Microglia- Monocyte Interactions following Perinatal Brain Injury

围产期脑损伤后小胶质细胞-单核细胞相互作用

• 批准号: 9198866
• 负责人: Chia-Yi Kuan
• 金额: $ 19.5万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9198866
• 关键词: Actins; Acute; Acute Brain Injuries; Address; Adopted; Adoptive Transfer; Adult; Animals; Antibodies; Architecture; Belief; Biological Neural Networks; Birth; Blood; Brain; Brain Hypoxia-Ischemia; Brain Injuries; Chimera organism; Cognitive deficits; Complication; Convulsions; Development; Elements; Embryonic Development; Endotoxins; Epilepsy; Excitatory Neurotoxins; Genetic; Hematopoietic stem cells; Hypersensitivity; Hypoxia; Impairment; Infection; Inflammation; Inflammatory; Inflammatory Response; Injection of therapeutic agent; Injury; Intravenous; Invaded; Kainic Acid; Label; Lead; Life; Lipopolysaccharides; Maps; Microglia; Morphology; Mus; Mutant Strains Mice; Neonatal; Neonatal Brain Injury; Newborn Infant; Outcome; Parabiosis; Pathogenicity; Perinatal; Perinatal Brain Injury; Perinatal Infection; Pharmacology; Predisposition; Public Health; Recruitment Activity; Research; Resistance; Role; Saline; Seizures; Stimulus; Surveys; Testing; Tissues; Yolk Sac; base; cytokine; excitotoxicity; experimental study; fetal; injured; irradiation; monocyte; monocyte chemoattractant protein 1 receptor; mouse model; neonatal brain; neonatal injury; neural circuit; neurodevelopment; newborn brain injury; novel therapeutics; perinatal injury; prevent; public health relevance; pup; response; tool

 DESCRIPTION (provided by applicant): This R21 application seeks to determine if infection-sensiztied perinatal hypoxic-ischemic injury promotes monocyte invasion of the CNS to induce acute brain injury and conversion to a microglia-like sub-inflammatory state. This is a significant subject because little is known about monocyte-micorglia interactions/transformation in the neomnatal brain and pro-inflammatory monocyte-derivatives may increase the brain susceptibility to kindling and convulsion after injury. Further, understanding how infiltrating monocytes contribute to injury may lead to novel therapeutic strategies. In this project, we will test the hypothesis that perinatal infection/hypoxic-ischemic injury promotes monocytes to invade the CNS and exert inflammatory and destructive actions. Later, some of these monocytes adopt the microglial identity but are locked-in in a pro-inflammatory state to raise the brain susceptibility to excitotoxins and the kindling to convulsions. We will test this hypothesis n two specific aims. Aim 1: Significance of invading monocytes in acute infection/HI brain injury of newborns. We will use bitransgenic CX3CR1-GFP: CCR2-RFP mice to label microglia and monocytes respectively, and subject these mice to endotoxin (LPS)-sensitized hypoxia-ischemia (HI) injury to test the influx of monocytes in neonatal brains and their expression of pro-inflammatory cytokines. Next, we will compare the responses by hemizygous CCR2RFP/+ and homozygous CCR2RFP/RFP mice (equivalent to CCR2-null and lacking the receptor for Monocyte Chemoattractant Protein-1) to LPS/HI insult, as well as the benefits of anti-CCR2 antagonists to assess the pathogenic role of monocytes. Aim 2: Developmental consequences of monocyte influx after perinatal infection/HI brain injury. We will intravenously transfer actin-GFP/CCR2-RFP monocytes into LPS/HI-injured murine pups and follow their developmental outcomes. Based on the GFP-revealed morphology and double labeling with anti-cytokine antibody, we wiil test whether monocytes convert to microglia and maintain a pro-inflammatory state in adult brains. Next, we will use CCR2-mutant mice and a selective CCR2 antagonist (RS102895), to test whether or not monocyte-derived microglia sensitize the brain response to the kainic acid excitotoxicity and PTZ-induced kindling to convulsions.

 描述（由应用提供）：该R21应用程序旨在确定感染伴有围产期缺氧 - 缺血性损伤是否会促进中枢神经系统的单核细胞侵袭，以诱导急性脑损伤并转化为小胶质细胞样的下炎性下炎性态。这是重要的 主题是因为对新生儿大脑和促炎单核细胞衍生物中的单核细胞 - 丝菌相互作用/转化知之甚少，可能会增加受伤后的大脑对发射和抽搐的敏感性。此外，了解浸润单核细胞如何促进损伤可能会导致新的治疗策略。在该项目中，我们将检验以下假设：围产期感染/缺氧缺血性损伤促进单核细胞侵入中枢神经系统并发挥炎症和破坏性作用。后来，其中一些单核细胞采用了小胶质细胞的身份，但在促炎状态下锁定，以提高大脑对兴奋毒素的敏感性和对抽搐的启动。我们将检验该假设n两个具体目标。 AIM 1：入侵单核细胞在急性感染/新生儿脑损伤中的重要性。我们将分别使用BITTRANSGENIC CX3CR1-GFP：CCR2-RFP小鼠标记小胶质细胞和单核细胞，并将这些小鼠对内毒素（LPS）敏感性低氧 - 疾病（HI）损伤进行测试，以测试单核细胞在新生儿脑料中的影响。接下来，我们将比较半齐的CCR2RFP/+和纯合CCR2RFP/RFP小鼠（相当于CCR2-null，缺乏单核细胞介绍蛋白-1）与LPS/HI损伤的受体，以及评估抗CCR2拮抗剂的好处，以评估抗Cr2拮抗剂的益处。目标2：围产期感染/HI脑损伤后单核细胞影响的发育后果。我们将静脉内将肌动蛋白GFP/CCR2-RFP单核细胞转移到LPS/HI损伤的鼠幼犬中，并遵循它们的发育结果。基于GFP的复发形态和抗伴侣抗体的双重标记，我们测试单核细胞是否转化为小胶质细胞并保持成人大脑中的促炎状态。接下来，我们将使用CCR2突变小鼠和选择性CCR2拮抗剂（RS102895）来测试单核细胞衍生的小胶质细胞敏感性是否脑对Kainic Acid兴奋性和PTZ诱导的对抽搐的发射。