Zhu Yalong, Zhou Jianhua, Ao Rongguang, Yu Baoqing
Orthopedics Department, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, Pudong, Shanghai 201399, China.
Int J Mol Sci. 2014 Jun 23;15(6):11190-203. doi: 10.3390/ijms150611190.
Here we report that 5'-monophosphate (AMP)-activated protein kinase (AMPK) agonist A-769662 inhibited hydrogen peroxide (H₂O₂)-induced viability loss and apoptosis of human and mouse osteoblast cells. H₂O₂-induced moderate AMPK activation in osteoblast cells, which was enhanced by A-769662. Inactivation of AMPK by its inhibitor compound C, or by target shRNA-mediated silencing and kinase dead (KD) mutation exacerbated H₂O₂-induced cytotoxicity in osteoblast cells. A-769662-mediated protective effect against H₂O₂ was also blocked by AMPK inhibition or depletion. A-769662 inhibited reactive oxygen species (ROS) accumulation by H₂O₂ in osteoblast cells. Meanwhile, H₂O₂-induced ATP depletion was inhibited by A-769662, but was aggravated by compound C. Further, H₂O₂ induced AMPK-dependent and pro-survival autophagy in cultured osteoblast cells, which was enhanced by A-769662. Our results suggested that activation of AMPK by H₂O₂ is anti-apoptosis and pro-survival in osteoblast cells, probably due to its anti-oxidant, pro-autophagy and ATP preservation abilities, and A-769662-mediated cell-protective effect in osteoblast cells requires AMPK activation. Our study suggests that A-769662 might be further investigated as a novel anti-osteonecrosis agent.
在此我们报告，5'-单磷酸腺苷（AMP）激活的蛋白激酶（AMPK）激动剂A-769662可抑制过氧化氢（H₂O₂）诱导的人及小鼠成骨细胞活力丧失和凋亡。H₂O₂可诱导成骨细胞中AMPK适度激活，而A-769662可增强这种激活。用其抑制剂化合物C、或通过靶向短发夹RNA介导的沉默以及激酶失活（KD）突变使AMPK失活，会加剧H₂O₂诱导的成骨细胞细胞毒性。AMPK抑制或缺失也会阻断A-769662介导的对H₂O₂的保护作用。A-769662可抑制H₂O₂在成骨细胞中诱导的活性氧（ROS）积累。同时，A-769662可抑制H₂O₂诱导的ATP消耗，但化合物C会加剧这种消耗。此外，H₂O₂可在培养的成骨细胞中诱导AMPK依赖性的促生存自噬，而A-769662可增强这种自噬。我们的结果表明，H₂O₂激活AMPK在成骨细胞中具有抗凋亡和促生存作用，这可能归因于其抗氧化、促自噬和ATP保存能力，并且A-769662介导的成骨细胞细胞保护作用需要AMPK激活。我们的研究表明，A-769662可能作为一种新型抗骨坏死药物有待进一步研究。
