Activation of HSF and selective increase in heat-shock proteins by acute dexamethasone treatment

L. Sun, J. Chang, S. R. Kirchhoff, Anne A Knowlton

Research output: Contribution to journalArticle

86 Scopus citations

Abstract

Heat-shock proteins (HSPs) are an important family of endogenous protective proteins, which increase in response to myocardial ischemia and other stresses. Overexpression of HSP72 is cardioprotective. We were interested in the regulation of heat-shock factor (HSF), the transcription factor for HSP genes. Previously we have observed that the inflammatory cytokine tumor necrosis factor-α increases HSP72 levels and postulated that dexamethasone might effect the heat shock response. In the adult rat cardiac myocyte we found that treatment with either low (10 μM)- or high (100 μM)- dose dexamethasone activated HSF by 2-6 h as determined by gel shift assay without evidence of cytotoxicity. Although HSF activation is a key step in expression of HSP72, this may not result in an increase in HSP72. We found that 10 μM dexamethasone increased HSP72 38%, and 100 μM dexamethasone increased HSP72 62% (P < 0.05). HSP27 and HSP60 were unchanged. The selective increase in HSP72 was associated with protection of the cardiac myocytes from hypoxia and reoxygenation. We conclude that dexamethasone is a novel inducer of the heat shock response.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Heart and Circulatory Physiology
Volume278
Issue number4 47-4
StatePublished - Apr 2000
Externally publishedYes

Keywords

  • Glucocorticoids
  • Heat-shock factor
  • Ischemia

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)

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