Chronic pathological conditions, such as type 2 diabetes mellitus, involve various mechanisms in promoting heart failure by remodelling energy metabolic pathways and impairing cardiac contractility. The major source of myocardial energetics has been reported to shifts from OXPHOS in normal conditions to glycolysis in heart failure. Therefore, we decided to focus on the effect of empagliflozin on energy metabolic status in the heart.Recently, we generated two types of transgenic mice to monitor energy metabolism, intracellular ATP levels (iATP Tg) and mitochondrial ATP levels (mATP Tg) using FRET biosensor “ATeam” in the whole body, organ, and cellular levels as well as in beating heart. We intercrossed these mice with db/db, a mouse model of type 2 diabetes, and examined the energy metabolism of the heart in the empagliflozin -treated or non-treated groups.db/db;iATP Tg mice were fed EMPA-containing diets (30 mg/kg b.w., day) from 7 weeks of age for 10 weeks, and the ATP levels in the heart were measured by imaging with a fluorescence microscope. The results showed that, unlike the lowered ATP levels in the placebo group, the intracellular ATP level in the heart was significantly increased in the empagliflozin-treated group. Also, the ATP level was recovered in this empagliflozin-treated group to the same level as the wild type.Next, 8 weeks-old db/db;mATP Tg mice received a single dose of empagliflozin (30 mg/kg b.w.) via oral gavage after 4 hr of fasting. After another 3 hr of fasting, monitor the mitochondrial ATP level of the heart in vivo under the fluorescent microscope. The results showed that, unlike the placebo group, the ATP level in the mitochondria of the heart was significantly increased in the empagliflozin-treated group.These results suggest that empagliflozin may restore normal remodelling of energy metabolism in type 2 diabetic hearts.
SD3, an Arabidopsis thaliana Homolog of TIM21, Affects Intracellular ATP Levels and Seedling Development