Abstract: PURPOSE: To investigate the effect of dental pulp stem cells on the senescence and proliferation of skin fibroblasts, and to explore the underlying mechanism. METHODS: Dental pulp stem cells (DPSCs) were extracted from human dental pulp and then skin fibroblasts were co-cultured with DPSCs. The experiment was divided into three groups: control group (single skin fibroblasts culture), conditioned medium group (skin fibroblasts cultured with DPSCs conditioned medium), direct co-culture group (skin fibroblast cultured with DPSCs in Transwell chambers). After co-culture, the senescence of fibroblasts was detected by SA-β-gal staining.CCK-8 method was used to detect the activity of fibroblasts. The cell cycle of fibroblasts was analyzed by flow cytometry. mRNA and protein expression levels of senescence related proteins p21, p53 and pRb were detected by RT-PCR and Western blot. SPSS 13.0 software package was used for statistical analysis of the experimental data. RESULTS: Compared with the control group, skin fibroblasts in the latter two groups showed decreased expression of SA-β-gal and increased proliferation ability. Cell cycle test showed that skin fibroblasts decreased in G1 phase and increased in S and G2 phase in conditioned medium group and direct co-culture group. RT-PCR and Western blot results showed decreased expression levels of p53, p21 mRNA and protein, and increased levels of pRb in conditioned medium group and direct co-culture group. CONCLUSIONS: Dental pulp stem cells and their conditioned medium have anti-aging effect on skin fibroblast. The results of this study provide theoretical basis for the clinical application of dental pulp stem cells in anti-aging.

Key words: Dental pulp stem cells, Skin fibroblasts, Co-culture, Conditioned medium, Anti-aging