Pancreatic stem cells differentiate into insulin-secreting cells on fibroblast-modified PLGA membranes

Abstract

Diabetes mellitus is an epidemic worldwide. Pancreatic stem cells can be induced to differentiate into insulin-secreting cells, this method is an effective way to solve the shortage of islet donor. Poly (lactic acid-co-glycolic acid (PLGA) copolymer is an excellent scaffold for tissue engineering as it presents good biocompatibility and film forming properties. In this study, we adopted biological methods, using fibroblast-coated PLGA diaphragm to form a biological membrane, and then pancreatic stem cells were cultured on the fibroblast-modified PLGA membrane and the two-step induction method was utilized to induce the differentiation of pancreatic stem cells into insulin-secreting cells. The proliferation and differentiation of pancreatic stem cells on the fibroblast-modified PLGA membrane as well as the expression of genes related to the differentiation of pancreatic stem cells were examined in both normal and induced cultures to explore the potential of fibroblast-modified PLGA membrane for the transplantation to treat diabetes mellitus. The results indicated that fibroblasts can effectively improve the cell compatibility and histocompatibility of the PLGA membrane and promote the proliferation and differentiation of pancreatic stem cells. After induction, real-time fluorescence quantitative PCR (FQRT-PCR) results showed there were more Notch receptors and its ligands expressed in the membranes of pancreatic stem cells than non-induced pancreatic stem cells or fibroblast. Semiconductor quantum dot coupled-anti-complex probe experiments revealed that induced pancreatic stem cells had higher expression levels of Notch 2 and Delta-like 1 than non-induced ones, which may regulate the expression of Neurogenin-3 (Ngn3) and Hairy/Enhancer of split-1 gene (Hes1) through Notch signaling interaction between fibroblasts and pancreatic stem cells as well as enhance the proliferation of pancreatic stem cells and their differentiation into insulin-secreting cells. Further, our study suggests that the fibroblast-modified PLGA membrane can be used as matrix material composed of pancreatic stem cells or other stem cells to construct artificial islet tissue for the treatment of diabetes mellitus.

Keywords: Cell differentiation; Islet-like cells; Notch signaling-related genes; PLGA membrane; Pancreatic stem cells.