• Journal of Life Science
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• v.16 no.6
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• pp.1052-1059
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• 2006

The heat shock response is induced by environmental stress, pathophysiological state and non-stress conditions and wide spread from bacteria to human. Although translations of most proteins are stopped under a heat shock response, heat shock proteins (HSPs) are produced to protect cell from stress. When heat shock response is induced, conformation of HSF1 was changed from monomer to trimer and HSF1 specifically binds to DNA, which was called a heat shock element(HSE) within the promoter of the heat shock genes. Human HSF1(hHSFl) contains five cysteine(Cys) residues. A thiol group(R-SH) of Cys is a strong nucleophile, the most readily oxidized and nitrosylated in amino acid chain. This consideration suggests that Cys residues may regulate the change of conformation and the activity of hHSF1 through a redox-dependent thiol/disulfide exchange reaction. We want to construct role of five Cys residues of hHSF by redox reagents. According to two studies, Cys residues are related to trimer formation of hHSF1. In this study, we want to demonstrate the correlation between structural change and DNA-binding activity of HSF1 through forming disulfide bond and trimerization. In this results, we could deduce that DNA binding activity of DNA binding domain wasn't affected by redox for always expose outside to easily bind to DNA. DNA binding activity of wild-type HSF's DNA binding domain was affected by conformational change, as conformational structure change (trimerization) caused DNA binding domain.

• Molecules and Cells
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• v.39 no.2
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• pp.163-168
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• 2016

Caffeine has both positive and negative effects on physiological functions in a dose-dependent manner. C. elegans has been used as an animal model to investigate the effects of caffeine on development. Caffeine treatment at a high dose (30 mM) showed detrimental effects and caused early larval arrest. We performed a comparative proteomic analysis to investigate the mode of action of high-dose caffeine treatment in C. elegans and found that the stress response proteins, heat shock protein (HSP)-4 (endoplasmic reticulum [ER] chaperone), HSP-6 (mitochondrial chaperone), and HSP-16 (cytosolic chaperone), were induced and their expression was regulated at the transcriptional level. These findings suggest that high-dose caffeine intake causes a strong stress response and activates all three stress-response pathways in the worms, including the ER-, mitochondrial-, and cytosolic pathways. RNA interference of each hsp gene or in triple combination retarded growth. In addition, caffeine treatment stimulated a food-avoidance behavior (aversion phenotype), which was enhanced by RNAi depletion of the hsp-4 gene. Therefore, up-regulation of hsp genes after caffeine treatment appeared to be the major responses to alleviate stress and protect against developmental arrest.

• BMB Reports
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• v.48 no.8
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• pp.467-472
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• 2015

Heat shock increases skin temperature during sun exposure and some evidence indicates that it may be involved in skin aging. The antioxidant response mediated by the transcription factor NF-E2-related factor 2 (Nrf2) is a critically important cellular defense mechanism that serves to limit skin aging. We investigated the effects of heat shock on collagenase expression when the antioxidant defense system was downregulated by knockdown of Nrf2. GSH and collagenases were analyzed, and the expression of inducible Nrf2, HO-1, and NQO1 was measured. HS68 cells were transfected with small interfering RNA against Nrf2. Heat shock induced the downregulation of Nrf2 in both the cytosol and nucleus and reduced the expression of HO-1, GSH, and NQO1. In addition, heat-exposed Nrf2-knockdown cells showed significantly increased levels of collagenase protein and decreased levels of procollagen. Our data suggest that Nrf2 plays an important role in protection against heat shock-induced collagen breakdown in skin. [BMB Reports 2015; 48(8): 467-472]

• BMB Reports
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• v.31 no.2
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• pp.201-208
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• 1998

Amino acid analogs, like other inducers of stress response, induce the synthesis of stress proteins in mammalian cells. In this study, Drosophila Kc cells, in which translation is tightly controlled during stress response, was treated with proline analogs, L-azetidine-2-carboxylic acid (AzC) and 3,4-dehydro-L-proline (dh-P). Kc cells exposed to AzC or dh-P induced the synthesis of several proteins which had the same molecular weights as known heat shock proteins. However, in Kc cells, normal protein synthesis still continued in the presence of amino acids analogs unlike in heat-shocked cells. For the induction of stress response, the incorporation of dh-P into the protein was not essential, but the incorporation of AzC was. The stress protein synthesis was regulated mainly at the transcriptional level by AzC, whereas it was regulated by dh-P at the transcription level and possibly posttranscription level. During recovery, the stress protein synthesis stopped sooner in analog-treated cells than in heat-shocked cells even though the accumulated amount of Hsp70 was much less in proline analogstreated cells. It could be concluded that the proline analogs, AzC and dh-P, induced stress response through a different mechanism from heat shock.

• Environmental Mutagens and Carcinogens
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• v.25 no.1
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• pp.32-39
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• 2005

In order to identify potential biomarkers of environmental monitoring, we evaluated heat shock genes expressions as effects of various environmental pollutants (nonylphenol, bisphenol-A, 17a­ethynyl estradiol, bis(2-ethylhexyl)phthalate, endosulfan, paraquat dichloride, chloropyriphos, fenitrothion, cadmium chloride, lead nitrate, potassium dichromate, benzo[a]pyrene and carbon tetrachloride) on larvae of aquatic midge Chironomus tentans (Diptera, Chironomidae). Heat shock protein 70 gene expression increased in most of chemicals treated larvae compared to control. The response was rapid and sensitive to low chemical concentrations but not stressor specific. In conjunction with stressor specific biomarkers, heat shock protein 70 gene expression in Chironomus might be developed for assessing exposure to environmental stressors in the fresh water ecosystem. Considering the potential of Chironomus larvae as biomonitoring species, heat shock gene expression has a considerable potential as a sensitive biomarker for environmental monitoring in Chironomus.

• Journal of Environmental Science International
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• v.12 no.6
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• pp.651-657
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• 2003

In order to examine if arsenic, one of environmental stresses, contributes to hypertension as one of cardiovas cular pathological factors, this study was perfarmed in vivo and in vitro, using intacted or pithed rats and aorta ring preparation, respectively. And also the relationship between expression of heat shock protein (HSP) 90 and vasoactives-induced contractile response was elucidated. To measure blood pressure, the carotid arterial pressure was recorded on physiograph(Grass Co. 79E) connected to strain gauge. On the other hand, contractile response of vascular ring preparation isolated from rat was determined in organ bath and was recorded on physiograph connected to isometric transducer. And HSP was detacted by Western blotting whole cell Iysis. Preganglionic nerve stimulation was increased by 26.0% in arterial pressure of rat treated with arsenic. Vascular contractile response was monitored and HSP were measured by Western blotting of whole Iysis prepared from samples exposed with 0, 0.5, 1, 2 and 4 mM of arsenic for 8 hours. The dose-vascular responses of potassium chloride were augmented by increasing dose of arsenic in the strips exposed to arsenic for 8 hours, and were not augmented for 1, 3, 5 hours. And the response of relaxation of rat aorta induced by histamine was not influenced by arsenic stress. The increase of HSP 90 expression in rat aorta was pronounced at 8 hours after 4 mM of arsenic treatment, but HSP 60 expression was not. Arsenic stress not only increased the expression of HSP 90 in the rat aorta, but also augmented contractions to potassium chloride. These results indicated that arsenic stress was sufficient to induce heat shock protein 90, resulting in increased vascular contractility in rat aorta.

• Journal of Marine Life Science
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• v.5 no.1
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• pp.17-24
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• 2020

We have identified a heat shock protein 70 gene from freshwater snail, Semisulcospira coreana. The freshwater snail HSP70 gene encode a polypeptide of 639 amino acids. Based on bioinformatic sequence characterization, HSP70 gene possessed three classical signature motifs and other conserved residues essential for their functionality. The phylogenetic analysis showed that S. coreana HSP70 had closet relationship with that of golden apple snails, Pomacea canaliculata. The HSP70 mRNA level was significantly up-regulated in response to thermal and salinity challenges. These results are in agreement with the results of other species, indicating that S. coreana HSP70 used be a potential molecular marker in response to external stressors and the regulatory process related to the HSP70 transcriptional response can be highly conserved among species.

• BMB Reports
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• v.38 no.5
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• pp.602-608
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• 2005

As a crucial transcription factor family, heat-shock factors were mainly analyzed and characterized in tomato and Arabidopsis. In this study, we isolated two putative heat shock factors OsHSF6 and OsHSF12 that interact specifically with heat-shock element (HSE) from Oryza sativa L by yeast one-hybrid method. The full-length cDNA of OsHSF6 and OsHSF12 have 1074bp and 920bp open reading frame (ORF), respectively. Analysis of the deduced amino acid sequences revealed that OsHSF6 was a class A heat shock factor (HSF) with all the conserved sequence elements characteristic of heat stress transcription factor, while OsHSF12 was a class B HSF with C-terminal domain (CTD) lacking of AHA motif. Bioinformatic analysis showed that the sequences and structures of two HSFs' DNA binding domain (DBD) had a high similarity with LpHSF24. The results of RT-PCR indicated OsHSF6 gene was expressed immediately after rice plants exposure to heat stress, and the transcription of OsHSF6 gene accumulated primarily in immature seeds, roots and leaves. However, we did not find the transcription of OsHSF12 gene in different organs and growth periods. Our results implied that OsHSF6 might be function as a HSF regulating early expression of stress genes in response to heat shock, and OsHSF12 might be act as a synergistic factor to regulate the expression of down-stream genes.

• Journal of Microbiology
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• v.44 no.5
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• pp.492-501
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• 2006

In this study, we attempted to characterize the physiological response to oxidative stress by heat shock in Saccharomyces cerevisiae KNU5377 (KNU5377) that ferments at a temperature of $40^{\circ}C$. The KNU5377 strain evidenced a very similar growth rate at $40^{\circ}C$ as was recorded under normal conditions. Unlike the laboratory strains of S. cerevisiae, the cell viability of KNU5377 was affected slightly under 2 hours of heat stress conditions at $43^{\circ}C$. KNU5377 evidenced a time-dependent increase in hydroperoxide levels, carbonyl contents, and malondialdehyde (MDA), which increased in the expression of a variety of cell rescue proteins containing Hsp104p, Ssap, Hsp30p, Sod1p, catalase, glutathione reductase, G6PDH, thioredoxin, thioredoxin peroxidase (Tsa1p), Adhp, Aldp, trehalose and glycogen at high temperature. Pma1/2p, Hsp90p and $H^+$-ATPase expression levels were reduced as the result of exposure to heat shock. With regard to cellular fatty acid composition, levels of unsaturated fatty acids (USFAs) were increased significantly at high temperatures ($43^{\circ}C$), and this was particularly true of oleic acid (C18:1). The results of this study indicated that oxidative stress as the result of heat shock may induce a more profound stimulation of trehalose, antioxidant enzymes, and heat shock proteins, as well as an increase in the USFAs ratios. This might contribute to cellular protective functions for the maintenance of cellular homeostasis, and may also contribute to membrane fluidity.

• The Korean Journal of Pharmacology
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• v.31 no.3
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• pp.323-331
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• 1995

Monocyte/macrophage infiltration is the well known initial features associated with the development of glomerular disease including non-immune mediated nephropathy. Tumor necrosis factor ${\alpha}(TNF{\alpha})$, a cytokine produced primarily by monocyte/macrophage, exhibits similar effects as observed at the initial stages and during the progression of glomerular injury. Because the mesangial cells are target cells for glomerular injury, the present study examined the effect of $TNF{\alpha}$ on glomerular mesangial cell membrane lipid peroxidation as an index of cytotoxicity attributing to $TNF{\alpha}$. Primary culture of rat mesangial cell was established by incubation of glomeruli isolated from male Sprague-Dawley rat kidneys utilizing a standard sieving method. The levels of lipid peroxides in the mesangial cells were quantitated by malondialdehyde- thiobarbituric acid adduct formation. During an 8 hour incubation at $37^{\circ}C$, $TNF{\alpha}$ at 10 to 10,000 units/ml increased the levels of lipid peroxides dose dependently. Western blot analysis demonstrated that a short thermal stress induced heat shock response and the synthesis of heat shock protein 70(hsp70) in this mesangial cells. Further, this induction of hsp 70 prevented increase of lipid peroxides in the mesangial cells exposed to $TNF{\alpha}$. These data suggest that $TNF{\alpha}-induced$ lipid peroxidation in the mesangial cells may have pathophysiological relevance to glomerular injury and prior induction of heat shock response may play a role in the cellular resistance against $TNF{\alpha}-induced$ glomerular injury.