title: Targeted activation of AMPK by GSK621 ameliorates H2O2-induced damages in osteoblasts.
abstract: GSK621 is a novel AMP-activated protein kinase (AMPK) activator. This study tested its potential cytoprotective effect in hydrogen peroxide (H2O2)-treated osteoblasts. In cultured MC3T3-E1 osteoblastic cells and primary murine osteoblasts, GSK621 significantly attenuated H2O2-induced cell death and apoptosis. AMPK activation was required for GSK621-induced osteoblast cytoprotection. Inhibition of AMPK, by AMPKα1 T172A mutation or shRNA silence, almost completely blocked GSK621-induced osteoblast cytoprotection. Reversely, introduction of a constitutively-active AMPKα1 (T172D) alleviated H2O2 injuries in MC3T3-E1 cells. Further, GSK621 increased nicotinamide adenine dinucleotide phosphate (NADPH) content in osteoblasts to inhibit H2O2-induced reactive oxygen species (ROS) production. Meanwhile, GSK621 activated cytoprotective autophagy in the osteoblasts. On the other hand, pharmacological inhibition of autophagy alleviated GSK621-mediated osteoblast cytoprotection against H2O2. These results suggest that targeted activation of AMPK by GSK621 ameliorates H2O2-induced osteoblast cell injuries.
authors.affiliation: Department of Orthopedics, Huai'an First People's Hospital, Nanjing Medical University, Huai'an, China.
authors.forename: Weidong
authors.initials: W
authors.lastname: Liu
authors.affiliation: Department of Endocrinology, Huai'an First People's Hospital, Nanjing Medical University, Huai'an, China.
authors.forename: Li
authors.initials: L
authors.lastname: Mao
authors.affiliation: Department of Orthopedics, Huai'an First People's Hospital, Nanjing Medical University, Huai'an, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Ji
authors.affiliation: Clinical Laboratory, Huai'an First People's Hospital, Nanjing Medical University, Huai'an, China.
authors.forename: Fengli
authors.initials: F
authors.lastname: Chen
authors.affiliation: Department of Orthopedics, Huai'an First People's Hospital, Nanjing Medical University, Huai'an, China.
authors.forename: Yuedong
authors.initials: Y
authors.lastname: Hao
authors.affiliation: Department of Orthopedics, Huai'an First People's Hospital, Nanjing Medical University, Huai'an, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Liu
mesh_terms: D016475:3T3 Cells; D055372:AMP-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001343:Autophagy / Q000187:drug effects; D019610:Cytoprotection; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D020536:Enzyme Activators / Q000494:pharmacology*; D006861:Hydrogen Peroxide / Q000633:toxicity*; D007093:Imidazoles / Q000494:pharmacology*; D051379:Mice; D009249:NADP / Q000378:metabolism; D010006:Osteoblasts / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology; D018384:Oxidative Stress / Q000187:drug effects; D061251:Primary Cell Culture; D011744:Pyrimidinones / Q000494:pharmacology*; D034622:RNA Interference; D017382:Reactive Oxygen Species / Q000378:metabolism; D014162:Transfection
chemical_list: D020536:Enzyme Activators; C000606536:GSK621; D007093:Imidazoles; D011744:Pyrimidinones; D017382:Reactive Oxygen Species; D009249:NADP; D006861:Hydrogen Peroxide; C548179:Prkaa1 protein, mouse; D055372:AMP-Activated Protein Kinases
keywords: AMPK; GSK621; osteoblasts; osteonecrosis; oxidative stress