Self-organized insulin-producing [beta]-cells differentiated from human omentum-derived stem cells and their in vivo therapeutic potential

Human omentum-derived mesenchymal stem cells (hO-MSCs) possess great potential to differentiate into multiple lineages and have self-renewal capacity, allowing them to be utilized as patient-specific cell-based therapeutics. Although the use of various stem cell-derived [beta]-cells has been proposed as a novel approach for treating diabetes mellitus, developing an efficient method to establish highly functional [beta]-cells remains challenging. We aimed to develop a novel cell culture platform that utilizes a fibroblast growth factor 2 (FGF2)-immobilized matrix to regulate the adhesion and differentiation of hO-MSCs into insulin-producing [beta]-cells via cell-matrix/cell-cell interactions. In our study, we evaluated the in vitro differentiation potential of hO-MSCs cultured on an FGF2-immobilized matrix and a round-bottom plate (RBP). Further, the in vivo therapeutic efficacy of the [beta]-cells transplanted into kidney capsules was evaluated using animal models with streptozotocin (STZ)-induced diabetes. Our findings demonstrated that cells cultured on an FGF2-immobilized matrix could self-organize into insulin-producing [beta]-cell progenitors, as evident from the upregulation of pancreatic [beta]-cell-specific markers (PDX-1, Insulin, and Glut-2). Moreover, we observed significant upregulation of heparan sulfate proteoglycan, gap junction proteins (Cx36 and Cx43), and cell adhesion molecules (E-cadherin and Ncam1) in cells cultured on the FGF2-immobilized matrix. In addition, in vivo transplantation of differentiated [beta]-cells into animal models of STZ-induced diabetes revealed their survival and engraftment as well as glucose-sensitive production of insulin within the host microenvironment, at over 4 weeks after transplantation. Our findings suggest that the FGF2-immobilized matrix can support initial cell adhesion, maturation, and glucose-stimulated insulin secretion within the host microenvironment. Such a cell culture platform can offer novel strategies to obtain functional pancreatic [beta]-cells from patient-specific cell sources, ultimately enabling better treatment for diabetes mellitus.