Negative Emotionality and Epigenetics During Puberty

In order to investigate epigenetic and neuroimaging correlates of negative emotionality in pubertal girls, the study employs a cross-sectional design, enrolling 50 pre-pubescent girls (8-10 years) and 50 post-pubescent girls (15-17 years) as healthy participants. Comprehensive data will be collected using self- and parent-report questionnaires on pubertal status, prenatal complications, adverse life events, stress and coping mechanisms, mood and anxiety symptoms, gender identity, and reproductive health. To delve into the neuronal correlates of stress, participants will undergo (f)MRI and MIST. Additionally, physiological stress responses will be assessed through heart rate and skin conductance measurements. Participants will provide blood, saliva, and hair samples for hormone, methylation and expression analysis. DNA methylation analysis will be performed on whole blood and saliva samples using pyrosequencing, focusing on genes that are responsive to estrogen and genes involved in estrogen signaling, based on the previous literature reporting an overrepresentation of estrogen-responsive genes among the differentially methylated sites across the entire genome in girls during puberty. The effects of methylation on gene expression will be measured using reverse transcription real-time PCR. Cortisol levels will be assessed from saliva collected six times during MIST to evaluate the acute stress response and from hair to assess chronic stress. Sex steroids such as estrogen and progesterone from blood will be analyzed using LC-MS/MS. The study aims to provide insights into the intricate relationship between epigenetic modifications, gene expression and negative emotionality (e.g., stress reactivity and internalizing symptoms) during puberty in girls.

• Correlation between DNA methylation and gene expression in candidate genes [Срок оценки: Measured once after MRI measurement (approximately 30 minutes)]
• Correlation between DNA methylation and HPA-axis response [Срок оценки: Measured six times: 1 hour before MIST(1), just before(1) and after(1) MIST, and three times more in 20-minute intervals after MIST. Each saliva collection lasts approx. 2 minutes.]
• Correlation between DNA methylation and subjective stress response [Срок оценки: Measured six times: 1 hour before MIST(1), just before(1) and after(1) MIST, and three times more in 20-minute intervals after MIST. Each rating takes approx. 10 minutes.]
• Correlation between DNA methylation and phsiological stress response [Срок оценки: Measured once: 20 minutes for phsiological data during MRI measurement]
• Correlation between DNA methylation and functional connectivity [Срок оценки: Measured once with resting-state functional MRI, approximately 10 mintes]
• Correlation between DNA methylation and brain gray matter structure [Срок оценки: Measured once with MPRAGE MRI, approximately 10 minutes. Analyzed and reported over the course of the study, in average of 1 year]