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Titolo:
K+-induced HSP-72 expression is mediated via rapid Ca2+ influx in renal epithelial cells
Autore:
Eickelberg, O; Geibel, J; Seebach, F; Giebisch, G; Kashgarian, M;
Indirizzi:
Yale Univ, Sch Med, Dept Pathol, New Haven, CT 06520 USA Yale Univ New Haven CT USA 06520 ed, Dept Pathol, New Haven, CT 06520 USA Yale Univ, Sch Med, Dept Surg, New Haven, CT 06520 USA Yale Univ New Haven CT USA 06520 Med, Dept Surg, New Haven, CT 06520 USA Yale Univ, Sch Med, Dept Cellular & Mol Physiol, New Haven, CT 06520 USA Yale Univ New Haven CT USA 06520 r & Mol Physiol, New Haven, CT 06520 USA
Titolo Testata:
AMERICAN JOURNAL OF PHYSIOLOGY-RENAL PHYSIOLOGY
fascicolo: 2, volume: 281, anno: 2001,
pagine: F280 - F287
SICI:
0363-6127(200108)281:2<F280:KHEIMV>2.0.ZU;2-Z
Fonte:
ISI
Lingua:
ENG
Soggetto:
HEAT-SHOCK PROTEINS; WARM ISCHEMIC-INJURY; MOLECULAR CHAPERONES; ELEMENTAL MICROANALYSIS; PROXIMAL TUBULES; STRESS-RESPONSE; MDCK CELLS; KIDNEY; MECHANISMS; BIOLOGY;
Keywords:
ischemia; heat shock proteins; LLC-PK1; stress response; calcium ion; potassium ion;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
47
Recensione:
Indirizzi per estratti:
Indirizzo: Eickelberg, O Yale Univ, Sch Med, Dept Pathol, 310 Cedar St, New Haven, CT06520 USA Yale Univ 310 Cedar St New Haven CT USA 06520 , CT 06520 USA
Citazione:
O. Eickelberg et al., "K+-induced HSP-72 expression is mediated via rapid Ca2+ influx in renal epithelial cells", AM J P-REN, 281(2), 2001, pp. F280-F287

Abstract

Pathophysiological stimuli, including hypoxia, lead to K+ efflux from the intracellular lumen to the extracellular space, thereby increasing local tissue K+ concentrations and depolarizing resident cells. In this study, we investigated the effects of increased extracellular K+ concentrations ([K+](e)) on heat shock protein (HSP) expression in the porcine proximal tubule epithelial cell line LLC-PK1. We analyzed HSP-25, HSP-72, HSC-73, and HSP-90protein expression by Western blot analyses and HSP-72 promoter activity by luciferase reporter gene assays using the proximal 1,440 bp of the HSP-72promoter. Elevating [K+](e) from 20 to 50 mM increased HSP-72 protein expression and promoter activity but did not affect HSP-25, HSC-73, or HSP-90 levels. Addition of identical concentrations of sodium chloride did not increase HSP-72 expression to a similar amount. The Ca2+ channel blocker diltiazem and the Ca2+-specific chelator EGTA-AM abolished high [K+](e)-induced HSP-72 expression by 69.7 and 75.2%, respectively, indicating that the transcriptional induction of HSP-72 involves Ca2+ influx. As measured by confocal microscopy using the Ca2+ dye fluo 3-AM, we also observed a rapid increase of intracellular Ca2+ concentration as early as 30 s after placing LLC-PK1 cells in high [K+](e). We further analyzed whether Ca2+ influx was necessary for induction of HSP-72 expression by high [K+](e) using Ca2+-free medium. Here, induction of HSP-72 in response to high [K+](e) was completely abolished. Our data thus demonstrate activation of a protective cellular response to ionic stress, e.g., elevated K+ concentrations, by specifically increasing protein levels of HSP-72.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 31/03/20 alle ore 03:15:25