1
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Zhang R, Zhang K. A unified model for regulating lipoprotein lipase activity. Trends Endocrinol Metab 2024; 35:490-504. [PMID: 38521668 DOI: 10.1016/j.tem.2024.02.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/25/2023] [Revised: 02/16/2024] [Accepted: 02/20/2024] [Indexed: 03/25/2024]
Abstract
The regulation of triglyceride (TG) tissue distribution, storage, and utilization, a fundamental process of energy homeostasis, critically depends on lipoprotein lipase (LPL). We review the intricate mechanisms by which LPL activity is regulated by angiopoietin-like proteins (ANGPTL3, 4, 8), apolipoproteins (APOA5, APOC3, APOC2), and the cAMP-responsive element-binding protein H (CREBH). ANGPTL8 functions as a molecular switch, through complex formation, activating ANGPTL3 while deactivating ANGPTL4 in their LPL inhibition. The ANGPTL3-4-8 model integrates the roles of the aforementioned proteins in TG partitioning between white adipose tissue (WAT) and oxidative tissues (heart and skeletal muscles) during the feed/fast cycle. This model offers a unified perspective on LPL regulation, providing insights into TG metabolism, metabolic diseases, and therapeutics.
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Affiliation(s)
- Ren Zhang
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI 48201, USA.
| | - Kezhong Zhang
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI 48201, USA
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2
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Chen YQ, Yang Y, Zhen EY, Beyer TP, Li H, Wen Y, Ehsani M, Jackson N, Xie K, Jung H, Scheithauer JL, Kumari A, Birrane G, Russell AM, Balasubramaniam D, Liao Z, Siegel RW, Qian Y, Ploug M, Young SG, Konrad RJ. Carboxyl-terminal sequences in APOA5 are important for suppressing ANGPTL3/8 activity. Proc Natl Acad Sci U S A 2024; 121:e2322332121. [PMID: 38625948 PMCID: PMC11046700 DOI: 10.1073/pnas.2322332121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2023] [Accepted: 03/16/2024] [Indexed: 04/18/2024] Open
Abstract
Apolipoprotein AV (APOA5) lowers plasma triglyceride (TG) levels by binding to the angiopoietin-like protein 3/8 complex (ANGPTL3/8) and suppressing its capacity to inhibit lipoprotein lipase (LPL) catalytic activity and its ability to detach LPL from binding sites within capillaries. However, the sequences in APOA5 that are required for suppressing ANGPTL3/8 activity have never been defined. A clue to the identity of those sequences was the presence of severe hypertriglyceridemia in two patients harboring an APOA5 mutation that truncates APOA5 by 35 residues ("APOA5Δ35"). We found that wild-type (WT) human APOA5, but not APOA5Δ35, suppressed ANGPTL3/8's ability to inhibit LPL catalytic activity. To pursue that finding, we prepared a mutant mouse APOA5 protein lacking 40 C-terminal amino acids ("APOA5Δ40"). Mouse WT-APOA5, but not APOA5Δ40, suppressed ANGPTL3/8's capacity to inhibit LPL catalytic activity and sharply reduced plasma TG levels in mice. WT-APOA5, but not APOA5Δ40, increased intracapillary LPL levels and reduced plasma TG levels in Apoa5-/- mice (where TG levels are high and intravascular LPL levels are low). Also, WT-APOA5, but not APOA5Δ40, blocked the ability of ANGPTL3/8 to detach LPL from cultured cells. Finally, an antibody against a synthetic peptide corresponding to the last 26 amino acids of mouse APOA5 reduced intracapillary LPL levels and increased plasma TG levels in WT mice. We conclude that C-terminal sequences in APOA5 are crucial for suppressing ANGPTL3/8 activity in vitro and for regulating intracapillary LPL levels and plasma TG levels in vivo.
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Affiliation(s)
- Yan Q. Chen
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN462585
| | - Ye Yang
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Eugene Y. Zhen
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN462585
| | - Thomas P. Beyer
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN462585
| | - Hongxia Li
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN462585
| | - Yi Wen
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN462585
| | - Mariam Ehsani
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN462585
| | - Nicholas Jackson
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Katherine Xie
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Hyesoo Jung
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Julia L. Scheithauer
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Anni Kumari
- Finsen Laboratory, Centre for Cancer and Organ Diseases, Copenhagen University Hospital-Rigshospitalet, DK-2200Copenhagen N, Denmark
- Finsen Laboratory, Biotech Research and Innovation Centre, University of Copenhagen, DK-2200Copenhagen N, Denmark
| | - Gabriel Birrane
- Division of Experimental Medicine, Beth Israel Deaconess Medical Center, Boston, MA02215
| | - Anna M. Russell
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN462585
| | | | - Zhongping Liao
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN462585
| | - Robert W. Siegel
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN462585
| | - Yuewei Qian
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN462585
| | - Michael Ploug
- Finsen Laboratory, Centre for Cancer and Organ Diseases, Copenhagen University Hospital-Rigshospitalet, DK-2200Copenhagen N, Denmark
- Finsen Laboratory, Biotech Research and Innovation Centre, University of Copenhagen, DK-2200Copenhagen N, Denmark
| | - Stephen G. Young
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Robert J. Konrad
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN462585
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3
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Wen Y, Chen YQ, Konrad RJ. Angiopoietin-like protein 8: a multifaceted protein instrumental in regulating triglyceride metabolism. Curr Opin Lipidol 2024; 35:58-65. [PMID: 37962908 DOI: 10.1097/mol.0000000000000910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
PURPOSE OF REVIEW The angiopoietin-like (ANGPTL) proteins ANGPTL3 and ANGPTL4 are critical lipoprotein lipase (LPL) inhibitors. This review discusses the unique ability of the insulin-responsive protein ANGPTL8 to regulate triglyceride (TG) metabolism by forming ANGPTL3/8 and ANGPTL4/8 complexes that control tissue-specific LPL activities. RECENT FINDINGS After feeding, ANGPTL4/8 acts locally in adipose tissue, has decreased LPL-inhibitory activity compared to ANGPTL4, and binds tissue plasminogen activator (tPA) and plasminogen to generate plasmin, which cleaves ANGPTL4/8 and other LPL inhibitors. This enables LPL to be fully active postprandially to promote efficient fatty acid (FA) uptake and minimize ectopic fat deposition. In contrast, liver-derived ANGPTL3/8 acts in an endocrine manner, has markedly increased LPL-inhibitory activity compared to ANGPTL3, and potently inhibits LPL in oxidative tissues to direct TG toward adipose tissue for storage. Circulating ANGPTL3/8 levels are strongly correlated with serum TG, and the ANGPTL3/8 LPL-inhibitory epitope is blocked by the TG-lowering protein apolipoprotein A5 (ApoA5). SUMMARY ANGPTL8 plays a crucial role in TG metabolism by forming ANGPTL3/8 and ANGPTL4/8 complexes that differentially modulate LPL activities in oxidative and adipose tissues respectively. Selective ANGPTL8 inhibition in the context of the ANGPTL3/8 complex has the potential to be a promising strategy for treating dyslipidemia.
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Affiliation(s)
- Yi Wen
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana, USA
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4
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Kimura T, Miyashita K, Fukamachi I, Fukamachi K, Ogura K, Yokoyama E, Tsunekawa K, Nagasawa T, Ploug M, Yang Y, Song W, Young SG, Beigneux AP, Nakajima K, Murakami M. Quantification of lipoprotein lipase in mouse plasma with a sandwich enzyme-linked immunosorbent assay. J Lipid Res 2024; 65:100532. [PMID: 38608546 PMCID: PMC11017283 DOI: 10.1016/j.jlr.2024.100532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 03/03/2024] [Accepted: 03/06/2024] [Indexed: 04/14/2024] Open
Abstract
To support in vivo and in vitro studies of intravascular triglyceride metabolism in mice, we created rat monoclonal antibodies (mAbs) against mouse LPL. Two mAbs, mAbs 23A1 and 31A5, were used to develop a sandwich ELISA for mouse LPL. The detection of mouse LPL by the ELISA was linear in concentrations ranging from 0.31 ng/ml to 20 ng/ml. The sensitivity of the ELISA made it possible to quantify LPL in serum and in both pre-heparin and post-heparin plasma samples (including in grossly lipemic samples). LPL mass and activity levels in the post-heparin plasma were lower in Gpihbp1-/- mice than in wild-type mice. In both groups of mice, LPL mass and activity levels were positively correlated. Our mAb-based sandwich ELISA for mouse LPL will be useful for any investigator who uses mouse models to study LPL-mediated intravascular lipolysis.
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Affiliation(s)
- Takao Kimura
- Department of Clinical Laboratory Medicine, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan; Clinical Laboratory Center, Gunma University Hospital, Maebashi, Gunma, Japan.
| | | | | | | | - Kazumi Ogura
- Immuno-Biological Laboratories, Fujioka, Gunma, Japan
| | | | - Katsuhiko Tsunekawa
- Department of Clinical Laboratory Medicine, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan; Clinical Laboratory Center, Gunma University Hospital, Maebashi, Gunma, Japan
| | - Takumi Nagasawa
- Department of Clinical Laboratory Medicine, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan; Clinical Laboratory Center, Gunma University Hospital, Maebashi, Gunma, Japan
| | - Michael Ploug
- Finsen Laboratory, Copenhagen University Hospital - Rigshospitalet, Copenhagen, Denmark; Biotech Research and Innovation Centre, University of Copenhagen, Copenhagen, Denmark
| | - Ye Yang
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Wenxin Song
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Stephen G Young
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA, USA; Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Anne P Beigneux
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Katsuyuki Nakajima
- Department of Clinical Laboratory Medicine, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan
| | - Masami Murakami
- Department of Clinical Laboratory Medicine, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan; Clinical Laboratory Center, Gunma University Hospital, Maebashi, Gunma, Japan
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Sylvers-Davie KL, Bierstedt KC, Schnieders MJ, Davies BSJ. Endothelial lipase variant T111I does not alter inhibition by angiopoietin-like proteins. Sci Rep 2024; 14:4246. [PMID: 38379026 PMCID: PMC10879187 DOI: 10.1038/s41598-024-54705-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 02/15/2024] [Indexed: 02/22/2024] Open
Abstract
High levels of HDL-C are correlated with a decreased risk of cardiovascular disease. HDL-C levels are modulated in part by the secreted phospholipase, endothelial lipase (EL), which hydrolyzes the phospholipids of HDL and decreases circulating HDL-C concentrations. A 584C/T polymorphism in LIPG, the gene which encodes EL, was first identified in individuals with increased HDL levels. This polymorphism results in a T111I point mutation the EL protein. The association between this variant, HDL levels, and the risk of coronary artery disease (CAD) in humans has been extensively studied, but the findings have been inconsistent. In this study, we took a biochemical approach, investigating how the T111I variant affected EL activity, structure, and stability. Moreover, we tested whether the T111I variant altered the inhibition of phospholipase activity by angiopoietin-like 3 (ANGPTL3) and angiopoietin-like 4 (ANGPTL4), two known EL inhibitors. We found that neither the stability nor enzymatic activity of EL was altered by the T111I variant. Moreover, we found no difference between wild-type and T111I EL in their ability to be inhibited by ANGPTL proteins. These data suggest that any effect this variant may have on HDL-C levels or cardiovascular disease are not mediated through alterations in these functions.
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Affiliation(s)
- Kelli L Sylvers-Davie
- Department of Biochemistry and Molecular Biology, University of Iowa, 169 Newton Rd., PBDB 3326, Iowa, IA, 52242, USA
- Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa, IA, 52242, USA
| | - Kaleb C Bierstedt
- Department of Biochemistry and Molecular Biology, University of Iowa, 169 Newton Rd., PBDB 3326, Iowa, IA, 52242, USA
- Department of Biomedical Engineering, University of Iowa, Iowa, IA, 52242, USA
| | - Michael J Schnieders
- Department of Biochemistry and Molecular Biology, University of Iowa, 169 Newton Rd., PBDB 3326, Iowa, IA, 52242, USA
- Department of Biomedical Engineering, University of Iowa, Iowa, IA, 52242, USA
| | - Brandon S J Davies
- Department of Biochemistry and Molecular Biology, University of Iowa, 169 Newton Rd., PBDB 3326, Iowa, IA, 52242, USA.
- Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa, IA, 52242, USA.
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Papadopoulou P, van der Pol R, van Hilten N, van Os WL, Pattipeiluhu R, Arias-Alpizar G, Knol RA, Noteborn W, Moradi MA, Ferraz MJ, Aerts JMFG, Sommerdijk N, Campbell F, Risselada HJ, Sevink GJA, Kros A. Phase-Separated Lipid-Based Nanoparticles: Selective Behavior at the Nano-Bio Interface. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2310872. [PMID: 37988682 DOI: 10.1002/adma.202310872] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Indexed: 11/23/2023]
Abstract
The membrane-protein interface on lipid-based nanoparticles influences their in vivo behavior. Better understanding may evolve current drug delivery methods toward effective targeted nanomedicine. Previously, the cell-selective accumulation of a liposome formulation in vivo is demonstrated, through the recognition of lipid phase-separation by triglyceride lipases. This exemplified how liposome morphology and composition can determine nanoparticle-protein interactions. Here, the lipase-induced compositional and morphological changes of phase-separated liposomes-which bear a lipid droplet in their bilayer- are investigated, and the mechanism upon which lipases recognize and bind to the particles is unravelled. The selective lipolytic degradation of the phase-separated lipid droplet is observed, while nanoparticle integrity remains intact. Next, the Tryptophan-rich loop of the lipase is identified as the region with which the enzymes bind to the particles. This preferential binding is due to lipid packing defects induced on the liposome surface by phase separation. In parallel, the existing knowledge that phase separation leads to in vivo selectivity, is utilized to generate phase-separated mRNA-LNPs that target cell-subsets in zebrafish embryos, with subsequent mRNA delivery and protein expression. Together, these findings can expand the current knowledge on selective nanoparticle-protein communications and in vivo behavior, aspects that will assist to gain control of lipid-based nanoparticles.
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Affiliation(s)
- Panagiota Papadopoulou
- Department of Supramolecular & Biomaterials Chemistry, Leiden Institute of Chemistry (LIC), Leiden University, P. O. Box 9502, Leiden, 2300 RA, The Netherlands
| | - Rianne van der Pol
- Department of Supramolecular & Biomaterials Chemistry, Leiden Institute of Chemistry (LIC), Leiden University, P. O. Box 9502, Leiden, 2300 RA, The Netherlands
| | - Niek van Hilten
- Department of Supramolecular & Biomaterials Chemistry, Leiden Institute of Chemistry (LIC), Leiden University, P. O. Box 9502, Leiden, 2300 RA, The Netherlands
| | - Winant L van Os
- Department of Supramolecular & Biomaterials Chemistry, Leiden Institute of Chemistry (LIC), Leiden University, P. O. Box 9502, Leiden, 2300 RA, The Netherlands
| | - Roy Pattipeiluhu
- Department of Supramolecular & Biomaterials Chemistry, Leiden Institute of Chemistry (LIC), Leiden University, P. O. Box 9502, Leiden, 2300 RA, The Netherlands
| | - Gabriela Arias-Alpizar
- Department of Supramolecular & Biomaterials Chemistry, Leiden Institute of Chemistry (LIC), Leiden University, P. O. Box 9502, Leiden, 2300 RA, The Netherlands
| | - Renzo Aron Knol
- Department of Supramolecular & Biomaterials Chemistry, Leiden Institute of Chemistry (LIC), Leiden University, P. O. Box 9502, Leiden, 2300 RA, The Netherlands
| | - Willem Noteborn
- NeCEN, Leiden University, Einsteinweg 55, Leiden, 2333 AL, The Netherlands
| | - Mohammad-Amin Moradi
- Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, P. O. Box 513, Eindhoven, 5600 MB, The Netherlands
| | - Maria Joao Ferraz
- Department of Medical Biochemistry, Leiden Institute of Chemistry (LIC), Leiden University, P. O. Box 9502, Leiden, 2300 RA, The Netherlands
| | | | - Nico Sommerdijk
- Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, P. O. Box 513, Eindhoven, 5600 MB, The Netherlands
- Department of Medical BioSciences and Radboud Technology Center - Electron Microscopy, Radboud University Medical Center, Nijmegen, 6525 GA, The Netherlands
| | - Frederick Campbell
- Department of Supramolecular & Biomaterials Chemistry, Leiden Institute of Chemistry (LIC), Leiden University, P. O. Box 9502, Leiden, 2300 RA, The Netherlands
| | - Herre Jelger Risselada
- Department of Supramolecular & Biomaterials Chemistry, Leiden Institute of Chemistry (LIC), Leiden University, P. O. Box 9502, Leiden, 2300 RA, The Netherlands
- Department of Physics, Technical University Dortmund, 44221, Dortmund, Germany
| | - Geert Jan Agur Sevink
- Department of Biophysical Organic Chemistry, Leiden Institute of Chemistry (LIC), Leiden University, P. O. Box 9502, Leiden, 2300 RA, The Netherlands
| | - Alexander Kros
- Department of Supramolecular & Biomaterials Chemistry, Leiden Institute of Chemistry (LIC), Leiden University, P. O. Box 9502, Leiden, 2300 RA, The Netherlands
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7
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Wheless A, Gunn KH, Neher SB. Macromolecular Interactions of Lipoprotein Lipase (LPL). Subcell Biochem 2024; 104:139-179. [PMID: 38963487 DOI: 10.1007/978-3-031-58843-3_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/05/2024]
Abstract
Lipoprotein lipase (LPL) is a critical enzyme in humans that provides fuel to peripheral tissues. LPL hydrolyzes triglycerides from the cores of lipoproteins that are circulating in plasma and interacts with receptors to mediate lipoprotein uptake, thus directing lipid distribution via catalytic and non-catalytic functions. Functional losses in LPL or any of its myriad of regulators alter lipid homeostasis and potentially affect the risk of developing cardiovascular disease-either increasing or decreasing the risk depending on the mutated protein. The extensive LPL regulatory network tunes LPL activity to allocate fatty acids according to the energetic needs of the organism and thus is nutritionally responsive and tissue dependent. Multiple pharmaceuticals in development manipulate or mimic these regulators, demonstrating their translational importance. Another facet of LPL biology is that the oligomeric state of the enzyme is also central to its regulation. Recent structural studies have solidified the idea that LPL is regulated not only by interactions with other binding partners but also by self-associations. Here, we review the complexities of the protein-protein and protein-lipid interactions that govern LPL structure and function.
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Affiliation(s)
- Anna Wheless
- University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Kathryn H Gunn
- University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Stony Brook University, Stony Brook, USA
| | - Saskia B Neher
- University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
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8
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Jiang S, Ren Z, Yang Y, Liu Q, Zhou S, Xiao Y. The GPIHBP1-LPL complex and its role in plasma triglyceride metabolism: Insights into chylomicronemia. Biomed Pharmacother 2023; 169:115874. [PMID: 37951027 DOI: 10.1016/j.biopha.2023.115874] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 11/06/2023] [Accepted: 11/07/2023] [Indexed: 11/13/2023] Open
Abstract
GPIHBP1 is a protein found in the endothelial cells of capillaries that is anchored by glycosylphosphatidylinositol and binds to high-density lipoproteins. GPIHBP1 attaches to lipoprotein lipase (LPL), subsequently carrying the enzyme and anchoring it to the capillary lumen. Enabling lipid metabolism is essential for the marginalization of lipoproteins alongside capillaries. Studies underscore the significance of GPIHBP1 in transporting, stabilizing, and aiding in the marginalization of LPL. The intricate interplay between GPIHBP1 and LPL has provided novel insights into chylomicronemia in recent years. Mutations hindering the formation or reducing the efficiency of the GPIHBP1-LPL complex are central to the onset of chylomicronemia. This review delves into the structural nuances of the GPIHBP1-LPL interaction, the consequences of mutations in the complex leading to chylomicronemia, and cutting-edge advancements in chylomicronemia treatment.
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Affiliation(s)
- Shali Jiang
- Department of Cardiovascular Medicine, Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, PR China; Xiangya School of Medicine, Central South University, Changsha, Hunan 410013, PR China
| | - Zhuoqun Ren
- Department of Cardiovascular Medicine, Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, PR China; Xiangya School of Medicine, Central South University, Changsha, Hunan 410013, PR China
| | - Yutao Yang
- Department of Cardiovascular Medicine, Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, PR China; Xiangya School of Medicine, Central South University, Changsha, Hunan 410013, PR China
| | - Qiming Liu
- Department of Cardiovascular Medicine, Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, PR China
| | - Shenghua Zhou
- Department of Cardiovascular Medicine, Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, PR China
| | - Yichao Xiao
- Department of Cardiovascular Medicine, Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, PR China.
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9
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Yang Y, Beigneux AP, Song W, Nguyen LP, Jung H, Tu Y, Weston TA, Tran CM, Xie K, Yu RG, Tran AP, Miyashita K, Nakajima K, Murakami M, Chen YQ, Zhen EY, Kim JR, Kim PH, Birrane G, Tontonoz P, Ploug M, Konrad RJ, Fong LG, Young SG. Hypertriglyceridemia in Apoa5-/- mice results from reduced amounts of lipoprotein lipase in the capillary lumen. J Clin Invest 2023; 133:e172600. [PMID: 37824203 PMCID: PMC10688983 DOI: 10.1172/jci172600] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 10/05/2023] [Indexed: 10/14/2023] Open
Abstract
Why apolipoprotein AV (APOA5) deficiency causes hypertriglyceridemia has remained unclear, but we have suspected that the underlying cause is reduced amounts of lipoprotein lipase (LPL) in capillaries. By routine immunohistochemistry, we observed reduced LPL staining of heart and brown adipose tissue (BAT) capillaries in Apoa5-/- mice. Also, after an intravenous injection of LPL-, CD31-, and GPIHBP1-specific mAbs, the binding of LPL Abs to heart and BAT capillaries (relative to CD31 or GPIHBP1 Abs) was reduced in Apoa5-/- mice. LPL levels in the postheparin plasma were also lower in Apoa5-/- mice. We suspected that a recent biochemical observation - that APOA5 binds to the ANGPTL3/8 complex and suppresses its capacity to inhibit LPL catalytic activity - could be related to the low intracapillary LPL levels in Apoa5-/- mice. We showed that an ANGPTL3/8-specific mAb (IBA490) and APOA5 normalized plasma triglyceride (TG) levels and intracapillary LPL levels in Apoa5-/- mice. We also showed that ANGPTL3/8 detached LPL from heparan sulfate proteoglycans and GPIHBP1 on the surface of cells and that the LPL detachment was blocked by IBA490 and APOA5. Our studies explain the hypertriglyceridemia in Apoa5-/- mice and further illuminate the molecular mechanisms that regulate plasma TG metabolism.
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Affiliation(s)
- Ye Yang
- Department of Medicine and
- Human Genetics, David Geffen School of Medicine, UCLA, Los Angeles, California, USA
| | | | | | | | | | | | | | | | | | | | | | - Kazuya Miyashita
- Department of Clinical Laboratory Medicine, Gunma University, Graduate School of Medicine, Maebashi, Gunma, Japan
| | - Katsuyuki Nakajima
- Department of Clinical Laboratory Medicine, Gunma University, Graduate School of Medicine, Maebashi, Gunma, Japan
| | - Masami Murakami
- Department of Clinical Laboratory Medicine, Gunma University, Graduate School of Medicine, Maebashi, Gunma, Japan
| | - Yan Q. Chen
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana, USA
| | - Eugene Y. Zhen
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana, USA
| | | | | | - Gabriel Birrane
- Division of Experimental Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - Peter Tontonoz
- Department of Pathology and Laboratory Medicine, UCLA, Los Angeles, California, USA
| | - Michael Ploug
- Finsen Laboratory, Copenhagen University Hospital–Rigshospitalet, Copenhagen, Denmark
- Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark
| | - Robert J. Konrad
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana, USA
| | | | - Stephen G. Young
- Department of Medicine and
- Human Genetics, David Geffen School of Medicine, UCLA, Los Angeles, California, USA
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10
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Zheng Z, Lyu W, Hong Q, Yang H, Li Y, Zhao S, Ren Y, Xiao Y. Phylogenetic and expression analysis of the angiopoietin-like gene family and their role in lipid metabolism in pigs. Anim Biosci 2023; 36:1517-1529. [PMID: 37170504 PMCID: PMC10475376 DOI: 10.5713/ab.23.0057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 03/12/2023] [Accepted: 04/19/2023] [Indexed: 05/13/2023] Open
Abstract
OBJECTIVE The objective of this study was to investigate the phylogenetic and expression analysis of the angiopoietin-like (ANGPTL) gene family and their role in lipid metabolism in pigs. METHODS In this study, the amino acid sequence analysis, phylogenetic analysis, and chromosome adjacent gene analysis were performed to identify the ANGPTL gene family in pigs. According to the body weight data from 60 Jinhua pigs, different tissues of 6 pigs with average body weight were used to determine the expression profile of ANGPTL1-8. The ileum, subcutaneous fat, and liver of 8 pigs with distinct fatness were selected to analyze the gene expression of ANGPTL3, ANGPTL4, and ANGPTL8. RESULTS The sequence length of ANGPTLs in pigs was between 1,186 and 1,991 bp, and the pig ANGPTL family members shared common features with human homologous genes, including the high similarity of the amino acid sequence and chromosome flanking genes. Amino acid sequence analysis showed that ANGPTL1-7 had a highly conserved domain except for ANGPTL8. Phylogenetic analysis showed that each ANGPTL homologous gene shared a common origin. Quantitative reverse-transcription polymerase chain reaction analysis showed that ANGPTL family members had different expression patterns in different tissues. ANGPTL3 and ANGPTL8 were mainly expressed in the liver, while ANGPTL4 was expressed in many other tissues, such as the intestine and subcutaneous fat. The expression levels of ANGPTL3 in the liver and ANGPTL4 in the liver, intestine and subcutaneous fat of Jinhua pigs with low propensity for adipogenesis were significantly higher than those of high propensity for adipogenesis. CONCLUSION These results increase our knowledge about the biological role of the ANGPTL family in this important economic species, it will also help to better understand the role of ANGPTL3, ANGPTL4, and ANGPTL8 in lipid metabolism of pigs, and provide innovative ideas for developing strategies to improve meat quality of pigs.
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Affiliation(s)
- Zibin Zheng
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Institute of Agro-product Safety and Nutrition, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021,
China
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing 100193,
China
| | - Wentao Lyu
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Institute of Agro-product Safety and Nutrition, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021,
China
| | - Qihua Hong
- College of Animal Sciences, Zhejiang University, Hangzhou 310058,
China
| | - Hua Yang
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Institute of Agro-product Safety and Nutrition, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021,
China
| | - Ying Li
- Guangdong Provincial Key Laboratory of Animal Molecular Design and Precise Breeding, College of Life Science and Engineering, Foshan University, Foshan 528000,
China
| | - Shengjun Zhao
- Hubei Key Laboratory of Animal Nutrition and Feed Science, Wuhan Polytechnic University, Wuhan 430023,
China
| | - Ying Ren
- Hubei Key Laboratory of Animal Nutrition and Feed Science, Wuhan Polytechnic University, Wuhan 430023,
China
| | - Yingping Xiao
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Institute of Agro-product Safety and Nutrition, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021,
China
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11
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Chen YQ, Zhen EY, Russell AM, Ehsani M, Siegel RW, Qian Y, Konrad RJ. Decoding the role of angiopoietin-like protein 4/8 complex-mediated plasmin generation in the regulation of LPL activity. J Lipid Res 2023; 64:100441. [PMID: 37666362 PMCID: PMC10550811 DOI: 10.1016/j.jlr.2023.100441] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Revised: 08/17/2023] [Accepted: 08/28/2023] [Indexed: 09/06/2023] Open
Abstract
After feeding, adipose tissue lipoprotein lipase (LPL) activity should be maximized, therefore the potent LPL-inhibitory activity of angiopoietin-like protein 4 (ANGPTL4) must be blocked by ANGPTL8 through formation of ANGPTL4/8 complexes. ANGPTL4/8 tightly binds and protects LPL but also partially inhibits its activity. Recently, we demonstrated ANGPTL4/8 also binds tissue plasminogen activator (tPA) and plasminogen to generate plasmin that cleaves ANGPTL4/8 to restore LPL activity. Although fully active LPL in the fat postprandially is desirable, ANGPTL4/8 removal could subject LPL to profound inhibition by ANGPTL3/8 (the most potent circulating LPL inhibitor), inhibition by other LPL inhibitors like ANGPTL4, ANGPTL3, and ApoC3 or interfere with ApoC2-mediated LPL activation. To understand better these potential paradoxes, we examined LPL inhibition by ANGPTL3/8, ANGPTL4, ANGPTL3, and ApoC3 and LPL stimulation by ApoC2 in the presence of ANGPTL4/8 + tPA + plasminogen. Remarkably, ANGPTL3/8-mediated LPL inhibition was almost completely blocked, with the mechanism being cleavage of fibrinogen-like domain-containing ANGPTL3 present in the ANGPTL3/8 complex. The LPL-inhibitory effects of ANGPTL4, ANGPTL3, and ApoC3 were also largely reduced in the presence of ANGPTL4/8 + tPA + plasminogen. In contrast, the ability of ApoC2 to stimulate LPL activity was unaffected by ANGPTL4/8-mediated plasmin generation. Together, these results explain how plasmin generated by increased postprandial ANGPTL4/8 levels in adipose tissue enables maximal LPL activity by preventing ANGPTL3/8, ANGPTL4, ANGPTL3, and ApoC3 from inhibiting LPL, while permitting ApoC2-mediated LPL activation to occur.
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Affiliation(s)
- Yan Q Chen
- Lilly Research Laboratories, Eli Lilly, and Company, Indianapolis, IN, USA
| | - Eugene Y Zhen
- Lilly Research Laboratories, Eli Lilly, and Company, Indianapolis, IN, USA
| | - Anna M Russell
- Lilly Research Laboratories, Eli Lilly, and Company, Indianapolis, IN, USA
| | - Mariam Ehsani
- Lilly Research Laboratories, Eli Lilly, and Company, Indianapolis, IN, USA
| | - Robert W Siegel
- Lilly Research Laboratories, Eli Lilly, and Company, Indianapolis, IN, USA
| | - Yuewei Qian
- Lilly Research Laboratories, Eli Lilly, and Company, Indianapolis, IN, USA
| | - Robert J Konrad
- Lilly Research Laboratories, Eli Lilly, and Company, Indianapolis, IN, USA.
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12
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Sylvers-Davie KL, Bierstedt KC, Schnieders MJ, Davies BSJ. Endothelial Lipase Variant, T111I, Does Not Alter Inhibition by Angiopoietin-like Proteins. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.18.553740. [PMID: 37693454 PMCID: PMC10491130 DOI: 10.1101/2023.08.18.553740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
High levels of HDL-C are correlated with a decreased risk of cardiovascular disease. HDL-C levels are modulated in part by the secreted phospholipase, endothelial lipase (EL), which hydrolyzes the phospholipids of HDL and decreases circulating HDL-C concentrations. A 584C/T polymorphism in LIPG, the gene which encodes EL, was first identified in individuals with increased HDL levels. This polymorphism results in a T111I point mutation the EL protein. The association between this variant, HDL levels, and the risk of coronary artery disease (CAD) in humans has been extensively studied, but the findings have been inconsistent. In this study, we took a biochemical approach, investigating how the T111I variant affected EL activity, structure, and stability. Moreover, we tested whether the T111I variant altered the inhibition of phospholipase activity by angiopoietin-like 3 (ANGPTL3) and angiopoietin-like 4 (ANGPTL4), two known EL inhibitors. We found that neither the stability nor enzymatic activity of EL was altered by the T111I variant. Moreover, we found no difference between wild-type and T111I EL in their ability to be inhibited by ANGPTL proteins. These data suggest that any effect this variant may have on HDL-C levels or cardiovascular disease are not mediated through alterations in these functions.
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Affiliation(s)
- Kelli L. Sylvers-Davie
- Department of Biochemistry and Molecular Biology, University of Iowa, Iowa City, IA 52242
- Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA 52242
| | - Kaleb C. Bierstedt
- Department of Biochemistry and Molecular Biology, University of Iowa, Iowa City, IA 52242
- Department of Biomedical Engineering, University of Iowa, Iowa City, IA 52242
| | - Michael J. Schnieders
- Department of Biochemistry and Molecular Biology, University of Iowa, Iowa City, IA 52242
- Department of Biomedical Engineering, University of Iowa, Iowa City, IA 52242
| | - Brandon S. J. Davies
- Department of Biochemistry and Molecular Biology, University of Iowa, Iowa City, IA 52242
- Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA 52242
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13
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Sviridov D, Dasseux A, Reimund M, Pryor M, Drake SK, Jarin Z, Wolska A, Pastor RW, Remaley AT. Short hydrocarbon stapled ApoC2-mimetic peptides activate lipoprotein lipase and lower plasma triglycerides in mice. Front Cardiovasc Med 2023; 10:1223920. [PMID: 37547254 PMCID: PMC10403075 DOI: 10.3389/fcvm.2023.1223920] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 07/11/2023] [Indexed: 08/08/2023] Open
Abstract
Introduction Defects in lipolysis can lead to hypertriglyceridemia, which can trigger acute pancreatitis and is also associated with cardiovascular disease. Decreasing plasma triglycerides (TGs) by activating lipoprotein lipase (LPL) with ApoC2 mimetic peptides is a new treatment strategy for hypertriglyceridemia. We recently described a dual ApoC2 mimetic/ApoC3 antagonist peptide called D6PV that effectively lowered TG in several mouse models but has limitations in terms of drug development. The aim of this study was to create the next generation of ApoC2 mimetic peptides. Methods We employed hydrocarbon staples, as well as select amino acid substitutions, to make short single helical mimetic peptides based on the last helix of ApoC2. Peptides were first tested for their ability to activate LPL and then in hypertriglyceridemia mouse models. All-atom simulations of peptides were performed in a lipid-trilayer model of TG-rich lipoproteins to discern their possible mechanism of action. Results We designed a single stapled peptide called SP1 (21 residues), and a double stapled (stitched) peptide called SP2 (21 residues) and its N-terminal acylated analogue, SP2a. The hydrocarbon staples increased the amphipathicity of the peptides and their ability to bind lipids without interfering with LPL activation. Indeed, from all-atom simulations, the conformations of SP1 and SP2a are restrained by the staples and maintains the proper orientation of the LPL activation motif, while still allowing their deeper insertion into the lipid-trilayer model. Intraperitoneal injection of stapled peptides (1-5 umoles/kg) into ApoC2-hypomorphic mice or human ApoC3-transgenic resulted in an 80%-90% reduction in plasma TG within 3 h, similar to the much longer D6PV peptide (41 residues). Other modifications (replacement L-Glu20, L-Glu21 with their D-isomers, N-methylation of Gly19, Met2NorLeu and Ala1alpha-methylAla substitutions, N-terminal octanoylation) were introduced into the SP2a peptide. These changes made SP2a highly resistant to proteolysis against trypsin, pepsin, and Proteinase K, while maintaining similar efficacy in lowering plasma TG in mice. Conclusion We describe a new generation of ApoC2 mimetic peptides based on hydron carbon stapling that are at least equally potent to earlier peptides but are much shorter and resistant to proteolysis and could be further developed into a new therapy for hypertriglyceridemia.
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Affiliation(s)
- Denis Sviridov
- Laboratory of Lipoprotein Metabolism, Translational Vascular Medicine Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, United States
| | - Amaury Dasseux
- Laboratory of Lipoprotein Metabolism, Translational Vascular Medicine Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, United States
| | - Mart Reimund
- Laboratory of Lipoprotein Metabolism, Translational Vascular Medicine Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, United States
| | - Milton Pryor
- Laboratory of Lipoprotein Metabolism, Translational Vascular Medicine Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, United States
| | - Steven K. Drake
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, United States
| | - Zack Jarin
- Laboratory of Computational Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, United States
| | - Anna Wolska
- Laboratory of Lipoprotein Metabolism, Translational Vascular Medicine Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, United States
| | - Richard W. Pastor
- Laboratory of Computational Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, United States
| | - Alan T. Remaley
- Laboratory of Lipoprotein Metabolism, Translational Vascular Medicine Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, United States
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14
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Kumari A, Grønnemose AL, Kristensen KK, Winther AML, Young SG, Jørgensen TJD, Ploug M. Inverse effects of APOC2 and ANGPTL4 on the conformational dynamics of lid-anchoring structures in lipoprotein lipase. Proc Natl Acad Sci U S A 2023; 120:e2221888120. [PMID: 37094117 PMCID: PMC10160976 DOI: 10.1073/pnas.2221888120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 03/28/2023] [Indexed: 04/26/2023] Open
Abstract
The lipolytic processing of triglyceride-rich lipoproteins (TRLs) by lipoprotein lipase (LPL) is crucial for the delivery of dietary lipids to the heart, skeletal muscle, and adipose tissue. The processing of TRLs by LPL is regulated in a tissue-specific manner by a complex interplay between activators and inhibitors. Angiopoietin-like protein 4 (ANGPTL4) inhibits LPL by reducing its thermal stability and catalyzing the irreversible unfolding of LPL's α/β-hydrolase domain. We previously mapped the ANGPTL4 binding site on LPL and defined the downstream unfolding events resulting in LPL inactivation. The binding of LPL to glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1 protects against LPL unfolding. The binding site on LPL for an activating cofactor, apolipoprotein C2 (APOC2), and the mechanisms by which APOC2 activates LPL have been unclear and controversial. Using hydrogen-deuterium exchange/mass spectrometry, we now show that APOC2's C-terminal α-helix binds to regions of LPL surrounding the catalytic pocket. Remarkably, APOC2's binding site on LPL overlaps with that for ANGPTL4, but their effects on LPL conformation are distinct. In contrast to ANGPTL4, APOC2 increases the thermal stability of LPL and protects it from unfolding. Also, the regions of LPL that anchor the lid are stabilized by APOC2 but destabilized by ANGPTL4, providing a plausible explanation for why APOC2 is an activator of LPL, while ANGPTL4 is an inhibitor. Our studies provide fresh insights into the molecular mechanisms by which APOC2 binds and stabilizes LPL-and properties that we suspect are relevant to the conformational gating of LPL's active site.
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Affiliation(s)
- Anni Kumari
- Finsen Laboratory, Copenhagen University Hospital-Rigshospitalet, DK-2200Copenhagen N, Denmark
- Finsen Laboratory, Biotech Research and Innovation Centre, University of Copenhagen, DK-2200Copenhagen N, Denmark
| | - Anne Louise Grønnemose
- Finsen Laboratory, Copenhagen University Hospital-Rigshospitalet, DK-2200Copenhagen N, Denmark
- Finsen Laboratory, Biotech Research and Innovation Centre, University of Copenhagen, DK-2200Copenhagen N, Denmark
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK–5320Odense, Denmark
| | - Kristian K. Kristensen
- Finsen Laboratory, Copenhagen University Hospital-Rigshospitalet, DK-2200Copenhagen N, Denmark
- Finsen Laboratory, Biotech Research and Innovation Centre, University of Copenhagen, DK-2200Copenhagen N, Denmark
| | - Anne-Marie L. Winther
- Finsen Laboratory, Copenhagen University Hospital-Rigshospitalet, DK-2200Copenhagen N, Denmark
- Finsen Laboratory, Biotech Research and Innovation Centre, University of Copenhagen, DK-2200Copenhagen N, Denmark
| | - Stephen G. Young
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Thomas J. D. Jørgensen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK–5320Odense, Denmark
| | - Michael Ploug
- Finsen Laboratory, Copenhagen University Hospital-Rigshospitalet, DK-2200Copenhagen N, Denmark
- Finsen Laboratory, Biotech Research and Innovation Centre, University of Copenhagen, DK-2200Copenhagen N, Denmark
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15
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Burks KH, Basu D, Goldberg IJ, Stitziel NO. Angiopoietin-like 3: An important protein in regulating lipoprotein levels. Best Pract Res Clin Endocrinol Metab 2023; 37:101688. [PMID: 35999139 PMCID: PMC9922336 DOI: 10.1016/j.beem.2022.101688] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
ANGPTL3 has emerged as a therapeutic target whose inhibition results in profound reductions of plasma lipids, including atherogenic triglyceride-rich lipoproteins and low-density lipoprotein cholesterol. The identification of ANGPTL3 deficiency as a cause of familial combined hypolipidemia in humans hastened the development of anti-ANGPTL3 therapeutic agents, including evinacumab (a monoclonal antibody inhibiting circulating ANGPTL3), vupanorsen (an antisense oligonucleotide [ASO] targeting hepatic ANGPTL3 mRNA for degradation), and others. Advances have also been made in ANGPTL3 vaccination and gene editing strategies, with the former still in preclinical phases and the latter in preparation for Phase 1 trials. Here, we review the discovery of ANGPTL3 as an important regulator of lipoprotein metabolism, molecular characteristics of the protein, mechanisms by which it regulates plasma lipids, and the clinical development of anti-ANGPTL3 agents. The clinical success of therapies inhibiting ANGPTL3 highlights the importance of this target as a novel approach in treating refractory hypertriglyceridemia and hypercholesterolemia.
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Affiliation(s)
- Kendall H Burks
- Center for Cardiovascular Research, Division of Cardiology, Department of Medicine, Washington University School of Medicine, Saint Louis, MO, USA; Medical Scientist Training Program, Washington University School of Medicine, Saint Louis, MO, USA
| | - Debapriya Basu
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, New York University Grossman School of Medicine, New York, NY, USA
| | - Ira J Goldberg
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, New York University Grossman School of Medicine, New York, NY, USA
| | - Nathan O Stitziel
- Center for Cardiovascular Research, Division of Cardiology, Department of Medicine, Washington University School of Medicine, Saint Louis, MO, USA; Department of Genetics, Washington University School of Medicine, Saint Louis, MO, USA; McDonnell Genome Institute, Washington University School of Medicine, Saint Louis, MO, USA.
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16
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Risti R, Gunn KH, Hiis-Hommuk K, Seeba NN, Karimi H, Villo L, Vendelin M, Neher SB, Lõokene A. Combined action of albumin and heparin regulates lipoprotein lipase oligomerization, stability, and ligand interactions. PLoS One 2023; 18:e0283358. [PMID: 37043509 PMCID: PMC10096250 DOI: 10.1371/journal.pone.0283358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 03/07/2023] [Indexed: 04/13/2023] Open
Abstract
Lipoprotein lipase (LPL), a crucial enzyme in the intravascular hydrolysis of triglyceride-rich lipoproteins, is a potential drug target for the treatment of hypertriglyceridemia. The activity and stability of LPL are influenced by a complex ligand network. Previous studies performed in dilute solutions suggest that LPL can appear in various oligomeric states. However, it was not known how the physiological environment, that is blood plasma, affects the action of LPL. In the current study, we demonstrate that albumin, the major protein component in blood plasma, has a significant impact on LPL stability, oligomerization, and ligand interactions. The effects induced by albumin could not solely be reproduced by the macromolecular crowding effect. Stabilization, isothermal titration calorimetry, and surface plasmon resonance studies revealed that albumin binds to LPL with affinity sufficient to form a complex in both the interstitial space and the capillaries. Negative stain transmission electron microscopy and raster image correlation spectroscopy showed that albumin, like heparin, induced reversible oligomerization of LPL. However, the albumin induced oligomers were structurally different from heparin-induced filament-like LPL oligomers. An intriguing observation was that no oligomers of either type were formed in the simultaneous presence of albumin and heparin. Our data also suggested that the oligomer formation protected LPL from the inactivation by its physiological regulator angiopoietin-like protein 4. The concentration of LPL and its environment could influence whether LPL follows irreversible inactivation and aggregation or reversible LPL oligomer formation, which might affect interactions with various ligands and drugs. In conclusion, the interplay between albumin and heparin could provide a mechanism for ensuring the dissociation of heparan sulfate-bound LPL oligomers into active LPL upon secretion into the interstitial space.
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Affiliation(s)
- Robert Risti
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Tallinn, Estonia
| | - Kathryn H. Gunn
- Department of Biochemistry and Biophysics, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Kristofer Hiis-Hommuk
- Laboratory of Systems Biology, Department of Cybernetics, Tallinn University of Technology, Tallinn, Estonia
| | - Natjan-Naatan Seeba
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Tallinn, Estonia
| | - Hamed Karimi
- Laboratory of Systems Biology, Department of Cybernetics, Tallinn University of Technology, Tallinn, Estonia
| | - Ly Villo
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Tallinn, Estonia
| | - Marko Vendelin
- Laboratory of Systems Biology, Department of Cybernetics, Tallinn University of Technology, Tallinn, Estonia
| | - Saskia B. Neher
- Department of Biochemistry and Biophysics, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Aivar Lõokene
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Tallinn, Estonia
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17
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Nartea R, Mitoiu BI, Ghiorghiu I. The Link between Magnesium Supplements and Statin Medication in Dyslipidemic Patients. Curr Issues Mol Biol 2023; 45:3146-3167. [PMID: 37185729 PMCID: PMC10136538 DOI: 10.3390/cimb45040205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 03/15/2023] [Accepted: 03/16/2023] [Indexed: 05/17/2023] Open
Abstract
Many investigations have discovered a connection between statins and magnesium supplements. On one hand, increasing research suggests that chronic hypomagnesemia may be an important factor in the etiology of some metabolic illnesses, including obesity and overweight, insulin resistance and type 2 diabetes mellitus, hypertension, alterations in lipid metabolism, and low-grade inflammation. Chronic metabolic problems seem to be prevented by a high Mg intake combined with diet and/or supplements. On the other hand, it is known that statins lower the frequency of cardiac events, stroke, and mortality, not by lowering LDL-C, but by the capacity to reduce mevalonate formation. That will enhance endothelial function, inhibit vascular smooth muscle cell proliferation and migration and encourage macrophages to promote plaque stability and regression while reducing inflammation. Taking these factors into consideration, we did an extensive analysis of the relevant literature, comparing the effects of Mg2 and statin medications on lipoproteins and, implicitly, on the key enzymes involved in cholesterol metabolism.
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Affiliation(s)
- Roxana Nartea
- Clinical Department 9, Carol Davila University of Medicine and Pharmacy, 050474 Bucharest, Romania
- National Institute for Rehabilitation, Physical Medicine and Balneoclimatology, 030079 Bucharest, Romania
| | - Brindusa Ilinca Mitoiu
- Clinical Department 9, Carol Davila University of Medicine and Pharmacy, 050474 Bucharest, Romania
- Agrippa Ionescu Clinical Emergency Hospital, 077016 Bucharest, Romania
| | - Ioana Ghiorghiu
- Clinical Department 9, Carol Davila University of Medicine and Pharmacy, 050474 Bucharest, Romania
- National Institute for Rehabilitation, Physical Medicine and Balneoclimatology, 030079 Bucharest, Romania
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18
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Song W, Yang Y, Heizer P, Tu Y, Weston TA, Kim JR, Munguia P, Jung H, Fong JLC, Tran C, Ploug M, Beigneux AP, Young SG, Fong LG. Intracapillary LPL levels in brown adipose tissue, visualized with an antibody-based approach, are regulated by ANGPTL4 at thermoneutral temperatures. Proc Natl Acad Sci U S A 2023; 120:e2219833120. [PMID: 36787365 PMCID: PMC9974459 DOI: 10.1073/pnas.2219833120] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 01/18/2023] [Indexed: 02/15/2023] Open
Abstract
Lipoprotein lipase (LPL) is secreted into the interstitial spaces by parenchymal cells and then transported into capillaries by GPIHBP1. LPL carries out the lipolytic processing of triglyceride (TG)-rich lipoproteins (TRLs), but the tissue-specific regulation of LPL is incompletely understood. Plasma levels of TG hydrolase activity after heparin injection are often used to draw inferences about intravascular LPL levels, but the validity of these inferences is unclear. Moreover, plasma TG hydrolase activity levels are not helpful for understanding LPL regulation in specific tissues. Here, we sought to elucidate LPL regulation under thermoneutral conditions (30 °C). To pursue this objective, we developed an antibody-based method to quantify (in a direct fashion) LPL levels inside capillaries. At 30 °C, intracapillary LPL levels fell sharply in brown adipose tissue (BAT) but not heart. The reduced intracapillary LPL levels were accompanied by reduced margination of TRLs along capillaries. ANGPTL4 expression in BAT increased fourfold at 30 °C, suggesting a potential explanation for the lower intracapillary LPL levels. Consistent with that idea, Angptl4 deficiency normalized both LPL levels and TRL margination in BAT at 30 °C. In Gpihbp1-/- mice housed at 30 °C, we observed an ANGPTL4-dependent decrease in LPL levels within the interstitial spaces of BAT, providing in vivo proof that ANGPTL4 regulates LPL levels before LPL transport into capillaries. In conclusion, our studies have illuminated intracapillary LPL regulation under thermoneutral conditions. Our approaches will be useful for defining the impact of genetic variation and metabolic disease on intracapillary LPL levels and TRL processing.
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Affiliation(s)
- Wenxin Song
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Ye Yang
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Patrick Heizer
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Yiping Tu
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Thomas A. Weston
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Joonyoung R. Kim
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Priscilla Munguia
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Hyesoo Jung
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Jared L.-C. Fong
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Caitlyn Tran
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Michael Ploug
- Finsen Laboratory, RigshospitaletDK-2200Copenhagen N, Denmark
- Biotech Research and Innovation Centre, University of CopenhagenDK-220Copenhagen N, Denmark
| | - Anne P. Beigneux
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Stephen G. Young
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Loren G. Fong
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
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Zhen EY, Chen YQ, Russell AM, Ehsani M, Siegel RW, Qian Y, Konrad RJ. Angiopoietin-like protein 4/8 complex-mediated plasmin generation leads to cleavage of the complex and restoration of LPL activity. Proc Natl Acad Sci U S A 2023; 120:e2214081120. [PMID: 36763533 PMCID: PMC9963551 DOI: 10.1073/pnas.2214081120] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 01/09/2023] [Indexed: 02/11/2023] Open
Abstract
Triglyceride (TG) metabolism is highly regulated by angiopoietin-like protein (ANGPTL) family members [Y. Q. Chen et al., J. Lipid Res. 61, 1203-1220 (2020)]. During feeding, ANGPTL8 forms complexes with the fibrinogen-like domain-containing protein ANGPTL4 in adipose tissue to decrease ANGPTL3/8- and ANGPTL4-mediated lipoprotein lipase (LPL)-inhibitory activity and promote TG hydrolysis and fatty acid (FA) uptake. The ANGPTL4/8 complex, however, tightly binds LPL and partially inhibits it in vitro. To try to reconcile the in vivo and in vitro data on ANGPTL4/8, we aimed to find novel binding partners of ANGPTL4/8. To that end, we performed pulldown experiments and found that ANGPTL4/8 bound both tissue plasminogen activator (tPA) and plasminogen, the precursor of the fibrinolytic enzyme plasmin. Remarkably, ANGPTL4/8 enhanced tPA activation of plasminogen to generate plasmin in a manner like that observed with fibrin, while minimal plasmin generation was observed with ANGPTL4 alone. The addition of tPA and plasminogen to LPL-bound ANGPTL4/8 caused rapid, complete ANGPTL4/8 cleavage and increased LPL activity. Restoration of LPL activity in the presence of ANGPTL4/8 was also achieved with plasmin but was blocked when catalytically inactive plasminogen (S760A) was added to tPA or when plasminogen activator inhibitor-1 was added to tPA + plasminogen, indicating that conversion of plasminogen to plasmin was essential. Together, these results suggest that LPL-bound ANGPTL4/8 mimics fibrin to recruit tPA and plasminogen to generate plasmin, which then cleaves ANGPTL4/8, enabling LPL activity to be increased. Our observations thus reveal a unique link between the ANGPTL4/8 complex and plasmin generation.
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Affiliation(s)
- Eugene Y. Zhen
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN46225
| | - Yan Q. Chen
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN46225
| | - Anna M. Russell
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN46225
| | - Mariam Ehsani
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN46225
| | - Robert W. Siegel
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN46225
| | - Yuewei Qian
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN46225
| | - Robert J. Konrad
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN46225
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Gu X, Wang L, Liu S, Shan T. Adipose tissue adipokines and lipokines: Functions and regulatory mechanism in skeletal muscle development and homeostasis. Metabolism 2023; 139:155379. [PMID: 36538987 DOI: 10.1016/j.metabol.2022.155379] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 11/29/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022]
Abstract
Skeletal muscle plays important roles in normal biological activities and whole-body energy homeostasis in humans. The growth and development of skeletal muscle also directly influence meat production and meat quality in animal production. Therefore, regulating the development and homeostasis of skeletal muscle is crucial for human health and animal production. Adipose tissue, which includes white adipose tissue (WAT) and brown adipose tissue (BAT), not only functions as an energy reserve but also has attracted substantial attention because of its role as an endocrine organ. The novel signalling molecules known as "adipokines" and "lipokines" that are secreted by adipose tissue were identified through the secretomic technique, which broadened our understanding of the previously unknown crosstalk between adipose tissue and skeletal muscle. In this review, we summarize and discuss the secretory role of adipose tissues, both WAT and BAT, as well as the regulatory roles of various adipokines and lipokines in skeletal muscle development and homeostasis. We suggest that adipokines and lipokines have potential as drug candidates for the treatment of skeletal muscle dysfunction and related metabolic diseases and as promising nutrients for improving animal production.
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Affiliation(s)
- Xin Gu
- College of Animal Sciences, Zhejiang University, Hangzhou, China; Key Laboratory of Molecular Animal Nutrition, Zhejiang University, Ministry of Education, China; Key Laboratory of Animal Feed and Nutrition of Zhejiang Province, Hangzhou, China
| | - Liyi Wang
- College of Animal Sciences, Zhejiang University, Hangzhou, China; Key Laboratory of Molecular Animal Nutrition, Zhejiang University, Ministry of Education, China; Key Laboratory of Animal Feed and Nutrition of Zhejiang Province, Hangzhou, China
| | - Shiqi Liu
- College of Animal Sciences, Zhejiang University, Hangzhou, China; Key Laboratory of Molecular Animal Nutrition, Zhejiang University, Ministry of Education, China; Key Laboratory of Animal Feed and Nutrition of Zhejiang Province, Hangzhou, China
| | - Tizhong Shan
- College of Animal Sciences, Zhejiang University, Hangzhou, China; Key Laboratory of Molecular Animal Nutrition, Zhejiang University, Ministry of Education, China; Key Laboratory of Animal Feed and Nutrition of Zhejiang Province, Hangzhou, China.
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21
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Pregnancy Toxemia in Ewes: A Review of Molecular Metabolic Mechanisms and Management Strategies. Metabolites 2023; 13:metabo13020149. [PMID: 36837768 PMCID: PMC9961611 DOI: 10.3390/metabo13020149] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Revised: 01/09/2023] [Accepted: 01/17/2023] [Indexed: 01/20/2023] Open
Abstract
Pregnancy toxemia is a nutritional metabolic disease during late gestation in small ruminants. The condition is characterized by disorders in carbohydrate and fat metabolism. Obese and multiparous ewes are particularly susceptible to pregnancy toxemia, which may lead to maternal death, abortion, or premature birth. Highly productive multiparous meat ewes are major breeding animals, which has led to an increased incidence of the disease. However, the pathogenesis of pregnancy toxemia remains unclear and adequate disease prevention and treatment strategies are absent. Investigating the pathogenesis of pregnancy toxemia, especially the metabolic pathways of hepatic lipids, is key to an improved understanding of the condition. This review provides a snapshot of the genes that are associated with lipid metabolism in the ovine liver, including genes involved in fatty acid oxidation, acetyl coenzyme metabolism, and triglyceride synthesis; describes the interrelationships between these genes; and summarizes the diagnosis, prevention, and treatment of pregnancy toxemia.
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22
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Górecka M, Krzemiński K, Mikulski T, Ziemba AW. ANGPTL4, IL-6 and TNF-α as regulators of lipid metabolism during a marathon run. Sci Rep 2022; 12:19940. [PMID: 36402848 PMCID: PMC9675781 DOI: 10.1038/s41598-022-17439-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 07/25/2022] [Indexed: 11/21/2022] Open
Abstract
The aim of the study was to reveal whether marathon running influences regulators of lipid metabolism i.e. angiopoietin-like protein 4 (ANGPTL4), interleukin 6 (IL-6) and tumor necrosis factor-α (TNF-α). Plasma concentration of ANGPTL4, IL-6, TNF-α and lipids were determined in samples collected from 11 male runners before the marathon, immediately after the run and at 90 min of recovery. Plasma ANGPTL4 increased during exercise from 55.5 ± 13.4 to 78.1 ± 15.0 ng/ml (P < 0.001). This was accompanied by a significant increase in IL-6, TNF-α, free fatty acids (FFA) and glycerol (Gly) and a decrease in triacylglycerols (TG). After 90 min of recovery ANGPTL4 and TG did not differ from the exercise values, while plasma IL-6, TNF-α, FFA and Gly concentration were significantly lower. The exercise-induced increase in plasma concentration of ANGPTL4 correlated positively with the rise in plasma IL-6, TNF-α, FFA and Gly and negatively with the duration of the run. The increase in plasma IL-6 and TNF-α correlated positively with the rise in Gly. Summarizing, marathon running induced an increase in plasma ANGPTL4 and the value was higher in faster runners. The increase in plasma FFA, IL-6 and TNF-α concentration during a marathon run may be involved in plasma ANGPTL4 release, which could be a compensatory mechanism against FFA-induced lipotoxicity and oxidative stress. All of the analyzed cytokines may stimulate lipolysis during exercise.
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Affiliation(s)
- Monika Górecka
- grid.413454.30000 0001 1958 0162Clinical and Research Department of Applied Physiology, Mossakowski Medical Research Institute, Polish Academy of Sciences, 5 Pawińskiego Street, 02-106 Warsaw, Poland
| | - Krzysztof Krzemiński
- grid.413454.30000 0001 1958 0162Clinical and Research Department of Applied Physiology, Mossakowski Medical Research Institute, Polish Academy of Sciences, 5 Pawińskiego Street, 02-106 Warsaw, Poland
| | - Tomasz Mikulski
- grid.413454.30000 0001 1958 0162Clinical and Research Department of Applied Physiology, Mossakowski Medical Research Institute, Polish Academy of Sciences, 5 Pawińskiego Street, 02-106 Warsaw, Poland
| | - Andrzej Wojciech Ziemba
- grid.413454.30000 0001 1958 0162Clinical and Research Department of Applied Physiology, Mossakowski Medical Research Institute, Polish Academy of Sciences, 5 Pawińskiego Street, 02-106 Warsaw, Poland
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23
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Wang Y, Liu L, Liu X, Tan X, Zhu Y, Luo N, Zhao G, Cui H, Wen J. SLC16A7 Promotes Triglyceride Deposition by De Novo Lipogenesis in Chicken Muscle Tissue. BIOLOGY 2022; 11:1547. [PMID: 36358250 PMCID: PMC9687483 DOI: 10.3390/biology11111547] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 09/22/2022] [Accepted: 10/08/2022] [Indexed: 07/30/2023]
Abstract
Triglyceride (TG) content in chicken muscle tissue signifies intramuscular fat (IMF) content, which is important for improving meat quality. However, the genetic basis of TG deposition in chicken is still unclear. Using 520 chickens from an artificially selected line with significantly increased IMF content and a control line, a genome-wide association study (GWAS) with TG content reports a region of 802 Kb located in chromosome 1. The XP-EHH and gene expression analysis together reveal that the solute carrier family 16 member A7 (SLC16A7) gene is the key candidate gene associated with TG content in chicken muscle tissue. Furthermore, the weighted gene co-expression network analysis (WGCNA) confirmed the regulatory effects of SLC16A7 on promoting TG deposition by de novo lipogenesis (DNL). Functional verification of SLC16A7 in vitro also supports this view, and reveals that this effect mainly occurs in myocytes. Our data highlight a potential IMF deposition pathway by DNL, induced by SLC16A7 in chicken myocytes. These findings will improve the understanding of IMF regulation in chicken and guide the formulation of breeding strategies for high-quality chicken.
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Affiliation(s)
- Yongli Wang
- State Key Laboratory of Animal Nutrition, Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Lu Liu
- College of Animal Science and Technology, College of Veterinary Medicine of Zhejiang A&F University, Hangzhou 311300, China
| | - Xiaojing Liu
- State Key Laboratory of Animal Nutrition, Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Xiaodong Tan
- State Key Laboratory of Animal Nutrition, Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Yuting Zhu
- State Key Laboratory of Animal Nutrition, Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Na Luo
- State Key Laboratory of Animal Nutrition, Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Guiping Zhao
- State Key Laboratory of Animal Nutrition, Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Huanxian Cui
- State Key Laboratory of Animal Nutrition, Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Jie Wen
- State Key Laboratory of Animal Nutrition, Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China
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Wen Y, Chen YQ, Konrad RJ. The Regulation of Triacylglycerol Metabolism and Lipoprotein Lipase Activity. Adv Biol (Weinh) 2022; 6:e2200093. [PMID: 35676229 DOI: 10.1002/adbi.202200093] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 05/03/2022] [Indexed: 01/28/2023]
Abstract
Triacylglycerol (TG) metabolism is tightly regulated to maintain a pool of TG within circulating lipoproteins that can be hydrolyzed in a tissue-specific manner by lipoprotein lipase (LPL) to enable the delivery of fatty acids to adipose or oxidative tissues as needed. Elevated serum TG concentrations, which result from a deficiency of LPL activity or, more commonly, an imbalance in the regulation of tissue-specific LPL activities, have been associated with an increased risk of atherosclerotic cardiovascular disease through multiple studies. Among the most critical LPL regulators are the angiopoietin-like (ANGPTL) proteins ANGPTL3, ANGPTL4, and ANGPTL8, and a number of different apolipoproteins including apolipoprotein A5 (ApoA5), apolipoprotein C2 (ApoC2), and apolipoprotein C3 (ApoC3). These ANGPTLs and apolipoproteins work together to orchestrate LPL activity and therefore play pivotal roles in TG partitioning, hydrolysis, and utilization. This review summarizes the mechanisms of action, epidemiological findings, and genetic data most relevant to these ANGPTLs and apolipoproteins. The interplay between these important regulators of TG metabolism in both fasted and fed states is highlighted with a holistic view toward understanding key concepts and interactions. Strategies for developing safe and effective therapeutics to reduce circulating TG by selectively targeting these ANGPTLs and apolipoproteins are also discussed.
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Affiliation(s)
- Yi Wen
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, 46285, USA
| | - Yan Q Chen
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, 46285, USA
| | - Robert J Konrad
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, 46285, USA
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Young SG, Song W, Yang Y, Birrane G, Jiang H, Beigneux AP, Ploug M, Fong LG. A protein of capillary endothelial cells, GPIHBP1, is crucial for plasma triglyceride metabolism. Proc Natl Acad Sci U S A 2022; 119:e2211136119. [PMID: 36037340 PMCID: PMC9457329 DOI: 10.1073/pnas.2211136119] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 07/18/2022] [Indexed: 11/18/2022] Open
Abstract
GPIHBP1, a protein of capillary endothelial cells (ECs), is a crucial partner for lipoprotein lipase (LPL) in the lipolytic processing of triglyceride-rich lipoproteins. GPIHBP1, which contains a three-fingered cysteine-rich LU (Ly6/uPAR) domain and an intrinsically disordered acidic domain (AD), captures LPL from within the interstitial spaces (where it is secreted by parenchymal cells) and shuttles it across ECs to the capillary lumen. Without GPIHBP1, LPL remains stranded within the interstitial spaces, causing severe hypertriglyceridemia (chylomicronemia). Biophysical studies revealed that GPIHBP1 stabilizes LPL structure and preserves LPL activity. That discovery was the key to crystallizing the GPIHBP1-LPL complex. The crystal structure revealed that GPIHBP1's LU domain binds, largely by hydrophobic contacts, to LPL's C-terminal lipid-binding domain and that the AD is positioned to project across and interact, by electrostatic forces, with a large basic patch spanning LPL's lipid-binding and catalytic domains. We uncovered three functions for GPIHBP1's AD. First, it accelerates the kinetics of LPL binding. Second, it preserves LPL activity by inhibiting unfolding of LPL's catalytic domain. Third, by sheathing LPL's basic patch, the AD makes it possible for LPL to move across ECs to the capillary lumen. Without the AD, GPIHBP1-bound LPL is trapped by persistent interactions between LPL and negatively charged heparan sulfate proteoglycans (HSPGs) on the abluminal surface of ECs. The AD interrupts the HSPG interactions, freeing LPL-GPIHBP1 complexes to move across ECs to the capillary lumen. GPIHBP1 is medically important; GPIHBP1 mutations cause lifelong chylomicronemia, and GPIHBP1 autoantibodies cause some acquired cases of chylomicronemia.
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Affiliation(s)
- Stephen G. Young
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - Wenxin Song
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - Ye Yang
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - Gabriel Birrane
- Division of Experimental Medicine, Beth Israel Deaconess Medical Center, Boston, MA 02215
| | - Haibo Jiang
- Department of Chemistry, The University of Hong Kong, Hong Kong, China
| | - Anne P. Beigneux
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - Michael Ploug
- Finsen Laboratory, Rigshospitalet, Copenhagen 2200N, Denmark
- Biotech Research and Innovation Centre, University of Copenhagen, Copenhagen, Denmark
| | - Loren G. Fong
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
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Oldham D, Wang H, Mullen J, Lietzke E, Sprenger K, Reigan P, Eckel RH, Bruce KD. Using Synthetic ApoC-II Peptides and nAngptl4 Fragments to Measure Lipoprotein Lipase Activity in Radiometric and Fluorescent Assays. Front Cardiovasc Med 2022; 9:926631. [PMID: 35911520 PMCID: PMC9329559 DOI: 10.3389/fcvm.2022.926631] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 06/16/2022] [Indexed: 11/13/2022] Open
Abstract
Lipoprotein lipase (LPL) plays a crucial role in preventing dyslipidemia by hydrolyzing triglycerides (TGs) in packaged lipoproteins. Since hypertriglyceridemia (HTG) is a major risk factor for cardiovascular disease (CVD), the leading cause of death worldwide, methods that accurately quantify the hydrolytic activity of LPL in clinical and pre-clinical samples are much needed. To date, the methods used to determine LPL activity vary considerably in their approach, in the LPL substrates used, and in the source of LPL activators and inhibitors used to quantify LPL-specific activity, rather than other lipases, e.g., hepatic lipase (HL) or endothelial lipase (EL) activity. Here, we describe methods recently optimized in our laboratory, using a synthetic ApoC-II peptide to activate LPL, and an n-terminal Angiopoietin-Like 4 fragment (nAngptl4) to inhibit LPL, presenting a cost-effective and reproducible method to measure LPL activity in human post-heparin plasma (PHP) and in LPL-enriched heparin released (HR) fractions from LPL secreting cells. We also describe a modified version of the triolein-based assay using human serum as a source of endogenous activators and inhibitors and to determine the relative abundance of circulating factors that regulate LPL activity. Finally, we describe how an ApoC-II peptide and nAngptl4 can be applied to high-throughput measurements of LPL activity using the EnzChek™ fluorescent TG analog substrate with PHP, bovine LPL, and HR LPL enriched fractions. In summary, this manuscript assesses the current methods of measuring LPL activity and makes new recommendations for measuring LPL-mediated hydrolysis in pre-clinical and clinical samples.
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Affiliation(s)
- Dean Oldham
- Division of Endocrinology, Metabolism and Diabetes, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Hong Wang
- Division of Endocrinology, Metabolism and Diabetes, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Juliet Mullen
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Emma Lietzke
- Department of Chemical Engineering, University of Colorado Boulder, Boulder, CO, United States
| | - Kayla Sprenger
- Department of Chemical Engineering, University of Colorado Boulder, Boulder, CO, United States
| | - Philip Reigan
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Robert H. Eckel
- Division of Endocrinology, Metabolism and Diabetes, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Kimberley D. Bruce
- Division of Endocrinology, Metabolism and Diabetes, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
- *Correspondence: Kimberley D. Bruce,
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Xue Z, Zhuang J, Bai H, Wang L, Lu H, Wang S, Zeng W, Zhang T. VDR mediated HSD3B1 to regulate lipid metabolism and promoted testosterone synthesis in mouse Leydig cells. Genes Genomics 2022; 44:583-592. [PMID: 35254654 DOI: 10.1007/s13258-022-01232-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 02/06/2022] [Indexed: 11/04/2022]
Abstract
BACKGROUND The vitamin D receptor (VDR) mediates the pleiotropic biological actions that include osteoporosis, immune responses and androgen synthesis wherein the VDR transcriptionally regulates expression of the genes involved in this complex process. 3β-Hydroxysteroid dehydrogenase-1 (HSD3B1) is an absolutely necessary enzyme for androgen synthesis. OBJECTIVE The purpose of the present study was to explore the molecular mechanism of VDR mediated HSD3B1 regulation of lipid metabolism and testosterone synthesis. METHODS The levels of VDR, HSD3B1 and lipid metabolism associated protein were determined by quantitative real-time polymerase chain reaction (RT-qPCR) or western blot. The levels of testosterone concentrations in cell culture media serum by enzyme-linked immunosorbent assay (ELISA). Targeted relationship between VDR and Hsd3b1 was evaluated by dual-luciferase reporter assay. RESULTS Based on the data analysis of mouse testicular proteome, we found that the expression of HSD3B1 was significantly reduced after VDR deletion. Here, we identified that Hsd3b1 was widely expressed in different tissues of mice by RT-qPCR, and was highly expressed in testis, and mainly located in testicular Leydig cells. Dual-luciferase assay confirmed that VDR could bind candidate vitamin D responsive elements (VDREs) in upstream region of Hsd3b1, and enhance gene expression. Furthermore, over-expression VDR and HSD3B1 significantly increased testosterone synthesis in mice Leydig cells. Meanwhile, Lpl expression was significantly down-regulated and Angptl4 expression was significantly up-regulated in the present of HSD3B1 overexpression. Both LPL and ANGPTL4 play important roles in regulating lipid metabolism. CONCLUSIONS The present study unveiled VDR mediated HSD3B1 to regulate lipid metabolism and promoted testosterone synthesis in mouse Leydig cells. These findings will greatly help us to understand the roles of VDR and HSD3B1 in testosterone synthesis and lipid metabolism.
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Affiliation(s)
- Zhen Xue
- School of Biological Science and Engineering, Shaanxi University of Technology, Hanzhong, 723001, China
| | - Jianan Zhuang
- School of Biological Science and Engineering, Shaanxi University of Technology, Hanzhong, 723001, China
| | - Hao Bai
- School of Biological Science and Engineering, Shaanxi University of Technology, Hanzhong, 723001, China
| | - Ling Wang
- School of Biological Science and Engineering, Shaanxi University of Technology, Hanzhong, 723001, China
- Shaanxi Province Key Laboratory of Bio-Resources, Shaanxi University of Technology, Hanzhong, 723001, China
- QinLing-Bashan Mountains Bioresources Comprehensive Development C. I. C., Shaanxi University of Technology, Hanzhong, 723001, China
| | - Hongzhao Lu
- School of Biological Science and Engineering, Shaanxi University of Technology, Hanzhong, 723001, China
- QinLing-Bashan Mountains Bioresources Comprehensive Development C. I. C., Shaanxi University of Technology, Hanzhong, 723001, China
- Qinba State Key Laboratory of Biological Resources and Ecological Environment, Shaanxi University of Technology, Hanzhong, 723001, China
| | - Shanshan Wang
- School of Biological Science and Engineering, Shaanxi University of Technology, Hanzhong, 723001, China
| | - Wenxian Zeng
- School of Biological Science and Engineering, Shaanxi University of Technology, Hanzhong, 723001, China
- QinLing-Bashan Mountains Bioresources Comprehensive Development C. I. C., Shaanxi University of Technology, Hanzhong, 723001, China
- Qinba State Key Laboratory of Biological Resources and Ecological Environment, Shaanxi University of Technology, Hanzhong, 723001, China
| | - Tao Zhang
- School of Biological Science and Engineering, Shaanxi University of Technology, Hanzhong, 723001, China.
- QinLing-Bashan Mountains Bioresources Comprehensive Development C. I. C., Shaanxi University of Technology, Hanzhong, 723001, China.
- Qinba State Key Laboratory of Biological Resources and Ecological Environment, Shaanxi University of Technology, Hanzhong, 723001, China.
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Abstract
PURPOSE OF REVIEW Lipoprotein lipase (LPL) is the rate-limiting enzyme for intravascular processing of circulating triglyceride-rich lipoproteins (TRLs). One emerging strategy for therapeutic lowering of plasma triglyceride levels aims at increasing the longevity of LPL activity by attenuating its inhibition from angiopoietin-like proteins (ANGPTL) 3, 4 and 8. This mini-review focuses on recent insights into the molecular mechanisms underpinning the regulation of LPL activity in the intravascular unit by ANGPTLs with special emphasis on ANGPTL4. RECENT FINDINGS Our knowledge on the molecular interplays between LPL, its endothelial transporter GPIHBP1, and its inhibitor(s) ANGPTL4, ANGPTL3 and ANGPTL8 have advanced considerably in the last 2 years and provides an outlined on how these proteins regulate the activity and compartmentalization of LPL. A decisive determinant instigating this control is the inherent protein instability of LPL at normal body temperature, a property that is reciprocally impacted by the binding of GPIHBP1 and ANGPTLs. Additional layers in this complex LPL regulation is provided by the different modulation of ANGPTL4 and ANGPTL3 activities by ANGPTL8 and the inhibition of ANGPTL3/8 complexes by apolipoprotein A5 (APOA5). SUMMARY Posttranslational regulation of LPL activity in the intravascular space is essential for the differential partitioning of TRLs across tissues and their lipolytic processing in response to nutritional cues.
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Affiliation(s)
- Michael Ploug
- Finsen Laboratory, Rigshospitalet
- Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark
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Abstract
Obesity has reached epidemic proportions and is a major contributor to insulin resistance (IR) and type 2 diabetes (T2D). Importantly, IR and T2D substantially increase the risk of cardiovascular (CV) disease. Although there are successful approaches to maintain glycemic control, there continue to be increased CV morbidity and mortality associated with metabolic disease. Therefore, there is an urgent need to understand the cellular and molecular processes that underlie cardiometabolic changes that occur during obesity so that optimal medical therapies can be designed to attenuate or prevent the sequelae of this disease. The vascular endothelium is in constant contact with the circulating milieu; thus, it is not surprising that obesity-driven elevations in lipids, glucose, and proinflammatory mediators induce endothelial dysfunction, vascular inflammation, and vascular remodeling in all segments of the vasculature. As cardiometabolic disease progresses, so do pathological changes in the entire vascular network, which can feed forward to exacerbate disease progression. Recent cellular and molecular data have implicated the vasculature as an initiating and instigating factor in the development of several cardiometabolic diseases. This Review discusses these findings in the context of atherosclerosis, IR and T2D, and heart failure with preserved ejection fraction. In addition, novel strategies to therapeutically target the vasculature to lessen cardiometabolic disease burden are introduced.
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30
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Song W, Beigneux AP, Winther AML, Kristensen KK, Grønnemose AL, Yang Y, Tu Y, Munguia P, Morales J, Jung H, de Jong PJ, Jung CJ, Miyashita K, Kimura T, Nakajima K, Murakami M, Birrane G, Jiang H, Tontonoz P, Ploug M, Fong LG, Young SG. Electrostatic sheathing of lipoprotein lipase is essential for its movement across capillary endothelial cells. J Clin Invest 2022; 132:157500. [PMID: 35229724 PMCID: PMC8884915 DOI: 10.1172/jci157500] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 01/19/2022] [Indexed: 12/18/2022] Open
Abstract
GPIHBP1, an endothelial cell (EC) protein, captures lipoprotein lipase (LPL) within the interstitial spaces (where it is secreted by myocytes and adipocytes) and transports it across ECs to its site of action in the capillary lumen. GPIHBP1’s 3-fingered LU domain is required for LPL binding, but the function of its acidic domain (AD) has remained unclear. We created mutant mice lacking the AD and found severe hypertriglyceridemia. As expected, the mutant GPIHBP1 retained the capacity to bind LPL. Unexpectedly, however, most of the GPIHBP1 and LPL in the mutant mice was located on the abluminal surface of ECs (explaining the hypertriglyceridemia). The GPIHBP1-bound LPL was trapped on the abluminal surface of ECs by electrostatic interactions between the large basic patch on the surface of LPL and negatively charged heparan sulfate proteoglycans (HSPGs) on the surface of ECs. GPIHBP1 trafficking across ECs in the mutant mice was normalized by disrupting LPL-HSPG electrostatic interactions with either heparin or an AD peptide. Thus, GPIHBP1’s AD plays a crucial function in plasma triglyceride metabolism; it sheathes LPL’s basic patch on the abluminal surface of ECs, thereby preventing LPL-HSPG interactions and freeing GPIHBP1-LPL complexes to move across ECs to the capillary lumen.
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Affiliation(s)
- Wenxin Song
- Department of Medicine, David Geffen School of Medicine, UCLA, Los Angeles, California, USA
| | - Anne P Beigneux
- Department of Medicine, David Geffen School of Medicine, UCLA, Los Angeles, California, USA
| | - Anne-Marie L Winther
- Finsen Laboratory, Rigshospitalet, Copenhagen, Denmark.,Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark
| | - Kristian K Kristensen
- Finsen Laboratory, Rigshospitalet, Copenhagen, Denmark.,Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark
| | - Anne L Grønnemose
- Finsen Laboratory, Rigshospitalet, Copenhagen, Denmark.,Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark
| | - Ye Yang
- Department of Medicine, David Geffen School of Medicine, UCLA, Los Angeles, California, USA
| | - Yiping Tu
- Department of Medicine, David Geffen School of Medicine, UCLA, Los Angeles, California, USA
| | - Priscilla Munguia
- Department of Medicine, David Geffen School of Medicine, UCLA, Los Angeles, California, USA
| | - Jazmin Morales
- Department of Medicine, David Geffen School of Medicine, UCLA, Los Angeles, California, USA
| | - Hyesoo Jung
- Department of Medicine, David Geffen School of Medicine, UCLA, Los Angeles, California, USA
| | - Pieter J de Jong
- Children's Hospital Oakland Research Institute, Oakland, California, USA
| | - Cris J Jung
- Children's Hospital Oakland Research Institute, Oakland, California, USA
| | - Kazuya Miyashita
- Department of Clinical Laboratory Medicine, Gunma University, Graduate School of Medicine, Maebashi, Gunma, Japan.,Immuno-Biological Laboratories (IBL), Fujioka, Gunma, Japan
| | - Takao Kimura
- Department of Clinical Laboratory Medicine, Gunma University, Graduate School of Medicine, Maebashi, Gunma, Japan
| | - Katsuyuki Nakajima
- Department of Clinical Laboratory Medicine, Gunma University, Graduate School of Medicine, Maebashi, Gunma, Japan
| | - Masami Murakami
- Department of Clinical Laboratory Medicine, Gunma University, Graduate School of Medicine, Maebashi, Gunma, Japan
| | - Gabriel Birrane
- Division of Experimental Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - Haibo Jiang
- Department of Chemistry, The University of Hong Kong, Hong Kong
| | - Peter Tontonoz
- Department of Pathology and Laboratory Medicine, UCLA, Los Angeles, California, USA
| | - Michael Ploug
- Finsen Laboratory, Rigshospitalet, Copenhagen, Denmark.,Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark
| | - Loren G Fong
- Department of Medicine, David Geffen School of Medicine, UCLA, Los Angeles, California, USA
| | - Stephen G Young
- Department of Medicine, David Geffen School of Medicine, UCLA, Los Angeles, California, USA.,Department of Human Genetics, David Geffen School of Medicine, UCLA, Los Angeles, California, USA
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31
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Abstract
PURPOSE OF REVIEW Over the last two decades, evolving discoveries around angiopoietin-like (ANGPTL) proteins, particularly ANGPTL3, ANGPTL4, and ANGPTL8, have generated significant interest in understanding their roles in fatty acid (FA) metabolism. Until recently, exactly how this protein family regulates lipoprotein lipase (LPL) in a tissue-specific manner to control FA partitioning has remained elusive. This review summarizes the latest insights into mechanisms by which ANGPTL3/4/8 proteins regulate postprandial FA partitioning. RECENT FINDINGS Accumulating evidence suggests that ANGPTL8 is an insulin-responsive protein that regulates ANGPTL3 and ANGPTL4 by forming complexes with them to increase or decrease markedly their respective LPL-inhibitory activities. After feeding, when insulin levels are high, ANGPTL3/8 secreted by hepatocytes acts in an endocrine manner to inhibit LPL in skeletal muscle, whereas ANGPTL4/8 secreted by adipocytes acts locally to preserve adipose tissue LPL activity, thus shifting FA toward the fat for storage. Insulin also decreases hepatic secretion of the endogenous ANGPTL3/8 inhibitor, apolipoprotein A5 (ApoA5), to accentuate ANGPTL3/8-mediated LPL inhibition in skeletal muscle. SUMMARY The ANGPTL3/4/8 protein family and ApoA5 play critical roles in directing FA toward adipose tissue postprandially. Selective targeting of these proteins holds significant promise for the treatment of dyslipidemias, metabolic syndrome, and their related comorbidities.
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Affiliation(s)
| | - Yan Q Chen
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana, USA
| | - Robert J Konrad
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana, USA
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32
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Liabotis A, Ardidie-Robouant C, Mailly P, Besbes S, Gutierrez C, Atlas Y, Muller L, Germain S, Monnot C. Angiopoietin-like 4-Induced 3D Capillary Morphogenesis Correlates to Stabilization of Endothelial Adherens Junctions and Restriction of VEGF-Induced Sprouting. Biomedicines 2022; 10:biomedicines10020206. [PMID: 35203415 PMCID: PMC8869696 DOI: 10.3390/biomedicines10020206] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 01/13/2022] [Accepted: 01/14/2022] [Indexed: 11/22/2022] Open
Abstract
Angiopoietin-like 4 (ANGPTL4) is a target of hypoxia that accumulates in the endothelial extracellular matrix. While ANGPTL4 is known to regulate angiogenesis and vascular permeability, its context-dependent role related to vascular endothelial growth factor (VEGF) has been suggested in capillary morphogenesis. We here thus develop in vitro 3D models coupled to imaging and morphometric analysis of capillaries to decipher ANGPTL4 functions either alone or in the presence of VEGF. ANGPTL4 induces the formation of barely branched and thin endothelial capillaries that display linear adherens junctions. However, ANGPTL4 counteracts VEGF-induced formation of abundant ramified capillaries presenting cell–cell junctions characterized by VE-cadherin containing reticular plaques and serrated structures. We further deciphered the early angiogenesis steps regulated by ANGPTL4. During the initial activation of endothelial cells, ANGPTL4 alone induces cell shape changes but limits the VEGF-induced cell elongation and unjamming. In the growing sprout, ANGPTL4 maintains cohesive VE-cadherin pattern and sustains moderate 3D cell migration but restricts VEGF-induced endothelium remodeling and cell migration. This effect is mediated by differential short- and long-term regulation of P-Y1175-VEGFR2 and ERK1-2 signaling by ANGPTL4. Our in vitro 3D models thus provide the first evidence that ANGPTL4 induces a specific capillary morphogenesis but also overcomes VEGF effect.
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Affiliation(s)
- Athanasia Liabotis
- Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS, INSERM, Université PSL, F-75005 Paris, France; (A.L.); (C.A.-R.); (P.M.); (S.B.); (C.G.); (Y.A.); (L.M.)
- Collège Doctoral, Sorbonne Université, F-75006 Paris, France
| | - Corinne Ardidie-Robouant
- Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS, INSERM, Université PSL, F-75005 Paris, France; (A.L.); (C.A.-R.); (P.M.); (S.B.); (C.G.); (Y.A.); (L.M.)
| | - Philippe Mailly
- Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS, INSERM, Université PSL, F-75005 Paris, France; (A.L.); (C.A.-R.); (P.M.); (S.B.); (C.G.); (Y.A.); (L.M.)
| | - Samaher Besbes
- Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS, INSERM, Université PSL, F-75005 Paris, France; (A.L.); (C.A.-R.); (P.M.); (S.B.); (C.G.); (Y.A.); (L.M.)
| | - Charly Gutierrez
- Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS, INSERM, Université PSL, F-75005 Paris, France; (A.L.); (C.A.-R.); (P.M.); (S.B.); (C.G.); (Y.A.); (L.M.)
| | - Yoann Atlas
- Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS, INSERM, Université PSL, F-75005 Paris, France; (A.L.); (C.A.-R.); (P.M.); (S.B.); (C.G.); (Y.A.); (L.M.)
- Collège Doctoral, Sorbonne Université, F-75006 Paris, France
| | - Laurent Muller
- Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS, INSERM, Université PSL, F-75005 Paris, France; (A.L.); (C.A.-R.); (P.M.); (S.B.); (C.G.); (Y.A.); (L.M.)
| | - Stéphane Germain
- Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS, INSERM, Université PSL, F-75005 Paris, France; (A.L.); (C.A.-R.); (P.M.); (S.B.); (C.G.); (Y.A.); (L.M.)
- Correspondence: (S.G.); (C.M.)
| | - Catherine Monnot
- Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS, INSERM, Université PSL, F-75005 Paris, France; (A.L.); (C.A.-R.); (P.M.); (S.B.); (C.G.); (Y.A.); (L.M.)
- Correspondence: (S.G.); (C.M.)
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33
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Tall AR, Thomas DG, Gonzalez-Cabodevilla AG, Goldberg IJ. Addressing dyslipidemic risk beyond LDL-cholesterol. J Clin Invest 2022; 132:148559. [PMID: 34981790 PMCID: PMC8718149 DOI: 10.1172/jci148559] [Citation(s) in RCA: 55] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Despite the success of LDL-lowering drugs in reducing cardiovascular disease (CVD), there remains a large burden of residual disease due in part to persistent dyslipidemia characterized by elevated levels of triglyceride-rich lipoproteins (TRLs) and reduced levels of HDL. This form of dyslipidemia is increasing globally as a result of the rising prevalence of obesity and metabolic syndrome. Accumulating evidence suggests that impaired hepatic clearance of cholesterol-rich TRL remnants leads to their accumulation in arteries, promoting foam cell formation and inflammation. Low levels of HDL may associate with reduced cholesterol efflux from foam cells, aggravating atherosclerosis. While fibrates and fish oils reduce TRL, they have not been uniformly successful in reducing CVD, and there is a large unmet need for new approaches to reduce remnants and CVD. Rare genetic variants that lower triglyceride levels via activation of lipolysis and associate with reduced CVD suggest new approaches to treating dyslipidemia. Apolipoprotein C3 (APOC3) and angiopoietin-like 3 (ANGPTL3) have emerged as targets for inhibition by antibody, antisense, or RNAi approaches. Inhibition of either molecule lowers TRL but respectively raises or lowers HDL levels. Large clinical trials of such agents in patients with high CVD risk and elevated levels of TRL will be required to demonstrate efficacy of these approaches.
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Affiliation(s)
- Alan R Tall
- Division of Molecular Medicine, Department of Medicine, Columbia University, New York, New York, USA
| | - David G Thomas
- Division of Molecular Medicine, Department of Medicine, Columbia University, New York, New York, USA
| | - Ainara G Gonzalez-Cabodevilla
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, New York University Grossman School of Medicine, New York, New York, USA
| | - Ira J Goldberg
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, New York University Grossman School of Medicine, New York, New York, USA
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34
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Zhang R, Zhang K. An updated ANGPTL3-4-8 model as a mechanism of triglyceride partitioning between fat and oxidative tissues. Prog Lipid Res 2022; 85:101140. [PMID: 34793860 PMCID: PMC8760165 DOI: 10.1016/j.plipres.2021.101140] [Citation(s) in RCA: 42] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 11/09/2021] [Accepted: 11/10/2021] [Indexed: 01/03/2023]
Abstract
In mammals, triglyceride (TG), the main form of lipids for storing and providing energy, is stored in white adipose tissue (WAT) after food intake, while during fasting it is routed to oxidative tissues (heart and skeletal muscle) for energy production, a process referred to as TG partitioning. Lipoprotein lipase (LPL), a rate-limiting enzyme in this fundamental physiological process, hydrolyzes circulating TG to generate free fatty acids that are taken up by peripheral tissues. The postprandial activity of LPL declines in oxidative tissues but rises in WAT, directing TG to WAT; the reverse is true during fasting. However, the molecular mechanism in regulating tissue-specific LPL activity during the fed-fast cycle has not been completely understood. Research on angiopoietin-like (ANGPTL) proteins (A3, A4, and A8) has resulted in an ANGPTL3-4-8 model to explain the TG partitioning between WAT and oxidative tissues. Food intake induces A8 expression in the liver and WAT. Liver A8 activates A3 by forming the A3-8 complex, which is then secreted into the circulation. The A3-8 complex acts in an endocrine manner to inhibit LPL in oxidative tissues. WAT A8 forms the A4-8 complex, which acts locally to block A4's LPL-inhibiting activity. Therefore, the postprandial activity of LPL is low in oxidative tissues but high in WAT, directing circulating TG to WAT. Conversely, during fasting, reduced A8 expression in the liver and WAT disables A3 from inhibiting oxidative-tissue LPL and restores WAT A4's LPL-inhibiting activity, respectively. Thus, the fasting LPL activity is high in oxidative tissues but low in WAT, directing TG to the former. According to the model, we hypothesize that A8 antagonism has the potential to simultaneously reduce TG and increase HDL-cholesterol plasma levels. Future research on A3, A4, and A8 can hopefully provide more insights into human health, disease, and therapeutics.
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Affiliation(s)
- Ren Zhang
- Center for Molecular Medicine and Genetics, School of Medicine, Wayne State University, 540 East Canfield Street, Detroit, MI 48201, USA.
| | - Kezhong Zhang
- Center for Molecular Medicine and Genetics, School of Medicine, Wayne State University, 540 East Canfield Street, Detroit, MI 48201, USA
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35
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Jayaraman S, Pérez A, Miñambres I, Sánchez-Quesada JL, Gursky O. Heparin binding triggers human VLDL remodeling by circulating lipoprotein lipase: Relevance to VLDL functionality in health and disease. Biochim Biophys Acta Mol Cell Biol Lipids 2022; 1867:159064. [PMID: 34610468 PMCID: PMC8595799 DOI: 10.1016/j.bbalip.2021.159064] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 09/13/2021] [Accepted: 09/29/2021] [Indexed: 02/06/2023]
Abstract
Hydrolysis of VLDL triacylglycerol (TG) by lipoprotein lipase (LpL) is a major step in energy metabolism and VLDL-to-LDL maturation. Most functional LpL is anchored to the vascular endothelium, yet a small amount circulates on TG-rich lipoproteins. As circulating LpL has low catalytic activity, its role in VLDL remodeling is unclear. We use pre-heparin plasma and heparin-sepharose affinity chromatography to isolate VLDL fractions from normolipidemic, hypertriglyceridemic, or type-2 diabetic subjects. LpL is detected only in the heparin-bound fraction. Transient binding to heparin activates this VLDL-associated LpL, which hydrolyses TG, leading to gradual VLDL remodeling into IDL/LDL and HDL-size particles. The products and the timeframe of this remodeling closely resemble VLDL-to-LDL maturation in vivo. Importantly, the VLDL fraction that does not bind heparin is not remodeled. This relatively inert LpL-free VLDL is rich in TG and apoC-III, poor in apoE and apoC-II, shows impaired functionality as a substrate for the exogenous LpL or CETP, and likely has prolonged residence time in blood, which is expected to promote atherogenesis. This non-bound VLDL fraction increases in hypertriglyceridemia and in type-2 diabetes but decreases upon diabetes treatment that restores the glycemic control. In stark contrast, heparin binding by LDL increases in type-2 diabetes triggering pro-atherogenic LDL modifications. Therefore, the effects of heparin binding are associated negatively with atherogenesis for VLDL but positively for LDL. Collectively, the results reveal that binding to glycosaminoglycans initiates VLDL remodeling by circulating LpL, and suggest heparin binding as a marker of VLDL functionality and a readout for treatment of metabolic disorders.
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Affiliation(s)
- Shobini Jayaraman
- Department of Physiology & Biophysics, Boston University School of Medicine, Boston, MA 02118, USA.,Corresponding author.
| | - Antonio Pérez
- Endocrinology Department of the Hospital de la Santa Creu i Sant Pau, Barcelona, Spain.,CIBER of Diabetes and Metabolic Diseases (CIBERDEM), Spain
| | - Inka Miñambres
- Endocrinology Department of the Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | - Jose Luis Sánchez-Quesada
- CIBER of Diabetes and Metabolic Diseases (CIBERDEM), Spain.,Cardiovascular Biochemistry Group, Research Institute of the Hospital de Sant Pau, CIBERDEM, Barcelona, Spain
| | - Olga Gursky
- Department of Physiology & Biophysics, Boston University School of Medicine, Boston, MA 02118, USA
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36
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Role and mechanism of the action of angiopoietin-like protein ANGPTL4 in plasma lipid metabolism. J Lipid Res 2021; 62:100150. [PMID: 34801488 PMCID: PMC8666355 DOI: 10.1016/j.jlr.2021.100150] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 10/27/2021] [Accepted: 10/29/2021] [Indexed: 11/24/2022] Open
Abstract
Triglycerides are carried in the bloodstream as the components of very low-density lipoproteins and chylomicrons. These circulating triglycerides are primarily hydrolyzed in muscle and adipose tissue by the enzyme lipoprotein lipase (LPL). The activity of LPL is regulated by numerous mechanisms, including by three members of the angiopoietin-like protein family: ANGPTL3, ANGPTL4, and ANGPTL8. In this review, we discuss the recent literature concerning the role and mechanism of action of ANGPTL4 in lipid metabolism. ANGPTL4 is a fasting- and lipid-induced factor secreted by numerous cells, including adipocytes, hepatocytes, (cardio)myocytes, and macrophages. In adipocytes, ANGPTL4 mediates the fasting-induced repression of LPL activity by promoting the unfolding of LPL, leading to the cleavage and subsequent degradation of LPL. The inhibition of LPL by ANGPTL4 is opposed by ANGPTL8, which keeps the LPL active after feeding. In macrophages and (cardio)myocytes, ANGPTL4 functions as a lipid-inducible feedback regulator of LPL-mediated lipid uptake. In comparison, in hepatocytes, ANGPTL4 functions as a local inhibitor of hepatic lipase and possibly as an endocrine inhibitor of LPL in extra-hepatic tissues. At the genetic level, loss-of-function mutations in ANGPTL4 are associated with lower plasma triglycerides and higher plasma HDL-C levels, and a reduced risk of coronary artery disease, suggesting that ANGPTL4 is a viable pharmacological target for reducing cardiovascular risk. Whole-body targeting of ANGPTL4 is contraindicated because of severe pathological complications, whereas liver-specific inactivation of ANGPTL4, either as monotherapy or coupled to anti-ANGPTL3 therapies might be a suitable strategy for lowering plasma triglycerides in selected patient groups. In conclusion, the tissue-specific targeting of ANGPTL4 appears to be a viable pharmacological approach to reduce circulating triglycerides.
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37
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Lund Winther AM, Kristensen KK, Kumari A, Ploug M. Expression and one-step purification of active lipoprotein lipase contemplated by biophysical considerations. J Lipid Res 2021; 62:100149. [PMID: 34780727 DOI: 10.1016/j.jlr.2021.100149] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Revised: 11/02/2021] [Accepted: 11/05/2021] [Indexed: 12/17/2022] Open
Abstract
Lipoprotein lipase (LPL) is essential for intravascular lipid metabolism and is of high medical relevance. Since LPL is notoriously unstable, there is an unmet need for a robust expression system producing high quantities of active and pure recombinant human LPL. We showed previously that bovine LPL purified from milk is unstable at body temperature (Tm is 34.8 °C), but in the presence of the endothelial transporter glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1 (GPIHBP1) LPL is stabile (Tm increases to 57.6 °C). Building on this information, we now designed an expression system for human LPL using Drosophila S2 cells grown in suspension at high cell density and at an advantageous temperature of 25 °C. We co-transfected S2 cells with human LPL, LMF1 and soluble GPIHBP1 to provide an efficient chaperoning and stabilization of LPL in all compartments during synthesis and after secretion into the conditioned medium. For LPL purification, we used heparin-Sepharose affinity chromatography, which disrupted LPL-GPIHBP1 complexes causing GPIHBP1 to elute with the flow-through of the conditioned media. This one-step purification procedure yielded high quantities of pure and active LPL (4‒28 mg/L). Purification of several human LPL variants (furin-cleavage resistant mutant R297A, active-site mutant S132A, and lipid-binding-deficient mutant W390A-W393A-W394A) as well as murine LPL underscores the versatility and robustness of this protocol. Notably, we were able to produce and purify LPL containing the cognate furin-cleavage site. This method provides an efficient and cost-effective approach to produce large quantities of LPL for biophysical and large-scale drug discovery studies.
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Affiliation(s)
- Anne-Marie Lund Winther
- Finsen Laboratory, Rigshospitalet, Copenhagen, Denmark; Biotech Research and Innovation Centre, University of Copenhagen, Copenhagen, Denmark.
| | - Kristian Kølby Kristensen
- Finsen Laboratory, Rigshospitalet, Copenhagen, Denmark; Biotech Research and Innovation Centre, University of Copenhagen, Copenhagen, Denmark
| | - Anni Kumari
- Finsen Laboratory, Rigshospitalet, Copenhagen, Denmark; Biotech Research and Innovation Centre, University of Copenhagen, Copenhagen, Denmark
| | - Michael Ploug
- Finsen Laboratory, Rigshospitalet, Copenhagen, Denmark; Biotech Research and Innovation Centre, University of Copenhagen, Copenhagen, Denmark
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38
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Spitler KM, Shetty SK, Cushing EM, Sylvers-Davie KL, Davies BSJ. Chronic high-fat feeding and prolonged fasting in liver-specific ANGPTL4 knockout mice. Am J Physiol Endocrinol Metab 2021; 321:E464-E478. [PMID: 34396783 PMCID: PMC8560380 DOI: 10.1152/ajpendo.00144.2021] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Obesity is associated with dyslipidemia, ectopic lipid deposition, and insulin resistance. In mice, the global or adipose-specific loss of function of the protein angiopoietin-like 4 (ANGPTL4) leads to decreased plasma triglyceride levels, enhanced adipose triglyceride uptake, and protection from high-fat diet (HFD)-induced glucose intolerance. ANGPTL4 is also expressed highly in the liver, but the role of liver-derived ANGPTL4 is unclear. The goal of this study was to determine the contribution of hepatocyte ANGPTL4 to triglyceride and glucose homeostasis in mice during a high-fat diet challenge. We generated hepatocyte-specific ANGPTL4 deficient (Angptl4LivKO) mice, fed them a 60% kcal/fat diet (HFD) for 6 mo and assessed triglyceride, liver, and glucose metabolic phenotypes. We also explored the effects of prolonged fasting on Angptl4LivKO mice. The loss of hepatocyte-derived ANGPTL4 led to no major changes in triglyceride partitioning or lipoprotein lipase activity compared with control mice. Interestingly, although there was no difference in fasting plasma triglyceride levels after a 6 h fast, after an 18-h fast, normal chow diet-fed Angptl4LivKO mice had lower triglyceride levels than control mice. On a HFD, Angptl4LivKO mice initially showed no difference in glucose tolerance and insulin sensitivity, but improved glucose tolerance emerged in these mice after 6 mo on HFD. Our data suggest that hepatocyte ANGPTL4 does not directly regulate triglyceride partitioning, but that loss of liver-derived ANGPTL4 may be protective from HFD-induced glucose intolerance and influence plasma triglyceride (TG) metabolism during prolonged fasting.NEW & NOTEWORTHY1) Angiopoietin-like 4 deficiency in hepatocytes (Angptl4LivKO) does not improve triglyceride phenotypes during high-fat feeding. 2) Angptl4LivKO mice have improved glucose tolerance after chronic high-fat diet. 3) Angptl4LivKO mice have decreased fasting plasma triglyceride levels after an 18-h fast, but not after a 6-h fast.
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Affiliation(s)
- Kathryn M Spitler
- Department of Biochemistry, Fraternal Order of Eagles Diabetes Research Center, and Obesity Research and Education Initiative, University of Iowa, Iowa City, Iowa
| | - Shwetha K Shetty
- Department of Biochemistry, Fraternal Order of Eagles Diabetes Research Center, and Obesity Research and Education Initiative, University of Iowa, Iowa City, Iowa
| | - Emily M Cushing
- Department of Biochemistry, Fraternal Order of Eagles Diabetes Research Center, and Obesity Research and Education Initiative, University of Iowa, Iowa City, Iowa
| | - Kelli L Sylvers-Davie
- Department of Biochemistry, Fraternal Order of Eagles Diabetes Research Center, and Obesity Research and Education Initiative, University of Iowa, Iowa City, Iowa
| | - Brandon S J Davies
- Department of Biochemistry, Fraternal Order of Eagles Diabetes Research Center, and Obesity Research and Education Initiative, University of Iowa, Iowa City, Iowa
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39
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Sylvers-Davie KL, Davies BSJ. Regulation of lipoprotein metabolism by ANGPTL3, ANGPTL4, and ANGPTL8. Am J Physiol Endocrinol Metab 2021; 321:E493-E508. [PMID: 34338039 PMCID: PMC8560382 DOI: 10.1152/ajpendo.00195.2021] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 07/14/2021] [Accepted: 07/26/2021] [Indexed: 01/28/2023]
Abstract
Triglyceride-rich lipoproteins deliver fatty acids to tissues for oxidation and for storage. Release of fatty acids from circulating lipoprotein triglycerides is carried out by lipoprotein lipase (LPL), thus LPL serves as a critical gatekeeper of fatty acid uptake into tissues. LPL activity is regulated by a number of extracellular proteins including three members of the angiopoietin-like family of proteins. In this review, we discuss our current understanding of how, where, and when ANGPTL3, ANGPTL4, and ANGPTL8 regulate lipoprotein lipase activity, with a particular emphasis on how these proteins interact with each other to coordinate triglyceride metabolism and fat partitioning.
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Affiliation(s)
- Kelli L Sylvers-Davie
- Department of Biochemistry, Fraternal Order of Eagles Diabetes Research Center, and Obesity Research and Education Initiative, University of Iowa, Iowa City, Iowa
| | - Brandon S J Davies
- Department of Biochemistry, Fraternal Order of Eagles Diabetes Research Center, and Obesity Research and Education Initiative, University of Iowa, Iowa City, Iowa
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Chen YQ, Pottanat TG, Siegel RW, Ehsani M, Qian YW, Konrad RJ. Angiopoietin-like protein 4 (ANGPTL4) is an inhibitor of endothelial lipase (EL) while the ANGPTL4/8 complex has reduced EL-inhibitory activity. Heliyon 2021; 7:e07898. [PMID: 34504977 PMCID: PMC8417300 DOI: 10.1016/j.heliyon.2021.e07898] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 07/14/2021] [Accepted: 08/27/2021] [Indexed: 11/26/2022] Open
Abstract
We previously demonstrated that angiopoietin-like protein 8 (ANGPTL8) forms ANGPTL3/8 and ANGPTL4/8 complexes that increase with feeding to direct fatty acids (FA) toward adipose tissue through differential modulation of lipoprotein lipase (LPL) activity. Each complex correlated inversely with high density lipoprotein cholesterol (HDL) in control subjects. We thus investigated ANGPTL3/8 and ANGPTL4/8 levels in type 2 diabetes patients, who can present with decreased HDL. While ANGPTL3/8 levels in type 2 diabetes patients were similar to those previously observed in normal controls, ANGPTL4/8 levels were roughly twice as high as those in control subjects. Concentrations of ANGPTL3/8 and ANGPTL4/8 in type 2 diabetes patients were inversely correlated with HDL, with the correlation being significant for ANGPTL4/8. We therefore measured the ability of the various ANGPTL proteins and complexes to inhibit endothelial lipase (EL), the enzyme which hydrolyzes phospholipids (PL) in HDL. While confirming ANGPTL3 as an EL inhibitor, we found that ANGPTL4 was a more potent EL inhibitor than ANGPTL3. Interestingly, we observed that while ANGPTL3/8 had increased EL-inhibitory activity compared to ANGPTL3 alone, ANGPTL4/8 exhibited decreased potency in inhibiting EL compared to ANGPTL4 alone. Together, these results show for the first time that ANGPTL4 is a more potent EL inhibitor than ANGPTL3 and suggest a possible reason for why ANGPTL4/8 levels are correlated inversely with HDL. ANGPTL4/8 levels are increased in patients with type 2 diabetes. ANGPTL4/8 levels are inversely correlated with HDL in type 2 diabetes patients. ANGPTL4 is an inhibitor of endothelial lipase (EL). ANGPTL4 inhibits EL more potently than ANGPTL3 inhibits EL. ANGPTL4/8 inhibits EL less potently than ANGPTL4 inhibits EL.
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Affiliation(s)
- Yan Q Chen
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Thomas G Pottanat
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA.,Department of Biology, Indiana University - Purdue University Indianapolis, Indianapolis, IN, USA
| | - Robert W Siegel
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Mariam Ehsani
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Yue-Wei Qian
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Robert J Konrad
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
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Kristensen KK, Leth-Espensen KZ, Kumari A, Grønnemose AL, Lund-Winther AM, Young SG, Ploug M. GPIHBP1 and ANGPTL4 Utilize Protein Disorder to Orchestrate Order in Plasma Triglyceride Metabolism and Regulate Compartmentalization of LPL Activity. Front Cell Dev Biol 2021; 9:702508. [PMID: 34336854 PMCID: PMC8319833 DOI: 10.3389/fcell.2021.702508] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 06/23/2021] [Indexed: 12/12/2022] Open
Abstract
Intravascular processing of triglyceride-rich lipoproteins (TRLs) is crucial for delivery of dietary lipids fueling energy metabolism in heart and skeletal muscle and for storage in white adipose tissue. During the last decade, mechanisms underlying focal lipolytic processing of TRLs along the luminal surface of capillaries have been clarified by fresh insights into the functions of lipoprotein lipase (LPL); LPL's dedicated transporter protein, glycosylphosphatidylinositol-anchored high density lipoprotein-binding protein 1 (GPIHBP1); and its endogenous inhibitors, angiopoietin-like (ANGPTL) proteins 3, 4, and 8. Key discoveries in LPL biology include solving the crystal structure of LPL, showing LPL is catalytically active as a monomer rather than as a homodimer, and that the borderline stability of LPL's hydrolase domain is crucial for the regulation of LPL activity. Another key discovery was understanding how ANGPTL4 regulates LPL activity. The binding of ANGPTL4 to LPL sequences adjacent to the catalytic cavity triggers cooperative and sequential unfolding of LPL's hydrolase domain resulting in irreversible collapse of the catalytic cavity and loss of LPL activity. Recent studies have highlighted the importance of the ANGPTL3-ANGPTL8 complex for endocrine regulation of LPL activity in oxidative organs (e.g., heart, skeletal muscle, brown adipose tissue), but the molecular mechanisms have not been fully defined. New insights have also been gained into LPL-GPIHBP1 interactions and how GPIHBP1 moves LPL to its site of action in the capillary lumen. GPIHBP1 is an atypical member of the LU (Ly6/uPAR) domain protein superfamily, containing an intrinsically disordered and highly acidic N-terminal extension and a disulfide bond-rich three-fingered LU domain. Both the disordered acidic domain and the folded LU domain are crucial for the stability and transport of LPL, and for modulating its susceptibility to ANGPTL4-mediated unfolding. This review focuses on recent advances in the biology and biochemistry of crucial proteins for intravascular lipolysis.
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Affiliation(s)
- Kristian Kølby Kristensen
- Finsen Laboratory, Rigshospitalet, Copenhagen, Denmark.,Biotech Research and Innovation Centre, University of Copenhagen, Copenhagen, Denmark
| | - Katrine Zinck Leth-Espensen
- Finsen Laboratory, Rigshospitalet, Copenhagen, Denmark.,Biotech Research and Innovation Centre, University of Copenhagen, Copenhagen, Denmark
| | - Anni Kumari
- Finsen Laboratory, Rigshospitalet, Copenhagen, Denmark.,Biotech Research and Innovation Centre, University of Copenhagen, Copenhagen, Denmark
| | - Anne Louise Grønnemose
- Finsen Laboratory, Rigshospitalet, Copenhagen, Denmark.,Biotech Research and Innovation Centre, University of Copenhagen, Copenhagen, Denmark
| | - Anne-Marie Lund-Winther
- Finsen Laboratory, Rigshospitalet, Copenhagen, Denmark.,Biotech Research and Innovation Centre, University of Copenhagen, Copenhagen, Denmark
| | - Stephen G Young
- Departments of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States.,Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Michael Ploug
- Finsen Laboratory, Rigshospitalet, Copenhagen, Denmark.,Biotech Research and Innovation Centre, University of Copenhagen, Copenhagen, Denmark
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Singh AK, Chaube B, Zhang X, Sun J, Citrin KM, Canfrán-Duque A, Aryal B, Rotllan N, Varela L, Lee RG, Horvath TL, Price NL, Suárez Y, Fernández-Hernando C. Hepatocyte-specific suppression of ANGPTL4 improves obesity-associated diabetes and mitigates atherosclerosis in mice. J Clin Invest 2021; 131:140989. [PMID: 34255741 PMCID: PMC8409581 DOI: 10.1172/jci140989] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 07/08/2021] [Indexed: 12/14/2022] Open
Abstract
Hepatic uptake and biosynthesis of fatty acids (FA), as well as the partitioning of FA into oxidative, storage, and secretory pathways are tightly regulated processes. Dysregulation of one or more of these processes can promote excess hepatic lipid accumulation, ultimately leading to systemic metabolic dysfunction. Angiopoietin-like-4 (ANGPTL4) is a secretory protein that inhibits lipoprotein lipase (LPL) and modulates triacylglycerol (TAG) homeostasis. To understand the role of ANGPTL4 in liver lipid metabolism under normal and high-fat fed conditions, we generated hepatocyte specific Angptl4 mutant mice (Hmut). Using metabolic turnover studies, we demonstrate that hepatic Angptl4 deficiency facilitates catabolism of TAG-rich lipoprotein (TRL) remnants in the liver via increased hepatic lipase (HL) activity, which results in a significant reduction in circulating TAG and cholesterol levels. Consequently, depletion of hepatocyte Angptl4 protects against diet-induce obesity, glucose intolerance, liver steatosis, and atherogenesis. Mechanistically, we demonstrate that loss of Angptl4 in hepatocytes promotes FA uptake which results in increased FA oxidation, ROS production, and AMPK activation. Finally, we demonstrate the utility of a targeted pharmacologic therapy that specifically inhibits Angptl4 gene expression in the liver and protects against diet-induced obesity, dyslipidemia, glucose intolerance, and liver damage, which likely occurs via increased HL activity. Notably, this novel inhibition strategy does not cause any of the deleterious effects previously observed with neutralizing antibodies.
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Affiliation(s)
- Abhishek K. Singh
- Vascular Biology and Therapeutics Program
- Integrative Cell Signaling and Neurobiology of Metabolism Program, Department of Comparative Medicine, and
| | - Balkrishna Chaube
- Vascular Biology and Therapeutics Program
- Integrative Cell Signaling and Neurobiology of Metabolism Program, Department of Comparative Medicine, and
| | - Xinbo Zhang
- Vascular Biology and Therapeutics Program
- Integrative Cell Signaling and Neurobiology of Metabolism Program, Department of Comparative Medicine, and
| | - Jonathan Sun
- Vascular Biology and Therapeutics Program
- Integrative Cell Signaling and Neurobiology of Metabolism Program, Department of Comparative Medicine, and
| | - Kathryn M. Citrin
- Vascular Biology and Therapeutics Program
- Integrative Cell Signaling and Neurobiology of Metabolism Program, Department of Comparative Medicine, and
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Alberto Canfrán-Duque
- Vascular Biology and Therapeutics Program
- Integrative Cell Signaling and Neurobiology of Metabolism Program, Department of Comparative Medicine, and
| | - Binod Aryal
- Vascular Biology and Therapeutics Program
- Integrative Cell Signaling and Neurobiology of Metabolism Program, Department of Comparative Medicine, and
| | - Noemi Rotllan
- Vascular Biology and Therapeutics Program
- Integrative Cell Signaling and Neurobiology of Metabolism Program, Department of Comparative Medicine, and
| | - Luis Varela
- Integrative Cell Signaling and Neurobiology of Metabolism Program, Department of Comparative Medicine, and
| | - Richard G. Lee
- Cardiovascular Group, Antisense Drug Discovery, Ionis Pharmaceuticals, Carlsbad, California, USA
| | - Tamas L. Horvath
- Integrative Cell Signaling and Neurobiology of Metabolism Program, Department of Comparative Medicine, and
| | - Nathan L. Price
- Vascular Biology and Therapeutics Program
- Integrative Cell Signaling and Neurobiology of Metabolism Program, Department of Comparative Medicine, and
| | - Yajaira Suárez
- Vascular Biology and Therapeutics Program
- Integrative Cell Signaling and Neurobiology of Metabolism Program, Department of Comparative Medicine, and
- Department of Pathology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Carlos Fernández-Hernando
- Vascular Biology and Therapeutics Program
- Integrative Cell Signaling and Neurobiology of Metabolism Program, Department of Comparative Medicine, and
- Department of Pathology, Yale University School of Medicine, New Haven, Connecticut, USA
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Shang R, Rodrigues B. Lipoprotein Lipase and Its Delivery of Fatty Acids to the Heart. Biomolecules 2021; 11:biom11071016. [PMID: 34356640 PMCID: PMC8301904 DOI: 10.3390/biom11071016] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Revised: 07/08/2021] [Accepted: 07/08/2021] [Indexed: 02/05/2023] Open
Abstract
Ninety percent of plasma fatty acids (FAs) are contained within lipoprotein-triglyceride, and lipoprotein lipase (LPL) is robustly expressed in the heart. Hence, LPL-mediated lipolysis of lipoproteins is suggested to be a key source of FAs for cardiac use. Lipoprotein clearance by LPL occurs at the apical surface of the endothelial cell lining of the coronary lumen. In the heart, the majority of LPL is produced in cardiomyocytes and subsequently is translocated to the apical luminal surface. Here, vascular LPL hydrolyzes lipoprotein-triglyceride to provide the heart with FAs for ATP generation. This article presents an overview of cardiac LPL, explains how the enzyme works, describes key molecules that regulate its activity and outlines how changes in LPL are brought about by physiological and pathological states such as fasting and diabetes, respectively.
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The Mechanism of Oral Melatonin Ameliorates Intestinal and Adipose Lipid Dysmetabolism Through Reducing Escherichia Coli-Derived Lipopolysaccharide. Cell Mol Gastroenterol Hepatol 2021; 12:1643-1667. [PMID: 34242820 PMCID: PMC8536535 DOI: 10.1016/j.jcmgh.2021.06.024] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 06/28/2021] [Accepted: 06/29/2021] [Indexed: 12/13/2022]
Abstract
BACKGROUND & AIMS Gut microbiota have been reported to be sensitive to circadian rhythms and host lipometabolism, respectively. Although melatonin-mediated beneficial efforts on many physiological sites have been revealed, the regulatory actions of oral melatonin on the communication between gut microbiota and host are still not clear. Angiopoietin-like 4 (ANGPTL4) has been shown to be strongly responsible for the regulation of systemic lipid metabolism. Herein, we identified that oral melatonin improved lipid dysmetabolism in ileum and epididymal white adipose tissue (eWAT) via gut microbiota and ileac ANGPTL4. METHODS Analyses of jet-lag (JL) mice, JL mice with oral melatonin administration (JL+MT), and the control for mRNA and protein expression regarding lipid uptake and accumulation in ileum and eWAT were made. Gut microbiome sequencing and experimental validation of target strains were included. Functional analysis of key factors/pathways in the various rodent models, including the depletion of gut microbiota, mono-colonization of Escherichia coli, and other genetic intervention was made. Analyses of transcriptional regulation and effects of melatonin on E coli-derived lipopolysaccharide (LPS) in vitro were made. RESULTS JL mice have a higher level of ileal lipid uptake, fat accumulation in eWAT, and lower level of circulating ANGPTL4 in comparison with the control mice. JL mice also showed a significantly higher abundance of E coli and LPS than the control mice. Conversely, oral melatonin supplementation remarkably reversed these phenotypes. The test of depletion of gut microbiota further demonstrated that oral melatonin-mediated improvements on lipometabolism in JL mice were dependent on the presence of gut microbiota. By mono-colonization of E coli, LPS has been determined to trigger these changes similar to JL. Furthermore, we found that LPS served as a pivotal link that contributed to activating toll-like receptor 4 (TLR4)/signal transducer and activator of transcription 3 (STAT3_/REV-ERBα) signaling to up-regulate nuclear factor interleukin-3-regulated protein (NFIL3) expression, resulting in increased lipid uptake in ileum. In MODE-K cells, the activation of NFIL3 has further been shown to inhibit ANGPTL4 transcription, which is closely associated with lipid uptake and transport in peripheral tissues. Finally, we confirmed that melatonin inhibited LPS via repressing the expression of LpxC in E coli. CONCLUSIONS Overall, oral melatonin decreased the quantity of E coli-generated LPS, which alleviated NFIL3-induced transcriptional inhibition of ANGPTL4 through TLR4/IL-22/STAT3 signaling in ileum, thereby resulting in the amelioration of ileal lipid intake and lower fat accumulation in eWAT. These results address a novel regulation of oral melatonin originating from gut microbiota to host distal tissues, suggesting that microbe-generated metabolites are potential therapies for melatonin-mediated improvement of circadian rhythm disruption and related metabolic syndrome.
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The Importance of Lipoprotein Lipase Regulation in Atherosclerosis. Biomedicines 2021; 9:biomedicines9070782. [PMID: 34356847 PMCID: PMC8301479 DOI: 10.3390/biomedicines9070782] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/02/2021] [Accepted: 07/04/2021] [Indexed: 02/07/2023] Open
Abstract
Lipoprotein lipase (LPL) plays a major role in the lipid homeostasis mainly by mediating the intravascular lipolysis of triglyceride rich lipoproteins. Impaired LPL activity leads to the accumulation of chylomicrons and very low-density lipoproteins (VLDL) in plasma, resulting in hypertriglyceridemia. While low-density lipoprotein cholesterol (LDL-C) is recognized as a primary risk factor for atherosclerosis, hypertriglyceridemia has been shown to be an independent risk factor for cardiovascular disease (CVD) and a residual risk factor in atherosclerosis development. In this review, we focus on the lipolysis machinery and discuss the potential role of triglycerides, remnant particles, and lipolysis mediators in the onset and progression of atherosclerotic cardiovascular disease (ASCVD). This review details a number of important factors involved in the maturation and transportation of LPL to the capillaries, where the triglycerides are hydrolyzed, generating remnant lipoproteins. Moreover, LPL and other factors involved in intravascular lipolysis are also reported to impact the clearance of remnant lipoproteins from plasma and promote lipoprotein retention in capillaries. Apolipoproteins (Apo) and angiopoietin-like proteins (ANGPTLs) play a crucial role in regulating LPL activity and recent insights into LPL regulation may elucidate new pharmacological means to address the challenge of hypertriglyceridemia in atherosclerosis development.
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Luo M, Fan R, Wang X, Lu J, Li P, Chu W, Hu Y, Chen X. Gualou Xiebai Banxia decoction ameliorates Poloxamer 407-induced hyperlipidemia. Biosci Rep 2021; 41:BSR20204216. [PMID: 34036306 PMCID: PMC8204229 DOI: 10.1042/bsr20204216] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 04/20/2021] [Accepted: 05/04/2021] [Indexed: 12/30/2022] Open
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Gualou Xiebai Banxia (GLXBBX) decoction is a well-known traditional Chinese herbal formula that was first discussed in the Synopsis of the Golden Chamber by Zhang Zhongjing in the Eastern Han Dynasty. In traditional Chinese medicine, GLXBBX is commonly prescribed to treat cardiovascular diseases, such as coronary heart disease and atherosclerosis. OBJECTIVE The present study aimed to examine GLXBBX's preventative capacity and elucidate the potential molecular mechanism of Poloxamer 407 (P407)-induced hyperlipidemia in rats. MATERIALS AND METHODS Both the control and model groups received pure water, and the test group also received a GLXBBX decoction. For each administration, 3 ml of the solution was administered orally. To establish hyperlipidemia, a solution mixed with 0.25 g/kg P407 dissolved in 0.9% normal saline was injected slowly into the abdominal cavity. At the end of the study, the rats' plasma lipid levels were calculated using an automatic biochemical analyzer to evaluate the preventative capability of the GLXBBX decoction, and the serum and liver of the rats were collected. RESULTS The GLXBBX decoction significantly improved P407-induced hyperlipidemia, including increased plasma triglycerides (TGs), aspartate aminotransferase (AST) elevation, and lipid accumulation. Moreover, GLXBBX decoction treatment increased lipoprotein lipase (LPL) activity and mRNA expression of LPL. Furthermore, GLXBBX significantly suppressed the mRNA expression of stearoyl-CoA desaturase (SCD1). CONCLUSION GLXBBX significantly improved P407-induced hyperlipidemia, which may have been related to enhanced LPL activity, increased LPL mRNA expression, and decreased mRNA expression of SCD1.
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Affiliation(s)
- Mingzhu Luo
- Affiliated Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu 611137, Sichuan, China
- Department of Operational Medicinal Research, Tianjin Institute of Environmental and Operational Medicine, Tianjin 300050, China
| | - Rong Fan
- Department of Operational Medicinal Research, Tianjin Institute of Environmental and Operational Medicine, Tianjin 300050, China
- Central Laboratory, Tianjin Xiqing Hospital, Tianjin 300380, China
| | - Xiaoming Wang
- Department of Operational Medicinal Research, Tianjin Institute of Environmental and Operational Medicine, Tianjin 300050, China
| | - Junyu Lu
- Department of Operational Medicinal Research, Tianjin Institute of Environmental and Operational Medicine, Tianjin 300050, China
| | - Ping Li
- Department of Operational Medicinal Research, Tianjin Institute of Environmental and Operational Medicine, Tianjin 300050, China
- Department of Pharmacology Research, Southwest Medical University, Luzhou 646000, Sichuan, China
| | - Wenbin Chu
- Department of Operational Medicinal Research, Tianjin Institute of Environmental and Operational Medicine, Tianjin 300050, China
| | - Yonghe Hu
- Department of Traditional Chinese Medicine, The General Hospital of Western Theater Command, Chengdu 611137, Sichuan, China
| | - Xuewei Chen
- Department of Operational Medicinal Research, Tianjin Institute of Environmental and Operational Medicine, Tianjin 300050, China
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Goldberg IJ, Cabodevilla AG, Samovski D, Cifarelli V, Basu D, Abumrad NA. Lipolytic enzymes and free fatty acids at the endothelial interface. Atherosclerosis 2021; 329:1-8. [PMID: 34130222 DOI: 10.1016/j.atherosclerosis.2021.05.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 05/12/2021] [Accepted: 05/21/2021] [Indexed: 01/17/2023]
Abstract
Lipids released from circulating lipoproteins by intravascular action of lipoprotein lipase (LpL) reach parenchymal cells in tissues with a non-fenestrated endothelium by transfer through or around endothelial cells. The actions of LpL are controlled at multiple sites, its synthesis and release by myocytes and adipocytes, its transit and association with the endothelial cell luminal surface, and finally its activation and inhibition by a number of proteins and by its product non-esterified fatty acids. Multiple pathways mediate endothelial transit of lipids into muscle and adipose tissues. These include movement of fatty acids via the endothelial cell fatty acid transporter CD36 and movement of whole or partially LpL-hydrolyzed lipoproteins via other apical endothelial cell receptors such as SR-B1and Alk1. Lipids also likely change the barrier function of the endothelium and operation of the paracellular pathway around endothelial cells. This review summarizes in vitro and in vivo support for the key role of endothelial cells in delivery of lipids and highlights incompletely understood processes that are the focus of active investigation.
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Affiliation(s)
- Ira J Goldberg
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, New York University Grossman School of Medicine, New York, NY, USA.
| | - Ainara G Cabodevilla
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, New York University Grossman School of Medicine, New York, NY, USA
| | - Dmitri Samovski
- Department of Medicine, Center for Human Nutrition, Washington University School of Medicine, Saint Louis, MO, USA
| | - Vincenza Cifarelli
- Department of Medicine, Center for Human Nutrition, Washington University School of Medicine, Saint Louis, MO, USA
| | - Debapriya Basu
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, New York University Grossman School of Medicine, New York, NY, USA
| | - Nada A Abumrad
- Department of Medicine, Center for Human Nutrition, Washington University School of Medicine, Saint Louis, MO, USA.
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Teratani T, Tomita K, Wada A, Sugihara N, Higashiyama M, Inaba K, Horiuchi K, Hanawa Y, Nishii S, Mizoguchi A, Tanemoto R, Ito S, Okada Y, Kurihara C, Akita Y, Narimatsu K, Watanabe C, Komoto S, Oike Y, Miura S, Hokari R, Kanai T. Angiopoietin-like protein 4 deficiency augments liver fibrosis in liver diseases such as nonalcoholic steatohepatitis in mice through enhanced free cholesterol accumulation in hepatic stellate cells. Hepatol Res 2021; 51:580-592. [PMID: 33247991 DOI: 10.1111/hepr.13603] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 11/18/2020] [Accepted: 11/24/2020] [Indexed: 12/13/2022]
Abstract
AIM We recently reported that lipoprotein lipase (LPL)-mediated free cholesterol (FC) accumulation in hepatic stellate cells (HSCs) augmented liver fibrosis in non-alcoholic steatohepatitis (NASH). The aim of the present study was to explore the role of angiopoietin-like protein 4 (Angptl4), an LPL inhibitor, in the pathogenesis of liver fibrosis in NASH. METHODS Angptl4-deficient or wild-type mice were used to investigate the role of Angptl4 in the pathogenesis of NASH induced by feeding a methionine- and choline-deficient diet. We also examined the effect of Angptl4 on FC accumulation in HSCs, and the subsequent activation of HSCs, using Angptl4-deficient HSCs. RESULTS In the NASH model, Angptl4-deficient mice had significantly aggravated liver fibrosis and activated HSCs without enhancement of hepatocellular injury, liver inflammation, or liver angiogenesis. FC levels were significantly higher in HSCs from Angptl4-deficient mice than in those from wild-type mice. Treatment with Angptl4 reversed low-density lipoprotein-induced FC accumulation in HSCs through the inhibition of LPL. The Angptl4 deficiency-induced FC accumulation in HSCs suppressed HSC expression of the transforming growth factor-β (TGF-ß) pseudoreceptor, bone morphogenetic protein, and activin membrane-bound inhibitor, and sensitized HSCs to TGF-β-induced activation in vivo and in vitro. CONCLUSIONS Angptl4 plays an important role in the pathogenesis of FC accumulation in HSCs. In addition, regulation of FC levels in HSCs by Angptl4 plays a critical role in the pathogenesis of liver fibrosis in NASH. Thus, Angptl4 could represent a novel therapeutic option for NASH.
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Affiliation(s)
- Toshiaki Teratani
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan
| | - Kengo Tomita
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, National Defense Medical College, Tokorozawa-shi, Saitama, Japan
| | - Akinori Wada
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, National Defense Medical College, Tokorozawa-shi, Saitama, Japan
| | - Nao Sugihara
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, National Defense Medical College, Tokorozawa-shi, Saitama, Japan
| | - Masaaki Higashiyama
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, National Defense Medical College, Tokorozawa-shi, Saitama, Japan
| | - Kenichi Inaba
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, National Defense Medical College, Tokorozawa-shi, Saitama, Japan
| | - Kazuki Horiuchi
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, National Defense Medical College, Tokorozawa-shi, Saitama, Japan
| | - Yoshinori Hanawa
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, National Defense Medical College, Tokorozawa-shi, Saitama, Japan
| | - Shin Nishii
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, National Defense Medical College, Tokorozawa-shi, Saitama, Japan
| | - Akinori Mizoguchi
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, National Defense Medical College, Tokorozawa-shi, Saitama, Japan
| | - Rina Tanemoto
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, National Defense Medical College, Tokorozawa-shi, Saitama, Japan
| | - Suguru Ito
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, National Defense Medical College, Tokorozawa-shi, Saitama, Japan
| | - Yoshikiyo Okada
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, National Defense Medical College, Tokorozawa-shi, Saitama, Japan
| | - Chie Kurihara
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, National Defense Medical College, Tokorozawa-shi, Saitama, Japan
| | - Yoshihiro Akita
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, National Defense Medical College, Tokorozawa-shi, Saitama, Japan
| | - Kazuyuki Narimatsu
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, National Defense Medical College, Tokorozawa-shi, Saitama, Japan
| | - Chikako Watanabe
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, National Defense Medical College, Tokorozawa-shi, Saitama, Japan
| | - Shunsuke Komoto
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, National Defense Medical College, Tokorozawa-shi, Saitama, Japan
| | - Yuichi Oike
- Department of Molecular Genetics, Graduate School of Medical Sciences, Kumamoto University, Chuo-ku, Kumamoto, Japan
| | - Soichiro Miura
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, National Defense Medical College, Tokorozawa-shi, Saitama, Japan.,International University of Health and Welfare Graduate School, Minato-ku, Tokyo, Japan
| | - Ryota Hokari
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, National Defense Medical College, Tokorozawa-shi, Saitama, Japan
| | - Takanori Kanai
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan
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The intrinsic instability of the hydrolase domain of lipoprotein lipase facilitates its inactivation by ANGPTL4-catalyzed unfolding. Proc Natl Acad Sci U S A 2021; 118:2026650118. [PMID: 33723082 DOI: 10.1073/pnas.2026650118] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The complex between lipoprotein lipase (LPL) and its endothelial receptor (GPIHBP1) is responsible for the lipolytic processing of triglyceride-rich lipoproteins (TRLs) along the capillary lumen, a physiologic process that releases lipid nutrients for vital organs such as heart and skeletal muscle. LPL activity is regulated in a tissue-specific manner by endogenous inhibitors (angiopoietin-like [ANGPTL] proteins 3, 4, and 8), but the molecular mechanisms are incompletely understood. ANGPTL4 catalyzes the inactivation of LPL monomers by triggering the irreversible unfolding of LPL's α/β-hydrolase domain. Here, we show that this unfolding is initiated by the binding of ANGPTL4 to sequences near LPL's catalytic site, including β2, β3-α3, and the lid. Using pulse-labeling hydrogen‒deuterium exchange mass spectrometry, we found that ANGPTL4 binding initiates conformational changes that are nucleated on β3-α3 and progress to β5 and β4-α4, ultimately leading to the irreversible unfolding of regions that form LPL's catalytic pocket. LPL unfolding is context dependent and varies with the thermal stability of LPL's α/β-hydrolase domain (T m of 34.8 °C). GPIHBP1 binding dramatically increases LPL stability (T m of 57.6 °C), while ANGPTL4 lowers the onset of LPL unfolding by ∼20 °C, both for LPL and LPL•GPIHBP1 complexes. These observations explain why the binding of GPIHBP1 to LPL retards the kinetics of ANGPTL4-mediated LPL inactivation at 37 °C but does not fully suppress inactivation. The allosteric mechanism by which ANGPTL4 catalyzes the irreversible unfolding and inactivation of LPL is an unprecedented pathway for regulating intravascular lipid metabolism.
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Gunn KH, Gutgsell AR, Xu Y, Johnson CV, Liu J, Neher SB. Comparison of angiopoietin-like protein 3 and 4 reveals structural and mechanistic similarities. J Biol Chem 2021; 296:100312. [PMID: 33482195 PMCID: PMC7949051 DOI: 10.1016/j.jbc.2021.100312] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 01/07/2021] [Accepted: 01/15/2021] [Indexed: 12/17/2022] Open
Abstract
Elevated plasma triglycerides are a risk factor for coronary artery disease, which is the leading cause of death worldwide. Lipoprotein lipase (LPL) reduces triglycerides in the blood by hydrolyzing them from triglyceride-rich lipoproteins to release free fatty acids. LPL activity is regulated in a nutritionally responsive manner by macromolecular inhibitors including angiopoietin-like proteins 3 and 4 (ANGPTL3 and ANGPTL4). However, the mechanism by which ANGPTL3 inhibits LPL is unclear, in part due to challenges in obtaining pure protein for study. We used a new purification protocol for the N-terminal domain of ANGPTL3, removing a DNA contaminant, and found DNA-free ANGPTL3 showed enhanced inhibition of LPL. Structural analysis showed that ANGPTL3 formed elongated, flexible trimers and hexamers that did not interconvert. ANGPTL4 formed only elongated flexible trimers. We compared the inhibition of ANGPTL3 and ANGPTL4 using human very-low-density lipoproteins as a substrate and found both were noncompetitive inhibitors. The inhibition constants for the trimeric ANGPTL3 (7.5 ± 0.7 nM) and ANGPTL4 (3.6 ± 1.0 nM) were only 2-fold different. Heparin has previously been reported to interfere with ANGPTL3 binding to LPL, so we questioned if the negatively charged heparin was acting in a similar fashion to the DNA contaminant. We found that ANGPTL3 inhibition is abolished by binding to low-molecular-weight heparin, whereas ANGPTL4 inhibition is not. Our data show new similarities and differences in how ANGPTL3 and ANGPTL4 regulate LPL and opens new avenues of investigating the effect of heparin on LPL inhibition by ANGPTL3.
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Affiliation(s)
- Kathryn H Gunn
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Aspen R Gutgsell
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Yongmei Xu
- Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Caitlin V Johnson
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Jian Liu
- Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Saskia B Neher
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, North Carolina, USA.
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