PGI2 IP receptor role in global ischemia in young and aged mice

描述（由申请人提供）：中风是西方人群死亡和长期残疾的第三大原因。类似损伤的结果在成年人中比在年轻人中更糟，但这种差异背后的机制尚不清楚。我的主要目标是找出临床相关的PGI 2作为炎症过程的调节剂的重要性，在老年和年轻小鼠的全脑缺血小鼠模型中解决这个问题。一个具有分子和行为神经科学神经学家专业知识和神经病理学家的跨学科研究团队将解决以下假设：与WT小鼠相比，老年前列环素受体（PGI 2）（IP）KO中由于全脑缺血引起的炎症反应增加将使学习和记忆性能恶化，降低局部脑血流量（rCBF），增加白细胞浸润和海马神经元细胞死亡。实验测试了特定的假设，即在老年小鼠中，增强的炎症反应导致全脑缺血后磷酸化CREB和CREB水平降低。通过证明与WT小鼠相比，IP KO小鼠的学习和记忆能力降低，海马细胞死亡增加，初步证实了这一假设。提出了四个具体目标来检验这些假设：1）确定与年轻小鼠（2-3月龄）相比，PGI 2（IP）受体的基因缺失是否会加重C57 B16老年小鼠（12-15月龄）的神经行为缺陷和神经元细胞死亡。2)确定与对照组相比，与年轻小鼠相比，在老年IP-/-小鼠中是否观察到绝对rCBF减弱和白细胞浸润增加。3)确定IP激动剂是否改善WT小鼠全脑缺血后的学习和记忆表现，而拮抗剂是否降低WT小鼠全脑缺血后的学习和记忆表现。4)免疫组化法检测全脑缺血后1h、3 h、1d、4d、7 d神经元细胞死亡情况，检测磷酸化CREB和CREB水平，探讨其作用机制。这些新型临床相关药物的开发可以为治疗全脑缺血和潜在的其他神经退行性疾病提供新的治疗策略。这项研究计划将通过开发治疗性PGI 2（IP）受体刺激药物来改善老年人的学习和记忆，并控制心脏骤停引起的脑损伤，从而具有直接的临床前重要性。 公共卫生相关性：中风和心脏骤停后的脑损伤是美国死亡的主要原因，估计每年有325，000人死亡。随着人口老龄化，中风或心脏骤停的发生率和结局可能会恶化，但这种差异的机制尚不清楚。这项研究计划将在年轻和老年临床前模型中测试PGI 2（IP）受体药物对潜在改善学习和记忆以及控制全球缺血性疾病引起的脑损伤的重要性。

DESCRIPTION (provided by applicant): Stroke is the third leading cause of death and long-term disability in the Western population. The results of a similar injury are worse in the adults than in young people, but the mechanisms underlying this difference are unknown. My main goal here is to find out the importance of clinically relevant PGI2 as a modulator of the inflammatory process, in global cerebral ischemia mouse model in old and young mice to address this question. An interdisciplinary research team with neurologist expertise in molecular and behavioral neuroscience and neuropathologist will address the hypotheses that increased inflammatory response due to global cerebral ischemia in older prostacyclin receptor ( PGI2) (IP) KO will worsen the learning and memory performance, decrease regional cerebral blood flow (rCBF), increase leukocyte infiltration and hippocampal neuronal cell death as compared to WT mice. The experiments test the specific hypothesis that in old mice, an enhanced inflammatory response results in decrease in phospho CREB and CREB levels after global cerebral ischemia. Preliminary data this hypothesis by demonstrating reduced learning and memory performance and increased hippocampal cell death in IP KO mice as compared to WT mice. Four specific aims are proposed to test these hypotheses: 1) Determine whether genetic deletion of PGI2 (IP) receptor will aggravate neurobehavioral deficit and neuronal cell death in C57Bl6 older mice (12-15 months old) as compared to younger mice (2-3 months old). 2) Determine whether attenuated absolute rCBF and increased leukocyte infiltration will be observed in older IP-/- as compared to young mice as compared to their controls. 3) Determines whether IP agonists improve and antagonists reduce learning and memory performance after global cerebral ischemia in WT mice. 4) Determine the neuronal cell death by performing immunohistochemistry and find out the mechanism of actions by investigating the phospho-CREB and CREB level at different time points- 1h, 3h and 1, 4 and 7d after global cerebral ischemia. Development of these novel clinically relevant drugs could provide a new therapeutic strategy against global cerebral ischemia and potentially other neurodegenerative disorders. This research proposal will have direct pre-clinical importance by developing therapeutic PGI2 (IP) receptor stimulating drugs to improve learning and memory and controlling brain damage induced by cardiac arrest in elderly people. PUBLIC HEALTH RELEVANCE: Stroke and brain damage following cardiac arrest are the leading causes of death in United States, accounting for an estimated 325,000 deaths each year. The increasing rate and outcomes of a stroke or cardiac arrest is likely to be worsening with the aging of the population, but the mechanisms underlying this difference are unknown. This research proposal will test the importance of PGI2 (IP) receptor drugs to potentially improve learning and memory and controlling brain damage induced by global ischemic conditions, in young and aged preclinical models.