Compositional perspectives on human brain aging

Using publicly available microarray data from the frontal cortex of 30 individuals, spanning the ages of 26–106 years old, we investigate the expression patterns of compositionally distinct genes during human brain aging. Our analyses revealed that at advance ages, GC-poor genes appear to be induced while GC-rich genes are repressed. Interestingly, investigations upon two different types of genes, named pivotal (permanently expressed genes) and non-pivotal (on-off regulated genes), revealed an induction of the GC-poor pivotal genes and a repression of the GC-richer non-pivotal genes at advanced ages. Summarizing, this study shows that genes with different compositional properties have opposite age-related expression patterns, suggesting an implication of different regulation mechanisms related to their localization in different chromatin structure, which correlates with the GC level. Finally, an innovative approach on investigating human aging process is suggested, which involves the base composition of genes.