Scientists have identified a genetic pathway that contributes to nicotine addiction and makes quitting smoking difficult. Quitting the toxic stick, the cigarette, is not an easy task and for some, it takes years while others just can’t seem to put it away.
It was found that a specific genes and microRNA (a class of small RNA molecules that help fine-tune gene expression) plays an essential role in determining how nicotine dependence and withdrawal responses are developed.
The study took a fresh look at a previously dismissed biological mechanism. Most research in the field has focused on how proteins called nicotine acetylcholine receptors contribute to dependence.
Researchers at the University of Michigan in the US examined withdrawal responses in the millimeter-long roundworms called Caenorhabditis elegans, which get hooked on nicotine just like humans.
They discovered a series of genes in the roundworms which were involved in a process that ultimately increased the production of the nicotine receptor proteins, with microRNAs playing a pivotal role, clues that may also carry over to the mammalian realm.
“We’re seeing a clear link between nicotine, microRNA, the receptor proteins, and nicotine-dependent behaviour,” Jianke Gong, lead author of the study and researcher, said.
“People believed this question had been settled,” said Shawn Xu, a professor at the University of Michigan. “But we have better tools now. We, as a field, need to take another look at this mechanism in nicotine addiction,” said Xu.
The discovery in C elegans will now lead other scientists to re-examine the role of these microRNAs in nicotine dependence in mammals and ultimately lead to a better understanding of what causes the dependence, researchers said.
The results of this study support the possibility to use the study of dependence and withdrawal responses in humans. The study was published in the scientific journal Cell Reports.