Dapagliflozin Treatment Attenuates the Interaction between the Renal Sodium Chloride Co-Transporter and Ezrin in Hypertensive Diabetic db/db Mice.

Abstract

Introduction: Ezrin is a protein that links the actin cytoskeleton to membrane proteins. The sodium chloride cotransporter (NCC) plays a key role in regulating total body electrolyte homeostasis and systemic blood pressure. Dapagliflozin, an SGLT2 inhibitor, is used to manage type 2 diabetes mellitus. We hypothesize dapagliflozin reduces sodium reabsorption and blood pressure by inhibiting the interaction between NCC and ezrin in the distal convoluted tubules of salt-loaded hypertensive mice.

Methods: Male diabetic db/db mice were salt loaded to induce hypertension and then given dapagliflozin or vehicle by oral gavage. The mice were subject to metabolic cage experiments and blood pressure was assessed using the tail-cuff method to study the impact of dapagliflozin compared to the vehicle. Protein expression of NCC and ezrin was evaluated using immunohistochemistry and Western blotting.

Results: Treatment with dapagliflozin lowered systolic blood pressure, raised urine sodium excretion, and lowered urinary potassium excretion. A decrease in phospho-NCC and ezrin proteins was observed in db/db mice treated with dapagliflozin. There was less co-localization of ezrin and phosphorylated NCC in dapagliflozin treated mice.

Conclusion: Collectively, we demonstrate that dapagliflozin reduces sodium retention and blood pressure via decreasing the density of renal NCC at the luminal membrane and the interaction between NCC and the actin cytoskeleton.