The effect of the heat shock response on ultrastructure of the centrosome of Drosophila cultured cells in interphase: possible relation with changes in the chemical state of calcium.

1993 ◽  
Vol 71 (11-12) ◽  
pp. 507-517 ◽  
Author(s):  
Christiane Marcaillou ◽  
Alain Debec ◽  
Sylvie Lauverjat ◽  
Armelle Saihi
Keyword(s):  
Heat Shock ◽  
Heat Shock Response ◽  
Cultured Cells ◽  
Chemical State ◽  
Ultrastructural Organization ◽  
Heat Shock Stress ◽  
Shock Response ◽  
Pericentriolar Material ◽  
Functional Inactivation ◽  
Drosophila Embryos

Previous observations have shown that the heat shock response affects the centrosome function. We compared the ultrastructural organization of the centrosome in control (23 °C) and heat-shocked (37 °C, 50 min) interphase Drosophila cells to detect the nature of the lesions that could alter this organelle. The centrosome apparatus showed only minor modifications after the stress and the architecture of the centrioles appeared unaffected. The main difference concerned the organization of pericentriolar material which appeared more condensed and clotted. In extreme cases this material seemed to collapse on the centrioles. Recent reports proposed that Ca2+ concentrations could modify the distribution of pericentriolar material. In this study, we measured the changes in total and bound calcium in control or heat-shocked cell samples. The hyperthermia stress induced an increase of about 80% in global calcium. However, there was a decrease of about 50% in bound calcium. A heat shock stress seemed therefore to promote a change from the bound to the free state for a noticeable proportion of the element. As a preliminary hypothesis, these changes in the chemical state of calcium could be related to alterations in the pericentriolar material and thus with the functional inactivation of the centrosome. This view is also supported by calcium analysis on early Drosophila embryos. Contrary to cultured cells, Drosophila embryos did not present a stress inactivation of centrosomes. Equally, a heat shock did not disturb the bound calcium level in embryos.Key words: Centrosome, ultrastructure, calcium, heat shock, Drosophila.

Identification of novel heat shock-induced long non-coding RNA in human cells

2020 ◽  
Author(s):  
Rena Onoguchi-Mizutani ◽  
Yoshihiro Kishi ◽  
Yoko Ogura ◽  
Yuuki Nishimura ◽  
Naoto Imamachi ◽  
...  
Keyword(s):  
Heat Shock ◽  
Heat Shock Response ◽  
A549 Cells ◽  
Heat Shock Factor 1 ◽  
Protein Coding ◽  
Heat Shock Stress ◽  
Non Coding Rna ◽  
Shock Response ◽  
Inducible Protein ◽  
Inducible Genes

Abstract The heat-shock response is a crucial system for survival of organisms under heat stress. During heat-shock stress, gene expression is globally suppressed, but expression of some genes, such as chaperone genes, is selectively promoted. These selectively activated genes have critical roles in the heat-shock response, so it is necessary to discover heat-inducible genes to reveal the overall heat-shock response picture. The expression profiling of heat-inducible protein-coding genes has been well-studied, but that of non-coding genes remains unclear in mammalian systems. Here, we used RNA-seq analysis of heat shock-treated A549 cells to identify seven novel long non-coding RNAs that responded to heat shock. We focussed on CTD-2377D24.6 RNA, which is most significantly induced by heat shock, and found that the promoter region of CTD-2377D24.6 contains the binding site for transcription factor HSF1 (heat shock factor 1), which plays a central role in the heat-shock response. We confirmed that HSF1 knockdown cancelled the induction of CTD-2377D24.6 RNA upon heat shock. These results suggest that CTD-2377D24.6 RNA is a novel heat shock-inducible transcript that is transcribed by HSF1.

Novel sterol glucosyltransferase involved in heat shock response in the animal tissue and cultured cells

2010 ◽  
Vol 163 ◽  
pp. S34
Author(s):  
Hisako Akiyama ◽  
Narie Sasaki ◽  
Susumu Kobayashi ◽  
Kimiko Murakami-Murofushi
Keyword(s):  
Heat Shock ◽  
Heat Shock Response ◽  
Cultured Cells ◽  
Animal Tissue ◽  
Shock Response

Heat shock protects L6 myotubes from catabolic effects of dexamethasone and prevents downregulation of NF-κB

2001 ◽  
Vol 281 (4) ◽  
pp. R1193-R1200 ◽  
Author(s):  
Guangju Luo ◽  
Xiaoyan Sun ◽  
Eric Hungness ◽  
Per-Olof Hasselgren
Keyword(s):  
Heat Shock ◽  
Protein Degradation ◽  
Heat Shock Response ◽  
Muscle Cells ◽  
Binding Activity ◽  
Mrna Levels ◽  
Dna Binding Activity ◽  
Heat Shock Stress ◽  
L6 Myotubes ◽  
Shock Response

Glucocorticoids are the most important mediator of muscle cachexia in various catabolic conditions. Recent studies suggest that the transcription factor NF-κB acts as a suppressor of genes in the ubiquitin-proteasome proteolytic pathway and that glucocorticoids increase muscle proteolysis by downregulating NF-κB activity. The heat shock (stress) response, characterized by the induction of heat shock proteins, confers a protective effect against a variety of harmful stimuli. In the present study, we tested the hypothesis that the heat shock response protects muscle cells from the catabolic effects of dexamethasone and prevents downregulation of NF-κB. Cultured L6 myotubes were subjected to heat shock (43°C for 1 h) followed by recovery at 37°C for 1 h. Thereafter, cells were treated for 6 h with 1 μM dexamethasone, during which period protein degradation was measured as release of TCA-soluble radioactivity from proteins that had been prelabeled with [3H]tyrosine. Heat shock resulted in increased protein and mRNA levels for heat shock protein 70. The increase in protein degradation induced by dexamethasone was prevented in cells expressing the heat shock response. In the same cells, dexamethasone-induced downregulation of NF-κB DNA binding activity was blocked. The present results suggest that the heat shock response may protect muscle cells from the catabolic effects of dexamethasone and that this effect of heat shock may be related to inhibited downregulation of NF-κB activity.

Developmentally regulated nuclear transport of transcription factors in Drosophila embryos enable the heat shock response

Development ◽  
1998 ◽  
Vol 125 (23) ◽  
pp. 4841-4850 ◽  
Author(s):  
Z. Wang ◽  
S. Lindquist
Keyword(s):  
Transcription Factors ◽  
Heat Shock ◽  
Heat Shock Response ◽  
Nuclear Transport ◽  
Binding Activity ◽  
Spatiotemporal Pattern ◽  
Dna Binding Activity ◽  
Early Embryos ◽  
Shock Response ◽  
Drosophila Embryos

Hsp70 is a broadly conserved thermotolerance factor, but inhibits growth at normal temperatures and cannot be induced in early embryos. We report that in Drosophila embryos the temporal and spatial patterns of Hsp70 inducibility were unexpectedly complex, with striking differences between the soma and the germline. In both, regulation occurred at the level of transcription. During the refractory period for Hsp70 induction, HSF (heat-shock transcription factor) exhibited specific DNA-binding activity characteristic of activation in extracts of heated embryos. Remarkably, however, HSF was restricted to the cytoplasm in intact embryos even after heat shock. HSF moved from the cytoplasm to the nucleus in the absence of heat precisely when the capacity to induce Hsp70 was acquired (cycle 12 of the germline, cycle 13 in the soma). During oogenesis, Hsp70 inducibility was lost in nurse cells around stage 10, in a posterior-to-anterior gradient and HSF redistributed from nucleus to cytoplasm in the same spatiotemporal pattern. In a highly inbred derivative of the Samarkind strain, HSF moved into embryonic nuclei earlier than in our standard wild-type strain. Correspondingly, Hsp70 was inducible earlier, confirming that nuclear transport of HSF controls the inducibility of Hsp70 in early embryos. We also report for the first time the nuclear import patterns of two general transcription factors, RNA polymerase subunit Ilc and TATA binding protein (TBP). Both enter nuclei in a highly synchronous manner, independently of each other and of HSF. The import of TBP coincides with the first reported appearance of transcripts in the embryo. We suggest that the potentiation of general and heat shock-specific transcription in Drosophila embryos is controlled by the developmentally programmed relocalization of general and heat shock-specific transcription factors. Restricted nuclear entry of HSF represents a newly described mechanism for regulating the heat-shock response.

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