24 August 2017
Converting resident glia into functional and subtype-specific neurons in vivo by delivering reprogramming genes directly to the brain provides a step forward toward the possibility of treating brain injuries or diseases. To date, it has been possible to obtain GABAergic and glutamatergic neurons via in vivo conversion, but the precise phenotype of these cells has not yet been analyzed in detail. Here, we show that neurons reprogrammed using Ascl1, Lmx1a, and Nurr1 functionally mature and integrate into existing brain circuitry and that the majority of the reprogrammed neurons have properties of fast-spiking, parvalbumin-containing interneurons. When testing different combinations of genes for neural conversion with a focus on pro-neural genes and dopamine fate determinants, we found that functional neurons can be generated using different gene combinations and in different brain regions and that most of the reprogrammed neurons become interneurons, independently of the combination of reprogramming factors used.
Reprogramed striatal NG2 glia yield neurons similar to fast-spiking interneurons
Reprogrammed neurons reach functional maturation after 12 weeks
Dopamine (DA) denervation leads to TH expression but no reprogramming into DA neurons
Variation in pro-neural genes or fate specifiers does not affect neuronal phenotype
In this study, Parmar, Ottosson, and colleagues show how endogenous NG2 glia can be reprogrammed into GABAergic interneurons of different subtypes, the majority of them with properties of fast-spiking parvalbumin-containing interneurons. This neuronal subtype has been implicated in several neurological diseases, and the findings can open up new therapeutic options.