Activation of a cortical neurogenesis transcriptional program during NEUROD1-induced astrocyte-to-neuron conversion

Abstract

AbstractNEUROD1-induced astrocyte-to-neuron (AtN) conversion has garnered significant attention as a potential therapeutic intervention to neurological disorders. To gain insight into the molecular regulations underlying this neuronal reprogramming process, we applied single-cell multiomics analyses onin vitroND1-induced AtN conversion to systematically investigate how ND1 changed the fate of astrocytes at transcriptomic and epigenetic levels. Our findings reveal that the initial immature astrocytes go through an intermediate state where both astrocytic and neuronal genes are activated at early stage of AtN conversion. ND1 directly reshapes the chromatin accessibility landscape of astrocytes to that of neurons, promoting expression of endogenousNeurod1 and otherneurogenic genes such asHes6, Insm1etc. Interestingly, cell proliferation status is highly correlated with conversion rate, and inhibition of cell division significantly reduces the conversion ratio. Moreover, in comparison with another AtN reprogramming transcription factor, ASCL1, external ND1 can activate endogenousNeurod1and directly promote neuronal gene transcription; whereas external ASCL1 hardly activates endogenousAscl1,leading to slower and inefficient conversion. Together, our studies demonstrate thatin vitroAtN conversion mimics neurogenic transcriptional program in embryonic neurogenesis.