Hierarchical cortical transcriptome disorganization in autism

Area of Science:

• Neuroscience
• Genomics
• Systems Biology

Background:

• Autism spectrum disorder (ASD) presents complex, heterogeneous causes.
• Transcriptomic studies reveal diverse dysregulated programs in ASD brains, including synaptic, immune, and cell cycle pathways.
• It remains unclear if these pathways are independent or part of a coordinated systems-level pathology.

Purpose of the Study:

• To investigate the coordinated nature of transcriptomic dysregulation in Autism Spectrum Disorder (ASD) cortical tissue.
• To identify common co-expression modules and their interactions within ASD cortical transcriptomes.
• To determine if observed transcriptomic changes reflect independent processes or hierarchical systems-level pathology.

Main Methods:

• Consensus weighted gene co-expression network analysis (WGCNA) applied to two ASD cortical transcriptome datasets.
• Identification of replicable differentially expressed modules using linear mixed-effect models and Bayesian statistics.
• Eigengene network analysis and protein-protein interaction analyses to assess module interactions and hierarchical organization.

Main Results:

• Ten replicable gene co-expression modules were found to be differentially expressed in the ASD cortex.
• These modules interact synergistically at the protein level, indicating coordinated, not independent, pathology.
• Key affected processes include downregulation of synaptic functions alongside upregulation of immune/inflammation, viral processes, and cell proliferation pathways.

Conclusions:

• ASD cortical transcriptome dysregulation involves coordinated transcriptional programs with synergistic systems-level effects.
• Studying individual biological processes in isolation is insufficient to understand the full scope of ASD pathology.
• Findings emphasize the importance of a systems-level approach to unraveling the complexities of Autism Spectrum Disorder.