TGFβ pathway inhibition redifferentiates human pancreatic islet β cells expanded in vitro

Ginat Toren-Haritan, Shimon Efrat

Research output: Contribution to journalArticlepeer-review


In-vitro expansion of insulin-producing cells from adult human pancreatic islets could provide an abundant cell source for diabetes therapy. However, proliferation of β-cell-derived (BCD) cells is associated with loss of phenotype and epithelial-mesenchymal transition (EMT). Nevertheless, BCD cells maintain open chromatin structure at β-cell genes, suggesting that they could be readily redifferentiated. The transforming growth factor β (TGFβ) pathway has been implicated in EMT in a range of cell types. Here we show that human islet cell expansion in vitro involves upregulation of the TGFβ pathway. Blocking TGFβ pathway activation using short hairpin RNA (shRNA) against TGFβ Receptor 1 (TGFBR1, ALK5) transcripts inhibits BCD cell proliferation and dedifferentiation. Treatment of expanded BCD cells with ALK5 shRNA results in their redifferentiation, as judged by expression of β-cell genes and decreased cell proliferation. These effects, which are reproducible in cells from multiple human donors, are mediated, at least in part, by AKT-FOXO1 signaling. ALK5 inhibition synergizes with a soluble factor cocktail to promote BCD cell redifferentiation. The combined treatment may offer a therapeutically applicable way for generating an abundant source of functional insulin-producing cells following ex-vivo expansion.

Original languageEnglish
Article numbere0139168
JournalPLoS ONE
Issue number9
StatePublished - 29 Sep 2015


FundersFunder number
Israel Science Foundation
Juvenile Diabetes Research Foundation International
Juvenile Diabetes Research Foundation United States of America31-2008-413, 916/11
Israel Science Foundation


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