Non-canonical NF-kappaB signaling and Sur1-Trpm4 in traumatic brain injury

背景：创伤性脑损伤（TBI）是神经精神疾病发展的主要危险因素 受伤后很长时间的问题，对生活质量产生负面影响。以前在TBI动物模型中的工作 反复表明，不良的神经行为后遗症，包括认知功能障碍，焦虑， 抑郁样症状与涉及小胶质细胞的慢性先天免疫反应有关， 星形胶质细胞尽管它在涉及大多数器官的许多炎症性疾病中的重要性已有记录 令人惊讶的是，包括脑，非经典NF-κ B信号传导（p52：RelB）尚未被鉴定 以前在TBI。我们实验室的新工作证明了非经典NF-κ B 肿瘤坏死因子样细胞凋亡弱诱导剂（TWEAK）的信号传导在TBI中很突出，尤其是在 星形胶质细胞，并持续数月。新的工作还确定了一个新的非经典NF-κ B下游靶点， kappaB -Sur 1-Trpm 4通道。Sur 1-Trpm 4以前与血脑屏障功能障碍有关，但 而不是脑外伤后星形胶质细胞功能或脑外伤后神经行为缺陷。初步数据显示，TWEAK- 诱导的非经典NF-κ B信号在TBI后1个月内进行性上调， 负责星形胶质细胞中Sur 1-Trpm的转录表达。此外，我们的初步数据表明， 星形胶质细胞的Sur 1-Trpm 4在调节下游细胞的表达中起着至关重要的作用， 趋化因子/离子型效应物，趋化因子（C-C基序）配体2（CCL 2），与炎症有关， 脑外伤后的神经行为缺陷阐明TWEAK、Sur 1-Trpm 4和CCL 2的病理三联体 星形胶质细胞的研究将建立非典型NF-κ B在TBI中的作用，并将鉴定新的，可药用的 目标是解决创伤后神经行为异常。越来越多的人对 非典型的NF-κ B信号传导有望突出用于选择性靶向的新的治疗策略。 描述：在目的1中，使用格列本脲沿着星形胶质细胞特异性 在雄性和雌性的两种TBI小鼠模型中缺失Abcc 8/Sur 1，我们将确认我们的试验数据 显示非典型的NF-κ B信号传导、Sur 1-Trpm 4表达和CCL 2表达是共同的。 存在于TBI后体内星形胶质细胞中，并且CCL 2表达和神经行为明确地与TBI相关。 星形胶质细胞Sur 1。在目标2中，我们将证实并扩展来自大脑的体内和体外初步数据， 输注TWEAK、染色质免疫沉淀和膜片钳，以确定非经典NF-κ B的作用。 kappaB在功能性Sur 1-Trpm 4通道表达中的作用。在目标3中，我们将扩展体内和体外 建立Sur 1-Trpm 4在调节Ca 2+依赖性基因转录中的作用的初步数据， 下游趋化因子/亲离子效应物，CCL 2通过活化的T细胞的核因子。这个项目，第一个 研究TBI中的非经典NF-κ B信号传导及其在Sur 1-Trpm 4表达中的作用， 确定新的、可药物治疗的靶点，以解决TBI后认知功能障碍、焦虑和抑郁。

BACKGROUND: Traumatic brain injury (TBI) is a major risk factor for the development of neuropsychiatric problems long after injury that negatively impact quality-of-life. Previous work in animal models of TBI has repeatedly shown that adverse neurobehavioral sequelae, including cognitive dysfunction, anxiety, and depression-like symptoms are associated with chronic innate immune responses involving microglia and astrocytes. Despite its documented importance in numerous inflammatory conditions involving most organs including the brain, surprisingly, non-canonical NF-kappaB signaling (p52:RelB) has not been identified previously in TBI. New work from our laboratory demonstrates the novel finding that non-canonical NF-kappaB signaling by tumor necrosis factor-like weak inducer of apoptosis (TWEAK) is prominent in TBI, especially in astrocytes, and persists for months. New work also identifies a novel downstream target of non-canonical NF- kappaB -- the Sur1-Trpm4 channel. Sur1-Trpm4 previously was linked to blood-brain barrier dysfunction, but not to post-TBI astrocyte function or post-TBI neurobehavioral deficits. Our preliminary data show that TWEAK- induced non-canonical NF-kappaB signaling is upregulated progressively during 1 month post-TBI, and may be responsible for transcriptional expression of Sur1-Trpm in astrocytes. Moreover, our preliminary data suggest that astrocytic Sur1-Trpm4 plays a crucial role in regulating the expression of the downstream chemokine/ionotropic effector, chemokine (C-C motif) ligand 2 (CCL2), implicated in inflammation and neurobehavioral deficits post-TBI. Elucidating the pathological triad involving TWEAK, Sur1-Trpm4 and CCL2 in astrocytes will establish the role of non-canonical NF-kappaB in TBI, and will identifying novel, drugable targets to address post-TBI neurobehavioral abnormalities. An increasingly sophisticated understanding of non-canonical NF-kappaB signaling promises to highlight novel therapeutic strategies for selective targeting. DESCRIPTION: In Aim 1, using delayed (day-3) administration of glibenclamide along with astrocyte-specific deletion of Abcc8/Sur1 in two mouse models of TBI in males and females, we will confirm our pilot data showing that non-canonical NF-kappaB signaling, Sur1-Trpm4 expression and CCL2 expression are co- present in astrocytes in vivo post-TBI, and that CCL2 expression and neurobehavior are explicitly linked to astrocytic Sur1. In Aim 2, we will corroborate and expand upon in vivo and in vitro preliminary data from brain infusion of TWEAK, chromatin immunoprecipitation, and patch clamp to establish the role of non-canonical NF- kappaB in the expression of functional Sur1-Trpm4 channels. In Aim 3, we will expand upon in vivo and in vitro preliminary data to establish the role of Sur1-Trpm4 in regulating Ca2+-dependent gene transcription of the downstream chemokine/ionotropic effector, CCL2 via nuclear factor of activated T cells. This project, the first to examine non-canonical NF-kappaB signaling in TBI and its role in Sur1-Trpm4 expression, is expected to identify novel, drugable targets to address post-TBI cognitive dysfunction, anxiety, and depression.