2022, Vol. 26 ›› Issue (24): 3865-3869

Epithelial differentiation of adipose stem cells induced by saliva in vitro

Li Xiaowen1, 2, Xu Yingjie1, 2, Jia Mengying1, 2, Shi Wei1, 2, Jia Xinyu1, 2, Gong Zhongcheng1, 2   

Abstract: BACKGROUND: Buccal fat pads are often used to repair oral and maxillofacial defects, which can rapidly differentiate the oral mucosa from the epithelium. Because the defect wound is exposed to saliva, it is believed that saliva may promote the epithelialization of adipose stem cells in the buccal fat pad.  
OBJECTIVE: To investigate the feasibility of promoting epithelial differentiation of rabbit adipose stem cells by induction of saliva in vitro.
METHODS:   Fat harvested from 2-3 months New Zealand white rabbit was isolated, cultured, generated adipose stem cells for passage. Passage 3 adipose stem cells were divided into three groups: negative control group, epidermal growth factor group and saliva group. Adipose stem cells were induced by 10 μg/L epidermal growth factor and 15% saliva in the epidermal growth factor group and saliva group. Cell morphology changes were observed under inverted microscope. The expression of cytokeratin 19 was detected by immunofluorescence and RT-PCR after 7 and 14 days of induction.  
RESULTS AND CONCLUSION: (1) After saliva induction, the morphology of adipose stem cells was gradually changed from long spindle shape to short spindle shape or even irregular oblate shape. (2) At 7 and 14 days, cytokeratin 19 was positively expressed in the epidermal growth factor and saliva groups, which was higher than that in the negative control group. The expression level of cytokeratin 19 in the 14-day induction group was significantly higher than that in the 7-day induction group. (3) The expression of cytokeratin 19 mRNA in epidermal growth factor and saliva groups was higher than that in negative control group (P < 0.01). The expression level at 14 days was significantly higher than that at 7 days (P < 0.01). (4) Results suggest that saliva can promote the epithelial differentiation of adipose stem cells to some extent.
Key words: stem cell, adipose stem cell, epidermal growth factor, saliva, epithelium, differentiation, cytokeratin 19