Department of Cardiovascular Medicine, Gunma University Graduate School of Medicine, 3-39-15 Showa-machi, Maebashi, Gunma, 371-8511, Japan.
Department of Laboratory Sciences, Gunma University Graduate School of Health Sciences, Maebashi, Gunma, Japan.
Sci Rep. 2023 Oct 21;13(1):18025. doi: 10.1038/s41598-023-45390-y.
Sodium-glucose cotransporter 2 inhibitors (SGLT2i) improve heart failure (HF) outcomes across a range of patient characteristics. A hypothesis that SGLT2i induce metabolic change similar to fasting has recently been proposed to explain their profound clinical benefits. However, it remains unclear whether SGLT2i primarily induce this change in physiological settings. Here, we demonstrate that empagliflozin administration under ad libitum feeding did not cause weight loss but did increase transcripts of the key nutrient sensors, AMP-activated protein kinase and nicotinamide phosphoribosyltransferase, and the master regulator of mitochondrial gene expression, PGC-1α, in quadriceps muscle in healthy mice. Expression of these genes correlated with that of PPARα and PPARδ target genes related to mitochondrial metabolism and oxidative stress response, and also correlated with serum ketone body β-hydroxybutyrate. These results were not observed in the heart. Collectively, this study revealed that empagliflozin activates transcriptional programs critical for sensing and adaptation to nutrient availability intrinsic to skeletal muscle rather than the heart even in normocaloric condition. As activation of PGC-1α is sufficient for metabolic switch from fatigable, glycolytic metabolism toward fatigue-resistant, oxidative mechanism in skeletal muscle myofibers, our findings may partly explain the improvement of exercise tolerance in patients with HF receiving empagliflozin.
钠-葡萄糖共转运蛋白 2 抑制剂(SGLT2i)在多种患者特征下改善心力衰竭(HF)结局。最近提出了一个假设,即 SGLT2i 诱导类似于禁食的代谢变化,以解释其深远的临床益处。然而,目前尚不清楚 SGLT2i 是否主要在生理环境中引起这种变化。在这里,我们证明在自由喂养条件下给予恩格列净不会导致体重减轻,但会增加关键营养传感器 AMP 激活的蛋白激酶和烟酰胺磷酸核糖转移酶以及线粒体基因表达的主要调节因子 PGC-1α 的转录本在健康小鼠的四头肌中。这些基因的表达与与线粒体代谢和氧化应激反应相关的 PPARα 和 PPARδ 靶基因的表达以及与血清酮体β-羟丁酸相关。这些结果在心脏中没有观察到。总的来说,这项研究表明,即使在正常热量条件下,恩格列净也能激活内在骨骼肌对营养可用性的感应和适应的关键转录程序,而不是心脏。由于 PGC-1α 的激活足以使骨骼肌肌纤维中的代谢从易疲劳的糖酵解代谢转变为抗疲劳的氧化机制,我们的发现可能部分解释了接受恩格列净治疗的 HF 患者运动耐量的改善。