title: DNA methylation profiles within the serotonin transporter gene moderate the association of 5-HTTLPR and cortisol stress reactivity.
abstract: The serotonin transporter gene-linked polymorphic region (5-HTTLPR) has been implicated in moderating vulnerability to stress-related psychopathology upon exposure to environmental adversity. A recent meta-analysis suggests a potential biological pathway conveying genotype-dependent stress sensitivity by demonstrating a small, but significant association of 5-HTTLPR and cortisol stress reactivity. An arguably more potent approach to detect larger effects when investigating the 5-HTTLPR stress sensitivity hypothesis is to account for both genetic and epigenetic variation in the serotonin transporter gene (SLC6A4). Here, we applied this approach in an experimental setting. Two hundred healthy adults were exposed to a laboratory stressor (Trier Social Stress Test) and cortisol response patterns were assessed as a function of 5-HTTLPR and DNA methylation profiles in SLC6A4. Specifically, we analyzed 83 CpG sites within a 799-bp promoter-associated CpG island of SLC6A4 using a highly sensitive bisulfite pyrosequencing method. Our results suggest that SLC6A4 methylation levels significantly moderate the association of 5-HTTLPR and cortisol stress reactivity. For individuals displaying low levels of SLC6A4 methylation, the S allele relates to increased cortisol stress reactivity in a dose-dependent fashion accounting for 7-9% of the variance in the endocrine stress response. By contrast, no such effect occurred under conditions of high SLC6A4 methylation, indicating that epigenetic changes may compensate for genotype-dependent differences in stress sensitivity. Studying epigenetic markers may advance gene-environment interaction research on 5-HTTLPR as they possibly capture the net effects of environmental influences relevant for stress-related phenotypes under serotonergic control.
authors.affiliation: Department of Biopsychology, Technische Universität Dresden, Dresden, Germany.
authors.forename: N
authors.initials: N
authors.lastname: Alexander
authors.affiliation: Department of Biopsychology, Technische Universität Dresden, Dresden, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Wankerl
authors.affiliation: Center for Psychobiology and Behavioral Medicine, Department of Psychology, University of Giessen, Giessen, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Hennig
authors.affiliation: Department of Biopsychology, Technische Universität Dresden, Dresden, Germany.
authors.forename: R
authors.identifier: 0000000286655248
authors.initials: R
authors.lastname: Miller
authors.affiliation: Department of Medical Psychology, Psychological Diagnostics and Research Methods, University of Regensburg, Regensburg, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Zänkert
authors.forename: S
authors.initials: S
authors.lastname: Steudte-Schmiedgen
authors.affiliation: Department of Biopsychology, Technische Universität Dresden, Dresden, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Stalder
authors.affiliation: Department of Biopsychology, Technische Universität Dresden, Dresden, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Kirschbaum
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D019175:DNA Methylation / Q000235:genetics*; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000235:genetics* / Q000378:metabolism; D008297:Male; D012463:Saliva / Q000378:metabolism; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics*; D013315:Stress, Psychological / Q000235:genetics*; D055815:Young Adult
chemical_list: C493230:SLC6A4 protein, human; D050486:Serotonin Plasma Membrane Transport Proteins; D006854:Hydrocortisone