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Lyu J, Jiang M, Zhu Z, Wu H, Kang H, Hao X, Cheng S, Guo H, Shen X, Wu T, Chang J, Wang C. Identification of biomarkers and potential therapeutic targets for pancreatic cancer by proteomic analysis in two prospective cohorts. CELL GENOMICS 2024; 4:100561. [PMID: 38754433 DOI: 10.1016/j.xgen.2024.100561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 12/12/2023] [Accepted: 04/21/2024] [Indexed: 05/18/2024]
Abstract
Pancreatic cancer (PC) is the deadliest malignancy due to late diagnosis. Aberrant alterations in the blood proteome might serve as biomarkers to facilitate early detection of PC. We designed a nested case-control study of incident PC based on a prospective cohort of 38,295 elderly Chinese participants with ∼5.7 years' follow-up. Forty matched case-control pairs passed the quality controls for the proximity extension assay of 1,463 serum proteins. With a lenient threshold of p < 0.005, we discovered regenerating family member 1A (REG1A), REG1B, tumor necrosis factor (TNF), and phospholipase A2 group IB (PLA2G1B) in association with incident PC, among which the two REG1 proteins were replicated using the UK Biobank Pharma Proteomics Project, with effect sizes increasing steadily as diagnosis time approaches the baseline. Mendelian randomization analysis further supported the potential causal effects of REG1 proteins on PC. Taken together, circulating REG1A and REG1B are promising biomarkers and potential therapeutic targets for the early detection and prevention of PC.
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Affiliation(s)
- Jingjing Lyu
- Ministry of Education Key Laboratory of Environment and Health, State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China; Department of Epidemiology and Biostatistics, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Minghui Jiang
- Ministry of Education Key Laboratory of Environment and Health, State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China; Department of Epidemiology and Biostatistics, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ziwei Zhu
- Ministry of Education Key Laboratory of Environment and Health, State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China; Department of Epidemiology and Biostatistics, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Hongji Wu
- Ministry of Education Key Laboratory of Environment and Health, State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China; Department of Epidemiology and Biostatistics, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Haonan Kang
- Ministry of Education Key Laboratory of Environment and Health, State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China; Department of Epidemiology and Biostatistics, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xingjie Hao
- Ministry of Education Key Laboratory of Environment and Health, State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China; Department of Epidemiology and Biostatistics, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Shanshan Cheng
- Ministry of Education Key Laboratory of Environment and Health, State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China; Department of Epidemiology and Biostatistics, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Huan Guo
- Ministry of Education Key Laboratory of Environment and Health, State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China; Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xia Shen
- Greater Bay Area Institute of Precision Medicine (Guangzhou), Fudan University, Guangzhou, China
| | - Tangchun Wu
- Ministry of Education Key Laboratory of Environment and Health, State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China; Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
| | - Jiang Chang
- Ministry of Education Key Laboratory of Environment and Health, State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China; Department of Health Toxicology, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
| | - Chaolong Wang
- Ministry of Education Key Laboratory of Environment and Health, State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China; Department of Epidemiology and Biostatistics, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
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Adamson SE, Adak S, Petersen MC, Higgins D, Spears LD, Zhang RM, Cedeno A, McKee A, Kumar A, Singh S, Hsu FF, McGill JB, Semenkovich CF. Decreased sarcoplasmic reticulum phospholipids in human skeletal muscle are associated with metabolic syndrome. J Lipid Res 2024; 65:100519. [PMID: 38354857 PMCID: PMC10937315 DOI: 10.1016/j.jlr.2024.100519] [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: 01/18/2024] [Revised: 02/08/2024] [Accepted: 02/09/2024] [Indexed: 02/16/2024] Open
Abstract
Metabolic syndrome affects more than one in three adults and is associated with increased risk of diabetes, cardiovascular disease, and all-cause mortality. Muscle insulin resistance is a major contributor to the development of the metabolic syndrome. Studies in mice have linked skeletal muscle sarcoplasmic reticulum (SR) phospholipid composition to sarcoplasmic/endoplasmic reticulum Ca2+-ATPase activity and insulin sensitivity. To determine if the presence of metabolic syndrome alters specific phosphatidylcholine (PC) and phosphatidylethanolamine (PE) species in human SR, we compared SR phospholipid composition in skeletal muscle from sedentary subjects with metabolic syndrome and sedentary control subjects without metabolic syndrome. Both total PC and total PE were significantly decreased in skeletal muscle SR of sedentary metabolic syndrome patients compared with sedentary controls, particularly in female participants, but there was no difference in the PC:PE ratio between groups. Total SR PC levels, but not total SR PE levels or PC:PE ratio, were significantly negatively correlated with BMI, waist circumference, total fat, visceral adipose tissue, triglycerides, fasting insulin, and homeostatic model assessment for insulin resistance. These findings are consistent with the existence of a relationship between skeletal muscle SR PC content and insulin resistance in humans.
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Affiliation(s)
- Samantha E Adamson
- Division of Endocrinology, Metabolism & Lipid Research, Washington University, St Louis, MO, USA
| | - Sangeeta Adak
- Division of Endocrinology, Metabolism & Lipid Research, Washington University, St Louis, MO, USA
| | - Max C Petersen
- Division of Endocrinology, Metabolism & Lipid Research, Washington University, St Louis, MO, USA
| | - Dustin Higgins
- Division of Endocrinology, Metabolism & Lipid Research, Washington University, St Louis, MO, USA
| | - Larry D Spears
- Division of Endocrinology, Metabolism & Lipid Research, Washington University, St Louis, MO, USA
| | - Rong Mei Zhang
- Division of Endocrinology, Metabolism & Lipid Research, Washington University, St Louis, MO, USA
| | - Andrea Cedeno
- Division of Endocrinology, Metabolism & Lipid Research, Washington University, St Louis, MO, USA
| | - Alexis McKee
- Division of Endocrinology, Metabolism & Lipid Research, Washington University, St Louis, MO, USA
| | - Aswathi Kumar
- Division of Endocrinology, Metabolism & Lipid Research, Washington University, St Louis, MO, USA
| | - Sudhir Singh
- Division of Endocrinology, Metabolism & Lipid Research, Washington University, St Louis, MO, USA
| | - Fong-Fu Hsu
- Division of Endocrinology, Metabolism & Lipid Research, Washington University, St Louis, MO, USA
| | - Janet B McGill
- Division of Endocrinology, Metabolism & Lipid Research, Washington University, St Louis, MO, USA
| | - Clay F Semenkovich
- Division of Endocrinology, Metabolism & Lipid Research, Washington University, St Louis, MO, USA; Department of Cell Biology & Physiology, Washington University, St Louis, MO, USA.
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3
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Murakami M, Sato H, Taketomi Y. Modulation of immunity by the secreted phospholipase A 2 family. Immunol Rev 2023; 317:42-70. [PMID: 37035998 DOI: 10.1111/imr.13205] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 03/23/2023] [Accepted: 03/28/2023] [Indexed: 04/11/2023]
Abstract
Among the phospholipase A2 (PLA2 ) superfamily, which typically catalyzes the sn-2 hydrolysis of phospholipids to yield fatty acids and lysophospholipids, the secreted PLA2 (sPLA2 ) family contains 11 isoforms in mammals. Individual sPLA2 s have unique enzymatic specificity toward fatty acids and polar heads of phospholipid substrates and display distinct tissue/cellular distributions, suggesting their distinct physiological functions. Recent studies using knockout and/or transgenic mice for a full set of sPLA2 s have revealed their roles in modulation of immunity and related disorders. Application of mass spectrometric lipidomics to these mice has enabled to identify target substrates and products of individual sPLA2 s in given tissue microenvironments. sPLA2 s hydrolyze not only phospholipids in the plasma membrane of activated, damaged or dying mammalian cells, but also extracellular phospholipids such as those in extracellular vesicles, microbe membranes, lipoproteins, surfactants, and dietary phospholipids, thereby exacerbating or ameliorating various diseases. The actions of sPLA2 s are dependent on, or independent of, the generation of fatty acid- or lysophospholipid-derived lipid mediators according to the pathophysiological contexts. In this review, we make an overview of our current understanding of the roles of individual sPLA2 s in various immune responses and associated diseases.
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Affiliation(s)
- Makoto Murakami
- Laboratory of Microenvironmental and Metabolic Health Science, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
- AMED-CREST, Japan Agency for Medical Research and Development, Tokyo, Japan
| | - Hiroyasu Sato
- Laboratory of Microenvironmental and Metabolic Health Science, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Yoshitaka Taketomi
- Laboratory of Microenvironmental and Metabolic Health Science, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
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Yamamoto K, Hakoi H, Nomura S, Murakami M. The Roles of sPLA 2s in Skin Homeostasis and Disease. Biomolecules 2023; 13:biom13040668. [PMID: 37189415 DOI: 10.3390/biom13040668] [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: 02/14/2023] [Revised: 03/21/2023] [Accepted: 04/10/2023] [Indexed: 05/17/2023] Open
Abstract
Among the phospholipase A2 (PLA2) family, the secreted PLA2 (sPLA2) family in mammals contains 11 members that exhibit unique tissue or cellular distributions and enzymatic properties. Current studies using knockout and/or transgenic mice for a nearly full set of sPLA2s, in combination with comprehensive lipidomics, have revealed the diverse pathophysiological roles of sPLA2s in various biological events. Individual sPLA2s exert specific functions within tissue microenvironments, likely through the hydrolysis of extracellular phospholipids. Lipids are an essential biological component for skin homeostasis, and disturbance of lipid metabolism by deletion or overexpression of lipid-metabolizing enzymes or lipid-sensing receptors often leads to skin abnormalities that are easily visible on the outside. Over the past decades, our studies using knockout and transgenic mice for various sPLA2s have uncovered several new aspects of these enzymes as modulators of skin homeostasis and disease. This article summarizes the roles of several sPLA2s in skin pathophysiology, providing additional insight into the research fields of sPLA2s, lipids, and skin biology.
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Affiliation(s)
- Kei Yamamoto
- Graduate School of Technology, Industrial and Social Sciences, Tokushima University, 2-1 Minami-jyosanjima, Tokushima 770-8513, Japan
| | - Haruka Hakoi
- Graduate School of Technology, Industrial and Social Sciences, Tokushima University, 2-1 Minami-jyosanjima, Tokushima 770-8513, Japan
| | - Saki Nomura
- Graduate School of Technology, Industrial and Social Sciences, Tokushima University, 2-1 Minami-jyosanjima, Tokushima 770-8513, Japan
| | - Makoto Murakami
- Laboratory of Microenvironmental and Metabolic Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo (UTokyo), 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan
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5
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Exploration of the Mechanism of Linoleic Acid Metabolism Dysregulation in Metabolic Syndrome. Genet Res (Camb) 2022; 2022:6793346. [PMID: 36518097 PMCID: PMC9722286 DOI: 10.1155/2022/6793346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 10/11/2022] [Accepted: 10/27/2022] [Indexed: 11/29/2022] Open
Abstract
We aimed to explore the mechanism of the linoleic acid metabolism in metabolic syndrome (MetS). RNA-seq data for 16 samples with or without MetS from the GSE145412 dataset were collected. Gene set variation analysis (GSVA), gene set enrichment analysis (GSEA), and gene differential expression analysis were performed. Expression data of differentially expressed genes (DEGs) involved in the linoleic acid metabolism pathway were mapped to the pathway by using Pathview for visualization. There were 19 and 10 differentially expressed biological processes in the disease group and healthy group, respectively. 9 KEGG pathways were differentially expressed in the disease group. Linoleic acid metabolism was the only differentially expressed pathway in the healthy group. The GSVA enrichment score of the linoleic acid metabolism pathway in the disease group was markedly lower than that in the healthy group. The GSEA result showed that the linoleic acid metabolism pathway was significantly downregulated in the disease group. JMJD7-PLA2G4B, PLA2G1B, PLA2G2D, CYP2C8, and CYP2J2 involved in the pathway were significantly downregulated in the disease group. This study may provide novel insight into MetS from the point of linoleic acid metabolism dysregulation.
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Old but New: Group IIA Phospholipase A 2 as a Modulator of Gut Microbiota. Metabolites 2022; 12:metabo12040352. [PMID: 35448539 PMCID: PMC9029192 DOI: 10.3390/metabo12040352] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 04/11/2022] [Accepted: 04/12/2022] [Indexed: 12/15/2022] Open
Abstract
Among the phospholipase A2 (PLA2) superfamily, the secreted PLA2 (sPLA2) family contains 11 mammalian isoforms that exhibit unique tissue or cellular distributions and enzymatic properties. Current studies using sPLA2-deficient or -overexpressed mouse strains, along with mass spectrometric lipidomics to determine sPLA2-driven lipid pathways, have revealed the diverse pathophysiological roles of sPLA2s in various biological events. In general, individual sPLA2s exert their specific functions within tissue microenvironments, where they are intrinsically expressed through hydrolysis of extracellular phospholipids. Recent studies have uncovered a new aspect of group IIA sPLA2 (sPLA2-IIA), a prototypic sPLA2 with the oldest research history among the mammalian PLA2s, as a modulator of the gut microbiota. In the intestine, Paneth cell-derived sPLA2-IIA acts as an antimicrobial protein to shape the gut microbiota, thereby secondarily affecting inflammation, allergy, and cancer in proximal and distal tissues. Knockout of intestinal sPLA2-IIA in BALB/c mice leads to alterations in skin cancer, psoriasis, and anaphylaxis, while overexpression of sPLA2-IIA in Pla2g2a-null C57BL/6 mice induces systemic inflammation and exacerbates arthritis. These phenotypes are associated with notable changes in gut microbiota and fecal metabolites, are variable in different animal facilities, and are abrogated after antibiotic treatment, co-housing, or fecal transfer. These studies open a new mechanistic action of this old sPLA2 and add the sPLA2 family to the growing list of endogenous factors capable of affecting the microbe–host interaction and thereby systemic homeostasis and diseases.
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Kuefner MS, Stephenson E, Savikj M, Smallwood HS, Dong Q, Payré C, Lambeau G, Park EA. Group IIA secreted phospholipase A2 (PLA2G2A) augments adipose tissue thermogenesis. FASEB J 2021; 35:e21881. [PMID: 34478587 DOI: 10.1096/fj.202002481rr] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 08/10/2021] [Accepted: 08/11/2021] [Indexed: 12/25/2022]
Abstract
Group IIA secreted phospholipase A2 (PLA2G2A) hydrolyzes glycerophospholipids at the sn-2 position resulting in the release of fatty acids and lysophospholipids. C57BL/6 mice do not express Pla2g2a due to a frameshift mutation (wild-type [WT] mice). We previously reported that transgenic expression of human PLA2G2A in C57BL/6 mice (IIA+ mice) protects against weight gain and insulin resistance, in part by increasing total energy expenditure. Additionally, we found that brown and white adipocytes from IIA+ mice have increased expression of mitochondrial uncoupling markers, such as uncoupling protein 1 (UCP1), peroxisome proliferator-activated receptor-gamma coactivator, and PR domain containing 16, suggesting that the energy expenditure phenotype might be due to an increased thermogenic capacity in adipose tissue. Here, we further characterize the impact of PLA2G2A on thermogenic mechanisms in adipose tissue. Metabolic analysis of WT and IIA+ mice revealed that even when housed within their thermoneutral zone, IIA+ mice have elevated energy expenditure compared to WT littermates. Increased energy expenditure in IIA+ mice is associated with increased citrate synthase activity in brown adipose tissue (BAT) and increased mitochondrial respiration in both brown and white adipocytes. We also observed that direct addition of recombinant PLA2G2A enzyme to in vitro cultured adipocytes results in the marked induction of UCP1 protein expression. Finally, we report that PLA2G2A induces the expression of numerous transcripts related to energy substrate transport and metabolism in BAT, suggestive of an increase in substrate flux to fuel BAT activity. These data demonstrate that PLA2G2A enhances adipose tissue thermogenesis, in part, through elevated substrate delivery and increased mitochondrial content in BAT.
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Affiliation(s)
- Michael S Kuefner
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Erin Stephenson
- Department of Anatomy, College of Graduate Studies and Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, Illinois, USA
| | - Mladen Savikj
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Heather S Smallwood
- Department of Pharmacology, The University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Qingming Dong
- Department of Pharmacology, The University of Tennessee Health Science Center, Memphis, Tennessee, USA.,Department of Veterans Affairs Medical Center, Memphis, Tennessee, USA
| | - Christine Payré
- Université Côte d'Azur, Centre National de la Recherche Scientifique, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne Sophia Antipolis, France
| | - Gérard Lambeau
- Université Côte d'Azur, Centre National de la Recherche Scientifique, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne Sophia Antipolis, France
| | - Edwards A Park
- Department of Pharmacology, The University of Tennessee Health Science Center, Memphis, Tennessee, USA.,Department of Veterans Affairs Medical Center, Memphis, Tennessee, USA
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Kuefner MS. Secretory Phospholipase A2s in Insulin Resistance and Metabolism. Front Endocrinol (Lausanne) 2021; 12:732726. [PMID: 34512555 PMCID: PMC8429832 DOI: 10.3389/fendo.2021.732726] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 08/09/2021] [Indexed: 01/01/2023] Open
Abstract
The phospholipases A2 (PLA2) superfamily encompasses enzymes commonly found in mammalian tissues and snake venom. Many of these enzymes have unique tissue distribution, function, and substrate specificity suggesting distinct biological roles. In the past, much of the research on secretory PLA2s has analyzed their roles in inflammation, anti-bacterial actions, and atherosclerosis. In recent studies utilizing a variety of mouse models, pancreatic islets, and clinical trials, a role for many of these enzymes in the control of metabolism and insulin action has been revealed. In this review, this research, and the unique contributions of the PLA2 enzymes in insulin resistance and metabolism.
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Updating Phospholipase A 2 Biology. Biomolecules 2020; 10:biom10101457. [PMID: 33086624 PMCID: PMC7603386 DOI: 10.3390/biom10101457] [Citation(s) in RCA: 93] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 10/09/2020] [Accepted: 10/15/2020] [Indexed: 12/30/2022] Open
Abstract
The phospholipase A2 (PLA2) superfamily contains more than 50 enzymes in mammals that are subdivided into several distinct families on a structural and biochemical basis. In principle, PLA2 has the capacity to hydrolyze the sn-2 position of glycerophospholipids to release fatty acids and lysophospholipids, yet several enzymes in this superfamily catalyze other reactions rather than or in addition to the PLA2 reaction. PLA2 enzymes play crucial roles in not only the production of lipid mediators, but also membrane remodeling, bioenergetics, and body surface barrier, thereby participating in a number of biological events. Accordingly, disturbance of PLA2-regulated lipid metabolism is often associated with various diseases. This review updates the current state of understanding of the classification, enzymatic properties, and biological functions of various enzymes belonging to the PLA2 superfamily, focusing particularly on the novel roles of PLA2s in vivo.
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Rescue of Hepatic Phospholipid Remodeling Defectin iPLA2β-Null Mice Attenuates Obese but Not Non-Obese Fatty Liver. Biomolecules 2020; 10:biom10091332. [PMID: 32957701 PMCID: PMC7565968 DOI: 10.3390/biom10091332] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 09/15/2020] [Accepted: 09/15/2020] [Indexed: 12/19/2022] Open
Abstract
Polymorphisms of group VIA calcium-independent phospholipase A2 (iPLA2β or PLA2G6) are positively associated with adiposity, blood lipids, and Type-2 diabetes. The ubiquitously expressed iPLA2β catalyzes the hydrolysis of phospholipids (PLs) to generate a fatty acid and a lysoPL. We studied the role of iPLA2β on PL metabolism in non-alcoholic fatty liver disease (NAFLD). By using global deletion iPLA2β-null mice, we investigated three NAFLD mouse models; genetic Ob/Ob and long-term high-fat-diet (HFD) feeding (representing obese NAFLD) as well as feeding with methionine- and choline-deficient (MCD) diet (representing non-obese NAFLD). A decrease of hepatic PLs containing monounsaturated- and polyunsaturated fatty acids and a decrease of the ratio between PLs and cholesterol esters were observed in all three NAFLD models. iPLA2β deficiency rescued these decreases in obese, but not in non-obese, NAFLD models. iPLA2β deficiency elicited protection against fatty liver and obesity in the order of Ob/Ob › HFD » MCD. Liver inflammation was not protected in HFD NAFLD, and that liver fibrosis was even exaggerated in non-obese MCD model. Thus, the rescue of hepatic PL remodeling defect observed in iPLA2β-null mice was critical for the protection against NAFLD and obesity. However, iPLA2β deletion in specific cell types such as macrophages may render liver inflammation and fibrosis, independent of steatosis protection.
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Sæle Ø, Rød KEL, Quinlivan VH, Li S, Farber SA. A novel system to quantify intestinal lipid digestion and transport. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1863:948-957. [PMID: 29778665 PMCID: PMC6054555 DOI: 10.1016/j.bbalip.2018.05.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 05/04/2018] [Accepted: 05/16/2018] [Indexed: 02/05/2023]
Abstract
The zebrafish larva is a powerful tool for the study of dietary triglyceride (TG) digestion and how fatty acids (FA) derived from dietary lipids are absorbed, metabolized and distributed to the body. While fluorescent FA analogues have enabled visualization of FA metabolism, methods for specifically assaying TG digestion are badly needed. Here we present a novel High Performance Liquid Chromatography (HPLC) method that quantitatively differentiates TG and phospholipid (PL) molecules with one or two fluorescent FA analogues. We show how this tool may be used to discriminate between undigested and digested TG or phosphatidylcholine (PC), and also the products of TG or PC that have been digested, absorbed and re-synthesized into new lipid molecules. Using this approach, we explored the dietary requirement of zebrafish larvae for phospholipids. Here we demonstrate that dietary TG is digested and absorbed in the intestinal epithelium, but without dietary PC, TG accumulates and is not transported out of the enterocytes. Consequently, intestinal ER stress increases and the ingested lipid is not available support the energy and metabolic needs of other tissues. In TG diets with PC, TG is readily transported from the intestine and subsequently metabolized.
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Affiliation(s)
- Øystein Sæle
- Institute of Marine Research, Strandgaten 229, 5004 Bergen, Norway.
| | - Kari Elin L Rød
- Institute of Marine Research, Strandgaten 229, 5004 Bergen, Norway
| | - Vanessa H Quinlivan
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218, USA; The Johns Hopkins University, Department of Biology, Baltimore, MD 21218, USA
| | - Shengrong Li
- Avanti Polar Lipids, Inc., 700 Industrial Park Drive, Alabaster, AL 35007-9105, USA
| | - Steven A Farber
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218, USA; The Johns Hopkins University, Department of Biology, Baltimore, MD 21218, USA.
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Cash JG, Konaniah E, Hegde N, Kuhel DG, Watanabe M, Romick-Rosendale L, Hui DY. Therapeutic reduction of lysophospholipids in the digestive tract recapitulates the metabolic benefits of bariatric surgery and promotes diabetes remission. Mol Metab 2018; 16:55-64. [PMID: 30087032 PMCID: PMC6158127 DOI: 10.1016/j.molmet.2018.07.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 07/10/2018] [Accepted: 07/23/2018] [Indexed: 01/07/2023] Open
Abstract
OBJECTIVE Obesity and obesity-related metabolic disorders are major health problems worldwide. The most effective obesity intervention is bariatric surgery. This study tested the hypothesis that bariatric surgery alters phospholipid metabolism in the gastrointestinal tract to favor a metabolically healthy gut microbiota profile and therapeutic intervention of phospholipid metabolism in the gastrointestinal may have similar metabolic benefits. METHODS The first study compared plasma levels of the bioactive lipid metabolites lysophospholipid and trimethylamine N-oxide (TMAO) as well as gut microbiota profile in high fat/carbohydrate (HFHC) diet-fed C57BL/6 mice with or without vertical sleeve gastrectomy (VSG) and in Pla2g1b-/- mice with group 1B phospholipase A2 gene inactivation. The second study examined the effectiveness of the non-absorbable secretory phospholipase A2 inhibitor methyl indoxam to reverse hyperglycemia and hyperlipidemia in HFHC diet-fed C57BL/6 mice after diabetes onset. RESULTS Both bariatric surgery and PLA2G1B inactivation were shown to reduce lysophospholipid content in the gastrointestinal tract, resulting in resistance to HFHC diet-induced alterations of the gut microbiota, reduction of the cardiovascular risk factors hyperlipidemia and TMAO, decreased adiposity, and prevention of HFHC diet-induced diabetes. Importantly, treatment of wild type mice with methyl indoxam after HFHC diet-induced onset of hyperlipidemia and hyperglycemia effectively restored normal plasma lipid and glucose levels and replicated the metabolic benefits of VSG surgery with diabetes remission and TMAO reduction. CONCLUSION These results provided pre-clinical evidence that PLA2G1B inhibition in the digestive tract may be a viable alternative option to bariatric surgery for obesity and obesity-related cardiometabolic disorder intervention.
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Affiliation(s)
- James G Cash
- Department of Pathology and Laboratory Medicine, Metabolic Diseases Research Center, University of Cincinnati College of Medicine, Cincinnati, OH, 45237, USA
| | - Eddy Konaniah
- Department of Pathology and Laboratory Medicine, Metabolic Diseases Research Center, University of Cincinnati College of Medicine, Cincinnati, OH, 45237, USA
| | - Narasimha Hegde
- Department of Pathology and Laboratory Medicine, Metabolic Diseases Research Center, University of Cincinnati College of Medicine, Cincinnati, OH, 45237, USA
| | - David G Kuhel
- Department of Pathology and Laboratory Medicine, Metabolic Diseases Research Center, University of Cincinnati College of Medicine, Cincinnati, OH, 45237, USA
| | - Miki Watanabe
- Department of Pathology and Laboratory Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
| | - Lindsey Romick-Rosendale
- Department of Pathology and Laboratory Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
| | - David Y Hui
- Department of Pathology and Laboratory Medicine, Metabolic Diseases Research Center, University of Cincinnati College of Medicine, Cincinnati, OH, 45237, USA.
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Hui DY. Group 1B phospholipase A 2 in metabolic and inflammatory disease modulation. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1864:784-788. [PMID: 30003964 DOI: 10.1016/j.bbalip.2018.07.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 07/02/2018] [Accepted: 07/05/2018] [Indexed: 12/11/2022]
Abstract
The group 1B phospholipase A2 (PLA2G1B) is a secreted phospholipase that catalyzes the hydrolytic removal of the sn-2 fatty acyl moiety from phospholipids. This enzyme is synthesized most abundantly in the pancreas and is also expressed in the lung. The first part of this review article focuses on the role of pancreatic-derived PLA2G1B in mediating lipid absorption and discusses how the PLA2G1B-derived metabolic product contributes to cardiometabolic diseases, including obesity, hyperinsulinemia, hyperlipidemia, and atherosclerosis. The anti-helminth properties of PLA2G1B will also be discussed. The second part of this review will focus on PLA2G1B expressed in the lung, and in vitro data suggest that how this enzyme may modulate lung inflammation via both hydrolytic activity-dependent and -dependent mechanisms. Finally, recent studies revealing a relationship between PLA2G1B and cancer will also be discussed. This article is part of a Special Issue entitled Novel functions of phospholipase A2 Guest Editors: Makoto Murakami and Gerard Lambeau.
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Affiliation(s)
- David Y Hui
- Department of Pathology and Laboratory Medicine, Metabolic Diseases Research Center, University of Cincinnati College of Medicine, Cincinnati, OH 45237, USA; Department of Pathology, Metabolic Diseases Research Center, University of Cincinnati College of Medicine, 2120 E. Galbraith Road, Cincinnati, OH 45237, United States.
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14
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Panchal SK, Bliss E, Brown L. Capsaicin in Metabolic Syndrome. Nutrients 2018; 10:E630. [PMID: 29772784 PMCID: PMC5986509 DOI: 10.3390/nu10050630] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2018] [Revised: 05/07/2018] [Accepted: 05/14/2018] [Indexed: 12/21/2022] Open
Abstract
Capsaicin, the major active constituent of chilli, is an agonist on transient receptor potential vanilloid channel 1 (TRPV1). TRPV1 is present on many metabolically active tissues, making it a potentially relevant target for metabolic interventions. Insulin resistance and obesity, being the major components of metabolic syndrome, increase the risk for the development of cardiovascular disease, type 2 diabetes, and non-alcoholic fatty liver disease. In vitro and pre-clinical studies have established the effectiveness of low-dose dietary capsaicin in attenuating metabolic disorders. These responses of capsaicin are mediated through activation of TRPV1, which can then modulate processes such as browning of adipocytes, and activation of metabolic modulators including AMP-activated protein kinase (AMPK), peroxisome proliferator-activated receptor α (PPARα), uncoupling protein 1 (UCP1), and glucagon-like peptide 1 (GLP-1). Modulation of these pathways by capsaicin can increase fat oxidation, improve insulin sensitivity, decrease body fat, and improve heart and liver function. Identifying suitable ways of administering capsaicin at an effective dose would warrant its clinical use through the activation of TRPV1. This review highlights the mechanistic options to improve metabolic syndrome with capsaicin.
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Affiliation(s)
- Sunil K Panchal
- Functional Foods Research Group, University of Southern Queensland, Toowoomba QLD 4350, Australia.
| | - Edward Bliss
- Functional Foods Research Group, University of Southern Queensland, Toowoomba QLD 4350, Australia.
- School of Health and Wellbeing, University of Southern Queensland, Toowoomba QLD 4350, Australia.
| | - Lindsay Brown
- Functional Foods Research Group, University of Southern Queensland, Toowoomba QLD 4350, Australia.
- School of Health and Wellbeing, University of Southern Queensland, Toowoomba QLD 4350, Australia.
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15
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MURAKAMI M. Lipoquality control by phospholipase A 2 enzymes. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2017; 93:677-702. [PMID: 29129849 PMCID: PMC5743847 DOI: 10.2183/pjab.93.043] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The phospholipase A2 (PLA2) family comprises a group of lipolytic enzymes that typically hydrolyze the sn-2 position of glycerophospholipids to give rise to fatty acids and lysophospholipids. The mammalian genome encodes more than 50 PLA2s or related enzymes, which are classified into several subfamilies on the basis of their structures and functions. From a general viewpoint, the PLA2 family has mainly been implicated in signal transduction, producing bioactive lipid mediators derived from fatty acids and lysophospholipids. Recent evidence indicates that PLA2s also contribute to phospholipid remodeling for membrane homeostasis or energy production for fatty acid β-oxidation. Accordingly, PLA2 enzymes can be regarded as one of the key regulators of the quality of lipids, which I herein refer to as lipoquality. Disturbance of PLA2-regulated lipoquality hampers tissue and cellular homeostasis and can be linked to various diseases. Here I overview the current state of understanding of the classification, enzymatic properties, and physiological functions of the PLA2 family.
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Affiliation(s)
- Makoto MURAKAMI
- Laboratory of Environmental and Metabolic Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, the University of Tokyo, Tokyo, Japan
- Lipid Metabolism Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
- AMED-CREST, Japan Agency for Medical Research and Development, Tokyo, Japan
- Correspondence should be addressed: M. Murakami, Laboratory of Environmental and Metabolic Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan (e-mail: )
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16
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Chen J, Chen L, Sanseau P, Freudenberg JM, Rajpal DK. Significant obesity-associated gene expression changes occur in the stomach but not intestines in obese mice. Physiol Rep 2016; 4:4/10/e12793. [PMID: 27207783 PMCID: PMC4886165 DOI: 10.14814/phy2.12793] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 04/07/2016] [Indexed: 12/15/2022] Open
Abstract
The gastrointestinal (GI) tract can have significant impact on the regulation of the whole‐body metabolism and may contribute to the development of obesity and diabetes. To systemically elucidate the role of the GI tract in obesity, we performed a transcriptomic analysis in different parts of the GI tract of two obese mouse models: ob/ob and high‐fat diet (HFD) fed mice. Compared to their lean controls, significant changes in the gene expression were observed in both obese mouse groups in the stomach (ob/ob: 959; HFD: 542). In addition, these changes were quantitatively much higher than in the intestine. Despite the difference in genetic background, the two mouse models shared 296 similar gene expression changes in the stomach. Among those genes, some had known associations to obesity, diabetes, and insulin resistance. In addition, the gene expression profiles strongly suggested an increased gastric acid secretion in both obese mouse models, probably through an activation of the gastrin pathway. In conclusion, our data reveal a previously unknown dominant connection between the stomach and obesity in murine models extensively used in research.
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Affiliation(s)
- Jing Chen
- Computational Biology, Target Sciences, GlaxoSmithKline, King of Prussia, Pennsylvania
| | - Lihong Chen
- Enteroendocrinology DPU, GlaxoSmithKline, Research Triangle Park, North Carolina
| | - Philippe Sanseau
- Computational Biology, Target Sciences, GlaxoSmithKline, King of Prussia, Pennsylvania
| | | | - Deepak K Rajpal
- Computational Biology, Target Sciences, GlaxoSmithKline, King of Prussia, Pennsylvania
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El Alaoui M, Soulère L, Noiriel A, Popowycz F, Khatib A, Queneau Y, Abousalham A. A continuous spectrophotometric assay that distinguishes between phospholipase A1 and A2 activities. J Lipid Res 2016; 57:1589-97. [PMID: 27194811 PMCID: PMC4959851 DOI: 10.1194/jlr.d065961] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 05/11/2016] [Indexed: 11/30/2022] Open
Abstract
A new spectrophotometric assay was developed to measure, continuously and specifically, phospholipase A1 (PLA1) or phospholipase A2 (PLA2) activities using synthetic glycerophosphatidylcholines (PCs) containing α-eleostearic acid, either at the sn-1 position [1-α-eleostearoyl-2-octadecyl-rac-glycero-3-phosphocholine (EOPC)] or at the sn-2 position [1-octadecyl-2-α-eleostearoyl-rac-glycero-3-phosphocholine (OEPC)]. The substrates were coated onto the wells of microtiter plates. A nonhydrolyzable ether bond, with a non-UV-absorbing alkyl chain, was introduced at the other sn position to prevent acyl chain migration during lipolysis. Upon enzyme action, α-eleostearic acid is liberated and then solubilized into the micellar phase. The PLA1 or PLA2 activity was measured by the increase in absorbance at 272 nm due to the transition of α-eleostearic acid from the adsorbed to the soluble state. EOPC and OEPC differentiate, with excellent accuracy, between PLA1 and PLA2 activity. Lecitase(®), guinea pig pancreatic lipase-related protein 2 (known to be a PLA1 enzyme), bee venom PLA2, and porcine pancreatic PLA2 were all used to validate the assay. Compared with current assays used for continuously measuring PLA1 or PLA2 activities and/or their inhibitors, the development of this sensitive enzymatic method, using coated PC substrate analogs to natural lipids and based on the UV spectroscopic properties of α-eleostearic acid, is a significant improvement.
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Affiliation(s)
- Meddy El Alaoui
- Univ Lyon, Université Lyon 1, UMR 5246, CNRS, INSA Lyon, CPE Lyon, Institut de Chimie et de Biochimie Moléculaires et Supramoléculaires (ICBMS), Métabolismes, Enzymes et Mécanismes Moléculaires (MEM), F-69622 Villeurbanne, France Univ Lyon, INSA Lyon, UMR 5246, CNRS, Université Lyon 1, CPE Lyon, Institut de Chimie et de Biochimie Moléculaires et Supramoléculaires (ICBMS), Chimie Organique et Bioorganique (COB), F-69621 Villeurbanne, France
| | - Laurent Soulère
- Univ Lyon, INSA Lyon, UMR 5246, CNRS, Université Lyon 1, CPE Lyon, Institut de Chimie et de Biochimie Moléculaires et Supramoléculaires (ICBMS), Chimie Organique et Bioorganique (COB), F-69621 Villeurbanne, France
| | - Alexandre Noiriel
- Univ Lyon, Université Lyon 1, UMR 5246, CNRS, INSA Lyon, CPE Lyon, Institut de Chimie et de Biochimie Moléculaires et Supramoléculaires (ICBMS), Métabolismes, Enzymes et Mécanismes Moléculaires (MEM), F-69622 Villeurbanne, France
| | - Florence Popowycz
- Univ Lyon, INSA Lyon, UMR 5246, CNRS, Université Lyon 1, CPE Lyon, Institut de Chimie et de Biochimie Moléculaires et Supramoléculaires (ICBMS), Chimie Organique et Bioorganique (COB), F-69621 Villeurbanne, France
| | - Abdallah Khatib
- Univ Lyon, Université Lyon 1, UMR 5246, CNRS, INSA Lyon, CPE Lyon, Institut de Chimie et de Biochimie Moléculaires et Supramoléculaires (ICBMS), Métabolismes, Enzymes et Mécanismes Moléculaires (MEM), F-69622 Villeurbanne, France
| | - Yves Queneau
- Univ Lyon, INSA Lyon, UMR 5246, CNRS, Université Lyon 1, CPE Lyon, Institut de Chimie et de Biochimie Moléculaires et Supramoléculaires (ICBMS), Chimie Organique et Bioorganique (COB), F-69621 Villeurbanne, France
| | - Abdelkarim Abousalham
- Univ Lyon, Université Lyon 1, UMR 5246, CNRS, INSA Lyon, CPE Lyon, Institut de Chimie et de Biochimie Moléculaires et Supramoléculaires (ICBMS), Métabolismes, Enzymes et Mécanismes Moléculaires (MEM), F-69622 Villeurbanne, France
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18
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Murakami M, Yamamoto K, Miki Y, Murase R, Sato H, Taketomi Y. The Roles of the Secreted Phospholipase A 2 Gene Family in Immunology. Adv Immunol 2016; 132:91-134. [PMID: 27769509 PMCID: PMC7112020 DOI: 10.1016/bs.ai.2016.05.001] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Within the phospholipase A2 (PLA2) family that hydrolyzes phospholipids to yield fatty acids and lysophospholipids, secreted PLA2 (sPLA2) enzymes comprise the largest group containing 11 isoforms in mammals. Individual sPLA2s exhibit unique tissue or cellular distributions and enzymatic properties, suggesting their distinct biological roles. Although PLA2 enzymes, particularly cytosolic PLA2 (cPLA2α), have long been implicated in inflammation by driving arachidonic acid metabolism, the precise biological roles of sPLA2s have remained a mystery over the last few decades. Recent studies employing mice gene-manipulated for individual sPLA2s, in combination with mass spectrometric lipidomics to identify their target substrates and products in vivo, have revealed their roles in diverse biological events, including immunity and associated disorders, through lipid mediator-dependent or -independent processes in given microenvironments. In this review, we summarize our current knowledge of the roles of sPLA2s in various immune responses and associated diseases.
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Affiliation(s)
- M Murakami
- Lipid Metabolism Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan; AMED-CREST, Japan Agency for Medical Research and Development, Tokyo, Japan.
| | - K Yamamoto
- Lipid Metabolism Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan; Faculty of Bioscience and Bioindustry, Tokushima University, Tokushima, Japan
| | - Y Miki
- Lipid Metabolism Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - R Murase
- Lipid Metabolism Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - H Sato
- Lipid Metabolism Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Y Taketomi
- Lipid Metabolism Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
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19
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Sato H, Taketomi Y, Murakami M. Metabolic regulation by secreted phospholipase A 2. Inflamm Regen 2016; 36:7. [PMID: 29259680 PMCID: PMC5725825 DOI: 10.1186/s41232-016-0012-7] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Accepted: 05/10/2016] [Indexed: 12/18/2022] Open
Abstract
Within the phospholipase A2 (PLA2) superfamily that hydrolyzes phospholipids to yield fatty acids and lysophospholipids, the secreted PLA2 (sPLA2) enzymes comprise the largest family that contains 11 isoforms in mammals. Individual sPLA2s exhibit unique distributions and specific enzymatic properties, suggesting their distinct biological roles. While sPLA2s have long been implicated in inflammation and atherosclerosis, it has become evident that they are involved in diverse biological events through lipid mediator-dependent or mediator-independent processes in a given microenvironment. In recent years, new biological aspects of sPLA2s have been revealed using their transgenic and knockout mouse models in combination with mass spectrometric lipidomics to unveil their target substrates and products in vivo. In this review, we summarize our current knowledge of the roles of sPLA2s in metabolic disorders including obesity, hepatic steatosis, diabetes, insulin resistance, and adipose tissue inflammation.
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Affiliation(s)
- Hiroyasu Sato
- Lipid Metabolism Project, The Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo, 156-8506 Japan
| | - Yoshitaka Taketomi
- Lipid Metabolism Project, The Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo, 156-8506 Japan
| | - Makoto Murakami
- Lipid Metabolism Project, The Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo, 156-8506 Japan.,AMED-CREST, Japan Agency for Medical Research and Development, Tokyo, 100-0004 Japan
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20
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Liver-specific overexpression of LPCAT3 reduces postprandial hyperglycemia and improves lipoprotein metabolic profile in mice. Nutr Diabetes 2016; 6:e206. [PMID: 27110687 PMCID: PMC4855257 DOI: 10.1038/nutd.2016.12] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 01/12/2016] [Accepted: 03/14/2016] [Indexed: 01/09/2023] Open
Abstract
Previous studies have shown that group 1B phospholipase A2-mediated absorption of lysophospholipids inhibits hepatic fatty acid β-oxidation and contributes directly to postprandial hyperglycemia and hyperlipidemia, leading to increased risk of cardiometabolic disease. The current study tested the possibility that increased expression of lysophosphatidylcholine acyltransferase-3 (LPCAT3), an enzyme that converts lysophosphatidylcholine to phosphatidylcholine in the liver, may alleviate the adverse effects of lysophospholipids absorbed after a lipid-glucose mixed meal. The injection of an adenovirus vector harboring the human LPCAT3 gene into C57BL/6 mice increased hepatic LPCAT3 expression fivefold compared with mice injected with a control LacZ adenovirus. Postprandial glucose tolerance tests after feeding these animals with a bolus lipid-glucose mixed meal revealed that LPCAT3 overexpression improved postprandial hyperglycemia and glucose tolerance compared with control mice with LacZ adenovirus injection. Mice with LPCAT3 overexpression also showed reduced very low density lipoprotein production and displayed elevated levels of the metabolic- and cardiovascular-protective large apoE-rich high density lipoproteins in plasma. The mechanism underlying the metabolic benefits of LPCAT3 overexpression was shown to be due to the alleviation of lysophospholipid inhibition of fatty acid β-oxidation in hepatocytes. Taken together, these results suggest that specific LPCAT3 induction in the liver may be a viable strategy for cardiometabolic disease intervention.
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21
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Murakami M, Sato H, Miki Y, Yamamoto K, Taketomi Y. A new era of secreted phospholipase A₂. J Lipid Res 2015; 56:1248-61. [PMID: 25805806 DOI: 10.1194/jlr.r058123] [Citation(s) in RCA: 161] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Indexed: 12/18/2022] Open
Abstract
Among more than 30 members of the phospholipase A2 (PLA2) superfamily, secreted PLA2 (sPLA2) enzymes represent the largest family, being Ca(2+)-dependent low-molecular-weight enzymes with a His-Asp catalytic dyad. Individual sPLA2s exhibit unique tissue and cellular distributions and enzymatic properties, suggesting their distinct biological roles. Recent studies using transgenic and knockout mice for nearly a full set of sPLA2 subtypes, in combination with sophisticated lipidomics as well as biochemical and cell biological studies, have revealed distinct contributions of individual sPLA2s to various pathophysiological events, including production of pro- and anti-inflammatory lipid mediators, regulation of membrane remodeling, degradation of foreign phospholipids in microbes or food, or modification of extracellular noncellular lipid components. In this review, we highlight the current understanding of the in vivo functions of sPLA2s and the underlying lipid pathways as revealed by a series of studies over the last decade.
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Affiliation(s)
- Makoto Murakami
- Lipid Metabolism Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan CREST, Japan Science and Technology Agency, Saitama 332-0012, Japan
| | - Hiroyasu Sato
- Lipid Metabolism Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Yoshimi Miki
- Lipid Metabolism Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Kei Yamamoto
- Lipid Metabolism Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Yoshitaka Taketomi
- Lipid Metabolism Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
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22
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El Alaoui M, Noiriel A, Soulère L, Grand L, Queneau Y, Abousalham A. Development of a high-throughput assay for measuring phospholipase A activity using synthetic 1,2-α-eleostearoyl-sn-glycero-3-phosphocholine coated on microtiter plates. Anal Chem 2014; 86:10576-83. [PMID: 25266374 DOI: 10.1021/ac502096v] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
To date, several sensitive methods, based on radiolabeled elements or sterically hindered fluorochrome groups, are usually employed to screen phospholipase A (PLA) activities. With the aim of developing a convenient, specific, sensitive, and continuous new ultraviolet (UV) spectrophotometric assay for PLA, we have synthesized a specific glycerophosphatidylcholine (PC) esterified at the sn-1 and sn-2 positions, with α-eleostearic acid (9Z, 11E, 13E-octadecatrienoic acid) purified from Aleurites fordii seed oil. The conjugated triene present in α-eleostearic acid constitutes an intrinsic chromophore and, consequently, confers the strong UV absorption properties of this free fatty acid as well as of the glycerophospholipids harboring it. This coated PC film cannot be desorbed by the various buffers used during PLA assays. Following the action of PLA at the oil-water interface, α-eleostearic acid is freed and desorbed from the film and then solubilized with β-cyclodextrin. The UV absorbance of the α-eleostearic acid is considerably enhanced due to the transformation from an adsorbed to a water-soluble state. The PLA activity can be measured continuously by recording the variations with time of the UV absorption spectra. The rate of lipolysis was monitored by measuring the increase of absorption at 272 nm, which was found to be linear with time and proportional to the amount of added PLA. This continuous high-throughput PLA assay could be used to screen new PLA and/or PLA inhibitors present in various biological samples.
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Affiliation(s)
- Meddy El Alaoui
- Institut de Chimie et de Biochimie Moléculaires et Supramoléculaires (ICBMS) UMR 5246 CNRS, Organisation et Dynamique des Membranes Biologiques, Université Lyon 1 , Bâtiment Raulin, 43 Boulevard du 11 Novembre 1918, 69622 Villeurbanne Cedex, France
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23
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Hollie NI, Konaniah ES, Goodin C, Hui DY. Group 1B phospholipase A₂ inactivation suppresses atherosclerosis and metabolic diseases in LDL receptor-deficient mice. Atherosclerosis 2014; 234:377-80. [PMID: 24747111 PMCID: PMC4037866 DOI: 10.1016/j.atherosclerosis.2014.03.027] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Revised: 03/22/2014] [Accepted: 03/24/2014] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Previous studies have shown that inactivation of the group 1B phospholipase A2 (Pla2g1b) suppresses diet-induced obesity, hyperglycemia, insulin resistance, and hyperlipidemia in C57BL/6 mice. A possible influence of Pla2g1b inactivation on atherosclerosis has not been addressed previously. The current study utilized LDL receptor-deficient (Ldlr(-/-)) mice with plasma lipid levels and distribution similar to hyperlipidemic human subjects as a preclinical animal model to test the effectiveness of Pla2g1b inactivation on atherosclerosis. METHODS AND RESULTS The Pla2g1b(+/+)Ldlr(-/-) and Pla2g1b(-/-)Ldlr(-/-) mice were fed a low fat chow diet or a hypercaloric diet with 58.5 kcal% fat and 25 kcal% sucrose for 10 weeks. Minimal differences were observed between Pla2g1b(+/+)Ldlr(-/-) and Pla2g1b(-/-)Ldlr(-/-) mice when the animals were maintained on the low fat chow diet. However, when the animals were maintained on the hypercaloric diet, the Pla2g1(+/+)Ldlr(-/-) mice showed the expected body weight gain but the Pla2g1b(-/-)Ldlr(-/-) mice were resistant to diet-induced body weight gain. The Pla2g1b(-/-)Ldlr(-/-) mice also displayed lower fasting glucose, insulin, and plasma lipid levels compared to the Pla2g1b(+/+)Ldlr(-/-) mice, which displayed robust hyperglycemia, hyperinsulinemia, and hyperlipidemia in response to the hypercaloric diet. Importantly, atherosclerotic lesions in the aortic roots were also reduced 7-fold in the Pla2g1b(-/-)Ldlr(-/-) mice. CONCLUSION The effectiveness of Pla2g1b inactivation to suppress diet-induced body weight gain and reduce diabetes and atherosclerosis in LDL receptor-deficient mice suggests that pharmacological inhibition of Pla2g1b may be a viable strategy to decrease diet-induced obesity and the risk of diabetes and atherosclerosis in humans.
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Affiliation(s)
- Norris I Hollie
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45237, USA
| | - Eddy S Konaniah
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45237, USA
| | - Colleen Goodin
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45237, USA
| | - David Y Hui
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45237, USA.
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24
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Hollie NI, Cash JG, Matlib MA, Wortman M, Basford JE, Abplanalp W, Hui DY. Micromolar changes in lysophosphatidylcholine concentration cause minor effects on mitochondrial permeability but major alterations in function. Biochim Biophys Acta Mol Cell Biol Lipids 2013; 1841:888-95. [PMID: 24315825 DOI: 10.1016/j.bbalip.2013.11.013] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Revised: 11/02/2013] [Accepted: 11/26/2013] [Indexed: 12/17/2022]
Abstract
Mice deficient in group 1b phospholipase A2 have decreased plasma lysophosphatidylcholine and increased hepatic oxidation that is inhibited by intraperitoneal lysophosphatidylcholine injection. This study sought to identify a mechanism for lysophosphatidylcholine-mediated inhibition of hepatic oxidative function. Results showed that in vitro incubation of isolated mitochondria with 40-200μM lysophosphatidylcholine caused cyclosporine A-resistant swelling in a concentration-dependent manner. However, when mitochondria were challenged with 220μM CaCl2, cyclosporine A protected against permeability transition induced by 40μM, but not 80μM lysophosphatidylcholine. Incubation with 40-120μM lysophosphatidylcholine also increased mitochondrial permeability to 75μM CaCl2 in a concentration-dependent manner. Interestingly, despite incubation with 80μM lysophosphatidylcholine, the mitochondrial membrane potential was steady in the presence of succinate, and oxidation rates and respiratory control indices were similar to controls in the presence of succinate, glutamate/malate, and palmitoyl-carnitine. However, mitochondrial oxidation rates were inhibited by 30-50% at 100μM lysophosphatidylcholine. Finally, while 40μM lysophosphatidylcholine has no effect on fatty acid oxidation and mitochondria remained impermeable in intact hepatocytes, 100μM lysophosphatidylcholine inhibited fatty acid stimulated oxidation and caused intracellular mitochondrial permeability. Taken together, these present data demonstrated that LPC concentration dependently modulates mitochondrial microenvironment, with low micromolar concentrations of lysophosphatidylcholine sufficient to change hepatic oxidation rate whereas higher concentrations are required to disrupt mitochondrial integrity.
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Affiliation(s)
- Norris I Hollie
- Department of Pathology and Laboratory Medicine, Metabolic Diseases Institute, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - James G Cash
- Department of Pathology and Laboratory Medicine, Metabolic Diseases Institute, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - M Abdul Matlib
- Department of Pharmacology and Cell Biophysics, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Matthew Wortman
- Department of Internal Medicine, Division of Endocrinology, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Joshua E Basford
- Department of Pathology and Laboratory Medicine, Metabolic Diseases Institute, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - William Abplanalp
- Department of Pathology and Laboratory Medicine, Metabolic Diseases Institute, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - David Y Hui
- Department of Pathology and Laboratory Medicine, Metabolic Diseases Institute, University of Cincinnati College of Medicine, Cincinnati, OH, USA.
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25
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Sharma P, Thakran S, Deng X, Elam MB, Park EA. Nuclear corepressors mediate the repression of phospholipase A2 group IIa gene transcription by thyroid hormone. J Biol Chem 2013; 288:16321-16333. [PMID: 23629656 DOI: 10.1074/jbc.m112.445569] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Secretory phospholipase A2 group IIa (PLA2g2a) is associated with inflammation, hyperlipidemia, and atherogenesis. Transcription of the PLA2g2a gene is induced by multiple cytokines. Here, we report the surprising observation that thyroid hormone (T3) inhibited PLA2g2a gene expression in human and rat hepatocytes as well as in rat liver. Moreover, T3 reduced the cytokine-mediated induction of PLA2g2a, suggesting that the thyroid status may modulate aspects of the inflammatory response. In an effort to dissect the mechanism of repression by T3, we cloned the PLA2g2a gene and identified a negative T3 response element in the promoter. This T3 receptor (TRβ)-binding site differed considerably from consensus T3 stimulatory elements. Using in vitro and in vivo binding assays, we found that TRβ bound directly to the PLA2g2a promoter as a heterodimer with the retinoid X receptor. Knockdown of nuclear corepressor or silencing mediator for retinoid and thyroid receptors by siRNA blocked the T3 inhibition of PLA2g2a. Using chromatin immunoprecipitation assays, we showed that nuclear corepressor and silencing mediator for retinoid and thyroid receptors were associated with the PLA2g2a gene in the presence of T3. In contrast with the established role of T3 to promote coactivator association with TRβ, our experiments demonstrate a novel inverse recruitment mechanism in which liganded TRβ recruits corepressors to inhibit PLA2g2a expression.
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Affiliation(s)
- Pragya Sharma
- Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee 38163
| | - Shalini Thakran
- Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee 38163
| | - Xiong Deng
- Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee 38163; Department of Veterans Affairs Medical Center, Memphis, Tennessee 38163
| | - Marshall B Elam
- Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee 38163; Department of Veterans Affairs Medical Center, Memphis, Tennessee 38163
| | - Edwards A Park
- Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee 38163.
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26
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Emerging roles of secreted phospholipase A2 enzymes: An update. Biochimie 2013; 95:43-50. [DOI: 10.1016/j.biochi.2012.09.007] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Accepted: 09/11/2012] [Indexed: 01/18/2023]
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Abstract
Non-systemic drugs act within the intestinal lumen without reaching the systemic circulation. The first generation included polymeric resins that sequester phosphate ions, potassium ions, or bile acids for the treatment of electrolyte imbalances or hypercholesteremia. The field has evolved towards non-absorbable small molecules or peptides targeting luminal enzymes or transporters for the treatment of mineral metabolism disorders, diabetes, gastrointestinal (GI) disorders, and enteric infections. From a drug design and development perspective, non-systemic agents offer novel opportunities to address unmet medical needs while minimizing toxicity risks, but also present new challenges, including developing a better understanding and control of non-transcellular leakage pathways into the systemic circulation. The pharmacokinetic-pharmacodynamic relationship of drugs acting in the GI tract can be complex due to the variability of intestinal transit, interaction with chyme, and the complex environment of the surface epithelia. We review the main classes of nonabsorbable agents at various stages of development, and their therapeutic potential and limitations. The rapid progress in the identification of intestinal receptors and transporters, their functional characterization and role in metabolic and inflammatory disorders, will undoubtedly renew interest in the development of novel, safe, non-systemic therapeutics.
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Abstract
PURPOSE OF REVIEW The phospholipase A2 (PLA2) family of proteins includes lipolytic enzymes that liberate the sn-2 fatty acyl chains from phospholipids to yield nonesterified fatty acids and lysophospholipids. The purpose of this review is to discuss recent findings showing distinct roles of several of these PLA2 enzymes in inflammatory metabolic diseases such as diabetes and atherosclerosis. RECENT FINDINGS The group 1B PLA2 digestion of phospholipids in the intestinal lumen facilitates postprandial lysophospholipid absorption, which suppresses hepatic fatty acid oxidation leading to increased VLDL synthesis, decreased glucose tolerance, and promotion of tissue lipid deposition to accentuate diet-induced hyperlipidemia, diabetes, and obesity. Other secretory PLA2s promote inflammatory metabolic diseases by generating bioactive lipid metabolites to induce inflammatory cytokine production, whereas the major intracellular PLA2s, cPLA2α, and iPLA2, generate arachidonic acid and lysophosphatic acid in response to extracellular stimuli to activate leukocyte chemotactic response. SUMMARY Each member of the PLA2 family of enzymes serves a distinct role in generating active lipid metabolites that promote inflammatory metabolic diseases including atherosclerosis, hyperlipidemia, obesity, and diabetes. The development of specific drugs that target one or more of these PLA2 enzymes may be novel strategies for treatment of these chronic inflammatory metabolic disorders.
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Affiliation(s)
- David Y Hui
- Department of Pathology, Metabolic Diseases Institute, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
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29
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Nakayama H, Morita Y, Kimura H, Ishihara K, Akiba S, Uenishi J. Synthesis of N-(trifluoromethyl-2-pyridinyl)arenesulfonamides as an inhibitor of secretory phospholipase A₂. Chem Pharm Bull (Tokyo) 2011; 59:783-6. [PMID: 21628920 DOI: 10.1248/cpb.59.783] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A series of N-(trifluoromethyl-2-pyridinyl)alkane- and arenesulfonamides 2-5 have been synthesized by the substitution reaction of 2-chloro(trifluoromethyl)pyridines 6 with alkane- and arenesulfonamides 7. Their inhibitory activities against secretory phospholipase A₂ of porcine pancreas were examined and the analog N-[4,5-bis(trifluoromethyl)-2-pyridinyl]-4-trifluoromethylbenzenesulfonamide 4i was shown to have the highest inhibitory activity, with an IC(50) value of 0.58 mM.
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Affiliation(s)
- Hitoshi Nakayama
- Department of Pharmaceutical Chemistry, Kyoto Pharmaceutical University, Misasagi, Yamashina, Kyoto, Japan.
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30
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Hollie NI, Hui DY. Group 1B phospholipase A₂ deficiency protects against diet-induced hyperlipidemia in mice. J Lipid Res 2011; 52:2005-11. [PMID: 21908646 DOI: 10.1194/jlr.m019463] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Excessive absorption of products of dietary fat digestion leads to type 2 diabetes and other obesity-related disorders. Mice deficient in the group 1B phospholipase A₂ (Pla2g1b), a gut digestive enzyme, are protected against diet-induced obesity and type 2 diabetes without displaying dietary lipid malabsorption. This study tested the hypothesis that inhibition of Pla2g1b protects against diet-induced hyperlipidemia. Results showed that the Pla2g1b(-/-) mice had decreased plasma triglyceride and cholesterol levels compared with Pla2g1b(+/+) mice subsequent to feeding a high-fat, high-carbohydrate (hypercaloric) diet. These differences were evident before differences in body weight gains were observed. Injection of Poloxamer 407 to inhibit lipolysis revealed decreased VLDL production in Pla2g1b(-/-) mice. Supplementation with lysophosphatidylcholine, the product of Pla2g1b hydrolysis, restored VLDL production rates in Pla2g1b(-/-) mice and further elevated VLDL production in Pla2g1b(+/+) mice. The Pla2g1b(-/-) mice also displayed decreased postprandial lipidemia compared with Pla2g1b(+/+) mice. These results show that, in addition to dietary fatty acids, gut-derived lysophospholipids derived from Pla2g1b hydrolysis of dietary and biliary phospholipids also promote hepatic VLDL production. Thus, the inhibition of lysophospholipid absorption via Pla2g1b inactivation may prove beneficial against diet-induced hyperlipidemia in addition to the protection against obesity and diabetes.
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Affiliation(s)
- Norris I Hollie
- Department of Pathology and Laboratory Medicine, Metabolic Diseases Institute, University of Cincinnati College of Medicine, Cincinnati, OH 45237, USA
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31
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Murakami M, Taketomi Y, Sato H, Yamamoto K. Secreted phospholipase A2 revisited. J Biochem 2011; 150:233-55. [PMID: 21746768 DOI: 10.1093/jb/mvr088] [Citation(s) in RCA: 150] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Phospholipase A(2) (PLA(2)) catalyses the hydrolysis of the sn-2 position of glycerophospholipids to yield fatty acids and lysophospholipids. So far, more than 30 enzymes that possess PLA(2) or related activity have been identified in mammals. About one third of these enzymes belong to the secreted PLA(2) (sPLA(2)) family, which comprises low molecular weight, Ca(2+) requiring, secreted enzymes with a His/Asp catalytic dyad. Individual sPLA(2)s display distinct localizations and enzymatic properties, suggesting their specialized biological roles. However, in contrast to intracellular PLA(2)s, whose roles in signal transduction and membrane homoeostasis have been well documented, the biological roles of sPLA(2)s in vivo have remained obscure until recently. Over the past decade, information fuelled by studies employing knockout and transgenic mice as well as specific inhibitors, in combination with lipidomics, has clarified when and where the different sPLA(2) isoforms are expressed, which isoforms are involved in what types of pathophysiology, and how they exhibit their specific functions. In this review, we highlight recent advances in PLA(2) research, focusing mainly on the physiological functions of sPLA(2)s and their modes of action on 'extracellular' phospholipid targets versus lipid mediator production.
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Affiliation(s)
- Makoto Murakami
- Lipid Metabolism Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan
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Thompson MJ, Louth JC, Ferrara S, Jackson MP, Sorrell FJ, Cochrane EJ, Gever J, Baxendale S, Silber BM, Roehl HH, Chen B. Discovery of 6-substituted indole-3-glyoxylamides as lead antiprion agents with enhanced cell line activity, improved microsomal stability and low toxicity. Eur J Med Chem 2011; 46:4125-32. [PMID: 21726921 DOI: 10.1016/j.ejmech.2011.06.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2011] [Revised: 06/09/2011] [Accepted: 06/10/2011] [Indexed: 10/18/2022]
Abstract
A series of highly potent indole-3-glyoxylamide based antiprion agents was previously characterized, focusing on optimization of structure-activity relationship (SAR) at positions 1-3 of the indole system. New libraries interrogating the SAR at indole C-4 to C-7 now demonstrate that introducing electron-withdrawing substituents at C-6 may improve biological activity by up to an order of magnitude, and additionally confer higher metabolic stability. For the present screening libraries, both the degree of potency and trends in SAR were consistent across two cell line models of prion disease, and the large majority of compounds showed no evidence of toxic effects in zebrafish. The foregoing observations thus make the indole-3-glyoxylamides an attractive lead series for continuing development as potential therapeutic agents against prion disease.
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Affiliation(s)
- Mark J Thompson
- Department of Chemistry, University of Sheffield, Krebs Institute, Brook Hill, Sheffield S3 7HF, UK.
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Sato H, Isogai Y, Masuda S, Taketomi Y, Miki Y, Kamei D, Hara S, Kobayashi T, Ishikawa Y, Ishii T, Ikeda K, Taguchi R, Ishimoto Y, Suzuki N, Yokota Y, Hanasaki K, Suzuki-Yamamoto T, Yamamoto K, Murakami M. Physiological roles of group X-secreted phospholipase A2 in reproduction, gastrointestinal phospholipid digestion, and neuronal function. J Biol Chem 2011; 286:11632-48. [PMID: 21266581 PMCID: PMC3064216 DOI: 10.1074/jbc.m110.206755] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2010] [Revised: 01/17/2011] [Indexed: 01/04/2023] Open
Abstract
Although the secreted phospholipase A(2) (sPLA(2)) family has been generally thought to participate in pathologic events such as inflammation and atherosclerosis, relatively high and constitutive expression of group X sPLA(2) (sPLA(2)-X) in restricted sites such as reproductive organs, the gastrointestinal tract, and peripheral neurons raises a question as to the roles played by this enzyme in the physiology of reproduction, digestion, and the nervous system. Herein we used mice with gene disruption or transgenic overexpression of sPLA(2)-X to clarify the homeostatic functions of this enzyme at these locations. Our results suggest that sPLA(2)-X regulates 1) the fertility of spermatozoa, not oocytes, beyond the step of flagellar motility, 2) gastrointestinal phospholipid digestion, perturbation of which is eventually linked to delayed onset of a lean phenotype with reduced adiposity, decreased plasma leptin, and improved muscle insulin tolerance, and 3) neuritogenesis of dorsal root ganglia and the duration of peripheral pain nociception. Thus, besides its inflammatory action proposed previously, sPLA(2)-X participates in physiologic processes including male fertility, gastrointestinal phospholipid digestion linked to adiposity, and neuronal outgrowth and sensing.
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Affiliation(s)
- Hiroyasu Sato
- From the Lipid Metabolism Project, the Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 256-8506
- the Department of Health Chemistry, School of Pharceutical Sciences, Showa University, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555
| | - Yuki Isogai
- From the Lipid Metabolism Project, the Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 256-8506
- the Department of Biology, Faculty of Science, Ochanomizu University, 2-1-1 Otsuka, Bunkyo-ku, Tokyo 112-8610
| | - Seiko Masuda
- From the Lipid Metabolism Project, the Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 256-8506
- the Department of Health Chemistry, School of Pharceutical Sciences, Showa University, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555
| | - Yoshitaka Taketomi
- From the Lipid Metabolism Project, the Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 256-8506
- the Department of Health Chemistry, School of Pharceutical Sciences, Showa University, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555
| | - Yoshimi Miki
- From the Lipid Metabolism Project, the Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 256-8506
- the Department of Health Chemistry, School of Pharceutical Sciences, Showa University, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555
| | - Daisuke Kamei
- the Department of Health Chemistry, School of Pharceutical Sciences, Showa University, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555
| | - Shuntaro Hara
- the Department of Health Chemistry, School of Pharceutical Sciences, Showa University, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555
| | - Tetsuyuki Kobayashi
- the Department of Biology, Faculty of Science, Ochanomizu University, 2-1-1 Otsuka, Bunkyo-ku, Tokyo 112-8610
| | - Yukio Ishikawa
- the Department of Pathology, Toho University School of Medicine, 5-21-16 Omori-Nishi, Ohta-ku, Tokyo 143-8540
| | - Toshiharu Ishii
- the Department of Pathology, Toho University School of Medicine, 5-21-16 Omori-Nishi, Ohta-ku, Tokyo 143-8540
| | - Kazutaka Ikeda
- the Department of Metabolome, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033
- the Department of Neutritional Science, Faculty of Health and Welfare Science, Okayama Prefectural University, Kuboki 111, Souja, Okayama 719-1197, and
| | - Ryo Taguchi
- the Department of Metabolome, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033
- CREST and
| | - Yoshikazu Ishimoto
- Shionogi Research Laboratories, Shionogi and Company Ltd, 3-1-1, Futaba-cho, Toyonaka, Osaka 561-0825
| | - Noriko Suzuki
- Shionogi Research Laboratories, Shionogi and Company Ltd, 3-1-1, Futaba-cho, Toyonaka, Osaka 561-0825
| | - Yasunori Yokota
- Shionogi Research Laboratories, Shionogi and Company Ltd, 3-1-1, Futaba-cho, Toyonaka, Osaka 561-0825
| | - Kohji Hanasaki
- Shionogi Research Laboratories, Shionogi and Company Ltd, 3-1-1, Futaba-cho, Toyonaka, Osaka 561-0825
| | - Toshiko Suzuki-Yamamoto
- the Department of Neutritional Science, Faculty of Health and Welfare Science, Okayama Prefectural University, Kuboki 111, Souja, Okayama 719-1197, and
| | - Kei Yamamoto
- From the Lipid Metabolism Project, the Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 256-8506
| | - Makoto Murakami
- From the Lipid Metabolism Project, the Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 256-8506
- PRESTO, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
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Murakami M, Sato H, Taketomi Y, Yamamoto K. Integrated lipidomics in the secreted phospholipase A(2) biology. Int J Mol Sci 2011; 12:1474-95. [PMID: 21673902 PMCID: PMC3111613 DOI: 10.3390/ijms12031474] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2011] [Revised: 02/18/2011] [Accepted: 02/24/2011] [Indexed: 12/22/2022] Open
Abstract
Mammalian genomes encode genes for more than 30 phospholipase A(2)s (PLA(2)s) or related enzymes, which are subdivided into several subgroups based on their structures, catalytic mechanisms, localizations and evolutionary relationships. More than one third of the PLA(2) enzymes belong to the secreted PLA(2) (sPLA(2)) family, which consists of low-molecular-weight, Ca(2+)-requiring extracellular enzymes, with a His-Asp catalytic dyad. Individual sPLA(2) isoforms exhibit unique tissue and cellular localizations and enzymatic properties, suggesting their distinct pathophysiological roles. Recent studies using transgenic and knockout mice for several sPLA(2) isoforms, in combination with lipidomics approaches, have revealed their distinct contributions to various biological events. Herein, we will describe several examples of sPLA(2)-mediated phospholipid metabolism in vivo, as revealed by integrated analysis of sPLA(2) transgenic/knockout mice and lipid mass spectrometry. Knowledge obtained from this approach greatly contributes to expanding our understanding of the sPLA(2) biology and pathophysiology.
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Affiliation(s)
- Makoto Murakami
- Lipid Metabolism Project, The Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan; E-Mails: (H.S.); (Y.T.); and (K.Y.)
| | - Hiroyasu Sato
- Lipid Metabolism Project, The Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan; E-Mails: (H.S.); (Y.T.); and (K.Y.)
| | - Yoshitaka Taketomi
- Lipid Metabolism Project, The Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan; E-Mails: (H.S.); (Y.T.); and (K.Y.)
| | - Kei Yamamoto
- Lipid Metabolism Project, The Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan; E-Mails: (H.S.); (Y.T.); and (K.Y.)
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35
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Murakami M, Taketomi Y, Miki Y, Sato H, Hirabayashi T, Yamamoto K. Recent progress in phospholipase A₂ research: from cells to animals to humans. Prog Lipid Res 2010; 50:152-92. [PMID: 21185866 DOI: 10.1016/j.plipres.2010.12.001] [Citation(s) in RCA: 368] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Mammalian genomes encode genes for more than 30 phospholipase A₂s (PLA₂s) or related enzymes, which are subdivided into several classes including low-molecular-weight secreted PLA₂s (sPLA₂s), Ca²+-dependent cytosolic PLA₂s (cPLA₂s), Ca²+-independent PLA₂s (iPLA₂s), platelet-activating factor acetylhydrolases (PAF-AHs), lysosomal PLA₂s, and a recently identified adipose-specific PLA. Of these, the intracellular cPLA₂ and iPLA₂ families and the extracellular sPLA₂ family are recognized as the "big three". From a general viewpoint, cPLA₂α (the prototypic cPLA₂ plays a major role in the initiation of arachidonic acid metabolism, the iPLA₂ family contributes to membrane homeostasis and energy metabolism, and the sPLA₂ family affects various biological events by modulating the extracellular phospholipid milieus. The cPLA₂ family evolved along with eicosanoid receptors when vertebrates first appeared, whereas the diverse branching of the iPLA₂ and sPLA₂ families during earlier eukaryote development suggests that they play fundamental roles in life-related processes. During the past decade, data concerning the unexplored roles of various PLA₂ enzymes in pathophysiology have emerged on the basis of studies using knockout and transgenic mice, the use of specific inhibitors, and information obtained from analysis of human diseases caused by mutations in PLA₂ genes. This review focuses on current understanding of the emerging biological functions of PLA₂s and related enzymes.
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Affiliation(s)
- Makoto Murakami
- Lipid Metabolism Project, The Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan.
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Abbott MJ, Tang T, Sul HS. The Role of Phospholipase A(2)-derived Mediators in Obesity. ACTA ACUST UNITED AC 2010; 7:e213-e218. [PMID: 21603130 DOI: 10.1016/j.ddmec.2011.01.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Obesity has become an epidemic and its prevalence is increasing exponentially. A great deal of focus has been given to understanding the molecular processes that regulate obesity. The characterization of phospholipase A(2)s, especially adipose-specific PLA(2), have lead to a proposed role of their downstream products in the progression of obesity and obesity related disorders. This review summarizes recent developments in the role of PLA(2) and their downstream effects in the development of metabolic disorders.
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Affiliation(s)
- Marcia J Abbott
- Department of Nutritional Science and Toxicology, University of California, Berkeley, CA 94720 USA
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Pancreatic acinar cell-specific overexpression of group 1B phospholipase A2 exacerbates diet-induced obesity and insulin resistance in mice. Int J Obes (Lond) 2010; 35:877-81. [PMID: 20938441 DOI: 10.1038/ijo.2010.215] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Genome-wide association studies have identified significant association between polymorphisms of the Group 1B phospholipase A(2) (PLA2G1B) gene and central obesity in humans. Previous studies have shown that Pla2g1b inactivation decreases post-prandial lysophospholipid absorption, and as a consequence increases hepatic fatty acid oxidation and protects against diet-induced obesity and glucose intolerance in mice. The present study showed that transgenic mice with pancreatic acinar cell-specific overexpression of the human PLA2G1B gene gained significantly more weight and displayed elevated insulin resistance characteristics, such as impaired glucose tolerance, compared with wild-type (WT) mice, when challenged with a high-fat/carbohydrate diet. Pre- and post-prandial plasma β-hydroxybutyrate levels were also lower, indicative of decreased hepatic fatty acid oxidation, in the hypercaloric diet-fed PLA2G1B transgenic mice. These, along with earlier observations of Pla2g1b-null mice, document that Pla2g1b expression level is an important determinant of susceptibility to diet-induced obesity and diabetes, suggesting that the relationship between PLA2G1B polymorphisms and obesity may be due to differences in PLA2G1B expression levels between these individuals. The ability of pancreas-specific overexpression of PLA2G1B to promote obesity and glucose intolerance suggests that target phospholipase activity in the digestive tract with non-absorbable inhibitors should be considered as a therapeutic option for metabolic disease therapy.
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38
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Li X, Shridas P, Forrest K, Bailey W, Webb NR. Group X secretory phospholipase A2 negatively regulates adipogenesis in murine models. FASEB J 2010; 24:4313-24. [PMID: 20585029 DOI: 10.1096/fj.10-154716] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Studies in vitro indicate that group X secretory phospholipase A(2) (GX sPLA(2)) potently releases arachidonic acid (AA) and lysophosphatidylcholine from mammalian cell membranes. To define the function of GX sPLA(2) in vivo, our laboratory recently generated C57BL/6 mice with targeted deletion of GX sPLA(2) (GX(-/-) mice). When fed a normal rodent diet, GX(-/-) mice gained significantly more weight and had increased adiposity compared to GX(+/+) mice, which was not attributable to alterations in food consumption or energy expenditure. When treated with adipogenic stimuli ex vivo, stromal vascular cells isolated from adipose tissue of GX(-/-) mice accumulated significantly more (20%) triglyceride compared to cells from GX(+/+) mice. Conversely, overexpression of GX sPLA(2), but not catalytically inactive GX sPLA(2), resulted in a significant 50% reduction in triglyceride accumulation in OP9 adipocytes. The induction of genes encoding adipogenic proteins (PPARγ, SREBP-1c, SCD1, and FAS) was also significantly blunted by 50-80% in OP9 cells overexpressing GX sPLA(2). Activation of the liver X receptor (LXR), a nuclear receptor known to up-regulate adipogenic gene expression, was suppressed in 3T3-L1 and OP9 cells when GX sPLA(2) was overexpressed. Thus, hydrolytic products generated by GX sPLA(2) negatively regulate adipogenesis, possibly by suppressing LXR activation.
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Affiliation(s)
- Xia Li
- Graduate Center for Nutritional Sciences, University of Kentucky Medical Center, Lexington, KY 40536-0200, USA
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Murakami M, Taketomi Y, Girard C, Yamamoto K, Lambeau G. Emerging roles of secreted phospholipase A2 enzymes: Lessons from transgenic and knockout mice. Biochimie 2010; 92:561-82. [PMID: 20347923 DOI: 10.1016/j.biochi.2010.03.015] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2009] [Accepted: 03/18/2010] [Indexed: 11/15/2022]
Abstract
Among the emerging phospholipase A(2) (PLA(2)) superfamily, the secreted PLA(2) (sPLA(2)) family consists of low-molecular-mass, Ca(2+)-requiring extracellular enzymes with a His-Asp catalytic dyad. To date, more than 10 sPLA(2) enzymes have been identified in mammals. Individual sPLA(2)s exhibit unique tissue and cellular localizations and enzymatic properties, suggesting their distinct pathophysiological roles. Despite numerous enzymatic and cell biological studies on this enzyme family in the past two decades, their precise in vivo functions still remain largely obscure. Recent studies using transgenic and knockout mice for several sPLA(2) enzymes, in combination with lipidomics approaches, have opened new insights into their distinct contributions to various biological events such as food digestion, host defense, inflammation, asthma and atherosclerosis. In this article, we overview the latest understanding of the pathophysiological functions of individual sPLA(2) isoforms fueled by studies employing transgenic and knockout mice for several sPLA(2)s.
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Affiliation(s)
- Makoto Murakami
- Biomembrane Signaling Project, The Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan.
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Labonté ED, Pfluger PT, Cash JG, Kuhel DG, Roja JC, Magness DP, Jandacek RJ, Tschöp MH, Hui DY. Postprandial lysophospholipid suppresses hepatic fatty acid oxidation: the molecular link between group 1B phospholipase A2 and diet-induced obesity. FASEB J 2010; 24:2516-24. [PMID: 20215528 DOI: 10.1096/fj.09-144436] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Decrease in fat catabolic rate on consuming a high-fat diet contributes to diet-induced obesity. This study used group 1B phospholipase A(2) (Pla2g1b)-deficient mice, which are resistant to hyperglycemia, to test the hypothesis that Pla2g1b and its lipolytic product lysophospholipid suppress hepatic fat utilization and energy metabolism in promoting diet-induced obesity. The metabolic consequences of hypercaloric diet, including body weight gain, energy expenditure, and fatty acid oxidation, were compared between Pla2g1b(+/+) and Pla2g1b(-/-) mice. The Pla2g1b(-/-) mice displayed normal energy balance when fed chow, but were resistant to obesity when challenged with a hypercaloric diet. Obesity resistance in Pla2g1b(-/-) mice is due to their ability to maintain elevated energy expenditure and core body temperature when subjected to hypercaloric diet, which was not observed in Pla2g1b(+/+) mice. The Pla2g1b(-/-) mice also displayed increased postprandial hepatic fat utilization due to increased expression of peroxisome proliferator-activated receptor (PPAR)-alpha, PPAR-delta, PPAR-gamma, cd36/Fat, and Ucp2, which coincided with reduced postprandial plasma lysophospholipid levels. Lysophospholipids produced by Pla2g1b hydrolysis suppress hepatic fat utilization and down-regulate energy expenditure, thereby preventing metabolically beneficial adaptation to a high-fat diet exposure in promoting diet-induced obesity and type 2 diabetes.
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Affiliation(s)
- Eric D Labonté
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, 2120 E. Galbraith Rd., Cincinnati, OH 45237, USA
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