Sodium‐Glucose Cotransporter 2 Inhibitor Canagliflozin Antagonizes Salt‐Sensitive Hypertension Through Modifying Transient Receptor Potential Channels 3 Mediated Vascular Calcium Handling

BACKGROUND: Salt‐sensitive hypertension is highly prevalent and associated with cardiorenal damage. Large clinical trials have demonstrated that SGLT2 (sodium‐glucose cotransporter 2) inhibitors exert hypotensive effect and cardiorenal protective benefits in patients with hypertension with and without diabetes. However, the underlying mechanism remains elusive. METHODS AND RESULTS: Dahl salt‐sensitive rats and salt‐insensitive controls were fed with 8% high‐salt diet and some of them were treated with canagliflozin. The blood pressure, urinary sodium excretion, and vascular function were detected. Transient receptor potential channel 3 (TRPC3) knockout mice were used to explain the mechanism. Canagliflozin treatment significantly reduced high‐salt‐induced hypertension and this effect was not totally dependent on urinary sodium excretion in salt‐sensitive hypertensive rats. Assay of vascular function and proteomics showed that canagliflozin significantly inhibited vascular cytoplasmic calcium increase and vasoconstriction in response to high‐salt diet. High salt intake increased vascular expression of TRPC3 in salt‐sensitive rats, which could be alleviated by canagliflozin treatment. Overexpression of TRPC3 mimicked salt‐induced vascular cytosolic calcium increase in vitro and knockout of TRPC3 erased the antihypertensive effect of canagliflozin. Mechanistically, high‐salt‐induced activation of NCX1 (sodium‐calcium exchanger 1) reverse mode increased cytoplasmic calcium level and vasoconstriction, which required TRPC3, and this process could be blocked by canagliflozin. CONCLUSIONS: We define a previously unrecognized role of TRPC3/NCX1 mediated vascular calcium dysfunction in the development of high‐salt‐induced hypertension, which can be improved by canagliflozin treatment. This pathway is potentially a novel therapeutic target to antagonize salt‐sensitive hypertension.