zearalenone and Asthma

Interleukin (IL)-17F plays a critical role in the pathophysiology of asthma. However, the precise role of IL-17F in airway smooth muscle cells (ASMCs) and its regulatory mechanisms remain to be defined. Therefore, we sought to investigate the expression of IL-6 by IL-17F and the involvement of transforming growth factor β-activated kinase 1 (TAK1) and nuclear factor (NF)-κB by in ASMCs.. ASMCs were cultured in the presence or absence of IL-17F. The expression of IL-6 gene and protein was analyzed using real-time PCR and ELISA, and the activation of TAK1 and NF-κB was detected by Western blotting. The effect of TAK1 inhibitor 5Z-7-oxozeaenol and NF-κB inhibitor BAY 11-7082 on the expression of IL-6 was investigated. Finally, the short interfering RNAs (siRNAs) targeting TAK1 and a subunit of NF-κB, p65 were transfected into ASMCs.. The expression of IL-6 gene and protein was significantly induced by IL-17F. IL-17F activated TAK1 and NF-κB in ASMCs. Transfection of siRNAs targeting TAK1 abolished IL-17F-induced phosphorylation of p65. Both 5Z-7-oxozeaenol and BAY 11-7082 significantly inhibited IL-17F-induced IL-6 production in a dose-dependent manner. Similarly, transfection of the cells with siRNAs targeting TAK1 and p65 inhibited the expression of IL-6.. Collectively, these results provided evidence supporting the potential importance of the Th17-ASMCs crosstalk via the IL-17F-IL-6 axis in airway inflammation and as a candidate pharmacological target for airway inflammatory diseases such as asthma.

Topics: Asthma; Humans; Interleukin-17; Interleukin-6; MAP Kinase Kinase Kinases; MAP Kinase Signaling System; Myocytes, Smooth Muscle; NF-kappa B; Nitriles; Sulfones; Zearalenone

Increased airway smooth muscle (ASM) mass is a major feature of airway remodeling in asthma and chronic obstructive pulmonary disease. Growth factors induce a proliferative ASM phenotype, characterized by an increased proliferative state and a decreased contractile protein expression, reducing contractility of the muscle. Transforming growth factor-β-activated kinase 1 (TAK1), a mitogen-activated protein kinase kinase kinase, is a key enzyme in proinflammatory signaling in various cell types; however, its function in ASM is unknown. The aim of this study was to investigate the role of TAK1 in growth factor-induced phenotypic modulation of ASM. Using bovine tracheal smooth muscle (BTSM) strips and cells, as well as human tracheal smooth muscle cells, we investigated the role of TAK1 in growth factor-induced proliferation and hypocontractility. Platelet-derived growth factor- (PDGF; 10 ng/ml) and fetal bovine serum (5%)-induced increases in DNA synthesis and cell number in bovine and human cells were significantly inhibited by pretreatment with the specific TAK1 inhibitor LL-Z-1640-2 (5Z-7-oxozeaenol; 100 nM). PDGF-induced DNA synthesis and extracellular signal-regulated kinase-1/2 phosphorylation in BTSM cells were strongly inhibited by both LL-Z-1640-2 pretreatment and transfection of dominant-negative TAK1. In addition, LL-Z-1640-2 inhibited PDGF-induced reduction of BTSM contractility and smooth muscle α-actin expression. The data indicate that TAK1 plays a major role in growth factor-induced phenotypic modulation of ASM.

Topics: Actins; Airway Remodeling; Animals; Asthma; Blotting, Western; Cattle; Cell Proliferation; DNA Replication; Extracellular Signal-Regulated MAP Kinases; Humans; MAP Kinase Kinase Kinases; Muscle Contraction; Muscle, Smooth; Myocytes, Smooth Muscle; Phosphorylation; Plasmids; Platelet-Derived Growth Factor; Pulmonary Disease, Chronic Obstructive; Signal Transduction; Trachea; Transfection; Zearalenone