Perinatal morphine exposure induces chromatin and transcriptomic remodeling to alter immune and metabolic function.

INTRODUCTION

Infants exposed to opioids in utero are at risk of developing Neonatal Opioid Withdrawal Syndrome (NOWS). Rodent models of perinatal opioid exposure can reliably recapitulate the acute withdrawal and developmental deficits exhibited in clinical NOWS, but few persisting phenotypes are consistently observed between studies, limiting mechanistic insight into the long-lasting effects of early-life opioid exposure.

METHODS

To investigate the enduring impact of perinatal opioid exposure, we employed a multi-region, multi-omic approach. We combined RNA sequencing (RNA-seq) and H3K27ac chromatin immunoprecipitation sequencing (ChIP-seq) from NeuN+ neuronal nuclei in a mouse model of NOWS. Additionally, cytokine levels were measured in the brain and spleen, and physiological responses were assessed under both basal and immune-challenged conditions.

RESULTS

Analysis revealed differentially expressed genes and H3K27ac modifications were enriched for immune and metabolic pathways in hypothalamic neurons. Transcription factor network inference identified state-dependent rewiring of immune and metabolic regulatory circuits, with Transcription factor 4 (TCF4) emerging as a convergent epigenomic and transcriptional hub under immune-challenged conditions. Consistent with molecular signatures, cytokine levels were suppressed in morphine-exposed mice both in adulthood, both at baseline and under immune-challenged conditions. Several metabolic properties, including changes in weight and basal body temperature, were also altered.

DISCUSSION: Our findings suggest that perinatal opioid exposure creates a lasting enhancer imprint in hypothalamic neurons, leading to suppressed baseline immune gene expression and altered regulatory responses to subsequent inflammatory challenges. These epigenomic and transcriptional changes may underlie the long-term physiological impacts of early-life opioid exposure, offering new insights into the enduring consequences of NOWS.