Bone marrow mesenchymal stem cells regulated hepatic stellate cells activation through LPS-TLR4 pathway

Objective To investigate whether bone marrow mesenchymal stem cells (BMSC) affect the hepatic stellate cells (LX2) through inhibiting LPS-TLR4 pathway, and to clarify the mechanism of LPS causing liver fibrosis by activating LX2.Methods Human BMSC and LX2 were isolated and cultured in vitro separately or co-cultured in transwell under different treatments in four groups, which were 2×105 BMSC and 2×105 LX2 (with 100μg/ml LPS stimulation) co-culture group, 2×105 BMSC and 2×105 LX2 (no LPS stimulation) co-culture group, 2×105 LX2 (with 100μg/ml LPS stimulation) group, 2×105 BMSC (with 100μg/ml LPS stimulation) group and 2×105 LX2 (no LPS stimulation) group.Supernatant of 6, 12, 36 and 48 hours after treatment was collected and detected for IL-8 and TGFβ expression by ELISA.The TLR4, Myd88 and NF-κB gene expression of LX2 were detected by RT-PCR.The SMA, TGFβ, TLR4, Myd88 and ColⅠ expression were detected by Western Blotting.NF-κB p65 expression in cell was observed by immunofluorescence.Results LPS can stimulate LX2 activation.Activated LX2 secreted more IL-8 and TGFβ than static LX2 respectively, P<0.05.Gene expression of α-SMA, TGFβ and ColⅠ were increased in activated LX2.NF-κB p65 was mainly expressed in nucleus of activated LX2.After co-culture with BMSC, LX2 activation by LPS was inhibited significantly as the SMA, TGFβ, TLR4, Myd88 and ColⅠ were reduced.NF-κB p65 was mainly expressed in cytoplasm.Conclusion BMSC can inhibit LX2 activation through LPS-TLR4 pathway.