Retracted: Heat‐shock pretreatment inhibits sorbitol‐induced apoptosis in K562, U937 and HeLa cells

Abstract

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 6 0.3°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. ' 2009 UICC

Phosphorylation of serine 4642 in the COOH-extremity of plectin by MNK2 and PKA modulates its interaction with intermediate filaments

“…6A). Upon increasing incubation times with anisomycin and sorbitol there was a progressive degradation of plectin, most likely reflecting proteolysis during apoptosis (Stegh et al, 2000) induced by these compounds (Marfe et al, 2009;Liu et al, 2013). In agreement with previous reports (Raingeaud et al, 1995;Kayali et al, 2000;Bagowski et al, 2003), we observed a rapid and long lasting stimulation of ERK1/2 in HeLa cells incubated with EGF, PMA and sorbitol, whereas anisomycin was a poor stimulator of ERK1/2.…”

RalA GTPase and MAP4K4 Function through NDR1 Activation in Stress Response and Apoptotic Signaling

“…Since RalA-Exocyst-MAP4K4 signaling regulates NDR1 activation (Figures 3-5) and NDR1 activation is necessary for efficient apoptosis signaling [35][36][37], the role of RalA in apoptosis caused by hyperosmolarity was explored in our settings (Figure 6). High osmolarity, such as 1 M sorbitol [57], but not 0.3 M sorbitol (data not shown), promoted after 2 hours the cleavage of caspase 3 ( Figure 6A), a well established marker for on-going apoptosis. Under these conditions, NDR1 was highly phosphorylated after 30 minutes and returned to the basal level after 3 hours ( Figure 6A).…”

The Role of Superoxide Dismutase in the Survival of <i>Mycobacterium tuberculosis</i> in Macrophages

“…Previous researches have indicated that apoptosis of host cell is inhibited because of increasing SOD enzyme activity (45)(46)(47)(48). In this study, apoptosis of ANA-1 cells was evaluated by caspase-3 activity and development of apoptotic bodies by Hoechst fluorescence staining.…”