Heat-shock pretreatment inhibits sorbitol-induced apoptosis in K562, U937 and HeLa cells.
The aim of this study was to determine whether heat-shock pretreatment exerted a protective effect against sorbitol-induced apoptotic cell death in K562, U937 and HeLa cell lines and whether such protection was associated with a decreased cytochrome c release from mithocondria and a decreased activation of caspase-9 and -3. Following heat-shock pretreatment (42 +/- 0.3 degrees C for 1 hr), these cell lines were exposed to sorbitol for 1 hr. Apoptosis was evaluated by DNA fragmentation, whereas caspase-9,-3 activation, cytochrome c release and heat-shock protein70 (HSP70) were assayed by Western Blot. Sorbitol exposure-induced apoptosis in these different cell lines with a marked activation of caspase-9 and caspase-3, whereas heat-shock pretreatment before sorbitol exposure, induced expression of HSP70 and inhibited sorbitol-mediated cytochrome c release and subsequent activation of caspase-9 and caspase-3. Similarly, overexpression of HSP70 in the three cell lines studied prevented caspase-9 cleavage and activation as well as cell death. Furthermore, we showed that the mRNA expression of iNOS decreased during both the heat-shock treatment and heat-shock pretreatment before sorbitol exposure. By contrast, the expression of Cu-Zn superoxide dismutase (SOD) and Mn-SOD proteins increased during heat-shock pretreatment before sorbitol exposure. We conclude that, heat-shock pretreatment protects different cell lines against sorbitol-induced apoptosis through a mechanism that is likely to involve SOD family members.
Marfe
Gabriella
G
Department of Experimental Medicine and Biochemical Sciences, University of Rome "Tor Vergata", Via Montpellier 1, Rome, Italy. gabriellamarfe@libero.it
Pucci
Bruna
B
De Martino
Luisa
L
Fiorito
Filomena
F
Di Stefano
Carla
C
Indelicato
Manuela
M
Aventaggiato
Michele
M
Russo
Matteo A
MA
Tafani
Marco
M
D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3 / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D045304:Cytochromes c / Q000378:metabolism; D053938:DNA Fragmentation; D018840:HSP70 Heat-Shock Proteins / Q000096:biosynthesis; D006367:HeLa Cells; D006358:Hot Temperature; D006801:Humans; D020014:K562 Cells; D052247:Nitric Oxide Synthase Type II / Q000235:genetics; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000032:analysis; D012333:RNA, Messenger / Q000032:analysis; D017382:Reactive Oxygen Species / Q000378:metabolism; D013012:Sorbitol / Q000494:pharmacology*; D013482:Superoxide Dismutase / Q000378:metabolism; D020298:U937 Cells; D051028:bcl-2-Associated X Protein / Q000032:analysis
C494826:BAX protein, human; D018840:HSP70 Heat-Shock Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D051028:bcl-2-Associated X Protein; D013012:Sorbitol; D045304:Cytochromes c; D052247:Nitric Oxide Synthase Type II; D013482:Superoxide Dismutase; D053148:Caspase 3; D053453:Caspase 9