Transforming growth factor-β stimulates the expression of eotaxin/CC chemokine ligand 11 and its promoter activity through binding site for nuclear factor-κβ in airway smooth muscle cells.

Abstract

BACKGROUND:

Chemokines ligands of CCR3 including eotaxin/CC chemokine ligand 11 (CCL11) may contribute to the pathogenesis of asthma. These chemokines and a growth factor (TGF-beta) may be involved in the process of airway remodelling.

OBJECTIVE:

We analysed the effects of TGF-beta on the expression of CCR3 ligands in human airway smooth muscle (HASM) cells and investigated the mechanisms.

METHODS:

HASM cells were cultured and treated with TGF-beta and Th2 cytokines IL-4 or IL-13. Expression of mRNA was analysed by real-time PCR. Secretion of CCL11 into the culture medium was analysed by ELISA. Transcriptional regulation of CCL11 was analysed by luciferase assay using CCL11 promoter-luciferase reporter plasmids.

RESULTS:

IL-4 or IL-13 significantly up-regulated the expression of mRNAs for CCL11 and CCL26. TGF-beta alone did not increase the expression of chemokine mRNAs, but enhanced the induction of only CCL11 by IL-4 or IL-13 among CCR3 ligands. Activity of the CCL11 promoter was stimulated by IL-4, and this activity was enhanced by TGF-beta. Activation by IL-4 or IL-4 plus TGF-beta was lost by mutation of the binding site for signal transducers and activators of transcription-6 (STAT6) in the promoter. Cooperative activation by IL-4 and TGF-beta was inhibited by mutation of the binding site for nuclear factor-kappaB (NF-kappaB) in the promoter. Pretreatment with an inhibitor of NF-kappaB and glucocorticoid fluticasone propionate significantly inhibited the expression of CCL11 mRNA induced by IL-4 plus TGF-beta, indicating the importance of NF-kappaB in the cooperative activation of CCL11 transcription by TGF-beta and IL-4.

CONCLUSION:

These results indicate that Th2 cytokines and TGF-beta may contribute to the pathogenesis of asthma by stimulating expression of CCL11. The transcription factors STAT6 and NF-kappaB may play pivotal roles in this process.

• Authors: S Matsukura, M Odaka, M Kurokawa, H Kuga, T Homma, H Takeuchi, K Notomi, F Kokubu, M Kawaguchi, R P Schleimer, M W Johnson, M Adachi
• Journal: Clinical and experimental allergy : journal of the British Society for Allergy and Clinical Immunology (Clin Exp Allergy) Vol. 40 Issue 5 Pg. 763-71 (May 2010) ISSN: 1365-2222 [Electronic] England
• PMID: 20214667 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Chemokine CCL11
• Interleukin-13
• NF-kappa B
• Recombinant Proteins
• Transforming Growth Factor beta
• Interleukin-4

Topics

• Asthma (genetics, immunology)
• Binding Sites
• Cell Line
• Chemokine CCL11 (genetics, metabolism)
• Gene Expression Regulation
• Humans
• Interleukin-13 (pharmacology)
• Interleukin-4 (pharmacology)
• Muscle, Smooth (drug effects, metabolism)
• NF-kappa B (metabolism)
• Promoter Regions, Genetic
• Protein Binding
• Recombinant Proteins (pharmacology)
• Th2 Cells (immunology)
• Transcription, Genetic
• Transforming Growth Factor beta (metabolism, pharmacology)
• Up-Regulation (drug effects)