Placental gene network modules are associated with maternal stress during pregnancy and infant temperament

Maternal psychosocial stress during pregnancy (MPSP) is a known contributor to maladaptive neurobehavioral development of the offspring; however, the underlying molecular mechanisms linking MPSP with childhood outcome remain largely unknown. Transcriptome-wide gene expression data were generated using RNA-seq from placenta samples collected in a multi-ethnic urban birth cohort in New York City (n = 129). Weighted gene co-expression network analysis (WGCNA) was used to characterize placental co-expression modules, which were then evaluated for their associations with MPSP and infant temperament. WGCNA revealed 16 gene coexpression modules. One module, enriched for regulation of chromosome organization/gene expression, was positively associated with MPSP and negatively associated with Regulatory Capacity (REG), a component of infant temperament. Two other modules, enriched for cotranslational protein targeting and cell cycle regulation, respectively, displayed negative associations with MPSP and positive associations with REG. A module enriched with oxidative phosphorylation/mitochondrial translation was positively associated with REG. These findings support the notion that the placenta provides a functional in utero link between MPSP and infant temperament, possibly through transcriptional regulation of placental gene expression.