马晨珂, 吴宪, 徐哲, 刘健, 张纪岩, 史套兴*
慢性心理应激会导致机体多种功能紊乱，其中包括免疫力下降。慢性心理应激能够负调节免疫系统，但机制尚未完 全阐明。免疫细胞，包括髓系来源细胞，由骨髓造血干细胞(hematopoietic stem cell, HSC)分化而来，在机体免疫中发挥重要 作用。本实验采用短期高强度束缚和长期温和束缚慢性心理应激小鼠模型，探讨不同限制性束缚模式对小鼠骨髓HSC和髓 系来源细胞的影响。长期温和束缚模型中，对小鼠连续束缚4周，每天束缚2次，每次束缚2 h (9:00到17:00间完成)；短期高 强度束缚模型中，小鼠连续束缚5天，每天束缚16 h (当日17:00到次日9:00)。束缚完成后，取小鼠骨髓和外周血进行白细胞 计数，流式细胞术检测小鼠骨髓HSC (Lin−CD117+Sca1+CD150+CD48−)和髓系细胞(CD11b+Ly6C+)的比例和绝对数，以及外周 血髓系细胞的比例和绝对数，BrdU掺入实验检测小鼠HSC增殖能力。实验结果表明，长期温和应激导致小鼠骨髓HSC的比 例和绝对数增加，而短期高强度应激导致小鼠骨髓HSC的绝对数下降，伴有HSC的增殖下降。两种束缚模式都使小鼠骨髓 和外周血CD11b+Ly6C+细胞的总数增加或呈现增加的趋势。综上所述，长期温和应激和短期高强度应激对小鼠HSC的比例 和绝对数影响不同；两种应激模型都可以使CD11b+Ly6C+细胞总数增加，HSC增多可能并不是CD11b+Ly6C+细胞增多的主要机制。
Different effects of long-term and short-term repeated restraints on the hematopoietic stem cells in mice
MA Chen-Ke, WU Xian, XU Zhe, LIU Jian, ZHANG Ji-Yan, SHI Tao-Xing*
Institute of Military Cognition and Brain Sciences, Academy of Military Medical Sciences, Beijing 100850, China
Humans with chronic psychological stress are prone to develop multiple disorders of body function including impairment of immune system. Chronic psychological stress has been reported to have negative effects on body immune system. However, the underlying mechanisms have not been clearly demonstrated. All immune cells are derived from hematopoietic stem cells (HSC) in the bone marrow, including myeloid cells which comprise the innate immunity as a pivotal component. In this study, to explore the effects of chronic psychological stress on HSC and myeloid cells, different repeated restraint sessions were applied, including long-term mild restraint in which mice were individually subjected to a 2 h restraint session twice daily (morning and afternoon/between 9:00 and 17:00) for 4 weeks, and short-term vigorous restraint in which mice were individually subjected to a 16 h restraint session (from 17:00 to 9:00 next day) for 5 days. At the end of restraint, mice were sacrificed and the total cell numbers in the bone marrow and peripheral blood were measured by cell counting. The proportions and absolute numbers of HSC (Lin−CD117+Sca1+CD150+CD48−) and myeloid cells (CD11b+Ly6C+) were detected by fluorescence activated cell sorting (FACS) analysis. Proliferation of HSC was measured by BrdU incorporation assay. The results indicated that the absolute number of HSC was increased upon long-term mild restraint, but was decreased upon short-term vigorous restraint with impaired proliferation. Both long-term mild restraint and short-term vigorous restraint led to the accumulation of CD11b+Ly6C+ cells in the bone marrow as well as in the peripheral blood, as indicated by the absolute cell numbers. Taken together, long-term chronic stress led to increased ratio and absolute number of HSC in mice, while short-term stress had opposite effects, which suggests that stress-induced accumulation of CD11b+Ly6C+ myeloid cells might not result from increased number of HSC.
通讯作者：史套兴 E-mail: email@example.com
马晨珂, 吴宪, 徐哲, 刘健, 张纪岩, 史套兴. 长期和短期限制性束缚对小鼠造血干细胞的不同影响[J]. 生理学报 2020; 72 (2): 167-174.
MA Chen-Ke, WU Xian, XU Zhe, LIU Jian, ZHANG Ji-Yan, SHI Tao-Xing. Different effects of long-term and short-term repeated restraints on the hematopoietic stem cells in mice. Acta Physiol Sin 2020; 72 (2): 167-174 (in Chinese with English abstract).