Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:4.6.1.2 (guanylate cyclase)
 8,497 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Membrane depolarization promotes neuronal survival through increases in intracellular calcium. Nitric oxide (NO) is a signaling molecule involved in many neuronal activity-dependent events. Since neuronal NO is generated by NO synthase (NOS) in a calcium-dependent manner and was shown to promote cell survival, we tested whether NO is involved in depolarization-promoted survival in neuronally differentiated PC12 cells. NOS inhibitor attenuated depolarization-promoted survival and NO donors promoted survival. This effect was partially cGMP-dependent as a guanylyl cyclase inhibitor decreased NO-promoted survival. Ras inhibitor, Erk blocker or phosphatidylinositol 3-kinase inhibitor decreased depolarization- or NO donor-promoted survival. Depolarization-induced Ras activation was blocked by NOS inhibitor. Inducible expression of dominant negative Ras or S-nitrosylation-defective Ras attenuated depolarization- or NO donor-promoted survival. Thus, NO might be a mediator via Ras and cGMP pathways in depolarization-promoted survival in neuronal PC12 cells.
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PMID:Nitric oxide mediates membrane depolarization-promoted survival of rat neuronal PC12 cells. 1281 42

We demonstrated previously that 3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole (YC-1), an activator of soluble guanylate cyclase (sGC), induces cyclooxygenase-2 (COX-2) expression via cGMP- and p44/42 mitogen-activated protein kinase-dependent pathways in human pulmonary epithelial A549 cells. In this study, we explore the role of Ras, phosphoinositide-3-OH-kinase (PI3K), Akt, and transcription factor nuclear factor-kappaB (NF-kappaB) in YC-1-induced COX-2 expression in A549 cells. A Ras inhibitor (manumycin A), a PI3K inhibitor (wortmannin), an Akt inhibitor (1l-6-Hydroxymethyl-chiro-inositol2-[(R)-2-O-methyl-3-O-octadecylcarbonate]), and an NF-kappaB inhibitor [pyrrolidine dithiocarbamate (PDTC)] all reduced YC-1-induced COX-2 expression. The YC-1-induced increase in COX activity was also blocked by manumycin A, wortmannin, PDTC, and the dominant-negative mutants for Ras (RasN17), Akt (Akt DN), and IkappaBalpha (IkappaBalphaM). The YC-1-induced increase in Ras activity was inhibited by an sGC inhibitor [1H-(1,2,4)oxadiazolo[4,3-a]quinozalin-1-one (ODQ)], a protein kinase G (PKG) inhibitor [1-oxo-9.12-epoxy-1H-diindolo[1,2,3-fg:3',2',1'-kl]pyrrolo[3,4-I][1,6]benzodiazocine-10-carboxylic acid methyl ester (KT-5823)], and manumycin A. YC-1-induced Akt activation was also inhibited by ODQ, KT-5823, manumycin A, and wortmannin. YC-1 caused the formation of an NF-kappaB-specific DNA-protein complex and an increase in kappaB-luciferase activity. YC-1-induced kappaB-luciferase activity was inhibited by ODQ, KT-5823, manumycin A, wortmannin, an Akt inhibitor, PDTC, RasN17, Akt DN, and IkappaBalphaM. Likewise, YC-1-induced IKKalpha/beta activation was inhibited by ODQ, KT-5823, manumycin A, wortmannin, and an Akt inhibitor. Furthermore, YC-1-induced COX-2 promoter activity was inhibited by manumycin A, RasN17, Akt DN, PDTC, and IkappaBalphaM. Taken together, these results indicate that YC-1 might activate the sGC/cGMP/PKG pathway to induce Ras and PI3K/Akt activation, which in turn initiates IKKalpha/beta and NF-kappaB activation and finally induces COX-2 expression in A549 cells.
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PMID:YC-1-induced cyclooxygenase-2 expression is mediated by cGMP-dependent activations of Ras, phosphoinositide-3-OH-kinase, Akt, and nuclear factor-kappaB in human pulmonary epithelial cells. 1532 48

Our previous study demonstrated that 3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole (YC-1) might activate the soluble guanylate cyclase (sGC)/cGMP/protein kinase G (PKG) pathway to induce cyclooxygenase-2 (COX-2) expression in human pulmonary epithelial cells (A549). In this study, we further investigated the role of Raf-1 in YC-1-induced nuclear factor-kappaB (NF-kappaB) activation and COX-2 expression in A549 cells. YC-1-induced COX-2 expression was attenuated by a Raf-1 inhibitor (GW 5074) in a concentration-dependent manner. Treatment of A549 cells with YC-1 or 8-bromo-cGMP, a cell-permeable cGMP analogue, induced Raf-1 Ser338 phosphorylation in a time-dependent manner. YC-1-mediated Raf-1 activation was inhibited by an sGC inhibitor (ODQ), a PKG inhibitor (KT-5823), a Ras inhibitor (manumycin A), a dominant negative Ras mutant (RasN17), a protein kinase C-alpha (PKC-alpha) inhibitor (Ro 32-0432), and a phosphoinositide-3-OH-kinase (PI3K) inhibitor (LY 294002). Pretreatment of A549 cells with either manumycin A or GW 5074 attenuated YC-1-induced p44/42 MAPK activation. The YC-1-mediated increase in IKKalpha/beta activation and kappaB-luciferase activity were attenuated by GW 5074, a MAPK/ERK kinase (MEK) inhibitor (PD 98059), and an ERK2 inhibitor (AG 126). Furthermore, YC-1-induced COX-2 promoter activity was also inhibited by GW 5074, PD 98059, and AG 126. These results indicate that YC-1 might activate the sGC/cGMP/PKG pathway to elicit Ras/Raf-1/p44/42 MAPK activation, which in turn induces IKKalpha/beta and NF-kappaB activation, and ultimately causes COX-2 expression in A549 cells. Moreover, PKC-alpha and PI3K signal might be involved in YC-1-induced Raf-1 activation.
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PMID:Involvement of Ras/Raf-1/p44/42 MAPK in YC-1-induced cyclooxygenase-2 expression in human pulmonary epithelial cells. 1971 11