Asahina Kinji, Tsai Shirley Y, Li Peng, Ishii Mamoru, Maxson Robert E, Sucov Henry M, Tsukamoto Hidekazu
Department of Pathology, Southern California Research Center for Alcoholic Liver and Pancreatic Diseases and Cirrhosis, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90033-9141, USA.
Hepatology. 2009 Mar;49(3):998-1011. doi: 10.1002/hep.22721.
The knowledge concerning fetal hepatic stellate cells (HSCs) is scarce, and their cell lineage and functions are largely unknown. The current study isolated fetal liver mesenchymal cells from a mouse expressing beta-galactosidase under the control of Msx2 promoter by fluorescence-activated cell sorting (FACS) and surveyed marker genes by microarray analysis. Based on the location and immunostaining with conventional and newly disclosed markers, we have identified three distinct populations of fetal liver mesenchymal cells expressing both desmin and p75 neurotrophin receptor (p75NTR): HSCs in the liver parenchyma; perivascular mesenchymal cells expressing alpha-smooth muscle actin (alpha-SMA); and submesothelial cells associated with the basal lamina beneath mesothelial cells and expressing activated leukocyte cell adhesion molecule (ALCAM) and platelet-derived growth factor receptor alpha. A transitional cell type from the submesothelial cell phenotype to fetal HSCs was also identified near the liver surface. Mesothelial cells expressed podoplanin and ALCAM. Ki-67 staining showed that proliferative activity of the submesothelial cells is higher than that of mesothelial cells and transitional cells. Using anti-ALCAM antibodies, submesothelial and mesothelial cells were isolated by FACS. The ALCAM(+) cells expressed hepatocyte growth factor and pleiotrophin. In culture, the ALCAM(+) cells rapidly acquired myofibroblastic morphology and alpha-SMA expression. The ALCAM(+) cells formed intracellular lipid droplets when embedded in collagen gel and treated with retinol, suggesting the potential for ALCAM(+) cells to differentiate to HSCs. Finally, we demonstrated that fetal HSCs, submesothelial cells, and perivascular mesenchymal cells are all derived from mesoderm by using MesP1-Cre and ROSA26 reporter mice.
Fetal HSCs, submesothelial cells, and perivascular mesenchymal cells are mesodermal in origin, and ALCAM(+) submesothelial cells may be a precursor for HSCs in developing liver.
关于胎儿肝星状细胞（HSC）的知识稀缺，其细胞谱系和功能大多未知。当前研究通过荧光激活细胞分选（FACS）从在Msx2启动子控制下表达β-半乳糖苷酶的小鼠中分离出胎儿肝间充质细胞，并通过微阵列分析检测标记基因。基于位置以及使用传统和新发现的标记进行免疫染色，我们鉴定出三种不同的胎儿肝间充质细胞群体，它们同时表达结蛋白和p75神经营养因子受体（p75NTR）：肝实质中的肝星状细胞；表达α-平滑肌肌动蛋白（α-SMA）的血管周围间充质细胞；以及与间皮细胞下方基膜相关并表达活化白细胞细胞粘附分子（ALCAM）和血小板衍生生长因子受体α的间皮下细胞。在肝表面附近还鉴定出一种从间皮下细胞表型向胎儿肝星状细胞过渡的细胞类型。间皮细胞表达血小板内皮细胞粘附分子和ALCAM。Ki-67染色显示间皮下细胞的增殖活性高于间皮细胞和过渡细胞。使用抗ALCAM抗体，通过FACS分离出间皮下细胞和间皮细胞。ALCAM(+)细胞表达肝细胞生长因子和多效生长因子。在培养中，ALCAM(+)细胞迅速获得肌成纤维细胞形态并表达α-SMA。当嵌入胶原凝胶并用视黄醇处理时，ALCAM(+)细胞形成细胞内脂质滴，表明ALCAM(+)细胞具有分化为肝星状细胞的潜力。最后，我们使用MesP1-Cre和ROSA26报告基因小鼠证明胎儿肝星状细胞、间皮下细胞和血管周围间充质细胞均起源于中胚层。
胎儿肝星状细胞、间皮下细胞和血管周围间充质细胞起源于中胚层，并且ALCAM(+)间皮下细胞可能是发育中肝脏肝星状细胞的前体。
