Apoptosis Effect Of585nm Pulsed Dye Laser In A Microcomedon Animal Model

Objective:Acne is a multi-factorial disease originating fromsebaceous follicles and its initial histological change is formation ofmicrocomedo.585nm pulsed dye laser(PDL) has been shown its beneficialeffects on non-inflammatory lesions of acne vulgaris，however，the exactmechanisms are not well identified.Our study evaluated the apoptosiseffects of585nm PDL treatment on microcomedo in an animal model.Methods: Microcomedo animal model was constructed by applicationof coal tar in rabbit ear and skin biopsy was obtained to evaluate the animalmodel. Levels of transforming growth factor β1(TGF-β1) were assessed byimmunohistochemistry and ELISA. Markers of apoptosis were assessed intreated and untreated animals by quantitative polymerase chain reaction(PCR).Results:The585nm PDL led to marked decrease of mean thicknessof the perifollicular epidermis after treatment （P=0.002）.Immunohistochemistry showed that TGF-β1protein remarkable increasesafter treatment（P=0.002）while ELISA essentially unchanged（P=0.394）.Increased apoptosis epithelial cells in folliculus（P=0.002）were obversed following the increased Caspase-3and Fas（P=0.001，P=0.001）. There wasa positive crrelation between TGF-β1expression and apoptosis inperifollicular epidermis of microcomedo animal mode（r=0.819，P=0.046）.Conclusion:The decreased mean thickness of the perifollicularepidermis and increased apoptosis epithelial cell in folliculus as well aslocal TGF-β1protein were observed after585nm Nd: YAG laser treatment.The induction of Fas and Caspase-3may contribute to thenon-inflammatory acne lesions, which may explains the therapeutic benefitof this laser for acne vulgaris.