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bionlp-st-ge-2016-reference

2_test

{"project":"2_test","denotations":[{"id":"18568240-12168567-22101112","span":{"begin":2313,"end":2314},"obj":"12168567"},{"id":"18568240-9442376-22101113","span":{"begin":2442,"end":2443},"obj":"9442376"},{"id":"18568240-2460096-22101114","span":{"begin":2708,"end":2709},"obj":"2460096"},{"id":"18568240-1847694-22101115","span":{"begin":3102,"end":3103},"obj":"1847694"},{"id":"18568240-12829247-22101116","span":{"begin":3321,"end":3322},"obj":"12829247"},{"id":"18568240-12829247-22101117","span":{"begin":3637,"end":3638},"obj":"12829247"},{"id":"18568240-15044179-22101117","span":{"begin":3637,"end":3638},"obj":"15044179"},{"id":"18568240-15221855-22101117","span":{"begin":3637,"end":3638},"obj":"15221855"},{"id":"18568240-8702838-22101118","span":{"begin":3946,"end":3947},"obj":"8702838"}],"text":"this study was to determine the effect of nonspecific phosphodiesterase inhibition on transcription factor activation and tumor necrosis factor-alpha (TNF-α) production in lipopolysaccharide (LPS)-stimulated human mononuclear cells.\n\nINTRODUCTION\nThe production of TNF-α following LPS stimulation is one of the key steps in bacterial sepsis and inflammation. The mechanism by which phosphodiesterase inhibition alters TNF-α production in the presence of LPS remains unclear.\n\nMETHODS\nHuman mononuclear cells were stimulated with LPS (1 μg/mL), in the presence and absence of Pentoxifylline (PTX; 20 mM), a nonspecific phosphodiesterase inhibitor. Western blotting of phosphorylated cytoplasmic I-κBα, nuclear factor-κB p65 (NF-κB), and nuclear cAMP-response element binding protein (CREB) was performed. DNA binding of NF-κB and CREB was verified by electrophoretic mobility shift assay. TNF-α levels were determined in the supernatant of stimulated cells in the presence and absence Protein kinase A inhibition by an enzyme-linked immunosorbent assay (ELISA).\n\nRESULTS\nPTX was demonstrated to significantly reduce cytoplasmic I-κBα phosphorylation, nuclear p65 phosphorylation, and the DNA binding activity of NF-κB. In contrast, PTX markedly enhanced the phosphorylation and DNA binding activity of CREB. Cells concomitantly treated with PTX and LPS secreted similar levels of TNF-α in the presence and absence Protein kinase A inhibition.\n\nDISCUSSION\nThe increased level of cAMP that results from phosphodiesterase inhibition affects cytoplasmic and nuclear events, resulting in the attenuation of NF-κB and the activation of CREB transcriptional DNA binding through pathways that are partially Protein kinase A-independent.\n\nCONCLUSION\nPTX-mediated phosphodiesterase inhibition occurs partially through a Protein kinase A-independent pathway and may serve as a useful tool in the attenuation of LPS-induced inflammation. \n\nINTRODUCTION\nThe bacterial membrane component lipopolysaccharide (LPS) is capable of initiating phosphorylation and activation of multiple host intracellular protein kinases and transcription factors. Transcription factor activation, which results in the modulation of gene transcription and protein synthesis, is a critical element in the defense mechanism of the host immune system.1,2\nLPS-induced transcription factor activation has been shown to be a key regulator of tumor necrosis factor-α (TNF-α) production.3 TNF-α is a potent pro-inflammatory cytokine involved in a wide spectrum of cellular responses. Furthermore, TNF-α synthesis can be attenuated in immune cells exposed to phosphodiesterase (PDE) inhibition after challenge by a variety of pro-inflammatory stimulants.4 The signaling mechanisms affected by PDE inhibition, which ultimately lead to the downregulation of TNF-α production, have not been well characterized in inflammatory cells.\nClassically, it has been demonstrated that PDE inhibition results in the intracellular accumulation of the second messenger cyclic adenosine-3,5-monophosphate (cAMP) and subsequent activation of Protein kinase A (PKA).5 PKA activation then leads to the phosphorylation of the transcription factor cAMP-response element binding protein (CREB), transmission of signals into the nucleus, and the subsequent modulation of gene transcription.6 This apparently simple linear cascade does not fully explain the mechanism by which an elevation in the intracellular cAMP level exerts wide-ranging effects on multiple cellular functions. There is a growing body of evidence suggesting that cAMP may function through both PKA-dependent and -independent mechanisms.6–8\nLPS-induced activation of the transcription factor nuclear factor-κB (NF-κB) has also been the focus of a great deal of research. It has been clearly demonstrated that agents that increase intracellular cAMP also inhibit NF-κB-dependent pro-inflammatory gene transcription, particularly of the TNF-α gene.9\nControversy exists regarding the exact mechanism(s) by which PDE inhibition down-regulates TNF-α production. Possibilities include, but are not limited to, inhibition of NF-κB DNA binding activity, downregulation of NF-κB transcriptional activity, increased CREB activation, and competition between NF-κB and CREB for common co-activators such as CREB binding protein (CBP). It is also not known whether these processes rely solely upon the activation of PKA.\nTherefore, the objective of the present study is to determine the effects of nonspecific PDE inhibition with 1-[5-oxohexyl]-3,7-dimethylxanthine (Pentoxifylline; PTX) on NF-κB and CREB activation in vitro in human mononuclear cells. With the use of specific inhibitors, we also investigated the role of PKA in LPS-induced TNF-α production.\n\nMATERIALS AND METHODS\nThis study was approved by the Human Research Protections Program and the Institutional Review Board. Written consent to participate in the study was obtained from all volunteers prior to blood donation.\nHeparinized Vacutainers were purchased from Becton Dickinson (San Jose, CA)."}

pmc-enju-pas

bionlp-st-ge-2016-spacy-parsed

UBERON-AE

{"project":"UBERON-AE","denotations":[{"id":"T1125","span":{"begin":2297,"end":2310},"obj":"http://purl.obolibrary.org/obo/UBERON_0002405"},{"id":"T2438","span":{"begin":4959,"end":4964},"obj":"http://purl.obolibrary.org/obo/UBERON_0000178"}],"text":"this study was to determine the effect of nonspecific phosphodiesterase inhibition on transcription factor activation and tumor necrosis factor-alpha (TNF-α) production in lipopolysaccharide (LPS)-stimulated human mononuclear cells.\n\nINTRODUCTION\nThe production of TNF-α following LPS stimulation is one of the key steps in bacterial sepsis and inflammation. The mechanism by which phosphodiesterase inhibition alters TNF-α production in the presence of LPS remains unclear.\n\nMETHODS\nHuman mononuclear cells were stimulated with LPS (1 μg/mL), in the presence and absence of Pentoxifylline (PTX; 20 mM), a nonspecific phosphodiesterase inhibitor. Western blotting of phosphorylated cytoplasmic I-κBα, nuclear factor-κB p65 (NF-κB), and nuclear cAMP-response element binding protein (CREB) was performed. DNA binding of NF-κB and CREB was verified by electrophoretic mobility shift assay. TNF-α levels were determined in the supernatant of stimulated cells in the presence and absence Protein kinase A inhibition by an enzyme-linked immunosorbent assay (ELISA).\n\nRESULTS\nPTX was demonstrated to significantly reduce cytoplasmic I-κBα phosphorylation, nuclear p65 phosphorylation, and the DNA binding activity of NF-κB. In contrast, PTX markedly enhanced the phosphorylation and DNA binding activity of CREB. Cells concomitantly treated with PTX and LPS secreted similar levels of TNF-α in the presence and absence Protein kinase A inhibition.\n\nDISCUSSION\nThe increased level of cAMP that results from phosphodiesterase inhibition affects cytoplasmic and nuclear events, resulting in the attenuation of NF-κB and the activation of CREB transcriptional DNA binding through pathways that are partially Protein kinase A-independent.\n\nCONCLUSION\nPTX-mediated phosphodiesterase inhibition occurs partially through a Protein kinase A-independent pathway and may serve as a useful tool in the attenuation of LPS-induced inflammation. \n\nINTRODUCTION\nThe bacterial membrane component lipopolysaccharide (LPS) is capable of initiating phosphorylation and activation of multiple host intracellular protein kinases and transcription factors. Transcription factor activation, which results in the modulation of gene transcription and protein synthesis, is a critical element in the defense mechanism of the host immune system.1,2\nLPS-induced transcription factor activation has been shown to be a key regulator of tumor necrosis factor-α (TNF-α) production.3 TNF-α is a potent pro-inflammatory cytokine involved in a wide spectrum of cellular responses. Furthermore, TNF-α synthesis can be attenuated in immune cells exposed to phosphodiesterase (PDE) inhibition after challenge by a variety of pro-inflammatory stimulants.4 The signaling mechanisms affected by PDE inhibition, which ultimately lead to the downregulation of TNF-α production, have not been well characterized in inflammatory cells.\nClassically, it has been demonstrated that PDE inhibition results in the intracellular accumulation of the second messenger cyclic adenosine-3,5-monophosphate (cAMP) and subsequent activation of Protein kinase A (PKA).5 PKA activation then leads to the phosphorylation of the transcription factor cAMP-response element binding protein (CREB), transmission of signals into the nucleus, and the subsequent modulation of gene transcription.6 This apparently simple linear cascade does not fully explain the mechanism by which an elevation in the intracellular cAMP level exerts wide-ranging effects on multiple cellular functions. There is a growing body of evidence suggesting that cAMP may function through both PKA-dependent and -independent mechanisms.6–8\nLPS-induced activation of the transcription factor nuclear factor-κB (NF-κB) has also been the focus of a great deal of research. It has been clearly demonstrated that agents that increase intracellular cAMP also inhibit NF-κB-dependent pro-inflammatory gene transcription, particularly of the TNF-α gene.9\nControversy exists regarding the exact mechanism(s) by which PDE inhibition down-regulates TNF-α production. Possibilities include, but are not limited to, inhibition of NF-κB DNA binding activity, downregulation of NF-κB transcriptional activity, increased CREB activation, and competition between NF-κB and CREB for common co-activators such as CREB binding protein (CBP). It is also not known whether these processes rely solely upon the activation of PKA.\nTherefore, the objective of the present study is to determine the effects of nonspecific PDE inhibition with 1-[5-oxohexyl]-3,7-dimethylxanthine (Pentoxifylline; PTX) on NF-κB and CREB activation in vitro in human mononuclear cells. With the use of specific inhibitors, we also investigated the role of PKA in LPS-induced TNF-α production.\n\nMATERIALS AND METHODS\nThis study was approved by the Human Research Protections Program and the Institutional Review Board. Written consent to participate in the study was obtained from all volunteers prior to blood donation.\nHeparinized Vacutainers were purchased from Becton Dickinson (San Jose, CA)."}

GO-BP

GO-MF

GO-CC

sentences

events-check-again

bionlp-st-ge-2016-reference-tees

bionlp-st-ge-2016-uniprot

test2

PMC:2664230 / 172-5223 JSONTXT

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PMC:2664230 / 172-5223 JSON TXT