title: MicroRNA-1 participates in nitric oxide-induced apoptotic insults to MC3T3-E1 cells by targeting heat-shock protein-70.
abstract: Our previous studies showed that nitric oxide (NO) could induce osteoblast apoptosis. MicroRNA-1 (miR-1), a skeletal- and cardiac muscle-specific small non-coding RNA, contributes to the regulation of multiple cell activities. In this study, we evaluated the roles of miR-1 in NO-induced insults to osteoblasts and the possible mechanisms. Exposure of mouse MC3T3-E1 cells to sodium nitroprusside (SNP) increased amounts of cellular NO and intracellular reactive oxygen species. Sequentially, SNP decreased cell survival but induced caspase-3 activation, DNA fragmentation, and cell apoptosis. In parallel, treatment with SNP induced miR-1 expression in a time-dependent manner. Application of miR-1 antisense inhibitors to osteoblasts caused significant inhibition of SNP-induced miR-1 expression. Knocking down miR-1 concurrently attenuated SNP-induced alterations in cell morphology and survival. Consecutively, SNP time-dependently inhibited heat-shock protein (HSP)-70 messenger (m)RNA and protein expressions. A bioinformatic search predicted the existence of miR-1-specific binding elements in the 3'-untranslational region of HSP-70 mRNA. Downregulation of miR-1 expression simultaneously lessened SNP-induced inhibition of HSP-70 mRNA and protein expressions. Consequently, SNP-induced modifications in the mitochondrial membrane potential, caspase-3 activation, DNA fragmentation, and apoptotic insults were significantly alleviated by miR-1 antisense inhibitors. Therefore, this study showed that miR-1 participates in NO-induced apoptotic insults through targeting HSP-70 gene expression.
authors: 1. Department of Orthopedic Surgery, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan ; 2. Cell Biology and Molecular Image Research Center, Taipei Medical University-Wan Fang Hospital, Taipei, Taiwan.
authors: Yong-Eng
authors: YE
authors: Lee
authors: 3. Department of Internal Medicine, Taipei Medical University-Wan Fang Hospital, Taipei, Taiwan.
authors: Chung-Ye
authors: CY
authors: Hong
authors: 2. Cell Biology and Molecular Image Research Center, Taipei Medical University-Wan Fang Hospital, Taipei, Taiwan.
authors: Yi-Ling
authors: YL
authors: Lin
authors: 2. Cell Biology and Molecular Image Research Center, Taipei Medical University-Wan Fang Hospital, Taipei, Taiwan ; 4. Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan. ; 5. Anesthetics and Toxicology Research Center, Taipei Medical University Hospital, Taipei, Taiwan.
authors: Ruei-Ming
authors: RM
authors: Chen
mesh_terms: D016475:3T3 Cells; D000818:Animals; D017209:Apoptosis / Q000235:genetics*; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D051379:Mice; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D009569:Nitric Oxide / Q000378:metabolism / Q000494:pharmacology*; D009599:Nitroprusside / Q000494:pharmacology; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D018840:HSP70 Heat-Shock Proteins; D035683:MicroRNAs; C517731:Mirn1 microRNA, mouse; D017382:Reactive Oxygen Species; D009599:Nitroprusside; D009569:Nitric Oxide
keywords: Apoptosis; HSP-70; MicroRNA-1; Mitochondria; Nitric oxide