastroenterology, Hepatology, and NutritionCincinnati Children's Hospital Medical CenterCincinnatiOhioUSA
| | - Kimberley J. Evason
- Department of Biochemistry and BiophysicsProgram in Developmental and Stem Cell BiologyLiver Center and Diabetes CenterUniversity of California, San FranciscoSan FranciscoCaliforniaUSA
- Huntsman Cancer Institute and Department of PathologyUniversity of UtahSalt Lake CityUtahUSA
| | - Changwen Zhang
- Division of Gastroenterology, Hepatology, and NutritionCincinnati Children's Hospital Medical CenterCincinnatiOhioUSA
| | - Makenzie N. Fourman
- Division of Gastroenterology, Hepatology, and NutritionCincinnati Children's Hospital Medical CenterCincinnatiOhioUSA
| | - Jiandong Liu
- Department of Biochemistry and BiophysicsProgram in Developmental and Stem Cell BiologyLiver Center and Diabetes CenterUniversity of California, San FranciscoSan FranciscoCaliforniaUSA
- McAllister Heart InstituteDepartment of Pathology and Laboratory MedicineSchool of MedicineThe University of North Carolina at Chapel HillChapel HillNorth CarolinaUSA
| | - Nikolay Ninov
- Department of Biochemistry and BiophysicsProgram in Developmental and Stem Cell BiologyLiver Center and Diabetes CenterUniversity of California, San FranciscoSan FranciscoCaliforniaUSA
- Center for Regenerative Therapies TU DresdenDresdenGermany
- Paul Langerhans Institute Dresden of the Helmholtz Center Munich at the University Hospital Carl Gustav Carus of TU DresdenGerman Center for Diabetes ResearchDresdenGermany
| | - Marion Delous
- Department of Biochemistry and BiophysicsProgram in Developmental and Stem Cell BiologyLiver Center and Diabetes CenterUniversity of California, San FranciscoSan FranciscoCaliforniaUSA
- Equipe GENDEVCentre de Recherche en Neurosciences de LyonInserm U1028CNRS UMR5292Universite Lyon 1Universite St EtienneLyonFrance
| | - Benoit Vanhollebeke
- Department of Biochemistry and BiophysicsProgram in Developmental and Stem Cell BiologyLiver Center and Diabetes CenterUniversity of California, San FranciscoSan FranciscoCaliforniaUSA
- Laboratory of Neurovascular SignalingDepartment of Molecular BiologyULB Neuroscience InstituteUniversite Libre de BruxellesGosseliesBelgium
| | - Ian Fiddes
- Department of Biochemistry and BiophysicsProgram in Developmental and Stem Cell BiologyLiver Center and Diabetes CenterUniversity of California, San FranciscoSan FranciscoCaliforniaUSA
| | - Jessica P. Otis
- Department of EmbryologyCarnegie Institution for ScienceBaltimoreMarylandUSA
- Department of BiologyJohns Hopkins UniversityBaltimoreMarylandUSA
- Department of Molecular and Cellular Biology and BiochemistryBrown UniversityProvidenceRhode IslandUSA
| | - Yariv Houvras
- Weill Cornell Medical College and New York Presbyterian HospitalNew YorkNew YorkUSA
| | - Steven A. Farber
- Department of EmbryologyCarnegie Institution for ScienceBaltimoreMarylandUSA
- Department of BiologyJohns Hopkins UniversityBaltimoreMarylandUSA
| | - Xiaolei Xu
- Department of Biochemistry and Molecular BiologyDepartment of Cardiovascular MedicineMayo ClinicRochesterMinnesotaUSA
| | - Xueying Lin
- Department of Biochemistry and Molecular BiologyDepartment of Cardiovascular MedicineMayo ClinicRochesterMinnesotaUSA
| | - Didier Y. R. Stainier
- Department of Biochemistry and BiophysicsProgram in Developmental and Stem Cell BiologyLiver Center and Diabetes CenterUniversity of California, San FranciscoSan FranciscoCaliforniaUSA
- Department of Developmental GeneticsMax Planck Institute for Heart and Lung ResearchBad NauheimGermany
| | - Chunyue Yin
- Division of Gastroenterology, Hepatology, and NutritionCincinnati Children's Hospital Medical CenterCincinnatiOhioUSA
- Department of Biochemistry and BiophysicsProgram in Developmental and Stem Cell BiologyLiver Center and Diabetes CenterUniversity of California, San FranciscoSan FranciscoCaliforniaUSA
- Division of Developmental BiologyCincinnati Children's Hospital Medical CenterCincinnatiOhioUSA
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A Planar Culture Model of Human Absorptive Enterocytes Reveals Metformin Increases Fatty Acid Oxidation and Export. Cell Mol Gastroenterol Hepatol 2022; 14:409-434. [PMID: 35489715 PMCID: PMC9305019 DOI: 10.1016/j.jcmgh.2022.04.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 04/06/2022] [Accepted: 04/18/2022] [Indexed: 12/13/2022]
Abstract
BACKGROUND & AIMS Fatty acid oxidation by absorptive enterocytes has been linked to the pathophysiology of type 2 diabetes, obesity, and dyslipidemia. Caco-2 and organoids have been used to study dietary lipid-handling processes including fatty acid oxidation, but are limited in physiological relevance or preclude simultaneous apical and basal access. Here, we developed a high-throughput planar human absorptive enterocyte monolayer system for investigating lipid handling, and then evaluated the role of fatty acid oxidation in fatty acid export, using etomoxir, C75, and the antidiabetic drug metformin. METHODS Single-cell RNA-sequencing, transcriptomics, and lineage trajectory was performed on primary human jejunum. In vivo absorptive enterocyte maturational states informed conditions used to differentiate human intestinal stem cells (ISCs) that mimic in vivo absorptive enterocyte maturation. The system was scaled for high-throughput drug screening. Fatty acid oxidation was modulated pharmacologically and BODIPY (Thermo Fisher Scientific, Waltham, MA) (B)-labeled fatty acids were used to evaluate fatty acid handling via fluorescence and thin-layer chromatography. RESULTS Single-cell RNA-sequencing shows increasing expression of lipid-handling genes as absorptive enterocytes mature. Culture conditions promote ISC differentiation into confluent absorptive enterocyte monolayers. Fatty acid-handling gene expression mimics in vivo maturational states. The fatty acid oxidation inhibitor etomoxir decreased apical-to-basolateral export of medium-chain B-C12 and long-chain B-C16 fatty acids, whereas the CPT1 agonist C75 and the antidiabetic drug metformin increased apical-to-basolateral export. Short-chain B-C5 was unaffected by fatty acid oxidation inhibition and diffused through absorptive enterocytes. CONCLUSIONS Primary human ISCs in culture undergo programmed maturation. Absorptive enterocyte monolayers show in vivo maturational states and lipid-handling gene expression profiles. Absorptive enterocytes create strong epithelial barriers in 96-Transwell format. Fatty acid export is proportional to fatty acid oxidation. Metformin enhances fatty acid oxidation and increases basolateral fatty acid export, supporting an intestine-specific role.
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Sæle Ø, Rød KEL, Quinlivan VH, Li S, Farber SA. A novel system to quantify intestinal lipid digestion and transport. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1863:948-957. [PMID: 29778665 PMCID: PMC6054555 DOI: 10.1016/j.bbalip.2018.05.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 05/04/2018] [Accepted: 05/16/2018] [Indexed: 02/05/2023]
Abstract
The zebrafish larva is a powerful tool for the study of dietary triglyceride (TG) digestion and how fatty acids (FA) derived from dietary lipids are absorbed, metabolized and distributed to the body. While fluorescent FA analogues have enabled visualization of FA metabolism, methods for specifically assaying TG digestion are badly needed. Here we present a novel High Performance Liquid Chromatography (HPLC) method that quantitatively differentiates TG and phospholipid (PL) molecules with one or two fluorescent FA analogues. We show how this tool may be used to discriminate between undigested and digested TG or phosphatidylcholine (PC), and also the products of TG or PC that have been digested, absorbed and re-synthesized into new lipid molecules. Using this approach, we explored the dietary requirement of zebrafish larvae for phospholipids. Here we demonstrate that dietary TG is digested and absorbed in the intestinal epithelium, but without dietary PC, TG accumulates and is not transported out of the enterocytes. Consequently, intestinal ER stress increases and the ingested lipid is not available support the energy and metabolic needs of other tissues. In TG diets with PC, TG is readily transported from the intestine and subsequently metabolized.
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Affiliation(s)
- Øystein Sæle
- Institute of Marine Research, Strandgaten 229, 5004 Bergen, Norway.
| | - Kari Elin L Rød
- Institute of Marine Research, Strandgaten 229, 5004 Bergen, Norway
| | - Vanessa H Quinlivan
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218, USA; The Johns Hopkins University, Department of Biology, Baltimore, MD 21218, USA
| | - Shengrong Li
- Avanti Polar Lipids, Inc., 700 Industrial Park Drive, Alabaster, AL 35007-9105, USA
| | - Steven A Farber
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218, USA; The Johns Hopkins University, Department of Biology, Baltimore, MD 21218, USA.
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4
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Roman-Padilla J, Rodríguez-Rúa A, Carballo C, Manchado M, Hachero-Cruzado I. Phylogeny and expression patterns of two apolipoprotein E genes in the flatfish Senegalese sole. Gene 2018; 643:7-16. [DOI: 10.1016/j.gene.2017.11.078] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 11/15/2017] [Accepted: 11/30/2017] [Indexed: 02/07/2023]
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5
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Quinlivan VH, Wilson MH, Ruzicka J, Farber SA. An HPLC-CAD/fluorescence lipidomics platform using fluorescent fatty acids as metabolic tracers. J Lipid Res 2017; 58:1008-1020. [PMID: 28280113 DOI: 10.1194/jlr.d072918] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 03/07/2017] [Indexed: 11/20/2022] Open
Abstract
Fluorescent lipids are important tools for live imaging in cell culture and animal models, yet their metabolism has not been well-characterized. Here we describe a novel combined HPLC and LC-MS/MS method developed to characterize both total lipid profiles and the products of fluorescently labeled lipids. Using this approach, we found that lipids labeled with the fluorescent tags, 4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene (BODIPY FL), 4,4-difluoro-5-(2-thienyl)-4-bora-3a,4a-diaza-s-indacene [BODIPY(558/568)], and dipyrrometheneboron difluoride undecanoic acid (TopFluor) are all metabolized into varying arrays of polar and nonpolar fluorescent lipid products when they are fed to larval zebrafish. Quantitative metabolic labeling experiments performed in this system revealed significant effects of total dietary lipid composition on fluorescent lipid partitioning. We provide evidence that cholesterol metabolism in the intestine is important in determining the metabolic fates of dietary FAs. Using this method, we found that inhibitors of dietary cholesterol absorption and esterification both decreased incorporation of dietary fluorescent FAs into cholesterol esters (CEs), suggesting that CE synthesis in enterocytes is primarily responsive to the availability of dietary cholesterol. These results are the first to comprehensively characterize fluorescent FA metabolism and to demonstrate their utility as metabolic labeling reagents, effectively coupling quantitative biochemistry with live imaging studies.
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Affiliation(s)
- Vanessa H Quinlivan
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218.,Department of Biology, Johns Hopkins University, Baltimore, MD 21218; and
| | - Meredith H Wilson
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218
| | | | - Steven A Farber
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218; .,Department of Biology, Johns Hopkins University, Baltimore, MD 21218; and
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6
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Quinlivan VH, Farber SA. Lipid Uptake, Metabolism, and Transport in the Larval Zebrafish. Front Endocrinol (Lausanne) 2017; 8:319. [PMID: 29209275 PMCID: PMC5701920 DOI: 10.3389/fendo.2017.00319] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 11/01/2017] [Indexed: 01/08/2023] Open
Abstract
The developing zebrafish is a well-established model system for studies of energy metabolism, and is amenable to genetic, physiological, and biochemical approaches. For the first 5 days of life, nutrients are absorbed from its endogenous maternally deposited yolk. At 5 days post-fertilization, the yolk is exhausted and the larva has a functional digestive system including intestine, liver, gallbladder, pancreas, and intestinal microbiota. The transparency of the larval zebrafish, and the genetic and physiological similarity of its digestive system to that of mammals make it a promising system in which to address questions of energy homeostasis relevant to human health. For example, apolipoprotein expression and function is similar in zebrafish and mammals, and transgenic animals may be used to examine both the transport of lipid from yolk to body in the embryo, and the trafficking of dietary lipids in the larva. Additionally, despite the identification of many fatty acid and lipid transport proteins expressed by vertebrates, the cell biological processes that mediate the transport of dietary lipids from the intestinal lumen to the interior of enterocytes remain to be elucidated. Genetic tractability and amenability to live imaging and a range of biochemical methods make the larval zebrafish an ideal model in which to address open questions in the field of lipid transport, energy homeostasis, and nutrient metabolism.
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Affiliation(s)
- Vanessa H. Quinlivan
- Carnegie Institution for Science (CIS), Baltimore, MD, United States
- The Johns Hopkins University, Baltimore, MD, United States
| | - Steven A. Farber
- Carnegie Institution for Science (CIS), Baltimore, MD, United States
- The Johns Hopkins University, Baltimore, MD, United States
- *Correspondence: Steven A. Farber,
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7
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Otis JP, Farber SA. High-fat Feeding Paradigm for Larval Zebrafish: Feeding, Live Imaging, and Quantification of Food Intake. J Vis Exp 2016. [PMID: 27842350 DOI: 10.3791/54735] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Zebrafish are emerging as a model of dietary lipid processing and metabolic disease. This protocol describes how to feed larval zebrafish a lipid-rich meal, which consists of an emulsion of chicken egg yolk liposomes created by sonicating egg yolk in embryo media. Detailed instructions are provided to screen larvae for egg yolk consumption so that larvae that fail to feed will not confound experimental results. The chicken egg yolk liposomes can be spiked with fluorescent lipid analogs, including fatty acids and cholesterol, enabling both systemic and subcellular visualization of dietary lipid processing. Several methods are described to mount larvae that are conducive to short- and long-term live imaging with both upright and inverted objectives at high and low magnification. Additionally presented is an assay to quantify larval food intake by extracting the lipids of larvae fed fluorescent lipid analogs, spotting the lipids on a thin layer chromatography plate, and quantifying the fluorescence. Finally, critical aspects of the procedures, important controls, options for modifying the protocols to address specific experimental questions, and potential limitations are discussed. These techniques can be applied not only to focused, hypothesis driven inquiries, but also to a variety of screens and live imaging techniques to study dietary lipid metabolism and the control of food intake.
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Affiliation(s)
- Jessica P Otis
- Department of Embryology, Carnegie Institution for Science
| | - Steven A Farber
- Department of Embryology, Carnegie Institution for Science; Department of Biology, Johns Hopkins University;
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8
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Anderson JL, Carten JD, Farber SA. Using fluorescent lipids in live zebrafish larvae: From imaging whole animal physiology to subcellular lipid trafficking. Methods Cell Biol 2016; 133:165-78. [PMID: 27263413 DOI: 10.1016/bs.mcb.2016.04.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Lipids serve essential functions in cells as signaling molecules, membrane components, and sources of energy. Defects in lipid metabolism are implicated in a number of pandemic human diseases, including diabetes, obesity, and hypercholesterolemia. Many aspects of how fatty acids and cholesterol are absorbed and processed by intestinal cells remain unclear and present a hurdle to developing approaches for disease prevention and treatment. Numerous studies have shown that the zebrafish is an excellent model for vertebrate lipid metabolism. In this chapter, we review commercially available fluorescent lipids that can be deployed in live zebrafish to better understand lipid signaling and metabolism. In this chapter, we present criteria one should consider when selecting specific fluorescent lipids for the study of digestive physiology or lipid metabolism in larval zebrafish.
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Affiliation(s)
- J L Anderson
- Carnegie Institution for Science, Baltimore, MD, United States
| | - J D Carten
- Carnegie Institution for Science, Baltimore, MD, United States
| | - S A Farber
- Carnegie Institution for Science, Baltimore, MD, United States
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9
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Kaneko G, Shirakami H, Hirano Y, Oba M, Yoshinaga H, Khieokhajonkhet A, Nagasaka R, Kondo H, Hirono I, Ushio H. Diversity of Lipid Distribution in Fish Skeletal Muscle. Zoolog Sci 2016; 33:170-8. [DOI: 10.2108/zs150096] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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10
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Falcinelli S, Rodiles A, Unniappan S, Picchietti S, Gioacchini G, Merrifield DL, Carnevali O. Probiotic treatment reduces appetite and glucose level in the zebrafish model. Sci Rep 2016; 6:18061. [PMID: 26727958 PMCID: PMC4700460 DOI: 10.1038/srep18061] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 11/03/2015] [Indexed: 02/08/2023] Open
Abstract
The gut microbiota regulates metabolic pathways that modulate the physiological state of hunger or satiety. Nutrients in the gut stimulate the release of several appetite modulators acting at central and peripheral levels to mediate appetite and glucose metabolism. After an eight-day exposure of zebrafish larvae to probiotic Lactobacillus rhamnosus, high-throughput sequence analysis evidenced the ability of the probiotic to modulate the microbial composition of the gastrointestinal tract. These changes were associated with a down-regulation and up-regulation of larval orexigenic and anorexigenic genes, respectively, an up-regulation of genes related to glucose level reduction and concomitantly reduced appetite and body glucose level. BODIPY-FL-pentanoic-acid staining revealed higher short chain fatty acids levels in the intestine of treated larvae. These results underline the capability of the probiotic to modulate the gut microbiota community and provides insight into how the probiotic interacts to regulate a novel gene network involved in glucose metabolism and appetite control, suggesting a possible role for L. rhamnosus in the treatment of impaired glucose tolerance and food intake disorders by gut microbiota manipulation.
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Affiliation(s)
- Silvia Falcinelli
- Dipartimento di Scienze della Vita e dell'Ambiente, Università Politecnica delle Marche, Ancona, Italy
| | - Ana Rodiles
- Aquatic Animal Nutrition and Health Research Group, School of Biological Sciences, Plymouth University, PL4 8AA, UK
| | - Suraj Unniappan
- Laboratory of Integrative Neuroendocrinology, Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan S7N 5B4, Canada
| | - Simona Picchietti
- Department for Innovation in Biological, Agro-food and Forest Systems (DIBAF), University of Tuscia, Viterbo, Italy
| | - Giorgia Gioacchini
- Dipartimento di Scienze della Vita e dell'Ambiente, Università Politecnica delle Marche, Ancona, Italy
| | - Daniel Lee Merrifield
- Aquatic Animal Nutrition and Health Research Group, School of Biological Sciences, Plymouth University, PL4 8AA, UK
| | - Oliana Carnevali
- Dipartimento di Scienze della Vita e dell'Ambiente, Università Politecnica delle Marche, Ancona, Italy
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11
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Otis JP, Zeituni EM, Thierer JH, Anderson JL, Brown AC, Boehm ED, Cerchione DM, Ceasrine AM, Avraham-Davidi I, Tempelhof H, Yaniv K, Farber SA. Zebrafish as a model for apolipoprotein biology: comprehensive expression analysis and a role for ApoA-IV in regulating food intake. Dis Model Mech 2015; 8:295-309. [PMID: 25633982 PMCID: PMC4348566 DOI: 10.1242/dmm.018754] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Improved understanding of lipoproteins, particles that transport lipids throughout the circulation, is vital to developing new treatments for the dyslipidemias associated with metabolic syndrome. Apolipoproteins are a key component of lipoproteins. Apolipoproteins are proteins that structure lipoproteins and regulate lipid metabolism through control of cellular lipid exchange. Constraints of cell culture and mouse models mean that there is a need for a complementary model that can replicate the complex in vivo milieu that regulates apolipoprotein and lipoprotein biology. Here, we further establish the utility of the genetically tractable and optically clear larval zebrafish as a model of apolipoprotein biology. Gene ancestry analyses were implemented to determine the closest human orthologs of the zebrafish apolipoprotein A-I (apoA-I), apoB, apoE and apoA-IV genes and therefore ensure that they have been correctly named. Their expression patterns throughout development were also analyzed, by whole-mount mRNA in situ hybridization (ISH). The ISH results emphasized the importance of apolipoproteins in transporting yolk and dietary lipids: mRNA expression of all apolipoproteins was observed in the yolk syncytial layer, and intestinal and liver expression was observed from 4-6 days post-fertilization (dpf). Furthermore, real-time PCR confirmed that transcription of three of the four zebrafish apoA-IV genes was increased 4 hours after the onset of a 1-hour high-fat feed. Therefore, we tested the hypothesis that zebrafish ApoA-IV performs a conserved role to that in rat in the regulation of food intake by transiently overexpressing ApoA-IVb.1 in transgenic larvae and quantifying ingestion of co-fed fluorescently labeled fatty acid during a high-fat meal as an indicator of food intake. Indeed, ApoA-IVb.1 overexpression decreased food intake by approximately one-third. This study comprehensively describes the expression and function of eleven zebrafish apolipoproteins and serves as a springboard for future investigations to elucidate their roles in development and disease in the larval zebrafish model.
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Affiliation(s)
- Jessica P Otis
- Carnegie Institution for Science, Department of Embryology, Baltimore, MD 21218, USA
| | - Erin M Zeituni
- Carnegie Institution for Science, Department of Embryology, Baltimore, MD 21218, USA
| | - James H Thierer
- Carnegie Institution for Science, Department of Embryology, Baltimore, MD 21218, USA Johns Hopkins University, Department of Biology, Baltimore, MD 21218, USA
| | - Jennifer L Anderson
- Carnegie Institution for Science, Department of Embryology, Baltimore, MD 21218, USA
| | - Alexandria C Brown
- Carnegie Institution for Science, Department of Embryology, Baltimore, MD 21218, USA
| | - Erica D Boehm
- Carnegie Institution for Science, Department of Embryology, Baltimore, MD 21218, USA Johns Hopkins University, Department of Biology, Baltimore, MD 21218, USA
| | - Derek M Cerchione
- Carnegie Institution for Science, Department of Embryology, Baltimore, MD 21218, USA Johns Hopkins University, Department of Biology, Baltimore, MD 21218, USA
| | - Alexis M Ceasrine
- Carnegie Institution for Science, Department of Embryology, Baltimore, MD 21218, USA Johns Hopkins University, Department of Biology, Baltimore, MD 21218, USA
| | - Inbal Avraham-Davidi
- Weizmann Institute of Science, Department of Biological Regulation, Rehovot 7610001, Israel
| | - Hanoch Tempelhof
- Weizmann Institute of Science, Department of Biological Regulation, Rehovot 7610001, Israel
| | - Karina Yaniv
- Weizmann Institute of Science, Department of Biological Regulation, Rehovot 7610001, Israel
| | - Steven A Farber
- Carnegie Institution for Science, Department of Embryology, Baltimore, MD 21218, USA Johns Hopkins University, Department of Biology, Baltimore, MD 21218, USA
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12
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Santoro MM. Zebrafish as a model to explore cell metabolism. Trends Endocrinol Metab 2014; 25:546-54. [PMID: 24997878 DOI: 10.1016/j.tem.2014.06.003] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Revised: 06/04/2014] [Accepted: 06/10/2014] [Indexed: 12/20/2022]
Abstract
Cell metabolism plays a key role in many essential biological processes. The recent availability of novel technologies and organisms to model cell metabolism in vivo is expanding current knowledge of cell metabolism. In this context, the zebrafish (Danio rerio) is emerging as a valuable model system to learn about the metabolic routes critical for cellular homeostasis. Here, the most recent methods and studies on cell metabolism are summarized, which support the overall value for the zebrafish model system not only to study metabolism but also metabolic disease states. It is envisioned that this small vertebrate system will help in the understanding of pathogenesis for numerous metabolic-related disorders in humans and in the identification of their therapeutic treatments.
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Affiliation(s)
- Massimo M Santoro
- Laboratory of Endothelial Molecular Biology, Vesalius Research Center, Department of Oncology, University of Leuven, Leuven, B-3000, Belgium; Laboratory of Endothelial Molecular Biology, Vesalius Research Center, VIB, Leuven, B-3000, Belgium.
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13
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Lin S, Wang X, Ji Z, Chang CH, Dong Y, Meng H, Liao YP, Wang M, Song TB, Kohan S, Xia T, Zink JI, Lin S, Nel AE. Aspect ratio plays a role in the hazard potential of CeO2 nanoparticles in mouse lung and zebrafish gastrointestinal tract. ACS NANO 2014; 8:4450-64. [PMID: 24720650 PMCID: PMC4059546 DOI: 10.1021/nn5012754] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
We have previously demonstrated that there is a relationship between the aspect ratio (AR) of CeO2 nanoparticles and in vitro hazard potential. CeO2 nanorods with AR ≥ 22 induced lysosomal damage and progressive effects on IL-1β production and cytotoxicity in the human myeloid cell line, THP-1. In order to determine whether this toxicological paradigm for long aspect ratio (LAR) CeO2 is also relevant in vivo, we performed comparative studies in the mouse lung and gastrointestinal tract (GIT) of zebrafish larvae. Although oropharyngeal aspiration could induce acute lung inflammation for CeO2 nanospheres and nanorods, only the nanorods with the highest AR (C5) induced significant IL-1β and TGF-β1 production in the bronchoalveolar lavage fluid at 21 days but did not induce pulmonary fibrosis. However, after a longer duration (44 days) exposure to 4 mg/kg of the C5 nanorods, more collagen production was seen with CeO2 nanorods vs nanospheres after correcting for Ce lung burden. Using an oral-exposure model in zebrafish larvae, we demonstrated that C5 nanorods also induced significant growth inhibition, a decrease in body weight, and delayed vertebral calcification. In contrast, CeO2 nanospheres and shorter nanorods had no effect. Histological and transmission electron microscopy analyses showed that the key injury mechanism of C5 was in the epithelial lining of the GIT, which demonstrated blunted microvilli and compromised digestive function. All considered, these data demonstrate that, similar to cellular studies, LAR CeO2 nanorods exhibit more toxicity in the lung and GIT, which could be relevant to inhalation and environmental hazard potential.
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Affiliation(s)
- Sijie Lin
- Center for Environmental Implications of Nanotechnology, California NanoSystems Institute, University of California, Los Angeles, California 90095, United States
| | - Xiang Wang
- Center for Environmental Implications of Nanotechnology, California NanoSystems Institute, University of California, Los Angeles, California 90095, United States
| | - Zhaoxia Ji
- Center for Environmental Implications of Nanotechnology, California NanoSystems Institute, University of California, Los Angeles, California 90095, United States
| | - Chong Hyun Chang
- Center for Environmental Implications of Nanotechnology, California NanoSystems Institute, University of California, Los Angeles, California 90095, United States
| | - Yuan Dong
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, California 90095, United States
| | - Huan Meng
- Center for Environmental Implications of Nanotechnology, California NanoSystems Institute, University of California, Los Angeles, California 90095, United States
- Division of NanoMedicine, Department of Medicine, University of California, Los Angeles, California 90095, United States
| | - Yu-Pei Liao
- Division of NanoMedicine, Department of Medicine, University of California, Los Angeles, California 90095, United States
| | - Meiying Wang
- Division of NanoMedicine, Department of Medicine, University of California, Los Angeles, California 90095, United States
| | - Tze-Bin Song
- Department of Materials Science and Engineering, University of California, Los Angeles, California 90095, United States
| | - Sirus Kohan
- Brain Research Institute, University of California, Los Angeles, California 90095, United States
| | - Tian Xia
- Center for Environmental Implications of Nanotechnology, California NanoSystems Institute, University of California, Los Angeles, California 90095, United States
- Division of NanoMedicine, Department of Medicine, University of California, Los Angeles, California 90095, United States
| | - Jeffrey I. Zink
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| | - Shuo Lin
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, California 90095, United States
| | - André E. Nel
- Center for Environmental Implications of Nanotechnology, California NanoSystems Institute, University of California, Los Angeles, California 90095, United States
- Division of NanoMedicine, Department of Medicine, University of California, Los Angeles, California 90095, United States
- Corresponding Author: Andre Nel, M.D., Department of Medicine, Division of NanoMedicine, UCLA School of Medicine, 52-175 CHS, 10833 Le Conte Ave, Los Angeles, CA 90095-1680. Tel: (310) 825-6620, Fax: (310) 206-8107,
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14
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Miyares RL, de Rezende VB, Farber SA. Zebrafish yolk lipid processing: a tractable tool for the study of vertebrate lipid transport and metabolism. Dis Model Mech 2014; 7:915-27. [PMID: 24812437 PMCID: PMC4073280 DOI: 10.1242/dmm.015800] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Dyslipidemias are a major cause of morbidity and mortality in the world, particularly in developed nations. Investigating lipid and lipoprotein metabolism in experimentally tractable animal models is a crucial step towards understanding and treating human dyslipidemias. The zebrafish, a well-established embryological model, is emerging as a notable system for studies of lipid metabolism. Here, we describe the value of the lecithotrophic, or yolk-metabolizing, stages of the zebrafish as a model for studying lipid metabolism and lipoprotein transport. We demonstrate methods to assay yolk lipid metabolism in embryonic and larval zebrafish. Injection of labeled fatty acids into the zebrafish yolk promotes efficient uptake into the circulation and rapid metabolism. Using a genetic model for abetalipoproteinemia, we show that the uptake of labeled fatty acids into the circulation is dependent on lipoprotein production. Furthermore, we examine the metabolic fate of exogenously delivered fatty acids by assaying their incorporation into complex lipids. Moreover, we demonstrate that this technique is amenable to genetic and pharmacologic studies.
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Affiliation(s)
- Rosa L Miyares
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218, USA. Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Vitor B de Rezende
- Department of Mental Health, School of Medicine of Federal University of Minas Gerais, 30130-100 Belo Horizonte, Brazil
| | - Steven A Farber
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218, USA.
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15
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Kassis T, Kohan AB, Weiler MJ, Nipper ME, Cornelius R, Tso P, Dixon JB. Dual-channel in-situ optical imaging system for quantifying lipid uptake and lymphatic pump function. JOURNAL OF BIOMEDICAL OPTICS 2012; 17:086005. [PMID: 23224192 PMCID: PMC3413897 DOI: 10.1117/1.jbo.17.8.086005] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Revised: 07/09/2012] [Accepted: 07/11/2012] [Indexed: 05/22/2023]
Abstract
Nearly all dietary lipids are transported from the intestine to venous circulation through the lymphatic system, yet the mechanisms that regulate this process remain unclear. Elucidating the mechanisms involved in the functional response of lymphatics to changes in lipid load would provide valuable insight into recent implications of lymphatic dysfunction in lipid related diseases. Therefore, we sought to develop an in situ imaging system to quantify and correlate lymphatic function as it relates to lipid transport. The imaging platform provides the capability of dual-channel imaging of both high-speed bright-field video and fluorescence simultaneously. Utilizing post-acquisition image processing algorithms, we can quantify correlations between vessel pump function, lymph flow, and lipid concentration of mesenteric lymphatic vessels in situ. All image analysis is automated with customized LabVIEW virtual instruments; local flow is measured through lymphocyte velocity tracking, vessel contraction through measurements of the vessel wall displacement, and lipid uptake through fluorescence intensity tracking of an orally administered fluorescently labelled fatty acid analogue, BODIPY FL C16. This system will prove to be an invaluable tool for scientists studying intestinal lymphatic function in health and disease, and those investigating strategies for targeting the lymphatics with orally delivered drugs to avoid first pass metabolism.
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Affiliation(s)
- Timothy Kassis
- Georgia Institute of Technology, Parker H. Petit Institute for Bioengineering and Bioscience, Atlanta, GA, USA
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