AIM： To isolate putative pancreatic stem cells （PSCs） from human adult tissues of pancreas duct using serumfree, conditioned medium. The characterization of surface phenotype of these PSCs was analyzed by flow cyto...AIM： To isolate putative pancreatic stem cells （PSCs） from human adult tissues of pancreas duct using serumfree, conditioned medium. The characterization of surface phenotype of these PSCs was analyzed by flow cytometry. The potential for pancreatic lineage and the capability of β-cell differentiation in these PSCs were evaluated as well. METHODS： By using serum-free medium supplemented with essential growth factors, we attempted to isolate the putative PSCs which has been reported to express nestin and pdx-1. The MatrigelTM was employed to evaluate the differential capacity of isolated cells. Dithizone staining, insulin content/secretion measurement, and immunohistochemistry staining were used to monitor the differentiation. Fluorescence activated cell sorting （FACS） was used to detect the phenotypic markers of putative PSCs. RESULTS： A monolayer of spindle-like cells was cultivated. The putative PSCs expressed pdx-1 and nestin. They were also able to differentiate into insulin-, glucagon-, and somatostatin-positive cells. The spectrum of phenotypic markers in PSCs was investigated; a similarity was revealed when using human bone marrow-derived stem cells as the comparative experiment, such as CD29, CD44, CD49, CD50, CD51, CD62E, PDGFR-α, CD73 （SH2）, CD81, CD105（SH3）. CONCLUSION： In this study, we successfully isolated PSCs from adult human pancreatic duct by using serumfree medium. These PSCs not only expressed nestin and pdx-1 but also exhibited markers attributable to mesenchymal stem cells. Although work is needed to elucidate the role of these cells, the application of these PSCs might be therapeutic strategies for diabetes mellitus.展开更多
AIM: The role of Pancreatic and Duodenal Homeobox-1(PDX-1) as a major regulator of pancreatic development determines the function and phenotype of β cell. In this study, potential plasticity of liver cells into pancr...AIM: The role of Pancreatic and Duodenal Homeobox-1(PDX-1) as a major regulator of pancreatic development determines the function and phenotype of β cell. In this study, potential plasticity of liver cells into pancreatic endocrine cells induced by PDX-1 was evaluated.METHODS: Human hepatoma cell line HepG2 was stably transfected with mammalian expression plasmid pcDNA3-PDX encoding human PDX-1 gene. Ectopic expression of PDX-1 and insulin were detected by RT-PCR,Western blot and/or immunostaining. PDX-1+ HepG2 cells were transplanted under renal capsule of STZ-induced diabetic nude mice (n = 16) to examine the inducing effect in vivo.RESULTS: Exogenous PDX-1 transgene was proved to express effectively in HepG2 cell at both mRNA and protein levels. The expression of endogenous insulin and some βcell-specific differentiation markers and transcription factors were not induced in PDX-1+ HepG2 cells. When transplanted under renal capsule of STZ-induced diabetic nude mice, PDX-1+ HepG2 cells did not generate insulinproducing cells. These data indicated that stable transfected PDX-1 could not convert hepatoma cell line HepG2 to pancreatic cells in vitro or in vivo. Mature hepatocytes might need much more complicated or rigorous conditions to be shifted to insulin-producing cells.CONCLUSION: The expression of exogenous PDX-1 is not sufficient to induce relatively mature hepatocytes differentiating into insulin-producing cells.展开更多
基金Supported by National Science Council, Yen-Tj ing-Ling Medical Foundation and Taipei Veterans General Hospital
文摘AIM： To isolate putative pancreatic stem cells （PSCs） from human adult tissues of pancreas duct using serumfree, conditioned medium. The characterization of surface phenotype of these PSCs was analyzed by flow cytometry. The potential for pancreatic lineage and the capability of β-cell differentiation in these PSCs were evaluated as well. METHODS： By using serum-free medium supplemented with essential growth factors, we attempted to isolate the putative PSCs which has been reported to express nestin and pdx-1. The MatrigelTM was employed to evaluate the differential capacity of isolated cells. Dithizone staining, insulin content/secretion measurement, and immunohistochemistry staining were used to monitor the differentiation. Fluorescence activated cell sorting （FACS） was used to detect the phenotypic markers of putative PSCs. RESULTS： A monolayer of spindle-like cells was cultivated. The putative PSCs expressed pdx-1 and nestin. They were also able to differentiate into insulin-, glucagon-, and somatostatin-positive cells. The spectrum of phenotypic markers in PSCs was investigated; a similarity was revealed when using human bone marrow-derived stem cells as the comparative experiment, such as CD29, CD44, CD49, CD50, CD51, CD62E, PDGFR-α, CD73 （SH2）, CD81, CD105（SH3）. CONCLUSION： In this study, we successfully isolated PSCs from adult human pancreatic duct by using serumfree medium. These PSCs not only expressed nestin and pdx-1 but also exhibited markers attributable to mesenchymal stem cells. Although work is needed to elucidate the role of these cells, the application of these PSCs might be therapeutic strategies for diabetes mellitus.
基金the National Natural Science Foundation of China,No. 30240087 the National High Technology Research and Development Program of China, No. 2003AA205090
文摘AIM: The role of Pancreatic and Duodenal Homeobox-1(PDX-1) as a major regulator of pancreatic development determines the function and phenotype of β cell. In this study, potential plasticity of liver cells into pancreatic endocrine cells induced by PDX-1 was evaluated.METHODS: Human hepatoma cell line HepG2 was stably transfected with mammalian expression plasmid pcDNA3-PDX encoding human PDX-1 gene. Ectopic expression of PDX-1 and insulin were detected by RT-PCR,Western blot and/or immunostaining. PDX-1+ HepG2 cells were transplanted under renal capsule of STZ-induced diabetic nude mice (n = 16) to examine the inducing effect in vivo.RESULTS: Exogenous PDX-1 transgene was proved to express effectively in HepG2 cell at both mRNA and protein levels. The expression of endogenous insulin and some βcell-specific differentiation markers and transcription factors were not induced in PDX-1+ HepG2 cells. When transplanted under renal capsule of STZ-induced diabetic nude mice, PDX-1+ HepG2 cells did not generate insulinproducing cells. These data indicated that stable transfected PDX-1 could not convert hepatoma cell line HepG2 to pancreatic cells in vitro or in vivo. Mature hepatocytes might need much more complicated or rigorous conditions to be shifted to insulin-producing cells.CONCLUSION: The expression of exogenous PDX-1 is not sufficient to induce relatively mature hepatocytes differentiating into insulin-producing cells.
