Growth stage-dependent changes of the levels of keratin 1 and keratin 10 as well as the green autofluorescence of the skin of the back and the ears of C57BL/6 mice under basal conditions and after UVC irradiation

Our previous studies have indicated that oxidative stress and inflammation can dose-dependently induce increased skins green autofluorescence (AF) of mice, which results at least partially from keratin 1 (K1) cleavage. Increased green AF was also found in patients skin of several major diseases, which may become a novel biomarker for non-invasive diagnosis. We also found age-dependent changes of the skins green AF of natural populations. In this study we tested our hypothesis that there are growth stage-dependent changes of K1 and keratin 10 (K10) levels in the skin of mice, which may underlie the age-dependent changes of the skins green AF. We found that in the skin of both mices back and ears, there were growth stage-dependent changes of the levels of K1 and K10 as well as the basal green AF. The K1 and K10 levels in the backs skin were significantly different from those in the ears skin. There were also growth stage-dependent changes of the UVC-induced changes of K1 and K10 levels of both the ears and the back. Collectively, our study has provided first evidence showing growth stage-dependent and differential changes of the levels of K1 and K10 as well as skins green AF in the back and the ears of mice under basal conditions and after UVC irradiation. These findings are valuable for understanding the age-dependent changes of the skins green AF of natural populations, which are also important for establishing the keratins AF-based method for non-invasive diagnosis of diseases.