Yi-Qi-Ping-Chuan-Fang Reduces TSLP Elevation Caused by LPS + Poly(I:C) via Inhibiting TLR4/MYD88/NF- B Signaling Pathway

Abstract

Objective. To explore the correlation between Thymic Stromal Lymphopoietin (TSLP) and the Nuclear Factor- (NF-) B signaling pathways in bronchial epithelial cells and to clarify whether the traditional Chinese medicine formula Yi-Qi-Ping-Chuan-Fang (YQPC) reduces inflammation by inhibiting TSLP/NF-B signaling pathways. Methods. Cells were stimulated with LPS + Poly(I:C) and treated with YQPC. The expressions of TSLP and NF-B signaling pathways related proteins P65, IK, IBa, P-P65, P-IK, P-IBa were detected. The effects of NF-B upstream molecules, Toll-like receptors 3 and 4, myeloid differentiation primary response gene 88 (Myd88), TIR-domain-containing adapter-inducing interferon-β (TRIF), and downstream inflammatory cytokines, TNF-α, IL-1β, IL-6, and IL-8, were assessed. Results. The mRNA and protein expressions of TSLP were significantly increased after LPS + Poly(I:C) stimulation, the total protein IBa and IK decreased (P < 0.05), and the phosphorylated protein P-P65, P-IK, and P-IBα increased. After YQPC treatment, the expression of TSLP, P-P65, P-IBa, and P-IK was significantly inhibited (P < 0.05). The activation of TLR4 and MyD88 decreased, and release of IL-1β, IL-6, IL-8, and TNF-α reduced (P < 0.05). Conclusion. In summary, the expression of TSLP is activated by the NF-B signaling pathway. YQPC alleviated inflammation by inhibiting TSLP through regulating the NF-B activation and translocation.