C Chang1, D Niu, H Zhou, F Li, F Gong. 1. Department of Immunology Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
Abstract
BACKGROUND: Extracellular microenvironment and intrinsic genetic programs determine the fate of stem cells. We observed whether mesenchymal stem cells (MSCs) contributed to insulin-producing cells in a manipulated microenvironment. METHODS: We delivered pancreatic pieces into Niobium-Coated Dynamatrix to construct a simulated pancreatic microenvironment, upon which soluble cytokine exchange and direct cell-cell contact between MSCs and pancreatic cells could occur. Bone marrow-derived MSCs were cultured upon the microenvironment. Differentiated isletlike cells were observed under an inverted microscope. Insulin in supernates was measurement by enzyme-linked immunosorbent assay. Insulin and c-peptide expression were verified by fluorescent immunocytochemistry and fluorescence in situ hybridization. Apoptosis of isletlike masses in high-glucose DMEM was detected by FACS. RESULTS: After 3 to 4 weeks in culture, typical isletlike masses were observed. Insulin secreted by differentiated cells (414.47+/-30.30 mIU/L) was much greater than that of undifferentiated cells (4.89+/-1.01 mIU/L; P<.05). Insulin and c-peptide expression were positive both in protein and mRNA levels. The transdifferentiated isletlike mass did not undergo apoptosis after another 3 weeks of culture in high-glucose DMEM. CONCLUSION: This simulated injury microenvironment without induction guided MSCs to functional isletlike cells hopefully to replace beta cells.
BACKGROUND: Extracellular microenvironment and intrinsic genetic programs determine the fate of stem cells. We observed whether mesenchymal stem cells (MSCs) contributed to insulin-producing cells in a manipulated microenvironment. METHODS: We delivered pancreatic pieces into Niobium-Coated Dynamatrix to construct a simulated pancreatic microenvironment, upon which soluble cytokine exchange and direct cell-cell contact between MSCs and pancreatic cells could occur. Bone marrow-derived MSCs were cultured upon the microenvironment. Differentiated isletlike cells were observed under an inverted microscope. Insulin in supernates was measurement by enzyme-linked immunosorbent assay. Insulin and c-peptide expression were verified by fluorescent immunocytochemistry and fluorescence in situ hybridization. Apoptosis of isletlike masses in high-glucoseDMEM was detected by FACS. RESULTS: After 3 to 4 weeks in culture, typical isletlike masses were observed. Insulin secreted by differentiated cells (414.47+/-30.30 mIU/L) was much greater than that of undifferentiated cells (4.89+/-1.01 mIU/L; P<.05). Insulin and c-peptide expression were positive both in protein and mRNA levels. The transdifferentiated isletlike mass did not undergo apoptosis after another 3 weeks of culture in high-glucoseDMEM. CONCLUSION: This simulated injury microenvironment without induction guided MSCs to functional isletlike cells hopefully to replace beta cells.