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Contursi A, Tacconelli S, Hofling U, Bruno A, Dovizio M, Ballerini P, Patrignani P. Biology and pharmacology of platelet-type 12-lipoxygenase in platelets, cancer cells, and their crosstalk. Biochem Pharmacol 2022; 205:115252. [PMID: 36130648 DOI: 10.1016/j.bcp.2022.115252] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 09/08/2022] [Accepted: 09/12/2022] [Indexed: 11/26/2022]
Abstract
Platelet-type lipoxygenase (pl12-LOX), encoded by ALOX12, catalyzes the production of the lipid mediator 12S-hydroperoxyeicosa-5,8,10,14-tetraenoic acid (12S-HpETE), which is quickly reduced by cellular peroxidases to form 12(S)-hydroxy-5,8,10,14-eicosatetraenoic acid (12S-HETE). Platelets express high levels of pl12-LOX and generate considerable amounts of 12S-HETE from arachidonic acid (AA; C20:4, n-6). The development of sensitive chiral liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods has allowed the accurate quantification of 12S-HETE in biological samples. Moreover, advances in the knowledge of the mechanism of action of 12S-HETE have been achieved. The orphan G-protein-coupled receptor 31 (GPR31) has been identified as the high-affinity 12S-HETE receptor. Moreover, upon platelet activation, 12S-HETE is produced, and significant amounts are found esterified to membrane phospholipids (PLs), such as phosphatidylethanolamine (PE) and phosphatidylcholine (PC), promoting thrombin generation. Platelets play many roles in cancer metastasis. Among them, the platelets' ability to interact with cancer cells and transfer platelet molecules by the release of extracellular vesicles (EVs) is noteworthy. Recently, it was found that platelets induce epithelial-mesenchymal transition(EMT) in cancer cells, a phenomenon known to confer high-grade malignancy, through the transfer of pl12-LOX contained in platelet-derived EVs. These cancer cells now generate 12-HETE, considered a key modulator of cancer metastasis. Interestingly, 12-HETE was mainly found esterified in plasmalogen phospholipids of cancer cells. This review summarizes the current knowledge on the regulation and functions of pl12-LOX in platelets and cancer cells and their crosstalk.Novel approaches to preventing cancer and metastasis by the pharmacological inhibition of pl12-LOX and the internalization of mEVs are discussed.
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Affiliation(s)
- Annalisa Contursi
- Center for Advanced Studies and Technology (CAST), "G. d'Annunzio" University, Chieti, Italy; Department of Neuroscience, Imaging and Clinical Science, "G. d'Annunzio" University, Chieti, Italy
| | - Stefania Tacconelli
- Center for Advanced Studies and Technology (CAST), "G. d'Annunzio" University, Chieti, Italy; Department of Neuroscience, Imaging and Clinical Science, "G. d'Annunzio" University, Chieti, Italy
| | - Ulrika Hofling
- Center for Advanced Studies and Technology (CAST), "G. d'Annunzio" University, Chieti, Italy; Department of Neuroscience, Imaging and Clinical Science, "G. d'Annunzio" University, Chieti, Italy
| | - Annalisa Bruno
- Center for Advanced Studies and Technology (CAST), "G. d'Annunzio" University, Chieti, Italy; Department of Neuroscience, Imaging and Clinical Science, "G. d'Annunzio" University, Chieti, Italy
| | - Melania Dovizio
- Center for Advanced Studies and Technology (CAST), "G. d'Annunzio" University, Chieti, Italy; Department of Neuroscience, Imaging and Clinical Science, "G. d'Annunzio" University, Chieti, Italy
| | - Patrizia Ballerini
- Center for Advanced Studies and Technology (CAST), "G. d'Annunzio" University, Chieti, Italy; Department of Innovative Technologies in Medicine and Dentistry, "G. d'Annunzio" University, Chieti, Italy
| | - Paola Patrignani
- Center for Advanced Studies and Technology (CAST), "G. d'Annunzio" University, Chieti, Italy; Department of Neuroscience, Imaging and Clinical Science, "G. d'Annunzio" University, Chieti, Italy.
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Cole BK, Lieb DC, Dobrian AD, Nadler JL. 12- and 15-lipoxygenases in adipose tissue inflammation. Prostaglandins Other Lipid Mediat 2013; 104-105:84-92. [PMID: 22951339 PMCID: PMC3526691 DOI: 10.1016/j.prostaglandins.2012.07.004] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2012] [Revised: 07/18/2012] [Accepted: 07/30/2012] [Indexed: 02/06/2023]
Abstract
The lipoxygenases (LOs) are principal enzymes involved in the oxidative metabolism of polyunsaturated fatty acids, including arachidonic acid. 12- and 15-LO and their lipid metabolites have been implicated in the development of insulin resistance and diabetes. Adipose tissue, and in particular visceral adipose tissue, plays a primary role in the development of the inflammation seen in these conditions. 12- and 15-LO and their lipid metabolites act as upstream regulators of many of the cytokines involved in the inflammatory response in adipose tissue. While the role that 12- and 15-LO play in chronically inflamed adipose tissue is becoming clearer, there are still many questions that remain unanswered regarding their activation, signaling pathways, and roles in healthy fat. 12- and 15-LO also generate products with anti-inflammatory properties that are under investigation. Therefore, 12- and 15-LO have the potential to be very important targets for therapeutics aimed at reducing insulin resistance and the comorbid conditions associated with obesity.
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Affiliation(s)
- Banumathi K. Cole
- Department of Internal Medicine, Strelitz Diabetes Center, Eastern Virginia Medical School, Norfolk, VA
| | - David C. Lieb
- Department of Internal Medicine, Strelitz Diabetes Center, Eastern Virginia Medical School, Norfolk, VA
| | - Anca D. Dobrian
- Department of Physiological Sciences, Eastern Virginia Medical School, Norfolk, VA
| | - Jerry L. Nadler
- Department of Internal Medicine, Strelitz Diabetes Center, Eastern Virginia Medical School, Norfolk, VA
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Stavniichuk R, Obrosov AA, Drel VR, Nadler JL, Obrosova IG, Yorek MA. 12/15-Lipoxygenase inhibition counteracts MAPK phosphorylation in mouse and cell culture models of diabetic peripheral neuropathy. ACTA ACUST UNITED AC 2013; 3. [PMID: 24175152 DOI: 10.4236/jdm.2013.33015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND Increased mitogen-activated protein kinase (MAPK) phosphorylation has been detected in peripheral nerve of human subjects and animal models with diabetes as well as high-glucose exposed human Schwann cells, and have been implicated in diabetic peripheral neuropathy. In our recent studies, leukocytetype 12/15-lipoxygenase inhibition or gene deficiency alleviated large and small nerve fiber dysfunction, but not intraepidermal nerve fiber loss in streptozotocin-diabetic mice. METHODS To address a mechanism we evaluated the potential for pharmacological 12/15-lipoxygenase inhibition to counteract excessive MAPK phosphorylation in mouse and cell culture models of diabetic neuropathy. C57Bl6/J mice were made diabetic with streptozotocin and maintained with or without the 12/15-lipoxygenase inhibitor cinnamyl-3,4-dihydroxy-α-cyanocinnamate (CDC). Human Schwann cells were cultured in 5.5 mM or 30 mM glucose with or without CDC. RESULTS 12(S) HETE concentrations (ELISA), as well as 12/15-lipoxygenase expression and p38 MAPK, ERK, and SAPK/JNK phosphorylation (all by Western blot analysis) were increased in the peripheral nerve and spinal cord of diabetic mice as well as in high glucose-exposed human Schwann cells. CDC counteracted diabetes-induced increase in 12(S)HETE concentrations (a measure of 12/15-lipoxygenase activity), but not 12/15-lipoxygenase overexpression, in sciatic nerve and spinal cord. The inhibitor blunted excessive p38 MAPK and ERK, but not SAPK/ JNK, phosphorylation in sciatic nerve and high glucose exposed human Schwann cells, but did not affect MAPK, ERK, and SAPK/JNK phosphorylation in spinal cord. CONCLUSION 12/15-lipoxygenase inhibition counteracts diabetes related MAPK phosphorylation in mouse and cell culture models of diabetic neuropathy and implies that 12/15-lipoxygenase inhibitors may be an effective treatment for diabetic peripheral neuropathy.
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Affiliation(s)
- Roman Stavniichuk
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, USA
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Liu Y, Wang H, Zhu Y, Chen L, Qu Y, Zhu Y. The protective effect of nordihydroguaiaretic acid on cerebral ischemia/reperfusion injury is mediated by the JNK pathway. Brain Res 2012; 1445:73-81. [DOI: 10.1016/j.brainres.2012.01.031] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2011] [Revised: 01/09/2012] [Accepted: 01/13/2012] [Indexed: 11/15/2022]
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Hitomi H, Mehta PK, Taniyama Y, Lassègue B, Seidel-Rogol B, San Martin A, Griendling KK. Vascular smooth muscle insulin resistance, but not hypertrophic signaling, is independent of angiotensin II-induced IRS-1 phosphorylation by JNK. Am J Physiol Cell Physiol 2011; 301:C1415-22. [PMID: 21900690 DOI: 10.1152/ajpcell.00017.2011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Angiotensin II (ANG II) has been implicated in the pathogenesis of diabetic micro- and macrovascular disease. In vascular smooth muscle cells (VSMCs), ANG II phosphorylates and degrades insulin receptor substrate-1 (IRS-1). While the pathway responsible for IRS-1 degradation in this system is unknown, c-Jun NH(2)-terminal kinase (JNK) has been linked with serine phosphorylation of IRS-1 and insulin resistance. We investigated the role of JNK in ANG II-induced IRS-1 phosphorylation, degradation, Akt activation, glucose uptake, and hypertrophic signaling, focusing on three IRS-1 phosphorylation sites: Ser302, Ser307, and Ser632. Maximal IRS-1 phosphorylation on Ser632 occurred at 5 min, on Ser307 at 30 min, and on Ser302 at 60 min. The JNK inhibitor SP600125 reduced ANG II-induced IRS-1 Ser307 phosphorylation (by 80%), IRS-1 Ser302 phosphorylation (by 70%), and IRS-1 Ser632 phosphorylation (by 50%). However, JNK inhibition had no effect on ANG II-mediated IRS-1 degradation, nor did it reverse the ANG II-induced decrease in Akt phosphorylation or glucose uptake. Transfection of VSMCs with mutants S307A, S302A, or S632A of IRS-1 did not block ANG II-mediated IRS-1 degradation. In contrast, JNK inhibition attenuated insulin-induced upregulation of collagen and smooth muscle α-actin in ANG II-pretreated cells. We conclude that phosphorylation of Ser307, Ser302, and Ser632 of IRS-1 is not involved in ANG II-mediated IRS-1 degradation, and that JNK alone does not mediate ANG II-stimulated IRS-1 degradation, but rather is responsible for the hypertrophic effects of insulin on smooth muscle.
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Affiliation(s)
- Hirofumi Hitomi
- Department of Medicine, Division of Cardiology, Emory University, 1639 Pierce Dr., Atlanta, GA 30322, USA
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Lim AKH, Ma FY, Nikolic-Paterson DJ, Ozols E, Young MJ, Bennett BL, Friedman GC, Tesch GH. Evaluation of JNK blockade as an early intervention treatment for type 1 diabetic nephropathy in hypertensive rats. Am J Nephrol 2011; 34:337-46. [PMID: 21876346 DOI: 10.1159/000331058] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Accepted: 07/19/2011] [Indexed: 11/19/2022]
Abstract
BACKGROUND/AIMS The c-Jun amino-terminal kinase (JNK) signaling pathway is activated in human kidney diseases and promotes renal injury in experimental glomerulonephritis. In this study, we examined whether JNK signaling plays a role in the development of diabetic nephropathy or in regulating hypertension, which exacerbates diabetic renal injury. METHODS Diabetes was induced in spontaneously hypertensive rats (SHR) using streptozotocin. At week 16 of diabetes, rats with equivalent hyperglycemia and albuminuria were randomized into groups which received no treatment, vehicle alone or a selective JNK inhibitor (CC-930, 60 mg/kg/bid) for 10 weeks. These rats were assessed for hypertension and progression of renal damage. RESULTS At week 16, diabetic rats showed increased kidney JNK activation compared with nondiabetic controls. Effective JNK inhibition was demonstrated at week 26 by reductions in c-Jun phosphorylation. CC-930 did not affect blood pressure, kidney hypertrophy, glomerular hyperfiltration, podocyte loss, glomerular fibrosis or tubulointerstitial injury in diabetic SHR. However, CC-930 reduced macrophages and ccl2 mRNA levels in diabetic kidneys. In contrast, CC-930 exacerbated albuminuria at week 26, which was associated with reduced glomerular mRNA levels of the podocyte-specific molecules, nephrin and podocin. CONCLUSION JNK inhibition does not prevent the progression of early diabetic renal injury in hypertensive rats, which contrasts with the ability of JNK inhibition to suppress albuminuria and injury in experimental glomerulonephritis.
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Affiliation(s)
- Andy K H Lim
- Department of Nephrology, Monash Medical Centre, 246 Clayton Road, Clayton, VIC 3168, Australia
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Martínez-Clemente M, Ferré N, Titos E, Horrillo R, González-Périz A, Morán-Salvador E, López-Vicario C, Miquel R, Arroyo V, Funk CD, Clària J. Disruption of the 12/15-lipoxygenase gene (Alox15) protects hyperlipidemic mice from nonalcoholic fatty liver disease. Hepatology 2010; 52:1980-91. [PMID: 20967760 DOI: 10.1002/hep.23928] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2010] [Accepted: 08/10/2010] [Indexed: 12/19/2022]
Abstract
UNLABELLED We have shown that Alox15, the gene encoding for 12/15-lipoxygenase (12/15-LO), is markedly up-regulated in livers from apolipoprotein E-deficient (ApoE(-/-)) mice, which spontaneously develop nonalcoholic fatty liver disease secondary to hyperlipidemia. In the current study, we used ApoE(-/-) mice with a targeted disruption of the Alox15 gene to assess the role of 12/15-LO in the development and progression of hepatic steatosis and inflammation. Compared with ApoE(-/-) mice, which exhibited extensive hepatic lipid accumulation and exacerbated inflammatory injury, ApoE/12/15-LO double-knockout (ApoE(-/-)/12/15-LO(-/-)) mice showed reduced serum alanine aminotransferase levels; decreased hepatic steatosis, inflammation, and macrophage infiltration; and decreased fatty acid synthase, tumor necrosis factor α (TNFα), monocyte chemoattractant protein-1 (MCP-1), interleukin (IL)-18, and IL-6 expression. Remarkably, disruption of Alox15 attenuated glucose intolerance and high-fat diet-induced insulin resistance, up-regulated insulin receptor substrate-2, and exerted opposite effects on hepatic c-Jun amino-terminal kinase and adenosine monophosphate-activated protein kinase phosphorylation, known negative and positive regulators of insulin signaling, respectively. In adipose tissue, the absence of Alox15 induced significant reductions in the expression of the proinflammatory and insulin-resistant adipokines MCP-1, TNFα, and resistin while increasing the expression of glucose transporter-4. Interestingly, compared with ApoE(-/-) mice, which exhibited increased hepatic caspase-3 staining, ApoE(-/-)/12/15-LO(-/-) mice showed attenuated hepatocellular injury. Consistent with this finding, hepatocytes isolated from ApoE(-/-) mice were more vulnerable to TNFα-induced programmed cell death, an effect that was not observed in hepatocytes carrying a targeted disruption of the Alox15 gene. CONCLUSION Collectively, our data suggest a potentially relevant mechanism linking 12/15-LO to the promotion of hepatic steatosis, insulin resistance, and inflammation in experimental liver disease of metabolic origin.
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Affiliation(s)
- Marcos Martínez-Clemente
- Department of Biochemistry and Molecular Genetics, Hospital Clínic, Centro de Investigaciones Biomédicas Esther Koplowitz, Institut d'Investigacions Biomèdiques August Pi i Sunyer, University of Barcelona, Spain
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Nagelin MH, Srinivasan S, Nadler JL, Hedrick CC. Murine 12/15-lipoxygenase regulates ATP-binding cassette transporter G1 protein degradation through p38- and JNK2-dependent pathways. J Biol Chem 2009; 284:31303-14. [PMID: 19713213 DOI: 10.1074/jbc.m109.028910] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
12/15-Lipoxygenase (12/15LO) plays a role in the pathogenesis of atherosclerosis and diabetes and has been implicated in low density lipoprotein oxidation. Murine macrophages express high levels of 12/15LO and are key cells involved in the accumulation and efflux of oxidized low density lipoprotein in the arterial wall. During this process, macrophages up-regulate scavenger receptors that regulate lipid uptake, and ATP-binding cassette (ABC) transporters, that regulate lipid efflux. We have previously demonstrated that 12/15LO enhances the turnover and serine phosphorylation of ABCG1. In the current study, we further elucidate the mechanisms by which 12/15LO regulates ABCG1. Proteasomal inhibitors blocked the down-regulation of ABCG1 expression and resulted in accumulation of phosphorylated ABCG1. Macrophages that lack 12/15LO have enhanced transporter expression, reduced ABCG1 phosphorylation, and increased cholesterol efflux. Conversely, macrophages that overexpress 12/15LO have reduced ABCG1 expression, increased transporter phosphorylation, and reduced cholesterol efflux. 12/15LO plays a key role in activating the MAPK pathway. Inhibition of the p38 or JNK pathways with pharmacological inhibitors or dominant negative constructs blocked 12S-hydroxyeicosatetranoic acid-mediated degradation of ABCG1. Moreover, we isolated macrophages from JNK1-, JNK2-, and MKK3-deficient mice to analyze the involvement of specific MAPK pathways. JNK2- and MKK3-, but not JNK1-deficient macrophages were resistant to the down-regulation of ABCG1 protein, reduction in efflux, and increase in serine phosphorylation by 12S-hydroxyeicosatetranoic acid. These findings provide evidence that 12/15LO regulates ABCG1 expression and function through p38- and JNK2-dependent mechanisms, and that targeting these pathways may provide novel approaches for regulating cholesterol homeostasis.
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Affiliation(s)
- Melissa H Nagelin
- Department of Pharmacology, The Robert M. Berne Cardiovascular Research Center, University of Virginia, Charlottesville, Virginia 22908, USA
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Weisinger G, Limor R, Marcus-Perlman Y, Knoll E, Kohen F, Schinder V, Firer M, Stern N. 12S-lipoxygenase protein associates with α-actin fibers in human umbilical artery vascular smooth muscle cells. Biochem Biophys Res Commun 2007; 356:554-60. [PMID: 17379189 DOI: 10.1016/j.bbrc.2007.03.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2007] [Accepted: 03/01/2007] [Indexed: 11/29/2022]
Abstract
The current study sets out to characterize the intracellular localization of the platelet-type 12S-lipoxygenase (12-LO), an enzyme involved in angiotensin-II induced signaling in vascular smooth muscle cells (VSMC). Immunohistochemical analysis of VSMC in vitro or human umbilical arteries in vivo showed a clear cytoplasmic localization. On immunogold electron microscopy, 12-LO was found primarily associated with cytoplasmic VSMC muscle fibrils. Upon angiotensin-II treatment of cultured VSMC, immunoprecipitated 12-LO was found bound to alpha-actin, a component of the cytoplasmic myofilaments. 12-LO/alpha-actin binding was blocked by VSMC pretreatment with the 12-LO inhibitors, baicalien or esculetine and the protein synthesis inhibitor, cycloheximide. Moreover, the binding of 12-LO to alpha-actin was not associated with 12-LO serine or tyrosine phosphorylation. These observations suggest a previously unrecognized angiotensin-II dependent protein interaction in VSMC through which 12-LO protein may be trafficked, for yet undiscovered purposes towards the much more abundantly expressed cytoskeletal protein alpha-actin.
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Affiliation(s)
- Gary Weisinger
- Institute of Endocrinology, Metabolism and Hypertension, Tel Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Israel.
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Wen Y, Gu J, Chakrabarti SK, Aylor K, Marshall J, Takahashi Y, Yoshimoto T, Nadler JL. The role of 12/15-lipoxygenase in the expression of interleukin-6 and tumor necrosis factor-alpha in macrophages. Endocrinology 2007; 148:1313-22. [PMID: 17170102 DOI: 10.1210/en.2006-0665] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
12/15-lipoxygenase (12/15-LO) enzyme and products have been associated with inflammation and atherosclerosis. However, the mechanism of effects of the 12/15-LO products has not been fully clarified. To study the role of 12/15-LO in cytokine expression, experiments with direct additions of the12/15-LO products, 12(S)-hydroxyeicosa tetraenoic acid or 12(S)-hydroperoxyeicosa-5Z, 8Z, 10E, or 14Z-tetraenoic acid to macrophages were first carried out, and results showed that the 12/15-LO products stimulated mRNA and protein expression of IL-6 and TNF-alpha in a dose-dependent manner. In contrast, an inactive analogue of 12(S)-hydroxyeicosa tetraenoic acid had no effect. To further explore the role of endogenous 12/15-LO in cytokine expression, we used an in vitro and in vivo model to test the effect of 12/15-LO overexpression. The models included Plox-86 cells, a J774A.1 cell line that stably overexpresses leukocyte-type 12/15-LO and primary mouse peritoneal macrophages (MPMs) from 12/15-LO transgenic mice. The results showed a clear increase in IL-6 and TNF-alpha expression in Plox-86 cells and MPMs from 12/15-LO transgenic mice, compared with mock-transfected J774A.1 cells and MPMs from control C57BL6 mice. IL-1beta, IL-12, and monocyte chemoattractant protein (MCP)-1 mRNA were also increased in Plox-86 cells. These data clearly suggest a clear role of 12/15-LO pathway in cytokine production. We also demonstrated that signaling pathways including protein kinase C, p38 MAPK (p38), c-jun NH(2)-terminal kinase as well as nicotinamide adenine dinucleotide phosphate oxidase are important for 12-(S)-hydroxyeicosatetraenoic acid-induced increases in IL-6 and TNF-alpha gene expression. These results suggest a potentially important mechanism linking 12/15-LO activation to chronic inflammation and atherosclerosis.
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Affiliation(s)
- Yeshao Wen
- Diabetes and Hormone Center, University of Virginia, Charlottesville, VA 22908, USA
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Kang SW, Natarajan R, Shahed A, Nast CC, LaPage J, Mundel P, Kashtan C, Adler SG. Role of 12-Lipoxygenase in the Stimulation of p38 Mitogen-Activated Protein Kinase and Collagen α5(IV) in Experimental Diabetic Nephropathy and in Glucose-Stimulated Podocytes. J Am Soc Nephrol 2003; 14:3178-87. [PMID: 14638916 DOI: 10.1097/01.asn.0000099702.16315.de] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
ABSTRACT. The 12-lipoxygenase (12-LO) pathway of arachidonic acid metabolism is implicated in extracellular matrix (ECM) synthesis, but its role in podocytes has not been studied. This study tested whether 12-LO induction by diabetes or by high glucose (HG) in cultured podocytes alters glomerular basement membrane by activating signal transduction pathways culminating in ECM synthesis. Sprague-Dawley rats received an injection of diluent (control [C]) or streptozotocin 65 mg/kg (DM) and were killed at 1 or 4 mo. Glomerular 12-LO mRNA and protein levels were higher in DM than in C glomeruli at 1 and 4 mo, and 12-LO localized predominantly in podocytes. Glomerular p38 mRNA and protein were higher in DM at months 1 and 4, but phospho-p38 mitogen-activated protein (MAPK) was increased only at month 1. Glomerular collagen α5(IV)/glutaraldehyde-3-phosphate dehydrogenase (GAPDH) mRNA ratio was increased in DM at month 1 but not at month 4, whereas collagen α5(IV) protein was higher at both 1 and 4 mo. Mouse podocytes were cultured in media with 25 mM glucose (HG) with or without the 12-LO inhibitor cinnamyl-3,4-dihydroxy-cyanocinnamate (CDC) or with 5.5 mM glucose + 19.5 mM mannitol (low glucose [LG+M]) for 10 d at 37°C. 12-LO mRNA and protein levels were higher in HG than in LG+M as was the p38 MAPK/GAPDH mRNA ratio. Phospho-p38 MAPK protein but not total p38 MAPK was higher in HG compared with LG+M. Collagen α5(IV)/GAPDH mRNA ratio and protein were higher in HG than in LG+M. 12-LO inhibition by CDC decreased HG-induced phospho-p38 MAPK and the phospho-p38/total p38 MAPK ratio, collagen α5(IV)/GAPDH mRNA ratio, and collagen α5(IV) protein expression. In summary, diabetes in vivo and exposure of podocytes to HG in vitro stimulated 12-LO, p38 MAPK, and collagen α5(IV) mRNA and (activated) protein. 12-LO inhibition by CDC diminished the expression of podocyte phospho-p38 MAPK and collagen α5(IV) mRNA and protein. These findings implicate 12-LO and the p38 MAPK signaling pathway in the mediation of ECM synthesis by podocytes in diabetes.
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Affiliation(s)
- Shin-Wook Kang
- Division of Nephrology and Hypertension, Department of Internal Medicine, Harbor-UCLA Research and Education Institute, Torrance, California 90509, USA
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Gu J, Wen Y, Mison A, Nadler JL. 12-lipoxygenase pathway increases aldosterone production, 3',5'-cyclic adenosine monophosphate response element-binding protein phosphorylation, and p38 mitogen-activated protein kinase activation in H295R human adrenocortical cells. Endocrinology 2003; 144:534-43. [PMID: 12538614 DOI: 10.1210/en.2002-220580] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Evidence suggests that the 12-lipoxygenase (LO) pathway mediates angiotensin II (Ang II)-induced aldosterone synthesis in adrenal glomerulosa cells. To study the mechanisms of 12-LO pathway on aldosterone synthesis, the human adrenocortical cell line, H295R, was transiently transfected with a mouse leukocyte type of 12-LO. Overexpression of 12-LO stimulated aldosterone production 2.7-fold as well as the reporter gene activity of CYP11B2 gene-encoding human aldosterone synthase by 5-fold over that in mock-transfected cells. Ang II further enhanced aldosterone production, which could be blocked by a 12-LO inhibitor, baicalein, in mock cells and cells overexpressing 12-LO. Ang II stimulated cAMP response element-binding protein (CREB) phosphorylation in a dose- and time-dependent fashion in parent H295R cells. Overexpression of 12-LO increased phosphorylation of CREB/activating transcription factor (ATF)-1 1.5-fold over that in mock cells under basal conditions. Ang II led to a further 5.2- and 7.5-fold increase in mock cells and 12-LO cells, respectively. Overexpression of 12-LO induced p38 MAPK activation. The 12-LO product, 12-hydroxyeicosatetraenoic acid, increased phosphorylation of CREB/ATF-1 3.6-fold and phosphorylation of p38 MAPK 8-fold over basal. The p38 MAPK inhibitor SB203580 inhibited Ang II- and 12-LO pathway-induced phosphorylated CREB/ATF-1, suggesting a role of p38 MAPK in Ang II and 12-LO pathway signaling. These results suggest that 12-LO stimulation leads to aldosterone production in H295R cells in part through activation of CREB/ATF-1 and p38 MAPK pathway.
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Affiliation(s)
- Jiali Gu
- Division of Endocrinology, Department of Internal Medicine, University of Virginia, Charlottesville, Virginia 22908, USA
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Reddy MA, Adler SG, Kim YS, Lanting L, Rossi J, Kang SW, Nadler JL, Shahed A, Natarajan R. Interaction of MAPK and 12-lipoxygenase pathways in growth and matrix protein expression in mesangial cells. Am J Physiol Renal Physiol 2002; 283:F985-94. [PMID: 12372774 DOI: 10.1152/ajprenal.00181.2002] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The lipoxygenase (LO) pathway of arachidonate metabolism and mitogen-activated protein kinases (MAPKs) can mediate cellular growth and ANG II effects in vascular smooth muscle cells. However, their role in renal mesangial cells (MC) is not very clear. ANG II treatment of rat MC significantly increased 12-LO mRNA expression and formation of the 12-LO product 12(S)-hydroxyeicosatetraenoic acid [12(S)-HETE; P < 0.03]. ANG II-induced [(3)H]leucine incorporation was blocked by an LO inhibitor, cinnamyl-3,4-dihydroxy-alpha-cyanocinnamate (P < 0.02). 12(S)-HETE and ANG II directly induced cellular hypertrophy and fibronectin (FN) expression (P < 0.01) to a similar extent. ANG II and 12(S)-HETE led to activation of p38(MAPK) and its target transcription factor cAMP-responsive element-binding protein (CREB). ANG II- and 12(S)-HETE-induced CREB activation and [(3)H]leucine incorporation were blocked by the p38(MAPK) inhibitor SB-202190. A specific molecular inhibitor of rat 12-LO mRNA, namely, a novel ribozyme, could attenuate ANG II-induced FN mRNA. Thus p38(MAPK)-dependent CREB activation may mediate ANG II- and LO product-induced FN expression and cellular growth in rat MC. ANG II effects may be mediated by the LO pathway. These results suggest a novel interaction between LO and p38(MAPK) activation in MC matrix synthesis associated with renal complications.
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Affiliation(s)
- Marpadga A Reddy
- Department of Diabetes, Beckman Research Institute of the City of Hope, Duarte California 91010, USA
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14
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Penumetcha M, Khan-Merchant N, Parthasarathy S. Enhanced solubilization and intestinal absorption of cholesterol by oxidized linoleic acid. J Lipid Res 2002. [DOI: 10.1016/s0022-2275(20)30463-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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15
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Reddy MA, Thimmalapura PR, Lanting L, Nadler JL, Fatima S, Natarajan R. The oxidized lipid and lipoxygenase product 12(S)-hydroxyeicosatetraenoic acid induces hypertrophy and fibronectin transcription in vascular smooth muscle cells via p38 MAPK and cAMP response element-binding protein activation. Mediation of angiotensin II effects. J Biol Chem 2002; 277:9920-8. [PMID: 11786549 DOI: 10.1074/jbc.m111305200] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Evidence suggests that the arachidonic acid metabolite of 12-lipoxygenase, 12(S)-hydroxyeicosatetraenoic acid (12(S)-HETE), not only mediates the effects of angiotensin II (AngII), but also has direct effects on hypertrophy and matrix protein production in vascular smooth muscle cells (VSMCs). This study is aimed at identifying the signaling pathways involved in these events. Treatment of porcine VSMCs with 12(S)-HETE led to the activation of Ras and p38 MAPK. It also stimulated phosphorylation, DNA-binding activity, and transactivation of the transcription factor cAMP response element (CRE)-binding protein. In addition, 12(S)-HETE induced transcription from a fibronectin promoter containing multiple CREs. AngII also induced transactivation of CRE-binding protein and transcription from the fibronectin promoter. A specific p38 MAPK inhibitor (SB202190) as well as a dominant-negative Ras mutant (Ras-N17) blocked both 12(S)-HETE and AngII effects. In addition, inhibitors of lipoxygenase also blocked AngII effects. Both 12(S)-HETE and AngII increased cellular hypertrophy with similar potency, and this was significantly blocked by SB202190. Stable overexpression of murine leukocyte-type 12/15-lipoxygenase in VSMCs increased the levels of cell-associated 12(S)-HETE as well as basal activity of both ERK and p38 MAPKs. Furthermore, these 12-lipoxygenase-overexpressing cells displayed significantly greater cellular hypertrophy relative to mock-transfected cells. These results show for the first time that oxidized lipids such as 12(S)-HETE can induce VSMC growth and matrix gene expression and mediate growth factor effects via activation of the Ras-MAPK pathway and key target transcription factors.
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MESH Headings
- 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid/chemistry
- 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid/metabolism
- Angiotensin II/metabolism
- Animals
- Cell Nucleus/metabolism
- Cells, Cultured
- Cyclic AMP/metabolism
- Cyclic AMP Response Element-Binding Protein/metabolism
- Enzyme Activation
- Enzyme Inhibitors/pharmacology
- Fibronectins/genetics
- Fibronectins/metabolism
- Hypertrophy
- Imidazoles/pharmacology
- Immunoblotting
- Lipid Metabolism
- Lipoxygenase/metabolism
- Luciferases/metabolism
- Mice
- Mitogen-Activated Protein Kinases/metabolism
- Muscle, Smooth, Vascular/cytology
- Oxygen/metabolism
- Phosphorylation
- Promoter Regions, Genetic
- Protein Binding
- Protein Transport
- Pyridines/pharmacology
- Signal Transduction
- Swine
- Time Factors
- Transcription, Genetic
- Transfection
- p38 Mitogen-Activated Protein Kinases
- ras Proteins/metabolism
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Affiliation(s)
- Marpadga A Reddy
- Gonda Diabetes Center, Beckman Research Institute of the City of Hope, Duarte, California 91010, USA
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16
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Strawn WB. Implications physiopathologiques et cliniques des r??cepteurs AT1/AT2 de l??angiotensine II dans les pathologies m??taboliques. Drugs 2002. [DOI: 10.2165/00003495-200262991-00004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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17
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Ding XZ, Tong WG, Adrian TE. 12-lipoxygenase metabolite 12(S)-HETE stimulates human pancreatic cancer cell proliferation via protein tyrosine phosphorylation and ERK activation. Int J Cancer 2001; 94:630-6. [PMID: 11745456 DOI: 10.1002/ijc.1527] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
We previously reported that inhibition of the 12-lipoxygenase pathway abolished proliferation and induced apoptosis in several pancreatic cancer cell lines. Furthermore, the 12-lipoxygenase product 12(S)-HETE stimulated pancreatic cancer cell proliferation and reversed 12-lipoxygenase inhibitor-induced growth inhibition. We investigated the underlying mechanism for 12(S)-HETE-induced pancreatic cancer cell proliferation, using 2 human pancreatic cancer cell lines, PANC-1 and HPAF. Cell proliferation was monitored by both thymidine incorporation and cell number. Western blotting was used to investigate the effect of 12(S)-HETE on cellular protein tyrosine phosphorylation as well as ERK, P38 MAPK and JNK/SAPK phosphorylation. 12(S)-HETE markedly stimulated proliferation of pancreatic cancer cells in a time- and concentration-dependent manner. In parallel, 12(S)-HETE induced tyrosine phosphorylation of multiple cellular proteins, while inhibition of tyrosine kinase by genestein abolished 12(S)-HETE-induced proliferation, indicating that intracellular protein tyrosine kinase activation is involved in the mitogenic effects of 12(S)-HETE. Following treatment with 12(S)-HETE, both ERK and P38 MAPK, but not JNK/SAPK, were phosphorylated. The specific MEK inhibitors PD098059 and U0126, which in turn suppress ERK, abolished 12(S)-HETE-stimulated proliferation. In contrast, inhibition of P38 MAPK with SB203580 did not affect 12(S)-HETE-stimulated pancreatic cancer cell proliferation. Furthermore, 12(S)-HETE-stimulated ERK phosphorylation was inhibited by genestein, indicating that tyrosine phosphorylation is essential for ERK activation. These findings suggest that both ERK and cellular protein tyrosine kinase activation are involved in 12(S)-HETE-induced pancreatic cancer cell proliferation but P38 and JNK/SAPK are not involved in this mitogenic effect.
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Affiliation(s)
- X Z Ding
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, NE, USA
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18
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Shih NL, Cheng TH, Loh SH, Cheng PY, Wang DL, Chen YS, Liu SH, Liew CC, Chen JJ. Reactive oxygen species modulate angiotensin II-induced beta-myosin heavy chain gene expression via Ras/Raf/extracellular signal-regulated kinase pathway in neonatal rat cardiomyocytes. Biochem Biophys Res Commun 2001; 283:143-8. [PMID: 11322781 DOI: 10.1006/bbrc.2001.4744] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Angiotensin II (Ang II) causes cardiomyocytes hypertrophy. Cardiac beta-myosin heavy chain (beta-MyHC) gene expression can be altered by Ang II. The molecular mechanisms are not completely known. Reactive oxygen species (ROS) are involved in signal transduction pathways of Ang II. However, the role of ROS on Ang II-induced beta-MyHC gene expression remains unclear. Here we found that Ang II increased beta-MyHC promoter activity and it was blocked by Ang II type 1 receptor antagonist losartan. Ang II dose-dependently increased the intracellular ROS. Cardiomyocytes cotransfected with a dominant negative mutant of Ras (RasN17), Raf-1 (Raf301), or a catalytically inactive mutant of extracellular signal regulated kinase (mERK2) inhibited Ang II-induced beta-MyHC promoter activity, indicating Ras/Raf/ERK pathway was involved. Antioxidants such as catalase or N-acetyl-cysteine decreased Ang II-activated ERK phosphorylation and inhibited Ang II-induced beta-MyHC promoter activity. These data indicate that Ang II increases beta-MyHC gene expression in part via the generation of ROS.
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Affiliation(s)
- N L Shih
- Department of Internal Medicine, Medical College of National Taiwan University, Taipei, Taiwan, Republic of China
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19
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Kang SW, Adler SG, Nast CC, LaPage J, Gu JL, Nadler JL, Natarajan R. 12-lipoxygenase is increased in glucose-stimulated mesangial cells and in experimental diabetic nephropathy. Kidney Int 2001; 59:1354-62. [PMID: 11260396 DOI: 10.1046/j.1523-1755.2001.0590041354.x] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
BACKGROUND Arachidonic acid-derived 12-lipoxygenase (12-LO) products have potent growth and chemotactic properties. The present studies examined whether 12-LO and fibronectin are induced in cultured rat mesangial cells (MCs) exposed to high glucose and whether they are expressed in experimental diabetic nephropathy. METHODS To determine the effect of high glucose on MC 12-LO mRNA and protein expression, rat MCs were incubated with RPMI medium containing 100 (NG) or 450 mg/dL glucose (HG). For animal studies, rats were injected with diluent (control) or streptozotocin. The latter were left untreated (DM) or treated with insulin (DM + I). At sacrifice after four months, GAPDH, 12-LO, and fibronectin mRNA were measured by competitive reverse transcription-polymerase chain reaction (RT-PCR) in microdissected glomeruli (G). Renal sections were semiquantitatively scored (0 to 4+) for diabetic changes and for 12-LO and fibronectin by immunohistochemistry. RESULTS 12-LO mRNA expression in MC exposed to HG (12.71 +/- 1.17 attm/microL) and DM G (1.78 +/- 0.65 x 10-3 attm/glomerulus) was significantly higher than those of MCs in NG media (6.71 +/- 0.78 attm/microL) and control G (0.34 +/- 0.12 x 10-3 attm/glomerulus, P < 0.005), respectively. Western blot revealed a 1.7- and a 2.8-fold increase in MC and G 12-LO protein expression, respectively (P < 0.05). The immunohistochemistry score for G 12-LO and diabetic nephropathy score was significantly greater in DM and DM + I than controls. MC and G GAPDH mRNA remained unchanged. CONCLUSIONS In MCs exposed to HG and in diabetic rat glomeruli, increments in 12-LO mRNA and protein are associated with changes modeling diabetic nephropathy. These findings suggest a role for the 12-LO pathway in the pathogenesis of diabetic nephropathy.
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Affiliation(s)
- S W Kang
- Division of Nephrology and Hypertension, Department of Internal Medicine, Harbor-UCLA Research and Education Institute, Torrance, California, USA
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20
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Fernandes D, Vlahos R, Stewart AG. Thrombin-stimulated DNA synthesis in human cultured airway smooth muscle occurs independently of products of cyclo-oxygenase or 5-lipoxygenase. Pulm Pharmacol Ther 2001; 13:241-8. [PMID: 11001867 DOI: 10.1006/pupt.2000.0251] [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: 01/01/2023]
Abstract
Arachidonic acid (AA) liberation and metabolism via cyclo-oxygenase or lipoxygenases may be an important regulatory pathway for mitogenic signalling in human cultured airway smooth muscle (ASM) cells. In cytokine-treated cells, thrombin markedly enhances production of the anti-mitogenic arachidonic acid metabolite, PGE(2). In this study, in the absence of cytokines, we examined the role of endogenous AA metabolism in thrombin-stimulated ASM DNA synthesis. Selective inhibitors of cyclo-oxygenase of 5-lipoxygenase metabolism had no significant effect on 0.3 U/ml thrombin-stimulated DNA synthesis. However, the non-selective, redox-active lipoxygenase inhibitors NDGA and BWA4C inhibited thrombin-stimulated DNA synthesis. Under basal conditions, and following stimulation by thrombin, the levels of the AA metabolites PGE(2), TxA(2), and LTC(4), remained below assay detection limits. Exogenous addition of AA, LTD(4), or 5-, 12-, and 15-HETE and HpETE metabolites had no consistent or substantial stimulatory effect on either basal or thrombin-stimulated DNA synthesis. These data suggest that the non-selective lipoxygenase inhibitors influence DNA synthesis via effects unrelated to lipoxygenase inhibition. The lack of detection of AA metabolites, the lack of influence of selective antagonists/inhibitors of the AA pathway, and the failure of selected AA metabolites to either enhance or directly stimulate DNA synthesis suggest that in the absence of cytokines, cyclo-oxygenase and lipoxygenase metabolism has little role in signalling of human ASM DNA synthesis by thrombin.
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Affiliation(s)
- D Fernandes
- Department of Pharmacology, University of Melbourne, Melbourne, Victoria, 3010, Australia
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21
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Wei C, Cardarelli MG, Downing SW, McLaughlin JS. The effect of angiotensin II on mitogen-activated protein kinase in human cardiomyocytes. J Renin Angiotensin Aldosterone Syst 2000; 1:379-84. [PMID: 11967827 DOI: 10.3317/jraas.2000.070] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
The role of angiotensin II (Ang II)-receptors on mitogen-activated protein kinase (MAPK) activation in cardiomyocytes remains controversial. Therefore, the current study was designed to investigate the actions of AT(1)- and AT(2)-receptors on Ang II-induced extracellular signal-regulated kinase (ERK), p38 and the c-Jun N-terminal kinase (JNK) MAPK activities in human cardiomyocytes. Human cardiac tissue was obtained from open-heart surgery (n=6). The cardiac tissue was minced and incubated in the special tissue culture system for 24 hours in the absence or presence of Ang II (10(-7) M). These studies were repeated with the AT(1)-receptor antagonist losartan (10(-6) M) or the AT(2)-receptor antagonist PD-123319 (10(-6) M). Immunohistochemical staining and Western blot analysis with phospho-antibodies were performed to determine ERK, JNK and p38 activities. Ang II increased ERK and p38 activities in human cardiomyocytes. The effects of Ang II were abolished by losartan and enhanced by PD-123319. Co-incubation with both losartan and PD-123319 resulted in a decrease of ERK and p38 activities in cardiomyocytes. The immunohistochemical staining of JNK showed no significant differences between Ang II alone, Ang II plus losartan and Ang II plus PD-123319 groups. In conclusion, Ang II has a potent effect on ERK and p38 MAPK activities in cardiomyocytes, by acting through AT(1)-receptors. This effect of Ang II is modified by AT(2)-receptors. Therefore, Ang II, via AT(1)- and AT(2)-receptor stimulation, has a distinct effect on MAPK activity in cardiomyocytes.
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Affiliation(s)
- C Wei
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
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22
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Abstract
Reactive oxygen species (ROS) are generated as by-products of cellular metabolism, primarily in the mitochondria. When cellular production of ROS overwhelms its antioxidant capacity, damage to cellular macromolecules such as lipids, protein, and DNA may ensue. Such a state of "oxidative stress" is thought to contribute to the pathogenesis of a number of human diseases including those of the lung. Recent studies have also implicated ROS that are generated by specialized plasma membrane oxidases in normal physiological signaling by growth factors and cytokines. In this review, we examine the evidence for ligand-induced generation of ROS, its cellular sources, and the signaling pathways that are activated. Emerging concepts on the mechanisms of signal transduction by ROS that involve alterations in cellular redox state and oxidative modifications of proteins are also discussed.
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Affiliation(s)
- V J Thannickal
- Pulmonary and Critical Care Division, Department of Medicine, New England Medical Center/Tupper Research Institute, Tufts University School of Medicine, Boston, Massachusetts 02111, USA.
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23
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Thibonnier M, Conarty DM, Plesnicher CL. Mediators of the mitogenic action of human V(1) vascular vasopressin receptors. Am J Physiol Heart Circ Physiol 2000; 279:H2529-39. [PMID: 11045991 DOI: 10.1152/ajpheart.2000.279.5.h2529] [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
Arginine vasopressin (AVP) activation of V(1) vascular receptors (V(1)Rs) stimulates cell growth and proliferation in different tissues via cellular signaling pathways that remain to be identified. To explore the intracellular mediators of the mitogenic action of V(1)R, Chinese hamster ovary (CHO) cells were stably transfected with the human V(1)R cDNA clone we isolated previously. We assessed AVP effects on kinase activation (immunoblotting with phosphospecific antibodies), DNA synthesis (tritiated thymidine uptake), cell cycle progression (flow cytometry analysis after nuclear labeling with propidium iodide), and cell proliferation (conversion of the colorimetric reagent MTS) in the presence or absence of various pathway inhibitors. AVP stimulation of V(1)Rs leads to the phosphorylation of several kinases, an increase in DNA synthesis, a progression through the S and G(2)-M phases of the cell cycle, and an increase in cell proliferation. The mediators of the mitogenic action of V(1)R activation included calcium mobilization, coupling to a G(q) protein, and the simultaneous and parallel activation of several kinases, mainly calcium/calmodulin-dependent kinase II, phosphatidylinositol 3 kinase, protein kinase C, and p42/p44 mitogen-activated protein kinase.
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Affiliation(s)
- M Thibonnier
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106-4951, USA.
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24
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Nie D, Tang K, Szekeres K, Trikha M, Honn KV. The role of eicosanoids in tumor growth and metastasis. ERNST SCHERING RESEARCH FOUNDATION WORKSHOP 2000:201-17. [PMID: 10943334 DOI: 10.1007/978-3-662-04047-8_10] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Affiliation(s)
- D Nie
- Department of Radiation Oncology, Wayne State University, Detroit, MI 48202, USA
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25
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26
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Griendling KK, Ushio-Fukai M. Reactive oxygen species as mediators of angiotensin II signaling. REGULATORY PEPTIDES 2000; 91:21-7. [PMID: 10967199 DOI: 10.1016/s0167-0115(00)00136-1] [Citation(s) in RCA: 323] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Angiotensin II stimulates a plethora of signaling pathways leading to cell growth and contraction. Recent work has shown that reactive oxygen species are involved in transducing many of the effects of angiotensin II, and are in fact produced in response to agonist-receptor binding. Angiotensin II stimulates a NAD(P)H oxidase to produce superoxide and hydrogen peroxide, both of which may act on intracellular growth-related proteins and enzymes to mediate the final physiological response. Of particular importance is hydrogen peroxide, which mediates angiotensin II stimulation of such important intracellular signals as EGF-receptor transactivation, p38 mitogen activated protein kinase, and Akt. Future work will be directed towards identifying other important redox-sensitive signaling pathways and their relationship to the physiology and pathophysiology of the renin-angiotensin system.
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Affiliation(s)
- K K Griendling
- Division of Cardiology, School of Medicine, Emory University, 319 WMB, 1639 Pierce Drive, 30322, Atlanta, GA 30322, USA.
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27
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Wen Y, Gu J, Knaus UG, Thomas L, Gonzales N, Nadler JL. Evidence that 12-lipoxygenase product 12-hydroxyeicosatetraenoic acid activates p21-activated kinase. Biochem J 2000; 349:481-7. [PMID: 10880347 PMCID: PMC1221171 DOI: 10.1042/0264-6021:3490481] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The effect of 12-hydroxyeicosatetraenoic acid (12-HETE), an arachidonic acid metabolite of 12-lipoxygenase, to activate p21(Rac/Cdc42)-activated kinase (PAK1) was studied in a Chinese hamster ovary fibroblast cell line overexpressing the rat vascular type-1a angiotensin II receptor (CHO-AT(1a)). 12-HETE (0.1 microM) treatment induced a time-dependent activation of PAK1, with a peak effect at 10 min (335 +/- 16% of control; n=3, P<0.001). The stimulatory effect of 12-HETE on PAK1 activity was dose-dependent, with the maximal activation at 0.01 microM (350+/-15% of control; n=3, P<0.001). A PAK1 fragment encoding the Cdc42/Rac binding domain (amino acid residues 67-150 of hPAK1 termed PBD), was transfected into CHO-AT(1a) cells. PBD transfection markedly reduced 12-HETE-induced PAK1 activation. Furthermore, transfection of dominant negative Cdc42 and Rac1 inhibited 12-HETE-induced PAK1, strongly suggesting that Cdc42 and Rac1 are the upstream activators of 12-HETE-induced PAK1 activation. Low concentrations (1.5 microM) of LY294002, a highly specific inhibitor of phosphoinositide 3-kinase (PI-3K), abolished 12-HETE-induced PAK1 activation, suggesting that PI-3K activation is upstream of 12-HETE-induced PAK1 activation. Transfection of dominant negative PAK1 blocked 12-HETE-induced PAK1, cJun N-terminal kinase (JNK1) and extracellular-signal-regulated kinase (ERK) activity, while transfection of constitutively active PAK1 stimulated PAK1, JNK1 and ERK activity, suggesting that PAK1 is an upstream activator of 12-HETE-induced JNK1 and ERK activation in these cells. We conclude that 12-HETE can activate Cdc42, Rac1 and PI-3K, which then participate as upstream signalling molecules for PAK1 and JNK1 activation.
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Affiliation(s)
- Y Wen
- Division of Endocrinology and Metabolism, University of Virginia Health Sciences Center, MR4 Building Room 5150, Lane Road, Charlottesville, VA 22908, USA
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28
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Abstract
The free radical nitric oxide (NO) has emerged in recent years as a fundamental signaling molecule for the maintenance of homeostasis, as well as a potent cytotoxic effector involved in the pathogenesis of a wide range of human diseases. Although this paradoxical fate has generated confusion, separating the biological actions of NO on the basis of its physiologic chemistry provides a conceptual framework which helps to distinguish between the beneficial and toxic consequences of NO, and to envision potential therapeutic strategies for the future. Under normal conditions, NO produced in low concentration acts as a messenger and cytoprotective (antioxidant) factor, via direct interactions with transition metals and other free radicals. Alternatively, when the circumstances allow the formation of substantial amounts of NO and modify the cellular microenvironment (formation of the superoxide radical), the chemistry of NO will turn into indirect effects consecutive to the formation of dinitrogen trioxide and peroxynitrite. These "reactive nitrogen species" will, in turn, mediate both oxidative and nitrosative stresses, which form the basis of the cytotoxicity generally attributed to NO, relevant to the pathophysiology of inflammation, circulatory shock, and ischemia-reperfusion injury.
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Affiliation(s)
- L Liaudet
- Division of Pulmonary Biology, Children's Hospital Research Foundation, Cincinnati, OH, USA
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29
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Nie D, Tang K, Szekeres K, Li L, Honn KV. Eicosanoid regulation of angiogenesis in human prostate carcinoma and its therapeutic implications. Ann N Y Acad Sci 2000; 905:165-76. [PMID: 10818452 DOI: 10.1111/j.1749-6632.2000.tb06548.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Cancer of the prostate is the most commonly diagnosed cancer in America. There are several lines of evidence implicating the involvement of arachidonate 12-lipoxygenase, an enzyme metabolizing arachidonic acid to form 12(S)-hydroxyeicosatetraenoic acid (HETE), in prostate cancer progression. First, as prostate cancer reaches a more advanced stage, the level of 12-lipoxygenase expression is increased. Second, overexpression of 12-lipoxygenase in human prostate cancer cells stimulates angiogenesis and tumor growth. Third, an inhibitor of 12-lipoxygenase has been found effective against metastatic prostate tumor growth, and the inhibition of 12-lipoxygenase is related with the reduction of tumor angiogenesis. Collectively, these studies suggest that 12-lipoxygenase regulates tumor angiogenesis in prostate cancer and that inhibition of 12-lipoxygenase is a novel therapeutic approach for the treatment of prostate cancers.
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Affiliation(s)
- D Nie
- Department of Radiation Oncology, Wayne State University, Detroit, Michigan 48202, USA
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30
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Patel RP, McAndrew J, Sellak H, White CR, Jo H, Freeman BA, Darley-Usmar VM. Biological aspects of reactive nitrogen species. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1411:385-400. [PMID: 10320671 DOI: 10.1016/s0005-2728(99)00028-6] [Citation(s) in RCA: 353] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Nitric oxide (NO) plays an important role as a cell-signalling molecule, anti-infective agent and, as most recently recognised, an antioxidant. The metabolic fate of NO gives rise to a further series of compounds, collectively known as the reactive nitrogen species (RNS), which possess their own unique characteristics. In this review we discuss this emerging aspect of the NO field in the context of the formation of the RNS and what is known about their effects on biological systems. While much of the insight into the RNS has been gained from the extensive chemical characterisation of these species, to reveal biological consequences this approach must be complemented by direct measures of physiological function. Although we do not know the consequences of many of the dominant chemical reactions of RNS an intriguing aspect is now emerging. This review will illustrate how, when specificity and amplification through cell signalling mechanisms are taken into account, the less significant reactions, in terms of yield or rates, can explain many of the biological responses of exposure of cells or physiological systems to RNS.
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Affiliation(s)
- R P Patel
- Center for Free Radical Biology, University of Alabama at Birmingham, Volker Hall Room GO38, 1670 University Boulevard, Birmingham, AL 35294-0019, USA
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31
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Lazou A, Sugden PH, Clerk A. Activation of mitogen-activated protein kinases (p38-MAPKs, SAPKs/JNKs and ERKs) by the G-protein-coupled receptor agonist phenylephrine in the perfused rat heart. Biochem J 1998; 332 ( Pt 2):459-65. [PMID: 9601075 PMCID: PMC1219501 DOI: 10.1042/bj3320459] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We investigated the ability of phenylephrine (PE), an alpha-adrenergic agonist and promoter of hypertrophic growth in the ventricular myocyte, to activate the three best-characterized mitogen-activated protein kinase (MAPK) subfamilies, namely p38-MAPKs, SAPKs/JNKs (i.e. stress-activated protein kinases/c-Jun N-terminal kinases) and ERKs (extracellularly responsive kinases), in perfused contracting rat hearts. Perfusion of hearts with 100 microM PE caused a rapid (maximal at 10 min) 12-fold activation of two p38-MAPK isoforms, as measured by subsequent phosphorylation of a p38-MAPK substrate, recombinant MAPK-activated protein kinase 2 (MAPKAPK2). This activation coincided with phosphorylation of p38-MAPK. Endogenous MAPKAPK2 was activated 4-5-fold in these perfusions and this was inhibited completely by the p38-MAPK inhibitor, SB203580 (10 microM). Activation of p38-MAPK and MAPKAPK2 was also detected in non-contracting hearts perfused with PE, indicating that the effects were not dependent on the positive inotropic/chronotropic properties of the agonist. Although SAPKs/JNKs were also rapidly activated, the activation (2-3-fold) was less than that of p38-MAPK. The ERKs were activated by perfusion with PE and the activation was at least 50% of that seen with 1 microM PMA, the most powerful activator of the ERKs yet identified in cardiac myocytes. These results indicate that, in addition to the ERKs, two MAPK subfamilies, whose activation is more usually associated with cellular stresses, are activated by the Gq/11-protein-coupled receptor (Gq/11PCR) agonist, PE, in whole hearts. These data indicate that Gq/11PCR agonists activate multiple MAPK signalling pathways in the heart, all of which may contribute to the overall response (e.g. the development of the hypertrophic phenotype).
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Affiliation(s)
- A Lazou
- Laboratory of Animal Physiology, Department of Zoology, School of Biology, Aristotelian University of Thessaloniki, Thessaloniki 54006, Greece
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