Brain mast cells and Chronic Fatigue Syndrome

描述（由申请人提供）：慢性疲劳综合征（CFS）是一种复杂的疾病，患病率高达1%。慢性疲劳综合症涉及神经、荷尔蒙和免疫系统，其症状包括疲劳、睡眠障碍、不适、肌肉疼痛、偏头痛、胃肠道不适和认知问题。慢性疲劳综合症患者可能存在一些线粒体“功能障碍”。许多CFS患者表现出异常的下丘脑-垂体-肾上腺（HPA）轴活动，而压力使症状恶化。中枢和外周细胞因子产生应答病毒感染或其他炎症刺激可能涉及，但没有明显的模式。慢性疲劳综合症通常与纤维肌痛、间质性膀胱炎（1C）、肠易激综合征（IBS）、偏头痛和创伤后应激障碍等其他疾病共病。神经免疫在慢性疲劳综合症中的相互作用仍是未知的，这在诊断和治疗方面造成了真空。肥大细胞及其介质与CFS共病的所有疾病都有关系。脑肥大细胞大量存在于正中隆起，与促肾上腺皮质激素释放激素（CRH）阳性的神经元并存，CRH在应激下分泌，我们发现CRH通过CRHR-1激活肥大细胞，导致血管内皮生长因子（VEGF）的释放，增加血管通透性和血脑屏障（BBB）的破坏。我们最近发现了线粒体解偶联蛋白2 （UCP2）的表达与肥大细胞活化之间的反比关系，UCP2也调节活性氧（ROS）和胞质钙的产生。慢性疲劳综合症没有有效的治疗方法。据报道，三环类抗抑郁药是有益的，我们的初步结果表明，只有三环阿米替林和某些天然类黄酮可以抑制肥大细胞分泌，降低细胞内钙离子水平。我们的假设是，外部触发因素，以及由压力分泌的CRH，激活间脑中枢和肥大细胞，导致促炎和疲劳产生分子的释放，这些可以被选择的类黄酮抑制。我们将研究：(1)CRH、病毒聚（l:C）、脂多糖（LPS）、神经紧张素（NT）、P物质（SP）和胸腺基质淋巴生成素（TSMP）或约束应激对雌性C57BL/6小鼠的影响：(a)使用强迫水浸泡测试疲劳，(b)通过测量荧光标记物AngioSense的脑水平测量血脑屏障破坏，以及(c)脑组织中组氨酸脱羧酶（HDC）、CRN、β -内啡肽、IL-6、IL- 8、IL-17、生长抑素、TNF、小鼠肥大细胞蛋白酶（MMCP）、尿皮质素2、UCP2和VEGF的表达；(2)利用c57bl来源的WW肥大细胞缺陷小鼠、NT -/-小鼠、SP -/-小鼠、CRHR-1研究了Aim 1中肥大细胞、NT、SP、相关CRHR的需求，以及UCP2在终点中的作用；(3)木犀草素/槲皮素/橄榄仁油类黄酮制剂对耐力和脑生物标志物的抑制作用。拟议的研究是假设驱动的，基于强有力的初步证据，具有创新性，极有可能获得适用于人类的新发现。

DESCRIPTION (provided by applicant): Chronic Fatigue Syndrome (CFS) is a complex disease with a prevalence as high as 1%. CFS involves the nervous, hormonal and immune systems with symptoms that include fatigue, sleep disturbances, malaise, muscle aches, migraines, gastrointestinal complaints and cognitive problems. There may be some mitochondrial "dysfunction" in CFS patients. Many CFS patients demonstrate abnormal hypothalamic-pituitary- adrenal (HPA) axis activity, while stress worsens symptoms. Central and peripheral cytokines produced in response to viral infections or other inflammatory stimuli may be implicated, but there is no distinct pattern. CFS is often comorbid with other disorders that include fibromyalgia, interstitial cystitis (1C), irritable bowel syndrome (IBS), migraines and post-traumatic stress disorder. Neuroimmune interactions in CFS are still unknown creating a vacuum in diagnosis and treatment. Mast cells and their mediators have been implicated in all diseases that are comorbid with CFS. Brain mast cells are abundant in the median eminence where they are juxtaposed to corticotropin-releasing hormone (CRH)-positive neurons and CRH is secreted under stress and we showed that CRH activates mast cells through CRHR-1 leading to release of vascular endothelial growth factor (VEGF), increased vascular permeability and blood-brain-barrier (BBB) disruption. We recently showed an inverse relationship between expression of the mitochondrial uncoupling protein 2 (UCP2), which also regulates production of reactive oxygen species (ROS) and cytosolic calcium, and mast cell activation. There are no effective therapies for CFS. Tricyclic antidepressants have been reported to be beneficial, and our preliminary results indicate that only the tricyclic amitriptyline, and certain natural flavonoids can inhibit mast cell secretion and reduce intracellular calcium ion levels. Our hypothesis is that external triggers, along with CRH secreted by stress, activate diencephalic centers and mast cells, leading to release of proinflammatory and fatigue producing molecules, and these can be inhibited by select flavonoids. We will investigate: (1) the effect of CRH, viral poly(l:C), lipopolysaccharide (LPS), neurotensin (NT), substance P (SP) and thymus stromal lymphopoietin (TSMP) or restraint stress using female C57BL/6 mice on: (a) Fatigue using the forced water immersion test, (b) BBB disruption by measuring brain levels of the fluorescent marker AngioSense, as well as (c) Brain expression of histidine decarboxylase (HDC), CRN, beta-endorphin, IL-6, IL- 8, IL-17, somatostatin, TNF, mouse mast cell protease (MMCP), urocortin 2, UCP2 and VEGF; (2) The requirement for mast cells, for NT, SP, the CRHR involved, and the role of UCP2 in the endpoints studied in Aim 1 by using C57BL-derived WW mast cell deficient mice, NT -/- mice, SP -/- mice, CRHR-1; CRHR-2 -/- and UCP2 -/- mice, (3) Inhibitory effect of a flavonoid formulation containing luteolin/quercetin/olive kernel oil on endurance and brain biomarkers. The proposed research is hypothesis-driven, is based on strong preliminary evidence, is innovative with high likelihood for novel findings with applicability to humans. PUBLIC HEALTH RELEVANCE: Chronic Fatigue Syndrome (CFS) is neuroimmunoendocrine disorder with no definite pathogenesis or curative therapy presently available. Recent evidence suggests that CFS may be related to activation of a unique immune cell, the mast cell, which could disrupt gut-blood-brain barrier and lead to brain inflammation and release of fatigue causing molecules. The proposed research is expected to advance our understanding of how activation of brain mast cells can contribute to inflammation and CFS, as well as to the development of novel and effective treatments.