Towards a Greater Understanding of Ageing within the Cardiovascular System: Unravelling the Impact of Doxorubicin-Induced Ageing in Cardiovascular Cells and the Therapeutic Potential of NRF2 Activation and Senolytics

Cardiovascular ageing is exacerbated by factors such as oxidative stress and high glucose levels, significantly contributes to age-related diseases. We aimed to elucidate potential therapeutic interventions for age-related cardiovascular disorders by investigating the effects of sub-toxic concentrations of doxorubicin on cardiac cells and evaluating the efficacy of two compounds, 2-cyano-3,12-dioxo-oleana-1,9(11)-dien-28-oic acid methyl ester (CDDO) and fisetin, in mitigating age-related markers, particularly in high glucose conditions. Initial experiments exposed human cardiac cell lines AC16 cells, and human cardiac fibroblasts (hcFB), and human cardiac endothelial cells (hCMEC), to sub-toxic doxorubicin concentrations under both low and high glucose conditions. Cells cultured in high glucose environments exhibited accelerated ageing and increased senescent markers compared to those in low glucose conditions. Subsequent treatment with CDDO and fisetin demonstrated a reduction in senescence markers in both low and high glucose conditions, indicating their potential as therapeutic agents for age-related cardiovascular diseases, even in high glucose environments. To enhance the physiological relevance of our model, we transitioned from traditional 2D cell cultures to a 3D tri-culture system incorporating iPSC-derived atrial cardiomyocytes (iPSC-ACMs), hcFBs, and hCMECs. This tri-culture system better emulated the complexity of the cardiovascular system in vivo. Notably, the iPSC-ACM tri-culture spheroids exhibited reduced senescence and functional changes in both low and high glucose conditions, providing valuable insights into disease mechanisms and potential treatment strategies for age-related cardiovascular disorders in varying metabolic environments. Functional analysis, particularly through calcium signalling, revealed dynamic changes in calcium transients, indicative of age-related functional alterations in cardiomyocytes. These findings underscore the importance of developing more physiologically relevant models to accurately study age-related cardiovascular diseases and evaluate potential therapeutic strategies, particularly in the context of high glucose. In summary, our study highlights the detrimental effects of oxidative stress and high glucose levels on the cardiovascular system and identifies promising therapeutic avenues for mitigating age-related cardiovascular dysfunction, even in metabolically challenging environments. By leveraging advanced cell culture techniques and incorporating iPSC-derived cardiomyocytes into a tri-culture system, we offer valuable insights into disease mechanisms and potential treatment strategies for age-related cardiovascular disorders in diverse metabolic conditions.