Effects of exosomes derived from placental mesenchymal stem cells on high glucose-induced senescence in human dermal fibroblasts

Abstract

Objective To explore the optimal conditions for inducing senescence in human dermal fibroblasts (HDFs) cultured in high glucose and observe the effect of exosomes derived from human placental mesenchymal stem cells (PMSCs) on the proliferation, migration and senescence of high glucose-induced fibroblasts. Methods HDFs were isolated from human foreskin tissue and cultured in the presence of 5.5 mmol/L glucose (normal control group), 26 mmol/L glucose (HG1 group) and 35 mmol/L glucose (HG2 group). CCK-8 assay was used to detect cell proliferation in each group on days 1, 3, 5 and 7 of cell culture. The cells cultured for 7 d were tested for migration within 24 h using cell scratch assay; reactive oxygen species (ROS) production in the cells was detected using 2′, 7′-dichlorofluorescein diacetic acid (DCFH) method, and β-galactosidase activity was analyzed using a β-galactosidase staining kit. The HDFs cultured in 35 mmol/L glucose for 7 d were exposed for 3 days to 5 μg/mL and 50 μg/mL exosomes, which were isolated from human PMSCs by differential ultracentrifugation, and the cell proliferation, migration, ROS levels and β-galactoside activity were assessed. Flow cytometry was used to analyze the cell cycle changes and Western blotting was performed to detect the expression of aging-related proteins p53 and p21 in the cells following treatment with the exosomes. Results Compared with the control cells, the HDFs in HG1 and HG2 groups exhibited significantly decreased proliferation and migration ability (P < 0.01) and increased ROS production (P < 0.01) and β-galactoside activity (P < 0.01). Treatment with the exosomes obviously promoted the proliferation and migration of HDFs cultured in high glucose (P < 0.01). At the concentration of 50 μg/mL, PMSC-derived exosomes significantly decreased ROS production and β-galactoside activity (P < 0.01) and obviously down-regulated the expression levels of p53 and p21 (P < 0.01) in the HDFs cultured in high glucose, whereas a low concentration (5 μg/mL) of the exosomes did not produce such effects. Conclusion Exosomes derived from PMSCs promote the proliferation and migration and alleviate oxidative stress-induced damage and cell senescence in high glucose-induced HDFs, the mechanism of which may involve the down-regulation of the aging-related proteins p53 and p21.

Keywords

• exosomes
• placental mesenchymal stem cells
• fibroblasts
• high glucose
• cell senescence
• cell
• cell proliferation
• cell migration