HMGB1 was negatively regulated by HSF1 and mediated the TLR4/MyD88/NF-κB signal pathway in asthma

Aims: The present study explored the function and regulatory mechanism of High mobility group box 1 (HMGB1) in asthma. Main methods: OVA (ovalbumin)-induced asthmatic mice model and LPS-treated cellular model were established in this study. Airway inflammation was measured through detecting the expression of IL-4, IL-5, IL-13 and Interferon-gamma (IFN-gamma) in serum and BALF (bronchoalveolar lavage fluid) by ELISA kits. Bioinformatics predictive analysis, ChIP assays, Luciferase reporter assay and Western blotting were used to explore the relation between HMGB1 and HSF1 (Heat shock factor 1). Key findings: HMGB1 expression was increased in OVA-induced asthmatic mice. Silencing HMGB1 attenuated the increasing of IgE, inflammatory factors (IL-4, IL-5 and IL-13), and airway hyperresponsiveness that induced by OVA. In addition, our study found that HSF1 directly bind with the HMGB1 promoter and negatively regulation of HMGB1. HSF-1 were upregulated in OVA-induced asthmatic mice, and knockdown of HSF1 aggravated the OVA-induced airway inflammation and airway hyperreactivity in mice may through promoting the expression of HMGB1 and the activation of the Toll-like receptor 4 (TLR4)/Myeloid differentiation primary response 88 (MyD88)/Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kappa B) signal pathway. Significance: The expression of HMGB1 could be negatively regulated by HSF1, and the TLR4/MyD88/NF-kappa B signal pathway was involved in HSF1/HMGB1-mediated regulation of asthma.