Int J Biol Sci 2015; 11(3):246-255. doi:10.7150/ijbs.11138
MicroRNA-1 Participates in Nitric Oxide-Induced Apoptotic Insults to MC3T3-E1 Cells by Targeting Heat-Shock Protein-70
1. Department of Orthopedic Surgery, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan
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.
Keywords: Nitric oxide, MicroRNA-1, Apoptosis, HSP-70, Mitochondria
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How to cite this article:
Lee YE, Hong CY, Lin YL, Chen RM. MicroRNA-1 Participates in Nitric Oxide-Induced Apoptotic Insults to MC3T3-E1 Cells by Targeting Heat-Shock Protein-70. Int J Biol Sci 2015; 11(3):246-255. doi:10.7150/ijbs.11138. Available from http://www.ijbs.com/v11p0246.htm