Canagliflozin Delays Aortic Valve Calcification by Enhancing the AMPK /Nrf2/ HO ‐1 Antioxidant Signaling Pathway in Valvular Interstitial Cells

Aortic valve calcification is a significant contributor to the development of aortic valve stenosis, a condition for which effective pharmacological treatments are currently limited. Sodium-glucose cotransporter 2 inhibitors, such as canagliflozin (CANA), have demonstrated promising cardioprotective effects, irrespective of diabetes status. This study aims to investigate the therapeutic effects and underlying mechanisms of CANA on aortic valve calcification. In an aortic valve wire injury mouse model, treatment with CANA significantly reduced aortic valve peak velocity, inhibited leaflet thickening, and decreased calcium deposition. Furthermore, CANA enhanced the expression of nuclear factor erythroid-2-related factor 2 (Nrf2) and heme oxygenase (HO-1) and reduced the levels of the oxidative stress marker 8-OHdG. In an in vitro osteogenic model of valvular interstitial cells (VICs), CANA treatment effectively reduced the expression of alkaline phosphatase (ALP) and runt-related transcription factor 2 and decreased the formation of calcium nodules. Additionally, CANA activated the Nrf2/HO-1 antioxidant signaling pathway in VICs under calcification induction conditions, while significantly reducing the accumulation of reactive oxygen species and mitochondrial superoxide. In an ex vivo model of human aortic valve calcification, CANA treatment led to a reduction in calcified nodule formation and ALP expression, along with the activation of the Nrf2/HO-1 signaling pathway and a decrease in 8-OHdG levels. The protective effects of CANA on aortic valve calcification were partially reversed by the Nrf2 inhibitor ML385 or small interfering RNA-mediated NRF2 knockdown, confirming the involvement of the Nrf2/HO-1 pathway. Importantly, CANA-induced Nrf2/HO-1 activation in VICs was mediated by the AMPK pathway. In summary, CANA effectively delayed aortic valve calcification by enhancing the AMPK/Nrf2/HO-1 antioxidant signaling pathway, suggesting that CANA may hold therapeutic potential for preventing or slowing the progression of aortic valve stenosis.