Heat Shock Protein Gene Expression Research Articles

Comparative Physiological and Transcriptomic Profiling Reveals the Characteristics of Tissue Tolerance Mechanisms in the japonica Rice Landrace Under Salt Stress

AbstractThe aim of this study was to characterize the tissue tolerance mechanisms of rice under salt stress. Our preliminary experiment identified a japonica rice landrace Shuzenji-kokumai (SZK), which is considered to be tissue-tolerant because it can maintain better growth than salt-sensitive rice varieties while having a high-Na+ concentration in the shoots under salt stress. These mechanisms differ from those of most salt-tolerant rice varieties, which have low Na+ concentrations in the shoots. We compared the physiological and molecular characteristics of SZK with those of FL478, a salt-tolerant variety, and Kunishi, a salt-sensitive variety. Under salt stress conditions, SZK accumulated high levels of Na+ in the roots, leaf sheaths, and leaf blades, which were almost as high as those in the salt-sensitive Kunishi. Simultaneously, SZK maintained better growth and physiological status, as determined by its higher dry weight, lower electrolyte leakage ratio, and lower malondialdehyde concentration. Expressions of OsNHX1 and OsNHX2 were upregulated in the leaf sheaths of SZK, suggesting that Na+ might be compartmentalized in the vacuoles to avoid cytosolic Na+ toxicity. In contrast, FL478 showed upregulation of OsHKT1;5 and OsSOS1 in the roots, which may exclude Na+ from the shoots. RNA-seq analysis showed that 4623 and 1998 differentially expressed genes were detected in the leaf sheaths and leaf blades of SZK, respectively. Among them, the HSP (heat shock protein) gene expression was highly up-regulated only in SZK, indicating that SZK protects against the protein damage caused by Na+ toxicity. Our findings suggest that SZK has atypical survival mechanisms under salt stress conditions. These mechanisms offer potential traits for improving salt tolerance in rice in terms of tissue tolerance.

Identification of reference genes and analysis of heat shock protein gene expression (Hsp90) in arta (Calligonum comosum L.) leaf under heat stress

In southern Tunisia, plants are subjected to high temperatures and disturbances, causing the degradation of soils and plants. Studying wild plants and their response to heat stress can facilitate their conservation and help ecosystem rehabilitation. Understanding heat stress responses has gradually become a hotspot in desert plant research. The adaptive responses of Calligonum comosum species to high temperature were examined in this regard. For C.comosum gene expression studies, reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) is the best technique, in addition to the use of appropriate reference genes. So, in our research, we analyzed four different housekeeping genes to select the most stable one during heat stress conditions. To analyze the results, we applied various statistical programs, including GeNorm, Normfinder, Bestkeeper, and the comparative ΔCt method, to identify the most appropriate reference genes for normalizing gene expression under heat stress conditions. Ultimately, our analysis revealed that α-tubulin (α-tub) emerged as the most stable reference gene.Additionally, we subjected C. comosum plants to thermal stress to elucidate the expression patterns of heat shock protein (hsp90) genes. Fourteen-day-old plants were exposed to a temperature of 60 °C for a period ranging from 30 to 240 min. The highest level of hsp90 gene expression was realized upon exposure to heat for 180 min, underscoring the upregulation of this protein in response to thermal stress.This study is the first systematic investigation for selecting reference genes for qPCR in C. comosum under heat stress. These findings will substantially benefit gene expression studies conducted under similar challenging conditions, contributing to our understanding of desert plant responses to heat stress.

Effects of Rumen-Protected L-Tryptophan Supplementation on Productivity, Physiological Indicators, Blood Profiles, and Heat Shock Protein Gene Expression in Lactating Holstein Cows under Heat Stress Conditions.

In this study, we examined the effects of rumen-protected L-tryptophan supplementation on the productivity and physiological metabolic indicators in lactating Holstein cows under heat stress conditions. The study involved eight early lactating Holstein cows (days in milk = 40 ± 9 days; milk yield 30 ± 1.5 kg/day; parity 1.09 ± 0.05, p < 0.05), four cows per experiment, with environmentally controlled chambers. In each experiment, two distinct heat stress conditions were created: a low-temperature and low-humidity (LTLH) condition at 25 °C with 35-50% humidity and a high-temperature and high-humidity (HTHH) condition at 31 °C with 80-95% humidity. During the adaptation phase, the cows were subjected to LTLH and HTHH conditions for 3 days. This was followed by a 4-day heat stress phase and then by a 7-day phase of heat stress, which were complemented by supplementation with rumen-protected L-tryptophan (ACT). The findings revealed that supplementation with ACT increased dry matter intake as well as milk yield and protein and decreased water intake, heart rate, and rectal temperature in the HTHH group (p < 0.05). For plateletcrit (PCT, p = 0.0600), the eosinophil percentage (EOS, p = 0.0880) showed a tendency to be lower, while the monocyte (MONO) and large unstained cells (LUC) amounts were increased in both groups (p < 0.05). Albumin and glucose levels were lower in the HTHH group (p < 0.05). The gene expressions of heat shock proteins 70 and 90 in the peripheral blood mononuclear cells were higher in the ACT group (HTHH, p < 0.05). These results suggest that ACT supplementation improved productivity, physiological indicators, blood characteristics, and gene expression in the peripheral blood mononuclear cells of early lactating Holstein cows under heat-stress conditions. In particular, ACT supplementation objectively relieved stress in these animals, suggesting that L-tryptophan has potential as a viable solution for combating heat-stress-induced effects on the cattle in dairy farming.

Association of heat-shock protein 70.1 gene with physiological and physical performance of Bali cattle.

Global warming challenges cattle productivity and welfare since it affects heat stress and scarce feed. The heat-shock protein 70 (HSP70) gene is essential in cytoprotection against stressors, protecting cells from dysregulated gene expression and apoptosis. This study aimed to identify significant genetic markers of the HSP70.1 gene that can be leveraged genetically to enhance thermotolerance and production in Bali cattle further. Animals were sampled from three different rearing systems. In this study, 83 healthy adult male Bali cattle without abnormalities were utilized. Single-nucleotide polymorphism (SNP) diversity associated with the physiological and physical traits of Bali cattle was assessed using SNPStat online software. Gene expression for putative SNPs and their genotypic groups was further evaluated. There were 15 polymorphic SNPs (c.-185G>A, c.-69T>G, c.10G>C, c.19A>G, c.45C>T, c.101INS, c.115T>C, c.130T>C, c.136G>T, c.159G>C, c.164G>T, c.234G>A, c.303G>A, c.333C>A, and c.456C>T) identified, of which 12 were associated with the assessed trait. Nine SNPs were associated with physiological traits, while eight were with physical traits. The c.136G>T as a novel, high minor allele frequency, and associative SNP was selected for HSP70 gene expression. Individuals with the TT genotype have a trim physique, susceptible physiology, and high HSP70 mRNA expression. On the other hand, the GG genotype was significantly associated with larger physique, lower physiology, and low HSP70 mRNA expression. The higher expression may indicate that HSP70.1 is involved in mitigating the deleterious effects of stress. As a result, the animal experienced negative energy balance, decreasing body size. Single-nucleotide polymorphism c.136G>T is a candidate biomarker for heat resistance traits in Bali cattle.

Detection of Heat Shock Protein (Hsp70) Gene Expression, Some Physiological and Histological Alterations in the Nile Tilapia (Orechromis niloticus) Treated with Boric Acid and Cadmium

Detection of Heat Shock Protein (Hsp70) Gene Expression, Some Physiological and Histological Alterations in the Nile Tilapia (Orechromis niloticus) Treated with Boric Acid and Cadmium

Synergistic induction of apoptosis in liver cancer cells: exploring the combined potential of doxorubicin and XL-888.

Combination therapy has been frequently preferred in treating various types of cancer in recent years. Targeted cancer therapy has also become one of the remarkable treatment modalities. Therefore, the aim of the study to investigate its cytotoxic and apoptotic effects on liver cancer cell lines by combining the classical chemotherapeutic drug doxorubicin (DOX) and a targeted agent, the new generation HSP90 inhibitor XL-888. The molecular docking method was used to predict the binding conformation of XL-888 on the human Hsp90. The single and combined cytotoxic effects of DOX and XL-888 on liver cancer cell lines HepG2 and HUH-7 were determined by MTT assay. The effect of the combined use of two drugs was evaluated using Chou and Talalay method. The levels of apoptotic genes and heat shock proteins gene and protein expression levels were investigated by quantitative real-time polymerase chain reaction and western blotting, respectively. Molecular docking results showed that XL-888 selectively binds to the ATP binding pocket of HSP90 with an estimated free binding energy of -7.8kcal/mol. DOX and XL-888 and their combination showed dose-dependent cytotoxic effect. The combination of drugs showed a synergistic effect on both cell lines. The results revealed that the combination of DOX and XL-888 potently induced apoptosis in liver cancer cell lines rather than using drugs alone. The combined treatment of DOX and XL-888 demonstrated synergistic cytotoxic and apoptotic effects on liver cancer cell lines, presenting a promising approach for combination therapy in liver cancer.

Zinc oxide and selenium nanoparticles can improve semen quality and heat shock protein expression in cryopreserved goat (Capra hircus) spermatozoa

BackgroundReactive oxygen species (ROS) are strongly linked with oxidative stress (OS) generated during the process of sperm cryopreservation. Indeed, cellular damage from ROS has been implicated during sperm cryopreservation which causes deterioration in sperm quality and antioxidant nanoparticles (NPs) have been successful in preventing such damage. The interaction of NPs with sperm cells has been less frequently explored in farm animals. ObjectiveThe present study explored the effect of NP supplementation on sperm ultrastructure, potential interaction with sperm membrane (plasma and acrosome membrane), heat shock protein (HSP) gene expression levels and sperm quality in cryopreserved buck semen. Materials and methodsThirty-two (32) ejaculates were collected from four (4) adult male bucks and then diluted in Tris- citric acid- fructose- egg yolk (TCFY) extender containing the Zinc-oxide (ZnO) and Selenium (Se) NP treatments (T0: Control; TZn: 0.1 mg/mL ZnO NPs and TSe: 1 µg/mL Se NPs) after initial evaluation. Diluted semen was packed in 0.25 mL French mini straws and then stored in liquid nitrogen (LN2). Sperm parameters, lipid peroxidation (LPO) profile, sperm head morphology ultrastructural classification under transmission electron microscope (TEM), potential interaction of NPs with sperm membrane and expression of HSP genes were evaluated in the different treatment groups. ResultsWe found a significant (p < 0.05) increase in the percentage of spermatozoa with intact plasma membrane, and intact acrosome in the ZnO (0.1 mg/mL) and Se (1 µg/mL) NP supplemented groups in comparison to the frozen control group. TEM assessment revealed no internalization of both ZnO and Se NPs into the sperm structure. Few occasional contacts of ZnO NPs with the sperm membrane and a few agglomerates of Se NPs around the area of damaged membranes were visualized. HSP70 and HSP90 mRNA levels were significantly (p < 0.001) higher in the NP supplemented groups in comparison to the control. HSP70 and HSP90 mRNA levels had a strong positive association with sperm motility and a weak to moderate association with other sperm parameters. ConclusionsCurrent findings indicated that ZnO NPs are more potent than Se NPs in ameliorating peroxidative damages during sperm cryopreservation, increases semen quality parameters possibly by increasing the expression levels of HSP genes in buck semen. Furthermore, NP supplementation may have a potential role in preserving sperm head ultrastructure by acting as an antioxidant and reducing OS during various degrees of cellular insults, which needs to be further explored.

Chronic heat stress induces the expression of HSP genes in the retina of chickens (Gallus gallus).

Introduction: Chronic heat stress during summer is a major challenge imposed by global warming. Chickens are more sensitive to heat stress than mammals because they lack sweat glands. Thus, chickens are more susceptible to heat stress during summer than other seasons. Induction of heat shock protein (HSP) genes is one of the primary defense mechanisms against heat stress. Tissue-specific responses exhibited by different classes of HSPs upon exposure to heat stress have been reported previously in different tissues including the heart, kidney, intestine, blood, and muscle, but not in the retina. Therefore, this study aimed to investigate the expression levels of HSP27, HSP40, HSP60, HSP70, and HSP90 in the retina under chronic heat stress. Methods: This study was conducted during the summers of 2020 and 2021 in Kuwait. Chickens (Gallus gallus) were divided into control and heat-treated groups and sacrificed at different developmental stages. Retinas were extracted and analyzed by using Real Time quantitative Polymerase Chain Reaction (RT-qPCR). Results: Our results from the summer of 2021 were similar to that from the summer of 2020, regardless of whether GAPDH or RPL5 was used as a gene normalizer. All five HSP genes were upregulated in the retina of 21-day-old heat-treated chickens and stayed upregulated until 35days of age, with the exception of HSP40, which was downregulated. The addition of two more developmental stages in the summer of 2021 showed that at 14days, all HSP genes were upregulated in the retina of heat-treated chickens. In contrast, at 28days, HSP27 and HSP40 were downregulated, whereas HSP60, HSP70, and HSP90 were upregulated. Furthermore, our results showed that under chronic heat stress, the highest upregulation of HSP genes was seen at the earliest developmental stages. Discussion: To the best of our knowledge, this is the first study to report the expression levels of HSP27, HSP40, HSP60, HSP70, and HSP90 in the retina under chronic heat stress. Some of our results match the previously reported expression levels of some HSPs in other tissues under heat stress. These results suggest that HSP gene expression can be used as a biomarker for chronic heat stress in the retina.

Expression of heat shock proteins HSPA1A, HSPA1B and TP53 in vulval lichen planus and vulval lichen sclerosus.

Heat shock proteins (HSPs) are proteins involved in protein folding and maturation. HSP expression is induced by heat shock or other stressors including cellular damage and hypoxia. The major groups, which are classified based on their molecular weight, include HSP27, HSP40, HSP60, HSP70, HSP90, and large HSP (HSP110 and glucose-regulated protein 170). The comparison of heat shock proteins and TP53 expression is yet not well studied in both vulval lichen sclerosus and lichen planus. Our aim was to assess the HSP and TP53 gene expression in women suffering from LS or LP and compare it within these groups and also healthy controls. The inclusion criteria were willingness to donate vulval biopsies, not currently or in the prior two weeks received any local nor systemic treatment for vulval disorder, age > 18 years old. The exclusion criteria were lack of consent, current vaginal infection confirmed with microbiological studies, current local or systemic treatment for vulval disease. 45 consecutive women were recruited into the study. All appropriate vulval samples were process by genetic analysis. The mean expression (± SD) of HPSA1A for controls was 5.52 ± 3.18, for LS was 7.44 ± 2.16 and for LP was 7.89 ± 2.48. The mean expression (± SD) of HPSA1B for controls was 6.54 ± 3.41, for LS was 9.94 ± 6.88 and for LP was 9.43 ± 2.31. The mean expression (± SD) of TP53 for controls was 9.11 ± 1.14, for LS was 9.94 ± 1.27 and for LP was 10.41 ± 2.00. HSPA1A expression was 3,8 higher in women with lichen sclerosus than in control group. Heat shock protein-70 is more often expressed in LS than in healthy controls. HSP-70 not only supports tumor growth and metastasis, but on the other hand mat help to develop immune-driven treatment strategies.

Dynamic coalescence of yeast Heat Shock Protein genes bypasses the requirement for actin.

Nuclear actin has been implicated in dynamic chromatin rearrangements in diverse eukaryotes. In mammalian cells, it is required to reposition double-strand DNA breaks to enable homologous recombination repair and to enhance transcription by facilitating RNA Pol II recruitment to gene promoters. In the yeast Saccharomyces cerevisiae, nuclear actin modulates interphase chromosome dynamics and is required to reposition the induced INO1 gene to the nuclear periphery. Here, we have investigated the role of actin in driving intergenic interactions between Heat Shock Factor 1 (Hsf1)-regulated Heat Shock Protein (HSP) genes in budding yeast. These genes, dispersed on multiple chromosomes, dramatically reposition following exposure of cells to acute thermal stress, leading to their clustering within dynamic biomolecular condensates. Using an auxin-induced degradation strategy, we found that conditional depletion of nucleators of either linear or branched F-actin (Bni1/Bnr1 and Arp2, respectively) had little or no effect on heat shock-induced HSP gene coalescence or transcription. In addition, we found that pretreatment of cells with latrunculin A, an inhibitor of both filamentous and monomeric actin, failed to affect intergenic interactions between activated HSP genes and their heat shock-induced intragenic looping and folding. Moreover, latrunculin A pretreatment had little effect on HSP gene expression at either RNA or protein levels. In notable contrast, we confirmed that repositioning of activated INO1 to the nuclear periphery and its proper expression do require actin. Collectively, our work suggests that transcriptional activation and 3D genome restructuring of thermally induced, Hsf1-regulated genes can occur in the absence of actin.

Effect of emodin on growth performance, antioxidant status, intestinal morphology and heat shock protein gene expressions of freshwater prawn (Macrobrachium rosenbergii)

The purpose of this study was to assess the effect of emodin on biochemical variables, antioxidant activity, heat shock protein gene expression and prawn intestinal morphology (Macrobrachium rosenbergii). Three feeds containing 0 mg kg–1 (T1, control group), 25 mg kg–1 (T2) and 50 mg kg–1 (T3) of emodin were formulated and fed for eight weeks. Alanine aminotransferase, total cholesterol and triglyceride contents were significantly lowered although glucose tended to increase following the emodin remedy. Superoxide dismutase variables in haemolymph were dramatically upgraded, whilst malondialdehyde and superoxide anion situations were significantly lowered when compared to control. Emodin supplementation had no influence on glutathione peroxidase contents. Emodin remedy dropped the expression of HSP60 and HSP90 genes in comparison to the control. In T2, the intestinal epithelial cells were complete, well-organised and tightly affixed to the basement membrane, in discrepancy to the slightly disunited basement membrane in the control group. The emodin-treated prawn individuals had a thicker and full intestinal morphology than the control groups. Supplementation with emodin at dosages of 25 mg kg–1 improved growth performance, blood biochemical, antioxidant capacity and immune gene expression.

Heat shock protein and antioxidant enzyme gene expression and fold changes in bone marrow samples from healthy rats

The hematopoiesis in the bone marrow in the early stages of life is very complex and involves many cellular factors under very strict micro-environments. The two important cellular factors are heat shock proteins and antioxidant enzymes. The aim of the study was to study the gene expression profile of healthy rats’ bone marrow cells and niches particularly heat shock proteins and antioxidant genes. A total of thirty healthy Wister Albino rats at one, two, and three months old were involved throughout the study. Bone marrow samples were collected at a specified date according to the study design and utilized for qPCR test for expression of Hsps27, 90α, 90β, and antioxidant enzymes glutathione peroxidase1 (GPX1), catalase CAT and superoxide dismutase (SOD3) genes. The results revealed that there was a clear expression of both Hsps90α andβ in bone marrow cells throughout the study as well as the GPX1 gene. Furthermore, there was an increase in fold change of Hsps90α and β as well as GPX1, CAT, and SOD3 proteins as age progressed. In conclusion, hematopoietic cell differentiation and proliferation are regulated by bone marrow microenvironment stress conditions and by the expression of different Hsps and antioxidant genes. The protein folding process is a defense mechanism to protect the HSCs, and progenitors from un/misfolded proteins and to keep proteostasis.

The effects of overwintering temperature on the survival of female adult mud crab, Scylla paramamosain, under recirculating aquaculture systems as examined by histological analysis of the hepatopancreas and expression of apoptosis-related genes

The effects of the overwintering temperature (8, 12, 16, and 20 °C) on survival, antioxidant capacity, and heat shock protein (HSP) gene expression in Scylla paramamosain were examined during an experimental period of eight weeks. The effects of the temperature on survival were parabolic, with the highest and lowest survival rates occurring at 16 °C and 8 °C, respectively. Histological examination of the hepatopancreas revealed that the hepatopancreas tissue structure remained intact and that cell boundaries were clearly observed at 16 °C and 20 °C. However, hepatopancreas cells in the 12 °C and 8 °C groups appeared to be vacuolated and indistinct, respectively. Furthermore, high levels of reactive oxygen species (ROS) and malondialdehyde (MDA) and low levels of total antioxidant capacity (T-AOC) and superoxide dismutase (SOD) in the hepatopancreas were observed in the 8 °C group. Hsp60 and hsp70 gene expression were dramatically upregulated, but hsp10, hsp40, hsp90, and glucose regulatory protein 78 (grp78) gene expression were downregulated at 8 °C. The terminal deoxynucleotidyl transferase deoxy-UTP nick end labeling (TUNEL) method showed that there was more DNA damage at 8 °C and 12 °C than at 16 °C. Moreover, apoptosis was significantly induced with decreasing temperature, and the 8 °C group had the highest apoptosis index. Overall, these results suggest that the overwintering temperature greatly impacts the survival of mud crabs and that these effects may be mediated through antioxidant, HSP response, and apoptosis pathways. Significantly, the optimal overwintering temperature for S. paramamosain was extrapolated to be 14.2–16.1 °C. This suggests that temperature control should be considered in the process of mud crab overwintering.

Metabolomics-Guided Comparison of Pollen and Microalgae-Based Artificial Diets in Honey Bees.

Managed honey bee colonies used for crop pollination are fed artificial diets to offset nutritional deficiencies related to land-use intensification and climate change. In this study, we formulated novel microalgae diets using Chlorella vulgaris and Arthrospira platensis (spirulina) biomass and fed them to young adult honey bee workers. Diet-induced changes in bee metabolite profiles were studied relative to a natural pollen diet using liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS) metabolomics. Untargeted analyses of pollen- and microalgae-fed bees revealed significant overlap, with 248 shared features determined by LC-MS and 87 shared features determined by GC-MS. Further metabolomic commonalities were evident upon subtraction of unique diet features. Twenty-five identified metabolites were influenced by diet, which included complex lipids, essential fatty acids, vitamins, and phytochemicals. The metabolomics results are useful to understand mechanisms underlying favorable growth performance as well as increased antioxidant and heat shock protein gene expression in bees fed the microalgae diets. We conclude that the tested microalgae have potential as sustainable feed additives and as a source of bee health-modulating natural products. Metabolomics-guided diet development could eventually help tailor feed interventions to achieve precision nutrition in honey bees and other livestock animals.

Genome-Wide Identification of Eucalyptus Heat Shock Transcription Factor Family and Their Transcriptional Analysis under Salt and Temperature Stresses.

Heat shock transcription factors (HSFs) activate heat shock protein gene expression by binding their promoters in response to heat stress and are considered to be pivotal transcription factors in plants. Eucalyptus is a superior source of fuel and commercial wood. During its growth, high temperature or other abiotic stresses could impact its defense capability and growth. Hsf genes have been cloned and sequenced in many plants, but rarely in Eucalyptus. In this study, we used bioinformatics methods to analyze and identify Eucalyptus Hsf genes, their chromosomal localization and structure. The phylogenetic relationship and conserved domains of their encoded proteins were further analyzed. A total of 36 Hsf genes were identified and authenticated from Eucalyptus, which were scattered across 11 chromosomes. They could be classified into three classes (A, B and C). Additionally, a large number of stress-related cis-regulatory elements were identified in the upstream promoter sequence of HSF, and cis-acting element analysis indicated that the expression of EgHsf may be regulated by plant growth and development, metabolism, hormones and stress responses. The expression profiles of five representative Hsf genes, EgHsf4, EgHsf9, EgHsf13, EgHsf24 and EgHsf32, under salt and temperature stresses were examined by qRT-PCR. The results show that the expression pattern of class B genes (EgHsf4, EgHsf24 and EgHsf32) was more tolerant to abiotic stresses than that of class A genes (EgHsf9 and EgHsf13). However, the expressions of all tested Hsf genes in six tissues were at different levels. Finally, we investigated the network of interplay between genes, and the results suggest that there may be synergistic effects between different Hsf genes in response to abiotic stresses. We conclude that the Hsf gene family played an important role in the growth and developmental processes of Eucalyptus and could be vital for maintaining cell homeostasis against external stresses. This study provides basic information on the members of the Hsf gene family in Eucalyptus and lays the foundation for the functional identification of related genes and the further investigation of their biological functions in plant stress regulation.

Drought Stress Pre-Treatment Triggers Thermotolerance Acquisition in Durum Wheat

Durum wheat is strongly affected by climatic constraints such as high temperatures and drought, which frequently lead to yield reduction. Damages due to high temperatures are related to plant thermotolerance, a trait determined by two components: basal and acquired thermotolerance. In this study, the effect of drought and heat stress imposed singularly or sequentially was investigated in ten durum wheat cultivars (cvs) at the physiological and molecular level. The traits analyzed were cell membrane stability, relative water content, proline content, and expression level of several genes for heat shock proteins (HSPs). Our results indicate that drought priming can induce the acquisition of thermotolerance in most cultivars already classified as able to acquire thermotolerance by heat pre-treatment. Proline accumulation was correlated to cell membrane stability, meaning that the most thermotolerant cvs were able to accumulate higher levels of proline. Acquired thermotolerance is also due to the activation of HSP gene expression; similarly, pre-treatment with water stress was able to activate HSPs expression. The results reported indicate that water stress plays an important role in inducing thermotolerance, comparable to mild heat stress pre-treatment. This is the first report on the effect of drought stress on the acquisition of thermotolerance.

Mouse precision-cut liver slices as an ex vivo model to study drug-induced cholestasis

Drugs are often withdrawn from the market due to the manifestation of drug-induced liver injury (DILI) in patients. Drug-induced cholestasis (DIC), defined as obstruction of hepatic bile flow due to medication, is one form of DILI. Because DILI is idiosyncratic, and the resulting cholestasis complex, there is no suitable in vitro model for early DIC detection during drug development. Our goal was to develop a mouse precision-cut liver slice (mPCLS) model to study DIC and to assess cholestasis development using conventional molecular biology and analytical chemistry methods. Cholestasis was induced in mPCLS through a 48-h-incubation with three drugs known to induce cholestasis in humans, namely chlorpromazine (15, 20, and 30 µM), cyclosporin A (1, 3, and 6 µM) or glibenclamide (25, 50, and 65 µM). A bile-acid mixture (16 µM) that is physiologically representative of the human bile-acid pool was added to the incubation medium with drug, and results were compared to incubations with no added bile acids. Treatment of PCLS with cholestatic drugs increased the intracellular bile-acid concentration of deoxycholic acid and modulated bile-transporter genes. Chlorpromazine led to the most pronounced cholestasis in 48 h, observed as increased toxicity; decreased protein and gene expression of the bile salt export pump; increased gene expression of multidrug resistance-associated protein 4; and accumulation of intracellular bile acids. Moreover, chlorpromazine-induced cholestasis exhibited some transition into fibrosis, evidenced by increased gene expression of collagen 1A1 and heatshock protein 47. In conclusion, we demonstrate that mPCLS can be used to study human DIC onset and progression in a 48 h period. We thus propose this model is suited for other similar studies of human DIC.

Fenofibrate Improves Cognitive Impairment Induced by High-Fat High-Fructose Diet: A Possible Role of Irisin and Heat Shock Proteins.

A high-fat, high-fructose diet (HFFD) impairs cognitive functions and increases susceptibility to neurodegenerative disorders. Irisin and heat shock protein 70 (HSP70) are well known for their role in neuroprotection. The possible neuroprotective effects of fenofibrate on HFFD-induced cognitive dysfunction and the involvement of irisin and HSP70 in these effects were investigated in this study. Rats were divided into normal control, HFFD, dimethylsulfoxide+HFFD, and fenofibrate+HFFD groups. At the end of the experiment, fenofibrate treatment restored hippocampus histological characteristics to almost normal and improved HFFD-induced cognitive deficit. It reduced body weight gain and had hypolipidemic effects by significantly lowering total cholesterol, triglycerides, and low-density lipoprotein cholesterol levels while increasing high-density lipoprotein cholesterol levels. It has antioxidant and anti-inflammatory effects as it significantly reduced the hippocampal malondialdehyde, interleukin-6, and tumor necrosis factor-alpha levels, while significantly increasing the reduced glutathione level. It prevented HFFD-induced hypoxia by significantly lowering hippocampal vascular endothelial growth factor and hypoxia-inducible factor-1 alpha levels. It significantly activated the hippocampal peroxisome proliferator-activated receptor-gamma coactivator-1 alpha (PGC-1α)/irisin/brain-derived neurotrophic factor pathway. It significantly increased hippocampal HSP70 while decreasing the HSP90 levels. It enhanced synaptic plasticity by significantly upregulating the hippocampal relative GluR1 gene expression. Furthermore, hippocampal irisin levels in the HFFD group were found to be positively correlated with cognitive function, hippocampal HSP70, and relative GluR1 gene expression levels, while negatively correlated with hippocampal HSP90 and HIF1α levels. Therefore, fenofibrate may be used as a potential medication to treat HFFD-induced neurodegenerative disorders.

Fatigue and expression of heat-shock protein genes in plaque psoriasis.

Chronic fatigue is common in patients with psoriasis, and heat-shock proteins (HSPs) have been suggested to influence fatigue. To evaluate gene expression patterns of selected HSPs in patients with psoriasis with high vs. low fatigue. Fatigue was assessed using the fatigue Visual Analogue Scale, and disease activity by the Psoriasis Area and Severity Index. Peripheral blood transcriptional profiling was performed using RNA sequencing (RNA-seq) of HSP genes from 10 patients with high fatigue, and compared with 10 patients with low fatigue. HSPB11, HSPBAP1, HSPA14, HSPA9P1, HSP90B1 and HSP90AB1 contributed most to separation of the two groups in a principal components analysis. Four of these genes (HSPB11, HSPA14, HSP90B1 and HSP90AB1) were further investigated by real-time reverse transcription quantitative PCR (RT-qPCR) in 20 patients with high- and 20 patients with low-fatigue scores. Both RNA-seq and RT-qPCR analyses revealed a tendency to higher expression levels of HSPB11 and lower expression of HSP90B1 in the high- vs. the low-fatigue group. Psoriasis disease activity had no influence on the expression levels of the studied HSP genes. Overall, the results suggest that some HSPs are involved in generation of fatigue in psoriasis, supporting the hypothesis that downregulatory innate immune responses influence fatigue.

Heat shock protein gene expression varies among tissues and populations in free-living birds

Abstract Climate change is dramatically altering our planet, yet our understanding of mechanisms of thermal tolerance is limited in wild birds. We characterized natural variation in heat shock protein (HSP) gene expression among tissues and populations of free-living Tree Swallows (Tachycineta bicolor). We focused on HSPs because they prevent cellular damage and promote recovery from heat stress. We used quantitative PCR to measure gene expression of 3 HSPs, including those in the HSP70 and HSP90 families that have robust experimental connections to heat in past literature. First, to evaluate how tissues and, by extension, the functions that they mediate, may vary in their thermal protection, we compared HSP gene expression among neural and peripheral tissues. We hypothesized that tissues with particularly vital functions would be more protected from heat as indicated by higher HSP gene expression. We found that brain tissues had consistently higher HSP gene expression compared to the pectoral muscle. Next, we compared HSP gene expression across 4 distinct populations that span over 20° of latitude (&amp;gt;2,300 km). We hypothesized that the more southern populations would have higher HSP gene expression, suggesting greater tolerance of, or experience with, warmer local conditions. We observed largely higher HSP gene expression in more southern populations than northern populations, although this pattern was more striking at the extremes (southern Indiana vs. Alaska), and it was stronger in some brain areas than others (ventromedial telencephalon vs. hypothalamus). These results shed light on the potential mechanisms that may underlie thermal tolerance differences among populations or among tissues.