Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.11.24 (mitogen-activated protein kinase)
 95,810 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Atherosclerosis preferentially occurs in areas of turbulent flow and low fluid shear stress, while laminar flow and high shear stress are atheroprotective. Well characterized atheroprotective mechanisms include inhibition of thrombosis (increased tissue-type plasminogen activator and decreased plasminogen activator inhibitor-1), inhibition of endothelial cell apoptosis, limitation of permeability (uptake of low-density lipoprotein), prevention of white blood cell binding and transmigration (no expression of adhesion molecules such as intercellular adhesion molecule-1 [ICAM-1] and vascular cell adhesion molecule-1 [VCAM-1] and no release of monocyte chemotactic protein-1) and increased bioavailability of nitric oxide (because of increased expression of endothelial nitric oxide synthase and manganese superoxide dismutase). Our lab has investigated flow-mediated inhibition of inflammatory cytokine action. In particular, we have shown that flow prevents tumor necrosis factor-alpha (TNF-alpha) mediated signal transduction. TNF regulates inflammatory gene expression (e.g., ICAM-1 and VCAM-1) in endothelial cells, in part, by stimulating mitogen activated protein (MAP) kinases that phosphorylate transcription factors. We hypothesized that fluid shear stress inhibits TNF inflammatory effects on endothelial cells by inhibiting TNF mediated activation of the c-Jun N-terminal kinase. To test this hypothesis, we determined the effects of steady laminar flow on TNF-stimulated activity of c-Jun N-terminal kinase. The results show that flow inhibits c-Jun N-terminal kinase activation through multiple mechanisms, including stimulation of counter-regulatory MAP kinases (extracellular signal regulated kinases [ERK]1/2 and ERK5) and inhibition of apoptosis signal-regulated kinase. In summary, the atheroprotective effects of steady laminar flow on the endothelium involve multiple synergistic mechanisms. These multiple mechanisms offer attractive targets for new drug therapies aimed at limiting atherosclerosis development and progression. (c) 2002 Prous Science. All rights reserved.
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PMID:Atheroprotective Mechanisms Activated by Fluid Shear Stress in Endothelial Cells. 1267 55

Monocytes from patients with sickle cell disease (SCD) are in an activated state. However, the mechanism of activation of monocytes in SCD is not known. Our studies showed that placenta growth factor (PlGF) activated monocytes and increased mRNA levels of cytokines (tumor necrosis factor-alpha [TNF-alpha] and interleukin-1beta [IL-1beta]) and chemokines (monocyte chemotactic protein-1 [MCP-1], IL-8, and macrophage inflammatory protein-1beta [MIP-1beta]) in both normal monocytes and in the THP-1 monocytic cell line. This increase in mRNA expression of cytochemokines was also reflected in monocytes derived from subjects with SCD. We studied the PlGF-mediated downstream cellular signaling events that caused increased transcription of inflammatory cytochemokines and chemotaxis of THP-1 monocytes. PlGF-mediated cytochemokine mRNA and protein expression was inhibited by PD98059 and wortmannin, inhibitors of mitogen-activated protein kinase kinase (MAPK/MEK) kinase and phosphatidylinositol-3 (PI3) kinase, respectively, but not by SB203580, a p38 kinase inhibitor. PlGF caused a time-dependent transient increase in phosphorylation of extracellular signal-regulated kinase-1/2 (ERK-1/2), which was completely inhibited by wortmannin, indicating that activation of PI3 kinase preceded MEK activation. PlGF also induced transient phosphorylation of AKT. MEK and PI3 kinase inhibitors and antibody to Flt-1 abrogated PlGF-induced chemotaxis of THP-1 monocytes. Overexpression of a dominant-negative AKT or a dominant-negative PI3 kinase p85 subunit in THP-1 monocytes attenuated the PlGF-mediated phosphorylation of ERK-1/2, cytochemokine secretion, and chemotaxis. Taken together, these data show that activation of monocytes by PlGF occurs via activation of Flt-1, which results in activation of PI3 kinase/AKT and ERK-1/2 pathways. Therefore, we propose that increased levels of PlGF in circulation play an important role in the inflammation observed in SCD via its effects on monocytes.
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PMID:Mechanism of monocyte activation and expression of proinflammatory cytochemokines by placenta growth factor. 1268 30

Vascular endothelial cells (ECs) continuously experience hemodynamic shear stress generated from blood flow. Previous studies have demonstrated that shear stress modulates monocyte chemotactic protein-1 (MCP-1) expression in ECs. This study explored the roles of protein kinase C (PKC), extracellular signal-regulated protein kinase (ERK1/2), and nitric oxide (NO) in sheared-induced MCP-1 expression in ECs. The activation of PKC-alpha and PKC-epsilon isoforms was observed in ECs exposed to shear stress. The use of an inhibitor (calphostin C) to PKC-alpha and PKC-epsilon decreased ERK1/2 activation and MCP-1 induction by shear, whereas an inhibitor (Go6976) to PKC-alpha did not affect ERK1/2 activation or MCP-1 induction. Inhibition of ERK1/2 activation by PD98059 blocked MCP-1 induction. Transfection of ECs with an antisense to PKC-epsilon abolished the shear inducibility of MCP-1 promoter. These results demonstrate that PKC-epsilon and ERK1/2 participate in shear-induced MCP-1 expression. We also examined the regulatory role of NO in MCP-1 expression. An NO donor (NOC18) suppressed shear-induced activation of PKC-epsilon and ERK1/2, and also repressed MCP-1 induction. Consistently, overexpression of endothelial nitric oxide synthase (eNOS) to enhance the endogenous generation of NO in ECs decreased the activation of PKC-epsilon and ERK1/2, and also inhibited MCP-1 expression. Taken together, these findings suggest that PKC-epsilon and ERK1/2 are critical in the signaling pathway(s) leading to the MCP-1 expression induced by shear stress. Additionally, this study indicates that NO, by repressing PKC-epsilon activity and ERK pathway activation, attenuates shear-induced MCP-1 expression.
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PMID:Activation of PKC-epsilon and ERK1/2 participates in shear-induced endothelial MCP-1 expression that is repressed by nitric oxide. 1270 52

The decidualized endometrium plays a role in regulating trophoblast invasion for successful implantation and maintenance of pregnancy. IL-1 beta, a proinflammatory cytokine, has been suggested to play a role in this process. Recently, several lines of evidence indicate the importance of p38 MAPK in various inflammatory responses. We investigated whether endometrial stromal cells (ESC) change their inflammatory responses to IL-1 beta as related to p38 MAPK phosphorylation during the process of decidualization. ESC were decidualized by the treatment with progesterone for 9 d, as determined as such by an increase in the production of prolactin and cAMP by the cells. Whereas IL-1 beta increased the production of IL-6, IL-8, and monocyte chemotactic protein-1, and expression of cyclooxygenase-2 mRNA in ESC cultured without treatment, the stimulatory effects of IL-1 beta were reduced in the decidualized cells. Treatment with SB202190, a p38 MAPK inhibitor, also reduced the stimulatory effects of IL-1 beta in nondecidualized ESC. P38 MAPK phosphorylation was increased by IL-1 beta in nondecidualized ESC, whereas the IL-1 beta-induced increase was suppressed in the decidualized cells. Treatment with 8-bromo-cAMP reduced IL-1 beta-induced phosphorylation of p38 MAPK in nondecidualized ESC. In contrast, treatment with H89, a protein kinase A inhibitor, reversed a reduction in IL-1 beta-induced p38 MAPK phosphorylation in the decidualized cells. In summary, decidualization seems to be a process during which endometrial cells diminish their response to IL-1 beta, a known key factor for implantation, leading to the down-regulation of inflammation-like events, which may be relevant to controlled trophoblast invasion. The altered property of decidualized cells is thought to be caused by attenuation of IL-1 beta-induced p38 MAPK phosphorylation in a way that involves the activation of the cAMP/protein kinase A pathway.
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PMID:Endometrial stromal cells undergoing decidualization down-regulate their properties to produce proinflammatory cytokines in response to interleukin-1 beta via reduced p38 mitogen-activated protein kinase phosphorylation. 1272 80

The role of mitogen-activated protein kinase (MAPK) pathways in the secretion of tumor necrosis factor (TNF)-alpha, interleukin (IL)-10, IL-8, and monocyte chemotactic protein-1 (MCP-1) was investigated in human monocytes that were infected with Mycobacterium tuberculosis H37Rv. Analysis of extracellular signal-regulated kinases 1 and 2 (ERK1/2) and p38 kinase showed rapid phosphorylation of both subfamilies in response to M. tuberculosis H37Rv. Using highly specific inhibitors of p38 (SB203580) and of MAPK kinase-1 (U0126 and PD98059), we found that both p38 and ERK were essential for M. tuberculosis H37Rv-induced TNF-alpha production, whereas activation of the p38 pathway, but not that of ERK, was essential for M. tuberculosis H37Rv-induced IL-10 production. Interestingly, the ERK pathway, but not that of p38, was critical for MCP-1 secretion from human monocytes that were infected with M. tuberculosis H37Rv. However, IL-8 secretion was not regulated by ERK1/2 or p38 MAPK. Collectively, these results suggest that induction of the MAPK pathway is required for the expression of TNF-alpha, IL-10, and MCP-1 by human monocytes during M. tuberculosis H37Rv infection.
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PMID:Role of mitogen-activated protein kinase pathways in the production of tumor necrosis factor-alpha, interleukin-10, and monocyte chemotactic protein-1 by Mycobacterium tuberculosis H37Rv-infected human monocytes. 1279 41

Mechanical forces such as shear stress can modulate gene and protein expressions and hence cellular functions by activating membrane sensors and intracellular signaling. Using cultured endothelial cells, we have shown that laminar shear stress causes a transient increase in monocyte chemotactic protein-1 (MCP-1) expression, which involves the Ras-MAP kinase signaling pathway. We have demonstrated that integrins and the vascular endothelial growth factor receptor Flk-1 can sense shear stress, with integrins being upstream to Flk-1. Other possible membrane components involved in the sensing of shear stress include G-protein coupled receptors, intercellular junction proteins, membrane glycocalyx, and the lipid bilayer. Mechano-transduction involves the participation of a multitude of sensors, signaling molecules, and genes. Microarray analysis has demonstrated that shear stress can upregulate and downregulate different genes. Sustained shear stress downregulates atherogenic genes (e.g., MCP-1 and the genes that facilitate lipid accumulation) and upregulates growth-arrest genes. In contrast, disturbed flow observed at branch points and simulated in step-flow channels causes sustained activation of MCP-1 and the genes facilitating cell turnover and lipid accumulation. These findings provide a molecular basis for the explanation of the preferential localization of atherosclerotic lesions at regions of disturbed flow, such as the arterial branch points. The combination of mechanics and biology (from molecules-cells to organs-systems) can help to elucidate the physiological processes of mechano-chemical transduction and improving the methods of the management of important clinical conditions such as coronary artery disease.
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PMID:Molecular and mechanical bases of focal lipid accumulation in arterial wall. 1286 76

Reactive oxygen species are involved in the activation of several mitogen-activated protein kinases (MAPKs), key-players in the production of several cytokines. Therefore the current study investigated whether N-acetylcysteine (NAC), an antioxidative agent, inhibits the interleukin (IL)-1beta-induced expression and production of eotaxin and monocyte chemotactic protein (MCP)-1 in human airway smooth muscle cells (HASMC). NAC (10 mM) decreased the expression of eotaxin and MCP-1, by 46 +/- 11% (n=7) and 87 +/- 4% (n=6), respectively; the eotaxin release was inhibited by 75 +/- 5% (n=7), whereas the MCP-1 release was decreased by 69 +/- 41% (n=10). NAC (1 mM) also decreased the IL-1beta-induced activation of p38 MAPK. Compared with unstimulated cells, a four-fold increase in 8-isoprostane production in IL-1beta-stimulated HASMC was observed, which could be inhibited by NAC in a concentration-dependent way, with a maximum inhibition of 39 +/- 12%, with 1 mM NAC. The present study demonstrated that N-acetylcysteine inhibits the interleukin-1beta-induced eotaxin and monocyte chemotactic protein 1 expression and production due to a decreased activation of p38 mitogen-activated protein kinase. This study has also shown that N-acetylcysteine decreases the interleukin-1beta-induced production of reactive oxygen species, as suggested by a reduction in the 8-isoprostane production.
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PMID:N-acetylcysteine reduces chemokine release via inhibition of p38 MAPK in human airway smooth muscle cells. 1288 49

It has been widely shown that many plant-derived compounds present significant anti-inflammatory effects. For this reason, they represent potential molecules for the development of new drugs, especially designed for the treatment and/or control of chronic inflammatory states such as rheumatism, asthma, inflammatory bowel diseases, atherosclerosis, etc. This review focuses on the naturally-occurring compounds with anti-inflammatory properties and attempts to correlate their actions with the modulation of cytokines and associated intracellular signalling pathways; it continues the review published in the November, 2003 issue of Planta Medica. Abbreviations. AP-1:activator protein-1 CCR1:chemokine receptor 1 CINC-1:cytokine-induced neutrophil chemoattractant 1 COX:cyclooxygenase EGCG:(-)-epigallocatechin gallate ELAM-1:endothelial-leukocyte adhesion molecule-1 ERK:extracellular signal-regulated kinase GRO:growth-related oncogene HUVEC:human umbilical vein endothelial cells ICAM-1:intercellular adhesion molecule-1 IFN:interferon IL:interleukin iNOS:inducible nitric oxide synthase IRA:the natural interleukin receptor activation JAK:janus kinase JNK:c-Jun NH2-terminal kinase LPS:lipopolysaccharide MAPK:mitogen-activated protein kinases MCP:monocyte chemotactic protein MHC:major histocompatibility complex MIP:macrophage inflammatory protein MMP:matrix metalloproteinases MPO:myeloperoxidase NF-kappaBnuclear factor kappa B NO:nitric oxide PAF:platelet aggregation factor PGEE:prostaglandin PK:protein kinase PMA/TPA:phorbol myristate acetate RANTES:regulated upon activation normal T-cell expressed and secreted TGF-beta:transforming growth factor-beta TNFalpha:tumour necrosis factor VCAM-1:vascular cell adhesion molecule-1
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PMID:Anti-inflammatory compounds of plant origin. Part II. modulation of pro-inflammatory cytokines, chemokines and adhesion molecules. 1499 84

Acute peritonitis, in which peritoneal mesothelial cells are directly exposed to bacterial components, is a major cause of peritoneal dysfunction in continuous ambulatory peritoneal dialysis patients. We have previously shown that Toll-like receptors (TLR) are expressed in kidney cells, and LPS induces TLR4-dependent chemokine production in tubular epithelial cells. The present work was designed to investigate the involvement of TLR, especially TLR4, in the lipid A-mediated chemokine production by murine peritoneal mesothelial cells (MPMC). A primary cell culture of MPMC from C3H/HeN mice (wild-type mice; LPS sensitive) and from C3H/HeJ mice (containing a point mutation of TLR4; LPS hyposensitive) was established. The expression profile of the TLR family and their accessory molecules, CD14 and MD-2, which are requisite for the LPS signaling pathway, was examined by RT-PCR, Northern blot test, and immunohistochemical staining. Synthetic lipid A-mediated chemokine production by MPMC was studied. The involvement of MAP kinase family (ERK, JNK, and p38 mitogen-activated protein kinase) and nuclear factor (NF)-kappaB in these processes was also studied. MPMC constitutively express TLR4, CD14, and MD-2. A prominent induction of monocyte chemotactic protein-1 (MCP-1) and macrophage inflammatory protein (MIP)-2 by MPMC was detected after lipid A stimulation and was strictly dependent on TLR4. Furthermore, TLR4-dependent chemokine production followed by leukocyte influx into the peritoneal cavity was also confirmed in vivo after stimulation with LPS. mRNA expression of MCP-1 was abolished by NF-kappaB inhibition, but were not affected by the inhibition of ERK, JNK, or p38. As compared with MCP-1, MIP-2 mRNA expression was inhibited by a high dose of curcumin but not by NF-kappaB decoy oligodeoxynucleotide and individual inhibitions of MAP kinase, suggesting that the additional signaling pathway with NF-kappaB might be involved in mRNA expression of MIP-2. These show that TLR4 is directly involved in the production of MCP-1 and MIP-2 by MPMC in a NF-kappaB-dependent manner, but the process does not require any MAP kinase activation. The results provide a candidate molecular target in prevention of it.
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PMID:Endotoxin-induced chemokine expression in murine peritoneal mesothelial cells: the role of toll-like receptor 4. 1510 Mar 69

Eosinophil-mediated diseases, such as allergic asthma, eosinophilic fasciitis, and certain hypersensitivity pulmonary disorders, are characterized by eosinophil infiltration and tissue injury. Mast cells and T cells often colocalize to these areas. Recent data suggest that mast cells can contribute to eosinophil-mediated inflammatory responses. Activation of mast cells can occur by antigen and immunoglobulin E (IgE) via the high-affinity receptor (FcepsilonRI) for IgE. The liberation of proteases, leukotrienes, lipid mediators, and histamine can contribute to tissue inflammation and allow recruitment of eosinophils to tissue. In addition, the synthesis and expression of a plethora of cytokines and chemokines (such as granulocyte-macrophage colony-stimulating factor [GM-CSF], interleukin-1 [IL-1], IL-3, IL-5, tumor necrosis factor-alpha [TNF-alpha], and the chemokines IL-8, regulated upon activation normal T cell expressed and secreted [RANTES], monocyte chemotactic protein-1 [MCP-1], and eotaxin) by mast cells can influence eosinophil biology. Stem cell factor (SCF)-c-kit, cytokine-cytokine receptor, and chemokine-chemokine receptor (CCR3) interactions leading to nuclear factor kappaB (NF-kappaB), mitogen-activated protein kinase (MAPK) expression, and other signaling pathways can modulate eosinophil function. Eosinophil hematopoiesis, activation, survival, and elaboration of mediators can all be regulated thus by mast cells in tissue. Moreover, because eosinophils can secrete SCF, eosinophils can regulate mast cell function in a paracrine manner. This two-way interaction between eosinophils and mast cells can pave the way for chronic inflammatory responses in a variety of human diseases. This review summarizes this pivotal interaction between human mast cells and eosinophils.
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PMID:The role of human mast cell-derived cytokines in eosinophil biology. 1515 10


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