Multi-region proteomic mapping identifies FTL1 and SERPINA3K as protective factors in cardiac aging

Aging is a well-recognized risk factor in cardiovascular diseases (CVDs), primarily due to its association with the gradual decline in cardiac function. This decline significantly influences the pathogenesis of common CVDs such as myocardial infarction and heart failure. Despite the existence of several proteomic atlases of the heart, the spatially resolved proteomic dynamics essential for understanding region-specific aging mechanisms in cardiac tissue remain incompletely characterized. In this study, we conducted a region-resolved quantitative proteomic profiling for various murine cardiac regions at three distinct stages of aging (3, 12, and 20-month-old), quantifying 6 650 proteins in the heart. Leveraging integrated bioinformatics and machine learning frameworks, we uncovered that FTL1 and SERPINA3K exhibit strong age-associated expression changes across all cardiac regions. Mechanistically, the knockdown of Ftl1 led to cardiomyocyte ferroptosis and senescence, phenotypes that were ameliorated by the ferroptosis inhibitor Ferrostatin-1. Furthermore, the depletion of Serpina3k exacerbated senescence and collagen deposition through the activation of the cGAS-STING-PERK axis, effects that can be reversed via the overexpression of Serpina3k or the knockdown of Sting. The protective effect of SERPINA3K was also demonstrated in vivo through AAV9-mediated cardiomyocyte-specific overexpression in middle-aged mice, which attenuated the cGAS-STING-PERK axis and mitigated age-related fibrosis. These results strongly demonstrated that FTL1 and SERPINA3K function as key regulators of cardiac aging. Collectively, this study provides a valuable region-resolved proteomic atlas of cardiac aging and identifies key protein regulators, thereby uncovering potential targets for cardio-protective interventions against age-related cardiovascular disorders.