Expression Of Inducible Heat Shock Protein Research Articles

Short-term dietary teprenone improved thermal tolerance and mitigated liver damage caused by heat stress in juvenile largemouth bass (Micropterus salmoides)

Heat stress seriously threatens fish survival and health, demanding immediate attention. Teprenone is a gastric mucosal protective agent that can induce heat shock protein expression. This research investigated the effects of teprenone on largemouth bass (Micropterus salmoides) subjected to heat stress. Juvenile fish were assigned to different groups: group C (control group, 0 mg teprenone/kg diet), T0, T200, T400, and T800 (0, 200, 400, and 800 mg teprenone/kg diet, respectively), which were fed for 3 days, followed by a day without the diet. All groups except group C were subjected to acute heat stress (from 24 °C to 35 °C at 1 °C per hour and then maintained at 35 °C for 3 h). The results were as follows: The critical thermal maxima were significantly higher in the T200, T400, and T800 groups compared with the T0 group (P < 0.05). Heat stress caused severe damage to the tissue morphology of the liver, while teprenone significantly reduced this injury (P < 0.05). Serum cortisol concentration decreased gradually as teprenone concentration increased, and the lowest concentration was observed in the T800 group (P < 0.05). Compared with the T0 group, the serum activities of aspartate aminotransferase, alanine aminotransferase, and gamma-glutamyl transferase were significantly lower in the T200, T400, and T800 groups (P < 0.05). The liver activities of catalase, total superoxide dismutase, and peroxidase were significantly higher in the T200 group than in the T0 group (P < 0.05). Transcript levels of the heat shock proteins (hsp90, hsp70, hspa5, and hsf1) and caspase family (caspase3 and caspase9) in the liver of the T200 group were significantly higher than those of the T0 group (P < 0.05). Western blot results showed that HSP70 and HSPA5 in the liver were significantly upregulated in the T200 group compared with the T0 group (P < 0.05). In summary, dietary teprenone improved thermal tolerance, alleviated heat stress damage in the liver, enhanced antioxidant capacity, and upregulated heat shock proteins in juvenile largemouth bass. This study offers theoretical support for applying teprenone in aquaculture to reduce financial losses caused by abiotic factors.

Greater physiological resistance to heat may favour an invasive freshwater turtle, enabling it to outcompete native species in a changing climate

Abstract Climate warming and biological invasion can interact to affect ecosystems, and the results of such interactions depend on whether invaders show physiological advantages in their responses to warming environments as compared with native species after the establishment and local adaptation. However, it has rarely been evaluated. The present study compared the heat tolerance of a globally invasive turtle, the red‐eared slider Trachemys scripta elegans, and two co‐occurring native turtle species in China, the Chinese soft‐shelled turtle Pelodiscus sinensis and Chinese pond turtle Mauremys reevesii, after acclimation in the same thermal environment. The expression patterns of heat shock factor 1 (HSF1), multiple heat shock proteins (HSPs) and telomere reverse transcriptase (TERT), and changes in relative telomere length (RTL) were then evaluated in liver and muscle of turtles under thermal stress. The results showed that T. scripta elegans had greater physiological resistance to heat than the co‐occurring native turtle species, and that this higher tolerance was accompanied by a higher temperature induction of the peak expression of inducible HSPs in liver and a higher onset temperature for the main inducible HSPs in muscle. During thermal stress, T. scripta elegans showed a better ability to maintain the expression levels of TERT under extremely hot conditions, whereas high temperatures inhibited TERT in muscles of native turtle species. Meanwhile, thermal stress did not cause telomere erosion in any of the three turtle species and some treatments can lead to slightly longer telomeres in T. scripta elegans or M. reevesii. Overall, the invasive turtle species showed higher heat tolerance and physiological advantages in enduring hot weather in comparison to the co‐occurring native turtle species. This may favour these invaders in situations of climate warming. Our study highlights the role of physiological adaptations displayed by invaders in achieving advantages over native species under climate change.

Therapeutic reconditioning of damaged lungs by transient heat stress during ex vivo lung perfusion

Ex vivo lung perfusion (EVLP) may serve as a platform for the pharmacologic repair of lung grafts before transplantation (LTx). We hypothesized that EVLP could also permit nonpharmacologic repair through the induction of a heat shock response, which confers stress adaptation via the expression of heat shock proteins (HSPs). Therefore, we evaluated whether transient heat application during EVLP (thermal preconditioning [TP]) might recondition damaged lungs before LTx. TP was performed during EVLP (3 hours) of rat lungs damaged by warm ischemia by transiently heating (30 minutes, 41.5 °C) the EVLP perfusate, followed by LTx (2 hours) reperfusion. We also assessed the TP (30 minutes, 42 °C) during EVLP (4 hours) of swine lungs damaged by prolonged cold ischemia. In rat lungs, TP induced HSP expression, reduced nuclear factor κB and inflammasome activity, oxidative stress, epithelial injury, inflammatory cytokines, necroptotic death signaling, and the expression of genes involved in innate immune and cell death pathways. After LTx, heated lungs displayed reduced inflammation, edema, histologic damage, improved compliance, and unchanged oxygenation. In pig lungs, TP induced HSP expression, reduced oxidative stress, inflammation, epithelial damage, vascular resistance, and ameliorated compliance. Collectively, these data indicate that transient heat application during EVLP promotes significant reconditioning of damaged lungs and improves their outcomes after transplantation.

Exposure to acetochlor impairs swim bladder formation, induces heat shock protein expression, and promotes locomotor activity in zebrafish (Danio rerio) larvae

Acetochlor is one of the most widely used herbicides in the world, however, there are few data on the sub-lethal effects of acetochlor on early developmental stages of fish. To address this, we measured survival, deformity, swim bladder formation, embryo oxygen consumption rates, reactive oxygen species (ROS) levels, transcripts (related to swim bladder formation, oxidative damage response, and apoptosis) and behavior responses following exposure to acetochlor (0.001 µM up to 125 µM). Exposure to acetochlor at concentrations 50 µM and above exerted 100% mortality after 3 dpf, and significantly reduced the size of the swim bladder (25 µM). In embryos, basal respiration, oligomycin-induced ATP production, and maximal respiration were decreased 30–60% following a 24 h exposure to 125 μM acetochlor. Acetochlor did not affect ROS levels up to 25 µM in larvae with acute exposure. Acetochlor at 25 µM increased mRNA levels of bax1, hsp70, and hsp90a by ~4-fold in larval zebrafish. In both the visual motor response and light-dark preference test, 25 µM acetochlor increased locomotor activity of larval fish. At lower exposure concentrations, 100 and 1000 nM acetochlor increased the mean time spent in the dark zone, suggesting promotion of anxiolytic behavior. This study presents a comprehensive evaluation of sublethal effects of acetochlor, spanning molecular responses to behavior, which can be used to refine risk assessment decisions for aquatic environments.

Protective effect of Zingiber zerumbet Smith extract on thermotolerance

Background: Global warming causes severe heat conditions. Heat stress contributes to higher morbidity of heatstroke in human and mortality in livestock. To protect them from heat stress, thermotolerance mechanisms were widely studied, and some studies suggest relationship between heat shock proteins (HSPs) and thermotolerance. HSPs were not induced by only heat shock but also some stimulations including bioactive compounds from plants. Zingiber zerumbet is a perennial herb found in many tropical countries, including Thailand. The rhizome of Zingiber zerumbet contains zerumbone that is a bioactive compound to induce HSPs expression in animal cells.Objective: To prevent higher morbidity of heatstroke in human and mortality in livestock by the heat stress, we investigated the effect of zerumbone, the extract of Zingiber zerumbet Smith, on thermotolerance, using a cell line and mice.Methods: The murine liver hepatoma cell line, Hepa1c1c7 cells, were incubated in medium supplemented with extract from rhizome of Zingiber zerumbet Simith containing zerumbone, and then the expression of heat shock proteins (HSP) 40, 70 and 90 were investigated by western blotting. Furthermore, we established the evaluation system of thermotolerance using mice, and studied the effect of the extract on the growth rate of mice under the heat shock treatment. Briefly, 4 weeks old C57BL6 mice were fed that with the extract (or vehicle) for a week before the first heat shock treatment (38 °C for an hour). Before and after five days heat treatment, body weights were measured. The protein expressions of heat shock proteins in liver were measured by western blotting using HSPs antibodies.Results: The extract of Zingiber zerumbet rhizome, equivalent to 50 μM zerumbone, significantly increased the expression of heat shock proteins (HSP40, HSP70, HSP90). The growth rate of the mice under the heat treatment were lower than control. The feeding with the extract containing 25 ppm zerumbone have significantly attenuated the decline of the growth rate led by the heat treatment, whereas there was little effect on mouse growth rate grown under normal conditions. The protein expression of HSP70 in the liver of zerumbone-fed mice was upregulated compared with control mice, equivalent to heat treatment without zerumbone. On the other hand, both treatments of zerumbone and heat resulted in highest HSP70 expression among four groups.Conclusion: Our study demonstrated that oral administration of the extract of Zingiber zerumbet Smith led to the attenuation of decline of growth rate induced by heat treatment. HSP70 expression in murine liver was enhanced by either feeding the extract or heat treatment. More interestingly, HSP70 expression was further enhanced by both treatments of zerumbone and heat. These results suggested that zerumbone may contribute to thermotolerance via, at least, HSP70 expression.Keywords: Zingiber zerumbet, thermotolerance, heat shock protein

Cardioprotective Role of Heat Shock Proteins in Atrial Fibrillation: From Mechanism of Action to Therapeutic and Diagnostic Target.

Atrial fibrillation (AF) is the most common age-related cardiac arrhythmia worldwide and is associated with ischemic stroke, heart failure, and substantial morbidity and mortality. Unfortunately, current AF therapy is only moderately effective and does not prevent AF progression from recurrent intermittent episodes (paroxysmal) to persistent and finally permanent AF. It has been recognized that AF persistence is related to the presence of electropathology. Electropathology is defined as structural damage, including degradation of sarcomere structures, in the atrial tissue which, in turn, impairs electrical conduction and subsequently the contractile function of atrial cardiomyocytes. Recent research findings indicate that derailed proteostasis underlies structural damage and, consequently, electrical conduction impairment. A healthy proteostasis is of vital importance for proper function of cells, including cardiomyocytes. Cells respond to a loss of proteostatic control by inducing a heat shock response (HSR), which results in heat shock protein (HSP) expression. Emerging clinical evidence indicates that AF-induced proteostasis derailment is rooted in exhaustion of HSPs. Cardiomyocytes lose defense against structural damage-inducing pathways, which drives progression of AF and induction of HSP expression. In particular, small HSPB1 conserves sarcomere structures by preventing their degradation by proteases, and overexpression of HSPB1 accelerates recovery from structural damage in experimental AF model systems. In this review, we provide an overview of the mechanisms of action of HSPs in preventing AF and discuss the therapeutic potential of HSP-inducing compounds in clinical AF, as well as the potential of HSPs as biomarkers to discriminate between the various stages of AF and recurrence of AF after treatment.

Betaine Supplementation May Improve Heat Tolerance: Potential Mechanisms in Humans.

Betaine has been demonstrated to increase tolerance to hypertonic and thermal stressors. At the cellular level, intracellular betaine functions similar to molecular chaperones, thereby reducing the need for inducible heat shock protein expression. In addition to stabilizing protein conformations, betaine has been demonstrated to reduce oxidative damage. For the enterocyte, during periods of reduced perfusion as well as greater oxidative, thermal, and hypertonic stress (i.e., prolonged exercise in hot-humid conditions), betaine results in greater villi length and evidence for greater membrane integrity. Collectively, this reduces exercise-induced gut permeability, protecting against bacterial translocation and endotoxemia. At the systemic level, chronic betaine intake has been shown to reduce core temperature, all-cause mortality, markers of inflammation, and change blood chemistry in several animal models when exposed to heat stress. Despite convincing research in cell culture and animal models, only one published study exists exploring betaine’s thermoregulatory function in humans. If the same premise holds true for humans, chronic betaine consumption may increase heat tolerance and provide another avenue of supplementation for those who find that heat stress is a major factor in their work, or training for exercise and sport. Yet, this remains speculative until data demonstrate such effects in humans.

Ovariectomy alters lengthening contraction induced heat shock protein expression.

Estrogen appears to play a role in minimizing skeletal muscle damage as well as regulating the expression of the protective heat shock proteins (HSPs). To clarify the relationship between estrogen, muscle HSP content, and muscle damage, tibialis anterior (TA) muscles from ovary-intact (OVI; n = 12) and ovariectomized (OVX; 3 weeks, n = 12) female Sprague-Dawley rats were subjected to either 20 or 40 lengthening contractions (LCs). Twenty-four hours after stimulation, TA muscles were removed, processed, and assessed for HSP25 and HSP72 content as well as muscle (damage) morphology. No differences in muscle contractile properties were observed in TA muscles between OVI and OVX animals for peak torque during the LCs. In unstressed TA muscles, the basal expression of HSP72 expression was decreased in OVX animals (P < 0.05) while HSP25 content remained unchanged. Following 20 LCs, HSP25 content was elevated (P < 0.05) in TA muscles from OVX animals but unchanged in muscles from OVI animals. Following 40 LCs, HSP25 content was elevated (P < 0.01) in TA muscles from both OVI and OVX animals while HSP72 content was elevated only in TA muscles from OVI animals (P < 0.05). Taken together, these data suggest the loss of ovarian hormones, such as estrogen, may impair the skeletal muscle cellular stress response thereby rendering muscles more susceptible to certain types of contraction induced damage. Novelty Ovariectomy alters muscle HSP72 content. Muscle contractile measures are maintained following ovariectomy.

The effect of propofol on hypoxia-modulated expression of heat shock proteins: potential mechanism in modulating blood-brain barrier permeability.

Heat shock proteins (HSPs) may be induced by hypoxia and alleviate blood-brain barrier (BBB) damage. The neuroprotective effect of propofol has been reported. We aimed to identify whether propofol induced HSPs expression and protected BBB integrity. Mouse astrocytes and microglia cells were cultured and exposed to hypoxia and propofol. The expression of HSP27, HSP32, HSP70, and HSP90, and the translocation of heat shock factor 1 (HSF1) and Nuclear factor-E2-related factor 2 (Nrf2) were investigated. Mouse brain microvascular endothelial cells, astrocytes, and microglial cells were co-cultured to establish in vitro BBB model, and the effects of hypoxia and propofol as well as HSPs knockdown/overexpression on BBB integrity were measured. Hypoxia (5% O2, 5% CO2, 90% humidity) treatment for 6h and 12h induced HSP27, HSP32, and HSP70 expression. Propofol (25μΜ) increased HSP27 and HSP32 expression, starting with exposure to hypoxia for 3h. Propofol induced HSF1 translocation from cytoplasmic to nuclear compartment, and blockade of HSF1 inhibited HSP27 expression in mouse astrocytes when they were exposed to hypoxia for 3h. Propofol induced Nrf2 translocation, and blockade of Nrf2 inhibited HSP32 expression in mouse microglial cells when they were exposed to hypoxia for 3h. Propofol protected hypoxia-impaired BBB integrity, and the effects were abolished by blockade of HSF1 and Nrf2. Overexpression of HSP27 and HSP32 alleviated hypoxia-impaired BBB integrity, and blockade of HSP27 and HSP32 expression ameliorated propofol-mediated protection against BBB impairment. Propofol may protect hypoxia-mediated BBB impairment. The mechanisms may involve HSF1-mediated HSP27 expression and Nrf2-mediated HSP32 expression.

Not changes in membrane fluidity but proteotoxic stress triggers heat shock protein expression in Chlamydomonas reinhardtii.

A conserved reaction of all organisms exposed to heat stress is an increased expression of heat shock proteins (HSPs). Several studies have proposed that HSP expression in heat-stressed plant cells is triggered by an increased fluidity of the plasma membrane. Among the main lines of evidence in support of this model are as follows: (a) the degree of membrane lipid saturation was higher in cells grown at elevated temperatures and correlated with a lower amplitude of HSP expression upon a temperature upshift, (b) membrane fluidizers induce HSP expression at physiological temperatures, and (c) membrane rigidifier dimethylsulfoxide dampens heat-induced HSP expression. Here, we tested whether this holds also for Chlamydomonas reinhardtii. We show that heat-induced HSP expression in cells grown at elevated temperatures was reduced because they already contained elevated levels of cytosolic HSP70A/90A that apparently act as negative regulators of heat shock factor 1. We find that membrane rigidifier dimethylsulfoxide impaired translation under heat stress conditions and that membrane fluidizer benzyl alcohol not only induced HSP expression but also caused protein aggregation. These findings support the classical model for the cytosolic unfolded protein response, according to which HSP expression is induced by the accumulation of unfolded proteins. Hence, the membrane fluidity model should be reconsidered.

Expression of HSP70 genes in skin of zebu (Tharparkar) and crossbred (Karan Fries) cattle during different seasons under tropical climatic conditions

Skin is most important environmental interface providing a protective envelope to animals. It's always under the influence of both internal and external stressors. Heat shock proteins (HSP) are highly conserved stress proteins which play crucial roles in environmental stress tolerance and thermal adaptation. Present study was planned to observe the relative mRNA expression of inducible (HSP70.1 and HSP70.2) and constitutive (HSP70.8) HSP in skin of zebu (Tharparkar) and crossbred (Karan Fries) cattle during different seasons. Skin biopsies were collected from rump region of each animal, aseptically during winter, spring and summer season. Quantitative real time polymerase chain reaction was performed to examine the gene expression of constitutive (HSP70.8) and inducible (HSP70.1 and HSP70.2) HSP in skin of both the breeds during different seasons. Present study observed higher expression of both constitutive and inducible HSP genes in both the breeds during summer and winter than spring season, but magnitude of increase was higher during summer than winter. During summer season, expression pattern of HSPs in skin showed breed differences, where constitutive HSP expression was higher in Tharparkar than Karan Fries and that of inducible HSP was higher in Karan Fries than Tharparkar. Hence, present study suggested that HSP may be conveniently used as biomarkers for assessing protective response of skin against heat stress in zebu and crossbred cattle. Variation in expression between breeds is associated with their heat tolerance and thermal adaptability. In summary, skin of zebu cattle (Tharparkar) is more resistant to summer stress than crossbred (Karan Fries), providing greater protection against heat stress during summer season. Superior skin protective mechanism of zebu (Tharparkar) than crossbred (Karan-Fries) cattle against heat stress may contribute to superior adaptability of zebu cattle to tropical climatic conditions than crossbreed.

Heat Stress Modulates Mycelium Growth, Heat Shock Protein Expression, Ganoderic Acid Biosynthesis, and Hyphal Branching of Ganoderma lucidum via Cytosolic Ca 2+

Heat stress (HS) influences the growth and development of organisms. Thus, a comprehensive understanding of how organisms sense HS and respond to it is required. Ganoderma lucidum, a higher basidiomycete with bioactive secondary metabolites, has become a potential model system due to the complete sequencing of its genome, transgenic systems, and reliable reverse genetic tools. In this study, we found that HS inhibited mycelium growth, reduced hyphal branching, and induced the accumulation of ganoderic acid biosynthesis and heat shock proteins (HSPs) in G. lucidum Our data showed that HS induced a significant increase in cytosolic Ca(2+) concentration. Further evidence showed that Ca(2+) might be a factor in the HS-mediated regulation of hyphal branching, ganoderic acid (GA) biosynthesis, and the accumulation of HSPs. Our results further showed that the calcium-permeable channel gene (cch)-silenced and phosphoinositide-specific phospholipase gene (plc)-silenced strains reduced the HS-induced increase in HSP expression compared with that observed for the wild type (WT). This study demonstrates that cytosolic Ca(2+) participates in heat shock signal transduction and regulates downstream events in filamentous fungi. Ganoderma lucidum, a higher basidiomycete with bioactive secondary metabolites, has become a potential model system for evaluating how environmental factors regulate the development and secondary metabolism of basidiomycetes. Heat stress (HS) is an important environmental challenge. In this study, we found that HS inhibited mycelium growth, reduced hyphal branching, and induced HSP expression and ganoderic acid biosynthesis in G. lucidum Further evidence showed that Ca(2+) might be a factor in the HS-mediated regulation of hyphal branching, GA biosynthesis, and the accumulation of HSPs. This study demonstrates that cytosolic Ca(2+) participates in heat shock signal transduction and regulates downstream events in filamentous fungi. Our research offers a new way to understand the mechanism underlying the physiological and metabolic responses to other environmental factors in G. lucidum This research may also provide the basis for heat shock signal transduction studies of other fungi.

Sublethal Photothermal Stimulation with a Micropulse Laser Induces Heat Shock Protein Expression in ARPE-19 Cells.

Purpose/Aim of the Study. Subthreshold micropulse diode laser photocoagulation is an effective treatment for macular edema. The molecular mechanisms underlying treatment success are poorly understood. Therefore, we investigated the effects of sublethal laser energy doses on a single layer of densely cultured ARPE-19 cells as a model of the human retinal pigment epithelium (RPE). Materials and Methods. A single layer of densely cultured human ARPE-19 cells was perpendicularly irradiated with a micropulse diode laser. Nonirradiated cells served as controls. Sublethal laser energy was applied to form a photocoagulation-like area in the cultured cell layers. Hsp70 expression was evaluated using quantitative polymerase chain reaction and immunocytochemistry. Results. Photocoagulation-like areas were successfully created in cultured ARPE-19 cell layers using sublethal laser energy with our laser irradiation system. Hsp70 mRNA expression in cell layers was induced within 30 min of laser irradiation, peaking at 3 h after irradiation. This increase was dependent on the number of laser pulses. Hsp70 upregulation was not observed in untreated cell layers. Immunostaining indicated that Hsp70 expression occurred concentrically around laser irradiation sites and persisted for 24 h following irradiation. Conclusion. Sublethal photothermal stimulation with a micropulse laser may facilitate Hsp70 expression in the RPE without inducing cellular damage.

L-Threonine induces heat shock protein expression and decreases apoptosis in heat-stressed intestinal epithelial cells

ObjectivesOsmotically acting amino acids can be cytoprotective following injury. As threonine (THR) induces osmotic cell swelling, our aim was to investigate the potential for THR to induce cellular protection in intestinal epithelial cells and evaluate possible mechanisms of protection. MethodsCells treated with a range of THR doses were evaluated following heat stress (HS) injury. Alpha-aminoisobutyric acid (AIB), a non-metabolizable amino acid analog, was used as an osmotic control. MTS assays were used to assess cell survival. Heat shock protein (HSP) expression and cleaved caspase-3 (CC3) were evaluated via Western blot. Cell morphology and cell size were analyzed via microscopy. ResultFollowing HS, THR treatment increased cell viability in a dose dependent manner vs. non-THR treated cells (CT). The non-metabolized amino acid analogue, AIB, also increased cell survival in heat-stressed cells versus HS controls. HSP70 and HSP25 expression increased with THR and AIB treatment versus HS controls. THR also increased HSP25 in non-stressed cells. Microscopic evaluation revealed both THR and AIB preserved the structural integrity of the actin cytoskeleton in heat-stressed cells versus HS controls. THR, but not AIB, enhanced nuclear translocation of HSP25 during HS. This nuclear translocation was associated with a 60% decrease in apoptosis in heat-stressed cells with THR. No antiapoptotic effect was observed with AIB. ConclusionsThis is the first demonstration that THR increases HSP70 and HSP 25 and protects cells from HS. THR's mechanism of protection may involve cytoskeletal stabilization, HSP up-regulation and nuclear translocation, and decreased apoptosis. THR's protection appears to involve both cell-swelling–dependent and –independent processes.

Proteome response to heat stress in the Antarctic clam Laternula elliptica

The proteome can be regarded as a molecular phenotype, as changes in protein expression patterns have a direct effect on organismal physiology and fitness. The analysis of the proteome can therefore be an invaluable tool for our understanding of the mechanisms underlying phenotypic changes in response to environmental change. However, proteomic studies on thermal stress in marine species have mainly focused on heat shock protein expression, and little information is available for other components of the cellular stress response. This is particularly limiting for Antarctic species, which can lack the ability to induce heat shock protein expression in response to experimentally induced heat stress. The present study analysed changes in protein expression patterns in the Antarctic clam Laternula elliptica after exposure to elevated temperatures using two dimensional gel electrophoresis and mass spectrometry. Acute exposure to elevated temperatures had an effect in global protein expression patterns, suggesting that L. elliptica has the capacity to alter protein expression in response to heat stress. Changes in the expression of 14 proteins out of 264 analysed were observed in response to different levels of heat stress. Four of the 14 proteins had database matches and were identified as the cytoskeletal protein tubulin and associated chaperone TCP-1, and the enzymes enolase and aldehyde dehydrogenase, part of the minimal stress proteome and involved in redox regulation.

Intramuscular Heating Through Fluidotherapy and Heat Shock Protein Response

Therapeutic modalities that can increase intramuscular temperature commonly are used to treat injuries in the clinical setting. Researchers recently have suggested that the physiologic changes occurring during an increase in temperature also could provide a cytoprotective effect for exercise-induced muscle damage. To determine if the Fluidotherapy treatment increases the inducible expression of heat shock protein (HSP), to identify the rate of heating that occurs in the lower extremity with Fluidotherapy treatment, and to evaluate the relationship between the inducible expression of HSP and temperature. Controlled laboratory study. Laboratory. Six male (age = 21.67 ± 1.63 years, height = 180.09 ± 4.83 cm, mass = 87.60 ± 10.51 kg) and 6 female (age = 24.60 ± 4.59 years, height = 151.05 ± 35.76 cm, mass = 55.59 ± 14.58 kg) college-aged students. One lower extremity was randomly selected to receive the heat treatment, and the other extremity received no treatment. We measured intramuscular temperature every 10 minutes, determining peak intramuscular temperature by 2 identical sequential measurements, and we analyzed the time to peak temperature. We analyzed the amount of HSP70 expression and HSP27P:T (ratio of HSP27 to the total HSP27 expression) in the gastrocnemius and soleus muscles and measured baseline skinfold thickness and estradiol levels. Fluidotherapy increased intramuscular temperature by 5.66 ± 0.78°C (t11 = 25.67, P < .001) compared with baseline temperature, with a peak temperature of 39.08°C ± 0.39°C occurring at 84.17 ± 6.69 minutes. We did not find a heat treatment effect for HSP70 or HSP27P:T in the gastrocnemius or soleus muscles (P > .05). Peak temperature and the percentage change of HSP70 were positively correlated for the gastrocnemius and soleus muscles (P < .05). We found no other correlations for skinfold thickness, sex, or estradiol levels (P > .05). No effect of sex for skinfold thickness or estradiol levels at baseline was discovered (P > .05). This Fluidotherapy protocol increased the intramuscular temperature to a therapeutic level; however, it did not stimulate inducible HSP70 or HSP27P:T in the soleus and gastrocnemius muscles regardless of sex or skinfold thickness. These data confirmed that Fluidotherapy is an effective heating modality but suggested it is not an effective method for stimulating an HSP response in the lower limb.

Effect of rapid temperature change on expression of hsp70 and hsp90 in grass carp(Ctenopharyngodon idella)

Grass carp(Ctenopharyngodon idella)is one of the most important cultured fishes in China.During transportation in summer,massive mortality often occurs.As molecular chaperones,Hsps assist cells in their recovery from stress and promote cytoprotection.Limited reports described the expression of Hsps in grass carp at high temperatures,and the relationship between oxygen consumption,expression of heat shock protein and mortality needs to be investigated based on the oxygen-and capability-limited thermal tolerance theory(OCLTT)to further elucidate the thermal adaptation of this species to high temperature in view of integrated biology.In the present study,the expressions of hsp70 and hsp90 after rapid temperature increase were studied.Grass carps were acclimated at 20 ℃ and then exposed to designated temperatures(20,22,24,26,28,30,32,34 ℃)for 3 h heat shock.After 2 h-recovery at 20 ℃,liver,muscle and gill of tested fish were sampled and hsp70 and hsp90 were determined using semi-quantitive real-time PCR.Expression of hsps increased with temperature increase until 32 ℃ in muscle and gill,and then decreased at 34 ℃.In liver,expression of hsps kept increasing in all temperature treatments.These results indicated that hsp70 and hsp90 were sensitive to temperature increase in grass carp.Analyzed heat shock proteins data with previous results of oxygen consumption and lethal temperatures of grass carp,the physiological adaptations of grass carp could be explained by oxygen-and capability-limited thermal tolerance theory(OCLTT),which pointed out that the imbalance between oxygen demand and tissue oxygen supply ability was the primary factor which limited organisms' thermal tolerance and the ability of aerobic metabolism greatly limited the survival of organism beyond critical temperatures.With temperature increase,the maximum value of oxygen consumption in grass carp occurred at 28 ℃,and then the oxygen consumption decreased when temperature was beyond 28 ℃,indicating a transformation from aerobic metabolism to anaerobic metabolism at this critical temperature.The expressions of heat shock proteins kept increasing until 32 ℃ in muscle and gill in grass carp,and provided defense against high temperature.However,this protection of heat shock proteins was limited and then death occurred when temperature was beyond 32 ℃.The change of metabolism,increase of oxygen free radicals and the consumption of energy due to stress proteins synthesis of grass carp were closely related to the decrease of capability of immune response when water temperature was beyond 28 ℃.In general,high water temperature could alter the metabolic pathway,induce heat shock protein expression,reduce immune response,and then cause large-scale mortality.Therefore,appropriate ways should be applied to maintain water temperature under 28 ℃ to avoid large-scale mortality during transportation.

Kinetics of thermally induced heat shock protein 27 and 70 expression by bone marrow‐derived mesenchymal stem cells

Although bone marrow-derived mesenchymal stem cells (MSCs) are an attractive cell therapy candidate, their potential is limited by poor survival following transplantation. Over-expression of anti-apoptotic heat shock proteins using viral vectors can improve the survival of these cells under stressful conditions in vitro and in vivo. It is also possible to induce heat shock protein expression in many cell types by simply exposing them to a transient, nonlethal elevation in temperature. The response profile of MSCs to such a thermal stress has not yet been reported. Therefore, this study sought to determine the kinetics of thermally induced heat shock protein expression by MSCs in vitro. To determine if heat shock protein expression was a function of thermal stress exposure time, MSCs were exposed to 42°C for 15, 30, 45, and 60 min and were harvested 24 h later. To establish the time-course of heat shock protein expression, MSCs were heat shocked for 60 min and harvested 2, 24, 48, 72, 96, and 120 h later. The cells were then analyzed for Hsp27 and Hsp70 expression by Western blot. Densitometric analysis revealed that exposure to a thermal stress induced expression of both Hsp27 and Hsp70 and that the level of expression was dependant on stress exposure time. Following 60 min of heat stress, both Hsp27 and Hsp70 accumulated maximal expression after 48 h with both proteins returning to constitutive expression levels by 120 h. This study demonstrates that heat shock protein expression can be induced in MSCs by a simple thermal stress.

Inducible hsp70 in the regulation of cancer cell survival: analysis of chaperone induction, expression and activity.

Understanding the mechanisms that control stress is central to realize how cells respond to environmental and physiological insults. All the more important is to reveal how tumour cells withstand their harsher growth conditions and cope with drug-induced apoptosis, since resistance to chemotherapy is the foremost complication when curing cancer. Intensive research on tumour biology over the past number of years has provided significant insights into the molecular events that occur during oncogenesis, and resistance to anti-cancer drugs has been shown to often rely on stress response and expression of inducible heat shock proteins (HSPs). However, with respect to the mechanisms guarding cancer cells against proteotoxic stresses and the modulatory effects that allow their survival, much remains to be defined. Heat shock proteins are molecules responsible for folding newly synthesized polypeptides under physiological conditions and misfolded proteins under stress, but their role in maintaining the transformed phenotype often goes beyond their conventional chaperone activity. Expression of inducible HSPs is known to correlate with limited sensitivity to apoptosis induced by diverse cytotoxic agents and dismal prognosis of several tumour types, however whether cancer cells survive because of the constitutive expression of heat shock proteins or the ability to induce them when adapting to the hostile microenvironment remains to be elucidated. Clear is that tumours appear nowadays more “addicted” to heat shock proteins than previously envisaged, and targeting HSPs represents a powerful approach and a future challenge for sensitizing tumours to therapy. This review will focus on the anti-apoptotic role of heat shock 70kDa protein (Hsp70), and how regulatory factors that control inducible Hsp70 synthesis, expression and activity may be relevant for response to stress and survival of cancer cells.

Comparative analysis on the expression of inducible HSPs in the silkworm, Bombyx mori

Heat shock proteins (HSPs), well-known in respond to various kinds of stress situations, have been widely studied in Drosophila. However, a few reports related to silkworm bombyx mori. Genetic and non-genetic factors affecting on the expression of some HSPs in heat-treated silkworm were studied at the present paper. The mRNA levels of HSPs were quantified by real-time quantitative RT-PCR method and compared with their expression in the proteome profiles. The results showed up-regulation of two small heat shock proteins (sHSPs), HSP19.9 and HSP20.4 and down-regulation of HSP70 in the fat body, testis and ovary of heat exposed larvae. Higher variation of the sHSPs than HSP70 was observed in the different conditions such as heat exposures and genetic backgrounds. Significant difference in the HSP19.9 expression between two breeds was observed which implied the importance of this gene in the genetic differences. There was significant difference between responses of severe and mild heat shocks after 4h heat recovery. The HSPs expression in male was significantly higher than that in female silkworm larva for all transcript measurements (P<0.001). Comparison of two methods of quantification showed a fair similarity between HSPs expression in the transcriptome and proteome levels. Nistari breed as a naturally thermo-tolerant breed was expressed lower HSPs than a thermo-sensitive breed.