Résumé
Objective To investigate the effect of lidocaine on Staphylococcus aureus exotoxin-stimulated peripheral blood mononuclear cells (PBMCs) from patients with atopic dermatitis (AD).Methods Peripheral blood samples were collected from 6 patients with AD,and PBMCs were isolated by a routine method.Then,the PBMCs were stimulated by the Staphylococcus aureus exotoxin toxic shock syndrome toxin-1 (TSST-1) in the absence or presence of lidocaine at varying concentrations.The 3H-TdR incorporation method was performed to detect the proliferation of monocytes,and enzyme-linked immunosorbent assay (ELISA) to quantify the levels of T helper type 1 (Th1) and Th2 cytokines released by PBMCs.Human HaCaT keratinocytes were co-cultured with lidocaine-and TSST-1-stimulated PBMCs from patients with AD for 72 hours,then,Western blot was conducted to examine the expression of filaggrin protein in HaCaT cells.Results TSST-1 (100 μg/L) significantly enhanced the proliferation of PBMCs from patients with AD (stimulation index =75 ± 2.12,P ＜ 0.05),as well as the release of tumor necrosis factor-α (TNF-α),interferon (IFN)-γ,interleukin (IL)-2,IL-12,IL-4,IL-5 and IL-13 by the PBMCs (all P ＜ 0.05).Compared with the blank control group,100 μmol/L lidocaine significantly inhibited the TSST-1-stimulated proliferation of PBMCs from patients with AD (stimulation index =58 ± 3.14,P＜ 0.05),as well as the release of IL-4,IL-5,IL-13,TNF-α and IFN-γ by the stimulated PBMCs (all P ＜ 0.05).Western blot showed that 100 μmol/L lidocaine significantly blocked the down-regulation of filaggrin expression in HaCaT cells (P ＜ 0.01).Conclusion Lidocaine has a significant inhibitory effect on the activation of TSST-1-stimulated PBMCs from patients with AD.
Résumé
<p><b>OBJECTIVE</b>To investigate the role of histone acetylation in regulating influenza virus replicative intermediate double-stranded RNA (dsRNA)-induced interleukin-6 (IL-6) expression in A549 cells.</p><p><b>METHODS</b>A549 cells were treated with influenza virus replicative intermediate dsRNA, histone deacetylase (HDAC) inhibitor trichostatin A (TSA), or HADC small interfering RNA (siRNA). The changes in the cellular IL-6 promoter activities were detected by dual-luciferase assay, and IL-6 mRNA and protein expressions in the cells were determined using real-time RT-PCR and ELISA, respectively.</p><p><b>RESULTS</b>Influenza virus replicative intermediate dsRNA obviously up-regulated IL-6 expression in the cells. HDAC inhibitor TSA significantly enhanced the activity of IL-6 promoter and increased IL-6 mRNA expression in A549 cells, and HDAC3 may play an important role in this process. HDAC inhibitor TSA and DNMT inhibitor DAC showed no synergic effect in regulating IL-6 expression.</p><p><b>CONCLUSIONS</b>Influenza virus replicative intermediate dsRNA-induced IL-6 expression in A549 cells is regulated by histone acetylation.</p>