不同光制对小鼠外周血免疫细胞近日节律的导引研究

Entrainment of different light regimens on the circadian rhythm of peripheral blood immune cells in mice

目的 探讨不同光制对小鼠外周血免疫细胞近日节律的影响.方法 将144只雄性C57BL/6小鼠置于每12 h的光暗循环条件下饲养4周,按随机数表法将小鼠随机分为3组,第1组：24只保持原来的光制;第2组：60只,模拟向东飞行位相提前12 h;第3组：60只,模拟向西飞行位相延迟12 h.第1组在改变光制前1 d和改变光制后第21天进行外周血采样,第2、3组在改变光制后的不同天数（第2、4、7、14、21天）进行外周血采样.在一昼夜的4个时间点（9：00、15：00、21：00、3：00）进行外周血取样.检测外周血相关的免疫组分,包括白细胞总数、淋巴细胞百分比、CD4＋淋巴细胞百分比、CD8＋淋巴细胞百分比、单核细胞及中性粒细胞计数,观察相关免疫细胞近日节律的变化.结果C57BL/6小鼠置于每12 h的光暗循环条件下饲养4周后,各免疫组分呈现不同的近日节律.随后在新光制下,外周血各免疫组分原有的近日节律发生了导引,模拟向西位相延迟组各免疫细胞的近日节律导引速度为2周,而模拟向东位提前组各免疫细胞的近日节律导引速度为3周.结论 在每 12 h 光暗循环条件下,小鼠外周血的各免疫组分存在此消彼长的现象,借此来维持免疫系统的平衡. 在新光制条件下,各免疫组分的近日节律受到了导引,相延迟组的免疫细胞近日节律导引速度快于位相提前组.

Objective To explore the entrainment effect of different light regimens on the circadian rhythms of peripheral blood immune cells in mice .Methods One hundred and forty-four male C57BL/6 mice were kept under the 12 h-light and 12 h-dark cycle for 4 weeks.Then, the animals were randomly divided into 3 groups.The 24 animals in group 1 were treated with the former light regimen , the 60 animals in group 2 were kept in the light regimen of phase advance 12 hours, simulating eastward flight, and another 60 animals in group 3 were kept in the light regimen of phase delay 12 hours, simulating westward flight.Peripheral blood samples of the animals in group 1 were collected respectively one day before and 21 days after changes of light regimens, and blood samples of the animals in group 2 and 3 were collected on different days （i.e.day 2, 4, 7, 14 and 21） after changes of light regimens .Peripheral blood samples were taken at 4 different timepoints in 24 hours （ i.e.9 ：00, 15：00, 21 ：00 and 3 ：00）.Detections were made in immune cells , including the numbers of leukocytes, the percentage of lymphocytes , the percentage of CD4 ＋lymphocytes, the percentage of CD8 ＋lymphocytes, as well as monocyte and granulocyte counts .Finally, the circadian rhythms of differentimmune cells were evaluated in the animals of different groups .Results The immune cells in the C57BL/6 mice displayed different circadian rhythms under the 12 h-light and 12 h-dark cycle for 4 weeks.Under the new light regimens, the circadian rhythms of immune cells were entrained .It took 2 weeks for the animals of the simulated westward flight phase delay group to entrain the circadian rhythm , while the rate of entrainment for the animals of the simulated eastward flight phase delay group was 3 weeks.Conclusions Under the 12 h-light and 12 h-dark cycle, immune cells in the peripheral blood displayed a rise and fall circadian rhythm , which might facilitate the balance of the immune system .However, under the new light regimens, the circadian rhythms of different immune cells in the peripheral blood were entrained , with the entrainment rate of immune cells in the phase delay group being faster than that of the phase advance group .