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Increased interleukin-17 production via a phosphoinositide 3-kinase/Akt and nuclear factor kappaB-dependent pathway in patients with rheumatoid arthritis.

Kim KW, Cho ML, Park MK, Yoon CH, Park SH, Lee SH, Kim HY - Arthritis Res. Ther. (2004)

Bottom Line: Anti-CD3 antibody activated the PI3K/Akt pathway; activation of this pathway resulted in a pronounced augmentation of nuclear factor kappaB (NF-kappaB) DNA-binding activity.However, inhibition of activator protein-1 and extracellular signal-regulated kinase 1/2 did not affect IL-17 production.These results suggest that signal transduction pathways dependent on PI3K/Akt and NF-kappaB are involved in the overproduction of the key inflammatory cytokine IL-17 in RA.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Medicine, Division of Rheumatology, The Center for Rheumatic Diseases, and The Rheumatism Research Center (RhRC), Catholic Research Institutes of Medical Sciences, Catholic University of Korea, Seoul, Korea. woon1212@catholic.ac.kr

ABSTRACT
Inflammatory mediators have been recognized as being important in the pathogenesis of rheumatoid arthritis (RA). Interleukin (IL)-17 is an important regulator of immune and inflammatory responses, including the induction of proinflammatory cytokines and osteoclastic bone resorption. Evidence for the expression and proinflammatory activity of IL-17 has been demonstrated in RA synovium and in animal models of RA. Although some cytokines (IL-15 and IL-23) have been reported to regulate IL-17 production, the intracellular signaling pathways that regulate IL-17 production remain unknown. In the present study, we investigated the role of the phosphoinositide 3-kinase (PI3K)/Akt pathway in the regulation of IL-17 production in RA. Peripheral blood mononuclear cells (PBMC) from patients with RA (n = 24) were separated, then stimulated with various agents including anti-CD3, anti-CD28, phytohemagglutinin (PHA) and several inflammatory cytokines and chemokines. IL-17 levels were determined by sandwich enzyme-linked immunosorbent assay and reverse transcription-polymerase chain reaction. The production of IL-17 was significantly increased in cells treated with anti-CD3 antibody with or without anti-CD28 and PHA (P < 0.05). Among tested cytokines and chemokines, IL-15, monocyte chemoattractant protein-1 and IL-6 upregulated IL-17 production (P < 0.05), whereas tumor necrosis factor-alpha, IL-1beta, IL-18 or transforming growth factor-beta did not. IL-17 was also detected in the PBMC of patients with osteoarthritis, but their expression levels were much lower than those of RA PBMC. Anti-CD3 antibody activated the PI3K/Akt pathway; activation of this pathway resulted in a pronounced augmentation of nuclear factor kappaB (NF-kappaB) DNA-binding activity. IL-17 production by activated RA PBMC is completely or partly blocked in the presence of the NF-kappaB inhibitor pyrrolidine dithiocarbamate and the PI3K/Akt inhibitor wortmannin and LY294002, respectively. However, inhibition of activator protein-1 and extracellular signal-regulated kinase 1/2 did not affect IL-17 production. These results suggest that signal transduction pathways dependent on PI3K/Akt and NF-kappaB are involved in the overproduction of the key inflammatory cytokine IL-17 in RA.

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Dose-dependent effects of LY294002 or pyrrolidine dithiocarbamate (PDTC) in peripheral blood mononuclear cells (PBMC) from patients with rheumatoid arthritis (RA). (a) Effect of inhibitors on interleukin (IL)-17 release by anti-CD3-stimulated PBMC from patients with RA. (b) Effects of LY294002 or PDTC on PBMC viability. PBMC were cultured at a concentration of 2 × 105 cells per well with medium, anti-CD3, anti-CD3 and LY294002 or PDTC under the conditions described in the Materials and methods section. After 24 hours of treatment, cell viability was assessed by the trypan blue dye exclusion method and expressed as a percentage with the formula 100 × (number of viable cells/number of both viable and dead cells).
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Figure 4: Dose-dependent effects of LY294002 or pyrrolidine dithiocarbamate (PDTC) in peripheral blood mononuclear cells (PBMC) from patients with rheumatoid arthritis (RA). (a) Effect of inhibitors on interleukin (IL)-17 release by anti-CD3-stimulated PBMC from patients with RA. (b) Effects of LY294002 or PDTC on PBMC viability. PBMC were cultured at a concentration of 2 × 105 cells per well with medium, anti-CD3, anti-CD3 and LY294002 or PDTC under the conditions described in the Materials and methods section. After 24 hours of treatment, cell viability was assessed by the trypan blue dye exclusion method and expressed as a percentage with the formula 100 × (number of viable cells/number of both viable and dead cells).

Mentions: The calcineurin inhibitors cyclosporin A and FK506 also downregulated the IL-17 secretion as well as the mitogen-activated protein kinase (MAPK) p38 inhibitor SB203580 did, whereas rapamycin and PD98059 had no effect on IL-17 levels (Fig. 3). To evaluate the possibility of non-specific inhibition by the drug at high concentrations, we observed the dose response of PDTC and LY294002 for the inhibition of IL-17 production in PBMC. There were dose-dependent inhibitions of IL-17 production with chemical inhibitors (Fig. 4a). The other inhibitors in addition to PDTC and LY294002 showed the same pattern of inhibition. Cytotoxic effects on PBMC by the chemical inhibitors at experimental concentrations were not observed (Fig. 4b).


Increased interleukin-17 production via a phosphoinositide 3-kinase/Akt and nuclear factor kappaB-dependent pathway in patients with rheumatoid arthritis.

Kim KW, Cho ML, Park MK, Yoon CH, Park SH, Lee SH, Kim HY - Arthritis Res. Ther. (2004)

Dose-dependent effects of LY294002 or pyrrolidine dithiocarbamate (PDTC) in peripheral blood mononuclear cells (PBMC) from patients with rheumatoid arthritis (RA). (a) Effect of inhibitors on interleukin (IL)-17 release by anti-CD3-stimulated PBMC from patients with RA. (b) Effects of LY294002 or PDTC on PBMC viability. PBMC were cultured at a concentration of 2 × 105 cells per well with medium, anti-CD3, anti-CD3 and LY294002 or PDTC under the conditions described in the Materials and methods section. After 24 hours of treatment, cell viability was assessed by the trypan blue dye exclusion method and expressed as a percentage with the formula 100 × (number of viable cells/number of both viable and dead cells).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC1064895&req=5

Figure 4: Dose-dependent effects of LY294002 or pyrrolidine dithiocarbamate (PDTC) in peripheral blood mononuclear cells (PBMC) from patients with rheumatoid arthritis (RA). (a) Effect of inhibitors on interleukin (IL)-17 release by anti-CD3-stimulated PBMC from patients with RA. (b) Effects of LY294002 or PDTC on PBMC viability. PBMC were cultured at a concentration of 2 × 105 cells per well with medium, anti-CD3, anti-CD3 and LY294002 or PDTC under the conditions described in the Materials and methods section. After 24 hours of treatment, cell viability was assessed by the trypan blue dye exclusion method and expressed as a percentage with the formula 100 × (number of viable cells/number of both viable and dead cells).
Mentions: The calcineurin inhibitors cyclosporin A and FK506 also downregulated the IL-17 secretion as well as the mitogen-activated protein kinase (MAPK) p38 inhibitor SB203580 did, whereas rapamycin and PD98059 had no effect on IL-17 levels (Fig. 3). To evaluate the possibility of non-specific inhibition by the drug at high concentrations, we observed the dose response of PDTC and LY294002 for the inhibition of IL-17 production in PBMC. There were dose-dependent inhibitions of IL-17 production with chemical inhibitors (Fig. 4a). The other inhibitors in addition to PDTC and LY294002 showed the same pattern of inhibition. Cytotoxic effects on PBMC by the chemical inhibitors at experimental concentrations were not observed (Fig. 4b).

Bottom Line: Anti-CD3 antibody activated the PI3K/Akt pathway; activation of this pathway resulted in a pronounced augmentation of nuclear factor kappaB (NF-kappaB) DNA-binding activity.However, inhibition of activator protein-1 and extracellular signal-regulated kinase 1/2 did not affect IL-17 production.These results suggest that signal transduction pathways dependent on PI3K/Akt and NF-kappaB are involved in the overproduction of the key inflammatory cytokine IL-17 in RA.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Medicine, Division of Rheumatology, The Center for Rheumatic Diseases, and The Rheumatism Research Center (RhRC), Catholic Research Institutes of Medical Sciences, Catholic University of Korea, Seoul, Korea. woon1212@catholic.ac.kr

ABSTRACT
Inflammatory mediators have been recognized as being important in the pathogenesis of rheumatoid arthritis (RA). Interleukin (IL)-17 is an important regulator of immune and inflammatory responses, including the induction of proinflammatory cytokines and osteoclastic bone resorption. Evidence for the expression and proinflammatory activity of IL-17 has been demonstrated in RA synovium and in animal models of RA. Although some cytokines (IL-15 and IL-23) have been reported to regulate IL-17 production, the intracellular signaling pathways that regulate IL-17 production remain unknown. In the present study, we investigated the role of the phosphoinositide 3-kinase (PI3K)/Akt pathway in the regulation of IL-17 production in RA. Peripheral blood mononuclear cells (PBMC) from patients with RA (n = 24) were separated, then stimulated with various agents including anti-CD3, anti-CD28, phytohemagglutinin (PHA) and several inflammatory cytokines and chemokines. IL-17 levels were determined by sandwich enzyme-linked immunosorbent assay and reverse transcription-polymerase chain reaction. The production of IL-17 was significantly increased in cells treated with anti-CD3 antibody with or without anti-CD28 and PHA (P < 0.05). Among tested cytokines and chemokines, IL-15, monocyte chemoattractant protein-1 and IL-6 upregulated IL-17 production (P < 0.05), whereas tumor necrosis factor-alpha, IL-1beta, IL-18 or transforming growth factor-beta did not. IL-17 was also detected in the PBMC of patients with osteoarthritis, but their expression levels were much lower than those of RA PBMC. Anti-CD3 antibody activated the PI3K/Akt pathway; activation of this pathway resulted in a pronounced augmentation of nuclear factor kappaB (NF-kappaB) DNA-binding activity. IL-17 production by activated RA PBMC is completely or partly blocked in the presence of the NF-kappaB inhibitor pyrrolidine dithiocarbamate and the PI3K/Akt inhibitor wortmannin and LY294002, respectively. However, inhibition of activator protein-1 and extracellular signal-regulated kinase 1/2 did not affect IL-17 production. These results suggest that signal transduction pathways dependent on PI3K/Akt and NF-kappaB are involved in the overproduction of the key inflammatory cytokine IL-17 in RA.

Show MeSH
Related in: MedlinePlus