PGE2 EP1 and EP3 receptors as therapeutic targets in intracerebral hemorrhage

描述（由申请人提供）：PGE 2、EP 1和EP 3受体作为脑出血的治疗靶点脑出血（ICH）是死亡率和发病率最高的卒中亚型;不幸的是，这种疾病受到的研究关注远远少于缺血性卒中。炎症机制，包括某些前列腺素（PG）介导的炎症机制，已被认为有助于ICH损伤的进展。特别是，在脑中占主导地位的PGE 2在血肿周围区域产生并积累。PGE 2通过四种称为EP 1-EP 4的G蛋白偶联受体亚型发挥作用。这些受体中的每一个在脑缺血的动物模型中具有不同的信号级联。EP 1和EP 3受体的遗传缺失或选择性抑制已显示在体内和体外均减少缺血性脑损伤。本报告的总体目标 R 01旨在研究抑制PGE 2 EP 1和EP 3受体是否可用作ICH的神经保护治疗，如果可以，则生成临床前疗效数据并阐明潜在机制。我们一直在研究PGE 2受体在脑出血损伤中的具体作用，并有初步数据表明，缺失或抑制EP 1或EP 3受体可减少脑出血损伤并改善功能结局。我们的数据还表明，Src激酶介导的EP 1毒性和Rho激酶（ROCK）介导的EP 3毒性后，ICH。因此，我们将测试的假设，即PGE 2 EP 1受体阻断减少脑出血损伤通过Src激酶信号通路，而EP 3受体阻断减少脑出血损伤通过ROCK信号通路。我们设计了三个具体的目标，利用自体血脑出血模型和胶原酶诱导的脑出血模型。考虑到PGE 2产生的增加有助于炎症反应的年龄相关功能障碍，并且衰老和性别差异影响ICH结局，本研究将在年轻雄性和雌性以及老年雄性小鼠中进行，以增强临床相关性。目的1将确定EP 1或EP 3受体的抑制是否改善ICH结局;目的2将确定Src激酶信号传导的抑制是否有助于ICH后EP 1受体阻断剂提供的神经保护，以及EP 1受体抑制是否减少凝血酶诱导的脑损伤;目的3将确定ROCK信号的抑制是否有助于ICH后EP 3受体阻断剂提供的神经保护，以及EP 3受体是否抑制降低凝血酶诱导的脑损伤。通过药理学、遗传学、影像学、组织学、分子学和细胞生物学方法，这项工作将提供关于选择性PGE 2 EP 1和EP 3受体抑制剂对ICH诱导的脑损伤的保护作用及其机制的新信息。需要该概念验证信息来计划ICH中选择性EP 1和EP 3受体拮抗剂的更详细临床前评估。 公共卫生相关性：脑出血（ICH）是一种破坏性的临床事件，其中破裂的血管将血液释放到大脑中。我们建议在两种小鼠ICH模型中测试PGE 2 EP 1和EP 3受体抑制的功效，并阐明这种抑制提供神经保护的潜在机制。如果EP 1和EP 3受体抑制在两种小鼠ICH模型中显示出一致的神经保护作用，则可能有助于设计新的ICH治疗干预措施。

DESCRIPTION (provided by applicant): PGE2 EP1 and EP3 receptors as therapeutic targets in intracerebral hemorrhage Intracerebral hemorrhage (ICH) is the stroke subtype with the highest mortality and morbidity; unfortunately, this condition has received far less research attention than has ischemic stroke. Inflammatory mechanisms, including those mediated by certain prostaglandins (PGs), have been suggested to contribute to the progression of ICH injury. In particular, PGE2, which is predominant in the brain, is produced and accumulates in the perihematomal region. PGE2 acts through four G-protein-coupled receptor subtypes known as EP1- EP4. Each of these receptors has distinct signaling cascades in animal models of cerebral ischemia. Genetic deletion or selective inhibition of the EP1 and EP3 receptors has been shown to reduce ischemic brain injury both in vivo and in vitro. The overall objective of this R01 is to investigate whether inhibition of PGE2 EP1 and EP3 receptors can be used as neuroprotective therapy in ICH, and if so, to generate preclinical efficacy data and elucidate the underlying mechanisms. We have been investigating the specific roles of PGE2 receptors in ICH injury and have preliminary data showing that deletion or inhibition of the EP1 or EP3 receptor reduces ICH injury and improves functional outcomes. Our data also indicate that Src kinase mediates EP1 toxicity and Rho kinase (ROCK) mediates EP3 toxicity after ICH. Consequently, we will test the hypothesis that PGE2 EP1 receptor blockade reduces ICH injury through the Src kinase signaling pathway, whereas EP3 receptor blockade reduces ICH injury through the ROCK signaling pathway. We have designed three specific aims that utilize the autologous blood ICH model and collagenase-induced ICH model. Considering that an increase in PGE2 production contributes to age-related dysfunction of the inflammatory responses and that aging and sex differences affect ICH outcomes, this research will be carried out in young male and female and aged male mice to enhance the clinical relevance. Aim 1 will determine whether inhibition of EP1 or EP3 receptors improves ICH outcomes; Aim 2 will determine whether inhibition of Src kinase signaling contributes to the neuroprotection afforded by EP1 receptor blockade after ICH and whether EP1 receptor inhibition decreases thrombin-induced brain damage; and Aim 3 will determine whether inhibition of ROCK signaling contributes to the neuroprotection afforded by EP3 receptor blockade after ICH and whether EP3 receptor inhibition decreases thrombin-induced brain damage. Through pharmacologic, genetic, imaging, histologic, molecular, and cellular biologic approaches, this work will provide novel information about the efficacy of selective PGE2 EP1 and EP3 receptor inhibition to protect against ICH-induced brain injury and the mechanisms by which such protection occurs. This proof-of-concept information is required to plan more detailed preclinical assessment of selective EP1 and EP3 receptor antagonists in ICH. PUBLIC HEALTH RELEVANCE: Intracerebral hemorrhage (ICH) is a devastating clinical event in which a burst blood vessel releases blood into the brain. We propose to test the efficacy of PGE2 EP1 and EP3 receptor inhibition in two mouse ICH models and to elucidate the underlying mechanisms by which such inhibition provides neuroprotection. If EP1 and EP3 receptor inhibition shows consistent neuroprotection in the two mouse ICH models, it could contribute to the design of novel therapeutic interventions for ICH.