Nuclear translocation and aggregate formation of heat shock cognate protein 70 (Hsc70) in oxidative stress and apoptosis

2000 ◽  
Vol 113 (16) ◽  
pp. 2845-2854
Author(s):  
Z. Dastoor ◽  
J. Dreyer

Recent evidence has shown a role for the heat shock cognate protein Hsc70 in the response to oxidative stress. We have investigated the subcellular distribution of Hsc70 by means of laser scanning confocal microscopy in neuroblastoma NB41A3 cells, in fibroblasts R6 cells and in R6-Bcl-2, an apoptosis-resistant cell line, and its function in oxidative stress and in apoptosis has been evaluated. Endogenous Hsc70 is localised predominantly in the cytoplasm in unstressed cells, whereas oxidative stress but not apoptosis induces its translocation into the nucleus. In transfected cells overexpressing Hsc70 increased nuclear translocation and aggregation of Hsc70 in intracellular speckles is observed after oxidative stress and, to a lesser degree, after exposure to apoptotic agents. Bcl-2 did not influence the movement of Hsc70 nor the formation of Hsc70-containing speckles. Nuclear translocation of Hsc70 can be modulated by the expression of components from a previously described plasma membrane oxidoreductase involved in the cellular response against oxidative stress. Our data may suggest a correlation between differential translocation of Hsc70 with specific functions in apoptosis and a potential role in the protection against reactive oxygen species.

2021 ◽  
Vol 22 (3) ◽  
pp. 1146
Author(s):  
Reinhard Ullmann ◽  
Benjamin Valentin Becker ◽  
Simone Rothmiller ◽  
Annette Schmidt ◽  
Horst Thiermann ◽  
...  

Sulfur mustard (SM) is a chemical warfare agent that can damage DNA via alkylation and oxidative stress. Because of its genotoxicity, SM is cancerogenic and the progenitor of many chemotherapeutics. Previously, we developed an SM-resistant cell line via chronic exposure of the popular keratinocyte cell line HaCaT to increasing doses of SM over a period of 40 months. In this study, we compared the genomic landscape of the SM-resistant cell line HaCaT/SM to its sensitive parental line HaCaT in order to gain insights into genetic changes associated with continuous alkylation and oxidative stress. We established chromosome numbers by cytogenetics, analyzed DNA copy number changes by means of array Comparative Genomic Hybridization (array CGH), employed the genome-wide chromosome conformation capture technique Hi-C to detect chromosomal translocations, and derived mutational signatures by whole-genome sequencing. We observed that chronic SM exposure eliminated the initially prevailing hypotetraploid cell population in favor of a hyperdiploid one, which contrasts with previous observations that link polyploidization to increased tolerance and adaptability toward genotoxic stress. Furthermore, we observed an accumulation of chromosomal translocations, frequently flanked by DNA copy number changes, which indicates a high rate of DNA double-strand breaks and their misrepair. HaCaT/SM-specific single-nucleotide variants showed enrichment of C > A and T > A transversions and a lower rate of deaminated cytosines in the CpG dinucleotide context. Given the frequent use of HaCaT in toxicology, this study provides a valuable data source with respect to the original genotype of HaCaT and the mutational signatures associated with chronic alkylation and oxidative stress.


2008 ◽  
Vol 294 (6) ◽  
pp. C1398-C1406 ◽  
Author(s):  
Elbert L. Lee ◽  
Yuichi Hasegawa ◽  
Takahiro Shimizu ◽  
Yasunobu Okada

Cisplatin, a platinum-based drug, is an important weapon against many types of cancer. It induces apoptosis by forming adducts with DNA, although many aspects of its mechanism of action remain to be clarified. Previously, we found a role for the volume-sensitive, outwardly rectifying Cl− channel in cisplatin-induced apoptosis. To investigate the possibility that cation channels also have a role in the cellular response to cisplatin, we examined the activity of cation channels in cisplatin-sensitive KB-3-1 (KB) epidermoid cancer cells by the whole cell patch-clamp method. A cation channel in KB cells, activated by hypotonic stress, was identified as the Ca2+-activated, intermediate-conductance K+ (IK1) channel on the basis of its requirement for intracellular Ca2+, its blockage by the blockers clotrimazole and triarylmethane-34, and its suppression by a dominant-negative construct. Activity of this channel was not observed in KCP-4 cells, a cisplatin-resistant cell line derived from KB cells, and its molecular expression, observed by semiquantitative RT-PCR and immunostaining, appeared much reduced. Cell volume measurements confirmed a physiological role for the IK1 channel as a component of the volume-regulatory machinery in KB cells. A possible role of the IK1 channel in cisplatin-induced apoptosis was investigated. It was found that clotrimazole and triarylmethane-34 inhibited a cisplatin-induced decrease in cell viability and increase in caspase-3/7 activity, whereas 1-ethyl-2-benzimidazolinone, an activator of the channel, had the opposite effect. Thus IK1 channel activity appears to mediate, at least in part, the response of KB cells to cisplatin treatment.


1996 ◽  
Vol 1 (3) ◽  
pp. 161 ◽  
Author(s):  
Lucien J. Houenou ◽  
Linxi Li ◽  
Ming Lei ◽  
Carol R. Kent ◽  
Michael Tytell

2001 ◽  
Vol 114 (9) ◽  
pp. 1643-1653 ◽  
Author(s):  
Z. Dastoor ◽  
J.L. Dreyer

Recent studies indicating a role of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) in apoptosis or oxidative stress has been reported. Using confocal laser-scanning microscopy, we have investigated the cellular distribution of GAPDH in central nervous system (CNS)-derived cells (neuroblastoma mNB41A3), in non-CNS derived cells (R6 fibroblast) and in an apoptosis-resistant Bcl2 overexpressing cell line (R6-Bcl2). Induction of apoptosis by staurosporine or MG132 and oxidative stress by H(2)O(2) or FeCN enhanced the nuclear translocation of endogenous GAPDH in all cell types, as detected by immunocytochemistry. In apoptotic cells, GAPDH expression is three times higher than in non-apoptotic cells. Consistent with a role for GAPDH in apoptosis, overexpression of a GAPDH-green fluorescent protein (GAPDH-GFP) hybrid increased nuclear import of GAPDH-GFP into transfected cells and the number of apoptotic cells, and made them more sensitive to agents that induce apoptosis. Bcl2 overexpression prevents nuclear translocation of GAPDH and apoptosis in untransfected cells, but not in transfected cells that overexpress GAPDH-GFP. Our observations indicate that nuclear translocation of GAPDH may play a role in apoptosis and oxidative stress, probably related to the activity of GAPDH as a DNA repair enzyme or as a nuclear carrier for pro-apoptotic molecules.


2021 ◽  
Vol 1869 (12) ◽  
pp. 140719
Author(s):  
Noeli Soares Melo Silva ◽  
Luiz Fernando de Camargo Rodrigues ◽  
Paulo Roberto Dores-Silva ◽  
Carlos Alberto Montanari ◽  
Carlos Henrique Inácio Ramos ◽  
...  

Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2124 ◽  
Author(s):  
Erna Sulistyowati ◽  
Mei-Yueh Lee ◽  
Lin-Chi Wu ◽  
Jong-Hau Hsu ◽  
Zen-Kong Dai ◽  
...  

Heat shock cognate protein 70 (HSC70), a molecular chaperone, is constitutively expressed by mammalian cells to regulate various cellular functions. It is associated with many diseases and is a potential therapeutic target. Although HSC70 also possesses an anti-inflammatory action, the mechanism of this action remains unclear. This current study aimed to assess the anti-inflammatory effects of HSC70 in murine macrophages RAW 264.7 exposed to lipopolysaccharides (LPS) and to explain its pathways. Mouse macrophages (RAW 264.7) in 0.1 µg/mL LPS incubation were pretreated with recombinant HSC70 (rHSC70) and different assays (Griess assay, enzyme-linked immune assay/ELISA, electrophoretic mobility shift assay/EMSA, gelatin zymography, and Western blotting) were performed to determine whether rHSC70 blocks pro-inflammatory mediators. The findings showed that rHSC70 attenuated the nitric oxide (NO) generation, tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6) expressions in LPS-stimulated RAW264.7 cells. In addition, rHSC70 preconditioning suppressed the activities and expressions of matrix metalloproteinase-2 (MMP-2) and MMP-9. Finally, rHSC70 diminished the nuclear translocation of nuclear factor-κB (NF-κB) and reduced the phosphorylation of extracellular-signal regulated kinases 1/2 (ERK1/2), c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinases (MAPK), and phosphatidylinositol-3-kinase (PI3K/Akt). We demonstrate that rHSC70 preconditioning exerts its anti-inflammatory effects through NO production constriction; TNF-α, and IL-6 suppression following down-regulation of inducible nitric oxide synthase (iNOS), cyclooxygenase 2 (COX-2), and MMP-2/MMP-9. Accordingly, it ameliorated the signal transduction of MAPKs, Akt/IκBα, and NF-κB pathways. Therefore, extracellular HSC70 plays a critical role in the innate immunity modulation and mechanisms of endogenous protective stimulation.


Sign in / Sign up

Export Citation Format

Share Document