Effects of μ-opoiod receptor on proliferation and migration of human epidermal stem cells in vitro

Abstract

Objective To investigate the affects of μ-opioid receptor activation on proliferation and migration of epidermal stem cells (ESCs) in vitro.Methods Primary human ESCs (hESCs) were isolated and cultured,and marked by both integrin β31 and eytokeratin 19 (CK19) to be identified.The hESCs of the second generation were cultured with K-SFM supplemented with 1 nmol/L β-endorphins in group A,with K-SFM supplemented with 10 nmol/L naloxone and 1 nmol/L β-endorphins in group B,and with K-SFM supplemented with no drugs in group C.The proliferative ability of hESCs in each group was determined by using methyl thiazol tetrazolium (MTT) assay for 5 consecutive days.The 100 μm scratch wounds were created by scraping confluent hESCs plated on Petri-dishes with a sterile pipette tip in vitro.The pictures of migrating cells from the wound edge were taken at 24,48,72 and 96 h after incubarton with different media.The wound healing rate was calculated by Image-Pro Plus software at 72 h.Results Cultured primary hESCs could adhere to the wall and showed cobblestone-like shape.Immunofluorescence staining showed the positive results for integrin β1 and CK19.The proliferation rate of hESCs detected hy using MTT assay was significantly higher in group A than in groups C,visibly higher in group C than in group B during the day 2 to day 5,and the difference between each two groups was statistically significant (P ＜ 0.05).In group A,the number of cells migrating the wound edge was greater than in group C,and less in group B than in group C at 24 h.The wound healing rate in groups A,B and C at 72 h was (91.80 ± 0.05) ％,(79.40 ± 0.06) ％,and (86.30 ± 0.75) ％ respectively,showing significant differences among groups (P ＜ 0.05).Conclusion The activation of μ-opioid receptor can promote the proliferation and migration of hESCs in vitro.The μ-opioid receptor may be involved in some modutory processes of skin metabolisms. Key words: Epidermal stem cells ; Opioid receptor ; Proliferation ; Migration