P6267Novel direct effects of SGLT2 inhibitor, Canagliflozin, on myocardial redox state in humans
P6267Novel direct effects of SGLT2 inhibitor, Canagliflozin, on myocardial redox state in humans
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P6267SGLT2 抑制剂 Canagliflozin 对人类心肌氧化还原状态的新的直接影响
DOI：
10.1093/eurheartj/ehz746.0866
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发表时间：
2019
影响因子：
39.3
通讯作者：
Kondo H
中科院分区：
文献类型：
--
作者：
Kondo H
背景钠葡萄糖协同转运蛋白2（SGLT 2）抑制剂是通过抑制肾脏对葡萄糖的重吸收来控制血糖水平的抗糖尿病药物。最近的临床试验表明，SGLT 2抑制剂在预防心力衰竭住院方面具有类效应。然而，其潜在的机制尚未完全阐明。PurposeWe调查了SGLT 2抑制剂Canagliflozin（Cana）对人类心肌氧化还原状态的直接影响。新鲜心肌组织与或不与Cana离体孵育，然后用于超氧化物定量和Western免疫印迹。用NADPH 100μM刺激来评价NADPH氧化酶活性，而用N（ω）-硝基-L-精氨酸甲酯（L-NAME，一种NOS抑制剂）来评价一氧化氮合酶（NOS）偶联。人心肌细胞（HCM）细胞系也被用于在体外验证的影响，Cana对myocardial. ResultsExvivo孵育的心肌与Cana显着降低基线（A）和NADPH氧化酶衍生的O2·−（B）和改善NOS耦合反映的正L-NAME δ O2·−值（C）。发现Cana对NADPH氧化酶活性的调节是由于GTP激活（D）减少和随后的Rac 1（NADPH氧化酶的关键亚基）膜转位（E）。Cana还减少了四氢生物蝶呤（BH 4）的氧化，增加了其生物利用度（F），这是改善NOS偶联的关键机制。与Cana孵育增强AMPK的磷酸化和下游信号传导ACC（未显示）。作为AMPK抑制剂的另外的化合物C显著逆转Cana的这些作用（A、B、C、D、E、F）。这些发现在HCM中重复（未显示）。与此同时，Cana增加了HCM细胞质中ADP/ATP的比例，这可以为AMPK activation.ConclusionsWe证明上游机制AMPK activation.ConclusionsWe第一次在人类中，Cana抑制心肌NADPH氧化酶的活性，并通过AMPK介导的途径提高NOS偶联。这可能是SGLT 2抑制剂心脏保护作用的潜在机制。
BackgroundSodium glucose cotransporter 2 (SGLT2) inhibitors are antidiabetic drugs that control plasma glucose levels by inhibiting reabsorption of glucose in kidney. Recent clinical trials have suggested a class effect of SGLT2 inhibitors in preventing hospitalization due to heart failure. However, the underlying mechanism has not been fully elucidated.PurposeWe investigated the direct effect of the SGLT2 inhibitor, Canagliflozin (Cana), on myocardial redox state in humans.MethodsThe study included 48 patients undergoing cardiac surgery. Fresh myocardial tissues were incubated ex vivo with or without Cana and then used for superoxide quantification and Western immunoblotting. NADPH-oxidases activity was evaluated with NADPH 100μM stimulation, while nitric oxide synthase (NOS) coupling was assessed by using N(ω)-nitro-L-arginine methyl ester (L-NAME, a NOS inhibitor). A human cardiomyocyte (HCM) cell line was also used for in vitro validation of the effects of Cana on myocardium.ResultsEx vivo incubation of myocardium with Cana significantly reduced baseline (A) and NADPH-oxidase-derived O2·− (B) and improved NOS coupling reflected by positive L-NAME delta O2·− values (C). Regulation of NADPH-oxidases activity by Cana was found to result from reduced GTP-activation (D) and consequent membrane translocation (E) of Rac1, a key subunit of NADPH-oxidases. Cana also reduced tetrahydrobiopterin (BH4) oxidation, increasing its bioavailability (F), which is a key mechanism to improve NOS coupling. Incubation with Cana enhanced phosphorylation of AMPK, and the downstream signalling, ACC (not shown). Additional Compound C, which is inhibitor of AMPK, significantly reversed these effects of Cana (A, B, C, D, E, F). These findings were replicated in HCM (not shown). In line with these, Cana increased the ADP/ATP ratio of cytoplasm in HCM, which could provide an upstream mechanism for AMPK activation.ConclusionsWe demonstrate for the first time in humans, that Cana suppresses myocardial NADPH-oxidases activity and improves NOS coupling through an AMPK-mediated pathway. This could be an underlying mechanism for the cardioprotective effects of SGLT2 inhibitors.