Parkinson's disease motor symptoms rescue by CRISPRa‐reprogramming astrocytes into GABAergic neurons.

Direct reprogramming based on genetic factors resembles a promising strategy to replace lost cells in degenerative diseases such as Parkinson's disease. For this, we developed a knock‐in mouse line carrying a dual dCas9 transactivator system (dCAM) allowing the conditional in vivo activation of endogenous genes. To enable a translational application, we additionally established an AAV‐based strategy carrying intein‐split‐dCas9 in combination with activators (AAV‐dCAS). Both approaches were successful in reprogramming striatal astrocytes into induced GABAergic neurons confirmed by single‐cell transcriptome analysis of reprogrammed neurons in vivo. These GABAergic neurons functionally integrate into striatal circuits, alleviating voluntary motor behavior aspects in a 6‐OHDA Parkinson's disease model. Our results suggest a novel intervention strategy beyond the restoration of dopamine levels. Thus, the AAV‐dCAS approach might enable an alternative route for clinical therapies of Parkinson's disease. Synopsis: GABAergic neurons generated by CRISPR‐mediated direct reprogramming of striatal astrocytes rescue voluntary motor behavior in a toxin‐induced murine model for Parkinson's disease, suggesting a novel intervention strategy beyond the restoration of dopamine levels. A novel CRISPRa mouse line dCAM is developed for the conditional induction of endogenous target genes.An AAV‐based split‐dCas9‐activator system is established for translational applications of CRISPRa.Direct reprogramming of murine striatal astrocytes using the factor combination Ascl1, Lmx1a, and Nr4a2 results in induced GABAergic neurons in vivo.Induced GABAergic neurons are capable of ameliorating specific motor symptoms of Parkinson's disease. [ABSTRACT FROM AUTHOR]