1
|
Delaitre C, Boisbrun M, Lecat S, Dupuis F. Targeting the Angiotensin II Type 1 Receptor in Cerebrovascular Diseases: Biased Signaling Raises New Hopes. Int J Mol Sci 2021; 22:ijms22136738. [PMID: 34201646 PMCID: PMC8269339 DOI: 10.3390/ijms22136738] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Revised: 06/17/2021] [Accepted: 06/20/2021] [Indexed: 12/20/2022] Open
Abstract
The physiological and pathophysiological relevance of the angiotensin II type 1 (AT1) G protein-coupled receptor no longer needs to be proven in the cardiovascular system. The renin–angiotensin system and the AT1 receptor are the targets of several classes of therapeutics (such as angiotensin converting enzyme inhibitors or angiotensin receptor blockers, ARBs) used as first-line treatments in cardiovascular diseases. The importance of AT1 in the regulation of the cerebrovascular system is also acknowledged. However, despite numerous beneficial effects in preclinical experiments, ARBs do not induce satisfactory curative results in clinical stroke studies. A better understanding of AT1 signaling and the development of biased AT1 agonists, able to selectively activate the β-arrestin transduction pathway rather than the Gq pathway, have led to new therapeutic strategies to target detrimental effects of AT1 activation. In this paper, we review the involvement of AT1 in cerebrovascular diseases as well as recent advances in the understanding of its molecular dynamics and biased or non-biased signaling. We also describe why these alternative signaling pathways induced by β-arrestin biased AT1 agonists could be considered as new therapeutic avenues for cerebrovascular diseases.
Collapse
Affiliation(s)
- Céline Delaitre
- CITHEFOR, Université de Lorraine, F-54000 Nancy, France;
- Biotechnologie et Signalisation Cellulaire, UMR7242 CNRS/Université de Strasbourg, 300 Boulevard Sébastien Brant, CS 10413, CEDEX, 67412 Illkirch-Graffenstaden, France;
| | | | - Sandra Lecat
- Biotechnologie et Signalisation Cellulaire, UMR7242 CNRS/Université de Strasbourg, 300 Boulevard Sébastien Brant, CS 10413, CEDEX, 67412 Illkirch-Graffenstaden, France;
| | - François Dupuis
- CITHEFOR, Université de Lorraine, F-54000 Nancy, France;
- Correspondence: ; Tel.: +33-372747272
| |
Collapse
|
2
|
de Queiroz DB, Ramos-Alves FE, Santos-Rocha J, Duarte GP, Xavier FE. Losartan reverses COX-2-dependent vascular dysfunction in offspring of hyperglycaemic rats. Life Sci 2017; 184:71-80. [PMID: 28712765 DOI: 10.1016/j.lfs.2017.07.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 07/11/2017] [Accepted: 07/12/2017] [Indexed: 12/16/2022]
Abstract
AIMS This study examined whether chronic treatment with losartan, an angiotensin II type 1 receptor (AT1R) antagonist, might reverse COX-2-mediated vascular dysfunction in mesenteric resistance arteries (MRA) from offspring of hyperglycaemic rats. MATERIALS AND METHODS Male 12-month-old offspring of hyperglycaemic (O-DR) and normoglycaemic (O-CR) rats were treated with losartan (15mg·kg·day-1) during 2months. Third order MRA of untreated and losartan-treated O-DR and O-CR were mounted in wire myograph for isometric tension measurements. COX-2 expression was analyzed by Western blot; TxA2, PGE2 and PGF2α release was measured using commercial kits. KEY FINDINGS O-DR showed increased blood pressure, impaired acetylcholine-induced vasodilation and increased noradrenaline-induced vasoconstriction than O-CR. All these parameters were normalized by losartan in O-DR. Pre-incubation of MRA with indomethacin (COX-1/2 inhibitor), NS-398 (COX-2 inhibitor) or tempol (superoxide dismutase mimetic) increased relaxation to acetylcholine and reduced contraction to noradrenaline only in O-DR. COX-2 expression, TxA2, PGE2 and PGF2α release were increased in O-DR. In losartan-treated O-DR, NS-398, indomethacin or tempol failed to produce any effect on acetylcholine or noradrenaline responses. Losartan treatment reduced COX-2 expression, TxA2, PGE2 and PGF2α release in O-DR. SIGNIFICANCE The present results reveal that chronic losartan administration in O-DR normalizes endothelial function in MRA by correcting the existing COX-2 overexpression and the imbalance between endothelium-derived relaxing and contracting factors. These findings not only support the beneficial effects of AT1 receptor antagonist in O-DR, but also suggest the implication of angiotensin II as a putative mediator of hyperglycemia-programmed vascular dysfunction in rats.
Collapse
Affiliation(s)
| | | | - Juliana Santos-Rocha
- Departamento de Fisiologia e Farmacologia, Universidade Federal de Pernambuco, Recife, Brazil
| | - Gloria Pinto Duarte
- Departamento de Fisiologia e Farmacologia, Universidade Federal de Pernambuco, Recife, Brazil
| | - Fabiano Elias Xavier
- Departamento de Fisiologia e Farmacologia, Universidade Federal de Pernambuco, Recife, Brazil.
| |
Collapse
|
3
|
Abstract
Nuclear lipid signaling is an established, widespread mechanism that operates in multiple cellular processes including proliferative and differentiative responses to a variety of stimuli. In this literature review with key references highlighted, we put forward the hypothesis that differential flow through various intracrine mechanisms can dictate resultant cellular actions such as mitosis, differentiation, or apoptosis.
Collapse
Affiliation(s)
- R S Gilmour
- Liggins Institute and Department of Pharmacology & Clinical Pharmacology, University of Auckland, Faculty of Medical and Health Sciences, New Zealand
| | | |
Collapse
|
4
|
Halici Z, Polat B, Cadirci E, Topcu A, Karakus E, Kose D, Albayrak A, Bayir Y. Inhibiting renin angiotensin system in rate limiting step by aliskiren as a new approach for preventing indomethacin induced gastric ulcers. Chem Biol Interact 2016; 258:266-75. [DOI: 10.1016/j.cbi.2016.09.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Revised: 09/07/2016] [Accepted: 09/15/2016] [Indexed: 01/01/2023]
|
5
|
Westphal E, Pilowski C, Koch S, Ebelt H, Müller-Werdan U, Werdan K, Loppnow H. Endotoxin-activated cultured neonatal rat cardiomyocytes express functional surface-associated interleukin-1α. ACTA ACUST UNITED AC 2016; 13:25-34. [PMID: 17621543 DOI: 10.1177/0968051907078609] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Interleukin-1 (IL-1) is a potent regulator of cardiovascular proliferation, apoptosis, contraction or production of inflammatory mediators. Thus, we investigated expression and function of IL-1 in cultured neonatal rat heart cells upon endotoxin stimulation. We show that cultured neonatal rat cardiomyocytes expressed IL—1α and IL—1β mRNA. The cells expressed functional cell-associated IL—1 activity and a specific anti-IL—1α-antibody inhibited the activity. Biologically active IL—1α was present at the cell surface of the cardiomyocytes, as indicated in co-culture experiments. Immunohistochemistry showed IL—1α-staining of the neonatal cardiomyocytes. Although the cells also expressed IL—1β mRNA, we did not detect IL—1β in the supernatants of cultured cardiomyocytes by ELISA or in immunohistochemical staining. Furthermore, neonatal and adult rat heart tissues expressed IL—1α mRNA, whereas fetal, but not adult, human cardiac tissues expressed detectable IL—1α mRNA. In contrast, IL-1β mRNA was present in rat and human fetal and adult samples. Furthermore, in patients with dilated or ischemic cardiomyopathy, we measured IL—1β, but not IL—1α, mRNA. These results provide evidence for the presence of functionally active IL—1α on the cell surface of neonatal rat cardiomyocytes and may suggest a differential role of IL—1α in regulation of cellular functions during development, aging and disease in rat and human heart cells.
Collapse
Affiliation(s)
- Elena Westphal
- Martin-Luther-Universität Halle-Wittenberg, Universitätsklinik und Poliklinik für Innere Medizin III, Halle, Germany
| | | | | | | | | | | | | |
Collapse
|
6
|
Toussaint F, Charbel C, Allen BG, Ledoux J. Vascular CaMKII: heart and brain in your arteries. Am J Physiol Cell Physiol 2016; 311:C462-78. [PMID: 27306369 DOI: 10.1152/ajpcell.00341.2015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 06/14/2016] [Indexed: 01/02/2023]
Abstract
First characterized in neuronal tissues, the multifunctional calcium/calmodulin-dependent protein kinase II (CaMKII) is a key signaling component in several mammalian biological systems. Its unique capacity to integrate various Ca(2+) signals into different specific outcomes is a precious asset to excitable and nonexcitable cells. Numerous studies have reported roles and mechanisms involving CaMKII in brain and heart tissues. However, corresponding functions in vascular cell types (endothelium and vascular smooth muscle cells) remained largely unexplored until recently. Investigation of the intracellular Ca(2+) dynamics, their impact on vascular cell function, the regulatory processes involved and more recently the spatially restricted oscillatory Ca(2+) signals and microdomains triggered significant interest towards proteins like CaMKII. Heteromultimerization of CaMKII isoforms (four isoforms and several splice variants) expands this kinase's peculiar capacity to decipher Ca(2+) signals and initiate specific signaling processes, and thus controlling cellular functions. The physiological functions that rely on CaMKII are unsurprisingly diverse, ranging from regulating contractile state and cellular proliferation to Ca(2+) homeostasis and cellular permeability. This review will focus on emerging evidence of CaMKII as an essential component of the vascular system, with a focus on the kinase isoform/splice variants and cellular system studied.
Collapse
Affiliation(s)
- Fanny Toussaint
- Research Center, Montreal Heart Institute, Montreal, Quebec, Canada; Department of Molecular and Integrative Physiology, Université de Montréal, Montreal Quebec, Canada
| | - Chimène Charbel
- Research Center, Montreal Heart Institute, Montreal, Quebec, Canada; Department of Pharmacology, Université de Montréal, Montreal Quebec, Canada
| | - Bruce G Allen
- Research Center, Montreal Heart Institute, Montreal, Quebec, Canada; Department of Medicine, Université de Montréal, Montreal Quebec, Canada; and Department of Biochemistry and Molecular Medicine, Université de Montréal, Montreal Quebec, Canada
| | - Jonathan Ledoux
- Research Center, Montreal Heart Institute, Montreal, Quebec, Canada; Department of Medicine, Université de Montréal, Montreal Quebec, Canada; and
| |
Collapse
|
7
|
Quadri SS, Culver SA, Li C, Siragy HM. Interaction of the renin angiotensin and cox systems in the kidney. Front Biosci (Schol Ed) 2016; 8:215-26. [PMID: 27100703 DOI: 10.2741/s459] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Cyclooxygenase-2 (COX-2) plays an important role in mediating actions of the renin-angiotensin system (RAS). This review sheds light on the recent developments regarding the complex interactions between components of RAS and COX-2; and their implications on renal function and disease. COX-2 is believed to counter regulate the effects of RAS activation and therefore counter balance the vasoconstriction effect of Ang II. In kidney, under normal conditions, these systems are essential for maintaining a balance between vasodilation and vasoconstriction. However, recent studies suggested a pivotal role for this interplay in pathology. COX-2 increases the renin release and Ang II formation leading to increase in blood pressure. COX-2 is also associated with diabetic nephropathy, where its upregulation in the kidney contributes to glomerular injury and albuminuria. Selective inhibition of COX-2 retards the progression of renal injury. COX-2 also mediates the pathologic effects of the (Pro)renin receptor (PRR) in the kidney. In summary, this review discusses the interaction between the RAS and COX-2 in health and disease.
Collapse
Affiliation(s)
- Syed S Quadri
- Division of Endocrinology and Metabolism, University of Virginia Health System, Charlottesville, VA
| | - Silas A Culver
- Division of Endocrinology and Metabolism, University of Virginia Health System, Charlottesville, VA
| | - Caixia Li
- Division of Endocrinology and Metabolism, University of Virginia Health System, Charlottesville, VA
| | - Helmy M Siragy
- Division of Endocrinology and Metabolism, University of Virginia Health System, Charlottesville, VA,
| |
Collapse
|
8
|
Khan NS, Song CY, Jennings BL, Estes AM, Fang XR, Bonventre JV, Malik KU. Cytosolic phospholipase A2α is critical for angiotensin II-induced hypertension and associated cardiovascular pathophysiology. Hypertension 2015; 65:784-92. [PMID: 25667212 DOI: 10.1161/hypertensionaha.114.04803] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Angiotensin II activates cytosolic phospholipase A(2)α (cPLA2α) and releases arachidonic acid from tissue phospholipids, which mediate or modulate ≥1 cardiovascular effects of angiotensin II and has been implicated in hypertension. Because arachidonic acid release is the rate limiting step in eicosanoid production, cPLA2α might play a central role in the development of angiotensin II-induced hypertension. To test this hypothesis, we investigated the effect of angiotensin II infusion for 13 days by micro-osmotic pumps on systolic blood pressure and associated pathogenesis in wild type (cPLA2α(+/+)) and cPLA2α(-/-) mice. Angiotensin II-induced increase in systolic blood pressure in cPLA2α(+/+) mice was abolished in cPLA2α(-/-) mice; increased systolic blood pressure was also abolished by the arachidonic acid metabolism inhibitor, 5,8,11,14-eicosatetraynoic acid in cPLA2α(+/+) mice. Angiotensin II in cPLA2α(+/+) mice increased cardiac cPLA2 activity and urinary eicosanoid excretion, decreased cardiac output, caused cardiovascular remodeling with endothelial dysfunction, and increased vascular reactivity in cPLA2α(+/+) mice; these changes were diminished in cPLA2α(-/-) mice. Angiotensin II also increased cardiac infiltration of F4/80(+) macrophages and CD3(+) T lymphocytes, cardiovascular oxidative stress, expression of endoplasmic reticulum stress markers p58(IPK), and CHOP in cPLA2α(+/+) but not cPLA2α(-/-) mice. Angiotensin II increased cardiac activity of ERK1/2 and cSrc in cPLA2α(+/+) but not cPLA2α(-/-) mice. These data suggest that angiotensin II-induced hypertension and associated cardiovascular pathophysiological changes are mediated by cPLA2α activation, most likely through the release of arachidonic acid and generation of eicosanoids with predominant prohypertensive effects and activation of ≥1 signaling molecules, including ERK1/2 and cSrc.
Collapse
Affiliation(s)
- Nayaab S Khan
- From the Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN (N.S.K., C.Y.S., B.L.J., A.M.E., X.R.F., K.U.M.); and Renal Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Harvard Institute of Medicine, Boston, MA (J.V.B.)
| | - Chi Young Song
- From the Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN (N.S.K., C.Y.S., B.L.J., A.M.E., X.R.F., K.U.M.); and Renal Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Harvard Institute of Medicine, Boston, MA (J.V.B.)
| | - Brett L Jennings
- From the Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN (N.S.K., C.Y.S., B.L.J., A.M.E., X.R.F., K.U.M.); and Renal Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Harvard Institute of Medicine, Boston, MA (J.V.B.)
| | - Anne M Estes
- From the Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN (N.S.K., C.Y.S., B.L.J., A.M.E., X.R.F., K.U.M.); and Renal Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Harvard Institute of Medicine, Boston, MA (J.V.B.)
| | - Xiao R Fang
- From the Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN (N.S.K., C.Y.S., B.L.J., A.M.E., X.R.F., K.U.M.); and Renal Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Harvard Institute of Medicine, Boston, MA (J.V.B.)
| | - Joseph V Bonventre
- From the Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN (N.S.K., C.Y.S., B.L.J., A.M.E., X.R.F., K.U.M.); and Renal Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Harvard Institute of Medicine, Boston, MA (J.V.B.)
| | - Kafait U Malik
- From the Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN (N.S.K., C.Y.S., B.L.J., A.M.E., X.R.F., K.U.M.); and Renal Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Harvard Institute of Medicine, Boston, MA (J.V.B.).
| |
Collapse
|
9
|
Nardicchi V, Ferrini M, Pilolli F, Angeli EB, Persichetti E, Beccari T, Mannucci R, Arcuri C, Donato R, Dorman RV, Goracci G. NGF Induces the Expression of Group IIA Secretory Phospholipase A2 in PC12 Cells: The Newly Synthesized Enzyme Is Addressed to Growing Neurites. Mol Neurobiol 2014; 50:15-25. [DOI: 10.1007/s12035-013-8621-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2013] [Accepted: 12/15/2013] [Indexed: 12/31/2022]
|
10
|
Frolov A, Dong H, Jiang M, Yang L, Cook EC, Matnani R, Hammock BD, Crofford LJ. Niemann-pick type C2 deficiency in human fibroblasts confers robust and selective activation of prostaglandin E2 biosynthesis. J Biol Chem 2013; 288:23696-703. [PMID: 23814065 DOI: 10.1074/jbc.m112.445916] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Activated fibroblasts, also known as myofibroblasts, are mediators of several major human pathologies including proliferative fibrotic disorders, invasive tumor growth, rheumatoid arthritis, and atherosclerosis. We previously identified Niemann-Pick type C2 (NPC2) protein as a negative regulator of fibroblast activation (Csepeggi, C., Jiang, M., Kojima, F., Crofford, L. J., and Frolov, A. (2011) J. Biol. Chem. 286, 2078-2087). Here we report that NPC2-deficiency leads to a dramatic up-regulation of the arachidonic acid (AA) metabolic pathway in human fibroblasts. The major enzymes in this pathway, cPLA2 type IVA, COX-2, and mPGES-1, were dramatically up-regulated at both the transcriptional and translational levels. The specific phenotypic changes resulted in a >10-fold increase in the production and secretion of a key modulator of inflammation and immunity, prostaglandin E2. More importantly, AA metabolome profiling by liquid chromatography/tandem mass-spectrometry revealed the very specific nature of prostaglandin E2 up-regulation as the other analyzed AA metabolites derived from the COX-2, cytochrome P450, 5/15-lipoxygenase, and non-enzymatic oxidative pathways were mostly down-regulated. Blocking activity of cPLA2 efficiently suppressed expression of inflammatory cytokines, IL-1β and IL-6, thereby identifying cPLA2 as an important regulator of the inflammatory program in NPC2-null cells. Altogether, these studies highlight NPC2 as a specific regulator of AA metabolism and inflammation that suggests potential for NPC2 protein or its related signaling in the treatment of inflammatory diseases characterized by the presence of activated fibroblasts.
Collapse
Affiliation(s)
- Andrey Frolov
- Division of Rheumatology, Department of Internal Medicine, University of Kentucky, Lexington, Kentucky 40536, USA.
| | | | | | | | | | | | | | | |
Collapse
|
11
|
Roghair RD, Volk KA, Lamb FS, Segar JL. Impact of maternal dexamethasone on coronary PGE(2) production and prostaglandin-dependent coronary reactivity. Am J Physiol Regul Integr Comp Physiol 2012; 303:R513-9. [PMID: 22832534 DOI: 10.1152/ajpregu.00658.2011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Intrauterine growth restriction is associated with increased fetal glucocorticoid exposure and an increased risk of adult coronary artery disease. Coronary arteries from sheep exposed to early gestation dexamethasone (Dex) have increased constriction to angiotensin II (ANG II). Prostaglandin E(2) (PGE(2)) helps maintain coronary dilation, but PGE(2) production is acutely decreased by Dex administration. We hypothesized early gestation Dex exposure impairs adult coronary PGE(2) production with subsequent increases in coronary reactivity. Dex was administered to ewes at 27-28 days gestation (term 145 days). Coronary reactivity was assessed by wire myography in offspring at 4 mo of age (N = 5 to 7). Coronary smooth muscle cells were cultured and prostaglandin production was measured after 90 min incubation with radiolabeled arachidonate. Coronary myocytes from Dex-exposed lambs had a significant decrease in PGE(2) production that was reversed with ANG II incubation. Dex-exposed coronary arteries had increased constriction to ANG II and attenuated dilatation to arachidonic acid, with the greatest difference seen after the endothelium was inactivated by rubbing. Preincubation with the cyclooxygenase (COX) inhibitor indomethacin altered control responses and recapitulated the heightened coronary tone seen following Dex exposure. We conclude that impaired coronary smooth muscle COX-mediated PGE(2) production contributes to the coronary dysfunction elicited by early gestation Dex. Programmed inhibition of vasodilatory prostanoid production may link an adverse intrauterine environment with adult coronary artery disease.
Collapse
Affiliation(s)
- Robert D Roghair
- Department of Pediatrics, 1270 CBRB, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA.
| | | | | | | |
Collapse
|
12
|
Calderon LE, Liu S, Su W, Xie Z, Guo Z, Eberhard W, Gong MC. iPLA2β overexpression in smooth muscle exacerbates angiotensin II-induced hypertension and vascular remodeling. PLoS One 2012; 7:e31850. [PMID: 22363752 PMCID: PMC3282780 DOI: 10.1371/journal.pone.0031850] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2011] [Accepted: 01/13/2012] [Indexed: 12/12/2022] Open
Abstract
Objectives Calcium independent group VIA phospholipase A2 (iPLA2β) is up-regulated in vascular smooth muscle cells in some diseases, but whether the up-regulated iPLA2β affects vascular morphology and blood pressure is unknown. The current study addresses this question by evaluating the basal- and angiotensin II infusion-induced vascular remodeling and hypertension in smooth muscle specific iPLA2β transgenic (iPLA2β -Tg) mice. Method and Results Blood pressure was monitored by radiotelemetry and vascular remodeling was assessed by morphologic analysis. We found that the angiotensin II-induced increase in diastolic pressure was significantly higher in iPLA2β-Tg than iPLA2β-Wt mice, whereas, the basal blood pressure was not significantly different. The media thickness and media∶lumen ratio of the mesenteric arteries were significantly increased in angiotensin II-infused iPLA2β-Tg mice. Analysis revealed no difference in vascular smooth muscle cell proliferation. In contrast, adenovirus-mediated iPLA2β overexpression in cultured vascular smooth muscle cells promoted angiotensin II-induced [3H]-leucine incorporation, indicating enhanced hypertrophy. Moreover, angiotensin II infusion-induced c-Jun phosphorylation in vascular smooth muscle cells overexpressing iPLA2β to higher levels, which was abolished by inhibition of 12/15 lipoxygenase. In addition, we found that angiotensin II up-regulated the endogenous iPLA2β protein in-vitro and in-vivo. Conclusion The present study reports that iPLA2β up-regulation exacerbates angiotensin II-induced vascular smooth muscle cell hypertrophy, vascular remodeling and hypertension via the 12/15 lipoxygenase and c-Jun pathways.
Collapse
MESH Headings
- Angiotensin II/administration & dosage
- Angiotensin II/pharmacology
- Animals
- Aorta, Thoracic/drug effects
- Aorta, Thoracic/physiopathology
- Arachidonate 15-Lipoxygenase
- Arachidonic Acid/metabolism
- Blood Pressure/drug effects
- Cell Proliferation/drug effects
- Diastole/drug effects
- Group VI Phospholipases A2/metabolism
- Hypertension/enzymology
- Hypertension/pathology
- Hypertension/physiopathology
- Hypertrophy
- Leucine/metabolism
- Mesenteric Arteries/drug effects
- Mesenteric Arteries/physiopathology
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/enzymology
- Muscle, Smooth, Vascular/pathology
- Muscle, Smooth, Vascular/physiopathology
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/enzymology
- Myocytes, Smooth Muscle/pathology
- Organ Specificity/drug effects
- Proto-Oncogene Proteins c-jun/metabolism
- Rats
- Signal Transduction/drug effects
- p38 Mitogen-Activated Protein Kinases/metabolism
Collapse
Affiliation(s)
- Lindsay E. Calderon
- Department of Molecular and Biomedical Pharmacology, University of Kentucky, Lexington, Kentucky, United States of America
| | - Shu Liu
- Department of Internal Medicine, University of Kentucky, Lexington, Kentucky, United States of America
| | - Wen Su
- Department of Internal Medicine, University of Kentucky, Lexington, Kentucky, United States of America
| | - Zhongwen Xie
- Department of Physiology, University of Kentucky, Lexington, Kentucky, United States of America
| | - Zhenheng Guo
- Department of Internal Medicine, University of Kentucky, Lexington, Kentucky, United States of America
| | - Wanda Eberhard
- Department of Physiology, University of Kentucky, Lexington, Kentucky, United States of America
| | - Ming C. Gong
- Department of Physiology, University of Kentucky, Lexington, Kentucky, United States of America
- * E-mail:
| |
Collapse
|
13
|
Ishida K, Matsumoto T, Taguchi K, Kamata K, Kobayashi T. Mechanisms underlying altered extracellular nucleotide-induced contractions in mesenteric arteries from rats in later-stage type 2 diabetes: effect of ANG II type 1 receptor antagonism. Am J Physiol Heart Circ Physiol 2011; 301:H1850-61. [PMID: 21856926 DOI: 10.1152/ajpheart.00502.2011] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Little is known about the vascular contractile responsiveness to, and signaling pathways for, extracellular nucleotides in the chronic stage of type 2 diabetes or whether the ANG II type 1 receptor blocker losartan might alter such responses. We hypothesized that nucleotide-induced arterial contractions are augmented in diabetic Goto-Kakizaki (GK) rats and that treatment with losartan would normalize the contractions. Here, we investigated the vasoconstrictor effects of ATP/UTP in superior mesenteric arteries isolated from GK rats (37-42 wk old) that had or had not received 2 wk of losartan (25 mg·kg(-1)·day(-1)). In arteries from GK rats (vs. those from Wistar rats), 1) ATP- and UTP-induced contractions, which were blocked by the nonselective P2 antagonist suramin, were enhanced, and these enhancements were suppressed by endothelial denudation, by cyclooxygenase (COX) inhibitors, or by a cytosolic phospholipase A(2) (cPLA(2)) inhibitor; 2) both nucleotides induced increased release of PGE(2) and PGF(2α); 3) nucleotide-stimulated cPLA(2) phosphorylations were increased; 4) COX-1 and COX-2 expressions were increased; and 5) neither P2Y2 nor P2Y6 receptor expression differed, but P2Y4 receptor expression was decreased. Mesenteric arteries from GK rats treated with losartan exhibited (vs. untreated GK) 1) reduced nucleotide-induced contractions, 2) suppressed UTP-induced release of PGE(2) and PGF(2α), 3) suppressed UTP-stimulated cPLA(2) phosphorylation, 4) normalized expressions of COX-2 and P2Y4 receptors, and 5) reduced superoxide generation. Our data suggest that the diabetes-related enhancement of ATP-mediated vasoconstriction was due to P2Y receptor-mediated activation of the cPLA(2)/COX pathway and, moreover, that losartan normalizes such contractions by a suppressing action within this pathway.
Collapse
Affiliation(s)
- Keiko Ishida
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University, Shinagawa-ku, Tokyo, Japan
| | | | | | | | | |
Collapse
|
14
|
Hedayat M, Mahmoudi MJ, Rose NR, Rezaei N. Proinflammatory cytokines in heart failure: double-edged swords. Heart Fail Rev 2011; 15:543-62. [PMID: 20405319 DOI: 10.1007/s10741-010-9168-4] [Citation(s) in RCA: 146] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Increased circulating and intracardiac levels of proinflammatory cytokines have been associated with chronic heart failure. Following an initial insult, the increased production of proinflammatory cytokines, including TNF-α, IL-6, IL-1, and IL-18, jeopardizes the surrounding tissue through propagation of the inflammatory response and direct effects on the cardiac myocyte structure and function. Cardiac myocyte hypertrophy, contractile dysfunction, cardiac myocyte apoptosis, and extracellular matrix remodeling contribute enormously to the development and progression of chronic heart failure. Despite the identification of efficacious pharmacological regimens and introduction of mechanical interventions, chronic heart failure remains among the leading causes of mortality worldwide. To introduce novel therapeutic strategies that modulate the inflammatory response in the context of the failing heart, it is of prime importance to determine the contributions of TNF-α, IL-6, IL-1, and IL-18 in mediating cardiac adaptive and maladaptive responses, as well as delineating their downstream intracellular signaling pathways and their potential therapeutic implications.
Collapse
Affiliation(s)
- Mona Hedayat
- Department of Internal Medicine, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | | | | | | |
Collapse
|
15
|
d'Emmanuele di Villa Bianca R, Sorrentino R, Coletta C, Mitidieri E, Rossi A, Vellecco V, Pinto A, Cirino G, Sorrentino R. Hydrogen sulfide-induced dual vascular effect involves arachidonic acid cascade in rat mesenteric arterial bed. J Pharmacol Exp Ther 2011; 337:59-64. [PMID: 21228064 DOI: 10.1124/jpet.110.176016] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Hydrogen sulfide (H(2)S), a novel gaseous transmitter, is considered a physiological regulator of vascular homeostasis. Recent evidence suggests H(2)S as an endothelium-hyperpolarizing factor (EDHF) candidate. To address this issue, we evaluated the vascular effect of sodium hydrogen sulfide (NaHS), an H(2)S donor, on the rat mesenteric arterial bed. NaHS concentration-response curve was performed on preconstricted mesenteric arterial bed. To assess the contribution of EDHF, we performed a pharmacologic dissection using indomethacin, N(G)-nitro-l-arginine methyl ester (l-NAME), or apamin and charybdotoxin as cyclooxygenase, nitric-oxide synthase, and calcium-dependent potassium channel inhibitors, respectively. In another set of experiments, we used 4-(4-octadecylphenyl)-4-oxobutenoic acid, baicalein, or proadifen as phospholipase A(2) (PLA(2)), lipoxygenase, and cytochrome P450 inhibitors, respectively. Finally, an immunofluorescence study was performed to support the involvement of PLA(2) in mesenteric artery challenged by NaHS. NaHS promoted a dual vascular effect (i.e., vasoconstriction and vasodilation). l-NAME or baicalein administration affected neither NaHS-mediated vasodilation nor vasoconstriction, whereas apamin and charybdotoxin significantly inhibited NaHS-induced relaxation. Pretreatment with PLA(2) inhibitor abolished both the contracting and the relaxant effect, whereas P450 cytochrome blocker significantly reduced NaHS-mediated relaxation. The immunofluorescence study showed that NaHS caused a migration of cytosolic PLA(2) close to the nucleus, which implicates activation of this enzyme. Our data indicate that H(2)S could activate PLA(2), which in turn releases arachidonic acid leading, initially, to vasoconstriction followed by vasodilation mediated by cytochrome P450-derived metabolites. Because EDHF has been presumed to be a cytochrome P450 derivative of the arachidonic acid, our results suggest that H(2)S acts through EHDF release.
Collapse
|
16
|
Campian ME, Verberne HJ, Hardziyenka M, de Groot EAA, van Moerkerken AF, van Eck-Smit BLF, Tan HL. Assessment of inflammation in patients with arrhythmogenic right ventricular cardiomyopathy/dysplasia. Eur J Nucl Med Mol Imaging 2010; 37:2079-85. [PMID: 20603720 PMCID: PMC2948173 DOI: 10.1007/s00259-010-1525-y] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2010] [Accepted: 06/03/2010] [Indexed: 01/25/2023]
Abstract
Purpose Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is a myocardial disease that predominantly affects the right ventricle (RV). Its hallmark feature is fibro-fatty replacement of RV myocardium. However, patchy inflammatory infiltrates in the RV are also consistently reported using autopsy and myocardial biopsy. Although the role of inflammation in ARVC/D is unresolved, the ability to assess inflammation non-invasively may aid in the diagnostic process. We aimed to establish whether cardiac inflammation can be assessed non-invasively in ARVC/D patients. Methods In eight ARVC/D patients and nine controls (haematology/oncology patients), the level of inflammatory activation was assessed by measuring plasma levels of inflammatory cytokines. Regional myocardial inflammation was assessed with 67Ga scintigraphy. Results ARVC/D patients had higher plasma levels than controls of the pro-inflammatory cytokines interleukin (IL)-1β (1.22 ± 0.07 vs 0.08 ± 0.01 pg/ml, p < 0.0001), IL-6 (3.16 ± 0.44 vs 0.38 ± 0.04 pg/ml, p < 0.0001) and tumour necrosis factor (TNF)-α (9.16 ± 0.90 vs 0.40 ± 0.06 pg/ml, p < 0.0001), while levels of the anti-inflammatory cytokine IL-10 were not significantly different (1.36 ± 0.15 vs 1.20 ± 0.30 pg/ml, p = 0.74). 67Ga uptake in the RV was higher in ARVC/D patients than in controls. In ARVC/D patients, 67Ga uptake in the RV wall was higher than in the interventricular septum or left ventricular wall. Conclusion Inflammation in the RV wall of ARVC/D patients can be detected non-invasively with the combined analysis of plasma levels of inflammatory cytokines and cardiac 67Ga scintigraphy.
Collapse
Affiliation(s)
- Maria E Campian
- University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands
| | | | | | | | | | | | | |
Collapse
|
17
|
Angiotensin II-dependent growth of vascular smooth muscle cells requires transactivation of the epidermal growth factor receptor via a cytosolic phospholipase A(2)-mediated release of arachidonic acid. Arch Biochem Biophys 2010; 498:50-6. [PMID: 20388488 DOI: 10.1016/j.abb.2010.04.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2010] [Revised: 04/06/2010] [Accepted: 04/07/2010] [Indexed: 11/19/2022]
Abstract
Angiotensin (Ang) II stimulates vascular smooth muscle cell (VSMC) growth via activation of cytosolic phospholipase A(2) (cPLA(2)), release of arachidonic acid (ArAc) and activation of mitogen-activated protein kinase (MAPK). The mechanism linking AT(1) receptor stimulation of ArAc release with MAPK activation may involve transactivation of the epidermal growth factor receptor (EGFR). In this study, Ang II increased phosphorylation of the EGFR and MAPK in cultured VSMC and these effects were attenuated by the cPLA(2) inhibitor arachidonyl trifluoromethyl ketone (AACOCF(3)), and restored by addition of ArAc. Ang II- or ArAc-induced phosphorylation of the EGFR and MAPK were abolished by the EGFR kinase inhibitor AG1478. Ang II or ArAc also stimulated VSMC growth that was blocked by AG1478 or the MAPK kinase (MEK) inhibitor PD98059. Thus, it appears that the cPLA(2)-dependent release of ArAc may provide a mechanism for the transactivation between the AT(1) receptor and the EGFR signaling cascade.
Collapse
|
18
|
De Souza AM, de Carvalho TLG, Lara LDS, Gomes-Quintana E, Lopes AG, Caruso-Neves C. The stimulatory effect of angiotensin II on Na(+)-ATPase activity involves sequential activation of phospholipases and sustained PKC activity. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2009; 1798:354-9. [PMID: 19958748 DOI: 10.1016/j.bbamem.2009.11.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2009] [Revised: 10/13/2009] [Accepted: 11/18/2009] [Indexed: 12/14/2022]
Abstract
Angiotensin II (Ang II) stimulates the proximal tubule Na(+)-ATPase through the AT(1) receptor/phosphoinositide phospholipase Cbeta (PI-PLCbeta)/protein kinase C (PKC) pathway. However, this pathway alone does not explain the sustained effect of Ang II on Na(+)-ATPase activity for 30 min. The aim of the present work was to elucidate the molecular mechanisms involved in the sustained effect of Ang II on Na(+)-ATPase activity. Ang II induced fast and correlated activation of Na(+)-ATPase and PKC activities with the maximal effect (115%) observed at 1 min and sustained for 30 min, indicating a pivotal role of PKC in the modulation of Na(+)-ATPase by Ang II. We observed that the sustained activation of PKC by Ang II depended on the sequential activation of phospholipase D and Ca(2+)-insensitive phospholipase A(2), forming phosphatidic acid and lysophosphatidic acid, respectively. The results indicate that PKC could be the final target and an integrator molecule of different signaling pathways triggered by Ang II, which could explain the sustained activation of Na(+)-ATPase by Ang II.
Collapse
Affiliation(s)
- Aloa Machado De Souza
- Instituto Federal de Educação Ciência e Tecnologia do Rio de Janeiro, Lúcio Tavares 1045, 26350-060 Centro, Nilópolis, Rio de Janeiro, Brazil
| | | | | | | | | | | |
Collapse
|
19
|
Ebermann L, Piper C, Kühl U, Klingel K, Schlattner U, Siafarikas N, Zeichhardt H, Schultheiss HP, Dörner A. Impact of myocardial inflammation on cytosolic and mitochondrial creatine kinase activity and expression. Basic Res Cardiol 2009; 104:247-57. [PMID: 19190956 DOI: 10.1007/s00395-008-0773-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2008] [Accepted: 12/05/2008] [Indexed: 11/26/2022]
Abstract
The disturbance of myocardial energy metabolism has been discussed as contributing to the progression of heart failure. Little however is known about the cardiac mitochondrial/cytosolic energy transfer in murine and human inflammatory heart disease. We examined the myocardial creatine kinase (CK) system, which connects mitochondrial ATP-producing and cytosolic ATP-consuming processes and is thus of central importance to the cellular energy homeostasis. The time course of expression and enzymatic activity of mitochondrial (mtCK) and cytosolic CK (cytCK) was investigated in Coxsackievirus B3 (CVB3)-infected SWR mice, which are susceptible to the development of chronic myocarditis. In addition, cytCK activity and isoform expression were analyzed in biopsies from patients with chronic inflammatory heart disease (n = 22). Cardiac CVB3 titer in CVB3-infected mice reached its maximum at 4 days post-infection (pi) and became undetectable at 28 days pi; cardiac inflammation cumulated 14 days pi but persisted through the 28-day survey. MtCK enzymatic activity was reduced by 40% without a concurrent decrease in mtCK protein during early and acute MC. Impaired mtCK activity was correlated with virus replication and increased level of interleukine 1beta (IL-1beta), tumor necrosis factor alpha (TNFalpha), and elevated catalase expression, a marker for intracellular oxidative stress. A reduction in cytCK activity of 48% was observed at day 14 pi and persisted to day 28 pi. This restriction was caused by a decrease in cytCK subunit expression but also by direct inhibition of specific cytCK activity. CytCK activity and expression were also reduced in myocardial biopsies from enterovirus genome-negative patients with inflammatory heart disease. The decrease in cytCK activity correlated with the number of infiltrating macrophages. Thus, viral infection and myocardial inflammation significantly influence the myocardial CK system via restriction of specific CK activity and down-regulation of cytCK protein. These changes may contribute to the progression of chronic inflammatory heart disease and malfunction of the heart.
Collapse
Affiliation(s)
- Linda Ebermann
- Centrum 11, Cardiology, Charité, University Medicine Berlin, Campus Benjamin Franklin, Berlin, Germany
| | | | | | | | | | | | | | | | | |
Collapse
|
20
|
p38 MAPK contributes to angiotensin II-induced COX-2 expression in aortic fibroblasts from normotensive and hypertensive rats. J Hypertens 2009; 27:142-54. [PMID: 19145780 DOI: 10.1097/hjh.0b013e328317a730] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE To investigate the effect of angiotensin II on cyclooxygenase-2 (COX-2) expression in aortic adventitial fibroblasts from normotensive [Wistar-Kyoto (WKY)] rats and spontaneously hypertensive rats (SHRs). METHODS Protein expression was determined by western blot, mRNA levels by real-time PCR, transcriptional activity by luciferase assays, superoxide anion (O2*-) production by dihydroethidine fluorescence and prostaglandin E2 by enzyme immunoassay. RESULTS Angiotensin II (0.1 micromol/l, 0.5-6 h) time dependently induced COX-2 protein expression, this effect being transient in fibroblasts from WKY rats and maintained over time in SHRs. Angiotensin II effect was abolished by valsartan (1 micromol/l), an angiotensin II type 1 receptor antagonist. Angiotensin II-induced prostaglandin E2 production was reduced by valsartan and the COX-2 inhibitor NS398 (1 micromol/l). Angiotensin II increased O2*- production more in SHR than WKY rats. This increase was reduced by apocynin (30 micromol/l) and allopurinol (10 micromol/l), respective nicotinamide adenine dinucleotide phosphate (NADPH) and xanthine oxidase inhibitors. However, angiotensin II-induced COX-2 expression was unaffected by apocynin, allopurinol, tempol (1 mmol/l) or catalase (1000 U/ml). Angiotensin II (2-30 min) induced p38 mitogen-activated protein kinase (MAPK) phosphorylation, transiently in WKY rats but sustained in SHRs. The p38 inhibitor SB203580 (10 micromol/l) reduced angiotensin II-induced COX-2 protein and mRNA levels. The angiotensin II effect was not prevented by inhibition of mRNA synthesis, and angiotensin II was unable to modulate COX-2 transcriptional activity. CONCLUSIONS Angiotensin II increases COX-2 expression in aortic fibroblasts through mechanisms including p38 MAPK pathway, independent of reactive oxygen species production and nonmediated by COX-2 transcriptional activity modulation. The sustained angiotensin-induced p38 MAPK activation in SHR cells might be related to the maintained COX-2 expression in this strain.
Collapse
|
21
|
Sudar E, Velebit J, Gluvic Z, Zakula Z, Lazic E, Vuksanovic-Topic L, Putnikovic B, Neskovic A, Isenovic ER. Hypothetical mechanism of sodium pump regulation by estradiol under primary hypertension. J Theor Biol 2008; 251:584-92. [PMID: 18304583 DOI: 10.1016/j.jtbi.2007.12.023] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2007] [Revised: 12/17/2007] [Accepted: 12/18/2007] [Indexed: 02/05/2023]
Abstract
Causal relationship between sodium and hypertension has been proposed and various changes in Na+,K+-ATPase (sodium pump) activity have been described in established primary hypertension. A number of direct vascular effects of estradiol have been reported, including its impact on the regulation of sodium pump activity and vasomotor tone. The effects of estradiol involve the activation of multiple signaling cascades, including phosphatydil inositol-3 kinase (PI3K) and p42/44 mitogen-activated protein kinase (p42/44(MAPK)). In addition, some of the effects of estradiol have been linked to activity of cytosolic phospholipase A(2) (cPLA(2)). One possible cardioprotective mechanism of estradiol involves of the interaction between estradiol and the rennin-angiotensin system (RAS). Elevated circulating and tissue levels of angiotensin II (Ang II) have been implicated in the development of hypertension and heart failure. The aim of our investigation was to elucidate the signaling mechanisms employed by estradiol and Ang II in mediating sodium pump, in vascular smooth muscle cells (VSMC). The aim of our investigation was to elucidate the signaling mechanisms employed by estradiol and Ang II in mediating sodium pump activity/expression in VSMC, with particular emphasis on PI3K/cPLA(2)/p42/44(MAPK) signaling pathways. Our primary hypothesis is that estradiol stimulates sodium pump activity/expression in VSMC via PI3K/cPLA(2)/p42/44(MAPK) dependent mechanism and, that impaired estradiol-stimulated sodium pump activity/expression in hypertensive rodent models (i.e. SHR), Ang II-mediated vascular impairment of estradiol is related to a decrease ability of estradiol to stimulate the PI3K/cPLA(2)/p42/44(MAPK) signaling pathways. An important corollary to this hypothesis is that in hypertensive state (i.e. SHR rats) the decreasing in ACE enzyme activity and/or AT1 receptor expression caused by administration of estradiol is accompanying with abrogated ability of Ang II to decrease IRS-1/PI3K association, and consequent PI3K/cPLA(2)/p42/44(MAPK) activity and associated sodium pump activity/expression. A clear characterization of how Ang II attenuates estradiol signaling may lead to a better understanding of the molecular mechanism(s) underlying pathophysiological conditions such as hypertension and to understanding how certain pathophysiological situations affect sodium pump activity/expression in VSMC.
Collapse
Affiliation(s)
- Emina Sudar
- Laboratory for Molecular Genetics and Radiobiology, Institute Vinca, P.O. Box 522, 11001 Belgrade, Serbia
| | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Esfandiarei M, Boroomand S, Suarez A, Si X, Rahmani M, McManus B. Coxsackievirus B3 activates nuclear factor kappa B transcription factor via a phosphatidylinositol-3 kinase/protein kinase B-dependent pathway to improve host cell viability. Cell Microbiol 2008; 9:2358-71. [PMID: 17848167 DOI: 10.1111/j.1462-5822.2007.00964.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Coxsackievirus B3 (CVB3) is the most common viral infectant of heart muscle. CVB3 directly injures cardiomyocytes. We have previously reported on a regulatory role for the phosphatidylinositol-3 kinase (PI3K)/protein kinase B (Akt) pathway during CVB3 infection. Yet, the mechanism underlying this regulatory role has not been elucidated. The PI3K/Akt pathway is involved in various cellular processes and exerts its function through the activation of several downstream effectors. Among them, nuclear factor kappa B (NFkappaB) transcription factor is involved in inflammation, survival and apoptosis. In this study, we investigated the role of NFkappaB as a potential downstream mediator of signals through the PI3K/Akt cascade, in regulating CVB3-induced cellular injury. We report that CVB3 infection induces the translocation of NFkappaB into the nucleus of infected cells. Inhibition of the PI3K/Akt pathway markedly decreases virus-induced NFkappaB activation. Further, NFkappaB inhibition significantly suppresses host viability, suggesting a pro-survival role for NFkappaB. Short-term treatment of cells with tumour necrosis factor-alpha (TNF-alpha), a potent activator of NFkappaB, promotes host cell viability without affecting virus replication. However, a prolonged treatment has a detrimental effect on cells, indicating the existence of a delicate balance between the anti- and pro-apoptotic roles of TNF-alpha in the setting of CVB3 infection.
Collapse
Affiliation(s)
- Mitra Esfandiarei
- The James Hogg iCAPTURE Centre for Cardiovascular and Pulmonary Research, Providence Health Care Research Institute/St. Paul's Hospital, Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
| | | | | | | | | | | |
Collapse
|
23
|
Xie Z, Gong MC, Su W, Turk J, Guo Z. Group VIA phospholipase A2 (iPLA2beta) participates in angiotensin II-induced transcriptional up-regulation of regulator of g-protein signaling-2 in vascular smooth muscle cells. J Biol Chem 2007; 282:25278-89. [PMID: 17613534 PMCID: PMC2096773 DOI: 10.1074/jbc.m611206200] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Rgs2 (regulator of G-protein signaling-2)-deficient mice exhibit severe hypertension, and genetic variations of RGS2 occur in hypertensive patients. RGS2 mRNA up-regulation by angiotensin II (Ang II) in vascular smooth muscle cells (VSMC) is a potentially important negative feedback mechanism in blood pressure homeostasis, but how it occurs is unknown. Here we demonstrate that group VIA phospholipase A2 (iPLA2beta) plays a pivotal role in Ang II-induced RGS2 mRNA up-regulation in VSMC by three independent approaches, including pharmacologic inhibition with a bromoenol lactone suicide substrate, suppression of iPLA2beta expression with antisense oligonucleotides, and genetic deletion in iPLA2beta-null mice. Selective inhibition of iPLA2beta by each of these approaches abolishes Ang II-induced RGS2 mRNA up-regulation. Furthermore, using adenovirus-mediated gene transfer, we demonstrate that restoration of iPLA2beta-expression in iPLA2beta-null VSMC reconstitutes the ability of Ang II to up-regulate RGS2 mRNA expression. In contrast, Ang II-induced vasodilator-stimulated phosphoprotein phosphorylation and Ang II receptor expression are unaffected. Moreover, in wild-type but not iPLA2beta-null VSMC, Ang II stimulates iPLA2 enzymatic activity significantly. Both arachidonic acid and lysophosphatidylcholine, products of iPLA2beta action, induce RGS2 mRNA up-regulation. Inhibition of lipoxygenases, particularly 15-lipoxygenase, and cyclooxygenases, but not cytochrome P450-dependent epoxygenases inhibits Ang II- or AA-induced RGS2 mRNA expression. Moreover, RGS2 protein expression is also up-regulated by Ang II, and this is attenuated by bromoenol lactone. Disruption of the Ang II/iPLA2beta/RGS2 feedback pathway in iPLA2beta-null cells potentiates Ang II-induced vasodilator-stimulated phosphoprotein and Akt phosphorylation in a time-dependent manner. Collectively, our results demonstrate that iPLA2beta participates in Ang II-induced transcriptional up-regulation of RGS2 in VSMC.
Collapse
MESH Headings
- Adenoviridae
- Angiotensin II/pharmacology
- Animals
- Arachidonic Acid/pharmacology
- Blood Pressure/drug effects
- Blood Pressure/physiology
- Cell Adhesion Molecules/metabolism
- Enzyme Activation/drug effects
- Enzyme Activation/physiology
- Gene Deletion
- Gene Expression Regulation, Enzymologic/drug effects
- Gene Expression Regulation, Enzymologic/physiology
- Group VI Phospholipases A2
- Homeostasis/drug effects
- Homeostasis/physiology
- Lysophosphatidylcholines/pharmacology
- Mice
- Mice, Knockout
- Microfilament Proteins/metabolism
- Muscle, Smooth, Vascular/enzymology
- Myocytes, Smooth Muscle/enzymology
- Naphthalenes/pharmacology
- Oligodeoxyribonucleotides, Antisense/pharmacology
- Oxidoreductases/antagonists & inhibitors
- Oxidoreductases/metabolism
- Phospholipases A/antagonists & inhibitors
- Phospholipases A/deficiency
- Phospholipases A/metabolism
- Phospholipases A2
- Phosphoproteins/metabolism
- Phosphorylation/drug effects
- Proto-Oncogene Proteins c-akt/metabolism
- Pyrones/pharmacology
- RGS Proteins/antagonists & inhibitors
- RGS Proteins/deficiency
- RGS Proteins/metabolism
- RNA, Messenger/biosynthesis
- RNA, Messenger/genetics
- Rats
- Rats, Sprague-Dawley
- Signal Transduction/drug effects
- Signal Transduction/physiology
- Time Factors
- Transcription, Genetic/drug effects
- Transcription, Genetic/physiology
- Transduction, Genetic
- Up-Regulation/drug effects
- Up-Regulation/physiology
- Vasoconstrictor Agents/pharmacology
Collapse
Affiliation(s)
- Zhongwen Xie
- Department of Physiology and the Graduate Center for Nutritional Sciences, University of Kentucky, Lexington, Kentucky 40536, USA
| | | | | | | | | |
Collapse
|
24
|
Alvarez Y, Pérez-Girón JV, Hernanz R, Briones AM, García-Redondo A, Beltrán A, Alonso MJ, Salaices M. Losartan Reduces the Increased Participation of Cyclooxygenase-2-Derived Products in Vascular Responses of Hypertensive Rats. J Pharmacol Exp Ther 2007; 321:381-8. [PMID: 17244722 DOI: 10.1124/jpet.106.115287] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This study analyzes the role of angiotensin II (Ang II), via AT1) receptors, in the involvement of cyclooxygenase (COX)-2-derived prostanoids in phenylephrine responses in normotensive rats (Wistar Kyoto; WKY) and spontaneously hypertensive rats (SHR). Aorta from rats untreated or treated for 12 weeks with losartan (15 mg/kg . day) or hydralazine plus hydrochlorothiazide (44 and 9.4 mg/kg . day, respectively) and vascular smooth muscle cells (VSMC) from SHR were used. Vascular reactivity was analyzed by isometric recording; COX-2 expression by Western blot and reverse transcription-polymerase chain reaction; prostaglandin (PG)I2, PGF(2alpha), 8-isoprostane, and total antioxidant status (TAS) by commercial kits; superoxide anion (O2*-) by lucigenin chemiluminescence; and plasmatic malondialdehyde (MDA) by thiobarbituric acid assay. The COX-2 inhibitor N-[2-(cyclohexyloxyl)-4-nitrophenyl]-methane sulfonamide (NS-398) at 1 microM reduced phenylephrine responses more in SHR than in WKY rats. COX-2 protein and mRNA expressions, PGF(2alpha), PGI2, 8-isoprostane, and O2*- production, and MDA levels were higher in SHR, but TAS was similar in both strains. Losartan, but not hydralazine-hydrochlorothiazide treatment, reduced COX-2 expression and the effect of NS-398 on phenylephrine responses in SHR. Losartan also increased TAS and reduced PGF(2alpha), PGI2, 8-isoprostane, and O2*- production and MDA levels in SHR. Ang II (0.1 microM) induced COX-2 expression in VSMC from SHR that was reduced by 30 microM apocynin and 100 microM allopurinol, NADPH oxidase, and xanthine oxidase inhibitors, respectively. In conclusion, AT1 receptor activation by Ang II could be involved in the increased participation of COX-2-derived contractile prostanoids in vasoconstriction to phenylephrine with hypertension, probably through COX-2 expression regulation. The increased oxidative stress seems to be one of the mechanisms involved.
Collapse
Affiliation(s)
- Yolanda Alvarez
- Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Spain
| | | | | | | | | | | | | | | |
Collapse
|
25
|
Kühl U, Pauschinger M, Poller W, Schultheiss HP. Anti-viral treatment in patients with virus-induced cardiomyopathy. ERNST SCHERING RESEARCH FOUNDATION WORKSHOP 2006:323-42. [PMID: 16329670 DOI: 10.1007/3-540-30822-9_18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Ongoing viral persistence in the myocardium is associated with an adverse prognosis of cardiomyopathy eventually resulting in a reduced capacity for work and thus it is associated with enormous social costs. Experimental and clinical data highlight that an imbalance of the cytokine network and a defect in the cytokine-induced immune response may constitute major causes leading to the development of virus persistence and progression of myocardial dysfunction. Reversibility of cardiac impairment during the early stages of the disease and the arising chance of specific treatment options demand early diagnosis and treatment of the disease. Our pilot data on anti-viral treatment using INF-beta showed beneficial clinical effects and suggest that some of the ventricular dysfunction and wall motion abnormalities resolved after elimination of the responsible agents. The data also suggest that elimination of cardiotropic viruses and associated clinical effects may occur even in DCM patients presenting with a long history.
Collapse
Affiliation(s)
- U Kühl
- Department of Cardiology and Pneumology, Campus Benjamin Franklin, Charité University Medicine Berlin, Germany.
| | | | | | | |
Collapse
|
26
|
Jaimes EA, Tian RX, Pearse D, Raij L. Up-regulation of glomerular COX-2 by angiotensin II: role of reactive oxygen species. Kidney Int 2006; 68:2143-53. [PMID: 16221213 DOI: 10.1111/j.1523-1755.2005.00670.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Prostaglandins such as prostaglandin E(2) (PGE(2)) and prostaglandin I(2) (PGI(2)) counteract the angiotensin II (Ang II)-induced vasoconstriction in the glomerular microcirculation. We have shown that Ang II promotes mesangial cell hypertrophy via reactive oxygen species (ROS), which originate from nicotinamide adenine dinucleotide phosphate and its reduced form (NADH/NADPH) oxidase. It has been reported that conditions associated with activation of the renin-angiotensin system result in increased glomerular cyclooxygenase-2 (COX-2) expression and activity. METHODS We designed studies to determine (1) whether Ang II induces COX-2 in the glomerulus in vivo in the glomerulus as well as in vitro in mesangial cells, (2) whether ROS originated from Ang II are involved, and (3) whether COX-2-derived prostaglandins modulate the growth promoting effects of Ang II in mesangial cells. Rats were infused with Ang II (0.7 mg/kg/day) for 5 days and glomerular COX-2 expression and activity assessed in isolated glomeruli. RESULTS Ang II increased glomerular PGE(2) production (100%) accompanied by a concomitant increase in glomerular COX-2 expression at the mRNA (1.7-fold) and protein level (sixfold). In mesangial cells, Ang II significantly increased mesangial cell PGE(2) (200%) and PGI(2) (100%) production as well as COX-2 mRNA that was prevented by the angiotensin type 1 (AT1) receptor blocker irbesartan and the COX-2 inhibitor NS-398. The NADPH oxidase inhibitor diphenyleneiodonium (DPI), the ROS scavenger tiron as well as catalase, inhibited Ang II-induced PGE(2) production suggesting that Ang II-induced ROS mediate COX-2 up-regulation. Strikingly, COX-2 inhibition as well as blockade of the type 1 PGE(2) receptor (EP1) prevented Ang II-induced mesangial cell hypertrophy suggesting that COX-2-derived prostaglandins, and specifically PGE(2), importantly contribute to the growth promoting effects of Ang II. CONCLUSION These studies suggest that blockade of specific PGE(2) receptors may be a novel strategy to modulate the pathologic effects of COX-2-derived prostaglandins without simultaneously affecting protective vasodilatory mechanisms.
Collapse
Affiliation(s)
- Edgar A Jaimes
- Nephrology Section, VA Medical Center, Miami, FL 33125, USA.
| | | | | | | |
Collapse
|
27
|
Wildroudt ML, Freeman EJ. Regulation of Akt by arachidonic acid and phosphoinositide 3-kinase in angiotensin II-stimulated vascular smooth muscle cells. Biochim Biophys Acta Mol Cell Biol Lipids 2006; 1761:11-6. [PMID: 16461001 DOI: 10.1016/j.bbalip.2005.11.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2005] [Revised: 11/28/2005] [Accepted: 11/28/2005] [Indexed: 10/25/2022]
Abstract
Angiotensin (Ang) II stimulates cytosolic phospholipase A2(cPLA(2))-dependent release of arachidonic acid (ArAc) in vascular smooth muscle cells (VSMC). ArAc release and production of reactive oxygen species (ROS) lead to the activation of downstream kinases resulting in VSMC growth. To determine the role of Akt in this pathway, we used VSMC to link Ang II-induced ArAc release and ROS production to the activation of Akt and VSMC growth. We observed that Ang II, ArAc, or H(2)O(2) increased Akt activation. The Akt inhibitor SH6 blocked Ang II-, ArAc-, or H(2)O(2)-induced Akt activation, as did inhibition of phosphoinositide 3-kinase (PI(3)K). Inhibition of cPLA(2) blocked Ang II effects, while the ROS scavenger NaC decreased Ang II- and ArAc-induced Akt activation. Inhibition of Akt blocked the (3)H-thymidine incorporation induced by all three agonists. Thus, Ang II-induced ArAc release and ROS production leads to the PI(3)K-dependant activation of Akt and VSMC growth.
Collapse
Affiliation(s)
- Maria L Wildroudt
- Kent State University, School of Biomedical Sciences, Cunningham Hall A229, Kent, OH 44242, USA
| | | |
Collapse
|
28
|
Hazan-Halevy I, Levy T, Wolak T, Lubarsky I, Levy R, Paran E. Stimulation of NADPH oxidase by angiotensin II in human neutrophils is mediated by ERK, p38 MAP-kinase and cytosolic phospholipase A2. J Hypertens 2005; 23:1183-90. [PMID: 15894894 DOI: 10.1097/01.hjh.0000170381.53955.68] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE The present research was designed to study the involvement of ERK and p38 MAP-kinase in cytosolic phospholipase A2 (cPLA2) and NADPH-oxidase activation by angiotensin II (Ang II) in human neutrophils. METHODS NADPH-oxidase activity was measured by reduction of cytochrome C. cPLA2 activity was measured in cell lysate using sonicated dispersions of 1-stearoyl-2-[C]arachidonyl phosphatidylcholine. Cells were incubated with MEK inhibitor UO126 or with p38 MAP-kinase inhibitor SB202190 prior to stimulation with Ang II. Translocation of p47, p67 and cPLA2 and phosphorylation of ERK and p38 MAP-kinase were measured by immunoblot analysis. RESULTS Ang II induced a dose-dependent activation of NADPH oxidase in neutrophils and monocytes as well as in differentiated PLB-985 cells towards neutrophil or monocyte lineages, but not in cPLA2-deficient differentiated PLB-985 cells. An immediate activation of both ERK and p38 MAP-kinase and of cPLA2 was induced by Ang II in human neutrophils. In addition, Ang II induced translocation of the cytosolic oxidase components, detected by translocation of p47, which preceded the translocation of cPLA2 induced by this agonist. The p38 MAP-kinase inhibitor SB202190 or the MEK-ERK pathway inhibitor UO126 totally inhibited the activation of both NADPH oxidase and cPLA2 as well as the translocation of cytosolic oxidase components and of cPLA2 to the membrane fractions. CONCLUSIONS These results suggest that either ERK or p38 MAP-kinase are involved in the activation of both cPLA2 and NADPH oxidase, and that cPLA2 is required for activation of the NADPH oxidase by Ang II in human neutrophils.
Collapse
Affiliation(s)
- Inbal Hazan-Halevy
- Hypertension Unit, Soroka Medical Center and Ben-Gurion University, Beer Sheva, Israel.
| | | | | | | | | | | |
Collapse
|
29
|
Abstract
In humans, infections with the group B coxsackieviruses (CVBs) range from asymptomatic infections to chronic, debilitating diseases. The CVBs are associated with chronic inflammatory diseases of the pancreas, heart, and central nervous system. A major focus in CVB pathogenesis is to understand the mechanisms by which these viruses cause acute diseases that resolve or acute diseases that progress to chronic diseases. The present review explores CVB infections in the development of acute and chronic pancreatitis. Mouse models of CVB-induced pancreatitis share many features with the human diseases and are providing insight into the multi-faceted processes of pancreatic tissue repair and irreversible tissue destruction. The development and progression of CVB-induced pancreatic inflammatory disease is an extremely complex process, involving both viral and host factors. The review examines the roles of the virus and host in contributing to the disease process. Recent studies of global gene expression during CVB-induced pancreatitis have increased our understanding of host factors that influence the outcome of infection and have highlighted interrelationships among complex biological programs. As we unravel the complexity of the disease process, the information gained will lead to the design of therapeutics that not only prevent the progression of chronic inflammatory disease, but that also restore functionality of affected tissues and organs.
Collapse
Affiliation(s)
- Sally Huber
- Department of Pathology, University of Vermont, Bington, Vermont, USA
| | | |
Collapse
|
30
|
Slater DM, Astle S, Bennett PR, Thornton S. Labour is associated with increased expression of type-IIA secretory phospholipase A2 but not type-IV cytosolic phospholipase A2 in human myometrium. ACTA ACUST UNITED AC 2004; 10:799-805. [PMID: 15361552 DOI: 10.1093/molehr/gah103] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Human labour is associated with increased prostaglandin synthesis within the uterus. The aim of this study was to examine the expression of the type-IV cytosolic phospholipase A2 (cPLA2-IV) and the type IIA secretory phospholipase A2 (sPLA2-IIA) in myometrium in association with labour onset at term and preterm deliveries. These enzymes are important for the release of the prostaglandin precursor, arachidonic acid, from phospholipid membrane stores. RT-PCR was used to determine differences in gene expression between non-labour and labour groups. Expression of sPLA2-IIA in human myometrium was significantly increased with pregnancy, and with labour, both at term and preterm. Expression of cPLA2-IV in myometrium was not significantly altered with respect to pregnancy or labour. Immunohistochemical analysis demonstrated differences in the spatial localization of cPLA2-IV and sPLA2-IIA protein in upper and lower segment myometrium. cPLA2-IV was predominantly in vascular endothelial cells, while sPLA2-IIA was observed in vascular, endothelial and smooth muscle cells. In addition, sPLA2-IIA showed a distinct nuclear or perinuclear localization in myometrial smooth muscle cells of the lower segment. We postulate that the increased expression of sPLA2-IIA rather than cPLA2-IV in the myometrium may play a role in the onset and/or maintenance of human parturition.
Collapse
Affiliation(s)
- Donna M Slater
- Biomedical Research Institute, Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, UK.
| | | | | | | |
Collapse
|
31
|
Abstract
Myocarditis is a complex disease in which distinct immunopathogenic mechanisms cause tissue injury. In some but not all cases, autoimmunity is a major pathogenic factor. Cross-reactivity between viral and myosin epitopes underlies both cellular and humoral autoimmunity in myocarditis. Thus, the genetics of the host as well as the virus determine disease pathogenicity. Innate immunity, as represented by gammadelta+ T cells, is important in determining disease susceptibility. The innate effectors rapidly localize in the infected myocardium and through release of IFNgamma (Vgamma4+ cells; BALB/c) or IL-4 (Vgamma1+ cells; C57Bl/6), modulate the developing adaptive immune response to either a Th1 or Th2 response, respectively. The Vgamma4+ cells in BALB/c mice recognize CD1d, a major histocompatibility complex class I-like antigen. The ligand for Vgamma1+ cells is unknown. Only infected myocytes up-regulate CD1d. Signaling through both infection (double stranded RNA) and TNFalpha is required for CD1d up-regulation.
Collapse
Affiliation(s)
- Sally Huber
- Department of Pathology, University of Vermont, Bington, Vermont 05405, USA.
| |
Collapse
|
32
|
Helliwell RJA, Berry EBE, O'Carroll SJ, Mitchell MD. Nuclear prostaglandin receptors: role in pregnancy and parturition? Prostaglandins Leukot Essent Fatty Acids 2004; 70:149-65. [PMID: 14683690 DOI: 10.1016/j.plefa.2003.04.005] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The key regulatory role of prostanoids [prostaglandins (PGs) and thromboxanes (TXs)] in the maintenance of pregnancy and initiation of parturition has been established. However, our understanding of how these events are fine-tuned by the recruitment of specific signaling pathways remains unclear. Whereas, initial thoughts were that PGs were lipophilic and would easily cross cell membranes without specific receptors or transport processes, it has since been realized that PG signaling occurs via specific cell surface G-protein coupled receptors (GPCRs) coupled to classical adenylate cyclase or inositol phosphate signaling pathways. Furthermore, specific PG transporters have been identified and cloned adding a further level of complexity to the regulation of paracrine action of these potent bioactive molecules. It is now apparent that PGs also activate nuclear receptors, opening the possibility of novel intracrine signaling mechanisms. The existence of intracrine signaling pathways is further supported by accumulating evidence linking the perinuclear localization of PG synthesizing enzymes with intracellular PG synthesis. This review will focus on the evidence for a role of nuclear actions of PGs in the regulation of pregnancy and parturition.
Collapse
Affiliation(s)
- Rachel J A Helliwell
- Department of Anatomy with Radiology, Faculty of Medicine and Health Science, The University of Auckland, Private Bag 92019, Auckland, New Zealand.
| | | | | | | |
Collapse
|
33
|
Luchtefeld M, Drexler H, Schieffer B. 5-Lipoxygenase is involved in the angiotensin II-induced NAD(P)H-oxidase activation. Biochem Biophys Res Commun 2003; 308:668-72. [PMID: 12914802 DOI: 10.1016/s0006-291x(03)01456-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Angiotensin II (ANG II)-induced interleukin (IL)-6 synthesis requires NAD(P)H-oxidase-derived superoxide anions. Since NAD(P)H-oxidase activation by cytokines involves 5-lipoxygenase (LOX)-derived leukotriene B(4) (LTB(4)) formation, we postulated that LTB(4) is involved in the ANG II-dependent NAD(P)H-oxidase activation. Therefore, 5-LOX expression and LTB(4) formation following ANG II (100nM) stimulation were determined in rat aortic smooth muscle cells (SMC). Reactive oxygen species (ROS)-formation and IL-6 mRNA expression were analyzed following ANG II and LTB(4) (0.6 microM) stimulation. 5-LOX mRNA and protein were detected in SMC. ANG II-induced LTB(4) formation at 2.5min and was followed by an increase in ROS-formation and IL-6 mRNA expression. Blockade of 5-LOX by MK886 (200nM) abrogated LTB(4)-formation, ROS-formation, and IL-6 mRNA expression. Moreover, LTB(4)-induced ROS-formation and IL-6 mRNA expression was abolished by NAD(P)H-oxidase inhibition using diphenyleneiodonium chloride (DPI 10 microM). In conclusion, the present study demonstrates that ANG II enhances LTB(4)-formation in an 5-LOX dependent manner. LTB(4) activates the vascular type NAD(P)H-oxidase, leading to an increase in IL-6 transcripts.
Collapse
Affiliation(s)
- Maren Luchtefeld
- Abteilung Kardiologie und Angiologie, Medizinische Hochschule Hannover, Germany
| | | | | |
Collapse
|
34
|
Dorman RV, Freeman EJ. Lead-dependent effects on arachidonic acid accumulation and the proliferation of vascular smooth muscle. J Biochem Mol Toxicol 2003; 16:245-53. [PMID: 12439866 DOI: 10.1002/jbt.10045] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Lead (Pb(2+)) has been implicated in the development of hypertension and atherosclerosis. The proliferation of vascular smooth muscle cells (VSMC) is a central feature of both conditions and there is evidence that Pb(2+) potentiates serum-dependent cell growth. The aim of this work was to examine the role of phospholipase A(2) in mitogen-dependent VSMC proliferation and determine if Pb(2+) interacts with this system in order to potentiate mitotic events. It was observed that cell proliferation induced by angiotensin II, or fetal bovine serum, required the activation of a Ca(2+)-dependent cytosolic phospholipase A(2) and the subsequent release of unesterified arachidonic acid. This path was affected by Pb(2+) as the metal increased the amount of arachidonic acid accumulation induced by either mitogen. In addition, Pb(2+) potentiated mitogen-induced DNA synthesis when present at lower doses (0.02 or 0.2 mg%), but had no effect on DNA synthesis, or cell numbers, in unstimulated cells. However, a high dose (2 mg%) of Pb(2+) attenuated the DNA synthesis stimulated by angiotensin II, or serum, but induced the accumulation of unesterified arachidonic acid in unstimulated cells. A biphasic effect of Pb(2+) on cell numbers and viability was also observed as 0.02 or 0.2 mg% Pb(2+) did not affect cell numbers or trypan blue exclusion in unstimulated cells, while 2 mg% Pb(2+) reduced cell numbers and viability. It appeared, therefore, that the lower concentrations of Pb(2+) increased arachidonic acid release and DNA synthesis only in stimulated VSMC, perhaps due to further activation of a Ca(2+)-dependent processes. In contrast, the high dose of Pb(2+) reduced DNA synthesis in stimulated cells and reduced cell numbers and viability in unstimulated cells, which may relate to the noted increase in unesterified arachidonic acid.
Collapse
MESH Headings
- Angiotensin II/pharmacology
- Animals
- Aorta, Thoracic
- Arachidonic Acid/metabolism
- Cell Count
- Cell Division/drug effects
- Cell Survival/drug effects
- Cells, Cultured
- DNA/biosynthesis
- Dose-Response Relationship, Drug
- Enzyme Activation
- Lead/toxicity
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Phospholipases A/metabolism
- Proteins/metabolism
- Rats
- Serum Albumin, Bovine/pharmacology
Collapse
Affiliation(s)
- Robert V Dorman
- Department of Biological Sciences, Kent State University, Kent, OH 44242, USA
| | | |
Collapse
|
35
|
Bregonzio C, Armando I, Ando H, Jezova M, Baiardi G, Saavedra JM. Anti-inflammatory effects of angiotensin II AT1 receptor antagonism prevent stress-induced gastric injury. Am J Physiol Gastrointest Liver Physiol 2003; 285:G414-23. [PMID: 12686508 DOI: 10.1152/ajpgi.00058.2003] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Stress reduces gastric blood flow and produces acute gastric mucosal lesions. We studied the role of angiotensin II in gastric blood flow and gastric ulceration during stress. Spontaneously hypertensive rats were pretreated for 14 days with the AT1 receptor antagonist candesartan before cold-restraint stress. AT1 receptors were localized in the endothelium of arteries in the gastric mucosa and in all gastric layers. AT1 blockade increased gastric blood flow by 40-50%, prevented gastric ulcer formation by 70-80% after cold-restraint stress, reduced the increase in adrenomedullary epinephrine and tyrosine hydroxylase mRNA without preventing the stress-induced increase in adrenal corticosterone, decreased the stress-induced expression of TNF-alpha and that of the adhesion protein ICAM-1 in arterial endothelium, decreased the neutrophil infiltration in the gastric mucosa, and decreased the gastric content of PGE2. AT1 receptor blockers prevent stress-induced ulcerations by a combination of gastric blood flow protection, decreased sympathoadrenal activation, and anti-inflammatory effects (with reduction in TNF-alpha and ICAM-1 expression leading to reduced neutrophil infiltration) while maintaining the protective glucocorticoid effects and PGE2 release. Angiotensin II has a crucial role, through stimulation of AT1 receptors, in the production and progression of stress-induced gastric injury, and AT1 receptor antagonists could be of therapeutic benefit.
Collapse
Affiliation(s)
- Claudia Bregonzio
- Section on Pharmacology, National Institute of Mental Health, National Institute of Health, Department of Health and Human Services, Bethesda, MD 20892, USA.
| | | | | | | | | | | |
Collapse
|
36
|
Fisher SD, Bowles NE, Towbin JA, Lipshultz SE. Mediators in HIV-associated cardiovascular disease: a focus on cytokines and genes. AIDS 2003; 17 Suppl 1:S29-35. [PMID: 12870528 DOI: 10.1097/00002030-200304001-00005] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
As longevity increases in HIV-infected individuals, late effects such as cardiovascular disease and, more specifically, symptomatic heart failure are emerging as leading health issues. In the present review, we discuss possible cytokine and gene-mediated effects on HIV-associated cardiovascular illness that may play a role in diagnosis, management, and therapy of HIV-associated heart failure.
Collapse
Affiliation(s)
- Stacy D Fisher
- Department of Medicine, Cardiology Unit, University of Rochester Medical Center, Rochester, New York 14642, USA
| | | | | | | |
Collapse
|
37
|
Fatima S, Yaghini FA, Ahmed A, Khandekar Z, Malik KU. CaM kinase IIalpha mediates norepinephrine-induced translocation of cytosolic phospholipase A2 to the nuclear envelope. J Cell Sci 2003; 116:353-65. [PMID: 12482921 DOI: 10.1242/jcs.00242] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Several growth factors, hormones and neurotransmitters, including norepinephrine, increase cellular calcium levels, promoting the translocation of cytosolic phospholipase A(2) to the nuclear envelope. This study was conducted to investigate the contributions of the calcium-binding protein calmodulin and of calcium-calmodulin-dependent protein kinase II to cytosolic phospholipase A(2) translocation to the nuclear envelope elicited by norepinephrine in rabbit aortic smooth-muscle cells. Norepinephrine caused cytosolic phospholipase A(2) accumulation around the nuclear envelope as determined from its immunofluorescence; cytosolic phospholipase A(2) translocation was blocked by inhibitors of calmodulin and calcium-calmodulin-dependent protein kinase II or calcium-calmodulin-dependent protein kinase IIalpha antisense oligonucleotide. Calmodulin and calcium-calmodulin-dependent protein kinase II inhibitors did not prevent cytosolic calcium increase but attenuated cytosolic phospholipase A(2) phosphorylation caused by norepinephrine or ionomycin. In vascular smooth-muscle cells reversibly permeabilized with beta-escin and treated with alkaline phosphatase, norepinephrine failed to cause cytosolic phospholipase A(2) phosphorylation and translocation to the nuclear envelope; these effects of norepinephrine were minimized by the phosphatase inhibitor okadaic acid. Recombinant cytosolic phospholipase A(2) phosphorylated by purified calcium-calmodulin-dependent protein kinase II, but not unphosphorylated or dephosphorylated cytosolic phospholipase A(2), introduced into permeabilized vascular smooth-muscle cells in the absence of calcium accumulated around the nuclear envelope. These data suggest that norepinephrine-induced translocation of cytosolic phospholipase A(2) to the nuclear envelope is mediated by its phosphorylation by calcium-calmodulin-dependent protein kinase II and that calcium alone is insufficient for cytosolic phospholipase A(2) translocation to the nuclear envelope in rabbit vascular smooth-muscle cells.
Collapse
Affiliation(s)
- Soghra Fatima
- Department of Pharmacology and Centers for Connective Tissue Diseases and Vascular Biology, College of Medicine, The University of Tennessee Center for Health Sciences, Memphis, TN 38163, USA
| | | | | | | | | |
Collapse
|
38
|
Silfani TN, Freeman EJ. Phosphatidylinositide 3-kinase regulates angiotensin II-induced cytosolic phospholipase A2 activity and growth in vascular smooth muscle cells. Arch Biochem Biophys 2002; 402:84-93. [PMID: 12051686 DOI: 10.1016/s0003-9861(02)00066-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Angiotensin (Ang) II via the AT(1) receptor acts as a mitogen in vascular smooth muscle cells (VSMC) through stimulation of multiple signaling mechanisms, including tyrosine kinases and mitogen-activated protein kinase (MAPK). In addition, cytosolic phospholipase A(2)(cPLA(2))-dependent release of arachidonic acid (AA) is linked to VSMC growth and we have reported that Ang II stimulates cPLA(2) activity via the AT(1) receptor. The coupling of Ang II to the activation of cPLA(2) appears to involve mechanisms both upstream and downstream of MAPK such that AA stimulates MAPK activity which phosphorylates cPLA(2) to further enhance AA release. However, the upstream mechanisms responsible for activation of cPLA(2) are not well-defined. One possibility includes phosphatidylinositide 3-kinase (PI3K), since PI3K has been reported to participate in the upstream signaling events linked to activation of MAPK. However, it is not known whether PI3K is involved in the Ang II-induced activation of cPLA(2) or if this mechanism is associated with the Ang II-mediated growth of VSMC. Therefore, we used cultured rat VSMC to examine the role of PI3K in the Ang II-dependent phosphorylation of cPLA(2), release of AA, and growth induced by Ang II. Exposure of VSMC to Ang II (100 nM) increased [(3)H]thymidine incorporation, cell number, and the release of [(3)H]AA. Also, using Western analysis, Ang II increased the phosphorylation of MAPK and cPLA(2) which were blocked by the MAPK kinase inhibitor PD98059 (10 microM/L). Similarly, the PI3K inhibitor LY294002 (10 microM/L) abolished the Ang II-mediated increase in MAPK phosphorylation, as well as phosphoserine-PLA(2). Further, inhibition of PI3K blocked the Ang II-induced release of AA and VSMC mitogenesis. However, exogenous AA was able to restore VSMC growth in the presence of LY294002, as well as reverse the inhibition of MAPK and cPLA(2) phosphorylation by LY294002. Thus, it appears from these data that Ang II stimulates the PI3K-sensitive release of AA which stimulates MAPK to phosphorylate cPLA(2) and enhance AA release. This mechanism may play an important role in the Ang II-induced growth of VSMC.
Collapse
Affiliation(s)
- Tonous N Silfani
- Department of Physiology, Northeastern Ohio Universities College of Medicine and Calhoun Research Laboratory, Akron General Medical Center, Akron, OH 44307, USA
| | | |
Collapse
|
39
|
Roks AJM. Improvement of endothelium-derived hyperpolarizing factor function by renin-angiotensin system inhibition: paving the way towards prevention of age-related endothelial dysfunction. J Hypertens 2002; 20:363-5. [PMID: 11875297 DOI: 10.1097/00004872-200203000-00005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
40
|
Stanke-Labesque F, Hardy G, Vergnaud S, Devillier P, Peoc'h M, Randon J, Bricca G, Caron F, Cracowski JL, Bessard G. Involvement of cysteinyl leukotrienes in angiotensin II-induced contraction in isolated aortas from transgenic (mRen-2)27 rats. J Hypertens 2002; 20:263-72. [PMID: 11821711 DOI: 10.1097/00004872-200202000-00016] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES We have previously reported that 5-lipoxygenase-derived products, and particularly the cysteinyl leukotrienes (CysLTs), were involved in angiotensin II (Ang II)-induced contractions in isolated aortas from spontaneously hypertensive rats. DESIGN The aim of this study was to assess the role of CysLTs in the vascular response to Ang II in an Ang II-dependent model of hypertension, the (mRen-2)27 transgenic rats (TGs). METHODS Intact aortic rings from TG and normotensive Sprague-Dawley rats (SDs) were suspended in organ chambers for isometric tension development in response to Ang II. In addition, the release of CysLTs in response to Ang II (0.3 micromol/l) was measured by enzyme immunoassay. RESULTS In isolated aortas from TG rats, pretreatment with the 5-lipoxygenase inhibitor (AA861, 10 micromol/l) or the CysLT1 receptor antagonist (MK571, 1 micromol/l) significantly (P < 0.05) reduced Ang II-induced contractions by 52 and 42%, respectively. In addition, Ang II induced a 2.6-fold increase in CysLT release (pg/mg dry weight tissue: 58.3 +/- 17.9 (Ang II, n = 7) versus 22.5 +/- 5.9 (basal, n = 7) P < 0.05), which was inhibited by the AT1 receptor antagonist losartan (1 micromol/l). In contrast, in aortas from SD rats, pretreatment with AA861 or MK571 did not alter Ang II-induced contraction and CysLT production remained unchanged after exposure to Ang II. CONCLUSION These data suggest that CysLTs are involved in the contractile responses to Ang II in isolated aortas from TG but not from SD rats.
Collapse
MESH Headings
- Angiotensin II/pharmacology
- Animals
- Animals, Genetically Modified/physiology
- Aorta/drug effects
- Aorta/physiology
- Arachidonate 5-Lipoxygenase/immunology
- Benzoquinones/pharmacology
- Blood Pressure/physiology
- Blotting, Western
- Body Weight/physiology
- Dose-Response Relationship, Drug
- Endothelium, Vascular/enzymology
- Endothelium, Vascular/immunology
- Leukotriene Antagonists
- Lipoxygenase Inhibitors/pharmacology
- Membrane Proteins
- Models, Animal
- Models, Cardiovascular
- Muscle Contraction/drug effects
- Muscle Contraction/physiology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/enzymology
- Muscle, Smooth, Vascular/immunology
- Muscle, Smooth, Vascular/physiology
- Rats
- Rats, Inbred SHR/genetics
- Rats, Sprague-Dawley/genetics
- Receptors, Leukotriene/biosynthesis
- Vascular Patency/drug effects
- Vascular Patency/physiology
- Vasoconstrictor Agents/pharmacology
Collapse
|
41
|
Berry C, Touyz R, Dominiczak AF, Webb RC, Johns DG. Angiotensin receptors: signaling, vascular pathophysiology, and interactions with ceramide. Am J Physiol Heart Circ Physiol 2001; 281:H2337-65. [PMID: 11709400 DOI: 10.1152/ajpheart.2001.281.6.h2337] [Citation(s) in RCA: 183] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Angiotensin II (ANG II) is a pleiotropic vasoactive peptide that binds to two distinct receptors: the ANG II type 1 (AT(1)) and type 2 (AT(2)) receptors. Activation of the renin-angiotensin system (RAS) results in vascular hypertrophy, vasoconstriction, salt and water retention, and hypertension. These effects are mediated predominantly by AT(1) receptors. Paradoxically, other ANG II-mediated effects, including cell death, vasodilation, and natriuresis, are mediated by AT(2) receptor activation. Our understanding of ANG II signaling mechanisms remains incomplete. AT(1) receptor activation triggers a variety of intracellular systems, including tyrosine kinase-induced protein phosphorylation, production of arachidonic acid metabolites, alteration of reactive oxidant species activities, and fluxes in intracellular Ca(2+) concentrations. AT(2) receptor activation leads to stimulation of bradykinin, nitric oxide production, and prostaglandin metabolism, which are, in large part, opposite to the effects of the AT(1) receptor. The signaling pathways of ANG II receptor activation are a focus of intense investigative effort. We critically appraise the literature on the signaling mechanisms whereby AT(1) and AT(2) receptors elicit their respective actions. We also consider the recently reported interaction between ANG II and ceramide, a lipid second messenger that mediates cytokine receptor activation. Finally, we discuss the potential physiological cross talk that may be operative between the angiotensin receptor subtypes in relation to health and cardiovascular disease. This may be clinically relevant, inasmuch as inhibitors of the RAS are increasingly used in treatment of hypertension and coronary heart disease, where activation of the RAS is recognized.
Collapse
Affiliation(s)
- C Berry
- Department of Medicine and Therapeutics, Western Infirmary, University of Glasgow, G11 6NT Glasgow, United Kingdom.
| | | | | | | | | |
Collapse
|
42
|
Cocco L, Martelli AM, Gilmour RS, Rhee SG, Manzoli FA. Nuclear phospholipase C and signaling. BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1530:1-14. [PMID: 11341954 DOI: 10.1016/s1388-1981(00)00169-4] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- L Cocco
- Cellular Signaling Laboratory, Department of Anatomical Sciences and Skeletal Muscle Pathophysiology, University of Bologna, Italy.
| | | | | | | | | |
Collapse
|
43
|
Barbaro G, Di Lorenzo G, Soldini M, Giancaspro G, Grisorio B, Pellicelli AM, D'Amati G, Barbarini G. Clinical course of cardiomyopathy in HIV-infected patients with or without encephalopathy related to the myocardial expression of tumour necrosis factor-alpha and nitric oxide synthase. AIDS 2000; 14:827-38. [PMID: 10839591 DOI: 10.1097/00002030-200005050-00009] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE To define whether the development of encephalopathy influences the clinical course of HIV-associated cardiomyopathy (HIV-DCM) in relation to the myocardial expression of tumour necrosis factor-alpha (TNF-alpha) and inducible nitric oxide synthase (iNOS). DESIGN Prospective study. SETTING University hospitals and AIDS centres. METHODS 115 HIV-infected patients with echocardiographic diagnosis of HIV-associated cardiomyopathy (34 with encephalopathy and 81 without encephalopathy) were followed for a mean of 24 +/- 3.2 months. All patients underwent endomyocardial biopsy for determination of myocardial immunostaining intensity of TNF-alpha and iNOS. Cerebrospinal fluid (CSF) from patients with encephalopathy was examined for the presence of viruses. Patients underwent clinical examination every 3 months and echocardiographic examination every 6 months. The intensity of TNF-alpha and iNOS immunostaining was also evaluated on postmortem cerebral tissue of patients who died of congestive heart failure (CHF). RESULTS A greater impairment of echocardiographic parameters was observed in patients with HIV-associated cardiomyopathy after development of encephalopathy. These parameters tended to worsen progressively during the follow-up period and were inversely correlated with HIV-1 viral load, CD4 cell count, mini mental status score and the intensity of myocardial and cerebral TNF-alpha and iNOS staining. CSF specimens were available in 29 patients with encephalopathy. HIV-1 sequences were detected in CSF of all these patients with cytomegalovirus sequences in two. The mortality rate for CHF was greater among patients with encephalopathy (73% versus 12%). CONCLUSIONS The development of encephalopathy has an adverse effect on the clinical course of HIV-associated cardiomyopathy. In the relationship between cardiomyopathy and encephalopathy, the activation of iNOS by TNF-alpha may have a significant pathogenetic role in HIV disease.
Collapse
Affiliation(s)
- G Barbaro
- Department of Emergency Medicine, University La Sapienza, Rome, Italy
| | | | | | | | | | | | | | | |
Collapse
|
44
|
Freeman EJ. The Ang II-induced growth of vascular smooth muscle cells involves a phospholipase D-mediated signaling mechanism. Arch Biochem Biophys 2000; 374:363-70. [PMID: 10666319 DOI: 10.1006/abbi.1999.1608] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Angiotensin (Ang) II acts as a mitogen in vascular smooth muscle cells (VSMC) via the activation of multiple signaling cascades, including phospholipase C, tyrosine kinase, and mitogen-activated protein kinase pathways. However, increasing evidence supports signal-activated phospholipases A(2) and D (PLD) as additional mechanisms. Stimulation of PLD results in phosphatidic acid (PA) formation, and PA has been linked to cell growth. However, the direct involvement of PA or its metabolite diacylglycerol (DAG) in Ang II-induced growth is unclear. PLD activity was measured in cultured rat VSMC prelabeled with [(3)H]oleic acid, while the incorporation of [(3)H]thymidine was used to monitor growth. We have previously reported the Ang II-dependent, AT(1)-coupled stimulation of PLD and growth in VSMC. Here, we show that Ang II (100 nM) and exogenous PLD (0.1-100 units/mL; Streptomyces chromofuscus) stimulated thymidine incorporation (43-208% above control). PA (100 nM-1 microM) also increased thymidine incorporation to 135% of control. Propranolol (100 nM-10 microM), which inhibits PA phosphohydrolase, blocked the growth stimulated by Ang II, PLD, or PA by as much as 95%, an effect not shared by other beta-adrenergic antagonists. Propranolol also increased the production of PA in the presence of Ang II by 320% and reduced DAG and arachidonic acid (AA) accumulation. The DAG lipase inhibitor RHC-80267 (1-10 microM) increased Ang II-induced DAG production, while attenuating thymidine incorporation and release of AA. Thus, it appears that activation of PLD, formation of PA, conversion of PA to DAG, and metabolism of DAG comprise an important signaling cascade in Ang II-induced growth of VSMC.
Collapse
Affiliation(s)
- E J Freeman
- Department of Internal Medicine, Calhoun Research Laboratory, Akron, Ohio 44307, USA
| |
Collapse
|
45
|
Ohnaka K, Numaguchi K, Yamakawa T, Inagami T. Induction of cyclooxygenase-2 by angiotensin II in cultured rat vascular smooth muscle cells. Hypertension 2000; 35:68-75. [PMID: 10642277 DOI: 10.1161/01.hyp.35.1.68] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Angiotensin II (Ang II) stimulates the release of prostaglandins (PGs) in various cells and tissues. Recently, cyclooxygenase-2 (COX-2) emerged as a new key regulator for PG synthesis. In the present study, we investigated whether Ang II regulates COX-2 expression in cultured rat vascular smooth muscle cells (VSMCs). Ang II markedly increased the expression of COX-2 mRNA in a time- and dose-dependent manner. This effect was completely blocked by the Ang II type 1 receptor antagonist losartan but not by the Ang II type 2 receptor antagonist PD123319. The p42/44 mitogen-activated protein kinase (MAPK) kinase-1 inhibitor PD98059 and the p38 MAPK inhibitor SB203580 significantly suppressed Ang II-induced COX-2 mRNA and protein expression. Ang II did not increase transcription of the COX-2 gene, as examined with a COX-2 promoter/luciferase chimeric plasmid construct. Instead, it suppressed the degradation of COX-2 mRNA. PD98059 and SB203580 markedly enhanced the decay of COX-2 mRNA induced by Ang II, implying that p42/44 and p38 MAPK activated by Ang II play a role in the regulation of COX-2 through stabilization of its mRNA. The COX-2-specific inhibitor NS-398 attenuated Ang II-stimulated DNA and protein synthesis, as well as PGE(2) production by VSMCs. These results suggest that Ang II regulates COX-2 expression and PG production and modulates cell proliferation through MAPK-mediated signaling pathways in rat VSMCs.
Collapse
Affiliation(s)
- K Ohnaka
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232-0146, USA
| | | | | | | |
Collapse
|
46
|
Gauntt C, Busbee D, Wood HJ, Reyna S, Barhoumi R, Burghardt R, McAnalley W, McDaniel HR. A glyconutritional mixture (Ambrotose®) provides some amelioration to mice with coxsackievirus-induced pancreatitis. AGE 1999; 22:149-58. [PMID: 23604423 PMCID: PMC3455415 DOI: 10.1007/s11357-999-0017-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Challenge of adolescent male CD-1 mice with a coxsackievirus B3 (CVB3) strain (CVB3m) induces mild to severe destruction of pancreatic acinar cells, but causes no deaths and does not induce hyperglycemia. A weekly parenteral (intraperitoneal) administration of a glyconutritional mixture (Ambrotose® to virus-challenged mice was assessed to determine if there were any benefits to recovery over an eight month period. Virus-challenged mice showed a significant weight loss over the initial five weeks of the experiment, but injection of Ambrotose® to similar virus-challenged mice restored the total body weight to levels found in normal mice. Normal mice given Ambrotose® exhibited a small weight gain. Mice given Ambrotose® showed reduced severity of pancreatitis, as evidenced by significant reductions in percentages of pancreatic acinar cells destroyed and proportion of sections of pancreata with destroyed acinar cells, compared to virus control-mice not injected with Ambrotose®. Statistical analyses of the extent of acinar cell pathology in all virus-challenged mice showed that Ambrotose® contributed significantly to recovery of the acinar cell population in virus-inoculated mice. Anti-viral antibody titers were not affected by Ambrotose® injections. One potential mechanism to explain the benefits derived from Ambrotose® injections came from studies of antioxidant levels of glutathione in splenic macrophages/monocytes. Whereas CVB3 challenge of mice reduced glutathione levels in the latter cells, Ambrotose® injections to virus-challenged mice restored glutathione levels to those found in normal mice. In summary, most but not all mice derived benefits from Ambrotose® injections, i.e. a reduction in pathology in the pancreas and restored levels of the antioxidant glutathione in macrophages/monocytes. Higher doses of Ambrotose® could provide greater benefits for more mice, a study for the future.
Collapse
|
47
|
Robinson NM, Zhang HY, Bevan AL, De Belder AJ, Moncada S, Martin JF, Archard LC. Induction of myocardial nitric oxide synthase by Coxsackie B3 virus in mice. Eur J Clin Invest 1999; 29:700-7. [PMID: 10457155 DOI: 10.1046/j.1365-2362.1999.00505.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Inducible nitric oxide synthase (iNOS) expression is regulated by cytokines. This study investigated whether Coxsackie group B virus (CVB) myocarditis resulted in an environment suitable for induction of NOS in the murine heart. MATERIALS AND METHODS Myocardium was removed from mice infected with CVB3 and from controls. Histology, reverse transcriptase polymerase reaction (RT-PCR) for murine iNOS, NOS enzyme activity and immunohistochemistry were assessed. RESULTS Histology revealed severe myocarditis 7 days after infection with CVB3 but not in controls. RT-PCR using primers for murine iNOS detected iNOS mRNA in infected mice but not in controls. Calcium-independent NOS activity increased by day 5 after infection with a peak at day 7. Calcium-dependent NOS activity was present throughout, with a trend to lower levels during peak calcium-independent activity. Immunohistochemistry revealed iNOS to be localized to inflammatory cells rather than to myocytes. CONCLUSION This study demonstrates the development of calcium-independent NOS activity and de novo gene transcription for iNOS in the murine myocardium in response to CVB3 infection. The nitric oxide produced at such high output may act at times as part of the immune defence as an antiviral agent and may be toxic to host tissue.
Collapse
Affiliation(s)
- N M Robinson
- King's College Hospital Medical School, London, UK.
| | | | | | | | | | | | | |
Collapse
|
48
|
Mitchell RA, Metz CN, Peng T, Bucala R. Sustained mitogen-activated protein kinase (MAPK) and cytoplasmic phospholipase A2 activation by macrophage migration inhibitory factor (MIF). Regulatory role in cell proliferation and glucocorticoid action. J Biol Chem 1999; 274:18100-6. [PMID: 10364264 DOI: 10.1074/jbc.274.25.18100] [Citation(s) in RCA: 354] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Macrophage migration inhibitory factor (MIF) is an important pro-inflammatory mediator with the unique ability to counter-regulate the inhibitory effects of glucocorticoids on immune cell activation. MIF is released from cells in response to glucocorticoids, certain pro-inflammatory stimuli, and mitogens and acts to regulate glucocorticoid action on the ensuing inflammatory response. To gain insight into the molecular mechanism of MIF action, we have examined the role of MIF in the proliferation and intracellular signaling events of the well characterized, NIH/3T3 fibroblast cell line. Both endogenously secreted and exogenously added MIFs stimulate the proliferation of NIH/3T3 cells, and this response is associated with the activation of the p44/p42 extracellular signal-regulated (ERK) mitogen-activated protein kinases (MAP). The MIF-induced activation of these kinases was sustained for a period of at least 24 h and was dependent upon protein kinase A activity. We further show that MIF regulates cytosolic phospholipase A2 activity via a protein kinase A and ERK dependent pathway and that the glucocorticoid suppression of cytokine-induced cytoplasmic phospholipase A2 activity and arachidonic acid release can be reversed by the addition of recombinant MIF. These studies indicate that the sustained activation of p44/p42 MAP kinase and subsequent arachidonate release by cytoplasmic phospholipase A2 are important features of the immunoregulatory and intracellular signaling events initiated by MIF and provide the first insight into the mechanisms that underlie the pro-proliferative and inflammatory properties of this mediator.
Collapse
Affiliation(s)
- R A Mitchell
- Department of Experimental Pathology, Albany Medical College, Albany, New York 12208, USA
| | | | | | | |
Collapse
|