Cardiology Division, Department of Medicine, Li Ka Shing Faculty of Medicine, the University of Hong Kong, Hong Kong SAR, Hong Kong, China.
Sci Rep. 2018 Oct 5;8(1):14872. doi: 10.1038/s41598-018-33293-2.
Empagliflozin, a sodium-glucose co-transporter (SGLT) inhibitor, reduces heart failure and sudden cardiac death but the underlying mechanisms remain elusive. In cardiomyocytes, SGLT1 and SGLT2 expression is upregulated in diabetes mellitus, heart failure, and myocardial infarction. We hypothesise that empagliflozin exerts direct effects on cardiomyocytes that attenuate diabetic cardiomyopathy. To test this hypothesis, cardiomyocytes derived from human induced pluripotent stem cells (hiPSCs) were used to test the potential effects of empagliflozin on neutralization of cardiac dysfunction induced by diabetic-like cultures. Our results indicated that insulin-free high glucose culture significantly increased the size of and NPPB, SGLT1 and SGLT2 expression of hiPSC-derived cardiomyocytes. In addition, high glucose-treated hiPSC-derived cardiomyocytes exhibited reduced contractility regardless of the increased calcium transient capacity. Interestingly, application of empagliflozin before or after high glucose treatment effectively reduced the high glucose-induced cardiac abnormalities. Since application of empagliflozin did not significantly alter viability or glycolytic capacity of the hiPSC-derived cardiomyocytes, it is plausible that empagliflozin exerts its effects via the down-regulation of SGLT1, SGLT2 and GLUT1 expression. These observations provide supportive evidence that may help explain its unexpected benefit observed in the EMPA-REG trial.
恩格列净是一种钠-葡萄糖协同转运蛋白(SGLT)抑制剂,可降低心力衰竭和心源性猝死的风险,但潜在机制仍不清楚。在心肌细胞中,SGLT1 和 SGLT2 的表达在糖尿病、心力衰竭和心肌梗死中上调。我们假设恩格列净对心肌细胞有直接作用,可以减轻糖尿病心肌病。为了验证这一假设,我们使用源自人诱导多能干细胞(hiPSC)的心肌细胞来测试恩格列净对糖尿病样培养物诱导的心脏功能障碍的中和作用的潜在影响。我们的结果表明,无胰岛素的高葡萄糖培养显著增加了 hiPSC 衍生的心肌细胞的大小和 NPPB、SGLT1 和 SGLT2 的表达。此外,高葡萄糖处理的 hiPSC 衍生的心肌细胞表现出收缩性降低,而无论钙瞬变能力增加如何。有趣的是,在高葡萄糖处理之前或之后应用恩格列净可有效降低高葡萄糖诱导的心脏异常。由于恩格列净的应用并未显著改变 hiPSC 衍生的心肌细胞的活力或糖酵解能力,因此恩格列净可能通过下调 SGLT1、SGLT2 和 GLUT1 的表达来发挥作用。这些观察结果提供了支持性证据,可能有助于解释其在 EMPA-REG 试验中观察到的意外益处。