Thy1-positive mesenchymal cells promote the maturation of CD49f-positive hepatic progenitor cells in the mouse fetal liver
Thy1-positive mesenchymal cells promote the maturation of CD49f-positive hepatic progenitor cells in the mouse fetal liver
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DOI：
10.1002/hep.20180
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发表时间：
2004-05-01
期刊：
影响因子：
13.5
通讯作者：
Ikai, I
中科院分区：
文献类型：
--
作者：
Hoppo, T;Fujii, H;Ikai, I
此前，我们报道了一种通过形成细胞聚集体来富集小鼠胎儿肝祖细胞（HPC）的系统。在本研究中，我们使用流式细胞仪从细胞聚集体中分选了两个细胞群：CD49f(+)Thyl(-)CD45(-)细胞（CD49f阳性细胞）和CD49f(+/-)Thy1(+)CD45(-)细胞（Thy1阳性细胞）。 CD49f 阳性细胞内胚层特异性标记物（如甲胎蛋白 (AFP)、白蛋白 (ALB) 和细胞角蛋白 19 (CK19)）染色呈阳性，因此被认为是 HPC。然而，Thy1 阳性细胞是形态异质的群体；逆转录聚合酶链反应 (RT-PCR) 和免疫细胞化学分析显示间充质细胞标记物的表达，例如 α-平滑肌肌动蛋白、结蛋白和波形蛋白，但不表达 AFP、ALB 或 CK19。因此，Thy1阳性细胞被认为属于间充质谱系。当这两个细胞群共培养时，CD49f 阳性集落形态成熟并储存大量糖原。此外，实时RT-PCR证明酪氨酸氨基转移酶和色氨酸加氧酶mRNA的表达增加，透射电子显微镜证实共培养的细胞产生成熟的肝细胞。然而，当CD49f阳性细胞单独培养或当两个群体单独培养时，CD49f阳性细胞不成熟。这些结果表明CD49f阳性细胞是原始肝内胚层细胞，具有分化为肝细胞的能力，并且Thy1阳性细胞通过直接细胞间接触促进CD49f阳性细胞的成熟。总之，我们能够分离 CD49f 阳性原始肝内胚层细胞和 Thy1 阳性间充质细胞，并证明这些细胞类型之间的细胞间接触对于肝前体的成熟是必需的。
Previously, we reported a system to enrich mouse fetal hepatic progenitor cells (HPCs) by forming cell aggregates. In this study, we sorted two cell populations, CD49f(+)Thyl(-)CD45(-)cells (CD49f-postive cells) and CD49f(+/-)Thy1(+)CD45(-) cells (Thy1-positive cells), from the cell aggregates using a flow cytometer. CD49f-positive cells stained positive for endodermal specific markers such as alpha-fetoprotein (AFP), albumin (ALB), and cytokeratin 19 (CK19), and are thus thought to be HPCs. However, Thy1-positive cells were a morphologically heterogeneous population; reverse-transcription polymerase chain reaction (RT-PCR) and immunocytochemical analyses revealed the expression of mesenchymal cell markers such as alpha-smooth muscle actin, desmin, and vimentin, but not of AFP, ALB, or CK19. Therefore, Thy1-positive cells were thought to be of a mesenchymal lineage. When these two cell populations were co-cultured, the CD49f-positive colonies matured morphologically and stored a significant amount of glycogen. Furthermore, real-time RT-PCR demonstrated an increased expression of tyrosine amino transferase and tryptophan oxygenase mRNA, and transmission electron microscopy confirmed that co-cultured cells produced mature hepatocytes. However, when CD49f-positive cells were cultured alone or when the two populations were cultured separately, the CD49f-positive cells did not mature. These results indicate that CD49f-positive cells are primitive hepatic endodermal cells with the capacity to differentiate into hepatocytes, and that Thy1-positive cells promote the maturation of CD49f-positive cells by direct cell-to-cell contact. In conclusion, we were able to isolate CD49f-positive primitive hepatic endodermal cells and Thy1-positive mesenchymal cells and to demonstrate the requirement of cell-to-cell contact between these cell types for the maturation of the hepatic precursors.