Moshfegh Cassandra M, Elkhatib Safwan K, Collins Christopher W, Kohl Allison J, Case Adam J
Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, NE, United States.
Front Behav Neurosci. 2019 May 14;13:103. doi: 10.3389/fnbeh.2019.00103. eCollection 2019.
Patients diagnosed with post-traumatic stress disorder (PTSD) are at a significantly elevated risk of developing comorbid inflammatory conditions, but the mechanisms underlying this predilection remain unclear. Our previous work has shown that T-lymphocytes exposed to elevated levels of norepinephrine (NE) displayed a pro-inflammatory signature reminiscent of an autoreactive phenotype. With this, we hypothesized that the increased sympathetic tone observed during psychological trauma may be promoting pro-inflammatory T-lymphocytes, which causes a predisposition to comorbid inflammatory conditions. Here, we examined the consequences of psychological trauma on splenic T-lymphocytes using a mouse model of repeated social defeat stress. Social defeat led to anxiety-like and depression-like behavior as has been previously described. The spleens of socially-defeated mice showed significant elevations of NE, tyrosine hydroxylase (TH), and acetylcholinesterase (ACHE) levels, which appeared to be due in part to increased expression within T-lymphocytes. Additionally, T-lymphocytes from stressed animals showed higher levels of pro-inflammatory cytokines and mitochondrial superoxide. Interestingly, in this model system, close associations exist within splenic T-lymphocytes amid the autonomic, inflammatory, and redox environments, but these only weakly correlate with individual behavioral differences among animals suggesting the psychological and physiological manifestations of trauma may not be tightly coupled. Last, we describe, for the first time, elevations in calprotectin levels within T-lymphocytes and in circulation of psychologically stressed animals. Calprotectin correlated with both behavioral and physiological changes after social defeat, suggesting the potential for a new biological marker and/or therapeutic target for psychological trauma and its inflammatory comorbidities.
被诊断患有创伤后应激障碍(PTSD)的患者发生合并炎症性疾病的风险显著升高,但其背后的机制尚不清楚。我们之前的研究表明,暴露于高水平去甲肾上腺素(NE)的T淋巴细胞表现出一种促炎特征,类似于自身反应性表型。据此,我们推测,心理创伤期间观察到的交感神经张力增加可能会促进促炎性T淋巴细胞的产生,从而导致易患合并炎症性疾病。在这里,我们使用重复社会挫败应激小鼠模型研究了心理创伤对脾T淋巴细胞的影响。社会挫败导致了如先前所述的焦虑样和抑郁样行为。遭受社会挫败的小鼠脾脏中NE、酪氨酸羟化酶(TH)和乙酰胆碱酯酶(ACHE)水平显著升高,这似乎部分归因于T淋巴细胞内表达的增加。此外,应激动物的T淋巴细胞显示出更高水平的促炎细胞因子和线粒体超氧化物。有趣的是,在这个模型系统中,脾T淋巴细胞在自主神经、炎症和氧化还原环境之间存在密切关联,但这些关联与动物个体行为差异仅呈弱相关,这表明创伤的心理和生理表现可能没有紧密联系。最后,我们首次描述了心理应激动物T淋巴细胞内和循环中钙卫蛋白水平的升高。钙卫蛋白与社会挫败后的行为和生理变化相关,这表明它有可能成为心理创伤及其炎症合并症的一种新的生物标志物和/或治疗靶点。