1
|
Barrett L, Curry N, Abu-Hanna J. Experimental Models of Traumatic Injuries: Do They Capture the Coagulopathy and Underlying Endotheliopathy Induced by Human Trauma? Int J Mol Sci 2023; 24:11174. [PMID: 37446351 PMCID: PMC10343021 DOI: 10.3390/ijms241311174] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 07/03/2023] [Accepted: 07/05/2023] [Indexed: 07/15/2023] Open
Abstract
Trauma-induced coagulopathy (TIC) is a major cause of morbidity and mortality in patients with traumatic injury. It describes the spectrum of coagulation abnormalities that occur because of the trauma itself and the body's response to the trauma. These coagulation abnormalities range from hypocoagulability and hyperfibrinolysis, resulting in potentially fatal bleeding, in the early stages of trauma to hypercoagulability, leading to widespread clot formation, in the later stages. Pathological changes in the vascular endothelium and its regulation of haemostasis, a phenomenon known as the endotheliopathy of trauma (EoT), are thought to underlie TIC. Our understanding of EoT and its contribution to TIC remains in its infancy largely due to the scarcity of experimental research. This review discusses the mechanisms employed by the vascular endothelium to regulate haemostasis and their dysregulation following traumatic injury before providing an overview of the available experimental in vitro and in vivo models of trauma and their applicability for the study of the EoT and its contribution to TIC.
Collapse
Affiliation(s)
- Liam Barrett
- Division of Anaesthesia, Department of Medicine, University of Cambridge, Cambridge CB2 1TN, UK;
- Emergency Department, Cambridge University Hospitals NHS Foundation Trust, Cambridge CB2 0QQ, UK
| | - Nicola Curry
- Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK;
- Oxford Haemophilia and Thrombosis Centre, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 7LD, UK
| | - Jeries Abu-Hanna
- Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK;
| |
Collapse
|
2
|
Hajtuch J, Iwicka E, Szczoczarz A, Flis D, Megiel E, Cieciórski P, Radomski MW, Santos-Martinez MJ, Inkielewicz-Stepniak I. The Pharmacological Effects of Silver Nanoparticles Functionalized with Eptifibatide on Platelets and Endothelial Cells. Int J Nanomedicine 2022; 17:4383-4400. [PMID: 36164554 PMCID: PMC9507977 DOI: 10.2147/ijn.s373691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 08/04/2022] [Indexed: 11/23/2022] Open
Abstract
Purpose In the search for new drug delivery platforms for cardiovascular diseases and coating of medical devices, we synthesized eptifibatide-functionalized silver nanoparticles (AgNPs-EPI) and examined the pharmacological activity of AgNPs-EPI on platelets and endothelial cells in vitro and ex vivo. Methods Spherical AgNPs linked to eptifibatide were synthesized and characterized. Cytotoxicity was measured in microvascular endothelial cells (HMEC-1), platelets and red blood cells. Platelet mitochondrial respiration was measured using the Oxygraph-2k, a high-resolution modular respirometry system. The effect of AgNPs-EPI on the aggregation of washed platelets was measured by light aggregometry and the ex vivo occlusion time was determined using a reference laboratory method. The surface amount of platelet receptors such as P-selectin and GPIIb/IIIa was measured. The influence of AgNPS-EPI on blood coagulation science was assessed. Finally, the effect of AgNPs-EPI on endothelial cells was measured by the levels of 6-keto-PGF1alpha, tPa, cGMP and vWF. Results We describe the synthesis of AgNPs using eptifibatide as the stabilizing ligand. The molecules of this drug are directly bonded to the surface of the nanoparticles. The synthesized AgNPs-EPI did not affect the viability of platelets, endothelial cells and erythrocytes. Preincubation of platelets with AgNPs-EPI protected by mitochondrial oxidative phosphorylation capacity. AgNPs-EPI inhibited aggregation-induced P-selectin expression and GPIIb/IIIa conformational changes in platelets. AgNPs-EPI caused prolongation of the occlusion time in the presence of collagen/ADP and collagen/adrenaline. AgNPs-EPI regulated levels of 6-keto-PGF1alpha, tPa, vWf and cGMP produced in thrombin stimulated HMEC-1 cells. Conclusion AgNPs-EPI show anti-aggregatory activity at concentrations lower than those required by the free drug acting via regulation of platelet aggregation, blood coagulation, and endothelial cell activity. Our results provide proof-of-principle evidence that AgNPs may be used as an effective delivery platform for antiplatelet drugs.
Collapse
Affiliation(s)
- Justyna Hajtuch
- Department of Pharmaceutical Pathophysiology, Medical University of Gdansk, Gdansk, Poland
| | - Eliza Iwicka
- Department of Pharmaceutical Pathophysiology, Medical University of Gdansk, Gdansk, Poland
| | - Anna Szczoczarz
- Department of Pharmaceutical Pathophysiology, Medical University of Gdansk, Gdansk, Poland
| | - Damian Flis
- Department of Pharmaceutical Pathophysiology, Medical University of Gdansk, Gdansk, Poland
| | | | | | - Marek Witold Radomski
- Department of Anatomy, Physiology and Pharmacology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Maria Jose Santos-Martinez
- School of Pharmacy and Pharmaceutical Sciences and School of Medicine, Trinity College Dublin, Dublin, Dublin 2, Ireland
| | | |
Collapse
|
3
|
Russo V, Fabiani D. Put out the fire: The pleiotropic anti-inflammatory action of non-vitamin K oral anticoagulants. Pharmacol Res 2022; 182:106335. [PMID: 35781059 DOI: 10.1016/j.phrs.2022.106335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 06/15/2022] [Accepted: 06/28/2022] [Indexed: 11/28/2022]
Abstract
Non-vitamin K antagonist oral anticoagulants (NOACs) should be the preferred anticoagulant strategy for preventing ischemic stroke in patients with atrial fibrillation (AF) at increased thromboembolic risk and for treating deep venous thromboembolism (DVT) in the general population. Beyond their inhibiting action on the activated factor X (FXa) or thrombin (FIIa), NOACs showed some pleiotropic anti-inflammatory effects. The present review aimed to describe the role of FXa and FIIa in the inflammation pathway and the potential anti-inflammatory effects of NOACs.
Collapse
Affiliation(s)
- Vincenzo Russo
- Cardiology Unit, Department of Medical Translational Sciences, University of Campania "Luigi Vanvitelli" - Monaldi Hospital, Naples, Italy.
| | - Dario Fabiani
- Cardiology Unit, Department of Medical Translational Sciences, University of Campania "Luigi Vanvitelli" - Monaldi Hospital, Naples, Italy
| |
Collapse
|
4
|
Tuo QZ, Liu Y, Xiang Z, Yan HF, Zou T, Shu Y, Ding XL, Zou JJ, Xu S, Tang F, Gong YQ, Li XL, Guo YJ, Zheng ZY, Deng AP, Yang ZZ, Li WJ, Zhang ST, Ayton S, Bush AI, Xu H, Dai L, Dong B, Lei P. Thrombin induces ACSL4-dependent ferroptosis during cerebral ischemia/reperfusion. Signal Transduct Target Ther 2022; 7:59. [PMID: 35197442 PMCID: PMC8866433 DOI: 10.1038/s41392-022-00917-z] [Citation(s) in RCA: 112] [Impact Index Per Article: 56.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 11/14/2021] [Accepted: 01/31/2022] [Indexed: 02/08/2023] Open
Abstract
Ischemic stroke represents a significant danger to human beings, especially the elderly. Interventions are only available to remove the clot, and the mechanism of neuronal death during ischemic stroke is still in debate. Ferroptosis is increasingly appreciated as a mechanism of cell death after ischemia in various organs. Here we report that the serine protease, thrombin, instigates ferroptotic signaling by promoting arachidonic acid mobilization and subsequent esterification by the ferroptotic gene, acyl-CoA synthetase long-chain family member 4 (ACSL4). An unbiased multi-omics approach identified thrombin and ACSL4 genes/proteins, and their pro-ferroptotic phosphatidylethanolamine lipid products, as prominently altered upon the middle cerebral artery occlusion in rodents. Genetically or pharmacologically inhibiting multiple points in this pathway attenuated outcomes of models of ischemia in vitro and in vivo. Therefore, the thrombin-ACSL4 axis may be a key therapeutic target to ameliorate ferroptotic neuronal injury during ischemic stroke.
Collapse
Affiliation(s)
- Qing-Zhang Tuo
- Department of Geriatrics and State Key Laboratory of Biotherapy, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, 610041, Chengdu, Sichuan, China
| | - Yu Liu
- Department of Geriatrics and State Key Laboratory of Biotherapy, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, 610041, Chengdu, Sichuan, China
| | - Zheng Xiang
- Department of Geriatrics and State Key Laboratory of Biotherapy, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, 610041, Chengdu, Sichuan, China
| | - Hong-Fa Yan
- Department of Neurology and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, 610041, Chengdu, Sichuan, China
| | - Ting Zou
- West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, 610041, Chengdu, Sichuan, China
| | - Yang Shu
- Department of Laboratory Medicine, Precision Medicine Center, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, 610041, Chengdu, Sichuan, China
| | - Xu-Long Ding
- Department of Neurology and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, 610041, Chengdu, Sichuan, China
| | - Jin-Jun Zou
- Department of Neurology and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, 610041, Chengdu, Sichuan, China
| | - Shuo Xu
- West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, 610041, Chengdu, Sichuan, China
| | - Fei Tang
- Department of Neurology and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, 610041, Chengdu, Sichuan, China
| | - Yan-Qiu Gong
- Department of Geriatrics and State Key Laboratory of Biotherapy, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, 610041, Chengdu, Sichuan, China
| | - Xiao-Lan Li
- Department of Neurology and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, 610041, Chengdu, Sichuan, China
| | - Yu-Jie Guo
- Department of Neurology and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, 610041, Chengdu, Sichuan, China
| | - Zhao-Yue Zheng
- Department of Geriatrics and State Key Laboratory of Biotherapy, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, 610041, Chengdu, Sichuan, China
| | - Ai-Ping Deng
- Department of Neurology and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, 610041, Chengdu, Sichuan, China
| | - Zhang-Zhong Yang
- Department of Neurology and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, 610041, Chengdu, Sichuan, China
| | - Wen-Jing Li
- Department of Neurology and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, 610041, Chengdu, Sichuan, China
| | - Shu-Ting Zhang
- Department of Neurology and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, 610041, Chengdu, Sichuan, China
| | - Scott Ayton
- Melbourne Dementia Research Centre, Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Ashley I Bush
- Melbourne Dementia Research Centre, Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Heng Xu
- Department of Laboratory Medicine, Precision Medicine Center, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, 610041, Chengdu, Sichuan, China
| | - Lunzhi Dai
- Department of Geriatrics and State Key Laboratory of Biotherapy, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, 610041, Chengdu, Sichuan, China.
| | - Biao Dong
- Department of Geriatrics and State Key Laboratory of Biotherapy, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, 610041, Chengdu, Sichuan, China.
| | - Peng Lei
- Department of Geriatrics and State Key Laboratory of Biotherapy, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, 610041, Chengdu, Sichuan, China. .,Department of Neurology and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, 610041, Chengdu, Sichuan, China. .,West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, 610041, Chengdu, Sichuan, China.
| |
Collapse
|
5
|
d'Uscio LV, He T, Katusic ZS. Expression and Processing of Amyloid Precursor Protein in Vascular Endothelium. Physiology (Bethesda) 2017; 32:20-32. [PMID: 27927802 DOI: 10.1152/physiol.00021.2016] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Amyloid precursor protein (APP) is evolutionary conserved protein expressed in endothelial cells of cerebral and peripheral arteries. In this review, we discuss mechanisms responsible for expression and proteolytic cleavage of APP in endothelial cells. We focus on physiological and pathological implications of APP expression in vascular endothelium.
Collapse
Affiliation(s)
- Livius V d'Uscio
- Departments of Anesthesiology and Molecular Pharmacology & Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Tongrong He
- Departments of Anesthesiology and Molecular Pharmacology & Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Zvonimir S Katusic
- Departments of Anesthesiology and Molecular Pharmacology & Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, Minnesota
| |
Collapse
|
6
|
Abstract
In the mammalian kidney, prostaglandins (PGs) are important mediators of physiologic processes, including modulation of vascular tone and salt and water. PGs arise from enzymatic metabolism of free arachidonic acid (AA), which is cleaved from membrane phospholipids by phospholipase A2 activity. The cyclooxygenase (COX) enzyme system is a major pathway for metabolism of AA in the kidney. COX are the enzymes responsible for the initial conversion of AA to PGG2 and subsequently to PGH2, which serves as the precursor for subsequent metabolism by PG and thromboxane synthases. In addition to high levels of expression of the "constitutive" rate-limiting enzyme responsible for prostanoid production, COX-1, the "inducible" isoform of cyclooxygenase, COX-2, is also constitutively expressed in the kidney and is highly regulated in response to alterations in intravascular volume. PGs and thromboxane A2 exert their biological functions predominantly through activation of specific 7-transmembrane G-protein-coupled receptors. COX metabolites have been shown to exert important physiologic functions in maintenance of renal blood flow, mediation of renin release and regulation of sodium excretion. In addition to physiologic regulation of prostanoid production in the kidney, increases in prostanoid production are also seen in a variety of inflammatory renal injuries, and COX metabolites may serve as mediators of inflammatory injury in renal disease.
Collapse
Affiliation(s)
- Raymond C Harris
- George M. O'Brien Kidney and Urologic Diseases Center and Division of Nephrology, Vanderbilt University School of Medicine and Nashville Veterans Affairs Hospital, Nashville, Tennessee, USA.
| | | |
Collapse
|
7
|
Abstract
OBJECTIVES To review the role of thrombin in physiology and clinical disease and to discuss the pharmacology of antithrombosis. DATA SOURCES Original research articles, scientific reviews, textbooks. HUMAN DATA SYNTHESIS Thrombin and thrombin receptors are involved in a variety of physiologic and pathologic processes resulting in a great deal of interest in thrombin-related pharmacologic intervention. VETERINARY DATA SYNTHESIS Although there is little clinical research data available on thrombin specifically in veterinary patients, some of the original research on protease activated receptors was performed at veterinary institutions and many of the human molecular biology studies have been done on animals including dogs. CONCLUSION Thrombin plays a significant role in coagulation, anticoagulation, and fibrinolysis. Antithrombotic treatment is focused on preventing thrombosis while maintaining hemostasis. Pharmaceutical agents are selected for the specific component of the coagulation pathway associated with a specific disease process, for a proven prophylactic benefit with procedures that carry a risk of thromboembolism, for rapidity of onset and ease of reversibility, for limited monitoring requirements, and for oral formulation and bioavailablity. Recent insight into other aspects of thrombin physiology presents an opportunity for pharmacologic intervention in a variety of other processes such as inflammation and sepsis, peripheral blood cell activation and chemotaxis, vascular endothelial and smooth muscle activity, cellular development and tissue repair, mitogenesis, neoplasia, and the function of nervous tissue following injury.
Collapse
Affiliation(s)
- Louis G Licari
- Department of Emergency and Critical Care, Fox Valley Animal Referral Center, Appleton, WI 54914, USA.
| | | |
Collapse
|
8
|
Burnette JO, White RE. PGI2 opens potassium channels in retinal pericytes by cyclic AMP-stimulated, cross-activation of PKG. Exp Eye Res 2006; 83:1359-65. [PMID: 16959250 DOI: 10.1016/j.exer.2006.07.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2006] [Revised: 06/09/2006] [Accepted: 07/13/2006] [Indexed: 11/25/2022]
Abstract
Pericytes exert an important influence on the control of retinal blood flow; however, little is known regarding the molecular basis of retinal pericyte excitability. The purpose of this study was to elucidate the signaling pathway of how prostacyclin (PGI2), an important endogenous regulator of retinal blood flow, stimulates potassium channel activity in retinal pericytes. Retinal pericytes were isolated from porcine eyeballs and plated on glass coverslips. Immunocytochemistry was performed to verify expression of the pericyte-specific ganglioside marker, 3G5 and smooth muscle alpha-actin. Activity of the large-conductance, voltage- and calcium-activated potassium (BKCa) channel was measured in retinal pericytes via single-channel patch-clamp, and channel identification was confirmed via biophysical and pharmacological characterization. PGI2 (10 microM) or beraprost (30 microM; more stable prostacyclin analog) dramatically stimulated the activity of BKCa channels isolated in cell-attached patches. These experiments strongly suggested that PGI2 stimulated BKCa channel activity via a diffusible second messenger. Similarly, chlorophenylthio (CPT)-cAMP (100 microM; membrane permeable cAMP derivative) induced a significant increase in BKCa channel activity; however, inhibition of the cAMP-dependent protein kinase (PKA) with 300 nM KT5720 could not reverse the stimulatory effect of either PGI2 or CPT-cAMP. In contrast, activation of BK(Ca) channels with either CPT-cAMP or PGI2 was abolished by 300 nM KT5823 (n=5, p<0.01), an inhibitor of the cGMP-dependent protein kinase (PKG). In addition, PGI2-stimulated channel activity was also attenuated by Rp-8-CPT-cGMPS, which inhibits PKG activity via a different mechanism. These findings demonstrate that prostacyclin, the most abundant prostanoid in the retinal circulation, is a potent stimulator of BKCa channel activity in retinal pericytes. Interestingly, this response appears to involve cAMP-stimulated cross-activation of PKG, and not PKA. Taken together, these findings could explain, at least in part, the cellular/molecular basis for PGI2-induced pericyte relaxation and augmentation of blood flow in the retina. Further, we propose PKG-dependent stimulation of BKCa channel activity as a new potential therapeutic target to combat decreased retinal blood flow seen in some disease states (e.g., diabetic retinopathy).
Collapse
Affiliation(s)
- Jason O Burnette
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta, GA 30912, USA
| | | |
Collapse
|
9
|
Syeda F, Grosjean J, Houliston RA, Keogh RJ, Carter TD, Paleolog E, Wheeler-Jones CPD. Cyclooxygenase-2 induction and prostacyclin release by protease-activated receptors in endothelial cells require cooperation between mitogen-activated protein kinase and NF-kappaB pathways. J Biol Chem 2006; 281:11792-804. [PMID: 16467309 DOI: 10.1074/jbc.m509292200] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The functional significance of protease-activated receptors (PARs) in endothelial cells is largely undefined, and the intracellular consequences of their activation are poorly understood. Here, we show that the serine protease thrombin, a PAR-1-selective peptide (TFLLRN), and SLIGKV (PAR-2-selective peptide) induce cyclooxygenase-2 (COX-2) protein and mRNA expression in human endothelial cells without modifying COX-1 expression. COX-2 induction was accompanied by sustained production of 6-keto-PGF1alpha, the stable hydrolysis product of prostacyclin, and this was inhibited by indomethacin and the COX-2-selective inhibitor NS398. PAR-1 and PAR-2 stimulation rapidly activated both ERK1/2 and p38MAPK, and pharmacological blockade of MEK with either PD98059 or U0126 or of p38MAPK by SB203580 or SB202190 strongly inhibited thrombin- and SLIGKV-induced COX-2 expression and 6-keto-PGF1alpha formation. Thrombin and peptide agonists of PAR-1 and PAR-2 increased luciferase activity in human umbilical vein endothelial cells infected with an NF-kappaB-dependent luciferase reporter adenovirus, and this, as well as PAR-induced 6-keto-PGF1alpha synthesis, was inhibited by co-infection with adenovirus encoding wild-type or mutated (Y42F) IkappaBalpha. Thrombin- and SLIGKV-induced COX-2 expression and 6-keto-PGF1alpha generation were markedly attenuated by the NF-kappaB inhibitor PG490 and partially inhibited by the proteasome pathway inhibitor MG-132. Activation of PAR-1 or PAR-2 promoted nuclear translocation and phosphorylation of p65-NF-kappaB, and thrombin-induced but not PAR-2-induced p65-NF-kappaB phosphorylation was reduced by inhibition of MEK or p38MAPK. Activation of PAR-4 by AYPGKF increased phosphorylation of ERK1/2 and p38MAPK without modifying NF-kappaB activation or COX-2 induction. Our data show that PAR-1 and PAR-2, but not PAR-4, are coupled with COX-2 expression and sustained endothelial production of vasculoprotective prostacyclin by mechanisms that depend on ERK1/2, p38MAPK, and IkappaBalpha-dependent NF-kappaB activation.
Collapse
Affiliation(s)
- Farisa Syeda
- Department of Veterinary Basic Sciences, Royal Veterinary College, Royal College Street, London NW1 0TU, United Kingdom
| | | | | | | | | | | | | |
Collapse
|
10
|
Tang EHC, Feletou M, Huang Y, Man RYK, Vanhoutte PM. Acetylcholine and sodium nitroprusside cause long-term inhibition of EDCF-mediated contractions. Am J Physiol Heart Circ Physiol 2005; 289:H2434-40. [PMID: 16040712 DOI: 10.1152/ajpheart.00568.2005] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Preliminary studies suggested that previous exposure to acetylcholine (ACh) exerts a delayed inhibition of subsequent contractions mediated by endothelium-derived contracting factor (EDCF). To confirm this long-term inhibitory effect of ACh and to determine whether nitric oxide (NO) mediates the phenomenon, we suspended rings of spontaneously hypertensive rat (SHR) aortas in organ chambers for the recording of isometric force. The rings were incubated in the absence or presence of Nω-nitro-l-arginine methyl ester (l-NAME; inhibitor of NO synthases) or 1 H-[1,2,4]oxadiazolo[4,3-α]quinoxalin-1-one (ODQ; inhibitor of soluble guanylyl cyclase) before exposure to increasing concentrations of ACh or sodium nitroprusside (SNP) during contractions to phenylephrine. Thereafter, EDCF-mediated contractions to ACh or the calcium ionophore A-23187 were elicited. If the rings were preexposed to ACh or SNP, the subsequent ACh-induced EDCF-mediated contractions were reduced compared with those obtained in rings of the same arteries not previously exposed to either agent. ODQ did not affect the inhibition caused by preexposure to ACh but significantly reduced that caused by preexposure to SNP. Previous exposure to SNP reduced, whereas previous exposure to ACh did not affect, endothelium-dependent contractions to A-23187. Previous exposure to either ACh or SNP did not affect the contractions to the thromboxane mimetic U-46619. Thus ACh and SNP exert delayed inhibition of EDCF-mediated contractions via distinct pathways. The effect of ACh is NO independent and upstream of the increase in calcium concentration that triggers the release of EDCF. The effect of SNP is downstream of the calcium rise and is mainly NO dependent.
Collapse
Affiliation(s)
- Eva H C Tang
- Dept. of Pharmacology, Univ. of Hong Kong, 2/F, Laboratory Block, Faculty of Medicine Bldg., 21 Sassoon Road, Pokfulam, Hong Kong
| | | | | | | | | |
Collapse
|
11
|
Affiliation(s)
- Greg Stratmann
- *Department of Anesthesia and Perioperative Care and †Pediatrics, University of California at San Francisco
| | | |
Collapse
|
12
|
Abstract
Hyperglycaemia appears to be a critical factor in the aetiology of diabetic retinopathy and initiates downstream events including: basement membrane thickening, pericyte drop out and retinal capillary non-perfusion. More recently, focus has been directed to the molecular basis of the disease process in diabetic retinopathy. Of particular importance in the development and progression of diabetic retinopathy is the role of growth factors (eg vascular endothelial growth factor, placenta growth factor and pigment epithelium-derived factor) together with specific receptors and obligate components of the signal transduction pathway needed to support them. Despite these advances there are still a number of important questions that remain to be answered before we can confidently target pathological signals. How does hyperglycaemia regulate retinal vessels? Which growth factors are most important and at what stage of retinopathy do they operate? What is the preferred point in the growth factor signalling cascade for therapeutic intervention? Answers to these questions will provide the basis for new therapeutic interventions in a debilitating ocular condition.
Collapse
Affiliation(s)
- J Cai
- Department of Optometry and Vision Sciences, Cardiff University, UK
| | | |
Collapse
|
13
|
Akamatsu N, Sawada S, Komatsu S, Tamagaki T, Hiranuma O, Kawahara T, Tsuda Y, Kono Y, Higaki T, Tada Y, Yamasaki S, Imamura H, Sato T, Tsuji H, Nakagawa M. Effect of cicletanine on the nitric oxide pathway in human umbilical vein endothelial cells. J Cardiovasc Pharmacol 2001; 38:174-82. [PMID: 11483866 DOI: 10.1097/00005344-200108000-00002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The purpose of this study was to evaluate the effects of cicletanine, a slightly diuretic antihypertensive drug, on human vascular endothelial cells with regard to nitric oxide, intracellular calcium concentration ([Ca2+]i), cyclic nucleotide, inositol 1,4,5-trisphosphate (IP3), and prostacyclin generation. Primary cultured human umbilical vein endothelial cells were used in this study. [Ca2+]i was measured by fura-2/AM. Cyclic adenosine monophosphate (AMP), cyclic guanosine monophosphate (GMP), IP3, and prostacyclin were measured by radioimmunoassay. Nitric oxide was measured by the Griess method. Cicletanine had no effect on [Ca2+]i. Cicletanine (10(-6)-10(-4) M) increased cyclic GMP but decreased prostacyclin generation. Cicletanine had no stimulating effect on cyclic AMP or IP3 generation. IP3 increased 45Ca release from storage sites. Cicletanine decreased prostacyclin generation via increase in cyclic GMP. Cicletanine had no stimulating effect on nitrogen oxides for 2 h after incubation but increased it after 3-24 h. Pretreatment with L-N(G)-monomethyl-arginine (L-NMMA) prevented this increase. The inhibitory effect of L-NMMA was prevented by pretreatment with L-arginine. These results indicate that nitric oxide and cyclic GMP may contribute to the antihypertensive action of cicletanine.
Collapse
Affiliation(s)
- N Akamatsu
- Second Department of Medicine, Kyoto Prefectural University of Medicine, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Abstract
Cyclooxygenase metabolizes arachidonic acid to a family of bioactive fatty acids designated prostaglandins. Two isoforms of cyclooxygenase exist, designated COX1 and COX2. These isoforms are expressed in distinct but important areas of the kidney. COX1 predominates in vascular smooth muscle and collecting ducts, whereas COX2 predominates in the macula densa and nearby cells in the cortical thick ascending limb. COX2 is also highly expressed in medullary interstitial cells. Whereas COX1 expression does not exhibit dynamic regulation, COX2 expression is subject to regulation by several environmental conditions, including salt intake, water intake, medullary tonicity, growth factors, cytokines, and adrenal steroids. Recently, COX2-selective non-steroidal anti-inflammatory drugs have become widely available. Many of the renal effects of non-selective non-steroidal anti-inflammatory drugs (including sodium retention, decreased glomerular filtration rate, and effects on renin-angiotensin levels) appear to be mediated by the inhibition of COX2 rather than COX1. Therefore, in contrast to the gastrointestinal-sparing effects of COX2-selective non-steroidal anti-inflammatory drugs, when considering the kidney, the same caution must be applied when using COX2-selective inhibitors as has been used with traditional non-selective non-steroidal anti-inflammatory drugs.
Collapse
Affiliation(s)
- M D Breyer
- Department of Medicine, Veterans Administration Medical Center and Vanderbilt University, Nashville, Tennessee, USA.
| | | |
Collapse
|