Mechanisms of Intestinal Inflammation - Associated Systemic Genotoxicity

描述(由申请人提供)：众所周知，炎症性肠病(IBD)患者患肠癌和结直肠癌的风险增加。自那以后，这种炎症对癌症序列的作用机制得到了广泛的研究。然而，较少描述的是疾病的肠外表现的发生机制，包括造血癌，如非霍奇金T细胞淋巴瘤，肝胆癌，以及其他实体癌和自身免疫性疾病。我们之前已经确定了慢性肠炎小鼠外周血白细胞的遗传毒性。全身性遗传毒性是慢性肠炎的一种以前未被认识到的重要后果，随着时间的推移，这可能会促进肠外疾病的发展。在这一应用中，我们建议确定肠道炎症相关的全身性DNA损伤的长期含义和涉及的机制。第一个目的是阐明慢性肠炎期间淋巴组织和非淋巴组织中多种细胞类型的基因毒性负荷，然后描述这些细胞可能造成的长期病理影响。我们的第二个目标是一个机制目标，在这个目标中，我们将确定在体内诱导全身遗传毒性和在体外诱导遗传毒性中细胞因子如TNF-1和IL-12的充分性，然后确定参与诱导细胞内RONS形成的受体下游的潜在信号通路。细胞因子处理后的从头蛋白合成的必要性以及细胞内ROS和DNA损伤的时间方案将通过成像分析和ROS清除剂的治疗来确定。在我们的第三个和第四个目标中，我们将分别测试肠道受损的白细胞循环到外周的假设，以及各种远程组织中的局部炎症反应导致全身遗传毒性的假设。通过将患有慢性肠炎的Ly5.1小鼠的血清或白细胞群体过继转移到同种基因Ly5.2小鼠中，并测试Ly5.2细胞的系统遗传毒性，将测试可能导致这种效应的远处组织中炎症反应的特定成分。总之，这些实验应该澄清将肠道炎症与全身遗传毒性联系起来的炎症介质和靶细胞类型。

DESCRIPTION (provided by applicant): Patients with inflammatory bowel disease (IBD) are known to be at increased risk for intestinal and colorectal cancer. Mechanisms of this inflammation to cancer sequence have since been extensively characterized. Less characterized, however, are the mechanisms involved in the development of extraintestinal manifestations of disease, including hematopoietic cancers such as non-Hodgkin's T-cell lymphomas, hepatobiliary cancers, and other solid cancers and autoimmune disorders. We have previously identified genotoxicity to peripheral leukocytes in mice with chronic intestinal inflammation. Systemic genotoxicity is there an important and previously unappreciated consequence of chronic intestinal inflammation, which over time may promote the development of extraintestinal disease. In this application, we propose to determine the long-term implications of and determine the mechanisms involved in intestinal inflammation-associated systemic DNA damage. The first aim will clarify genotoxic load to multiple cell types in lymphoid and non-lymphoid tissues during chronic intestinal inflammation, and then characterize the long-term pathological effects these may impose. Our second aim is a mechanistic aim in which we will determine the sufficiency of cytokines such as TNF-1 and IL-12 in inducing systemic genotoxicity in vivo and in inducing genotoxicity in vitro, and then identify potential signaling pathways downstream of the receptors involved in induction of intracellular RONS formation. Necessity of de novo protein synthesis post-cytokine treatment and the temporal scheme of intracellular ROS and DNA damage will be determined via imaging analysis and treatment with ROS scavengers. In our third and fourth aims, we will test the hypothesis that damaged leukocytes from the gut circulate into the periphery, and the hypothesis that a local inflammatory response in various distant tissues are responsible for systemic genotoxicity, respectively. Specific components of the inflammatory response in distant tissues that may be responsible for this effect will be tested via adoptive transfer of serum or leukocyte populations from Ly5.1 mice with chronic intestinal inflammation into congenic Ly5.2 mice, and testing for systemic genotoxicity in Ly5.2 cells. Together, these experiments should clarify the inflammatory mediators and target cell types that link intestinal inflammation with systemic genotoxicity.