Abstract: Objective To investigate the effects of paracrine hepatocyte growth factor (HGF) secreted by rat bone marrow mesenchymal stem cells on proliferation, apoptosis and activation of hepatic stellate cells after rat bone marrow mesenchymal stem cells (BMSCs) and hepatic stellate cells (HSCs) were co-cultured in vitro. Methods The whole bone marrow adherent method was used to isolate, culture and purify rat BMSCs, and HSCs were cultured. The semi-permeable membrane of six-well plate was used to establish a two-layer cell co-culture system with indirect contact. The study consisted of group H (HSCs were cultured alone), H-H group (HSCs and HSCs were co-cultured), M-H group (BMSCs and HSCs were co-cultured), M-H-C group (BMSCs and HSCs were co-cultured with c-met inhibitor). Cells in each group were cultured for 48 hours. BMSCs were identified and the apoptosis rate of HSCs was detected by flow cytometry. The proliferation of HSCs was detected by MTT assay, and the expression level of alpha smooth muscle actin (α-SMA) in HSCs was detected quantitatively by immunofluorescence confocal method. The concentration of HGF in the supernate of the coculture system was determined by ELISA. Results MSCs overexpressed positive surface molecules CD29 and CD90, and low expression of hematopoietic cell surface marker CD45. BMSCs could significantly inhibit the proliferation and activation of HSCs, and promote apoptosis of HSCs. The concentration of HGF in the supernate was significantly higher in M-H group than that in the other groups. Conclusion BMSCs can promote the apoptosis of HSCs, inhibit the proliferation and activation of HSCs through paracrine HGF in the co-culture of BMSCs and HSCs.

Key words: mesenchymal stem cells, bone marrow, hepatocyte growth factor, coculture techniques, paracrine, hepatic stellate cells