PGI2 restrains immunopathogenesis in hypertension

项目总结 高血压是一种定义为血压大于130/80毫米汞柱的疾病。高血压 对心血管疾病的发病率和死亡率有很大影响。虽然血液的重要性 压力控制已经变得非常清楚，我们仍然远未了解真正的病因 高血压。近年来，炎症被确定在高血压中起因果作用。具体来说， 免疫细胞在疾病过程中侵入靶器官，并释放细胞因子，导致终末期 器官受损。一些研究已经确定了树突状细胞(DC)和单核细胞的抗原提呈。 对高血压的发生有重要作用。此外，促炎T细胞使疾病持续存在。反- 炎性T调节细胞(Treg)可以控制高血压反应。有趣的是，有证据表明 长期使用环氧合酶抑制剂，可以防止花生四烯酸(AA)代谢到 前列腺素和血栓素会增加血压。前列腺素I2(PGI2)是一种AA代谢物， 我们实验室已经确定具有免疫调节作用。我们的团队已经证明了PGI2作用于 直接抑制促炎DC和CD4+Th1和Th2细胞的功能，同时促进 致耐受DC的功能。然而，前列腺素I2对高血压患者免疫细胞功能的影响是 未知。先前的一项研究表明，缺乏PGI2受体IP的小鼠会出现升高 高盐饮食对血压的影响，提示PGI2信号对控制血液很重要 压力升高对刺激的反应。此外，我有初步数据表明PGI2控制 对高血压刺激的炎症反应。具体地说，IP缺乏的小鼠增加了渗透 与野生型(WT)小鼠对血管紧张素II(Ang II)的反应相比，T细胞进入它们的主动脉的数量增加了。此外, 在Ang II输注过程中输注PGI2类似物Treprostinil可防止T细胞的渗透， WT小鼠的单核/巨噬细胞和DC进入主动脉与接受Ang II和 曲普替尼的载体。因此，这些最近的研究和我的初步数据让我提出了假设 前列腺素I2促进高血压时的抗炎反应。为了检验这一假设，我们将使用 高血压小鼠模型和来自正常血压和高血压小鼠和人类的原代细胞： 目标1(K99)：验证PGI2在高血压期间促进Treg功能和稳定性的假设， 从而对抗T细胞的促炎亚群；以及目标2(R00)：检验以下假设 在高血压期间，PGI2抑制促炎性DC并促进耐受性DC功能。 确定前列腺素I2控制高血压免疫反应的机制将极大地 为高血压的治疗开辟新的领域和新的治疗方向。这些建议 学习，以及我提出的职业发展计划，将为我的职业生涯奠定基础 在出色的环境中担任独立调查员。

PROJECT SUMMARY Hypertension is a disease defined as blood pressure that is greater than 130/80mmHg. Hypertension contributes significantly to cardiovascular disease morbidity and mortality. While the importance of blood pressure control has become abundantly clear, we are still far from understanding the true etiology of hypertension. In recent years, inflammation was determined to play a causal role in hypertension. Specifically, immune cells invade target organs during the course of the disease and release cytokines that cause end- organ damage. Several studies have determined antigen presentation by dendritic cells (DCs) and monocytes is important for initiation of hypertension. In addition, pro-inflammatory T cells perpetuate the disease. Anti- inflammatory T regulatory cells (Treg) can control the hypertensive response. Interestingly, evidence suggests that long-lasting use of cyclooxygenase inhibitors, which prevent metabolism of arachidonic acid (AA) to prostaglandins and thromboxane, increases blood pressure. Prostaglandin I2 (PGI2) is an AA metabolite that our laboratory has determined has immunomodulatory effects. Our group has demonstrated that PGI2 acts to directly inhibit the functionality of pro-inflammatory DCs and CD4+ Th1 and Th2 cells, while promoting the function of tolerogenic DCs. However, the impact of PGI2 on the functionality of immune cells in hypertension is unknown. A previous study has demonstrated that mice deficient in the receptor for PGI2, IP, develop elevated blood pressure in response to high salt diet, suggesting that PGI2 signaling is important for controlling blood pressure elevation in response to stimuli. Further, I have preliminary data which suggests that PGI2 controls the inflammatory response to hypertensive stimuli. Specifically, mice deficient in IP have increased infiltration of T cells into their aortas compared to wild-type (WT) mice in response to angiotensin II (Ang II). In addition, infusion of the PGI2 analog treprostinil during the course of Ang II infusion prevents the infiltration of T cells, monocytes/macrophages and DCs into the aorta of WT mice compared to WT mice that received Ang II and the vehicle for treprostinil. Thus, these recent studies and my preliminary data lead me to hypothesize that PGI2 promotes anti-inflammatory responses during hypertension. To test this hypothesis we will use mouse models of hypertension and primary cells from normotensive and hypertensive mice and humans to: Aim 1 (K99): Test the hypothesis that PGI2 promotes Treg function and stability during hypertension, thereby counteracting pro-inflammatory subsets of T cells; and Aim 2 (R00): Test the hypothesis that PGI2 restrains pro-inflammatory DC and promotes tolerogenic DC function during hypertension. Determining the mechanisms by which PGI2 controls the immune response to hypertension will greatly advance the field and result in new therapeutic directions for the treatment of hypertension. These proposed studies, along with my proposed career development plan, will provide a foundation for my career as an independent investigator in an outstanding environment.