Pro-inflammatory Mediator Crosstalk Induces COX-2 in Myofibroblasts via PKC/PKD

促炎介质串扰通过 PKC/PKD 诱导肌成纤维细胞中的 COX-2

• 批准号: 8844124
• 负责人: James Yoo
• 金额: $ 7.63万
• 依托单位: TUFTS MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-05-01 至 2015-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8844124
• 关键词: Pro; inflammatory; Mediator; Crosstalk; Induces

DESCRIPTION (provided by applicant): Following the completion of my surgical training in General and Colorectal Surgery, I sought an academic position where I would have the best opportunity to achieve my long-term career goals of becoming an independently funded investigator, as well as an outstanding clinician and teacher. My life-long mentor, Dr. Jeffrey Matthews, guided my decisions in terms of choosing an academic environment where these goals would be strongly supported. I met with Dr. Enrique Rozengurt during the recruitment process, and his willingness to serve as my research mentor was a major factor in my decision to join the UCLA Department of Surgery in 2006. With the full support of my department, I have been working with Dr. Rozengurt since my arrival at UCLA. Under his guidance, I have laid the groundwork of a research proposal (this grant) that will serve as the foundation of an independent research program. With the additional guidance and expertise of Dr. Charalabos Pothoulakis, and the full support of my Department of Surgery under the leadership of Dr. Ronald Busuttil, I feel well positioned to succeed in my pursuit of a successful research career. Dr. Rozengurt, Dr. Pothoulakis, and Dr. Busuttil comprise my Advisory Committee, and with their help I have designed a Career Development Plan consisting of graduate level courses, weekly research seminars/lectures, formal laboratory meetings, and participation in national research conferences. My short-term goals are to gain expertise in areas of signal transduction and murine models of inflammation and colitis-associated cancer as I develop my own distinct focus of research. The association between chronic ulcerative colitis and the development of colorectal cancer is a well- established but incompletely understood phenomenon. Though the fundamental mechanism is not known, there has been a growing awareness of the contribution of the underlying intestinal stroma on inflammation-associated cancer. Colonic myofibroblasts are a subpopulation of cells located within the stroma of the GI tract that have been linked to both inflammation and tumorigenesis, and are a major source of cyclo-oxygenase 2 (COX-2), a critical enzyme also involved in these processes. However, the cell signaling pathways regulating COX-2 expression in myofibroblasts have not been well studied. Protein kinase D (PKD), the founding member of a new family of protein kinases that includes PKD2 and PKD3, has been implicated in important cellular functions but the expression, regulation and function of PKD in myofibroblasts, both in response to pro-inflammatory mediators and/or in the production of local regulators, has not been investigated. The central hypothesis of this proposal is that pro-inflammatory mediators activate a novel PKD phosphorylation cascade that plays a critical role in signal transduction pathways regulating colonic myofibroblast function. Using the human colonic myofibroblast cell line 18Co, our Preliminary Data demonstrate a synergistic upregulation of COX-2 protein expression following treatment with the inflammatory mediators TNF-( (TNF) and bradykinin (BK). This effect appears to be mediated by unique cross talk interactions between the distinct signaling pathways downstream of TNF and BK, leading to amplified PKD activation in direct association with a dramatic increase in COX-2 expression. The Specific Aims of this proposal are to 1) fully characterize the synergistic expression of COX-2 in response to pro-inflammatory mediators in colonic myofibroblasts, 2) identify mechanisms of signaling cross talk between pro-inflammatory mediators responsible for the synergy, 3) define the role of PKC/PKD signaling in the expression of COX-2 in myofibroblasts, and 4) substantiate the physiologic significance of these findings using a mouse model of colitis-associated cancer. Experimental results will also be confirmed using myofibroblast cells extracted from human colonic tissue taken at the time of surgery. Potential cross talk between TNF and BK in the synergistic enhancement of COX-2 expression in colonic myofibroblasts, mediated through PKD, may play an important role in colitis-associated cancer. PKD signaling may regulate key biological functions of myofibroblasts in the setting of inflammation.

描述(由申请人提供)： 在完成了普通外科和结直肠外科的外科培训后，我寻求了一个学术职位，在那里我将有最好的机会实现我的长期职业目标--成为一名独立资助的研究人员，以及一名杰出的临床医生和教师。我的终生导师杰弗里·马修斯博士指导了我的决定，选择了一个强烈支持这些目标的学术环境。在招聘过程中，我会见了恩里克·罗曾古特医生，他愿意担任我的研究导师是我在2006年决定加入加州大学洛杉矶分校外科的一个主要因素。在我所在部门的全力支持下，自我来到加州大学洛杉矶分校以来，我一直与Rozengurt博士合作。在他的指导下，我已经为一项研究提案(这笔拨款)奠定了基础，该提案将作为独立研究计划的基础。有了Charalabos Potulakis博士的额外指导和专业知识，以及在Ronald Busuttil博士领导下我的外科部门的全力支持，我感到自己处于有利地位，能够在追求成功的研究事业中取得成功。Rozengurt博士、Potulakis博士和Busuttil博士组成了我的咨询委员会，在他们的帮助下，我设计了一个职业发展计划，包括研究生水平课程、每周研究研讨会/讲座、正式实验室会议和参加国家研究会议。我的短期目标是在发展自己独特的研究重点的同时，获得信号转导领域的专业知识，以及炎症和结肠炎相关癌症的小鼠模型。 慢性溃疡性结肠炎与结直肠癌的发展之间的联系是一个众所周知但还不完全了解的现象。虽然基本机制尚不清楚，但人们越来越意识到潜在的肠道间质在炎症相关癌症中的作用。结肠肌成纤维细胞是位于胃肠道间质中的一种细胞亚群，与炎症和肿瘤发生有关，也是环氧合酶2(COX-2)的主要来源，COX-2是参与这些过程的关键酶。然而，调控肌成纤维细胞环氧合酶-2表达的细胞信号通路还没有得到很好的研究。蛋白激酶D(PKD)是包括PKD2和PKD3在内的一个新的蛋白激酶家族的创始成员，参与了重要的细胞功能，但PKD在肌成纤维细胞中的表达、调节和功能尚未被研究，这既是对促炎介质的反应，也是对局部调节物质的产生。这一建议的中心假设是，促炎介质激活了一种新的PKD磷酸化级联反应，该信号转导通路在调节结肠肌成纤维细胞功能的信号转导通路中发挥关键作用。使用人结肠肌成纤维细胞系18Co，我们的初步数据显示，在炎性介质肿瘤坏死因子(TNF)和缓激肽(BK)处理后，COX-2蛋白的表达协同上调。这一效应似乎是由肿瘤坏死因子和BK下游不同信号通路之间独特的串扰相互作用所介导的，导致放大的PKD激活与COX-2表达的显著增加直接相关。这一建议的具体目的是：1)充分表征COX-2在结肠成纤维细胞中对促炎介质的协同表达，2)确定促炎介质之间协同作用的信号串扰机制，3)确定PKC/PKD信号在肌成纤维细胞COX-2表达中的作用，以及4)利用结肠炎相关癌症的小鼠模型证实这些发现的生理学意义。实验结果也将通过从手术时采集的人结肠组织中提取的肌成纤维细胞来证实。肿瘤坏死因子和BK可能通过PKD在协同增强结肠肌成纤维细胞COX-2表达中的相互作用，可能在结肠炎相关性癌症中起重要作用。在炎症过程中，PKD信号可能调节肌成纤维细胞的关键生物学功能。