THE ROLE OF SPHINGOSINE KINASE IN MAST CELL SIGNALING

鞘氨醇激酶在肥大细胞信号传导中的作用

• 批准号: 6638133
• 负责人: OKSOON H CHOI
• 金额: $ 13.23万
• 依托单位: MEHARRY MEDICAL COLLEGE
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-04-01 至 2003-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6638133
• 关键词: antibody receptor; calcineurin; calcium flux; cell line; endoplasmic reticulum; enzyme activity; mast cell; mitogen activated protein kinase; phospholipase C; phosphotransferases; sphingosine

DESCRIPTION (Adapted from applicant's abstract) Antigen stimulation of mast cells through high affinity receptors for IgE (FceR1) leads to Ca2+ mobilization and, as a consequence, the release of inflammatory mediators that are responsible for allergic diseases such as asthma. It is generally believed that inositol 1,4,5-trisphoshate (IP3) is responsible for mobilizing Ca2+ from the intracellular endoplasmic reticulum (ER) stores. Recently, the applicants have shown that the amount of IP3 produced by FceR1 stimulation is not sufficient to cause Ca2+ mobilization through FceR1, suggesting that an alternative pathway might be involved. The goal of this proposal is to test the hypothesis that the sphingosine kinase (SK) pathway via the production of sphingosine 1-phosphate (S1P) plays an important role in Ca2+ mobilization through FceR1 in mast cells. In addition, the signaling mechanisms, which are upstream and downstream of FceRI-mediated mast cells. In addition, the signaling mechanisms, which are upstream and downstream of FceR1-mediated SK activation, will be investigated. In these studies, a mast cell line, RBL-2H3 cells will be used as a model system as FceR1-mediated signaling has been extensively studied in this cell line. Strategies will be 1) To determine whether S1P is produced in the ER membrane upon FceR1 stimulation and whether this production correlates with in Ca2+ mobilization from the ER because S1P, not being diffusible to the cytosol, must act close to the site where it is produced. 2) To determine the role of SK pathway in FceR1-mediated Ca2+ mobilization by overexpressing the cytosolic SK (cSK) or by inhibiting PLCg. Since the cSK has recently been purified and cloned, the role of cSK and PLCg in FceR1-mediated Ca2+ mobilization will be investigated. 3) To identify the upstream signaling events that are activated by FceR1 and mediated SK activation. As possible candidates for the upstream signals, Syk tyrosine kinase and Ca2+-dependent serine/threonine protein phosphatase calcineurin will be investigated. 4) To identify the signaling events that are dependent on SK activation. Specifically FceR1-mediated activity of PLD and MAPK and will be examined. The long-term goal of the proposal is to develop a therapeutic intervention for allergic diseases such as asthma by elucidating the underlying mechanisms of Ca2+-dependent release of inflammatory mediators.

描述 （改编自申请人的摘要）通过 IgE的高亲和力受体（FCER1）导致CA2+动员，作为一个 结果，释放负责的炎症介质 过敏性疾病，例如哮喘。 通常认为肌醇 1,4,5-Trisphoshate（IP3）负责从 细胞内内质网（ER）存储。 最近，申请人 已经表明，FCER1刺激产生的IP3量不是 足以通过FCER1引起Ca2+动员，这表明 可能涉及替代途径。 该提议的目的是检验鞘氨酸的假设 通过生产1-磷酸盐（S1P）发挥的激酶（SK）途径 在肥大细胞中通过FCER1动员Ca2+动员的重要作用。 在 此外，信号机制是上游和下游的 FCERI介导的肥大细胞。 另外，信号传导机制是 将研究FCER1介导的SK激活的上游和下游。 在这些研究中，肥大细胞系将将RBL-2H3细胞用作模型 系统作为FCER1介导的信号传导已在此细胞中进行了广泛研究 线。 策略将为1）确定是否在ER中产生S1P FCER1刺激后的膜以及该产量是否与IN相关 Ca2+来自ER的动员，因为S1P不可扩展到 细胞质，必须在生产的地点附近起作用。 2）确定 SK途径在FCER1介导的Ca2+动员中的作用，通过过表达 胞质SK（CSK）或通过抑制PLCG。 由于CSK最近是 纯化和克隆，CSK和PLCG在FCER1介导的Ca2+中的作用 将研究动员。 3）识别上游信号传导 被FCER1激活和介导的SK激活的事件。 尽可能 上游信号，SYK酪氨酸激酶和Ca2+依赖性的候选者 丝氨酸/苏氨酸蛋白磷酸酶钙调蛋白将被研究。 4）到 确定取决于SK激活的信号事件。 将检查PLD和MAPK的FCER1介导的活性，并将检查。 该提案的长期目标是开发治疗性干预 对于过敏性疾病，例如通过阐明基本机制来进行哮喘 Ca2+依赖性炎症介质的释放。