@article {Puls818823, author = {Brendan Puls and Yan Ding and Fengyu Zhang and Mengjie Pan and Zhuofan Lei and Zifei Pei and Mei Jiang and Yuting Bai and Cody Forsyth and Morgan Metzger and Tanvi Rana and Lei Zhang and Xiaoyun Ding and Matthew Keefe and Alice Cai and Austin Redilla and Michael Lai and Kevin He and Hedong Li and Gong Chen}, title = {Regeneration of dorsal spinal cord neurons after injury via in situ NeuroD1-mediated astrocyte-to-neuron conversion}, elocation-id = {818823}, year = {2019}, doi = {10.1101/818823}, publisher = {Cold Spring Harbor Laboratory}, abstract = {Spinal cord injury (SCI) often leads to impaired motor and sensory functions, partially because the injury-induced neuronal loss cannot be easily replenished through endogenous mechanisms. In vivo neuronal reprogramming has emerged as a novel technology to regenerate neurons from endogenous glial cells by forced expression of neurogenic transcription factors. We have previously demonstrated successful astrocyte-to-neuron conversion in mouse brains with injury or Alzheimer{\textquoteright}s disease by overexpressing a single neural transcription factor NeuroD1 via retroviruses. Here we demonstrate regeneration of dorsal spinal cord neurons from reactive astrocytes after SCI via adeno-associated virus (AAV), a more clinically relevant gene delivery system. We find that NeuroD1 converts reactive astrocytes into neurons in the dorsal horn of stab-injured spinal cord with high efficiency (\~{}95\%). Interestingly, NeuroD1-converted neurons in the dorsal horn mostly acquire glutamatergic neuronal subtype, expressing spinal cord-specific markers such as Tlx3 but not brain-specific markers such as Tbr1, suggesting that the astrocytic lineage and local microenvironment affect the cell fate of conversion. Electrophysiological recordings show that the NeuroD1-converted neurons can functionally mature and integrate into local spinal cord circuitry by displaying repetitive action potentials and spontaneous synaptic responses. We further show that NeuroD1-mediated neuronal conversion can occur in the contusive SCI model, allowing future studies of evaluating this reprogramming technology for functional recovery after SCI. In conclusion, this study may suggest a paradigm shift for spinal cord repair using in vivo astrocyte-to-neuron conversion technology to generate functional neurons in the grey matter.}, URL = {https://www.biorxiv.org/content/early/2019/11/06/818823}, eprint = {https://www.biorxiv.org/content/early/2019/11/06/818823.full.pdf}, journal = {bioRxiv} }