Intrauterine exposure to nicotine through maternal vaping disrupts embryonic lung and skeletal development via the Kcnj2 potassium channel.

Introduction:
This text presents a study examining the effects of maternal nicotine vaping on fetal lung and skeletal development in mice. The researchers hypothesized that moderate daily exposure to nicotine vapor during the entirety of gestation would disrupt fetal lung and skeletal development.

Key Points:

* Pregnant wildtype and Kcnj2KO/KO dams were exposed to nicotine vapor or room air throughout gestation.
* Exposure began upon observation of the vaginal plug and terminated on E18.0.
* at E18.5, embryos were collected, lungs were harvested for histology and whole transcriptome sequencing, and skeletons were isolated and stained with alcian blue and alizarin red.
* Maternal plasma cotinine levels confirmed nicotine exposure in dams.
* Litter size and embryo weight were decreased in nicotine vaped litters.
* Vaped wildtype lungs had reduced airspace area compared to controls, and Kcnj2KO/KO lungs had smaller airspaces than wildtype controls.
* Whole transcriptome RNa sequencing revealed that vaping lead to upregulated pathways related to mitochondrial dysfunction, protein expression and degradation, metabolism, and DNa damage, and downregulated pathways controlling lung development.
* Nicotine-vaped embryos had craniofacial defects that were exacerbated by reduced Kcnj2 function, and shorter femurs and humerus bones that were also exacerbated by reduced Kcnj2 function.

Main Message:
The study found that maternal nicotine vaping during pregnancy resulted in decreased litter size, growth restriction in some embryos, and disrupted fetal lung and skeletal development. The effects on lung development were due in part to inhibition of Kcnj2, and the transcriptomic response in maternally vaped embryonic lungs was similar to cigarette smoke exposed adult mouse lungs. The craniofacial and skeletal defects observed in nicotine-vaped embryos were also exacerbated by reduced Kcnj2 function. These findings suggest that maternal nicotine vaping may directly impact embryonic development through inhibition of Kcnj2 channels.

Ozekin Yh, Saal ML, hernandez-Pineda R, et al. Intrauterine exposure to nicotine through maternal vaping disrupts embryonic lung and skeletal development via the Kcnj2 potassium channel. Dev Biol. 2023. doi:10.1016/j.ydbio.2023.06.002