The NRF2/ID2 Axis in Vascular Smooth Muscle Cells: Novel Insights into the Interplay between Vascular Calcification and Aging

OBJECTIVE Vascular calcification (VC) significantly contributes to cardiovascular morbidity and mortality and escalates with age. However, effective pharmaceutical interventions are lacking, and the molecular mechanisms linking aging to VC remain elusive. This study explores the role of nuclear factor erythroid 2-related factor 2 (NRF2) in VC, specifically focusing on the interplay between vascular senescence and oxidative stress (OS). APPROACH AND RESULTS Using a chronological aging mouse model, we noted a significant decline in the expression and activity of Nrf2 in the aortas of aged mice, coinciding with increased medial VC. Administering NRF2 activators effectively reduced this calcification. In the vascular smooth muscle cell (VSMC)-specific Nrf2 knockout ( Nrf2SMCKO ) models, created using adenine and Vitamin D, there was an increase in calcium deposition within the aortic medial layer, alongside heightened VSMC senescence and OS. Furthermore, NRF2 knockout exacerbated VC in aortic rings and primary VSMCs in high-phosphate conditions, while Nrf2 overexpression in VSMCs inhibited calcium deposition by alleviating cell senescence and OS. RNAseq analysis of the aortas from Nrf2SMCKO and control mice highlighted a significant downstream regulator of Inhibitor of DNA Binding 2 (ID2). Our results show that reduced NRF2 levels lead to increased VSMC senescence, characterized by heightened p16 expression and diminished ID2 expression. Inhibiting ID2 negated NRF2’s protective effects against VSMC senescence and VC. CONCLUSION This study emphasizes the critical role of NRF2 dysfunction in the nexus of vascular senescence, OS, and VC. It proposes the NRF2-ID2 axis in VSMCs as a promising therapeutic target for reducing VC and mitigating age-related cardiovascular diseases. Highlights ### Competing Interest Statement The authors have declared no competing interest. * ### Nonstandard Abbreviations and Acronyms VC : vascular calcification OS: oxidative stress NRF2 : nuclear factor erythroid 2-related factor 2 ID2: inhibitor of DNA binding 2 VSMC : vascular smooth muscle cell CKD: chronic kidney disease CRF : chronic renal failure ESRD: end-stage renal disease SASP : senescence-associated secretory phenotype ROS: reactive oxygen species SOD : superoxide dismutase