Placental transcriptomics reveals alterations in metabolic and transport gene programs following prenatal cannabis smoke exposure

Prenatal exposure to cannabis smoke appears to trigger specific alterations in the placenta's gene expression profile, according to a recent study. Researchers examined the placental transcriptome of pregnant mice that were exposed to cannabis cigarette smoke or regular air between embryonic days 6.5 and 18.5. The analysis, which used microarray-based profiling and adjusted for fetal sex, revealed 23 genes with different expression levels.

Interestingly, these changes were not easily distinguished by exposure group, but certain gene signatures were altered.

In the exposed placentae, the expression of labyrinth-associated transcriptional signatures decreased, while junctional-associated signatures increased. This suggests a shift in the placenta's structure and function. A closer look at the pathways revealed that genes related to fatty acid metabolism, bioenergetics, and transmembrane transport were negatively altered, while those involved in RNA processing and transcriptional regulation were positively affected. Despite these changes, the placental respiratory measurements remained unchanged.

To validate these findings, quantitative PCR was used to confirm altered expression of multiple transport-related genes. Additionally, the expression of genes associated with the electron transport chain was found to be altered, even though the placenta's respiratory capacity was preserved. Overall, the study suggests that prenatal cannabis smoke exposure leads to subtle yet coordinated changes in the placenta's transcriptional landscape.

These changes involve metabolic, transport-associated, and gene-regulatory pathways, as well as shifts in specific compartments. Understanding these pathways could provide valuable insights into the effects of cannabis smoke on placental function during pregnancy.