In Human Macrophages the Complement Component C5a Induces the Expression of Oncostatin M via AP-1 Activation

Abstract

Objective-Macrophages produce the cytokine oncostatin M (OSM), which beside other functions is also involved in inflammation. The complement component C5a mobilizes and activates these cells at inflammatory sites. We examined the effect of C5a on OSM production in human monocytes and in human monocyte-derived macrophages. Methods and Results-For macrophage transformation peripheral blood monocytes were cultivated for 8 to 10 days in the presence of human serum. C5a significantly increased in these cells OSM antigen as determined by specific ELISA and mRNA as quantitated by real-time polymerase chain reaction in these cells as well as in plaque macrophages. This effect was blocked by antibodies against the receptor C5aR/CD88 and by pertussis toxin. The C5a-induced phosphorylation of p38 and JNK and the C5a-induced increase in OSM production in macrophages was abolished by 2 p38 inhibitors and by a JNK inhibitor. Furthermore C5a increased the nuclear translocation of c-fos and c-jun. Using different OSM promoter deletion mutant constructs we show that the putative AP-1 element is responsible for activation of OSM promoter activity by C5a. Key Words: atherosclerosis Ⅲ macrophages Ⅲ inflammation Ⅲ complement Ⅲ oncostatin M M acrophages by producing a vast array of biomolecules play a key role in a variety of physiological and pathophysiological processes such as immunity, inflammation, and tissue remodeling. 1 Among these biomolecules are various inflammatory cytokines such as tumor necrosis factor (TNF)-␣, interleukin (IL)-1, or IL-6. 2 Macrophages are also considered to be the major producers of oncostatin M (OSM), which is a multifunctional cytokine belonging to the glycoprotein 130 (gp130) receptor cytokine family. 3-5 OSM was originally isolated from phorbol 12-myristate 13-acetate (PMA)-treated human histolytic lymphoma U937 cells and plays a critical role in numerous physiological and pathophysiological events including inflammation, hematopoiesis, tissue remodeling, development, and cell growth. 6,7 Besides macrophages also T cells, neutrophils, osteoblasts, dendritic cells, Kaposi's sarcoma cells, and microglia produce OSM. 8 -13 Its expression is upregulated by granulocyte-macrophage colony stimulating factor (GM-CSF), IL-3, human chorionic gonadotropin (hCG), HIV-1, lipopolysaccharide (LPS), cisplatin, or prostaglandin (PG) E2. 11,[13][14][15][16] The potent anaphylatoxin C5a is generated during complement activation through cleavage of C5 and is released at the inflammatory site. There, C5a mediates immune and inflammatory processes such as increased vascular permeability, spasmogenesis, immune regulation, and the release of a variety of inflammatory cytokines and mediators. 17,18 C5a is a strong chemoattractant and is involved in the recruitment of inflammatory cells such as T lymphocytes, eosinophils, neutrophils, and monocytes and is regarded as the most potent chemoattractant for the latter 2 cell types. 19,20 It contributes to rapid mobilization of phagocytic cells to and activation of these cells...

Osteopontin Promotes Oncostatin M Production in Human Osteoblasts: Implication of Rheumatoid Arthritis Therapy

“…It has been reported that c-Jun is recruited to the OSM promoter, which contains an AP-1 binding site (19,33). The binding of c-Jun to the AP-1 element on the OSM promoter after OPN stimulation was confirmed through ChIP (Fig.…”

Thrombin induces the expression of oncostatin M via AP-1 activation in human macrophages: a link between coagulation and inflammation

“…38 When MDMs were incubated with rhC5a alone, a significant increase in OSM production compared with untreated control cells was observed. Pretreatment of the cells with PPACK did not affect this rhC5a-induced OSM up-regulation in MDMs (OSM in nanograms per milliliter per 24 hours: control: 41.8 Ϯ 10.2; rhC5a: 372.6 Ϯ 29.2; rhC5a ϩ PPACK: 381.0 Ϯ 16.5 ng/mL; P Ͻ .05).…”

“…To rule out a possible unspecific inhibitory effect of PPACK on ␣-thrombin-induced up-regulation of OSM, cells that were preincubated with PPACK for 1 hour at 37°C were stimulated for 24 hours at 37°C with rhC5a (0.5 M), which has been previously shown by us to significantly up-regulate OSM production in MDMs. 38 When MDMs were incubated with rhC5a alone, a significant increase in OSM production compared with untreated control cells was observed. Pretreatment of the cells with PPACK did not affect this rhC5a-induced OSM up-regulation in MDMs (OSM in nanograms per milliliter per 24 hours: control: 41.8 Ϯ 10.2; rhC5a: 372.6 Ϯ 29.2; rhC5a ϩ PPACK: 381.0 Ϯ 16.5 ng/mL; P Ͻ .05).…”

“…38 A 304-bp, a 194-bp, a 109-bp, and a 304-bp construct with a mutated AP-1 site were used, respectively. 39 Transfection of MDMs and luciferase assays were carried out as described by Ma et al 39 Briefly, MDMs were seeded into 48-well plates at a concentration of 100 000 cells/well and transfection was performed using jetPEI-Macrophage (Polyplus-transfection) according to the manufacturer's instructions 24 hours before stimulation with ␣-thrombin.…”

Intratumoural inflammation and endocrine resistance in breast cancer

“…Unlike IL6, its production appears to be largely restricted to specific inflammatory/immune cell subsets such as macrophages, T cells, neutrophils and dendritic cells (Chen & Benveniste 2004, Queen et al 2005, Kastl et al 2008. OSM signals through two receptor complexes defined by OSMR or leukaemia inhibitory factor receptor (LIFR) subunits in combination with a common gp130 receptor subunit (also shared with IL6R).…”