Glucocorticoid induced G-CSF in lung inflammation

项目摘要：糖皮质激素在治疗炎症中是不可或缺的，尽管它们不是 能有效治疗重症哮喘和急性呼吸窘迫综合征患者的中性粒细胞肺部炎症。 我们的长期目标是开发新的糖皮质激素疗法，提高疗效/风险比。的目标是 这项提议是为了确定消除G-CSF信号是否会允许糖皮质激素促进 中性粒细胞凋亡和减轻肺部炎症。我们最近发现糖皮质激素 显著升高G-CSF，一种促进中性粒细胞的细胞因子。G-CSF近年来被公认为是一种 类固醇抗药性肺炎性疾病的原因。我们假设糖皮质激素保护中性粒细胞 通过G-CSF的刺激，抑制细胞凋亡，增强中性粒细胞功能。G-CSF的诱导是由GR启动的 G-启动子上的核因子-CSFB p50相互作用。糖皮质激素对肺组织产生G-CSF的诱导作用 常驻细胞持续肺部炎症。阻断G-CSF信号将增加糖皮质激素的疗效 绕过中性粒细胞引起的肺部炎症。为了验证我们的假设，我们将在体外检查系统。 在活体内。目标1中的研究将检验GR和p50相互作用介导G-CSF表达的假设 在肺部的不同类型的细胞中。AIM 2的研究将确定糖皮质激素诱导的G-CSF在 两种小鼠模型中性粒细胞的存活、功能、运输和中性粒细胞肺部炎症。我们将使用 阻断G-CSF诱导的三种方法：使用G-CSFR缺失小鼠，抗G-CSF中和抗体，以及 我们已经确定了两种能够抑制G-诱导的天然核因子-脑脊液B抑制剂：姜黄素和 巴特内酯。我们的初步数据表明糖皮质激素受体(GR)和核因子-B都是必需的 对于G-CSF的诱导，p50，而不是p65，被招募到与GR相同的G-CSF启动子区域。 在糖皮质激素刺激下，多个肺内驻留细胞和浸润性白细胞产生G-CSF。 用中和抗体阻断G-CSF信号通路可阻断糖皮质激素和IL-1的β保护作用 防止中性粒细胞发生凋亡。姜黄素联合糖皮质激素降低肺G-CSF和 脂多糖肺损伤模型中中性粒细胞的数量。建议的研究将加深我们对 糖皮质激素诱导的G-CSF在中性粒细胞显性糖皮质激素抵抗疾病中的作用抑制G- 预计脑脊液信号转导可增强糖皮质激素抑制呼吸道损伤的能力。 改善中性粒细胞活性，减轻肺部炎症。

Project Summary: Glucocorticoids are indispensable in the treatment of inflammation although they are not effective in treating neutrophilic lung inflammation in severe asthma and acute respiratory distress syndrome. Our long-term goal is to develop new glucocorticoid regimens with improved efficacy/risk ratios. The goal of this proposal is to determine whether eliminating G-CSF signaling will allow glucocorticoids to promote neutrophil apoptosis and ameliorate lung inflammation. We have recently discovered that glucocorticoids significantly elevate G-CSF, a neutrophil promoting cytokine. G-CSF in recent years has been recognized as a cause of steroid-resistant lung inflammatory disorders. We hypothesize that glucocorticoids protect neutrophil from apoptosis and enhance neutrophil function via stimulation of G-CSF. G-CSF induction is initiated by GR and NF-B p50 interaction on the G-CSF promoter. Glucocorticoid-induction of G-CSF production in lung resident cells sustains lung inflammation. Blocking G-CSF signaling will increase the efficacy of glucocorticoids in circumventing neutrophil-driven lung inflammation. To test our hypotheses, we will examine systems in vitro and in vivo. Studies in Aim 1 will test the hypothesis that GR and p50 interactions mediate G-CSF expression in various cell types in lungs. Studies in Aim 2 will determine the role of glucocorticoid-induced G-CSF in neutrophil survival, functions, trafficking, and neutrophilic lung inflammation in two murine models. We will use three approaches to block G-CSF induction: using G-CSFR null mice, anti-G-CSF neutralizing antibodies, and two natural NF-B inhibitors that we have identified to be able to inhibit G-CSF-induction: curcumin and parthenolide. Our preliminary data indicate that both the glucocorticoid receptor (GR) and NF-B were required for G-CSF induction and p50, but not p65, was recruited to the same region of G-CSF promoter as GR. Multiple lung resident cells and infiltrating leukocytes produced G-CSF upon glucocorticoid stimulation. Blocking G-CSF signaling using neutralizing antibodies abolished glucocorticoid and IL-1β protection of neutrophils from undergoing apoptosis. Curcumin in combination with glucocorticoids reduced lung G-CSF and neutrophil numbers in an LPS lung injury model. The proposed studies will improve our understanding of the role of glucocorticoid-induced G-CSF in neutrophil-dominant glucocorticoid-resistant diseases. Inhibiting G- CSF signaling is anticipated to increase the ability of glucocorticoids to suppress the airway-damaging activities of neutrophils and ameliorate lung inflammation.