Differential transcript usage in the Parkinson's disease brain.

Area of Science:

• Neuroscience
• Genomics
• Molecular Biology

Background:

• Differential gene expression studies have identified molecular signatures for Parkinson's disease (PD).
• The role of differential transcript usage (DTU) in PD pathogenesis remains largely unexplored.
• Conventional gene expression analysis may miss crucial transcriptomic alterations.

Purpose of the Study:

• To conduct the first genome-wide study of DTU in Parkinson's disease.
• To identify novel PD-associated genes and pathways through DTU analysis.
• To assess the functional consequences of DTU in the PD brain.

Main Methods:

• RNA sequencing was performed on prefrontal cortex samples from 49 individuals across two independent PD case-control cohorts.
• DTU was assessed using DRIMSeq and DEXSeq tools, focusing on transcript-count based approaches.
• Replication analysis was conducted across both cohorts to validate DTU events.

Main Results:

• Multiple PD-associated DTU events were detected, with 23 events in 19 genes replicating across cohorts.
• DTU in genes like THEM5, SLC16A1, and BCHE predicted significant functional consequences, including altered protein function and non-coding isoforms.
• Genes with PD-associated DTU were enriched in pathways like reactive oxygen species generation and protein homeostasis, and were largely missed by differential gene expression analysis.

Conclusions:

• DTU analysis provides novel insights into the Parkinson's disease transcriptomic landscape.
• DTU identifies previously unrecognized PD-associated genes and highlights potential functional alterations in the PD brain.
• DTU analysis is a crucial complement to differential gene expression studies for a comprehensive understanding of PD-associated transcriptomic changes.