Roles of hemocytes and bioactive lipids in the modulation of neuronal excitability and seizure behavior in Drosophila voltage-gated sodium channel mutants

项目摘要 神经系统和免疫系统之间的局部和全身相互作用在以下方面发挥重要作用： 各种生理和病理过程。该项目的长期目标是获得一个基本的 了解神经免疫通讯如何促进神经发育的调节， 生理学和行为，使用实验模式生物果蝇具有 进化上保守的先天免疫系统本应用程序的总体目标是揭示 和先天免疫细胞和中枢神经系统之间的功能相互作用的机制， 电压门控钠（Nav）对果蝇神经元兴奋性和行为亢进的调节 通道突变体，paraShu。该项目是基于有趣的发现，即：1）paraShu成人癫痫发作的严重程度是 显著抑制饮食补充β-3多不饱和脂肪酸（PUFAs）β-亚麻酸 (ALA)2）血细胞（巨噬细胞样血细胞）特异性敲除GstS 1，哺乳动物的果蝇直系同源物 前列腺素D合酶，模拟饮食ALA的作用;和3）饮食ALA和GstS 1敲低都是 在发育过程中有效抑制成年突变体的癫痫发作。核心假设是， 成年paraShu通过生物学中先天免疫细胞的作用通过神经发育调节 涉及生物活性脂质介质的过程。为了研究这一假设，将追求两个具体目标： 1)确定血细胞在调节paraShu神经元兴奋性和行为亢进中的作用 突变体;和2）鉴定参与成体的血细胞依赖性调节的基因和信号通路。 癫痫发作对于第一个目标，血细胞的功能将受到遗传干扰，对神经系统的影响将被破坏。 发育、电生理特性和癫痫发作行为将在存在或 使用自由移动或拴系行为的成年果蝇以及分离的果蝇， 从突变幼虫脑中制备的原代神经元培养物。对于第二个目标，候选基因方法 将被用于识别参与假定的脂质信号传导过程的基因，脂质组学分析将被用于 进行，以确定在氧化脂质的变化，脂质介质产生的多不饱和脂肪酸，在突变体中， 表型修饰物的存在或不存在。这项多学科研究有望揭示 血细胞在Nav神经元兴奋性和行为发作的饮食依赖性调节中的作用 通道突变体，并提供了新的遗传和分子的见解，在很大程度上未开发的脂质信号转导 在遗传易感神经表型的调节中起重要作用的通路。的 该项目具有科学和临床意义，因为它将导致对塑料的更深层次的欣赏， 神经系统受免疫系统控制的交互性，并有望提供有价值的 对未来预防和治疗与异常免疫相关的神经系统疾病的策略的见解 功能

PROJECT SUMMARY Local and systemic interactions between the nervous system and immune system play important roles in various physiological and pathological processes. The long-term goal of this project is to obtain a fundamental understanding of how neuroimmune communications contribute to the regulation of neural development, physiology, and behavior using an experimental model organism Drosophila melanogaster possessing the evolutionarily conserved innate immune system. The overall objective in this application is to reveal the roles and mechanisms of functional interactions between innate immune cells and the central nervous system in the modulation of neuronal excitability and behavioral hyperactivity in seizure-prone fly voltage-gated sodium (Nav) channel mutant, paraShu. The project is based on intriguing findings that: 1) paraShu adult seizure severity is significantly suppressed by diet supplemented with -3 polyunsaturated fatty acids (PUFAs) -linolenic acid (ALA); 2) hemocyte (macrophage-like blood cell)-specific knockdown of GstS1, a fly ortholog of mammalian prostaglandin D synthase, mimics the effect of dietary ALA; and 3) both dietary ALA and GstS1 knockdown are effective during development to suppress seizures in adult mutants. The central hypothesis is that the severity of adult paraShu is modulated through neural development by the action of innate immune cells in the biological processes involving bioactive lipid mediators. Two specific aims will be pursued to investigate the hypothesis: 1) Define the roles of hemocytes in modulation of neuronal excitability and behavioral hyperactivity in paraShu mutants; and 2) Identify genes and signaling pathways involved in hemocyte-dependent modulation of adult seizures. For the first aim, hemocyte functions will be genetically perturbed and the effects on neural development, electrophysiological properties, and seizure behavior will be examined in the presence or absence of phenotypic modifiers using freely moving or tethered behaving adult flies as well as dissociated primary neuronal cultures prepared from mutant larval brains. For the second aim, a candidate gene approach will be used to identify genes involved in putative lipid signaling processes, and lipidomics analysis will be carried out to determine the changes in oxylipins, lipid mediators produced from PUFAs, in the mutants in the presence or absence of phenotypic modifiers. The proposed multidisciplinary research is expected to reveal the roles of hemocytes in the diet-dependent modulation of neuronal excitability and behavioral seizures in Nav channel mutants, and provide novel genetic and molecular insights into the largely unexplored lipid signaling pathways that play important roles in the modulation of genetically predisposed neurological phenotypes. The project is scientifically and clinically significant because it will lead to a deeper appreciation of the plastic and interactive nature of the nervous system controlled by the immune system, and is expected to provide valuable insights into future strategies to prevent and treat nervous system disorders associated with aberrant immune function.