Changes in Adropin Levels in Brain and Peripheral Tissues with Aging

Adropin is a bioactive peptide found in the brain and various peripheral tissues. Evidence suggests that aging significantly decreases brain adropin levels, and interventions that elevate adropin may help alleviate age-related neurological disorders such as ischemic stroke and cognitive decline. However, the impact of aging on peripheral tissue adropin levels and its relationship with the neural recognition molecule NB-3/contactin-6 in the brain remains unclear. In this study, we quantified adropin using immunoblotting in brain and peripheral tissues (liver, lung, kidney, spleen, ileum, colon) from young (8–10 weeks) and aged (18–20 months) male mice. Results indicated a significant decrease in brain adropin levels in aged mice, while peripheral tissues showed no significant changes compared to young controls. Additionally, levels of NB-3/contactin-6, a potential adropin receptor and Notch1 ligand, were lower in aged brains. Co-immunoprecipitation demonstrated that adropin physically associates with brain NB-3. Notably, the age-related reduction in brain adropin correlates with increased oxidative stress markers (gp91phox and 4-hydroxynonenal). We provide the first evidence that aging is linked to a concurrent loss of adropin and NB-3 in the brain but not in peripheral tissues. Interventions to maintain brain adropin levels could help mitigate the brain’s aging process and alleviate age-related neurological dysfunction