Nicotine Influence on Vascular and Neurocognitive Function with In-utero Electronic Cigarette Exposure

Emerging studies find arteriolar dysfunction in offspring with in-utero electronic cigarette (Ecig) exposure, but the long-term effect on offspring's cerebrovascular vascular and neurocognitive health is poorly understood. Ecigs provides a unique opportunity to directly evaluate the contributions of inhaled nicotine from the vehicle e-liquid - which was not possible with traditional cigarettes. Moreover, many Ecigs have variable power settings, which can alter the toxicity of the aerosol cloud produced. We hypothesize maternal vaping at different wattages will have variable effects on cerebrovascular function in the offspring, and that these effects would be independent of nicotine. We used time-mated female Sprague-Dawley rats with Ecig exposure from gestation day (GD)2-21. We studied male and female offspring for vascular and neurocognitive function at 1-, 3-, 6- and 12-months of age. We found that, both sexes, offspring with in-utero exposure (at 5w and 30w Ecig conditions) exhibited impaired middle cerebral artery (MCA) reactivity. While the magnitude of impairment was greater at higher that lower watts, Ecig at 5-watts still exhibited significant impairments in MCA function (suggesting the harm threshold for blood vessels is very low). Vascular dysfunction was evident with or without nicotine in the e-liquid, but nicotine exposure resulted in short-term memory deficits, evidence of neuronal damage, and increased astrocyte interaction with endothelial cells in 6- and 12-month-old offspring. We also observed altered expression of clock genes and antioxidant signaling pathways, along with a decrease in sirtuin-1 expression, decreased ratio of beta-amyloid Aβ 42/40 protein expression, and increased in NOX1, which are consistent with redox imbalance, neuroinflammation, and advancing cellular senescence. These preclinical data provide evidence suggesting that in utero exposure to Ecigs from maternal vaping can be expected to adversely affect the brain health of offspring in their adult life and that neurocognitive outcomes are worsened with exposure to nicotine.