Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0043167 (pertussis)
19,595 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have previously identified a Galpha(i/o)-protein-coupled receptor (TG1019/OXE) using 5-oxo-6E,8Z,11Z,14Z-eicosatetraenoic acid (5-oxo-ETE) as its ligand. We investigated signal transduction from TG1019 following stimulation with 5-oxo-ETE and role of TG1019 in 5-oxo-ETE-induced chemotaxis, using Chinese hamster ovary cells expressing TG1019 (CHO/TG1019 cells). 5-Oxo-ETE induced intracellular calcium mobilization and rapid activation of MEK/ERK and PI3K/Akt pathways in CHO/TG1019 cells. CHO/TG1019 cells stimulated with 5-oxo-ETE and other eicosanoids exhibited chemotaxis with efficacies related to agonistic activity of each eicosanoid for TG1019. Pretreatment of the cells with pertussis toxin, a phospholipase C (PLC) inhibitor (U73122) or a PI3K inhibitor (LY294002), markedly suppressed 5-oxo-ETE-induced chemotaxis, whereas pretreatment with a MEK inhibitor (PD98059) had no significant effect on the chemotaxis. Our results show that TG1019 mediates 5-oxo-ETE-induced chemotaxis and that signals from TG1019 are transduced via Galpha(i/o) protein to PLC/calcium mobilization, MEK/ERK, and PI3K/Akt, among which PLC and PI3K would play important roles in the chemotaxis.
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PMID:TG1019/OXE, a Galpha(i/o)-protein-coupled receptor, mediates 5-oxo-eicosatetraenoic acid-induced chemotaxis. 1603 85

A number of G protein-coupled receptors have been shown to stimulate tuberin phosphorylation, which is critical for the regulation of translation and is apparently involved in neurotrophin-promoted survival of serum-deprived cells. Here, in HEK 293 cells transiently expressing the delta-, kappa-, or mu-opioid receptors, Western blotting analysis using a phosphospecific anti-tuberin antibody revealed a dose- and time-dependent increase in tuberin phosphorylation upon stimulation by specific opioid agonists. In NG108-15, PC12, and SH-SY5Y cells that endogenously express delta-, kappa-, and mu-opioid receptors, respectively, specific opioid agonists also stimulated tuberin phosphorylation in a dose- and time-dependent manner. Pretreatment of cells with pertussis toxin or PI3K inhibitor wortmannin blocked the opioid-stimulated tuberin phosphorylation, implicating the possible involvement of the G(i/o) proteins and the phosphatidylinositol-3 kinase/Akt pathway in opioid-induced tuberin phosphorylation. This is the first study that demonstrates the regulatory role of opioid receptors on tuberin.
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PMID:Activation of delta-, kappa-, and mu-opioid receptors induces phosphorylation of tuberin in transfected HEK 293 cells and native cells. 1605 16

The neuropeptide pituitary adenylate cyclase-activating protein (PACAP) acts via the G protein-coupled receptor vasoactive intestinal peptide/PACAP receptor-1 to induce phospholipase C/calcium and MAPK-dependent proinflammatory activities in human polymorphonuclear neutrophils (PMNs). In this study, we evaluate other mechanisms that regulate PACAP-evoked calcium transients, the nature of the calcium sources, and the role of calcium in proinflammatory activities. Reduction in the activity of PMNs to respond to PACAP was observed after cell exposure to inhibitors of the cAMP/protein kinase A, protein kinase C, and PI3K pathways, to pertussis toxin, genistein, and after chelation of intracellular calcium or after extracellular calcium depletion. Mobilization of intracellular calcium stores was based on the fact that PACAP-associated calcium transient was decreased after exposure to 1) thapsigargin, 2) Xestospongin C, and 3) the protonophore carbonyl cyanide 4-(trifluoromethoxy) phenyl hydrazone; inhibition of calcium increase by calcium channel blockers, by nifedipine and verapamil, indicated that PACAP was also acting on calcium influx. Such mobilization was not dependent on a functional actin cytoskeleton. Homologous desensitization with nanomoles of PACAP concentration and heterologous receptors desensibilization by G protein-coupled receptor agonists were observed. Intracellular calcium depletion modulated PACAP-associated ERK but not p38 phosphorylation; in contrast, extracellular calcium depletion modulated PACAP-associated p38 but not ERK phosphorylation. In PACAP-treated PMNs, reactive oxygen species production and CD11b membrane up-regulation in contrast to lactoferrin release were dependent on both intra- and extracellular calcium, whereas matrix metalloproteinase-9 release was unaffected by extracellular calcium depletion. These data indicate that both extracellular and intracellular calcium play key roles in PACAP proinflammatory activities.
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PMID:Differential calcium regulation of proinflammatory activities in human neutrophils exposed to the neuropeptide pituitary adenylate cyclase-activating protein. 1614 59

Intestinal myofibroblasts have been implicated in the pathogenesis of chronic inflammatory conditions such as Crohn's disease via interactions with an elaborate network of cytokines, growth factors, and other inflammatory mediators. CXCR3 is a Galpha(i) protein-coupled receptor that binds the proinflammatory chemokines CXCL9, CXCL10, and CXCL11, which are released from the intestinal epithelium. The three CXCR3 ligands shared the ability to activate biochemical (e.g., PI3K and MAPK activation) and functional events (actin reorganization) in intestinal myofibroblasts. However, CXCL11 is unique in its ability to elevate intracellular calcium. Surprisingly, although CXCR3 mRNA is detectable in these myofibroblasts, there is no detectable surface expression of CXCR3. Furthermore, the biochemical responses and actin reorganization stimulated by the CXCR3 ligands in intestinal myofibroblasts are insensitive to the Galpha(i) inhibitor, pertussis toxin. This suggests either the existence of differential receptor coupling mechanisms in myofibroblasts for CXCR3 that are distinct from those observed in PBLs and/or that these cells express a modified or variant CXCR3 compared with the CXCR3 expressed on PBLs.
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PMID:The chemokines CXCL9, CXCL10, and CXCL11 differentially stimulate G alpha i-independent signaling and actin responses in human intestinal myofibroblasts. 1621 Jun 47

APJ, a G protein-coupled receptor, has an endogenous ligand called apelin. APJ and apelain are highly expressed in the cardiovascular system from embryo to adulthood. It has been shown that apelin elicited the migration of APJ-expressing cells, but details of the receptor signaling have not been identified. To address the signal transduction molecular mechanisms of the apelin/APJ-induced cell motility, we established human embryonic kidney 293T cells stably expressing the mouse APJ (APJ/293T). APJ/293T cells exhibited a specific [(Glp65, Nle75, Tyr77) [125I]]-Apelin13 binding activity (Kd = 4.45 nM). Apelin induced Akt/PKB phosphorylation in APJ/293T cells, but not in the intact 293T cells (-/293T cells). This APJ-dependent activation of Akt/PKB was significantly inhibited by the pretreatment of pertussis toxin (PTx) and a PI3K inhibitor, LY29004. In addition, apelin enhanced focal adhesion kinase (FAK) phosphorylation and increased focal adhesion formation with staining for F-actin in APJ/293T cells. PTx and LY29004 significantly suppressed these responses to apelin. Moreover, we examined the migration activity by using a scratch-test. Apelin strongly accelerated the cell motility in APJ/293T cells, and this activity was abolished by PTx and LY29004. These results indicated that the apelin/APJ signaling coupled with the PTx-sensitive G-protein activates Akt/PKB and FAK proteins through PI3K.
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PMID:G protein-coupled APJ receptor signaling induces focal adhesion formation and cell motility. 1621 Dec 45

Human airway epithelial cells (HAEC) constitutively express the CXC chemokine receptor CXCR3, which regulates epithelial cell movement. In diseases such as chronic obstructive pulmonary disease and asthma, characterized by denudation of the epithelial lining, epithelial cell migration may contribute to airway repair and reconstitution. This study compared the potency and efficacy of three CXCR3 ligands, I-TAC/CXCL11, IP-10/CXCL10, and Mig/CXCL9, as inducers of chemotaxis in HAEC and examined the underlying signaling pathways involved. Studies were performed in cultured HAEC from normal subjects and the 16-HBE cell line. In normal HAEC, the efficacy of I-TAC-induced chemotaxis was 349 +/- 88% (mean +/- SE) of the medium control and approximately one-half the response to epidermal growth factor, a highly potent chemoattractant. In normal HAEC, Mig, IP-10, and I-TAC induced chemotaxis with similar potency and a rank order of efficacy of I-TAC = IP-10 > Mig. Preincubation with pertussis toxin completely blocked CXCR3-induced migration. Of interest, intracellular [Ca(2+)] did not rise in response to I-TAC, IP-10, or Mig. I-TAC induced a rapid phosphorylation (5-10 min) of two of the three MAPKs, i.e., p38 and ERK1/2. Pretreatment of HAEC with the p38 inhibitor SB 20358 or the PI3K inhibitor wortmannin dose-dependently inhibited the chemotactic response to I-TAC. In contrast, the ERK1/2 inhibitor U0126 had no effect on chemotaxis. These data indicate that in HAEC, CXCR3-mediated chemotaxis involves a G protein, which activates both the p38 MAPK and PI3K pathways in a calcium-independent fashion.
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PMID:CXCR3 chemokine receptor-induced chemotaxis in human airway epithelial cells: role of p38 MAPK and PI3K signaling pathways. 1646 4

Endogenous catecholamines released during myocardial ischemia have been considered both to aggravate cell injury and exacerbate arrhythmias and to exert a protective action on the post-ischemic contractile function. The present work was addressed to look for evidence to explain this controversy. The effects of cardiac catecholamine depletion and of alpha- and beta-adrenoceptor (AR) blockade on the post-ischemic contractile dysfunction, as well as its possible relationship with cardiac oxidative stress, were studied in isolated and perfused rat hearts submitted to 20 min of ischemia and 30 min of reperfusion (stunning). Catecholamine depletion improves the contractile recovery in the stunned heart. This mechanical effect was associated with decreased levels of lipid peroxidation. A similar enhancement of the contractile function during reperfusion was detected after the simultaneous blockade of alpha 1- and beta-ARs with prazosin plus propranolol. To ascertain which specific AR pathway was involved in the effects of catecholamines on the stunned heart, selective AR blockers, prazosin (alpha 1-blocker), atenolol (beta 1-blocker), ICI 118,551 (beta 2-blocker) and selective inhibitors of Gi-PI3K pathway (pertussis toxin and wortmannin) were alternatively combined. The results indicate that catecholamines released during ischemia exert a dual action on the contractile behavior of the stunned heart: a deleterious effect, related to the activation of the beta 2-AR-Gi-PI3K-pathway, which was counteracted by a beneficial effect, triggered by the stimulation of alpha 1-AR. Neither the depression nor the enhancement of the post-ischemic contractile recovery were related with the increase in ROS formation induced by endogenous catecholamines.
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PMID:beta 2-Adrenergic stimulation is involved in the contractile dysfunction of the stunned heart. 1657 88

Previously we reported that the G protein-coupled receptor (GPCR) agonist thrombin potentiated the mitogenic effect of epidermal growth factor (EGF) on human airway smooth muscle (ASM) by promoting sustained late-phase activation of PI3K and p70S6K via a pathway dependent on Gbetagamma subunits of heterotrimeric G proteins. Here, we provide additional mechanistic insight and reveal the robustness of this phenomenon by demonstrating that H1 histamine and thromboxane receptors utilize the same mechanism to augment ASM growth via specific activation of the heterotrimeric G protein G(q/11). Thrombin, histamine, and U46619 all enhanced EGF-stimulated [3H]-thymidine incorporation as well as late-phase Akt and p70S6K phosphorylation in ASM cultures. Heterologous expression of Gbetagamma sequestrants (GRK2CT-GFP or Galpha(i)G203A), as well as GRK2NT-GFP (an RGS protein for G(q/11)) but neither p115RhoGEFRGS-GFP (an RGS for G(12/13)) nor pertussis toxin pretreatment (inactivating G(i/o)), attenuated the effects on both signaling and growth. Inhibition of Rho, Rho kinase, or Src, or modulation of arrestin expression did not significantly affect the cooperative signaling by EGF and any of the GPCR agonists. Thus, G(q/11)-coupled receptors are the principal GPCR subfamily mediating cooperative mitogenic signaling in ASM, acting through Gbetagamma-dependent, and Src/arrestin-independent activation of PI3K and p70S6K.
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PMID:Cooperative mitogenic signaling by G protein-coupled receptors and growth factors is dependent on G(q/11). 1672 77

We present evidence for a novel TLR2 function in transmodulating the adhesive activities of human monocytes in response to the fimbriae of Porphyromonas gingivalis, a pathogen implicated in chronic periodontitis and atherosclerosis. Monocyte recruitment into the subendothelium is a crucial step in atherosclerosis, and we investigated the role of P. gingivalis fimbriae in stimulating monocyte adhesion to endothelial cells and transendothelial migration. Fimbriae induced CD11b/CD18-dependent adhesion of human monocytes or mouse macrophages to endothelial receptor ICAM-1; these activities were inhibited by TLR2 blockade or deficiency or by pharmacological inhibitors of PI3K. Moreover, this inducible adhesive activity was sensitive to the action of Clostridium difficile toxin B, but was not affected by Clostridium botulinum C3 exoenzyme, pertussis toxin, or cholera toxin. Accordingly, we subsequently showed through the use of dominant negative signaling mutants of small GTPases, that Rac1 mediates the ability of fimbria-stimulated monocytes to bind ICAM-1. A dominant negative mutant of Rac1 also inhibited the lipid kinase activity of PI3K suggesting that Rac1 acts upstream of PI3K in this proadhesive pathway. Furthermore, fimbriae stimulated monocyte adhesion to HUVEC and transmigration across HUVEC monolayers; both activities required TLR2 and Rac1 signaling and were dependent upon ICAM-1 and the high-affinity state of CD11b/CD18. P. gingivalis-stimulated monocytes displayed enhanced transendothelial migration compared with monocytes stimulated with nonfimbriated isogenic mutants. Thus, P. gingivalis fimbriae activate a novel proadhesive pathway in human monocytes, involving TLR2, Rac1, PI3K, and CD11b/CD18, which may constitute a mechanistic basis linking P. gingivalis to inflammatory atherosclerotic processes.
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PMID:TLR2 transmodulates monocyte adhesion and transmigration via Rac1- and PI3K-mediated inside-out signaling in response to Porphyromonas gingivalis fimbriae. 1675 12

Endocrine-disrupting compounds (EDCs) may interfere with neuronal development due to high levels of accumulation in biological tissue and potentially aberrant steroid signaling. Treatment of dissociated embryonic Xenopus spinal cord neurons with the EDC, nonylphenol (NP), did not alter cell survival or neurite outgrowth but inhibited neurotrophin-induced neurite outgrowth, effects that were recapitulated by treatment with comparable concentrations of 17 beta-estradiol (E2) and beta-estradiol 6-(O-carboxy-methyl)oxime: BSA (E2-BSA), but not a synthetic androgen. Effects of NP were not inhibited by the nuclear estrogen receptor antagonist, ICI 182,780, but were inhibited by the G protein antagonist, pertussis toxin. Nerve growth factor (NGF)-induced neurite outgrowth in Xenopus neurons was shown to require MAPK signaling. NP did not affect TrkA expression, MAPK signaling, or phosphatidylinositol 3' kinase-Akt-glycogen synthase kinase 3 beta (PI3K-Akt-GSK3 beta) signaling in Xenopus. The ability of NP to inhibit NGF-induced neurite outgrowth without altering survival was recapitulated in the rat pheochromocytoma (PC12) cell line. As with Xenopus neurons, the inhibitory actions of NP in PC12 cells were not antagonized by ICI 182,780 and did not involve alterations in signaling along either the MAPK or PI3K-Akt-GSK3 beta pathways. NP did significantly inhibit the ability of NGF to increase protein kinase A activity in this cell line. These data have important implications with respect to potentially deleterious effects of NP exposure during early neural development and highlight the fact that bioaccumulation of EDCs, such as NP, may elicit very disparate effects along divergent signaling pathways than those that arise from the actions of physiological levels of endogenous estrogens.
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PMID:The endocrine-disrupting compound, nonylphenol, inhibits neurotrophin-dependent neurite outgrowth. 1677 73


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