Objective: To investigate the expression pattern of histone deacetylase 9 (HDAC9) in peripheral blood of asthmatics and its effect on immune cells (Th2, Th17, Tregs) involved in the pathogenesis of asthma.
Methods: Forty-seven asthmatics from Ruijin Hospital were recruited and assigned to intermittent, mild and moderate-severe groups. Lung function test and Asthma Control Questionnaire were performed to evaluate asthma control and severity. Twenty healthy donors were enrolled as controls. GATA3, IL-4, and HDAC9 mRNA expression levels were measured by SYRB Green Real-time PCR. The cytokine IL-17-mainly produced by Th17 cells and TGF-β-mainly produced by Treg cells, were measured by ELISA.
Results: The GATA3 and IL-4 mRNA expression levels (28.12 ± 7.57 and 743.6 ± 312.8) were up-regulated in asthmatics as compared to the healthy controls [0.56 ± 0.22, 0.7 ± 0.8 (U = 16.00, 37.00, P < 0.01)]. The HDAC9 mRNA expression levels of intermittent, mild and moderate-severe groups were 3.20 ± 0.50, 89.6 ± 18.0, 323.0 ± 65.3, respectively, which were associated with the severity of disease (H = 11.32, P < 0.05). The level of IL-17 in asthmatic group was (83 ± 55) ng/L, which was up-regulated as compared to the healthy control [(34 ± 22) ng/L (U = 153.50, P < 0.01)]. The level of TGF-β was decreased in the asthmatic groups as compared to the healthy control, but the difference did not reach significance. HDAC9 mRNA expression level was positively correlated with GATA3 mRNA expression level (r = 0.482, P < 0.05), and also with IL-4 mRNA expression (r = 0.432, P < 0.05) and IL-17 (r = 0.538, P < 0.05), but negatively correlated with TGF-β (r = -0.417, P < 0.05). In patients with moderate-severe asthma, HDAC9 mRNA expression level was negatively correlated with FEV(1)% (r = -0.657, P < 0.05).
Conclusion: HDAC9 mRNA expression was up-regulated in peripheral blood of asthmatics, which was not only associate with the Th2 master transcriptional factors GATA3, cytokine IL-4 mRNA, Th17 and Treg cell-related cytokines, but also with FEV(1)% in moderate-severe asthma.