Department of Cardiovascular, the Fourth People's Hospital of Shenzhen, Shenzhen, 518033, People's Republic of China,
Mol Cell Biochem. 2014 Apr;389(1-2):249-56. doi: 10.1007/s11010-013-1946-6. Epub 2013 Dec 28.
Diabetic cardiomyopathy (DCM) has become a major cause of diabetes-related morbidity and mortality. Increasing evidences have proved that hydrogen sulfide (H2S) fulfills a positive role in regulating diabetic myocardial injury. The present study was designed to determine whether GYY4137, a novel H2S-releasing molecule, protected H9c2 cells against high glucose (HG)-induced cytotoxicity by activation of the AMPK/mTOR signal pathway. H9c2 cells were incubated in normal glucose (5.5 mM), 22, 33, and 44 mM glucose for 24 h to mimic the hyperglycemia in DCM in vitro. Then we added 50, 100, and 200 μM GYY4137, and measured the cell viability, lactate dehydrogenase (LDH) enzyme activity, and mitochondrial membrane potential (MMP). 0.5 mM 5-amino-4-imidazole-carboxamide riboside (AICAR, an AMPK activator) and 1 mM adenine 9-β-D-arabinofuranoside (Ara-A, an AMPK inhibitor) were used to identity whether the AMPK/mTOR signal pathway was involved in GYY4137-mediated cardioprotection. We demonstrated that HG decreased cell viability and increased LDH enzyme activity in a concentration-dependent manner. 33 mM HG treatment for 24 h was chosen as our model group for further study. Both 100 and 200 μM GYY4137 treatments significantly attenuated HG-induced cell viability decrement, LDH enzyme activity increase, and MMP collapse. AICAR had similar effects to GYY4137 treatment while Ara-A attenuated GYY4137-mediated cardioprotection. Importantly, both GYY4137 and AICAR increased AMPK phosphorylation and decreased mTOR phosphorylation compared with the HG model group while Ara-A attenuated GYY4137-mediated AMPK phosphorylation increase and mTOR phosphorylation decrement. In conclusion, we propose that GYY4137 likely protects against HG-induced cytotoxicity by activation of the AMPK/mTOR signal pathway in H9c2 cells.
糖尿病心肌病（DCM）已成为糖尿病相关发病率和死亡率的主要原因。越来越多的证据表明，硫化氢（H2S）在调节糖尿病心肌损伤方面发挥着积极作用。本研究旨在确定新型 H2S 释放分子 GYY4137 是否通过激活 AMPK/mTOR 信号通路来保护 H9c2 细胞免受高糖（HG）诱导的细胞毒性。将 H9c2 细胞在正常葡萄糖（5.5mM）、22、33 和 44mM 葡萄糖中孵育 24 小时，以模拟体外 DCM 中的高血糖。然后我们加入 50、100 和 200μMGYY4137，测量细胞活力、乳酸脱氢酶（LDH）酶活性和线粒体膜电位（MMP）。使用 0.5mM5-氨基-4-咪唑甲酰胺核糖核苷酸（AICAR，AMPK 激活剂）和 1mM 腺嘌呤 9-β-D-阿拉伯呋喃糖苷（Ara-A，AMPK 抑制剂）来确定 AMPK/mTOR 信号通路是否参与 GYY4137 介导的心脏保护作用。我们表明，HG 以浓度依赖性方式降低细胞活力并增加 LDH 酶活性。选择 33mM HG 处理 24 小时作为进一步研究的模型组。100 和 200μMGYY4137 处理均显著减轻 HG 诱导的细胞活力降低、LDH 酶活性增加和 MMP 崩溃。AICAR 与 GYY4137 处理具有相似的作用，而 Ara-A 则减弱了 GYY4137 介导的心脏保护作用。重要的是，与 HG 模型组相比，GYY4137 和 AICAR 均增加了 AMPK 磷酸化并降低了 mTOR 磷酸化，而 Ara-A 减弱了 GYY4137 介导的 AMPK 磷酸化增加和 mTOR 磷酸化减少。总之，我们提出 GYY4137 通过激活 H9c2 细胞中的 AMPK/mTOR 信号通路来防止 HG 诱导的细胞毒性。
