Cardiac Tissue Chip Model Provides A Platform For Studying Age-related Cardiovascular Complications By Recapitulating Important Hallmarks Of Senescence And Myocardial Ischemia

Introduction: With the rise in the elderly population, there has been an exponential growth in cardiovascular diseases and age-related complications. This necessitates a platform for studying cardiovascular disease in the context of aging. Hypothesis: An engineered cardiac tissue model that can recapitulate critical aspects of aging can be used to study age-related diseases of the cardiovascular system. Methods: Senescence was induced in rat cardiomyoblasts using an acute low-dose doxorubicin treatment. The presence of important senescent markers in the cells like enlarged and flattened nuclei, increased ROS activity, elevated p53 production, DNA damage response foci, and increased expression of cell cycle inhibitor p16 INK4a was evaluated. These senescent cells were then used to engineer cardiac tissue, which was subjected to hemodynamic stresses associated with the pressure-volume changes in the heart. Myocardial ischemia was imposed in the aging cardiac tissue model using hypoxic treatment. Results: Under normal hemodynamic loading, the engineered cardiac tissue retained its cardiac cell characteristics and showed cell alignment along with age-related changes in structure and gene expression. The myocardial ischemic model of the tissue revealed major pathological hallmarks of the disease like increased cell death and natriuretic peptide expression. Conclusion: Our model and methodology provide an effective platform for studying the cardiovascular disease pathologies associated with aging and screening drugs against age-related complications.