Exosome-mediated transfer of microRNAs promotes mouse iPSCs differentiation into therapeutic insulin-producing cells

Abstract Purpose Exosome-based therapeutic approaches have been applied in diabetes. In the present study, we explored the effect of exosomes on iPSCs differentiation into insulin-producing cells and its underlying mechanisms. Methods Exosomes were isolated by ultracentrifugation from MIN6 cells and identified by Transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA) and Western blot. PKH67 tracer and transwell assay were used to confirm exosome delivery into iPSCs. QRT-PCR was applied to detect key pancreatic gene expression and miRNAs expression in differentiated iPSCs. Insulin expression was assessed by flow cytometry (FCM) and immunofluorescence. The mechanism underlying exosome induction capacity for iPSCs was determined via RNA-interference of Argonaute-2 (Ago2). Streptozotozin(STZ) was used to establish diabetic mouse model to verify the function of differentiated β-like cells. Results MIN6-derived exosomes promoted the key pancreatic gene expression and immunofluorescence for Nkx6.1 and insulin remarkably, confirming the capability of exosomes for iPSCs differentiation. Moreover, transplantation of differentiated iPSCs efficiently enhanced IPGTT and partially control hyperglycemia in T1D mice. Knockdown of Ago2 in MIN6 cells affect exosomal miRNAs expression and pancreatic gene expression and insulin secretion in iPSCs.The therapeutic effect in vivo was weakened, further indicating decreased exosomal miRNA affect iPSCs differentiation.7 specific exosomal miRNAs were selected for single-assay validation. MiR-706, miR-709, miR-466c-5p and miR-423-5p were found dynamic changed during differentiation stages. Conclusion Exosomes is an effective and convenient induction approach for iPSCs differentiation into functional insulin secreting cells.The effect was downregulated via Ago2 knockdown illustrates the mechanisms are highly relevant to specific miRNAs enriched in exosomes.