The Role of Sphingolipids in Inflammatory Bowel Disease

描述(由申请人提供)：这项提议的广泛的长期目标是研究炎症性肠病(IBD)所涉及的病理学中鞘氨醇-1-磷酸(S1P)的来源，并将其合成酶-鞘氨醇激酶1(SKI)与特定的抑制剂作为潜在的治疗该疾病的新方法。在特定的目标1中，我们将确定结肠组织SK1是IBD中SI P的来源。这将通过使用小鼠骨髓嵌合体模型和溃疡性结肠炎小鼠模型来完成。我们将(I)通过同时照射野生型和鞘氨醇激酶-1基因敲除小鼠来建立骨髓嵌合小鼠，并用宿主血液或来自相反品系的血液重建它们的血液。然后，我们将(Ii)使用DSS诱导骨髓嵌合小鼠的结肠炎，并检测疾病参数：如体重减轻、结肠缩短、脾肿大、疾病的组织学标志、血液和组织SK1活性以及鞘磷脂的变化。接下来，我们将(Hi)用流式细胞术检测细胞炎症反应和结肠组织炎症的潜在机制，例如DSS注射的骨髓嵌合小鼠产生的TNFor和C0X2。这些研究与人类健康有明显的联系，应该确定IBD中SI P的来源，以便进行潜在的靶向治疗。在具体目标2中，我们将开发新的SKI抑制剂，作为治疗IBD的潜在新疗法。这一目标将检验抑制SKI将改善IBD严重程度的子假说。为此，我们将(1)评估我们新开发的SK1抑制剂抑制FHC人结肠上皮细胞中SK1的TNFa激活和下游信号的能力。我们将通过Real Time-RT-PCR和Western blotting检测这些下游效应。我们还将(Ii)通过任一种方法来治疗使用SKI抑制剂的小鼠。或者静脉注射。注射并评估组织和血液SKI以及它们对DSS诱导的结肠炎的反应1.这些研究促进了SKI抑制剂作为IBD新的治疗方法的进展。 公共卫生相关性：这项研究与人类健康和疾病直接相关。目前IBD的治疗方法包括全身免疫抑制和类固醇的使用，导致患者出现不良副作用，导致依从性问题。这种疾病的治疗需要更多副作用更少的特异性靶点。这项研究的目的就是找到一种新的治疗方法，抑制疾病的细胞机制，改善患者的健康。

DESCRIPTION (provided by applicant): The broad long-term objective of this proposal is to examine the source sphingosine-1-phosphate (S1P) in the pathology involved in inflammatory bowel disease (IBD), and target its synthetic enzyme, sphingosine kinase 1 (SKI) with specific inhibitors as a potential novel therapeutic approach to the disease. In Specific Aim 1, we will establish that colon tissue SK1 is the source of SI P in IBD. This will be done by using a mouse bone marrow chimera model in conjunction with a mouse model of ulcerative colitis. We will (i) establish bone marrow chimeric mice, by irradiating both wild-type and sphingosine kinase-1 knockout mice and reconstitute their blood with either host blood or blood from the opposite strain. We will then (ii) administer DSS to induce colitis in bone marrow chimeric mice, and examine parameters of disease: such as weight loss, colon shortening, splenomegaly, histologic markers of disease, blood and tissue SK1 activity, as well as sphingolipid changes. Next we will (Hi) examine the cellular inflammatory responses with flow cytometry and the underlying mechanisms of inflammation in colon tissue, such as TNFor and C0X2 production from DSS-administered, bone marrow chimeric mice. These studies have an obvious link to human health and should firmly establish the source of SI P in IBD to allow potential targeting of therapy. In Specific Aim 2 we will develop novel SKI inhibitors as potential new therapeutic modalities for the treatment of IBD. This aim will test the sub-hypothesis that inhibiting SKI will ameliorate the severity of IBD. To this end we will (1) evaluate our newly developed SK1 inhibitors as to their ability to inhibit TNFa activation of SK1 and downstream signaling in FHC human colon epithelial cells. We will examine these downstream effects by Real Time-RTPCR and western blotting. We will also (ii) treat mice with SKI inhibitors by either i.p. or i.v. injection and evaluate tissue and blood SKI as well as their response to DSS- induced colitis as done for Specific Aim 1. These studies advance SKI inhibitors as novel therapeutic approaches to IBD. PUBLIC HEALTH RELEVANCE: This research is directly related to human health and disease. Current therapies for IBD involve general immunosuppression and the use of steriods, causing undesirable side effects in patients leading to issues of compliance. More specific targets with less side effects are needed for treatment of this disease. This research is targeted at finding just that, a novel therapeutic that inhibits the cellular mechanism of disease and improving patient health.