Engineered Extracellular Vesicles from Human Skin Cells Induce Pro--Cell Conversions in Pancreatic Ductal Cells

Direct nuclear reprogramming has the potential to enable the development of beta cell replacement therapies for diabetes that do not require the use of progenitor/stem cell populations. However, despite their promise, current approaches to beta cell-directed reprogramming rely heavily on the use of viral vectors. Herein, the use of extracellular vesicles (EVs) derived from human dermal fibroblasts (HDFs) is explored as novel nonviral carriers of endocrine cell-patterning transcription factors, to transfect and transdifferentiate pancreatic ductal epithelial cells (PDCs) into hormone-expressing cells. Electrotransfection of HDFs with expression plasmids for Pdx1, Ngn3, and MafA (PNM) leads to the release of EVs loaded with PNM at the gene, mRNA, and protein levels. Exposing PDC cultures to PNM-loaded EVs leads to successful transfection and increases PNM expression in PDCs, which ultimately result in endocrine cell-directed conversions based on the expression of insulin/c-peptide, glucagon, and glucose transporter 2 (Glut2). These findings are further corroborated in vivo in a mouse model following intraductal injection of PNM- versus sham-loaded EVs. Collectively, these findings suggest that dermal fibroblast-derived EVs can potentially serve as a powerful platform technology for the development and deployment of nonviral reprogramming-based cell therapies for insulin-dependent diabetes.