Functional alterations and transcriptomic changes during zebrafish cardiac aging.

Aging dramatically increases the risk of cardiovascular diseases in human. Animal models are of great value to study cardiac aging, and zebrafish have become a popular model for aging study recently. However, there is limited knowledge about the progression and regulation of cardiac aging in zebrafish. In this study we first validated the effectiveness of a panel of aging-related markers and revealed their spatial-temporal specificity. Using these markers, we discovered that cardiac aging in zebrafish initiated at mid-age around 24 months, followed by a gradual progression marked with increased DNA damage, inflammatory response and reduced mitochondrial function. Furthermore, we showed aging-related expression profile change in zebrafish hearts was similar to that in rat hearts. Overall, our results provide a deeper insight into the cardiac aging process in zebrafish, which will set up foundation for generating novel cardiac aging models suitable for large scale screening of pharmaceutical targets.