Cold stress in the harvest period: effects on tobacco leaf quality and curing characteristics.

BACKGROUND: Weather change in high-altitude areas subjects mature tobacco (Nicotiana tabacum L.) to cold stress, which damages tobacco leaf yield and quality. A brupt diurnal temperature differences (the daily temperature dropping more than 20 °C) along with rainfall in tobacco-growing areas at an altitude above 2450 m, caused cold stress to field-grown tobacco. RESULTS: After the flue-cured tobacco suffered cold stress in the field, the surface color of tobacco leaves changed and obvious large browning areas were appeared, and the curing availability was extremely poor. Further research found the quality of fresh tobacco leaves, the content of key chemical components, and the production quality were greatly reduced by cold stress. We hypothesize that cold stress in high altitude environments destroyed the antioxidant enzyme system of mature flue-cured tobacco. Therefore, the quality of fresh tobacco leaves, the content of key chemical components, and the production quality were greatly reduced by cold stress. CONCLUSION: This study confirmed that cold stress in high-altitude tobacco areas was the main reason for the browning of tobacco leaves during the tobacco curing process. This adverse environment seriously damaged the quality of tobacco leaves, but can be mitigated by pay attention to the weather forecast and pick tobacco leaves in advance.

HSF1 Attenuates LPS-Induced Acute Lung Injury in Mice by Suppressing Macrophage Infiltration.

Heat shock factor 1 (HSF1) is a transcription factor involved in the heat shock response and other biological processes. We have unveiled here an important role of HSF1 in acute lung injury (ALI). HSF1 knockout mice were used as a model of lipopolysaccharide- (LPS-) induced ALI. Lung damage was aggravated, and macrophage infiltration increased significantly in the bronchoalveolar lavage fluid (BALF) and lung tissue of HSF-/- mice compared with the damage observed in HSF1+/+ mice. Upon LPS stimulation, HSF-/- mice showed higher levels of monocyte chemoattractant protein-1 (MCP-1) in the serum, BALF, and lung tissue and increased the expression of MCP-1 and chemokine (C-C motif) receptor 2 (CCR2) on the surface of macrophages compared with those in HSF1+/+. Electrophoretic mobility shift assays (EMSA) and dual luciferase reporter assays revealed that HSF1 could directly bind to heat shock elements (HSE) in the promoter regions of MCP-1 and its receptor CCR2, thereby inhibiting the expression of both genes. We concluded that HSF1 attenuated LPS-induced ALI in mice by directly suppressing the transcription of MCP-1/CCR2, which in turn reduced macrophage infiltration.

CaHsfA1d Improves Plant Thermotolerance via Regulating the Expression of Stress- and Antioxidant-Related Genes.

Heat shock transcription factor (Hsf) plays an important role in regulating plant thermotolerance. The function and regulatory mechanism of CaHsfA1d in heat stress tolerance of pepper have not been reported yet. In this study, phylogenetic tree and sequence analyses confirmed that CaHsfA1d is a class A Hsf. CaHsfA1d harbored transcriptional function and predicted the aromatic, hydrophobic, and acidic (AHA) motif mediated function of CaHsfA1d as a transcription activator. Subcellular localization assay showed that CaHsfA1d protein is localized in the nucleus. The CaHsfA1d was transcriptionally up-regulated at high temperatures and its expression in the thermotolerant pepper line R9 was more sensitive than that in thermosensitive pepper line B6. The function of CaHsfA1d under heat stress was characterized in CaHsfA1d-silenced pepper plants and CaHsfA1d-overexpression Arabidopsis plants. Silencing of the CaHsfA1d reduced the thermotolerance of the pepper, while CaHsfA1d-overexpression Arabidopsis plants exhibited an increased insensitivity to high temperatures. Moreover, the CaHsfA1d maintained the H2O2 dynamic balance under heat stress and increased the expression of Hsfs, Hsps (heat shock protein), and antioxidant gene AtGSTU5 (glutathione S-transferase class tau 5) in transgenic lines. Our findings clearly indicate that CaHsfA1d improved the plant thermotolerance via regulating the expression of stress- and antioxidant-related genes.

Comparative transcriptome analysis reveals heat stress-responsive genes and their signalling pathways in lilies (Lilium longiflorum vs. Lilium distichum).

The lily, a famous bulbous flower, is seriously affected by high temperatures, which affect their growth and production. To date, the signalling pathways and the molecular mechanisms related to heat response in Lilium have not been elucidated. In this study, a comparative transcriptome analysis was performed in an important thermo-tolerant flower, L. longiflorum, and a thermo-sensitive flower, L. distichum. Lily seedlings were first exposed to heat stress at 42°C for different lengths of time, and the optimal time-points (2 h and 24 h) were selected for RNA sequencing (RNA-seq). Approximately 66.51, 66.21, and 65.36 Mb clean reads were identified from three libraries of L. longiflorum (LL_CK, LL_T2h and LL_T24h, respectively) and 66.18, 66.03, and 65.16 Mb clean reads were obtained from three libraries of L. distichum (LD_CK, LD_T2h and LD_T24h, respectively) after rRNA removing. A total of 34,301 unigenes showed similarity to known proteins in the database NCBI non-redundant protein (NR), Swiss-Prot proteins, InterPro proteins, Clusters of Orthologous Groups (COG) and Kyoto Encyclopedia of Genes and Genomes (KEGG). In addition, 1,621 genes were differentially expressed in the overlapping libraries between LL_DEGs and LD_DEGs; of these genes, 352 DEGs were obviously upregulated in L. longiflorum and downregulated in L. distichum during heat stress, including 4-coumarate, CoA ligase (4CL), caffeoyl-CoA O-methyltransferase (CCoAOMT), peroxidase, pathogenesis-related protein 10 family genes (PR10s), 14-3-3 protein, leucine-rich repeat receptor-like protein kinase, and glycine-rich cell wall structural protein-like. These genes were mainly involved in metabolic pathways, phenylpropanoid biosynthesis, plant-pathogen interactions, plant hormone signal transduction, and kinase signalling pathways. Quantitative RT-PCR was performed to validate the expression profiling of these DEGs in RNA-seq data. Taken together, the results obtained in the present study provide a comprehensive sequence resource for the discovery of heat-resistance genes and reveal potential key components that are responsive to heat stress in lilies, which may help to elucidate the heat signal transcription networks and facilitate heat-resistance breeding in lily.

Genome-wide characterization and expression analysis of the heat shock transcription factor family in pumpkin (Cucurbita moschata).

BACKGROUND: Crop quality and yield are affected by abiotic and biotic stresses, and heat shock transcription factors (Hsfs) are considered to play important roles in regulating plant tolerance under various stresses. To investigate the response of Cucurbita moschata to abiotic stress, we analyzed the genome of C. moschata. RESULTS: In this research, a total of 36 C. moschata Hsf (CmHsf) members were identified and classified into three subfamilies (I, II, and III) according to their amino acid sequence identity. The Hsfs of the same subfamily usually exhibit a similar gene structure (intron-exon distribution) and conserved domains (DNA-binding and other functional domains). Chromosome localization analysis showed that the 36 CmHsfs were unevenly distributed on 18 of the 21 chromosomes (except for Cm_Chr00, Cm_Chr08 and Cm_Chr20), among which 18 genes formed 9 duplicated gene pairs that have undergone segmental duplication events. The Ka/Ks ratio showed that the duplicated CmHsfs have mainly experienced strong purifying selection. High-level synteny was observed between C. moschata and other Cucurbitaceae species. CONCLUSIONS: The expression profile of CmHsfs in the roots, stems, cotyledons and true leaves revealed that the CmHsfs exhibit tissue specificity. The analysis of cis-acting elements and quantitative real-time polymerase chain reaction (qRT-PCR) revealed that some key CmHsfs were activated by cold stress, heat stress, hormones and salicylic acid. This study lays the foundation for revealing the role of CmHsfs in resistance to various stresses, which is of great significance for the selection of stress-tolerant C. moschata.

Standardized Methods for Measuring Induction of the Heat Shock Response in Caenorhabditis elegans.

The heat shock response (HSR) is a cellular stress response induced by cytosolic protein misfolding that functions to restore protein folding homeostasis, or proteostasis. Caenorhabditis elegans occupies a unique and powerful niche for HSR research because the HSR can be assessed at the molecular, cellular, and organismal levels. Therefore, changes at the molecular level can be visualized at the cellular level and their impacts on physiology can be quantitated at the organismal level. While assays for measuring the HSR are straightforward, variations in the timing, temperature, and methodology described in the literature make it challenging to compare results across studies. Furthermore, these issues act as a barrier for anyone seeking to incorporate HSR analysis into their research. Here, a series of protocols is presented for measuring induction of the HSR in a robust and reproducible manner with RT-qPCR, fluorescent reporters, and an organismal thermorecovery assay. Additionally, we show that a widely used thermotolerance assay is not dependent on the well-established master regulator of the HSR, HSF-1, and therefore should not be used for HSR research. Finally, variations in these assays found in the literature are discussed and best practices are proposed to help standardize results across the field, ultimately facilitating neurodegenerative disease, aging, and HSR research.

The seed-specific heat shock factor A9 regulates the depth of dormancy in Medicago truncatula seeds via ABA signalling.

During the later stages of seed maturation, two key adaptive traits are acquired that contribute to seed lifespan and dispersal, longevity and dormancy. The seed-specific heat shock transcription factor A9 is an important hub gene in the transcriptional network of late seed maturation. Here, we demonstrate that HSFA9 plays a role in thermotolerance rather than in ex situ seed conservation. Storage of hsfa9 seeds of Medicago truncatula and Arabidopsis had comparable lifespan at moderate storage relative humidity (RH), whereas at high RH, hsfa9 seeds lost their viability much faster than wild type seeds. Furthermore, we show that in M. truncatula, Mthsfa9 seeds acquired more dormancy during late maturation than wild type. Transient expression of MtHSFA9 in hairy roots and transcriptome analysis of Mthsfa9 Tnt1 insertion mutants identified a deregulation of genes involved in ABA biosynthesis, catabolism and signalling. Consistent with these results, Mthsfa9 seeds exhibited increased ABA levels and higher sensitivity to ABA. These data suggest that in legumes, HSFA9 acts as a negative regulator of the depth of seed dormancy during seed development via the modulation of hormonal balance.

Serotonin signaling by maternal neurons upon stress ensures progeny survival.

Germ cells are vulnerable to stress. Therefore, how organisms protect their future progeny from damage in a fluctuating environment is a fundamental question in biology. We show that in Caenorhabditis elegans, serotonin released by maternal neurons during stress ensures the viability and stress resilience of future offspring. Serotonin acts through a signal transduction pathway conserved between C. elegans and mammalian cells to enable the transcription factor HSF1 to alter chromatin in soon-to-be fertilized germ cells by recruiting the histone chaperone FACT, displacing histones, and initiating protective gene expression. Without serotonin release by maternal neurons, FACT is not recruited by HSF1 in germ cells, transcription occurs but is delayed, and progeny of stressed C. elegans mothers fail to complete development. These studies uncover a novel mechanism by which stress sensing by neurons is coupled to transcription response times of germ cells to protect future offspring.

HMGB1 was negatively regulated by HSF1 and mediated the TLR4/MyD88/NF-κB signal pathway in asthma.

AIMS: The present study explored the function and regulatory mechanism of High mobility group box 1 (HMGB1) in asthma. MAIN METHODS: OVA (ovalbumin)-induced asthmatic mice model and LPS-treated cellular model were established in this study. Airway inflammation was measured through detecting the expression of IL-4, IL-5, IL-13 and Interferon-γ (IFN-γ) in serum and BALF (bronchoalveolar lavage fluid) by ELISA kits. Bioinformatics predictive analysis, ChIP assays, Luciferase reporter assay and Western blotting were used to explore the relation between HMGB1 and HSF1 (Heat shock factor 1). KEY FINDINGS: HMGB1 expression was increased in OVA-induced asthmatic mice. Silencing HMGB1 attenuated the increasing of IgE, inflammatory factors (IL-4, IL-5 and IL-13), and airway hyperresponsiveness that induced by OVA. In addition, our study found that HSF1 directly bind with the HMGB1 promoter and negatively regulation of HMGB1. HSF-1 were upregulated in OVA-induced asthmatic mice, and knockdown of HSF1 aggravated the OVA-induced airway inflammation and airway hyperreactivity in mice may through promoting the expression of HMGB1 and the activation of the Toll-like receptor 4 (TLR4)/Myeloid differentiation primary response 88 (MyD88)/Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signal pathway. SIGNIFICANCE: The expression of HMGB1 could be negatively regulated by HSF1, and the TLR4/MyD88/NF-κB signal pathway was involved in HSF1/HMGB1-mediated regulation of asthma.

Differential expression of HSF1 and HSPA6 genes and physiological responses in Angus and Simmental cattle breeds.

The aim of this study was to identify whether more and less adapted Angus and Simmental cattle differed in physiological responses and expression of the heat shock factor 1 (HSF1) and the heat shock 70 kDa protein 6 (HSPA6), when subjected to heat stress. Thirty bulls (n = 15 ANG; n = 15 SIM), extremes "more adapted" and "less adapted" within each breed were selected to the heat tolerance test. They were selected according to an index based on the average of the respiratory rate obtained on two hot summer days from one hundred bulls. Before the heat tolerance test day, animals were taken to a paddock with water, grass and shade until 7 a.m. of the following day for morning measurements. They were kept in the barn without access to water and shade until 1 p.m. for the afternoon measurements. Respiratory rate in the morning (MRR) and afternoon (ARR), hair coat surface temperature in the morning (MST) and afternoon (AST), rectal temperature in the morning (MRT) and afternoon (ART) were measured and blood samples were collected for expression analysis of the HSF1 and HSPA6 genes. The MIXED procedure of SAS was used for all statistical analysis. The more adapted Simmental group had lesser values of MRR (P = 0.023) and MRT (P = 0.095), but there was no difference within Angus breed. The ARR was greater (P = 0.004) in less adapted animals for both breeds. The ART was lower in the Simmental breed (P < 0.001). Less adapted had greater levels of mRNA of HSF1 (P = 0.06) and HSPA6 (P = 0.09). In conclusion, respiratory rate, rectal temperature and expression of the HSF1 and HSPA6 genes can be indicators of thermotolerance in taurine cattle. Both breeds show physiologically similar responses under heat stress conditions.

ZmHsf05, a new heat shock transcription factor from Zea mays L. improves thermotolerance in Arabidopsis thaliana and rescues thermotolerance defects of the athsfa2 mutant.

High temperature directly affects the yield and quality of crops. Plant Hsfs play vital roles in plant response to heat shock. In the present study, ZmHsf05 was isolated from maize (Zea mays L.) using homologous cloning methods. The sequencing analysis demonstrated that CDS of ZmHsf05 was 1080 bp length and encoded a protein containing 359 amino acids. The putative amino acid sequence of ZmHsf05 contained typical Hsf domains, such as DBD, OD, NLS and AHA motif. Subcellular localization assays displayed that the ZmHsf05 is localized to the nucleus. ZmHsf05 was expressed in many maize tissues and its expression level was increased by heat stress treatment. ZmHsf05 rescued the reduced thermotolerance of the athsfa2 mutant in Arabidopsis seedlings. Arabidopsis seedlings of ZmHsf05-overexpressing increased both the basal and acquired thermotolerances. After heat stress, the ZmHsf05-overexpressing lines showed enhanced survival rate and chlorophyll content compared with WT seedlings. The expression of Hsps was up-regulated in the ZmHsf05-overexpressing Arabidopsis lines after heat stress treatment. These results suggested that ZmHsf05 plays an important role in both basal and acquired thermotolerance in plants.

HSF1/HSP pathway in the hippocampus is involved in SIRT1-mediated caloric restriction-induced neuroprotection after surgery in aged mice.

Postoperative cognitive dysfunction is common in the elderly. Endoplasmic reticulum stress (ER-stress) increases neuronal apoptosis after surgery, and chaperone molecules, such as heat shock proteins (HSPs), help reduce unfolded protein reactions, thereby promoting protein homeostasis. Mammal sirtuin1 (SIRT1)-mediated deacetylation of heat shock factor 1 (HSF1) upregulates HSF1 binding to the HSP70 promoter. Caloric restriction (CR) improves cognition in many neurodegenerative models. In this study, we evaluated whether CR improves impaired learning and memory after surgery by attenuating ER-stress in an SIRT1-dependent manner. Male 18-month-old C57BL/6J mice receiving a 12-week CR or an ad libitum (AL) diet pre-intervention were challenged with tibial open fracture surgery and anesthesia or no treatment. We found a significant protective effect of CR on memory in contextual fear conditioning test after surgery compared with the AL group. CR alleviated ER-stress and neuronal apoptosis in the hippocampus induced by surgery. CR increased HSP70 expression through the HSF1/HSP pathway in a SIRT1-mediated manner, and inhibition of SIRT1 in the hippocampus by lentivirus injection partially reduced the benefits of CR (increased HSP70, deacetylated HSF1, reduced ER-stress, and improved memory). Taken together, our results showed that CR alleviates memory impairment postoperatively via attenuation of ER-stress in the hippocampus in an SIRT1-dependent manner, and the SIRT1/HSF1/HSP70 pathway is involved in this process.

Mapping of domains of heat stress transcription factor OsHsfA6a responsible for its transactivation activity.

Elevated temperatures affect the growth and reproduction of crop plants and thus have become concern worldwide. Hsp101/ClpB protein is a major molecular chaperone, performing dis-aggregation of protein aggregates formed during heat stress. In rice, OsHsfA6a binds to the promoter of OsHsp101/ClpB-C and regulates its expression. In this study, analysis of C-terminal domains of ClassA OsHsfs revealed the presence of aromatic, hydrophobic, acidic (AHA) and nuclear export signal (NES) motifs in all the members. Using deletion constructs, we show that the activation potential of OsHsfA6a is confined in the C-terminal activation domain comprising of AHA and NES sequences. The results obtained in yeast were complemented with transient expression of reporter in protoplast (TERP) based assay. Detailed analysis of OsHsfA6a splice variants shows the presence of one full version and a DBD truncated smaller version whose existence needs experimental evidences. Phylogeny analysis revealed that OsHsfA6a has diverged from A6a/A6b forms of Arabidopsis and tomato and has no expressologs. OsHsfA6a in-silico network was enriched in MAP kinases along with Hsp70 and Hsp90 proteins. Thus, it appears that regulation of OsClpB-C by HsfA6a is unique in rice and activation potential of OsHsfA6a resides in the single AHA motif located in the C-terminal domain.

Heat shock factor 1 suppresses the HIV-induced inflammatory response by inhibiting nuclear factor-κB.

The persistent inflammation aggravated by a disordered immune response is considered to be the major cause of CD4+ T cell depletion in lymphoid tissue, which impels the progression of AIDS. Here, we report that heat shock factor 1 (HSF1) works as an innate repressor of HIV-induced inflammation. The activation of HSF1 was found to accompany inflammation during HIV infection. Further research uncovered that HSF1 activation inhibited HIV-induced inflammation. In addition, HSF1 overexpression suppressed the inflammatory response induced by HIV, while HSF1 deficiency exacerbated that inflammation. Mechanistically, HSF1 was found to compete with nuclear factor-κB (NF-κB) in the nucleus. Generally, our report highlights that HSF1 is an important host factor in regulating HIV-induced inflammation and may work as a potential target for curing AIDS.

HSF4 transcriptional regulates HMOX-1 expression in HLECs.

The major causes for cataract formation are free radicals, which are neutralized by the endogenous antioxidants. However, how the human lens clean these harmful free radicals is still unclear. Transcriptional factor heat shock factor 4 (HSF4) is a cataract-causing gene and plays important roles during lens development. Here we show that HMOX-1, an anti-oxidase, is a bona fide transcriptional target gene of HSF4 in HLECs (human lens epithelial cells). HSF4 directly binds to the HSE element in HMOX-1 promoter to mediate its mRNA transcription and protein accumulation. The HSE element located at the region of -389 bp to -362 bp upstream from the TSS (transcription start site), which is critical for HMOX-1 transcriptional activation. Furthermore, knockdown of HSF4 by siRNA inhibited HMOX-1 expression. Thus, these data revealed a novel transcription target of HSF4 and provided new insights into anti-oxidation regulation in lens and age-related cataract.

Gene expression regulation by heat-shock proteins: the cardinal roles of HSF1 and Hsp90.

The ability to permit gene expression is managed by a set of relatively well known regulatory mechanisms. Nonetheless, this property can also be acquired during a life span as a consequence of environmental stimuli. Interestingly, some acquired information can be passed to the next generation of individuals without modifying gene information, but instead by the manner in which cells read and process such information. Molecular chaperones are classically related to the proper preservation of protein folding and anti-aggregation properties, but one of them, heat-shock protein 90 (Hsp90), is a refined sensor of protein function facilitating the biological activity of properly folded client proteins that already have a preserved tertiary structure. Interestingly, Hsp90 can also function as a critical switch able to regulate biological responses due to its association with key client proteins such as histone deacetylases or DNA methylases. Thus, a growing amount of evidence has connected the action of Hsp90 to post-translational modifications of soluble nuclear factors, DNA, and histones, which epigenetically affect gene expression upon the onset of an unfriendly environment. This response is commanded by the activation of the transcription factor heat-shock factor 1 (HSF1). Even though numerous stresses of diverse nature are known to trigger the stress response by activation of HSF1, it is still unknown whether there are different types of molecular sensors for each type of stimulus. In the present review, we will discuss various aspects of the regulatory action of HSF1 and Hsp90 on transcriptional regulation, and how this regulation may affect genetic assimilation mechanisms and the health of individuals.

Role of heat shock factor 1 expression in the microenvironment of intrahepatic cholangiocarcinomas.

BACKGROUND AND AIM: Heat shock factor 1 (HSF1), a master regulator of heat shock response, has been shown to play a multifaceted role in cancer progression. However, the clinical significance and biological effect of HSF1 expression in intrahepatic cholangiocarcinoma (IHCC) remain unknown. METHODS: Forty-nine patients with IHCC who underwent hepatic resection were enrolled in this study. HSF1 expression in tumor tissue was determined by immunohistochemistry, and patients were divided into two groups, those with high (n = 20) and low (n = 29) HSF1 expression. Clinicopathological factors including prognosis were compared in these two groups. RESULTS: HSF1 expression was significantly higher in tumors than in normal tissue. The overall survival rate was significantly lower in patients with high than low HSF1. Multivariate analysis showed that high HSF1 expression was a factor independently prognostic of patient survival. CONCLUSION: High HSF1 expression in tumor tissues may be a prognostic biomarker in patients with IHCC.

Chrysanthemum CmHSFA4 gene positively regulates salt stress tolerance in transgenic chrysanthemum.

Salinity-induced Na+ toxicity and oxidative stress hamper plant growth. Here, we showed that expression of the chrysanthemum CmHSFA4, a homologue of the heat-shock factor AtHSFA4a, is inducible by salt and localizes to the nucleus. It is a transcription activator binding with HSE. Chrysanthemum overexpressing CmHSFA4 displayed enhanced salinity tolerance by limiting Na+ accumulation while maintaining K+ concentration, which is consistent with the up-regulation of ion transporters CmSOS1 and CmHKT2. Additionally, the transgenic plants reduced H2 O2 and O2∙- accumulation under salinity, which could be due to up-regulation of ROS scavenger activities such as SOD, APX and CAT as well as CmHSP70, CmHSP90. Together, these results suggest that CmHSFA4 conferred salinity tolerance in chrysanthemum as a consequence of Na+ /K+ ion and ROS homeostasis.

The Role of HSF1 Protein in Malignant Transformation.

BACKGROUND: The heat shock transcription factor, HSF1, is the main regulator of the proteotoxic stress response that orchestrates the adaptation of cells to stress conditions such as elevated temperature, oxidative stress, and proteotoxic stress. As such, HSF1 regulates a large number of stress response-related genes, primarily those encoding heat shock proteins (HSPs). HSPs are molecular chaperones involved in the acquisition of native protein conformations and the prevention of protein degradation, and they also contribute to the removal of denatured proteins via the proteasome. Representative members of the HSP family are HSP70 and HSP90. The stress response is a highly conserved mechanism across all eukaryotes, and HSF1 has been linked to a number of physiological processes (ribosomal biogenesis, translation, transcription, cell cycle, and metabolism) and pathological disorders (neurodegenerative disorders such as Parkinson´s and Alzheimer´s diseases). HSF1 activation is also prominent in different types of cancer (prostate, breast, colorectal carcinoma etc.) where it correlates with tumor aggressiveness and poor prognosis. HSF1 is therefore considered a diagnostic and prognostic marker and is currently being targeted to develop new cancer therapies. Several inhibitors of HSF1 have already been synthesized, but their molecular mechanism (s) of action, specificity those of HSF1, nontoxicity in healthy tissues, and their efficacy in targeting tumor cells remain to be elucidated. PURPOSE: This review summarizes known mechanisms of HSF1 regulation and activation, the role of HSF1 during malignant transformation, and the potential of designing small molecule HSF1 inhibitors for cancer therapy. Key words: HSF1 transcription factor - molecular chaperones - cellular stress - tumor transformation - cancer This work was supported by the project MEYS - NPS I - LO1413. The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers. Accepted: 10. 8. 2018.

[Advances in the research of effects of heat-shock factor 1 and heat-shock proteins on wound healing and the mechanism].

Heat-shock proteins (HSPs) are the protective proteins expressed by cells under stress. Heat-shock factors (HSFs) are the key factors to regulate HSPs. Researches about the effects of HSF1 and HSPs in cells after stress and the mechanism have become the important entry point to explore the cell response in wound healing after trauma. This article reviews the effects of HSPs and HSF1 which regulate the proteins on wound healing and the mechanism, so as to deliver message for studying effects of intervening HSF1 on expression of HSPs and wound healing and the mechanism.