Abstract：Objective: To study the effect of human umbilical cord mesenchymal stem cells derived exosomes(HucMSC-ex) on collagen synthesis in hepatic stella cell line (LX-2) and its mechanism. Methods: HucMSC-ex was identified by transmission electron microscopy for morphology and western blotting for exosomal markers CD9 and CD63 expression. The mRNA levels of Col1, Col3, TGF-βR1 and Let-7b in LX-2 cells were detected by qRT-PCR. The level of TGF-βR1 protein in LX-2 cells was detected by western blotting. Results: HucMSC-ex are membrane vesicles with a diameter of 30-100 nm and express exosomal markers CD9 and CD63. Compared with the control group, HucMSC-ex significantly reduced Col1, Col3 and TGF-βR1 expression (all P<0.001), promoted Let-7b expression (all P<0.001). Let-7b mimics transfection downregulated TGF-βR1 and α-SMA expression in LX-2 cells (both P<0.05). Conclusion: HucMSC-ex may inhibit LX-2 activation through delivering Let-7b to regulate TGF-βR1 expression in hepatic stellate cells.
［Key words］Let7b; human umbilical cord mesenchymal stem cells derived exosomes; hepatic stellate cells
2018, Vol. 28 
