OBJECTIVETo construct a method to culture pancreatic progenitor cells in hanging drop and on floating filter,and to examine if pancreatic progenitor cells can differentiate into mature endocrine cells with this method.

METHODSMurine embryos at day 12.5 were isolated and digested into single cells,which were then cultured in hanging drop for 24h and formed spheres.Spheres were cultured on the filter for 6 days,which floated in the dish containing medium.During culture,the expressions of pancreas duodenum homeobox-1(PDX-1)and neurogenin3(Ngn3)were determined.The expressions of endocrine and exocrine markers,insulin,glucagon,and carboxypeptidase(CPA)were determined on day 7 by immunohistochemistry.Insulin secretion of spheres stimulated by glucose was detected by ELISA.The changes of pancreatic marker expressions during culture were monitored by real-time polymerase chain reaction(PCR).

RESULTSOne day after the culture,there were still a large amount of PDX-1 positive cells in pancreatic spheres,and these cells proliferated.On day 3,high expression of Ngn3 was detected,and the Ngn3-positive cells did not proliferate.On day 7,The expressions of endocrine and exocrine markers in the differentiated pancreatic progenitor cells were detected,which were consistent with that in vivo.Insulin was secreted by spheres upon the stimulation of glucose.

CONCLUSIONIn hanging drop and on floating filter,pancreatic progenitor cells can differentiate into mature endocrine cells.

Animals ; Cell Culture Techniques ; Cell Differentiation ; Cells, Cultured ; Endocrine Cells ; cytology ; Homeodomain Proteins ; metabolism ; Insulin ; metabolism ; Mice ; Pancreas ; cytology ; Stem Cells ; cytology ; Trans-Activators ; metabolism

The ontogeny and distribution of gastrin- and serotonin-immunoreactive (IR) cell in the proventriculus of chicks (Gallus gallus domestica, n = 60) in different growth periods was examined immunohistochemically using antisera specific to gastrin and serotonin. Gastrin and serotonin-IR cells were detected in chick proventriculus. Gastrin-IR cells were first evident after 12 days of incubation in lamina epithelialis and compound glands, while serotonin-IR cells were observed only in compound glands at that same time. Gastrin-IR and serotonin-IR cells increased in frequency on incubation day 14 and 16, respectively. Towards the end of incubation, gastrin- and serotonin-IR cell numbers decreased. In adult chicken, both IR cells were present but not lower numbers. The observations demonstrate the presence of gastrin- and serotonin-IR cells in the proventriculus of developing chicks in temporally changing frequencies.
Animals ; Chick Embryo/*metabolism ; Endocrine Cells/cytology/metabolism ; Gastrins/*metabolism ; Gene Expression Regulation, Developmental/physiology ; Proventriculus/*embryology/*metabolism ; Serotonin/*metabolism

OBJECTIVETo establish a new culture method to induce the differentiation of embryonic pancreatic cells into mature endocrine cells.

METHODSMouse embryos at day 12.5 were used and embryonic pancreata were isolated. The isolated embryonic pancreata were cultured on the filter for 7 days, which floated in the dish containing medium. During culture, the expression of pancreas duodenum homeobox-1 (PDX-1), a pancreatic stem cell marker, was examined at day 1. The expression of neurogenin 3 (Ngn3), a pancreatic progenitor cell marker, was examined at day 3. The expressions of endocrine and exocrine markers, insulin, glucagon, and carboxypeptidase (CPA) were examined at day 7 by immunohistochemistry. The kinetics of pancreatic marker expression during culture was assayed by real-time PCR.

RESULTSMany pancreatic stem cells still existed in embryonic pancreata cultured for 1 day; meanwhile, these pancreatic stem cells proliferated in high rate. A large amount of pancreatic progenitor cells were found in embryonic pancreata cultured for 3 days.Pancreatic stem/progenitor cells differentiated into mature endocrine and exocrine cells in embryonic pancreata after having been cultured for 7 days. Furthermore, the expression pattern of pancreatic marker is consistent with that in vivo.

CONCLUSIONWe successfully established a new culture method, with which embryonic pancreatic cells can efficiently differentiate into mature endocrine cell.

Animals ; Basic Helix-Loop-Helix Transcription Factors ; metabolism ; Cell Culture Techniques ; Cell Differentiation ; Cells, Cultured ; Embryo, Mammalian ; Endocrine Cells ; cytology ; Female ; Homeodomain Proteins ; metabolism ; Male ; Mice ; Nerve Tissue Proteins ; metabolism ; Pancreas ; cytology ; Trans-Activators ; metabolism