#1299 The SGLT2 inhibitor canagliflozin, but not dapagliflozin or empagliflozin, ameliorates vascular calcification in a mouse model of nephrocalcinosis

Abstract

Abstract Background and Aims Vascular calcification, defined as the abnormal deposition of minerals in blood vessels, is a major cardiovascular risk factor in patients with kidney failure. Sodium-glucose co-transporter 2 (SGLT2) inhibitors, commonly known as gliflozins, are a class of pharmaceutical compounds that have revolutionised the therapeutic management of type 2 diabetes. These drugs target the SGLT2 transporter, increasing glucose elimination through the urine, effectively lowering hyperglycaemia. In addition to their effect on blood sugar control, SGLT2 inhibitors have recently gained attention for potential cardiovascular benefits in patients with type 2 diabetes, chronic kidney disease (CKD) or established cardiovascular disease. Initially thought to be secondary to the promotion of urinary sodium and glucose excretion and weight loss, recent studies have also reported direct effects of gliflozins on the vascular compartment. Given the significant impact of vascular calcification on cardiovascular health in patients with kidney failure, the aim of this study was to investigate whether the three different SGLT2 inhibitors (canagliflozin, empagliflozin and dapagliflozin) could reduce the development of vascular calcification. Method Western blotting was used to investigate SGLT2 expression in mouse and human vascular smooth muscle cells (VSMC) and vascular explants. Human and mouse aortic VSMC and mouse aorta and human epigastric and iliac artery segments were treated with calcification medium supplemented with 1 or 5 µM of gliflozins. A nephrocalcinosis mouse model consisting of 2 weeks of high phosphorus diet (2%) in female DBA/2 mice was used in in vivo experiments. The animals were treated daily with the different gliflozins (3 mg/kg/j) by oral gavage. Calcium deposits were quantified using a quantitative colorimetric assay and alizarin red staining, blood and urine glucose levels were measured using a quantitative colorimetric assay and glomerular filtration rate (GFR) was measured using sinistrin-FITC excretion. Results We observed that SGLT2 is expressed in mouse and human vessels and vascular smooth muscle cells (VSMC). Treatment with canagliflozin, but not dapagliflozin or empagliflozin, reduced calcification in vitro, in human and mouse VSMC and ex vivo, in mouse aorta and human epigastric and iliac artery segments. The high phosphorus diet in mice led to nephrocalcinosis associated with impaired renal function as well as vascular calcification development in the aorta. In this model, although all 3 gliflozins showed efficacy in increasing urinary glucose excretion, blood glucose levels were not affected by gliflozins and renal function was not improved. However, canagliflozin, but not dapagliflozin or empagliflozin, significantly reduced vascular calcification in this nephrocalcinosis mouse model. Conclusion Our study demonstrated that canagliflozin reduces vascular calcification development, highlighting its potential as a therapeutic strategy. This protective effect was found to be drug-dependent and not class-dependent, as the other two SGLT2 inhibitors, dapagliflozin and empagliflozin, showed no significant effect on vascular calcification. Further studies are needed to understand the mechanisms and pathways involved and to determine whether the differential effect of the gliflozins is due to an off-target action of canagliflozin on other SGLT transporters.