Department of Pharmaceutical and Administrative Sciences, College of Pharmacy and Health Sciences, Western New England University, Springfield, MA, United States.
Northampton High School, Northampton, MA, United States.
Front Immunol. 2018 Oct 23;9:2414. doi: 10.3389/fimmu.2018.02414. eCollection 2018.
Mast cells are highly versatile cells that perform a variety of functions depending on the immune trigger, context of activation, and cytokine stimulus. Antigen-mediated mast cell responses are regulated by transcriptional processes that result in the induction of numerous genes contributing to mast cell function. Recently, we also showed that exposure to dietary agents with known epigenetic actions such as curcumin can suppress mast cell-mediated food allergy, suggesting that mast cell responses may be epigenetically regulated. To further assess the effects of epigenetic modifications on mast cell function, we examined the behavior of bone marrow-derived mast cells (BMMCs) in response to trichostatin A (TSA) treatment, a well-studied histone deacetylase inhibitor. IgE-mediated BMMC activation resulted in enhanced expression and secretion of IL-4, IL-6, TNF-α, and IL-13. In contrast, pretreatment with TSA resulted in altered cytokine secretion. This was accompanied by decreased expression of FcεRI and mast cell degranulation. Interestingly, exposure to non-IgE stimuli such as IL-33, was also affected by TSA treatment. Furthermore, continuous TSA exposure contributed to mast cell apoptosis and a decrease in survival. Further examination revealed an increase in I-κBα and a decrease in phospho-relA levels in TSA-treated BMMCs, suggesting that TSA alters transcriptional processes, resulting in enhancement of I-κBα transcription and decreased NF-κB activation. Lastly, treatment of wild-type mice with TSA in a model of ovalbumin-induced food allergy resulted in a significant attenuation in the development of food allergy symptoms including decreases in allergic diarrhea and mast cell activation. These data therefore suggest that the epigenetic regulation of mast cell activation during immune responses may occur altered histone acetylation, and that exposure to dietary substances may induce epigenetic modifications that modulate mast cell function.
肥大细胞是多功能细胞,其功能取决于免疫触发、激活的上下文和细胞因子刺激。抗原介导的肥大细胞反应受转录过程调控,导致诱导众多基因参与肥大细胞功能。最近,我们还表明,暴露于具有已知表观遗传作用的膳食剂,如姜黄素,可以抑制肥大细胞介导的食物过敏,这表明肥大细胞反应可能受到表观遗传调控。为了进一步评估表观遗传修饰对肥大细胞功能的影响,我们研究了骨髓来源的肥大细胞(BMMC)对曲古抑菌素 A(TSA)治疗的反应,TSA 是一种研究充分的组蛋白去乙酰化酶抑制剂。IgE 介导的 BMMC 激活导致 IL-4、IL-6、TNF-α 和 IL-13 的表达和分泌增强。相比之下,TSA 的预处理导致细胞因子分泌发生改变。这伴随着 FcεRI 的表达下调和肥大细胞脱颗粒。有趣的是,暴露于非 IgE 刺激物,如 IL-33,也受到 TSA 处理的影响。此外,持续的 TSA 暴露导致肥大细胞凋亡和存活率下降。进一步研究表明,TSA 处理的 BMMC 中 I-κBα 增加和磷酸化 RelA 水平降低,表明 TSA 改变转录过程,导致 I-κBα 转录增强和 NF-κB 激活降低。最后,在卵清蛋白诱导的食物过敏模型中,用 TSA 处理野生型小鼠导致食物过敏症状的发展明显减弱,包括过敏腹泻和肥大细胞活化减少。因此,这些数据表明,免疫反应期间肥大细胞激活的表观遗传调控可能通过改变组蛋白乙酰化发生,并且暴露于膳食物质可能诱导调节肥大细胞功能的表观遗传修饰。