中文摘要：

目的：通过收集 TGFβ1刺激过的前体细胞条件培养基，观察其对 HSC 的影响。方法收集 TGFβ1预处理的前体细胞条件培养基，培养 HSC 细胞48 h，观察 HSC 活化程度及细胞外基质相关指标的变化。结果经 TGFβ1刺激后的前体细胞形态明显变大变圆，胞质比例明显增加，核质比减少。去除 TGFβ1刺激后，发现 TGFβ1刺激超过24 h，前体细胞的上皮-间质转换发生逆转，表现为α-平滑肌肌动蛋白（α-smooth muscle actin，α-SMA）蛋白表达量下降，24 h、36 h 及48 h 分别为对照组的1.31倍（P ＞0.05）、0.97倍（P ＝0.027）、1.08倍（P ＝0.058）。与对照组相比，TGFβ1刺激后前体细胞的条件培养基对 HSCs 的细胞形态无明显差别。进一步分析发现，TGFβ1刺激前体细胞6h 后，其条件培养基促使星状细胞α-SMA 及细胞外基质标志物金属蛋白酶组织抑制剂-1（tissue inhibitor of metalloproteinase，TIMP-1）在蛋白及基因水平上（分别为对照组的4.12倍及2.64倍）的表达；然而刺激超过24h 上述作用相反，在蛋白水平表现为α-SMA 表达降低而 TIMP-1的表达无明显变化，在基因水平α-SMA 及 TIMP-1均呈降低趋势（24 h、36 h、48 h 分别为对照组0.81倍及0.98倍、0.96倍及0.61倍、0.63倍及0.76倍）。结论去除 TGFβ1的刺激后，其诱导的上皮-间质转换可发生逆转，并在逆转过程中可影响星状细胞的活化。

英文摘要：

Objective In chronic liver injury,activated hepatic stellate cells （HSCs）have intimate contact with hepatic progenitor cells （HPCs）.HPCs,which pretreated with TGFβ1 ,could affect activation of HSCs in indirect co-culture system in vitro.However,it is still unclear whether HPCs＇condition medium pretreated with TGFβ1 could affect HSCs.Objective To investigate the effects of HPCs＇conditioned medium which pretreated with TGFβ1 on HSCs.Methods Conditioned medium of HPCs pretreated with TGFβ1 was collected to observe effects on activation of HSCs and extracellular matrix.Results Firstly,after treated with TGFβ1 ,morphology of HPCs had been changed significantly. Then removing TGFβ1 and adding fresh medium for 48 hours,TGFβ1-induced myofibroblast phenotype was reversed after treated with more than 24h.Secondly,conditioned medium of HPCs pretreated with TGFβ1 was collected to culture HSCs for 48h,which showed no difference with control group in the morphology.On further analysis,after treated with TGFβ1 for 6h,conditioned medium of HPCs enhanced the expression ofα-SMA and TIMP-1 of HSCs at levels of protein and gene. However,pretreatment for more than 24h would lead to an opposite effect.To be specific,expressions ofα-SMA decreased at levels of protein and gene,whereas lower expression of TIMP-1 only was detected at level of gene.Conclusion Removing TGFβ1 could reverse transition of hepatic progenitor cells,and affect activation of HSCs.