scholarly journals Hsp70 Protects Mitotic Cells against Heat-induced Centrosome Damage and Division Abnormalities

2005 ◽  
Vol 16 (8) ◽  
pp. 3776-3785 ◽  
Author(s):  
Henderika M.J. Hut ◽  
Harm H. Kampinga ◽  
Ody C.M. Sibon

The effect of heat shock on centrosomes has been mainly studied in interphase cells. Centrosomes play a key role in proper segregation of DNA during mitosis. However, the direct effect and consequences of heat shock on mitotic cells and a possible cellular defense system against proteotoxic stress during mitosis have not been described in detail. Here, we show that mild heat shock, applied during mitosis, causes loss of dynamitin/p50 antibody staining from centrosomes and kinetochores. In addition, it induces division errors in most cells and in the remaining cells progression through mitosis is delayed. Expression of heat shock protein (Hsp)70 protects against most heat-induced division abnormalities. On heat shock, Hsp70 is rapidly recruited to mitotic centrosomes and normal progression through mitosis is observed immediately after release of Hsp70 from centrosomes. In addition, Hsp70 expression coincides with restoration of dynamitin/p50 antibody staining at centrosomes but not at kinetochores. Our data show that during mitosis, centrosomes are particularly affected resulting in abnormal mitosis. Hsp70 is sufficient to protect against most division abnormalities, demonstrating the involvement of Hsp70 in a repair mechanism of heat-damaged mitotic centrosomes.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 2005-2005 ◽  
Author(s):  
Marion Pocaly ◽  
Valérie Lagarde ◽  
Gabriel Etienne ◽  
Jean-Antoine Ribeil ◽  
Marc Bonneu ◽  
...  

Abstract Imatinib is an effective therapy for chronic myeloid leukemia (CML), a myeloproliferative syndrome characterised by the expression of the recombinant oncoprotein Bcr-Abl. Imatinib inhibits Bcr-Abl tyrosine kinase activity leading to apoptosis of leukemic cells sparing normal hematopoiesis. Several mechanisms of resistance to imatinib have been identified both in vitro and in vivo: Bcr-Abl mutations, an over-expression of the Bcr-Abl kinase itself or other tyrosine kinase bypass. To identify unknown mechanism, we used an imatinib resistant cell line (K562-R) generated from the erythroblastic cell line K562 (K562-S) (Blood, 2000; 93: 1070–1079) for which all described mechanisms of resistance have been previously invalidated. Previous results from a proteomic study identified some chaperon proteins such as heat shock proteins with an increased expression level in K562-R. One of them, the heat shock protein 70, Hsp70, has a 3 fold increase expression level in K562-R cells, results which have been confirmed by western-blot analysis. To characterise the role of Hsp 70 in imatinib resistance, we inhibit Hsp 70 expression by RNA silencing (siRNA) in K562-R cells and over-express it in K562-S cells. Inhibition of Hsp70 protein expression by siRNA decrease Hsp70 expression rapidly over 90% at day 4 which is associated with a significant reduction of viability (66 ± 6%, n = 5, p < 0.03). Over expression of Hsp 70 in K562-S cells induced a significant increase of resistance to imatinib since the addition of imatinib only increases mortality by 27 ± 5 % in comparison to 52 ± 4 % for K562-S cells (n = 4, p < 0.001). Detection of HSF-1 phosphorylation, the major transcription factor involved in Hsp 70 expression, did not show significant differences between K562-S and K562-R cells although over a 3 fold increase is detected in the mRNA level of Hsp 70 in K562-R cells by quantitative PCR. Furthermore, the comparison of Hsp70 expression in mononuclear cells of 7 CML patients before imatinib treatment and at the relapse time shows that Hsp 70 is increased in imatinib resistant patients suggesting it could also play a role in resistance in vivo. Present study confirmed that over expression of Hsp 70 in the cell line K562-R is involved in the mechanism of imatinib resistance in vitro. Moreover, the correlation between the increase of Hsp 70 in CML patient cells and resistance suggests it could be an interesting marker and potentially a therapeutic target.


2021 ◽  
Author(s):  
Ho Khoi ◽  
Kohei Homma ◽  
Jun Takanari ◽  
Hanako Bai ◽  
Manabu Kawahara ◽  
...  

Abstract Heat shock protein 70 (HSP70) is a well-known heat shock (HS)-induced protein that acts as an intracellular chaperone to protect cells against stress conditions. Although HS induces HSP70 expression to acquire stress-resistant ability to cells, HS causes toxicity to cells by increasing reactive oxygen species (ROS). Recently, a standardized extract of Asparagus officinalis stem (EAS), produced from the by-product of asparagus, was found to induce HSP70 expression without HS and regulate cellular redox balance in the cells. However, the effect of EAS on the function of reproductive cells remains unknown. In the present study, we investigated the effect of EAS on HSP70 induction and oxidative redox balance in cultured bovine cumulus-granulosa(CG) cells. EAS significantly increased HSP70 expression, whereas no effect was observed in HSP27 and − 90 under non-heat stress condition. EAS decreased ROS generation and DNA damage, and increased glutathione (GSH) synthesis both under non-HS and HS conditions. Moreover, EAS synergistically increased HSP70 and HSF1 expression. EAS also increased progesterone (P4) levels in CG cells. HSP70 inhibitor significantly decreased GSH and increased ROS, as well as decreased HSF1, Nrf2, and Keap1 in the presence of EAS. These results suggest that EAS regulates redox balance through HSP70 in bovine CG cells.


2020 ◽  
Vol 14 (01) ◽  
pp. 031-037
Author(s):  
Utari Kresnoadi ◽  
Retno Pudji Rahayu ◽  
Maretaningtias Dwi Ariani ◽  
Soesanto Soesanto

Abstract Objective This study aims to combine natural propolis with bovine bone graft (BBG) as a means of extraction socket preservation after 3 and 7 days toward expression of heat shock protein (HSP) 70 and osteocalcin to regenerate bone. Materials and Methods The Cavia cobaya were divided into eight groups, each consisting of seven samples. Their lower left incisors were extracted and induced with PEG, propolis extract, BBG, and a combination of propolis extract BBG. The research subjects were terminated on days 3 and 7 postextraction. Immunohistochemical and histopathological examinations were subsequently performed to observe HSP 70 expression, osteocalcin expression, osteoblasts, and osteoclasts. Statistical Analysis Data obtained were then analyzed with one-way analysis of variance (ANOVA) and Tukey’s honestly significant difference (HSD) tests. Results Both the groups with the combination of propolis extract and BBG on days 3 and 7 were found to present the highest number of HSP70 expression, osteocalcin expression, and osteoblast cells as well as the lowest number of osteoclasts. Conclusion Both the groups with the combination of propolis extract and BBG on days 3 and 7 were found to present the highest number of HSP70 expression, osteocalcin expression, and osteoblast cells as well as the lowest number of osteoclasts.


2004 ◽  
Vol 82 (6) ◽  
pp. 363-371 ◽  
Author(s):  
R M Narayansingh ◽  
M Senchyna ◽  
M M Vijayan ◽  
J C Carlson

In this study we examined the mechanism of corpus luteum (CL) regression by measuring changes in expression of prostaglandin G/H synthase-1 (PGHS-1) and -2 (PGHS-2) in day 4 CL and inducible heat shock protein 70 (HSP-70) in day 4 and day 9 CL of immature superovulated rats. The rats were superovulated and treated with 500 µg of prostaglandin F2α (PGF2α) on day 4 or day 9 after CL formation. Ovaries and serial blood samples were removed during the 24-hour period following treatment. Plasma progesterone was determined by radioimmunoassay while mRNA abundance and protein expression were assessed by semiquantitative RT-PCR and immunoblot analysis, respectively. One hour after PGF2α, both day 4 and day 9 rats exhibited a significant decrease in progesterone secretion; however, there was a greater decrease in day 9 rats. In ovarian samples removed on day 4, there was a significant increase in mRNA for PGHS-2 at 1 hour after PGF2α. PGHS-1 mRNA content remained unchanged. Immunoblot analyses showed an increase in PGHS-2 protein expression only at 8 h. There were no changes in PGHS-1 protein expression. In day 9 rats, ovarian HSP-70 protein levels increased by 50% after PGF2α injection; however, on day 4 there was no change in expression of this protein over the sampling period. These results suggest that expression of PGHS-2 may be involved in inhibiting progesterone production and that expression of HSP-70 may be required for complete CL regression in the rat.Key words: rat, prostaglandin F2α, corpus luteum, prostaglandin G/H synthase, heat shock protein-70.


2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Liping Tao ◽  
Hai Zou ◽  
Zhimin Huang

Infection ofHelicobacter pylori (H. pylori)changed the proliferation of gastric epithelial cells and decreased the expression of heat shock protein 70 (HSP70). However, the effects ofH. pylorion the proliferation of gastric epithelial cells and the roles of HSP70 during the progress need further investigation.Objective.To investigate the effects ofHelicobacter pylori (H. pylori)and heat shock protein 70 (HSP70) on the proliferation of human gastric epithelial cells.Methods. H. pyloriand a human gastric epithelial cell line (AGS) were cocultured. The proliferation of AGS cells was quantitated by an MTT assay, and the expression of HSP70 in AGS cells was detected by Western blotting. HSP70 expression in AGS cells was silenced by small interfering RNA (siRNA) to investigate the role of HSP70. ThesiRNA-treated AGS cells were cocultured withH. pyloriand cell proliferation was measured by an MTT assay.Results.The proliferation of AGS cells was accelerated by coculturing withH. pylorifor 4 and 8 h, but was suppressed at 24 and 48 h. HSP70 expression was decreased in AGS cells infected byH. pylorifor 48 h. The proliferation in HSP70-silenced AGS cells was inhibited after coculturing withH. pylorifor 24 and 48 h compared with the control group.Conclusions.Coculture ofH. pylorialtered the proliferation of gastric epithelial cells and decreased HSP70 expression. HSP70 knockdown supplemented the inhibitory effect ofH. pylorion proliferation of epithelial cells. These results indicate that the effects ofH. pylorion the proliferation of gastric epithelial cells at least partially depend on the decreased expression of HSP70 induced by the bacterium.


2017 ◽  
Vol 95 (6) ◽  
pp. 732-742 ◽  
Author(s):  
Abdelaziz M. Hussein ◽  
Khaled M. Abbas ◽  
Osama A. Abulseoud ◽  
El-Hussainy M.A. El-Hussainy

The present study investigated the effects of ferulic acid (FA) on pentylenetetrazole (PTZ)-induced seizures, oxidative stress markers (malondialdehyde (MDA), catalase, and reduced glutathione (GSH)), connexin (Cx) 43, heat shock protein 70 (Hsp 70), and monoamines (serotonin (5-HT) and norepinephrine (NE)) levels in a rat model of PTZ-induced kindling. Sixty Sprague Dawley rats were divided into 5 equal groups: (a) normal group; (b) FA group: normal rats received FA at a dose of 40 mg/kg daily; (c) PTZ group: normal rats received PTZ at a dose of 50 mg/kg i.p. on alternate days for 15 days; (d) FA-before group: treatment was the same as for the PTZ group, except rats received FA; and (e) FA-after group: rats received FA from sixth dose of PTZ. PTZ caused a significant increase in MDA, Cx43, and Hsp70 along with a significant decrease in GSH, 5-HT, and NE levels and CAT activity in the hippocampus (p < 0.05). Pre- and post-treatment with FA caused significant improvement in behavioral parameters, MDA, CAT, GSH, 5-HT, NE, Cx43 expression, and Hsp70 expression in the hippocampal region (p < 0.05). We conclude that FA has neuroprotective effects in PTZ-induced epilepsy, which might be due to attenuation of oxidative stress and Cx43 expression and upregulation of neuroprotective Hsp70 and neurotransmitters (5-HT and NE).


1995 ◽  
Vol 309 (2) ◽  
pp. 453-459 ◽  
Author(s):  
L Tacchini ◽  
G Pogliaghi ◽  
L Radice ◽  
E Anzon ◽  
A Bernelli-Zazzera

Post-ischaemic reperfusion increases the level of the major heat-shock (stress) protein hsp 70 and of its mRNA by transcriptional mechanisms, and activates the binding of the heat-shock factor HSF to the consensus sequence HSE. In common with CoCl2 treatment, post-ischaemic reperfusion increases the level of haem oxygenase mRNA, an indicator of oxidative stress, but CoCl2 does not seem to induce the expression of the hsp 70 gene [Tacchini, Schiaffonati, Pappalardo, Gatti and Bernelli-Zazzera (1993) Lab. Invest. 68, 465-471]. Starting from these observations, we have now studied the expression of two genes of the hsp 70 family and of other possibly related genes under conditions of oxidative stress. Three different chemicals, which cause oxidative stress by various mechanisms and induce haem oxygenase, enhance the expression of the cognate hsc 73 gene, but do not activate the inducible hsp 70 gene. Expression of the other genes that have been studied seems to vary in intensity and/or time course, in relation to the particular mechanism of action of any single agent. The pattern of induction of the early-immediate response genes c-fos and c-jun observed during oxidative stress differs from that found in post-ischaemic reperfused livers. Oxidative-stress-inducing agents do not promote the binding of HSF to its consensus sequence HSE, such as occurs in heat-shock and post-ischaemic reperfusion, and fail to activate AP-1 (activator protein 1). With the possible exception of Phorone, the oxidative stress chemically induced in rat liver activates NFkB (nuclear factor kB) and AP-2 (activator protein 2) transcription factors.


Sign in / Sign up

Export Citation Format

Share Document