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Keller MP, O’Connor C, Bitzer M, Schueler KL, Stapleton DS, Emfinger CH, Broman AT, Hodgin JB, Attie AD. Genetic Analysis of Obesity-Induced Diabetic Nephropathy in BTBR Mice. Diabetes 2024; 73:312-317. [PMID: 37935024 PMCID: PMC10796299 DOI: 10.2337/db23-0444] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 10/24/2023] [Indexed: 11/09/2023]
Abstract
Diabetic nephropathy (DN) is the leading cause of end-stage renal disease in the U.S. and has a significant impact on human suffering. Leptin-deficient BTBR (BTBRob/ob) mice develop hallmark features of obesity-induced DN, whereas leptin-deficient C57BL/6J (B6ob/ob) mice do not. To identify genetic loci that underlie this strain difference, we constructed an F2 intercross between BTBRob/ob and B6ob/ob mice. We isolated kidneys from 460 F2 mice and histologically scored them for percent mesangial matrix and glomerular volume (∼50 glomeruli per mouse), yielding ∼45,000 distinct measures in total. The same histological measurements were made in kidneys from B6 and BTBR mice, either lean or obese (Lepob/ob), at 4 and 10 weeks of age, allowing us to assess the contribution of strain, age, and obesity to glomerular pathology. All F2 mice were genotyped for ∼5,000 single nucleotide polymorphisms (SNPs), ∼2,000 of which were polymorphic between B6 and BTBR, enabling us to identify a quantitative trait locus (QTL) on chromosome 7, with a peak at ∼30 Mbp, for percent mesangial matrix, glomerular volume, and mesangial volume. The podocyte-specific gene nephrin (Nphs1) is physically located at the QTL and contains high-impact SNPs in BTBR, including several missense variants within the extracellular immunoglobulin-like domains. ARTICLE HIGHLIGHTS
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Affiliation(s)
- Mark P. Keller
- Department of Biochemistry, University of Wisconsin–Madison
| | - Chris O’Connor
- Division of Nephrology, Department of Internal Medicine, University of Michigan, Ann Arbor, MI
| | - Markus Bitzer
- Division of Nephrology, Department of Internal Medicine, University of Michigan, Ann Arbor, MI
| | | | | | | | - Aimee Teo Broman
- Department of Biostatistics and Medical Informatics, University of Wisconsin–Madison
| | | | - Alan D. Attie
- Department of Biochemistry, University of Wisconsin–Madison
- Department of Chemistry, University of Wisconsin–Madison, Madison, WI
- Department of Medicine, University of Wisconsin–Madison
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2
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Price TR, Emfinger CH, Schueler KL, King S, Nicholson R, Beck T, Yandell BS, Summers SA, Holland WL, Krauss RM, Keller MP, Attie AD. Identification of genetic drivers of plasma lipoprotein size in the Diversity Outbred mouse population. J Lipid Res 2023; 64:100471. [PMID: 37944753 PMCID: PMC10750189 DOI: 10.1016/j.jlr.2023.100471] [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: 08/30/2023] [Revised: 10/28/2023] [Accepted: 10/31/2023] [Indexed: 11/12/2023] Open
Abstract
Despite great progress in understanding lipoprotein physiology, there is still much to be learned about the genetic drivers of lipoprotein abundance, composition, and function. We used ion mobility spectrometry to survey 16 plasma lipoprotein subfractions in 500 Diversity Outbred mice maintained on a Western-style diet. We identified 21 quantitative trait loci (QTL) affecting lipoprotein abundance. To refine the QTL and link them to disease risk in humans, we asked if the human homologs of genes located at each QTL were associated with lipid traits in human genome-wide association studies. Integration of mouse QTL with human genome-wide association studies yielded candidate gene drivers for 18 of the 21 QTL. This approach enabled us to nominate the gene encoding the neutral ceramidase, Asah2, as a novel candidate driver at a QTL on chromosome 19 for large HDL particles (HDL-2b). To experimentally validate Asah2, we surveyed lipoproteins in Asah2-/- mice. Compared to wild-type mice, female Asah2-/- mice showed an increase in several lipoproteins, including HDL. Our results provide insights into the genetic regulation of circulating lipoproteins, as well as mechanisms by which lipoprotein subfractions may affect cardiovascular disease risk in humans.
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Affiliation(s)
- Tara R Price
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA
| | | | - Kathryn L Schueler
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Sarah King
- School of Medicine, University of California-San Francisco, San Francisco, CA, USA
| | - Rebekah Nicholson
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, USA
| | - Tim Beck
- Department of Genetics and Genome Biology, University of Leicester, Leicester, UK
| | - Brian S Yandell
- Department of Statistics, University of Wisconsin-Madison, Madison, WI, USA
| | - Scott A Summers
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, USA
| | - William L Holland
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, USA
| | - Ronald M Krauss
- School of Medicine, University of California-San Francisco, San Francisco, CA, USA
| | - Mark P Keller
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Alan D Attie
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA.
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3
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Emfinger CH, Clark LE, Yandell B, Schueler KL, Simonett SP, Stapleton DS, Mitok KA, Merrins MJ, Keller MP, Attie AD. Novel regulators of islet function identified from genetic variation in mouse islet Ca 2+ oscillations. eLife 2023; 12:RP88189. [PMID: 37787501 PMCID: PMC10547476 DOI: 10.7554/elife.88189] [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] [Indexed: 10/04/2023] Open
Abstract
Insufficient insulin secretion to meet metabolic demand results in diabetes. The intracellular flux of Ca2+ into β-cells triggers insulin release. Since genetics strongly influences variation in islet secretory responses, we surveyed islet Ca2+ dynamics in eight genetically diverse mouse strains. We found high strain variation in response to four conditions: (1) 8 mM glucose; (2) 8 mM glucose plus amino acids; (3) 8 mM glucose, amino acids, plus 10 nM glucose-dependent insulinotropic polypeptide (GIP); and (4) 2 mM glucose. These stimuli interrogate β-cell function, α- to β-cell signaling, and incretin responses. We then correlated components of the Ca2+ waveforms to islet protein abundances in the same strains used for the Ca2+ measurements. To focus on proteins relevant to human islet function, we identified human orthologues of correlated mouse proteins that are proximal to glycemic-associated single-nucleotide polymorphisms in human genome-wide association studies. Several orthologues have previously been shown to regulate insulin secretion (e.g. ABCC8, PCSK1, and GCK), supporting our mouse-to-human integration as a discovery platform. By integrating these data, we nominate novel regulators of islet Ca2+ oscillations and insulin secretion with potential relevance for human islet function. We also provide a resource for identifying appropriate mouse strains in which to study these regulators.
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Affiliation(s)
| | - Lauren E Clark
- Department of Biochemistry, University of Wisconsin-MadisonMadisonUnited States
| | - Brian Yandell
- Department of Statistics, University of Wisconsin-MadisonMadisonUnited States
| | - Kathryn L Schueler
- Department of Biochemistry, University of Wisconsin-MadisonMadisonUnited States
| | - Shane P Simonett
- Department of Biochemistry, University of Wisconsin-MadisonMadisonUnited States
| | - Donnie S Stapleton
- Department of Biochemistry, University of Wisconsin-MadisonMadisonUnited States
| | - Kelly A Mitok
- Department of Biochemistry, University of Wisconsin-MadisonMadisonUnited States
| | - Matthew J Merrins
- Department of Medicine, Division of Endocrinology, University of Wisconsin-MadisonMadisonUnited States
- William S. Middleton Memorial Veterans HospitalMadisonUnited States
| | - Mark P Keller
- Department of Biochemistry, University of Wisconsin-MadisonMadisonUnited States
| | - Alan D Attie
- Department of Biochemistry, University of Wisconsin-MadisonMadisonUnited States
- Department of Medicine, Division of Endocrinology, University of Wisconsin-MadisonMadisonUnited States
- Department of Chemistry, University of Wisconsin-MadisonMadisonUnited States
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4
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de Klerk E, Xiao Y, Emfinger CH, Keller MP, Berrios DI, Loconte V, Ekman AA, White KL, Cardone RL, Kibbey RG, Attie AD, Hebrok M. Loss of ZNF148 enhances insulin secretion in human pancreatic β cells. JCI Insight 2023; 8:157572. [PMID: 37288664 PMCID: PMC10393241 DOI: 10.1172/jci.insight.157572] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 04/05/2023] [Indexed: 06/09/2023] Open
Abstract
Insulin secretion from pancreatic β cells is essential to the maintenance of glucose homeostasis. Defects in this process result in diabetes. Identifying genetic regulators that impair insulin secretion is crucial for the identification of novel therapeutic targets. Here, we show that reduction of ZNF148 in human islets, and its deletion in stem cell-derived β cells (SC-β cells), enhances insulin secretion. Transcriptomics of ZNF148-deficient SC-β cells identifies increased expression of annexin and S100 genes whose proteins form tetrameric complexes involved in regulation of insulin vesicle trafficking and exocytosis. ZNF148 in SC-β cells prevents translocation of annexin A2 from the nucleus to its functional place at the cell membrane via direct repression of S100A16 expression. These findings point to ZNF148 as a regulator of annexin-S100 complexes in human β cells and suggest that suppression of ZNF148 may provide a novel therapeutic strategy to enhance insulin secretion.
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Affiliation(s)
| | - Yini Xiao
- UCSF Diabetes Center, UCSF, San Francisco, California, USA
| | - Christopher H Emfinger
- Department of Biochemistry, University of Wisconsin-Madison, DeLuca Biochemistry Laboratories, Madison, Wisconsin, USA
| | - Mark P Keller
- Department of Biochemistry, University of Wisconsin-Madison, DeLuca Biochemistry Laboratories, Madison, Wisconsin, USA
| | | | - Valentina Loconte
- Department of Anatomy, School of Medicine, UCSF, San Francisco, California, USA
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
- National Center for X-ray Tomography, Advanced Light Source, Berkeley, California, USA
| | - Axel A Ekman
- National Center for X-ray Tomography, Advanced Light Source, Berkeley, California, USA
| | - Kate L White
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
- Department of Chemistry, Bridge Institute, Michelson Center for Convergent Bioscience, University of Southern California, Los Angeles, California, USA
| | - Rebecca L Cardone
- Department of Internal Medicine (Endocrinology), Yale University, New Haven, Connecticut, USA
| | - Richard G Kibbey
- Department of Internal Medicine (Endocrinology), Yale University, New Haven, Connecticut, USA
| | - Alan D Attie
- Departments of Biochemistry, Chemistry, and Medicine, University of Wisconsin-Madison, DeLuca Biochemistry Laboratories, Madison, Wisconsin, USA
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5
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Emfinger CH, de Klerk E, Schueler KL, Rabaglia ME, Stapleton DS, Simonett SP, Mitok KA, Wang Z, Liu X, Paulo JA, Yu Q, Cardone RL, Foster HR, Lewandowski SL, Perales JC, Kendziorski CM, Gygi SP, Kibbey RG, Keller MP, Hebrok M, Merrins MJ, Attie AD. β Cell-specific deletion of Zfp148 improves nutrient-stimulated β cell Ca2+ responses. JCI Insight 2022; 7:e154198. [PMID: 35603790 PMCID: PMC9220824 DOI: 10.1172/jci.insight.154198] [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: 08/19/2021] [Accepted: 04/20/2022] [Indexed: 12/05/2022] Open
Abstract
Insulin secretion from pancreatic β cells is essential for glucose homeostasis. An insufficient response to the demand for insulin results in diabetes. We previously showed that β cell-specific deletion of Zfp148 (β-Zfp148KO) improves glucose tolerance and insulin secretion in mice. Here, we performed Ca2+ imaging of islets from β‑Zfp148KO and control mice fed both a chow and a Western-style diet. β-Zfp148KO islets demonstrated improved sensitivity and sustained Ca2+ oscillations in response to elevated glucose levels. β-Zfp148KO islets also exhibited elevated sensitivity to amino acid-induced Ca2+ influx under low glucose conditions, suggesting enhanced mitochondrial phosphoenolpyruvate-dependent (PEP-dependent), ATP-sensitive K+ channel closure, independent of glycolysis. RNA-Seq and proteomics of β-Zfp148KO islets revealed altered levels of enzymes involved in amino acid metabolism (specifically, SLC3A2, SLC7A8, GLS, GLS2, PSPH, PHGDH, and PSAT1) and intermediary metabolism (namely, GOT1 and PCK2), consistent with altered PEP cycling. In agreement with this, β-Zfp148KO islets displayed enhanced insulin secretion in response to l-glutamine and activation of glutamate dehydrogenase. Understanding pathways controlled by ZFP148 may provide promising strategies for improving β cell function that are robust to the metabolic challenge imposed by a Western diet.
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Affiliation(s)
| | | | - Kathryn L. Schueler
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Mary E. Rabaglia
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Donnie S. Stapleton
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Shane P. Simonett
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Kelly A. Mitok
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Ziyue Wang
- Department of Biostatistics and Medical Informatics, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Biostatistics and Computational Biology Branch, National Institute of Environmental Health Sciences, Durham, North Carolina, USA
| | - Xinyue Liu
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, USA
| | - Joao A. Paulo
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, USA
| | - Qing Yu
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, USA
| | - Rebecca L. Cardone
- Department of Internal Medicine (Endocrinology), Yale University, New Haven, Connecticut, USA
| | - Hannah R. Foster
- Department of Medicine, Division of Endocrinology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Sophie L. Lewandowski
- Department of Medicine, Division of Endocrinology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - José C. Perales
- Department of Physiological Sciences, School of Medicine, University of Barcelona, L’Hospitalet del Llobregat, Barcelona, Spain
| | - Christina M. Kendziorski
- Department of Biostatistics and Medical Informatics, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Steven P. Gygi
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, USA
| | - Richard G. Kibbey
- Department of Internal Medicine (Endocrinology), Yale University, New Haven, Connecticut, USA
- Department of Cellular and Molecular Physiology, Yale University, New Haven, Connecticut, USA
| | - Mark P. Keller
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | | | - Matthew J. Merrins
- Department of Medicine, Division of Endocrinology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin, USA
| | - Alan D. Attie
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA
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6
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Keller MP, Rabaglia ME, Schueler KL, Stapleton DS, Gatti DM, Vincent M, Mitok KA, Wang Z, Ishimura T, Simonett SP, Emfinger CH, Das R, Beck T, Kendziorski C, Broman KW, Yandell BS, Churchill GA, Attie AD. Gene loci associated with insulin secretion in islets from non-diabetic mice. J Clin Invest 2019; 129:4419-4432. [PMID: 31343992 DOI: 10.1172/jci129143] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Genetic susceptibility to type 2 diabetes is primarily due to β-cell dysfunction. However, a genetic study to directly interrogate β-cell function ex vivo has never been previously performed. We isolated 233,447 islets from 483 Diversity Outbred (DO) mice maintained on a Western-style diet, and measured insulin secretion in response to a variety of secretagogues. Insulin secretion from DO islets ranged >1,000-fold even though none of the mice were diabetic. The insulin secretory response to each secretagogue had a unique genetic architecture; some of the loci were specific for one condition, whereas others overlapped. Human loci that are syntenic to many of the insulin secretion QTL from mouse are associated with diabetes-related SNPs in human genome-wide association studies. We report on three genes, Ptpn18, Hunk and Zfp148, where the phenotype predictions from the genetic screen were fulfilled in our studies of transgenic mouse models. These three genes encode a non-receptor type protein tyrosine phosphatase, a serine/threonine protein kinase, and a Krϋppel-type zinc-finger transcription factor, respectively. Our results demonstrate that genetic variation in insulin secretion that can lead to type 2 diabetes is discoverable in non-diabetic individuals.
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Affiliation(s)
- Mark P Keller
- University of Wisconsin-Madison, Biochemistry Department, Madison, Wisconsin, USA
| | - Mary E Rabaglia
- University of Wisconsin-Madison, Biochemistry Department, Madison, Wisconsin, USA
| | - Kathryn L Schueler
- University of Wisconsin-Madison, Biochemistry Department, Madison, Wisconsin, USA
| | - Donnie S Stapleton
- University of Wisconsin-Madison, Biochemistry Department, Madison, Wisconsin, USA
| | | | | | - Kelly A Mitok
- University of Wisconsin-Madison, Biochemistry Department, Madison, Wisconsin, USA
| | - Ziyue Wang
- University of Wisconsin-Madison, Department of Biostatistics and Medical Informatics, Madison, Wisconsin, USA
| | | | - Shane P Simonett
- University of Wisconsin-Madison, Biochemistry Department, Madison, Wisconsin, USA
| | | | - Rahul Das
- University of Wisconsin-Madison, Biochemistry Department, Madison, Wisconsin, USA
| | - Tim Beck
- Department of Genetics and Genome Biology, University of Leicester, Leicester, United Kingdom
| | - Christina Kendziorski
- University of Wisconsin-Madison, Department of Biostatistics and Medical Informatics, Madison, Wisconsin, USA
| | - Karl W Broman
- University of Wisconsin-Madison, Department of Biostatistics and Medical Informatics, Madison, Wisconsin, USA
| | - Brian S Yandell
- University of Wisconsin-Madison, Department of Horticulture, Madison, Wisconsin, USA
| | | | - Alan D Attie
- University of Wisconsin-Madison, Biochemistry Department, Madison, Wisconsin, USA
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7
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Emfinger CH, Lőrincz R, Wang Y, York NW, Singareddy SS, Ikle JM, Tryon RC, McClenaghan C, Shyr ZA, Huang Y, Reissaus CA, Meyer D, Piston DW, Hyrc K, Remedi MS, Nichols CG. Beta-cell excitability and excitability-driven diabetes in adult Zebrafish islets. Physiol Rep 2019; 7:e14101. [PMID: 31161721 PMCID: PMC6546968 DOI: 10.14814/phy2.14101] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [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: 04/23/2019] [Revised: 04/30/2019] [Accepted: 04/30/2019] [Indexed: 12/15/2022] Open
Abstract
Islet β-cell membrane excitability is a well-established regulator of mammalian insulin secretion, and defects in β-cell excitability are linked to multiple forms of diabetes. Evolutionary conservation of islet excitability in lower organisms is largely unexplored. Here we show that adult zebrafish islet calcium levels rise in response to elevated extracellular [glucose], with similar concentration-response relationship to mammalian β-cells. However, zebrafish islet calcium transients are nor well coupled, with a shallower glucose-dependence of cytoplasmic calcium concentration. We have also generated transgenic zebrafish that conditionally express gain-of-function mutations in ATP-sensitive K+ channels (KATP -GOF) in β-cells. Following induction, these fish become profoundly diabetic, paralleling features of mammalian diabetes resulting from equivalent mutations. KATP -GOF fish become severely hyperglycemic, with slowed growth, and their islets lose glucose-induced calcium responses. These results indicate that, although lacking tight cell-cell coupling of intracellular Ca2+ , adult zebrafish islets recapitulate similar excitability-driven β-cell glucose responsiveness to those in mammals, and exhibit profound susceptibility to diabetes as a result of inexcitability. While illustrating evolutionary conservation of islet excitability in lower vertebrates, these results also provide important validation of zebrafish as a suitable animal model in which to identify modulators of islet excitability and diabetes.
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Affiliation(s)
- Christopher H. Emfinger
- Department of Cell Biology and PhysiologyWashington University in St. LouisSt. LouisMissouri
- Department of MedicineDivision of Endocrinology, Metabolism, and Lipid ResearchWashington University in St. Louis School of MedicineSt. LouisMissouri
- Center for the Investigation of Membrane Excitability DiseasesWashington University in St. Louis School of MedicineSt. LouisMissouri
| | - Réka Lőrincz
- Department of Cell Biology and PhysiologyWashington University in St. LouisSt. LouisMissouri
- Center for the Investigation of Membrane Excitability DiseasesWashington University in St. Louis School of MedicineSt. LouisMissouri
- Institute of Molecular Biology/CMBILeopold‐Franzens‐University InnsbruckInnsbruckAustria
| | - Yixi Wang
- Department of Cell Biology and PhysiologyWashington University in St. LouisSt. LouisMissouri
- Center for the Investigation of Membrane Excitability DiseasesWashington University in St. Louis School of MedicineSt. LouisMissouri
| | - Nathaniel W. York
- Department of Cell Biology and PhysiologyWashington University in St. LouisSt. LouisMissouri
- Center for the Investigation of Membrane Excitability DiseasesWashington University in St. Louis School of MedicineSt. LouisMissouri
| | - Soma S. Singareddy
- Department of Cell Biology and PhysiologyWashington University in St. LouisSt. LouisMissouri
- Center for the Investigation of Membrane Excitability DiseasesWashington University in St. Louis School of MedicineSt. LouisMissouri
| | - Jennifer M. Ikle
- Department of Cell Biology and PhysiologyWashington University in St. LouisSt. LouisMissouri
- Center for the Investigation of Membrane Excitability DiseasesWashington University in St. Louis School of MedicineSt. LouisMissouri
- Department of PediatricsWashington University in St. Louis School of MedicineSt. LouisMissouri
- Present address:
Department of CardiologyRenmin Hospital of Wuhan UniversityWuhanChina
| | - Robert C. Tryon
- Department of Cell Biology and PhysiologyWashington University in St. LouisSt. LouisMissouri
- Center for the Investigation of Membrane Excitability DiseasesWashington University in St. Louis School of MedicineSt. LouisMissouri
| | - Conor McClenaghan
- Department of Cell Biology and PhysiologyWashington University in St. LouisSt. LouisMissouri
- Center for the Investigation of Membrane Excitability DiseasesWashington University in St. Louis School of MedicineSt. LouisMissouri
| | - Zeenat A. Shyr
- Department of MedicineDivision of Endocrinology, Metabolism, and Lipid ResearchWashington University in St. Louis School of MedicineSt. LouisMissouri
- Center for the Investigation of Membrane Excitability DiseasesWashington University in St. Louis School of MedicineSt. LouisMissouri
| | - Yan Huang
- Department of Cell Biology and PhysiologyWashington University in St. LouisSt. LouisMissouri
- Center for the Investigation of Membrane Excitability DiseasesWashington University in St. Louis School of MedicineSt. LouisMissouri
- Department of PediatricsWashington University in St. Louis School of MedicineSt. LouisMissouri
- Present address:
Department of CardiologyRenmin Hospital of Wuhan UniversityWuhanChina
| | - Christopher A. Reissaus
- Department of Cell Biology and PhysiologyWashington University in St. LouisSt. LouisMissouri
| | - Dirk Meyer
- Institute of Molecular Biology/CMBILeopold‐Franzens‐University InnsbruckInnsbruckAustria
| | - David W. Piston
- Department of Cell Biology and PhysiologyWashington University in St. LouisSt. LouisMissouri
- Center for the Investigation of Membrane Excitability DiseasesWashington University in St. Louis School of MedicineSt. LouisMissouri
| | - Krzysztof Hyrc
- Center for the Investigation of Membrane Excitability DiseasesWashington University in St. Louis School of MedicineSt. LouisMissouri
| | - Maria S. Remedi
- Department of Cell Biology and PhysiologyWashington University in St. LouisSt. LouisMissouri
- Department of MedicineDivision of Endocrinology, Metabolism, and Lipid ResearchWashington University in St. Louis School of MedicineSt. LouisMissouri
- Center for the Investigation of Membrane Excitability DiseasesWashington University in St. Louis School of MedicineSt. LouisMissouri
| | - Colin G. Nichols
- Department of Cell Biology and PhysiologyWashington University in St. LouisSt. LouisMissouri
- Center for the Investigation of Membrane Excitability DiseasesWashington University in St. Louis School of MedicineSt. LouisMissouri
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Emfinger CH, Yan Z, Welscher A, Hung P, McAllister W, Hruz PW, Nichols CG, Remedi MS. Contribution of systemic inflammation to permanence of K ATP-induced neonatal diabetes in mice. Am J Physiol Endocrinol Metab 2018; 315:E1121-E1132. [PMID: 30226997 PMCID: PMC6336961 DOI: 10.1152/ajpendo.00137.2018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [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] [Indexed: 01/20/2023]
Abstract
Gain-of-function (GOF) mutations in the ATP-sensitive potassium (KATP) channels cause neonatal diabetes. Despite the well-established genetic root of the disease, pathways modulating disease severity and treatment effectiveness remain poorly understood. Patient phenotypes can vary from severe diabetes to remission, even in individuals with the same mutation and within the same family, suggesting that subtle modifiers can influence disease outcome. We have tested the underlying mechanism of transient vs. permanent neonatal diabetes in KATP-GOF mice treated for 14 days with glibenclamide. Some KATP-GOF mice show remission of diabetes and enhanced insulin sensitivity long after diabetes treatment has ended, while others maintain severe insulin-resistance. However, insulin sensitivity is not different between the two groups before or during diabetes induction, suggesting that improved sensitivity is a consequence, rather than the cause of, remission, implicating other factors modulating glucose early in diabetes progression. Leptin, glucagon, insulin, and glucagon-like peptide-1 are not different between remitters and nonremitters. However, liver glucose production is significantly reduced before transgene induction in remitter, relative to nonremitter and nontreated, mice. Surprisingly, while subsequent remitter animals exhibited normal serum cytokines, nonremitter mice showed increased cytokines, which paralleled the divergence in blood glucose. Together, these results suggest that systemic inflammation may play a role in the remitting versus non-remitting outcome. Supporting this conclusion, treatment with the anti-inflammatory meloxicam significantly increased the fraction of remitting animals. Beyond neonatal diabetes, the potential for inflammation and glucose production to exacerbate other forms of diabetes from a compensated state to a glucotoxic state should be considered.
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Affiliation(s)
- Christopher H Emfinger
- Department of Medicine, Washington University in St. Louis , St. Louis, Missouri
- Department of Cell Biology and Physiology, Washington University in St. Louis , St. Louis, Missouri
- Center for the Investigation of Membrane Excitability Diseases, Washington University in St. Louis , St. Louis, Missouri
| | - Zihan Yan
- Department of Medicine, Washington University in St. Louis , St. Louis, Missouri
| | - Alecia Welscher
- Department of Medicine, Washington University in St. Louis , St. Louis, Missouri
| | - Peter Hung
- Department of Cell Biology and Physiology, Washington University in St. Louis , St. Louis, Missouri
| | - William McAllister
- Department of Medicine, Washington University in St. Louis , St. Louis, Missouri
| | - Paul W Hruz
- Department of Pediatrics, Washington University in St. Louis , St. Louis, Missouri
| | - Colin G Nichols
- Department of Cell Biology and Physiology, Washington University in St. Louis , St. Louis, Missouri
- Center for the Investigation of Membrane Excitability Diseases, Washington University in St. Louis , St. Louis, Missouri
| | - Maria S Remedi
- Department of Medicine, Washington University in St. Louis , St. Louis, Missouri
- Department of Cell Biology and Physiology, Washington University in St. Louis , St. Louis, Missouri
- Center for the Investigation of Membrane Excitability Diseases, Washington University in St. Louis , St. Louis, Missouri
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Zhu L, Luu T, Emfinger CH, Parks BA, Shi J, Trefts E, Zeng F, Kuklenyik Z, Harris RC, Wasserman DH, Fazio S, Stafford JM. CETP Inhibition Improves HDL Function but Leads to Fatty Liver and Insulin Resistance in CETP-Expressing Transgenic Mice on a High-Fat Diet. Diabetes 2018; 67:2494-2506. [PMID: 30213825 PMCID: PMC6245220 DOI: 10.2337/db18-0474] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 09/05/2018] [Indexed: 02/06/2023]
Abstract
In clinical trials, inhibition of cholesteryl ester transfer protein (CETP) raises HDL cholesterol levels but does not robustly improve cardiovascular outcomes. Approximately two-thirds of trial participants are obese. Lower plasma CETP activity is associated with increased cardiovascular risk in human studies, and protective aspects of CETP have been observed in mice fed a high-fat diet (HFD) with regard to metabolic outcomes. To define whether CETP inhibition has different effects depending on the presence of obesity, we performed short-term anacetrapib treatment in chow- and HFD-fed CETP transgenic mice. Anacetrapib raised HDL cholesterol and improved aspects of HDL functionality, including reverse cholesterol transport, and HDL's antioxidative capacity in HFD-fed mice was better than in chow-fed mice. Anacetrapib worsened the anti-inflammatory capacity of HDL in HFD-fed mice. The HDL proteome was markedly different with anacetrapib treatment in HFD- versus chow-fed mice. Despite benefits on HDL, anacetrapib led to liver triglyceride accumulation and insulin resistance in HFD-fed mice. Overall, our results support a physiologic importance of CETP in protecting from fatty liver and demonstrate context selectivity of CETP inhibition that might be important in obese subjects.
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Affiliation(s)
- Lin Zhu
- Veterans Administration Tennessee Valley Healthcare System, Vanderbilt University School of Medicine, Nashville, TN
- Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University School of Medicine, Nashville, TN
| | - Thao Luu
- Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University School of Medicine, Nashville, TN
| | - Christopher H Emfinger
- Veterans Administration Tennessee Valley Healthcare System, Vanderbilt University School of Medicine, Nashville, TN
- Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University School of Medicine, Nashville, TN
| | - Bryan A Parks
- Division of Laboratory Sciences, Centers for Disease Control and Prevention, Atlanta, GA
| | - Jeanne Shi
- Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University School of Medicine, Nashville, TN
- Trinity College of Art and Science, Duke University, Durham, NC
| | - Elijah Trefts
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN
| | - Fenghua Zeng
- Division of Nephrology and Hypertension, Vanderbilt University School of Medicine, Nashville, TN
| | - Zsuzsanna Kuklenyik
- Division of Laboratory Sciences, Centers for Disease Control and Prevention, Atlanta, GA
| | - Raymond C Harris
- Division of Nephrology and Hypertension, Vanderbilt University School of Medicine, Nashville, TN
| | - David H Wasserman
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN
| | - Sergio Fazio
- The Center for Preventive Cardiology at the Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR
| | - John M Stafford
- Veterans Administration Tennessee Valley Healthcare System, Vanderbilt University School of Medicine, Nashville, TN
- Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University School of Medicine, Nashville, TN
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN
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10
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Abstract
Assessing the response of pancreatic islet cells to glucose stimulation is important for understanding β-cell function. Zebrafish are a promising model for studies of metabolism in general, including stimulus-secretion coupling in the pancreas. We used transgenic zebrafish embryos expressing a genetically-encoded Ca2+ sensor in pancreatic β-cells to monitor a key step in glucose induced insulin secretion; the elevations of intracellular [Ca2+]i. In vivo and ex vivo analyses of [Ca2+]i demonstrate that β-cell responsiveness to glucose is well established in late embryogenesis and that embryonic β-cells also respond to free fatty acid and amino acid challenges. In vivo imaging of whole embryos further shows that indirect glucose administration, for example by yolk injection, results in a slow and asynchronous induction of β-cell [Ca2+]i responses, while intravenous glucose injections cause immediate and islet-wide synchronized [Ca2+]i fluctuations. Finally, we demonstrate that embryos with disrupted mutation of the CaV1.2 channel gene cacna1c are hyperglycemic and that this phenotype is associated with glucose-independent [Ca2+]i fluctuation in β-cells. The data reveal a novel central role of cacna1c in β-cell specific stimulus-secretion coupling in zebrafish and demonstrate that the novel approach we propose - to monitor the [Ca2+]i dynamics in embryonic β-cells in vivo - will help to expand the understanding of β-cell physiological functions in healthy and diseased states.
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Affiliation(s)
- Reka Lorincz
- Institute of Molecular Biology/CMBI, University of Innsbruck, Innsbruck, Austria
| | - Christopher H. Emfinger
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO, USA
- Center for the Investigation of Membrane Excitability Diseases (CIMED), Washington University School of Medicine, St. Louis, MO, USA
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Andrea Walcher
- Institute of Molecular Biology/CMBI, University of Innsbruck, Innsbruck, Austria
| | - Michael Giolai
- Institute of Molecular Biology/CMBI, University of Innsbruck, Innsbruck, Austria
| | - Claudia Krautgasser
- Institute of Molecular Biology/CMBI, University of Innsbruck, Innsbruck, Austria
| | - Maria S. Remedi
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO, USA
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Colin G. Nichols
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO, USA
- Center for the Investigation of Membrane Excitability Diseases (CIMED), Washington University School of Medicine, St. Louis, MO, USA
| | - Dirk Meyer
- Institute of Molecular Biology/CMBI, University of Innsbruck, Innsbruck, Austria
- CONTACT Dirk Meyer Institute of Molecular Biology/CMBI, University of Innsbruck, Technikerstrasse 25, Innsbruck 6020, Austria
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11
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Emfinger CH, Welscher A, Yan Z, Wang Y, Conway H, Moss JB, Moss LG, Remedi MS, Nichols CG. Expression and function of ATP-dependent potassium channels in zebrafish islet β-cells. R Soc Open Sci 2017; 4:160808. [PMID: 28386438 PMCID: PMC5367309 DOI: 10.1098/rsos.160808] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 01/06/2017] [Indexed: 05/04/2023]
Abstract
ATP-sensitive potassium channels (KATP channels) are critical nutrient sensors in many mammalian tissues. In the pancreas, KATP channels are essential for coupling glucose metabolism to insulin secretion. While orthologous genes for many components of metabolism-secretion coupling in mammals are present in lower vertebrates, their expression, functionality and ultimate impact on body glucose homeostasis are unclear. In this paper, we demonstrate that zebrafish islet β-cells express functional KATP channels of similar subunit composition, structure and metabolic sensitivity to their mammalian counterparts. We further show that pharmacological activation of native zebrafish KATP using diazoxide, a specific KATP channel opener, is sufficient to disturb glucose tolerance in adult zebrafish. That β-cell KATP channel expression and function are conserved between zebrafish and mammals illustrates the evolutionary conservation of islet metabolic sensing from fish to humans, and lends relevance to the use of zebrafish to model islet glucose sensing and diseases of membrane excitability such as neonatal diabetes.
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Affiliation(s)
- Christopher H. Emfinger
- Department of Cell Biology and Physiology, Washington University in St Louis, St Louis, MO, USA
- Division of Endocrinology, Metabolism, and Lipid Research, Department of Medicine, Washington University in St Louis, St Louis, MO, USA
- Center for the Investigation of Membrane Excitability Diseases, Washington University in St Louis, St Louis, MO, USA
| | - Alecia Welscher
- Division of Endocrinology, Metabolism, and Lipid Research, Department of Medicine, Washington University in St Louis, St Louis, MO, USA
- Center for the Investigation of Membrane Excitability Diseases, Washington University in St Louis, St Louis, MO, USA
| | - Zihan Yan
- Division of Endocrinology, Metabolism, and Lipid Research, Department of Medicine, Washington University in St Louis, St Louis, MO, USA
- Center for the Investigation of Membrane Excitability Diseases, Washington University in St Louis, St Louis, MO, USA
| | - Yixi Wang
- Department of Cell Biology and Physiology, Washington University in St Louis, St Louis, MO, USA
- Center for the Investigation of Membrane Excitability Diseases, Washington University in St Louis, St Louis, MO, USA
| | - Hannah Conway
- Division of Endocrinology, Metabolism, and Lipid Research, Department of Medicine, Washington University in St Louis, St Louis, MO, USA
| | - Jennifer B. Moss
- Division of Endocrinology, Metabolism, and Nutrition and DMPI, Duke University Medical Center, Durham, NC, USA
| | - Larry G. Moss
- Division of Endocrinology, Metabolism, and Nutrition and DMPI, Duke University Medical Center, Durham, NC, USA
| | - Maria S. Remedi
- Department of Cell Biology and Physiology, Washington University in St Louis, St Louis, MO, USA
- Division of Endocrinology, Metabolism, and Lipid Research, Department of Medicine, Washington University in St Louis, St Louis, MO, USA
- Center for the Investigation of Membrane Excitability Diseases, Washington University in St Louis, St Louis, MO, USA
| | - Colin G. Nichols
- Department of Cell Biology and Physiology, Washington University in St Louis, St Louis, MO, USA
- Center for the Investigation of Membrane Excitability Diseases, Washington University in St Louis, St Louis, MO, USA
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12
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Abstract
The development of insulin resistance in the liver is a key event that drives dyslipidemia and predicts diabetes and cardiovascular risk with obesity. Clinical data show that estrogen signaling in males helps prevent adiposity and insulin resistance, which may be mediated through estrogen receptor-α (ERα). The tissues and pathways that mediate the benefits of estrogen signaling in males with obesity are not well defined. In female mice, ERα signaling in the liver helps to correct pathway-selective insulin resistance with estrogen treatment after ovariectomy. We assessed the importance of liver estrogen signaling in males using liver ERα-knockout (LKO) mice fed a high-fat diet (HFD). We found that the LKO male mice had decreased insulin sensitivity compared with their wild-type floxed (fl/fl) littermates during hyperinsulinemic euglycemic clamps. Insulin failed to suppress endogenous glucose production in LKO mice, indicating liver insulin resistance. Insulin promoted glucose disappearance in LKO and fl/fl mice similarly. In the liver, insulin failed to induce phosphorylation of Akt-Ser(473) and exclude FOXO1 from the nucleus in LKO mice, a pathway important for liver glucose and lipid metabolism. Liver triglycerides and diacylglycerides were also increased in LKO mice, which corresponded with dysregulation of insulin-stimulated ACC phosphorylation and DGAT1/2 protein levels. Our studies demonstrate that estrogen signaling through ERα in the liver helps prevent whole body and hepatic insulin resistance associated with HFD feeding in males. Augmenting hepatic estrogen signaling through ERα may lessen the impact of obesity on diabetes and cardiovascular risk in males.
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Affiliation(s)
- Lin Zhu
- Division of Diabetes, Endocrinology, and Metabolism, Department of Internal Medicine, and
| | - Melissa N Martinez
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Christopher H Emfinger
- Tennessee Valley Healthcare System, Division of Diabetes, Endocrinology, and Metabolism, Department of Internal Medicine, and
| | - Brian T Palmisano
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - John M Stafford
- Tennessee Valley Healthcare System, Division of Diabetes, Endocrinology, and Metabolism, Department of Internal Medicine, and Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
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13
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Martinez MN, Emfinger CH, Overton M, Hill S, Ramaswamy TS, Cappel DA, Wu K, Fazio S, McDonald WH, Hachey DL, Tabb DL, Stafford JM. Obesity and altered glucose metabolism impact HDL composition in CETP transgenic mice: a role for ovarian hormones. J Lipid Res 2012; 53:379-389. [PMID: 22215797 PMCID: PMC3276461 DOI: 10.1194/jlr.m019752] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [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: 08/26/2011] [Revised: 12/15/2011] [Indexed: 01/03/2023] Open
Abstract
Mechanisms underlying changes in HDL composition caused by obesity are poorly defined, partly because mice lack expression of cholesteryl ester transfer protein (CETP), which shuttles triglyceride and cholesteryl ester between lipoproteins. Because menopause is associated with weight gain, altered glucose metabolism, and changes in HDL, we tested the effect of feeding a high-fat diet (HFD) and ovariectomy (OVX) on glucose metabolism and HDL composition in CETP transgenic mice. After OVX, female CETP-expressing mice had accelerated weight gain with HFD-feeding and impaired glucose tolerance by hyperglycemic clamp techniques, compared with OVX mice fed a low-fat diet (LFD). Sham-operated mice (SHAM) did not show HFD-induced weight gain and had less glucose intolerance than OVX mice. Using shotgun HDL proteomics, HFD-feeding in OVX mice had a large effect on HDL composition, including increased levels of apoA2, apoA4, apoC2, and apoC3, proteins involved in TG metabolism. These changes were associated with decreased hepatic expression of SR-B1, ABCA1, and LDL receptor, proteins involved in modulating the lipid content of HDL. In SHAM mice, there were minimal changes in HDL composition with HFD feeding. These studies suggest that the absence of ovarian hormones negatively influences the response to high-fat feeding in terms of glucose tolerance and HDL composition. CETP-expressing mice may represent a useful model to define how metabolic changes affect HDL composition and function.
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Affiliation(s)
| | | | - Matthew Overton
- Department of Molecular Physiology & Biophysics; University of North Carolina, Chapel Hill
| | | | | | | | - Ke Wu
- Division of Diabetes, Endocrinology, & Metabolism; Wuhan University
| | - Sergio Fazio
- Atherosclerosis Research Unit, Division of Cardiovascular Medicine
| | - W Hayes McDonald
- Mass Spectroscopy Research Center Vanderbilt University School of Medicine
| | - David L Hachey
- Mass Spectroscopy Research Center Vanderbilt University School of Medicine
| | | | - John M Stafford
- Department of Molecular Physiology & Biophysics; Tennessee Valley Healthcare System; Division of Diabetes, Endocrinology, & Metabolism.
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