Epithelial mesenchymal transition during the development of ductal plate in human liver and its significance / 第二军医大学学报

Objective To investigate the expression of markers for epithelial-mesenchymal transition (EMT) during the development of ductal plate in human liver, so as to discuss the role of EMT during ductal plate development in the liver. Methods Immunohistochemical method was used to examine the expression of EMT markers (CK19, vimentin, and ccSMA) in the liver tissues of 31 fetuses of 8-40 weeks old. Results From the 8th gestation week onwards (ductal plate phase, remodeling phase of ductal plate, and formation phase of bile ducts), the CK19-positive cells in the portal tract were gradually increased, vimentin/ ccSMA-positive portal mesenchymal cells were gradually decreased, and CK19-positive cells were negatively correlated with vimentin/ ccSMA expression ones (vimentin: r=- 0. 820, P

Immunohistochemical characterization of hepatic stem cells in developing human liver / 第二军医大学学报

Objective: To investigate the immunohistochemical characterization of hepatic stem cells in the developing human liver, so as to study the origin, differentiation and migration of hepatic stem cells. Methods: H-E staining and immunohistochemical methods were used to observe the expression of hepatic/cholangiocellular differentiation markers (AFP, GST-π, CK7, CK19) and hematopoietic stem cell markers (CD34 and c-kit) in several kinds of cells obtained from thirty 4- to 35-week old fetal liver samples. Results: AFP expression appeared in fetal liver at 4 weeks' gestation, peaked during 16-24 weeks' gestation and decreased gradually afterwards; finally weak signals were only found in some ductal plate cells and a few limiting plate cells. GST-π was detected in hepatic cord cells from the 6th week and in the ductal plate cells from the 8th week; 26 weeks later, only some ductal plate cells and a few limiting plate cells showed positive signals. CK19 expression peaked during 6th to 11th week in hepatic cord cells and decreased gradually afterwards, except for that in the ductal plates. CK7 expression was limited in the ductal plate cells and bile duct cells from the 14th week. CD34 and c-kit were detected at the 8th week in some ductal plate cells and a few mononuclear cells in the hepatic cords/mesenchymal tissue of portal area; after 21 weeks, CD34 and c-kit were found only in ductal plate cells and a few mononuclear cells in the hepatic mesenchymal tissue of portal areas. Conclusion: Fetal hepatocytes at 4-16 weeks' gestation are mainly constituted by hepatic stem cells with bi-potential differentiation capacity. At 16 weeks' gestation, most hepatic cord cells begin to differentiate into hepatocytes and abundant hepatic stem cells remain in the ductal plate (the origin site of Hering canals). It is also indicated that the hematopoietic stem cells may give rise to some hepatic stem cells in embryonic liver. These indirectly support the hypothesis about the location and origin of liver stem cells in "liver valley hypothesis" reported previously.

Role of hepatic stem cells in hepatic regeneration / 第二军医大学学报

Hepatic stem cells transplantation might be an important treatment strategy for patients with end stage liver diseases and related research has become a focus of recent studies. Hepatic stem cells of different sources have great therapeutic potential in clinical practice, but much research still need to be done before it can be used as a routine method in clinical practice. This review discusses the characteristics of hepatic stem cells and its role in liver regeneration after liver damage.

Isolation and identification of hepatic stem cells from rat fetal liver in vitro / 吉林大学学报(医学版)

Objective To isolate and cultivate hepatic stem cells(HSCs) from rat fetal liver in vitro and identify their biological features.Methods Collagenase perfusion method and mechanical cutting method were used to isolate HSCs from rat fetal liver which were then cultivated by H-DMEM containing 10% fetal bovine serum.The cell surface antigen expression of HSCs was observed with immunocytochemical method under confocal laser scanning microscope.Results The isolated HSCs from rat fetal liver grew to monolayer 5 d after cultivation in vitro.They presented pykno-round cells and distinct borderline under the light microscope.After 8 d the cells grew like epithelium.These cells expressed AFP antigen,CK 18 and CK19.Conclusion The cultivated cells are proved to be HSCs and can proliferate quickly in vitro.

Chemical carcinogen 3’-me-DAB affects proliferation and migration of rat hepatic stem cells / 第三军医大学学报

Objective To explore the relationship between hepatic stem cells and hematopoietic stem cells by detecting the expression of OV6 and CD34 in rat hepatic oval cells. Methods Healthy SD rat were fed with chemical carcinogen 3’-me-DAB for 4 weeks, then the rat hepatic tissue samples were obtained. The rats fed with normal forage served as normal controls. The expressions of OV6 and CD34, specific markers for oval cells and hematopoietic stem cells respectively, in rat hepatic stem cells were detected by immunocytochemical staining (ABC method). Results The oval cells positive for OV6 and CD34 were found in the limiting plate of portal area, mainly located around the Hering canal. In addition, some oval cells positive for OV6 and CD34 were found migrating to hepatic lobule, scattering in the hepatic cords. A great many mononuclear stem cells positive for OV6 and CD34 were also found in the hepatic parenchyma. Conclusion 3’-me-DAB could stimulate the proliferation of hepatic oval cells and hematopoietic stem cells and cause the hematopoietic stem cells derived from bone marrow to migrate to hepatic parenchyma and differentiate.

Parenchymal and Nonparenchymal Cellular Responses in Human Hepatic Regeneration

To characterize cellular responses during hepatic regeneration, we examined 13 explant livers and 5 liver allografts by immunohistochemistry for cytokeratin 7, HepPar1, CD68, alpha-smooth muscle actin (alpha-SMA) and proliferating cell nuclear antigen as well as reticulin and Masson-trichrome staining. Within a week after liver damage, elongated CD68-positive cells were detected along the border of necrotic area. The number of alpha-SMA-positive cells was slightly increased along the sinusoids. Ductular proliferation or fibrosis was negligible. After one or two weeks, the size and number of CD68-positive cells were markedly increased. alpha-SMA-positive cells increased in number within lobules and portal tracts. Ductular proliferation occurred predominantly at the limiting plate or along the border of necrotic areas. After one month, necrotic parenchyma was replaced by many ductules, CD68-positive cells, alpha-SMA-positive cells. Nodules of regenerating hepatocytes and irregular fibrosis were diffusely present. Other nonparenchymal cells were not significantly changed. These observations indicate that chronological interaction between nonparenchymal and parenchymal cells occur during the course of human hepatic regeneration and suggest extensive porto-periportal fibrosis more than a few months after the onset of fulminant hepatitis is a major indicator of chronic functional impairment necessitating liver transplantation.

Role of hepatic stem cells in hepatic regeneration / 第二军医大学学报

Hepatic stem cells transplantation might be an important treatment strategy for patients with end stage liver diseases and related research has become a focus of recent studies.Hepatic stem cells of different sources have great therapeutic potential in clinical practice,but much research still need to be done before it can be used as a routine method in clinical practice. This review discusses the characteristics of hepatic stem cells and its role in liver regeneration after liver damage.

Immunohistochemical characterization of hepatic stem cells in developing human liver / 第二军医大学学报

Objective:To investigate the immunohistochemical characterization of hepatic stem cells in the developing human liver, so as to study the origin, differentiation and migration of hepatic stem cells. Methods: H-E staining and immunohistochemical methods were used to observe the expression of hepatic/cholangiocellular differentiation markers (AFP,GST-?,CK7,CK19) and hematopoietic stem cell markers (CD34 and c-kit) in several kinds of cells obtained from thirty 4-to 35-week old fetal liver samples. Results: AFP expression appeared in fetal liver at 4 weeks’ gestation,peaked during 16-24 weeks’ gestation and decreased gradually afterwards; finally weak signals were only found in some ductal plate cells and a few limiting plate cells. GST-? was detected in hepatic cord cells from the 6th week and in the ductal plate cells from the 8th week; 26 weeks later, only some ductal plate cells and a few limiting plate cells showed positive signals. CK19 expression peaked during 6th to 11th week in hepatic cord cells and decreased gradually afterwards, except for that in the ductal plates. CK7 expression was limited in the ductal plate cells and bile duct cells from the 14th week. CD34 and c-kit were detected at the 8th week in some ductal plate cells and a few mononuclear cells in the hepatic cords/mesenchymal tissue of portal area; after 21 weeks, CD34 and c-kit were found only in ductal plate cells and a few mononuclear cells in the hepatic mesenchymal tissue of portal areas. Conclusion: Fetal hepatocytes at 4-16 weeks’ gestation are mainly constituted by hepatic stem cells with bi-potential differentiation capacity. At 16 weeks’ gestation, most hepatic cord cells begin to differentiate into hepatocytes and abundant hepatic stem cells remain in the ductal plate (the origin site of Hering canals). It is also indicated that the hematopoietic stem cells may give rise to some hepatic stem cells in embryonic liver. These indirectly support the hypothesis about the location and origin of liver stem cells in “liver valley hypothesis” reported previously.