Rapid Conversion of Fibroblasts into Functional Forebrain GABAergic Interneurons by Direct Genetic Reprogramming

Area of Science:

• Neuroscience
• Stem Cell Biology
• Genetics

Background:

• Transplanting GABAergic interneurons (INs) shows promise for treating neurological disorders like epilepsy.
• Current methods for generating GABAergic INs, such as embryonic stem cell differentiation, have limitations for disease modeling and transplantation.

Purpose of the Study:

• To identify a method for generating functional GABAergic interneurons from non-neuronal cells.
• To assess the potential of these induced GABAergic interneurons (iGABA-INs) for cell-based therapies and disease modeling.

Main Methods:

• Overexpression of five specific transcription factors (Foxg1, Sox2, Ascl1, Dlx5, Lhx6) in mouse fibroblasts.
• Characterization of induced GABAergic interneurons (iGABA-INs) for molecular signatures, electrophysiological properties, and synaptic function.
• Grafting of iGABA-INs into the mouse hippocampus and assessment of survival, maturation, and functional integration using optogenetics.

Main Results:

• The five factors successfully converted mouse fibroblasts into iGABA-INs with molecular profiles resembling telencephalic INs.
• iGABA-INs exhibited mature firing patterns, formed functional synapses, released GABA, and survived/matured after transplantation into the mouse hippocampus.
• Optogenetic stimulation confirmed functional integration of grafted iGABA-INs, inhibiting host neuron activity.
• The same five factors also converted human cells into functional GABAergic INs.

Conclusions:

• A five-factor cocktail can reprogram fibroblasts into functional iGABA-INs with therapeutic potential.
• iGABA-INs demonstrate successful integration and function in vivo, suggesting their utility for cell-based therapies.
• This approach offers a promising avenue for disease modeling and developing new treatments for neurological disorders.