Age-associated changes in gene expression in human brain and isolated neurons

Area of Science:

• Neuroscience
• Genetics
• Aging Research

Background:

• Previous research suggests gene expression correlates with chronological age.
• Identifying consistent age-associated genes across studies and tissues remains a challenge.

Purpose of the Study:

• To identify reproducible gene expression signatures associated with aging in the human brain.
• To determine which age-associated genes are consistent across different brain regions and tissues.

Main Methods:

• Analysis of gene expression in human frontal cortex and cerebellum samples using microarrays.
• Replication of findings in independent sample sets and using quantitative reverse transcriptase polymerase chain reaction.
• Laser capture microdissection to isolate specific cell types (Purkinje neurons).
• Weighted gene correlation network analysis to identify gene modules associated with age.

Main Results:

• Identified 60 statistically significant, reproducible gene expression associations with chronological age in the human brain.
• Found more significant associations in the frontal cortex than the cerebellum.
• Replicated 5 gene associations in isolated Purkinje neurons, with RHBDL3 showing the strongest association.
• Discovered age-associated gene modules, some enriched for mitochondrial genes, indicating coordinated changes in cellular function.

Conclusions:

• A distinct and reproducible gene expression signature for human brain aging exists.
• Specific genes, like RHBDL3, demonstrate robust age-related expression changes.
• Aging in the brain involves coordinated changes in gene expression, including those related to mitochondrial function.