骨髓间充质干细胞通过调节LPS-TLR4通路抑制肝星形细胞活化的作用机制

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

目的研究人骨髓间充质干细胞(BMSC)是否可通过干预LPS-TLR4通路,调控肝星状细胞(HSC)LX2活化,阐明BMSC在肝纤维化形成中的作用。方法体外共培养BMSC、LX2,分为BMSC+LX2(LPS刺激)组、TLR4阻断剂+LX2(LPS刺激)组、LX2(LPS刺激)组、BMSC(LPS刺激)组、LX2(无LPS刺激)组,培养6、12、36、48 h;收集上清,ELISA检测IL-8及TGFβ表达,RT-PCR检测LX2的TLR4、Myd88及NF-κB的表达,Western Blot检测TGFβ、SMA、ColⅠ、MyD88、TLR4表达。免疫荧光检测NF-κB细胞内表达情况。结果 LPS可以刺激LX2活化,活化的LX2分泌IL-8及TGFβ增多,TGFβ、SMA、ColⅠ、MyD88、TLR4表达增加,NF-κB p65主要为核内表达。与BMSC共培养后,LPS导致的LX2活化减弱,LX2的TGF-β、SMA、ColⅠ、MyD88、TLR4的表达下降,NF-κB p65胞浆表达为主。结论 BMSC可以通过干预LPS-TLR4通路抑制LX2的活化。

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,P0.05.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.