RESUMEN
Conditioned media from various sources comprise numerous growth factors and cytokines and are known to promote the regeneration of damaged tissues. Among these, natural killer cell conditioned medium (NKCdM) has been shown to stimulate collagen synthesis and the migration of fibroblasts during the wound healing process. With a longterm aim of developing a treatment for skin photoaging, the ability of NKCdM to prevent ultravioletB (UVB) damage was assessed in neonatal human dermal fibroblasts (NHDFs) and an in vitro reconstructed skin model. The factors present in NKCdM were profiled using an antibody array analysis. Protein and mRNA levels in UVB exposed NHDFs treated with NKCdM were measured by western blotting and quantitative reverse transcriptionPCR, respectively. The total antioxidant capacity of NKCdM was determined to assess its ability to suppress reactive oxygen species. The antiphotoaging effect of NKCdM was also assessed in a 3D reconstituted human full skin model. NKCdM induced proliferation of UVBtreated NHDFs, increased procollagen expression, and decreased matrix metalloproteinase (MMP)1 expression. NKCdM also exhibited a potent antioxidant activity as measured by the total antioxidant capacity. NKCdM inhibited UVBinduced collagen degradation by inactivating MAPK signaling. NKCdM also elicited potential antiwrinkle effects by inhibiting the UVBinduced increase in MMP1 expression levels in a 3D reconstituted human full skin model. Taken together, the suppression of both UVBinduced MMP1 expression and JNK activation by NKCdM suggests NKCdM as a possible candidate antiskin aging agent.