Limits...
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.

Show MeSH

Related in: MedlinePlus

Levels of interleukin (IL)-17 production in peripheral blood mononuclear cells from patients with rheumatoid arthritis (RA; n = 24), patients with osteoarthritis (OA) (n = 14) and normal individuals (n = 14). Each peripheral blood mononuclear cell was stimulated for 24 hours with or without phytohemagglutinin (PHA; 5 μg/ml). IL-17 was measured in culture supernatants by sandwich enzyme-linked immunosorbent assay. Data are expressed as means and SEM. One representative result of five independent experiments is shown. Student's t-test was used to compare each group. *, P < 0.05; **, P < 0.001.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC1064895&req=5

Figure 1: Levels of interleukin (IL)-17 production in peripheral blood mononuclear cells from patients with rheumatoid arthritis (RA; n = 24), patients with osteoarthritis (OA) (n = 14) and normal individuals (n = 14). Each peripheral blood mononuclear cell was stimulated for 24 hours with or without phytohemagglutinin (PHA; 5 μg/ml). IL-17 was measured in culture supernatants by sandwich enzyme-linked immunosorbent assay. Data are expressed as means and SEM. One representative result of five independent experiments is shown. Student's t-test was used to compare each group. *, P < 0.05; **, P < 0.001.

Mentions: PBMC were separated and cultured with PHA (5 μg/ml) from patients with RA, patients with OA, and age-matched normal controls; IL-17 levels were then determined in the culture supernatants (Fig. 1). Although the amounts of basal IL-17 secretion were not different between RA, OA and normal controls (62 ± 31, 43 ± 19 and 43 ± 10 pg/ml, respectively), the IL-17 production stimulated by PHA was significantly higher in RA PBMC than in those from OA and controls (768 ± 295 versus 463 ± 211 pg/ml [P < 0.05] and 241 ± 29 pg/ml [P < 0.001]).


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)

Levels of interleukin (IL)-17 production in peripheral blood mononuclear cells from patients with rheumatoid arthritis (RA; n = 24), patients with osteoarthritis (OA) (n = 14) and normal individuals (n = 14). Each peripheral blood mononuclear cell was stimulated for 24 hours with or without phytohemagglutinin (PHA; 5 μg/ml). IL-17 was measured in culture supernatants by sandwich enzyme-linked immunosorbent assay. Data are expressed as means and SEM. One representative result of five independent experiments is shown. Student's t-test was used to compare each group. *, P < 0.05; **, P < 0.001.
© Copyright Policy
Related In: Results  -  Collection

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

Figure 1: Levels of interleukin (IL)-17 production in peripheral blood mononuclear cells from patients with rheumatoid arthritis (RA; n = 24), patients with osteoarthritis (OA) (n = 14) and normal individuals (n = 14). Each peripheral blood mononuclear cell was stimulated for 24 hours with or without phytohemagglutinin (PHA; 5 μg/ml). IL-17 was measured in culture supernatants by sandwich enzyme-linked immunosorbent assay. Data are expressed as means and SEM. One representative result of five independent experiments is shown. Student's t-test was used to compare each group. *, P < 0.05; **, P < 0.001.
Mentions: PBMC were separated and cultured with PHA (5 μg/ml) from patients with RA, patients with OA, and age-matched normal controls; IL-17 levels were then determined in the culture supernatants (Fig. 1). Although the amounts of basal IL-17 secretion were not different between RA, OA and normal controls (62 ± 31, 43 ± 19 and 43 ± 10 pg/ml, respectively), the IL-17 production stimulated by PHA was significantly higher in RA PBMC than in those from OA and controls (768 ± 295 versus 463 ± 211 pg/ml [P < 0.05] and 241 ± 29 pg/ml [P < 0.001]).

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