1345 Suppression of autophagy compromises sweat secretion in aged mice

Abstract

Autophagy has been implicated in stress responses and cell differentiation in normal and diseased skin, however, the relative importance of autophagy in the various cell types of the skin is not fully understood. Here we investigated the role of autophagy in sweat glands of mouse models. The essential autophagy gene Atg7 was inactivated by Cre-lox recombination in keratin K14-positive precursor cells of epithelia and glands. The abundance of the autophagy substrate p62/sequestosome 1 was determined by immunofluorescence analysis. Sweat secretion was determined by the iodine-starch test on the soles of fully autophagy-competent control mice and mice carrying the epithelium-specific deletion of Atg7. The suppression of Atg7-dependent autophagy led to the accumulation of p62/sequestosome 1 (Sqstm1) in the secretory part of the sweat glands. Sweat secretion was normal in young Atg7f/f K14-Cre mice, but the number of active sweat glands was significantly reduced in Atg7f/f K14-Cre mice at an age of 10-14 months. These results suggest a previously unknown and possibly clinically relevant role of autophagy in the maintenance of sweat secretion during aging.