Biomarkers in the HPA axis and inflammatory pathways for maladaptive stress response in children

下丘脑-垂体-肾上腺(HPA)轴的激活是对应激的一种适应性反应。但是，当 反复激活，可能会导致HPA轴失调。童年时期的压力改变了生物系统和 调节HPA轴和免疫反应的基因的表达持续了几十年。 压力还会增加患抑郁症和创伤后应激障碍的风险，这种风险会一直持续到成年。 两者都与自杀风险增加有关。然而，不同的神经内分泌特征 描述为抑郁症患者皮质醇增加和糖皮质激素受体(GR)反应性降低； PTSD患者皮质醇减弱，GR反应性增强。炎症，也与压力有关，是 据信是由于GR敏感性降低所致，可能是皮质醇长期升高的结果。还没有 炎症与抑郁症和创伤后应激障碍都有关联，显然这很难纠正。 GR反应性的不同模式。不一致的hpa轴剖面也不符合高压 这些疾病之间的共病比率。我们的首要目标是研究HPA轴的轨迹 和炎症途径对儿童压力的反应；以及确定预测 适应不良的应激反应。我们建议新招收200名12-17岁家长的孩子 在确诊(摄入)后3个月内被诊断为晚期癌症(压力)，并在6岁和6岁时进行随访 服药后18个月。这一群体将使我们能够研究压力反应的展开，这是 几乎不可能捕捉到其他压力源。我们还将招募和跟踪100名来自家庭的儿童 如果父母或兄弟姐妹没有患癌症或慢性病或死亡(对照)。我们建议测量 HPA轴和炎症途径中的基因表达；头发皮质醇浓度(HCC)测量 慢性HPA轴活动；唾液皮质醇测量皮质醇唤醒反应(CAR)；GR敏感性；C- 反应蛋白和炎性细胞因子；并收集临床数据。我们假设在三个月内 父母诊断，应激儿童会表现出HPA轴和炎症基因的表达增加 与对照组相比，肝细胞癌、CAR和炎症标志物增加；但GR敏感性没有差异。在……里面 对慢性应激的反应，应激儿童会表现出HPA轴基因表达减少，GR增强 与对照组相比，随着时间的推移，肝细胞癌和CAR呈下降趋势。他们还将继续展示 炎症基因表达增加和炎症。早期的生物反应及其 轨迹将预测症状学(抑郁症、创伤后应激障碍和自杀意念)和抑郁症的发生以及 创伤后应激障碍；这些关系将受到预先存在的和正在进行的脆弱性和保护性的影响 各种因素。这项研究将促进我们对神经生物学、环境和行为的理解 儿童应激反应的途径及其对精神疾病易感性的影响。它还将导致 在儿童早期发出风险信号的生物标记物，可以作为早期预防和干预的目标。

Activation of the hypothalamic-pituitary-adrenal (HPA) axis is an adaptive response to stress. However, when repeatedly activated, HPA axis dysregulation can result. Stress in childhood alters biological systems and the expression of genes regulating HPA axis and immune responses in a manner that persists across decades. Stress is also associated with increased risk for depression and PTSD, a risk that continues into adulthood, and both are associated with increased risk for suicidality. However different neuroendocrine profiles are described with increased cortisol and reduced glucocorticoid receptor (GR) responsiveness in depression; and attenuated cortisol and enhanced GR responsiveness in PTSD. Inflammation, also associated with stress, is believed to result from reduced GR sensitivity, possibly as a result of chronically elevated cortisol. Yet inflammation is associated with both depression and PTSD, which is difficult to rectify with their apparently differential pattern of GR responsiveness. The discrepant HPA axis profiles also do not conform with the high comorbidity rate between these disorders. Our overarching goal is to examine the trajectories of the HPA axis and inflammatory pathways in response to stress in children; and identify biological trajectories that predict maladaptive stress responses. We propose to recruit 200 children, aged 12-17 years, of parents newly diagnosed with advanced stage cancer (stress) within 3 months of diagnosis (intake) and follow them at 6 and 18 months following intake. This population will allow us to study the unfolding of stress responses, which is almost impossible to capture for other stressors. We will also recruit and follow 100 children from families where a parent or siblings do not have cancer or chronic illness or death (controls). We propose to measure gene expression in the HPA axis and inflammatory pathways; hair cortisol concentrations (HCC) to measure chronic HPA axis activity; salivary cortisol to measure cortisol awakening response (CAR); GR sensitivity; C- Reactive Protein and inflammatory cytokines; and collect clinical data. We hypothesize that within 3 months of parental diagnosis, stress children will show increased expression of HPA axis and inflammatory genes and increased HCC, CAR, and inflammatory markers compared to controls; but no differences in GR sensitivity. In response to chronic stress, stress children will show decreased expression of HPA axis genes, enhanced GR sensitivity, and decreased HCC and CAR over time compared to controls. They will also continue to show increased expression of inflammatory genes and inflammation. Biological responses early on and their trajectories will predict symptomatology (depression, PTSD, and suicidal ideation) and onset of depression and PTSD; and these relationships will be influenced by pre-existing and ongoing vulnerability and protective factors. This study will advance our understanding of the neurobiological, environmental, and behavioral pathways of stress responses in children and its impact on liability to psychiatric illness. It will also result in biomarkers that signal risk in children early on and can be targeted by early preventions and interventions.