牙髓干细胞对皮肤成纤维细胞衰老及增殖能力的影响

目的：研究牙髓干细胞对皮肤成纤维细胞衰老及增殖能力的影响,并初步探讨其机制。方法：从人牙髓中提取,培养牙髓干细胞,与皮肤成纤维细胞分组共培养,分为3组：对照组（单纯皮肤成纤维细胞培养）、条件培养基组（利用牙髓干细胞条件培养基培养成纤维细胞）、直接共培养组（采用Transwell共培养小室）。共培养后,进行 β半乳糖苷酶（SA-β-gal）染色,检测成纤维细胞的衰老情况;利用 CCK-8 法检测各组成纤维细胞的活性;流式细胞仪分析成纤维细胞的细胞周期变化;采用RT-PCR和 Western免疫印迹检测各组成纤维细胞衰老相关蛋白 p21、p53以及pRb 的mRNA和蛋白表达水平。采用SPSS 13.0软件包对数据进行统计学分析。结果：与空白组相比,后2组的皮肤成纤维细胞表达β半乳糖苷酶降低、增殖能力增强、G1期细胞减少而S期和G2期增多, p53、p21 mRNA和蛋白表达水平降低而PRb表达升高。结论：牙髓干细胞及其条件培养基具有抗皮肤成纤维细胞衰老的作用,为牙髓干细胞在抗皮肤衰老方面的临床应用提供了依据。

Anti-aging effect of dental pulp stem cells on skin fibroblasts

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.