Modulation of Sodium-Dependent Transporters Expression in Normal Human Keratinocytes by a Sodium Rich Isotonic Thermal Water

Abstract

Background/Aim: In order to show that water can participate to the skin defense in front of different stress, we investigated the effect of an isotonic thermal water notably rich in Sodium (i.e. the Uriage thermal water) on 1) The taurine transporter (TauT) expression in human normal keratinocytes irradiated or not by UVB; and 2) the Sodium-dependent vitamin C transporter 1 (SVCT1) expression in human normal keratinocytes issued from two “young” and two “aged” subjects, irradiated or not by UVB. Methods and Results: Using sensible and specific TAUT and SVCT1 ELISA assays developed in house, we provide 1) the unambiguous demonstration that the Uriage thermal water is able to help the epidermis to maintain its taurine content under UVB irradiation; 2) the first example of an altered SVCT1 expression in “aged” keratinocytes and of a significant positive effect of the Uriage thermal water on this altered SVCT1 production; and 3) arguments showing that Uriage thermal water is also able to participate to the regulation of the SVCT1 production in UVB-irradiated keratinocytes. Conclusion: Taking together, these results suggest that the Uriage thermal water could act to efficiently protect the skin from dehydration through its effect on TauT and SVCT1 expression, and furthermore, to allow a more efficient taurine and ascorbic acid supplying to the epidermis in order to protect him from other aggressions such as oxidant stress for example.