De-repression of heat shock transcription factor-1 in interleukin-6- treated hepatocytes is mediated by downregulation of glycogen synthase kinase 3beta and MAPK/ERK-1

Stephen J Wigmore, Kathryn Sangster, Stephen J McNally, Ewen M Harrison, James A Ross, Kenneth C H Fearon, O James Garden

Research output: Contribution to journalArticlepeer-review

Abstract / Description of output

Expression of inducible heat shock protein (HSP70) requires activation of heat shock transcription factor-1 (HSF-1). Recent evidence suggests that interleukin-6 (IL-6) can modify the response of HSF-1 to heat. We hypothesized that IL-6 would prime the HSP response by causing de-repression of HSF-1 resulting in augmented HSP expression in stressed cells. In this study we show that IL-6 has no direct effect on HSP70 expression at 37 degrees C but does augment HSP70 expression in response to heat. IL-6 treatment decreased active MAPK/pERK and glycogen synthase kinase 3beta (GSK3beta) expression and GSK3beta kinase activity. In IL-6-treated cells, monomeric HSF-1 accumulated in the cytoplasm and nucleus, bound DNA but was transcriptionally inactive. On exposure to heat shock this modified monomer assumed the transcriptionally active phenotype with trimerization and hyperphosphorylation evident. The increased induction of HSP70 in IL-6 and heat-treated cells was inhibited using PI3-kinase inhibitors or Akt inhibition and was HSF-1 dependent. IL-6, via the PI3-kinase/Akt pathway leads to inhibition of the repressive kinases MAPK/pERK and GSK3beta, and this converts inactive HSF-1 to an intermediate DNA-binding form augmenting transcriptional activation in the presence of a second stressor.
Original languageEnglish
Pages (from-to)413-20
Number of pages8
JournalInternational Journal of Molecular Medicine
Volume19
Issue number3
Publication statusPublished - 2007

Fingerprint

Dive into the research topics of 'De-repression of heat shock transcription factor-1 in interleukin-6- treated hepatocytes is mediated by downregulation of glycogen synthase kinase 3beta and MAPK/ERK-1'. Together they form a unique fingerprint.

Cite this