• Journal of Life Science
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• v.26 no.12
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• pp.1360-1366
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• 2016

Heat shock proteins (HSPs) are induced in response to various physiological or environmental stressors. However, the transcriptional activation of HSPs is regulated by a family of heat shock factors (HSFs). Fish models provide an ideal system for examining the biochemical and molecular mechanisms of adaptation to various temperatures and water environments. In this study, we examined the pattern differentials of heat shock factor 1 (HSF1) and expression of heat shock protein 70 (HSP70) in response to thermal stress in goldfish and mouse hepatocyte cultures by immune-blot analysis. Goldfish HSF1 (gfHSF1) changed from a monomer to a trimer at $33^{\circ}C$ and showed slightly at $37^{\circ}C$, whereas mouse HSF1 (mHSF1) did so at $42^{\circ}C$. This experiment showed similar results to a previous study, indicating that gfHSF1 and mHSF1 play different temperature in the stress response. We also examined the activation conditions of the purified recombinant proteins in human HSF1 (hmHSF1) and gfHSF1 using CD spectroscopy and immune-blot analysis. The purified recombinant HSF1s were treated from $25^{\circ}C$ to $42^{\circ}C$. Structural changes were observed in hmHSF1 and gfHSF1 according to the heat-treatment conditions. These results revealed that both mammal HSF1 (human and mouse HSF1) and fish HSF1 exhibited temperature-dependent changes; however, their optimal activation temperatures differed.

• Yonsei Medical Journal
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• v.59 no.9
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• pp.1041-1048
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• 2018

Purpose: Heat shock factor 1 (HSF1) is a key regulator of the heat shock response and plays an important role in various cancers. However, the role of HSF1 in gastric cancer is still unknown. The present study evaluated the function of HSF1 and related mechanisms in gastric cancer. Materials and Methods: The expression levels of HSF1 in normal and gastric cancer tissues were compared using cDNA microarray data from the NCBI Gene Expression Omnibus (GEO) dataset. The proliferation of gastric cancer cells was analyzed using the WST assay. Transwell migration and invasion assays were used to evaluate the migration and invasion abilities of gastric cancer cells. Protein levels of HSF1 were analyzed using immunohistochemical staining of tissue microarrays from patients with gastric cancer. Results: HSF1 expression was significantly higher in gastric cancer tissue than in normal tissue. Knockdown of HSF1 reduced the proliferation, migration, and invasion of gastric cancer cells, while HSF1 overexpression promoted proliferation, migration, and invasion of gastric cancer cells. Furthermore, HSF1 promoted the proliferation of gastric cancer cells in vivo. In Kaplan-Meier analysis, high levels of HSF1 were associated with poor prognosis for patients with gastric cancer (p=0.028). Conclusion: HSF1 may be closely associated with the proliferation and motility of gastric cancer cells and poor prognosis of patients with gastric cancer. Accordingly, HSF1 could serve as a prognostic marker for gastric cancer.

• Bulletin of the Korean Chemical Society
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• v.34 no.11
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• pp.3405-3409
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• 2013

The activation of heat shock factor 1 (HSF1) can be induced by the changes in environmental pH, but the mechanism of HSF1 activation by acidification is not completely understood. This paper reports that a low pH (pH~6.0) can trigger human HSF1 activation. Considering the involvement of the imidazole group of histidine residues under acid pH stress, an in vitro EMSA experiment, Trp-fluorescence spectroscopy, and protein structural analysis showed that the residue, His83, is the essential for pH-dependent human HSF1-activation. To determine the roles of His83 in the HSF1-mediated stress response affecting the cellular acid resistance, mouse embryo fibroblasts with normal wild-type or mutant mouse HSF1 expression were preconditioned by heating or pH stress. The results suggest that His83 is essential for HSF1 activation or the HSF1-mediated transcription of heat shock proteins, in protecting cells from acid pH stress.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.3
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• pp.31-39
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• 2021

In this study, the fiber blending ratio and strain rate effect on the tensile properties synergy effect of hybrid fiber reinforced cement composite was evaluated. Hooked steel fiber(HSF) and smooth steel fiber(SSF) were used for reinforcing fiber. The fiber blending ratio of HSF+SSF were 1.5+0.5, 1.0+1.0 and 0.5+1.5vol.%. As a results, in the cement composite(HSF2.0) reinforced with HSF, as the strain rate increases, the tensile stress sharply decreased after the peak stress because of the decrease in the number of straightened pull-out fibers by increase of micro cracks in the matrix around HSF. When 0.5 vol.% of SSF was mixed, the micro cracks was effectively controlled at the static rate, but it was not effective in controlling micro cracks and improving the pull-out resistance of HSF at the high rate. On the other hand, the specimen(HSF1.0SSF1.0) in which 1.0vol.% HSF and 1.0vol.% SSF were mixed, each fibers controls against micro and macro cracks, and SSF improves the pull-out resistance of HSF effectively. Thus, the fiber blending effect of the strain capacity and energy absorption capacity was significantly increased at the high rate, and it showed the highest dynamic increase factor of the tensile strength, strain capacity and peak toughness. On the other hand, the incorporation of 1.5 vol.% SSF increases the number of fibers in the matrix and improves the pull-out resistance of HSF, resulting in the highest fiber blending effect of tensile strength and softening toughness. But as a low volume fraction of HSF which controlling macro crack, it was not effective for synergy of strain capacity and peak toughness.

• 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.6
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• pp.477-483
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• 2016

Heat shock factors (Hsfs) are central regulators of abiotic stress responses, especially heat stress responses, in plants. In the current study, we characterized the activity of the Hsf gene HsfA3 in Arabidopsis under oxidative stress conditions. HsfA3 transcription in seedlings was induced by reactive oxygen species (ROS), exogenous hydrogen peroxide ($H_2O_2$), and an endogenous $H_2O_2$ propagator, 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone (DBMIB). HsfA3-overexpressing transgenic plants exhibited increased oxidative stress tolerance compared to untransformed wild-type plants (WT), as revealed by changes in fresh weight, chlorophyll fluorescence, and ion leakage under light conditions. The expression of several genes encoding galactinol synthase (GolS), a key enzyme in the biosynthesis of raffinose family oligosaccharides (RFOs), which function as antioxidants in plant cells, was induced in HsfA3 overexpressors. In addition, galactinol levels were higher in HsfA3 overexpressors than in WT under unstressed conditions. In transient transactivation assays using Arabidopsis leaf protoplasts, HsfA3 activated the transcription of a reporter gene driven by the GolS1 or GolS2 promoter. Electrophoretic mobility shift assays showed that GolS1 and GolS2 are directly regulated by HsfA3. Taken together, these findings provide evidence that GolS1 and GolS2 are directly regulated by HsfA3 and that GolS enzymes play an important role in improving oxidative stress tolerance by increasing galactinol biosynthesis in Arabidopsis.

• Clinical and Experimental Reproductive Medicine
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• v.37 no.2
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• pp.125-134
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• 2010

Objective: The aim of this study was to measure the concentrations of cytokines contained in the hydrosalpingeal fluid and to evaluate the effect on the mouse embryo development with the different cytokine concentration. Methods: The hydrosalpingeal fluids (HSF) were collected during the surgery for hydrosalpinx which was confirmed by hysterosalphingogram. The cytokines in HSF including interleukin (IL)-$1{\alpha}$, IL-$1{\beta}$, IL-2, IL-4, IL-6, IL-8, IL-10, TNF-$\alpha$, Interferon-$\gamma$ (IFN-$\gamma$), vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), monocyte chemotactic protein-1 (MCP-1) were measured by ELISA method. HSF were added up to culture media with 5%, 10%, and 30% concentrations. The blastulation rates were compared. Results: IL-$\alpha$, IL-$1{\beta}$, IL-2, IL-4, IL-6, IL-8, IL-10, TNF-$\alpha$, IFN-$\bamma$, VEGF, EGF, and MCP-1 were detected, but the concentrations were different from each sample. IL-6 and IL-10 were increased in HSF-1 group, and IFN-$\gamma$, MCP-1, VEGF were increased in HSF-2 compared with normal serum range. The Th1/Th2 ratio of HSF-2 (IFN-$\gamma$:IL10) was highly elevated to 61.64, compared with that of HSF-1 (3.69). The blastulation rate was significantly decreased in HSF-2 group (27.7%) compared those of the HSF-1 group (74%) and control group (76.7%). It showed the trend that the blastulation rate was decreased depending on the concentration HSF of culture media in HSF-2 group, but it was not statistically significant. Conclusion: The composition and concentration of cytokines in each HSF were different, and increased proinflammatory cytokines in HSF might be associated with poor embryonic development. Further study will be needed about the effect of each cytokines in HSF.

• Proceedings of the Microbiological Society of Korea Conference
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• 2005.05a
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• pp.105-109
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• 2005

Heat Shock Transcription Factor (HSF), and the promoter heat Shock Element (HSE), are among the most highly conserved transcriptional regulatory elements in nature. HSF mediates the transcriptional response of eukaryotic cells to heat, infection and inflammation, pharmacological agents, and other stresses. While HSF is essential for cell viability in yeast, oogenesis and early development in Drosophila, extended life-span in C. elegans, and extra-embryonic development and stress resistance in mammals, little is known about its full range of biological target genes. We used whole genome analyses to identify virtually all of the direct transcriptional targets of yeast HSF, representing nearly three percent of the genomic loci. The majority of the identified loci are heat-inducibly bound by yeast HSF, and the target genes encode proteins that have a broad range of biological functions including protein folding and degradation, energy generation, protein secretion, maintenance of cell integrity, small molecule transport, cell signaling, and transcription. Approximately 30% of the HSF direct target genes are also induced by the diauxic shift, in which glucose levels begin to be depleted. We demonstrate that phosphorylation of HSF by Snf1 kinase is responsible for expression of a subset of HSF targets upon glucose starvation.

• International Journal of Industrial Entomology and Biomaterials
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• v.21 no.2
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• pp.169-174
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• 2010

Hydrolysate silk fibroin (HSF) is a fibrous protein composed of parallel $\beta$-structures and is made from pure silk elements including 18 amino acids, with glycine, alanine, and serine comprising of over 80% of the amino acids. Numerous studies have documented a range of effects of HSF, including moisturizing, antioxidant activity, nervous system disorders, and many more. We investigated whether HSF has anti-obesity effects in vitro. The effects of HSF inhibition on lipid accumulation and acceleration of lipid degradation in 3T3-L1 cells were studied. Treatment of 3T3-L1 cells with HSF caused significant inhibition of cell viability, an increase in glycerol release, and a decreased in adipocyte differentiation. Moreover HSF stimulated downregulated of adipogenic enzyme expressions (PPAR${\gamma}$ and C/EBP${\alpha}$) and up-regulated of fatty oxidation enzyme expressions (CPT-1 and UCP-2). Based on these results, hydrolysate silk fibroin can be suggested as a potential therapeutic substance as part of a prevention or treatment strategy for obesity.

• The Korean Journal of Physiology and Pharmacology
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• v.22 no.4
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• pp.457-465
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• 2018

The expression of BCL-2 interacting cell death suppressor (BIS), an anti-stress or anti-apoptotic protein, has been shown to be regulated at the transcriptional level by heat shock factor 1 (HSF1) upon various stresses. Recently, HSF1 was also shown to bind to BIS, but the significance of these protein-protein interactions on HSF1 activity has not been fully defined. In the present study, we observed that complete depletion of BIS using a CRISPR/Cas9 system in A549 non-small cell lung cancer did not affect the induction of heat shock protein (HSP) 70 and HSP27 mRNAs under various stress conditions such as heat shock, proteotoxic stress, and oxidative stress. The lack of a functional association of BIS with HSF1 activity was also demonstrated by transient downregulation of BIS by siRNA in A549 and U87 glioblastoma cells. Endogenous BIS mRNA levels were significantly suppressed in BIS knockout (KO) A549 cells compared to BIS wild type (WT) A549 cells at the constitutive and inducible levels. The promoter activities of BIS and HSP70 as well as the degradation rate of BIS mRNA were not influenced by depletion of BIS. In addition, the expression levels of the mutant BIS construct, in which 14 bp were deleted as in BIS-KO A549 cells, were not different from those of the WT BIS construct, indicating that mRNA stability was not the mechanism for autoregulation of BIS. Our results suggested that BIS was not required for HSF1 activity, but was required for its own expression, which involved an HSF1-independent pathway.