Detect The Damage Of Low Dose UVA To Human Facial Skin Employing Nested-PCR

Objective To investigate whether the low dose ultraviolet A is harmful or not to normal human facial skin. It provides basis for people to protect from photoaging effectively in daily life.Materials and Methods Skin specimens from 14 healthy individuals were obtained after the "eyebag removal" operation (from July 2005 to January 2006). The right skin specimens were irradiated by UVA of lmw/cm~2 in low temperature for one hour. The left skin specimens were placed in the same condition covered with silver paper. Removed the epidermis after immersed in Dispase II and Collagenase I solution respectively. Extracted the total cellular DNA of fibroblasts and ran nested-PCR. Scanned the gel into computer, detected the band images, transformed them into figures with affiliated software and calculated the frequency of mitochondrial DNA common deletion. SPSS10.0 were used to achieve final statistic results.Results The frequency of mitochondrial DNA common deletion in UVA-exposed cells is significantly higher (0.285+0.193) than that of UVA-unexposed cells (0.098+0.175) with t=4.793 and P<0.05. The frequency of mitochondrial DNA common deletion in normal fibroblasts has no relationship with age.Conclusion Exposed to low dose UVA induced damage to human facial skin which also accelerated the process of photoaging. People should pay enough attention to UVA. It is better for them to take effective measures to protect from it. As a semiquantitative method nested-PCR is simple and useful in detecting DNA mutations, but its limited accuracy needs to be improved.