Differentiation Of Mesenchymal Stem Cells Derived From Human Bone Marrow Into Islet β-like Cells

AIM:To investigate the possibility of human fetal bone mesenchymal stem cells differented into insulin-secreting cells in appropriate condition.Content:Bone marrow mesenchymal stem cells were isolated, screened and purified from 20 cases of aborted fetal limbs.and characterized phenotypically by flow cytom-etry including markers CD 14, CD73, CD117, CD147. And fat differentiation of BMSCs to prove whether the characteristics of stem cells.collected fetal pancreas and cultured with two medium which contained fetal bovine serum or umbilical cord ser-rum, comparied the growth and the secretion of the two group and identified them. bone marrow mesenchymal stem cells co-cultured with islet cells which cultured with cord blood serum by transwell culture dishes.the morphological changes in fetal BM-SCs and islet cells were analyzed under a phase contrast microscopy.Methods:1,Bone marrow were inspired from the aborted fetal limbs,mononuclear cells were isolated by density gradient centrifugation and cultured in vitro.The higher purity of BMSCs were obtained by keeping the adherent cells and removal of nonadherent cells repeated.2,P3 or P 4 BMSC populations were collected, detecting expressed the surface marker expression of BMSCs by flow cytometrie analysis and the efficiency of differentiation into fat was assessed by related method.3,Islets isolated by enzymatic digestion, and cultured with fetal bovine serum or cord blood serum in vitro to simulate the living environment of islet and identified by chemical methods dithizone staining and electron microscopy.4,Bone marrow mesenchymal stem cells co-cultured with islet cells, the morphological changes under a phase contrast microscopy and insulin secretions of BMSCs under the stimulation of fetal islet cells were detected by radioimmunoassay at 3,6,9,12 day. Isletβ-like cell clusters were identified by dithizone staining and anti-insulin immunoeytochemistry staining and electron microscopy.Result:1,The highly purified BMSCs were obtained by density gradient centrifugation and keeping the adherent cells derived from human bone marrow and the BMSCs showed long fusiform or spindle and fibroblast-like shaped after repeated passages 3. the BMSC surface markers specific CD 117, CD 147, CD73 were highly expressed,In contrast CD 14 were barely detectable by flow cytometry. under inductive medium in vitro, the BMSCs could be induced into fat which were positive when stained by Oil Red O.2,The cord blood serum group getting the amount of islet cells is several times and more than 75% purity by Dithizone staining than the FBS group, the two group has no special difference in electron microscopy.3,The undifferentiated BMSCs exhibited were adherent long spindle-shaped cells. After induction, cells gradually became round and formed clusters.the differentiated BMSCs contained secretory granules and secreted abundant insulin and formed islet-like cell clusters that exhibited positive dithizone staining and immunocytochemical staining at 9 days. No insulin was detected in the control group.Conclusion:1,Pure BMSCs were obtained from long bones of aborted fetal limbs. Stem cells are functionally defined by their capacity to self-renew and differentiate into one or more terminal cell types in vitro.2,The cord blood serum Group have a higher quantity and quality and more of pancreatic islets and more life environment for pancreatic islets cells in vitro. This is the better basis for the next experiment.3,Fetal bone marrow mesenehymal stem cells have the potentiality to differentiate into insulin-producing cells by the stimulation of Micro-environment which can make the islet transplantation alternative success.