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Badawi R, Asghar MN, Abd-Elsalam S, Elshweikh SA, Haydara T, Alnabawy SM, Elkadeem M, ElKhalawany W, Soliman S, Elkhouly R, Soliman S, Watany M, Khalif M, Elfert A. Amyloid A in Serum and Ascitic Fluid as a Novel Diagnostic Marker of Spontaneous Bacterial Peritonitis. Antiinflamm Antiallergy Agents Med Chem 2021; 19:140-148. [PMID: 30931865 PMCID: PMC7475799 DOI: 10.2174/1871523018666190401154447] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 03/13/2019] [Accepted: 03/21/2019] [Indexed: 12/18/2022]
Abstract
Background: Diagnosis of Spontaneous Bacterial Peritonitis (SBP) depends mainly on ascetic fluid culture which may be negative in spite of the clinical suggestion of SBP and high ascetic fluid neutrophilic count. Aims: This study aimed to evaluate the biological importance of amyloid A biomarker in both serum and ascetic fluid to diagnose SBP as early as possible and to compare it to other markers (C-reactive protein (CRP), and the neutrophil-to-lymphocyte ratio (NLR)). Methods: This study included 37 patients with hepatic ascites; twenty-two of them had SBP, and 15 patients did not have SBP. Serum and ascetic fluid amyloid A, ascetic fluid neutrophil, C-reactive protein, and neutrophil-to-lymphocyte ratio were measured in all subjects before the start of antimicrobial chemotherapy to the infected ones. Results: Both the serum and ascetic fluid amyloid and also, CRP were significantly higher in patients infected with ascetic fluid than others. The cut-off point of serum amyloid A for early detection of SBP was 9.25ug/ml with the high sensitivity and specificity. For ascetic amyloid A, the sensitivity and specificity were 90.09% and 60% at cut-off point 2.85ug/ml, respectively. Conclusion: Amyloid A in serum and ascitic fluid can be considered as a good biomarker for early diagnosis of SBP.
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Affiliation(s)
- Rehab Badawi
- Tropical Medicine and Infectious Diseases, Faculty of Medicine, Tanta University, Tanta, Egypt
| | - Muhammad N Asghar
- Department of Biosciences, Abo Akademi University, 20500 Turku, Finland.,Department of Medical Biology, University of Quebec at Trois-Riveres, Quebec, Canada
| | - Sherief Abd-Elsalam
- Tropical Medicine and Infectious Diseases, Faculty of Medicine, Tanta University, Tanta, Egypt
| | | | - Tamer Haydara
- Internal Medicine Department, Kafr-Elsheikh University, Kafr El- Shaikh, Egypt
| | | | - Mahmoud Elkadeem
- Tropical Medicine and Infectious Diseases, Faculty of Medicine, Tanta University, Tanta, Egypt
| | - Walaa ElKhalawany
- Tropical Medicine and Infectious Diseases, Faculty of Medicine, Tanta University, Tanta, Egypt
| | - Samah Soliman
- Tropical Medicine and Infectious Diseases, Faculty of Medicine, Tanta University, Tanta, Egypt
| | - Reham Elkhouly
- Tropical Medicine and Infectious Diseases, Faculty of Medicine, Tanta University, Tanta, Egypt
| | - Shimaa Soliman
- Public Health and Community Medicine, Faculty of Medicine, Menoufia University Menoufia, Egypt
| | - Mona Watany
- Clinical Pathology, Faculty of Medicine, Tanta University, Tanta, Egypt
| | - Mai Khalif
- Tropical Medicine and Infectious Diseases, Faculty of Medicine, Tanta University, Tanta, Egypt
| | - Asem Elfert
- Tropical Medicine and Infectious Diseases, Faculty of Medicine, Tanta University, Tanta, Egypt
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2
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Chami B, Hossain F, Hambly TW, Cai X, Aran R, Fong G, Vellajo A, Martin NJJ, Wang X, Dennis JM, Sharma A, Shihata WA, Chin-Dusting JPF, de Haan JB, Sharland A, Geczy CL, Freedman B, Witting PK. Serum Amyloid A Stimulates Vascular and Renal Dysfunction in Apolipoprotein E-Deficient Mice Fed a Normal Chow Diet. Front Immunol 2019; 10:380. [PMID: 30899260 PMCID: PMC6416175 DOI: 10.3389/fimmu.2019.00380] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 02/14/2019] [Indexed: 12/19/2022] Open
Abstract
Elevated serum amyloid A (SAA) levels may promote endothelial dysfunction, which is linked to cardiovascular and renal pathologies. We investigated the effect of SAA on vascular and renal function in apolipoprotein E-deficient (ApoE−/−) mice. Male ApoE−/− mice received vehicle (control), low-level lipopolysaccharide (LPS), or recombinant human SAA by i.p. injection every third day for 2 weeks. Heart, aorta and kidney were harvested between 3 days and 18 weeks after treatment. SAA administration increased vascular cell adhesion molecule (VCAM)-1 expression and circulating monocyte chemotactic protein (MCP)-1 and decreased aortic cyclic guanosine monophosphate (cGMP), consistent with SAA inhibiting nitric oxide bioactivity. In addition, binding of labeled leukocytes to excised aorta increased as monitored using an ex vivo leukocyte adhesion assay. Renal injury was evident 4 weeks after commencement of SAA treatment, manifesting as increased plasma urea, urinary protein, oxidized lipids, urinary kidney injury molecule (KIM)-1 and multiple cytokines and chemokines in kidney tissue, relative to controls. Phosphorylation of nuclear-factor-kappa-beta (NFκB-p-P65), tissue factor (TF), and macrophage recruitment increased in kidneys from ApoE−/− mice 4 weeks after SAA treatment, confirming that SAA elicited a pro-inflammatory and pro-thrombotic phenotype. These data indicate that SAA impairs endothelial and renal function in ApoE−/− mice in the absence of a high-fat diet.
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Affiliation(s)
- Belal Chami
- Discipline of Pathology, Charles Perkins Centre, The University of Sydney, Sydney, NSW, Australia
| | - Farjaneh Hossain
- Discipline of Pathology, Charles Perkins Centre, The University of Sydney, Sydney, NSW, Australia
| | - Thomas W Hambly
- Discipline of Pathology, Charles Perkins Centre, The University of Sydney, Sydney, NSW, Australia
| | - Xiaoping Cai
- Discipline of Pathology, Charles Perkins Centre, The University of Sydney, Sydney, NSW, Australia
| | - Roshanak Aran
- Discipline of Pathology, Charles Perkins Centre, The University of Sydney, Sydney, NSW, Australia
| | - Genevieve Fong
- Discipline of Pathology, Charles Perkins Centre, The University of Sydney, Sydney, NSW, Australia
| | - Abigail Vellajo
- Discipline of Pathology, Charles Perkins Centre, The University of Sydney, Sydney, NSW, Australia
| | - Nathan J J Martin
- Discipline of Pathology, Charles Perkins Centre, The University of Sydney, Sydney, NSW, Australia
| | - XiaoSuo Wang
- Discipline of Pathology, Charles Perkins Centre, The University of Sydney, Sydney, NSW, Australia
| | - Joanne M Dennis
- Discipline of Pathology, Charles Perkins Centre, The University of Sydney, Sydney, NSW, Australia
| | - Arpeeta Sharma
- Department of Medicine, Monash University, Melbourne, VIC, Australia
| | - Waled A Shihata
- Cardiovascular Disease Program, Biomedicine Discovery Institute, Monash University, Melbourne, VIC, Australia.,Department of Pharmacology, Monash University, Melbourne, VIC, Australia.,Baker Heart and Diabetes Institute, Melbourne, VIC, Australia
| | - Jaye P F Chin-Dusting
- Cardiovascular Disease Program, Biomedicine Discovery Institute, Monash University, Melbourne, VIC, Australia.,Department of Pharmacology, Monash University, Melbourne, VIC, Australia.,Baker Heart and Diabetes Institute, Melbourne, VIC, Australia
| | - Judy B de Haan
- Baker Heart and Diabetes Institute, Melbourne, VIC, Australia
| | - Alexandra Sharland
- Transplantation Immunobiology Group, Charles Perkins Centre, The University of Sydney, Sydney, NSW, Australia
| | - Carolyn L Geczy
- School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Ben Freedman
- ANZAC Research and Heart Research Institutes, Charles Perkins Centre, University of Sydney, Sydney, NSW, Australia
| | - Paul K Witting
- Discipline of Pathology, Charles Perkins Centre, The University of Sydney, Sydney, NSW, Australia
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3
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Ganjali S, Ricciuti B, Pirro M, Butler AE, Atkin SL, Banach M, Sahebkar A. High-Density Lipoprotein Components and Functionality in Cancer: State-of-the-Art. Trends Endocrinol Metab 2019; 30:12-24. [PMID: 30473465 DOI: 10.1016/j.tem.2018.10.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 10/26/2018] [Accepted: 10/26/2018] [Indexed: 01/05/2023]
Abstract
Cancer is the second leading cause of death in western countries, and thus represents a major global public health issue. Whilst it is well-recognized that diet, obesity, and smoking are risk factors for cancer, the role of low levels of high-density lipoprotein cholesterol (HDL-C) in cancer is less well appreciated. Conflicting evidence suggests that serum HDL-C levels may be either positively or negatively associated with cancer incidence and mortality. Such disparate associations are supported in part by the multitude of high-density lipoprotein (HDL) functions that can all have an impact on cancer cell biology. The aim of this review is to provide a comprehensive overview of the crosstalk between HDLs and cancer, focusing on the molecular mechanisms underlying this association.
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Affiliation(s)
- Shiva Ganjali
- Department of Medical Biotechnology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Biagio Ricciuti
- Department of Medical Oncology, S. Maria della Misericordia Hospital, Perugia, Italy
| | - Matteo Pirro
- Unit of Internal Medicine, Department of Medicine, University of Perugia, Perugia, Italy
| | - Alexandra E Butler
- Diabetes Research Center, Qatar Biomedical Research Institute, Doha, Qatar
| | | | - Maciej Banach
- Department of Hypertension, WAM University Hospital in Lodz, Medical University of Lodz, Zeromskiego 113, Lodz, Poland; Polish Mother's Memorial Hospital Research Institute (PMMHRI), Lodz, Poland
| | - Amirhossein Sahebkar
- Biotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran; Neurogenic Inflammation Research Center, Mashhad University of Medical Sciences, Mashhad, Iran; School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
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4
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Zhao J, Piao X, Wu Y, Xu P, He Z. Association of SAA gene polymorphism with ischemic stroke in northern Chinese Han population. J Neurol Sci 2017; 380:101-105. [PMID: 28870546 DOI: 10.1016/j.jns.2017.07.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 06/15/2017] [Accepted: 07/07/2017] [Indexed: 10/19/2022]
Abstract
BACKGROUND Serum amyloid A protein (SAA) is known as an inflammatory factor and an apolipoprotein that can replace apolipoprotein A-I/II components as the major apolipoprotein of high-density lipoprotein (HDL), which is related to atherosclerosis. The present study is aimed to evaluate whether the SAA gene polymorphism is involved in ischemic stroke in northern Chinese Han population. METHODS In a case-control study, the participants included 396 patients (239 males, 157 females) with ischemic stroke and 360 healthy subjects (211 males, 149 females). The rs12218 polymorphism of the SAA gene was analyzed by polymerase chain reaction and restriction fragment length polymorphism, while the rs2468844 polymorphism of the SAA gene was analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. RESULTS The frequencies of the CC genotype and the C allele of rs12218 were higher in participants with ischemic stroke than in the control group (P=0.020 in males, P=0.001 in large-artery atherosclerosis group, LAA). The frequencies of the AG genotype and the G allele of rs2468844 were higher in participants with ischemic stroke than in the control group (P=0.040 in males, P=0.011 in large-artery atherosclerosis group). Multiple logistic regression analysis revealed the significance of the rs12218 in males and in large-artery atherosclerosis group after adjustment for confounding factors. CONCLUSION The rs12218 polymorphism of the SAA gene was associated with ischemic stroke in males and in patients with large-artery atherosclerosis group in northern Chinese Han population.
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Affiliation(s)
- Jie Zhao
- Department of Neurology, Affiliated Zhongshan Hospital of Dalian University, Dalian 116001, China
| | - Xiangyu Piao
- Department of Neurology, Affiliated Zhongshan Hospital of Dalian University, Dalian 116001, China
| | - Yue Wu
- Department of Orthopedics, Affiliated Zhongshan Hospital of Dalian University, Dalian 116001, China
| | - Ping Xu
- Department of Neurology, The Fifth People's Hospital of Dalian, Dalian 116021, China
| | - Zhiyi He
- Department of Neurology, The First Affiliated Hospital of China Medical University, Shenyang 110001, China.
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Serum Amyloid A Induces a Vascular Smooth Muscle Cell Phenotype Switch through the p38 MAPK Signaling Pathway. BIOMED RESEARCH INTERNATIONAL 2017. [PMID: 28642873 PMCID: PMC5469989 DOI: 10.1155/2017/4941379] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Atherosclerosis is an important pathological condition which is accompanied by a vascular smooth muscle cell (VSMC) phenotype switch toward a synthetic phenotype. As an acute-phase protein, Serum Amyloid A (SAA) is thought to have a close relationship to atherosclerosis development. However, no study has investigated the direct effect of SAA on the VSMC phenotype switch, as well as the underlying mechanisms. The purpose of our study was to explore the effect of SAA on the VSMC phenotype switch and the potential mechanisms involved. In our study, we found that SAA induced the VSMC phenotype switch which reduced expression of the smooth muscle cell (SMC) marker and enhanced expression of the matrix synthesis related marker. The proliferative ability of VSMCs was also increased by SAA treatment. Furthermore, our research found that SAA activated the ERK1/2 and p38 MAPK signaling pathways. Finally, by applying the ERK1/2 and p38 inhibitors, U0126 and SB203580, we demonstrated that the SAA-induced VSMC phenotype switch was p38-dependent. Taken together, these results indicated that SAA may play an important role in promoting the VSMC phenotype switch through the p38 MAPK signaling pathway.
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Serum amyloid A receptor blockade and incorporation into high-density lipoprotein modulates its pro-inflammatory and pro-thrombotic activities on vascular endothelial cells. Int J Mol Sci 2015; 16:11101-24. [PMID: 25988387 PMCID: PMC4463692 DOI: 10.3390/ijms160511101] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Revised: 03/25/2015] [Accepted: 04/27/2015] [Indexed: 02/07/2023] Open
Abstract
The acute phase protein serum amyloid A (SAA), a marker of inflammation, induces expression of pro-inflammatory and pro-thrombotic mediators including ICAM-1, VCAM-1, IL-6, IL-8, MCP-1 and tissue factor (TF) in both monocytes/macrophages and endothelial cells, and induces endothelial dysfunction—a precursor to atherosclerosis. In this study, we determined the effect of pharmacological inhibition of known SAA receptors on pro-inflammatory and pro-thrombotic activities of SAA in human carotid artery endothelial cells (HCtAEC). HCtAEC were pre-treated with inhibitors of formyl peptide receptor-like-1 (FPRL-1), WRW4; receptor for advanced glycation-endproducts (RAGE), (endogenous secretory RAGE; esRAGE) and toll-like receptors-2/4 (TLR2/4) (OxPapC), before stimulation by added SAA. Inhibitor activity was also compared to high-density lipoprotein (HDL), a known inhibitor of SAA-induced effects on endothelial cells. SAA significantly increased gene expression of TF, NFκB and TNF and protein levels of TF and VEGF in HCtAEC. These effects were inhibited to variable extents by WRW4, esRAGE and OxPapC either alone or in combination, suggesting involvement of endothelial cell SAA receptors in pro-atherogenic gene expression. In contrast, HDL consistently showed the greatest inhibitory action, and often abrogated SAA-mediated responses. Increasing HDL levels relative to circulating free SAA may prevent SAA-mediated endothelial dysfunction and ameliorate atherogenesis.
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7
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Hua S, Song C, Geczy CL, Freedman SB, Witting PK. A role for acute-phase serum amyloid A and high-density lipoprotein in oxidative stress, endothelial dysfunction and atherosclerosis. Redox Rep 2013; 14:187-96. [DOI: 10.1179/135100009x12525712409490] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
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8
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Witting PK, Song C, Hsu K, Hua S, Parry SN, Aran R, Geczy C, Freedman SB. The acute-phase protein serum amyloid A induces endothelial dysfunction that is inhibited by high-density lipoprotein. Free Radic Biol Med 2011; 51:1390-8. [PMID: 21784147 DOI: 10.1016/j.freeradbiomed.2011.06.031] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2010] [Revised: 06/24/2011] [Accepted: 06/25/2011] [Indexed: 11/17/2022]
Abstract
The acute-phase protein serum amyloid A (SAA) is elevated during inflammation and may be deposited in atheroma where it promotes atherosclerosis. We investigated the proatherogenic effects of SAA on the vascular endothelium and their regulation by high-density lipoprotein (HDL). Exposure of human aortic endothelial cells (HAEC) to SAA (0.25-25μg/ml) decreased nitric oxide ((•)NO) synthesis/bioavailability, although the endothelial NO synthase monomer-to-dimer ratio was unaffected. SAA (10μg/ml) stimulated a Ca(2+) influx linked to apocynin-sensitive superoxide radical anion (O(2)(•-)) production. Gene expression for arginase-1, nuclear factor κB (NF-κB), interleukin-8, and tissue factor (TF) increased within 4h of SAA stimulation. Enzymatically active Arg-1/2 was detected in HAEC cultured with SAA for 24h. Therefore, in addition to modulating (•)NO bioavailability by stimulating O(2)(•-) production in the endothelium, SAA modulated vascular l-Arg bioavailability. SAA also diminished relaxation of preconstricted aortic rings induced by acetylcholine, and added superoxide dismutase restored the vascular response. Preincubation of HAEC with HDL (100 or 200, but not 50, μg/ml) before (not after) SAA treatment ameliorated the Ca(2+) influx and O(2)(•-) production; decreased TF, NF-κB, and Arg-1 gene expression; and preserved overall vascular function. Thus, SAA may promote endothelial dysfunction by modulating (•)NO and l-Arg bioavailability, and HDL pretreatment may be protective. The relative HDL to SAA concentrations may regulate the proatherogenic properties of SAA on the vascular endothelium.
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Affiliation(s)
- Paul K Witting
- Discipline of Pathology, Sydney Medical School, The University of Sydney, Sydney, NSW 2006, Australia
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9
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Dong Z, Wu T, Qin W, An C, Wang Z, Zhang M, Zhang Y, Zhang C, An F. Serum amyloid A directly accelerates the progression of atherosclerosis in apolipoprotein E-deficient mice. Mol Med 2011; 17:1357-64. [PMID: 21953420 DOI: 10.2119/molmed.2011.00186] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Accepted: 09/20/2011] [Indexed: 11/06/2022] Open
Abstract
Although serum amyloid A (SAA) is an excellent marker for coronary artery disease, its direct effect on atherogenesis in vivo is obscure. In this study we investigated the direct effect of SAA on promoting the formation of atherosclerosis in apolipoprotein E-deficient (ApoE⁻/⁻) mice. Murine SAA lentivirus was constructed and injected into ApoE⁻/⁻ mice intravenously. Then, experimental mice were fed a chow diet (5% fat and no added cholesterol) for 14 wks. The aortic atherosclerotic lesion area was larger with than without SAA treatment. With increased SAA levels, the plasma levels of interleukin-6 and tumor necrosis factor-α were significantly increased. Macrophage infiltration in atherosclerotic regions was enhanced with SAA treatment. A migration assay revealed prominent dose-dependent chemotaxis of SAA to macrophages. Furthermore, the expression of monocyte chemotactic protein-1 and vascular cell adhesion molecule-1 (VCAM-1) was upregulated significantly with SAA treatment. SAA-induced VCAM-1 production was detected in human aortic endothelial cells in vitro. Thus, an increase in plasma SAA directly accelerates the progression of atherosclerosis in ApoE⁻/⁻ mice. SAA is not only a risk marker for atherosclerosis but also an active participant in atherogenesis.
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Affiliation(s)
- Zhe Dong
- Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health, Shandong University Qilu Hospital, Jinan, Shandong, China
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10
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Xie X, Ma YT, Yang YN, Fu ZY, Li XM, Huang D, Ma X, Chen BD, Liu F. Polymorphisms in the SAA1/2 gene are associated with carotid intima media thickness in healthy Han Chinese subjects: the Cardiovascular Risk Survey. PLoS One 2010; 5:e13997. [PMID: 21103356 PMCID: PMC2982816 DOI: 10.1371/journal.pone.0013997] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2010] [Accepted: 10/26/2010] [Indexed: 01/07/2023] Open
Abstract
Background Serum amyloid A protein (SAA) is not only an inflammatory factor, but also an apolipoprotein that can replace apolipoprotein A1 (apoA1) as the major apolipoprotein of high-density lipoprotein (HDL), which has been linked to atherosclerosis. However, the relationship between genetic polymorphisms of SAA and the intima-media thickness (IMT) of the common carotid artery in healthy subjects remains unclear. We investigated the role of SAA1 and SAA2 gene polymorphisms with IMT in a cohort of healthy subjects participating in the Cardiovascular Risk Survey (CRS) study. Methodology/Principal Findings Anthropometric and B-mode ultrasound of the carotid IMT were measured in 1914 subjects (849 men; 1065 women) recruited from seven cities in Xinjiang province, (western China). Four SNPs (rs12218, rs2229338, rs1059559, and rs2468844) were genotyped by use of the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The SNP rs12218 was associated with carotid IMT by analyses of a dominate model (P<0.001) and additive model (P = 0.003), and the difference remained significant after multivariate adjustment (P = 0.008, P<0.001, respectively). This relationship was also observed in rs2468844 after multivariate adjustment by recessive model analysis (P = 0.011) but this was not observed in rs2229338 and rs1059559 before and after multivariate adjustment. These associations were not modified by serum HDL concentration. Furthermore, there were significant interactions between rs2468844 and rs12218 (interaction P<0.001) and rs2229338 (interaction P = 0.001) on carotid IMT. Conclusion/Significance Both rs12218 of the SAA1 gene and rs2468844 of SAA2 gene are associated with carotid IMT in healthy Han Chinese subjects.
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Affiliation(s)
- Xiang Xie
- Department of Cardiology, First Affiliated Hospital of Xinjiang Medical University, Urumqi, China
- Xinjiang Key Laboratory of Cardiovascular Disease Research, Urumqi, China
| | - Yi-Tong Ma
- Department of Cardiology, First Affiliated Hospital of Xinjiang Medical University, Urumqi, China
- Xinjiang Key Laboratory of Cardiovascular Disease Research, Urumqi, China
- * E-mail:
| | - Yi-Ning Yang
- Department of Cardiology, First Affiliated Hospital of Xinjiang Medical University, Urumqi, China
- Xinjiang Key Laboratory of Cardiovascular Disease Research, Urumqi, China
| | - Zhen-Yan Fu
- Department of Cardiology, First Affiliated Hospital of Xinjiang Medical University, Urumqi, China
- Xinjiang Key Laboratory of Cardiovascular Disease Research, Urumqi, China
| | - Xiao-Mei Li
- Department of Cardiology, First Affiliated Hospital of Xinjiang Medical University, Urumqi, China
- Xinjiang Key Laboratory of Cardiovascular Disease Research, Urumqi, China
| | - Ding Huang
- Department of Cardiology, First Affiliated Hospital of Xinjiang Medical University, Urumqi, China
| | - Xiang Ma
- Department of Cardiology, First Affiliated Hospital of Xinjiang Medical University, Urumqi, China
- Xinjiang Key Laboratory of Cardiovascular Disease Research, Urumqi, China
| | - Bang-Dang Chen
- Xinjiang Key Laboratory of Cardiovascular Disease Research, Urumqi, China
| | - Fen Liu
- Xinjiang Key Laboratory of Cardiovascular Disease Research, Urumqi, China
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Mullan RH, McCormick J, Connolly M, Bresnihan B, Veale DJ, Fearon U. A role for the high-density lipoprotein receptor SR-B1 in synovial inflammation via serum amyloid-A. THE AMERICAN JOURNAL OF PATHOLOGY 2010; 176:1999-2008. [PMID: 20304957 DOI: 10.2353/ajpath.2010.090014] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Acute phase apoprotein Serum Amyloid A (A-SAA), which is strongly expressed in rheumatoid arthritis synovial membrane (RA SM), induces angiogenesis, adhesion molecule expression, and matrix metalloproteinase production through the G-coupled receptor FPRL-1. Here we report alternative signaling through the high-density lipoprotein receptor scavenger receptor-class B type 1 (SR-B1). Quantitative expression/localization of SR-B1 in RA SM, RA fibroblast-like cells (FLCs), and microvascular endothelial cells (ECs) was assessed by Western blotting and immunohistology/fluorescence. A-SAA-mediated effects were examined using a specific antibody against SR-B1 or amphipathic alpha-Helical Peptides (the SR-B1 antagonists L-37pA and D-37pA), in RA FLCs and ECs. Adhesion molecule expression and cytokine production were quantified using flow cytometry and ELISA. SR-B1 was strongly expressed in the RA SM lining layer and endothelial/perivascular regions compared with osteoarthritis SM or normal control synovium. Differential SR-B1 expression in RA FLC lines (n = 5) and ECs correlated closely with A-SAA, but not tumor necrosis factor alpha-induced intercellular adhesion molecule-1 upregulation. A-SAA-induced interleukin-6 and -8 production was inhibited in the presence of anti-SR-B1 in human microvascular endothelial cells and RA FLCs. Moreover, D-37pA and L-37pA inhibited A-SAA-induced vascular cell adhesion molecule-1 and intercellular adhesion molecule expression from ECs in a dose-dependent manner. As SR-B1 is expressed in RA synovial tissue and mediates A-SAA-induced pro-inflammatory pathways, a better understanding of A-SAA-mediated inflammatory pathways may lead to novel treatment strategies for RA.
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Affiliation(s)
- Ronan Hugh Mullan
- Education and Research Centre, St. Vincent's University Hospital, Elm Park, Dublin 4, Ireland
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12
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Elimova E, Kisilevsky R, Ancsin JB. Heparan sulfate promotes the aggregation of HDL‐associated serum amyloid A: evidence for a proamyloidogenic histidine molecular switch. FASEB J 2009; 23:3436-48. [DOI: 10.1096/fj.09-134981] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Elena Elimova
- Department of Biochemistry Queen's University Kingston Ontario Canada
- Department of Medicine University of Ottawa Ottawa ON K1H 8L6 Canada
| | - Robert Kisilevsky
- Department of Biochemistry Queen's University Kingston Ontario Canada
- Department of Pathology and Molecular Medicine Queen's University Kingston Ontario Canada
- The Syl and Molly Apps Research Centre Kingston General Hospital Kingston Ontario Canada
| | - John B. Ancsin
- Department of Biochemistry Queen's University Kingston Ontario Canada
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13
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Tam SP, Kisilevsky R, Ancsin JB. Acute-phase-HDL remodeling by heparan sulfate generates a novel lipoprotein with exceptional cholesterol efflux activity from macrophages. PLoS One 2008; 3:e3867. [PMID: 19057652 PMCID: PMC2588651 DOI: 10.1371/journal.pone.0003867] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2008] [Accepted: 11/11/2008] [Indexed: 01/13/2023] Open
Abstract
During episodes of acute-inflammation high-density lipoproteins (HDL), the carrier of so-called good cholesterol, experiences a major change in apolipoprotein composition and becomes acute-phase HDL (AP-HDL). This altered, but physiologically important, HDL has an increased binding affinity for macrophages that is dependent on cell surface heparan sulfate (HS). While exploring the properties of AP-HDLratioHS interactions we discovered that HS caused significant remodeling of AP-HDL. The physical nature of this change in structure and its potential importance for cholesterol efflux from cholesterol-loaded macrophages was therefore investigated. In the presence of heparin, or HS, AP-HDL solutions at pH 5.2 became turbid within minutes. Analysis by centrifugation and gel electrophoresis indicated that AP-HDL was remodeled generating novel lipid poor particles composed only of apolipoprotein AI, which we designate beta2. This remodeling is dependent on pH, glycosaminoglycan type, is promoted by Ca(2+) and is independent of protease or lipase activity. Compared to HDL and AP-HDL, remodeled AP-HDL (S-HDL-SAA), containing beta2 particles, demonstrated a 3-fold greater cholesterol efflux activity from cholesterol-loaded macrophage. Because the identified conditions causing this change in AP-HDL structure and function can exist physiologically at the surface of the macrophage, or in its endosomes, we postulate that AP-HDL contains latent functionalities that become apparent and active when it associates with macrophage cell surface/endosomal HS. In this way initial steps in the reverse cholesterol transport pathway are focused at sites of injury to mobilize cholesterol from macrophages that are actively participating in the phagocytosis of damaged membranes rich in cholesterol. The mechanism may also be of relevance to aspects of atherogenesis.
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Affiliation(s)
- Shui-Pang Tam
- Department of Pathology and Molecular Medicine, Queen's University, The Syl and Molly Apps Research Center, Kingston General Hospital, Kingston, Ontario, Canada
| | - Robert Kisilevsky
- Department of Pathology and Molecular Medicine, Queen's University, The Syl and Molly Apps Research Center, Kingston General Hospital, Kingston, Ontario, Canada
- Department of Biochemistry, Queen's University, The Syl and Molly Apps Research Center, Kingston General Hospital, Kingston, Ontario, Canada
| | - John B. Ancsin
- Department of Pathology and Molecular Medicine, Queen's University, The Syl and Molly Apps Research Center, Kingston General Hospital, Kingston, Ontario, Canada
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14
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Cai H, Song C, Endoh I, Goyette J, Jessup W, Freedman SB, McNeil HP, Geczy CL. Serum Amyloid A Induces Monocyte Tissue Factor. THE JOURNAL OF IMMUNOLOGY 2007; 178:1852-60. [PMID: 17237436 DOI: 10.4049/jimmunol.178.3.1852] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
C-reactive protein (CRP) and serum amyloid A (SAA) increase in the blood of patients with inflammatory conditions and CRP-induced monocyte tissue factor (TF) may contribute to inflammation-associated thrombosis. This study demonstrates that SAA is a potent and rapid inducer of human monocyte TF. SAA induced TF mRNA in PBMC within 30 min and optimal procoagulant activity within 4 h, whereas CRP (25 mug/ml)-induced activity was minimal at this time. Unlike CRP, SAA did not synergize with LPS. Procoagulant activity was inhibited by anti-TF and was dependent on factors VII and X, and TF Ag levels were elevated on CD14(+) monocytes. Responses were optimal with lymphocytes, although these were not obligatory. Inhibitor studies indicate activation of NF-kappaB through the ERK1/2 and p38 MAPK pathways; the cyclo-oxygenase pathway was not involved. SAA-induced TF was partially inhibited by high-density lipoprotein, but not by low-density lipoprotein or by apolipoprotein A-I. SAA is a ligand for the receptor for advanced glycation end products (RAGE), and TF generation was suppressed by approximately 50% by a RAGE competitor, soluble RAGE, and by approximately 85% by anti-RAGE IgG. However, another RAGE ligand, high mobility group box-1 protein, capable of inducing monocyte chemotactic protein-1 mRNA in 2 h, did not induce TF within 24 h. Cross-linking studies confirmed SAA binding to soluble RAGE. Elevated SAA is a marker of disease activity in patients with rheumatoid arthritis, and PBMC from patients with rheumatoid arthritis were more sensitive to SAA than normals, suggesting a new link between inflammation and thrombosis.
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Affiliation(s)
- Hong Cai
- Inflammatory Diseases Research Unit, School of Medical Sciences, University of New South Wales, Sydney, Australia
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15
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Okino AM, Bürger C, Cardoso JR, Lavado EL, Lotufo PA, Campa A. The acute-phase proteins serum amyloid A and C reactive protein in transudates and exudates. Mediators Inflamm 2007; 2006:47297. [PMID: 16864904 PMCID: PMC1570385 DOI: 10.1155/mi/2006/47297] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The distinction between exudates and transudates is very important
in the patient management. Here we evaluate whether the
acute-phase protein serum amyloid A (SAA), in comparison with C
reactive protein (CRP) and total protein (TP), can be useful in
this discrimination. CRP, SAA, and TP were
determined in 36 exudate samples (27 pleural and 9 ascitic) and in
12 transudates (9 pleural and 3 ascitic). CRP, SAA, and TP
were measured. SAA present in the exudate
corresponded to 10% of the amount found in serum, that is, the
exudate/serum ratio (E/S) was 0.10 ± 0.13. For comparison, the
exudate/serum ratio for CRP and TP was 0.39 ± 0.37 and 0.68 ± 0.15, respectively. There was a strong positive correlation
between serum and exudate SAA concentration (r = 0.764;p < 0.0001). The concentration of SAA in transudates was low
and did not overlap with that found in exudates (0.02-0.21 versus
0.8–360.5 g/mL). SAA in pleural and ascitic exudates results
mainly from leakage of the serum protein via the inflamed
membrane. A comparison of the E/S ratio of SAA and CRP points SAA
as a very good marker in discriminating between exudates and
transudates.
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Affiliation(s)
- Alessandra M. Okino
- Departamento de Patologia, Análises Clínicas
e Toxicológicas, Centro de Ciências da Saúde,
Universidade Estadual de Londrina, CEP 86051-990
Paraná, Brazil
- Departamento de Análises Clínicas e
Toxicológicas, Faculdade de Ciências Farmacêuticas,
Universidade de São Paulo, CEP 05508-900 São
Paulo, Brazil
| | - Cristiani Bürger
- Departamento de Análises Clínicas e
Toxicológicas, Faculdade de Ciências Farmacêuticas,
Universidade de São Paulo, CEP 05508-900 São
Paulo, Brazil
- Núcleo de Investigações
Químico-Farmacêuticas, Centro de Ciências da
Saúde, Universidade do Vale do Itajaí, CEP
88302-202 Santa Catarina, Brazil
| | - Jefferson R. Cardoso
- Departamento de Fisioterapia, Centro de Ciências
da Saúde, Universidade Estadual de Londrina, CEP 86051-990
Paraná, Brazil
| | - Edson L. Lavado
- Departamento de Fisioterapia, Centro de Ciências
da Saúde, Universidade Estadual de Londrina, CEP 86051-990
Paraná, Brazil
| | - Paulo A. Lotufo
- Hospital Universitário, Universidade de São
Paulo, CEP 05508-900 São Paulo, Brazil
| | - Ana Campa
- Departamento de Análises Clínicas e
Toxicológicas, Faculdade de Ciências Farmacêuticas,
Universidade de São Paulo, CEP 05508-900 São
Paulo, Brazil
- *Ana Campa:
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16
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Abstract
Inflammation long has been recognized as a hallmark of atherosclerotic lesions, but more recently attention has focused on chronic low-level elevations of specific plasma inflammatory proteins such as C-reactive protein (CRP) and serum amyloid A (SAA), which may not only represent markers of atherosclerosis risk but also participate directly in atherogenesis. This article briefly reviews evidence for and against potential roles of CRP as an atherosclerosis risk marker and in athero-genesis. The remainder of the article focuses on SAA, an inflammatory protein that is carried on, and may fundamentally alter the function of, high-density lipoprotein. Data are reviewed regarding the regulation of SAA by dietary cholesterol, obesity, and insulin resistance, and its potential role as an atherosclerosis mediator. Lying at the intersection of inflammation, dyslipidemia, obesity, and insulin resistance, SAA may play a key role in regulating the contributions of these processes to atherogenesis.
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Affiliation(s)
- Kevin D O'Brien
- Division of Cardiology, University of Washington, Seattle 98195-6422, USA.
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17
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O'Brien KD, McDonald TO, Kunjathoor V, Eng K, Knopp EA, Lewis K, Lopez R, Kirk EA, Chait A, Wight TN, deBeer FC, LeBoeuf RC. Serum Amyloid A and Lipoprotein Retention in Murine Models of Atherosclerosis. Arterioscler Thromb Vasc Biol 2005; 25:785-90. [PMID: 15692094 DOI: 10.1161/01.atv.0000158383.65277.2b] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Objective—
Elevated serum amyloid A (SAA) levels are associated with increased cardiovascular risk in humans. Because SAA associates primarily with lipoproteins in plasma and has proteoglycan binding domains, we postulated that SAA might mediate lipoprotein retention on atherosclerotic extracellular matrix.
Methods and Results—
Immunohistochemistry was performed for SAA, apolipoprotein A-I (apoA-I), apolipoprotein B (apoB), and perlecan on proximal aortic lesions from chow-fed low-density lipoprotein receptor (LDLR)
−/−
and apoE
−/−
mice euthanized at 10, 50, and 70 weeks. SAA was detected on atherosclerotic lesion extracellular matrix at all time points in both strains. SAA area correlated highly with lesion areas (apoE
−/−
,
r
=0.76; LDLR
−/−
,
r
=0.86), apoA-I areas (apoE
−/−
,
r
=0.88; LDLR
−/−
,
r
=0.80), apoB areas (apoE
−/−
,
r
=0.74; LDLR
−/−
,
r
=0.89), and perlecan areas (apoE
−/−
,
r
=0.83; LDLR
−/−
,
r
=0.79) (all
P
<0.0001). In vitro, SAA enrichment increased high-density lipoprotein (HDL) binding to heparan sulfate proteoglycans, and immunoprecipitation experiments using plasma from apoE
−/−
and LDLR
−/−
mice demonstrated that SAA was present on both apoA-I–containing and apoB-containing lipoproteins.
Conclusions—
In chow-fed apoE
−/−
and LDLR
−/−
mice, SAA is deposited in murine atherosclerosis at all stages of lesion development, and SAA immunoreactive area correlates highly with lesion area, apoA-I area, apoB area, and perlecan area. These findings are consistent with a possible role for SAA-mediated lipoprotein retention in atherosclerosis.
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Affiliation(s)
- Kevin D O'Brien
- Division of Cardiology, University of Washington, Seattle, WA 98195-6422, USA.
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18
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Wu A, Hinds CJ, Thiemermann C. High-density lipoproteins in sepsis and septic shock: metabolism, actions, and therapeutic applications. Shock 2004; 21:210-21. [PMID: 14770033 DOI: 10.1097/01.shk.0000111661.09279.82] [Citation(s) in RCA: 137] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Sepsis and septic shock are important causes of morbidity and lethality in noncoronary intensive care units. Circulating levels of high-density lipoproteins (HDLs) are reduced in sepsis/septic shock, and the magnitude of this reduction is positively correlated with the severity of the illness. The mechanisms underlying this phenomenon are incompletely understood, although increased levels of several acute-phase proteins, including serum amyloid A (SAA) and secretory phospholipase A2 (sPLA2), may contribute to the decrease in plasma HDLs. It has been suggested that HDLs possess anti-inflammatory properties and, hence, may play a crucial role in innate immunity by regulating the inflammatory response as well as being capable of reducing the severity of organ injury in animals and patients with septic shock. These protective effects of HDLs are mediated mainly via (a) lipopolysaccharide (LPS) binding and neutralization, (b) the HDL-associated enzymes, plasma paraoxonase (PON1) and platelet-activating factor acetylhydrolase (PAF-AH), which protect low-density lipoproteins against peroxidative damage, (c) inhibition of the expression of endothelial cell adhesion molecules and release of proinflammatory cytokines, which prevents inflammatory cell infiltration and subsequent multiple organ dysfunction, and (d) stimulation of the expression of endothelial nitric oxide synthase (eNOS). Thus, HDL exerts potent anti-inflammatory effects, some of which are independent of endotoxin binding and might be useful in the treatment of patients with not only sepsis/septic shock but also other conditions associated with an uncontrolled inflammatory response, such as ischemia-reperfusion injury and hemorrhagic shock.
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Affiliation(s)
- Aihua Wu
- Department of Anaesthesia, Beijing Hospital, Beijing 100730, PR China
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19
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Lewis KE, Kirk EA, McDonald TO, Wang S, Wight TN, O'Brien KD, Chait A. Increase in serum amyloid a evoked by dietary cholesterol is associated with increased atherosclerosis in mice. Circulation 2004; 110:540-5. [PMID: 15277327 DOI: 10.1161/01.cir.0000136819.93989.e1] [Citation(s) in RCA: 135] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Elevated serum amyloid A (SAA) levels are associated with increased cardiovascular risk. SAA levels can be increased by dietary fat and cholesterol. Moreover, SAA can cause lipoproteins to bind extracellular vascular proteoglycans, a process that is critical in atherogenesis. Therefore, we hypothesized that diet-induced increases in SAA would increase atherosclerosis independent of their effect on plasma cholesterol levels. METHODS AND RESULTS Female LDL-receptor-null (LDLR-/-) mice were fed high-saturated fat diets (21%, wt/wt), with or without added cholesterol (0.15%, wt/wt), for 10 weeks. Compared with chow-fed controls, the high-fat diets increased plasma SAA levels. Addition of cholesterol further increased SAA levels 2-fold (P<0.05) without further increasing plasma cholesterol levels. Addition of dietary cholesterol also increased atherosclerosis (P<0.05). Four lines of evidence suggest that SAA actually might cause atherosclerosis: (1) SAA levels when mice were euthanized correlated with the extent of atherosclerosis (r=0.49; P<0.02); (2) SAA levels after 5 weeks of diet correlated with the extent of atherosclerosis at 10 weeks (r=0.66; P<0.01); (3) binding of HDL from these animals to proteoglycans in vitro was related to the HDL-SAA content (r=0.65; P<0.01); and (4) immunoreactive SAA was present in lesion areas enriched with both proteoglycans and apolipoprotein A-I, the major HDL apolipoprotein. CONCLUSIONS Addition of cholesterol to a high-fat diet increased plasma SAA levels and atherosclerosis independent of an adverse effect on plasma lipoproteins, consistent with the hypothesis that SAA may promote atherosclerosis directly by mediating retention of SAA-enriched HDL to vascular proteoglycans.
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Affiliation(s)
- Katherine E Lewis
- Department of Medicine, University of Washington, Seattle, Wash 98195-6426, USA
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20
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Levels JHM, Lemaire LCJM, van den Ende AE, van Deventer SJH, van Lanschot JJB. Lipid composition and lipopolysaccharide binding capacity of lipoproteins in plasma and lymph of patients with systemic inflammatory response syndrome and multiple organ failure. Crit Care Med 2003; 31:1647-53. [PMID: 12794399 DOI: 10.1097/01.ccm.0000063260.07222.76] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Lipopolysaccharide (LPS), the major glycolipid component of Gram-negative bacterial outer membranes, is a potent endotoxin responsible for many of the directly or indirectly induced symptoms of infection. Lipoproteins (in particular, high-density lipoproteins) sequester LPS, thereby acting as a humoral detoxification mechanism. PATIENTS Differences in the lipoprotein composition in human plasma and lymph of a control patient group (n = 5) without systemic inflammatory response syndrome (non-SIRS/MOF) and patients with SIRS and multiple organ failure (MOF, n = 9) were studied. The LPS binding capacity of the lipoproteins in SIRS/MOF and non-SIRS/MOF patients was investigated by rechallenge of the plasma and lymph with fluorescently labeled LPS ex vivo. The lipoprotein composition was analyzed using immunochemical techniques and high-performance gel permeation chromatography. RESULTS In the non-SIRS/MOF patient group, plasma and lymph levels of apolipoprotein A-I (600 and 450 mg/L, respectively), apolipoprotein B (440 and 280 mg/L, respectively), total cholesterol (2.88 and 1.05 mM, respectively), and total triglycerides (0.67 and 0.97 mM, respectively) were observed. In the SIRS/MOF group, a decrease of apolipoprotein A-I (-55% in plasma and lymph), a decrease of apolipoprotein B (-43% in plasma and -38% in lymph), and a decrease of total cholesterol levels (-54% in plasma and -37% in lymph) were demonstrated. However, the triglyceride levels in the SIRS/MOF group showed a 30% increase in plasma and a 47% decrease in lymph compared with the non-SIRS/MOF patients. In SIRS/MOF patients, a 2.8-fold increase in plasma and a 1.8-fold increase in lymph of the LPS low-density lipoprotein/high-density lipoprotein ratio was observed, indicating that the relative LPS binding capacity of the lipoproteins in the SIRS/MOF patient group showed a trend to be shifted mainly toward low-density lipoproteins. Furthermore, in plasma and lymph of four SIRS/MOF patients, a novel cholesterol-containing high-density lipoprotein-like particle was found that barely had LPS binding capacity (<5%). CONCLUSIONS In the SIRS/MOF patients, the changes in lipoprotein composition in lymph are a reflection of those in plasma, except for the triglyceride levels. In comparison with the non-SIRS/MOF patients, the SIRS/MOF patients show a shifted LPS binding capacity of high-density lipoproteins toward low-density lipoproteins in plasma and in lymph. Moreover, in plasma and lymph, novel cholesterol-containing particles, resembling high-density lipoprotein, were identified in the SIRS/MOF patient group.
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Affiliation(s)
- Johannes H M Levels
- Department of Vascular Medicine, Academic Medical Center, Amsterdam, the Netherlands
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21
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Artl A, Marsche G, Pussinen P, Knipping G, Sattler W, Malle E. Impaired capacity of acute-phase high density lipoprotein particles to deliver cholesteryl ester to the human HUH-7 hepatoma cell line. Int J Biochem Cell Biol 2002; 34:370-81. [PMID: 11854036 DOI: 10.1016/s1357-2725(01)00132-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The major role of native high density lipoprotein (HDL) is to carry cholesterol from peripheral tissues to the liver for bile excretion. As acute-phase (AP)-HDL has a decreased ability for cellular cholesterol efflux but an increased capacity for cholesteryl ester (CE) delivery to peripheral tissues, the interaction of AP-HDL with human hepatoma cells was studied. Binding studies to HUH-7 cells revealed saturable binding properties for HDL and AP-HDL at 4 degrees C. At 37 degrees C, specific cell-association of (125)I- and [1,2,6,7-(3)H]-cholesteryl palmitate ([(3)H]CE)-labeled lipoprotein particles was 2.2- and 1.6-fold higher for HDL indicating that total CE delivery was significantly (P<0.05) higher for HDL in comparison to AP-HDL. In parallel, selective CE uptake (the difference between total lipid uptake and holoparticle uptake) from AP-HDL was decreased compared with HDL. The fact that the capacity for cellular cholesterol efflux from HUH-7 cells is slightly impaired by AP-HDL (compared with HDL) is of support that scavenger receptor class B, type I (SR-BI), the only receptor so far known to mediate bi-directional lipid flux, might be involved in altered HUH-7 cholesterol hemostasis by AP-HDL. Our in vitro findings suggest that HDL and AP-HDL interact differently with cells of hepatic origin resulting in decreased hepatic cholesterol removal from the circulation during the AP reaction.
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Affiliation(s)
- Andreas Artl
- Institute of Medical Biochemistry and Molecular Biology, Karl-Franzens University Graz, Harrachgasse 21, A-8010 Graz, Austria
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22
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Ely S, Bonatesta R, Ancsin JB, Kindy M, Kisilevsky R. The in-vitro influence of serum amyloid A isoforms on enzymes that regulate the balance between esterified and un-esterified cholesterol. Amyloid 2001; 8:169-81. [PMID: 11676294 DOI: 10.3109/13506120109007360] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The intracellular balance between un-esterified and esterified cholesterol is regulated by two enzyme activities, cholesterol ester hydrolases, which drive the balance in favor of un-esterified cholesterol, and acyl-CoA:cholesterol acyl transferase (ACAT) which acts in the opposite direction. During acute inflammation apo-serum amyloid A (apoSAA) isoforms 1.1 and 2.1 become major constituents of high density lipoprotein and this complex is internalized by macrophages. Mixtures of the two isoforms have been shown to enhance cholesterol esterase activity. Using a purified form of the pancreatic enzyme we have explored the mechanism by which apoSAA may accomplish this stimulation. The pancreatic esterase cleaves cholesteryl-oleate with a Km of 0.255 mM, releasing both cholesterol and oleate. Cholesterol exhibits a product inhibition which is relieved by isoform 2.1 but not 1.1 nor apolipoprotein A-I. The NH2-terminal 16 residues of isoform 2.1 had no effect on the esterase, but the 80 residue peptide constituting its COOH-terminus possessed the stimulatory property. Purified isoforms 1.1, 2.1, 2.2, apolipoprotein A-I, the NH2-terminal 16 residues and COOH-terminal 80 residues of isoform 2.1 were also examined for their effects on macrophage ACAT activity. Isoforms 2.1 and 2.2 produced dose dependent inhibitions of up to 50%, (p<0.001). Isoform 1.1, and apoA-I had no effect on ACAT activity. The NH2-terminal 16 residue peptide of isoform 2.1 reduced the ACAT activity in a dose dependent manner by 74% (p<0.001), whereas the COOH-terminal 80 residues, in contrast to its enhancing effect on the esterase, had no inhibitory effect on ACAT. Such complementary but opposite effects of isoform 2.1 on ACAT and the esterase are consistent with a role for this protein in shifting the balance between unesterified (transportable) and esterified (storage) forms of cholesterol in favor of the latter. They suggest that apoSAA2.1 may mediate cholesterol mobilization at sites of tissue injury.
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Affiliation(s)
- S Ely
- Department of Pathology, Queen's University, Kingston General Hospital, Ontario, Canada
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