Brain microRNAs differentially expressed in age-related cerebral pathologies

Area of Science:

• Neuroscience
• Genetics
• Aging Research

Background:

• Age-related cerebral pathologies, including Alzheimer's disease (AD), Lewy body pathology, arteriolosclerosis, cerebral amyloid angiopathy, and Limbic-predominant Age-related TDP-43 Encephalopathy Neuropathological Change (LATE-NC), are common but their biological basis is not fully understood.
• MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression and are implicated in various biological processes, including aging and disease.

Purpose of the Study:

• To investigate the association between specific microRNAs (miRNAs) and ten distinct age-related cerebral pathologies.
• To identify miRNAs that are uniquely linked to individual pathologies or shared across multiple conditions.

Main Methods:

• Analysis of miRNA sequencing profiles from the dorsolateral prefrontal cortex of 617 brain donors.
• Statistical adjustment for age, sex, education, and co-existing cerebral pathologies to identify specific miRNA associations.
• Gene set enrichment analysis to explore the functional relevance of identified miRNAs.

Main Results:

• Identified specific miRNAs associated with Alzheimer's disease (AD) pathology (75 miRNAs), Lewy body pathology (45 miRNAs), arteriolosclerosis (3 miRNAs), cerebral amyloid angiopathy (1 miRNA), and LATE-NC (4 miRNAs) after adjusting for confounding factors.
• Found shared miRNA associations between AD and Lewy body pathology (14 miRNAs), and between AD and cerebral amyloid angiopathy (1 miRNA).
• Gene set enrichment analysis revealed that miRNAs linked to arteriolosclerosis target genes involved in crucial pathways such as glutathione metabolism, synaptic function, cellular transport, and innate immunity.

Conclusions:

• MicroRNAs are significantly associated with multiple age-related cerebral pathologies.
• Specific miRNA signatures may contribute to distinct or overlapping pathologies, providing potential biomarkers and therapeutic targets.
• These findings establish a foundation for further mechanistic studies into the role of miRNAs in brain aging and neurodegeneration.