Function and Regulation of Human Cytochrome P4502S1

描述（由申请人提供）：本申请代表授予R 01 ES 015384的竞争性修订，以响应通知编号（NOT-OD-09-058）和通知标题：NIH宣布恢复法案资金可用于竞争性修订申请。在本研究中，我们分析了细胞色素P450 2S 1（CYP 2S 1）的功能和酶活性。在本修订版“CYP 2S 1与哮喘”中，我们将扩展这些研究，以研究CYP 2S 1在哮喘发生和发展中的作用。我们的几个（未发表的）观察结果表明，这种酶在这种疾病中起作用，特别是，可能起反调节机制的作用，以减轻个别哮喘发作的严重程度。这些意见包括以下内容。(a)Cyp 2s 1在小鼠（和人）肺中高度表达。(b)缺氧在缺氧诱导因子（HIF）介导的过程中上调小鼠和人细胞系以及小鼠肺中Cyp 2s 1的表达。(c)在哮喘小鼠模型中，HIF是哮喘样反应所必需的。(d)Cyp 2s 1在小鼠哮喘样反应中上调。(e)Cyp 2s 1在类花生酸的降解中非常活跃，已知其中许多类花生酸与哮喘的发生和发展密切相关。具体目标1将测试我们的假设，Cyp 2s 1活性减少哮喘反应。为此，将利用新开发的Cyp 2s 1基因敲除小鼠来确定Cyp 2s 1活性的丧失是否会增强急性和慢性阶段的哮喘样症状的表现。具体目标2将测试我们的假设，即在哮喘样反应期间Cyp 2s 1敲除小鼠和野生型小鼠之间的类花生酸谱不同，从而为前者增强的哮喘样反应提供了潜在的解释。为此，（a）将检查纯化的小鼠Cyp 2s 1和来自用哮喘诱导方案处理或未处理的两种类型的上述小鼠的微粒体对相关类花生酸的代谢，和（B）将测定来自这些小鼠的肺、细支气管灌洗液（BAL）和血清中类花生酸的分布。特异性目标2将由此鉴定其在小鼠组织中的浓度与哮喘样反应的严重程度相关的类二十烷酸，并且还确定这些类二十烷酸是否是Cyp 2s 1的底物，从而鉴定可能负责介导Cyp 2s 1对哮喘样反应的保护作用的特定类二十烷酸。我们的研究将潜在地指出哮喘治疗的新靶点，即CYP 2S 1。我们以前的研究表明，蔬菜中发现的某些天然化合物可以上调Cyp 2s 1。因此，这些化合物可能代表哮喘的潜在新疗法。 公共卫生相关性：这些研究将为一种重要的环境疾病-哮喘提供机制性的见解。此外，他们有望将酶CYP 2S 1鉴定为治疗、改善或预防哮喘的药物的新分子靶点。这些物质可能包括某些影响蔬菜中CYP 2S 1活性的天然化学物质。

DESCRIPTION (provided by applicant): This application represents a Competitive Revision to grant R01ES015384, in response to the Notice Number (NOT-OD-09-058) and Notice Title: NIH Announces the Availability of Recovery Act funds for Competitive Revision Applications. In the parent grant, we are analyzing the function and enzymatic activity of the enzyme, cytochrome P450 2S1 (CYP2S1). In this revision, "CYP2S1 and Asthma", we will now extend these studies to investigate the role of CYP2S1 in the initiation and progression of asthma. Several of our (unpublished) observations suggest that this enzyme plays a role in this disease, and in particular, may function as a counter- regulatory mechanism to diminish the severity of individual asthmatic episodes. These observations include the following. (a) Cyp2s1 is highly expressed in mouse (and human) lung. (b) Hypoxia upregulates Cyp2s1 expression in mouse and human cell lines and in mouse lung in a process mediated by Hypoxia Inducible Factor (HIF). (c) HIF is required for the asthma-like response in a mouse model of asthma. (d) Cyp2s1 is upregulated in mouse lung during the asthma-like response. (e) Cyp2s1 is very active in the degradation of eicosanoids, many of which are known to be intimately involved in the initiation and progression of asthma. Specific Aim 1 will test our hypothesis that Cyp2s1 activity diminishes the asthmatic response. To this end, a newly developed knockout mouse for Cyp2s1 will be utilized to ascertain whether loss of Cyp2s1 activity enhances the manifestations of asthma-like symptoms in both the acute and chronic phases. Specific Aim 2 will test our hypothesis that the profile of eicosanoids differs between Cyp2s1 knockout and wild-type mice during the asthma-like response, thus providing a potential explanation for the enhanced asthma-like response in the former. To this end, (a) the metabolism of relevant eicosanoids by purified mouse Cyp2s1 and by microsomes from both types of the above mice treated or untreated with the asthma-inducing protocol, will be examined, and (b) the profiles of eicosanoids in lungs, bronchiolar lavage fluid (BAL) and sera from these mice will be determined. Specific Aim 2 will thereby identify eicosanoids whose concentrations in mouse tissues correlate with the severity of the asthma-like response, and also determine whether these eicosanoids are substrates of Cyp2s1, thus identifying the particular eicosanoid(s) that are likely responsible for mediating the protective effect of Cyp2s1 towards the asthma-like response. Our studies will potentially point to a novel target for asthma therapy, namely CYP2S1. Our previous studies suggest that certain natural compounds found in vegetables can upregulate Cyp2s1. These compounds therefore may represent potential novel therapeutics for asthma. PUBLIC HEALTH RELEVANCE: These studies will provide mechanistic insight into an important environmental disease - asthma. Furthermore, they promise to identify the enzyme CYP2S1 as a novel molecular target for agents for the treatment, amelioration or prevention of asthma. Such agents could include certain natural chemicals that impact the activity of CYP2S1, which are found in vegetables.