Role of Signal Transduction in Burn and Wound Healing

危重患者并不是一个同质的群体，他们的炎症反应状态是不断变化的，从过度激活到免疫抑制。调节这些反应的细胞控制开关包括一个广泛的细胞内信号转导通路网络，如有丝分裂原激活蛋白激酶（MAPK）家族。我们专注于p38和ERK这两个重要的MAPK家族，它们调节炎症反应和细胞凋亡。为了阐明参与MAPK激活的不同途径，我们设计了一个体外实验模型。利用野生型、CD14敲除小鼠和脂多糖结合蛋白（LBP）敲除小鼠的腹膜巨噬细胞，我们将研究响应脂多糖（LPS）刺激的细胞和MAPK激活的不同途径。令人惊讶的是，我们的初步数据表明，LPS激活CD14敲除中的p38 MAPK与野生型一样多或更多。这表明lps诱导的p38 MAPK激活存在非cd14途径。在第二组实验中，我们将通过修改MAPK激活来研究潜在的治疗方法。美国因烧伤造成的死亡和残疾在工业化国家中排名第一。在初始热损伤后数天内，细胞会发生渐进性死亡和凋亡。在上皮细胞中，p38激活是促凋亡的，而ERK激活是抑制凋亡的。我们假设抑制p38和/或激活ERK会抑制热损伤后的细胞死亡。目的是防止可能主要愈合的部分烧伤转变为全层烧伤。在体内热损伤伤口模型中，我们将研究局部丝裂原激活蛋白激酶抑制剂/激活剂的有效性和安全性。我们将首先描述烧伤小鼠皮肤MAPK激活、细胞因子产生和上皮细胞凋亡的反应。然后，我们将使用局部p38抑制剂和ERK激活剂来研究它们对细胞死亡的影响。这项奖助金提案包括一项培训计划，通过完成核心课程和经常与导师和顾问的教学会议。候选人将在Stewart C. Wang博士的指导下学习先进的技术，同时完成研究计划。目标是让候选人成为一名独立的研究人员，拥有自己的资助。

Critically injured patients are not a homogenous group, and the state of their inflammatory response is in flux, ranging from hyperactivation to immunosuppression. The cellular control switches that regulate these responses include an extensive network of intracellular signal transduction pathways, such as the mitogenactivatedprotein kinase (MAPK) families. We have focused on p38 and ERK, two important MAPK families, regulating inflammatory response and apoptosis. In order to elucidate the different pathways involved in MAPK activation we have devised an in vitro experimental model. Using peritoneal macrophages from wild type, CD14 knockout, and lipopolysaccharide-binding-protein (LBP) knockout mice, we will examine different pathways of cell and MAPK activation in response to lipopolysaccharide (LPS) stimulation. Surprisingly, our preliminary data demonstrated that LPS activates p38 MAPK in the CD14 knockouts as much or more than the wild type. This suggests a non-CD14 pathway for LPS-induced p38 MAPK activation. In a second set of experiments, we will investigate the potential therapeutic approaches by modifying MAPK activation. The United States ranks first among industrialized nations in death and disability from burn injuries. There is a progressive cell death and apoptosis that extends to several days after the initial thermal injury. In epithelial cells p38 activation is pro-apoptotic, while ERK activation inhibits apoptosis. We hypothesize that inhibiting p38 and/or activating ERK will inhibit cell death in response to thermal injury. The goal is to prevent conversion of a partial-thickness burn, which may heal primarily, to a full-thickness burn. In an in vivo thermal injury wound model, we will investigate the efficacy and safety of topical mitogen-activated protein kinase inhibitors/activators. We will first characterize the dermal MAPK activation, cytokine production, and epithelial apoptosis in response to burn injury in mice. We will then use topical inhibitors of both p38 and activators of ERK to study their effect on cell death. This grant proposal is composed of a training plan through the completion of core curriculum of courses and frequent didactic sessions with mentors and advisors. The candidate will gain knowledge of advanced techniques under the tutlelage of Dr. Stewart C. Wang, while working on the research proposal. The goal is for the candidate to become an independent researcher with his own grants.