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)

Endothelin-1 has dual vasoactive effects, mediating vasoconstriction via ETA receptor activation of vascular smooth muscle cells and vasorelaxation via ETB receptor activation of endothelial cells. Although it is commonly accepted that endothelin-1 binding to endothelial cell ETB receptors stimulates nitric oxide (NO) synthesis and subsequent smooth muscle relaxation, the signaling pathways downstream of ETB receptor activation are unknown. Here, using a model in which we have utilized isolated primary endothelial cells, we demonstrate that ET-1 binding to sinusoidal endothelial cell ETB receptors led to increased protein kinase B/Akt phosphorylation, endothelial cell nitric-oxide synthase (eNOS) phosphorylation, and NO synthesis. Furthermore, eNOS activation was not dependent on tyrosine phosphorylation, and pretreatment of endothelial cells with pertussis toxin as well as overexpression of a dominant negative G-protein-coupled receptor kinase construct that sequesters betagamma subunits inhibited Akt phosphorylation and NO synthesis. Taken together, the data elucidate a G-protein-coupled receptor signaling pathway for ETB receptor-mediated NO production and call attention to the absolute requirement for heterotrimeric G-protein betagamma subunits in this cascade.
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PMID:Endothelin-1 activates endothelial cell nitric-oxide synthase via heterotrimeric G-protein betagamma subunit signaling to protein jinase B/Akt. 1452 27

In vitro experiments were performed to investigate the actions of endothelin-1 (ET-1) on vasomotion and vasospasm in guinea-pig mesenteric lymphatics. ET-1 modulated lymphatic vasomotion independent of the endothelium, with lower concentrations (<or=10 nm) increasing lymphatic vasomotion and higher concentrations (>or=100 nm) causing vasospasm. ET-1-induced increases in vasomotion were accompanied by an increase in tonic [Ca2+]i. These actions were inhibited by the ETA receptor antagonist BQ-123 (1 microm), the phospholipase C (PLC) inhibitor U73122 (5 microm), removal of extracellular Ca2+, chelation of intracellular Ca2+ with BAPTA/AM (10 microm), the store Ca2+-ATPase inhibitor thapsigargin (1 microm), caffeine (10 mm) and the inositol 1,4,5-trisphosphate (IP3) receptor blocker heparin and 2-APB (30 microm). In contrast, the ETB receptor antagonist BQ-788 (1 microm), ryanodine (1 & 20 microm), pertussis toxin (PTx) or Cs+ had no significant actions on vasomotion or the magnitude of increase in tonic [Ca2+]i. ET-1-induced vasospasm was accompanied by a transient increase in smooth muscle [Ca2+]i followed by a sustained plateau, an action that was abolished by removal of extracellular Ca2+, but only marginally inhibited by nifedipine (1 microm). Caffeine (10 mm), SKF 96165 (30 microm) or U73122 (5 microm) together with nifedipine (1 microm) abolished ET-1-induced vasospasm and increase in [Ca2+]i. These results indicate that ET-1 increases lymphatic vasomotion by acting on smooth muscle ETA receptors and activation of G-protein-PLC-IP3 cascade, which is known to cause pacemaker Ca2+ release and resultant pacemaker potentials. High concentrations of ET-1 cause a failure in Ca2+ homeostasis causing vasospasm, triggered by excessive Ca2+ influx primarily through store-operated channels (SOCs) with l-Ca2+ voltage-operated channels (VOCs) also contributing, but to a much lesser extent.
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PMID:ET-1-associated vasomotion and vasospasm in lymphatic vessels of the guinea-pig mesentery. 1462 68

Atrial natriuretic peptide (ANP)-C receptor activation has been shown to inhibit adenylyl cyclase (AC) activity as well as to stimulate phospholipase C (PLC) signaling pathways. The present studies were undertaken to investigate whether ANP-C receptor-mediated decreased cAMP levels contribute to the activation of PLC signaling. C-ANP(4-23) [des(Gln(18),Ser(19), Glu(20),Leu(21),Gly(22))ANP(4-23)-NH(2)], a ring-deleted peptide of ANP that interacts specifically with ANP-C receptor, stimulated inositol 1,4,5-tris-phosphate (IP(3)) production (PLC activity) in A10 vascular smooth muscle cells in a concentration- and time-dependent manner. The maximal stimulation observed was about 75% at 2 h of treatment, with an apparent EC(50) of about 20 to 30 nM. Pertussis toxin treatment of the cells completely abolished the C-ANP(4-23)-mediated stimulation of IP(3) production. Forskolin (FSK), a stimulator of adenylyl cyclase, dibutyryl cAMP (db cAMP), and isoproterenol (ISO), a beta-adrenergic agonist that stimulates adenylyl cyclase activity and cAMP levels, inhibited IP(3) production by about 35, 30, and 50%, respectively, whereas dideoxyadenosine (DDA), an inhibitor of adenylyl cyclase activity, and oxotremorine stimulated IP(3) production by about 90 and 80%, respectively, in these cells, suggesting a functional interaction between these two signaling pathways. Treatment of the cells with antisense oligonucleotide of ANP-C receptor that attenuated ANP-C receptor-mediated inhibition of adenylyl cyclase resulted in a complete attenuation of C-ANP(4-23)-induced stimulation of IP(3) formation, whereas FSK, db cAMP, and ISO-mediated decrease and oxotremorine and endothelin-1 (ET-1)-induced increase in IP(3) production was not affected by this treatment. Furthermore, C-ANP(4-23)-induced increase in IP(3) formation was significantly potentiated by DDA and inhibited by FSK and db cAMP, whereas ET-1-induced increase in IP(3) production was not affected by FSK. In addition, N-[2-(4-bromocinnamylamino)ethyl]-5-isoquinoline (H-89), an inhibitor of protein kinase A, completely abolished C-ANP(4-23) and not ET-1-induced stimulation of IP(3) production. These results indicate that ANP-C receptor activation by C-ANP(4-23) and resulting decrease in cAMP levels may be responsible for the activation of phosphatidylinositol (PI) turnover signaling, suggesting a cross-talk between ANP-C receptor-mediated adenylyl cyclase and PLC signaling pathways.
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PMID:Atrial natriuretic peptide-C receptor-induced attenuation of adenylyl cyclase signaling activates phosphatidylinositol turnover in A10 vascular smooth muscle cells. 1504 21

The involvement of G proteins in the mechanism underlying the increased atrial natriuretic factor (ANF) secretion observed after atrial muscle stretch (stretch-secretion coupling) was assessed using a combined pharmacological, immunocytochemical, and tissue fractionation approach. It was found that G(i/o) inhibition by pertussis toxin (PTX) abolished stretch-secretion coupling without affecting baseline secretion through a mechanism that is independent of G(q) signaling agonists. Mastoparan-7, a G(i/o) agonist, significantly increased ANF secretion even in the absence of muscle stretch through a PTX-sensitive mechanism. By confocal and electron immunocytochemistry, ANF and G(o) partially colocalized, whereas ultracentrifugation analysis suggested the presence of two populations of granules, one of which was partially associated with G(o), as demonstrated by Western blotting. PTX did not affect basal or endothelin-1-stimulated ANF secretion, in line with the view that endothelin-1 signals mainly through G(q). It is concluded there are at least two types of regulated secretory processes in atrial cardiocytes: one is acutely responsive to muscle stretch and is PTX sensitive, and the other is G(q)mediated and PTX insensitive and may be responsible for changes in secretion after chronic changes in the neuroendocrine environment.
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PMID:Participation of G proteins in natriuretic peptide hormone secretion from heart atria. 1530 19

Using adenoviruses encoding RGS2, RGS4 and Lsc (regulator of G protein signalling (RGS) domain of p115 RhoGEF), we investigated the contributions of G(q/11), Gi and G(12/13) proteins to G protein-coupled receptor (GPCR)-mediated activation of the extracellular signal-regulated kinase (ERK) pathway in adult rat ventricular myocytes (ARVM). Exposure to phenylephrine, endothelin-1 (ET-1) or thrombin induced significant activation of ERK1/2 and their downstream target 90 kDa ribosomal S6 kinase (p90RSK), which was abolished by overexpression of RGS4 (inhibits signalling via G(q/11) and Gi) or RGS2 (inhibits signalling via G(q/11)). Pertussis toxin (inhibits signalling via Gi) only partially attenuated the activation of ERK1/2 and p90(RSK) by phenylephrine and ET-1, but abolished such activation by thrombin. Overexpression of Lsc (inhibits signalling via G(12/13)) did not affect the responses to phenylephrine and ET-1, but suppressed the activation of ERK1/2 and p90RSK by thrombin. We conclude that full activation of the ERK pathway in ARVM by alpha1-adrenergic, ET-1 and thrombin receptors requires the activation of distinct families of heterotrimeric G proteins.
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PMID:Regulation of the extracellular signal-regulated kinase pathway in adult myocardium: differential roles of G(q/11), Gi and G(12/13) proteins in signalling by alpha1-adrenergic, endothelin-1 and thrombin-sensitive protease-activated receptors. 1568 40

We have previously demonstrated that endothelin-1 (ET-1)-induced extracellular signal-regulated kinase (Erk) activity via the ETB receptor (EDNRB) is mediated through two independent pathways, a protein kinase C-dependent pathway and a pertussis toxin (PTX)-sensitive pathway, in astrocytes. In this study, we showed that the molar potency of ET-1 to induce Erk activation was two orders of magnitude higher in dibutyryl cAMP (DBcAMP)-treated astrocytes than in quiescent astrocytes. This DBcAMP-enhanced molar potency of ET-1 in Erk activation was selectively inhibited by pretreatment of astrocytes with PTX. The expression level of EDNRB in astrocytes was markedly upregulated by DBcAMP-induced cytodifferentiation. However, this up-regulation was simply attributed to the high expression of low-affinity sites. The molar potency of ET-1 to induce both stimulation of inositol trisphosphate production and activation of protein kinase C in DBcAMP-treated astrocytes was similar to that in quiescent astrocytes. On the contrary, the molar potency of ET-1 to induce accumulation of Ras-GTP was two orders of magnitude higher in DBcAMP-treated astrocytes than in quiescent astrocytes, which was consistent with the case of ET-1-induced Erk activation. Moreover, the ET-1-induced Ras activation was PTX sensitive. These results suggest that cytodifferentiation selectively enhances the PTXsensitive Ras/Erk pathway induced by ET-1 in astrocytes, and that cytodifferentiation-induced EDNRB up-regulation might not contribute to this selective potentiation of ET-1 signaling.
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PMID:Cytodifferentiation enhances Erk activation induced by endothelin-1 in primary cultured astrocytes. 1583 8

The peptide, endothelin-1 (ET-1) regulates proliferative responses in numerous cell types. Recently, a dual ET receptor antagonist was shown to prevent the increase in airway smooth muscle cell (SMC) proliferation that accompanies airway smooth muscle remodeling in a rat model of experimental asthma. Thus, we used [(3)H]-thymidine incorporation assays and western immunoblotting to identify signaling pathways that regulate proliferative responses in cultured rat tracheal SMC. Our data indicate that ET-1 activation of the ET A receptor subtype induced [(3)H]-thymidine incorporation and activation of ERK 1/2 in primary rat tracheal SMC. ET-1-induced [(3)H]-thymidine incorporation and activation of ERK 1/2 were inhibited by pretreatment of SMC with pertussis toxin or down regulation of phorbol ester responsive isoforms of PKC. While ET- 1-induced ERK 1/2 activation was unaffected following inhibition of Rho kinase, ET-1-induced [(3)H]-thymidine incorporation was abrogated. ET-1 also potentiated [(3)H]-thymidine incorporation as well as cell proliferation of SMC stimulated with PDGF-BB and this response did not appear to be regulated by ERK1/ 2. These data demonstrate that ET-1 induces activation of multiple G proteins that regulate rat tracheal SMC proliferative responses, likely through signaling pathways downstream of ERK1/2 and Rho kinase.
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PMID:Endothelin-1 regulates proliferative responses, both alone and synergistically with PDGF, in rat tracheal smooth muscle cells. 1654 20

Beta1Pix (PAK-interacting exchange factor) is a recently identified guanine nucleotide exchange factor (GEF) for the Rho family small G protein Cdc42/Rac. On stimulation with extracellular signals, GEFs induce the exchange of guanosine diphosphate to guanosine triphosphate, resulting in the activation of the small guanosine 5C-triphosphatases. This activation enables the signal to propagate to downstream effectors. Herein, we show that G(salpha) stimulation by cholera toxin increased Cdc42 activation by endothelin-1 (ET-1), whereas pertussis toxin had no effect. H-89, a protein kinase A (PKA) inhibitor, strongly inhibited Cdc42 activation by ET-1. Moreover, the overexpression of beta1Pix enhanced ET-1-induced Cdc42 activation. The essential role of beta1Pix in ET-1-induced Cdc42 activation was evidenced by the blocking of Cdc42 activation in cells expressing beta1Pix mutant lacking the ability to bind PAK (beta1Pix SH3m[W43K]) or mutant lacking GEF activity (beta1PixdeltaDH). The overexpression of mutant lacking the pleckstrin homology domain beta1PixdeltaPH, which is unable to bind phospholipids, had no effect on Cdc42 activation. These results demonstrate that beta1Pix, along with PKA, plays a crucial role in the regulation of Cdc42 activation by ET-1.
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PMID:Endothelin 1 stimulates beta1Pix-dependent activation of Cdc42 through the G(salpha) pathway. 1674 Sep 95

Sphingosine 1-phosphate (S1P), a bioactive sphingolipid involved in diverse biological processes, is generated by sphingosine kinase (SphK) and acts via intracellular and/or extracellular mechanisms. We used biochemical, pharmacological, and physiological approaches to investigate in rat myometrium the contractile effect of exogenous S1P and the possible contribution of SphK in endothelin-1 (ET-1)-mediated contraction. S1P stimulated uterine contractility (EC(50) = 1 microM and maximal response = 5 microM) by a pertussis toxin-insensitive and a phospholipse C (PLC)-independent pathway. Phosphorylated FTY720, which interacts with all S1P receptors, except S1P(2) receptors, failed to mimic S1P contractile response, indicating that the effects of S1P involved S1P(2) receptors that are expressed in myometrium. Contraction mediated by S1P and ET-1 required extracellular calcium and Rho kinase activation. Inhibition of SphK reduced ET-1-mediated contraction. ET-1, via ET(A) receptors coupled to pertussis toxin-insensitive G proteins, stimulated SphK1 activity and induced its translocation to the membranes. Myometrial contraction triggered by ET-1 is consecutive to the sequential activation of PLC, protein kinase C, SphK1 and Rho kinase. Prolonged exposure of the myometrium to S1P downregulated S1P(2) receptors and abolished the contraction induced by exogenous S1P. However, in these conditions, the tension triggered by ET-1 was not reduced, indicating that SphK activated by ET-1 contributed to its contractile effect via a S1P(2) receptor-independent process. Our findings demonstrated that exogenous S1P and SphK activity regulated myometrial contraction and may be of physiological relevance in the regulation of uterine motility during gestation and parturition.
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PMID:Exogenous sphingosine 1-phosphate and sphingosine kinase activated by endothelin-1 induced myometrial contraction through differential mechanisms. 1695 68

The expression of the negative Regulator of G protein signaling 16 (RGS16) is rapidly induced in cardiomyocytes by various stimuli. To identify the promoter of the mouse RGS16 gene, a 1.8-kb deoxyribonucleic acid fragment 5' of the RGS16-coding region was subcloned into a firefly-luciferase reporter vector and four overlapping fragments were analyzed. The luciferase production was quantified in neonatal rat cardiac myocytes (NRCM). A 0.6-kb fragment that induced a tenfold increase in luciferase activity contained the minimal promoter sequence. Its activity was twofold stimulated by fetal calf serum, endothelin-1 (ET-1), and sphingosine 1-phosphate (S1P), which stimuli also elevated the level of RGS16 protein. Stimulation of NRCM with ET-1 induced activation of the monomeric GTPases RhoA and Rac1, whereas S1P and the selective S1P1 receptor agonist SEW2871 only induced a pronounced activation of Rac1. In accordance, the treatment with the Rho-, Rac-, and Cdc42-inactivating Clostridium difficile Toxin B (TcdB) 10463 inhibited ET-1 and S1P-induced transcriptional activation. The ET-1-induced activation was insensitive to pertussis toxin but selectively suppressed by the RhoA-C-specific C2I-C3 ADP-ribosyl transferase and the ET(B) receptor antagonist BQ788. The S1P-induced activation was specifically inhibited by pertussis toxin and the Rac-inactivating TcdB 1470. All stimulated transcriptional activity was abolished by the negative transcription factor Yin Yang 1 (YY1), which binds to a consensus sequence within the minimal promoter. Taken together, our data show that most likely ET(B)- and S1P1-receptors induce RGS16 protein expression in cardiac myocytes by increasing the transcriptional activity of the rgs16 gene. This activation is mediated by heterotrimeric G proteins, Rho GTPases, and is under negative control of the transcription factor YY1.
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PMID:Sphingosine-1-phosphate and endothelin-1 induce the expression of rgs16 protein in cardiac myocytes by transcriptional activation of the rgs16 gene. 1804 43


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