title: Osmotically-induced genes are controlled by the transcription factor TonEBP in cultured cardiomyocytes.
abstract: Changes in cardiac osmolarity occur in myocardial infarction. Osmoregulatory mechanisms may, therefore, play a crucial role in cardiomyocyte survival. Tonicity-responsive enhancer binding protein (TonEBP) is a key transcription factor participating in the adaptation of cells to increases in tonicity. However, it is unknown whether cardiac TonEBP is activated by tonicity. Hypertonicity activated transcriptional activity of TonEBP, increased the amounts of both TonEBP mRNA and protein, and induced both the mRNA and protein of TonEBP target genes (aldose reductase and heat shock protein-70). Hypotonicity decreased the amount of TonEBP protein indicating bidirectional osmoregulation of this transcription factor. Adenoviral expression of a dominant negative TonEBP suppressed the hypertonicity-dependent increase of aldose reductase protein. These results indicated that TonEBP controls osmoregulatory mechanisms in cardiomyocytes.
authors.affiliation: Centro FONDAP de Estudios Moleculares de la Célula, Universidad de Chile, Olivos 1007, Santiago 838-0492, Chile.
authors.forename: Paola
authors.initials: P
authors.lastname: Navarro
authors.forename: Mario
authors.initials: M
authors.lastname: Chiong
authors.forename: Karen
authors.initials: K
authors.lastname: Volkwein
authors.forename: Francisco
authors.initials: F
authors.lastname: Moraga
authors.forename: María Paz
authors.initials: MP
authors.lastname: Ocaranza
authors.forename: Jorge E
authors.initials: JE
authors.lastname: Jalil
authors.forename: Sun Woo
authors.initials: SW
authors.lastname: Lim
authors.forename: Jeong-Ah
authors.initials: JA
authors.lastname: Kim
authors.forename: H Moo
authors.initials: HM
authors.lastname: Kwon
authors.forename: Sergio
authors.initials: S
authors.lastname: Lavandero
mesh_terms: D000449:Aldehyde Reductase / Q000235:genetics; D000818:Animals; D002478:Cells, Cultured; D005786:Gene Expression Regulation; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics; D032383:Myocytes, Cardiac / Q000378:metabolism*; D009995:Osmosis; D051381:Rats; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D018840:HSP70 Heat-Shock Proteins; C118125:NFAT5 protein, human; D014157:Transcription Factors; D000449:Aldehyde Reductase