Menstrual Blood-derived Stem Cells Ameliorate Liver Fibrosis And The Underlying Mechanism

Mesenchymal stem cells (MSCs) may possessgreat application valuesin regenerative medicine for treating these chronic liver diseases (CLDs). Human menstrual blood is a novel source of MSCs, termed MenSCs (menstrual blood-derived stem cells), showing a high proliferation rate and can be obtained through a simple, safe, painless procedure.More importantly, in contrast to bone marrow MSCs, MenSCs nearly have no ethical concerns. Although the therapeutic efficacy of MenSCs has been explored in some diseases, their effects on liver fibrosis are still unclear.In the present research, we explored the therapeutic effects of MenSC transplantation in a CCI4 (carbon tetrachloride)-induced liver fibrosis model in mouse.We observed that after two weeks’transplantation, MenSCs could obviously improve serum liver functions (ALT, AST, ALP and TBIL),which was further verified by pathological detection (sirius red staining). Additionally, the expression profiles of a-smooth muscle actin (a-SMA)and transforming growth factor-β1 (TGF-β1) by immunohistochemistry, qRT-PCR (quantitative real-time PCR) and western blot (except TGF-β1) evidenced that the excitation of HSCs (hepatic stellate cells) was suppressed post two weeks’transplantation of MenSCs. To observe the fate of the transplanted cells,in vivo imaging was applied and the results indicated that the homing was specific to the injury site.Moreover, tracking of GFP-expressing MenSCs demonstrated that few differentiated into functional hepatocyte-like cells. These results revealed that MenSCs markedly improved liver function, attenuated collagen fiber deposition, and inhibited activated HSCs up to 2 weeks after transplantation.To clarifythe possible mechanismsinvolved in this therapeutic ability of MenSCs, indirect co-culture systembetween MenSCs and HSCs (LX-2 cell lines) was utilized for exploring the effect of MenSCs on LX-2 cells in vitro.The transwell experimentssuggested thatMenSCs had a suppressive role on the proliferation of LX-2 cells and regulated cell cycle of LX-2 cells by blocking the G0/G1 phase cells. Furthermore,MCP-1 (monocyte chemoattractant protein-1), IL-6 (interleukin-6), HGF(hepatocyte growth factor), GRO(growth-related oncogene), IL-8 (interleukin-8), and OPG (osteoprotegerin)exert vital paracrine effectto inhibit HSCs activation according to antibody arrays in the transwell systems (including LX-2 group,co-culture group, and MenSCs group). More specifically, further ELISA analysis for cell supernatants and cell lysates proved these.In conclusion, we provide a preliminary evidence for the anti-fibrotic capability of MenSCs in CCl4-injured mouse model of liver fibrosis. We further demonstrate that soluble factors secreted by MenSCs have an inhibitory function on the activation of HSCs and theblock of HSCs cycle in vitro. Potential paracrine cytokines may include MCP-1, IL-6, HGF, GRO, IL-8 and osteoprotegerin. Collectively, MenSCs may be a potential therapeutic means for treating CLDs and clinical application.