Abstract
Introduction
Circulating microparticles (MPs) from patients with coronary artery diseases (CAD) have been shown to promote endothelial senescence and dysfunction involving the pro-oxidant local angiotensin system. Sodium-glucose cotransporters (SGLTs)2 inhibitors decreased the risk of cardiovascular disease in patients with type 2 diabetes and this effect appears to be independent of glycemic control. Moreover, high glucose and H2O2 have been shown to cause a redox-sensitive upregulation of SGLT1 and 2 in coronary artery endothelial cells (ECs).
Aim
Therefore, this study examined whether angiotensin II (Ang II, a potent NADPH oxidase-dependent inducer of oxidative stress) and CAD MPs stimulate SGLT1 and 2 expression in ECs, and assessed their role in the induction of endothelial dysfunction.
Methods
ECs were isolated from porcine coronary arteries. The protein expression level was assessed by Western blot analysis and immunocytochemical staining, oxidative stress using dihydroethidium staining, and senescence by senescence-associated beta-galactosidase activity (SA-beta-gal activity). Circulating CAD MPs were collected from blood samples of patients (61–79 year) with established cardiovascular disease.
Results
Control ECs expressed low levels of SGLT1 and SGLT2 proteins. Exposure of ECs to Ang II caused a time- and concentration-dependent increase in the protein level of SGLT1 and SGLT2 with a significant increase observed at concentrations as low as 10 nM. Exposure of ECs to CAD MPs (10 nM PhtdSer eq) from 3/5 patients increased the SGLT1 and SGLT2 protein level. An increased SGLT1 and SGLT2 immunofluorescence signal was also observed in response to Ang II and H2O2. Ang II increased the level of oxidative stress, SA-beta-gal activity, senescence markers (p53, p21 and p16), VCAM-1, MCP-1, tissue factor (TF) and the local angiotensin system (ACE, AT1R), and down-regulated that of eNOS. CAD MPs from 4/5 patients decreased eNOS level and from 5/5 patients increased VCAM-1 level. All the Ang II-induced effects were prevented by the dual SGLT1/2 inhibitor LX-4211 and the selective SGLT2 inhibitor, empagliflozin.
Conclusions
The present findings indicate that CAD MPs and Ang II upregulate the expression of SGLT1 and SGLT2 protein levels in ECs, and that they promote endothelial dysfunction. They further suggest that inhibition of SGLT1 and/or SGLT2 might be an attractive strategy to protect the arterial wall and, hence, the development of cardiovascular diseases.
Acknowledgement/Funding
Unrestricted research grant from Boehringer Ingelheim Pharma GmbH & Co. KG
Angiotensin II induced oxidative stress-mediated upregulation of sodium-glucose cotransporters 1 and 2 (SGLTs) expression in cultured coronary artery endothelial cells
