Lineage conversion of mouse fibroblasts to pancreatic α-cells.

α-cells, which synthesize glucagon, also support β-cell survival and have the capacity to transdifferentiate into β-cells. However, the role of α-cells in pathological conditions and their putative clinical applications remain elusive due in large part to the lack of mature α-cells. Here, we present a new technique to generate functional α-like cells. α-like cells (iAlpha cells) were generated from mouse fibroblasts by transduction of transcription factors, including Hhex, Foxa3, Gata4, Pdx1 and Pax4, which induce α-cell-specific gene expression and glucagon secretion in response to KCl and Arg stimulation. The cell functions in vivo and in vitro were evaluated. Lineage-specific and functional-related gene expression was tested by realtime PCR, insulin tolerance test (ITT), glucose tolerance test (GTT), Ki67 and glucagon immunohistochemistry analysis were done in iAlpha cells transplanted nude mice. iAlpha cells possess α-cell function in vitro and alter blood glucose levels in vivo. Transplantation of iAlpha cells into nude mice resulted in insulin resistance and increased β-cell proliferation. Taken together, we present a novel strategy to generate functional α-like cells for the purposes of disease modeling and regenerative medicine.