Shotgun label-free proteomic analysis for identification of proteins in HaCaT human skin keratinocytes regulated by the administration of collagen from soft-shelled turtle.

Soft-shelled turtles (Pelodiscus sinensis) are widely distributed in some Asian countries, and we previously reported that soft-shelled turtle tissue could be a useful material for collagen. In the present study, we performed shotgun liquid chromatography (LC)/mass spectrometry (MS)-based global proteomic analysis of collagen-administered human keratinocytes to examine the functional effects of collagen from soft-shelled turtle on human skin. Using a semiquantitative method based on spectral counting, we were able to successfully identify 187 proteins with expression levels that were changed more than twofold by the administration of collagen from soft-shelled turtle. Based on Gene Ontology analysis, the functions of these proteins closely correlated with cell-cell adhesion. In addition, epithelial-mesenchymal transition was induced by the administration of collagen from soft-shelled turtle through the down-regulation of E-cadherin expression. Moreover, collagen-administered keratinocytes significantly facilitated wound healing compared with nontreated cells in an in vitro scratch wound healing assay. These findings suggest that collagen from soft-shelled turtle provides significant benefits for skin wound healing and may be a useful material for pharmaceuticals and medical care products. © 2017 The Authors Journal of Biomedical Materials Research Part B: Applied Biomaterials Published by Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 2403-2413, 2018.