Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.11.12 (PKG)
 2,515 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Nuclear factor kappa B (NF-kappa B), consisting of p50 and p65, is bound to a cytoplasmic retention protein, I kappa B, in a resting state, and the stimulation of cells with a variety of inflammatory stimuli induces the dissociation of NF-kappa B from I kappa B and the nuclear translocation of NF-kappa B, thereby activating several genes involved in inflammatory responses, such as interleukin (IL)-6, IL-8, and tumor necrosis factor alpha. In order to elucidate the precise mechanism of NF-kappa B activation, we have established lipopolysaccharide (LPS)-dependent NF-kappa B activation in a cell-free system using plasma membrane-enriched, cytosol, and nuclear fractions extracted from a human monocytic cell line, THP-1, by disruption with sonication followed by a differential centrifugation. The combination of plasma membrane-enriched fraction and cytosol was sufficient to activate NF-kappa B in a LPS/CD14-dependent manner only in the presence of ATP as judged by the binding of NF-kappa B to the IL-8 gene kappa B site on an electrophoretic mobility shift assay. LPS-dependent NF-kappa B activation was inhibited by protein kinase inhibitors, such as staurosporine, herbimycin A, tyrphostin, and genistein, but not mitogen-activated protein kinase substrate, cGMP-dependent protein kinase, cAMP-dependent protein kinase, protein kinase C, and calmodulin-dependent protein kinase II inhibitory peptides, suggesting that staurosporine-sensitive kinase(s) as well as tyrosine kinase(s) are involved in LPS-mediated NF-kappa B activation. In addition, LPS induced the phosphorylation of I kappa B-alpha, starting at 5 min after the stimulation in a cell-free system. Moreover, the phosphorylation was inhibited by herbimycin A and tyrphostin, but not staurosporine, suggesting that these protein kinase inhibitors act at distinct steps of signal transmission. Establishment of ligand-dependent activation of NF-kappa B in a cell-free system will facilitate identification of protein kinase(s) and its substrate(s) involved in LPS-mediated NF-kappa B activation.
 ...
PMID:Establishment of lipopolysaccharide-dependent nuclear factor kappa B activation in a cell-free system. 787 68

Relatively high concentrations of azathioprine had an inhibitory effect on interleukin 8 (IL-8)- or formyl-methionyl-leucyl-phenylalanine-activated (fMLP)-chemotaxis by human neutrophils. However, application of low concentrations of azathioprine in a concentration gradient gave a chemotactic stimulation to random migration. Stimulation of migration was maximal at a concentration of 5 microM azathioprine; at higher concentrations stimulation decreased again. The activating effect of azathioprine is located in the mercaptopurine moiety of the molecule, since mercaptopurine also stimulated neutrophil migration. In contrast to some other chemotactic agents such as fMLP and IL-8, an activating concentration (5 microM) of azathioprine did not cause an upregulation of CD11b expression on neutrophils in suspension. High concentrations of azathioprine (1 mM) inhibited CD11b expression of fMLP- or IL-8- activated neutrophils; the latter could explain the inhibitory effect of azathioprine. Azathioprine caused a transient stimulation of cGMP level; inhibitors of guanylate cyclase inhibited azathioprine-stimulated migration, suggesting that cGMP was associated with the stimulating effect of azathioprine on migration. Antagonists of cGMP-dependent protein kinase (G-kinase) strongly inhibited azathioprine-activated migration, indicating that the effect of azathioprine proceeds via G-kinase. The antagonists had only a marginal effect on inhibition of IL-8-activated chemotaxis by high concentrations of azathioprine, thus the G-kinase seems not to be of great importance on the inhibitory effect of azathioprine.
 ...
PMID:A cyclic GMP- and G-kinase-dependent effect of azathioprine on migration by human neutrophils. 928 61

In vivo, vascular walls are exposed to mechanical stretch, which may promote atherogenesis. This study was designed to investigate the effect of mechanical stretch on the production and gene expression of cytokines in endothelial cells (ECs) of human umbilical veins. ECs were cultured on flexible silicone membranes and exposed to cyclic mechanical stretch. Although the secretion levels of interleukin (IL)-1beta, tumor necrosis factor-alpha, IL-6, granulocyte (G) -colony stimulating factor (CSF), G and macrophage (M) -CSF, and M-CSF were not affected by cyclic stretch over 24 hours, the levels of IL-8 and monocyte chemotactic and activating factor (MCAF)/monocyte chemoattractant protein-1 (MCP-1) were significantly increased by cyclic stretch. Northern blot analysis indicated that the mRNA levels of IL-8 and MCAF/MCP-1 were upregulated by cyclic stretch as a function of its intensity. Cytochalasin D, which disrupts the actin cytoskeleton, abolished the stretch-induced gene expression of IL-8 and MCAF/MCP-1. In contrast, neither inhibition of stretch-activated ion channels nor disruption of microtubules affected the induction of these chemokines by cyclic stretch. Northern blot analysis using enzyme inhibitors showed that phospholipase C, protein kinase C, and tyrosine kinase were involved in the stretch-induced gene expression of IL-8 and MCAF/MCP-1, whereas cAMP- or cGMP-dependent protein kinase was not. In conclusion, cyclic stretch enhanced the secretion and gene expression of IL-8 and MCAF/MCP-1 in a stretch-dependent fashion, and the integrity of the actin cytoskeleton and activities of phospholipase C, protein kinase C, and tyrosine kinase may be essential in the process of stretch-induced gene induction of IL-8 and MCAF/MCP-1.
 ...
PMID:Cyclic stretch upregulates production of interleukin-8 and monocyte chemotactic and activating factor/monocyte chemoattractant protein-1 in human endothelial cells. 963 28

The regulation of neutrophil functions by Type I cGMP-dependent protein kinase (cGKI) was investigated in wild-type (WT) and cGKI-deficient (cGKI-/-) mice. We demonstrate that murine neutrophils expressed cGKIalpha. Similar to the regulation of Ca2+ by cGKI in other cells, there was a cGMP-dependent decrease in Ca2+ transients in response to C5a in WT, but not cGKI-/- bone marrow neutrophils. In vitro chemotaxis of bone marrow neutrophils to C5a or IL-8 was significantly greater in cGKI-/- than in WT. Enhanced chemotaxis was also observed with cGKI-/- peritoneal exudate neutrophils (PE-N). In vivo chemotaxis with an arachidonic acid-induced inflammatory ear model revealed an increase in both ear weight and myeloperoxidase (MPO) activity in ear punches of cGKI-/- vs WT mice. These changes were attributable to enhanced vascular permeability and increased neutrophil infiltration. The total extractable content of MPO, but not lysozyme, was significantly greater in cGKI-/- than in WT PE-N. Furthermore, the percentage of MPO released in response to fMLP from cGKI-/- (69%) was greater than that from WT PE-N (36%). PMA failed to induce MPO release from PE-N of either genotype. In contrast, fMLP and PMA released equivalent amounts of lysozyme from PE-N. However, the percentage released was less in cGKI-/- (approximately 60%) than in WT (approximately 90%) PE-N. Superoxide release (maximum velocity) revealed no genotype differences in responses to PMA or fMLP stimulation. In summary, these results show that cGKIalpha down-regulates Ca2+ transients and chemotaxis in murine neutrophils. The regulatory influences of cGKIalpha on the secretagogue responses are complex, depending on the granule subtype.
 ...
PMID:Neutrophil dysfunction in guanosine 3',5'-cyclic monophosphate-dependent protein kinase I-deficient mice. 1603 36

Vasodilator-stimulated phosphoprotein (VASP) is a cAMP-dependent protein kinase A (PKA) substrate, which links cellular signaling to cytoskeletal organization and cellular movement. VASP is phosphorylated by PKA on serine 157 (Ser 157), which is required for VASP function in platelet adhesion and fibroblast motility. Our hypothesis is that PKA regulates neutrophil migration through VASP Ser 157 phosphorylation. The objective of this study was to characterize VASP Ser 157 phosphorylation in chemoattractant-stimulated neutrophils. fMLF, IL-8, leukotriene B(4), or platelet-activating factor stimulation resulted in an initial increase in VASP Ser 157 phosphorylation, which was maximal by 30 s and was followed by a return to baseline Ser 157 phosphorylation by 10 min. In contrast, stimulation with the nonchemoattractant, proinflammatory cytokine TNF-alpha did not affect Ser 157 phosphorylation. The kinetics of fMLF-induced VASP Ser 157 phosphorylation levels closely matched the kinetics of the fold-change in F-actin levels in fMLF-stimulated neutrophils. fMLF-induced Ser 157 phosphorylation was abolished by pretreatment with the PKA inhibitor H89 and the adenylyl cyclase inhibitor SQ22536. In contrast, fMLF-induced Ser 157 phosphorylation was unaffected by the PKC inhibitors calphostin and staurosporine, the PKG inhibitors Rp-8-pCPT-cGMP and KT5823, and the calmodulin-dependent protein kinase II inhibitor KN-62. Inhibition of adhesion with EDTA or the anti-beta2-integrin antibody IB4 did not alter fMLF-induced VASP phosphorylation or dephosphorylation. These data show that chemoattractant stimulation of human neutrophils induces a rapid and transient PKA-dependent VASP Ser 157 phosphorylation. Adhesion does not appear to be an important regulator of the state of VASP Ser 157 phosphorylation in chemoattractant-stimulated neutrophils.
 ...
PMID:Regulation of VASP serine 157 phosphorylation in human neutrophils after stimulation by a chemoattractant. 1768 42

Cigarette smoke mediated oxidative stress and endothelial dysfunction are important processes in the pathogenesis of several lung disorders. In this study we evaluated the effect of PDE5 inhibition on pulmonary artery endothelial dysfunction induced by cigarette smoke in vitro. Human pulmonary artery endothelial cells (HPAEC) were incubated in the absence or presence of PDE5 inhibitor sildenafil (10 nM-1 microM), PKG agonist 8-Br-cGMP (1mM), or the antioxidants dyphenyleneiodonium (DPI 1 microM) and N-acetylcysteine (NAC 1mM) for 30 min. Then, cigarette smoke extract (CSE) was added for 24h. CSE (2.5-10%)-induced ROS generation was suppressed by DPI, and partially reversed by sildenafil and 8-Br-cGMP. Decreases in intracellular levels of cGMP and extracellular NO induced by CSE were reversed by sildenafil and DPI. Furthermore, CSE-induced pg91(phox) and PDE5 mRNA overexpression were suppressed by both sildenafil and DPI. CSE (2.5-10%) induced upregulation of IL-6, IL-8 and Ang-2, and decreased Ang-1 expression in parallel to apoptosis which were partially suppressed by sildenafil, 8-Br-cGMP, DPI and NAC. This study demonstrates that PDE5 inhibition attenuates the oxidant burden and the inflammatory and remodeling effects of CSE in human HPAEC which may contribute to the therapeutic value of PDE5 inhibitors for pulmonary disorders coursing with endothelial dysfunction.
 ...
PMID:Cigarette smoke-induced pulmonary endothelial dysfunction is partially suppressed by sildenafil. 2009 83

Mycoplasma infection can cause many diseases in pigs, resulting in great economic losses in pork production. Innate immune responses are thought to play critical roles in the pathogenesis of mycoplasma disease. However, the molecular events involved in immune responses remain to be determined. Hence, the object of this study was to use RNA-Seq to investigate the gene expression profiles of the innate immune response mediated by FSL-1 in pig monocyte-derived macrophages (MDMs). The results revealed that 1442 genes were differentially expressed in the FSL-1 group compared with the control groups, of which 777 genes were upregulated and 665 genes were downregulated. KEGG pathway analysis showed that the upregulated genes were mainly involved in innate immune-related pathways including the TNF signaling pathway, cytokine-cytokine receptor interaction, Toll-like receptor signaling pathway, Jak-STAT signaling pathway, chemokine signaling pathway, NOD-like receptor signaling pathway and NF-kappa B signaling pathway. The downregulated genes were only involved in the cGMP-PKG signaling pathway and glycerophospholipid metabolism. Our results showed that FSL-1 stimulation activated the TLR2 signaling pathway and resulted in diverse inflammatory responses. FSL-1 induced the transcription of numerous protein-coding genes involved in a complex network of innate immune-related pathways. We speculate that TNF, IL1B, IL6, NFKB1, NFKBIA, CXCL2, CXCL8, CXCL10, CCL2, CCL4 and CCL5 were the most likely hub genes that play important roles in the above pathways. This study identified the differentially expressed genes and their related signaling pathways, contributing to the comprehensive understanding of the mechanisms underlying host-pathogen interactions during mycoplasma infection and providing a reference model for further studies.
 ...
PMID:Transcriptome sequencing analysis of porcine MDM response to FSL-1 stimulation. 3168 75