Targeted BDNF upregulation via upstream open reading frame disruption.

Area of Science:

• Molecular Biology
• Neuroscience
• Genetics

Background:

• The 5' untranslated region (UTR) of messenger RNA contains regulatory elements that control translation.
• Upstream open reading frames (uORFs) within the 5' UTR are known regulators of gene expression.
• Brain-derived neurotrophic factor (BDNF) is crucial for neuronal survival and function, and its expression is tightly regulated.

Purpose of the Study:

• To investigate the role of uORFs in regulating BDNF translation.
• To explore methods for modulating BDNF protein levels through uORF manipulation.

Main Methods:

• Bioinformatic analysis to predict uORFs in BDNF 5' UTRs.
• Experimental validation of uORF function using reporter constructs.
• Gene editing techniques (adenine base editing) to disrupt specific uORFs.

Main Results:

• uORFs were identified in most BDNF transcript isoforms, with several experimentally confirmed to repress translation.
• Deletion of a 5' UTR exon in a non-expressed BDNF variant led to reporter upregulation, dependent on uORFs and RNA structure.
• Base editing-mediated disruption of a uORF start codon in a common BDNF variant increased endogenous BDNF protein expression by approximately 1.8-fold.

Conclusions:

• uORFs significantly contribute to the post-transcriptional regulation of BDNF.
• Targeting uORFs, particularly via base editing, presents a viable strategy for enhancing BDNF protein expression.