Transcriptome-based chemical screens identify several compounds facilitate cellular reprogramming [T_HF_iHeps_SMs_RNAseq]

Here, we identify Interleukin-1 Receptor-Associated Kinase 4 (IRAK4), a key innate immune kinase, as a previously unrecognized barrier to multi-lineage reprogramming. We discovered that pharmacological inhibition of IRAK4 potently enhances reprogramming of mouse embryonic fibroblasts (MEFs) through the chemically activated multi-lineage priming (CaMP) state and extraembryonic endoderm (XEN)-like intermediates, significantly increasing colony formation and expression of core XEN regulators (Sox17/Gata4/Sall4/Foxa2).

Genetic knockdown of Irak4 similarly accelerated reprogramming, while its overexpression blocked cell fate transitions. Mechanistically, IRAK4 inhibition remodels cell cycle dynamics, shortening G0/G1 and lengthening G2/M phases to license transcriptional plasticity. Crucially, IRAK4 suppression also enhanced direct lineage conversion, boosting the efficiency and functional maturity of MEF-derived hepatocyte-like cells (iHeps) via elevated albumin/Cyp3a11 expression, glycogen storage, and detoxification capacity.