Lack of social contacts could induce psychiatric features and lead to various behavioral and neurochemical abnormalities in rodents. Social isolation stress (SIS) is a valid paradigm of depressive- and anxiety-like behaviors in animals. It has demonstrated that psychiatric disorder could affect the peripheral blood population of very small embryonic-like stem cells (VSELs). The aim of the current study is to evaluate the role of VSELs in behavioral impairments induced by SIS through neuroinflammation in mice. Behavioral experiments were evaluated by using forced swimming test (FST), open field test (OFT), and splash test in male NMRI mice. In addition, plasma and bone marrow samples, as well as hippocampus, were collected to evaluate the population of VSELs, nitrite level, and inflammatory cytokines by using flow cytometry and ELISA. Behavioral tasks showed that SIS could induce depressive- and anxiety-like behaviors in mice. Data obtained from flow cytometry showed that VSELs significantly increased in socially isolated animals in bone marrow, peripheral blood, and hippocampus. Also, TNF-α, IL-1β, and IL-6 significantly increased in hippocampal and plasma samples in socially isolated animals. Correlation analysis indicated that mice with higher VSELs counts have better results in behavioral tasks, and lower pro-inflammatory cytokines as well as nitrite level in mice. In conclusion, VSELs could be used as a biological marker to enhance diagnostic accuracy as well as predicting the prognosis. Also, increment in the VSELs counts might decrease the neuro-inflammation and subsequently improve the behavioral impairments induced by SIS.

缺乏社交接触可能会诱发精神病特征，并导致啮齿动物的各种行为和神经化学异常。社会孤立压力 (SIS) 是动物抑郁和焦虑样行为的有效范式。已经证明，精神疾病可能会影响非常小的胚胎样干细胞 (VSEL) 的外周血群。当前研究的目的是评估 VSEL 在 SIS 通过小鼠神经炎症诱导的行为障碍中的作用。通过在雄性 NMRI 小鼠中使用强迫游泳试验 (FST)、露天试验 (OFT) 和飞溅试验来评估行为实验。此外，收集血浆和骨髓样本以及海马体以通过使用流式细胞术和 ELISA 评估 VSEL 的数量、亚硝酸盐水平和炎性细胞因子。行为任务表明，SIS 可以诱导小鼠的抑郁和焦虑样行为。从流式细胞术获得的数据显示，在社会隔离动物的骨髓、外周血和海马中，VSEL 显着增加。此外，在社会隔离动物的海马和血浆样本中，TNF-α、IL-1β 和 IL-6 显着增加。相关性分析表明，具有较高 VSELs 计数的小鼠在行为任务中具有更好的结果，并且小鼠的促炎细胞因子和亚硝酸盐水平较低。总之，VSEL 可用作生物标志物，以提高诊断准确性以及预测预后。此外，VSELs 计数的增加可能会减少神经炎症，并随后改善 SIS 引起的行为障碍。