Role of Signal Transduction in Burn and Wound Healing

严重创伤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广泛的细胞内信号转导网络，如有丝分裂原激活的蛋白激酶(MAPK)家族。我们重点研究了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基因敲除和脂多糖结合蛋白(LBP)基因敲除小鼠的腹膜巨噬细胞，我们将检测细胞和MAPK在脂多糖(LPS)刺激下激活的不同途径。令人惊讶的是，我们的初步数据显示，内毒素在CD14基因敲除中激活p38MAPK的程度与野生型一样多或更多。提示内毒素通过非CD14途径激活p38MAPK。在第二组实验中，我们将通过改变MAPK的激活来研究潜在的治疗方法。美国的烧伤致死和致残人数在工业化国家中排名第一。在最初的热损伤后，有一种进行性的细胞死亡和凋亡，并持续到数天。在上皮细胞中，p38的激活促进了细胞的凋亡，而ERK的激活则抑制了细胞的凋亡。我们推测，抑制p38和/或激活ERK将抑制热损伤反应中的细胞死亡。这样做的目的是防止部分深度烧伤转变为全面烧伤。在体内热损伤创伤模型中，我们将研究局部应用丝裂原活化蛋白激酶抑制剂/激活剂的有效性和安全性。我们将首先研究烧伤小鼠皮肤MAPK的激活、细胞因子的产生和上皮细胞的凋亡。然后，我们将使用p38的局部抑制剂和ERK的激活剂来研究它们对细胞死亡的影响。这项赠款建议包括通过完成核心课程的培训计划以及经常与导师和顾问进行授课。应聘者将在王斯图尔特博士的指导下，在研究提案的同时获得先进技术的知识。目标是让候选人成为一名拥有自己的拨款的独立研究人员。

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.