IDE1 can induce definitive endoderm from embryonic stem cells. It has been shown to induce the differentiation of Sox17+/FoxA2+-expressing pancreatic progenitors from human and mouse embryonic stems cells (EC50: 125.5 nM in vitro) by activating the TGF-β signaling pathway. IDE1-derived endodermal cells injected into E8.75 mouse embryos ex vivo have been shown to incorporate into the developing gut tube, contributing to its formation.

IDE1 enhances the definitive endoderm (DE) differentiation of human-induced pluripotent stem cells (hiPSCs) with Activin A/Wnt3a being significantly more potent in both 2D and 3D cultures than IDE1. IDE1 could efficiently induces DE differentiation through various protocols in vitro. Treatment of the hiPSCs-derived EBs with IDE-1 shows minor increase (p<0.01) of DE-markers cells compared to Activin A/Wnt3a treatment. IDE1 possess several advantages over other inducing factors including high permeability, influence, diversity, low cost, and easy to use and for the first time, Melton’s team showed that Activin A can be substituted by two cell-permeable small molecules, IDE1 and IDE2. IDE1 could induce phosphorylation of Smad2 after incubation for 24 h or more at levels comparable to those induced by Activin A treatment. Treatment of hiPSCs with IDE1 (2 mM) also leads to endodermal differentiation but with a significantly lower efficiency than Activin A/Wnt3a[1].

LSD1 enzyme assay: LSD1 activity was measured using a horseradish peroxidase (HRP) coupled assay with amplex red as an electron donor. The formation of product over time is measured using fluorescence intensity, Ex 531 nm and Em 595 nm, in a PerkinElmer EnVision plate reader. Final assay conditions are: 5 nM LSD1, 2.5 μM H3K4me2 peptide, 50 mM HEPES pH 7, 1 U/ml of HRP, 1 mM CHAPS, 0.03% dBSA and 10 μM amplex red.