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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] [What about the content of this article? (0)] [Affiliation(s)] [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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D’Aquila T, Sirohi D, Grabowski JM, Hedrick VE, Paul LN, Greenberg AS, Kuhn RJ, Buhman KK. Characterization of the proteome of cytoplasmic lipid droplets in mouse enterocytes after a dietary fat challenge. PLoS One 2015; 10:e0126823. [PMID: 25992653 PMCID: PMC4436333 DOI: 10.1371/journal.pone.0126823] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Accepted: 04/08/2015] [Indexed: 01/23/2023] Open
Abstract
Dietary fat absorption by the small intestine is a multistep process that regulates the uptake and delivery of essential nutrients and energy. One step of this process is the temporary storage of dietary fat in cytoplasmic lipid droplets (CLDs). The storage and mobilization of dietary fat is thought to be regulated by proteins that associate with the CLD; however, mechanistic details of this process are currently unknown. In this study we analyzed the proteome of CLDs isolated from enterocytes harvested from the small intestine of mice following a dietary fat challenge. In this analysis we identified 181 proteins associated with the CLD fraction, of which 37 are associated with known lipid related metabolic pathways. We confirmed the localization of several of these proteins on or around the CLD through confocal and electron microscopy, including perilipin 3, apolipoprotein A-IV, and acyl-CoA synthetase long-chain family member 5. The identification of the enterocyte CLD proteome provides new insight into potential regulators of CLD metabolism and the process of dietary fat absorption.
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Affiliation(s)
- Theresa D’Aquila
- Department of Nutrition Science, Purdue University, West Lafayette, Indiana, United States of America
| | - Devika Sirohi
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, United States of America
- Bindley Bioscience Center, Purdue University, West Lafayette, Indiana, United States of America
| | - Jeffrey M. Grabowski
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, United States of America
- Department of Entomology, Purdue University, West Lafayette, Indiana, United States of America
| | - Victoria E. Hedrick
- Bindley Bioscience Center, Purdue University, West Lafayette, Indiana, United States of America
| | - Lake N. Paul
- Bindley Bioscience Center, Purdue University, West Lafayette, Indiana, United States of America
| | - Andrew S. Greenberg
- Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, Massachusetts, United States of America
| | - Richard J. Kuhn
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, United States of America
- Bindley Bioscience Center, Purdue University, West Lafayette, Indiana, United States of America
| | - Kimberly K. Buhman
- Department of Nutrition Science, Purdue University, West Lafayette, Indiana, United States of America
- * E-mail:
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Erion DM, Lapworth A, Amor PA, Bai G, Vera NB, Clark RW, Yan Q, Zhu Y, Ross TT, Purkal J, Gorgoglione M, Zhang G, Bonato V, Baker L, Barucci N, D’Aquila T, Robertson A, Aiello RJ, Yan J, Trimmer J, Rolph TP, Pfefferkorn JA. The hepatoselective glucokinase activator PF-04991532 ameliorates hyperglycemia without causing hepatic steatosis in diabetic rats. PLoS One 2014; 9:e97139. [PMID: 24858947 PMCID: PMC4032240 DOI: 10.1371/journal.pone.0097139] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2013] [Accepted: 04/01/2014] [Indexed: 02/04/2023] Open
Abstract
Hyperglycemia resulting from type 2 diabetes mellitus (T2DM) is the main cause of diabetic complications such as retinopathy and neuropathy. A reduction in hyperglycemia has been shown to prevent these associated complications supporting the importance of glucose control. Glucokinase converts glucose to glucose-6-phosphate and determines glucose flux into the β-cells and hepatocytes. Since activation of glucokinase in β-cells is associated with increased risk of hypoglycemia, we hypothesized that selectively activating hepatic glucokinase would reduce fasting and postprandial glucose with minimal risk of hypoglycemia. Previous studies have shown that hepatic glucokinase overexpression is able to restore glucose homeostasis in diabetic models; however, these overexpression experiments have also revealed that excessive increases in hepatic glucokinase activity may also cause hepatosteatosis. Herein we sought to evaluate whether liver specific pharmacological activation of hepatic glucokinase is an effective strategy to reduce hyperglycemia without causing adverse hepatic lipids changes. To test this hypothesis, we evaluated a hepatoselective glucokinase activator, PF-04991532, in Goto-Kakizaki rats. In these studies, PF-04991532 reduced plasma glucose concentrations independent of changes in insulin concentrations in a dose-dependent manner both acutely and after 28 days of sub-chronic treatment. During a hyperglycemic clamp in Goto-Kakizaki rats, the glucose infusion rate was increased approximately 5-fold with PF-04991532. This increase in glucose infusion can be partially attributed to the 60% reduction in endogenous glucose production. While PF-04991532 induced dose-dependent increases in plasma triglyceride concentrations it had no effect on hepatic triglyceride concentrations in Goto-Kakizaki rats. Interestingly, PF-04991532 decreased intracellular AMP concentrations and increased hepatic futile cycling. These data suggest that hepatoselective glucokinase activation may offer glycemic control without inducing hepatic steatosis supporting the evaluation of tissue specific activators in clinical trials.
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Affiliation(s)
- Derek M. Erion
- Cardiovascular, Metabolic & Endocrine Disease Research Unit, Pfizer Worldwide Research & Development, Cambridge, Massachusetts, United States of America
- * E-mail:
| | - Amanda Lapworth
- Cardiovascular, Metabolic & Endocrine Disease Research Unit, Pfizer Worldwide Research & Development, Cambridge, Massachusetts, United States of America
| | - Paul A. Amor
- Cardiovascular, Metabolic & Endocrine Disease Research Unit, Pfizer Worldwide Research & Development, Cambridge, Massachusetts, United States of America
| | - Guoyun Bai
- Groton Center of Chemistry, Pfizer Worldwide Research & Development, Groton, Connecticut, United States of America
| | - Nicholas B. Vera
- Cardiovascular, Metabolic & Endocrine Disease Research Unit, Pfizer Worldwide Research & Development, Cambridge, Massachusetts, United States of America
| | - Ronald W. Clark
- Cardiovascular, Metabolic & Endocrine Disease Research Unit, Pfizer Worldwide Research & Development, Cambridge, Massachusetts, United States of America
| | - Qingyun Yan
- Cardiovascular, Metabolic & Endocrine Disease Research Unit, Pfizer Worldwide Research & Development, Cambridge, Massachusetts, United States of America
| | - Yimin Zhu
- Cardiovascular, Metabolic & Endocrine Disease Research Unit, Pfizer Worldwide Research & Development, Cambridge, Massachusetts, United States of America
| | - Trenton T. Ross
- Cardiovascular, Metabolic & Endocrine Disease Research Unit, Pfizer Worldwide Research & Development, Cambridge, Massachusetts, United States of America
| | - Julie Purkal
- Cardiovascular, Metabolic & Endocrine Disease Research Unit, Pfizer Worldwide Research & Development, Cambridge, Massachusetts, United States of America
| | - Matthew Gorgoglione
- Cardiovascular, Metabolic & Endocrine Disease Research Unit, Pfizer Worldwide Research & Development, Cambridge, Massachusetts, United States of America
| | - Guodong Zhang
- Groton Center of Chemistry, Pfizer Worldwide Research & Development, Groton, Connecticut, United States of America
| | - Vinicius Bonato
- Cardiovascular, Metabolic & Endocrine Disease Research Unit, Pfizer Worldwide Research & Development, Cambridge, Massachusetts, United States of America
| | - Levenia Baker
- Cardiovascular, Metabolic & Endocrine Disease Research Unit, Pfizer Worldwide Research & Development, Cambridge, Massachusetts, United States of America
| | - Nicole Barucci
- Cardiovascular, Metabolic & Endocrine Disease Research Unit, Pfizer Worldwide Research & Development, Cambridge, Massachusetts, United States of America
| | - Theresa D’Aquila
- Cardiovascular, Metabolic & Endocrine Disease Research Unit, Pfizer Worldwide Research & Development, Cambridge, Massachusetts, United States of America
| | - Alan Robertson
- Cardiovascular, Metabolic & Endocrine Disease Research Unit, Pfizer Worldwide Research & Development, Cambridge, Massachusetts, United States of America
| | - Robert J. Aiello
- Cardiovascular, Metabolic & Endocrine Disease Research Unit, Pfizer Worldwide Research & Development, Cambridge, Massachusetts, United States of America
| | - Jiangli Yan
- Groton Center of Chemistry, Pfizer Worldwide Research & Development, Groton, Connecticut, United States of America
| | - Jeff Trimmer
- Cardiovascular, Metabolic & Endocrine Disease Research Unit, Pfizer Worldwide Research & Development, Cambridge, Massachusetts, United States of America
| | - Timothy P. Rolph
- Cardiovascular, Metabolic & Endocrine Disease Research Unit, Pfizer Worldwide Research & Development, Cambridge, Massachusetts, United States of America
| | - Jeffrey A. Pfefferkorn
- Cardiovascular, Metabolic & Endocrine Disease Research Unit, Pfizer Worldwide Research & Development, Cambridge, Massachusetts, United States of America
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Pfefferkorn JA, Guzman-Perez A, Litchfield J, Aiello R, Treadway JL, Pettersen J, Minich ML, Filipski KJ, Jones CS, Tu M, Aspnes G, Risley H, Bian J, Stevens BD, Bourassa P, D’Aquila T, Baker L, Barucci N, Robertson AS, Bourbonais F, Derksen DR, MacDougall M, Cabrera O, Chen J, Lapworth AL, Landro JA, Zavadoski WJ, Atkinson K, Haddish-Berhane N, Tan B, Yao L, Kosa RE, Varma MV, Feng B, Duignan DB, El-Kattan A, Murdande S, Liu S, Ammirati M, Knafels J, DaSilva-Jardine P, Sweet L, Liras S, Rolph TP. Discovery of (S)-6-(3-Cyclopentyl-2-(4-(trifluoromethyl)-1H-imidazol-1-yl)propanamido)nicotinic Acid as a Hepatoselective Glucokinase Activator Clinical Candidate for Treating Type 2 Diabetes Mellitus. J Med Chem 2012; 55:1318-33. [DOI: 10.1021/jm2014887] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Jeffrey A. Pfefferkorn
- Cambridge Laboratories, Pfizer Worldwide Research & Development, 620 Memorial Drive, Cambridge, Massachusetts 02139, United States
| | - Angel Guzman-Perez
- Groton Laboratories, Pfizer Worldwide Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - John Litchfield
- Groton Laboratories, Pfizer Worldwide Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Robert Aiello
- Groton Laboratories, Pfizer Worldwide Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Judith L. Treadway
- Groton Laboratories, Pfizer Worldwide Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - John Pettersen
- Groton Laboratories, Pfizer Worldwide Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Martha L. Minich
- Groton Laboratories, Pfizer Worldwide Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Kevin J. Filipski
- Cambridge Laboratories, Pfizer Worldwide Research & Development, 620 Memorial Drive, Cambridge, Massachusetts 02139, United States
| | - Christopher S. Jones
- Groton Laboratories, Pfizer Worldwide Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Meihua Tu
- Cambridge Laboratories, Pfizer Worldwide Research & Development, 620 Memorial Drive, Cambridge, Massachusetts 02139, United States
| | - Gary Aspnes
- Groton Laboratories, Pfizer Worldwide Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Hud Risley
- Groton Laboratories, Pfizer Worldwide Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Jianwei Bian
- Groton Laboratories, Pfizer Worldwide Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Benjamin D. Stevens
- Cambridge Laboratories, Pfizer Worldwide Research & Development, 620 Memorial Drive, Cambridge, Massachusetts 02139, United States
| | - Patricia Bourassa
- Groton Laboratories, Pfizer Worldwide Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Theresa D’Aquila
- Groton Laboratories, Pfizer Worldwide Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Levenia Baker
- Groton Laboratories, Pfizer Worldwide Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Nicole Barucci
- Groton Laboratories, Pfizer Worldwide Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Alan S. Robertson
- Groton Laboratories, Pfizer Worldwide Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Francis Bourbonais
- Groton Laboratories, Pfizer Worldwide Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - David R. Derksen
- Groton Laboratories, Pfizer Worldwide Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Margit MacDougall
- Groton Laboratories, Pfizer Worldwide Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Over Cabrera
- Cambridge Laboratories, Pfizer Worldwide Research & Development, 620 Memorial Drive, Cambridge, Massachusetts 02139, United States
| | - Jing Chen
- Groton Laboratories, Pfizer Worldwide Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Amanda Lee Lapworth
- Cambridge Laboratories, Pfizer Worldwide Research & Development, 620 Memorial Drive, Cambridge, Massachusetts 02139, United States
| | - James A. Landro
- Groton Laboratories, Pfizer Worldwide Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - William J. Zavadoski
- Groton Laboratories, Pfizer Worldwide Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Karen Atkinson
- Groton Laboratories, Pfizer Worldwide Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Nahor Haddish-Berhane
- Groton Laboratories, Pfizer Worldwide Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Beijing Tan
- Groton Laboratories, Pfizer Worldwide Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Lili Yao
- Groton Laboratories, Pfizer Worldwide Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Rachel E. Kosa
- Groton Laboratories, Pfizer Worldwide Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Manthena V. Varma
- Groton Laboratories, Pfizer Worldwide Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Bo Feng
- Groton Laboratories, Pfizer Worldwide Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - David B. Duignan
- Groton Laboratories, Pfizer Worldwide Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Ayman El-Kattan
- Groton Laboratories, Pfizer Worldwide Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Sharad Murdande
- Groton Laboratories, Pfizer Worldwide Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Shenping Liu
- Groton Laboratories, Pfizer Worldwide Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Mark Ammirati
- Groton Laboratories, Pfizer Worldwide Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - John Knafels
- Groton Laboratories, Pfizer Worldwide Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Paul DaSilva-Jardine
- Cambridge Laboratories, Pfizer Worldwide Research & Development, 620 Memorial Drive, Cambridge, Massachusetts 02139, United States
| | - Laurel Sweet
- Groton Laboratories, Pfizer Worldwide Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Spiros Liras
- Cambridge Laboratories, Pfizer Worldwide Research & Development, 620 Memorial Drive, Cambridge, Massachusetts 02139, United States
| | - Timothy P. Rolph
- Cambridge Laboratories, Pfizer Worldwide Research & Development, 620 Memorial Drive, Cambridge, Massachusetts 02139, United States
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