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Query: UMLS:C0043167 (
pertussis
)
19,595
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Multiple sclerosis (MS) is the most common of the immune demyelinating disorders of the central nervous system (CNS). Leukocyte/endothelial interactions are important steps in the progression of the disease and substances that interfere with these activities have been evaluated as potential therapeutic agents. Cannabinoid receptor agonists have been shown to downregulate immune responses and there is preliminary evidence that they may slow the progress of MS. The purpose of this investigation was to determine how cannabinoid receptor agonists interfere with leukocyte rolling and adhesion. This was investigated in an experimental autoimmune encephalomyelitis (EAE) model using six to eight week old C57BL/6 mice. Mouse myelin oligodendrocyte protein and
pertussis
toxin were used to induce EAE. WIN 55212-2, CB1 and
CB2
antagonist were given. By use of in vivo intravital microscopy, leukocyte/endothelial interactions were evaluated via a cranial window implanted two days before. The results demonstrated that EAE increases leukocyte rolling and firm adhesion in the brain, and that this increased leukocyte/endothelial interaction can be attenuated by administration of WIN 55212-2. Furthermore, use of the selective antagonists for the CB1 receptor (SR 141716A) and the
CB2
receptor (SR144528) in this study demonstrated that the cannabinoid's inhibitory effects on leukocyte/endothelial interactions can be mediated by activating
CB2
receptor.
...
PMID:Win 55212-2, a cannabinoid receptor agonist, attenuates leukocyte/endothelial interactions in an experimental autoimmune encephalomyelitis model. 1512 61
1 Noladin ether has recently been reported to be an endocannabinoid, with selectivity for the cannabinoid (CB) CB1 receptor. In the present study, we investigated the effects of noladin ether in the rat isolated mesenteric arterial bed, cultured dorsal root ganglia (DRG) cells and human vanilloid (TRPV1)-receptor-expressing HEK293 cells (TRPV1-HEK293 cells). 2 Electrical field stimulation of the mesenteric bed evoked frequency-dependent vasorelaxation due to the action of calcitonin gene-related peptide (CGRP) released from sensory nerves. Noladin ether (0.1-3 microm) attenuated sensory neurogenic relaxation in a concentration-dependent manner. Noladin ether (1 microm) reduced vasorelaxation at a submaximal frequency (8 Hz), from 57.3+/-6.8 to 23.3+/-3.8% (P<0.05, n=4). 3 The inhibitory effects of noladin ether were unaffected by the CB1 antagonists SR141716A and LY320135, and the
CB2
antagonist SR144528 (1 microm). 4 Noladin ether had no effect on vasorelaxation elicited by exogenous CGRP or capsaicin. These data suggest that noladin ether is acting at a prejunctional site and no interaction with TRPV1 is involved. 5 In mesenteric beds from
pertussis
toxin (PTX)-pretreated rats, the inhibitory actions of noladin ether on sensory neurotransmission were abolished, indicating the involvement of G(i/o) protein-coupled receptors. 6 Noladin ether evoked a concentration-dependent increase in intracellular Ca2+ concentration in TRPV1-HEK293 cells at 10 microm (36.5+/-3.2% of maximal capsaicin-induced response), but it was a less potent agonist than both capsaicin and anandamide and at 1 microm it was essentially inactive. Noladin ether (1 microm) had no effect on capsaicin-evoked Ca2+ responses in DRG cells, and produced no response alone, indicating it neither modulates nor acts directly on TRPV1 receptors. 7 These data demonstrate that noladin ether attenuates sensory neurotransmission in rat mesenteric arteries via a non-CB1 non-
CB2
PTX-sensitive prejunctional site, independently of TRPV1 receptors.
...
PMID:Noladin ether, a putative endocannabinoid, attenuates sensory neurotransmission in the rat isolated mesenteric arterial bed via a non-CB1/CB2 G(i/o) linked receptor. 1514 62
2-arachidonoylglycerol (2-AG) is an endogenous cannabinoid receptor ligand. To date, two types of cannabinoid receptors have been identified: the CB1 receptor, abundantly expressed in the brain, and the
CB2
receptor, expressed in various lymphoid tissues such as the spleen. The CB1 receptor has been assumed to play an important role in the regulation of synaptic transmission, whereas the physiological roles of the
CB2
receptor remain obscure. In this study, we examined whether the
CB2
receptor is present in human eosinophils and found that the
CB2
receptor is expressed in human peripheral blood eosinophils. In contrast, human neutrophils do not contain a significant amount of the
CB2
receptor. We then examined the effect of 2-AG on the motility of eosinophils. We found that 2-AG induces the migration of human eosinophilic leukemia EoL-1 cells. The migration evoked by 2-AG was abolished in the presence of SR144528, a
CB2
receptor antagonist, or by pretreatment of the cells with
pertussis
toxin, suggesting that the
CB2
receptor and Gi/o are involved in the 2-AG-induced migration. The migration of EoL-1 cells induced by 2-AG was suggested to be a result of chemotaxis. In contrast to 2-AG, neither anandamide nor free arachidonic acid elicited the migration. Finally, we examined the effect of 2-AG on human peripheral blood eosinophils and neutrophils and found that 2-AG induces migration of eosinophils but not neutrophils. These results suggest that the
CB2
receptor and its endogenous ligand 2-AG may be closely involved in allergic inflammation accompanied by the infiltration of eosinophils.
...
PMID:2-arachidonoylglycerol, an endogenous cannabinoid receptor ligand, induces the migration of EoL-1 human eosinophilic leukemia cells and human peripheral blood eosinophils. 1531 28
Delta9-Tetrahydrocannabinol, a major psychoactive constituent of marijuana, interacts with specific receptors, i.e. the cannabinoid receptors, thereby eliciting a variety of pharmacological responses. To date, two types of cannabinoid receptors have been identified: the CB1 receptor, which is abundantly expressed in the nervous system, and the
CB2
receptor, which is predominantly expressed in the immune system. Previously, we investigated in detail the structure-activity relationship of various cannabinoid receptor ligands and found that 2-AG (2-arachidonoylglycerol) is the most efficacious agonist. We have proposed that 2-AG is the true natural ligand for both the CB1 and
CB2
receptors. Despite the potential physiological importance of 2-AG, not much information is available concerning its biological activities towards mammalian tissues and cells. In the present study, we examined the effect of 2-AG on morphology as well as the actin filament system in differentiated HL-60 cells, which express the
CB2
receptor. We found that 2-AG induces rapid morphological changes such as the extension of pseudopods. We also found that it provokes a rapid actin polymerization in these cells. Actin polymerization induced by 2-AG was abolished when cells were treated with SR144528, a
CB2
receptor antagonist, and
pertussis
toxin, suggesting that the response was mediated by the
CB2
receptor and G(i/o). A phosphoinositide 3-kinase, Rho family small G-proteins and a tyrosine kinase were also suggested to be involved. Reorganization of the actin filament system is known to be indispensable for a variety of cellular events; it is possible that 2-AG plays physiologically essential roles in various inflammatory cells and immune-competent cells by inducing a rapid actin rearrangement.
...
PMID:2-arachidonoylglycerol, an endogenous cannabinoid receptor ligand, induces rapid actin polymerization in HL-60 cells differentiated into macrophage-like cells. 1545 4
The vascular effects of cannabinoids have been compared in the rat isolated aorta. Delta9-Tetrahydrocannabinol (THC), anandamide and N-arachidonoyl-dopamine (NADA) all caused vasorelaxation to similar degrees in pre-constricted aortae. Vasorelaxation to THC was inhibited by in vivo pre-treatment with
pertussis
toxin (10 microg/kg) or with the synthetic cannabinoid CP55,940 (((-)-cis-3-[2-hydroxy-4-(1,1-dimethylheptyl)phenyl]-trans-4-(3-hydroxypropyl)cyclohexanol), acutely or chronically), exposure to capsaicin in vitro (10 microM for 1 h), and de-endothelialisation. Vasorelaxation to anandamide was only inhibited by
pertussis
toxin and chronic CP55,940 pre-treatment (0.4 mg/kg for 11 days). Vasorelaxation to NADA was inhibited by
pertussis
toxin and chronic CP55,940 pre-treatment, and by de-endothelialisation. The vasorelaxant effects of the cannabinoids were not inhibited by cannabinoid CB1 receptor antagonism; however, vasorelaxation to both CP55,940 and THC was inhibited by cannabinoid
CB2
receptor antagonism. Vasorelaxation to all cannabinoids was enhanced in the presence of indomethacin (10 microM). THC also caused vasoconstriction of the aorta while anandamide, NADA, CP55,940 and WIN 55,212-2 (R(+)-[2,3-dihydro-5-methyl-3-[(morpholinyl)methyl]pyrrolo[1,2,3-de]-1,4benzoxazin-yl]-(1-naphthalenyl)methanone mesylate) did not. The vasoconstrictor effects of THC were inhibited by in vivo pre-treatment with
pertussis
toxin or CP55,940, acute exposure to CP55,940, cannabinoid CB1 receptor antagonism and cyclooxygenase inhibition. These results demonstrate the opposing vascular effects of cannabinoids in the rat aorta, and although vasorelaxation to each of the cannabinoids is of similar magnitude, it is mediated through different pathways. This gives further indication of the different vascular actions of cannabinoid compounds.
...
PMID:Vascular effects of delta 9-tetrahydrocannabinol (THC), anandamide and N-arachidonoyldopamine (NADA) in the rat isolated aorta. 1565 11
We evaluated the ability of cannabidiol (CBD) to impair the migration of tumor cells stimulated by conditioned medium. CBD caused concentration-dependent inhibition of the migration of U87 glioma cells, quantified in a Boyden chamber. Since these cells express both cannabinoid CB1 and
CB2
receptors in the membrane, we also evaluated their engagement in the antimigratory effect of CBD. The inhibition of cell was not antagonized either by the selective cannabinoid receptor antagonists SR141716 (CB1) and SR144528 (
CB2
) or by pretreatment with
pertussis
toxin, indicating no involvement of classical cannabinoid receptors and/or receptors coupled to Gi/o proteins. These results reinforce the evidence of antitumoral properties of CBD, demonstrating its ability to limit tumor invasion, although the mechanism of its pharmacological effects remains to be clarified.
...
PMID:Cannabidiol inhibits human glioma cell migration through a cannabinoid receptor-independent mechanism. 1570 28
Noladin ether (NE) is a putative endogenously occurring cannabinoid demonstrating agonist activity at CB1 receptors. Because of reported selective affinity for CB1 receptors, the pharmacological actions of NE at
CB2
receptors have not been examined. Therefore, the purpose of this study was to characterize the binding and functional properties of NE at human
CB2
receptors stably expressed in Chinese hamster ovary (CHO) cells as well as in HL-60 cells, which express
CB2
receptors endogenously. Surprisingly, in transfected CHO cells, NE exhibits a relatively high nanomolar affinity for
CB2
receptors (K(i) = 480 nM), comparable to that observed for the endocannabinoid 2-arachidonoyl glycerol (2-AG) (K(i) = 1016 nM). Furthermore, NE activates G proteins and inhibits the intracellular effector adenylyl cyclase with equivalent efficacy relative to the full cannabinoid agonists 2-AG and CP 55,940 (CP) [(-)-cis-3-[2-hydroxy-4-(1,1-dimethylheptyl)phenyl]-trans-4-(3-hydroxypropyl) cyclohexanol]. The rank order of potency for G protein activation and effector regulation by the three agonists is similar to their apparent affinity for
CB2
receptors; CP > NE > or = 2-AG. Regulation of adenylyl cyclase activity by all agonists is inhibited by
pertussis
toxin pretreatment or by coincubation with AM630 [6-iodo-2-methyl-1-[2-(4-morpholinyl)ethyl]-1H-indol-3-yl](4-methoxyphenyl)-methanone], a
CB2
antagonist. Chronic treatment with NE or CP results in
CB2
receptor desensitization and down-regulation. All agonists also inhibit adenylyl cyclase activity in HL-60 cells. Together, these data indicate that NE acts as a full agonist at human
CB2
receptors and thus might have important physiological functions at peripheral cannabinoid receptors.
...
PMID:The endocannabinoid noladin ether acts as a full agonist at human CB2 cannabinoid receptors. 1590 5
Cardiac contractility in cirrhosis is normal at baseline but hyporesponsive to stimuli, a phenomenon known as 'cirrhotic cardiomyopathy'. The pathogenesis remains unclear. Endocannabinoids are vasoactive, but have not previously been examined in the cirrhotic heart. We therefore aimed to systematically clarify a possible role of endocannabinoids in the pathogenesis of cirrhotic cardiomyopathy. Cirrhosis was induced in Sprague-Dawley rats by bile duct ligation; controls underwent a sham operation. At 4 weeks after operation, isolated left ventricular papillary muscle contractility was studied. Dose-response curve for a beta-adrenergic agonist isoproterenol was constructed in the presence and absence of a CB-1 antagonist AM251 (1 microM). Cirrhotic muscles had a blunted response to isoproterenol, which was completely restored by AM251. Dose-response curves to anandamide, and CB-1 and
CB-2
protein and mRNA expression in Western blot and reverse transcriptase-polymerase chain reaction experiments were not significantly different between cirrhotic and sham muscles. Force-frequency relationship studies were performed in cirrhotic and normal muscles. At higher frequencies, anandamide reuptake blockers (VDM11 and AM404) significantly enhanced muscle relaxation in cirrhotic muscles, but not in controls. This effect was completely blocked by AM251 and
pertussis
toxin, whereas tetrodotoxin partially reversed it. Taken together, these results indicate a pathogenic role for increased local (neuronal) production of endocannabinoids, mediated by a G(i)-protein-dependent CB-1-responsive pathway in cirrhotic cardiomyopathy. The increased tachycardia-stress-induced release of endocannabinoids may help explain why contractility is normal at baseline but attenuated with stress.
...
PMID:Role of endocannabinoids in the pathogenesis of cirrhotic cardiomyopathy in bile duct-ligated rats. 1602 38
This study examined the ability of the endocannabinoids 2-arachidonoyl glycerol (2-AG) and noladin ether as well as the synthetic cannabinoid CP-55,940 [(-)-cis-3-[2-hydroxy-4-(1,1-dimethylheptyl)phenyl]-trans-4-(3-hydroxypropyl) cyclohexanol] to regulate three intracellular effectors via
CB2
receptors in transfected Chinese hamster ovary cells. Although the three agonists regulate all effectors with equivalent efficacy, the rank order of potencies differs depending on which effector is evaluated. Noladin ether and CP-55,940 most potently inhibit adenylyl cyclase, requiring higher concentrations to stimulate the extracellular signal-regulated kinase subgroup of the mitogen-activated protein kinases (extracellular signal-regulated kinase-mitogen-activated protein kinase; ERK-MAPK) and Ca(2+)-transients. In contrast, 2-AG most potently activates ERK-MAPK, necessitating greater concentrations to inhibit adenylyl cyclase and even higher amounts to stimulate Ca(2+)-transients. Endocannabinoids also seem to be more "efficient" agonists at
CB2
receptors relative to synthetic agonists. 2-AG and noladin ether require occupancy of less than one-half the number of receptors to produce comparable regulation of adenylyl cyclase and ERK-MAPK, relative to the synthetic cannabinoid CP-55,940. The
CB2
antagonist 6-iodo-2-methyl-1-[2-(4-morpholinyl)-ethyl]-1H-indol-3-yl](4-methoxyphenyl)-methanone (AM630) reverses the actions of all agonists except Ca(2+)-transient stimulation by 2-AG. However, the effect of 2-AG on Ca(2+)-transients is attenuated by a second
CB2
antagonist N-[(1S)-endo-1,3,3-trimethylbicyclo[2.2.1]heptan-2-yl]-5-(4-chloro-3-methylphenyl)-1-(4-methylbenzyl)-1-pyrazole-3-carboxamide (SR144528). This suggests that 2-AG stimulates Ca(2+)-transients by binding to sites on
CB2
receptors distinct from those occupied by AM630 and the other cannabinoids examined. Agonists produce no effects in
pertussis
toxin-treated cells. In summary, cannabinoid agonists distinctly bind to
CB2
receptors and display different rank order of potencies and fractional receptor occupancies for regulation of intracellular effectors. These data provide direct evidence for agonist-directed trafficking of response by endocannabinoids acting at
CB2
receptors.
...
PMID:Agonist-directed trafficking of response by endocannabinoids acting at CB2 receptors. 1608 74
R(+)WIN 55,212-2 is a synthetic cannabinoid that controls disease progression in models of multiple sclerosis. This is associated with its ability to reduce migration of leukocytes into the central nervous system. Because leukocyte migration is dependent on induction of adhesion molecules and chemokines by pro-inflammatory cytokines, we examined the effects of R(+)WIN 55,212-2 on their expression. Using 1321N1 astrocytoma and A-172 glioblastoma as cell models we show that R(+)WIN 55,212-2, but not its inactive chiral form S(-)WIN 55,212-2, strongly inhibits the interleukin-1 (IL-1) induction of the adhesion molecules intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) and the chemokine IL-8. This inhibition is not mediated via the CB1 or
CB2
cannabinoid receptors, because their selective antagonists and
pertussis
toxin failed to affect the inhibitory effects of R(+)WIN 55,212-2. Furthermore reverse transcription-PCR analysis did not detect the expression of either receptor in 1321N1 cells. R(+)WIN 55,212-2 was shown to inhibit adhesion molecule and chemokine expression at the level of transcription, because it strongly inhibited the IL-1 induction of ICAM-1, VCAM-1, and IL-8 mRNAs and blocked the IL-1 activation of their promoters. The NFkappaB pathway was then assessed as a lead target for R(+)WIN 55,212-2. NFkappaB was measured by expression of a transfected NFkappaB-regulated reporter gene. Using this assay, R(+)WIN 55,212-2 strongly inhibited IL-1 activation of NFkappaB. Furthermore R(+)WIN 55,212-2 inhibited the ability of overexpressed Myd88, Tak-1, and IKK-2 to induce the reporter gene suggesting that R(+)WIN 55,212-2 acts at or downstream of IKK-2 in the IL-1 pathway. However R(+)WIN 55,212-2 failed to inhibit IL-1-induced degradation of IkappaBalpha, excluding IKK-2 as a direct target. In addition electrophoretic mobility shift and chromatin immunoprecipitation assays showed that R(+)WIN 55,212-2 does not regulate the IL-1-induced nuclear translocation of NFkappaB or the ability of the latter to bind to promoters regulating expression of ICAM-1 and IL-8. These data suggest that R(+)WIN 55,212-2 blocks IL-1 signaling by inhibiting the transactivation potential of NFkappaB.
...
PMID:The synthetic cannabinoid R(+)WIN 55,212-2 inhibits the interleukin-1 signaling pathway in human astrocytes in a cannabinoid receptor-independent manner. 1610 34
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