Abstract: Xia Rushan, Gu Jing, Tao Shiqin, Yang Lijia. Department of Dermatology, Wuxi No. 2 People′s Hospital, Nanjing Medical University, Wuxi 214002, Jiangsu, China Corresponding author: Yang Lijia, Email: yanglijia726@163.com 【Abstract】 Objective To study the expression of secreted proteins in aggregated dermal papilla cells （DPCs）. Methods DPCs were isolated from human scalp tissue and subjected to primary culture and subculture. Aggregated and non-aggregated DPCs served as the subject of this study. Secreted proteins were prepared from these cells and subjected to two-dimensional polyacrylamide gel electrophoresis. Differentially expressed proteins were screened by the PDQuest image analysis software. Protein spots were digested and identified by matrix-assisted laser desorption/ionization time-of-flight （MALDI-TOF） mass spectrometry, and finally analyzed using the National Center for Biotechnology Information （NCBI） non-redundant （Nr） protein database. Results Two-dimensional electrophoresis maps with good repeatability and high resolution were established. Image analysis of 2-D gels revealed that the average number of detected protein spots was 1 134 ± 52 and 1 078 ± 36 in aggregated and non-aggregated DPCs respectively, and the majority of these protein spots were matched between aggregated and non-aggregated DPCs. Twenty-eight protein spots showed more than 5-fold difference between the two groups of cells, and 10 proteins were preliminarily identified as differentially expressed proteins by peptide-mass fingerprinting. Of these differentially expressed proteins, 8 proteins including Rhogdi 1, filamin A , cystatin C, fibronectin, cyclophilin A, procollagen C proteinase enhancer 1, tissue inhibitor of metalloproteinase and tissue inhibitor of metalloproteinase-2 were up-regulated, and 2 proteins including neuropolypeptide h3 and matrix metalloproteinase-3/tissue inhibitor of metalloproteinase-1 complex were down-regulated in aggregated DPCs compared with non-aggregated DPCs. Conclusions Differentially expressed proteins between aggregated and non-aggregated DPCs are mainly implicated in cell signaling pathway, cellular proliferation and differentiation, extracellular matrix synthesis and degradation, and so on.

Key words: Dermal papilla cells, Secretory proteins, Electrophoresis, gel, two-dimensional, MALDI-TOF mass spectrometry