Does empagliflozin alter the expression of mitochondrial regulatory proteins in human myocardium during short-term atrial tachypacing ex vivo?
Empagliflozin modulates mitochondrial regulatory proteins and reduces oxygen consumption in human atrial tissue during tachypacing, suggesting a potential mechanism for its benefits in atrial fibrillation.
Atrial fibrillation (AF) is associated with energetic deficiency and oxidative stress due to mitochondrial dysfunction, resulting in electric remodeling. Long-term treatment was found to ameliorate mitochondrial function and decrease inducibility in animal models. No studies examine the short-term effect of SGLT-2 inhibitors administration in AF. In the present study, the samples of the right atrial appendage collected from 10 patients subjected to elective cardiac surgery were sliced and incubated in a control buffer (EMPA 0), 0.2 µmol/L empagliflozin (EMPA 0.2), or 1.0 µmol/L (EMPA 1). The expression of mitochondrial biogenesis, fission, and fusion proteins was measured by Western blot after 30 min of electrical stimulation (control-1 Hz or tachypacing-5 Hz). The PGC-1α protein expression was increased after 30 min of stimulation with 1 Hz when incubated under a higher concentration of empagliflozin. After tachypacing, EMPA 0.2 increased PGC-1α, while EMPA 1.0 upregulated NRF-1. Both concentrations increased NRF-2 during control stimulation. The oxygen consumption was higher in AF, and was decreased by SGLT-2i. Empagliflozin exerts dynamic effects on the expression of PGC-1α and other proteins involved in mitochondrial function and oxidative stress in cardiomyocytes and may modulate cellular response to tachycardia.
Muszyński et al. (Sat,) studied this question.