P2X3 is a Female-Dominant Amplifier of Mast Cell Function

项目摘要 过敏性疾病发病率的上升是一个公共卫生挑战，需要新的干预措施。当桅杆 由IgE激活的细胞在疾病病理中具有已知的作用，肥大细胞生物学的基本方面仍然存在 不清楚。尤其需要了解特定性别的影响。雌性小鼠的肥大细胞 更强的IgE诱导的反应，这是对更高的过敏发生率和敏感度的补充 女性中的哮喘。为了重新调整药物的用途，我们发现氟西汀(百忧解)有效地抑制了 肥大细胞由IgE激活。这些数据在体外、体内和人类肥大细胞中都是一致的。然而， 氟西汀的作用明显受女性限制。我们的结果表明，氟西汀具有非靶向作用 P2X3，一种三磷酸腺苷激活的阳离子通道，通常与疼痛信号有关。我们发现肥大细胞 响应IgE信号，迅速释放ATP，表明P2X3是在自分泌循环中被触发的。P2X3是 在女性肥大细胞上容易检测到，但在男性肥大细胞上检测不到，这可能解释了为什么女性肥大细胞有更强的IgE 回应。与氟西汀一样，P2X3选择性抑制剂极大地抑制肥大细胞对IgE或ATP的反应。 其他P2X蛋白的抑制剂不起作用。我们的研究将检验这样一种假设，即IgE信号诱导ATP 释放有选择性地激活女性体内的P2X3，放大过敏性炎症。这条途径可以提供 过敏性疾病中性二型性的解释和临床靶点。 我们有三个具体目标： 目的1：我们将检验关于P2X3增强女性肥大细胞功能的假说。 目的2：我们将验证氟西汀通过抑制P2X3功能和表达发挥作用的假说。 目的3：我们将检验这一假设，即P2X3是过敏性呼吸道炎症的基本部分，可以 目标是女性。

Project Summary The rising incidence of allergic disease is a public health challenge needing novel interventions. While mast cell activation by IgE has a known role in disease pathology, fundamental aspects of mast cell biology remain unclear. There is a particular need to understand sex-specific effects. Mast cells from female mice have stronger IgE-induced responses, an observation complementing the greater incidence and acuity of allergic asthma among women. In an effort to repurpose drugs, we found that fluoxetine (Prozac) potently suppresses mast cell activation by IgE. These data were consistent in vitro, in vivo, and with human mast cells. However, fluoxetine effects were strikingly female-restricted. Our results indicate fluoxetine has an off-target effect on P2X3, an ATP-activated cationic channel most often associated with pain signaling. We find that mast cells rapidly release ATP in response to IgE signaling, suggesting P2X3 is triggered in an autocrine loop. P2X3 was readily detectable on female but not male mast cells and may explain why female mast cells have stronger IgE responses. Like fluoxetine, P2X3-selective inhibitors greatly suppressed mast cell responses to IgE or ATP. Inhibitors of other P2X proteins had no effect. Our study will test the hypothesis that IgE signaling elicits ATP release that activates P2X3 selectively in females, amplifying allergic inflammation. This pathway could offer an explanation and a clinical target for sexual dimorphism in allergic disease. We have three Specific Aims: Aim 1: We will test the hypothesis that P2X3 enhances mast cell function in females. Aim 2: We will test the hypothesis that fluoxetine acts by suppressing P2X3 function and expression. Aim 3: We will test the hypothesis that P2X3 is a fundamental part of allergic airway inflammation that can be targeted in females.