Prenatal E-Cigarette Exposure Reprograms the Cardiac Proteome and Increases Ischemia Susceptibility in a Sex-Dependent Manner

Prenatal e-cigarette (e-cig) exposure has been associated with adverse cardiovascular outcomes in offspring, yet the underlying molecular mechanisms remain poorly understood. Using a rat model of gestational e-cig aerosol exposure combined with quantitative LC-MS/MS proteomics and integrated KEGG, Gene Ontology (GO), protein-protein interaction (PPI), and EggNOG analyses, we identified profound and sexually dimorphic alterations in the neonatal cardiac proteome. There was extensive mitochondrial and metabolic dysregulation in the developing heart following prenatal e-cig exposure. In male offspring, enriched pathways included oxidative phosphorylation, tricarboxylic acid (TCA) cycle activity, and respiratory chain assembly, indicating disruption of mitochondrial energy metabolism. In contrast, female offspring exhibited prominent dysregulation of mitochondrial chaperones (Hspa9, Hspa4) and ribosomal proteins (Rps11, Rpl11, Rps3), suggesting impaired proteostasis and translational capacity. PPI and KEGG analyses further revealed sex-dependent perturbations of signaling and structural protein networks critical for cardiac contractility, cardiomyopathy progression, and myocardial stress resilience. Males primarily showed alterations in sarcomeric, structural, and metabolic proteins, whereas females exhibited widespread disruption of GPCR/cAMP/PKA-mediated regulatory pathways. These early-life proteomic alterations translated into functional deficits in adulthood, with males displaying impaired baseline cardiac function and exacerbated ischemia/reperfusion (I/R) injury, while females showed preserved baseline function but heightened susceptibility to I/R stress. Collectively, these findings demonstrate that prenatal e-cig exposure programs long-lasting, sex-specific cardiac vulnerability through early-life proteomic reorganization, providing mechanistic insight into developmental cardiotoxicity and informing risk assessment during pregnancy.