ISR inhibition reverses pancreatic β-cell failure in Wolfram syndrome models

Pancreatic β-cell failure induced by WFS1 deficiency is manifested in wolfram syndrome (WS). The lack of a suitable human model in WS has hampered the progress in developing new treatments. Here, human pluripotent stem cell derived pancreatic β cells (SC-β cells) harboring WFS1-deficiency and mouse model of β cell-specific Wfs1 knockout were applied to model β-cell failure in WS. Single-cell RNA sequencing of WFS1-deficient SC-β cells revealed two cell fates along pseudotime trajectory including maturation and stress branch. WFS1 deficiency blocked β-cell fate trajectory to maturation but pushed it towards stress trajectory leading to β-cell failure. We generated hESCs reporter cell line (MEL1 Nkx6.1:linker2a:mCherry; INSGFP/w) that enable to precisely and dynamically trace SC-β cells during differentiated stages. Meanwhile, WFS1 knockout hESCs reporter cell line (WFS1-/-) was established by using a CRISPR/Cas9 knock-out strategy to mimic severe mutations identified from WS patients. We performed single-cell RNA sequencing (scRNA-Seq) for WT and WFS1-/- SC-islets by sorting out GFP and mCherry double-positive SC-β cells with high INS and NKX6.1 expression