期刊
AMINO ACIDS
卷 40, 期 3, 页码 895-911出版社
SPRINGER WIEN
DOI: 10.1007/s00726-010-0728-7
关键词
Mitochondria; Heart; Metabolism; Glucose
资金
- NHLBI NIH HHS [R01 HL094419, R01 HL083320-03, R01 HL083320-03S1, R01 HL094419-03, R01 HL083320, R01 HL083320-02, R01 HL083320-04, R01 HL094419-01A1, R01 HL083320-01A1, R01 HL094419-02, R01 HL083320-05] Funding Source: Medline
O-linked beta-N-acetylglucosamine (O-GlcNAc) is an inducible, dynamically cycling and reversible post-translational modification of Ser/Thr residues of nucleocytoplasmic and mitochondrial proteins. We recently discovered that O-GlcNAcylation confers cytoprotection in the heart via attenuating the formation of mitochondrial permeability transition pore (mPTP) and the subsequent loss of mitochondrial membrane potential. Because Ca2+ overload and reactive oxygen species (ROS) generation are prominent features of post-ischemic injury and favor mPTP formation, we ascertained whether O-GlcNAcylation mitigates mPTP formation via its effects on Ca2+ overload and ROS generation. Subjecting neonatal rat cardiac myocytes (NRCMs, n a parts per thousand yen 6 per group) to hypoxia, or mice (n a parts per thousand yen 4 per group) to myocardial ischemia reduced O-GlcNAcylation, which later increased during reoxygenation/reperfusion. NRCMs (n a parts per thousand yen 4 per group) infected with an adenovirus carrying nothing (control), adenoviral O-GlcNAc transferase (adds O-GlcNAc to proteins, AdOGT), adenoviral O-GlcNAcase (removes O-GlcNAc to proteins, AdOGA), vehicle or PUGNAc (blocks OGA; increases O-GlcNAc levels) were subjected to hypoxia-reoxygenation or H2O2, and changes in Ca2+ levels (via Fluo-4AM and Rhod-2AM), ROS (via DCF) and mPTP formation (via calcein-MitoTracker Red colocalization) were assessed using time-lapse fluorescence microscopy. Both OGT and OGA overexpression did not significantly (P > 0.05) alter baseline Ca2+ or ROS levels. However, AdOGT significantly (P < 0.05) attenuated both hypoxia and oxidative stress-induced Ca2+ overload and ROS generation. Additionally, OGA inhibition mitigated both H2O2-induced Ca2+ overload and ROS generation. Although AdOGA exacerbated both hypoxia and H2O2-induced ROS generation, it had no effect on H2O2-induced Ca2+ overload. We conclude that inhibition of Ca2+ overload and ROS generation (inducers of mPTP) might be one mechanism through which O-GlcNAcylation reduces ischemia/hypoxia-mediated mPTP formation.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据