Temporally specific gene expression and chromatin remodeling programs regulate a conserved Pdyn enhancer

Area of Science:

• Neuroscience
• Molecular Biology
• Genetics

Background:

• Neuronal adaptations involve dynamic gene expression waves, with immediate early genes (IEGs) regulating late response genes (LRGs).
• The molecular mechanisms linking IEGs to LRGs and their role in chromatin remodeling are not well understood.

Purpose of the Study:

• To investigate the interplay between IEGs and LRGs in activity-driven neuronal responses.
• To characterize chromatin accessibility changes and identify regulatory elements involved in late gene expression.

Main Methods:

• Transcriptomic and chromatin accessibility profiling in rat striatal neurons.
• CRISPR-based functional assays to validate enhancer activity.
• Analysis of conserved regulatory elements in human cells.

Main Results:

• Neuronal depolarization induced IEG expression at 1 hour and LRG expression, including neuropeptides and synaptic proteins, at 4 hours.
• Significant chromatin remodeling and increased accessibility at thousands of non-coding sites occurred at 4 hours, dependent on IEG protein synthesis.
• A conserved enhancer regulating prodynorphin (Pdyn) transcription was identified and functionally validated.

Conclusions:

• IEGs play a critical role in activity-dependent chromatin remodeling at enhancers.
• A conserved Pdyn enhancer is essential for Pdyn expression and may be a therapeutic target for Pdyn-related neuropsychiatric disorders.