Figure 2.

Differentiation of bone marrow mesenchymal stem cells of human first-trimester abortus into islet-like cell clusters. Many irregular cell clusters formed in the first-stage induction (A), became compact in the second-stage induction (B), and became spherical with blurred boundaries among adjacent cells in the third-stage induction, similar to the morphology of the islets of Langerhans, whereas some of the nonclustered cells adhered to the dish bottom and became similar to bone marrow mesenchymal stem cells of human first-trimester abortus in shape in the nonadherent induction group (C), (D). Irregular cell clusters after the first-stage induction (E) became hemispherical in the second-stage induction (F), uplifted with blurred boundaries among adjacent cells in the third-stage induction in the adherent induction group (G), (H), and always adhered to the dish bottom. Transmission electron microscopy showing a large number of endocrine cells (I) and secretion granules in cytoplasma of the cells in the cell clusters from the nonadherent induction group (J) and the adherent induction group (K) after the three-stage induction, histologically similar to those in fetal pancreatic islets as the positive control (L).