Department of Psychology, University of Florida, Gainesville, FL, USA; Department of Aging and Geriatric Research, Institute on Aging, University of Florida, Gainesville, FL, USA; Center for Cognitive Aging and Memory, Department of Clinical and Health Psychology, University of Florida, Gainesville, FL, USA.
Department of Psychology, University of Florida, Gainesville, FL, USA.
Int J Psychophysiol. 2019 Feb;136:22-32. doi: 10.1016/j.ijpsycho.2018.01.008. Epub 2018 Feb 2.
The neuropeptide oxytocin (OT) has been implicated in a wide range of affiliative processes. OT exerts its functions via OT receptors, which are encoded by the oxytocin receptor gene (OXTR). Epigenetic modification of OXTR through the process of DNA methylation has been associated with individual differences in behavioral phenotypes. Specifically, lower levels of OXTR methylation have been linked to better social and affective functioning. However, research on epigenetic mechanisms of OXTR is scarce in non-clinical populations, and even less is known about epigenetic variability across adulthood. The present study assessed methylation levels at OXTR CpG site -934 and plasma OT levels in 22 young (20-31 years, M = 23.6) and 34 older (63-80 years, M = 71.4) participants. Lower levels of OXTR methylation and higher plasma OT levels were associated with less self-reported attachment anxiety in young but not older participants, with largely independent contributions of OXTR methylation and plasma OT levels. In contrast, in the overall sample, lower levels of OXTR methylation were associated with higher self-reported attachment avoidance. Age analysis suggested that these results were largely driven by young adults. Plasma OT levels were unrelated to attachment avoidance. Taken together, these findings support the emerging notion in the literature that epigenetic properties of OXTR, in addition to endogenous OT levels, are related to adult attachment. Further, the age effects observed in the associations between OXTR methylation, plasma OT, and adult attachment emphasize the importance of adopting a developmental perspective when studying properties of the OT system and their relation to affiliative processes. Findings contribute to growing evidence suggesting that epigenetic modification of genes regulating OT pathways and endogenous OT levels are associated with the way people form and maintain intimate social relationships.
神经肽催产素（OT）被牵涉到广泛的亲和过程中。OT 通过 OT 受体发挥作用，OT 受体由催产素受体基因（OXTR）编码。通过 DNA 甲基化过程对 OXTR 的表观遗传修饰与行为表型的个体差异有关。具体来说，较低水平的 OXTR 甲基化与更好的社会和情感功能有关。然而，非临床人群中关于 OXTR 的表观遗传机制的研究很少，并且关于成年期跨个体的表观遗传变异性知之甚少。本研究评估了 22 名年轻（20-31 岁，M=23.6）和 34 名年长（63-80 岁，M=71.4）参与者的 OXTR CpG 位点-934 的甲基化水平和血浆 OT 水平。较低水平的 OXTR 甲基化和较高的血浆 OT 水平与年轻参与者而非年长参与者的自我报告依恋焦虑程度较低有关，OXTR 甲基化和血浆 OT 水平的贡献基本独立。相比之下，在总体样本中，较低水平的 OXTR 甲基化与较高的自我报告依恋回避有关。年龄分析表明，这些结果主要是由年轻成年人驱动的。血浆 OT 水平与依恋回避无关。总之，这些发现支持文献中新兴的观点，即 OXTR 的表观遗传特性，除了内源性 OT 水平外，与成人依恋有关。此外，在 OXTR 甲基化、血浆 OT 和成人依恋之间的关联中观察到的年龄效应强调了在研究 OT 系统的特性及其与亲和过程的关系时采用发展视角的重要性。研究结果为越来越多的证据提供了支持，这些证据表明，调节 OT 途径的基因的表观遗传修饰和内源性 OT 水平与人们形成和维持亲密社会关系的方式有关。
