Epigenetics and Protective Factors in the Preterm Infant

Summary

Preterm infants (PT) spend their first weeks of life in the Neonatal Intensive Care Unit (NICU) where they are exposed to unfavorable conditions with different effects on child development including long-term alterations in epigenetic regulation (DNA methylation). Recent studies document that these epigenetic changes are associated with behavioral modifications, such as altered stress reactivity at 3 months and 4 years. A growing number of studies suggest that protective Developmental Care (DC) procedures (e.g., breastfeeding, skin-to-skin contact (SSC), maternal holding) positively impact neurophysiological and behavioral adaptation of PT with long-term effects. Additionally, a neuro-imaging study reported that parental support in the NICU is associated with improved brain connectivity. While in term (FT) infants, parental interpersonal touch (breastfeeding, affectionate touch) is associated with reduced methylation and activation of specific brain areas associated with affective interpersonal touch, to date no study has investigated whether DC practices and maternal care in NICU (specifically, SSC) buffer methylation and support the brain response to affectionate physical touch in PT. The present study investigates the association between DC procedures in NICU, DNA methylation, and brain responses to affectionate touch, investigated through the use of MRI, at 2 months of age (corrected for prematurity), controlling for: (1) birth status (PT vs FT); (2) the duration of SSC during the NICU stay; (3) parental affectionate touch in the home environment and during mother-child interaction.

Conditions

• Preterm Birth
• Parent-Child Relations
• Epigenetics

Interventions

GENETIC

DNA methylation of target genes

The methylation status of target genes (BDNF, SLC6A4, OXTR, NR3C1) will be investigated. Cord blood will be collected at birth for PT and FT, only for PT a peripheral blood sample will be collected at hospital discharge, during routine clinical procedures. Genomic DNA will be extracted from aliquots of 0. 2 ml of each blood sample with the GeneElute Blood Genomic DNA kit (Sigma) and stored at -20°C. Aliquots of 250 ng of each DNA will be edited for methylation analysis with the EZ DNA Methylation Lightning kit (Zymo Research). Amplification of samples and their preparation for NGS sequencing will be performed. Samples will be sequenced on NextSeq 500 (Illumina). Individual processed sequences (PE reads) will be independently aligned to reference sequences using a parallel Smith-Waterman algorithm. Only reads that consistently align to the same reference sequence will be retained. At each CpG site in each analyzed sequence, the frequencies of the four bases will be evaluated.

DIAGNOSTIC_TEST

Functional Magnetic Resonance Imaging (fMRI) acquisition

Infants will undergo an MRI exam with a 3 Tesla Philips Achieva scanner and a 32-channel head coil. a trained experimenter will apply tactile stimulation associated with affective touch characteristics to the child with a soft brush on the right anterior tibial region in proximal and distal directions. The length of the stimulated area will be measured to cover approximately 15 cm, and tactile stimulations will be applied at a rate of 5 cm/s for 15s, with randomized intervals between stimuli of 10-15s (resulting in 5 stimulations in a 15s block). A regular audio signal will help the researcher to keep a constant stroke velocity. Audio commands will also be used to direct the experimenter. Infant must be asleep (natural sleep) during the fMRI acquisition.

Sponsors & Collaborators

• IRCCS Eugenio Medea

  lead OTHER

Eligibility

Max Age

30 Minutes

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2019-01-01

Primary Completion

2024-04-04

Completion

2024-09-04

Countries

• Italy

Study Locations