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

基本信息

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
项目类别：
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

项目摘要

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（由申请人提供）：本 R21 申请旨在确定感染敏感的围产期缺氧缺血性损伤是否会促进单核细胞侵入中枢神经系统，从而诱导急性脑损伤并转化为小胶质细胞样亚炎症状态。由于对新生儿大脑中单核细胞-小胶质细胞相互作用/转化知之甚少，促炎性单核细胞衍生物可能会增加大脑对损伤后点燃和惊厥的敏感性。此外，了解浸润单核细胞如何导致损伤可能会导致新的治疗策略。在这个项目中，我们将检验围产期感染/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作用的假设。后来，其中一些单核细胞采用了小胶质细胞特性，但被锁定在促炎症状态，以提高大脑对兴奋性毒素的敏感性并引发惊厥。我们将在两个具体目标中检验这一假设：目标 1：入侵的意义。新生儿急性感染/HI脑损伤中的单核细胞我们将使用双转基因CX3CR1-GFP：CCR2-RFP小鼠分别标记小胶质细胞和单核细胞，并进行研究。这些小鼠对内毒素 (LPS) 致敏的缺氧缺血 (HI) 损伤进行测试，以测试新生儿大脑中单核细胞的流入及其促炎细胞因子的表达。接下来，我们将比较半合子 CCR2RFP/+ 和纯合子 CCR2RFP/ 的反应。 RFP 小鼠（相当于 CCR2 缺失且缺乏单核细胞趋化蛋白-1 受体）至 LPS/HI目标 2：围产期感染/HI 脑损伤后单核细胞流入损伤的发育后果我们将静脉注射肌动蛋白-GFP/CCR2-RFP 单核细胞至 LPS/HI 损伤的小鼠幼崽中，并根据 GFP 显示的形态跟踪其发育结果。和抗细胞因子抗体双重标记，我们将测试单核细胞是否转化为小胶质细胞并在成年大脑中维持促炎状态接下来，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是否使大脑对炎症反应敏感。红藻氨酸兴奋性毒性和 PTZ 引起的惊厥点燃。