基于CX3CL1/CX3CR1/BDNF通路介导小胶质细胞活化研究慢性心理应激神经元损伤的分子机制与枸杞多糖的干预作用

Stress is closely related to the pathogenesis of a variety of neurological and psychiatric disorders, and which involves inflammation and immune system responses through the whole regulation of stress damage, repair always. ..Stress is the microglia modulating involved neuron damage in CNS, and the process that the inflammatory reaction and immune system responses regulation is participated all around...Complementary expression of CX3CL1 on neurons and CX3CR1 on microglia establishes a unique communication system whereby neurons constitutively express and release CX3CL1 to regulate activation of microglia in psychological stress process...How to implement regulation of microglia to produce pharmacological effects of drugs is still unclear. But considered relevant to inhibit the activation of Microglia is well established...CX3CL1/CX3CR1 signaling pathway is an important signal pathway regulation of Microglia activate the central nervous system. It is closely related to the pathophysiological process of stress - related diseases and is an important target for drug therapy...Lycium barbarum polysaccharide（LBP ) is the major extract from Tradition Chinese Medicine Wolfberry(or Lycium barbarm, Solanaceae). It has a variety of pharmacological action on immune enhancement and Neuroprotection effect...In this study, we will employ the chronic unpredicted mild stress (CUMS) as the animal model and lipopolysaccharide（LPS）-induced neuroinflammation in BV2 microglial cells as an in vitro model in neuroprotective research of the LBP. ..Combing behavior pharmacological method, biochemical method , BrdU labeling, siRNA interference method and biology and bioinformatics, we will evaluate the neuroprotective effect of LBP and reveal the functional role in neuroprotective area of the functional extract Lycium barbarum polysaccharide from Ningxia Wolfberry, and we also attempt to unravel its mechanisms of the neuron protection in molecular level by modulating the CX3CL1/CX3CR1/BDNF signaling pathway.

慢性心理应激与多种神经、精神系统疾病密切相关。小胶质细胞在应激下中枢炎性反应及免疫系统应答调控中具有重要作用。应激过程中神经元分泌的不规则趋化因子 (CX3CL1)与小胶质细胞的膜受体（CX3CR1）结合，对其产生适应性调节的同时，实现二者在相关炎症反应中交互作用。而这一信号途径的异常调控是慢性应激及其相关疾病病理生理发生的重要原因和药物治疗的靶标。枸杞多糖（LBP）是中药材枸杞的主要功能成分，具有免疫增强和神经保护等多种药理作用。本研究拟采用小鼠慢性不可预见性温和应激模型（CUMS）、脂多糖（LPS）诱导BV2细胞活化的体外神经炎症模型。通过行为药理学、siRNA干扰技术、BrdU标记、分子生物学技术、生物信息学等，从整体-细胞水平进行观察，以期阐明LBP通过对CX3CL1/CX3CR1/BDNF信号转导通路的调控，实现对慢性应激导致小胶质细胞活化的抑制和对神经元损伤保护作用的分子机制。

项目研究计划，主旨以小胶质细胞为靶标，探讨小胶质细胞激活后极化表型调控在慢性心理应激所致中枢炎症反应对实验动物抑郁、焦虑行为及学习记忆的影响，并探讨宁夏道地药材枸杞子（Wolfberry；Lycium barbarm, Solanaceae）活性成分枸杞多糖 (Lycium barbarum polysaccharide, LBP )的保护作用及作用机制。.项目实施过程中，建立小鼠慢性应激模型、脂多糖诱导急性炎性模型及小胶质细胞炎性模型，以CX3CL1/CX3CR1/ NF-kB 信号通路为靶向分子，利用行为药理学、组织形态学及分子生物学方法，从整体-细胞水平进行了研究。结果初步揭示了，枸杞多糖对中枢海马脑区中小胶质细胞极化表型状态的调控，可能参与其对慢性应激损伤的保护作用；其次，枸杞多糖对LPS引起的体外小胶质细胞神经炎症反应的保护作用可能涉及TLR4/NF-κB 通路介导的小胶质细胞的极化调控有关。 .在研究过程中，我们发现“以LPS诱导小鼠抑郁样行为模型”的研究，是近年关于心理应激所致中枢炎症反应造成实验动物抑郁、焦虑行为及学习记忆损害的重要手段。故此，我们在建模的基础上，着重开展基于急性炎症相关机制介入枸杞干预慢性心理应激损伤研究研究。我们应用脂多糖（LPS）诱导小鼠急性炎症模型，还揭示枸杞多糖对中枢海马脑区中小胶质细胞极化表型状态的调控，可能参与其对脂多糖诱导小鼠急性炎症损伤的保护作用。且机制涉及CX3CL1/CX3CR1/ NF-κB信号通路的调控。.上述结果提示，枸杞子及其多糖提取部位可能作为功能食品，在慢性心理应激（Chronic Psychological Stress）引起的诸多亚健康状态的预防和干预具有一定的应用前景。同时，为宁夏道地药材枸杞子的开发利用提供了新的视角和药理学理论依据。