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Tamiya-Koizumi K, Otoki Y, Nakagawa K, Kannagi R, Mizutani N, Suzuki M, Kyogashima M, Iwaki S, Aoyama M, Murate T, Kitatani K, Kuga T, Mizutani Y, Tokumura A. Cellular concentrations of plasmalogen species containing a polyunsaturated fatty acid significantly increase under hypoxia in human colorectal cancer, Caco2 cells. Biochem Biophys Res Commun 2022; 611:1-7. [DOI: 10.1016/j.bbrc.2022.04.061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 04/13/2022] [Indexed: 11/02/2022]
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Wang W, Xie Y, Liu L, King GJ, White P, Ding G, Wang S, Cai H, Wang C, Xu F, Shi L. Genetic Control of Seed Phytate Accumulation and the Development of Low-Phytate Crops: A Review and Perspective. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2022; 70:3375-3390. [PMID: 35275483 DOI: 10.1021/acs.jafc.1c06831] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Breeding low phytic acid (lpa) crops is a strategy that has potential to both improve the nutritional quality of food and feed and contribute to the sustainability of agriculture. Here, we review the lipid-independent and -dependent pathways of phytate synthesis and their regulatory mechanisms in plants. We compare the genetic variation of the phytate concentration and distribution in seeds between dicot and monocot species as well as the associated temporal and spatial expression patterns of the genes involved in phytate synthesis and transport. Quantitative trait loci or significant single nucleotide polymorphisms for the seed phytate concentration have been identified in different plant species by linkage and association mapping, and some genes have been cloned from lpa mutants. We summarize the effects of various lpa mutations on important agronomic traits in crop plants and propose SULTR3;3 and SULTR3;4 as optimal target genes for lpa crop breeding.
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Affiliation(s)
- Wei Wang
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China
- Microelement Research Center, Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China
| | - Yiwen Xie
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China
- Microelement Research Center, Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China
| | - Lei Liu
- Southern Cross Plant Science, Southern Cross University, Lismore New South Wales 2480, Australia
| | - Graham J King
- Southern Cross Plant Science, Southern Cross University, Lismore New South Wales 2480, Australia
| | - Philip White
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China
- The James Hutton Institute, Invergowrie, Dundee DD2 5DA, United Kingdom
| | - Guangda Ding
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China
- Microelement Research Center, Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China
| | - Sheliang Wang
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China
- Microelement Research Center, Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China
| | - Hongmei Cai
- Microelement Research Center, Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China
| | - Chuang Wang
- Microelement Research Center, Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China
| | - Fangsen Xu
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China
- Microelement Research Center, Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China
| | - Lei Shi
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China
- Microelement Research Center, Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China
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Tong C, Chen Y, Tan Y, Liu L, Waters DLE, Rose TJ, Shu Q, Bao J. Analysis of Lysophospholipid Content in Low Phytate Rice Mutants. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2017; 65:5435-5441. [PMID: 28603982 DOI: 10.1021/acs.jafc.7b01576] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
As a fundamental component of nucleic acids, phospholipids, and adenosine triphosphate, phosphorus (P) is critical to all life forms, however, the molecular mechanism of P translocation and distribution in rice grains are still not understood. Here, with the use of five different low phytic acid (lpa) rice mutants, the redistribution in the main P-containing compounds in rice grain, phytic acid (PA), lysophospholipid (LPL), and inorganic P (Pi), was investigated. The lpa mutants showed a significant decrease in PA and phytate-phosphorus (PA-P) concentration with a concomitant increase in Pi concentration. Moreover, defects in the OsST and OsMIK genes result in a great reduction of specific LPL components and LPL-phosphorus (LPL-P) contents in rice grain. In contrast, defective OsMRP5 and Os2-PGK genes led to a significant increase in individual LPL components. The effect of the Os2-PGK gene on the LPL accumulation was validated using breeding lines derived from a cross between KBNT-lpa (Os2-PGK mutation) and Jiahe218. This study demonstrates that these rice lpa mutants lead to the redistribution of Pi in endosperm and modify LPL biosynthesis. Increase LPLs in the endosperm in the lpa mutants may have practical applications in rice breeding to produce "healthier" rice.
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Affiliation(s)
- Chuan Tong
- Institute of Nuclear Agricultural Sciences, College of Agriculture and Biotechnology, Zhejiang University , Huajiachi Campus, Hangzhou, 310029, China
- Southern Cross Plant Science, Southern Cross University , Lismore, New South Wales 2480, Australia
| | - Yaling Chen
- Institute of Nuclear Agricultural Sciences, College of Agriculture and Biotechnology, Zhejiang University , Huajiachi Campus, Hangzhou, 310029, China
| | - Yuanyuan Tan
- Institute of Crop Sciences, College of Agriculture and Biotechnology, Zhejiang University , Hangzhou, 310029, China
| | - Lei Liu
- Southern Cross Plant Science, Southern Cross University , Lismore, New South Wales 2480, Australia
| | - Daniel L E Waters
- Southern Cross Plant Science, Southern Cross University , Lismore, New South Wales 2480, Australia
| | - Terry J Rose
- Southern Cross Plant Science, Southern Cross University , Lismore, New South Wales 2480, Australia
- Southern Cross Geoscience, Southern Cross University , Lismore, New South Wales 2480, Australia
| | - Qingyao Shu
- Institute of Crop Sciences, College of Agriculture and Biotechnology, Zhejiang University , Hangzhou, 310029, China
| | - Jinsong Bao
- Institute of Nuclear Agricultural Sciences, College of Agriculture and Biotechnology, Zhejiang University , Huajiachi Campus, Hangzhou, 310029, China
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Saab S, Mazzocco J, Creuzot-Garcher CP, Bron AM, Bretillon L, Acar N. Plasmalogens in the retina: From occurrence in retinal cell membranes to potential involvement in pathophysiology of retinal diseases. Biochimie 2014; 107 Pt A:58-65. [DOI: 10.1016/j.biochi.2014.07.023] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Accepted: 07/26/2014] [Indexed: 10/24/2022]
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Nishimukai M, Maeba R, Ikuta A, Asakawa N, Kamiya K, Yamada S, Yokota T, Sakakibara M, Tsutsui H, Sakurai T, Takahashi Y, Hui SP, Chiba H, Okazaki T, Hara H. Serum choline plasmalogens—those with oleic acid in sn− 2—are biomarkers for coronary artery disease. Clin Chim Acta 2014; 437:147-54. [DOI: 10.1016/j.cca.2014.07.024] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Revised: 07/07/2014] [Accepted: 07/17/2014] [Indexed: 10/25/2022]
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Nishimukai M, Maeba R, Yamazaki Y, Nezu T, Sakurai T, Takahashi Y, Hui SP, Chiba H, Okazaki T, Hara H. Serum choline plasmalogens, particularly those with oleic acid in sn-2, are associated with proatherogenic state. J Lipid Res 2014; 55:956-65. [PMID: 24616482 DOI: 10.1194/jlr.p045591] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Serum plasmalogens (Pls) (1-O-alk-1'-enyl-2-acyl glycerophospholipids) are of particular interest for studies on metabolic disorders associated with oxidative stress and chronic inflammation. Serum levels of Pls are known to correlate positively with HDL-cholesterol (HDL-C); however, few studies have examined serum Pls molecular species in association with pathophysiological conditions and their clinical significance. To clarify these, we determined serum levels of individual ether glycerophospholipids in Japanese asymptomatic cohorts (n = 428; 362 male and 66 female subjects) by LC/MS/MS, and examined their correlations with clinical parameters. We found that the proportion of choline Pls (PlsCho) among total serum phospholipids was significantly lower in the male group over 40 years old and was associated with multiple risk parameters more strongly than HDL-C. The abundance of serum PlsCho with oleic acid (18:1) in sn-2 exhibited the strongest positive correlation with serum concentrations of adiponectin and HDL-C, while being inversely associated with waist circumference and the serum levels of TG and small dense LDL-cholesterol. The characterization of serum ether glycerophospholipids verified the specificity of PlsCho, particularly the ones with 18:1 in sn-2, as a sensitive biomarker for the atherogenic state.
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Affiliation(s)
- Megumi Nishimukai
- Division of Applied Bioscience, Research Faculty of Agriculture, Hokkaido University, Sapporo, Hokkaido 060-8589, Japan
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Dennis EA, Cao J, Hsu YH, Magrioti V, Kokotos G. Phospholipase A2 enzymes: physical structure, biological function, disease implication, chemical inhibition, and therapeutic intervention. Chem Rev 2011; 111:6130-85. [PMID: 21910409 PMCID: PMC3196595 DOI: 10.1021/cr200085w] [Citation(s) in RCA: 804] [Impact Index Per Article: 61.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Edward A. Dennis
- Department of Chemistry and Biochemistry and Pharmacology, School of Medicine, University of California, San Diego, La Jolla, California 92093-0601
| | - Jian Cao
- Department of Chemistry and Biochemistry and Pharmacology, School of Medicine, University of California, San Diego, La Jolla, California 92093-0601
| | - Yuan-Hao Hsu
- Department of Chemistry and Biochemistry and Pharmacology, School of Medicine, University of California, San Diego, La Jolla, California 92093-0601
| | - Victoria Magrioti
- Laboratory of Organic Chemistry, Department of Chemistry, University of Athens, Panepistimiopolis, Athens 15771, Greece
| | - George Kokotos
- Laboratory of Organic Chemistry, Department of Chemistry, University of Athens, Panepistimiopolis, Athens 15771, Greece
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Gonsalves C, Kalra VK. Endothelin-1–Induced Macrophage Inflammatory Protein-1β Expression in Monocytic Cells Involves Hypoxia-Inducible Factor-1α and AP-1 and Is Negatively Regulated by microRNA-195. THE JOURNAL OF IMMUNOLOGY 2010; 185:6253-64. [DOI: 10.4049/jimmunol.1000660] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Gonsalves CS, Kalra VK. Hypoxia-mediated expression of 5-lipoxygenase-activating protein involves HIF-1alpha and NF-kappaB and microRNAs 135a and 199a-5p. THE JOURNAL OF IMMUNOLOGY 2010; 184:3878-88. [PMID: 20194722 DOI: 10.4049/jimmunol.0902594] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Hypoxia occurs in a number of pathological states, such as pulmonary, hematological, and cardiovascular disorders. In this study, we examined the molecular mechanism by which hypoxia contributes to increased leukotriene formation. Our studies showed hypoxia augmented the expression of 5-lipoxygenase activating protein (FLAP), a key enzyme in leukotriene formation, in both human pulmonary microvascular endothelial cells and a transformed human brain endothelial cell line. Hypoxia-induced FLAP mRNA expression involved activation of NADPH-oxidase, PI-3 kinase, mitogen-activated protein kinase, NF-kappaB, and hypoxia-inducible factor (HIF)-1alpha. Hypoxia-induced FLAP promoter activity was attenuated on mutation of hypoxia-response elements (HREs) and NF-kappaB binding motif in the FLAP promoter. Hypoxia also augmented binding of HIF-1alpha to HREs in FLAP promoter as demonstrated by EMSA with nuclear extracts. Furthermore, chromain immunoprecipitation analysis showed HIF-1alpha bound to HREs in native chromatin obtained from hypoxia-treated cells. Next, we examined the role of HIF-1alpha regulated microRNAs on FLAP expression. Our studies showed decreased expression of miR-135a and miR-199a-5p in response to hypoxia. However, overexpression of anti-miR-135a and anti-miR-199a-5p oligonucleotides led to a several fold increased FLAP mRNA and protein expression. These studies demonstrate for the first time that hypoxia-mediated FLAP expression is regulated by HREs and NF-kappaB site in its promoter, and negatively regulated by miR-135a and miR-199a-5p, which target the 3'-UTR of FLAP mRNA. An understanding of these regulatory pathways provides new avenues to ameliorate leukotriene formation and hence reactive airway disease, and inflammation in individuals who have sickle cell disease.
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Affiliation(s)
- Caryn S Gonsalves
- Department of Biochemistry and Molecular Biology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
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Coupled calcium and zinc dyshomeostasis and oxidative stress in cardiac myocytes and mitochondria of rats with chronic aldosteronism. J Cardiovasc Pharmacol 2009; 53:414-23. [PMID: 19333130 DOI: 10.1097/fjc.0b013e3181a15e77] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A dyshomeostasis of extra- and intracellular Ca(2+) and Zn(2+) occurs in rats receiving chronic aldosterone/salt treatment (ALDOST). Herein, we hypothesized that the dyshomeostasis of intracellular Ca(2+) and Zn(2+) is intrinsically coupled that alters the redox state of cardiac myocytes and mitochondria, with Ca(2+) serving as a pro-oxidant and Zn(2+) as an antioxidant. Toward this end, we harvested hearts from rats receiving 4 weeks of ALDOST alone or cotreatment with either spironolactone (Spiro), an aldosterone receptor antagonist, or amlodipine (Amlod), an L-type Ca(2+) channel blocker, and from age/sex-matched untreated controls. In each group, we monitored cardiomyocyte [Ca(2+)]i and [Zn(2+)]i and mitochondrial [Ca(2+)]m and [Zn(2+)]m; biomarkers of oxidative stress and antioxidant defenses; expression of Zn transporters, Zip1 and ZnT-1; metallothionein-1, a Zn(2+)-binding protein; and metal response element transcription factor-1, a [Zn(2+)]i sensor and regulator of antioxidant defenses. Compared with controls, at 4-week ALDOST, we found the following: (a) increased [Ca(2+)]i and [Zn(2+)]i, together with increased [Ca(2+)]m and [Zn(2+)]m, each of which could be prevented by Spiro and attenuated with Amlod; (b) increased levels of 3-nitrotyrosine and 4-hydroxy-2-nonenal in cardiomyocytes, together with increased H(2)O(2) production, malondialdehyde, and oxidized glutathione in mitochondria that were coincident with increased activities of Cu/Zn superoxide dismutase and glutathione peroxidase; and (c) increased expression of metallothionein-1, Zip1 and ZnT-1, and metal response element transcription factor-1, attenuated by Spiro. Thus, an intrinsically coupled dyshomeostasis of intracellular Ca(2+) and Zn(2+) occurs in cardiac myocytes and mitochondria in rats receiving ALDOST, where it serves to alter their redox state through a respective induction of oxidative stress and generation of antioxidant defenses. The importance of therapeutic strategies that can uncouple these two divalent cations and modulate their ratio in favor of sustained antioxidant defenses is therefore suggested.
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Hoffmann EK, Lambert IH, Pedersen SF. Physiology of cell volume regulation in vertebrates. Physiol Rev 2009; 89:193-277. [PMID: 19126758 DOI: 10.1152/physrev.00037.2007] [Citation(s) in RCA: 1014] [Impact Index Per Article: 67.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The ability to control cell volume is pivotal for cell function. Cell volume perturbation elicits a wide array of signaling events, leading to protective (e.g., cytoskeletal rearrangement) and adaptive (e.g., altered expression of osmolyte transporters and heat shock proteins) measures and, in most cases, activation of volume regulatory osmolyte transport. After acute swelling, cell volume is regulated by the process of regulatory volume decrease (RVD), which involves the activation of KCl cotransport and of channels mediating K(+), Cl(-), and taurine efflux. Conversely, after acute shrinkage, cell volume is regulated by the process of regulatory volume increase (RVI), which is mediated primarily by Na(+)/H(+) exchange, Na(+)-K(+)-2Cl(-) cotransport, and Na(+) channels. Here, we review in detail the current knowledge regarding the molecular identity of these transport pathways and their regulation by, e.g., membrane deformation, ionic strength, Ca(2+), protein kinases and phosphatases, cytoskeletal elements, GTP binding proteins, lipid mediators, and reactive oxygen species, upon changes in cell volume. We also discuss the nature of the upstream elements in volume sensing in vertebrate organisms. Importantly, cell volume impacts on a wide array of physiological processes, including transepithelial transport; cell migration, proliferation, and death; and changes in cell volume function as specific signals regulating these processes. A discussion of this issue concludes the review.
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Affiliation(s)
- Else K Hoffmann
- Department of Biology, University of Copenhagen, Copenhagen, Denmark.
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Ngoi SM, Tovey MG, Vella AT. Targeting poly(I:C) to the TLR3-independent pathway boosts effector CD8 T cell differentiation through IFN-alpha/beta. THE JOURNAL OF IMMUNOLOGY 2008; 181:7670-80. [PMID: 19017955 DOI: 10.4049/jimmunol.181.11.7670] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Poly(I:C) is an adjuvant used for antitumor treatment and vaccines because of its prominent effects on CD8 T cells and NK cells. Poly(I:C) binds TLR3 and this interaction is thought to be central for driving cell-mediated immune responses. We investigated the importance of TLR3 in poly(I:C)-mediated endogenous CD8 T cell responses using the pathogenic T cell stimulant Staphylococcus aureus enterotoxin A. While the responsive CD8 T cells expanded comparably in both wild-type and TLR3(-/-) mice, differentiation of effector CD8 T cells was enhanced by poly(I:C) in the TLR3(-/-) mice. A higher percentage of Ag-specific CD8 T cells became IFN-gamma and TNF-alpha producers in the absence of TLR3 signaling. Consistent with this boosted response was the observation that TLR3-deficient cells synthesized less IL-10 compared with TLR3-sufficient cells in response to poly(I:C). Ultimately, however, the fundamental mechanism of CD8 effector T cell differentiation through the TLR3-independent pathway was shown to be completely IFN-alpha/beta-dependent. Administration of IFN-alpha/beta-neutralizing Abs abolished the poly(I:C) effects in TLR3(-/-) mice. These findings reveal specific roles of how dsRNA receptors shape CD8 T cell responses, which should be considered as poly(I:C) is authenticated as a therapeutic adjuvant used in vaccines.
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Affiliation(s)
- Soo M Ngoi
- Department of Immunology, University of Connecticut Health Center, Farmington, CT 06030, USA
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Gaposchkin DP, Farber HW, Zoeller RA. On the importance of plasmalogen status in stimulated arachidonic acid release in the macrophage cell line RAW 264.7. Biochim Biophys Acta Mol Cell Biol Lipids 2008; 1781:213-9. [DOI: 10.1016/j.bbalip.2008.01.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2007] [Revised: 01/30/2008] [Accepted: 01/31/2008] [Indexed: 11/25/2022]
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White MC, McHowat J. Protease activation of calcium-independent phospholipase A2 leads to neutrophil recruitment to coronary artery endothelial cells. Thromb Res 2006; 120:597-605. [PMID: 17188740 PMCID: PMC2170458 DOI: 10.1016/j.thromres.2006.11.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2006] [Revised: 10/18/2006] [Accepted: 11/14/2006] [Indexed: 11/28/2022]
Abstract
INTRODUCTION Thrombin or tryptase cleavage of protease-activated receptors (PAR) on human coronary artery endothelial cells (HCAEC) results in activation of a membrane-associated, calcium-independent phospholipase A2 (iPLA2) that selectively hydrolyzes plasmalogen phospholipids. Atherosclerotic plaque rupture results in a coronary ischemic event in which HCAEC in the ischemic area would be exposed to increased thrombin concentrations in addition to tryptase released by activated mast cells present in the plaque. MATERIALS AND METHODS HCAEC were stimulated with thrombin or tryptase in the absence or presence of bromoenol lactone (BEL), a selective iPLA2 inhibitor, and iPLA2 activation, accumulation of biologically active membrane phospholipid-derived metabolites, upregulation of cell surface P-selectin expression and neutrophil adherence were measured. RESULTS HCAEC exposed to thrombin or tryptase stimulation demonstrated an increase in iPLA2 activity and arachidonic acid release. Additionally, stimulated HCAEC demonstrated increased platelet-activating factor (PAF) production and cell surface P-selectin expression, resulting in increased adhesion of neutrophils to HCAEC monolayers. Pretreatment with bromoenol lactone to inhibit iPLA2, blocked membrane phospholipid-derived metabolite production, increased cell surface P-selectin expression and neutrophil adherence. CONCLUSIONS The similar biochemical and cellular responses in HCAEC exposed to thrombin or tryptase stimulation suggest that the cleavage of two separate PAR serve to extend the range of proteases to which the cells respond rather than resulting in separate intracellular events. This suggests that in conditions such as thrombosis and atherosclerosis that multiple mechanisms can activate the inflammatory response.
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Affiliation(s)
- Maureen C White
- Saint Louis University School of Medicine, Department of Pathology, 1402 S. Grand, St. Louis, MO 63104, United States.
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