The Endocrine Program, Department of Animal Sciences, Rutgers, The State University of New Jersey, 67 Poultry Farm Lane, New Brunswick, NJ, USA.
Department of Psychology, College of Sciences, San Diego State University, San Diego, CA, USA.
Sci Rep. 2024 Aug 27;14(1):19886. doi: 10.1038/s41598-024-71023-z.
Prenatal alcohol-exposed (AE) infants and children often demonstrate disrupted sleep patterns, including more frequent awakenings, reduced total sleep time, and more night-to-night sleep variability. Despite the strong connection between sleep patterns and circadian rhythmicity, relatively little is known about circadian rhythm disruptions in individuals with AE. Recently, several reports demonstrated that evaluating the expression patterns of human clock genes in biological fluids could reveal an individual's circadian phenotype. Human saliva offers an emerging and easily available physiological sample that can be collected non-invasively for core-clock gene transcript analyses. We compared the expression patterns of core-clock genes and their regulatory genes in salivary samples of children aged 6-10 years-old with and without AE during the light cycle between ZT0-ZT11. We isolated the RNA from the samples and measured the expression patterns of core clock genes and clock regulating genes using the human specific primers with quantitative real-time PCR. Analysis of core clock genes expression levels in saliva samples from AE children indicates significantly altered levels in expression of core-clock BMAL1, CLOCK, PER1-3 and CRY1,2, as compared to those in age-matched control children. We did not find any sex difference in levels of clock genes in AE and control groups. Cosinor analysis was used to evaluate the rhythmic pattern of these clock genes, which identified circadian patterns in the levels of core clock genes in the control group but absent in the AE group. The gene expression profile of a salivary circadian biomarker ARRB1 was rhythmic in saliva of control children but was arhythmic in AE children. Altered expression patterns were also observed in clock regulatory genes: NPAS2, NFL3, NR1D1, DEC1, DEC2, and DBP, as well as chromatin modifiers: MLL1, P300, SIRT1, EZH2, HDAC3, and ZR1D1, known to maintain rhythmic expression of core-clock genes. Overall, these findings provide the first evidence that AE disturbs the circadian patten expression of core clock genes and clock-regulatory chromatin modifiers in saliva.
产前酒精暴露（AE）的婴儿和儿童常表现出睡眠模式紊乱，包括更频繁的觉醒、总睡眠时间减少以及夜间睡眠变化更大。尽管睡眠模式与昼夜节律之间存在很强的联系，但关于 AE 个体的昼夜节律紊乱相对知之甚少。最近，有几项报告表明，评估生物体液中人类时钟基因的表达模式可以揭示个体的昼夜节律表型。人类唾液提供了一种新兴的、易于获得的生理样本，可以非侵入性地采集，用于核心时钟基因转录分析。我们比较了 AE 儿童和年龄匹配的对照组儿童在光周期内（ZT0-ZT11）唾液样本中核心时钟基因及其调节基因的表达模式。我们从样本中分离 RNA，并使用定量实时 PCR 用人类特异性引物测量核心时钟基因和时钟调节基因的表达模式。AE 儿童唾液样本中核心时钟基因表达水平的分析表明，与年龄匹配的对照组儿童相比，核心时钟基因 BMAL1、CLOCK、PER1-3 和 CRY1、2 的表达水平明显改变。我们没有发现 AE 和对照组儿童时钟基因水平存在任何性别差异。余弦分析用于评估这些时钟基因的节律模式，结果表明在对照组中核心时钟基因的水平存在昼夜节律模式，但在 AE 组中不存在。控制组儿童唾液中的生物钟基因 ARRB1 的基因表达谱呈节律性，但 AE 儿童的节律性消失。时钟调节基因的表达模式也发生了改变：NPAS2、NFL3、NR1D1、DEC1、DEC2 和 DBP，以及染色质修饰因子：MLL1、P300、SIRT1、EZH2、HDAC3 和 ZR1D1，这些因子已知维持核心时钟基因的节律性表达。总的来说，这些发现首次提供了证据，表明 AE 扰乱了唾液中核心时钟基因和时钟调节染色质修饰因子的昼夜节律表达模式。
