Institute of Laboratory Medicine and Pathobiochemistry, Molecular Diagnostics, Philipps University Marburg, Research Facility at ZTI, Hans-Meerwein-Strasse 3, 35043 Marburg, Germany; International Inflammation (in-FLAME) Network, Worldwide Universities Network (WUN), Australia.
Department of Ethology, Wild Life and Laboratory Animals, Faculty of Veterinary Medicine, Universidad Nacional Autónoma de México, Avenida Universidad 3000, 04510 Mexico City, Mexico; Psychoneuroimmunology Laboratory, Department of Psychosomatics and Psychotherapy, University of Gießen, Aulweg 123, D-35385 Gießen, Germany.
Psychoneuroendocrinology. 2017 Dec;86:134-143. doi: 10.1016/j.psyneuen.2017.09.007. Epub 2017 Sep 8.
To study pathogenic stress-effects in health and disease, it is paramount to define easy access parameters for non-invasive analysis of biological change in response to stress. Hair samples successfully provide this access for the study of hypothalamus-pituitary-adrenal axis (HPA) changes. In this study, we assess the hair expression and corresponding epigenetic changes of a neurotrophin essential for autonomic nervous system function and mental health: brain derived neurotrophic factor (BDNF). In three independent studies in healthy academic volunteers (study I: German students, N=36; study II, German academic population sample, N=28; study III: Mexican students, N=115), BDNF protein expression or BDNF gene (BDNF) histone acetylation was determined. Simultaneously, mental distress and distress-associated somatic complaints were assessed by self-report. In study I, we found a negative correlation between hair-BDNF protein level and hair-cortisol as well as between hair-BDNF and somatic complaints, while hair-cortisol correlated positively with mental distress. In study II, we found a negative correlation between H4 histone acetylation at the BDNF gene P4-promoter and somatic complaints. Regression analysis confirmed confounder stability of associations in both studies. In study III, we confirmed study I and found lower hair-BDNF protein level in volunteers with high somatic complaints, who also reported higher mental distress during the end of term exams. The results indicate that BDNF protein levels can be detected in clipped hair and are associated with somatic complaints and stress in life. In addition, we concluded that plucked hair can provide material for the study of epigenetic changes in stress-affected tissues. These tools can prove valuable for future studies on distress, both under experimental and field conditions.
为了研究健康和疾病中的致病应激效应，确定非侵入性分析应激反应中生物变化的便捷途径至关重要。毛发样本为研究下丘脑-垂体-肾上腺轴（HPA）变化提供了这种途径。在这项研究中，我们评估了神经生长因子（BDNF）的毛发表达和相应的表观遗传变化，BDNF 是自主神经系统功能和心理健康所必需的神经营养因子。在三个独立的健康学术志愿者研究中（研究 I：德国学生，N=36；研究 II：德国学术人群样本，N=28；研究 III：墨西哥学生，N=115），测定了 BDNF 蛋白表达或 BDNF 基因（BDNF）组蛋白乙酰化。同时，通过自我报告评估精神困扰和与困扰相关的躯体抱怨。在研究 I 中，我们发现毛发-BDNF 蛋白水平与毛发皮质醇之间以及毛发-BDNF 与躯体抱怨之间呈负相关，而毛发皮质醇与精神困扰呈正相关。在研究 II 中，我们发现 BDNF 基因 P4-启动子处 H4 组蛋白乙酰化与躯体抱怨呈负相关。回归分析证实了这两项研究中关联的混杂因素稳定性。在研究 III 中，我们证实了研究 I 的结果，并发现躯体抱怨高的志愿者的毛发-BDNF 蛋白水平较低，这些志愿者在期末考试期间报告的精神困扰也更高。研究结果表明，可以从剪下的毛发中检测到 BDNF 蛋白水平，并且与躯体抱怨和生活中的压力有关。此外，我们得出结论，拔出的毛发可以为研究受应激影响组织中的表观遗传变化提供材料。这些工具在实验和现场条件下研究痛苦都将具有重要价值。
