POST-EXERCISE ION CHANNEL GENE EXPRESSION BIOMARKERS IN CFS

描述(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记物来诊断或临床处理症状。直到最近，感知肌肉疲劳和疼痛的外周过程还不清楚；然而，我们团队和其他人进行的动物模型研究已经澄清，离子通道受体(包括酸敏感离子通道3或ASIC3，ATP敏感嘌呤能2X或P2X，以及TRPV1或辣椒素受体)的复合体可以检测肌肉工作中增加的代谢副产物(ATP、乳酸和pH变化)。这些离子通道受体的数量不是固定的，但可以随着炎症过程或运动的反应而显着增加。在R21拨款的支持下，我们完成了第一项翻译研究，显示在中等运动25分钟(年龄预测的最大心率的70%)后，CFs中这些受体的调节失调。使用运动后0.5至48小时的血液样本，CFS患者而不是健康对照组显示，存在于白细胞上的这些疲劳感知离子通道受体的表达迅速和持续增加，以及肾上腺素能α-2a、β-1和β-2受体以及促炎和抗炎细胞因子的增加(Light等人，2009年；White等人，2010年)。我们最近还发现，这种运动后基因表达谱明显地将CFS患者与多发性硬化症或纤维肌痛患者区分开来。这项研究将在我们现有的178名受试者数据库中增加140名受试者(包括70名CFS患者)，其中包括50名CFS患者和50名对照组，所有受试者都使用相同的中等强度运动挑战，在运动前和运动后4次采集血液。我们计划使用全基因组微阵列和带有靶向基因的qPCR，包括离子通道和肾上腺素能受体、免疫基因，以及包括XPR1、神经肽Y、HPA轴受体和转录因子在内的几个新基因。我们的目的是检验是否：1)使用严格的生物标记物评估标准，使用我们的运动后基因表达谱可以明显区分CFS患者和健康对照组；2)CFS患者也不同于患有严重抑郁障碍的患者和有癌症相关疲劳的前列腺癌患者；3)这些图谱可靠地区分CFS的女性和男性，以及通过运动后α-2a肾上腺素能受体表达增加和减少确定的CFS患者亚组。这项研究将为这些基因表达指标作为CFS整体和关键亚组的诊断生物标记物提供强有力的测试。这也将为进一步研究可能引发、维持或恶化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的靶点。

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.