Mechanism of inflammation-induced steroid resistance

描述(由申请人提供)： 虽然类固醇在控制哮喘方面非常有效，但一些患者即使对大剂量也没有反应。类固醇耐药是一个名副其实的健康挑战，因为缺乏治疗替代方案，而且由于类固醇耐药患者占哮喘相关医疗费用的50%以上，这是一种经济负担。这位候选人目前在宾夕法尼亚大学的研究重点是研究呼吸道平滑肌(ASM)的类固醇抵抗，这是一种与肺部疾病相关的组织。目前和在该奖项的指导阶段(K99)进行的研究的短期目标是描绘类固醇疗效减弱的分子机制。这项研究将在该奖项的独立阶段(R00)进行，最终目的是开发新的治疗方案来治疗类固醇抗药性哮喘患者。候选人的长期目标是建立自己的独立研究计划，并提交R01申请。这一建议的中心假设是新颖的，并指出促哮喘细胞因子通过三条通路的协同激活而损害ASM细胞的类固醇功能：(I)GRβ，一种可作为GC作用抑制物的类固醇受体β亚型(将在目标1中讨论)，(Ii)IRF-1，一种调节许多炎症基因的转录因子(将在目标2中讨论)，以及(Iii)丝氨酸/苏氨酸蛋白磷酸酶5(PP5)，在不同的细胞系中被证明是类固醇作用的抑制因子(将在目标3中讨论)。本提案的三个目的都将依赖于多种互补的方法，如siRNA技术、报告载体的转染以及结构性活性或显性负性蛋白的过度表达、共免疫沉淀和共定位技术、染色质免疫沉淀和凝胶移位分析。随后，这一奖项将极大地提高候选人的技术技能，并将拓宽他在分子药理学和细胞生物学方面的专业知识。我们认为，我们的建议与公众健康相关，因为提高对导致类固醇耐药因素的了解将有助于设计新的治疗剂或替代方案来治疗类固醇耐药哮喘患者。

DESCRIPTION (provided by applicant): Although steroids are highly effective in the control of asthma, some patients fail to respond even to high doses. Steroid resistance is a veritable health challenge due to the absence of therapeutic alternatives and a financial burden as steroid-resistant patients account for more than 50% of asthma related healthcare costs. The candidate's current research at the University of Pennsylvania focuses in studying steroid resistance in airway smooth muscle (ASM), a tissue that is relevant for lung diseases. The short term goal of the studies performed currently and during the mentored phase of this award (K99) is to delineate the molecular mechanisms that underlay the diminished efficacy of steroids. This study will be pursued during the independent phase of this award (R00) with the ultimate objective to develop new therapeutic options to treat steroid-resistant asthmatics. The candidate's long term goal is to establish his own independent research program and submit an R01 application. The central hypothesis of this proposal is novel and states that pro-asthmatic cytokines impair steroid function in ASM cells through the coordinated activation of three pathways: (i) GR beta, a steroid receptor beta isoform that can act as an inhibitor of GC actions (will be addressed in Aim 1), (ii) IRF-1, a transcription factor that regulates many inflammatory genes (will be addressed in Aim 2), and (iii) Serine/threonine protein phosphatase 5 (PP5), shown to act as an inhibitor of steroid actions in different cell lines (will be addressed in Aim 3). All three Aims of the present proposal will rely on multiple complementary approaches such as siRNA technology, transfection of reporter vectors as well as over-expression of constitutively active or dominant negative proteins, co-immunoprecipitation and co-localization techniques, chromatin immunoprecipitation and gel shift assays. Subsequently, this award will dramatically enhance the candidate's technical skills and will broaden his expertise in molecular pharmacology and cell biology. We believe that our proposal is relevant to public health since improving the knowledge about the factors that lead to steroid resistance will help design new therapeutic agents or alternatives to treat steroid-resistant asthmatics.