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Hsp27 associates with actin and limits injury in energy depleted renal epithelia. J Am Soc Nephrol 2003 Jan;14(1):98-106

Date

12/31/2002

Pubmed ID

12506142

DOI

10.1097/01.asn.0000038687.24289.83

Scopus ID

2-s2.0-0037221627   45 Citations

Abstract

The purpose of the study was to determine whether Hsp27 interacts with actin and could protect against selected manifestations of injury from energy depletion in renal epithelia. LLC-PK1 cells were stably transfected to overexpress human Hsp27 tagged with green fluorescence protein (GFP). Transfected expression of the labeled Hsp27 did not reduce endogenous Hsp25 levels in the cells compared with either nontransfected cells or cells transfected with GFP alone used as the transfectant control (G). By fluorescence energy transfer (FRET) between GFP-tagged Hsp27 and rhodamine phalloidin-decorated actin, minimal interaction was found in uninjured control cells. In ATP-depleted cells, Hsp27 was associated closely with F-actin at lateral cell boundaries and with aggregated actin within the cell body. Less Hsp27 interaction with actin was found during recovery; but when adjusted for total phalloidin fluorescence, FRET between Hsp27 and F-actin did not change between 2-h ATP depletion and 4-h recovery. Where Hsp27 association with actin persisted during recovery, it was principally with the residual aggregates of actin in the cell body. Detachment of Na,K-ATPase from the cytoskeleton at 2-h ATP depletion was significantly less in Hsp27 cells compared with transfectant control G cells but not at 4-h ATP depletion. Detachment of ezrin from the cytoskeleton during ATP depletion was nearly complete and was not prevented in the Hsp27 cells. Protection of the Hsp27 cells was not attributable to preservation of cellular ATP levels. Hsp27 appears to have specific actions in renal epithelia subjected to energy depletion, including interacting with actin to preserve architecture in specific intracellular domains.

Author List

Van Why SK, Mann AS, Ardito T, Thulin G, Ferris S, Macleod MA, Kashgarian M, Siegel NJ

Author

Scott K. Van Why MD Professor in the Pediatrics department at Medical College of Wisconsin




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

Actins
Adenosine Triphosphate
Animals
Cytoprotection
Cytoskeletal Proteins
Energy Metabolism
Epithelium
Fluorescence Resonance Energy Transfer
HSP27 Heat-Shock Proteins
Heat-Shock Proteins
Humans
Kidney
LLC-PK1 Cells
Molecular Chaperones
Neoplasm Proteins
Swine
Transfection