Transgenic mouse models of Alzheimer’s disease exposed to cigarette smoke display increased disease abnormalities in the brain reports a study in Nature Communications this week. The findings provide new insights into a potential environmental risk factor of Alzheimer’s disease.
Alzheimer's disease is the most common type of senile dementia in the elderly population in the Western world. There have been many contradictory reports from studies in animals on the potential effects of nicotine on Alzheimer's disease pathology. Human epidemiological studies have demonstrated that smoking might increase the risk of Alzheimer's disease. However, no studies so far have looked directly at the effect of cigarette smoke exposure on Alzheimer's disease pathology. Claudio Soto and colleagues find that exposing transgenic mice to cigarette smoke increases the severity of some of the abnormalities in the brain that are typical of Alzheimer's disease, such as neuroinflammation and the build up of amyloid plaques and defective tau protein.
The authors acknowledge that further studies are needed to elucidate the mechanisms that are responsible for the increase in Alzheimer's disease pathology, and whether the same effect is also observed in humans. However, their results highlight cigarette smoke as an important environmental risk factor, not only for Alzheimer's disease, but possibly also for other protein misfolding diseases.