Abstract: Objective: To determine the effects of pathogen-associated molecular patterns (PAMPs) on proliferation and differentiation of epidermal cells. Methods: The proliferation and differentiation of epidermal cells invivo 3D-SeboSkin model were detected after treated with PAMPs, namely lipopolysaccharide (LPS), lipoteichoic acid (LTA) and peptidoglycan (PGN) in different concentrations (2,20,200 μg/mL). After culture for 7 days, the epidermal skin area was calculated using PhotoShop software. The proliferation and differentiation of epidermal cells were detected by immunohistochemical labeling with Ki67 and cytokeratin 10 (CK10). The stained area and the integrated optical density (IOD) of each image were calculated by the Image J software and the Image-Pro Plus software respectively. Results: After the stimulation with LPS, LTA and PGN, the epidermal thickness was increased in a concentration-dependent manner. In addition, the expression of Ki67 in the basal epidermal layer and of CK10 at the suprabasal epidermis was enhanced. Conclusion: PAMPs promote the proliferation and differentiation of human epidermal keratinocytes in vitro, indicating that skin microbes may play an important role in mantaining a normal epidermal biology and skin barrier function.

Key words: 3D-SeboSkin model, pathogen-associated molecular patterns, epidermal, proliferation, differentiation