Oxidative stress, microRNAs and cytosolic calcium homeostasis

Reactive oxygen species increase cytosolic [Ca²⁺], (Ca_i), and also modulate the expression of some microRNAs (miRNAs), however the link among oxidative stress, miRNAs and Ca_i is poorly characterized. In this review we have focused on three groups of miRNAs: (a) miRNAs that are modulated both by ROS and Ca_i: miR-181a and miR-205; (b) miRNAs that are modulated by ROS and have an effect on Ca_i: miR-1, miR-21, miR-24, miR-25, miR-185 and miR-214; (c) miRNAs that modulate both ROS and Ca_i: miR-133; miR-145, miR-495, and we have analyzed their effects on cell signaling and cell function. Finally, in the last section we have examined the role of these miRNAs in the skin, under conditions associated with enhanced oxidative stress, i.e. skin aging, the response to ultraviolet light and two important skin diseases, psoriasis and atopic dermatitis. It is apparent that although some experimental evidence is already available on (a) the role of Ca_i in miRNAs expression and (b) on the ability of some miRNAs to modulate Ca_i-dependent intracellular signaling, these research lines are still largely unexplored and represent important areas of future studies.