scholarly journals Morphological study of the mammalian stress response: characterization of changes in cytoplasmic organelles, cytoskeleton, and nucleoli, and appearance of intranuclear actin filaments in rat fibroblasts after heat-shock treatment.

1985 ◽  
Vol 101 (4) ◽  
pp. 1198-1211 ◽  
Author(s):  
W J Welch ◽  
J P Suhan
Keyword(s):  
Stress Response ◽  
Heat Shock ◽  
Actin Filaments ◽  
Stress Proteins ◽  
Morphological Changes ◽  
Shock Treatment ◽  
Immunological Methods ◽  
Heat Shock Treatment ◽  
Rat Fibroblasts ◽  
Cytoskeletal Elements

Using both electron microscopy and immunological methods, we have characterized a number of changes occurring in rat fibroblasts after heat-shock treatment. Incubation of the cells for 3 h at 42 degrees-43 degrees C resulted in a number of changes within the cytoplasm including: a disruption and fragmentation of the Golgi complex; a modest swelling of the mitochondria and subtle alterations in the packing of the cristae; and alterations in cytoskeletal elements, specifically a collapse and aggregation of the vimentin-containing intermediate filaments around the nucleus. A number of striking changes were also found within the nuclei of the heat-treated cells: (a) We observed the appearance of rod-shaped bodies consisting of densely packed filaments. Using biochemical and immunological methods, these nuclear inclusion bodies were shown to be comprised of actin filaments. (b) Considerable alterations in the integrity of the nucleoli were observed after the heat-shock treatment. Specifically, there appeared to be a general relaxation in the condensation state of the nucleoli, changes in both the number and size of the granular ribonucleoprotein components, and finally a reorganization of the nucleolar fibrillar reticulum. These morphological changes in the integrity of the nucleoli are of significant interest since previous work as well as studies presented here show that two of the mammalian stress proteins, the major stress-induced 72-kD protein and the 110-kD protein, localize within the nucleoli of the cells after heat-shock treatment. We discuss these morphological changes with regards to the known biological and biochemical events that occur in cells after induction of the stress response.

scholarly journals Characterization of the thermotolerant cell. I. Effects on protein synthesis activity and the regulation of heat-shock protein 70 expression.

1988 ◽  
Vol 106 (4) ◽  
pp. 1105-1116 ◽  
Author(s):  
L A Mizzen ◽  
W J Welch
Keyword(s):  
Protein Synthesis ◽  
Heat Shock ◽  
Stress Proteins ◽  
Stress Protein ◽  
Shock Treatment ◽  
Heat Shock Treatment ◽  
Normal Medium ◽  
Growth Environment ◽  
Mammalian Cell Lines ◽  
C 30

Exposure of mammalian cells to a nonlethal heat-shock treatment, followed by a recovery period at 37 degrees C, results in increased cell survival after a subsequent and otherwise lethal heat-shock treatment. Here we characterize this phenomenon, termed acquired thermotolerance, at the level of translation. In a number of different mammalian cell lines given a severe 45 degrees C/30-min shock and then returned to 37 degrees C, protein synthesis was completely inhibited for as long as 5 h. Upon resumption of translational activity, there was a marked induction of heat-shock (or stress) protein synthesis, which continued for several hours. In contrast, cells first made thermotolerant (by a pretreatment consisting of a 43 degrees C/1.5-h shock and further recovery at 37 degrees C) and then presented with the 45 degrees C/30-min shock exhibited considerably less translational inhibition and an overall reduction in the amount of subsequent stress protein synthesis. The acquisition and duration of such "translational tolerance" was correlated with the expression, accumulation, and relative half-lives of the major stress proteins of 72 and 73 kD. Other agents that induce the synthesis of the stress proteins, such as sodium arsenite, similarly resulted in the acquisition of translational tolerance. The probable role of the stress proteins in the acquisition of translational tolerance was further indicated by the inability of the amino acid analogue, L-azetidine 2-carboxylic acid, an inducer of nonfunctional stress proteins, to render cells translationally tolerant. If, however, analogue-treated cells were allowed to recover in normal medium, and hence produce functional stress proteins, full translational tolerance was observed. Finally, we present data indicating that the 72- and 73-kD stress proteins, in contrast to the other major stress proteins (of 110, 90, and 28 kD), are subject to strict regulation in the stressed cell. Quantitation of 72- and 73-kD synthesis after heat-shock treatment under a number of conditions revealed that "titration" of 72/73-kD synthesis in response to stress may represent a mechanism by which the cell monitors its local growth environment.

scholarly journals Characterization of the thermotolerant cell. II. Effects on the intracellular distribution of heat-shock protein 70, intermediate filaments, and small nuclear ribonucleoprotein complexes.

1988 ◽  
Vol 106 (4) ◽  
pp. 1117-1130 ◽  
Author(s):  
W J Welch ◽  
L A Mizzen
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Stress Proteins ◽  
Intracellular Distribution ◽  
Shock Treatment ◽  
Heat Shock Treatment ◽  
Ribonucleoprotein Complexes ◽  
Small Nuclear Ribonucleoprotein ◽  
Nuclear Ribonucleoprotein ◽  
In Cells

Here we further characterize a number of properties inherent to the thermotolerant cell. In the preceding paper, we showed that the acquisition of the thermotolerant state (by a prior induction of the heat-shock proteins) renders cells translationally tolerant to a subsequent severe heat-shock treatment and thereby results in faster kinetics of both the synthesis and subsequent repression of the stress proteins. Because of the apparent integral role of the 70-kD stress proteins in the acquisition of tolerance, we compared the intracellular distribution of these proteins in both tolerant and nontolerant cells before and after a severe 45 degrees C/30-min shock. In both HeLa and rat embryo fibroblasts, the synthesis and migration of the major stress-induced 72-kD protein into the nucleolus and its subsequent exit was markedly faster in the tolerant cells as compared with the nontolerant cells. Migration of preexisting 72-kD into the nucleolus was shown to be dependent upon heat-shock treatment and independent of active heat-shock protein synthesis. Using both microinjection and immunological techniques, we observed that the constitutive and abundant 73-kD stress protein similarly showed a redistribution from the cytoplasm and nucleus into the nucleolus as a function of heat-shock treatment. We show also that other lesions that occur in cells after heat shock can be prevented or at least minimized if the cells are first made tolerant. Specifically, the heat-induced collapse of the intermediate filament cytoskeleton did not occur in cells rendered thermotolerant. Similarly, the disruption of intranuclear staining patterns of the small nuclear ribonucleoprotein complexes after heat-shock treatment was less apparent in tolerant cells exposed to a subsequent heat-shock treatment.

Heat-induced triploids in Brycon amazonicus: a strategic fish species for aquaculture and conservation

Zygote ◽  
2021 ◽  
pp. 1-5
Author(s):  
Nivaldo Ferreira do Nascimento ◽  
Rafaela Manchin Bertolini ◽  
Lucia Soares Lopez ◽  
Laura Satiko Okada Nakaghi ◽  
Paulo Sérgio Monzani ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Heat Shock ◽  
Early Development ◽  
Fish Species ◽  
Survival Rates ◽  
Shock Treatment ◽  
Hatching Rate ◽  
Heat Shock Treatment ◽  
Control Survival ◽  
Ploidy Status

Summary Triploidization plays an important role in aquaculture and surrogate technologies. In this study, we induced triploidy in the matrinxã fish (Brycon amazonicus) using a heat-shock technique. Embryos at 2 min post fertilization (mpf) were heat shocked at 38°C, 40°C, or 42°C for 2 min. Untreated, intact embryos were used as a control. Survival rates during early development were monitored and ploidy status was confirmed using flow cytometry and nuclear diameter analysis of erythrocytes. The hatching rate reduced with heat-shock treatment, and heat-shock treatments at 42°C resulted in no hatching events. Optimal results were obtained at 40°C with 95% of larvae exhibiting triploidy. Therefore, we report that heat-shock treatments of embryos (2 mpf) at 40°C for 2 min is an effective way to induce triploid individuals in B. amazonicus.

scholarly journals DNA damage and heat shock dually regulate genes in Saccharomyces cerevisiae.

1986 ◽  
Vol 6 (1) ◽  
pp. 90-96 ◽  
Author(s):  
T McClanahan ◽  
K McEntee
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Dna Damage ◽  
Heat Shock ◽  
Shock Treatment ◽  
Northern Hybridization ◽  
Heat Shock Treatment ◽  
Base Pairs ◽  
S1 Nuclease ◽  
Hsp70 Family ◽  
Transcriptional Start Sites

Two Saccharomyces cerevisiae genes isolated in a differential hybridization screening for DNA damage regulation (DDR genes) were also transcriptionally regulated by heat shock treatment. A 0.45-kilobase transcript homologous to the DDRA2 gene and a 1.25-kilobase transcript homologous to the DDR48 gene accumulated after exposure of cells to 4-nitroquinoline-1-oxide (NQO; 1 to 1.5 microgram/ml) or brief heat shock (20 min at 37 degrees C). The DDRA2 transcript, which was undetectable in untreated cells, was induced to high levels by these treatments, and the DDR48 transcript increased more than 10-fold as demonstrated by Northern hybridization analysis. Two findings argue that dual regulation of stress-responsive genes is not common in S. cerevisiae. First, two members of the heat shock-inducible hsp70 family of S. cerevisiae, YG100 and YG102, were not induced by exposure to NQO. Second, at least one other DNA-damage-inducible gene, DIN1, was not regulated by heat shock treatment. We examined the structure of the induced RNA homologous to DDRA2 after heat shock and NQO treatments by S1 nuclease protection experiments. Our results demonstrated that the DDRA2 transcript initiates equally frequently at two sites separated by 5 base pairs. Both transcriptional start sites were utilized when cells were exposed to either NQO or heat shock treatment. These results indicate that DDRA2 and DDR48 are members of a unique dually regulated stress-responsive family of genes in S. cerevisiae.

Repetitive Dictyostelium heat-shock promotor functions in Saccharomyces cerevisiae

1984 ◽  
Vol 4 (4) ◽  
pp. 591-598
Author(s):  
J Cappello ◽  
C Zuker ◽  
H F Lodish
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Heat Shock ◽  
Nucleotide Sequence ◽  
Dna Sequence ◽  
Base Pair ◽  
Shock Treatment ◽  
Yeast Cells ◽  
Genomic Segment ◽  
Heat Shock Treatment ◽  
Shock Response

The Dictyostelium genome contains 40 copies of a 4.7-kilobase repetitive and apparently transposable DNA sequence (DIRS-1) and about 250 smaller elements that appear to be deletions or rearrangements of DIRS-1. Transcripts of these sequences are induced during differentiation and also by heat shock treatment of growing cells. We showed that one such cloned element, pB41.6 (2.5 kilobases) contains a nucleotide sequence identical to the Drosophila consensus heat shock promotor. To test whether this sequence might indeed control the expression of DIRS-1-related RNAs, we have cloned this genomic segment into yeast cells. In yeast cells, 41.6 directs synthesis of a 1.7-kilobase RNA that is induced at least 10-fold by heat shock. Transcription initiates at about 124 bases 3' of the putative promotor sequence and terminates within the 41.6 insert. A 381-base-pair subclone that contains the putative promotor sequence is sufficient to induce the heat shock response of 41.6 in yeast cells.

Heat Shock Treatment Enhances Graft Cell Survival in Skeletal Myoblast Transplantation to the Heart

Circulation ◽  
2000 ◽  
Vol 102 (suppl_3) ◽  
Author(s):  
Ken Suzuki ◽  
Ryszard T. Smolenski ◽  
Jay Jayakumar ◽  
Bari Murtuza ◽  
Nigel J. Brand ◽  
...  
Keyword(s):  
Heat Shock ◽  
Cell Survival ◽  
Cell Transplantation ◽  
Shock Treatment ◽  
Heat Shock Treatment ◽  
Skeletal Myoblast ◽  
Skeletal Myoblasts ◽  
Myoblast Transplantation ◽  
Hypoxia Reoxygenation

Background —Graft survival after skeletal myoblast transplantation is affected by various pathological processes caused by environmental stress. Heat shock is known to afford protection of several aspects of cell metabolism and function. We hypothesized that prior heat shock treatment of graft cells would improve their survival after cell transplantation. Methods and Results —L6 rat skeletal myoblasts expressing β-galactosidase (β-gal) were subjected to heat shock (42°C, 1 hour). Increased expression of heat shock protein 72 was detected 24 hours later in the heat-shocked cells. After hypoxia-reoxygenation in vitro, lactate dehydrogenase leakage was significantly attenuated in the heat-shocked cells; in addition, the percentage of early apoptosis was lower in this group measured by flow cytometry with annexin V staining. For the in vivo study, 1×10 6 heat-shocked (hsCTx) or normal-cultured (CTx) myoblasts were infused into the explanted rat hearts through the coronary artery followed by heterotopic heart transplantation. β-gal activity was significantly higher in the hsCTx group after cell transplantation, with an estimated 8×10 6 surviving cells per heart in the hsCTx group and 5×10 6 cells in the CTx group on day 28. Discrete loci of grafted cells were globally observed in the myocardium of the hsCTx and CTx groups, with a higher frequency in the hsCTx group. Surviving myoblasts occasionally differentiated into myotubes and had integrated with the native cardiomyocytes. Conclusions —Heat-shocked skeletal myoblasts demonstrated improved tolerance to hypoxia-reoxygenation insult in vitro and enhanced survival when grafted into the heart. Heat shock treatment could be useful in improving graft cell survival in cell transplantation.

scholarly journals Enhancing the thermotolerance of tomato seedlings by heat shock treatment

2019 ◽  
Vol 57 (4) ◽  
pp. 1184-1192 ◽  
Author(s):  
Z.Q. YANG ◽  
C. XU ◽  
M.T. WANG ◽  
H.L. ZHAO ◽  
Y.J. ZHENG ◽  
...  
Keyword(s):  
Heat Shock ◽  
Shock Treatment ◽  
Heat Shock Treatment ◽  
Tomato Seedlings
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