Direct neuronal reprogramming: emerging therapeutic strategies for neurodegenerative disorders

Area of Science:

• Neuroscience
• Regenerative Medicine
• Cell Biology

Background:

• Central nervous system injuries and neurodegenerative diseases present significant therapeutic challenges due to limited neuronal regeneration.
• Current treatments often manage symptoms rather than addressing neuronal loss, with stem cell therapies and surgery facing limitations like immune rejection and efficacy issues.
• Direct neuronal reprogramming of endogenous somatic cells is an emerging strategy to restore lost neurons.

Purpose of the Study:

• To review traditional neuronal reprogramming techniques and their limitations.
• To explore novel in-vivo strategies for overcoming previous challenges.
• To analyze clinical trial outcomes and identify knowledge gaps for future research.

Main Methods:

• Evaluation of traditional in-vitro reprogramming using lineage-specific transcription factors.
• Exploration of in-vivo approaches utilizing small molecules, nonviral gene delivery, and CRISPR-based activation.
• Analysis of combined methodologies integrating transcription factors with epigenetic modifiers, microRNAs, and neurotrophic factors.

Main Results:

• In-vivo and combined reprogramming methods aim to reduce complexity and improve cell survival compared to traditional in-vitro techniques.
• Despite advancements, clinical translation remains modest, with early trials showing limited functional improvements.
• Challenges include off-target effects, inconsistent delivery specificity, and unresolved immunogenicity.

Conclusions:

• Direct neuronal reprogramming provides a viable autologous therapy for neurodegenerative diseases and brain injuries.
• Novel in-vivo and combined approaches show promise but require further preclinical validation and safety assessments.
• Future research should focus on refining delivery platforms, minimizing off-target effects, and developing biomarkers for monitoring conversion and outcomes.