Development of method of transdifferentiation of human umbilical cord blood cells to hepatocyte

脐带血含有多种类型的干细胞。脐带血中的一种干细胞可以转分化为肝细胞。因此，脐带血细胞含有肝细胞祖细胞或干细胞样细胞。鉴别这些祖细胞对肝脏再生医学的发展具有重要意义。我们试图用NOD/SCID小鼠在人脐带血细胞中鉴定这些细胞。cd&阳性细胞耗尽后，用CD34、CD38和c-kit分离干细胞。这些细胞在急性肝损伤后被引入NOD/SCID小鼠体内，并以人白蛋白mRNA为标记物，评估其转分化为肝细胞的能力。因此，cd34阳性细胞含有较多的肝祖细胞，cd34阳性、cd38阳性细胞与cd -34阳性、cd -38阴性细胞转分化时间不同。cdt不是分离肝祖细胞的有用标记物。Fish方法证实了人脐带血细胞与小鼠肝细胞的融合细胞和脐带血细胞向肝细胞的转分化细胞的存在。重要的是，这两种细胞都表达人白蛋白。这些数据表明肝细胞样细胞由经分化的肝细胞和脐带血细胞与肝细胞融合的细胞组成。

Umbilical cord blood contains many types of stem cells. One kind of stem cells in cord blood can transdifferentiate into hepatocytes. Therefore, cord blood cells contain hepatocyte-progenitor cells or stem-like cells. It is very important to identify these progenitor cells in order to develop regenerative medicine in the field of hepatology. We tried to identy these cells in human cord cells using NOD/SCID mice. After depletion of CD&positive cells, CD34, CD38 and c-kit were used for isolation of stem cells. These cells were introduced into NOD/SCID mice after acute liver injury, and were assessed to transdifferentiate into hepatocyte using human albumin mRNA as a marker. As a result, CD34-positive cells contain many hepatic progenitor cells, and CD34-positive, CD38-positive cells and CD-34-positive, CD-38-negative cells are different in the time of transdifferentiation. cidt is not a useful marker in isolating hepatic progenitor cells. Fish method identified that both fusion cells of human cord blood cells and mouse hepatocytes and transdifferentiated cells from cord blood cells to hepatocytes actually exist. Importnatly, both cells express human albumin. These data suggest that hepatocyte-like cells are composed of trnasdifferentiated hepatocyte and fused cells between cord blood cells and hepatocytes.