Faculty Collaboration Database

The maximal cytoprotective function of the heat shock protein 27 is dependent on heat shock protein 70. Biochim Biophys Acta 2011 Jan;1813(1):129-35

Date

10/12/2010

Pubmed ID

20934464

Pubmed Central ID

PMC3014454

DOI

10.1016/j.bbamcr.2010.08.012

Scopus ID

2-s2.0-78650746851 (requires institutional sign-in at Scopus site)   16 Citations

Abstract

Endogenous heat shock proteins (HSPs) 70 and 25/27 are induced in renal cells by injury from energy depletion. Transfected over-expression of HSPs 70 or 27 (human analogue of HSP25), provide protection against renal cell injury from ATP deprivation. This study examines whether over-expressed HSP27 depends on induction of endogenous HSPs, in particular HSP70, to afford protection against cell injury. LLC-PK1 cells transfected with HSP27 (27OE cells) were injured by ATP depletion for 2h and recovered for 4h in the presence of HSF decoy, HSP70 specific siRNA (siRNA-70) and their respective controls. Injury in the presence of HSF decoy, a synthetic oligonucleotide identical to the heat shock element, the nuclear binding site of HSF, decreased HSP70 induction by 80% without affecting the over-expression of transfected HSP27. The HSP70 stress response was completely ablated in the presence of siRNA-70. Protection against injury, provided by over-expression of HSP27, was reduced by treatment with HSF decoy and abolished by treatment with siRNA-70. Immunoprecipitation studies demonstrated association of HSP27 with actin that was not affected by either treatment with HSF decoy or siRNA. Therefore, HSP27 is dependent on HSP70 to provide its maximal cytoprotective effect, but not for its interaction with actin. This study suggests that, while it has specific action on the cytoskeleton, HSP 25/27 must have coordinated activity with other HSP classes, especially HSP70, to provide the full extent of resistance to injury from energy depletion.

Author List

Sreedharan R, Riordan M, Thullin G, Van Why S, Siegel NJ, Kashgarian M

MESH terms used to index this publication - Major topics in bold

Animals
Cytoprotection
DNA-Binding Proteins
HSP27 Heat-Shock Proteins
HSP70 Heat-Shock Proteins
Heat Shock Transcription Factors
Heat-Shock Proteins
Heat-Shock Response
Humans
Immunoprecipitation
LLC-PK1 Cells
Molecular Chaperones
Oligonucleotides
RNA, Small Interfering
Swine
Transcription Factors