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Upon heat shock, activated heat shock transcription factor 1 (HSF1) binds to the heat shock response elements (HSEs) in the promoters of mammalian heat shock protein (HSP)‐encoding genes and recruits the preinitiation complex and coactivators, including Mediator. These transcriptional regulators may be concentrated in phase‐separated condensates around the promoters, but they are too minute to be characterized in detail. We herein established HSF1−/− mouse embryonic fibroblasts harbouring HSP72‐derived multiple HSE arrays and visualized the condensates of fluorescent protein‐tagged HSF1 with liquid‐like properties upon heat shock. Using this experimental system, we demonstrate that endogenous MED12, a subunit of Mediator, is concentrated in artificial HSF1 condensates upon heat shock. Furthermore, the knockdown of MED12 markedly reduces the size of condensates, suggesting an important role for MED12 in HSF1 condensate formation. [ABSTRACT FROM AUTHOR]

During the heat shock response (HSR), heat shock factor (HSF1 in mammals) binds to target gene promoters, resulting in increased expression of heat shock proteins that help maintain protein homeostasis and ensure cell survival. Besides HSF1, only a relatively few transcription factors with a specific role in ensuring correctly regulated gene expression during the HSR have been described. Here, we use proteomic and genomic (CRISPR) screening to identify a role for RPRD1B in the response to heat shock. Indeed, cells depleted for RPRD1B are heat shock sensitive and show decreased expression of key heat shock proteins (HSPs). These results add to our understanding of the connection between basic gene expression mechanisms and the HSR. [ABSTRACT FROM AUTHOR]

The heat stress response activates the transcription factor heat shock factor 1 (HSF1), which subsequently upregulates heat shock proteins to maintain the integrity of the proteome. HSF1 activation requires nuclear localization, trimerization, DNA binding, phosphorylation and gene transactivation. Phosphorylation at S326 is an important regulator of HSF1 transcriptional activity. Phosphorylation at S326 is mediated by AKT1, mTOR, p38, MEK1 and DYRK2. Here, we observed activation of HSF1 by AKT1 independently of mTOR. AKT2 also phosphorylated S326 of HSF1 but showed weak ability to activate HSF1. Similarly, mTOR, p38, MEK1 and DYRK2 all phosphorylated S326 but AKT1 was the most potent activator. Mass spectrometry showed that AKT1 also phosphorylated HSF1 at T142, S230 and T527 in addition to S326, whereas the other kinases did not. Subsequent investigation revealed that phosphorylation at T142 is necessary for HSF1 trimerization and that S230, S326 and T527 are required for HSF1 gene transactivation and recruitment of TFIIB and CDK9. Interestingly, T527 as a phosphorylated residue has not been previously shown and sits in the transactivation domain, further implying a role for this site in HSF1 gene transactivation. This study suggests that HSF1 hyperphosphorylation is targeted and these specific residues have direct function in regulating HSF1 transcriptional activity. [ABSTRACT FROM AUTHOR]

Background: Human placenta-derived multipotent cells (hPDMCs) are isolated from a source uncomplicated by ethical issues and are ideal for therapeutic applications because of their capacity for multilineage differentiation and proven immunosuppressive properties. It is known that heat shock preconditioning induces the upregulation of heat shock proteins (HSPs), which enhance survival and engraftment of embryonic stem cells (ESCs) during transplantation in live animal models, although whether heat shock preconditioning has the same effects in hPDMCs is unclear. Methods: The hPDMCs were isolated from placenta of healthy donors. The cells were treated with heat shock (43 °C, 15 min), followed by evaluation of cell viability. Furthermore, the HSPs expression was assessed by Western blot, qPCR. The reactive oxygen species (ROS) production and signal pathway activation were determined by flow cytometry and Western blot, respectively. The regulatory pathways involved in HSPs expression were examined by pretreatment with chemical inhibitors, and siRNAs of MAPK, Akt, and heat shock factor 1 (HSF1), followed by determination of HSPs expression. Results: This study demonstrates that heat shock treatment induced ROS generation and HPSs expression in hPDMCs. Heat shock stimulation also increased p38 MAPK and Akt phosphorylation. These effects were reduced by inhibitors of ROS, p38 MAPK and Akt. Moreover, we found that heat shock treatment enhanced nuclear translocation of the HSF1 in hPDMCs, representing activation of HSF1. Pretreatment of hPDMCs with ROS scavengers, SB203580 and Akt inhibitors also reduced the translocation of HSF1 induced by heat shock. Conclusions: Our data indicate that heat shock acts via ROS to activate p38 MAPK and Akt signaling, which subsequently activates HSF1, leading to HSP activation and contributing to the protective role of hPDMCs. [ABSTRACT FROM AUTHOR]

The heat shock transcription factor HSF1 regulates the inducible Hsp gene transcription, whereas HSF2 is involved in the constitutive transcription. HSFs can work for the non-heat shock genes transcription in a case-specific manner to facilitate normal cellular functions. Here, we demonstrate that HSF2 acts as an upstream regulator of heat shock-induced autophagy response in a rat histiocytoma. The heat-induced HSF2 transactivates the B-cell translocation gene-2 (BTG2) transcription, and the latter acts as a transcriptional coactivator for superoxide dismutase (SOD2). The altered HSF2 promoter occupancy on the BTG2 promoter enhances BTG2 transcription. Since SOD2 regulation is linked to mitochondrial redox sensing, HSF2 appears to act as a redox sensor in deciding the cell fate. The HSF2 shRNA or NFE2L2/BTG2 siRNA treatments have interfered with the autophagy response. We demonstrate that HSF2 is an upstream activator of autophagy response, and the HSF2-BTG2-SOD2 axis acts as a switch between the non-selective (micro/macro) and selective (chaperone-mediated) autophagy. Heat shock primarily induced HSF2 transcription, which correlated with autophagy activation. The heat shock-induced HSF2 transactivated BTG2 , which co-activated the SOD2 transcription, switching the non-selective (macro/micro) autophagy response to selective (chaperone-mediated) autophagy response. The HSF2-BTG2-SOD2 axis appears to regulate autophagy response. [Display omitted] • The heat-induced HSF2 transactivates BTG2 , a tumor suppressor and antioxidant protein. • HSF2 induced BTG2 as a transcriptional coactivator induced the transcription of SOD2. • The HSF2-BTG2-SOD2 axis reverted the macroautophagy response to microautophagy. • The HSF2-BTG2-SOD2 axis appears to be conserved and obligatory for fine-tuning the autophagy response. [ABSTRACT FROM AUTHOR]

High temperature is a major constrait limiting the yield and quality of wheat. Wheat heat shock transcription factor (Hsf) plays important roles in regulating plant response to heat shock. In previous study, we found there are 82 Hsfs in wheat and TaHsfA2–11 expression was obviously upregulated by heat stress. In this study, we aim to investigate TaHsfA2–11 function and regulating mechanism in response to heat shock through genetic transformation into wheat Fielder. Gene expression analyses results showed that TaHsfA2–11 was expressed in all detected tissues and the most highly expressed level was in wheat mature roots. The expression level of TaHsfA2–11 was strongly upregulated by heat shock in wheat leaves. Subcellular localization results represented that TaHsfA2–11 is located to the nucleus. Transgenic wheat seedlings overexpressing TaHsfA2–11 showed stronger thermotolerance than the control Fielder after treated under 50 °C for 12 h. After heat shock, the TaHsfA2–11 overexpressing lines showed increased survival rate, chlorophyll content, POD (Peroxidase) activity, SOD (Superoxide dismutase) activity and photosynthetic rate, and decreased relative electrolyte leakage and MDA (malondialdehyde) content compared with Fielder. The results of RNA-sequence data demonstrated that TaHsfA2–11 can regulate many heat response genes, such as Hsp genes TaHsp16.6 and TaHsp21 , ER (Endoplasmic reticulum) stress genes TaBiP2 and TaERDJ3A, photoprotectant for PSII gene TaELIPHV58 , flavone biosynthesis related genes TaUGT-2A and TaPMaT , etc after heat stress. These results showed that TaHsfA2–11 can impove thermotolerance perhaps through effecting signal pathway of heat, ER stress, photosynthesis and ROS (Reactive Oxygen Species). The findings will provide useful gene resource for performing genetic modification of wheat thermotolerance in heat-resistant breeding. • TaHsfA2-11 up-regulated in wheat response to HS, H 2 O 2 and SA treatment. • TaHsfA2-11 has transactivation transcriptional activity. • Overexpression of TaHsfA2-11 in wheat improves thermotolerance. [ABSTRACT FROM AUTHOR]

SUMO is a protein modification whose conjugate levels peak during acute heat stress. Here, we found that SUMO is also critical for plant longevity when Arabidopsis experiences a prolonged non-damaging period of 28 °C. Thermo-lethality at 28 °C was seen in sumo1/2 knockdown mutants but not in any other mutant of the SUMO pathway tested. Autoimmunity due to low SUMO1/2 expression levels was not causal for this thermo-lethality. The role of SUMO in thermo-resilience was also distinct from its requirement for thermomorphogenesis—a growth response triggered by the same warm temperature, as only the latter response was also dependent on the SUMO ligase SIZ1. Thermo-resilience at 28 °C and (acquired) thermotolerance, a response that allows plants to recover and acclimate to brief extreme temperatures, both depend on the HEAT SHOCK TRANSCRIPTION FACTOR A1 (HSFA1). Acquired thermotolerance was, however, normal in the sumo1/2 knockdown mutant. Thus, SUMO-dependent thermo-resilience is potentially controlled in a different way from the protein damage pathway that underpins thermotolerance. Close inspection of shoot apices revealed that the cell patterning and tissue integrity of the shoot apex of the SUMO1/2 knockdown mutant was lost at 28 °C but not 22 °C. We thus describe a novel SUMO-dependent phenotype. [ABSTRACT FROM AUTHOR]

With global warming as a major environment concern over the coming years, heat tolerance is an important trait for forest tree survival during the predicted future warmer weather conditions. Cryptomeria japonica is a coniferous species widely distributed throughout Japan, and thus, can adapt to a wide range of air temperatures. To elucidate genes involved in heat response in Cryptomeria japonica, transcriptome analysis was conducted for seedlings under heat shock conditions. To test whether heat acclimation affects levels of gene expression, half of the seedlings were pretreated with moderately high temperatures prior to heat shock. De novo assembly of the transcriptome generated 107,924 unigenes and the analysis of differentially expressed genes was conducted using these unigenes. A total of 5217 differentially expressed genes were identified. Most genes upregulated by heat shock, regardless of pre-heat treatment, were conserved to heat response genes of angiosperm species, such as heat shock factors (Hsf) and heat shock proteins (Hsp). Pre-heating of seedlings affected expression levels of several Hsfs and their induction was lower in pre-heated seedlings than in seedlings without pre-heat treatment. This suggests a conserved role of Hsfs in heat response and heat acclimation in seed plants. On the other hand, many unknown genes were upregulated in only seedlings without pre-heat treatment after heat exposure. Notably, expression of gypsy/Ty3 type retrotransposons was dramatically induced. These findings provide valuable information to develop a better understanding of the molecular mechanisms of heat response and acclimation in C. japonica. [ABSTRACT FROM AUTHOR]

Heat shock response (HSR) is a universal mechanism in all organisms upon heat shock (HS) to prevent stress damages. It is under tight regulation by heat shock factors (HSFs) and heat shock proteins (HSPs). On the attenuation of HSR, Heat Shock Factor Binding Protein1 (HSBP1) interacts with HSF1 and thus converting the active trimer form of HSF1 to inert monomer state. Thus, play an important role in regulating heat shock genes. The present study aimed to explore single nucleotide polymorphism (SNP) in HSBP1 and their association with the thermo tolerance traits (respiration rate, rectal temperature and heat tolerance coefficient) for identification of most thermal adapted Murrah buffaloes. Two hundred female Murrah buffaloes were genotyped using custom sequencing to identify SNP. Only one novel SNPs in exon 3 at position g.1892C>T and two nucleotide variation g.1327C>G and g.1202C>T were identified through direct DNA sequence scanning. Homozygous wild type genotypes (CC) were found in higher frequency (0.84, n=168) than homozygous recessive (0.10, n=20) and heterozygous (0.06, n=12) mutant genotypes at SNP locus g.1892C>T. The association among the different genotype of this SNP locus with thermo tolerance was analyzed using Generalized Linear Model procedure in Statistical Analysis System. However, no significant difference was detected among the genotypes in terms of thermo tolerance traits in the study. [ABSTRACT FROM AUTHOR]

Heat shock (HS) initiates rapid, extensive, and evolutionarily conserved changes in transcription that are accompanied by chromatin decondensation and nucleosome loss at HS loci. Here we have employed in situ Hi-C to determine how heat stress affects longrange chromatin conformation in human and Drosophila cells. We found that compartments and topologically associating domains (TADs) remain unchanged by an acute HS. Knockdown of Heat Shock Factor 1 (HSF1), the master transcriptional regulator of the HS response, identified HSF1-dependent genes and revealed that up-regulation is often mediated by distal HSF1 bound enhancers. HSF1-dependent genes were usually found in the same TAD as the nearest HSF1 binding site. Although most interactions between HSF1 binding sites and target promoters were established in the nonheat shock (NHS) condition, a subset increased contact frequency following HS. Integrating information about HSF1 binding strength, RNA polymerase abundance at the HSF1 bound sites (putative enhancers), and contact frequency with a target promoter accurately predicted which up-regulated genes were direct targets of HSF1 during HS. Our results suggest that the chromatin conformation necessary for a robust HS response is preestablished in NHS cells of diverse metazoan species. [ABSTRACT FROM AUTHOR]

Cancer cells having stably integrated genes encoding tumor-associated antigens could be utilized as a vaccine, in-vitro stimulators of antigen-primed T-cells, and target for cytotoxicity assay, etc. Lipofection is a simple and safer technique for stable transfection of plasmid DNA. However, the poor rate of genomic integration has limited its application. In the current study, the effect of mild and transient heat shock following lipofection on the improvement of genomic integration was evaluated. The cDNA fragments encoding chicken MMP-11peptide (V32-K365) and the immunoglobulin-like domain 2 of chicken VEGFR-2 were cloned separately into pcDNA3.1 vector. Lipofection was carried out using Lipofectamine® 2000 (Life Technologies, USA) in 4T1 cells followed by a heat shock at 42°C for 10 min. Transfected cells were selected for a period of four weeks against 500 µg/mL G418 in RPMI 1640 media supplemented with 10% fetal bovine serum. Distinct G418-resistant colonies appeared after 14 days of selection. Heat shock significantly (P <0.05) increased the number of viable colonies following antibiotic selection. The immunofluorescent study confirmed the stable integration of the target DNAs into the cells. It is concluded that mild and brief heat shock following lipofection improves the stable integration of recombinant pcDNA3.1 plasmids into 4T1 cells. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • High temperature stimulates photosynthesis, yield, and the nitrate concentration. • Heat effects are potentiated by high CO 2 action resulting in beneficial effects for the plants. • Nitrogen starvation effects are ameliorated to a great extent by the action of high CO 2. • Plant growth-promoting rhizobacteria hardly enhanced plant growth and development in N starvation conditions. Abstract The atmospheric CO 2 concentration and the frequency and severity of heat waves are increasing, and the nitrogen - key to plant development - supplied to crops leaches easily, polluting ground water. In this experiment, these three elements were combined, in order to unravel the physiological mechanisms involved in the plant response to this future scenario. Sweet pepper seedlings were exposed to distinct nitrate inputs (nutrient solutions containing 12 mM, 5 mM and 0 mM of N) and plant growth-promoting rhizobacteria, a high CO 2 concentration (1000 μmol mol-1), and a heat shock (43 °C), in a controlled environment. Physiological markers - such as photosynthesis rate, stomatal conductance (gs), water use efficiency (WUE), chlorophylls, chlorophyll fluorescence, lipid peroxidation, anions, and free amino acids - were measured. Exposure to the high temperature did not lead to any measurable stress in the sweet pepper plants. In fact, it augmented photosynthesis and the nitrate concentration, particularly at the elevated CO 2 concentration. Heat shock did not suppose any detriment for the plants beyond the expected increases in gs and WUE. On the contrary, heat triggered many processes that ended up favoring photosynthesis; when combined with elevated CO 2 , the result was even more beneficial for the plants. On the other hand, nitrogen starvation produced serious damage - such as decreases in the photosynthesis rate and chlorophylls and increases in lipid peroxidation and the levels of anions, cysteine, leucine, and phenylalanine in the plant - which was ameliorated to a great extent by the action of high CO 2. Finally, the plant growth-promoting rhizobacteria hardly enhanced plant growth and development, giving results similar to those of the nitrogen withdrawal treatment. [ABSTRACT FROM AUTHOR]

Abstract Thioredoxins (Trxs) are small ubiquitous proteins that participate in dithiol-disulfide exchange reactions. In contrast to animals and prokaryotes, plants possess different types of Trxs that play a vital role in a number of different cellular processes. Two full-length cDNAs encoding different Trx h isoforms, designated VvTrx h 2 and VvTrx h 3, were isolated and cloned from grape (Vitis vinifera L. cv. Askari) berry tissue by rapid amplification of cDNA ends (RACE) method. VvTrx h 2 and VvTrx h 3 were heterologously expressed in Escherichia coli and their activities were compared using DTT-dependent insulin reduction and 5,5′-dithio-bis (2-nitrobenzoic acid) (DTNB) reduction activities. The NADPH-dependent DTNB reduction assay demonstrated that the both VvTrx h isoforms were reduced by NADPH-dependent thioredoxin reductase (NTR) from E. coli. Under heat shock treatment, the recombinant VvTrx h proteins formed the oligomeric structures at above 50 °C with a decrease in their disulfide reductase activities. The redox-dependent structural changes of VvTrx h 2 and VvTrx h 3 revealed that their oligomeric structures were changed into monomers and significantly increased their disulfide reductase activities. Furthermore, the both recombinant proteins were able to conserve a DTNB reduction activity even after 15 min heating at 99 °C. [ABSTRACT FROM AUTHOR]

The heat shock response is crucial for organism survival in natural environments. RNA structure is known to influence numerous processes related to gene expression, but there have been few studies on the global RNA structurome as it prevails in vivo. Moreover, how heat shock rapidly affects RNA structure genomewide in living systems remains unknown. We report here in vivo heat-regulated RNA structuromes. We applied Structure-seq chemical [dimethyl sulfate (DMS)] structure probing to rice (Oryza sativa L.) seedlings with and without 10 min of 42 °C heat shock and obtained structural data on >14,000 mRNAs. We show that RNA secondary structure broadly regulates gene expression in response to heat shock in this essential crop species. Our results indicate significant heatinduced elevation of DMS reactivity in the global transcriptome, revealing RNA unfolding over this biological temperature range. Our parallel Ribo-seq analysis provides no evidence for a correlation between RNA unfolding and heat-induced changes in translation, in contrast to the paradigm established in prokaryotes, wherein melting of RNA thermometers promotes translation. Instead, we find that heat-induced DMS reactivity increases correlate with significant decreases in transcript abundance, as quantified from an RNA-seq time course, indicating that mRNA unfolding promotes transcript degradation. The mechanistic basis for this outcome appears to be mRNA unfolding at both 5' and 3'-UTRs that facilitates access to the RNA degradation machinery. Our results thus reveal unexpected paradigms governing RNA structural changes and the eukaryotic RNA life cycle. [ABSTRACT FROM AUTHOR]

Cellular transcriptional programs are tightly controlled but can profoundly change in response to environmental challenges or stress. Here we describe global changes in mammalian RNA polymerase II (Pol II) occupancy at mRNA genes in response to heat shock and after recovery from the stress. After a short heat shock, Pol II occupancy across thousands of genes decreased, consistent with widespread transcriptional repression, whereas Pol II occupancy increased at a small number of genes in a manner consistent with activation. Most striking, however, was loss of the Pol II peak near the 3= ends of mRNA genes, coupled to a gain in polymerase occupancy extending tens of kilobases downstream of 3= ends. Typical patterns of 3= end occupancy were largely restored 60 min after cells returned to normal growth temperatures. These changes in polymerase occupancy revealed a heat shock-induced loss of normal termination, which was potent, global, and reversible. The occupancy of the termination factor CPSF73 at the 3= ends of representative genes was reduced after heat shock, suggesting a mechanism for impaired termination. The data support a model in which heat shock induces widespread repression of transcriptional initiation and loss of transcription termination, which reverses as cells return to homeostasis. [ABSTRACT FROM AUTHOR]

In the Ross Sea region (average temperature of −1.87 °C), shelf water warming up to +0.8-+1.4 °C is predicted by 2200, so there is an urgent need to understand how organisms can respond to rising temperatures. In this study, we analyzed the effect of a heat shock on the fatty acid (FAs) composition of muscle of the Antarctic teleost Trematomus bernacchii , caught in Terra Nova Bay (Ross Sea), and held in fish tanks at 0, +1 or +2 °C, for 1, 5 and 10 days. In general, heat shock produced, beyond a reduction in total lipid content correlated to the temperature, an increase in the percentage of saturated FAs, and a decrease in mono-unsaturated FAs; however, the level of poly-unsaturated FAs did not seem to directly correlate with temperature. Principal component analysis indicated that both temperature and exposure time affect the composition of FAs in the muscle probably through an alteration of the metabolic pathways of FAs. In this study, we demonstrated that T. bernacchii was capable to rapidly acclimatize to a heat shock. This study contributes to increasing knowledge on the effect of temperature on the lipid composition of T. bernacchii and is complementary to previous studies on the gene expression and biochemistry of this species face multiple stressors. [ABSTRACT FROM AUTHOR]

The heat shock response (HSR) is characterized by the rapid and robust induction of heat shock proteins (HSPs), including HSP70, in response to heat shock and is regulated by heat shock transcription factor 1 (HSF1) in mammalian cells. Poly(ADP-ribose) polymerase 1 (PARP1), which can form a complex with HSF1 through the scaffold protein PARP13, has been suggested to be involved in the HSR. However, its effects on and the regulatory mechanisms of the HSR are not well understood. Here we show that prior to heat shock, the HSF1-PARP13-PARP1 complex binds to the HSP70 promoter. In response to heat shock, activated and auto- PARylated PARP1 dissociates from HSF1-PARP13 and is redistributed throughout the HSP70 locus. Remarkably, chromatin in the HSP70 promoter is initially PARylated at high levels and decondensed, whereas chromatin in the gene body is moderately PARylated afterwards. Activated HSF1 then binds to the promoter efficiently and promotes the HSR. Chromatin PARylation and HSF1 binding to the promoter are also facilitated by the phosphorylation-dependent dissociation of PARP13. Furthermore, the HSR and proteostasis capacity are reduced by pretreatment with genotoxic stresses, which disrupt the ternary complex. These results illuminate one of the priming mechanisms of the HSR that facilitates the binding of HSF1 to DNA during heat shock. [ABSTRACT FROM AUTHOR]

External and internal stimuli cause modifications to gene and biochemical pathways. In turn, demonstrating that biological systems continuously make short-term adaptations both to set-points, and to the range of "normal" capacity, due to mild conditional changes, or to subtoxic, nondamaging levels of chemical agents. This is termed as "Adaptive Homeostasis," defined with the following: "The transient expansion or contraction of the homeostatic range in response to exposure to sub-toxic, nondamaging, signaling molecules or events, or the removal or cessation of such molecules or events." Research from several laboratories, including our own, found that adaptive homeostasis declines with age in organisms as diverse as worms, flies, and mammals, and decreases with senescence in mammalian cell cultures. We suggest that diminishing adaptive homeostasis may play a causal role as a factor responsible for the aging phenotype. Furthermore, although studies of humans, animals, and model organisms are often limited to a single sex, and cell culture studies may even be conducted with lines whose donor's sex was unknown, studies reveal distinct sexual dimorphism in adaptive homeostasis. Interestingly, although young males and females may exhibit dramatic differences in adaptive capacities and/or preferences, these distinctions are lost with age as adaptive homeostasis patterns converge. [ABSTRACT FROM AUTHOR]

Heat stress is an important domain of research in livestock due to its negative impact on production and disease resistance. The augmentation of stress in the body stimulates the antioxidative activity comprising various enzymes (viz., catalase, superoxide dismutase), metabolites (reduced glutathione, etc.), vitamins, minerals, etc. to combat the situation. The major key players involved in regulation of heat shock response in eukaryotes are the transcription factors, called as heat shock factors (HSF). They activate the heat shock protein (HSP) genes by binding to their promoters. Lymphocytes are considered to be the best model to evaluate the immunity in any living body as it contains plethora of white blood cells (WBCs).In this study, the peripheral blood mononuclear cells (PBMC) obtained from non-lactating Sahiwal vis-à-vis crossbred (Holstein Friesian × Sahiwal) cattle with 75% or more exotic inheritance were subjected to heat shock at 39, 41, and 43 °C in three different incubators, in vitro. The cell count and viability test of pre and post heat stress of concerned PBMCs indicated that the crossbreeds are more prone to heat stress as compared to Sahiwal. The reverse transcription PCR (qRT-PCR) expression data revealed an increment in HSF1 expression at 41 °C which subsequently declined (non-significantly) at 43 °C in both breeds post 1 h heat shock. However, the association between the HSF 1 expression and antioxidative activity through correlation analysis was found to be non-significant ( P < 0.05), though enzymatic activity appeared to behave in a similar fashion in both breeds at 5% level of significance ( P < 0.05). This rule out the role of HSF1 expression level on the activity of enzymes involved in oxidative stress in vitro in zebu and crossbred cattle. [ABSTRACT FROM AUTHOR]

The effect of cold shock (10 °C for 2 h) and heat shock (42 °C for 45 min) treatments on the viability of Brucella melitensis under adverse conditions was investigated. Viability of B. melitensis cells during storage at 4 °C was significantly affected by cold shock and heat shock treatments. While cold-shocked cells became more resistant to cold storage, a significant decrease in the viable population of heat-shocked cells was observed. Similarly, cold-shocked cells of B. melitensis became more resistant and heat-shocked cells became more susceptible to acidic conditions. Although cold shock treatment did not affect the thermal tolerance of B. melitensis, heat shock treatment increased significantly the thermal tolerance of the bacterium. Nevertheless, these shock treatments, under the conditions tested, did not alter the susceptibility of B. melitensis to incubation at −18 °C and the presence of 10% NaCl. Practical applications In the food industry, cooling chains and heating processes could potentially induce a cold or heat shock phenomenon. Hence, this information should be taken into account in the development of food preservation measures and for conducting risk assessments on the importance of this pathogen in food processing operations. [ABSTRACT FROM AUTHOR]

The present study conducted to investigate the effect of heat stress and early age of thermal condition (at 3 days of age) for broiler chickens were fed diets supplemented with or without chromium picolinate (CrPic) to study its effects on growth performance, some physiological parameters, plasma biochemical traits as well as, immune response, heat shock proteins and carcass characteristics. Unsexed 300 one-day-old Hubbard broiler chicks were individually weighed and randomly distributed into 5 experimental treatments with 3 replicates (20 chicks each) per pen from 1-42 days of age. The 1st treatment (T1) served as a control and was fed a control basal diet and reared under natural conditions (25°C). The 2nd treatment (T2) and 3rd treatment (T3) were daily exposed to heat stress (33°C)and 65% relative humidity and 1200 μg/chromium picolinate (CrPic) /kg diet was added for T3 only, the 4th treatment (T4) and 5th treatment (T5) were daily exposed to heat stress (33°C) during the experimental period and at 3 days of age were exposed to early age of thermal condition (early heat shock exposure) and 1200 μg/chromium picolinate (CrPic) /kg diet was added for T5 only. After the end of thermal condition atearly age T4 and T5 returned to be reared underdaily heat stress (33°C). The obtained results showed that heat stress caused a significantly (p≤0.05) decrease body weight (BW), weight gain (BWG), feed intake (FI), feed conversion (FC), hemoglobin concentration (Hb), red blood cells (RBCs), white blood cells (WBCs), lymphocytes% (L%), antibody titers against infectious bronchitis virus (IBV), Newcastle virus (NDV), influenza viruses (H9N2), immunoglobulin G (IgG) and immunoglobulinM (IgM) concentrations, totalprotein, albumin and high density lipoprotein (HDL), superoxide dismutase (SOD), glutathione peroxidase (GPX), Triiodothyronine (T3) and thyroxine (T4) hormones. While, there were significant (p≤0.05) increases mortality rate, respiration rate, heterophils % (H %), H/L ratio, glucose, cholesterol, LDL, total lipids and triglycerides, corticosterone, total antioxidant capacity (TAOC), HSP70 expression of liver and abdominal fat as compared with the thermoneutral control broiler chicks.However, supplementation of chromium to the broiler chicks diet was able to alleviate many of deleterious effects. The present results indicate that the supplementation of diets with 1200 μg/chromium picolinate (CrPic)/kg diethas been considered to overcome the deleterious effects of heat stress on broiler performance. [ABSTRACT FROM AUTHOR]

Heat shock factor 1 (Hsf1) is a transcription factor that is often described as the master regulator of the heat shock response in all eukaryotes. However, due to its essentiality in yeast, Hsf1's contribution to the transcriptome under basal and heat shock conditions has never been directly determined. Using a chemical genetics approach that allowed rapid Hsf1 inactivation, my colleagues and I have recently shown that the bulk of the heat shock response is Hsf1 independent. Rather than inducing genes responsible for carrying out the various cellular processes required for adaptation to thermal stress, Hsf1 controls a dedicated set of chaperone protein genes devoted to restoring protein-folding homeostasis. The limited scope of the Hsf1 regulon belies its outsize importance in cellular fitness. [ABSTRACT FROM AUTHOR]

Background:Agents targeting HSP90 and GRP94 are seldom tested in stressed contexts such as heat shock (HS) or the unfolded protein response (UPR). Tumor stress often activates HSPs and the UPR as pro-survival mechanisms. This begs the question of stress effects on chemotherapeutic efficacy, particularly with drugs targeting chaperones such as HSP90 or GRP94. We tested the utility of several HSP90 inhibitors, including PU-H71 (targeting GRP94), on a primary canine lung cancer line under HS/UPR stress compared to control conditions. Methods:We cultured canine bronchoalveolar adenocarcinoma cells that showed high endogenous HSP90 and GRP94 expression; these levels substantially increased upon HS or UPR induction. We treated cells with HSP90 inhibitors 17-DMAG, 17-AAG or PU-H71 under standard conditions, HS or UPR. Cell viability/survival was assayed. Antibody arrays measured intracellular signalling and apoptosis profiles. Results:HS and UPR had varying effects on cells treated with different HSP90 inhibitors; in particular, HS and UPR promoted resistance to inhibitors in short-term assays, but combinations of UPR stress and PU-H571 showed potent cytotoxic activity in longer-term assays. Array data indicated altered signalling pathways, with apoptotic and pro-survival implications. UPR induction + dual targeting of HSP90 and GRP94 swayed the balance toward apoptosis. Conclusion:Cellular stresses, endemic to tumors, or interventionally inducible, can deflect or enhance chemo-efficacy, particularly with chaperone-targeting drugs. Stress is likely not held accountable when testing new pharmacologics or assessing currently-used drugs. A better understanding of stress impacts on drug activities should be critical in improving therapeutic targeting and in discerning mechanisms of drug resistance. [ABSTRACT FROM AUTHOR]

Tetraploid induction has been conducted on temperate oysters but not on tropical oysters. In this study, different heat shocks (32, 35 and 38°C) and cold shocks (1, 4 and 7°C) were used to induce tetraploidy in two tropical oyster species, Crassostrea belcheri and Crassostrea iredalei, through meiosis I inhibition. Temperature shocks were applied on the newly fertilized eggs at 8-10 min post fertilization and terminated when second polar bodies began to form in the control eggs. The ploidy of the larvae and spat was determined via direct chromosome count. The percentage of larval survival until Day 20 was low (between 0.4% and 42.9%) for both temperature shocks and oyster species. No surviving larva was recorded for induction at 1, 4 and 38°C. Tetraploid spat was only recorded in C. iredalei but the percentage is low through heat shock induction of 32 and 35°C. This study shows that the tetraploid induction success rate was slightly higher in C. iredalei compared to C. belcheri. No surviving tetraploid spat were recorded for both oyster species through the cold shock method. This study shows that heat shock can be used to inhibit meiosis for the production of tetraploids but more experiments need to be conducted to determine the optimum temperature when dealing with tropical oysters. [ABSTRACT FROM AUTHOR]

In anaerobic digesters, temperature fluctuation could lead to process instability and failure. It is still not well understood how digester microbiota as a whole respond to heat shock, and what specific organisms are vulnerable to perturbation or responsible for process recovery after perturbation. To address these questions, a mesophilic benzoate-degrading methanogenic culture enriched from digester was subjected to different levels of heat shock. Three types of methane production profiles after perturbation were observed in comparison to the control: uninhibited, inhibited with later recovery, and inhibited without recovery. These responses were correlated with the microbial community compositions based on the analyses of 16S rRNA and 16S rRNA gene. Specifically, the primary benzoate-degrading syntroph was highly affected by heat shock, and its abundance and activity were both crucial to the restoration of benzoate degradation after heat shock. In contrast, methanogens were stable regardless whether methane production was inhibited. Populations related to ' Candidatus Cloacimonetes' and Firmicutes showed stimulated growth. These observations indicated distinct physiological traits and ecological niches associated with individual microbial groups. The results obtained after exposure to heat shock can be critical to more comprehensive characterization of digester ecology under perturbations. Significance and Impact of the Study Anaerobic digestion is an essential step in municipal wastewater treatment owing to its striking capacity of reducing wasted sludge and recovering energy. However, as an elaborate microbial process, it requires constant temperature control and is sensitive to heat shock. In this study, we explored the microbial response to heat shock of a methanogenic culture enriched from anaerobic digester sludge. Microorganisms that were vulnerable to perturbation or responsible for process recovery after perturbation were identified. [ABSTRACT FROM AUTHOR]

The objectives were to test whether (1) melatonin blocks inhibition of embryonic development caused by heat shock at the zygote stage, and (2) the frequency of a thermoprotective allele for HSPA1L is increased in blastocysts formed from heat-shocked zygotes as compared with blastocysts from control zygotes. It was hypothesized that melatonin prevents effects of heat shock on development by reducing accumulation of reactive oxygen species (ROS) and that embryos inheriting the thermoprotective allele of HSPA1L would be more likely to survive heat shock. Effects of 1 μM melatonin on ROS were determined in experiments 1 and 2. Zygotes were cultured at 38.5 or 40°C for 3 h in the presence of CellROX reagent (ThermoFisher Scientific, Waltham, MA). Culture was in a low [5% (vol/vol)] oxygen (experiment 1) or low or high [21% (vol/vol)] oxygen environment (experiment 2). Heat shock and high oxygen increased ROS; melatonin decreased ROS. Development was assessed in experiments 3 and 4. In experiment 3, zygotes were cultured in low oxygen ± 1 μM melatonin and exposed to 38.5 or 40°C for 12 h (experiment 1) beginning 8 h after fertilization. Melatonin did not protect the embryo from heat shock. Experiment 4 was performed similarly except that temperature treatments (38.5 or 40°C, 24 h) were performed in a low or high oxygen environment (2 × 2 × 2 factorial design with temperature, melatonin, and oxygen concentration as main effects), and blastocysts were genotyped for a deletion (D) mutation (C→D) in the promoter region of HSPA1L associated with thermotolerance. Heat shock decreased percent of zygotes developing to the blastocyst stage independent of melatonin or oxygen concentration. Frequency of genotypes for HSPA1L was affected by oxygen concentration and temperature, with an increase in the D allele for blastocysts that developed in high oxygen and following heat shock. It was concluded that (1) lack of effect of melatonin or oxygen concentration on embryonic development means that the negative effects of heat shock on the zygote are not mediated by ROS, (2) previously reported effect of melatonin on fertility of heat-stressed cows might involve actions independent of the antioxidant properties of melatonin, and (3) the deletion mutation in the promoter of HSPA1L confers protection to the zygote from heat shock and high oxygen. Perhaps, embryonic survival during heat stress could be improved by selecting for thermotolerant genotypes. [ABSTRACT FROM AUTHOR]

The present investigation was conducted to appraise the physiochemical adjustments in contrasting maize cultivars, namely, PakAfgoi (tolerant) and EV-5098 (sensitive) subjected to heat shock. Seven-day-old seedlings were exposed to heat shock for different time intervals (1, 3, 6, 24, 48 and 72 h) and data for various physiochemical attributes determined to appraise time course changes in maize. After 72 h of heat shock, the plants were grown under normal conditions for 5 d and data for different growth attributes and photosynthetic pigments recorded. Exposure to heat shock reduced growth and photosynthetic pigments in maize cultivars. The plants exposed to heat shock for up to 3 h recovered growth and photosynthetic pigments when stress was relieved. A time course rise in the relative membrane permeability, hydrogen peroxide (H2O2) and malondialdehyde contents was recorded particularly in the EV-5098 indicating that heat shock-induced oxidative stress. Activities of different enzymatic antioxidants greatly altered due to heat shock. For instance, an increase in superoxide dismutase activity was recorded in both maize cultivars. The activity of ascorbate peroxidase was greater in Pak-Afgoi. However, the peroxidase and catalase activities were higher in plants of EV-5098. Heat shock caused a significant rise in the proline and decline in the total free amino acids. Overall, the performance of Pak-Afgoi was better in terms of having lesser oxidative damage and greater cellular levels of proline. The results suggested that oxidative stress indicators (relative membrane permeability, H2O2 and malondialdehyde) and proline can be used as markers for heat shock tolerant plants. [ABSTRACT FROM AUTHOR]

PurposePatchouli alcohol (PA) is used to treat gastrointestinal dysfunction. The purpose of this study was to ascertain the function of PA in the regulated process of oxidative stress in rat intestinal epithelial cells (IEC-6).Materials and methodsOxidative stress was stimulated by exposing IEC-6 cells to heat shock (42 °C for 3 h). IEC-6 cells in treatment groups were pretreated with various concentrations of PA (10, 40, and 80 ng/mL) for 3 h before heat shock.ResultsHeat shock caused damage to the morphology of IEC-6 cells, and increased reactive oxygen species (ROS) level and malondialdehyde (MDA) content. Moreover, mRNA and protein expression by target genes related to oxidative stress in heat shock were also altered. Specifically, the mRNA expression byHSP70,HSP90, GSH-px,NRF2ndHO-1were all increased, and Nrf2 and Keap1 protein expression were increased after heat shock. However, pretreatment with PA weakened the level of damage to the cellular morphology, and decreased the MDA content caused by heat shock, indicating PA had cytoprotective activities. Pretreatment with PA at high dose significantly increased generation of intracellular ROS. Compared with the heat shock group alone, PA pretreatment significantly decreased the mRNA expression byHSP70,HSP90,SOD,CAT,GSH-px,KEAP1andHO-1. Furthermore, the high dose of PA significantly increased Nrf2 protein expression, while both the intermediate and high dose of PA significantly increased HO-1 protein expression.ConclusionHeat-shock-induced oxidative stress in IEC-6 cells, and PA could alleviate the Nrf2-Keap1 cellular oxidative stress responses. [ABSTRACT FROM PUBLISHER]

Objective: Excitotoxicity is the accumulation of excess glutamate in the synaptic space observed in neurodegenerative diseases. The heat shock pathway is activated in stressful situations. HSF1 is the main regulator of the heat shock pathway. Activation of the HSF1 complex occurs through the interaction of HSF1 and eEF1a proteins with HSR1 non-coding RNA. The three factors come together to form an RNA-protein complex. Our aim is to investigate whether the heat shock pathway, which is activated in all other stress situations, is activated in glia and neuronal cells in the case of kainic acid (KA)- induced excitotoxicity and its mechanism. Methods: In IHA and SHSY-5Y cells, excitotoxicity was established with KA and measured by MTT and glutamate assay. HSF1 complex trimerization in these cells was observed by western blot technique. Protein levels of HSF1 and eEF1a constituting the HSF1 complex were determined by western blot and gene expression of HSR1 non-coding RNA by qPCR. Results: As a result of MTT assay, cell death increased when KA was given to cells (p=0.028 for IHA, p=0.0016 for SHSY-5Y). In the CA group, on the other hand, glutamate secretion decreased, in accordance with MTT, due to cell death (p: 0.0169 (12 hours for IHA), p=0.035 (24 hours), p=0.0025 (48 hours); for SHSY-5Y= p=0.0425 (12 hours), p=0.0078 (24 hours), p=0.0038 (48 hours) Results are statistically significant according to T-test In SHSY-5Y cells, HSF1 monomer and oligomers are more expressed as a result of KA treatment. This is due to the increase in HSF1 protein expression rather than the difference in trimerization capacity. No change in HSF1 expression or trimerization was observed in IHA cells as a result of KA treatment.EEF1a protein (p=0.7316) and HSR1 non-coding RNA, which forms the HSF1 complex, were not observed in both cell lines. There was no statistically significant difference in the levels of KA treatment before and after CA treatment (p=0.139 for IHA, p=0.752 for SHSY-5Y). Conclusion: Activation of the heat shock pathway and HSF1 also occurs during excitotoxicity, but only in neuronal cells. The elucidation of this mechanism will be very important in the development of drugs and treatments against neurodegenerative diseases. [ABSTRACT FROM AUTHOR]

Regulation of the heat shock response (HSR) is essential in all living systems. In E. coli, the HSR is regulated by an alternative σ factor, σ32, which is encoded by the rpoH gene. The mRNA of rpoH adopts a complex secondary structure that is critical for the proper translation of the σ32 protein. At low temperatures, the rpoH gene transcript forms a highly structured mRNA containing several three-way junctions, including a rare perfectly paired three-way junction (3WJ). This complex secondary structure serves as a primitive but highly effective strategy for the thermal control of gene expression. In this work, the first small-molecule modulators of the E. coli σ32 mRNA temperature sensor are reported. [ABSTRACT FROM AUTHOR]

Biocompatible nanoparticles are good candidates to label bacteria for imaging and diagnosis purposes. A high labeling efficiency reduces the concentration of nanoparticles required for labeling and allows the labeled bacteria to be tracked for longer periods. This report explores the optimal labeling strategy for Pseudomonas aeruginosa , a common gram-negative opportunistic pathogen, with quantum dots. Three strategies including direct incubation, calcium chloride treatment, and heat shock are compared and the labeling efficiency is assessed through fluorescence microscopy and flow cytometry analysis. Of the three, heat shock is finally selected due to its comparable labeling efficiency and simplicity. Through the assay of the respiration rate of bacteria together with morphology analysis, the heat shock process does not show any negative effect over the cells activity even at sub-toxic concentrations. [ABSTRACT FROM AUTHOR]

Several species belonging to the genus Entamoeba can colonize the mouth or the human gut; however, only Entamoeba histolytica is pathogenic to the host, causing the disease amoebiasis. This illness is responsible for one hundred thousand human deaths per year worldwide, affecting mainly underdeveloped countries. Throughout its entire life cycle and invasion of human tissues, the parasite is constantly subjected to stress conditions. Under in vitro culture, this microaerophilic parasite can tolerate up to 5 % oxygen concentrations; however, during tissue invasion the parasite has to cope with the higher oxygen content found in well-perfused tissues (4-14 %) and with reactive oxygen and nitrogen species derived from both host and parasite. In this work, the role of the amoebic oxygen reduction pathway (ORP) and heat shock response (HSP) are analyzed in relation to E. histolytica pathogenicity. The data suggest that in contrast with non-pathogenic E. dispar, the higher level of ORP and HSPs displayed by E. histolytica enables its survival in tissues by diminishing and detoxifying intracellular oxidants and repairing damaged proteins to allow metabolic fluxes, replication and immune evasion. [ABSTRACT FROM AUTHOR]

Increasing incubation temperatures, caused by global climate change or thermal effluent from industrial processes, may influence embryonic development of fish. This study investigates the cumulative effects of increased incubation temperature and repeated heat shocks on developing Lake Whitefish ( Coregonus clupeaformis ) embryos. We studied the effects of three constant incubation temperatures (2 °C, 5 °C or 8 °C water) and weekly, 1-h heat shocks (+3 °C) on hatching time, survival and morphology of embryos, as these endpoints may be particularly susceptible to temperature changes. The constant temperatures represent the predicted magnitude of elevated water temperatures from climate change and industrial thermal plumes. Time to the pre-hatch stage decreased as constant incubation temperature increased (148 d at 2 °C, 92 d at 5 °C, 50 d at 8 °C), but weekly heat shocks did not affect time to hatch. Mean survival rates and embryo morphometrics were compared at specific developmental time-points (blastopore, eyed, fin flutter and pre-hatch) across all treatments. Constant incubation temperatures or +3 °C heat-shock exposures did not significantly alter cumulative survival percentage (~50% cumulative survival to pre-hatch stage). Constant warm incubation temperatures did result in differences in morphology in pre-hatch stage embryos. 8 °C and 5 °C embryos were significantly smaller and had larger yolks than 2 °C embryos, but heat-shocked embryos did not differ from their respective constant temperature treatment groups. Elevated incubation temperatures may adversely alter Lake Whitefish embryo size at hatch, but weekly 1-h heat shocks did not affect size or survival at hatch. These results suggest that intermittent bouts of warm water effluent (e.g., variable industrial emissions) are less likely to negatively affect Lake Whitefish embryonic development than warmer constant incubation temperatures that may occur due to climate change. [ABSTRACT FROM AUTHOR]

When organisms are exposed to an increase in temperature, they undergo a heat shock response (HSR) regulated by the transcription factor heat shock factor 1 (HSF-1). The heat shock response includes the rapid changes in gene expression initiated by binding of HSF-1 to response elements in the promoters of heat shock genes. Heat shock proteins function as molecular chaperones to protect proteins during periods of elevated temperature and other stress. During infection, hookworm infective third stage larvae (L3) undergo a temperature shift from ambient to host temperature. This increased temperature is required for the resumption of feeding and activation of L3, but whether this increase initiates a heat shock response is unknown. To investigate the role of the heat shock in hookworm L3 activation and parasitic development, we identified and characterized the expression profile of several components of the heat shock response in the hookworm Ancylostoma caninum . We cloned DNAs encoding an hsp70 family member ( Aca-hsp-1 ) and an hsp90 family member ( Aca-daf-21 ). Exposure to a heat shock of 42 °C for one hour caused significant up-regulation of both genes, which slowly returned to near baseline levels following one hour attenuation at 22 °C. Neither gene was up-regulated in response to host temperature (37 °C). Conversely, levels of hsf-1 remained unchanged during heat shock, but increased in response to incubation at 37 °C. During activation, both hsp-1 and daf-21 are down regulated early, although daf-21 levels increase significantly in non-activated control larvae after 12 h, and slightly in activated larvae by 24 h incubation. The heat shock response modulators celastrol and KNK437 were tested for their effects on gene expression during heat shock and activation. Pre-incubation with celastrol, an HSP90 inhibitor that promotes heat shock gene expression, slightly up-regulated expression of both hsp-1 and daf-21 during heat shock. KNK437, an inhibitor of heat shock protein expression, slightly down regulated both genes under similar conditions. Both modulators inhibited activation-associated feeding, but neither had an effect on hsp-1 levels in activated L3 at 16 h. Both celastrol and KNK437 prevent the up-regulation of daf-21 and hsf-1 seen in non-activated control larvae during activation, and significantly down regulated expression of the HSF-1 negative regulator Aca-hsb-1 in activated larvae. Expression levels of heat shock response factors were examined in developing Ancylostoma ceylanicum larvae recovered from infected hosts and found to differ significantly from the expression profile of activated L3, suggesting that feeding during in vitro activation is regulated differently than parasitic development. Our results indicate that a classical heat shock response is not induced at host temperature and is suppressed during larval recovery and parasitic development in the host, but a partial heat shock response is induced after extended incubation at host temperature in the absence of a developmental signal, possibly to protect against heat stress. [ABSTRACT FROM AUTHOR]

Background aims. Mesenchymal stromal cells (MSCs) are an attractive candidate for autologous cell therapy, but regenerative potential can be compromised with extensive in vitro cell passaging. Development of viable cell therapies must address the effect of in vitro passaging to maintain overall ftinctionality of expanded MSCs. Methods. We examined the effect of repeated mild heat shock on the proliferation and differentiation capability of human adipose-derived MSCs. Adipose tissue MSCs were characterized by means of fluorescence activated cell sorting analysis for expression of CD3, CD 14, CD 19, CD34, CD44, CD45, CD73, CD90 and CD105. Similarly, the expression of SIRT-1, p l6 INK4il and p21 was determined by means of polymerase chain reaction. Measurements of population doubling, doubling time and superoxide dismutase activity were also determined. Differentiation of expanded MSCs into bone and adipose were analyzed qualitatively and quantitatively. Results. The strategy led to an increase in expression of SIRT-1 concomitant with enhanced viability, proliferation and delayed senescence. The stressed MSCs showed better differentiation into osteoblasts and adipocytes. Conclusions. The results indicate that mild heat shock could be used to maintain MSC proliferative and differentiation potential. [ABSTRACT FROM AUTHOR]

Trans-generational immune priming ( TGIP) describes the transfer of immune stimulation to the next generation. As stress and immunity are closely connected, we here address the question whether trans-generational effects on immunity and resistance can also be elicited by a nonpathogen stress treatment of parents. General stressors have been shown to induce immunity to pathogens within individuals. However, to our knowledge, it is as of yet unknown whether stress can also induce trans-generational effects on immunity and resistance. We exposed a parental generation (mothers, fathers, or both parents) of the red flour beetle Tribolium castaneum, a species where TGIP has been previously been demonstrated, to either a brief heat or cold shock and examined offspring survival after bacterial infection with the entomopathogen Bacillus thuringiensis. We also studied phenoloxidase activity, a key enzyme of the insect innate immune system that has previously been demonstrated to be up-regulated upon TGIP. We quantified parental fecundity and offspring developmental time to evaluate whether trans-generational priming might have costs. Offspring resistance was found to be significantly increased when both parents received a cold shock. Offspring phenoloxidase activity was also higher when mothers or both parents were cold-shocked. By contrast, parental heat shock reduced offspring phenoloxidase activity. Moreover, parental cold or heat shock delayed offspring development. In sum, we conclude that trans-generational priming for resistance could not only be elicited by pathogens or pathogen-derived components, but also by more general cues that are indicative of a stressful environment. The interaction between stress responses and the immune system might play an important role also for trans-generational effects. [ABSTRACT FROM AUTHOR]

The present study was designed to evaluate how environmental factors in a dry-summer subtropical climate in Terceira- Azores (situated in the North Atlantic Ocean: 38° 43' N 27° 12' W) can affect dairy cow (Holstein) fertility, as well as seasonal influence on in vitro oocytes maturation and embryos development. Impact of heat shock (HS) effects on in vitro oocyte's maturation and further embryo development after in vitro fertilization (IVF) was also evaluated. For such purpose the result of the first artificial insemination (AI) performed 60 to 90 days after calving of 6,300 cows were recorded for one year. In parallel, climatic data was obtained at different elevation points (n = 5) from 0 to 1,000 m and grazing points from 0 to 500 m, in Terceira island, and the temperature humidity index (THI) was calculated. For in vitro experiments, oocytes (n = 706) were collected weekly during all year, for meiotic maturation and IVF. Further, to evaluate HS effect, 891 oocytes were collected in the cold moths (December, January, February and March) and divided in three groups treated to HS for 24 h during in vitro maturation at: C (Control = 38.5°C), HS1 (39.5#176;C) and HS2 (40.5#176;C). Oocytes from each group were used for meiotic assessment and IVF. Cleavage, morula and blastocyst development were evaluated respectively on day 2, 6, and 9 after IVF. A negative correlation between cow's conception rate (CR) and THI in grazing points (-91.3%; p<0.001) was observed. Mean THI in warmer months (June, July, August and September) was 71.7±0.7 and the CR (40.2±1.5%) while in cold months THI was 62.8±0.2 and CR was 63.8±0.4%. A similar impact was obtained with in vitro results in which nuclear maturation rate (NMR) ranged from 78.4% (±8.0) to 44.3% (±8.1), while embryos development ranged from 53.8% (±5.8) to 36.3% (±3.3) in cold and warmer months respectively. In vitro HS results showed a significant decline (p<0.05) on NMR of oocytes for every 1#176;C rising temperature (78.4±8.0, 21.7±3.1 and 8.9±2.2, respectively for C, HS1, and HS2). Similar results were observed in cleavage rate and embryo development, showing a clear correlation (96.9 p<0.05) between NMR and embryo development with respect to temperatures. Results clearly demonstrated that, up to a THI of 70.6, a decrease in the CR occurs in first AI after calving; this impairment was confirmed with in vitro results. [ABSTRACT FROM AUTHOR]

Mandarin fish, Siniperca chuatsi, is an economically important fish due to its large size, fast growth, and delicious flesh. It is widely cultured in China. In this paper, triploidy in mandarin fish S. chuatsi was induced by heat shock. The most effective triploidy induction was achieved at 41°C, 8 min after fertilization for 2 min resulting in 40% triploid fish. There were no significant differences in the survival rates among the three treatment groups. Ploidy of fish was determined with a flow cytometer and chromosome counting. In conclusion, this paper presents optimal conditions for triploidy induction in mandarin fish with heat shock. The results will contribute to enhancement of its production in culture. [ABSTRACT FROM AUTHOR]

Transcription factors heat shock factor (Hsf)1 and nuclear factor-erythroid 2 p45-related factor (Nrf)2 are critical for adaptation and survival. Each is maintained at low basal levels, but is robustly activated by various stimuli, including cysteine-reactive small molecules (inducers). Although each is regulated by distinct mechanisms, it is emerging that these transcription factors engage in crosstalk by sharing overlapping transcriptional targets, such as heat shock protein (HSP)70, p62, and activating transcription factor (ATF)3, and in certain cases, compensating for each other. Critically, activation of Hsf1 or Nrf2 affects the cellular redox balance by promoting the reduced state. Conversely, deletion of Hsf1 or Nrf2 is associated with oxidative stress and impaired mitochondrial function. Transient activation of Hsf1 and Nrf2 is cytoprotective, but their persistent upregulation may be detrimental, causing cardiomyopathy or accelerating carcinogenesis, and should be considered when designing strategies for disease prevention and treatment. [ABSTRACT FROM AUTHOR]

Macrophages (Mϕs) play an important role in the inflammatory response during injury by participating in the removal of injurious stimuli, such as bacteria, and promoting tissue healing to restore homeostasis. Mϕs can acquire distinct functional phenotypes along a spectrum between two opposite stages (M1/M2) during activation. In the present study, we induced a stress response in Mϕs via heat shock (HS) and found that it incurred an increase in phagocytosis (1.6-fold, P < 0.05) and bacterial killing (2.8-fold, P < 0.01). Upon heat stress activation, Mϕs respond to group B Streptococcus (GBS) infection with lower levels of pro-inflammatory cytokines, TNF-α (2.25-fold, P < 0.01), IL-6 (7-fold, P < 0.001), and inducible nitric oxide synthase (iNOS) (2.22-fold, P < 0.05), but higher levels of the anti-inflammatory cytokine IL-10 (3.9-fold, P < 0.01). Stressed Mϕs exposed to GBS display rapid phagosome maturation, increased extracellular trap (ET) formation and elevated cathelicidin antimicrobial peptide expression (2.5-fold, P < 0.001). These findings are consistent with a heretofore uncharacterized Mϕ activation state formed in response to stress, associated with secretion of large quantities of anti-inflammatory mediators and redirection of antimicrobial mechanisms to NADPH-oxidase-independent pathways. This 'friendly activation' of Mϕs is characterized by increased bactericidal activity and more rapid and controlled resolution of the inflammatory response. Key Messages: [ABSTRACT FROM AUTHOR]

The sensitivity of insect nervous systems to anoxia can be modulated genetically and pharmacologically, but the cellular mechanisms responsible are poorly understood. We examined the effect of a heat shock pretreatment (HS) on the sensitivity of the locust (Locusta migratoria) nervous system to anoxia induced by water immersion. Prior HS made locusts more resistant to anoxia by increasing the time taken to enter a coma and by reducing the time taken to recover the ability to stand. Anoxic comas were accompanied by surges of extracellular potassium ions in the neuropile of the metathoracic ganglion, and HS reduced the time taken for clearance of excess extracellular potassium ions. This could not be attributed to a decrease in the activity of protein kinase G, which was increased by HS. In homogenates of the metathoracic ganglion, HS had only a mild effect on the activity of Na+-K+-ATPase. However, we demonstrated that HS caused a threefold increase in the immunofluorescent localization of the α-subunit of Na+-K+-ATPase in metathoracic neuronal plasma membranes relative to background labeling of the nucleus.We conclude that HS induced trafficking of Na+-K+-ATPase into neuronal plasma membranes and suggest that this was at least partially responsible for the increased resistance to anoxia and the increased rate of recovery of neural function after a disturbance of K+ homeostasis. [ABSTRACT FROM AUTHOR]

Maternal stress can have long-lasting epigenetic effects on offspring. To examine how epigenetic changes are triggered by stress, we examined the effects of activating the universal stress-responsive heat shock transcription factor HSF-1 in the germline of Caenorhabditis elegans. We show that, when activated in germ cells, HSF-1 recruits MET-2, the putative histone 3 lysine 9 (H3K9) methyltransferase responsible for repressive H3K9me2 (H3K9 dimethyl) marks in chromatin, and negatively bookmarks the insulin receptor daf-2 and other HSF-1 target genes. Increased H3K9me2 at these genes persists in adult progeny and shifts their stress response strategy away from inducible chaperone expression as a mechanism to survive stress and instead rely on decreased insulin/insulin growth factor (IGF-1)-like signaling (IIS). Depending on the duration of maternal heat stress exposure, this epigenetic memory is inherited by the next generation. Thus, paradoxically, HSF-1 recruits the germline machinery normally responsible for erasing transcriptional memory but, instead, establishes a heritable epigenetic memory of prior stress exposure. [Display omitted] • Germline activation of HSF-1 triggers heritable epigenetic changes in C. elegans • HSF-1 recruits the putative H3K9 methyltransferase MET-2 to bookmark daf-2 • HSF-1 causes transcriptional switching of stress response strategies of offspring • Maternal heat shock duration sets the heritability of H3K9me2 bookmarking Das et al. show that the transcription factor HSF-1, activated in the C. elegans germline by heat shock, bookmarks target genes by directly recruiting the putative H3K9 methyltransferase MET-2. This causes a transcriptional switch in offspring away from inducible chaperone expression as a stress survival mechanism toward decreased insulin/IGF-1-like signaling and DAF-16. [ABSTRACT FROM AUTHOR]

Heat shock proteins (Hsps) have long been candidates for ecological adaptation given their unequivocal role in mitigating cell damage from heat stress, but linking Hsps to heat tolerance has proven difficult given the complexity of thermal adaptation. Experimental evolution has been utilized to examine direct and correlated responses to selection for increased heat tolerance in Drosophila , often focusing on the major Hsp family Hsp70 and/or the master regulator HSF as a selection response, but rarely on other aspects of the heat shock complex. We examined Hsp70 and co-chaperone stv isoform transcript expression in Australian D. melanogaster lines selected for static heat tolerance, and observed a temporal and stv isoform specific, coordinated transcriptional selection response with Hsp70 , suggesting that increased chaperone output accompanied increased heat tolerance. We hypothesize that the coordinated evolutionary response of Hsp70 and stv may have arisen as a correlated response resulting from a shared regulatory hierarchy. Our work highlights the complexity and specificity of the heat shock response in D. melanogaster. The selected lines examined also showed correlated responses for other measures of heat tolerance, and the coevolution of Hsp70 and stv provide new avenues to examine the common mechanisms underpinning direct and correlated phenotypic responses to selection for heat tolerance. • Variation in inducible expression of Hsp70 has been often been examined as a selection response to increased heat tolerance, either alone or with the master regulator Heat Shock Factor (HSF). • We utilized Australian D. melanogaster experimental evolution lines selected for increased heat tolerance to examine a novel aspect of the heat shock machinery, co-evolution of Hsp70 the Hsp70 co-chaperone gene stv expression. • We report a temporal and stv isoform specific coordinated transcriptional selection response with Hsp70 , demonstrating that previously unexplored mechanisms of the heat shock response show evolutionary capacity to increase chaperone output concomitant with increased heat tolerance. • We hypothesize that the transcriptional coordination between Hsp70 and heat inducible stv isoforms has arisen from a shared regulatory hierarchy. • This work contributes more broadly to the growing field of understanding the role of cell chaperones and their interactions in natural thermal adaptation. [ABSTRACT FROM AUTHOR]

Heat shock proteins (HSP) serve as chaperones to maintain the physiological conformation and function of numerous cellular proteins when the ambient temperature is increased. To determine how accurate the general assumption that HSP gene expression is increased in febrile situations is, the RNA levels of the HSF1 (heat shock transcription factor 1) gene and certain HSP genes were determined in three cell lines cultured at 37˚C or 39˚C for three days. At 39˚C, the expression of HSF1, HSPB1, HSP90AA1 and HSP70A1L genes demonstrated complex changes in the ratios of expression levels between different RNA variants of the same gene. Several older versions of the RNAs of certain HSP genes that have been replaced by a newer version in the National Center for Biotechnology Information database were also detected, indicating that the older versions are actually RNA variants of these genes. The present study cloned four new RNA variants of the HSP27-encoding HSPB1 gene, which together encode three short HSP27 peptides. Reanalysis of the proteomics data from our previous studies also demonstrated that proteins from certain HSP genes could be detected simultaneously at multiple positions using SDS-PAGE, suggesting that these genes may engender multiple protein isoforms. These results collectively suggested that, besides increasing their expression, certain HSP and associated genes also use alternative transcription start sites to produce multiple RNA transcripts and use alternative splicing of a transcript to produce multiple mature RNAs, as important mechanisms for responding to an increased ambient temperature in vitro. [ABSTRACT FROM AUTHOR]

Spermatocytes are among the most heat-sensitive cells and the exposure of testes to heat shock results in their Heat Shock Factor 1 (HSF1)-mediated apoptosis. Several lines of evidence suggest that pleckstrin-homology-like domain family A, member 1 (PHLDA1) plays a role in promoting heat shock-induced cell death in spermatogenic cells, yet its precise physiological role is not well understood. Aiming to elucidate the hypothetical role of PHLDA1 in HSF1-mediated apoptosis of spermatogenic cells we characterized its expression in mouse testes during normal development and after heat shock. We stated that transcription of Phlda1 is upregulated by heat shock in many adult mouse organs including the testes. Analyzes of the Phlda1 expression during postnatal development indicate that it is expressed in pre-meiotic or somatic cells of the testis. It starts to be transcribed much earlier than spermatocytes are fully developed and its transcripts and protein products do not accumulate further in the later stages. Moreover, neither heat shock nor expression of constitutively active HSF1 results in the accumulation of PHLDA1 protein in meiotic and post-meiotic cells although both conditions induce massive apoptosis of spermatocytes. Furthermore, the overexpression of PHLDA1 in NIH3T3 cells leads to cell detachment, yet classical apoptosis is not observed. Therefore, our findings indicate that PHLDA1 cannot directly contribute to the heat-induced apoptosis of spermatocytes. Instead, PHLDA1 could hypothetically participate in death of spermatocytes indirectly via activation of changes in the somatic or pre-meiotic cells present in the testes. [ABSTRACT FROM AUTHOR]

• Prenatal maternal stress increases risk for neuropsychiatric disorders in offspring. • Heat shock factor and oxidative stress mechanisms are implicated in prenatal stress. • These cellular stress mechanisms may be targets for neuropsychiatric interventions. Development of the brain prenatally is affected by maternal experience and exposure. Prenatal maternal psychological stress changes brain development and results in increased risk for neuropsychiatric disorders. In this review, multiple levels of prenatal stress mechanisms (offspring brain, placenta, and maternal physiology) are discussed and their intersection with cellular stress mechanisms explicated. Heat shock factors and oxidative stress are closely related to each other and converge with the inflammation, hormones, and cellular development that have been more deeply explored as the basis of prenatal stress risk. Increasing evidence implicates cellular stress mechanisms in neuropsychiatric disorders associated with prenatal stress including affective disorders, schizophrenia, and child-onset psychiatric disorders. Heat shock factors and oxidative stress also have links with the mechanisms involved in other kinds of prenatal stress including external exposures such as environmental toxicants and internal disruptions such as preeclampsia. Integrative understanding of developmental neurobiology with these cellular and physiological mechanisms is necessary to reduce risks and promote healthy brain development. [ABSTRACT FROM AUTHOR]

Changes of Selenoprotein F (SELENOF) protein levels have been reported during selenium supplementation, stressful, and pathological conditions. However, the mechanisms of how these external factors regulate SELENOF gene expression are largely unknown. In this study, HEK293T cells were chosen as an in vitro model. The 5′-flanking regions of SELENOF were analyzed for promoter features. Dual-Glo Luciferase assays were used to detect promoter activities. Putative binding sites of Heat Shock Factor 1 (HSF1) were predicted in silico and the associations were further proved by chromatin immunoprecipitation (ChIP) assay. Selenate and tunicamycin (Tm) treatment were used to induce SELENOF up-regulation. The fold changes in SELENOF expression and other relative proteins were analyzed by Q-PCR and western blot. Our results showed that selenate and Tm treatment up-regulated SELENOF at mRNA and protein levels. SELENOF 5′-flanking regions from −818 to −248 were identified as core positive regulatory element regions. Four putative HSF1 binding sites were predicted in regions from −1430 to −248, and six out of seven primers detected positive results in ChIP assay. HSF1 over-expression and heat shock activation increased the promoter activities, and mRNA and protein levels of SELENOF. Over-expression and knockdown of HSF1 showed transcriptional regulation effects on SELENOF during selenate and Tm treatment. In conclusion, HSF1 was discovered as one of the transcription factors that were associated with SELENOF 5′-flanking regions and mediated the up-regulation of SELENOF during selenate and Tm treatment. Our work has provided experimental data for the molecular mechanism of SELENOF gene regulation, as well as uncovered the involvement of HSF1 in selenotranscriptomic for the first time. [ABSTRACT FROM AUTHOR]

Heat Shock Factor A2 (HsfA2) is part of the Heat Shock Factor (HSF) network, and plays an essential role beyond heat shock in environmental stress responses and cellular homeostatic control. Arabidopsis thaliana cell cultures derived from wild type (WT) ecotype Col-0 and a knockout line deficient in the gene encoding HSFA2 (HSFA2 KO) were grown aboard the International Space Station (ISS) to ascertain whether the HSF network functions in the adaptation to the novel environment of spaceflight. Microarray gene expression data were analyzed using a two-part comparative approach. First, genes differentially expressed between the two environments (spaceflight to ground) were identified within the same genotype, which represented physiological adaptation to spaceflight. Second, gene expression profiles were compared between the two genotypes (HSFA2 KO to WT) within the same environment, which defined genes uniquely required by each genotype on the ground and in spaceflight-adapted states. Results showed that the endoplasmic reticulum (ER) stress and unfolded protein response (UPR) define the HSFA2 KO cells' physiological state irrespective of the environment, and likely resulted from a deficiency in the chaperone-mediated protein folding machinery in the mutant. Results further suggested that additional to its universal stress response role, HsfA2 also has specific roles in the physiological adaptation to spaceflight through cell wall remodeling, signal perception and transduction, and starch biosynthesis. Disabling HsfA2 altered the physiological state of the cells, and impacted the mechanisms induced to adapt to spaceflight, and identified HsfA2-dependent genes that are important to the adaption of wild type cells to spaceflight. Collectively these data indicate a non-thermal role for the HSF network in spaceflight adaptation. [ABSTRACT FROM AUTHOR]

The master regulator of thermal stress response, Hsf1, is also an essential determinant for viability and virulence in Candida albicans. Our recent studies highlighted that apart from ubiquitous roles of Hsf1 at higher temperatures, it also has myriad non-heat shock responsive roles essential under iron deprivation and drug defense. Here, we further explored its implications in the normal cellular functioning, by profiling its genome-wide occupancy using chromatin immuno-precipitation coupled to high-density tiling arrays under basal and iron deprived conditions. Hsf1 recruitment profiles revealed that it binds to promoters of 660 genes of varied functions, under both the conditions, however, elicited variability in intensity of binding. For instance, Hsf1 binding was observed on several genes of oxidative and osmotic stress response, cell wall integrity, iron homeostasis, mitochondrial, hyphal and multidrug transporters. Additionally, the present study divulged a novel motif under basal conditions comprising, -GTGn3GTGn3GTG- where, Hsf1 displays strong occupancy at significant number of sites on several promoters distinct from the heat induced motif. Hence, by binding to and regulating major chaperones, stress responsive genes and drug resistance regulators, Hsf1 is imperative in regulating various cellular machineries. The current study provides a framework for understanding novel aspects of how Hsf1 coordinates diverse cellular functions. [ABSTRACT FROM AUTHOR]

High environmentaltemperature can be a stress factor for poultry, thus it can cause reduced productivity traits. The animals can be protected from such negative effects with increased adaptation capabilities through the usage of special keeping technologies. Therefore, during this study our aim was to investigate the impact of heat treatment and heat shock on chicken embryos and on chicken PGCs by using in vitro culture system. As a heat treatment, the 2-day old chicks were kept at 38.5°C for 12 hours. Later, in case of the heat stress, animals were kept at 30°C for 12 weeks. Experimental animals were measured for spermatological traits, while embryological parameters were collected from the progeny of the experimental group. We performed our experiments on the Transylvanian Naked Neck breed. Three different types of experimental groups were used: heat treated and heat stressed (HTHS), non-heat treated, but heat stressed (HS) and non-treated, non-stressed (C). The main embryological, spermatological and productivity parameters were measured regularly. PGC cultures were derived from blood which was isolated from 2.5-day (HH16) embryos, and then samples were collected after 23, 30 and 50 days of culturing. DNA and RNA were isolated at each time points and samples were prepared for immunostaining. In the heat-treated group significantly less abnormal embryonic development was observed when the parents were heat stressed. The heat treatment also caused significant growth in the egg production. Difference was not found in the percentage of abnormally developed embryos. The heat treatment did not have any effect on the spermatological parameters. In the treated group, almost twice as many eggs (46.8%) were experienced, which were appropriate for the PGC culturing, than in the non-treated group (29.8%). In HTHS and HS populations derivation rate was approximately the same (72.3% and 78.6%), however in the C group it was 60%. We could establish 39 PGC cultures from the used 56 embryos. 29 cell lines were frozen. The expression of the pluripotency markers and the HSP70 heat shock protein gene were detectable in the cell cultures. The expression of the HSP70 was considerably higher in the gonads of HTHS and HS embryos than in the C group. [ABSTRACT FROM AUTHOR]