biostudies-literatureAngiolillo S2019 STARS Grants program2021 STARS Grants program20https://www.ebi.ac.uk/biostudies/studies/S-EPMC12868028biostudies-literatureUnknown76(1)The generation of engineered neurons via Neurogenin-2 (NGN2) overexpression, starting from human induced pluripotent stem cells (hiPSCs), is a powerful tool for modeling neurological diseases. However, using stabilized hiPSCs as a starting point significantly increases the time required to obtain a valuable human neuronal model in vitro. Here, we demonstrated that as little as 3 days of transient expression of reprogramming factors in human fibroblasts can unlock the ability of these cells to transdifferentiate into neurons upon overexpression of NGN2. We used single-cell transcriptomic data to dissect the distinct cell identities that emerge during reprogramming. We identified three distinct reprogramming intermediate populations responsive to NGN2-mediated neuronal induction and found thJournal of molecular neuroscience : MNEarly Reprogramming Intermediates Enable Direct Neuronal Conversion Via NGN2.PMC12868028EnCOriNeuronsGesualdo AElvassore NAngiolillo SLaterza CFrison RGagliano OQin WfalseEarly Reprogramming Intermediates Enable Direct Neuronal Conversion Via NGN2.The generation of engineered neurons via Neurogenin-2 (NGN2) overexpression, starting from human induced pluripotent stem cells (hiPSCs), is a powerful tool for modeling neurological diseases. However, using stabilized hiPSCs as a starting point significantly increases the time required to obtain a valuable human neuronal model in vitro. Here, we demonstrated that as little as 3 days of transient expression of reprogramming factors in human fibroblasts can unlock the ability of these cells to transdifferentiate into neurons upon overexpression of NGN2. We used single-cell transcriptomic data to dissect the distinct cell identities that emerge during reprogramming. We identified three distinct reprogramming intermediate populations responsive to NGN2-mediated neuronal induction and found th2026-01-01T00:00:00Z2026 Feb2026-07-05T03:10:48.28Z2026-07-05T03:08:25.779ZS-EPMC128680284163240910.1007/s12031-025-02460-2