Fig. 4: SIRT6 deficiency inhibites IL-17A expression in airway epithelium.

a KEGG enrichment analysis in the lung tissues of WT mice in ASA model compared to control. b Gene expression of Th17 type immune response was assessed by Gene set enrichment analysis (GSEA). c A volcano plot showed Il-17A and other upregulated genes encoding inflammatory products (red, downregulated genes; brown, downregulated genes). d–g qRT-PCR (n = 3), ELISA (AE-Sirt6^fl/fl-Control, AE-Sirt6^Δ/Δ-Control, AE-Sirt6^Δ/Δ-Asthma n = 6; AE-Sirt6^fl/fl-Asthma n = 5) and Western blot (n = 3) analysis of IL-17A in lung homogenates from AE-Sirt6^fl/fl and AE-Sirt6^Δ/Δ mice treated with HDM/LPS in ASA model. h, i Representative of IL-17A expression (Red) in airway epithelium cells (SCGB1A1, Green) of AE-Sirt6^fl/fl and AE-Sirt6^Δ/Δ mice treated with HDM/LPS in ASA model. Quantification was done using Image J software (n = 5). j, k Representative of IL-17A expression (Red) in airway epithelium cells (SCGB1A1, Green) of bronchial biopsy samples from control donors (n = 5) and asthmatic patients (n = 10). Quantification was analyzed by using Image J software. l, m The levels of IL-17A in the BALF from control donors (n = 5) and asthmatic patients (n = 10) were detected using ELISA. The correlation between SIRT6 expression in airway epithelium and IL-17A levels in BALF was investigated using Spearman analysis. n–q HBE cells were transfected with Sirt6 small interfering RNA (siRNA) or Sirt6 plasmid for 24 h and were then treated with HDM/LPS for another 24 h. The expression of IL-17A was studied by using Western blot and ELISA analysis. r, s HBE cells were pretreated with Sirt6 siRNA or Sirt6 plasmid for 24 h and then transfected with the IL17A-reporter plasmid. Luciferase activity was then measured in HDM/LPS-treated and untreated cells. Data are shown as means ± SEM and three or more independent experiments were performed. Significance was calculated by one-way ANOVA followed by Tukey’s post-hoc test for (d, e–g–i–k, l–o–q, r, s).