Analysis in activation of hepatic stem/progenitor cells and development of application to hepatic tissue engineering

椭圆细胞和小肝细胞（SHs）被称为肝干细胞和祖细胞，Thy1和CD44分别被用作标记。尽管卵形细胞被认为可以通过SHs分化为成熟肝细胞，但其分化过程的细节尚不清楚。在本实验中，我们使用了从d -半乳糖胺处理的大鼠肝脏中分离的Thy1^+卵形细胞和CD44^+细胞。(1) EGF、碱性FGF、HGF均可触发经分选的Thy1^+细胞向肝脏分化形成上皮细胞集落。(2) Thy1^+卵圆细胞和CD44^+细胞能够分化为肝细胞，诱导的肝细胞的肝成熟程度可能不等于正常的常驻肝细胞。(3)肝部分切除术后，将Thy1^+、CD44^+细胞和mhh移植到逆转录酶治疗的肝脏中。干细胞和祖细胞都能在宿主肝脏中分化为肝细胞。Thy1^+、CD44^+细胞的长期再生效率和存活时间都很低。细胞寿命短可能是由于细胞衰老所致。

Oval cells and small hepatocytes(SHs) are known as hepatic stem and progenitor cells, and Thy1 and CD44 are used as a marker, respectively. Although oval cells are believed to differentiate into mature hepatocytes(MHs) through SHs, the details of their differentiation process are not well understood. In the present experiment we used Thy1^+ oval and CD44^+cells isolated from D-galactosamine-treated rat livers. (1) EGF, basic FGF, or HGF could trigger the hepatic differentiation of sorted Thy1^+ cells to form epithelial cell colonies. (2) Thy1^+oval and CD44^+cells are able to differentiate into hepatocytes, the degree of hepatic maturation of the induced hepatocytes may not be equal to that of normal resident ones. (3) Thy1^+, CD44^+cells and MHs were transplanted into livers treated with retrorsine following partial hepatectomy. Both stem and progenitor cells could differentiate into hepatocytes in host livers. Repopulation efficiency and the survival period of Thy1^+, CD44^+ cells in the long term was very low. The short life of the cells may be due to their cellular senescence.