1
|
Protective Role of Platelets in Myocardial Infarction and Ischemia/Reperfusion Injury. Cardiol Res Pract 2021; 2021:5545416. [PMID: 34123416 PMCID: PMC8169247 DOI: 10.1155/2021/5545416] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 05/05/2021] [Indexed: 12/26/2022] Open
Abstract
Thrombotic occlusion of the coronary artery is a key component in the pathogenesis of myocardial ischemia and myocardial infarction (MI). The standard therapy for ischemia is revascularization and restoration of blood flow to previously ischemic myocardium. Paradoxically, reperfusion may result in further tissue damage called ischemia/reperfusion injury (IRI). Platelets play a major role in the pathogenesis of MI and IRI, since they contribute to the thrombus and microthrombi formation, inflammation, release of immunomodulatory mediators, and vasoconstrictive molecules. Antiplatelet therapies have proven efficacy in the prevention of thrombosis and play a protective role in cardiac IRI. Beyond the deterioration effect of platelets in MI and IRI, in the 90s the first reports on a protective effect of molecules released from platelets during MI appeared. However, the role of platelets in cardioprotection is still poorly understood. This review describes the involvement of platelets in MI, IRI, and inflammation. It mainly focuses on the protective role of platelets in MI and IRI. Platelets are involved in cardioprotection based on platelet-releasing molecules and antiplatelet therapy, apart from antiaggregatory effects. Additionally, the use of platelet-derived microparticles as possible markers of MI, with and without comorbidities, and their role in cardioprotection are discussed. This review is aimed at illustrating the present knowledge on the role of platelets in MI and IRI, especially in a context of cardioprotection.
Collapse
|
2
|
Chen Q, Song Q, Yang X, Han H, Zhang X, Liao Y, Zhang W, Ye J, Cheng S, Xu F. Characterization of a novel levopimaradiene synthase gene responsible for the biosynthesis of terpene trilactones in Ginkgo biloba. PLANT SIGNALING & BEHAVIOR 2021; 16:1885906. [PMID: 33570442 PMCID: PMC7971208 DOI: 10.1080/15592324.2021.1885906] [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: 12/15/2020] [Revised: 01/31/2021] [Accepted: 02/01/2021] [Indexed: 06/12/2023]
Abstract
Terpene trilactones (TTLs) are the main medicinal compounds of Ginkgo biloba. Levopimaradiene synthase (LPS) is the crucial enzyme that catalyzes TTLs biosynthesis in G. biloba. In this study, a novel LPS gene (designated as GbLPS2) was cloned from G. biloba leaves. The open reading frame of GbLPS2 gene was 2520 bp in length, encoding a predicted polypeptide of 840 amino acids. Phylogenetic analysis revealed that the GbLPS2 was highly homologous with reported LPS proteins in other plants. On the basis of the genomic DNA (gDNA) template, a 4308 bp gDNA sequence of GbLPS2 and a 913 bp promoter sequence were amplified. Cis-acting elements in promoter analysis indicated that GbLPS2 could be regulated by methyl jasmonate (MeJA) and abscisic acid (ABA). Tissue-specific expression analysis revealed that GbLPS2 was mainly expressed in roots and ovulate strobilus. MeJA treatment could significantly induce the expression level of GbLPS2 and increase the content of TTLs. This study illustrates the structure and the tissue-specific expression pattern of GbLPS2 and demonstrates that exogenous hormones regulated the expression of GbLPS2 and TTL content in G. biloba. Our results provide a target gene for the enhancement of TTL content in G. biloba via genetic engineering.
Collapse
Affiliation(s)
- Qiangwen Chen
- College of Horticulture and Gardening, Yangtze University, Jingzhou, Hubei, China
| | - Qiling Song
- College of Horticulture and Gardening, Yangtze University, Jingzhou, Hubei, China
- Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees of the Ministry of Education and the Key Laboratory of Non-Wood Forest Products of Forestry Ministry, Central South University of Forestry and Technology, Changsha, Hunan, China
| | - Xiaoyan Yang
- College of Horticulture and Gardening, Yangtze University, Jingzhou, Hubei, China
| | - Huan Han
- College of Horticulture and Gardening, Yangtze University, Jingzhou, Hubei, China
| | - Xian Zhang
- College of Horticulture and Gardening, Yangtze University, Jingzhou, Hubei, China
| | - Yongling Liao
- College of Horticulture and Gardening, Yangtze University, Jingzhou, Hubei, China
| | - Weiwei Zhang
- College of Horticulture and Gardening, Yangtze University, Jingzhou, Hubei, China
| | - Jiabao Ye
- College of Horticulture and Gardening, Yangtze University, Jingzhou, Hubei, China
| | - Shuiyuan Cheng
- National R&D for Se-rich Agricultural Products Processing Technology, Wuhan Polytechnic University, Wuhan, China
| | - Feng Xu
- College of Horticulture and Gardening, Yangtze University, Jingzhou, Hubei, China
| |
Collapse
|
3
|
Chorell E, Olsson T, Jansson JH, Wennberg P. Lysophospholipids as Predictive Markers of ST-Elevation Myocardial Infarction (STEMI) and Non-ST-Elevation Myocardial Infarction (NSTEMI). Metabolites 2020; 11:metabo11010025. [PMID: 33396480 PMCID: PMC7823877 DOI: 10.3390/metabo11010025] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 12/22/2020] [Accepted: 12/28/2020] [Indexed: 12/14/2022] Open
Abstract
The present study explored patterns of circulating metabolites and proteins that can predict future risk for ST-elevation myocardial infarction (STEMI) and non-ST-elevation myocardial infarction (NSTEMI). We conducted a prospective nested case-control study in northern Sweden in individuals who developed STEMI (N = 50) and NSTEMI (N = 50) within 5 years and individually matched controls (N = 100). Fasted plasma samples were subjected to multiplatform mass spectrometry-based metabolomics and multiplex protein analyses. Multivariate analyses were used to elucidate infarction-specific metabolite and protein risk profiles associated with future incident STEMI and NSTEMI. We found that altered lysophosphatidylcholine (LPC) to lysophosphatidylethanolamine (LPE) ratio predicted STEMI and NSTEMI events in different ways. In STEMI, lysophospholipids (mainly LPEs) were lower, whereas in NSTEMI, lysophospholipids (mainly LPEs) were higher. We found a similar response for all detected lysophospholipids but significant alterations only for those containing linoleic acid (C18:2, p < 0.05). Patients with STEMI had higher secretoglobin family 3A member 2 and tartrate-resistant acid phosphate type 5 and lower platelet-derived growth factor subunit A, which are proteins associated with atherosclerosis severity and plaque development mediated via altered phospholipid metabolism. In contrast, patients with NSTEMI had higher levels of proteins associated with inflammation and macrophage activation, including interleukin 6, C-reactive protein, chemerin, and cathepsin X and D. The STEMI risk marker profile includes factors closely related to the development of unstable plaque, including a higher LPC:LPE ratio, whereas NSTEMI is characterized by a lower LPC:LPE ratio and increased inflammation.
Collapse
Affiliation(s)
- Elin Chorell
- Department of Public Health and Clinical Medicine, Umeå University, SE-901 87 Umeå, Sweden;
- Correspondence: ; Tel.: +46-(0)90-785-1326
| | - Tommy Olsson
- Department of Public Health and Clinical Medicine, Umeå University, SE-901 87 Umeå, Sweden;
| | - Jan-Håkan Jansson
- Research Unit Skellefteå, Department of Public Health and Clinical Medicine, Umeå University, 90187 Umeå, Sweden;
| | - Patrik Wennberg
- Department of Public Health and Clinical Medicine, Family Medicine, Medicine, Umeå University, 90187 Umeå, Sweden;
| |
Collapse
|
4
|
Forty Years Since the Structural Elucidation of Platelet-Activating Factor (PAF): Historical, Current, and Future Research Perspectives. Molecules 2019; 24:molecules24234414. [PMID: 31816871 PMCID: PMC6930554 DOI: 10.3390/molecules24234414] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2019] [Revised: 11/29/2019] [Accepted: 12/02/2019] [Indexed: 12/11/2022] Open
Abstract
In the late 1960s, Barbaro and Zvaifler described a substance that caused antigen induced histamine release from rabbit platelets producing antibodies in passive cutaneous anaphylaxis. Henson described a ‘soluble factor’ released from leukocytes that induced vasoactive amine release in platelets. Later observations by Siraganuan and Osler observed the existence of a diluted substance that had the capacity to cause platelet activation. In 1972, the term platelet-activating factor (PAF) was coined by Benveniste, Henson, and Cochrane. The structure of PAF was later elucidated by Demopoulos, Pinckard, and Hanahan in 1979. These studies introduced the research world to PAF, which is now recognised as a potent phospholipid mediator. Since its introduction to the literature, research on PAF has grown due to interest in its vital cell signalling functions and more sinisterly its role as a pro-inflammatory molecule in several chronic diseases including cardiovascular disease and cancer. As it is forty years since the structural elucidation of PAF, the aim of this review is to provide a historical account of the discovery of PAF and to provide a general overview of current and future perspectives on PAF research in physiology and pathophysiology.
Collapse
|
5
|
Bi C, Li PL, Liao Y, Rao HY, Li PB, Yi J, Wang WY, Su WW. Pharmacodynamic effects of Dan-hong injection in rats with blood stasis syndrome. Biomed Pharmacother 2019; 118:109187. [DOI: 10.1016/j.biopha.2019.109187] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 06/14/2019] [Accepted: 06/28/2019] [Indexed: 01/23/2023] Open
|
6
|
Lordan R, Tsoupras A, Zabetakis I. The Potential Role of Dietary Platelet-Activating Factor Inhibitors in Cancer Prevention and Treatment. Adv Nutr 2019; 10:148-164. [PMID: 30721934 PMCID: PMC6370273 DOI: 10.1093/advances/nmy090] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 09/11/2018] [Accepted: 10/10/2018] [Indexed: 12/11/2022] Open
Abstract
Cancer is the second leading cause of mortality worldwide. The role of unresolved inflammation in cancer progression and metastasis is well established. Platelet-activating factor (PAF) is a key proinflammatory mediator in the initiation and progression of cancer. Evidence suggests that PAF is integral to suppression of the immune system and promotion of metastasis and tumor growth by altering local angiogenic and cytokine networks. Interactions between PAF and its receptor may have a role in various digestive, skin, and hormone-dependent cancers. Diet plays a critical role in the prevention of cancer and its treatment. Research indicates that the Mediterranean diet may reduce the incidence of several cancers in which dietary PAF inhibitors have a role. Dietary PAF inhibitors such as polar lipids have demonstrated inhibitory effects against the physiological actions of PAF in cancer and other chronic inflammatory conditions in vitro and in vivo. In addition, experimental models of radiotherapy and chemotherapy demonstrate that inhibition of PAF as adjuvant therapy may lead to more favorable outcomes. Although promising, there is limited evidence on the potential benefits of dietary PAF inhibitors on cancer prevention or treatment. Therefore, further extensive research is required to assess the effects of various dietary factors and PAF inhibitors and to elucidate the mechanisms in prevention of cancer progression and metastasis at a molecular level.
Collapse
Affiliation(s)
- Ronan Lordan
- Department of Biological Sciences, University of Limerick, Limerick, Ireland
| | - Alexandros Tsoupras
- Department of Biological Sciences, University of Limerick, Limerick, Ireland
| | - Ioannis Zabetakis
- Department of Biological Sciences, University of Limerick, Limerick, Ireland
| |
Collapse
|
7
|
Sato A, Ebina K. A biotinylated peptide, BP21, as a novel potent anti-anaphylactic agent targeting platelet-activating factor. J Pept Sci 2017. [PMID: 28627122 DOI: 10.1002/psc.3019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Platelet-activating factor (PAF) is an important mediator of anaphylaxis and is therefore an anti-anaphylactic drug target. We recently reported that synthetic N-terminally biotinylated peptides (BP4-BP29) inhibit PAF by directly interacting with PAF and its metabolite/precursor lyso-PAF. In this study, we investigated whether the biotinylated peptides can inhibit anaphylactic reactions in vivo. In mouse models of anaphylaxis, one of the peptides, BP21, markedly and dose-dependently inhibited hypothermia with a maximum dose-response within 30 min after administration, even at doses 20 times lesser than doses of the known PAF antagonist CV-3988. In contrast, the anti-hypothermic effect of BGP21, in which the Tyr-Lys-Asp-Gly sequence in BP21 was modified to a Gly-Gly-Gly-Gly sequence, was less than that of BP21. The alanine scanning and shuffling the amino acid residues of BP4 (Tyr-Lys-Asp-Gly) demonstrated that the Tyr-Lys-Asp-Gly consensus sequence is important for the inhibitory effect of the peptide on hypothermia. BP21 also suppressed vascular permeability during anaphylaxis with a maximum dose-response within 30 min of administration. In a rat model of hind paw oedema, BP21 significantly inhibited the oedema induced by PAF but not that induced by the other pro-inflammatory mediators, such as histamine, serotonin, and bradykinin. Tryptophan fluorescence measurements showed that BP21 interacted with PAF, but not with histamine, serotonin, or bradykinin. In contrast, BGP21 did not interact with PAF. These results suggest that biotinylated peptides, especially BP21, can specifically and markedly inhibit anaphylactic reactions in vivo and that this involves direct interaction of its Tyr-Lys-Asp-Gly region with PAF. Therefore, a biotinylated peptide, BP21, can be used as novel potential anti-anaphylactic drugs targeting PAF. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd.
Collapse
Affiliation(s)
- Akira Sato
- Faculty of Pharmacy, Iwaki Meisei University, 5-5-1 Chuodai-Iino, Iwaki, Fukushima, 970-8551, Japan
| | - Keiichi Ebina
- Faculty of Pharmacy, Iwaki Meisei University, 5-5-1 Chuodai-Iino, Iwaki, Fukushima, 970-8551, Japan
| |
Collapse
|
8
|
Palur Ramakrishnan AVK, Varghese TP, Vanapalli S, Nair NK, Mingate MD. Platelet activating factor: A potential biomarker in acute coronary syndrome? Cardiovasc Ther 2016; 35:64-70. [DOI: 10.1111/1755-5922.12233] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Revised: 10/07/2016] [Accepted: 10/25/2016] [Indexed: 11/28/2022] Open
Affiliation(s)
| | - Treesa P. Varghese
- Department of Pharmacy Practice; JSS College of Pharmacy (Jagadguru Sri Shivarathreeswara University, Mysore); Udhagamandalam Tamil Nadu India
| | - Sreedevi Vanapalli
- Department of Pharmacy Practice; JSS College of Pharmacy (Jagadguru Sri Shivarathreeswara University, Mysore); Udhagamandalam Tamil Nadu India
| | - Narayanan K. Nair
- Department of Pharmacy Practice; JSS College of Pharmacy (Jagadguru Sri Shivarathreeswara University, Mysore); Udhagamandalam Tamil Nadu India
| | - Menge Denis Mingate
- Department of Pharmacy Practice; JSS College of Pharmacy (Jagadguru Sri Shivarathreeswara University, Mysore); Udhagamandalam Tamil Nadu India
| |
Collapse
|
9
|
Megson IL, Whitfield PD, Zabetakis I. Lipids and cardiovascular disease: where does dietary intervention sit alongside statin therapy? Food Funct 2016; 7:2603-14. [PMID: 27109548 DOI: 10.1039/c6fo00024j] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The Seven Countries Study suggested an association between serum cholesterol and cardiovascular disease (CVD). However, the association was not consistent across the various cohorts of participants in different countries; while it was very clear in US and Northern European cohorts, it was weak in Southern European and Japanese cohorts. Nevertheless, the study triggered research into cholesterol-lowering drug strategies, ultimately leading to the development of statins amongst others. Clinical evidence in support of statins is strong and the vast majority of the medical community advocate these drugs as highly effective first-line therapeutics in primary and secondary prevention of CVD. However, growing evidence of side-effects associated with statins in a significant proportion of patients suggests that these drugs are not a universal solution to CVD. There is a need, therefore, to revisit the evidence and to re-appraise the relative importance of cholesterol amongst many other lipids as potential modulators of atherogenesis. In this review, we assess the relative merits of statin therapy in CVD versus dietary interventions that impact on lipids other than cholesterol, including omega-3 fatty acids and polar lipid fractions of various foods (e.g. fish and olive oil). We conclude that careful design around the lipid components of dietary interventions presents a credible alternative in patients who are intolerant to statins or averse to taking such drugs.
Collapse
Affiliation(s)
- Ian L Megson
- Department of Diabetes & Cardiovascular Science, University of the Highlands & Islands, UK
| | | | | |
Collapse
|
10
|
Sato A, Yokoyama I, Ebina K. Angiotensin peptides attenuate platelet-activating factor-induced inflammatory activity in rats. Peptides 2015; 73:60-6. [PMID: 26348270 DOI: 10.1016/j.peptides.2015.09.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 09/04/2015] [Accepted: 09/04/2015] [Indexed: 11/24/2022]
Abstract
Angiotensin (Ang)--a peptide that is part of the renin-angiotensin system-induces vasoconstriction and a subsequent increase in blood pressure; Ang peptides, especially AngII, can also act as potent pro-inflammatory mediators. Platelet-activating factor (PAF) is a potent phospholipid mediator that is implicated in many inflammatory diseases. In this study, we investigated the effects of Ang peptides (AngII, AngIII, and AngIV) on PAF-induced inflammatory activity. In experiments using a rat hind-paw oedema model, AngII markedly and dose-dependently attenuated the paw oedema induced by PAF. The inhibitory effects of AngIII and AngIV on PAF-induced paw oedema were lower than that of AngII. Two Ang receptors, the AT1 and AT2 receptors, did not affect the AngII-mediated attenuation of PAF-induced paw oedema. Moreover, intrinsic tyrosine fluorescence studies demonstrated that AngII, AngIII, and AngIV interact with PAF, and that their affinities were closely correlated with their inhibitory effects on PAF-induced rat paw oedema. Also, AngII interacted with metabolite/precursor of PAF (lyso-PAF), and an oxidized phospholipid, 1-palmitoyl-2-(5'-oxo-valeroyl)-sn-glycero-3-phosphocholine (POVPC), which bears a marked structural resemblance to PAF. Furthermore, POVPC dose-dependently inhibited AngII-mediated attenuation of PAF-induced paw oedema. These results suggest that Ang peptides can attenuate PAF-induced inflammatory activity through binding to PAF and lyso-PAF in rats. Therefore, Ang peptides may be closely involved in the regulation of many inflammatory diseases caused by PAF.
Collapse
Affiliation(s)
- Akira Sato
- Faculty of Pharmacy, Iwaki Meisei University, 5-5-1, Chuodai-Iino, Iwaki, Fukushima 970-8551, Japan.
| | - Izumi Yokoyama
- Faculty of Pharmacy, Iwaki Meisei University, 5-5-1, Chuodai-Iino, Iwaki, Fukushima 970-8551, Japan
| | - Keiichi Ebina
- Faculty of Pharmacy, Iwaki Meisei University, 5-5-1, Chuodai-Iino, Iwaki, Fukushima 970-8551, Japan
| |
Collapse
|
11
|
Sato A, Yokoyama I, Ebina K. Biotinylated heptapeptides substituted with a D-amino acid as platelet-activating factor inhibitors. Eur J Pharmacol 2015; 764:202-207. [PMID: 26142829 DOI: 10.1016/j.ejphar.2015.06.062] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 06/22/2015] [Accepted: 06/30/2015] [Indexed: 10/23/2022]
Abstract
Platelet-activating factor (PAF), a potent lipid mediator, is implicated in many inflammatory diseases, and therefore may serve as a direct target for anti-inflammatory drugs. We previously reported that synthetic biotinylated peptides having a Tyr-Lys-Asp-Gly sequence markedly inhibit PAF-induced inflammation by direct binding, and that two synthetic fluorescence-labelled heptapeptides (Lys-Trp-Tyr-Lys-Asp-Gly-Asp and D-Lys-Trp-Tyr-Lys-Asp-Gly-Asp) with high stability in plasma specifically bind to PAF-like lipids (oxidized- and lyso-phosphatidylchoine). In this study, synthetic heptapeptides (Lys-Trp-Tyr-Lys-Asp-Gly-Asp) coupled to a biotin molecule through the N-terminal amino group and ε-amino group of N-terminus Lys, (Btn)KP6 and K(Btn)P6, respectively, and their biotinylated peptides substituted with D-Lys at the N-terminus, (Btn)dKP6 and dK(Btn)P6, respectively, were investigated for their effects on PAF-induced inflammation. In the experiments using a rat model of hind paw oedema, (Btn)KP6, K(Btn)P6, (Btn)dKP6, and dK(Btn)P6 significantly inhibited PAF-induced paw oedema, with the highest inhibitory effect exhibited by dK(Btn)P6. The inhibitory effect of D-Tyr-D-Lys-D-Asp-Gly tetrapeptide on PAF-induced paw oedema was much lower than that of Tyr-Lys-Asp-Gly tetrapeptide. In the experiments using tryptophan fluorescence spectroscopy, (Btn)KP6, K(Btn)P6, (Btn)dKP6, and dK(Btn)P6 bound to PAF dose-dependently, with dK(Btn)P6 showing the strongest binding affinity, indicating that its affinity appears to be closely correlated with its inhibitory effect on PAF-induced inflammation. These results suggest that direct binding of (Btn)KP6, K(Btn)P6, (Btn)dKP6, and dK(Btn)P6 to PAF can lead to marked inhibition of PAF-induced inflammation, and these agents, particularly dK(Btn)P6, may be useful as anti-inflammatory drugs targeting PAF with high stability in plasma.
Collapse
Affiliation(s)
- Akira Sato
- Faculty of Pharmacy, Iwaki Meisei University, 5-5-1, Chuodai-Iino, Iwaki, Fukushima 970-8551, Japan.
| | - Izumi Yokoyama
- Faculty of Pharmacy, Iwaki Meisei University, 5-5-1, Chuodai-Iino, Iwaki, Fukushima 970-8551, Japan
| | - Keiichi Ebina
- Faculty of Pharmacy, Iwaki Meisei University, 5-5-1, Chuodai-Iino, Iwaki, Fukushima 970-8551, Japan
| |
Collapse
|
12
|
C-reactive protein specifically enhances platelet-activating factor-induced inflammatory activity in vivo. Eur J Pharmacol 2014; 745:46-51. [DOI: 10.1016/j.ejphar.2014.10.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 09/16/2014] [Accepted: 10/06/2014] [Indexed: 11/19/2022]
|
13
|
|
14
|
Common mechanism in endothelin-3 and PAF receptor function for anti-inflammatory responses. Eur J Pharmacol 2013; 718:30-3. [DOI: 10.1016/j.ejphar.2013.09.025] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Revised: 08/20/2013] [Accepted: 09/08/2013] [Indexed: 11/17/2022]
|
15
|
Sato A, Suzuki T, Oikawa K, Ohta R, Ebina K. An endothelin-3-related synthetic biotinylated pentapeptide as a novel inhibitor of platelet-activating factor. Eur J Pharmacol 2013; 714:142-7. [DOI: 10.1016/j.ejphar.2013.05.050] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2013] [Revised: 05/23/2013] [Accepted: 05/30/2013] [Indexed: 12/31/2022]
|
16
|
Sato A, Ebina K. Endothelin-3 at low concentrations attenuates inflammatory responses via the endothelin B2 receptor. Inflamm Res 2013; 62:417-24. [DOI: 10.1007/s00011-013-0594-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2012] [Revised: 10/22/2012] [Accepted: 01/08/2013] [Indexed: 10/27/2022] Open
|
17
|
Sato A, Kumagai T, Aoki J, Ebina K. Synthetic biotinylated peptide compounds derived from Asp-hemolysin: novel potent inhibitors of platelet-activating factor. Eur J Pharmacol 2012; 685:205-12. [PMID: 22542654 DOI: 10.1016/j.ejphar.2012.04.025] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2011] [Revised: 03/22/2012] [Accepted: 04/05/2012] [Indexed: 11/29/2022]
Abstract
Platelet-activating factor (PAF: 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine), a potent inflammatory mediator, is implicated in many inflammatory diseases and may possibly serve as a direct target for anti-inflammatory drugs. We have previously reported that Asp-hemolysin-related synthetic peptides (P4-P29) inhibit the bioactivities of oxidized low-density lipoprotein (ox-LDL) containing PAF-like lipids by direct binding to ox-LDL, which plays a key role in the atherosclerotic inflammatory process. In this study, we investigated whether these peptides inhibit the bioactivities of PAF by binding to PAF and its metabolite/precursor lyso-PAF. In in vitro experiments, P21, one of the peptides, bound to both PAF and lyso-PAF in a dose-dependent manner and markedly inhibited PAF-induced apoptosis in human umbilical vein endothelial cells. Moreover, in in vivo experiments, P4 and P21, particularly their N-terminally biotinylated peptide compounds (BP4 and BP21), inhibited PAF-induced rat paw oedema dose dependently and markedly, and showed sufficient inhibition of the oedema even at doses 150-300 times less than the doses of PAF antagonists. These results provide evidence that direct binding of N-terminally biotinylated peptide compounds derived from Asp-hemolysin to PAF and lyso-PAF leads to a dramatic inhibition of the bioactivities of PAF, both in vitro and in vivo, and strongly suggesting that these compounds may be useful as a novel type of anti-inflammatory drug for the treatment of several inflammatory diseases caused by PAF.
Collapse
Affiliation(s)
- Akira Sato
- Faculty of Pharmacy, Iwaki Meisei University, 5-5-1 Chuodai-Iino, Iwaki, Fukushima, 970-8551 Japan.
| | | | | | | |
Collapse
|
18
|
In vivo anti-atherogenic properties of cultured gilthead sea bream (Sparus aurata) polar lipid extracts in hypercholesterolaemic rabbits. Food Chem 2010. [DOI: 10.1016/j.foodchem.2009.11.023] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
19
|
Cho KH. Biomedicinal implications of high-density lipoprotein: its composition, structure, functions, and clinical applications. BMB Rep 2009; 42:393-400. [DOI: 10.5483/bmbrep.2009.42.7.393] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
|
20
|
Olson N, O'Meara ES, Jenny NS, Folsom AR, Bovill EG, Furberg CD, Heckbert SR, Psaty BM, Cushman M. Lipoprotein-associated phospholipase A2 and risk of venous thrombosis in older adults. Am J Hematol 2008; 83:524-7. [PMID: 18383322 DOI: 10.1002/ajh.21182] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Lipoprotein-associated phospholipase A2 (Lp-PLA2) is an enzyme involved in inflammation and platelet function. Inherited deficiency and elevated levels are associated with atherosclerosis. Given potential common etiologies of atherosclerosis and venous thrombosis (VT), we hypothesized that low and high Lp-PLA2 would be associated with VT risk. Lp-PLA(2) mass and activity were measured in baseline samples of Cardiovascular Health Study participants (5,888 men and women age > or =65), excluding 354 reporting pre-baseline VT. The study endpoint was VT unrelated to cancer after 11.6 years follow-up. Hazard ratios were estimated using Cox proportional hazard models, adjusting for age, race, sex, and body-mass index. With 129 cases of VT, there was no association of Lp-PLA2 activity with risk. Adjusted hazard ratios were 1.19 (CI 0.62, 2.29) and 0.87 (CI 0.43, 1.76) for the lowest and highest decile, respectively, compared to the 10-25th percentile. Corresponding hazard ratios for Lp-PLA2 mass were 1.63 (CI 0.79, 3.34) and 1.33 (CI 0.61, 2.87). Results were robust to several definitions of low or high Lp-PLA2. While the association of Lp-PLA(2) levels with arterial disease events implies a role for this enzyme in atherogenesis, our findings suggest that it is not prothrombotic.
Collapse
Affiliation(s)
- Nels Olson
- Department of Pathology, University of Vermont College of Medicine, Burlington, Vermont, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Antithrombotic and antiatherosclerotic properties of olive oil and olive pomace polar extracts in rabbits. Mediators Inflamm 2008; 2007:36204. [PMID: 18253466 PMCID: PMC1940054 DOI: 10.1155/2007/36204] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2007] [Revised: 04/12/2007] [Accepted: 05/06/2007] [Indexed: 11/18/2022] Open
Abstract
Olive oil polar lipid (OOPL) extract has been reported to inhibit atherosclerosis development on rabbits. Olive pomace polar lipid (PPL) extract inhibits PAF activity in vitro and the most potent antagonist has been identified as a glycerylether-sn-2-acetyl glycolipid with common structural characteristics with the respective potent antagonist of OOPL. The aim of this study was to investigate the effect of PPL on early atherosclerosis development on rabbits and to compare it with the antiatherosclerotic effect of OOPL. OOPL and PPL inhibition potency, towards both PAF action and PAF binding, was tested in vitro on washed rabbit platelets. Consequently, rabbits were divided into three groups (A, B, and C). All groups were fed atherogenic diet for 22 days. Atherogenic diets in groups B and C were enriched with OOPL and PPL, respectively. At the end of the experimental time, rabbits were euthanized and aortic samples were examined histopathologically. OOPL and PPL inhibited PAF-induced aggregation, as well as specific PAF binding, with PPL being more potent. Free and bound PAF levels and PAF-AH activity were significantly elevated at the end of the experimental time. Plasma total cholesterol, HDL cholesterol, LDL cholesterol, and triglycerides levels were also found increased. Groups B and C exhibited significantly increased
values of EC50 compared to group A. Histopathological examination revealed that the development of early atherosclerosis lesions in groups B and C were significantly inhibited compared to group A. Significant differences were noted in the early atherosclerosis lesions between groups B and C, thus indicating that PPL exhibit its anti-atherosclerotic activity by blocking PAF receptor. Specific PAF antagonists with similar in vitro and in vivo bioactivity to those that have been previously reported in OOPL exist in PPL.
Collapse
|
22
|
Ayscough A, Whittaker M. Patent Update: Pulmonary-Allergy, Dermatological, Gastrointestinal & Arthritis: Platelet-activating factor receptor antagonists. Expert Opin Ther Pat 2008. [DOI: 10.1517/13543776.5.7.653] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
23
|
Winkler K, Hoffmann MM, Winkelmann BR, Friedrich I, Schäfer G, Seelhorst U, Wellnitz B, Wieland H, Boehm BO, März W. Lipoprotein-associated phospholipase A2 predicts 5-year cardiac mortality independently of established risk factors and adds prognostic information in patients with low and medium high-sensitivity C-reactive protein (the Ludwigshafen risk and cardiovascular health study). Clin Chem 2007; 53:1440-7. [PMID: 17573419 DOI: 10.1373/clinchem.2007.086298] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND Lipoprotein-associated phospholipase A(2) (LpPLA(2)), also denoted as platelet-activating factor acetylhydrolase, is a lipoprotein-bound enzyme involved in inflammation and atherosclerosis. In this cohort study we investigated LpPLA(2) activity to predict cardiac mortality in patients scheduled for coronary angiography. METHODS LpPLA(2) activity was determined in 2513 patients with and in 719 patients without angiographically confirmed coronary artery disease (CAD). RESULTS During the median observation period of 5.5 years, 501 patients died. In patients with tertiles of LpPLA(2) activity of 420-509 U/L or >or=510 U/L, unadjusted hazard ratios (HRs) for cardiac death were 1.7 (95% CI 1.3-2.4; P = 0.001), and 1.9 (95% CI 1.4-2.5; P <0.001), respectively, compared with patients with LpPLA(2) activity <or=419 U/L. After we accounted for established risk factors and included angiographic CAD status, high-sensitivity C-reactive protein (hsCRP), and N-terminal pro-B-type natriuretic peptide, the 3rd tertile of LpPLA(2) activity predicted cardiac 5-year mortality with an HR of 2.0 (95% CI 1.4-3.1; P = 0.001). LpPLA(2) activity increased the adjusted risk for cardiac death by 2-fold in patients with hsCRP <3 mg/L in the 2nd (HR 2.4, 95% CI 1.4-4.2; P = 0.002) and 3rd (HR 2.1, 95% CI 1.1-4.0; P = 0.02) tertiles of LpPLA(2) activity and in patients with hsCRP of 3-10 mg/L in the 3rd tertile (HR 1.9, 95% CI 1.0-3.6; P = 0.03) of LpPLA(2) activity. CONCLUSIONS LpPLA(2) activity predicts risk for 5-year cardiac mortality independently from established risk factors and indicates risk for cardiac death in patients with low and medium-high hsCRP concentrations. Therefore, LpPLA(2) activity may provide information for the identification and management of patients at risk beyond established risk stratification strategies.
Collapse
Affiliation(s)
- Karl Winkler
- Department of Clinical Chemistry, University Medical Center Freiburg, Germany.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
24
|
Okamura K, Miura SI, Zhang B, Uehara Y, Matsuo K, Kumagai K, Saku K. Ratio of LDL- to HDL-Associated Platelet-Activating Factor Acetylhydrolase may be a Marker of Inflammation in Patients With Paroxysmal Atrial Fibrillation. Circ J 2007; 71:214-9. [PMID: 17251670 DOI: 10.1253/circj.71.214] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND A higher plasma concentration of highly-sensitive C-reactive protein (hs-CRP) has been found in patients with atrial fibrillation (AF). In addition, low-density lipoprotein (LDL)-associated platelet-activating factor acetylhydrolase (L-PAF-AH) is associated with inflammation. Therefore, the association between AF and PAF-AH was examined. METHODS AND RESULTS Eighty subjects who were not taking aspirin or statin were investigated, and classified into paroxysmal AF (n=41) and normal sinus rhythm (NSR, n=39) groups. The lipid profile was analyzed by capillary isotachophoresis (cITP), plasma hs-CRP, plasma PAF-AH, high-density lipoprotein (HDL)-associated (H-PAF-AH), and L-PAF-AH. Although there were no significant differences in total cholesterol, HDL, LDL, hs-CRP, or plasma PAF-AH between the 2 groups, L-PAF-AH and the L-PAF-AH/H-PAF-AH ratio in the paroxysmal AF group were both significantly higher than in the NSR group. Interestingly, the ratio of L-PAF-AH to H-PAF-AH positively correlated with the left atrial diameter in all subjects. Although there were no differences in plasma lipoprotein subfractions, as characterized by cITP, slow-migrating LDL positively correlated with L-PAF-AH in both groups. CONCLUSIONS The distribution of PAF-AH was associated with paroxysmal AF and may be a marker of inflammation in patients with paroxysmal AF. Antiinflammatory and antioxidant therapy that targets these factors might be effective for preventing paroxysmal AF.
Collapse
Affiliation(s)
- Keisuke Okamura
- Department of Cardiology, Fukuoka University School of Medicine, Japan
| | | | | | | | | | | | | |
Collapse
|
25
|
Fragopoulou E, Iatrou C, Antonopoulou S, Ruan XZ, Fernando RL, Powis SH, Moorhead JF, Varghese Z. Platelet-activating factor (PAF) increase intracellular lipid accumulation by increasing both LDL and scavenger receptors in human mesangial cells. ACTA ACUST UNITED AC 2006; 147:281-9. [PMID: 16750665 DOI: 10.1016/j.lab.2006.01.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2005] [Revised: 01/24/2006] [Accepted: 01/25/2006] [Indexed: 11/28/2022]
Abstract
Intra- and extracellular lipid accumulation and the production of inflammatory mediators by renal and accessory cells may play an important role in the initiation and progression of these lesions. Platelet activating factor (PAF) is a biologically active phospholipid that is produced by various cells upon activation by different stimuli. It has been suggested that PAF plays a role in atherogenesis, and several studies indicated its participation in the pathogenesis of renal diseases. The aim of this study is to investigate the role of PAF on intracellular lipid accumulation and gene regulation of lipoprotein receptors in human mesangial cells (HMCs). A human mesangial cell line (HMC) was used to study the effects of PAF on foam cell formation by Oil red O staining and on the expression of LDLr, SR-AI, and PAF-R mRNA using RT-PCR. Native LDL caused foam cell formation in HMC in the presence of PAF. PAF enhanced LDLr expression and overrode LDL receptor suppression induced by a high concentration of LDL. Moreover, it enhanced SR-AI expression. PAF also caused increase in PAF-R expression. The above data suggest that PAF enhances its own receptor expression and then increases lipid accumulation by dysregulating LDL receptor regulation and inducing scavenger receptor expression in HMCs. These results suggest that PAF has a potential role in lipid mediated renal injury.
Collapse
MESH Headings
- Cell Line, Transformed
- Cholesterol, LDL/pharmacokinetics
- Foam Cells/cytology
- Foam Cells/metabolism
- Gene Expression Regulation/drug effects
- Gene Expression Regulation/physiology
- Glomerulosclerosis, Focal Segmental/metabolism
- Glomerulosclerosis, Focal Segmental/physiopathology
- Humans
- Lipid Metabolism/drug effects
- Lipid Metabolism/physiology
- Mesangial Cells/cytology
- Mesangial Cells/drug effects
- Mesangial Cells/metabolism
- Platelet Activating Factor/metabolism
- Platelet Activating Factor/pharmacology
- Platelet Membrane Glycoproteins/genetics
- Platelet Membrane Glycoproteins/metabolism
- RNA, Messenger/analysis
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/metabolism
- Receptors, LDL/genetics
- Receptors, LDL/metabolism
- Scavenger Receptors, Class A/genetics
- Scavenger Receptors, Class A/metabolism
- Tritium
Collapse
Affiliation(s)
- Elizabeth Fragopoulou
- Faculty of Chemistry, National and Kapodistrian University of Athens, Athens, Greece
| | | | | | | | | | | | | | | |
Collapse
|
26
|
Karantonis HC, Antonopoulou S, Perrea DN, Sokolis DP, Theocharis SE, Kavantzas N, Iliopoulos DG, Demopoulos CA. In vivo antiatherogenic properties of olive oil and its constituent lipid classes in hyperlipidemic rabbits. Nutr Metab Cardiovasc Dis 2006; 16:174-185. [PMID: 16580585 DOI: 10.1016/j.numecd.2005.07.003] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2004] [Revised: 06/06/2005] [Accepted: 07/07/2005] [Indexed: 10/25/2022]
Abstract
BACKGROUND AND AIM The consumption of olive oil has been associated with lower incidence of cardiovascular disease in the Mediterranean countries. This may be due in part to the action of platelet-activating factor (PAF) antagonists which we have previously demonstrated to be present in olive oil. In order to assess the in vivo effects of olive oil lipids and PAF in the development of atherosclerosis, the effects of diet supplementation with olive oil (OO), olive oil polar lipid extract (OOPLE) and olive oil neutral lipid extract (OONLE) were studied in rabbits fed a cholesterol-enriched diet. METHODS AND RESULTS Rabbits were fed for 45 days with atherogenic diet (Group A) supplemented with OO (Group B), OOPLE (Group C) or OONLE (Group D). Lipoprotein profiles, plasma in vitro oxidation, blood PAF levels, PAF-induced platelet aggregation and PAF-acetylhydrolase (PAF-AH) activity, were measured on day 0 and 45. Atherosclerotic lesions formed in the aortic wall and wall elasticity were assessed on day 45. Changes in lipid profile were in accordance with previous studies. Blood PAF levels were higher in group A and decreased in group D on day 45. In rabbits fed an atherogenic diet (Group A) blood PAF and PAF-AH increased, atherosclerotic lesions formed and the elasticity of vessel walls declined. In animals fed olive oil (Group B) or OOPLE (Group C) blood PAF-AH increased, platelet aggregation was attenuated, less oxidation occurred in plasma, lesion thickness was reduced and vessel walls retained elasticity. Most of these beneficial changes were not seen in animals fed OONLE (Group D) although blood PAF and plasma oxidation were lower. CONCLUSIONS The antiatherogenic effects of OO result from OOPLE. The beneficial effect of these factors is linked to PAF metabolism and proaggregant activity.
Collapse
Affiliation(s)
- Haralabos C Karantonis
- Laboratory of Biochemistry, Faculty of Chemistry, National and Kapodistrian University of Athens, Panepistimioupolis, Greece
| | | | | | | | | | | | | | | |
Collapse
|
27
|
Fernandes ES, Passos GF, Campos MM, de Souza GEP, Fittipaldi JF, Pesquero JL, Teixeira MM, Calixto JB. Cytokines and neutrophils as important mediators of platelet-activating factor-induced kinin B1 receptor expression. Br J Pharmacol 2005; 146:209-16. [PMID: 16025141 PMCID: PMC1576273 DOI: 10.1038/sj.bjp.0706327] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
PAF injection into the rat paw is accompanied by the concomitant activation of NF-kappaB and neutrophil influx, which appears to be relevant to the up-regulation of kinin B1 receptors. Herein, we analyse the role of TNF-alpha and IL-1beta production for PAF-induced B1 receptor upregulation in the rat paw. Additionally, we evaluate how cytokine production and neutrophil migration fit into the temporal sequence of events leading to PAF-induced B1 receptor upregulation. In our experiments, treatment with PAF resulted in a marked increase of B1 receptor-mediated paw oedema and in situ production of TNF-alpha at 1 h and IL-1beta at 3 and 6 h later. B1 receptor-mediated paw oedema was significantly inhibited by anti-TNF-alpha antibody and by interleukin-1 receptor antagonist (IRA). TNF-alpha was necessary for the local PAF-induced IL-1beta production. NF-kappaB blocker PDTC prevented the production of both TNF-alpha and IL-1beta, indicating that cytokine production is NF-kappaB dependent. Depletion of neutrophils with an anti-PMN antibody prevented IL-1beta, but not TNF-alpha, production. Although both TNF-alpha and IL-1beta are relevant to functional B1 receptor upregulation, PAF-induced increase in B1 receptor mRNA was markedly suppressed by anti-TNF-alpha and, to a lesser extent, by IRA. B1 receptor mRNA expression was also prevented by the anti-PMN antibody. In conclusion, the activation of the TNF-alpha/neutrophil axis by PAF seems to be sufficient for B1 receptor mRNA production. However, the TNF-alpha/neutrophil axis is also necessary for IL-1beta production. These two processes might lead to the appearance of functional kinin B1 upregulation receptors in vivo after PAF treatment.
Collapse
Affiliation(s)
- Elizabeth S Fernandes
- Department of Pharmacology, CCB, Centre of Biological Sciences, Universidade Federal de Santa Catarina, Campus Universitário, Trindade, Florianópolis, SC 88049-900, Brazil
| | - Giselle F Passos
- Department of Pharmacology, CCB, Centre of Biological Sciences, Universidade Federal de Santa Catarina, Campus Universitário, Trindade, Florianópolis, SC 88049-900, Brazil
| | - Maria M Campos
- Department of Pharmacology, CCB, Centre of Biological Sciences, Universidade Federal de Santa Catarina, Campus Universitário, Trindade, Florianópolis, SC 88049-900, Brazil
| | - Glória E P de Souza
- Laboratory of Pharmacology, Faculty of Pharmaceutical Sciences of Ribeirão, USP Ribeirão Preto, SP, Brazil
| | | | - Jorge L Pesquero
- Department of Physiology and Biophysics, Belo Horizonte, MG, Brazil
| | - Mauro M Teixeira
- Department of Biochemistry and Immunology, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - João B Calixto
- Department of Pharmacology, CCB, Centre of Biological Sciences, Universidade Federal de Santa Catarina, Campus Universitário, Trindade, Florianópolis, SC 88049-900, Brazil
- Author for correspondence:
| |
Collapse
|
28
|
Winkler K, Winkelmann BR, Scharnagl H, Hoffmann MM, Grawitz AB, Nauck M, Böhm BO, März W. Platelet-activating factor acetylhydrolase activity indicates angiographic coronary artery disease independently of systemic inflammation and other risk factors: the Ludwigshafen Risk and Cardiovascular Health Study. Circulation 2005; 111:980-7. [PMID: 15710755 DOI: 10.1161/01.cir.0000156457.35971.c8] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND Platelet-activating factor acetylhydrolase (PAF-AH), also denoted as lipoprotein-associated phospholipase A2, is a lipoprotein-bound enzyme that is possibly involved in inflammation and atherosclerosis. This study investigates the relationship of PAF-AH activity to angiographic coronary artery disease (CAD), the use of cardiovascular drugs, and other established risk factors. METHODS AND RESULTS PAF-AH activity, lipoproteins, sensitive C-reactive protein (sCRP), fibrinogen, serum amyloid A, and white blood cell count were determined in 2454 subjects with angiographically confirmed CAD and in 694 control subjects. PAF-AH activity was highly correlated with LDL cholesterol (r=0.517), apolipoprotein B (r=0.644), and non-HDL cholesterol (r=0.648) but not with sCRP or fibrinogen. PAF-AH activity was lower in women than in men and was affected by the intake of lipid-lowering drugs (-12%; P<0.001), aspirin (-6%; P<0.001), beta-blockers (-6%; P<0.001), and digitalis (+7%; P<0.001). Unlike sCRP, fibrinogen, and serum amyloid A, PAF-AH activity was not elevated in unstable angina, non-ST-elevation myocardial infarction, or ST-elevation myocardial infarction. When nonusers of lipid-lowering drugs were examined, PAF-AH activity was associated with the severity of CAD and the number of coronary vessels with significant stenoses. In individuals not taking lipid-lowering drugs and after adjustment for use of aspirin, beta-blocker, and digitalis, the odds ratio for CAD associated with increasing PAF-AH activity was 1.39 (95% CI 1.26 to 1.54, P<0.001), a finding that was robust against further adjustments. CONCLUSIONS PAF-AH activity is not an indicator of the systemic inflammation that accompanies acute coronary syndromes. PAF-AH activity is affected by a number of cardiovascular drugs; however, after such medication use was accounted for, PAF-AH activity was associated with angiographic CAD, complementary to sCRP and independently of established risk factors such as LDL cholesterol.
Collapse
Affiliation(s)
- Karl Winkler
- Department of Medicine, University of Freiburg, Freiburg, Germany.
| | | | | | | | | | | | | | | |
Collapse
|
29
|
Demopoulos CA, Karantonis HC, Antonopoulou S. Platelet activating factor— a molecular link between atherosclerosis theories. EUR J LIPID SCI TECH 2003. [DOI: 10.1002/ejlt.200300845] [Citation(s) in RCA: 118] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
30
|
McDonagh PF, Hokama JY, Gale SC, Logan JJ, Davis-Gorman G, Goldman S, Copeland JG. Chronic expression of platelet adhesion proteins is associated with severe ischemic heart disease in type 2 diabetic patients: Chronic platelet activation in diabetic heart patients. J Diabetes Complications 2003; 17:269-78. [PMID: 12954156 DOI: 10.1016/s1056-8727(02)00246-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Cardiac ischemia is a serious complication of type 2 diabetes. However, the pathophysiology underlying the increased severity of myocardial ischemia in diabetes is not clear. This study tested the hypothesis that platelet adhesion protein expression is chronically increased in older type 2 diabetic patients with established ischemic heart disease (IHD) compared to age-matched, nondiabetic patients with IHD. We compared the chronic expression of two platelet adhesion proteins, P-selectin and GPIIb/IIIa, in whole blood and the platelet reactivity to an acute stimulus. We found that the expression of platelet P-selectin was chronically increased in the nondiabetic patients with IHD compared to normal subjects. P-selectin expression was further increased in the diabetic patients with IHD compared to the nondiabetic IHD patients (P<.05). The results were stratified to examine the potential effect of aspirin usage on adhesion protein expression. We found that the expression of the activated GPIIb/IIIa complex was significantly reduced in those diabetic cardiac patients who were taking aspirin (P<.05). These findings indicate that, in patients with IHD, platelet adhesion proteins are chronically expressed and that the level of expression is increased more in IHD patients with type 2 diabetes. This complication of diabetes may exacerbate thrombus formation during a recurrent event, increasing the severity of ischemic injury. The results give further support to the use of aspirin in type 2 diabetics with established cardiac disease.
Collapse
Affiliation(s)
- Paul F McDonagh
- Cardiovascular and Thoracic Surgery and the Sarver Heart Center, University of Arizona Health Sciences Center, Tucson, AZ 85724, USA.
| | | | | | | | | | | | | |
Collapse
|
31
|
Perron A, Chen ZG, Gingras D, Dupre DJ, Stankova J, Rola-Pleszczynski M. Agonist-independent desensitization and internalization of the human platelet-activating factor receptor by coumermycin-gyrase B-induced dimerization. J Biol Chem 2003; 278:27956-65. [PMID: 12756251 DOI: 10.1074/jbc.m212302200] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Platelet-activating factor (PAF) is a phospholipid with potent and diverse physiological actions, particularly as a mediator of inflammation. We have reported previously that mutant G protein-coupled receptors (GPCRs) affect the functional properties of coexpressed wild-type human PAF receptor (hPAFR) (Le Gouill, C., Parent, J. L., Caron, C. A., Gaudreau, R., Volkov, L., Rola-Pleszczynski, M., and Stankova, J. (1999) J. Biol. Chem. 274, 12548-12554). Increasing evidence suggests that dimerization of GPCRs may play an important role in the regulation of their biological activity. Additional data have also suggested that dimerization may be important in the subsequent internalization of the delta-opioid receptor. To investigate the specific role of dimerization in the internalization process of GPCRs, we generated a fusion protein of hPAFR and bacterial DNA gyrase B (GyrB), dimerized through the addition of coumermycin. We found that dimerization potentiates PAF-induced internalization of hPAFR-GyrB in Chinese hamster ovary cells stably expressing c-Myc-hPAFR-GyrB. Coumermycin-driven dimerization was also sufficient to induce an agonist-independent sequestration process in an arrestin- and clathrin-independent manner. Moreover, the protein kinase C inhibitors staurosporine and GF109203X blocked the coumermycin-induced desensitization of hPAFR-GyrB, suggesting the implication of protein kinase C in the molecular mechanism mediating the agonist-independent desensitization of the receptor. Taken together, these findings suggest a novel mechanism of GPCR desensitization and internalization triggered by dimerization.
Collapse
Affiliation(s)
- Amelie Perron
- Immunology Division, Department of Pediatrics, Faculty of Medicine, University of Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
| | | | | | | | | | | |
Collapse
|
32
|
Fernandes ES, Passos GF, Campos MM, Araújo JGVC, Pesquero JL, Avelllar MC, Teixeira MM, Calixto JB. Mechanisms underlying the modulatory action of platelet activating factor (PAF) on the upregulation of kinin B1 receptors in the rat paw. Br J Pharmacol 2003; 139:973-81. [PMID: 12839871 PMCID: PMC1573912 DOI: 10.1038/sj.bjp.0705314] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
1. The present study evaluated the ability of the administration of platelet activating factor (PAF) to induce the upregulation of B(1) receptors in the rat paw. 2. Local treatment with PAF resulted in a time-dependent increase of oedema formation induced by the B(1) receptor agonist des-Arg(9)-BK (des-Arg(9)-bradykinin), but not by the B(2) receptor agonist tyrosine(8)-bradykinin. Functional upregulation of B(1) receptors was accompanied by a prominent increase of B(1) receptor mRNA expression in the rat paw. 3. In PAF-treated paws, des-Arg(9)-BK-induced oedema formation was significantly inhibited by the B(1) receptor antagonists des-Arg(9)-[Leu(8)]-BK and R-715. The effects of PAF pretreatment were receptor operated, as assessed by the effects of the PAF receptor antagonist WEB2086 or by desensitisation of PAF receptors. 4. The protein synthesis inhibitor cycloheximide, the anti-inflammatory steroid dexamethasone or the nuclear factor (NF-kappaB) blockers pyrrolidine-dithiocarbamate (PDTC) and Nalpha-tosyl-L-chloromethylketone significantly blocked the functional upregulation of B(1) receptors. 5. The selectin inhibitor fucoidin, an anti-CD18 antibody or an anti-rat neutrophil antiserum, also significantly prevented des-Arg(9)-BK-induced paw oedema in rats pretreated with PAF. 6. Intradermal injection of PAF induced a 25-fold increase of myeloperoxidase activity in the rat paw, a response that was significantly inhibited by fucoidin, anti-CD-18, anti-rat neutrophil antiserum or PDTC. 7. Local treatment with PAF also resulted in a marked increase of NF-kappaB activation, an effect largely prevented by PDTC or by the anti-rat neutrophil antiserum. 8. Collectively, the present results indicate that the induction of B(1) receptors following treatment with the chemotatic mediator PAF is dependent on the recruitment of neutrophils, an event that is under the control of adhesion molecules, protein synthesis and NF-kappaB activation. These findings provide new insights into the role played by cell migration and chemotatic factors on B(1) receptor upregulation in vivo.
Collapse
Affiliation(s)
- Elizabeth S Fernandes
- Department of Pharmacology, Centre of Biological Sciences, Universidade Federal de Santa Catarina, Rua Ferreira Lima, 82, Florianópolis, SC 88015-420, Brazil
| | - Giselle F Passos
- Department of Pharmacology, Centre of Biological Sciences, Universidade Federal de Santa Catarina, Rua Ferreira Lima, 82, Florianópolis, SC 88015-420, Brazil
| | - Maria M Campos
- Department of Pharmacology, Centre of Biological Sciences, Universidade Federal de Santa Catarina, Rua Ferreira Lima, 82, Florianópolis, SC 88015-420, Brazil
| | - José G V C Araújo
- Department of Physiology and Biophysics, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Jorge L Pesquero
- Department of Physiology and Biophysics, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Maria C Avelllar
- Section of Experimental Endocrinology, Department of Pharmacology, Universidade Federal de São Paulo – Escola Paulista de Medicina, São Paulo, 04044-020, Brazil
| | - Mauro M Teixeira
- Department of Biochemistry and Immunology, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - João B Calixto
- Department of Pharmacology, Centre of Biological Sciences, Universidade Federal de Santa Catarina, Rua Ferreira Lima, 82, Florianópolis, SC 88015-420, Brazil
- Author for correspondence:
| |
Collapse
|
33
|
Tsimihodimos V, Kakafika A, Tambaki AP, Bairaktari E, Chapman MJ, Elisaf M, Tselepis AD. Fenofibrate induces HDL-associated PAF-AH but attenuates enzyme activity associated with apoB-containing lipoproteins. J Lipid Res 2003; 44:927-34. [PMID: 12611907 DOI: 10.1194/jlr.m200452-jlr200] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human plasma platelet-activating factor acetylhydrolase (PAF-AH) is an enzyme associated mainly with the apolipoprotein B (apoB)-containing lipoproteins and primarily with LDL. A small proportion of enzymatic activity is also associated with HDL. Plasma paraoxonase 1 (PON1) is an esterase exclusively associated with HDL. The effect of fenofibrate on PAF-AH and PON1 activities in patients with dyslipidemias of Types IIA, IIB, and IV were studied. Fenofibrate reduced plasma PAF-AH activity in all patient groups. In Type IIA patients, this reduction was mainly due to a fall in enzyme activity associated with the dense LDL subspecies, whereas in Type IIB and Type IV patients, it was due to the decrease in PAF-AH activity associated with both the VLDL+IDL and dense LDL subspecies. Drug therapy in Type IIB and Type IV patients significantly increased the HDL-associated PAF-AH activity due to the increase in enzyme activity associated with the HDL-3c subfraction. Fenofibrate did not affect serum PON1 activities toward paraoxon and phenylacetate in either patient group. The fenofibrate-induced elevation of HDL-associated PAF-AH activity in dyslipidemic patients of Type IIB and Type IV, as well as the reduction in enzyme activity associated with atherogenic apoB-containing lipoproteins in all patient groups, may represent a new and important antiatherogenic effect of this potent lipid-modulating agent.
Collapse
|
34
|
Corl CM, Cao YZ, Cohen ZS, Sordillo LM. Oxidant stress enhances Lyso-PAF-AcT activity by modifying phospholipase D and phosphatidic acid in aortic endothelial cells. Biochem Biophys Res Commun 2003; 302:610-4. [PMID: 12615078 DOI: 10.1016/s0006-291x(03)00223-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Oxidant stress, as a consequence of selenium (Se) deficiency, alters production of vasoactive compounds including platelet-activating factor (PAF). Recent studies report that enhanced PAF production during Se deficiency is a consequence of increased lyso-PAF:acetyl-coenzyme A acetyltransferase (Lyso-PAF-AcT) activity. To elucidate the mechanism behind increased Lyso-PAF-AcT activity during oxidant stress, phospholipase D (PLD) activity and phosphatidic acid (PA) production were examined. Increased PLD activity and PA production were exhibited in bovine aortic endothelial cells using a Se-deficient model of oxidant stress. The direct effects of PLD and PA on Lyso-PAF-AcT activity were assessed using selective inhibitors and repletion experiments. Following the inhibition of PLD and addition of exogenous PA, Lyso-PAF-AcT activity significantly decreased and increased, respectively. Therefore, Se deficiency enhances Lyso-PAF-AcT activity in part by modifying PLD and PA. This suggests a novel link between Se status and PAF production, providing potential upstream therapeutic targets for PAF regulation under conditions of oxidant stress.
Collapse
Affiliation(s)
- C M Corl
- Department of Veterinary Science, The Pennsylvania State University, 115 Henning Building, University Park, PA 16802, USA
| | | | | | | |
Collapse
|
35
|
Grippo AJ, Francis J, Weiss RM, Felder RB, Johnson AK. Cytokine mediation of experimental heart failure-induced anhedonia. Am J Physiol Regul Integr Comp Physiol 2003; 284:R666-73. [PMID: 12611391 DOI: 10.1152/ajpregu.00430.2002] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Immune system dysfunction is hypothesized to influence several disease states, including cardiovascular disease and psychological depression. The comorbidity of depression and coronary artery disease may be influenced by immune system-brain interactions involving proinflammatory cytokines. The present studies evaluated an index of depression in a rodent model of heart failure by measuring responses to rewarding electrical brain stimulation, which provides an experimental procedure to operationally define anhedonia in rats. Heart failure led to a rightward shift in the current-response relationship in the brain stimulation paradigm, indicative of reduced rewarding properties of the brain stimulation (i.e., anhedonia). Acute treatment with a tumor necrosis factor antagonist, etanercept, reduced circulating tumor necrosis factor- levels in rats with heart failure and restored responding for electrical brain stimulation. The current findings have implications for the study of pathophysiological mechanisms underlying the association of cardiovascular disease and depression.
Collapse
Affiliation(s)
- Angela J Grippo
- Department of Psychology, The University of Iowa, Iowa City, Iowa 52242, USA
| | | | | | | | | |
Collapse
|
36
|
Tselepis AD, John Chapman M. Inflammation, bioactive lipids and atherosclerosis: potential roles of a lipoprotein-associated phospholipase A2, platelet activating factor-acetylhydrolase. ATHEROSCLEROSIS SUPP 2002; 3:57-68. [PMID: 12573364 DOI: 10.1016/s1567-5688(02)00045-4] [Citation(s) in RCA: 229] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
It is well established that inflammation is an integral feature of atherosclerosis and of the cardiovascular diseases which it underlies. Oxidative stress is also recognized as a key actor in atherogenesis, in which it is closely associated with the inflammatory response and bioactive lipid formation. Several bioactive lipids have been identified in the atherosclerotic plaque, including the potent inflammatory mediator platelet activating factor (PAF), PAF-like lipids, oxidised phospholipids (oxPL) and lysophosphatidylcholine (lyso-PC). Recent evidence has established a central role of two phospholipases (PL) in atherogenesis, the non-pancreatic Type II secretory phospholipase A(2) (sPLA(2)) and the lipoprotein-associated PLA(2)-alternatively termed as PAF-acetylhydrolase (PAF-AH). sPLA(2) is calcium-dependent and hydrolyses the sn-2 acyl group of glycerophospholipids of lipoproteins and cell membranes to produce lyso-PC and free fatty acids. It is also implicated in isoprostane production from oxPL. sPLA(2) is an acute phase reactant, which is upregulated by inflammatory cytokines and may represent a new independent risk factor for coronary heart disease. In contrast to sPLA(2), PAF-AH is calcium-independent and is specific for short acyl groups at the sn-2 position of the phospholipid substrate and with the exception of PAF, can equally hydrolyze oxPL to generate lyso-PC and oxidized fatty acids. Thus PAF-AH plays a key role in the degradation of proinflammatory oxPL and in the generation of lyso-PC and oxidized fatty acids. PAF-AH equally can also hydrolyze short-chain diacylglycerols, triacylglycerols, and acetylated alkanols, and displays a PLA(1) activity. Whereas sPLA(2) may represent a new independent risk factor for coronary artery disease, the potential relevance of PAF-AH to atherosclerosis remains the subject of debate, and recent results suggest that the potential role of the LDL-associated PAF-AH in atherogenesis may be distinct to that of the HDL-associated enzyme. This review is focused on the main structural and catalytic features of plasma PAF-AH, on the association of the enzyme with distinct lipoprotein particle subspecies, on its cellular sources, and finally on the potential significance of this lipoprotein-associated PLA(2) in cardiovascular disease.
Collapse
|
37
|
Abstract
Psychological depression is shown to be associated with several aspects of coronary artery disease (CAD), including arrhythmias, myocardial infarction, heart failure and sudden death. The physiological mechanisms accounting for this association are unclear. Hypothalamic-pituitary-adrenal dysregulation, diminished heart rate variability, altered blood platelet function and noncompliance with medial treatments have been proposed as mechanisms underlying depression and cardiovascular disease. Recent evidence also suggests that reduced baroreflex sensitivity, impaired immune function, chronic fatigue and the co-morbidity of depression and anxiety may be involved in the relationship between depression and cardiovascular dysregulation. An experimental strategy using animal models for investigating underlying physiological abnormalities in depression is presented. A key to understanding the bidirectional association between depression and heart disease is to determine whether there are common changes in brain systems that are associated with these conditions. Such approaches may hold promise for advancing our understanding of the interaction between this mood disorder and CAD.
Collapse
Affiliation(s)
- Angela J Grippo
- Department of Psychology, The University of Iowa, Iowa City 52242-1407, USA
| | | |
Collapse
|
38
|
McManus LM, Pinckard RN. PAF, a putative mediator of oral inflammation. CRITICAL REVIEWS IN ORAL BIOLOGY AND MEDICINE : AN OFFICIAL PUBLICATION OF THE AMERICAN ASSOCIATION OF ORAL BIOLOGISTS 2002; 11:240-58. [PMID: 12002818 DOI: 10.1177/10454411000110020701] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
PAF, or platelet-activating factor, is a family of structurally related phospholipids (1-O-alkyl/acyl/alkenyl-2-acetyl-sn-glycero-3-phosphocholine) which possesses a wide spectrum of potent pro-inflammatory actions. These phospholipids are synthesized by a diverse array of cells, including neutrophilic polymorphonuclear leukocytes (PMN), platelets, mast cells, monocytes/macrophages, vascular endothelial cells, and lymphocytes. PAF targets these and other cells via specific, G-protein-coupled receptors to initiate intracrine, autocrine, paracrine, and juxtacrine cell activation. Of importance, these unique acetylated phospholipids are frequently synthesized in concert with pro-inflammatory lipid mediators derived from arachidonic acid. Since PAF synergizes with these and other mediators to amplify the inflammatory response, it seems likely that PAF plays an integral, perhaps pivotal, role in acute and chronic inflammatory processes. PAF is present in the mixed saliva of dentate, but not edentulous, human subjects. The levels of PAF in mixed saliva or in gingival crevicular fluid and tissues are significantly increased during oral inflammatory conditions such as periodontitis and mucositis. Interestingly, the levels of salivary PAF correlate with the extent/severity of these oral diseases. These observations suggest that PAF may participate in pathophysiologic events during the course of oral inflammation. The availability of specific PAF receptor antagonists and human recombinant PAF-acetylhydrolase (PAF-AH), a plasma enzyme which rapidly destroys PAF, should provide clinical tools for the investigation of the role of PAF in these and other inflammatory disorders; and perhaps, ultimately, some of these reagents may prove to be therapeutically useful in the treatment and management of these conditions.
Collapse
Affiliation(s)
- L M McManus
- Department of Pathology, The University of Texas Health Science Center, San Antonio 78229, USA.
| | | |
Collapse
|
39
|
Tsimihodimos V, Karabina SAP, Tambaki AP, Bairaktari E, Goudevenos JA, Chapman MJ, Elisaf M, Tselepis AD. Atorvastatin preferentially reduces LDL-associated platelet-activating factor acetylhydrolase activity in dyslipidemias of type IIA and type IIB. Arterioscler Thromb Vasc Biol 2002; 22:306-11. [PMID: 11834533 DOI: 10.1161/hq0202.102918] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Human plasma platelet-activating factor acetylhydrolase (PAF-AH) is a phospholipase A(2) that is primarily associated with low density lipoprotein (LDL). PAF-AH activity has also been found in high density lipoprotein (HDL), although it has recently been indicated that there is no PAF-AH protein in HDL. Plasma paraoxonase 1 (PON1) is an HDL-associated esterase, which also exhibits PAF-AH-like activity. The effect of atorvastatin (20 mg per day for 4 months) on PAF-AH and PON1 activities in patients with dyslipidemia of type IIA (n=55) or type IIB (n=21) was studied. In both patient groups, atorvastatin significantly reduced plasma PAF-AH activity because of the decrease in LDL plasma levels and the preferential decrease in PAF-AH activity on dense LDL subfractions (LDL-4 and LDL-5). Drug therapy did not affect HDL-associated PAF-AH activity or serum PON1 activities toward paraoxon and phenylacetate in either patient group. However, because of the reduction in LDL cholesterol levels, the ratios of HDL-associated PAF-AH and serum PON1 activities to LDL cholesterol levels were significantly increased after drug administration. The reduction of the LDL-associated PAF-AH activity and the elevation in the ratios of HDL-associated PAF-AH and PON1 activities to LDL plasma levels may represent a new dimension in the antiatherogenic effect of atorvastatin.
Collapse
|
40
|
Tsimihodimos V, Karabina SAP, Tambaki AP, Bairaktari E, Miltiadous G, Goudevenos JA, Cariolou MA, Chapman MJ, Tselepis AD, Elisaf M. Altered distribution of platelet-activating factor-acetylhydrolase activity between LDL and HDL as a function of the severity of hypercholesterolemia. J Lipid Res 2002. [DOI: 10.1016/s0022-2275(20)30167-x] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|
41
|
Michalis LK, Tambaki AP, Katsouras CS, Goudevenos JA, Kolettis T, Adamides K, Tselepis AD, Sideris DA. Platelet hyperaggregability to platelet activating factor (PAF) in non-ST elevation acute coronary syndromes. Curr Med Res Opin 2002; 18:108-12. [PMID: 12017208 DOI: 10.1185/030079902125000381] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
It is known that myocardial ischaemia increases platelet aggregatory response to various agonists, ex vivo. We investigated the platelet aggregatory response to platelet activating factor (PAF), ex vivo, in patients with non-ST elevation acute coronary syndromes and determined the specificity and sensitivity of this response. Thirty-two consecutive patients with non-ST elevation acute coronary syndromes and 20 healthy volunteers were studied. Platelet aggregation in platelet-rich plasma was studied on the day of admission. The maximal aggregation achieved within 2 min after the addition of PAF (100 nM) was expressed as a percentage of 100% light transmission. PAF EC50 values were defined as the concentration that induces 50% of maximal aggregation. The PAF EC50 values of the non-ST elevation acute coronary syndromes patients were significantly lower compared to those of the controls (p < 0.0001). The maximal percentage of aggregation was also significantly higher (p < 0.0005). Ninety-one per cent of the patients were correctly classified using PAF EC50 values (specificity 90.0% and sensitivity 91.2%); the corresponding results using the maximal percentage of aggregation were 80% (specificity 70.0% and sensitivity 87.5%). The estimated values used as thresholds were 22.47 nM and 17.97 for the PAF EC50 and the maximal percentage of aggregation, respectively. The results of the present study suggest that platelet hyperaggregability to PAF, ex vivo, in non-ST elevation acute coronary syndromes is characterised by a high specificity and sensitivity, and thus it may represent a mechanism contributing to the pathophysiology of acute coronary syndromes.
Collapse
Affiliation(s)
- L K Michalis
- Department of Cardiology, University Hospital of Ioannina, Greece.
| | | | | | | | | | | | | | | |
Collapse
|
42
|
Abstract
Increased LDL oxidation is associated with coronary artery disease. The predictive value of circulating oxidized LDL is additive to the Global Risk Assessment Score for cardiovascular risk prediction based on age, gender, total and HDL cholesterol, diabetes, hypertension, and smoking. Circulating oxidized LDL does not originate from extensive metal ion-induced oxidation in the blood but from mild oxidation in the arterial wall by cell-associated lipoxygenase and/or myeloperoxidase. Oxidized LDL induces atherosclerosis by stimulating monocyte infiltration and smooth muscle cell migration and proliferation. It contributes to atherothrombosis by inducing endothelial cell apoptosis, and thus plaque erosion, by impairing the anticoagulant balance in endothelium, stimulating tissue factor production by smooth muscle cells, and inducing apoptosis in macrophages. HDL cholesterol levels are inversely related to risk of coronary artery disease. HDL prevents atherosclerosis by reverting the stimulatory effect of oxidized LDL on monocyte infiltration. The HDL-associated enzyme paraoxonase inhibits the oxidation of LDL. PAF-acetyl hydrolase, which circulates in association with HDL and is produced in the arterial wall by macrophages, degrades bioactive oxidized phospholipids. Both enzymes actively protect hypercholesterolemic mice against atherosclerosis. Oxidized LDL inhibits these enzymes. Thus, oxidized LDL and HDL are indeed antagonists in the development of cardiovascular disease.
Collapse
MESH Headings
- 1-Alkyl-2-acetylglycerophosphocholine Esterase
- Animals
- Aryldialkylphosphatase
- Coronary Artery Disease/etiology
- Esterases/metabolism
- Humans
- Lipoproteins, HDL/antagonists & inhibitors
- Lipoproteins, HDL/physiology
- Lipoproteins, LDL/antagonists & inhibitors
- Lipoproteins, LDL/metabolism
- Lipoproteins, LDL/physiology
- Membrane Proteins
- Mice
- Models, Cardiovascular
- Phospholipases A/metabolism
- Receptors, Immunologic/biosynthesis
- Receptors, Lipoprotein
- Receptors, Scavenger
- Scavenger Receptors, Class B
- Thrombosis/etiology
Collapse
Affiliation(s)
- A Mertens
- Center for Experimental Surgery and Anesthesiology, Katholieke Universiteit Leuven, Belgium
| | | |
Collapse
|
43
|
Abstract
Secretory phospholipase A(2) (PLA(2)) can be proatherogenic both in the circulation and in the arterial wall. In blood plasma, PLA(2) can modify the circulating lipoproteins and so induce formation of small dense LDL particles, which are associated with increased risk for cardiovascular disease. In the arterial wall, PLA(2) can hydrolyze lipoproteins. The PLA(2)-modified lipoproteins bind tightly to extracellular proteoglycans, which may lead to their enhanced retention in the arterial wall. The modified lipoproteins may also aggregate and fuse, which can lead to accumulation of their lipids within the extracellular matrix. The PLA(2)-modified particles are more susceptible to further modifications by other enzymes and agents and can be taken up by macrophages, leading to accumulation of intracellular lipids. In addition, lysophospholipids and free fatty acids, the hydrolysis products of PLA(2), promote atherogenesis. Thus, these lipid mediators can be carried, either by the PLA(2)-modified lipoproteins themselves or by albumin, into the arterial cells, which then undergo functional alterations. This may, in turn, lead to specific changes in the extracellular matrix, which increase the retention and accumulation of lipoproteins within the matrix. In the present article, we discuss the possible actions of PLA(2) enzymes, especially PLA(2)-IIA, in the arterial wall during atherogenesis.
Collapse
Affiliation(s)
- E Hurt-Camejo
- AstraZeneca R&D, Cell Biology and Biochemistry, Mölndal, Sweden.
| | | | | | | | | |
Collapse
|
44
|
Tsoukatos DC, Liapikos TA, Tselepis AD, Chapman MJ, Ninio E. Platelet-activating factor acetylhydrolase and transacetylase activities in human plasma low-density lipoprotein. Biochem J 2001; 357:457-64. [PMID: 11439095 PMCID: PMC1221972 DOI: 10.1042/0264-6021:3570457] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
In this study, we demonstrate the presence of a transacetylase activity in human plasma low-density lipoprotein (LDL) that transfers short-chain fatty acids from platelet-activating factor (PAF) and its close ether- and ester-linked analogues to ether/ester-linked lysophospholipids (lyso-PL). We show evidence that both PAF acetylhydrolase (PAF-AH) and transacetylase activities are inhibited to the same extent by serine esterase inhibitors, are resistant to heat treatment, and exhibit identical distributions in lipoprotein classes and in LDL subfractions. Additionally, the competitive inhibition of PAF-AH by lyso-PL, and the evidence that the recombinant PAF-AH also showed a similar transacetylase activity, suggest that PAF-AH is responsible for both activities. Using PAF as a donor molecule and lyso-PAF (1-O-alkyl-sn-glycero-3-phosphocholine) as an acceptor, the transacetylase activity showed typical allosteric kinetics, due to the positive co-operativity of the substrates, with apparent Vmax=19.6+/-3.4 nmol/min per mg of protein, apparent h=2.0+/-0.3 and apparent [S]0.5=9.4+/-2.3 microM at saturation for the concentration of lyso-PAF. The substrate specificity of the donor molecules was decreased by increasing the chain length of the acyl moiety in the sn-2 position of the glycerol. The ether linkage in the sn-1 position of the substrate was 30% more effective than the ester bond; cholesteryl acetate was inactive as an acetyl donor. The two acceptors tested, lyso-PAF and the ester-linked lyso-PC (1-acyl-sn-glycero-3-phosphocholine), showed similar specificity. Addition of exogenous lyso-PAF induced the transient formation of PAF-like aggregating activity predominantely in small dense LDL subfractions upon oxidation. We conclude that PAF-AH possesses both transacetylase and acetylhydrolase activities which remove PAF and its ether-linked analogues from LDL particles upon LDL oxidation. However, in atherogenic small dense LDL-5 particles, the transacetylase activity may acetylate extracellular lyso-PAF into biologically active PAF.
Collapse
Affiliation(s)
- D C Tsoukatos
- Laboratory of Biochemistry, Department of Chemistry, University of Ioannina, 45110 Ioannina, Greece.
| | | | | | | | | |
Collapse
|
45
|
Quarck R, De Geest B, Stengel D, Mertens A, Lox M, Theilmeier G, Michiels C, Raes M, Bult H, Collen D, Van Veldhoven P, Ninio E, Holvoet P. Adenovirus-Mediated Gene Transfer of Human Platelet-Activating Factor–Acetylhydrolase Prevents Injury-Induced Neointima Formation and Reduces Spontaneous Atherosclerosis in Apolipoprotein E–Deficient Mice. Circulation 2001; 103:2495-500. [PMID: 11369691 DOI: 10.1161/01.cir.103.20.2495] [Citation(s) in RCA: 148] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background
—Atherosclerosis is characterized by an early inflammatory response involving proinflammatory mediators such as platelet-activating factor (PAF)-like phospholipids, which are inactivated by PAF-acetylhydrolase (PAF-AH). The effect of adenovirus-mediated expression of PAF-AH on injury-induced neointima formation and spontaneous atherosclerosis was studied in apolipoprotein E–deficient mice.
Methods and Results
—Intravenous administration of an adenovirus (5×10
8
plaque-forming units) directing liver-specific expression of human PAF-AH resulted in a 3.5-fold increase of plasma PAF-AH activity at day 7 (
P
<0.001); this was associated with a 2.4- and 2.3-fold decrease in malondialdehyde-modified LDL autoantibodies and the lysophosphatidylcholine/phosphatidylcholine ratio, respectively (
P
<0.001 for both). Non-HDL and HDL cholesterol levels in
PAF-AH
–treated mice were similar to those of control virus-treated mice. Seven days after virus injection, endothelial denudation of the common left carotid artery was induced with a guidewire. Neointima formation was assessed 18 days later.
PAF-AH
gene transfer reduced oxidized lipoproteins by 82% (
P
<0.001), macrophages by 69% (
P
=0.006), and smooth muscle cells by 84% (
P
=0.002) in the arterial wall. This resulted in a 77% reduction (
P
<0.001) of neointimal area. Six weeks after adenovirus-mediated gene transfer, spontaneous atherosclerotic lesions in the aortic root were analyzed.
PAF-AH
gene transfer reduced atherosclerotic lesions by 42% (
P
=0.02) in male mice, whereas a nonsignificant 14% reduction was observed in female mice. Basal and PAF-AH activity after gene transfer were higher in male mice than in female mice (
P
=0.01 and
P
=0.04, respectively).
Conclusions
—Gene transfer of
PAF-AH
inhibited injury-induced neointima formation and spontaneous atherosclerosis in apolipoprotein E–deficient mice. Our data indicate that PAF-AH, by reducing oxidized lipoprotein accumulation, is a potent protective enzyme against atherosclerosis.
Collapse
Affiliation(s)
- R Quarck
- Center for Molecular and Vascular Biology, Department of Experimental Surgery and Anesthesiology, Katholieke Universiteit Leuven, Leuven, Belgium
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
46
|
Rodrigo L, Mackness B, Durrington PN, Hernandez A, Mackness MI. Hydrolysis of platelet-activating factor by human serum paraoxonase. Biochem J 2001; 354:1-7. [PMID: 11171072 PMCID: PMC1221621 DOI: 10.1042/0264-6021:3540001] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Human serum paraoxonase (human PON1) has been shown to be important in the metabolism of phospholipid and cholesteryl ester hydroperoxides, thereby preventing the oxidation of low-density lipoprotein (LDL) and retarding atherogenesis. However, the exact substrate specificity of PON1 has not been established. In the present study we show that purified PON1 hydrolyses platelet-activating factor (PAF). We could find no evidence for contamination of our preparation with authentic platelet-activating-factor acetylhydrolase (PAFAH) by immunoblotting with a PAFAH monoclonal antibody or by sequencing the purified protein. In addition the specific PAFAH inhibitor SB-222657 did not affect the ability of PON1 to hydrolyse PAF (30.1+/-2.8 micromol/min per mg of protein with no inhibitor; 31.4+/-2.2 micromol/min per mg of protein with 100 nM inhibitor) or phenyl acetate (242.6+/-30.8 versus 240.8+/-31.5 micromol/min per mg of protein with and without inhibitor respectively). SB-222657 was also unable to inhibit PAF hydrolysis by isolated human high-density lipoprotein (HDL), but completely abolished the activity of human LDL. Ostrich (Struthio camelus) HDL, which does not contain PON1, was unable to hydrolyse PAF. These data provide evidence that PON1 may limit the action of this bioactive pro-inflammatory phospholipid.
Collapse
Affiliation(s)
- L Rodrigo
- Departamento de Medicina Legal y Toxicologia, Facultad de Medicina, Universidad de Granada, Avenida de Madrid No 11, 18071 Granada, Spain
| | | | | | | | | |
Collapse
|
47
|
Tjoelker LW, Stafforini DM. Platelet-activating factor acetylhydrolases in health and disease. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1488:102-23. [PMID: 11080681 DOI: 10.1016/s1388-1981(00)00114-1] [Citation(s) in RCA: 125] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The platelet-activating factor (PAF) acetylhydrolases catalyze hydrolysis of the sn-2 ester bond of PAF and related pro-inflammatory phospholipids and thus attenuate their bioactivity. One secreted (plasma) and four intracellular isozymes have been described. The intracellular isozymes are distinguished by differences in primary sequence, tissue localization, subunit composition, and substrate preferences. The most thoroughly characterized intracellular isoform, Ib, is a G-protein-like complex with two catalytic subunits (alpha1 and alpha2) and a regulatory beta subunit. The beta subunit is a product of the LIS1 gene, mutations of which cause Miller-Dieker lissencephaly. Isoform II is a single polypeptide that is homologous to the plasma PAF acetylhydrolase and has antioxidant activity in several systems. Plasma PAF acetylhydrolase is also a single polypeptide with a catalytic triad of amino acids that is characteristic of the alpha/beta hydrolases. Deficiency of this enzyme has been associated with a number of pathologies. The most common inactivating mutation, V279F, is found in >30% of randomly surveyed Japanese subjects (4% homozygous, 27% heterozygous). The prevalence of the mutant allele is significantly greater in patients with asthma, stroke, myocardial infarction, brain hemorrhage, and nonfamilial cardiomyopathy. Preclinical studies have demonstrated that recombinant plasma PAF acetylhydrolase can prevent or attenuate pathologic inflammation in a number of animal models. In addition, preliminary clinical results suggest that the recombinant enzyme may have pharmacologic potential in human inflammatory disease as well. These observations underscore the physiological importance of the PAF acetylhydrolases and point toward new approaches for controlling pathologic inflammation.
Collapse
|
48
|
Ibe BO, Sander FC, Raj JU. Platelet-activating factor receptors in lamb lungs are downregulated immediately after birth. Am J Physiol Heart Circ Physiol 2000; 278:H1168-76. [PMID: 10749711 DOI: 10.1152/ajpheart.2000.278.4.h1168] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Platelet-activating factor (PAF) is a phospholipid with diverse biological functions mediated by a G protein-coupled receptor. We determined PAF receptor binding in lung membranes of four groups of perinatal lambs. Membrane protein (100 microg/ml) was incubated for 60 min at 30 degrees C with 0.5-24 nM of acetyl-[(3)H]PAF in 30 mM Tris buffer, pH 7.2, containing 0.25% BSA, 10 mM MgCl(2), and 125 mM choline chloride. PAF bound to membrane was isolated and quantified by scintillation spectrometry, followed with Scatchard analysis for receptor density (B(max)). The B(max) (means +/- SE, fmol/mg protein) were 445.8 +/- 12.3, 244.2 +/- 3.3, 250.6 +/- 3.6, and 419. 9 +/- 8.6 for the fetal, 90-min-old, <1-day-old, and 6- to 12-day-old lambs, respectively. The B(max) for the 90-min-old and <1-day-old lambs were not different but were significantly lower than those of either the term fetal or 6- to 12-day-old lambs. These data show a significant decrease in PAF binding to its receptor and in PAF B(max) in lung membranes of immediate newborn lambs. The dissociation constants (K(D), nM) were 7.7 +/- 0.52, 11.5 +/- 0.34, 6.9 +/- 0.48, and 5.0 +/- 0.53 for fetal, 90-min-old, <1-day-old, and 6- to 12-day-old newborn lamb lungs, respectively. The K(D) of the 90-min-old lamb was the highest of all. PAF receptor gene measured by RT-PCR showed a significant downregulation of PAF receptor gene mRNA in lungs of lambs <1 day old, suggesting a transcriptional regulation of PAF receptor gene expression in the immediate newborn period. We speculate that decreased PAF receptor binding immediately after birth will facilitate the fall in pulmonary vascular resistance in the immediate newborn period.
Collapse
Affiliation(s)
- B O Ibe
- Department of Pediatrics, Harbor-University of California at Los Angeles Medical Center, Torrance, California 90502, USA.
| | | | | |
Collapse
|
49
|
Ibe BO, Sander FC, Raj JU. Platelet activating factor acetylhydrolase activity in lamb lungs is up-regulated in the immediate newborn period. Mol Genet Metab 2000; 69:46-55. [PMID: 10655157 DOI: 10.1006/mgme.1999.2940] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We recently showed that platelet activating factor (PAF) is an important modulator of pulmonary vasomotor tone in the fetus, with a significant decrease in circulating PAF levels in the immediate newborn period. In this study, we have determined PAF catabolism by PAF acetylhydrolase (PAF-Ah) in lungs of near-term fetal and newborn 2- to 16-h (<1 day) and 6- to 12-day-old lambs. The rate of PAF catabolism by lung homogenate protein from the three groups of lamb lungs was studied at 37 degrees C in 30 mM Tris buffer, pH 7.5, containing 0.01% BSA. Each lung homogenate protein was incubated for 10 min with 50 microM [(3)H]acetyl-PAF at pO(2) <50 Torr (hypoxia) and approximately 100 Torr (normoxia). PAF-Ah activity was quantified as amount of lyso-PAF produced. PAF-Ah activity (means +/- SEM, nmol lyso-PAF/min/mg protein) in fetal lung homogenate was 1.19 +/- 0.14 and 2.46 +/- 0.05 during hypoxia and normoxia, respectively. The corresponding values for the newborns were newborn <1 day, 1.65 +/- 0.26 and 2.95 +/- 0.07 and newborn 6-12 days, 1.25 +/- 0.10 and 2.84 +/- 0.05. In all groups, PAF-Ah activity was higher in normoxia than in hypoxia. During normoxia, PAF-Ah activity in newborn <1 day was significantly higher than the activity in fetus, but similar to the activity in newborn 6- to 12-day-old lamb lungs. These data show a significant up-regulation of PAF-Ah activity in lungs in the immediate newborn period. PAF-Ah gene expression measured by RT-PCR showed a significant up-regulation of the PAF-Ah gene in lungs of lambs <1 day old, suggesting a transcriptional regulation of the PAF-Ah gene in the immediate newborn period. These results suggest that up-regulation of PAF-Ah activity after birth with oxygenation will result in a decrease in circulating PAF levels, thereby facilitating the fall in pulmonary vascular resistance in the immediate newborn period.
Collapse
Affiliation(s)
- B O Ibe
- Department of Pediatrics, Harbor-UCLA Medical Center, Torrance, California, 90502, USA
| | | | | |
Collapse
|
50
|
Wu R, Lemne C, De Faire U, Frostegârd J. Antibodies to platelet-activating factor are associated with borderline hypertension, early atherosclerosis and the metabolic syndrome. J Intern Med 1999; 246:389-97. [PMID: 10583710 DOI: 10.1046/j.1365-2796.1999.00570.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE Platelet-activating factor (PAF) is a phospholipid inflammatory mediator which is synthesized by a variety of cells, including monocytes and endothelial cells, and PAF can be retained in activated endothelial cell membranes. Furthermore, PAF-like lipids are produced in other phospholipid membranes as in oxidized LDL. Atherosclerosis is a chronic inflammation in the artery wall, but little is known about the role of immune reactions in the early stages of development of cardiovascular disease. In the present study we investigated if there are antibodies to PAF (aPAF) that may play a role in borderline hypertension and early atherosclerosis. DESIGN Seventy-three men with borderline hypertension (BHT) and 73 age-matched normotensive (NT) men (diastolic blood pressure 85-94 and <80 mmHg, respectively) were recruited from a population screening programme. Antibody levels were determined by use of ELISA. Carotid intima-media (IM)-thickness and atherosclerosis was determined by B-mode ultrasonography. RESULTS BHT men had 49.3% higher aPAF levels of IgG class than NT controls (P = 0.0007). Antibodies to the biologically inactive lysoPAF did not differ between BHT and NT group. aPAF levels were associated with IM-thickness in the left (P = 0.02) and right (P = 0.009) carotid artery. Furthermore, aPAF levels were enhanced in individuals with the metabolic syndrome (n = 44) as compared to those without (n = 102; P = 0.009), and also significantly associated with insulin levels (P = 0.02) and insulin resistance (P = 0.02). CONCLUSIONS aPAF antibodies may reflect early vascular changes and thus serve as novel markers for disease, and they may also be pathogenic, by eliciting an inflammatory reaction in the vascular wall.
Collapse
Affiliation(s)
- R Wu
- Department of Medicine, Karolinska Hospital, Stockholm, Sweden
| | | | | | | |
Collapse
|