Epigenetic regulation of proinflammatory responses in the skin

摘要 我们已经证明，基底表皮中染色质重塑剂Mi-2 β的缺失导致了 促炎和应激反应基因的快速上调， 明显的环境信号或皮肤屏障缺陷。这些数据支持这样的假设， 免疫细胞调节基因，通常由环境损伤在表皮中诱导， 直接和积极抑制染色质调节剂，在条件下，表皮 体内平衡我们现在建议研究基于染色质的机制， 免疫调节基因在角质形成细胞中保持稳定表达， 机械或环境损伤如何激活信号通路， 机制等 在第一个目标中，我们将建立"抗炎"染色质景观， 控制角质形成细胞稳态的转录因子网络。全基因 方法将用于角质形成细胞，以建立基因网络， 并在功能上受Mi-2 β控制。Mi-2 β相关的调节元件类型 他们所处的染色质构型将被确定。顺序是- 以协同或拮抗方式功能性相互作用的特异性DNA结合因子 将识别Mi-2 β。最后，染色质调节子和转录的全部功能 以Mi-2 β-独立的方式参与促炎基因调控的因素将是 也建立了。 在第二个目标中，我们将确定环境信号如何诱导亲- 角质形成细胞中炎性基因表达。环境信号对 将研究改变染色质调节因子和转录因子的活性。 我们将首先检查Mi-2 β和表观遗传之间的因果关系， 在其靶基因的调节结构域的转录因子组成。然后我们将测试 环境信号如何通过改变Mi的活性来诱导促炎基因， 2 β及其相关的染色质调节因子和转录因子。关键的作用 在这一分子过程中的调节候选物将通过遗传学方法进一步评估。 在小鼠和人角质形成细胞中的干扰研究。 这些研究的结果将使我们能够探索保守的机制， 有助于人类皮肤病与促炎的基础上，并提供新的途径 进行治疗干预。

ABSTRACT We have shown that loss of the chromatin remodeler Mi-2β in the basal epidermis causes rapid up-regulation of pro-inflammatory and stress response genes in the absence of any overt environmental signals or a skin barrier defect. These data support the hypothesis that immune cell regulatory genes, normally induced in the epidermis by environmental insults, are directly and actively repressed by chromatin regulators, under conditions of epidermal homeostasis. We now propose to study the chromatin-based mechanisms by which immune-regulatory genes are kept poised for expression in keratinocytes and to determine how activation of signaling pathways by mechanical or environmental insult reverses these mechanisms. In the first aim, we will establish the “anti-inflammatory” chromatin landscape and transcription factor network that control keratinocyte homeostasis. Genome-wide approaches will be used in keratinocytes to establish the gene networks that are directly and functionally controlled by Mi-2β. The types of regulatory elements that Mi-2β associates with, and the chromatin configuration that they are in will be established. The sequence- specific DNA binding factors that functionally interact in a synergistic or antagonistic fashion with Mi-2β will be identified. Finally, the repertoire of chromatin regulators and transcription factors involved in pro-inflammatory gene regulation in a Mi-2β−independent fashion will be also established. In the second aim, we will determine how environmental signals induce pro- inflammatory gene expression in keratinocytes. The effect of environmental signals on altering the activity of both chromatin regulators and transcription factors will be studied. We will first examine the cause-effect relationship between Mi-2β and the epigenetic and transcription factor makeup at the regulatory domains of its target genes. We will then test how environmental signals induce pro-inflammatory genes by altering the activities of Mi- 2β and associated chromatin regulators and transcription factors. The role of key regulatory candidates in this molecular process will be further evaluated by genetic interference studies in mouse and human keratinocytes. The outcome of these studies will allow us to probe into conserved mechanisms that contribute to human skin disease with a pro-inflammatory basis and provide new avenues for therapeutic intervention.