From the Department of Surgery, Division of Surgical Sciences, University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, New Brunswick, NJ.
Crit Care Med. 2010 Mar;38(3):751-8. doi: 10.1097/CCM.0b013e3181cd131c.
The intravenous administration of a bolus dose of endotoxin to healthy human subjects triggers acute systemic inflammatory responses that include cytokine production and dynamic changes in gene expression in peripheral blood leukocytes. This study sought to determine the state of clock gene expression in human peripheral blood leukocytes, and leukocyte subpopulations, challenged with in vivo endotoxin at two circadian/diurnal phases of the clock.
Clinical and laboratory investigation.
University-based research laboratory and clinical research center.
Human volunteers.
Human subjects were administered a standard dose of endotoxin (2 ng/kg) or saline at either 0900 or 2100 hrs. Blood samples were collected at selected time points pre- and postinfusion.
Clock gene expression was determined in human peripheral blood leukocytes, neutrophils, and monocytes by quantitative real-time polymerase chain reaction. The fold change for each gene was determined by use of the 2 method. We show that endotoxin causes profound suppression of circadian clock gene expression, clearly manifested in human peripheral blood leukocytes, neutrophils, and monocytes. Clock, Cry1-2, Per3, CSNK1epsilon, Rora, and Rev-erb gene expression were all reduced by 80% to 90% with the nadir between 3 and 6 hrs postinfusion. Per1 and Per2 reached an expression nadir between 13 and 17 hrs postinfusion. The levels of plasma interleukin-6 and tumor necrosis factor peaked and then returned to baseline within 6 hrs. In contrast, clock gene expression remained suppressed for up to 17 hrs irrespective of the phase of the clock at the time of the endotoxin challenge. Endotoxin did not perturb the melatonin secretory rhythm.
Circadian clock gene expression in peripheral blood leukocytes is dramatically altered and possibly uncoupled from the activity of the central clock during periods of acute systemic inflammation. The realignment of the central and peripheral clocks may constitute a previously unappreciated key factor affecting recovery from disease in humans.
静脉注射内毒素给健康人体引发急性全身炎症反应，包括细胞因子的产生和外周血白细胞基因表达的动态变化。本研究旨在确定生物钟基因在人类外周血白细胞和白细胞亚群中的表达状态，以及在生物钟的两个昼夜/日周期相位下，用内毒素对其进行挑战。
临床和实验室研究。
以大学为基础的研究实验室和临床研究中心。
人类志愿者。
人体接受标准剂量的内毒素（2ng/kg）或盐水，分别在 0900 或 2100 小时。在输注前和输注后选择时间点采集血样。
通过实时定量聚合酶链反应测定人类外周血白细胞、中性粒细胞和单核细胞中的时钟基因表达。使用 2 法确定每个基因的倍数变化。我们表明，内毒素导致生物钟基因表达的明显抑制，这在人类外周血白细胞、中性粒细胞和单核细胞中表现得很明显。时钟、Cry1-2、Per3、CSNK1epsilon、Rora 和 Rev-erb 基因的表达都减少了 80%到 90%，最低点出现在输注后 3 到 6 小时之间。Per1 和 Per2 的表达最低点出现在输注后 13 到 17 小时之间。血浆白细胞介素 6 和肿瘤坏死因子的水平达到峰值，然后在 6 小时内恢复到基线。相比之下，无论内毒素挑战时生物钟的相位如何，时钟基因的表达在 17 小时内仍受到抑制。内毒素不会干扰褪黑素分泌节律。
外周血白细胞中的生物钟基因表达在急性全身炎症期间发生显著改变，并且可能与中央生物钟的活动脱耦。中央和外周时钟的重新调整可能是影响人类疾病恢复的一个以前未被认识的关键因素。
