Influence of fluoride on neuronal differentiation in dopaminergic differentiation SH-SY5Y cells

Abstract

Fluoride is widely used in dentistry to prevent dental caries by increasing the fluoride content in saliva and aiding enamel remineralization. Excessive fluoride in the blood can cause adverse health effects such as fluorosis, which alter cerebral function. The influence of fluoride on dopaminergic neurons however, remains largely unclear. The present study examined the effect of sodium fluoride toxicity on dopaminergic neurons in retinoic acid-induced differentiation in SH-SY5Y cells. Cell viability was reduced by fluoride in both time- and concentration-dependent manners. Moreover, immunoblot analysis showed that fluoride decreased neuronal marker microtubule-associated protein-2 expression and levels of tyrosine hydroxylase, a rate-determining step enzyme in dopamine synthesis, even at a nonlethal dose. These results suggest that fluorosis may adversely affect dopaminergic neurons and may have harmful effects in individuals with degenerative dopaminergic neuron conditions, such as Parkinson's disease.