1
|
Scott KF, Mann TJ, Fatima S, Sajinovic M, Razdan A, Kim RR, Cooper A, Roohullah A, Bryant KJ, Gamage KK, Harman DG, Vafaee F, Graham GG, Church WB, Russell PJ, Dong Q, de Souza P. Human Group IIA Phospholipase A 2-Three Decades on from Its Discovery. Molecules 2021; 26:molecules26237267. [PMID: 34885848 PMCID: PMC8658914 DOI: 10.3390/molecules26237267] [Citation(s) in RCA: 3] [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: 11/08/2021] [Revised: 11/21/2021] [Accepted: 11/22/2021] [Indexed: 12/13/2022] Open
Abstract
Phospholipase A2 (PLA2) enzymes were first recognized as an enzyme activity class in 1961. The secreted (sPLA2) enzymes were the first of the five major classes of human PLA2s to be identified and now number nine catalytically-active structurally homologous proteins. The best-studied of these, group IIA sPLA2, has a clear role in the physiological response to infection and minor injury and acts as an amplifier of pathological inflammation. The enzyme has been a target for anti-inflammatory drug development in multiple disorders where chronic inflammation is a driver of pathology since its cloning in 1989. Despite intensive effort, no clinically approved medicines targeting the enzyme activity have yet been developed. This review catalogues the major discoveries in the human group IIA sPLA2 field, focusing on features of enzyme function that may explain this lack of success and discusses future research that may assist in realizing the potential benefit of targeting this enzyme. Functionally-selective inhibitors together with isoform-selective inhibitors are necessary to limit the apparent toxicity of previous drugs. There is also a need to define the relevance of the catalytic function of hGIIA to human inflammatory pathology relative to its recently-discovered catalysis-independent function.
Collapse
Affiliation(s)
- Kieran F. Scott
- School of Medicine, Western Sydney University, Campbelltown, NSW 2560, Australia; (T.J.M.); (S.F.); (A.C.); (A.R.); (P.d.S.)
- Ingham Institute of Applied Medical Research, Liverpool, NSW 2170, Australia; (M.S.); (A.R.)
- Correspondence: ; Tel.: +61-2-8738-9026
| | - Timothy J. Mann
- School of Medicine, Western Sydney University, Campbelltown, NSW 2560, Australia; (T.J.M.); (S.F.); (A.C.); (A.R.); (P.d.S.)
- Ingham Institute of Applied Medical Research, Liverpool, NSW 2170, Australia; (M.S.); (A.R.)
| | - Shadma Fatima
- School of Medicine, Western Sydney University, Campbelltown, NSW 2560, Australia; (T.J.M.); (S.F.); (A.C.); (A.R.); (P.d.S.)
- Ingham Institute of Applied Medical Research, Liverpool, NSW 2170, Australia; (M.S.); (A.R.)
- School of Biotechnology and Biological Sciences, University of New South Wales (UNSW Sydney), Sydney, NSW 2052, Australia;
| | - Mila Sajinovic
- Ingham Institute of Applied Medical Research, Liverpool, NSW 2170, Australia; (M.S.); (A.R.)
| | - Anshuli Razdan
- Ingham Institute of Applied Medical Research, Liverpool, NSW 2170, Australia; (M.S.); (A.R.)
| | - Ryung Rae Kim
- School of Pharmacy, Faculty of Medicine and Health, University of Sydney, Sydney, NSW 2006, Australia; (R.R.K.); (W.B.C.)
| | - Adam Cooper
- School of Medicine, Western Sydney University, Campbelltown, NSW 2560, Australia; (T.J.M.); (S.F.); (A.C.); (A.R.); (P.d.S.)
- Ingham Institute of Applied Medical Research, Liverpool, NSW 2170, Australia; (M.S.); (A.R.)
- Liverpool Cancer Therapy Centre, Liverpool Hospital, Liverpool, NSW 2170, Australia
| | - Aflah Roohullah
- School of Medicine, Western Sydney University, Campbelltown, NSW 2560, Australia; (T.J.M.); (S.F.); (A.C.); (A.R.); (P.d.S.)
- Ingham Institute of Applied Medical Research, Liverpool, NSW 2170, Australia; (M.S.); (A.R.)
- Liverpool Cancer Therapy Centre, Liverpool Hospital, Liverpool, NSW 2170, Australia
| | - Katherine J. Bryant
- School of Photovoltaic and Renewable Energy Engineering, UNSW Sydney, Sydney, NSW 2052, Australia;
| | - Kasuni K. Gamage
- School of Science, Western Sydney University, Campbelltown, NSW 2560, Australia; (K.K.G.); (D.G.H.)
| | - David G. Harman
- School of Science, Western Sydney University, Campbelltown, NSW 2560, Australia; (K.K.G.); (D.G.H.)
| | - Fatemeh Vafaee
- School of Biotechnology and Biological Sciences, University of New South Wales (UNSW Sydney), Sydney, NSW 2052, Australia;
- UNSW Data Science Hub, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Garry G. Graham
- Department of Clinical Pharmacology, St Vincent’s Hospital Sydney, Darlinghurst, NSW 2010, Australia;
- School of Medical Sciences, UNSW Sydney, Sydney, NSW 2052, Australia
| | - W. Bret Church
- School of Pharmacy, Faculty of Medicine and Health, University of Sydney, Sydney, NSW 2006, Australia; (R.R.K.); (W.B.C.)
| | - Pamela J. Russell
- Australian Prostate Cancer Research Centre—QUT, Brisbane, QLD 4102, Australia;
| | - Qihan Dong
- Chinese Medicine Anti-Cancer Evaluation Program, Greg Brown Laboratory, Central Clinical School and Charles Perkins Centre, The University of Sydney, Sydney, NSW 2006, Australia;
| | - Paul de Souza
- School of Medicine, Western Sydney University, Campbelltown, NSW 2560, Australia; (T.J.M.); (S.F.); (A.C.); (A.R.); (P.d.S.)
- Ingham Institute of Applied Medical Research, Liverpool, NSW 2170, Australia; (M.S.); (A.R.)
- School of Medicine, UNSW Sydney, Sydney, NSW 2052, Australia
| |
Collapse
|
2
|
Kim RR, Chen Z, J. Mann T, Bastard K, F. Scott K, Church WB. Structural and Functional Aspects of Targeting the Secreted Human Group IIA Phospholipase A 2. Molecules 2020; 25:molecules25194459. [PMID: 32998383 PMCID: PMC7583969 DOI: 10.3390/molecules25194459] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 09/20/2020] [Accepted: 09/25/2020] [Indexed: 12/11/2022] Open
Abstract
Human group IIA secretory phospholipase A2 (hGIIA) promotes the proliferation of cancer cells, making it a compelling therapeutic target, but it is also significant in other inflammatory conditions. Consequently, suitable inhibitors of hGIIA have always been sought. The activation of phospholipases A2 and the catalysis of glycerophospholipid substrates generally leads to the release of fatty acids such as arachidonic acid (AA) and lysophospholipid, which are then converted to mediator compounds, including prostaglandins, leukotrienes, and the platelet-activating factor. However, this ability of hGIIA to provide AA is not a complete explanation of its biological role in inflammation, as it has now been shown that it also exerts proinflammatory effects by a catalysis-independent mechanism. This mechanism is likely to be highly dependent on key specific molecular interactions, and the full mechanistic descriptions of this remain elusive. The current candidates for the protein partners that may mediate this catalysis-independent mechanism are also introduced in this review. A key discovery has been that selective inhibition of the catalysis-independent activity of hGIIA is achieved with cyclised derivatives of a pentapeptide, FLSYK, derived from the primary sequence of hGIIA. The effects of hGIIA on cell function appear to vary depending on the pathology studied, and so its mechanism of action is complex and context-dependent. This review is comprehensive and covers the most recent developments in the understanding of the many facets of hGIIA function and inhibition and the insight they provide into their clinical application for disease treatment. A cyclic analogue of FLSYK, c2, the most potent analogue known, has now been taken into clinical trials targeting advanced prostate cancer.
Collapse
Affiliation(s)
- Ryung Rae Kim
- School of Pharmacy, Faculty of Medicine and Health, University of Sydney, Sydney, NSW 2006, Australia; (R.R.K.); (Z.C.); (K.B.)
| | - Zheng Chen
- School of Pharmacy, Faculty of Medicine and Health, University of Sydney, Sydney, NSW 2006, Australia; (R.R.K.); (Z.C.); (K.B.)
| | - Timothy J. Mann
- School of Medicine, Western Sydney University, Centre for Oncology, Education and Research Translation and The Ingham Institute, Liverpool, NSW 2170, Australia;
| | - Karine Bastard
- School of Pharmacy, Faculty of Medicine and Health, University of Sydney, Sydney, NSW 2006, Australia; (R.R.K.); (Z.C.); (K.B.)
| | - Kieran F. Scott
- School of Medicine, Western Sydney University, Centre for Oncology, Education and Research Translation and The Ingham Institute, Liverpool, NSW 2170, Australia;
- Correspondence: (K.F.S.); (W.B.C.); Tel.: +61-2-8738-9026 (K.F.S.); +61-2-9036-6569 (W.B.C.)
| | - W. Bret Church
- School of Pharmacy, Faculty of Medicine and Health, University of Sydney, Sydney, NSW 2006, Australia; (R.R.K.); (Z.C.); (K.B.)
- Correspondence: (K.F.S.); (W.B.C.); Tel.: +61-2-8738-9026 (K.F.S.); +61-2-9036-6569 (W.B.C.)
| |
Collapse
|
3
|
Olsen I. Relationship between serine dipeptide lipids of commensal Bacteroidetes and atherosclerosis. J Oral Microbiol 2018; 10:1453224. [PMID: 29686782 PMCID: PMC5907637 DOI: 10.1080/20002297.2018.1453224] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 03/08/2018] [Indexed: 10/24/2022] Open
Affiliation(s)
- Ingar Olsen
- Department of Oral Biology, Faculty of Dentistry, University of Oslo, Oslo, Norway
| |
Collapse
|
4
|
Nemati R, Dietz C, Anstadt EJ, Cervantes J, Liu Y, Dewhirst FE, Clark RB, Finegold S, Gallagher JJ, Smith MB, Yao X, Nichols FC. Deposition and hydrolysis of serine dipeptide lipids of Bacteroidetes bacteria in human arteries: relationship to atherosclerosis. J Lipid Res 2017; 58:1999-2007. [PMID: 28814639 DOI: 10.1194/jlr.m077792] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 07/17/2017] [Indexed: 11/20/2022] Open
Abstract
Multiple reaction monitoring-MS analysis of lipid extracts from human carotid endarterectomy and carotid artery samples from young individuals consistently demonstrated the presence of bacterial serine dipeptide lipid classes, including Lipid 654, an agonist for human and mouse Toll-like receptor (TLR)2, and Lipid 430, the deacylated product of Lipid 654. The relative levels of Lipid 654 and Lipid 430 were also determined in common oral and intestinal bacteria from the phylum Bacteroidetes and human serum and brain samples from healthy adults. The median Lipid 430/Lipid 654 ratio observed in carotid endarterectomy samples was significantly higher than the median ratio in lipid extracts of common oral and intestinal Bacteroidetes bacteria, and serum and brain samples from healthy subjects. More importantly, the median Lipid 430/Lipid 654 ratio was significantly elevated in carotid endarterectomies when compared with control artery samples. Our results indicate that deacylation of Lipid 654 to Lipid 430 likely occurs in diseased artery walls due to phospholipase A2 enzyme activity. These results suggest that commensal Bacteriodetes bacteria of the gut and the oral cavity may contribute to the pathogenesis of TLR2-dependent atherosclerosis through serine dipeptide lipid deposition and metabolism in artery walls.
Collapse
Affiliation(s)
- Reza Nemati
- Department of Chemistry University of Connecticut, Storrs, CT 06269
| | | | - Emily J Anstadt
- Department of Immunology and Medicine, University of Connecticut School of Medicine, Farmington, CT 06030
| | - Jorge Cervantes
- Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center, El Paso, TX 79905
| | - Yaling Liu
- Department of Oral Health and Diagnostic Sciences, University of Connecticut School of Dental Medicine, Farmington, CT 06030
| | - Floyd E Dewhirst
- Department of Microbiology, The Forsyth Institute, Cambridge, MA 02142 and Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine, Boston, MA 02115
| | - Robert B Clark
- Department of Immunology and Medicine, University of Connecticut School of Medicine, Farmington, CT 06030
| | - Sydney Finegold
- Infectious Disease Division, Veterans Affairs Medical Center, Los Angeles, CA 90073 and Departments of Medicine and Microbiology, Immunology, and Molecular Genetics, University of California Los Angeles, Los Angeles, CA 90024
| | | | - Michael B Smith
- Department of Chemistry University of Connecticut, Storrs, CT 06269
| | - Xudong Yao
- Department of Chemistry University of Connecticut, Storrs, CT 06269.,Institute for Systems Genomics, University of Connecticut, Storrs, CT 06269
| | - Frank C Nichols
- Department of Oral Health and Diagnostic Sciences, University of Connecticut School of Dental Medicine, Farmington, CT 06030
| |
Collapse
|
5
|
Gao X, Gong H, Men P, Zhou L, Ye D. Design, Synthesis, and Biological Evaluation of Novel Dual Inhibitors of Secretory Phospholipase A2 and Sphingomyelin Synthase. CHINESE J CHEM 2013. [DOI: 10.1002/cjoc.201300079] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
6
|
Lind L, Simon T, Johansson L, Kotti S, Hansen T, Machecourt J, Ninio E, Tedgui A, Danchin N, Ahlström H, Mallat Z. Circulating levels of secretory- and lipoprotein-associated phospholipase A2 activities: relation to atherosclerotic plaques and future all-cause mortality. Eur Heart J 2012; 33:2946-54. [PMID: 22711753 DOI: 10.1093/eurheartj/ehs132] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
AIMS Secretory- and lipoprotein-associated phospholipases A2 (sPLA2 and Lp-PLA2) are enzymes both suggested to be of importance for atherosclerosis. We investigated relationships between the activities of these enzymes in the circulation and atherosclerosis as well as future clinical events. METHODS AND RESULTS The population-based Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study included 1016 randomly selected subjects, all aged 70. The prevalence of carotid artery plaques was recorded by ultrasound (n= 954), and arterial stenosis was assessed by whole-body magnetic resonance angiography (WBMRA, n= 302). Secretory-associated phospholipase A2 [odds ratio 1.23 for 1 SD increase, 95% confidence interval (CI): 1.05-1.44, P= 0.007], but not Lp-PLA2 (P= 0.26), activity was significantly related to carotid atherosclerosis and to the amount of stenosis at WBMRA (P= 0.006) following adjustment for multiple risk factors (waist circumference, serum triglycerides, body mass index, C-reactive protein, high density lipoprotein-C, low density lipoprotein-C, triglycerides, GFR, fasting glucose, blood pressure, statin use, and exercise habits). Secretory-associated phospholipase A2 [hazard ratio (HR) 1.45 for 1 SD increase, 95% CI: 1.15-1.84, P= 0.001], but not Lp-PLA2 (HR 0.95, P= 0.55), activity was a significant risk factor for all-cause mortality (114 had died) during 7.0 years follow-up after adjustment for the risk factors described above. In a sample of 1029 post-myocardial infarction (MI) patients (French registry of Acute ST-elevation and non-ST-elevation Myocardial Infarction), sPLA2 (adjusted HR 1.32 for 1 unit increase, 95% CI: 1.02-1.71, P= 0.036), but not Lp-PLA2 (HR 1.03, P= 0.90), activity predicted death or recurrent MI during 1-year follow-up (n= 136 cases). CONCLUSION sPLA2 activity was related to atherosclerosis and predicted all-cause mortality in a sample of elderly subjects, as well as death or MI in post-MI patients.
Collapse
Affiliation(s)
- Lars Lind
- Department of Medical Sciences, Uppsala University Hospital, Uppsala, Sweden
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
7
|
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.
Collapse
Affiliation(s)
- David Y Hui
- Department of Pathology, Metabolic Diseases Institute, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| |
Collapse
|
8
|
Mallat Z, Lambeau G, Tedgui A. Lipoprotein-associated and secreted phospholipases A₂ in cardiovascular disease: roles as biological effectors and biomarkers. Circulation 2010; 122:2183-200. [PMID: 21098459 DOI: 10.1161/circulationaha.110.936393] [Citation(s) in RCA: 128] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Ziad Mallat
- INSERM, Paris-Cardiovascular Research Center, Université Paris Descartes, UMR, Paris, France
| | | | | |
Collapse
|
9
|
Tiwari A. Current and emerging paradigms in the therapeutic management of atherosclerosis. Expert Opin Ther Targets 2009; 12:1523-46. [PMID: 19007321 DOI: 10.1517/14728220802544061] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
BACKGROUND The pathogenesis of atherosclerosis lies in abnormalities in lipoprotein metabolism leading to pathological interactions with vessel walls and the release of inflammatory components, which further aggravate the disease condition. OBJECTIVE To elucidate current and emerging trends in drug discovery towards the development of new entities regulating lipoprotein metabolism and inflammatory components to combat the progression of atherosclerosis. METHODS Research/review articles in the public domain and press releases were employed. RESULTS/CONCLUSION With the recent failure of torcetrapib and succinobucol, drug discovery and development efforts towards the treatment of atherosclerosis have received a big jolt and have been slowed down to a certain extent [corrected]. But this could be a starting point for several new mechanisms that are emerging to discover new drugs to combat the disease.
Collapse
Affiliation(s)
- Atul Tiwari
- Jubilant Biosys Ltd., CardioMetabolic Disorder Group, Drug Discovery Unit-Biology, #96, 2nd Stage, Industrial Suburb, Yeshwantpur, Bangalore-560022, Karnatka, India.
| |
Collapse
|
10
|
Karabina SA, Brochériou I, Le Naour G, Agrapart M, Durand H, Gelb M, Lambeau G, Ninio E. Atherogenic properties of LDL particles modified by human group X secreted phospholipase A2 on human endothelial cell function. FASEB J 2006; 20:2547-9. [PMID: 17077289 DOI: 10.1096/fj.06-6018fje] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Increasing evidence suggests that secreted phospholipases A2 (sPLA2s) play an important role in the pathophysiology of atherosclerosis. Among sPLA2s, the human group X (hGX) enzyme has the highest catalytic activity toward phosphatidylcholine, one of the major phospholipid species of cell membranes and low-density lipoprotein (LDL). Our study examined the presence of hGX sPLA2 in human atherosclerotic lesions and investigated the ability of hGX modified LDL to alter human endothelial cell (HUVEC) function. Our results show that hGX sPLA2 is present in human atherosclerotic lesions and that the hydrolysis of LDL by hGX sPLA2 results in a modified particle that induces lipid accumulation in human monocyte-derived macrophages. Acting on endothelial cells, hGX-modified LDL activates the MAP kinase pathway, which leads to increased arachidonic acid release, increased expression of adhesion molecules on the surface of HUVEC, and increased adhesion of monocytes to HUVEC monolayers. Together, our data suggest that LDL modified by hGX, rather than hGX itself may have strong proinflammatory and proatherogenic properties, which could play an important role in the propagation of atherosclerosis.
Collapse
Affiliation(s)
- Sonia-Athina Karabina
- INSERM UMRS 525, Faculté de Médecine Pierre et Marie Curie, 91, boulevard de l'Hôpital, 75634 Paris, France.
| | | | | | | | | | | | | | | |
Collapse
|
11
|
Menschikowski M, Hagelgans A, Siegert G. Secretory phospholipase A2 of group IIA: Is it an offensive or a defensive player during atherosclerosis and other inflammatory diseases? Prostaglandins Other Lipid Mediat 2006; 79:1-33. [PMID: 16516807 DOI: 10.1016/j.prostaglandins.2005.10.005] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2005] [Revised: 10/29/2005] [Accepted: 10/31/2005] [Indexed: 02/07/2023]
Abstract
Since its discovery in the serum of patients with severe inflammation and in rheumatoid arthritic fluids, the secretory phospholipase A2 of group IIA (sPLA2-IIA) has been chiefly considered as a proinflammatory enzyme, the result of which has been very intense interest in selective inhibitors of sPLA2-IIA in the hope of developing new and efficient therapies for inflammatory diseases. The recent discovery of the antibacterial properties of sPLA2-IIA, however, has raised the question of whether the upregulation of sPLA2-IIA during inflammation is to be considered uniformly negative and the hindrance of sPLA2-IIA in every instance beneficial. The aim of this review is for this reason, along with the results of various investigations which argue for the proinflammatory and proatherogenic effects of an upregulation of sPLA2-IIA, also to array data alongside which point to a protective function of sPLA2-IIA during inflammation. Thus, it could be shown that sPLA2-IIA, apart from the bactericidal effects, possesses also antithrombotic properties and indeed plays a possible role in the resolution of inflammation and the accelerated clearance of oxidatively modified lipoproteins during inflammation via the liver and adrenals. Based on these multipotent properties the knowledge of the function of sPLA2-IIA during inflammation is a fundamental prerequisite for the development and establishment of new therapeutic strategies to prevent and treat severe inflammatory diseases up to and including sepsis.
Collapse
Affiliation(s)
- Mario Menschikowski
- Technische Universität Dresden, Medizinische Fakultät Carl Gustav Carus, Institut für Klinische Chemie and Laboratoriumsmedizin, Fetscherstrasse 74, D-01307 Dresden, Germany.
| | | | | |
Collapse
|
12
|
Eckey R, Menschikowski M, Lattke P, Jaross W. Increased hepatic cholesterol accumulation in transgenic mice overexpressing human secretory phospholipase A2 group IIA. Inflammation 2005; 28:59-65. [PMID: 15379211 DOI: 10.1023/b:ifla.0000033021.44105.9c] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
It has been demonstrated in transgenic mice that the overexpression of human phospholipase A2 group IIA (sPLA2), an acute-phase reactant, is associated with depressed plasma cholesterol levels, altered lipoprotein compositions, and increased lipid depositions in aortic walls. It was the aim of the present study to investigate whether the reduced plasma cholesterol levels in sPLA2-transgenic mice may be due to an increased transfer of lipids from sPLA2-modified lipoproteins to the liver and/or other nonvascular tissues. Ten sPLA2-transgenic mice and an equal number of nontransgenic littermates were fed a cholesterol-enriched (1%) diet for 13 weeks. After autopsy, cholesterol and triglyceride concentrations were measured in homogenates of liver, spleen, kidney, and myocardial tissues. Compared to the nontransgenic controls, the sPLA2-transgenic mice exhibited significantly lower plasma cholesterol levels, which was due to a reduction in both HDL and beta-lipoprotein (LDL + beta-VLDL) cholesterol. Liver tissues from the transgenic mice were found to contain significantly increased concentrations of free and esterified cholesterol, which was not associated with increased triglyceride concentrations. Spleen, kidney, and heart tissues of the two animal groups showed no significant differences in cholesterol or triglyceride concentrations. The findings suggest that the overexpression of human secretory phospholipase A2 group IIA leads to an enhanced delivery of cholesterol from phospholipolysed lipoproteins to the liver. This mechanism is likely to contribute to the development of hypocholesterolemia observed in patients with inflammatory diseases.
Collapse
Affiliation(s)
- Rolf Eckey
- Institute for Clinical Chemistry and Laboratory Medicine, Medical Faculty, Technical University of Dresden, Dresden, Germany.
| | | | | | | |
Collapse
|
13
|
Jaross W, Eckey R, Menschikowski M. Biological effects of secretory phospholipase A(2) group IIA on lipoproteins and in atherogenesis. Eur J Clin Invest 2002; 32:383-93. [PMID: 12059982 DOI: 10.1046/j.1365-2362.2002.01000.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Secretory phospholipase A(2) group IIA(sPLA(2) IIA) can be produced and secreted by various cell types either constitutionally or as an acute-phase reactant upon stimulation by proinflammatory cytokines. The enzyme prefers phosphatidylethanolamine and phosphatidylserine as substrates. One important biological function may be the hydrolytic destruction of bacterial membranes. It has been demonstrated, however, that sPLA(2) can also hydrolyse the phospholipid monolayers of high density lipoprotein (HDL) and low density lipoprotein (LDL) in vitro. Secretory phospholipase A(2)-modified LDL show increased affinity to glycosaminoglycans and proteoglycans, a tendency to aggregate, and an enhanced ability to deliver cholesterol to cells. Incubation of cultured macrophages with PLA(2)-treated LDL and HDL is associated with increased intracellular lipid accumulation, resulting in the formation of foam cells. Elevated sPLA(2)(IIA) activity in blood serum leads to an increased clearance of serum cholesterol. Secretory phospholipase A(2)(IIA) can also be detected in the intima, adventitia and media of the atherosclerotic wall not only in developed lesions but also in very early stages of atherosclerosis. The presence of DNA of Chlamydia pneumoniae, herpes simplex virus, and cytomegalovirus was found to be associated with sPLA(2)(IIA) expression and other signs of local inflammation. Thus, sPLA(2)(IIA) appears to be one important link between the lipid and the inflammation hypothesis of atherosclerosis.
Collapse
Affiliation(s)
- Werner Jaross
- Institute for Clinical Chemistry and Laboratory Medicine, Medical Faculty, Technical University of Dresden, Germany.
| | | | | |
Collapse
|
14
|
Abstract
Dendritic cells constitute a unique family of cells able to induce primary immune responses. Over the past decade, immunologists have been increasingly preoccupied with dendritic cells and dendritic cells are now seen as a panacea for vaccine development, tumour immunotherapy and a host of other immunological applications. The recent finding of dendritic cells accumulating in atherosclerotic lesions should stimulate investigation of their contributions to atherogenesis and their potential use in anti-atherosclerosis therapies.
Collapse
Affiliation(s)
- Y V Bobryshev
- Lipid Metabolism Unit, Massachusetts General Hospital, Harvard Medical School, Boston 02114, USA.
| |
Collapse
|
15
|
Menschikowski M, Rosner-Schiering A, Eckey R, Mueller E, Koch R, Jaross W. Expression of secretory group IIA phospholipase A(2) in relation to the presence of microbial agents, macrophage infiltrates, and transcripts of proinflammatory cytokines in human aortic tissues. Arterioscler Thromb Vasc Biol 2000; 20:751-62. [PMID: 10712401 DOI: 10.1161/01.atv.20.3.751] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Recent seroepidemiological and immunohistochemical studies have demonstrated an association between microbial infections and atherosclerosis. However, the mechanisms underlying this association are widely unknown. In the present study, arterial specimens obtained at autopsy after sudden death were analyzed concerning (1) the presence of Chlamydia pneumoniae, cytomegalovirus, herpes simplex virus, and Helicobacter pylori; (2) the expression of secretory group IIA phospholipase A(2) (sPLA(2)-IIA) and of proinflammatory cytokines; and (3) the stage of atherosclerosis. Genomic DNA of microbial pathogens was determined by the polymerase chain reaction technique. The expression of sPLA(2)-IIA was studied immunohistochemically by using monoclonal antibodies against human sPLA(2)-IIA. Transcripts specific for sPLA(2)-IIA, interleukin-1beta, tumor necrosis factor-alpha, and interferon-gamma were identified by reverse transcription-polymerase chain reaction. In 18 of 102 analyzed specimens, DNA of microbial pathogens was found. Thirteen sections were positive for C pneumoniae, whereas 2 specimens were positive either for cytomegalovirus or for herpes simplex virus. One section contained genomic DNA of all 3 pathogens simultaneously. None of the analyzed tissues exhibited nucleic acids specific for H pylori. In addition to macrophage infiltrates, the presence of microbial DNA was closely associated with the occurrence of transcripts specific for proinflammatory cytokines and sPLA(2)-IIA. Pathogens as well as sPLA(2)-IIA and cytokines were found to be present not only in advanced but also in early stages of atherosclerosis. In tissues negative for sPLA(2)-IIA and cytokine expression, none of the pathogens could be identified. Because macrophages exposed to phospholipase A(2)-treated lipoproteins are transformed into foam cells in vitro, the results of this study suggest an alternative mechanism by which microbial infections may act in a proatherogenic fashion in vessel walls.
Collapse
MESH Headings
- Adolescent
- Adult
- Aged
- Aged, 80 and over
- Aorta, Abdominal/immunology
- Aorta, Abdominal/microbiology
- Aorta, Abdominal/virology
- Aorta, Thoracic/immunology
- Aorta, Thoracic/microbiology
- Aorta, Thoracic/virology
- Arteriosclerosis/immunology
- Arteriosclerosis/microbiology
- Arteriosclerosis/virology
- Child
- Child, Preschool
- Chlamydia Infections/immunology
- Chlamydophila pneumoniae/genetics
- Cytomegalovirus/genetics
- DNA, Bacterial/analysis
- DNA, Viral/analysis
- Female
- Group II Phospholipases A2
- Helicobacter Infections/immunology
- Helicobacter pylori/genetics
- Humans
- Infant
- Interferon-gamma/genetics
- Interleukin-1/genetics
- Macrophages/immunology
- Macrophages/microbiology
- Macrophages/virology
- Male
- Middle Aged
- Oligonucleotide Probes
- Phospholipases A/genetics
- Phospholipases A/immunology
- RNA, Messenger/analysis
- Reverse Transcriptase Polymerase Chain Reaction
- Simplexvirus/genetics
- Transcription, Genetic
- Tumor Necrosis Factor-alpha/genetics
Collapse
Affiliation(s)
- M Menschikowski
- Institut für Klinische Chemie und Laboratoriumsmedizin, Technische Universität Dresden, Medizinische Fakultät "Carl Gustav Carus," Germany.
| | | | | | | | | | | |
Collapse
|
16
|
Häkkinen T, Luoma JS, Hiltunen MO, Macphee CH, Milliner KJ, Patel L, Rice SQ, Tew DG, Karkola K, Ylä-Herttuala S. Lipoprotein-associated phospholipase A(2), platelet-activating factor acetylhydrolase, is expressed by macrophages in human and rabbit atherosclerotic lesions. Arterioscler Thromb Vasc Biol 1999; 19:2909-17. [PMID: 10591668 DOI: 10.1161/01.atv.19.12.2909] [Citation(s) in RCA: 177] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We studied the expression of lipoprotein-associated phospholipase A(2) (Lp-PLA(2)), an enzyme capable of hydrolyzing platelet-activating factor (PAF), PAF-like phospholipids, and polar-modified phosphatidylcholines, in human and rabbit atherosclerotic lesions. Oxidative modification of low-density lipoprotein, which plays an important role in atherogenesis, generates biologically active PAF-like modified phospholipid derivatives with polar fatty acid chains. PAF is known to have a potent proinflammatory activity and is inactivated by its hydrolysis. On the other hand, lysophosphatidylcholine and oxidized fatty acids released from oxidized low-density lipoprotein as a result of Lp-PLA(2) activity are thought to be involved in the progression of atherosclerosis. Using combined in situ hybridization and immunocytochemistry, we detected Lp-PLA(2) mRNA and protein in macrophages in both human and rabbit atherosclerotic lesions. Reverse transcriptase-polymerase chain reaction analysis indicated an increased expression of Lp-PLA(2) mRNA in human atherosclerotic lesions. In addition, approximately 6-fold higher Lp-PLA(2) activity was detected in atherosclerotic aortas of Watanabe heritable hyperlipidemic rabbits compared with normal aortas from control rabbits. It is concluded that (1) macrophages in both human and rabbit atherosclerotic lesions express Lp-PLA(2), which could cleave any oxidatively modified phosphatidylcholine present in the lesion area, and (2) modulation of Lp-PLA(2) activity could lead to antiatherogenic effects in the vessel wall.
Collapse
Affiliation(s)
- T Häkkinen
- A.I. Virtanen Institute, University of Kuopio, Kuopio, Finland
| | | | | | | | | | | | | | | | | | | |
Collapse
|