A newly discovered feedback loop involving estrogen may explain why women might become dependent on nicotine more quickly and with less nicotine exposure than men. The research could lead to new treatments for women who are having trouble quitting nicotine-containing products such as cigarettes.
Sally Pauss is a doctoral student at the University of Kentucky College of Medicine in Lexington. She led the project.
The researchers found that the sex hormone estrogen induces the expression of olfactomedins, proteins that are suppressed by nicotine in key areas of the brain involved in reward and addiction. The findings suggest that estrogen–nicotine–olfactomedin interactions could be targeted with therapies to help control nicotine consumption.
For the new study, the researchers used large sequencing datasets of estrogen-induced genes to identify genes that are expressed in the brain and exhibit a hormone function. They found just one class of genes that met these criteria: those coding for olfactomedins. They then performed a series of studies with human uterine cells and rats to better understand the interactions between olfactomedins, estrogen and nicotine. The results suggested that estrogen activation of olfactomedins — which is suppressed when nicotine is present — might serve as a feedback loop for driving nicotine addiction processes by activating areas of the brain’s reward circuitry such as the nucleus accumbens.
American Society for Biochemistry and Molecular Biology (ASBMB) release on Newswise
