Role of 12/15-lipoxygenase in the expression of MCP-1 in mouse macrophages

2008 ◽  
Vol 294 (4) ◽  
pp. H1933-H1938 ◽  
Author(s):  
Yeshao Wen ◽  
Jiali Gu ◽  
George E. Vandenhoff ◽  
Xiaoping Liu ◽  
Jerry L. Nadler
Keyword(s):  
Protein Kinase ◽  
Nadph Oxidase ◽  
Mrna Expression ◽  
Cell Line ◽  
Oxidase Activity ◽  
Mitogen Activated Protein Kinase ◽  
Macrophage Cell Line ◽  
Macrophage Cell ◽  
Nadph Oxidase Activity

Monocyte chemoattractant protein (MCP)-1 plays a key role in atherosclerosis and inflammation associated with visceral adiposity by inducing mononuclear cell migration. Evidence shows that mouse peritoneal macrophages (MPM) express a 12-lipoxygenase (12/15-LO) that has been clearly linked to accelerated atherosclerosis in mouse models and increased monocyte endothelial interactions in both rodent and human cells. However, the role of 12/15-LO products in regulating MCP-1 expression in macrophages has not been clarified. In this study, we tested the role of 12/15-LO products using MPM and the mouse macrophage cell line, J774A.1 cells. We found that 12(S)-hydroxyeicosatetraenoic acid [12(S)-HETE] increased MCP-1 mRNA and protein expression in J774A.1 cells and MPM. In contrast, 12(R)-HETE, a lipid not derived from 12/15-LO, did not affect MCP-1 expression. 15(S)-HETE also increased MCP-1 mRNA expression, but the effect was less compared with 12(S)-HETE. MCP-1 mRNA expression was upregulated in a macrophage cell line stably overexpressing 12/15-LO (Plox-86 cells) and in MPM isolated from a 12/15-LO transgenic mouse. In addition, the expression of MCP-1 was downregulated in MPM isolated from 12/15-LO knockout mice. 12(S)-HETE-induced MCP-1 mRNA expression was attenuated by specific inhibitors of protein kinase C (PKC) and p38 mitogen-activated protein kinase (p38). 12(S)-HETE also directly activated NADPH oxidase activity. Two NADPH oxidase inhibitors, apocynin and diphenyleneiodonium chloride, blocked 12(S)-HETE-induced MCP-1 mRNA. Apocynin attenuated 12(S)-HETE-induced MCP-1 protein secretion. These data show that 12(S)-HETE increases MCP-1 expression by inducing PKC, p38, and NADPH oxidase activity. These results suggest a potentially important mechanism linking 12/15-LO activation to MCP-1 expression that induces inflammatory cell infiltration.

scholarly journals Chicken avian β-defensin 8 modulates immune response via the mitogen-activated protein kinase signaling pathways in a chicken macrophage cell line

2020 ◽  
Author(s):  
Yeojin Hong ◽  
Thu Thao Pham ◽  
Jiae Lee ◽  
Hyun S. Lillehoj ◽  
Yeong Ho Hong
Keyword(s):  
Protein Kinase ◽  
Cell Line ◽  
Signaling Pathway ◽  
Proinflammatory Cytokines ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Macrophage Cell Line ◽  
Macrophage Cell ◽  
Mitogen Activated Protein ◽  
Chicken Macrophage

Abstract Background: Defensins are antimicrobial peptides composed of three conserved disulfide bridges, a β-sheet, and both hydrophobic and cationic amino acids. In this study, we aimed to demonstrate the immunomodulation role of avian β-defensin 8 (AvBD8) in a chicken macrophage cell line. Results: Chicken AvBD8 stimulated the expression of proinflammatory cytokines (interleukin (IL)-1β, interferon-γ, and IL-12p40) and chemokines (CCL4, CXCL13, and CCL20) in macrophages. Furthermore, by western blotting and immunocytochemistry, we confirmed that AvBD8 activated the mitogen-activated protein kinase (MAPK) signaling pathway via extracellular regulated kinases 1/2 (ERK1/2) and p38 signaling molecules. Conclusion: Overall, AvBD8 regulates host immune system as not only an antimicrobial peptide, but also an immunomodulator by activating the MAPK signaling pathway and inducing the expression of proinflammatory cytokines and chemokines.

SYNERGISTIC UP-REGULATION OF IκBα mRNA EXPRESSION IN A MURINE MACROPHAGE CELL LINE FOLLOWING EXPOSURE TO GLUCAN PHOSPHATE AND ENDOTOXIN

Shock ◽  
1997 ◽  
Vol 7 (Supplement) ◽  
pp. 92
Author(s):  
David Williams ◽  
Tuanzhu Ha ◽  
Chuanfu Li ◽  
Antje Müller ◽  
John Raptis ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Cell Line ◽  
Murine Macrophage ◽  
Macrophage Cell Line ◽  
Macrophage Cell ◽  
Murine Macrophage Cell Line ◽  
Line Following

scholarly journals IGF-I increases the expression of fibronectin by Nox4-dependent Akt phosphorylation in renal tubular epithelial cells

2012 ◽  
Vol 302 (1) ◽  
pp. C122-C130 ◽  
Author(s):  
David D. New ◽  
Karen Block ◽  
Basant Bhandhari ◽  
Yves Gorin ◽  
Hanna E. Abboud
Keyword(s):  
Epithelial Cells ◽  
Nadph Oxidase ◽  
Oxidase Activity ◽  
Dominant Negative ◽  
Tubular Epithelial Cells ◽  
Nadph Oxidase Activity ◽  
Akt Phosphorylation ◽  
Fibronectin Expression ◽  
Igf I

Extracellular matrix accumulation contributes to the progression of chronic kidney disease. Many growth factors including insulin-like growth factor-I (IGF-I) enhance matrix protein accumulation. Proximal tubular epithelial cells (PTCs) synthesize matrix proteins. NADPH oxidases are major sources of reactive oxygen species (ROS), important signaling molecules that mediate biological responses in a variety of cells and tissue. We investigated the mechanism by which IGF-I regulates fibronectin accumulation in PTCs and the role of a potential redox-dependent signaling pathway. IGF-I induces an increase in NADPH-dependent superoxide generation, enhances the release of hydrogen peroxide, and increases the expression of NADPH oxidase 4 (Nox4) in PTCs. IGF-I also stimulates phosphorylation of Akt, and inhibition of Akt or its upstream activator phosphatidylinositol 3-kinase attenuates IGF-I-induced fibronectin accumulation. Expression of dominant negative Akt also inhibits IGF-I-induced expression of fibronectin, indicating a role for this kinase in fibronectin accumulation. Expression of dominant negative adenovirus Nox4 inhibits IGF-I-induced NADPH oxidase activity, Akt phosphorylation, and fibronectin protein expression. Moreover, transfection of small interfering RNA targeting Nox4 decreases Nox4 protein expression and blocks IGF-I-induced Akt phosphorylation and the increase in fibronectin, placing Nox4 and ROS upstream of Akt signaling pathway. To confirm the role of Nox4, PTCs were infected with adenovirus construct expressing wild-type Nox4. Ad-Nox4, but not control Ad-green fluorescent protein, upregulated Nox4 expression and increased NADPH oxidase activity as well as fibronectin expression. Taken together, these results provide the first evidence for a role of Nox4 in IGF-I-induced Akt phosphorylation and fibronectin expression in tubular epithelial cells.

scholarly journals FcγR-stimulated activation of the NADPH oxidase: phosphoinositide-binding protein p40phox regulates NADPH oxidase activity after enzyme assembly on the phagosome

Blood ◽  
2008 ◽  
Vol 112 (9) ◽  
pp. 3867-3877 ◽  
Author(s):  
Wei Tian ◽  
Xing Jun Li ◽  
Natalie D. Stull ◽  
Wenyu Ming ◽  
Chang-Il Suh ◽  
...  
Keyword(s):  
Nadph Oxidase ◽  
Oxidase Activity ◽  
Superoxide Production ◽  
Resting Cells ◽  
Cellular Activation ◽  
Nadph Oxidase Activity ◽  
Phagocyte Nadph Oxidase ◽  
Before And After ◽  
Membrane Bound

AbstractThe phagocyte NADPH oxidase generates superoxide for microbial killing, and includes a membrane-bound flavocytochrome b558 and cytosolic p67phox, p47phox, and p40phox subunits that undergo membrane translocation upon cellular activation. The function of p40phox, which binds p67phox in resting cells, is incompletely understood. Recent studies showed that phagocytosis-induced superoxide production is stimulated by p40phox and its binding to phosphatidylinositol-3-phosphate (PI3P), a phosphoinositide enriched in membranes of internalized phagosomes. To better define the role of p40phox in FcγR-induced oxidase activation, we used immunofluorescence and real-time imaging of FcγR-induced phagocytosis. YFP-tagged p67phox and p40phox translocated to granulocyte phagosomes before phagosome internalization and accumulation of a probe for PI3P. p67phox and p47phox accumulation on nascent and internalized phagosomes did not require p40phox or PI3 kinase activity, although superoxide production before and after phagosome sealing was decreased by mutation of the p40phox PI3P-binding domain or wortmannin. Translocation of p40phox to nascent phagosomes required binding to p67phox but not PI3P, although the loss of PI3P binding reduced p40phox retention after phagosome internalization. We conclude that p40phox functions primarily to regulate FcγR-induced NADPH oxidase activity rather than assembly, and stimulates superoxide production via a PI3P signal that increases after phagosome internalization.

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