POST-EXERCISE ION CHANNEL GENE EXPRESSION BIOMARKERS IN CFS

描述（由申请人提供）：慢性疲劳综合征（CFS）是一种复杂的多症状疾病，缺乏客观的血液生物标志物用于症状的诊断或临床管理。直到最近，参与感知肌肉疲劳和疼痛的外周过程尚不清楚；然而，我们和其他人的动物模型研究表明，离子通道受体的复合物（包括酸感应离子通道3或ASIC3， ATP感应嘌呤能2X或P2X，以及TRPV1或辣椒素受体）共同作用可以检测肌肉中代谢副产物（ATP，乳酸和pH值变化）的增加。这些离子通道受体的数量不是固定的，但可以在炎症过程或运动的反应中显着增加。在R21基金的支持下，我们完成了第一项转化研究，显示在25分钟的适度运动（以年龄预测最大心率的70%）后，这些受体在CFS中出现失调。在运动后0.5至48小时的血液样本中，CFS患者而非健康对照显示，白细胞上存在的这些疲劳感知离子通道受体的表达迅速而持续地增加，肾上腺素能α -2a、β -1和β -2受体以及促炎性和抗炎性细胞因子的表达也增加（Light等，2009；White等，2010）。我们最近还发现，这种运动后基因表达谱可以清楚地将CFS患者与没有合并CFS的多发性硬化症或纤维肌痛患者区分开来。本研究将在现有178名受试者的基础上再增加140名受试者（包括70名CFS患者），其中包括50名CFS患者和50名对照者，所有受试者都使用相同的适度运动挑战，在运动前和运动后分别进行4次血液采样。我们计划使用全基因组微阵列和qPCR结合靶基因，包括离子通道和肾上腺素能受体、免疫基因，以及一些新的基因，包括XPR1、神经肽Y、HPA轴受体和转录因子。我们的目的是研究：1)使用严格的STARD生物标志物评估标准，通过我们的运动后基因表达谱是否可以将CFS患者与健康对照明显区分开来；2)CFS患者也与重度抑郁症患者和前列腺癌患者有癌症相关疲劳；3)这些特征可靠地区分女性和男性CFS，以及通过运动后α -2a肾上腺素能受体表达的增加和减少来识别CFS患者亚组。这项研究将为这些基因表达测量作为CFS整体和关键亚组的诊断生物标志物提供强有力的测试。这也将为进一步研究可能引发、维持或加重CFS症状的失调通路奠定基础，并为有效的治疗干预提供潜在靶点。

DESCRIPTION (provided by applicant): Chronic fatigue syndrome (CFS) is a complex multisymptom disorder that lacks objective blood-based biomarkers to use in diagnosis or clinical management of symptoms. Until recently, the peripheral processes involved in sensing muscle fatigue and pain were unknown; however, animal model studies by our group and others have clarified that a complex of ion channel receptors (including Acid Sensing Ion Channel-3 or ASIC3, ATP-sensing Purinergic 2X or P2X, and TRPV1 or capsaicin receptors) working together can detect increased metabolic by-products of work in muscle (ATP, lactate and pH changes). The numbers of these ion channel receptors are not fixed but can increase markedly in response to inflammatory processes or exercise. Supported by an R21 grant, we completed the first translational study to show dysregulation of these receptors in CFS after 25 min of moderate exercise (at 70% of age-predicted maximum heart rate). Using blood samples from 0.5 through 48 hours after exercise, CFS patients but not healthy controls showed both rapid and sustained increases in expression of these fatigue-sensing ion channel receptors present on leukocytes, together with increases in adrenergic alpha-2a, beta-1 and beta-2 receptors, and of both pro- and anti-inflammatory cytokines (Light, et al., 2009; White et al, 2010). We also recently showed that this post-exercise gene expression profile clearly differentiated patients with CFS from those with multiple sclerosis or fibromyalgia without comorbid CFS. The present study will add 140 additional subjects (including 70 CFS patients) to our existing database of 178 subjects that already includes 50 CFS patients and 50 controls, all studied using the same moderate exercise challenge, with blood sampling before and at 4 times after exercise. We plan to use both full genomic microarrays plus qPCR with targeted genes including ion channel and adrenergic receptors, immune genes, plus several new genes including XPR1, neuropeptide Y, HPA axis receptors, and transcription factors. Our aims are to examine whether: 1) using stringent STARD criteria for biomarker evaluation, CFS patients can be clearly differentiated from healthy controls using our post-exercise gene expression profiles, 2) CFS patients also differ from patients with major depressive disorder and patients with prostate cancer who have cancer-related fatigue; 3) these profiles reliably differentiate women vs. men with CFS, and subgroups of CFS patients identified by post-exercise increases vs. decreases in alpha-2a adrenergic receptor expression. This investigation will provide a strong test of these gene expression measures as diagnostic biomarkers in CFS as a whole and in key subgroups. It will also lay a foundation for further translational research on dysregulated pathways that may initiate, maintain or worsen symptoms of CFS, and provide potential targets for effective therapeutic intervention.