Prenatal PM2.5 exposure disrupts cortical excitatory/inhibitory balance in male offspring by suppressing Lhx8-regulated cholinergic homeostasis and cell adhesion.

Abstract

Prenatal exposure to fine particulate matter (PM2.5) is a critical risk factor for neurodevelopmental impairment in male offspring; however, its effects on synaptic development and the underlying transcription factor (TF) regulatory networks remain poorly understood. To address this, we established a mouse model of prenatal PM2.5 exposure and tracked the cortical development of male offspring across different postnatal stages. We found that prenatal PM2.5 exposure persistently shifted the cortical excitatory/inhibitory (E/I) balance toward inhibition in male offspring, as evidenced by the sustained upregulation of the inhibitory postsynaptic scaffolding protein Gephyrin (GEPH) at postnatal days (PND) 1, 7, and 21. Combined multi-platform transcriptomic profiling, including RNA-sequencing (RNA-seq) and transcriptomic microarray, further identified 14 differentially expressed TFs in the cortex of weaning-aged offspring. Notably, among these TFs, Lhx8 showed the most significant enrichment of target genes in neurodevelopment-related pathways, and its expression remained consistently suppressed following exposure. Mechanistically, Lhx8 downregulation disrupted cholinergic and GABAergic homeostasis, characterized by defective cholinergic neuron development due to CHAT inhibition and a compensatory upregulation of GABRA1. Furthermore, reduced Lhx8 expression repressed multiple cell adhesion-related genes, including Cadm2, Cdh10, Pgrmc1, and Cd36, which collectively contributes to neurodevelopmental deficits in male offspring, potentially through the dysregulation of synaptogenesis. Collectively, from a transcriptional network perspective, this study provides a novel mechanistic framework explaining prenatal PM2.5 exposure-induced neurodevelopmental abnormalities, highlighting potential molecular targets for early intervention in ambient air pollution-associated neurodevelopmental disorders.