title: Hypoxia promotes AMP-activated protein kinase (AMPK) and induces apoptosis in mouse osteoblasts.
abstract: The hypoxic environment around the fracture site develops post the blood flow disruption and leads to osteoblast cell death and further impairs fracture healing. Hypoxia usually leads to the mitochondrial dysfunction and then results in apoptotic cell death. AMPK is ubiquitously expressed and functions as an intracellular fuel sensor by maintaining energy balance, as is potentially activated by hypoxia, ischemia, and ROS, however, the regulatory role of AMPK in hypoxia-induced apoptosis in osteoblasts and in the fracture healing has not been identified. In present study, we firstly determined the apoptosis induction by hypoxia in mouse osteoblastic MC3T3-E1 cells via examining the apoptotic cells and the activation of apoptosis-related molecules, then investigated the activation of AMPK signaling by hypoxia via analyzing the phosphorylation of AMPKα and ACC1, finally we explored the association of the AMPK activation with the hypoxia-induced apoptosis using loss-of-function strategy. Results demonstrated that hypoxia induced apoptosis in MC3T3-E1 cells and activated the AMPK signaling. And the knockdown of AMPK via chemical treatment or RNA interfering significantly decreased the hypoxia-induced apoptosis in MC3T3-E1 cells. Taken together, present study unveiled the regulatory role of AMPK signaling in the hypoxia-induced osteoblast apoptosis.
authors.affiliation: Department of Hand Microsurgery, The Second Affiliated Hospital of Inner Mongolia Medical University Inner Mongolia, Hohhot 010030, China.
authors.forename: Zengtao
authors.initials: Z
authors.lastname: Hao
authors.affiliation: Department of Hand Microsurgery, The Second Affiliated Hospital of Inner Mongolia Medical University Inner Mongolia, Hohhot 010030, China.
authors.forename: Yuxia
authors.initials: Y
authors.lastname: Ma
authors.affiliation: Department of Hand Microsurgery, The Second Affiliated Hospital of Inner Mongolia Medical University Inner Mongolia, Hohhot 010030, China.
authors.forename: Jihong
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Hand Microsurgery, The Second Affiliated Hospital of Inner Mongolia Medical University Inner Mongolia, Hohhot 010030, China.
authors.forename: Dongsheng
authors.initials: D
authors.lastname: Fan
authors.affiliation: Department of Hand Microsurgery, The Second Affiliated Hospital of Inner Mongolia Medical University Inner Mongolia, Hohhot 010030, China.
authors.forename: Chaoqian
authors.initials: C
authors.lastname: Han
authors.affiliation: Department of Hand Microsurgery, The Second Affiliated Hospital of Inner Mongolia Medical University Inner Mongolia, Hohhot 010030, China.
authors.forename: Yongfei
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Hand Microsurgery, The Second Affiliated Hospital of Inner Mongolia Medical University Inner Mongolia, Hohhot 010030, China.
authors.forename: Yuntao
authors.initials: Y
authors.lastname: Ji
authors.affiliation: Department of Hand Microsurgery, The Second Affiliated Hospital of Inner Mongolia Medical University Inner Mongolia, Hohhot 010030, China.
authors.forename: Shuzheng
authors.initials: S
authors.lastname: Wen
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D000123:Acetyltransferases / Q000378:metabolism; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D015687:Cell Hypoxia; D002460:Cell Line; D004789:Enzyme Activation; D051379:Mice; D010006:Osteoblasts / Q000187:drug effects / Q000201:enzymology* / Q000473:pathology; D010766:Phosphorylation; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D021122:Protein Subunits; D034622:RNA Interference; D015398:Signal Transduction; D013997:Time Factors; D014162:Transfection
chemical_list: D047428:Protein Kinase Inhibitors; D021122:Protein Subunits; D000123:Acetyltransferases; C055210:aminoglycoside N1-acetyltransferase; D055372:AMP-Activated Protein Kinases
keywords: AMP-activated protein kinase (AMPK); Hypoxia; MC3T3-E1 cells; apoptosis