title: RNA-Seq analysis of high NaCl-induced gene expression.
abstract: High extracellular NaCl is known to change expression of numerous genes, many of which are regulated by the osmoprotective transcription factor nuclear factor of activated T cells-5 (NFAT5). In the present study we employed RNA-Seq to provide a comprehensive, unbiased account of genes regulated by high NaCl in mouse embryonic fibroblast cells (MEFs). To identify genes regulated by NFAT5 we compared wild-type MEFs (WT-MEFs) to MEFs in which mutation of the NFAT5 gene inhibits its transcriptional activity (Null-MEFs). In WT-MEFs adding NaCl to raise osmolality from 300 to 500 mosmol/kg for 24 h increases expression of 167 genes and reduces expression of 412. Raising osmolality through multiple passages (adapted cells) increases expression of 196 genes and reduces expression of 528. In Null-MEFs, after 24 h of high NaCl, expression of 217 genes increase and 428 decrease, while in adapted Null-MEFs 143 increase and 622 decrease. Fewer than 10% of genes are regulated in common between WT- and null-MEFs, indicating a profound difference in regulation of high-NaCl induced genes induced by NFAT5 compared with those induced in the absence of NFAT5. Based on our findings we suggest a mechanism for this phenomenon, which had previously been unexplained. The NFAT5 DNA-binding motif (osmotic response element) is overrepresented in the vicinity of genes that NFAT5 upregulates, but not genes that it downregulates. We used Gene Ontology and manual curation to determine the function of the genes targeted by NFAT5, revealing many novel consequences of NFAT5 transcriptional activity.
authors.affiliation: Systems Biology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Izumi
authors.affiliation: Systems Biology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland.
authors.forename: Wenjing
authors.initials: W
authors.lastname: Yang
authors.affiliation: Systems Biology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Systems Biology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland Maurice_burg@nih.gov.
authors.forename: Maurice B
authors.initials: MB
authors.lastname: Burg
authors.affiliation: Systems Biology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland.
authors.forename: Joan D
authors.initials: JD
authors.lastname: Ferraris
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects; D000818:Animals; D001665:Binding Sites; D015536:Down-Regulation / Q000187:drug effects; D004622:Embryo, Mammalian / Q000166:cytology; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects*; D063990:Gene Ontology; D050856:Interferon Regulatory Factor-1 / Q000378:metabolism; D051379:Mice; D008954:Models, Biological; D009154:Mutation / Q000235:genetics; D050778:NFATC Transcription Factors / Q000235:genetics; D017423:Sequence Analysis, RNA / Q000379:methods*; D012965:Sodium Chloride / Q000494:pharmacology*; D014158:Transcription, Genetic / Q000187:drug effects; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D050856:Interferon Regulatory Factor-1; C494258:Irf1 protein, mouse; D050778:NFATC Transcription Factors; D012965:Sodium Chloride
keywords: GO analysis; NFAT5; RNA; hypertonicity; osmotic