title: Gene silencing mediated by endogenous microRNAs under heat stress conditions in mammalian cells.
abstract: Heat shock, sudden change in temperature, triggers various responses in cells for protecting the cells from such a severe circumstance. Here we investigated gene silencing mediated by endogenous microRNAs (miRNAs) in mammalian cells exposed to a mild hyperthermia, by means of miRNA activity assay using a luciferase reporter gene as well as miRNA expression analysis using a DNA microarray. Our findings indicated that the gene silencing activities involving miRNAs were enhanced without increasing in their expression levels under heat-stress conditions. Additionally, the gene silencing activity appeared to be independent of the cytoprotective action involving heat shock proteins that are immediately activated in heat-shocked cells and that function as molecular chaperons for restoring heat-denatured proteins to normal proteins. Our current findings suggested the possibility that gene silencing involving endogenous miRNAs might play a subsidiary role in heat-shocked cells for an aggressive inhibition of the expression of heat-denatured proteins.
authors: Department of Molecular Pharmacology, National Institute of Neuroscience, NCNP, Kodaira, Tokyo, Japan.
authors: Masashi
authors: M
authors: Fukuoka
authors: Department of Molecular Pharmacology, National Institute of Neuroscience, NCNP, Kodaira, Tokyo, Japan.
authors: Mariko
authors: M
authors: Yoshida
authors: Department of Molecular Pharmacology, National Institute of Neuroscience, NCNP, Kodaira, Tokyo, Japan.
authors: Akiko
authors: A
authors: Eda
authors: Department of Molecular Pharmacology, National Institute of Neuroscience, NCNP, Kodaira, Tokyo, Japan.
authors: Masaki
authors: M
authors: Takahashi
authors: Department of Molecular Pharmacology, National Institute of Neuroscience, NCNP, Kodaira, Tokyo, Japan.
authors: Hirohiko
authors: H
authors: Hohjoh
mesh_terms: D060565:Argonaute Proteins / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D055785:Gene Knockdown Techniques; D020868:Gene Silencing; D018841:HSP90 Heat-Shock Proteins / Q000235:genetics; D006367:HeLa Cells; D000076249:Heat Shock Transcription Factors; D018869:Heat-Shock Response / Q000235:genetics*; D006801:Humans; D035683:MicroRNAs / Q000235:genetics*; D034622:RNA Interference; D043244:Ribonuclease III / Q000235:genetics; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics; D059467:Transcriptome
chemical_list: C466422:AGO2 protein, human; D060565:Argonaute Proteins; D004268:DNA-Binding Proteins; D018841:HSP90 Heat-Shock Proteins; D000076249:Heat Shock Transcription Factors; D035683:MicroRNAs; D014157:Transcription Factors; D043244:Ribonuclease III