title: A-769662 protects osteoblasts from hydrogen dioxide-induced apoptosis through activating of AMP-activated protein kinase (AMPK).
abstract: 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.
authors: Orthopedics Department, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, Pudong, Shanghai 201399, China. pdzhuzhu@hotmail.com.
authors: Yalong
authors: Y
authors: Zhu
authors: Orthopedics Department, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, Pudong, Shanghai 201399, China. jianhuazhou126@126.com.
authors: Jianhua
authors: J
authors: Zhou
authors: Orthopedics Department, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, Pudong, Shanghai 201399, China. doctorybq@163.com.
authors: Rongguang
authors: R
authors: Ao
authors: Orthopedics Department, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, Pudong, Shanghai 201399, China. doctorybqshanghai@163.com.
authors: Baoqing
authors: B
authors: Yu
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D001713:Biphenyl Compounds; D002460:Cell Line; D004789:Enzyme Activation / Q000187:drug effects; D020536:Enzyme Activators / Q000494:pharmacology; D006801:Humans; D006861:Hydrogen Peroxide / Q000633:toxicity; D051379:Mice; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D011753:Pyrones / Q000494:pharmacology*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D013876:Thiophenes / Q000494:pharmacology*
chemical_list: D001713:Biphenyl Compounds; D020536:Enzyme Activators; D011753:Pyrones; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species; D013876:Thiophenes; D000255:Adenosine Triphosphate; D006861:Hydrogen Peroxide; D055372:AMP-Activated Protein Kinases; C512408:4-hydroxy-3-(4-(2-hydroxyphenyl)phenyl)-6-oxo-7H-thieno(2,3-b)pyridine-5-carbonitrile