Identification of islet-like structures differentiated from bone marrow mesenchymal stem cells induced by pancreatic tissue lysate / 中国组织工程研究

ABSTRACT

BACKGROUND: Bone marrow mesenchymal stem cells have been induced into islet-like cell mass in vitro. However, little researches reported on the morphological changes of cells, the types of endocrine cells in the islet-like cell mass and their relationships. OBJECTIVE: To investigate the morphological changes of cells in the differentiation of bone marrow mesenchymal stem cells into islet-like structure and to explore the composition and distribution of endocrine cells. METHODS: Passage 3 bone marrow mesenchymal stem cells growing well were cultured and expanded until the cell colonies occupies 80% of the bottom of the culture bottle, and the pancreatic tissue lysate was added for continuous induction. Dithizone staining was used to screen the islet-like cell mass directly differentiated from bone marrow mesenchymal stem cells. The types and distribution of endocrine cells were identified by Mallory staining. Expressions of insulin, C-peptide, glucagon and somatostatin protein were detected by immunofluorescence cytochemical staining. RESULTS AND CONCLUSION: (1) Dithizone staining showed that the number of positive cells was increased over the induction time. (2) Mallory staining showed the red α-like cells were located in the periphery of the islet-like cell mass, the yellow β-like cells located in the center and periphery, and the light blue fibroblasts were distributed around the cell mass. (3) Immunofluorescence staining showed insulin, C-peptide, glucagon and somatostatin positive cells in the islet-like cell mass. To conclude, under certain microenvironment, bone marrow mesenchymal stem cells can differentiate into islet-like structures which containing α, β, δ-like cells, and are surrounded by fibroblast-like cells.