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Sample records for circulating heat shock

  1. Circulating Heat Shock Proteins in Women With a History of Recurrent Vulvovaginitis

    Directory of Open Access Journals (Sweden)

    S. S. Witkin

    1999-01-01

    Full Text Available Objective: Predisposing factors influencing recurrences of bacterial vaginosis (BV or vaginitis from Candida remain unidentified for most women. As a component of studies to determine host susceptibility factors to genital tractiiafeetions in women, we measured expression of the 60-kDa and 70-kDa heat shock proteins (hsp60 and hsp70, respectively in the circulation of women with or without a history of recurrent BV or candidal vaginitis and with or without a current lower genital tract infection. Heat shock protein expression is associated with a down-regulation of proinflammatory immune responses that would inhibit microbial infection.

  2. Sickle Cell Vaso-occlusive Crisis Induces the Release of Circulating Serum Heat Shock Protein-70

    OpenAIRE

    Adewoye, Adeboye H; Klings, Elizabeth S.; Farber, Harrison W.; Palaima, Elizabeth; Bausero, Maria A.; McMahon, Lillian; Odhiambo, Adam; Surinder, Safaya; Yoder, Mark; Martin H Steinberg; Asea, Alexzander

    2005-01-01

    Inflammation may play an important role in the pathophysiology of sickle cell disease (SCD), and recent studies have identified the 70-kDa heat shock protein (Hsp70) as an important mediator of inflammatory responses. Here we demonstrate a significant increase in circulating serum Hsp70 level in SCD during vaso-occlusive crisis (VOC) as compared with baseline steady-state levels (P < 0.05) and a significant increase in Hsp70 levels in SCD at baseline compared with normal controls (P < 0.05). ...

  3. Circulating heat shock protein 60 levels are elevated in HIV patients and are reduced by anti-retroviral therapy.

    Directory of Open Access Journals (Sweden)

    Itaru Anraku

    Full Text Available Circulating heat shock protein 60 (Hsp60 and heat shock protein 10 (Hsp10 have been associated with pro- and anti-inflammatory activity, respectively. To determine whether these heat shock proteins might be associated with the immune activation seen in HIV-infected patients, the plasma levels of Hsp60 and Hsp10 were determined in a cohort of 20 HIV-infected patients before and after effective combination anti-retroviral therapy (cART. We show for the first time that circulating Hsp60 levels are elevated in HIV-infected patients, with levels significantly reduced after cART, but still higher than those in HIV-negative individuals. Hsp60 levels correlated significantly with viral load, CD4 counts, and circulating soluble CD14 and lipopolysaccharide levels. No differences or correlations were seen for Hsp10 levels. Elevated circulating Hsp60 may contribute to the immune dysfunction and non-AIDS clinical events seen in HIV-infected patients.

  4. Heat shock protein 90 is responsible for hyperdynamic circulation in portal hypertensive rats

    Institute of Scientific and Technical Information of China (English)

    Jian-Hua Ai; Zhen Yang; Fa-Zu Qiu; Tong Zhu

    2003-01-01

    AIM: To examine the participation of HSP90 in portal hypertensive rat mesentery in vitro.METHODS: Immunohistochemistry and Western-blot were used to examine the expression of HSP90 in mesenteric vasculature. HSP90 mRNA was detected by RT-PCR, and the role of HSP90 in hyperdynamic circulation was examined by in vitro mesenteric perfusion studies.RESULTS: HSP90 was overexpressed in endothelium of mesentery vasculature in animals with experimental portal hypertension induced by partial portal vein ligation (PVL) compared with normal animals. Geldanamycin (GA), a special inhibitor of HsPg0 signaling, attenuated ACh-dependent vasodilation but did not affect vasodilation in response to sodium nitroprusside in normal rats. In PVL animals, the perfused mesentery was hyporesponsive to vasoconstrictor methoxamine. GA significantly potentiated methoxamineinduced vasoconstrictor after PVL.CONCLUSION: HsPg0 plays a key role in NO-dependent hyperdynamic circulation in portal hypertension and provides a novel method for future treatment of portal hypertension.

  5. Increased circulating heat shock protein 70 (HSPA1A) levels in gestational diabetes mellitus: a pilot study.

    Science.gov (United States)

    Garamvölgyi, Zoltán; Prohászka, Zoltán; Rigó, János; Kecskeméti, András; Molvarec, Attila

    2015-07-01

    Recent data indicate that serum Hsp70 (HSPA1A) levels are increased in type 1 and 2 diabetes mellitus. However, there is no report in the literature on circulating Hsp70 levels in gestational diabetes mellitus. In this pilot study, we measured serum Hsp70 levels in 11 pregnant women with pregestational diabetes, 38 women with gestational diabetes, and 40 healthy pregnant women with ELISA. Plasma glucose levels, serum insulin concentrations, HbA1c values, and the Homeostatic Model Assessment-Insulin Resistance (HOMA-IR) index were also determined. According to our results, serum Hsp70 concentrations were significantly higher in women with pregestational and gestational diabetes mellitus than in healthy pregnant women. In addition, pregestational diabetic women had significantly higher Hsp70 levels than those with gestational diabetes. Furthermore, in the group of women with gestational diabetes mellitus, serum Hsp70 levels showed a significant positive correlation with HbA1c values. However, there was no other relationship between clinical features and metabolic parameters of the study subjects and their serum Hsp70 levels in either study group. In conclusion, we demonstrated for the first time in the literature that serum Hsp70 levels are increased and correlate with HbA1c values in women with gestational diabetes mellitus. Nevertheless, further studies are needed to determine whether circulating Hsp70 plays a causative role in the pathogenesis of gestational diabetes or elevated serum Hsp70 levels are only consequences of the disease. PMID:25720752

  6. Relationship Between Circulating Heat Shock Protein 70 and Heart Failure after Acute Myocardial Infarction%血清热休克蛋白70与急性心肌梗死后心力衰竭的相关性

    Institute of Scientific and Technical Information of China (English)

    尹晓姝; 李林锋

    2011-01-01

    Circulating heat shock protein 70 is a highly conservative protein. Studies have found that atherosclerotic plaques express heat shock protein 70, and it has been found that heat shock protein 70 is closely related to coronary heart disease. Recently it has also been found that heat shock protein 70 is highly expressed in patients with heart failure after acute myocardial infarction. Therefore, heat shock protein 70 is expected to become a new diagnostic marker in patients with heart failure after acute myocardial infarction. This article reviews the role of heat shock protein 70 in patients with heart failure after acute myocardial infarction.%血清热休克蛋白70是一种高度保守的分子蛋白,其在应激时总被高度诱导.研究发现在动脉粥样硬化斑块中有热休克蛋白70的表达,且抗原递呈细胞也高度激活.热休克蛋白70与冠心病密切相关,且与冠状动脉病变程度有关,新近国外研究报道,热休克蛋白70在急性心肌梗死后心力衰竭患者中高度表达.现综述热休克蛋白70与急性心肌梗死后心力衰竭的相关性,热休克蛋白70有望成为急性心肌梗死后心力衰竭的新诊断标记物及判断病情的重要指标.

  7. Environmental temperature and stocking density effects on acute phase proteins, heat shock protein 70, circulating corticosterone and performance in broiler chickens

    Science.gov (United States)

    Najafi, Pardis; Zulkifli, Idrus; Amat Jajuli, Nurfarahin; Farjam, Abdoreza Soleimani; Ramiah, Suriya Kumari; Amir, Anna Aryani; O'Reily, Emily; Eckersall, David

    2015-11-01

    An experiment was conducted to determine the effect of different stocking densities on serum corticosterone (CORT), ovotransferrin (OVT), α1-acid glycoprotein (AGP) and ceruloplasmin (CP) concentrations, brain heat shock protein (HSP) 70 expression and performance in broiler chickens exposed to unheated and heated conditions. Day-old chicks were stocked at 0.100 m2/bird (low density (LD)) or 0.063 m2/bird (high density (HD)), in battery cages and housed in environmentally controlled rooms. From 21 to 35 days of age, birds from each stocking density group were exposed to either 24 or 32 °C. Growth performance was recorded during the heat treatment period, and blood and brain samples were collected to determine CORT, OVT, AGP, CP and HSP 70 levels on day 35. Heat treatment but not stocking density was detrimental to growth performance. There were significant temperature × density interactions for CORT, CP and OVT on day 35. Although HD elevated CORT, CP and OVT when compared to LD, the effects of the former were more obvious under heated condition. Both temperature and density had significant effect on AGP and HSP 70. In conclusion, irrespective of temperature, high stocking density was physiologically stressful to broiler chickens, as indicated by CORT, AGP, CP, OVT and HSP 70, but not detrimental to growth performance and survivability. As it was shown in the present study, AGP, CP and OVT could be useful biomarkers to determine the effect of overcrowding and high temperature on the welfare of broiler chickens.

  8. Early Response Roles for Prolactin Cortisol and Circulating and Cellular Levels of Heat Shock Proteins 72 and 90α in Severe Sepsis and SIRS

    Directory of Open Access Journals (Sweden)

    K. Vardas

    2014-01-01

    Full Text Available Objective. To evaluate the early heat shock protein (HSP and hormonal stress response of intensive care unit (ICU patients with severe sepsis/septic shock (SS or systemic inflammatory response syndrome (SIRS compared to healthy subjects (H. Methods. Patients with early (first 48 hrs SS (n=29 or SIRS (n=29 admitted to a university ICU and 16 H were enrolled in the study. Serum prolactin, cortisol, and plasma ACTH were determined using immunoassay analyzers. ELISA was used to evaluate extracellular HSPs (eHSP90α, eHSP72 and interleukins. Mean fluorescence intensity (MFI values for intracellular HSPs (iHSP72, iHSP90α were measured using 4-colour flow-cytometry. Results. Prolactin, cortisol, and eHSP90α levels were significantly increased in SS patients compared to SIRS and H (P<0.003. ACTH and eHSP72 were significantly higher in SS and SIRS compared to H (P<0.005. SS monocytes expressed lower iHSP72 MFI levels compared to H (P=0.03. Prolactin was related with SAPS III and APACHE II scores and cortisol with eHSP90α, IL-6, and lactate (P<0.05. In SS and SIRS eHSP90α was related with eHSP72, IL-6, and IL-10. Conclusion. Prolactin, apart from cortisol, may have a role in the acute stress response in severe sepsis. In this early-onset inflammatory process, cortisol relates to eHSP90α, monocytes suppress iHSP72, and plasma eHSP72 increases.

  9. Heat shock proteins in the kidney.

    Science.gov (United States)

    Sreedharan, Rajasree; Van Why, Scott K

    2016-10-01

    Heat shock proteins (Hsps) are essential to cell survival through their function as protein chaperones. The role they play in kidney health and disease is varied. Hsp induction may be either beneficial or detrimental to the kidney, depending on the specific Hsp, type of cell, and context. This review addresses the role of Hsps in the kidney, including during development, as osmoprotectants, and in various kidney disease models. Heat shock transcription factor, activated by a stress on renal cells, induces Hsp elaboration and separately regulates immune responses that can contribute to renal injury. Induced Hsps in the intracellular compartment are mostly beneficial in the kidney by stabilizing and restoring cell architecture and function through acting as protein chaperones. Intracellular Hsps also inhibit apoptosis and facilitate cell proliferation, preserving renal tubule viability after acute injury, but enhancing progression of cystic kidney disease and malignancy. Induced Hsps in the extracellular compartment, either circulating or located on outer cell membranes, are mainly detrimental through enhancing inflammation pathways to injury. Correctly harnessing these stress proteins promises the opportunity to alter the course of acute and chronic kidney disease. PMID:26913726

  10. Heat shock proteins and immunotherapy

    Institute of Scientific and Technical Information of China (English)

    XinZHAO; XueMeiXU; GuoxingSONG

    2005-01-01

    Being one of the most abundant intracellular proteins,heat shock proteins(HSPs) have many housekeeping functions which are crucial for the survival of organisms.In addition,some HSPs are new immunoactive molecules which play important roles in both adaptive and innate immunity.They could activate CD8+ and CD4+ lymphocytes,induce innate immune response including natural killer(NK) cell activation and cytokine secretion,and induce maturation of dendritic cells(DCs).These characteristics have been used for immunotherapy of various types of cancers and infectious disenses.This review focuses on the main HSP families——HSP70 and 90 families.The mechanism of HSPs’ function in eliciting immune response are elucidated and various forms of HSPs used in immunotherapy are discussed in details.At the end of this review,authors summarize clinical trials related to HSPs and evaluate their clinical efficacy.

  11. Heat shock proteins in multiple myeloma

    OpenAIRE

    Zhang, Lei; Jacqueline H L Fok; Davies, Faith E.

    2014-01-01

    Heat shock proteins are molecular chaperones with a central role in protein folding and cellular protein homeostasis. They also play major roles in the development of cancer and in recent years have emerged as promising therapeutic targets. In this review, we discuss the known molecular mechanisms of various heat shock protein families and their involvement in cancer and in particular, multiple myeloma. In addition, we address the current progress and challenges in pharmacologically targeting...

  12. Boiling Heat Transfer in Circulating Fluidized Beds

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A model is proposed to predict boiling heat transfer coefficient in a three-phase circulating fluidized bed (CFB), which is a new type of evaporation boiling means for enhancing heat transfer and preventing fouling. To verify the model, experiments are conducted in a stainless steel column with 39mm ID and 2.0m height, in which the heat transfer coefficient is measured for different superficial velocities, steam pressures, particle concentrations and materials of particle. As the steam pressure and particle concentrations increase, the heat transfer coefficient in the bed increases. The heat transfer coefficient increases with the liquid velocity but it exhibits a local minimum. The heat transfer coefficient is correlated with cluster renewed model and two-mechanism method. The prediction of the model is in good agreement with experimental data.

  13. Boiling Heat Transfer in Circulating Fluidized Beds

    Institute of Scientific and Technical Information of China (English)

    张利斌; 李修伦

    2001-01-01

    A model is proposed to predict boiling heat transfer coefficient in a three-phase circulating fluidized bed (CFB), which is a new type of evaporation boiling means for enhancing heat transfer and preventing fouling. To verify the model, experiments are conducted in a stainless steel column with 39 mm ID and 2.0 m height, in which the heat transfer coefficient is measured for different superficial velocities, steam pressures, particle concentrations and materials of particle. As the steam pressure and particle concentrations increase, the heat transfer coefficient in the bed increases. The heat transfer coefficient increases with the liquid velocity but it exhibits a local minimum.The heat transfer coefficient is correlated with cluster renewed model and two-mechanism method. The prediction of the model is in good agreement with experimental data.

  14. Biophoton emission induced by heat shock.

    Directory of Open Access Journals (Sweden)

    Katsuhiro Kobayashi

    Full Text Available Ultraweak biophoton emission originates from the generation of reactive oxygen species (ROS that are produced in mitochondria as by-products of cellular respiration. In healthy cells, the concentration of ROS is minimized by a system of biological antioxidants. However, heat shock changes the equilibrium between oxidative stress and antioxidant activity, that is, a rapid rise in temperature induces biophoton emission from ROS. Although the rate and intensity of biophoton emission was observed to increase in response to elevated temperatures, pretreatment at lower high temperatures inhibited photon emission at higher temperatures. Biophoton measurements are useful for observing and evaluating heat shock.

  15. Heating Cooling Flows with Weak Shock Waves

    OpenAIRE

    Mathews, W. G.; Faltenbacher, A.; Brighenti, F

    2005-01-01

    The discovery of extended, approximately spherical weak shock waves in the hot intercluster gas in Perseus and Virgo has precipitated the notion that these waves may be the primary heating process that explains why so little gas cools to low temperatures. This type of heating has received additional support from recent gasdynamical models. We show here that outward propagating, dissipating waves deposit most of their energy near the center of the cluster atmosphere. Consequently, if the gas i...

  16. Heat shock protein expression enhances heat tolerance of reptile embryos

    OpenAIRE

    Gao, Jing; Zhang, Wen; Dang, Wei; Mou, Yi; Gao, Yuan; Sun, Bao-Jun; Du, Wei-Guo

    2014-01-01

    The role of heat shock proteins (HSPs) in heat tolerance has been demonstrated in cultured cells and animal tissues, but rarely in whole organisms because of methodological difficulties associated with gene manipulation. By comparing HSP70 expression patterns among representative species of reptiles and birds, and by determining the effect of HSP70 overexpression on embryonic development and hatchling traits, we have identified the role of HSP70 in the heat tolerance of amniote embryos. Consi...

  17. Emissive spectra of shock-heated argon

    International Nuclear Information System (INIS)

    To study the radiant properties of argon under weak shock compression, an aluminum target filled with gaseous argon at ambient states was impacted by a tungsten alloy projectile which was launched from a two-stage light gun to 2.00 km/s. The radiant signals of single shock-compressed argon were recorded by a six-channel pyrometer and oscilloscopes, which varied with time linearly for the five channels from 405 nm to 700 nm and exponentially for the channel 800 nm, and the corresponding velocity of shock wave was determined to be 4.10 ± 0.09 km/s. By the present experiment, it has been shown that the absorbability of the shock-heated argon is low for visual light and the optical depths of argon gas turn from thin to thick as wavelengths gradually increase. The time-resolved spectra in the rising-front of the radiant signal in the re-shocked argon were recorded by means of an OMA, and strong emissive spectrum bands near 450 nm light-wave length but no linear spectrum were found. The emissive spectrum properties of shock-compression argon were qualitatively explained by the state parameters and ionization degree

  18. Association of heat shock proteins, heat shock factors and male infertility

    Institute of Scientific and Technical Information of China (English)

    Zi-Liang Ji; Yong-Gang Duan; Li-Sha Mou; Jean-Pierre Allam; Gerhard Haidl; Zhi-Ming Cai

    2012-01-01

    It has been well established that heat shock proteins(HSP) and heat shock factors(HSF) are involved in wide varieties of physiological regulation process and signal pathway.Numerous members of heat shock family exhibit a cell-type-specific expression pattern during spermatogenesis and play crucial roles in germ cell development.This led to the emerging studies to reveal the association between heat shock family and male infertility.Aberrant expressions ofHSP/HSFs observed in sterile men and animal models indicate the two opposite effects, both protective and harmful, of heat shock family on male fertility.Moreover,HSP/HSFs are also involved in the two major causes of male infertility.It seems that different behaviors of HSP/HSFs patients with varicocele andChlamydia trachomatis infection lead to distinct outcomes of male fertility.In addition, emerging evidence has demonstrated that the altered expression ofHSP/HSFs may be responsible for the abnormal germ cell apoptosis and subsequently results in impaired spermatogenesis.Therefore, heat shock family may play an important role in the quality-control of germ cells during spermatogenesis, raising the prospect of their utility for novel treatment targets in male infertility.

  19. Signal Transduction Pathways Leading to Heat Shock Transcription

    OpenAIRE

    Calderwood, S K; Xie, Y.; X. Wang; Khaleque, M. A.; Chou, S. D.; Murshid, A.; Prince, T.; Zhang, Y.

    2010-01-01

    Heat shock proteins (HSP) are essential for intracellular protein folding during stress and protect cells from denaturation and aggregation cascades that can lead to cell death. HSP genes are regulated at the transcriptional level by heat shock transcription factor 1 (HSF1) that is activated by stress and binds to heat shock elements in HSP genes. The activation of HSF1 during heat shock involves conversion from an inert monomer to a DNA binding trimer through a series of intramolecular foldi...

  20. Heat shock protection against cold stress of Drosophila melanogaster.

    OpenAIRE

    Burton, V; Mitchell, H K; Young, P.; Petersen, N S

    1988-01-01

    Heat shock protein synthesis can be induced during recovery from cold treatment of Drosophila melanogaster larvae. Survival of larvae after a cold treatment is dramatically improved by a mild heat shock just before the cold shock. The conditions which induce tolerance to cold are similar to those which confer tolerance to heat.

  1. Heat Shock Proteins (HSPs: a Review

    Directory of Open Access Journals (Sweden)

    Jana Tkáčová

    2012-05-01

    Full Text Available Heat shock proteins (HSPs are a large class of proteins that have been conserved throughout evolution and exist by prokaryote and eukaryote organisms. Heat shock proteins play an important role in protein homeostasis. They can found in all major cellular compartments. The HSP90 family are important in the formation of the steroid receptor complex. The HSP70 family is necessary for protein synthesis, translocation, and folding. HSP60 family is important in protein stability. Many factors, e. g. heavy metals and organic toxic substances, elevated temperature in all cells responsive to the formation of proteins called stress proteins. This is happening with a simple bacterium and with complex of neurons too. The concentration of HSPs in muscle in young and adults birds is increasing rapidly in the cellular stress. Increasing HSPs leads to significant changes in gene expression, which lead to reconstruction of skeletal muscle.

  2. Heat Shock Protein 90 in Alzheimer's Disease

    OpenAIRE

    Jiang-Rong Ou; Meng-Shan Tan; An-Mu Xie; Jin-Tai Yu; Lan Tan

    2014-01-01

    Alzheimer’s disease (AD) is the first most common neurodegenerative disease. Despite a large amount of research, the pathogenetic mechanism of AD has not yet been clarified. The two hallmarks of the pathology of AD are the extracellular senile plaques (SPs) of aggregated amyloid-beta (Aβ) peptide and the accumulation of the intracellular microtubule-associated protein tau into fibrillar aggregates. Heat shock proteins (HSPs) play a key role in preventing protein misfolding and aggregation, an...

  3. Heat Shock Proteins in the Human Eye

    OpenAIRE

    Lærke Urbak; Henrik Vorum

    2010-01-01

    Heat shock proteins (Hsps) are believed to primarily protect and maintain cell viability under stressful conditions such as those occurring during thermal and oxidative challenges chiefly by refolding and stabilizing proteins. Hsps are found throughout the various tissues of the eye where they are thought to confer protection from disease states such as cataract, glaucoma, and cancer. This minireview summarizes the placement, properties, and roles of Hsps in the eye and aims to provide a bett...

  4. Biophoton Emission Induced by Heat Shock

    OpenAIRE

    Kobayashi, Katsuhiro; Okabe, Hirotaka; Kawano, Shinya; Hidaka, Yoshiki; Hara, Kazuhiro

    2014-01-01

    Ultraweak biophoton emission originates from the generation of reactive oxygen species (ROS) that are produced in mitochondria as by-products of cellular respiration. In healthy cells, the concentration of ROS is minimized by a system of biological antioxidants. However, heat shock changes the equilibrium between oxidative stress and antioxidant activity, that is, a rapid rise in temperature induces biophoton emission from ROS. Although the rate and intensity of biophoton emission was observe...

  5. Heat shock protein 90 in neurodegenerative diseases

    Directory of Open Access Journals (Sweden)

    Rodina Anna

    2010-06-01

    Full Text Available Abstract Hsp90 is a molecular chaperone with important roles in regulating pathogenic transformation. In addition to its well-characterized functions in malignancy, recent evidence from several laboratories suggests a role for Hsp90 in maintaining the functional stability of neuronal proteins of aberrant capacity, whether mutated or over-activated, allowing and sustaining the accumulation of toxic aggregates. In addition, Hsp90 regulates the activity of the transcription factor heat shock factor-1 (HSF-1, the master regulator of the heat shock response, mechanism that cells use for protection when exposed to conditions of stress. These biological functions therefore propose Hsp90 inhibition as a dual therapeutic modality in neurodegenerative diseases. First, by suppressing aberrant neuronal activity, Hsp90 inhibitors may ameliorate protein aggregation and its associated toxicity. Second, by activation of HSF-1 and the subsequent induction of heat shock proteins, such as Hsp70, Hsp90 inhibitors may redirect neuronal aggregate formation, and protect against protein toxicity. This mini-review will summarize our current knowledge on Hsp90 in neurodegeneration and will focus on the potential beneficial application of Hsp90 inhibitors in neurodegenerative diseases.

  6. Heat-shock proteins and development

    International Nuclear Information System (INIS)

    Heat-shock proteins (HSP) and their genes are generally activated in response to general environmental stress as well as temperature shock. Recent studies have shown that many of the stress protein genes are activated in the absence of stress, with some HSPs appearing at specific stages of development, in specific tissues, and even during the normal cell growth cycle. This review article, with over 100 references, focuses on the appearance of the HSPs and activation of their genes during normal development of an organism and during the life cycle of various microorganisms that experience widely different temperatures in their environment. Some general properties of HSPs and their genes are described in Escherichia coli, Drosophila, tumor cells, and bone marrow cells. A discussion of the role of HSPs during viral infection is also included. The evidence presented in this review suggests that heat-shock gene expression is regulated by multiple control elements responding to varying events in the cell, the organism, and the surrounding environment. In the eukaryote, HSP genes have evolved to form families consisting of isoproteins with distinct but related functions

  7. Heat Shock Proteins in the Human Eye

    Directory of Open Access Journals (Sweden)

    Lærke Urbak

    2010-01-01

    Full Text Available Heat shock proteins (Hsps are believed to primarily protect and maintain cell viability under stressful conditions such as those occurring during thermal and oxidative challenges chiefly by refolding and stabilizing proteins. Hsps are found throughout the various tissues of the eye where they are thought to confer protection from disease states such as cataract, glaucoma, and cancer. This minireview summarizes the placement, properties, and roles of Hsps in the eye and aims to provide a better comprehension of their function and involvement in ocular disease pathogenesis.

  8. Impact of heat shock on heat shock proteins expression,biological and commercial traits of Bombyx mori

    Institute of Scientific and Technical Information of China (English)

    VASUDHA B. CHAVADI; APARNA H. S OSALEGOWDA; MANJUNATHA H.B OREGOWDA

    2006-01-01

    We report the thermotolerance of new bivoltine silkworm, Bombyx mori strains NB4D2, KSO1, NP2, CSR2 and CSR4 and differential expression of heat shock proteins at different instars. Different instars of silkworm larva were subjected to heat shock at 35℃,40℃ and 45℃ for 2 hours followed by 2 hours recovery. Heat shock proteins were analyzed by SDS-PAGE. The impact of heat shock on commercial traits of cocoons was analyzed by following different strategies in terms of acquired thermotolerance over control. Comparatively NP2 exhibited better survivability than other strains. Resistance to heat shock was increased as larval development proceeds in the order of first instar > second instar > third instar > fourth instar > fifth instar in all silkworm strains. Expression of heat shock proteins varies in different instars. 90 kDa in the first, second and third instars, 84 kDa in the fourth instar and 84, 62, 60, 47 and 33 kDa heat shock proteins in fifth instar was observed in response to heat shock. Relative influence of heat shock on commercial traits that correspond to different stages was significant in all strains. In NB4D2, cocoon and shell weight significantly increased to 17.52% and 19.44% over control respectively. Heat shock proteins as molecular markers for evaluation and evolution of thermotolerant silkworm strains for tropics was discussed.

  9. Barcoding heat shock proteins to human diseases : looking beyond the heat shock response

    NARCIS (Netherlands)

    Kakkar, Vaishali; Meister-Broekema, Melanie; Minoia, Melania; Carra, Serena; Kampinga, Harm H.

    2014-01-01

    There are numerous human diseases that are associated with protein misfolding and the formation of toxic protein aggregates. Activating the heat shock response (HSR) - and thus generally restoring the disturbed protein homeostasis associated with such diseases - has often been suggested as a therape

  10. Heat shock proteins: Molecules with assorted functions

    Institute of Scientific and Technical Information of China (English)

    Surajit SARKAR; M. Dhruba SINGH; Renu YADAV; K. P. ARUNKUMAR; Geoffrey W. PITTMAN

    2011-01-01

    Heat shock proteins (Hsps) or molecular chaperones,are highly conserved protein families present in all studied organisms.Following cellular stress,the intracellular concentration of Hsps generally increases several folds.Hsps undergo ATP-driven conformational changes to stabilize unfolded proteins or unfold them for transiocation across membranes or mark them for degradation.They are broadly classified in several families according to their molecular weights and functional properties.Extensive studies during the past few decades suggest that Hsps play a vital role in both normal cellular homeostasis and stress response.Hsps have been reported to interact with numerous substrates and are involved in many biological functions such as cellular communication,immune response,protein transport,apoptosis,cell cycle regulation,gametogenesis and aging.The present review attempts to provide a brief overview of various Hsps and summarizes their involvement in diverse biological activities.

  11. Riboflavin protects mice against liposaccharide-induced shock through expression of heat shock protein 25

    Science.gov (United States)

    Riboflavin (vitamin B2) is a water-soluble vitamin essential for normal cellular functions, growth and development. The study was aimed at investigating the effects of vitamin B2 on the survival rate, and expressions of tissue heat shock protein 25 (HSP25) and heat shock factor 1 (HSF1) in mice und...

  12. Some Aspects Concerning Convective Circulation Mode of Heat Transfer in Furnace to Wood Heat Treatment

    OpenAIRE

    Nadia Potoceanu

    2007-01-01

    The paper presented the most aspects of convective circulate mode of heat transfer : heat transfer through the boundary layer formed at the surface of the heat generator; heat transfer in the heat carrier and heat transfer through the boundary layer formed at the heated surface

  13. Structure of fast shocks in the presence of heat conduction

    Science.gov (United States)

    Tsai, C. L.; Chen, H. H.; Wu, B. H.; Lee, L. C.

    2007-12-01

    There are three types of magnetohydrodynamic (MHD) shocks: the fast shock, intermediate shock, and slow shock. The structure of slow shocks and intermediate shocks in the presence of heat conduction has been studied earlier [C. L. Tsai, R. H. Tsai, B. H. Wu, and L. C. Lee, Phys. Plasmas 9, 1185 (2002); C. L. Tsai, B. H. Wu, and L. C. Lee, Phys. Plasmas 12, 82501 (2005)]. Based on one-dimensional MHD numerical simulations with a heat conduction term, the evolution and structure of fast shocks are studied. The fast shock will form a foreshock in the presence of heat conduction. The foreshock is formed due to the heat flow from downstream to upstream and located in the immediate upstream of the main shock. In the steady state, the value of diffusion velocity Vd in the foreshock is found to nearly equal the upstream convection velocity in the fast shock frame. It is found that the density jump across the main shock in high Mach number case can be much larger than 4 in the early simulation time. However the density jump will gradually evolve to a value smaller than 4 at steady state. By using the modified Rankine-Hugoniot relations with heat flux, the density jump across the fast shock is examined for various upstream parameters. The results show that the calculated density jump with heat flux is very close to the simulation value and the density jump can far exceed the maximum value of 4 without heat conduction. The structure of foreshock and main shock is also studied under different plasma parameters, such as the heat conductivity K0, the ratio of upstream plasma pressure to magnetic pressure β1, Alfvén Mach number MA1, and the angle θ1 between shock normal and magnetic field. It is found that as the upstream shock parameters K0, β1, and MA1 increase or θ1 decreases, the width of foreshock Ld increases. The present results can be applied to fast shocks in the solar corona, solar wind, and magnetosphere, in which the heat conduction effects are important.

  14. Z-Pinch Experiments with Shock Heating

    International Nuclear Information System (INIS)

    Two z-pinch experiments are reported. The first is a linear pinch whose results have encouraged the authors to construct the second, a toroidal system. In these experiments, a shock produces plasma temperatures higher than have been produced by ohmic heating. Theory predicts that with the higher temperatures the drift instabilities can be avoided resulting in a reduction of the anomalous field diffusion. MHD calculations predict stable configurations for some diffuse z-pinch profiles with a reversed Bz field external to the pinch, and a conducting wall. The linear z-pinch experiment has a length of 30 cm, a diameter of 10 cm and the discharge current is ∼ 200 kA. Initial values of Bθ of 80 kG/μs produce the shock. A magnetic energy storage system generates the necessary high voltage ≲ 80 kV. Probes measure the initial shock structure and plasma pressure profiles. Together with holographic interferometric density measurements, they yield temperatures (Ti + Te) of 750 eV and peak densities of 1016/cm3 with initial pressure of 30 mTorr of deuterium. The limit of sensitivity of the holographic technique prevents data from being obtained at a lower filling pressure where higher plasma temperatures should be obtained. The plasma column exhibits gross stability for times of the order of the time scale of the experiment (∼8 μs). One-dimensional MHD calculations are performed both with classical and anomalous resistivities. The results, including density and magnetic field profiles, are compared with experiment. The toroidal experiment has a major diameter of 76 cm and a minor diameter of 10.25 cm. A 500 kj inductive energy storage system develops a peak voltage of ≤ 320 kV around the circumference of the torus with maximum plasma currents of about 200 kA. Iron cores couple the primary to the plasma secondary circuit. Toroidal equilibrium calculations have been made for diffuse plasma profiles. A numerical stability analysis of these toroidal equilibria, free

  15. Diminished heat shock response in the aged myocardium

    OpenAIRE

    Locke, Marius; Tanguay, Robert M.

    1996-01-01

    Induction of heat shock proteins (Hsps), Hsp72 in particular, has been associated with myocardial protection. Since a decreased Hsp response has been reported to occur with aging, it was of interest to determine if hearts from aged animals also demonstrate an altered heat shock response and subsequent myocardial protection. Adult (6 months old) and aged (22 months old) Fischer 344 rats were heat stressed by raising their rectal temperatures to 41 °C for 10 min. At selected times following hea...

  16. Heat shock protein 90: the cancer chaperone

    Indian Academy of Sciences (India)

    Len Neckers

    2007-04-01

    Heat shock protein 90 (Hsp90) is a molecular chaperone required for the stability and function of a number of conditionally activated and/or expressed signalling proteins, as well as multiple mutated, chimeric, and/or over-expressed signalling proteins, that promote cancer cell growth and/or survival. Hsp90 inhibitors are unique in that, although they are directed towards a specific molecular target, they simultaneously inhibit multiple cellular signalling pathways. By inhibiting nodal points in multiple overlapping survival pathways utilized by cancer cells, combination of an Hsp90 inhibitor with standard chemotherapeutic agents may dramatically increase the in vivo efficacy of the standard agent. Hsp90 inhibitors may circumvent the characteristic genetic plasticity that has allowed cancer cells to eventually evade the toxic effects of most molecularly targeted agents. The mechanism-based use of Hsp90 inhibitors, both alone and in combination with other drugs, should be effective toward multiple forms of cancer. Further, because Hsp90 inhibitors also induce Hsf-1-dependent expression of Hsp70, and because certain mutated Hsp90 client proteins are neurotoxic, these drugs display ameliorative properties in several neurodegenerative disease models, suggesting a novel role for Hsp90 inhibitors in treating multiple pathologies involving neurodegeneration.

  17. Chromosome Behavior of Heat Shock Induced Triploid in Fenneropenaeus Chinensis

    Institute of Scientific and Technical Information of China (English)

    张晓军; 李富花; 相建海

    2003-01-01

    Triploidy was induced in Chinese shrimp Fenneropenaeus chinensis by 30 + 0.5 ℃ heat shock treatment (initiated at 20 min after fertilization) for 10 min to inhibit the release of PB2 at 18.0℃ . The highest triploid rate obtained was 84.5% in nauplius stage. The effect of heat shock treatment on meiosis and cleavage of eggs was investigated in this work aimed to establish ef ficient procedures for triploid induction and to gain understanding of the mechanism of triploid production. Three pronuclei that could be observed in the treated eggs under fluorescence microscope developed into triploid embryos. Some abnormal chromosome behavior was observed in heat shocked eggs.

  18. Heat shock response of Trichinella spiralis and T. pseudospiralis

    OpenAIRE

    Ko, RCC; Fan, L.

    1996-01-01

    Heat shock proteins (HSPs) were documented for the first time in both somatic extracts and excretory/secretory (ES) products of the infective-stage larvae of Trichinella spiralis and T. pseudospiralis. Larvae recovered from muscles of infected mice were heat shocked at 37, 40, 43 and 45 degrees C in RPMI 1640 medium containing L(-)[35S]methionine. Somatic extracts and ES products of heat-shocked worms were then analysed by SDS-PAGE, autoradiography and laser densitometry. Prominent bands of H...

  19. Plasma Heating by Strong Shock Waves

    International Nuclear Information System (INIS)

    About 104 cm3 of plasma at T ∼ 1 keV, n ∼ 1 x 1016 cm-3, were created by fast collisional shock waves in an electromagnetic shock tube. The speed of these shock waves ranges up to 4 x 108cm/s, corresponding to an acoustic Mach number of 3200 and an Alfvén-Mach number of 15. These experiments were performed in a 3-metre-long coaxial electromagnetic shock tube, employing a 60-μf, 120-kV capacitor bank which produces a 2 x 106 -A drive current. The pre-shock hydrogen initial state was T = 239°K, p = 50 mTorr. The preshock 7.2- kG transverse magnetic field was used to keep the shock thickness small and retard plasma interaction with the walls. Separation of the transverse ionizing shock wave from the driving current was clearly observed, and a hot dense plasma was created behind the shock wave. The state of this plasma was determined by laser interferometer measurements, X-ray bremsstrahlung spectra, a particle energy analyser, probes, and neutron detectors. The shock-created plasma contained an azimuthal magnetic field of B ∼ 22 kG. When deuterium gas was used, neutrons were detected and we estimate a yield of about 5 x 105 neutrons per shot. The transverse ionizing shock thickness, as determined by magnetic field structure, was found to be from 5 to 80 cm thick, the larger values occurring at higher shock speeds. These thicknesses are found to agree with the calculations made from a two-fluid MHD computer code employing classical plasma transport properties. The calculated structure of these collisional shock waves predict that the ion temperature substantially exceeds the electron temperature. (author)

  20. Heat shock transcription factors regulate heat induced cell death in a rat histiocytoma

    Indian Academy of Sciences (India)

    Kolla V, P Rasad; Aftab Taiyab; D Jyothi; Usha K Srinivas; Amere S Sreedhar

    2007-04-01

    Heat shock response is associated with the synthesis of heat shock proteins (Hsps) which is strictly regulated by different members of heat shock transcription factors (HSFs). We previously reported that a rat histiocytoma, BC-8 failed to synthesize Hsps when subjected to typical heat shock conditions (42°C, 60 min). The lack of Hsp synthesis in these cells was due to a failure in HSF1 DNA binding activity. In the present study we report that BC-8 tumor cells when subjected to heat shock at higher temperature (43°C, 60 min) or incubation for longer time at 42°C, exhibited necrosis characteristics; however, under mild heat shock (42°C, 30 min) conditions cells showed activation of autophagy. Mild heat shock treatment induced proteolysis of HSF1, and under similar conditions we observed an increase in HSF2 expression followed by its enhanced DNA binding activity. Inhibiting HSF1 proteolysis by reversible proteasome inhibition failed to inhibit heat shock induced autophagy. Compromising HSF2 expression but not HSF1 resulted in the inhibition of autophagy, suggesting HSF2 dependent activation of autophagy. We are reporting for the first time that HSF2 is heat inducible and functions in heat shock induced autophagic cell death in BC-8 tumor cells.

  1. Modification of tooth development by heat shock protein 60

    OpenAIRE

    Papp Tamás; Polyák Angéla; Papp Krisztina; Mészár Zoltán (1977-) (állatorvos); Zákány Róza (1963-) (anatómus-, kötőszövetbiológus); Mészár-Katona Éva (1986-) (Ph.D hallgató); Terdik Tünde (1969-) (analitikus); Chang, Hwa Ham; Felszeghy Szabolcs Béla (1972-) (fogorvos, anatómus, kötőszövetbiológus)

    2016-01-01

    Although several heat shock proteins have been investigated in relation to tooth development, no available information is available about the spatial and temporal expression pattern of heat shock protein 60 (Hsp 60). To characterize Hsp 60 expression in the structures of the developing tooth germ, we used Western blotting, immunohistochemistry and in situ hybridization. Hsp 60 was present in high amounts in the inner and outer enamel epithelia, enamel knot (EK) and stratum intermedium (SI). H...

  2. Heat Shock Proteins in Tendinopathy: Novel Molecular Regulators

    OpenAIRE

    Neal L. Millar; George A. C. Murrell

    2012-01-01

    Tendon disorders—tendinopathies—are the primary reason for musculoskeletal consultation in primary care and account for up to 30% of rheumatological consultations. Whilst the molecular pathophysiology of tendinopathy remains difficult to interpret the disease process involving repetitive stress, and cellular load provides important mechanistic insight into the area of heat shock proteins which spans many disease processes in the autoimmune community. Heat shock proteins, also called damage-as...

  3. Metabolite changes associated with heat shocked avian fibroblast mitochondira

    OpenAIRE

    Schlesinger, Milton J.; Ryan, Christine; Chi, Maggie M.-Y.; Carter, Joyce G.; Pusateri, Mary Ellen; Lowry, Oliver H.

    1997-01-01

    A previous report from our laboratory (Collier et al 1993) showed that the elongated tubules of mitochondria in the cytoplasm of cultured chicken embryo fibroblasts collpased to irregularly shaped structures surrounding the nuclear membrane after a 1 h heat shock treatment. The normal mitochondiral morphology reappeared upon removal of then thermal stress. We have now determined that several changes occured in mitochondrial-related metabolites under these same heat shock and recovery conditio...

  4. Impact of geothermal heating on the global ocean circulation

    OpenAIRE

    Adcroft, A.; Scott, J; Marotzke, J.

    2001-01-01

    The response of a global circulation model to a uniform geothermal heat flux of 50 mW m(-2) through the sea floor is examined. If the geothermal heat input were transported upward purely by diffusion, the deep ocean would warm by 1.2 degreesC. However, geothermal heating induces a substantial change in the deep circulation which is larger than previously assumed and subsequently the warming of the deep ocean is only a quarter of that suggested by the diffusive limit. The numerical ocean model...

  5. Oil Circulation Effects on Evaporation Heat Transfer in Brazed Plate Heat Exchanger using R134A

    OpenAIRE

    Jang, Jaekyoo; Chang, Youngsoo; Kang, Byungha

    2012-01-01

    Experimental study was performed for oil circulation effects on evaporation heat transfer in the brazed type plate heat exchangers using R134A. In this study, distribution device was installed to ensure uniform flow distribution in the refrigerant flow passage, which enhances heat transfer performance of plate type heat exchanger. Tests were conducted for three evaporation temperature; 33℃, 37℃, and 41℃ and several oil circulation conditions. The nominal conditions of refrigerant are as follo...

  6. Heat shock protein and heat shock factor 1 expression and localization in vaccinia virus infected human monocyte derived macrophages

    Directory of Open Access Journals (Sweden)

    Dziedzic Jakub

    2005-10-01

    Full Text Available Abstract Background Viruses remain one of the inducers of the stress response in the infected cells. Heat shock response induced by vaccinia virus (VV infection was studied in vitro in human blood monocyte derived macrophages (MDMs as blood cells usually constitute the primary site of the infection. Methods Human blood monocytes were cultured for 12 – 14 days. The transcripts of heat shock factor 1 (HSF1, heat shock protein 70 (HSP70, heat shock protein 90 (HSP90 and two viral genes (E3L and F17R were assayed by reverse transcriptase-polymerase chain reaction (RT-PCR, and the corresponding proteins measured by Western blot. Heat shock factor 1 DNA binding activities were estimated by electrophoretic mobility shift assay (EMSA and its subcellular localization analyzed by immunocytofluorescence. Results It appeared that infection with vaccinia virus leads to activation of the heat shock factor 1. Activation of HSF1 causes increased synthesis of an inducible form of the HSP70 both at the mRNA and the protein level. Although HSP90 mRNA was enhanced in vaccinia virus infected cells, the HSP90 protein content remained unchanged. At the time of maximum vaccinia virus gene expression, an inhibitory effect of the infection on the heat shock protein and the heat shock factor 1 was most pronounced. Moreover, at the early phase of the infection translocation of HSP70 and HSP90 from the cytoplasm to the nucleus of the infected cells was observed. Conclusion Preferential nuclear accumulation of HSP70, the major stress-inducible chaperone protein, suggests that VV employs this particular mechanism of cytoprotection to protect the infected cell rather than to help viral replication. The results taken together with our previuos data on monocytes or MDMs infected with VV or S. aureus strongly argue that VV employs multiple cellular antiapoptotic/cytoprotective mechanisms to prolong viability and proinflammatory activity of the cells of monocytic

  7. Ion heating and energy redistribution across supercritical perpendicular shocks: Application to planetary and interplanetary shocks

    Science.gov (United States)

    Yang, Z.; Liu, Y. D.; Richardson, J. D.; Parks, G. K.

    2013-12-01

    We investigate how the ion dissipative process across supercritical perpendicular shocks depends on the shock front micro-structures. At a collisionless plasma shock, the dissipation and micro-structure of the shock font are dominated by wave-particle interactions. Comparison of the ion thermalization at different kinds of shocks, e.g., planetary and interplanetary shocks, can quantify how much interaction is occurring at the shock boundary. Investigation of this problem for diverse solar wind (SW) conditions will yield important information on the dependences of the ion thermalization and energy redistribution on plasma parameters. With the aid of a successful automatic separation method [Yang et al., 2009], the incident ions at the shock can be divided into two parts: reflected (R) ions and directly transmitted (DT) ions. Corresponding heating efficiency of each population of ions at the shock can be calculated respectively. Wilkinson & Schwartz [1990] have theorized that the amount of reflected ions at perpendicular shocks depends on plasma parameters. Based on the Rankine-Hugoniot (R-H) conservation laws, they found that the fraction reflected is strongly dependent on the magnitude of the ratio of specific heat capacities γ chosen in the R-H relations. The main goal of this work is to investigate how the plasma parameters, e.g. the particle velocity distribution, the plasma beta value, seed populations, etc. (from a particle dynamic point of view), control the amount of reflected ions by using one-dimensional (1-D) full-particle-cell simulations. The simulation results may help to explain the ion heating efficiency and energy redistribution at shocks observed by Cluster, Wind, Voyager, etc.

  8. A Flashing Simulator for Natural Circulation Heated Systems

    International Nuclear Information System (INIS)

    Many of the next generation of nuclear reactors rely on natural circulation, either as the primary mode of heat removal or as a passive safety mechanism. Flashing-induced instabilities are of concern during startup of natural-circulation loops and small-scale natural-circulation light water reactors. (Flashing refers to the beginning of (adiabatic) boiling in the unheated riser when there is no boiling upstream.) A simulator with significantly enhanced modeling and simulation capabilities is being developed to analyze flashing and flashing-induced instabilities. The model allows an arbitrary number of nodes in both the heated section (allowing axially varying heat flux) and in the unheated riser section. Preliminary simulations using the model show that it can capture the location of flashing in the experiments conducted on the Dodewaard reactor very well

  9. Identifying gene regulatory modules of heat shock response in yeast

    Directory of Open Access Journals (Sweden)

    Li Wen-Hsiung

    2008-09-01

    Full Text Available Abstract Background A gene regulatory module (GRM is a set of genes that is regulated by the same set of transcription factors (TFs. By organizing the genome into GRMs, a living cell can coordinate the activities of many genes in response to various internal and external stimuli. Therefore, identifying GRMs is helpful for understanding gene regulation. Results Integrating transcription factor binding site (TFBS, mutant, ChIP-chip, and heat shock time series gene expression data, we develop a method, called Heat-Inducible Module Identification Algorithm (HIMIA, for reconstructing GRMs of yeast heat shock response. Unlike previous module inference tools which are static statistics-based methods, HIMIA is a dynamic system model-based method that utilizes the dynamic nature of time series gene expression data. HIMIA identifies 29 GRMs, which in total contain 182 heat-inducible genes regulated by 12 heat-responsive TFs. Using various types of published data, we validate the biological relevance of the identified GRMs. Our analysis suggests that different combinations of a fairly small number of heat-responsive TFs regulate a large number of genes involved in heat shock response and that there may exist crosstalk between heat shock response and other cellular processes. Using HIMIA, we identify 68 uncharacterized genes that may be involved in heat shock response and we also identify their plausible heat-responsive regulators. Furthermore, HIMIA is capable of assigning the regulatory roles of the TFs that regulate GRMs and Cst6, Hsf1, Msn2, Msn4, and Yap1 are found to be activators of several GRMs. In addition, HIMIA refines two clusters of genes involved in heat shock response and provides a better understanding of how the complex expression program of heat shock response is regulated. Finally, we show that HIMIA outperforms four current module inference tools (GRAM, MOFA, ReMoDisvovery, and SAMBA, and we conduct two randomization tests to show that

  10. Heat shock response in photosynthetic organisms: membrane and lipid connections.

    NARCIS (Netherlands)

    I. Horvath; A. Glatz; H. Nakamoto; M.L. Mishkind; T. Munnik; Y. Saidi; P. Goloubinoff; J.L. Harwood; L. Vigh

    2012-01-01

    The ability of photosynthetic organisms to adapt to increases in environmental temperatures is becoming more important with climate change. Heat stress is known to induce heat-shock proteins (HSPs) many of which act as chaperones. Traditionally, it has been thought that protein denaturation acts as

  11. The impact of oceanic heat transport on the atmospheric circulation

    CERN Document Server

    Knietzsch, Marc-Andre; Lunkeit, Frank

    2014-01-01

    A general circulation model of intermediate complexity with an idealized earthlike aquaplanet setup is used to study the impact of changes in the oceanic heat transport on the global atmospheric circulation. Focus is put on the Lorenz energy cycle and the atmospheric mean meridional circulation. The latter is analysed by means of the Kuo-Eliassen equation. The atmospheric heat transport compensates the imposed oceanic heat transport changes to a large extent in conjunction with significant modification of the general circulation. Up to a maximum about 3PW, an increase of the oceanic heat transport leads to an increase of the global mean near surface temperature and a decrease of its equator-to-pole gradient. For larger transports, the gradient is reduced further but the global mean remains approximately constant. This is linked to a cooling and a reversal of the temperature gradient in the tropics. A larger oceanic heat transport leads to a reduction of all reservoirs and conversions of the Lorenz energy cycl...

  12. Exercise-induced ROS in heat shock proteins response.

    Science.gov (United States)

    Dimauro, Ivan; Mercatelli, Neri; Caporossi, Daniela

    2016-09-01

    Cells have evolved multiple and sophisticated stress response mechanisms aiming to prevent macromolecular (including proteins, lipids, and nucleic acids) damage and to maintain or re-establish cellular homeostasis. Heat shock proteins (HSPs) are among the most highly conserved, ubiquitous, and abundant proteins in all organisms. Originally discovered more than 50 years ago through heat shock stress, they display multiple, remarkable roles inside and outside cells under a variety of stresses, including also oxidative stress and radiation, recognizing unfolded or misfolded proteins and facilitating their restructuring. Exercise consists in a combination of physiological stresses, such as metabolic disturbances, changes in circulating levels of hormones, increased temperature, induction of mild to severe inflammatory state, increased production of reactive oxygen and nitrogen species (ROS and RNS). As a consequence, exercise is one of the main stimuli associated with a robust increase in different HSPs in several tissues, which appears to be also fundamental in facilitating the cellular remodeling processes related to the training regime. Among all factors involved in the exercise-related modulation of HSPs level, the ROS production in the contracting muscle or in other tissues represents one of the most attracting, but still under discussion, mechanism. Following exhaustive or damaging muscle exercise, major oxidative damage to proteins and lipids is likely involved in HSP expression, together with mechanically induced damage to muscle proteins and the inflammatory response occurring several days into the recovery period. Instead, the transient and reversible oxidation of proteins by physiological concentrations of ROS seems to be involved in the activation of stress response following non-damaging muscle exercise. This review aims to provide a critical update on the role of HSPs response in exercise-induced adaptation or damage in humans, focusing on experimental

  13. Heating and generation of suprathermal particles at collisionless shocks

    International Nuclear Information System (INIS)

    Collisionless plasma shocks are different from ordinary collisional fluid shocks in several important respects. They do not in general heat the electrons and ions equally, nor do they produce Maxwellian velocity distributions downstream. Furthermore, they commonly generate suprathermal particles which propagate into the upstream region, giving advance warning of the presence of the shock and providing a ''seed'' population for further acceleration to high energies. Recent space observations and theory have revealed a great deal about the heating mechanisms which occur in collisionless shocks and about the origin of the various suprathermal particle populations which are found in association with them. An overview of the present understanding of these subjects is presented herein. 83 refs., 8 figs

  14. Decay heat removal in HTGR by natural circulation

    International Nuclear Information System (INIS)

    The coolability of 1000MWt HTGR under complete loss of forced flow conditions was investigated. A dynamic simulator for nuclear power plants (DSNP) program was developed to study the evolution of natural circulation during loss of forced flow (LOF). It was concluded that a passive cooling device, having 0.3% heat removal capacity of nominal decay heat rate, is sufficient for emergency cooling of the proposed plant under total LOF. (author)

  15. Nuclear phenotype changes after heat shock in Panstrongylus megistus (Burmeister

    Directory of Open Access Journals (Sweden)

    Garcia Simone L

    2000-01-01

    Full Text Available The nuclear phenotypes of Malpighian tubule epithelial cells of male nymphs of the blood-sucking insect, Panstrongylus megistus, subjected to short- and long-duration heat shocks at 40ºC were analyzed immediately after the shock and 10 and 30 days later. Normal nuclei with a usual heterochromatic body as well as phenotypes indicative of survival (unravelled heterochromatin, giants and death (apoptosis, necrosis responses were observed in control and treated specimens. However, all nuclear phenotypes, except the normal ones, were more frequent in shocked specimens. Similarly altered phenotypes have also been reported in Triatoma infestans following heat shock, although at different frequencies. The frequency of the various nuclear phenotypes observed in this study suggests that the forms of cell survival observed were not sufficient or efficient enough to protect all of the Malpighian tubule cells from the deleterious effects of stress. In agreement with studies on P. megistus survival following heat shock, only long-duration shock produced strongly deleterious effects.

  16. Heat Shock Proteins in Tendinopathy: Novel Molecular Regulators

    Directory of Open Access Journals (Sweden)

    Neal L. Millar

    2012-01-01

    Full Text Available Tendon disorders—tendinopathies—are the primary reason for musculoskeletal consultation in primary care and account for up to 30% of rheumatological consultations. Whilst the molecular pathophysiology of tendinopathy remains difficult to interpret the disease process involving repetitive stress, and cellular load provides important mechanistic insight into the area of heat shock proteins which spans many disease processes in the autoimmune community. Heat shock proteins, also called damage-associated molecular patterns (DAMPs, are rapidly released following nonprogrammed cell death, are key effectors of the innate immune system, and critically restore homeostasis by promoting the reconstruction of the effected tissue. Our investigations have highlighted a key role for HSPs in tendion disease which may ultimately affect tissue rescue mechanisms in tendon pathology. This paper aims to provide an overview of the biology of heat shock proteins in soft tissue and how these mediators may be important regulators of inflammatory mediators and matrix regulation in tendinopathy.

  17. Circuit architecture explains functional similarity of bacterial heat shock responses

    CERN Document Server

    Inoue, Masayo; Trusina, Ala

    2012-01-01

    Heat shock response is a stress response to temperature changes and a consecutive increase in amounts of unfolded proteins. To restore homeostasis, cells upregulate chaperones facilitating protein folding by means of transcription factors (TF). We here investigate two heat shock systems: one characteristic to gram negative bacteria, mediated by transcriptional activator sigma32 in E. coli, and another characteristic to gram positive bacteria, mediated by transcriptional repressor HrcA in L. lactis. We construct simple mathematical model of the two systems focusing on the negative feedbacks, where free chaperons suppress sigma32 activation in the former, while they activate HrcA repression in the latter. We demonstrate that both systems, in spite of the difference at the TF regulation level, are capable of showing very similar heat shock dynamics. We find that differences in regulation impose distinct constrains on chaperone-TF binding affinities: the binding constant of free sigma32 to chaperon DnaK, known to...

  18. The impact of oceanic heat transport on the atmospheric circulation

    Directory of Open Access Journals (Sweden)

    M.-A. Knietzsch

    2014-11-01

    Full Text Available A general circulation model of intermediate complexity with an idealized earthlike aquaplanet setup is used to study the impact of changes in the oceanic heat transport on the global atmospheric circulation. Focus is put on the Lorenz energy cycle and the atmospheric mean meridional circulation. The latter is analysed by means of the Kuo–Eliassen equation. The atmospheric heat transport compensates the imposed oceanic heat transport changes to a large extent in conjunction with significant modification of the general circulation. Up to a maximum about 3 PW, an increase of the oceanic heat transport leads to an increase of the global mean near-surface temperature and a decrease of its equator-to-pole gradient. For larger transports, the gradient is reduced further but the global mean remains approximately constant. This is linked to a cooling and a reversal of the temperature gradient in the tropics. A larger oceanic heat transport leads to a reduction of all reservoirs and conversions of the Lorenz energy cycle but of different relative magnitude for the individual components. The available potential energy of the zonal mean flow and its conversion to eddy available potential energy are affected most. Both the Hadley and Ferrel cell show a decline for increasing oceanic heat transport, with the Hadley cell being more sensitive. Both cells exhibit a poleward shift of their maxima, and the Hadley cell broadens for larger oceanic transports. The partitioning, by means of the Kuo–Eliassen equation, reveals that zonal mean diabatic heating and friction are the most important sources for changes of the Hadley cell, while the behaviour of the Ferrell cell is mostly controlled by friction.

  19. Borehole model for simulation transport geothermal heat with heat pipe system and with forced circulation of heat carrier

    Directory of Open Access Journals (Sweden)

    Lenhard Richard

    2012-04-01

    Full Text Available In the call OPVaV-2008/2.2/01-SORO Operational Programme Research and Development - knowledge and technology transfer from research and development into practice (ITMS-26220220057, whose strategic goal is "Device to use low-potential geothermal heat without forced circulation of heat carrier deep in the well "in the Department of Energy laboratory techniques to construct a simulator of transport low potential of geothermal energy in comparative test-drilling in the laboratory. The article describes a device that was designed as a scale model of two deep boreholes each of which withdraws the earth's heat by heat transfer technology and heat carrier. Device using forced circulation of heat carrier will respond in the construction of equipment currently used to transport heat from deep borehole. As the heat carrier will be used CO2. Facilities without using forced circulation of heat carrier, the new technology, which will be used as heat carrier ammonia (NH3.

  20. Heat shock response improves heterologous protein secretion in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Hou, Jin; Österlund, Tobias; Liu, Zihe;

    2013-01-01

    The yeast Saccharomyces cerevisiae is a widely used platform for the production of heterologous proteins of medical or industrial interest. However, heterologous protein productivity is often low due to limitations of the host strain. Heat shock response (HSR) is an inducible, global, cellular...... the accumulation of mis-folded or aggregated proteins. In this work, we over-expressed a mutant HSF1 gene HSF1-R206S which can constitutively activate HSR, so the heat shock response was induced at different levels, and we studied the impact of HSR on heterologous protein secretion. We found that moderate and high...

  1. OPG's approach of crediting natural circulation in outage heat sinks

    International Nuclear Information System (INIS)

    A review of crediting natural circulation as a backup means of removing the reactor core decay heat during an outage in Ontario Power Generation's nuclear stations was completed in 2000. The objective was to define the configurations and conditions under which natural circulation can be confidently credited as an effective heat transport mechanism for use in shutdown heat sink management. The project was an interdisciplinary program, and involved analyses in the areas of heat transport system thermalhydaulics, fuel and fuel channel thermal and mechanical behaviour, radiation physics, and probabilistic risks. The assessment shows that it is economically acceptable to credit natural circulation as a backup means of removing the core decay heat whenever the no fuel failure criteria are met. The economic risks associated with such a potential use decrease with time after shutdown. The waiting times after shutdown when there would be various levels of risks of damaging the pressure tubes and fuel bundles were derived for use in planning maintenance activities so as to minimize the economic risks. (author)

  2. Geothermal heating, diapycnal mixing and the abyssal circulation

    OpenAIRE

    J. Emile-Geay; Madec, G.

    2009-01-01

    The dynamical role of geothermal heating in abyssal circulation is reconsidered using three independent arguments. First, we show that a uniform geothermal heat flux close to the observed average (86.4 mW m−2) supplies as much heat to near-bottom water as a diapycnal mixing rate of ~10−4 m2 s−1 – the canonical value thought to be responsible for the magnitude of the presen...

  3. Transient Behaviour of a Heat Pipe with Extracapillary Circulation

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Heat pipe devices, for their typical working mode, are particularly suitable for zero gravity applications, and have also been considered for applications in space satellites with nuclear generators because of the absence of active systems for the coolant circulation. The present work reports the results of experimental tests carried out on a heat pipe facility designed to investigate the thermal-hydraulic performance of a water heat pipe. The device layout, configuration and geometry, simulate a heat pipe working mode utilizable in space applications under zero gravity conditions. The evaporating section, completely lined (covered) with wicks (sintered stainless steel), and nearly plane shaped, is housed in a cylindrical container. The obtained results show that the system can approach steady-state conditions, at a pressure of 4 bar and with a heat flux transferred of about 150 W/cm2, supporting an electric power step of about 1.8 Kw.

  4. HEAT SHOCK PROTEINS IN DIABETES AND WOUND HEALING

    OpenAIRE

    Atalay, Mustafa; Oksala, Niku; Lappalainen, Jani; David E Laaksonen; Sen, Chandan K.; Roy, Sashwati

    2009-01-01

    The heat shock proteins (HSPs), originally identified as heat-inducible gene products, are a highly conserved family of proteins that respond to a wide variety of stress. Although HSPs are among the most abundant intracellular proteins, they are expressed at low levels under normal physiological conditions, and show marked induction in response to various stressors. HSPs function primarily as molecular chaperones, facilitating the folding of other cellular proteins, preventing protein aggrega...

  5. Heat shock protein 90 is required for sexual and asexual development, virulence, and heat shock response in Fusarium graminearum

    Science.gov (United States)

    Bui, Duc-Cuong; Lee, Yoonji; Lim, Jae Yun; Fu, Minmin; Kim, Jin-Cheol; Choi, Gyung Ja; Son, Hokyoung; Lee, Yin-Won

    2016-01-01

    Eukaryotic cells repress global translation and selectively upregulate stress response proteins by altering multiple steps in gene expression. In this study, genome-wide transcriptome analysis of cellular adaptation to thermal stress was performed on the plant pathogenic fungus Fusarium graminearum. The results revealed that profound alterations in gene expression were required for heat shock responses in F. graminearum. Among these proteins, heat shock protein 90 (FgHsp90) was revealed to play a central role in heat shock stress responses in this fungus. FgHsp90 was highly expressed and exclusively localised to nuclei in response to heat stress. Moreover, our comprehensive functional characterisation of FgHsp90 provides clear genetic evidence supporting its crucial roles in the vegetative growth, reproduction, and virulence of F. graminearum. In particular, FgHsp90 performs multiple functions as a transcriptional regulator of conidiation. Our findings provide new insight into the mechanisms underlying adaptation to heat shock and the roles of Hsp90 in fungal development.

  6. Heat shock protein 90 is required for sexual and asexual development, virulence, and heat shock response in Fusarium graminearum.

    Science.gov (United States)

    Bui, Duc-Cuong; Lee, Yoonji; Lim, Jae Yun; Fu, Minmin; Kim, Jin-Cheol; Choi, Gyung Ja; Son, Hokyoung; Lee, Yin-Won

    2016-01-01

    Eukaryotic cells repress global translation and selectively upregulate stress response proteins by altering multiple steps in gene expression. In this study, genome-wide transcriptome analysis of cellular adaptation to thermal stress was performed on the plant pathogenic fungus Fusarium graminearum. The results revealed that profound alterations in gene expression were required for heat shock responses in F. graminearum. Among these proteins, heat shock protein 90 (FgHsp90) was revealed to play a central role in heat shock stress responses in this fungus. FgHsp90 was highly expressed and exclusively localised to nuclei in response to heat stress. Moreover, our comprehensive functional characterisation of FgHsp90 provides clear genetic evidence supporting its crucial roles in the vegetative growth, reproduction, and virulence of F. graminearum. In particular, FgHsp90 performs multiple functions as a transcriptional regulator of conidiation. Our findings provide new insight into the mechanisms underlying adaptation to heat shock and the roles of Hsp90 in fungal development. PMID:27306495

  7. Circuit architecture explains functional similarity of bacterial heat shock responses

    International Nuclear Information System (INIS)

    Heat shock response is a stress response to temperature changes and a consecutive increase in amounts of unfolded proteins. To restore homeostasis, cells upregulate chaperones facilitating protein folding by means of transcription factors (TFs). We here investigate two heat shock systems: one characteristic to gram negative bacteria, mediated by transcriptional activator σ32 in E. coli, and another characteristic to gram positive bacteria, mediated by transcriptional repressor HrcA in L. lactis. We construct simple mathematical models of the two systems focusing on the negative feedbacks, where free chaperones suppress σ32 activation in the former, while they activate HrcA repression in the latter. We demonstrate that both systems, in spite of the difference at the TF regulation level, are capable of showing very similar heat shock dynamics. We find that differences in regulation impose distinct constraints on chaperone–TF binding affinities: the binding constant of free σ32 to chaperone DnaK, known to be in 100 nM range, set the lower limit of amount of free chaperone that the system can sense the change at the heat shock, while the binding affinity of HrcA to chaperone GroE set the upper limit and have to be rather large extending into the micromolar range. (paper)

  8. A SIMPLE EXPERIMENTAL MODEL OF HEAT SHOCK RESPONSE IN RATS

    Directory of Open Access Journals (Sweden)

    Tufi Neder Meyer

    1998-10-01

    Full Text Available Objective: To obtain a simple model for the elicitation of the heat shock response in rats. Design: Laboratory study. Setting: University research laboratories. Sample: Seventy-nine adult male albino rats (weight range 200 g to 570 g. Procedures: Exposure to heat stress by heating animals in a warm bath for 5 min after their rectal temperatures reached 107.60 F (420 C. Liver and lung samples were collected for heat-shock protein 70 (HSP70 detection (Western analysis. Results: Western analysis was positive for HSP70 in the liver and in the lungs of heated animals. There was a temporal correlation between heating and HSP70 detection: it was strongest 1 day after heating and reduced afterwards. No heated animals died. Conclusion: These data show that heating rats in a warm (45o C bath, according to parameters set in this model, elicits efficiently the heat shock response.OBJETIVO: Obter um modelo simples para tentar esclarecer a resposta ao choque térmico em ratos. LOCAL: Laboratório de pesquisa da Universidade. MÉTODO: Amostra: 79 ratos albinos, adultos, entre 200g a 570g. Procedimentos: Exposição ao calor, em banho quente, por 5 minutos, após a temperatura retal chegar a 42 graus centigrados. Biópsias de fígado e pulmão foram obtidas para detectar a proteina 70 (HSP 70, pelo "Western blot". RESULTADOS: As análises foram positivas nos animais aquecidos, com uma correlação entre aquecimento e constatação da HSP 70. Foi mais elevada no primeiro dia e não houve óbitos nos animais aquecidos. CONCLUSÃO: Os ratos aquecidos a 45 graus centígrados respondem eficientemente ao choque térmico.

  9. Shock Waves and Turbulent Heating in Low-Density Plasmas

    International Nuclear Information System (INIS)

    Shock heating and shock structures are studied in theta-pinch-like devices in a wide range of plasma parameters ne, B1, mi, and of wave speeds u1 (3 x 106 cms-1 ≤ u1 ≤ 108 cm-1). Densities and temperatures were determined locally by interferometry and by Thomson scattering. Magnetic and electric fields were measured with small high-frequency probes. Previous investigations of perpendicular, hydromagnetic shocks at β1 A A, critical at densities above 1014 cm-3 are extended to densities close to 1013 cm-3 and to other mass ratios me/mi. Shocks are nearly collision-free even with respect to the initial state. A scaling law is obtained for the effective collision frequency veff, deduced from measured turbulent-heating rates and current densities. Results show that veff ≈ 10-3 (Te/Ti) (vd/cs) ωpi. Studies are extended to small Alfvén-Mach numbers, where shock structures are still collision-dominated. Comparison with theory shows good agreement. In the same density range, shocks are generated at β1 ≈ 0.3, and with MA >> MA critical- from the observed election heating rates and the electron density jump, together with the shock relations, estimates for turbulent ion-heating rates are obtained. Investigation of the structure of collision-dominated shocks in magnetic field-free plasma shows that electron temperature and density front are well separated; the width of separation agrees with theoretical estimates. Attempts are made to heat low-density (n ≤ 1013 cm-3), magnetic-field-free plasma by fast magnetic compression. In deuterium, an anomalously broad current sheath is observed. Nevertheless, deuteron temperatures of ≈ 10 keV and relatively high values of the local β (β ≈ 10) are achieved in a low-energy theta-pinch (≈ 10 kj) . Electric and magnetic field fluctuations of large amplitude occur. In argon, at large radii, a stationary electromagnetic sheath is found with a width of a few c/ωpe and an electric potential jump as required by theory. Ion

  10. Heat shock response and mammal adaptation to high elevation (hypoxia)

    Institute of Scientific and Technical Information of China (English)

    WANG Xiaolin; XU Cunshuan; WANG Xiujie; WANG Dongjie; WANG Qingshang; ZHANG Baochen

    2006-01-01

    The mammal's high elevation (hypoxia) adaptation was studied by using the immunological and the molecular biological methods to understand the significance of Hsp (hypoxia) adaptation in the organic high elevation, through the mammal heat shock response. (1) From high elevation to low elevation (natural hypoxia): Western blot and conventional RT-PCR and real-time fluorescence quota PCR were adopted. Expression difference of heat shock protein of 70 (Hsp70) and natural expression of brain tissue of Hsp70 gene was determined in the cardiac muscle tissue among the different elevation mammals (yak). (2)From low elevation to high elevation (hypoxia induction):The mammals (domestic rabbits) from the low elevation were sent directly to the areas with different high elevations like 2300, 3300 and 5000 m above sea level to be raised for a period of 3 weeks before being slaughtered and the genetic inductive expression of the brain tissue of Hsp70 was determined with RT-PCR. The result indicated that all of the mammals at different elevations possessed their heat shock response gene. Hsp70 of the high elevation mammal rose abruptly under stress and might be induced to come into being by high elevation (hypoxia). The speedy synthesis of Hsp70 in the process of heat shock response is suitable to maintain the cells' normal physiological functions under stress. The Hsp70 has its threshold value. The altitude of 5000 m above sea level is the best condition for the heat shock response, and it starts to reduce when the altitude is over 6000 m above sea level. The Hsp70 production quantity and the cell hypoxia bearing capacity have their direct ratio.

  11. Inhibition of Heat Shock Protein 90 Prevents HIV Rebound*

    Science.gov (United States)

    Joshi, Pheroze; Maidji, Ekaterina; Stoddart, Cheryl A.

    2016-01-01

    HIV evades eradication because transcriptionally dormant proviral genomes persist in long-lived reservoirs of resting CD4+ T cells and myeloid cells, which are the source of viral rebound after cessation of antiretroviral therapy. Dormant HIV genomes readily produce infectious virus upon cellular activation because host transcription factors activated specifically by cell stress and heat shock mediate full-length HIV transcription. The molecular chaperone heat shock protein 90 (Hsp90) is overexpressed during heat shock and activates inducible cellular transcription factors. Here we show that heat shock accelerates HIV transcription through induction of Hsp90 activity, which activates essential HIV-specific cellular transcription factors (NF-κB, NFAT, and STAT5), and that inhibition of Hsp90 greatly reduces gene expression mediated by these factors. More importantly, we show that Hsp90 controls virus transcription in vivo by specific Hsp90 inhibitors in clinical development, tanespimycin (17-(allylamino)-17-demethoxygeldanamycin) and AUY922, which durably prevented viral rebound in HIV-infected humanized NOD scid IL-2Rγ−/− bone marrow-liver-thymus mice up to 11 weeks after treatment cessation. Despite the absence of rebound viremia, we were able to recover infectious HIV from PBMC with heat shock. Replication-competent virus was detected in spleen cells from these nonviremic Hsp90 inhibitor-treated mice, indicating the presence of a tissue reservoir of persistent infection. Our novel findings provide in vivo evidence that inhibition of Hsp90 activity prevents HIV gene expression in replication-competent cellular reservoirs that would typically cause rebound in plasma viremia after antiretroviral therapy cessation. Alternating or supplementing Hsp90 inhibitors with current antiretroviral therapy regimens could conceivably suppress rebound viremia from persistent HIV reservoirs. PMID:26957545

  12. Shock Heating of the Merging Galaxy Cluster A521

    Science.gov (United States)

    Bourdin, H.; Mazzotta, P.; Markevitch, M.; Giacintucci, S.; Brunetti, G.

    2013-01-01

    A521 is an interacting galaxy cluster located at z = 0.247, hosting a low-frequency radio halo connected to an eastern radio relic. Previous Chandra observations hinted at the presence of an X-ray brightness edge at the position of the relic, which may be a shock front. We analyze a deep observation of A521 recently performed with XMM-Newton in order to probe the cluster structure up to the outermost regions covered by the radio emission. The cluster atmosphere exhibits various brightness and temperature anisotropies. In particular, two cluster cores appear to be separated by two cold fronts. We find two shock fronts, one that was suggested by Chandra and that is propagating to the east, and another to the southwestern cluster outskirt. The two main interacting clusters appear to be separated by a shock-heated region, which exhibits a spatial correlation with the radio halo. The outer edge of the radio relic coincides spatially with a shock front, suggesting that this shock is responsible for the generation of cosmic-ray electrons in the relic. The propagation direction and Mach number of the shock front derived from the gas density jump, M = 2.4 +/- 0.2, are consistent with expectations from the radio spectral index, under the assumption of Fermi I acceleration mechanism.

  13. Overexpression of colligin 2 in glioma vasculatureis associated with overexpression of heat shock factor 2

    NARCIS (Netherlands)

    D.A.M. Mustafa (Dana); A.M. Sieuwerts (Anieta); P.P. Zheng (Pingpin); J.M. Kros (Johan)

    2010-01-01

    textabstractIn previous studies we found expression of the protein collig in 2 (heat shock protein 47 (HSP47), SERPINH1) in glioma neovasculature while not in normal brain tissue. Generally, the regulation of heat shock gene expression in eukaryotes is mediated by heat shock factors (HSF). In mammal

  14. Role of heat shock protein 70 in innate alloimmunity

    Directory of Open Access Journals (Sweden)

    Walter G. eLand

    2012-01-01

    Full Text Available This article briefly describes our own experience with the proven demonstration of heat shock protein 70 in reperfused renal allografts from brain-deaddonors and reflects about its potential role as a typical damage-associated molecular pattern (DAMP in the setting of innate alloimmunity. In fact, our group was able to demonstrate a dramatic up-regulation of heat shock protein 70 expression after postischemic reperfusion of renal allografts. Of note, up-regulation of this stress protein expression, although to a lesser extent, was already observed after cold storage of the organ indicating that this molecule is already induced in the stressed organism of a brain-dead donor. However, whether or not the dramatic up-regulation of heat shock protein 70 expression contributes to mounting an innate alloimmune response cannot be judged in view of these clinical findings.Nevertheless, heat shock protein 70, since generated in association with postischemic reperfusion-induced allograft injury, can be called a typical DAMP - as can everymolecule be termed a DAMP that is generated in associationwith any stressful tissue injury regardless of its final positive or negative regulatory function within the innate immune response elicited by it.In fact, as we discuss in this article, the context-dependent, even contradistinctive activities of heat shock protein 70 reflect the biological phenomenon that, throughout evolution, mammals have developed an elaborate network of positive and negative regulatory mechanisms, which provide balance between defensive and protective measures against unwarranted destruction of the host. In this sense, up-regulated expression of heat shock protein 70 in an injured allograft might reflect a pure protective response against the severe oxidative injury of a reperfused donor organ. On the other hand, up-regulated expression of this stress protein in an injured allograft might reflect a(futile attempt of the innate immune system to

  15. Characteristics of fluid flow and heat transfer in a fluidized heat exchanger with circulating solid particles

    International Nuclear Information System (INIS)

    The commercial viability of heat exchanger is mainly dependent on its long-term fouling characteristic because the fouling increase the pressure loss and degrades the thermal performance of a heat exchanger. An experimental study was performed to investigate the characteristics of fluid flow and heat transfer in a fluidized bed heat exchanger with circulating various solid particles. The present work showed that the higher densities of particles had higher drag force coefficients, and the increases in heat transfer were in the order of sand, copper, steel, aluminum, and glass below Reynolds number of 5,000

  16. The Molecular Evolution of the Small Heat-Shock Proteins in Plants

    OpenAIRE

    Waters, E. R.

    1995-01-01

    The small heat-shock proteins have undergone a tremendous diversification in plants; whereas only a single small heat-shock protein is found in fungi and many animals, over 20 different small heat-shock proteins are found in higher plants. The small heat-shock proteins in plants have diversified in both sequence and cellular localization and are encoded by at least five gene families. In this study, 44 small heat-shock protein DNA and amino acid sequences were examined, using both phylogeneti...

  17. Serum Heat Shock Protein 70 Concentration in Relation to Polycystic Ovary Syndrome in a Non-Obese Chinese Population

    OpenAIRE

    Gao, Hui; Meng, Jie; Xu, Mengjing; Zhang, Shun; Ghose, Bishwajit; LIU Jun; Yao, Ping; Yan, Hong; Wang, Di; Liu, Liegang

    2013-01-01

    Background Polycystic ovary syndrome (PCOS) represents the most common cause of anovulatory infertility and affects 6-15% of women of reproductive age. However, the underlying etiology is still poorly understood. In this study, we attempted to examine the association between circulating heat shock protein 70 (Hsp70) concentrations and PCOS in a non-obese Chinese population. Methods and Results Human peripheral blood from 52 patients with PCOS and 57 healthy controls, matched for age and BMI, ...

  18. Implication of Heat Shock Factors in Tumorigenesis: Therapeutical Potential

    Directory of Open Access Journals (Sweden)

    Aurelie de Thonel

    2011-03-01

    Full Text Available Heat Shock Factors (HSF form a family of transcription factors (four in mammals which were named according to the discovery of their activation by a heat shock. HSFs trigger the expression of genes encoding Heat Shock Proteins (HSPs that function as molecular chaperones, contributing to establish a cytoprotective state to various proteotoxic stresses and in pathological conditions. Increasing evidence indicates that this ancient transcriptional protective program acts genome-widely and performs unexpected functions in the absence of experimentally defined stress. Indeed, HSFs are able to re-shape cellular pathways controlling longevity, growth, metabolism and development. The most well studied HSF, HSF1, has been found at elevated levels in tumors with high metastatic potential and is associated with poor prognosis. This is partly explained by the above-mentioned cytoprotective (HSP-dependent function that may enable cancer cells to adapt to the initial oncogenic stress and to support malignant transformation. Nevertheless, HSF1 operates as major multifaceted enhancers of tumorigenesis through, not only the induction of classical heat shock genes, but also of “non-classical” targets. Indeed, in cancer cells, HSF1 regulates genes involved in core cellular functions including proliferation, survival, migration, protein synthesis, signal transduction, and glucose metabolism, making HSF1 a very attractive target in cancer therapy. In this review, we describe the different physiological roles of HSFs as well as the recent discoveries in term of non-cogenic potential of these HSFs, more specifically associated to the activation of “non-classical” HSF target genes. We also present an update on the compounds with potent HSF1-modulating activity of potential interest as anti-cancer therapeutic agents.

  19. Implication of Heat Shock Factors in Tumorigenesis: Therapeutical Potential

    Energy Technology Data Exchange (ETDEWEB)

    Thonel, Aurelie de [INSERM U866, Dijon (France); Faculty of Medicine and Pharmacy, University of Burgundy, 21033 Dijon (France); Mezger, Valerie, E-mail: valerie.mezger@univ-paris-diderot.fr [CNRS, UMR7216 Epigenetics and Cell Fate, Paris (France); University Paris Diderot, 75013 Paris (France); Garrido, Carmen, E-mail: valerie.mezger@univ-paris-diderot.fr [INSERM U866, Dijon (France); Faculty of Medicine and Pharmacy, University of Burgundy, 21033 Dijon (France); CHU, Dijon BP1542, Dijon (France)

    2011-03-07

    Heat Shock Factors (HSF) form a family of transcription factors (four in mammals) which were named according to the discovery of their activation by a heat shock. HSFs trigger the expression of genes encoding Heat Shock Proteins (HSPs) that function as molecular chaperones, contributing to establish a cytoprotective state to various proteotoxic stresses and in pathological conditions. Increasing evidence indicates that this ancient transcriptional protective program acts genome-widely and performs unexpected functions in the absence of experimentally defined stress. Indeed, HSFs are able to re-shape cellular pathways controlling longevity, growth, metabolism and development. The most well studied HSF, HSF1, has been found at elevated levels in tumors with high metastatic potential and is associated with poor prognosis. This is partly explained by the above-mentioned cytoprotective (HSP-dependent) function that may enable cancer cells to adapt to the initial oncogenic stress and to support malignant transformation. Nevertheless, HSF1 operates as major multifaceted enhancers of tumorigenesis through, not only the induction of classical heat shock genes, but also of “non-classical” targets. Indeed, in cancer cells, HSF1 regulates genes involved in core cellular functions including proliferation, survival, migration, protein synthesis, signal transduction, and glucose metabolism, making HSF1 a very attractive target in cancer therapy. In this review, we describe the different physiological roles of HSFs as well as the recent discoveries in term of non-cogenic potential of these HSFs, more specifically associated to the activation of “non-classical” HSF target genes. We also present an update on the compounds with potent HSF1-modulating activity of potential interest as anti-cancer therapeutic agents.

  20. Role of Heat Shock Proteins in Stem Cell Behavior

    OpenAIRE

    Fan, Guo-Chang

    2012-01-01

    Stress response is well appreciated to induce the expression of heat shock proteins (Hsps) in the cell. Numerous studies have demonstrated that Hsps function as molecular chaperones in the stabilization of intracellular proteins, repairing damaged proteins, and assisting in protein translocation. Various kinds of stem cells (embryonic stem cells, adult stem cells, or induced pluripotent stem cells) have to maintain their stemness and, under certain circumstances, undergo stress. Therefore, Hs...

  1. Immunity to Heat Shock Proteins and Pregnancy Outcome

    Directory of Open Access Journals (Sweden)

    S. S. Witkin

    1999-01-01

    Full Text Available Heat shock proteins are among the first proteins produced by the zygote after fertilization. In addition, the maternal decidua also expresses heat shock proteins during the early stages of pregnancy. Autoimmunity to heat shock proteins is not typically evident in healthy women of reproductive age. However, a chronic microbial infection, such as an asymptomatic Chlamydia trachomatis upper genital tract infection, results in prolonged exposure of the immune system to the microbial 60 kDa heat shock protein (hsp60. This may result in immunity to conserved hsp60 epitopes and subsequent autoimmunity to self hsp60. Women undergoing in vitro fertilization (IVF who never realized they had a chlamydial infection but who were positive for cervical antichlamydial immunoglobulin A (IgA antibodies had a much lower pregnancy rate than did women who were negative for these antibodies. Furthermore, cervical IgA antibodies to the chlamydial hsp60, as well as to a synthetic peptide corresponding to an hsp60 epitope present in both the chlamydial and human hsp60, also correlated with IVF failure. In vitro incubation of newly fertilized human embryos in medium containing maternal serum was shown to be deleterious to embryo development if the sera was positive for antibodies reactive with human hsp60. In another study, the ability of human hsp60 to elicit a lymphocyte proliferative response (cell-mediated immunity correlated with a history of spontaneous early stage pregnancy loss. Thus, autoimmunity to hsp60 might increase susceptibility to early stage pregnancy loss. Infect. Dis. Obstet. Gynecol. 7:35–38, 1999.

  2. 壽The heat shock response and cytoprotection of the intestinal epithelium

    OpenAIRE

    Malago, Joshua J.; Koninkx, Jos F. J. G.; van Dijk, Jaap E.

    2002-01-01

    Following heat stress, the mammalian intestinal epithelial cells respond by producing heat shock proteins that confer protection under stressful conditions, which would otherwise lead to cell damage or death. Some of the noxious processes against which the heat shock response protects cells include heat stress, infection, and inflammation. The mechanisms of heat shock response–induced cytoprotection involve inhibition of proinflammatory cytokine production and induction of cellular proliferat...

  3. Transcription regulation of HYPK by Heat Shock Factor 1.

    Directory of Open Access Journals (Sweden)

    Srijit Das

    Full Text Available HYPK (Huntingtin Yeast Partner K was originally identified by yeast two-hybrid assay as an interactor of Huntingtin, the protein mutated in Huntington's disease. HYPK was characterized earlier as an intrinsically unstructured protein having chaperone-like activity in vitro and in vivo. HYPK has the ability of reducing rate of aggregate formation and subsequent toxicity caused by mutant Huntingtin. Further investigation revealed that HYPK is involved in diverse cellular processes and required for normal functioning of cells. In this study we observed that hyperthermia increases HYPK expression in human and mouse cells in culture. Expression of exogenous Heat Shock Factor 1 (HSF1, upon heat treatment could induce HYPK expression, whereas HSF1 knockdown reduced endogenous as well as heat-induced HYPK expression. Putative HSF1-binding site present in the promoter of human HYPK gene was identified and validated by reporter assay. Chromatin immunoprecipitation revealed in vivo interaction of HSF1 and RNA polymerase II with HYPK promoter sequence. Additionally, acetylation of histone H4, a known epigenetic marker of inducible HSF1 binding, was observed in response to heat shock in HYPK gene promoter. Overexpression of HYPK inhibited cells from lethal heat-induced death whereas knockdown of HYPK made the cells susceptible to lethal heat shock-induced death. Apart from elevated temperature, HYPK was also upregulated by hypoxia and proteasome inhibition, two other forms of cellular stress. We concluded that chaperone-like protein HYPK is induced by cellular stress and under transcriptional regulation of HSF1.

  4. THE ROLE OF HEAT SHOCK PROTEIN (HSP IN ORAL DISEASE

    Directory of Open Access Journals (Sweden)

    Theresia Indah Budhy

    2015-06-01

    Full Text Available Heat Shock Protein (HSP is a molecular chaperone that prevents stress-induced aggregation of partially denatured proteins and promotes their return to native confirmation when the condition is favorable. As molecular chaperones, the HSP protect protein structure and activity, thereby preventing disease, but they may contribute to cell malfunction if they are perturbed. Intracellular quantities and cellular localization of HSP was changed in response to anoxia/hypoxia, heat and oxidation, and in relation to pathological status. This review discusses the role of HSP in several human medical condition particularly in oral mucosa.

  5. Competition between shock and turbulent heating in coronal loop system

    CERN Document Server

    Matsumoto, Takuma

    2016-01-01

    2.5-dimensional magnetohydrodynamic (MHD) simulations are performed with high spatial resolution in order to distinguish between competing models of the coronal heating problem. A single coronal loop powered by Alfv\\'{e}n waves excited in the photosphere is the target of the present study. The coronal structure is reproduced in our simulations as a natural consequence of the transportation and dissipation of Alfv\\'{e}n waves. Further, the coronal structure is maintained as the spatial resolution is changed from 25 to 3 km, although the temperature at the loop top increases with the spatial resolution. The heating mechanisms change gradually across the magnetic canopy at a height of 4 Mm. Below the magnetic canopy, both the shock and the MHD turbulence are dominant heating processes. Above the magnetic canopy, the shock heating rate reduces to less than 10 % of the total heating rate while the MHD turbulence provides significant energy to balance the radiative cooling and thermal conduction loss or gain. The i...

  6. Competition between shock and turbulent heating in coronal loop system

    Science.gov (United States)

    Matsumoto, Takuma

    2016-08-01

    2.5-dimensional magnetohydrodynamic (MHD) simulations are performed with high spatial resolution in order to distinguish between competing models of the coronal heating problem. A single coronal loop powered by Alfvén waves excited in the photosphere is the target of the present study. The coronal structure is reproduced in our simulations as a natural consequence of the transportation and dissipation of Alfvén waves. Further, the coronal structure is maintained as the spatial resolution is changed from 25 to 3 km, although the temperature at the loop top increases with the spatial resolution. The heating mechanisms change gradually across the magnetic canopy at a height of 4 Mm. Below the magnetic canopy, both the shock and the MHD turbulence are dominant heating processes. Above the magnetic canopy, the shock heating rate reduces to less than 10 % of the total heating rate while the MHD turbulence provides significant energy to balance the radiative cooling and thermal conduction loss or gain. The importance of compressibility shown in the present study would significantly impact on the prospects of successful MHD turbulence theory in the solar chromosphere.

  7. Investigations into natural circulation driven heat removal systems

    International Nuclear Information System (INIS)

    Passive safety systems can make an important contribution to decay heat removal in existing and next Generation NPP. Two-phase natural circulation systems have under certain circumstances instabilities which have to be analysed in detail. For this reason the test facility GENEVA has been constructed and commissioned at the TU Dresden. The experiments described in the experimental matrix will be started this year. First experimental data showed flow instabilities e.g. flashing as expected. Generic studies are necessary to examine two-phase flow and especially two-phase flow instabilities in further detail. The influence of subcooling and the diameters of downcomer and riser are of particular interest. These will help to evaluate the system behaviour of passive heat removal systems as well as their safety and reliability for nuclear reactors. (orig.)

  8. A heat shock protein 90 β isoform involved in immune response to bacteria challenge and heat shock from Miichthys miiuy.

    Science.gov (United States)

    Wei, Tao; Gao, Yunhang; Wang, Rixin; Xu, Tianjun

    2013-08-01

    Heat shock protein 90 (HSP90) is highly conserved molecular chaperone that plays a critical role in cellular stress response. In this study, we reported the identification and functional analysis of a heat shock protein 90 gene from miiuy croaker (designated Mimi-HSP90). Mimi-HSP90 contained five conserved HSP90 protein family signatures and shared 89.6%-99.5% similarity with other known HSP90 β isoform. Homology analysis and structure comparison further indicated that Mimi-HSP90 should be β isoform member of the HSP90 family. The molecular evolutionary analysis showed that HSP90 was under an overall strong purifying select pressure among fish species. Mimi-HSP90 gene was constitutively expressed in ten examined tissues, and the expression level of liver was higher than in other tissues. The expression level of Mimi-HSP90 gene under bacterial infection and heat shock were analyzed by real-time quantitative RT-PCR, resulted in significant changes in liver, spleen, and kidney tissues. The purified recombinant pET-HSP90 protein was used to produce the polyclonal antibody in mice. The specificity of the antibody was determined by Western blot analysis. All results suggested that Mimi-HSP90 was involved in thermal stress and immune response in miiuy croaker. PMID:23684810

  9. The heat shock factor family from Triticum aestivum in response to heat and other major abiotic stresses and their role in regulation of heat shock protein genes

    OpenAIRE

    Xue, Gang-ping; Sadat, Shahab; Drenth, Janneke; McIntyre, C. Lynne

    2013-01-01

    Heat shock factors (Hsfs) play a central regulatory role in acquired thermotolerance. To understand the role of the major molecular players in wheat adaptation to heat stress, the Hsf family was investigated in Triticum aestivum. Bioinformatic and phylogenetic analyses identified 56 TaHsf members, which are classified into A, B, and C classes. Many TaHsfs were constitutively expressed. Subclass A6 members were predominantly expressed in the endosperm under non-stress conditions. Upon heat str...

  10. Protein denaturation in intact hepatocytes and isolated cellular organelles during heat shock

    OpenAIRE

    1993-01-01

    There is circumstantial evidence that protein denaturation occurs in cells during heat shock at hyperthermic temperatures and that denatured or damaged protein is the primary inducer of the heat shock response. However, there is no direct evidence regarding the extent of denaturation of normal cellular proteins during heat shock. Differential scanning calorimetry (DSC) is the most direct method of monitoring protein denaturation or unfolding. Due to the fundamental parameter measured, heat fl...

  11. Integrative analysis of the heat shock response in Aspergillus fumigatus

    Directory of Open Access Journals (Sweden)

    Brakhage Axel A

    2010-01-01

    Full Text Available Abstract Background Aspergillus fumigatus is a thermotolerant human-pathogenic mold and the most common cause of invasive aspergillosis (IA in immunocompromised patients. Its predominance is based on several factors most of which are still unknown. The thermotolerance of A. fumigatus is one of the traits which have been assigned to pathogenicity. It allows the fungus to grow at temperatures up to and above that of a fevered human host. To elucidate the mechanisms of heat resistance, we analyzed the change of the A. fumigatus proteome during a temperature shift from 30°C to 48°C by 2D-fluorescence difference gel electrophoresis (DIGE. To improve 2D gel image analysis results, protein spot quantitation was optimized by missing value imputation and normalization. Differentially regulated proteins were compared to previously published transcriptome data of A. fumigatus. The study was augmented by bioinformatical analysis of transcription factor binding sites (TFBSs in the promoter region of genes whose corresponding proteins were differentially regulated upon heat shock. Results 91 differentially regulated protein spots, representing 64 different proteins, were identified by mass spectrometry (MS. They showed a continuous up-, down- or an oscillating regulation. Many of the identified proteins were involved in protein folding (chaperones, oxidative stress response, signal transduction, transcription, translation, carbohydrate and nitrogen metabolism. A correlation between alteration of transcript levels and corresponding proteins was detected for half of the differentially regulated proteins. Interestingly, some previously undescribed putative targets for the heat shock regulator Hsf1 were identified. This provides evidence for Hsf1-dependent regulation of mannitol biosynthesis, translation, cytoskeletal dynamics and cell division in A. fumigatus. Furthermore, computational analysis of promoters revealed putative binding sites for an AP-2alpha

  12. Global transcriptome analysis of the heat shock response ofshewanella oneidensis

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Haichun; Wang, Sarah; Liu, Xueduan; Yan, Tinfeng; Wu, Liyou; Alm, Eric; Arkin, Adam P.; Thompson, Dorothea K.; Zhou, Jizhong

    2004-04-30

    Shewanella oneidensis is an important model organism for bioremediation studies because of its diverse respiratory capabilities. However, the genetic basis and regulatory mechanisms underlying the ability of S. oneidensis to survive and adapt to various environmentally relevant stresses is poorly understood. To define this organism's molecular response to elevated growth temperatures, temporal gene expression profiles were examined in cells subjected to heat stress using whole-genome DNA microarrays for S. oneidensis MR-1. Approximately 15 percent (711) of the predicted S. oneidensis genes represented on the microarray were significantly up- or down-regulated (P < 0.05) over a 25-min period following shift to the heat shock temperature (42 C). As expected, the majority of S. oneidensis genes exhibiting homology to known chaperones and heat shock proteins (Hsps) were highly and transiently induced. In addition, a number of predicted genes encoding enzymes in glycolys is and the pentose cycle, [NiFe] dehydrogenase, serine proteases, transcriptional regulators (MerR, LysR, and TetR families), histidine kinases, and hypothetical proteins were induced in response to heat stress. Genes encoding membrane proteins were differentially expressed, suggesting that cells possibly alter their membrane composition or structure in response to variations in growth temperature. A substantial number of the genes encoding ribosomal proteins displayed down-regulated co-expression patterns in response to heat stress, as did genes encoding prophage and flagellar proteins. Finally, based on computational comparative analysis of the upstream promoter regions of S.oneidensis heat-inducible genes, a putative regulatory motif, showing high conservation to the Escherichia coli sigma 32-binding consensus sequence, was identified.

  13. A Comprehensive Method of Identifying Heat Shock Proteins (HSPs

    Directory of Open Access Journals (Sweden)

    Pielesz A

    2016-03-01

    Full Text Available Because no model will ever completely replicate clinical human wound healing, it is essential that the model utilized be selected with care. Anatomically and physiologically, poultry skin is similar to human skin in many respects. Therefore, organic chicken skin (an ex-vivo burninjured skin model was analysed in this study. Acetate electrophoresis (CAE, microbiological procedure, Fourier-transform infrared spectrometry (FTIR and scanning electron microscopy analysis (SEM were all carried out after heating samples of model chicken skin to a temperature simulating a burn incident and stimulating the release of Heat Shock Proteins (HSPs. Aggregates of smaller molecular weight, HSP37 proteins, were isolated by cellulose acetate electrophoresis. FTIR tests revealed that heating a dry organic chicken skin to boiling point leads to the production of β-sheet aggregates, which are the response of protein to thermal shock. Aggregates of HSP37 are produced in thermal injury and not all the antimicrobial activity of the skin is lost in this model. So, antimicrobial peptides found in the burnt skin, HSP proteins were confirmed by microscopic, microbiological, electrophoretic and spectroscopic examination.

  14. Heat Shock Protein Expression During Gametogenesis and Embryogenesis

    Directory of Open Access Journals (Sweden)

    S. S. Witkin

    1999-01-01

    Full Text Available When cells are subjected to various stress factors, they increase the production of a group of proteins called heat shock proteins (hsp. Heat shock proteins are highly conserved proteins present in organisms ranging from bacteria to man. Heat shock proteins enable cells to survive adverse environmental conditions by preventing protein denaturation. Thus the physiological and pathological potential of hsps is enormous and has been studied widely over the past two decades. The presence or absence of hsps influences almost every aspect of reproduction. They are among the first proteins produced during mammalian embryo development. In this report, the production of hsps in gametogenesis and early embryo development is described. It has been suggested that prolonged and asymptomatic infections trigger immunity to microbial hsp epitopes that are also expressed in man. This may be relevant for human reproduction, since many couples with fertility problems have had a previous genital tract infection. Antibodies to bacterial and human hsps are present at high titers in sera of many patients undergoing in vitro fertilization. In a mouse embryo culture model, these antibodies impaired the mouse embryo development at unique developmental stages. The gross morphology of these embryos resembled cells undergoing apoptosis. The TUNEL (terminal deoxynucleotidyl transferase-mediated X-dUTP nick end labeling staining pattern, which is a common marker of apoptosis, revealed that embryos cultured in the presence of hsp antibodies stained TUNEL-positive more often than unexposed embryos. These data extend preexisting findings showing the detrimental effect of immune sensitization to hsps on embryo development. Infect. Dis. Obstet. Gynecol. 7:10–16, 1999.

  15. Numerical simulation of shell-side heat transfer and flow of natural circulation heat exchanger

    International Nuclear Information System (INIS)

    In order to analyze the influence on the heat transfer and flow characteristics of the heat exchanger model of different solving models and structures, a variety of transformation to the model equivalent for the heat exchanger was studied. In this paper, Fluent software was used to simulate the temperature-field and flow-field of the equivalent model, and investigate its heat-transferring and flow characteristics. Through comparative analysis of the distribution of temperature-field and flow-field for different models, the heat-transferring process and natural convection situation of heat exchanger were deeply understood. The results show that the temperature difference between the inside and outside of the natural circulation heat exchanger tubes is larger and the flow is more complex, so the turbulence model is the more reasonable choice. Asymmetry of tubes position makes the flow and heat transfer of the fluid on both sides to be dissymmetrical and makes the fluid interaction, and increases the role of natural convection. The complex structure of heat exchanger makes the flow and heat transfer of the fluid on both sides to be irregular to some extent when straight tubes into C-bent are transformed, and all these make the turbulence intensity increase and improve the effect of heat transfer. (authors)

  16. Sodium Experiments on Natural Circulation Decay Heat Removal and 3D Simulation of Plenum Thermal Hydraulics

    International Nuclear Information System (INIS)

    Natural circulation decay heat removal is one of the significant issues for fast reactor safety, especially in long term station blackout events. Several sodium experiments were carried out using a 7-subassembly core model for core thermal hydraulics under natural circulation conditions and for onset transients of natural circulation in a decay heat removal system (DHRS) including natural draft. Significant heat removal via inter-wrapper flow was confirmed in the experiments. Solidification of sodium in an air cooler is one of key issues in loss of heat sink events. Natural circulation characteristics under long-term decay heat removal were also obtained. Multi-dimensional phenomena, e.g., thermal stratification and bypass flow in plenums and/or heat exchangers, may influence the natural circulation. Thus, 3D simulation method was developed for entire region in the primary loop. Comparison of temperature distributions in a DHRS heat exchanger between experiment and analysis was done. (author)

  17. Intra-Binary Shock Heating of Black Widow Companions

    CERN Document Server

    Romani, Roger W

    2016-01-01

    The low mass companions of evaporating binary pulsars (black widows and their ilk) are strongly heated on the side facing the pulsar. However in high-quality photometric and spectroscopic data the heating pattern does not match that expected for direct pulsar illumination. Here we explore heating mediated by an intra-binary shock (IBS). We develop a simple analytic model and implement it in the popular `ICARUS' light curve code. The model is parameterized by the wind momentum ratio beta and velocity v_Rel v_orb and assumes that the reprocessed pulsar wind emits prompt particles or radiation to heat the companion surface. We illustrate an interesting range of light curve asymmetries controlled by these parameters. The code also computes the IBS synchrotron emission pattern, and thus can model black widow X-ray light curves. As a test we apply the results to the high quality asymmetric optical light curves of PSR J2215+5135; the resulting fit gives a substantial improvement upon direct heating models and produc...

  18. Intra-binary Shock Heating of Black Widow Companions

    Science.gov (United States)

    Romani, Roger W.; Sanchez, Nicolas

    2016-09-01

    The low-mass companions of evaporating binary pulsars (black widows and similar) are strongly heated on the side facing the pulsar. However, in high-quality photometric and spectroscopic data, the heating pattern does not match that expected for direct pulsar illumination. Here we explore a model where the pulsar power is intercepted by an intra-binary shock (IBS) before heating the low-mass companion. We develop a simple analytic model and implement it in the popular “ICARUS” light curve code. The model is parameterized by the wind momentum ratio β and the companion wind speed {f}v{v}{{orb}}, and assumes that the reprocessed pulsar wind emits prompt particles or radiation to heat the companion surface. We illustrate an interesting range of light curve asymmetries controlled by these parameters. The code also computes the IBS synchrotron emission pattern, and thus can model black widow X-ray light curves. As a test, we apply the results to the high-quality asymmetric optical light curves of PSR J2215+5135; the resulting fit gives a substantial improvement upon direct heating models and produces an X-ray light curve consistent with that seen. The IBS model parameters imply that at the present loss rate, the companion evaporation has a characteristic timescale of {τ }{{evap}}≈ 150 Myr. Still, the model is not fully satisfactory, indicating that there are additional unmodeled physical effects.

  19. Constitutive heat shock protein 70 (HSC70) expression in rainbow trout hepatocytes: effect of heat shock and heavy metal exposure.

    Science.gov (United States)

    Boone, Adrienne N; Vijayan, Mathilakath M

    2002-06-01

    The 70-kDa family of heat shock proteins plays an important role as molecular chaperones in unstressed and stressed cells. The constitutive member of the 70 family (hsc70) is crucial for the chaperoning function of unstressed cells, whereas the inducible form (hsp70) is important for allowing cells to cope with acute stressor insult, especially those affecting the protein machinery. In fish, the role of hsc70 in the cellular stress response process is less clear primarily because of the lack of a fish-specific antibody for hsc70 detection. In this study, we purified hsc70 to homogeneity from trout liver using a three-step purification protocol with differential centrifugation, ATP-agarose affinity chromatography and electroelution. Polyclonal antibodies to trout hsc70 generated in rabbits cross-reacted strongly with both purified trout hsc70 protein and also purified recombinant bovine hsc70. Two-dimensional electrophoresis followed by Western blotting confirmed that the isoelectric point of rainbow trout hsc70 was more acidic than hsp70. Using this antibody, we detected hsc70 content in the liver, heart, gill and skeletal muscle of unstressed rainbow trout. Primary cultures of trout hepatocytes subjected to a heat shock (+15 degrees C for 1 h) or exposed to either CuSO(4) (200 microM for 24 h), CdCl(2) (10 microM for 24 h) or NaAsO(2) (50 microM for 1 h) resulted in higher hsp70 accumulation over a 24-h period. However, hsc70 content showed no change with either heat shock or heavy metal exposure suggesting that hsc70 is not modulated by sublethal acute stressors in trout hepatocytes. Taken together, we have for the first time generated polyclonal antibodies specific to rainbow trout hsc70 and this antibody will allow for the characterization of the role of hsc70 in the cellular stress response process in fish. PMID:12106899

  20. Stress-Specific Activation and Repression of Heat Shock Factors 1 and 2

    OpenAIRE

    Mathew, Anu; Mathur, Sameer K.; Jolly, Caroline; Fox, Susan G.; Kim, Soojin; Richard I Morimoto

    2001-01-01

    Vertebrate cells express a family of heat shock transcription factors (HSF1 to HSF4) that coordinate the inducible regulation of heat shock genes in response to diverse signals. HSF1 is potent and activated rapidly though transiently by heat shock, whereas HSF2 is a less active transcriptional regulator but can retain its DNA binding properties for extended periods. Consequently, the differential activation of HSF1 and HSF2 by various stresses may be critical for cells to survive repeated and...

  1. Report on the VIIth International Symposium on Heat Shock Proteins in Biology & Medicine

    OpenAIRE

    Calderwood, Stuart K; Hightower, Lawrence E.

    2014-01-01

    This seventh symposium in a series on heat shock proteins in biology and medicine was held November 1–5, 2014, at the Hilton Hotel in Old Town Alexandria, Virginia. Approximately 70 participants including principal investigators, postdoctoral fellows, and graduate students were in attendance. The major themes were: new properties of heat shock proteins (HSPs) and heat shock factor (HSF) and role in the etiology of cancer, molecular chaperones in aging, extracellular HSPs in inflammation and i...

  2. Heat Shock Protein 90 and Heat Shock Response%热激蛋白90与热激应答

    Institute of Scientific and Technical Information of China (English)

    李娟; 杨惠; 周元国

    2008-01-01

    热激蛋白90(heat shock protein 90,HSP90)作为机体重要的分子伴侣之一,主要是维持机体内环境的稳态.在机体遭受内外界刺激时,体内氧化-抗氧化平衡失调诱发机体热激应答,诱导HSP90高表达来抵御刺激对机体造成的损伤.

  3. CIRCE, a novel heat shock element involved in regulation of heat shock operon dnaK of Bacillus subtilis.

    OpenAIRE

    Zuber, U; Schumann, W

    1994-01-01

    The dnaK and groESL operons of Bacillus subtilis are preceded by a potential sigma 43 promoter sequence (recognized by the vegetative sigma factor) and by an inverted repeat (IR) consisting of 9 bp separated by a 9-bp spacer. Since this IR has been found in many bacterial species, we suspected that it might be involved in heat shock regulation. In order to test this hypothesis, three different mutational alterations of three bases were introduced within the IR preceding the dnaK operon. These...

  4. Heat-shock-induced cellular responses to temperature elevations occurring during orthopaedic cutting

    OpenAIRE

    E.B Dolan; Haugh, M. G.; Tallon, D.; Casey, C.; McNamara, L. M.

    2012-01-01

    Severe heat-shock to bone cells caused during orthopaedic procedures can result in thermal damage, leading to cell death and initiating bone resorption. By contrast, mild heat-shock has been proposed to induce bone regeneration. In this study, bone cells are exposed to heat-shock for short durations occurring during surgical cutting. Cellular viability, necrosis and apoptosis are investigated immediately after heat-shock and following recovery of 12, 24 h and 4 days, in osteocyte-like MLO-Y4 ...

  5. Heat shock-induced interactions among nuclear HSFs detected by fluorescence cross-correlation spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Pack, Chan-Gi, E-mail: changipack@amc.seoul.kr [Asan Institute for Life Sciences, University of Ulsan, College of Medicine, Asan Medical Center, Seoul 138-736 (Korea, Republic of); Ahn, Sang-Gun [Dept. of Pathology, College of Dentistry, Chosun University, Seosuk-dong, Dong-gu, Gwangju 501-759 (Korea, Republic of)

    2015-07-31

    The cellular response to stress is primarily controlled in cells via transcriptional activation by heat shock factor 1 (HSF1). HSF1 is well-known to form homotrimers for activation upon heat shock and subsequently bind to target DNAs, such as heat-shock elements, by forming stress granules. A previous study demonstrated that nuclear HSF1 and HSF2 molecules in live cells interacted with target DNAs on the stress granules. However, the process underlying the binding interactions of HSF family in cells upon heat shock remains unclear. This study demonstrate for the first time that the interaction kinetics among nuclear HSF1, HSF2, and HSF4 upon heat shock can be detected directly in live cells using dual color fluorescence cross-correlation spectroscopy (FCCS). FCCS analyses indicated that the binding between HSFs was dramatically changed by heat shock. Interestingly, the recovery kinetics of interaction between HSF1 molecules after heat shock could be represented by changes in the relative interaction amplitude and mobility. - Highlights: • The binding interactions among nuclear HSFs were successfully detected. • The binding kinetics between HSF1s during recovery was quantified. • HSF2 and HSF4 strongly formed hetero-complex, even before heat shock. • Nuclear HSF2 and HSF4 bound to HSF1 only after heat shock.

  6. An atypical unfolded protein response in heat shocked cells.

    Directory of Open Access Journals (Sweden)

    Lonneke Heldens

    Full Text Available BACKGROUND: The heat shock response (HSR and the unfolded protein response (UPR are both activated by proteotoxic stress, although in different compartments, and share cellular resources. How these resources are allocated when both responses are active is not known. Insight in possible crosstalk will help understanding the consequences of failure of these systems in (age-related disease. RESULTS: In heat stressed HEK293 cells synthesis of the canonical UPR transcription factors XBP1s and ATF4 was detected as well as HSF1 independent activation of the promoters of the ER resident chaperones HSPA5 (BiP and DNAJB9 (ERdj4. However, the heat stress activation of the DNAJB9 promoter, a XBP1s target, was not blocked in cells expressing a dominant negative IRE1α mutant, and thus did not require XBP1s. Furthermore, the DNA element required for heat stress activation of the DNAJB9 promoter is distinct from the ATF4 and ATF6 target elements; even though inhibition of eIF2α phosphorylation resulted in a decreased activation of the DNAJB9 promoter upon heat stress, suggesting a role for an eIF2α phosphorylation dependent product. CONCLUSIONS: The initial step in the UPR, synthesis of transcription factors, is activated by heat stress but the second step, transcriptional transactivation by these factors, is blocked and these pathways of the UPR are thus not productive. Expression of canonical ER chaperones is part of the response of heat stressed cells but another set of transcription factors has been recruited to regulate expression of these ER chaperones.

  7. Cleaning and Heat Transfer in Heat Exchanger with Circulating Fluidized Beds

    Science.gov (United States)

    Kang, Ho Keun; Ahn, Soo Whan; Choi, Jong Woong; Lee, Byung Chang

    2010-06-01

    Fluidized bed type heat exchangers are known to increase the heat transfer and prevent the fouling. For proper design of circulating fluidized bed heat exchanger it is important to know the effect of design and operating parameters on the bed to the wall heat transfer coefficient. The present experimental and numerical study was conducted to investigate the effects of circulating solid particles on the characteristics of fluid flow, heat transfer and cleaning effect in the fluidized bed vertical shell and tube type heat exchanger with counterflow, at which a variety of solid particles such as glass (3 mmF), aluminum (2˜3 mmF), steel (2˜2.5 mmF), copper (2.5 mmF) and sand (2˜4 mmF) were used in the fluidized bed with a smooth tube. Seven different solid particles have the same volume, and the effects of various parameters such as water flow rates, particle diameter, materials and geometry were investigated. The present experimental and numerical results showed that the flow velocity range for collision of particles to the tube wall was higher with heavier density solid particles, and the increase in heat transfer was in the order of sand, copper, steel, aluminum, and glass. This behaviour might be attributed to the parameters such as surface roughness or particle heat capacity. Fouling examination using 25,500 ppm of ferric oxide (Fe2O3) revealed that the tube inside wall is cleaned by a mild and continuous scouring action of fluidized solid particles. The fluidized solid particles not only keep the surface clean, but they also break up the boundary layer improving the heat transfer coefficient even at low fluid velocities.

  8. Heat shock genes – integrating cell survival and death

    Indian Academy of Sciences (India)

    Richa Arya; Moushami Mallik; Subhash C Lakhotia

    2007-04-01

    Heat shock induced gene expression and other cellular responses help limit the damage caused by stress and thus facilitate cellular recovery. Cellular damage also triggers apoptotic cell death through several pathways. This paper briefly reviews interactions of the major heat shock proteins with components of the apoptotic pathways. Hsp90, which acts as a chaperone for unstable signal transducers to keep them poised for activation, interacts with RIP and Akt and promotes NF-B mediated inhibition of apoptosis; in addition it also blocks some steps in the apoptotic pathways. Hsp70 is mostly anti-apoptotic and acts at several levels like inhibition of translocation of Bax into mitochondria, release of cytochrome c from mitochondria, formation of apoptosome and inhibition of activation of initiator caspases. Hsp70 also modulates JNK, NF-B and Akt signaling pathways in the apoptotic cascade. In contrast, Hsp60 has both anti- and pro-apoptotic roles. Cytosolic Hsp60 prevents translocation of the pro-apoptotic protein Bax into mitochondria and thus promotes cell survival but it also promotes maturation of procaspase-3, essential for caspase mediated cell death. Our recent in vivo studies show that RNAi for the Hsp60D in Drosophila melanogaster prevents induced apoptosis. Hsp27 exerts its anti-apoptotic influence by inhibiting cytochrome c and TNF-mediated cell death. crystallin suppresses caspase-8 and cytochrome c mediated activation of caspase-3. Studies in our laboratory also reveal that absence or reduced levels of the developmentally active as well as stress induced non-coding hsr transcripts, which are known to sequester diverse hnRNPs and related nuclear RNA-binding proteins, block induced apoptosis in Drosophila. Modulation of the apoptotic pathways by Hsps reflects their roles as ``weak links” between various ``hubs” in cellular networks. On the other hand, non-coding RNAs, by virtue of their potential to bind with multiple proteins, can act as ``hubs” in

  9. Hormonal modulation of the heat shock response: insights from fish with divergent cortisol stress responses

    DEFF Research Database (Denmark)

    LeBlanc, Sacha; Höglund, Erik; Gilmour, Kathleen M.;

    2012-01-01

    Acute temperature stress in animals results in increases in heat shock proteins (HSPs) and stress hormones. There is evidence that stress hormones influence the magnitude of the heat shock response; however, their role is equivocal. To determine whether and how stress hormones may affect the heat...... shock response, we capitalized on two lines of rainbow trout specifically bred for their high (HR) and low (LR) cortisol response to stress. We predicted that LR fish, with a low cortisol but high catecholamine response to stress, would induce higher levels of HSPs after acute heat stress than HR trout....... We found that HR fish have significantly higher increases in both catecholamines and cortisol compared with LR fish, and LR fish had no appreciable stress hormone response to heat shock. This unexpected finding prevented further interpretation of the hormonal modulation of the heat shock response but...

  10. A minimal titration modelization of the mammalian dynamical heat shock response

    CERN Document Server

    Aude, Sivéry; Thommen, Quentin

    2015-01-01

    Environmental stress, such as oxidative or heat stress, induces the activation of the Heat Shock Response (HSR) which leads to an increase in the heat shock proteins (HSPs) level. These HSPs act as molecular chaperones to maintain proteostasis. Even if the main heat shock response partners are well known, a detailed description of the dynamical properties of the HSR network is still missing. In this study, we derive a minimal mathematical model of cellular response to heat shock that reproduces available experimental data sets both on transcription factor activity and cell viability. This simplistic model highlights the key mechanistic processes that rule the HSR network and reveals (i) the titration of Heat Shock Factor 1 (HSF1) by chaperones as the guiding line of the network, (ii) that protein triage governs the fate of damaged proteins and (iii) three different temperature regimes describing normal, acute or chronic stress.

  11. Differential expression of heat shock transcription factors and heat shock proteins after acute and chronic heat stress in laying chickens (Gallus gallus.

    Directory of Open Access Journals (Sweden)

    Jingjing Xie

    Full Text Available Heat stress due to high environmental temperature negatively influences animal performances. To better understand the biological impact of heat stress, laying broiler breeder chickens were subjected either to acute (step-wisely increasing temperature from 21 to 35°C within 24 hours or chronic (32°C for 8 weeks high temperature exposure. High temperature challenges significantly elevated body temperature of experimental birds (P<0.05. However, oxidation status of lipid and protein and expression of heat shock transcription factors (HSFs and heat shock proteins (HSPs 70 and 90 were differently affected by acute and chronic treatment. Tissue-specific responses to thermal challenge were also found among heart, liver and muscle. In the heart, acute heat challenge affected lipid oxidation (P = 0.05 and gene expression of all 4 HSF gene expression was upregulated (P<0.05. During chronic heat treatment, the HSP 70 mRNA level was increased (P<0.05 and HSP 90 mRNA (P<0.05 was decreased. In the liver, oxidation of protein was alleviated during acute heat challenge (P<0.05, however, gene expression HSF2, 3 and 4 and HSP 70 were highly induced (P<0.05. HSP90 expression was increased by chronic thermal treatment (P<0.05. In the muscle, both types of heat stress increased protein oxidation, but HSFs and HSPs gene expression remained unaltered. Only tendencies to increase were observed in HSP 70 (P = 0.052 and 90 (P = 0.054 gene expression after acute heat stress. The differential expressions of HSF and HSP genes in different tissues of laying broiler breeder chickens suggested that anti-heat stress mechanisms might be provoked more profoundly in the heart, by which the muscle was least protected during heat stress. In addition to HSP, HSFs gene expression could be used as a marker during acute heat stress.

  12. Volume, heat, and freshwater transports of the global ocean circulation 1993-2000, estimated from a general circulation model constrained by World Ocean Circulation Experiment (WOCE) data

    OpenAIRE

    Stammer, D.; C. Wunsch; R. Giering; Eckert, C.; P. Heimbach; J. Marotzke; Adcroft, A.; Hill, C.; Marshall, J

    2003-01-01

    An analysis of ocean volume, heat, and freshwater transports from a fully constrained general circulation model (GCM) is described. Output from a data synthesis, or state estimation, method is used by which the model was forced to large-scale, time-varying global ocean data sets over 1993 through 2000. Time-mean horizontal transports, estimated from this fully time-dependent circulation, have converged with independent time-independent estimates from box inversions over most parts of the worl...

  13. Characterization of the heat shock response in Brucella abortus and isolation of the genes encoding the GroE heat shock proteins.

    OpenAIRE

    Lin, J.; Adams, L G; Ficht, T A

    1992-01-01

    In an effort to define the heat shock response in the bovine intracellular pathogen Brucella abortus, a rough variant lacking extensive lipopolysaccharide was pulse-labeled with [35S]methionine following exposure to elevated temperatures. The major heat shock proteins observed following sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography migrate at 70, 62, 18, and 10 kDa. The maximum response was observed between 42 and 46 degrees C and within 2 to 3 h of the shif in...

  14. HEAT SHOCK PROTEIN gp96 AND CANCER IMMUNOTHERAPY

    Institute of Scientific and Technical Information of China (English)

    岳培彬; 杨树德; 黄常志

    2002-01-01

    Heat shock protein gp96 is a highly conserved and monomorphic glycoprotein in the endoplasmic reticulum.It functions as molecular chaperone and can associate with a variety of antigenic peptides noncovalently in vivo and in vitro. Recent studies have indicated that gp96 molecules participate in major histocompatibility complex class I - restricted antigen presentation pathway. Immunization of mice with gp96 preparations isolated from cancer cells can elicit a cancer - specific protective T cell immune response that is recallable, which is a prerequisite for gp96 as a therapeutic vaccine against cancers. The immunogenicity of gp96 molecules has been attributed to the antigenic peptides associated with them. These phenomena provide a new pathway for cancer immunotherapy. The mechanism that the gp96 -peptide complex induces specific immune response and the explorations for gp96 - peptide complex as a therapeutic cancer vaccine are reviewed.

  15. HEAT SHOCK PROTEIN 70 AND EXERCISE: MORPHOFUNCTIONAL RELATIONSHIPS

    Directory of Open Access Journals (Sweden)

    Giuseppe Battaglia

    2008-01-01

    Full Text Available The expression of Heat Shock Proteins (HSPs is one of the most defensive mechanism against cellular stress, HSPs are an heterogeneous family of molecules highly maintained across the species during the evolution. Exercise training represents the most important source of stress in the skeletal muscle and it triggers the increase of the expression of HSPs, particularly Hsp70, into the cells, plays the intracellular role of chaperone and stress sensor. It has been shown that the expression of Hsp70 as cell response to stress is directly proportional to stress intensity. Several authors described Hsp70 trends as result of different training protocols in both human and animal skeletal muscles, getting out contrasting results. The purpose of this review is to clarify the influence of exercise on the production of Hsp70. Further experiments are necessary to understand better the Hsp70 role in damage induced by physical training to schedule an optimal workout program.

  16. Heat Shock Protein 90 regulates encystation in Entamoeba

    Directory of Open Access Journals (Sweden)

    Meetali eSingh

    2015-10-01

    Full Text Available Enteric protozoan Entamoeba histolytica is a major cause of debilitating diarrheal infection worldwide with high morbidity and mortality. Even though the clinical burden of this parasite is very high, this infection is categorized as a neglected disease. Parasite is transmitted through feco-oral route and exhibit two distinct stages namely – trophozoites and cysts. Mechanism and regulation of encystation is not clearly understood. Previous studies have established the role of Heat shock protein 90 (Hsp90 in regulating stage transition in various protozoan parasites like Giardia, Plasmodium, Leishmania and Toxoplasma. Our study for the first time reports that Hsp90 plays a crucial role in life cycle of Entamoeba as well. We identify Hsp90 to be a negative regulator of encystation in Entamoeba. We also show that Hsp90 inhibition interferes with the process of phagocytosis in Entamoeba. Overall, we show that Hsp90 plays an important role in virulence and transmission of Entamoeba.

  17. Role of heat shock proteins in cell apoptosis

    Directory of Open Access Journals (Sweden)

    Arleta Kaźmierczuk

    2010-06-01

    Full Text Available Apoptosis is, apart from necrosis and autophagy, one of the possible cell death mechanisms eliminating needless, not normal or infected cells. This process ensures quantitative and qualitative cell control of organisms. Apoptosis is tightly regulated, it requires both activation of a large number of genes and energy input. Up-to-date two main apoptotic pathways have been recognized – external/receptor and internal, processed with the participation of mitochondria. Heat shock proteins HSPs, the molecules known from their chaperone activity and molecular conservatism, play essential functions in the course of apoptosis. Among that proteins family, i.e. HSP100, 90, 70, 60, 40 and small molecular (sHSP, there are agents mainly protective against programmed cell death. However, in some conditions some of these proteins may promote apoptosis. This review describes different key apoptotic proteins interacting with main members of HSP family and the consequence of these events for cell survival or apoptosis.

  18. Transcriptional regulation of an hsp70 heat shock gene in the yeast Saccharomyces cerevisiae.

    OpenAIRE

    Slater, M R; Craig, E A

    1987-01-01

    The yeast Saccharomyces cerevisiae contains three heat-inducible hsp70 genes. We have characterized the promoter region of the hsp70 heat shock gene YG100, that also displays a basal level of expression. Deletion of the distal region of the promoter resulted in an 80% drop in the basal level of expression without affecting expression after heat shock. Progressive-deletion analysis suggested that sequences necessary for heat-inducible expression are more proximal, within 233 base pairs of the ...

  19. Protein kinase A binds and activates heat shock factor 1.

    Directory of Open Access Journals (Sweden)

    Ayesha Murshid

    Full Text Available BACKGROUND: Many inducible transcription factors are regulated through batteries of posttranslational modifications that couple their activity to inducing stimuli. We have studied such regulation of Heat Shock Factor 1 (HSF1, a key protein in control of the heat shock response, and a participant in carcinogenisis, neurological health and aging. As the mechanisms involved in the intracellular regulation of HSF1 in good health and its dysregulation in disease are still incomplete we are investigating the role of posttranslational modifications in such regulation. METHODOLOGY/PRINCIPAL FINDINGS: In a proteomic study of HSF1 binding partners, we have discovered its association with the pleiotropic protein kinase A (PKA. HSF1 binds avidly to the catalytic subunit of PKA, (PKAcα and becomes phosphorylated on a novel serine phosphorylation site within its central regulatory domain (serine 320 or S320, both in vitro and in vivo. Intracellular PKAcα levels and phosphorylation of HSF1 at S320 were both required for HSF1 to be localized to the nucleus, bind to response elements in the promoter of an HSF1 target gene (hsp70.1 and activate hsp70.1 after stress. Reduction in PKAcα levels by small hairpin RNA led to HSF1 exclusion from the nucleus, its exodus from the hsp70.1 promoter and decreased hsp70.1 transcription. Likewise, null mutation of HSF1 at S320 by alanine substitution for serine led to an HSF1 species excluded from the nucleus and deficient in hsp70.1 activation. CONCLUSIONS: These findings of PKA regulation of HSF1 through S320 phosphorylation add to our knowledge of the signaling networks converging on this factor and may contribute to elucidating its complex roles in the stress response and understanding HSF1 dysregulation in disease.

  20. Modification of tooth development by heat shock protein 60.

    Science.gov (United States)

    Papp, Tamas; Polyak, Angela; Papp, Krisztina; Meszar, Zoltan; Zakany, Roza; Meszar-Katona, Eva; Tünde, Palne Terdik; Ham, Chang Hwa; Felszeghy, Szabolcs

    2016-01-01

    Although several heat shock proteins have been investigated in relation to tooth development, no available information is available about the spatial and temporal expression pattern of heat shock protein 60 (Hsp 60). To characterize Hsp 60 expression in the structures of the developing tooth germ, we used Western blotting, immunohistochemistry and in situ hybridization. Hsp 60 was present in high amounts in the inner and outer enamel epithelia, enamel knot (EK) and stratum intermedium (SI). Hsp 60 also appeared in odontoblasts beginning in the bell stage. To obtain data on the possible effect of Hsp 60 on isolated lower incisors from mice, we performed in vitro culturing. To investigate the effect of exogenous Hsp 60 on the cell cycle during culturing, we used the 5-bromo-2-deoxyuridine (BrdU) incorporation test on dental cells. Exogenously administered Hsp 60 caused bluntness at the apical part of the 16.5-day-old tooth germs, but it did not influence the proliferation rate of dental cells. We identified the expression of Hsp 60 in the developing tooth germ, which was present in high concentrations in the inner and outer enamel epithelia, EK, SI and odontoblasts. High concentration of exogenous Hsp 60 can cause abnormal morphology of the tooth germ, but it did not influence the proliferation rate of the dental cells. Our results suggest that increased levels of Hsp 60 may cause abnormalities in the morphological development of the tooth germ and support the data on the significance of Hsp during the developmental processes. PMID:27025262

  1. A family of related proteins is encoded by the major Drosophila heat shock gene family

    International Nuclear Information System (INIS)

    At least four proteins of 70,000 to 75,000 molecular weight (70-75K) were synthesized from mRNA which hybridized with a cloned heat shock gene previously shown to be localized to the 87A and 87C heat shock puff sites. These in vitro-synthesized proteins were indistinguishable from in vivo-synthesized heat shock-induced proteins when analyzed on sodium dodecyl sulfate-polyacrylamide gels. A comparison of the pattern of this group of proteins synthesized in vivo during a 5-min pulse or during continuous labeling indicates that the 72-75K proteins are probably not kinetic precursors to the major 70K heat shock protein. Partial digestion products generated with V8 protease indicated that the 70-75K heat shock proteins are closely related, but that there are clear differences between them. The partial digestion patterns obtained from heat shock proteins from the Kc cell line and from the Oregon R strain of Drosophila melanogaster are very similar. Genetic analysis of the patterns of 70-75K heat shock protein synthesis indicated that the genes encoding at least two of the three 72-75K heat shock proteins are located outside of the major 87A and 87C puff sites

  2. Synthesis of the low molecular weight heat shock proteins in plants

    International Nuclear Information System (INIS)

    Heat shock of living tissue induces the synthesis of a unique group of proteins, the heat shock proteins. In plants, the major group of heat shock proteins has a molecular mass of 15 to 25 kilodaltons. Accumulation to these proteins to stainable levels has been reported in only a few species. To examine accumulation of the low molecular weight heat shock proteins in a broader range of species, two-dimensional electrophoresis was used to resolve total protein from the following species: soybean (Glycine max L. Merr., var Wayne), pea (Pisum sativum L., var Early Alaska), sunflower (Helianthus annuus L.), wheat (Triticum asetivum L.), rice (Oryza sativa L., cv IR-36), maize (Zea mays L.), pearl millet (Pennisetum americanum L. Leeke, line 23DB), and Panicum miliaceum L. When identified by both silver staining and incorporation of radiolabel, a diverse array of low molecular weight heat shock proteins was synthesized in each of these species. These proteins accumulated to significant levels after three hours of heat shock but exhibited considerable heterogeneity in isoelectric point, molecular weight, stainability, and radiolabel incorporation. Although most appeared to be synthesized only during heat shock, some were detectable at low levels in control tissue. Compared to the monocots, a higher proportion of low molecular weight heat shock proteins was detectable in control tissues from dicots

  3. Heat protective role and mechanism of heat shock protein Hpc60

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A cytosolic heat shock protein named Hpc60 has been purified by immunoaffinity chromatography from pea leaves and its function has been examined in vitro. Results show that Hpc60 may suppress the aggregation of luciferase (LUC), protect lactate dehydrogenase (LDH) and ascorbate peroxidase (APX) from thermal inactivation. It also shows that Mg2+, ATP and pH affect the protective function of Hpc60 in different manners.

  4. Hsp27 enhances recovery of splicing as well as rephosphorylation of SRp38 after heat shock

    OpenAIRE

    Marin Vinader, L.; Shin, C.; Onnekink, C; Manley, J L; Lubsen, N H

    2005-01-01

    A heat stress causes a rapid inhibition of splicing. Exogenous expression of Hsp27 did not prevent that inhibition but enhanced the recovery of splicing afterward. Another small heat shock protein, αB-crystallin, had no effect. Hsp27, but not αB-crystallin, also hastened rephosphorylation of SRp38—dephosphorylated a potent inhibitor of splicing—after a heat shock, although it did not prevent dephosphorylation by a heat shock. The effect of Hsp27 on rephosphorylation of SRp38 required phosphor...

  5. Heating a plasma by a broadband stream of fast electrons: Fast ignition, shock ignition, and Gbar shock wave applications

    Energy Technology Data Exchange (ETDEWEB)

    Gus’kov, S. Yu., E-mail: guskov@sci.lebedev.ru [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation); Nicolai, Ph.; Ribeyre, X.; Tikhonchuk, V. T. [Centre Lasers Intenses et Applications, University of Bordeaux-CNRS-CEA (France)

    2015-09-15

    An exact analytic solution is found for the steady-state distribution function of fast electrons with an arbitrary initial spectrum irradiating a planar low-Z plasma with an arbitrary density distribution. The solution is applied to study the heating of a material by fast electrons of different spectra such as a monoenergetic spectrum, a step-like distribution in a given energy range, and a Maxwellian spectrum, which is inherent in laser-produced fast electrons. The heating of shock- and fast-ignited precompressed inertial confinement fusion (ICF) targets as well as the heating of a target designed to generate a Gbar shock wave for equation of state (EOS) experiments by laser-produced fast electrons with a Maxwellian spectrum is investigated. A relation is established between the energies of two groups of Maxwellian fast electrons, which are responsible for generation of a shock wave and heating the upstream material (preheating). The minimum energy of the fast and shock igniting beams as well as of the beam for a Gbar shock wave generation increases with the spectral width of the electron distribution.

  6. Induction of heat shock proteins in B-cell exosomes.

    Science.gov (United States)

    Clayton, Aled; Turkes, Attilla; Navabi, Hossein; Mason, Malcolm D; Tabi, Zsuzsanna

    2005-08-15

    Exosomes are nanometer-sized vesicles secreted by a diverse range of live cells that probably have physiological roles in modulating cellular immunity. The extracellular factors that regulate the quantity and phenotype of exosomes produced are poorly understood, and the properties of exosomes that dictate their immune functions are not yet clear. We investigated the effect of cellular stress on the exosomes produced by B-lymphoblastoid cell lines. Under steady-state conditions, the exosomes were positive for hsp27, hsc70, hsp70 and hsp90, and other recognised exosome markers such as MHC class I, CD81, and LAMP-2. Exposing cells to heat stress (42 degrees C for up to 3 hours), resulted in a marked increase in these heat shock proteins (hsps), while the expression of other stress proteins such as hsp60 and gp96 remained negative, and other exosome markers remained unchanged. Stress also triggered a small increase in the quantity of exosomes produced [with a ratio of 1.245+/-0.07 to 1 (mean+/-s.e.m., n=20) of 3-hour-stress-exosomes to control-exosomes]. Flow-cytometric analysis of exosome-coated beads and immuno-precipitation of intact exosomes demonstrated that hsps were located within the exosome lumen, and not present at the exosome-surface, suggesting that such exosomes may not interact with target cells through cell-surface hsp-receptors. Functional studies further supported this finding, in that exosomes from control or heat-stressed B cells did not trigger dendritic cell maturation, assessed by analysis of dendritic-cell-surface phenotype, and cytokine secretion profile. Our findings demonstrate that specific alterations in exosome phenotype are a hitherto unknown component of the cellular response to environmental stress and their extracellular function does not involve the direct activation of dendritic cells. PMID:16046478

  7. Heating of Heavy Ions by Interplanetary Coronal Mass Ejection (ICME) Driven Collisionless Shocks

    CERN Document Server

    Korreck, K E; Lepri, S T; Raines, J M

    2006-01-01

    Shock heating and particle acceleration processes are some of the most fundamental physical phenomena of plasma physics with countless applications in laboratory physics, space physics, and astrophysics. This study is motivated by previous observations of non-thermal heating of heavy ions in astrophysical shocks (Korreck et al. 2004). Here, we focus on shocks driven by Interplanetary Coronal Mass Ejections (ICMEs) which heat the solar wind and accelerate particles. This study focuses specifically on the heating of heavy ions caused by these shocks. Previous studies have focused only on the two dynamically dominant species, H+ and He2+ . This study utilizes thermal properties measured by the Solar Wind Ion Composition Spectrometer (SWICS) aboard the Advanced Composition Explorer (ACE) spacecraft to examine heavy ion heating. This instrument provides data for many heavy ions not previously available for detailed study, such as Oxygen (O6+, O7+), Carbon (C5+, C6+), and Iron (Fe10+). The ion heating is found to d...

  8. Impact of cloud radiative heating on East Asian summer monsoon circulation

    International Nuclear Information System (INIS)

    The impacts of cloud radiative heating on the East Asian Summer Monsoon (EASM) over southeastern China (105°–125°E, 20°–35°N) are addressed by using the Community Atmosphere Model version 5 (CAM5). Sensitivity experiments demonstrate that the radiative heating of clouds leads to a positive effect on the local EASM circulation over southeastern China. Without the radiative heating of clouds, the EASM circulation and precipitation would be much weaker than that in normal conditions. The longwave heating of clouds dominates the changes of EASM circulation. The positive effect of clouds on EASM circulation is explained by the thermodynamic energy equation, i.e. the different heating rate between cloud base and cloud top enhances the convective instability over southeastern China, which consequently enhances updraft. The strong updraft would further result in a southward meridional wind above the center of the updraft through Sverdrup vorticity balance. (letter)

  9. Effects of Heat Stress on Yeast Heat Shock Factor-Promoter Binding In Vivo

    Institute of Scientific and Technical Information of China (English)

    Ning LI; Le-Min ZHANG; Ke-Qin ZHANG; Jing-Shi DENG; Ralf PR(A)NDL; Fritz SCH(O)FFL

    2006-01-01

    Heat shock factor-DNA interaction is critical for understanding the regulatory mechanisms of stress-induced gene expression in eukaryotes. In this study, we analyzed the in vivo binding of yeast heat shock factor (HSF) to the promoters of target genes ScSSA1, ScSSA4, HSP30 and HSP104, using chromatin immunoprecipitation. Previous work suggested that yeast HSF is constitutively bound to DNA at all temperatures. Expression of HSF target genes is regulated at the post-transcriptional level. However, our results indicated that HSF does not bind to the promoters of ScSSA4 and HSP30 at normal temperature (23 ℃). Binding to these promoters is rapidly induced by heat stress at 39 ℃. HSF binds to ScSSA1 and HSP104 promoters under non-stress conditions, but at a low level. Heat stress rapidly leads to a notable increase in the binding of HSF to these two genes. The kinetics of the level of HSF-promoter binding correlate well with the expression of target genes, suggesting that the expression of HSF target genes is at least partially the result of HSF-promoter binding stability and subsequent transcription stimulation.

  10. Expression profile of heat shock response factors during hookworm larval activation and parasitic development.

    Science.gov (United States)

    Gelmedin, Verena; Delaney, Angela; Jennelle, Lucas; Hawdon, John M

    2015-07-01

    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 12h, and slightly in activated larvae by 24h 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

  11. Errors in macromolecular synthesis after stress : a study of the possible protective role of the small heat shock proteins

    NARCIS (Netherlands)

    Marin Vinader, L.

    2006-01-01

    The general goal of this thesis was to gain insight in what small heat shock proteins (sHsps) do with respect to macromolecular synthesis during a stressful situation in the cell. It is known that after a non-lethal heat shock, cells are better protected against a subsequent more severe heat shock,

  12. Heat-shock-induced cellular responses to temperature elevations occurring during orthopaedic cutting.

    Science.gov (United States)

    Dolan, E B; Haugh, M G; Tallon, D; Casey, C; McNamara, L M

    2012-12-01

    Severe heat-shock to bone cells caused during orthopaedic procedures can result in thermal damage, leading to cell death and initiating bone resorption. By contrast, mild heat-shock has been proposed to induce bone regeneration. In this study, bone cells are exposed to heat-shock for short durations occurring during surgical cutting. Cellular viability, necrosis and apoptosis are investigated immediately after heat-shock and following recovery of 12, 24 h and 4 days, in osteocyte-like MLO-Y4 and osteoblast-like MC3T3-E1 cells, using flow cytometry. The regeneration capacity of heat-shocked Balb/c mesenchymal stem cells (MSCs) and MC3T3-E1s has been investigated following 7 and 14 day's recovery, by quantifying proliferation, differentiation and mineralization. An immediate necrotic response to heat-shock was shown in cells exposed to elevated temperatures (45°C, 47°C and most severe at 60°C). A longer-term apoptotic response is induced in MLO-Y4s and, to a lesser extent, in MC3T3-E1s. Heat-shock-induced differentiation and mineralization by MSCs. These findings indicate that heat-shock is more likely to induce apoptosis in osteocytes than osteoblasts, which might reflect their role as sensors detecting and communicating damage within bone. Furthermore, it is shown for the first time that mild heat-shock (less than equal to 47°C) for durations occurring during surgical cutting can positively enhance osseointegration by osteoprogenitors. PMID:22915633

  13. Experimental study on circulation characteristics of secondary passive heat removal system for Chinese pressurized water reactor

    International Nuclear Information System (INIS)

    Nuclear safety has attracted increasingly global attention. The secondary side natural circulation heat removal system is one of several passive safety systems designed to ensure the safety of the reactor core. The passive heat removal systems are also adopted in the safety system design of Chinese third-generation pressurized water reactor. To complete its design and verify its feasibility, an experimental facility, which is named SPHRS, was built to investigate the heat removal capacity and the stability characteristics of the steam generator secondary side passive heat removal system. The experimental facility consists of a steam generator simulator, an instrumented condenser test section with a secondary pool boiling section, a pump, a water storage tank, and associated piping and instrumentation. The heat removal capacity under varying pressures and characteristics of natural circulation at steady-state as well as system power input drop condition were obtained. The results show that the SPHRS has sufficient capacity to remove the decay heat. It is found that the natural circulation can be maintained under different pressures, the heat load sudden change condition as well, which indicates that the SPHRS natural circulation has good stability. - Highlights: • The stability of secondary side passive heat removal system of a PWR was studied. • The heat removal capacity of the condenser tube was investigated. • The natural circulation characteristics of SPHRS were investigated

  14. Heat-Shock Protein 90-Targeted Nano Anticancer Therapy.

    Science.gov (United States)

    Rochani, Ankit K; Ravindran Girija, Aswathy; Borah, Ankita; Maekawa, Toru; Sakthi Kumar, D

    2016-04-01

    Suboptimal chemotherapy of anticancer drugs may be attributed to a variety of cellular mechanisms, which synergize to dodge the drug responses. Nearly 2 decades of heat-shock protein 90 (Hsp90)-targeted drug discovery has shown that the mono-therapy with Hsp90 inhibitors seems to be relatively ineffective compared with combination treatment due to several cellular dodging mechanisms. In this article, we have tried to analyze and review the Hsp90 and mammalian target of rapamycin (m-TOR)-mediated drug resistance mechanisms. By using this information we have discussed about the rationale behind use of drug combinations that includes both or any one of these inhibitors for cancer therapy. Currently, biodegradable nano vector (NV)-loaded novel drug delivery systems have shown to resolve the problems of poor bioavailability. NVs of drugs such as paclitaxel, doxorubicin, daunorubicin, and others have been successfully introduced for medicinal use. Hence, looking at the success of NVs, in this article we have also discussed the progress made in the delivery of biodegradable NV-loaded Hsp90 and m-TOR-targeted inhibitors in multiple drug combinations. We have also discussed the possible ways by which the market success of biodegradable NVs can positively impact the clinical trials of anti-Hsp90 and m-TOR combination strategy. PMID:26886301

  15. Post heat shock tolerance: a neuroimmunological anti-inflammatory phenomenon

    Directory of Open Access Journals (Sweden)

    Jazani Nima

    2009-03-01

    Full Text Available Abstract We previously showed that the progression of burn-induced injury was inhibited by exposing the peripheral area of injured skin to sublethal hyperthermia following the burn. We called this phenomenon post-heat shock tolerance. Here we suggest a mechanism for this phenomenon. Exposure of the peripheral primary hyperalgesic/allodynic area of burned skin to local hyperthermia (45°C, 30 seconds, which is a non-painful stimulus for normal skin, results in a painful sensation transmitted by nociceptors. This hyperthermia is too mild to induce any tissue injury, but it does result in pain due to burn-induced hyperalgesia/allodynia. This mild painful stimulus can result in the induction of descending anti-nociceptive mechanisms, especially in the adjacent burned area. Some of these inhibitory mechanisms, such as alterations of sympathetic outflow and the production of endogenous opioids, can modify peripheral tissue inflammation. This decrease in burn-induced inflammation can diminish the progression of burn injury.

  16. Heat shock protein expression in canine malignant mammary tumours

    Directory of Open Access Journals (Sweden)

    Sarli Giuseppe

    2006-06-01

    Full Text Available Abstract Background Abnormal levels of Heat Shock Proteins (HSPs have been observed in many human neoplasms including breast cancer and it has been demonstrated that they have both prognostic and therapeutic implications. In this study, we evaluated immunohistochemical expression of HSPs in normal and neoplastic canine mammary glands and confronted these results with overall survival (OS, in order to understand the role of HSPs in carcinogenesis and to establish their potential prognostic and/or therapeutic value. Methods Immunohistochemical expression of Hsp27, Hsp72, Hsp73 and Hsp90 was evaluated in 3 normal canine mammary glands and 30 malignant mammary tumours (10 in situ carcinomas, 10 invasive carcinomas limited to local structures without identifiable invasion of blood or lymphatic vessels, 10 carcinomas with invasion of blood or lymphatic vessels and/or metastases to regional lymph nodes. A semi-quantitative method was used for the analysis of the results. Results Widespread constitutive expression of Hsp73 and Hsp90 was detected in normal tissue, Hsp72 appeared to be focally distributed and Hsp27 showed a negative to rare weak immunostaining. In mammary tumours, a significant increase in Hsp27 (P Conclusion These results suggest that Hsp27, Hsp72 and Hsp90 are involved in canine mammary gland carcinogenesis. In addition, Hsp27 appears to be implicated in tumour invasiveness and its high immunodetection in invasive tumours is indicative of a poorer clinical outcome.

  17. The Involvement of Heat Shock Proteins in Murine Liver Regeneration

    Institute of Scientific and Technical Information of China (English)

    Qing Shi; Zhongjun Dong; Haiming Wei

    2007-01-01

    Partial hepatectomy (PHx) in mammals is a very common experimental model to investigate the process of liver regeneration. The surgery itself could give birth to a series of stresses, such as the temporary raise of body temperature and the ischaemia-reperfusion injury. Heat shock proteins (HSPs) were a family of stress-inducible proteins involved in maintaining cell homeostasis and regulating the immune system. In our study, we intended to investigate the expression and role of HSPs in liver regeneration. Using RT-PCR and Western blotting, we determined the expression in regenerating liver of HSP27, HSP60, HSP70 and HSP90 in mRNA level and protein level, respectively, with mice treated with sham operation as controls. We also used quercertin as an inhibitior of HSPs to explore their effects on liver regeneration. We found that hepatic expression of HSPs increased at the early phase of liver regeneration and declined to the constitutively low level later. Moreover, quercetin pretreatment delayed the progress of liver regeneration in mice via inhibition of HSPs. The results indicated that HSPs played an important role in liver regeneration.

  18. Heat Shock Proteins in Human Endometrium Throughout the Menstrual Cycle

    Directory of Open Access Journals (Sweden)

    J. Broome

    1999-01-01

    Full Text Available Human endometrium, in response to steroid hormones, undergoes characteristic cycles of proliferation, secretory changes, and tissue shedding. Human endometrium expresses a molecular repertoire which includes the heat shock proteins (Hsps Hsp27, Hsp60, Hsp70, Hsp90, and alpha crystallin B chain. The expression of Hsp27, Hsp60, and the constitutive form of Hsp70 (Hsc70 shows a sharp increase in human endometrium after ovulation. The maximal expression of the molecular chaperone, alpha crystallin B chain, occurs during the secretory phase. In view of known functions of the Hsps, it is likely that these proteins are involved in protection of the endometrial proteins against factors with the potential to lead to protein denaturation. Tumor necrosis factor-α (TNF-α is a cytotoxic cytokine that is produced in progressive amounts during the secretory phase. The function of the Hsps may be to protect cells against the cytotoxic damage of TNF-α, particularly during the critical period of “implantation window.” Infect. Dis. Obstet. Gynecol. 7:5–9, 1999. (C 1999 Wiley-Liss, Inc.

  19. Heat-shock protein 90 in Candida albicans

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Researches on Candidal heat-shock protein 90 (HSP90) in recent years are summarized.Candida albicans is a commensal pathogen in human and animals.In immunocompromised individuals it behaves as an opportunist pathogen,giving rise to superficial or systemic infections.Systemic candidosis is a common cause of death among immunocompromised and debilitated patients,in which the mortality is as high as 70%.HSP90 is now recognized as an immunodominant antigen in C.albicans and plays a key role in systemic candidosis as a molecular chaperone.The 47-ku peptide is the breakdown product of HSP90.Patients who has recovered from systemic candidosis produce high titre of antibodies to 47-ku antigen,whereas the fatal cases have little antibody or falling titres.The three commonest epitopes of candidal HSP90 have been mapped,epitopes C,B and H.Epitopes C and H are immunogenic.The antibody probes of both epitopes may be developed into a new serological test agents for systemic candidosis due to rather high specificity and sensitivity.The recent results establish HSP90 as an ATP-dependent chaperone that is involved in the folding of cell regulatory proteins and in the refolding of stress-denatured polypeptides.Some researches on fungal HSP90 and the treatment of patients with candidosis are reviewed as well.

  20. Heat shock response of the blue crab Portunus pelagicus:thermal stress and acclimation

    Institute of Scientific and Technical Information of China (English)

    Suhaila Qari

    2014-01-01

    Objective:To determine the effect of prior heat shock on the CTMax of differently acclimated Portunus pelagicus (P. pelagicus) as well as the time course of the changes in CTMax post heat shock. Methods: Crabs P. pelagicus were held in laboratory aquaria in tanks, which were supplied with filtered and aerated seawater. Crabs were acclimated at 20 °C, 25 °C, 30 °C and 35 °C for 3 weeks before their CTMax was determined. The CTMax was recorded for each crab as the median temperature during the 5 min period when a crab was not able to right itself, the average CTMax was calculated. The effect of heat shock on subsequent CTMax was measured. Crabs were heat shocked at temperature 1 °C lower than the CTMax for 20 min, followed by either 0.5 h, 1 h or 1.5 h recovery at 20 °C. The same procedure was repeated at other acclimation temperatures (25 °C, 30 °C and 35 °C). Results: Temperature acclimation of P. pelargicus from 20-35 °C progressively increased the CTMax. Acclimation at 35 °C the CTMax was 42.66 °C, whereas acclimation at 20 °C the CTMax was 39.8 °C. In P. pelagicus acclimated, at 20 °C the CTMax values after heat shock were significantly higher than crabs in control for 30 min, 1 h and 1.5 h after heat shock. In the 25 °C and 30 °C acclimated crabs, the CTMax values after heat shock were significantly higher than control only in 30 min and 1 h after heat shock. No significant differences in 35 °C acclimated crabs between control and heat shocked crabs were found after recovery for 30 min, 1 h, or 1.5 h. Conclusions: Heat shock caused significant rises in the CTMax, however, this increase was progressively reduced with longer recovery times at the acclimation temperature. For 20 °C acclimated crabs, the increased CTMax was still evident after 90 min, but for 25 °C and 30 °C crabs, the response was over after 90 min. Heat shock of 35 °C crabs was problematical, the CTMax gave no increased thermotolerance. It must be concluded that the

  1. Characterization of Streptomyces albus 18-kilodalton heat shock-responsive protein.

    OpenAIRE

    Servant, P; Mazodier, P

    1995-01-01

    In Streptomyces albus during the heat shock response, a small heat shock protein of 18 kDa is dramatically induced. This protein was purified, and internal sequences revealed that S. albus HSP18 showed a marked homology with proteins belonging to the family of small heat shock proteins. The corresponding gene was isolated and sequenced. DNA sequence analysis confirmed that the hsp18 gene product is an analog of the 18-kDa antigen of Mycobacterium leprae. No hsp18 mRNA could be detected at 30 ...

  2. Reassembly and protection of small nuclear ribonucleoprotein particles by heat shock proteins in yeast cells.

    OpenAIRE

    Bracken, A P; Bond, U

    1999-01-01

    The process of mRNA splicing is sensitive to in vivo thermal inactivation, but can be protected by pretreatment of cells under conditions that induce heat-shock proteins (Hsps). This latter phenomenon is known as "splicing thermotolerance". In this article we demonstrate that the small nuclear ribonucleoprotein particles (snRNPs) are in vivo targets of thermal damage within the splicing apparatus in heat-shocked yeast cells. Following a heat shock, levels of the tri-snRNP (U4/U6.U5), free U6 ...

  3. [Small heat shock proteins and adaptation to hypertermia in various Drosophila species].

    Science.gov (United States)

    Shilova, V Iu; Garbuz, D G; Evgen'ev, M B; Zatsepina, O G

    2006-01-01

    Expression level and kinetics of accumulation of small heat shock proteins (21-27 kDa group) have been investigated in three Drosophila species differing significantly by temperature niche and thermosensitivity. It was shown that low-latitude thermotolerant species D. virilis exceeds the high-latitude thermosensitive closely-related species D. lummei as well as distant thermosensitive species D. melanogaster in terms of small heat shock proteins expression and accumulation after temperature elevation. The data obtained enable to postulate an important role of small heat shock proteins in organism basal thermotolerance and general adaptation to adverse conditions of environment. PMID:16637267

  4. Spatial Structure and Collisionless Electron Heating in Balmer-dominated Shocks

    OpenAIRE

    van Adelsberg, Matthew; Heng, Kevin; McCray, Richard; Raymond, John C.

    2008-01-01

    Balmer-dominated shocks in supernova remnants (SNRs) produce strong hydrogen lines with a two-component profile composed of a narrow contribution from cold upstream hydrogen atoms, and a broad contribution from hydrogen atoms that have undergone charge transfer reactions with hot protons. Observations of emission lines from edge-wise shocks in SNRs can constrain the gas velocity and collisionless electron heating at the shock front. Downstream hydrogen atoms engage in charge transfer, excitat...

  5. Estimation of thermal shock resistance of fine porous alumina by infrared radiation heating method

    OpenAIRE

    Iwamoto, Yuji; Honda, Sawao; Ogihara, Yuki; Kishi, Tsunego; イワモト, ユウジ; ホンダ, サワオ; 岩本, 雄二; 本多, 沢雄

    2009-01-01

    The thermal shock resistance of α-alumina porous capillary, the support material for hydrogen-permselective microporous ceramic membrane was studied. To study the effect of porosity on the thermal shock resistance systematically, porous alumina with different porosities was fabricated, and the thermal shock resistance of the fabricated samples as well as the porous capillary was estimated by the infrared radiation heating method. The mechanical and thermal properties concerned to the thermal ...

  6. Transgenic sickle cell trait mice do not exhibit abnormal thermoregulatory and stress responses to heat shock exposure.

    Science.gov (United States)

    Chen, Yifan; Islam, Aminul

    2016-07-01

    There remains controversy over whether individuals with sickle cell trait (SCT) are vulnerable to health risks during physical activity in high temperatures. We examined thermoregulatory and stress-related responses to heat exposure in SCT and wild-type (WT) mice. No significant differences in core temperature (Tc) were observed between SCT and WT mice during heat exposure. There was no correlation between peak Tc during heat exposure and levels of hemoglobin S in SCT mice. Basal levels of circulating inflammatory and stress-related markers were not significantly different between SCT and WT mice. Although heat exposure caused significant increases in plasma interleukins 1β and 6, and 8-isoprostane in SCT and WT mice, no differences were found between SCT and WT mice with similar thermal response profiles during heat exposure. SCT mice had significantly higher expression of heat shock protein 72 in heart, liver and gastrocnemius muscle than WT mice under control and post-heat conditions. In conclusion, there is neither thermoregulatory dysfunction nor abnormal stress-related response in SCT mice exposed to moderate heat. The hemoglobin variant in mice is associated with altered tissue stress protein homeostasis. PMID:27282581

  7. Analysis of heat shock gene expression in Lactococcus lactis MG1363

    DEFF Research Database (Denmark)

    Arnau, José; Sørensen, Kim; Appel, Karen Fuglede;

    1996-01-01

    The induction of the heat shock response in Lactococcus lactis subsp. cremoris strain MG1363 was analysed at the RNA level using a novel RNA isolation procedure to prevent degradation. Cloning of the dnaJ and groEL homologous was carried out. Nothern blot analysis showed a similar induction pattern...... heat shock response in L. lactis MG1363 is presented. A gene located downstream of the dnaK operon in strain MG1363, named orf4, was shown not to be regulated by heat shock......., although maximum induction was observed earlier for orf1 and grpE. Novel transcript sizes were detected in heat-shocked cells. The induction kinetics observed for ftsH suggested a different regulation for this gene. Experimental evidence for a prenounced transcriptional regulation being involved in the...

  8. In vitro association of mitochondrial ATP-dependent protease with mitochondrial heat-shock proteins

    International Nuclear Information System (INIS)

    Specific antibodies against the mitochondrial ATP-dependent protease and heat-shock proteins were used to study the association of these proteins with an abnormal bacterial protein, CRAG. It was shown that the mitochondrial ATP-dependent protease from rat liver and Zajdela hepatoma bind to the CRAG protein and that this binding was mediated through the heat-shock proteins. It was also demonstrated that the protease associated with heat-shock proteins is capable of degrading large proteins as well as small peptides in an ATP-dependent fashion. Zajdela hepatoma mitochondria, with enhanced mitochondrial proteolysis, were shown to contain more ATP-dependent protease associated with heat-shock proteins. (author)

  9. Simplified thermal-hydraulic analysis of single phase natural circulation circuit with two heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Pinheiro, Larissa Cunha; Su, Jian, E-mail: larissa@lasme.coppe.ufrj.br, E-mail: sujian@lasme.coppe.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenhraria Nuclear; Cotta, Renato Machado, E-mail: cotta@mecanica.coppe.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (POLI/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Dept. de Engenharia Mecanica

    2015-07-01

    Single phase natural circulation circuits composed of two convective heat exchangers and connecting tubes are important for the passive heat removal from spent fuel pools (SFP). To keep the structural integrity of the stored spent fuel assemblies, continuously cooling has to be provided in order to avoid increase at the pool temperature and subsequent uncovering of the fuel and enhanced reaction between water and metal releasing hydrogen. Decay heat can achieve considerably high amounts of energy e.g. in the AP1000, considering the emergency fuel assemblies, the maximum heat decay will reach 13 MW in the 15th day (Westinghouse Electric Company, 2010). A highly efficient alternative to do so is by means of natural circulation, which is cost-effective compared to active cooling systems and is inherently safer since presents less associated devices and no external work is required. Many researchers have investigated safety and stability aspects of natural circulation loops (NCL). However, there is a lack of literature concerning the improvement of NCL through a standard unified methodology, especially for natural circulation circuits with two heat exchangers. In the present study, a simplified thermal-hydraulic analysis of single phase natural circulation circuit with two heat exchanges is presented. Relevant dimensionless key groups were proposed to for the design and safety analysis of a scaled NCL for the cooling of spent fuel storage pool with convective cooling and heating. (author)

  10. Mechanism of protonophores-mediated induction of heat-shock response in Escherichia coli

    Directory of Open Access Journals (Sweden)

    Saha Swati

    2009-01-01

    Full Text Available Abstract Background Protonophores are the agents that dissipate the proton-motive-force (PMF across E. coli plasma membrane. As the PMF is known to be an energy source for the translocation of membrane and periplasmic proteins after their initial syntheses in cell cytoplasm, protonophores therefore inhibit the translocation phenomenon. In addition, protonophores also induce heat-shock-like stress response in E. coli cell. In this study, our motivation was to investigate that how the protonophores-mediated phenomena like inhibition of protein translocation and induction of heat-shock proteins in E. coli were correlated. Results Induction of heat-shock-like response in E. coli attained the maximum level after about 20 minutes of cell growth in the presence of a protonophore like carbonyl cyanide m-chloro phenylhydrazone (CCCP or 2, 4-dinitrophenol (DNP. With induction, cellular level of the heat-shock regulator protein sigma-32 also increased. The increase in sigma-32 level was resulted solely from its stabilization, not from its increased synthesis. On the other hand, the protonophores inhibited the translocation of the periplasmic protein alkaline phosphatase (AP, resulting its accumulation in cell cytosol partly in aggregated and partly in dispersed form. On further cell growth, after withdrawal of the protonophores, the previously accumulated AP could not be translocated out; instead the AP-aggregate had been degraded perhaps by an induced heat-shock protease ClpP. Moreover, the non-translocated AP formed binary complex with the induced heat-shock chaperone DnaK and the excess cellular concentration of DnaK disallowed the induction of heat-shock response by the protonophores. Conclusion Our experimental results suggested that the protonophores-mediated accumulation and aggregation of membrane proteins (like AP in cell cytosol had signaled the induction of heat-shock proteins in E. coli and the non-translocated protein aggregates were possibly

  11. Heat shock proteins and hypometabolism: adaptive strategy for proteome preservation

    Directory of Open Access Journals (Sweden)

    Storey KB

    2011-03-01

    Full Text Available Kenneth B Storey, Janet M StoreyDepartments of Biology and Chemistry, Carleton University, Ottawa, ON, CanadaAbstract: To survive under harsh environmental conditions many organisms retreat into hypometabolic states where metabolic rate may be reduced by 80% or more and energy use is reprioritized to emphasize key functions that sustain viability and provide cytoprotection. ATP-expensive activities, such as gene expression, protein turnover (synthesis and degradation, and the cell cycle, are largely shut down. As a consequence, mechanisms that stabilize the existing cellular proteome can become critical for long-term survival. Heat shock proteins (HSPs are well-known for their actions as chaperones that act to fold new proteins or refold proteins that are damaged. Indeed, they are part of the “minimal stress proteome” that appears to be a ubiquitous response by all cells as they attempt, successfully or unsuccessfully, to deal with stress. The present review summarizes evidence that HSPs are also a conserved feature of natural animal hypometabolism including the phenomena of estivation, hibernation, diapause, cold-hardiness, anaerobiosis, and anhydrobiosis. That is, organisms that retreat into dormant or torpid states in anticipation that environmental conditions may become too difficult for normal life also integrate the use of HSPs to protect their proteome while hypometabolic. Multiple studies show a common upregulation of expression of hsp genes and/or HSP proteins prior to or during hypometabolism in organisms as diverse as ground squirrels, turtles, land snails, insects, and brine shrimp and in situations of both preprogrammed dormancies (eg, seasonal or life stage specific and opportunistic hypometabolism (eg, triggered by desiccation or lack of oxygen. Hence, HSPs are not just a “shock” response that attempts to rescue cells from damaging stress but are a key protective strategy that is an integral component of natural states of

  12. The Difficulty of the Heating of Cluster Cooling Flows by Sound Waves and Weak Shocks

    OpenAIRE

    Fujita, Yutaka; Suzuki, Takeru Ken

    2006-01-01

    We investigate heating of the cool core of a galaxy cluster through the dissipation of sound waves and weak shocks excited by the activities of the central active galactic nucleus (AGN). Using a weak shock theory, we show that this heating mechanism alone cannot reproduce observed temperature and density profiles of a cluster, because the dissipation length of the waves is much smaller than the size of the core and thus the wave energy is not distributed to the whole core.

  13. Role of heat shock factor-1 activation in the doxorubicin-induced heart failure in mice

    OpenAIRE

    Vedam, Kaushik; Nishijima, Yoshinori; Druhan, Lawrence J.; Khan, Mahmood; Moldovan, Nicanor I.; Zweier, Jay L.; Ilangovan, Govindasamy

    2010-01-01

    Treating cancer patients with chemotherapeutics, such as doxorubicin (Dox), cause dilated cardiomyopathy and congestive heart failure because of oxidative stress. On the other hand, heat shock factor-1 (HSF-1), a transcription factor for heat shock proteins (Hsps), is also known to be activated in response to oxidative stress. However, the possible role of HSF-1 activation and the resultant Hsp25 in chemotherapeutic-induced heart failure has not been investigated. Using HSF-1 wild-type (HSF-1...

  14. Elevated serine catabolism is associated with the heat shock response in Escherichia coli.

    OpenAIRE

    Matthews, R G; Neidhardt, F C

    1989-01-01

    The biochemical events associated with the heat shock response are not well understood in any organism, nor have the signals that initiate the induction of heat shock protein synthesis been identified. In this work, we demonstrate that the rate of serine catabolism of Escherichia coli cells grown in glucose minimal medium supplemented with serine is elevated three- to sevenfold when the growth temperature is shifted from 37 to 44 degrees C. Elevations in growth temperature and mutations or tr...

  15. Proteotoxic stress of cancer: implication of the heat-shock response in oncogenesis

    OpenAIRE

    Dai, Chengkai; Dai, Siyuan; Cao, Junyue

    2012-01-01

    Organisms frequently encounter a wide variety of proteotoxic stressors. The heat-shock response, an ancient cytoprotective mechanism, has evolved to augment organismal survival and longevity in the face of proteotoxic stress from without and within. These broadly recognized beneficial effects, ironically, contrast sharply with its emerging role as a culprit in the pathogenesis of cancers. Here, we present an overview of the normal biology of the heat-shock response and highlight its implicati...

  16. Heat Shock-Enhanced Conjugation Efficiency in Standard Campylobacter jejuni Strains

    OpenAIRE

    Zeng, Ximin; Ardeshna, Devarshi; Lin, Jun

    2015-01-01

    Campylobacter jejuni, the leading bacterial cause of human gastroenteritis in the United States, displays significant strain diversity due to horizontal gene transfer. Conjugation is an important horizontal gene transfer mechanism contributing to the evolution of bacterial pathogenesis and antimicrobial resistance. It has been observed that heat shock could increase transformation efficiency in some bacteria. In this study, the effect of heat shock on C. jejuni conjugation efficiency and the ...

  17. Heat Shock Transcription Factor 1-Deficiency Attenuates Overloading-Associated Hypertrophy of Mouse Soleus Muscle

    OpenAIRE

    Tomoyuki Koya; Sono Nishizawa; Yoshitaka Ohno; Ayumi Goto; Akihiro Ikuta; Miho Suzuki; Tomotaka Ohira; Tatsuro Egawa; Akira Nakai; Takao Sugiura; Yoshinobu Ohira; Toshitada Yoshioka; Moroe Beppu; Katsumasa Goto

    2013-01-01

    Hypertrophic stimuli, such as mechanical stress and overloading, induce stress response, which is mediated by heat shock transcription factor 1 (HSF1), and up-regulate heat shock proteins (HSPs) in mammalian skeletal muscles. Therefore, HSF1-associated stress response may play a key role in loading-associated skeletal muscle hypertrophy. The purpose of this study was to investigate the effects of HSF1-deficiency on skeletal muscle hypertrophy caused by overloading. Functional overloading on t...

  18. Detection of viable Giardia cysts by amplification of heat shock-induced mRNA.

    OpenAIRE

    Abbaszadegan, M; Huber, M. S.; Gerba, C P; Pepper, I L

    1997-01-01

    Primers obtained from gene sequences coding for heat shock proteins (HSP) were used to specifically detect enteric protozoans of the genus Giardia. The HSP primers amplified Giardia DNA or the corresponding RNA sequences obtained from lysed cysts and gave a 163-bp product. Since the presence of the product did not indicate whether the cysts were viable, these amplifications are a presence/absence test only. In contrast, amplification of heat shock-induced mRNA utilizing the same HSP primers w...

  19. A small heat shock/α-crystallin protein from encysted Artemia embryos suppresses tubulin denaturation

    OpenAIRE

    Day, Rossalyn M.; Gupta, Jagdish S.; MacRae, Thomas H.

    2003-01-01

    Small heat shock/α-crystallin proteins function as molecular chaperones, protecting other proteins from irreversible denaturation by an energy-independent process. The brine shrimp, Artemia franciscana, produces a small heat shock/α-crystallin protein termed p26, found in embryos undergoing encystment, diapause, and metabolic arrest. These embryos withstand long-term anoxia and other stresses normally expected to cause death, a property likely dependent on molecular chaperone activity. The as...

  20. Arctigenin from Fructus Arctii is a novel suppressor of heat shock response in mammalian cells

    OpenAIRE

    Ishihara, Keiichi; Yamagishi, Nobuyuki; Saito, Youhei; TAKASAKI, Midori; Konoshima, Takao; Hatayama, Takumi

    2006-01-01

    Because heat shock proteins (Hsps) are involved in protecting cells and in the pathophysiology of diseases such as inflammation, cancer, and neurodegenerative disorders, the use of regulators of the expression of Hsps in mammalian cells seems to be useful as a potential therapeutic modality. To identify compounds that modulate the response to heat shock, we analyzed several natural products using a mammalian cell line containing an hsp promoter-regulated reporter gene. In this study, we found...

  1. Infrared emission from shock-heated dust around SN 1987A

    International Nuclear Information System (INIS)

    Infrared emission as well as x-ray emission from SN 1987A will be enhanced substantially when the blast shock hits the dusty cricumstellar medium which has formed in the red-supergiant stage of the progenitor. The infrared luminosity of the shock-heated circumstellar dust may exceed the combined x-ray luminosity of the reverse-shocked supernova ejecta and the blast-shocked circumstellar medium despite considerable destruction of the dust grains through sputtering by the x-ray emitting gas. (author)

  2. Volume, heat, and freshwater transports of the global ocean circulation 1993-2000, estimated from a general circulation model constrained by World Ocean Circulation Experiment (WOCE) data

    Science.gov (United States)

    Stammer, D.; Wunsch, C.; Giering, R.; Eckert, C.; Heimbach, P.; Marotzke, J.; Adcroft, A.; Hill, C. N.; Marshall, J.

    2003-01-01

    An analysis of ocean volume, heat, and freshwater transports from a fully constrained general circulation model (GCM) is described. Output from a data synthesis, or state estimation, method is used by which the model was forced to large-scale, time-varying global ocean data sets over 1993 through 2000. Time-mean horizontal transports, estimated from this fully time-dependent circulation, have converged with independent time-independent estimates from box inversions over most parts of the world ocean but especially in the southern hemisphere. However, heat transport estimates differ substantially in the North Atlantic where our estimates result in only 1/2 previous results. The models drift over the estimation period is consistent with observations from TOPEX/Poseidon in their spatial pattern, but smaller in their amplitudes by about a factor of 2. Associated temperature and salinity changes are complex, and both point toward air-sea interaction over water mass formation regions as the primary source for changes in the deep ocean. The estimated mean circulation around Australia involves a net volume transport of 11 Sv through the Indonesian Throughflow and the Mozambique Channel. In addition, we show that this flow regime exists on all timescales above 1 month, rendering the variability in the South Pacific strongly coupled to the Indian Ocean. Moreover, the dynamically consistent variations in the model show temporal variability of oceanic heat transports, heat storage, and atmospheric exchanges that are complex and with a strong dependence upon location, depth, and timescale. Our results demonstrate the great potential of an ocean state estimation system to provide a dynamical description of the time-dependent observed heat transport and heat content changes and their relation to air-sea interactions.

  3. Impact of Heat-Shock Treatment on Yellowing of Pak Choy Leaves

    Institute of Scientific and Technical Information of China (English)

    WANG Xiang-yang; SHEN Lian-qing; YUAN Hai-na

    2004-01-01

    The physiological mechanism of maintaining the green colour of pak choy leaves (Brassica rapa var chinensis) with heat-shock treatment was studied. Chlorophyll in the outer leaves of pak choy degraded rapidly during storage at ambient temperature (20 ± 2℃), a slight yellow appeared. Heat-shock treatment (46- 50℃) had a mild effect on maintaining the green colour of outer leaves. Normal chlorophyll degradation was associated with a binding of chlorophyll with chlorophyll-binding-protein preceding chlorophyll breakdown.Heat-shock treatment was found to reduce the binding-capacity between chlorophyllbinding-protein and chlorophyll. In the chlorophyll degradation pathway, pheide dioxygenase was synthesized during leaf senescence which was considered to be a key enzyme in chlorophyll degradation. Activity of this enzyme was reduced following heat-shock treatment, which might explain the observed reduction in chlorophyll breakdown. Two groups of heat-shock proteins were detected in treated leaves, the first group containing proteins from 54KDa to 74 Kda, and the second group contained proteins from 15 KDa to 29KDa. Heat-shock treatment was also found to retard the decline of glucose and fructose (the main energy substrates) of outer leaves.

  4. Induced Levels of Heat Shock Proteins in dnaK mutants of Lactococcus lactis

    DEFF Research Database (Denmark)

    Koch, Birgit; Hammer, Karin; Vogensen, Finn K.;

    1998-01-01

    The bacterial heat shock response is characterized by the elevated expression of a number of chaperone complexes and proteases including the DnaK-GrpE-DnaJ and the GroELS chaperone complexes. In order to investigate the importance of the DnaK chaperone complex for the growth and the heat shock...... the inferred substrate binding site of the DnaK protein, exhibits a pronounced temperature sensitive phenotype and shows altered regulation of the heat shock response. The expression of the heat shock proteins are increased at the normal growth temperature measured both as protein synthesis rates and...... mRNA levels which indicate that DnaK could be involved in the regulation of the heat shock response in Lactococcus lactis. In Bacillus subtilis it has been found by Mogk,A., G.Homouth, C. Scholz, L. Kim, F.X. Schmid, and W. Schumann. 1997. EMBO J. 16: 4579-4590, that the activity of the heat shock...

  5. Factors influencing the kinetics of heat shock protein expression in human lymphocytes

    International Nuclear Information System (INIS)

    Full text: All organisms, from bacteria to humans, respond to various forms of environmental stresses by inducing the synthesis of a highly conserved set of proteins, the heat shock proteins (hsps) or stress proteins. Many hsps are also expressed constitutively at lower levels and in this capacity perform essential cellular functions including protein trafficking and chaperone activity. Our approach was to follow the kinetics of hsp expression in both control and heat shocked human peripheral lymphocytes from young and old individuals. Heat shock treatment was at 42 deg C for 1 h and samples were taken at various time points during heat shock and following recovery at 37 deg C. Samples were analysed using both 35[S] methionine-labelling and western blot analysis. In addition, we investigated the possible role of phosphorylation in modulating the activity of hsps utilising phospho-specific antibodies in western blot analysis as well as metabolic 32[P] phosphate-labelling. Our study showed that hsp expression is elevated at the end of heat shock treatment, but can be seen at a lower level from 30 min during heat shock. The time taken to reach maximal induction varied for different hsps. For example hsp 70 appeared to peak at 3 h following recovery, which is consistent with previous findings. The results from western blots using phospho-specific antibodies and also the de novo synthesis of 32[P] phosphate-labelled hsps are preliminary and experiments are currently in progress

  6. Short communication: lack of breed differences in responses of bovine spermatozoa to heat shock.

    Science.gov (United States)

    Chandolia, R K; Reinertsen, E M; Hansen, P J

    1999-12-01

    An experiment was conducted to test whether the magnitude of effects of heat shock on spermatozoal function were less for thermotolerant breeds (Brahman and other breeds with Brahman influence) than for breeds that evolved in northern Europe (Angus and Holstein). Frozen spermatozoa were thawed, purified by Percoll gradient centrifugation and incubated at 38.5, 41, or 42 degrees C for 4 h. Sperm motility was then analyzed with a Hamilton Thorn Motility Analyzer. Heat shock reduced the percentage of sperm that were motile, mean track speed, and mean path velocity. There were no significant breed x temperature interactions for these traits. The mean frequency of tail beat tended to be reduced by heat shock in bulls of Brahman-influenced breeds and, to a lesser extent, in Brahman bulls, but it was not affected by heat shock in Angus or Holstein bulls. For no traits were there significant temperature x bull within breed interactions. Overall, results indicate that 1) heat shock reduces motility of bovine spermatozoa and 2) genetic effects are unlikely to be an important determinant of the function of ejaculated sperm following heat shock. PMID:10629808

  7. The effects of drying following heat shock exposure of the desert moss Syntrichia caninervis

    Energy Technology Data Exchange (ETDEWEB)

    Xu Shujun; Liu Chunjiang [School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240 (China); Jiang Pingan [College of Pratacultural and Environmental Science, Xinjiang Agricultural University, Urumqi 830052 (China); Cai Weimin [School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Wang Yan [School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China)], E-mail: xusj@mail.sjtu.edu.cn

    2009-03-15

    Desert mosses are components of biological soil crusts (BSCs) and their ecological functions make assessment and protection of these mosses a high-ranking management priority in desert regions. Drying is thought to be useful for desert mosses surviving heat shock. In this study, we investigated the role of drying by monitoring the responses of physiological characters and asexual reproduction in the typical desert moss Syntrichia caninervis. Heat significantly decreased chlorophyll content and weakened rapid recovery of photochemical activity, and increased carotenoid content and membrane permeability. Lethal temperatures significantly destroyed shoot regeneration potential. In comparison with heat alone, drying significantly increased protonema emergence time and depressed protonema emergence area. Drying combined with heat accelerated water loss, followed by a decrease of photosynthetic activity. Drying had different influences on membrane permeability at different temperatures. When moss leaves were subjected to a combined stress of drying and heat shock, photosynthesis was maintained mainly due to the effects of drying on physiological activity although the cellular morphological integrity was affected. Drying caused opposing effects on moss physiological and reproductive characteristics. On the one hand, drying caused a positive synergistic effect with heat shock when the temperature was below 40 deg. C. On the other hand, drying showed antagonism with heat shock when the moss was subjected to temperatures higher than 40 deg. C. These findings may help in understanding the survival mechanism of dessert mosses under heat shock stress which will be helpful for the artificial reconstruction of BSCs.

  8. The detection and role of heat shock protein 70 in various nondisease conditions and disease conditions: a literature review.

    Science.gov (United States)

    Qu, Baoge; Jia, Yiguo; Liu, Yuanxun; Wang, Hui; Ren, Guangying; Wang, Hong

    2015-11-01

    As an intracellular polypeptide, heat shock protein 70 (HSP70) can be exposed on the plasma membrane and/or released into the circulation. However, the role of HSP70 in various nondisease and disease conditions remains unknown. Quantitative methods for the detection of HSP70 have been used in clinical studies, revealing that an increase in circulating HSP70 is associated with various types of exercise, elderly patients presenting with inflammation, mobile phones, inflammation, sepsis, chronic obstructive pulmonary disease, asthma, carotid intima-media thickness, glutamine-treated ill patients, mortality, diabetes mellitus, active chronic glomerulonephritis, and cancers. Circulating HSP70 decreases with age in humans and in obstructive sleep apnea, arteriosclerosis, atrial fibrillation (AF) following coronary artery bypass surgery, nonalcoholic fatty liver disease, moderate-to-severe alcoholic fatty liver disease, hepatic steatosis, and Helicobacter pylori infection. In conclusion, quantitative methods can be used to detect HSP70, particularly in determining circulating HSP70 levels, using more convenient and rapid screening methods. Studies have shown that changes in HSP70 are associated with various nondisease and disease conditions; thus, HSP70 might be a novel potential biomarker reflecting various nondisease conditions and also the severity of disease conditions. However, the reliability and accuracy, as well as the underlying mechanism, of this relationship remain poorly understood, and large-sample clinical research must be performed to verify the role. PMID:26139132

  9. THEORY AND EXPERIMENT ON THE VISCOUS HEATING OF FLUID DAMPER UNDER SHOCK ENVIRONMENT

    Institute of Scientific and Technical Information of China (English)

    CHU Deying; ZHANG Zhiyi; WANG Gongxian; HUA Hongxing; WANG Yu

    2008-01-01

    A specially designed fluid damper used as negative shock pulse generator in the shock resistance test system to dissipate the shock input energy in transient time duration is presented. The theoretical modeling based on the three-dimensional equation of heat transfer through a fluid element is created to predict the viscous heating in the fluid damper under shock conditions. A comprehensive experimental program that investigates the problem of viscous heating in the fluid damper under different shock conditions is conducted on the shock test machine to validate the analytical expression. Temperature histories for the fluid within the damper at two locations, the annular-orifice and the-end-of stroke of the damper, are recorded. The experimental results show that the theoretical model can offer a very dependable prediction for the temperature histories in the damper for increasing input velocity. The theoretical model and experimental data both clearly indicate that the viscous heating in the damper is directly related to the maximum shock velocity input and the pressure between the two sides of the piston head.

  10. Optimum structural design of a heat exchanger for gas-circulation systems

    International Nuclear Information System (INIS)

    Highlights: • The fluid flow structure and heat transfer characters of a finned-tube heat exchanger was numerically investigated. • The optimized heat exchanger is more compact and easy to be miniaturized and utilized. • A novel configuration of tubes region is proposed to reduce the pressure drop penalty of the optimized heat exchanger. • The comprehensive performance of the optimized heat exchanger is enhanced. - Abstract: T-type gas-circulation systems are widely used in gas lasers to remove waste heat from the discharge process. The structure of the heat exchanger is a very important factor that affects the performance of a T-type gas-circulation system. To develop a high-performance heat exchanger for such a gas-circulation application, a computational fluid dynamics approach was adopted for this study. A three-dimensional numerical model was established. A detailed study focused on the influence of the shape of the channel and the location of the finned tubes on the performance of the heat exchanger. Based on the heat-transfer characteristics and the flow structure, a novel geometric structure was proposed to reduce the volume of the heat exchanger. Comprehensive simulations to determine the optimum locations for the finned tubes were also conducted. As a result of this optimization, the heat exchanger for a T-type gas-circulation system could be made more compact and its pressure loss penalty decreased by 11.5% even though its heat-transfer ability remained unchanged. In addition, the results of a theoretical analysis and numerical simulation were found to be in good agreement with the results of the experiment, indicating the validity of the results of the research

  11. Network analysis of oyster transcriptome revealed a cascade of cellular responses during recovery after heat shock.

    Directory of Open Access Journals (Sweden)

    Lingling Zhang

    Full Text Available Oysters, as a major group of marine bivalves, can tolerate a wide range of natural and anthropogenic stressors including heat stress. Recent studies have shown that oysters pretreated with heat shock can result in induced heat tolerance. A systematic study of cellular recovery from heat shock may provide insights into the mechanism of acquired thermal tolerance. In this study, we performed the first network analysis of oyster transcriptome by reanalyzing microarray data from a previous study. Network analysis revealed a cascade of cellular responses during oyster recovery after heat shock and identified responsive gene modules and key genes. Our study demonstrates the power of network analysis in a non-model organism with poor gene annotations, which can lead to new discoveries that go beyond the focus on individual genes.

  12. A constitutive heat shock element-binding factor is immunologically identical to the Ku autoantigen.

    Science.gov (United States)

    Kim, D; Ouyang, H; Yang, S H; Nussenzweig, A; Burgman, P; Li, G C

    1995-06-23

    Analysis of the heat shock element (HSE)-binding proteins in extracts of rodent cells, during heat shock and their post-heat shock recovery, indicates that the regulation of heat shock response involves a constitutive HSE-binding factor (CHBF), in addition to the heat-inducible heat shock factor HSF1. We purified the CHBF to apparent homogeneity from HeLa cells using column chromatographic techniques including an HSE oligonucleotide affinity column. The purified CHBF consists of two polypeptides with apparent molecular masses of 70 and 86 kDa. Immunoblot and gel mobility shift analysis verify that CHBF is identical or closely related to the Ku autoantigen. The DNA binding characteristics of CHBF to double-stranded or single-stranded DNA are similar to that of Ku autoantigen. In gel mobility shift analysis using purified CHBF and recombinant human HSF1, CHBF competes with HSF1 for the binding of DNA sequences containing HSEs in vitro. Furthermore, when Rat-1 cells were co-transfected with human Ku expression vectors and the hsp70-promoter-driven luciferase reporter gene, thermal induction of luciferase is significantly suppressed relative to cells transfected with only the hsp70-luciferase construct. These data suggest a role of CHBF (or Ku protein) in the regulation of heat response in vivo. PMID:7797514

  13. Aberrant Expression and Secretion of Heat Shock Protein 90 in Patients with Bullous Pemphigoid

    Science.gov (United States)

    Tukaj, Stefan; Kleszczyński, Konrad; Vafia, Katerina; Groth, Stephanie; Meyersburg, Damian; Trzonkowski, Piotr; Ludwig, Ralf J.; Zillikens, Detlef; Schmidt, Enno; Fischer, Tobias W.; Kasperkiewicz, Michael

    2013-01-01

    The cell stress chaperone heat shock protein 90 (Hsp90) has been implicated in inflammatory responses and its inhibition has proven successful in different mouse models of autoimmune diseases, including epidermolysis bullosa acquisita. Here, we investigated expression levels and secretory responses of Hsp90 in patients with bullous pemphigoid (BP), the most common subepidermal autoimmune blistering skin disease. In comparison to healthy controls, the following observations were made: (i) Hsp90 was highly expressed in the skin of BP patients, whereas its serum levels were decreased and inversely associated with IgG autoantibody levels against the NC16A immunodominant region of the BP180 autoantigen, (ii) in contrast, neither aberrant levels of circulating Hsp90 nor any correlation of this protein with serum autoantibodies was found in a control cohort of autoimmune bullous disease patients with pemphigus vulgaris, (iii) Hsp90 was highly expressed in and restrictedly released from peripheral blood mononuclear cells of BP patients, and (iv) Hsp90 was potently induced in and restrictedly secreted from human keratinocyte (HaCaT) cells by BP serum and isolated anti-BP180 NC16A IgG autoantibodies, respectively. Our results reveal an upregulated Hsp90 expression at the site of inflammation and an autoantibody-mediated dysregulation of the intracellular and extracellular distribution of this chaperone in BP patients. These findings suggest that Hsp90 may play a pathophysiological role and represent a novel potential treatment target in BP. PMID:23936217

  14. Aberrant expression and secretion of heat shock protein 90 in patients with bullous pemphigoid.

    Directory of Open Access Journals (Sweden)

    Stefan Tukaj

    Full Text Available The cell stress chaperone heat shock protein 90 (Hsp90 has been implicated in inflammatory responses and its inhibition has proven successful in different mouse models of autoimmune diseases, including epidermolysis bullosa acquisita. Here, we investigated expression levels and secretory responses of Hsp90 in patients with bullous pemphigoid (BP, the most common subepidermal autoimmune blistering skin disease. In comparison to healthy controls, the following observations were made: (i Hsp90 was highly expressed in the skin of BP patients, whereas its serum levels were decreased and inversely associated with IgG autoantibody levels against the NC16A immunodominant region of the BP180 autoantigen, (ii in contrast, neither aberrant levels of circulating Hsp90 nor any correlation of this protein with serum autoantibodies was found in a control cohort of autoimmune bullous disease patients with pemphigus vulgaris, (iii Hsp90 was highly expressed in and restrictedly released from peripheral blood mononuclear cells of BP patients, and (iv Hsp90 was potently induced in and restrictedly secreted from human keratinocyte (HaCaT cells by BP serum and isolated anti-BP180 NC16A IgG autoantibodies, respectively. Our results reveal an upregulated Hsp90 expression at the site of inflammation and an autoantibody-mediated dysregulation of the intracellular and extracellular distribution of this chaperone in BP patients. These findings suggest that Hsp90 may play a pathophysiological role and represent a novel potential treatment target in BP.

  15. PARAMETERS OF WATER CIRCULATION NETWORK FOR A DISTRICT HEATING AND COOLING SYSTEM

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In a district heating and cooling system, i.e. Beijing combined heating cooling and power (CHCP) system studied here, high temperature water generated by two cogeneration plants circulates through a network between the plants and heat substations. At heat substations, supply water of high temperature from the network drives absorption chillers for air-conditioning in summer and meets space heating demands in winter or domestic hot water demands by heat exchangers in the whole year. The parameters, i.e. supply/return water temperature in the network, has a great impact on primary energy consumption (PEC) of the absorption chillers, circulation pumps and domestic hot water (DHW), which is studied in this paper.

  16. An experimental study on the flow instabilities and critical heat flux under natural circulation

    International Nuclear Information System (INIS)

    This study has been carried out to investigate the hydrodynamic stabilities of natural circulation and to analyze Critical Heat Flux (CHF) characteristics for the natural and forced circulation. A low pressure experimental loop was constructed, and experiments under various conditions have been performed. In the experiments of the natural circulation, flow oscillations and the average mass flux have been observed. Several parameters such as heat flux, the inlet temperature of test section, friction valve opening and riser length have been varied in order to investigate their effects on the flow stability of the natural circulation system. The results show that the flow instability has strongly dependent on geometric conditions and operating parameters, the inlet temperature and the heat flux of test section. It was found that unstable region for the heat flux and the inlet temperature exists between the single-phase stable region of low heat and low inlet temperature and the two-phase stable region of very high heat flux and high inlet temperature. The CHF data from the natural and forced circulation experiments have been compared each other to identify the effects of the flow instabilities on the CHF for the natural circulation mode. The test conditions were low flow less than 70 kg/m2s of water in vertical round tube with diameter of 0.008m at near atmospheric pressure. In this study, no difference in CHF values is observed between natural and fored circulation. Since low flow usually has the oscillation characteristic of relatively low amplitude and high frequency, the effect of the flow instabilities on the CHF seems to be negligible

  17. Heat shock protein90 in lobular neoplasia of the breast

    International Nuclear Information System (INIS)

    Heat shock protein 90 (Hsp90) overexpression has been implicated in breast carcinogenesis, with putative prognostic and therapeutic implications. The purpose of this study is to evaluate the immunohistochemical expression of Hsp90 and to examine whether Hsp90 expression is associated with estrogen receptor alpha (ER-alpha) and beta (ER-beta) immunostaining in lobular neoplasia (LN) of the breast. Tissue specimens were taken from 44 patients with LN. Immunohistochemical assessment of Hsp90, ER-alpha and ER-beta was performed both in the lesion and the adjacent normal breast ducts and lobules; the latter serving as control. As far as Hsp90 evaluation is concerned: i) the percentage of positive cells, and ii) the intensity was separately analyzed. Additionally, the Allred score was adopted and calculated. Accordingly, Allred score was separately evaluated for ER-alpha and ER-beta. The intensity was treated as an ordinal variable-score (0: negative, low: 1, moderate: 2, high: 3). Statistical analysis followed. Hsp90 immunoreactivity was mainly cytoplasmic in both the epithelial cells of normal breast (ducts and lobules) and LN. Some epithelial cells of LN also showed nuclear staining, but all the LN foci mainly disclosed a positive cytoplasmic immunoreaction for Hsp90. In addition, rare intralobular inflammatory cells showed a slight immunoreaction. The percentage of Hsp90 positive cells in the LN areas was equal to 67.1 ± 12.2%, whereas the respective percentage in the normal adjacent breast tissue was 69.1 ± 11.6%; the difference was not statistically significant. The intensity score of Hsp90 staining was 1.82 ± 0.72 in LN foci, while in the normal adjacent tissue the intensity score was 2.14 ± 0.64. This difference was statistically significant (p = 0.029, Wilcoxon matched-pairs signed-ranks test). The Hsp90 Allred score was 6.46 ± 1.14 in the LN foci, significantly lower than in the normal adjacent tissue (6.91 ± 0.92, p = 0.049, Wilcoxon matched-pairs signed

  18. Heat shock protein90 in lobular neoplasia of the breast

    Directory of Open Access Journals (Sweden)

    Patsouris Efstratios

    2008-10-01

    Full Text Available Abstract Background Heat shock protein 90 (Hsp90 overexpression has been implicated in breast carcinogenesis, with putative prognostic and therapeutic implications. The purpose of this study is to evaluate the immunohistochemical expression of Hsp90 and to examine whether Hsp90 expression is associated with estrogen receptor alpha (ER-alpha and beta (ER-beta immunostaining in lobular neoplasia (LN of the breast. Methods Tissue specimens were taken from 44 patients with LN. Immunohistochemical assessment of Hsp90, ER-alpha and ER-beta was performed both in the lesion and the adjacent normal breast ducts and lobules; the latter serving as control. As far as Hsp90 evaluation is concerned: i the percentage of positive cells, and ii the intensity was separately analyzed. Additionally, the Allred score was adopted and calculated. Accordingly, Allred score was separately evaluated for ER-alpha and ER-beta. The intensity was treated as an ordinal variable-score (0: negative, low: 1, moderate: 2, high: 3. Statistical analysis followed. Results Hsp90 immunoreactivity was mainly cytoplasmic in both the epithelial cells of normal breast (ducts and lobules and LN. Some epithelial cells of LN also showed nuclear staining, but all the LN foci mainly disclosed a positive cytoplasmic immunoreaction for Hsp90. In addition, rare intralobular inflammatory cells showed a slight immunoreaction. The percentage of Hsp90 positive cells in the LN areas was equal to 67.1 ± 12.2%, whereas the respective percentage in the normal adjacent breast tissue was 69.1 ± 11.6%; the difference was not statistically significant. The intensity score of Hsp90 staining was 1.82 ± 0.72 in LN foci, while in the normal adjacent tissue the intensity score was 2.14 ± 0.64. This difference was statistically significant (p = 0.029, Wilcoxon matched-pairs signed-ranks test. The Hsp90 Allred score was 6.46 ± 1.14 in the LN foci, significantly lower than in the normal adjacent tissue (6.91

  19. Heat shock protein expression in canine malignant mammary tumours

    International Nuclear Information System (INIS)

    Abnormal levels of Heat Shock Proteins (HSPs) have been observed in many human neoplasms including breast cancer and it has been demonstrated that they have both prognostic and therapeutic implications. In this study, we evaluated immunohistochemical expression of HSPs in normal and neoplastic canine mammary glands and confronted these results with overall survival (OS), in order to understand the role of HSPs in carcinogenesis and to establish their potential prognostic and/or therapeutic value. Immunohistochemical expression of Hsp27, Hsp72, Hsp73 and Hsp90 was evaluated in 3 normal canine mammary glands and 30 malignant mammary tumours (10 in situ carcinomas, 10 invasive carcinomas limited to local structures without identifiable invasion of blood or lymphatic vessels, 10 carcinomas with invasion of blood or lymphatic vessels and/or metastases to regional lymph nodes). A semi-quantitative method was used for the analysis of the results. Widespread constitutive expression of Hsp73 and Hsp90 was detected in normal tissue, Hsp72 appeared to be focally distributed and Hsp27 showed a negative to rare weak immunostaining. In mammary tumours, a significant increase in Hsp27 (P < 0.01), Hsp72 (P < 0.05) and Hsp90 (P < 0.01) expression was observed as well as a significant reduction in Hsp73 (P < 0.01) immunoreactivity compared to normal mammary gland tissue. Hsp27 demonstrated a strong positivity in infiltrating tumour cells and metaplastic squamous elements of invasive groups. High Hsp27 expression also appeared to be significantly correlated to a shorter OS (P = 0.00087). Intense immunolabelling of Hsp72 and Hsp73 was frequently detected in infiltrative or inflammatory tumour areas. Hsp90 expression was high in all tumours and, like Hsp73, it also showed an intense positivity in lymphatic emboli. These results suggest that Hsp27, Hsp72 and Hsp90 are involved in canine mammary gland carcinogenesis. In addition, Hsp27 appears to be implicated in tumour invasiveness and

  20. The Transcriptional Heat Shock Response of Salmonella Typhimurium Shows Hysteresis and Heated Cells Show Increased Resistance to Heat and Acid Stress

    DEFF Research Database (Denmark)

    Pin, C.; Hansen, Trine; Munoz-Cuevas, M.;

    2012-01-01

    -regulated genes, implying that down-regulation was significantly less synchronized than upregulation. The hysteretic transcriptional response to heat shock was accompanied by higher resistance to inactivation at 50uC as well as cross-resistance to inactivation at pH 3; however, growth rates and lag times at 43u...... 120 up-regulated genes during the heat shock remained up-regulated 30 minutes after the temperature was set back to 25uC, while only 86 out of 293 down regulated genes remained down regulated 30 minutes after the heat shock ceased. Thus, the majority of the induced genes exhibited hysteresis, i.......e., they remained up-regulated after the environmental stress ceased. At 25uC the transcriptional regulation of genes encoding for heat shock proteins was determined by the previous environment. Gene networks constructed with up-regulated genes were significantly more modular than those of down...

  1. A study on Heat Transfer for Immersed Tube in Internally Circulating Fluidized Bed

    Institute of Scientific and Technical Information of China (English)

    TianWendong; HaoJinhua; 等

    1999-01-01

    Heat transfer coefficients for horizontally immersed tubes have been studied in a model of ICFB(Inter-nally Circulating Fluidized Bed).The characteristics in ICFB were found to be significantly different from those in bubbing bed.There is a flowing zone with high velocity in the heat exchange zone.The heat transfer coefficients strongly depend on the fluidized velocity in the flowing zone.The heat exchange process and suitable bed temperature can be controlled according to this feature.Based on the results of the experiments,a formulation for heat transfer has been developed.

  2. Regulation of cyclooxygenase-2 expression by heat: a novel aspect of heat shock factor 1 function in human cells.

    Directory of Open Access Journals (Sweden)

    Antonio Rossi

    Full Text Available The heat-shock response, a fundamental defense mechanism against proteotoxic stress, is regulated by a family of heat-shock transcription factors (HSF. In humans HSF1 is considered the central regulator of heat-induced transcriptional responses. The main targets for HSF1 are specific promoter elements (HSE located upstream of heat-shock genes encoding cytoprotective heat-shock proteins (HSP with chaperone function. In addition to its cytoprotective function, HSF1 was recently hypothesized to play a more complex role, regulating the expression of non-HSP genes; however, the non-canonical role of HSF1 is still poorly understood. Herein we report that heat-stress promotes the expression of cyclooxygenase-2 (COX-2, a key regulator of inflammation controlling prostanoid and thromboxane synthesis, resulting in the production of high levels of prostaglandin-E(2 in human cells. We show that heat-induced COX-2 expression is regulated at the transcriptional level via HSF1-mediated signaling and identify, by in-vitro reporter gene activity assay and deletion-mutant constructs analysis, the COX-2 heat-responsive promoter region and a new distal cis-acting HSE located at position -2495 from the transcription start site. As shown by ChIP analysis, HSF1 is recruited to the COX-2 promoter rapidly after heat treatment; by using shRNA-mediated HSF1 suppression and HSE-deletion from the COX-2 promoter, we demonstrate that HSF1 plays a central role in the transcriptional control of COX-2 by heat. Finally, COX-2 transcription is also induced at febrile temperatures in endothelial cells, suggesting that HSF1-dependent COX-2 expression could contribute to increasing blood prostaglandin levels during fever. The results identify COX-2 as a human non-classical heat-responsive gene, unveiling a new aspect of HSF1 function.

  3. Differential heat shock response of primary human cell cultures and established cell lines

    DEFF Research Database (Denmark)

    Richter, W W; Issinger, O G

    1986-01-01

    degrees C treatment, whereas in immortalized cell lines usually 90% of the cells were found in suspension. Enhanced expression of the major heat shock protein (hsp 70) was found in all heat-treated cells. In contrast to the primary cell cultures, established and transformed cell lines synthesized a...

  4. Heat transfer to water from a vertical tube bundle under natural-circulation conditions

    International Nuclear Information System (INIS)

    The natural circulation heat transfer data for longitudinal flow of water outside a vertical rod bundle are needed for developing correlations which can be used in best estimate computer codes to model thermal-hydraulic behavior of nuclear reactor cores under accident or shutdown conditions. The heat transfer coefficient between the fuel rod surface and the coolant is the key parameter required to predict the fuel temperature. Because of the absence of the required heat transfer coefficient data base under natural circulation conditions, experiments have been performed in a natural circulation loop. A seven-tube bundle having a pitch-to-diameter ratio of 1.25 was used as a test heat exchanger. A circulating flow was established in the loop, because of buoyancy differences between its two vertical legs. Steady-state and transient heat transfer measurements have been made over as wide a range of thermal conditions as possible with the system. Steady state heat transfer data were correlated in terms of relevant dimensionless parameters. Empirical correlations for the average Nusselt number, in terms of Reynolds number, Rayleigh number and the ratio of Grashof to Reynolds number are given

  5. Heat Transfer in a Liquid-Solid Circulating Fluidized Bed Reactor with Low Surface Tension Media

    Institute of Scientific and Technical Information of China (English)

    HR Jin; H Lim; DH Lim; Y Kang; Ki-Won Jun

    2013-01-01

    Heat transfer characteristics between the immersed heater and the bed content were studied in the riser of a liquid-solid circulating fluidized bed, whose diameter and height were 0.102 m (ID) and 2.5 m, respectively. Effects of liquid velocity, particle size, surface tension of liquid phase and solid circulation rate on the overall heat transfer coefficient were examined. The heat transfer coefficient increased with increasing particle size or solid cir-culation rate due to the higher potential of particles to contact with the heater surface and promote turbulence near the heater surface. The value of heat transfer coefficient increased gradually with increase in the surface tension of liquid phase, due to the slight increase of solid holdup. The heat transfer coefficient increased with the liquid veloc-ity even in the higher range, due to the solid circulation prevented the decrease in solid holdup, in contrast to that in the conventional liquid-solid fluidized beds. The values of heat transfer coefficient were well correlated in terms of dimensionless groups as well as operating variables.

  6. Atmospheric Diabatic Heating in Different Weather States and the General Circulation

    Science.gov (United States)

    Rossow, William B.; Zhang, Yuanchong; Tselioudis, George

    2016-01-01

    Analysis of multiple global satellite products identifies distinctive weather states of the atmosphere from the mesoscale pattern of cloud properties and quantifies the associated diabatic heating/cooling by radiative flux divergence, precipitation, and surface sensible heat flux. The results show that the forcing for the atmospheric general circulation is a very dynamic process, varying strongly at weather space-time scales, comprising relatively infrequent, strong heating events by ''stormy'' weather and more nearly continuous, weak cooling by ''fair'' weather. Such behavior undercuts the value of analyses of time-averaged energy exchanges in observations or numerical models. It is proposed that an analysis of the joint time-related variations of the global weather states and the general circulation on weather space-time scales might be used to establish useful ''feedback like'' relationships between cloud processes and the large-scale circulation.

  7. Experimental studies on natural circulation decay heat removal in Japan Sodium Cooled Fast Reactor (JSFR)

    International Nuclear Information System (INIS)

    Fully natural circulation system is adopted in a decay heat removal system (DHRS) of the designs of Japan Sodium Cooled Fast Reactor (JSFR). Several investigations of experiments and simulation methods on this DHRS were performed. Water experiments were carried out for the primary heat transportation system including a reactor vessel and heat exchangers of DHRS using a 1/10 model. As for the DHRS loop, sodium experiments were carried out, especially for a heat exchanger installed in an Intermediate Heat Exchanger (IHX). Here, several results of the sodium experiments were described. Transient characteristics during the start up in the air system of the air cooler, secondary loop of DHRS, and the primary loop were examined by the sodium experiments. Smooth increases of natural circulation flow rates in all systems of air and sodium were confirmed. Verifications of numerical simulation methods are planned based on the water and sodium experiments in this investigation plan. (author)

  8. The SIRT1 modulators AROS and DBC1 regulate HSF1 activity and the heat shock response.

    Directory of Open Access Journals (Sweden)

    Rachel Raynes

    Full Text Available The heat shock response, the cellular response to protein damaging stress, is critical in maintaining proteostasis. The heat shock response is regulated by the transcription factor HSF1, which is activated upon heat shock and other stresses to induce the expression of molecular chaperones. SIRT1 has previously been shown to activate HSF1 by deacetylating it, leading to increased DNA binding ability. We have investigated how the heat shock response may be controlled by factors influencing SIRT1 activity. We found that heat shock results in an increase in the cellular NAD(+/NADH ratio and an increase in recruitment of SIRT1 to the hsp70 promoter. Furthermore, we found that the SIRT1 modulators AROS and DBC1 have an impact on hsp70 transcription, HSF1 acetylation status, and HSF1 recruitment to the hsp70 promoter. Therefore, AROS and DBC1 are now two new targets available for therapeutic regulation of the heat shock response.

  9. Validated TRNSYS model for forced circulation solar water heating systems with flat plate and heat pipe evacuated tube collectors

    OpenAIRE

    MC CORMACK, SARAH

    2011-01-01

    PUBLISHED This paper presents a validated TRNSYS model for forced circulation solar water heating systems used in temperate climates. The systems consist of two flat plate collectors (FPC) and a heat pipe evacuated tube collector (ETC) as well as identical auxiliary components. The systems were fitted with an automated unit that controlled the immersion heaters and hot water demand profile to mimic hot water usage in a typical European domestic dwelling. The main component of the TRNSYS mo...

  10. Validated TRNSYS Model for Forced Circulation Solar Water Heating Systems with Flat Plate and Heat Pipe Evacuated Tube Collectors

    OpenAIRE

    Ayompe, Lacour; Duffy, Aidan; MCCORMACK, SARAH; Conlon, Michael

    2011-01-01

    This paper presents a validated TRNSYS model for forced circulation solar water heating systems used in temperate climates. The systems consist of two flat plate collectors (FPC) and a heat pipe evacuated tube collector (ETC) as well as identical auxiliary components. The systems were fitted with an automated unit that controlled the immersion heaters and hot water demand profile to mimic hot water usage in a typical European domestic dwelling. The main component of the TRNSYS model was the T...

  11. Post-shock-revival evolutions in the neutrino-heating mechanism of core-collapse supernovae

    CERN Document Server

    Yamamoto, Yu; Nagakura, Hiroki; Yamada, Shoichi

    2012-01-01

    We perform some experimental simulations in spherical symmetry and axisymmetry to understand the post-shock-revival evolution of core-collapse supernovae. Assuming that the stalled shock wave is relaunched by neutrino heating and employing the so-called light bulb approximation, we induce shock revival by raising the neutrino luminosity by hand up to the critical value, which is also determined by dynamical simulations. We incorporate nuclear network calculations with a consistent equation of state in the simulations to account for the energy release by nuclear reactions and their feedback to hydrodynamics. Varying the shock-relaunch time rather arbitrarily, we investigate the ensuing long-term evolutions systematically, paying particular attention to the explosion energy and nucleosynthetic yields as a function of this relaunch time, or equivalently the accretion rate at shock revival. We study in detail how the diagnostic explosion energy approaches the asymptotic value and which physical processes contribu...

  12. Shock initiation of the TATB based explosive PBX 9502 heated to ~ 76∘C

    Science.gov (United States)

    Gustavsen, Richard; Gehr, Russell; Bucholtz, Scott; Pacheco, Adam; Bartram, Brian

    2015-06-01

    Recently we reported on shock initiation of PBX 9502 (95 wt.% tri-amino-trinitro-benzene, 5 wt.% Kel-F800 binder) cooled to -55°C and to 77K Shock waves were generated by gas-gun driven plate impacts and reactive flow in the cooled PBX 9502 was measured with embedded electromagnetic gauges. Here we use similar methods to warm the explosive to ~ 76°C. The explosive sample is heated by warm air flowing through channels in an aluminum sample mounting plate and a copper tubing coil surrounding the sample. Temperature in the sample is monitored using six type-E thermocouples. Results show increased shock sensitivity; time and distance to detonation onset vs. initial shock pressure are shorter than when the sample is initially at ambient temperature. Our results are consistent with those reported by Dallman & Wackerle. Particle velocity wave profiles were also obtained during the shock-to-detonation transition and will be presented.

  13. Influence of local natural circulation on the passive residual heat removal in nuclear reactor

    International Nuclear Information System (INIS)

    The primary system of reactor and passive residual heat removal system are modeled using the code RELAP5/ MOD3.2. In order to model the heterogeneous flow in the U-tubes of steam generator under natural circulation, the U -tubes are classified according to their lengths, then each class is divided into different nodes and flow lines. The new method can simulate the reverse flow characteristics in the inverted U-tubes. This paper provides the distribution of forward flow and reverse flow in the inverted U-tubes of the steam generator (SG) under residual heat removal conditions in the natural circulation case. (authors)

  14. Sleep deprivation increase the expression of inducible heat shock protein 70 in rat gastric mucosa

    Institute of Scientific and Technical Information of China (English)

    Xi-Zhong Shen1; Marcel W.L. Koo; Chi-Hin Cho

    2001-01-01

    AIM To .investigate if sleep deprivation is able to increase the expression of inducible heat shock protein 70 in gastric mucosa and its possible role in mucosal defense. METHODS Rats for sleep disruption were placed inside a computerized rotating drum, gastric mucosa was taken from rats with 1, 3 and 7 d sleep deprivation. RT-PCR,immunohistochemistry and Western blotting were used to determine the expression of heat shock protein 70.Ethanol (500 mL@ L 1, I.g.) was used to induce gastric muceea damage. RESULTS RT-PCR, Western blotting and immunostaining confirmed that the sleep deprivation as a stress resulted in significantly greater expression of inducible heat shock protein 70 in gastric mucosa of rats. After the 500mL@ L-1 ethanol challenge, the ulcer area found in the rats with 7 d sleep deprivation (19.15 ± 4.2) mm2 was significantly lower (P<0.01) than the corresponding control (53.7 ± 8.1) mm2. CONCLUSION Sleep deprivation as a stress, in addition to lowering the gastric mucosal barrier, is able to stimulate the expression of inducible heat shock protein 70 in gastric mucosa of rats, the heat shock protein 70 may play an important role in gastric mucosal protection.

  15. Spatial control of calcineurin in response to heat shock in fission yeast.

    Science.gov (United States)

    Higa, Mari; Kita, Ayako; Hagihara, Kanako; Kitai, Yuki; Doi, Akira; Nagasoko, Rie; Satoh, Ryosuke; Sugiura, Reiko

    2015-02-01

    In fission yeast, Ppb1, the Ca2+/calmodulin-dependent protein phosphatase calcineurin regulates multiple biological processes, such as cytokinesis, Ca2+-homeostasis, membrane trafficking and cell wall integrity. Calcineurin dephosphorylates the Prz1 transcription factor, leading to its nuclear translocation and gene expression under the control of CDRE (calcineurin-dependent response element). Although the calcineurin-mediated spatial control of downstream transcription factors has been intensively studied in many organisms, less is known about the spatial regulation of calcineurin on stresses. Here, we show that heat shock stimulates calcineurin-dependent nuclear translocation of Prz1 and CDRE-dependent gene expression. Notably, calcineurin exhibited a dramatic change in subcellular localization, translocating from diffuse cytoplasmic to dot-like structures on heat shock. The calcineurin dots colocalized with Dcp2 or Pabp, the constituent of P-bodies or stress granules, respectively, thus suggesting that calcineurin is a component of RNA granules under heat shock. Importantly, the calcineurin inhibitor FK506 markedly inhibited the accumulation of calcineurin granules, whereas the constitutively active calcineurin strongly accumulated in the granules on heat shock, suggesting that phosphatase activity is important for calcineurin localization. Notably, the depletion of calcineurin induced a rapid appearance of Nrd1- and Pabp-positive RNA granules. The possible roles of calcineurin in response to heat shock will be discussed. PMID:25529221

  16. Isolation and characterization of a small heat shock protein gene from maize.

    Science.gov (United States)

    Dietrich, P S; Bouchard, R A; Casey, E S; Sinibaldi, R M

    1991-08-01

    A maize (Zea mays L.) genomic clone (Zmempr 9') was isolated on the basis of its homology to a meiotically expressed Lilium sequence. Radiolabeled probe made from the maize genomic clone detected complementary RNA at high fidelity. Furthermore, it hybridized to RNA isolated from staged (an interval that is coincident with meiotic prophase) maize tassel spikelets. Complimentary RNA was strongly (at least 50-fold) induced during heat shock of maize somatic tissue and appeared as a single size class in Northern blot hybridizations. Sequencing of the complete coding region of Zmempr 9' confirmed the homology of the inferred amino acid sequence to other small heat shock proteins. Consensus sequences found in the flanking regions corresponded to the usual signals for initiation of RNA transcription, polyadenylate addition, and the induction of heat shock genes. The latter sequences conferred heat shock-specific transient expression in electroporated protoplasts when cloned into promoterless reporter gene plasmid constructs. Hybrid-selected translations revealed specific translation products ranging from 15 to 18 kilodaltons, providing evidence that this gene is a member of a related multigene family. We therefore conclude that this maize genomic DNA clone, recovered through its homology to clones for meiotic transcripts in lily, represents a genuine maize small heat shock protein gene. PMID:16668329

  17. Impaired heat shock response in cells expressing full-length polyglutamine-expanded huntingtin.

    Directory of Open Access Journals (Sweden)

    Sidhartha M Chafekar

    Full Text Available The molecular mechanisms by which polyglutamine (polyQ-expanded huntingtin (Htt causes neurodegeneration in Huntington's disease (HD remain unclear. The malfunction of cellular proteostasis has been suggested as central in HD pathogenesis and also as a target of therapeutic interventions for the treatment of HD. We present results that offer a previously unexplored perspective regarding impaired proteostasis in HD. We find that, under non-stress conditions, the proteostatic capacity of cells expressing full length polyQ-expanded Htt is adequate. Yet, under stress conditions, the presence of polyQ-expanded Htt impairs the heat shock response, a key component of cellular proteostasis. This impaired heat shock response results in a reduced capacity to withstand the damage caused by cellular stress. We demonstrate that in cells expressing polyQ-expanded Htt the levels of heat shock transcription factor 1 (HSF1 are reduced, and, as a consequence, these cells have an impaired a heat shock response. Also, we found reduced HSF1 and HSP70 levels in the striata of HD knock-in mice when compared to wild-type mice. Our results suggests that full length, non-aggregated polyQ-expanded Htt blocks the effective induction of the heat shock response under stress conditions and may thus trigger the accumulation of cellular damage during the course of HD pathogenesis.

  18. PARP-1 transcriptional activity is regulated by sumoylation upon heat shock.

    Science.gov (United States)

    Martin, Nadine; Schwamborn, Klaus; Schreiber, Valérie; Werner, Andreas; Guillier, Christelle; Zhang, Xiang-Dong; Bischof, Oliver; Seeler, Jacob-S; Dejean, Anne

    2009-11-18

    Heat shock and other environmental stresses rapidly induce transcriptional responses subject to regulation by a variety of post-translational modifications. Among these, poly(ADP-ribosyl)ation and sumoylation have received growing attention. Here we show that the SUMO E3 ligase PIASy interacts with the poly(ADP-ribose) polymerase PARP-1, and that PIASy mediates heat shock-induced poly-sumoylation of PARP-1. Furthermore, PIASy, and hence sumoylation, appears indispensable for full activation of the inducible HSP70.1 gene. Chromatin immunoprecipitation experiments show that PIASy, SUMO and the SUMO-conjugating enzyme Ubc9 are rapidly recruited to the HSP70.1 promoter upon heat shock, and that they are subsequently released with kinetics similar to PARP-1. Finally, we provide evidence that the SUMO-targeted ubiquitin ligase RNF4 mediates heat-shock-inducible ubiquitination of PARP-1, regulates the stability of PARP-1, and, like PIASy, is a positive regulator of HSP70.1 gene activity. These results, thus, point to a novel mechanism for regulating PARP-1 transcription function, and suggest crosstalk between sumoylation and RNF4-mediated ubiquitination in regulating gene expression in response to heat shock. PMID:19779455

  19. Expression of heat shock protein70 in oral submucous fibrosis and oral squamous cell carcinoma: An immunohistochemical study

    OpenAIRE

    M Thubashini; Malathi, N.; L Kannan

    2011-01-01

    Background: Heat shock proteins are a highly conserved group of protective cellular proteins whose synthesis is increased in response to a variety of environmental or pathophysiological stresses. Heat shock proteins are useful biomarkers for carcinogenesis in tissues and signal the degree of differentiation and the aggressiveness of cancers. Regulation of heat shock protein 70 (HSP70) expression in oral submucous fibrosis is not known much, and the aim of this study was to evaluate HSP70 expr...

  20. Air Circulation and Heat Exchange Under Reduced Pressures

    Science.gov (United States)

    Rygalov, V.; Wheeler, R.; Dixon, M.; Fowler, P.; Hillhouse, L.

    2010-01-01

    Heat exchange rates decrease non-linearly with reductions in atmospheric pressure. This decrease creates risk of thermal stress (elevated leaf temperatures) for plants under reduced pressures. Forced convection (fans) significantly increases heat exchange rate under almost all pressures except below 10 kPa. Plant cultivation techniques under reduced pressures will require forced convection. The cooling curve technique is a reliable means of assessing the influence of environmental variables like pressure and gravity on gas exchange of plant. These results represent the extremes of gas exchange conditions for simple systems under variable pressures. In reality, dense plant canopies will exhibit responses in between these extremes. More research is needed to understand the dependence of forced convection on atmospheric pressure. The overall thermal balance model should include latent and radiative exchange components.

  1. The time development of a blast wave with shock-heated electrons

    Science.gov (United States)

    Edgar, R. J.; Cox, D. P.

    1984-01-01

    Accurate approximations are presented for the time development of both edge conditions and internal structures of a blast wave with shock heated electrons, and equal ion and electron temperatures at the shock. The cases considered evolve in cavities with power law ambient densities (including the uniform ambient density case) and have negligible external pressure. Account is taken of possible saturation of the thermal conduction flux. The structures evolve smoothly to the adiabatic structures.

  2. The time development of a blast wave with shock heated electrons

    Science.gov (United States)

    Edgar, R. J.; Cox, D. P.

    1983-01-01

    Accurate approximations are presented for the time development of both edge conditions and internal structures of a blast wave with shock heated electrons, and equal ion and electron temperatures at the shock. The cases considered evolve in cavities with power law ambient densities (including the uniform ambient density case) and have negligible external pressure. Account is taken of possible saturation of the thermal conduction flux. The structures evolve smoothly to the adiabatic structures.

  3. Increased light intensity induces heat shock protein Hsp60 in coral species

    OpenAIRE

    Chow, Ari M.; Ferrier-Pagès, Christine; Khalouei, Sam; Reynaud, Stéphanie; Brown, Ian R.

    2009-01-01

    The effect of increased light intensity and heat stress on heat shock protein Hsp60 was examined in two coral species using a branched coral and a laminar coral, selected for their different resistance to environmental perturbation. Transient Hsp60 induction was observed in the laminar coral following either light or thermal stress. Sustained induction was observed when these stresses were combined. The branched coral exhibited comparatively weak transient Hsp60 induction after heat stress an...

  4. Numerical simulation of heat fluxes in a two-temperature plasma at shock tube walls

    Science.gov (United States)

    Kuznetsov, E. A.; Poniaev, S. A.

    2015-12-01

    Numerical simulation of a two-temperature three-component Xenon plasma flow is presented. A solver based on the OpenFOAM CFD software package is developed. The heat flux at the shock tube end wall is calculated and compared with experimental data. It is shown that the heat flux due to electrons can be as high as 14% of the total heat flux.

  5. Errors in macromolecular synthesis after stress : a study of the possible protective role of the small heat shock proteins

    OpenAIRE

    Marin Vinader, L.

    2006-01-01

    The general goal of this thesis was to gain insight in what small heat shock proteins (sHsps) do with respect to macromolecular synthesis during a stressful situation in the cell. It is known that after a non-lethal heat shock, cells are better protected against a subsequent more severe heat shock, a phenomenon known as thermotolerance and attributed to the presence of the heat shock proteins. The question we asked first is whether the error rate in macromolecular synthesis (transcription, RN...

  6. Conditions for shock revival by neutrino heating in core-collapse supernovae

    Science.gov (United States)

    Janka, H.-Th.

    2001-03-01

    Energy deposition by neutrinos can rejuvenate the stalled bounce shock and can provide the energy for the supernova explosion of a massive star. This neutrino-heating mechanism, though investigated by numerical simulations and analytic studies, is not finally accepted or proven as the trigger of the explosion. Part of the problem is that different groups have obtained seemingly discrepant results, and the complexity of the hydrodynamic models often hampers a clear and simple interpretation of the results. This demands a deeper theoretical understanding of the requirements of a successful shock revival. A toy model is developed here for discussing the neutrino heating phase analytically. The neutron star atmosphere between the neutrinosphere and the supernova shock can well be considered to be in hydrostatic equilibrium, with a layer of net neutrino cooling below the gain radius and a layer of net neutrino heating above. Since the mass infall rate to the shock is in general different from the rate at which gas is advected into the neutron star, the mass in the gain layer varies with time. Moreover, the gain layer receives additional energy input by neutrinos emitted from the neutrinosphere and the cooling layer. Therefore the determination of the shock evolution requires a time-dependent treatment. To this end the hydrodynamical equations of continuity and energy are integrated over the volume of the gain layer to obtain conservation laws for the total mass and energy in this layer. The radius and velocity of the supernova shock can then be calculated from global properties of the gain layer as solutions of an initial value problem, which expresses the fact that the behavior of the shock is controlled by the cumulative effects of neutrino heating and mass accumulation in the gain layer. The described toy model produces steady-state accretion and mass outflow from the nascent neutron star as special cases. The approach is useful to illuminate the conditions that can

  7. Sub-lethal heat stress causes apoptosis in an Antarctic fish that lacks an inducible heat shock response.

    Science.gov (United States)

    Sleadd, Isaac M; Lee, Marissa; Hassumani, Daniel O; Stecyk, Tonya M A; Zeitz, Otto K; Buckley, Bradley A

    2014-08-01

    The endemic fish fauna of the Southern Ocean are cold-adapted stenotherms and are acutely sensitive to elevated temperature. Many of these species lack a heat shock response and cannot increase the production of heat shock proteins in their tissues. However, some species retain the ability to induce other stress-responsive genes, some of which are involved in cell cycle arrest and apoptosis. Here, the effect of heat on cell cycle stage and its ability to induce apoptosis were tested in thermally stressed hepatocytes from a common Antarctic fish species from McMurdo Sound in the Ross Sea. Levels of proliferating cell nuclear antigen were also measured as a marker of progression through the cell cycle. The results of these studies demonstrate that even sub-lethal heat stress can have deleterious impacts at the cellular level on these environmentally sensitive species. PMID:25086982

  8. Effects of calmodulin on DNA-binding activity of heat shock transcription factor in vitro

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The DNA-binding activity of heat shock transcription factor (HSF) was induced by heat shock (HS) of a whole cell extract. Addition of antiserum, specific to CaM, to a whole cell extract reduced bind of the HSF to the heat shock element (HSE) with maize, and the re-addition of CaM to the sample restored the activity of the HSF for binding to HSE. In addition, DNA-binding activity of the HSF was also induced by directly adding CaM to a whole cell extract at non-HS temperature with maize. Similar results were obtained with wheat and tomato. Our observations provide the first example of the involvement of CaM in regulation of the DNA-binding activity of the HSF.

  9. Suppression of first cleavage in the Mexican axolotl (Ambystoma mexicanum) by heat shock or hydrostatic pressure

    Energy Technology Data Exchange (ETDEWEB)

    Gillespie, L.L.; Armstrong, J.B.

    1981-12-01

    Androgenetic diploid axolotls were produced by ultraviolet inactivation of the egg pronucleus shortly after fertilization, followed by suppression of the first cleavage division by hydrostatic pressure or heat shock. After treatment at 14,000 psi for 8 minutes, diploidy was restored in 74% of the embryos, but only 0.8% survived to hatching. A 36-37 degrees C heat shock of 10-minutes duration, applied 5.5 hours after the eggs were collected, yielded a slightly lower percentage of diploids. However, the proportion surviving to hatching was significantly greater (up to 4.6%). A second generation of androgenetic diploids was produced from one of the oldest of the first generation males with a similar degree of success. The lack of significant improvement suggests that the low survival is due to the heat shock per se and not to the uncovering of recessive lethal genes carried by the parent.

  10. Initial crystallographic studies of a small heat-shock protein from Xylella fastidiosa

    International Nuclear Information System (INIS)

    Initial crystallographic studies of the X. fastidiosa small heat-shock protein HSP17.9 are reported. The ORF XF2234 in the Xylella fastidiosa genome was identified as encoding a small heat-shock protein of 17.9 kDa (HSP17.9). HSP17.9 was found as one of the proteins that are induced during X. fastidiosa proliferation and infection in citrus culture. Recombinant HSP17.9 was crystallized and surface atomic force microscopy experiments were conducted with the aim of better characterizing the HSP17.9 crystals. X-ray diffraction data were collected at 2.7 Å resolution. The crystal belonged to space group P4322, with unit-cell parameters a = 68.90, b = 68.90, c = 72.51 Å, and is the first small heat-shock protein to crystallize in this space group

  11. Compound A, a selective glucocorticoid receptor modulator, enhances heat shock protein Hsp70 gene promoter activation.

    Directory of Open Access Journals (Sweden)

    Ilse M Beck

    Full Text Available Compound A possesses glucocorticoid receptor (GR-dependent anti-inflammatory properties. Just like classical GR ligands, Compound A can repress NF-κB-mediated gene expression. However, the monomeric Compound A-activated GR is unable to trigger glucocorticoid response element-regulated gene expression. The heat shock response potently activates heat shock factor 1 (HSF1, upregulates Hsp70, a known GR chaperone, and also modulates various aspects of inflammation. We found that the selective GR modulator Compound A and heat shock trigger similar cellular effects in A549 lung epithelial cells. With regard to their anti-inflammatory mechanism, heat shock and Compound A are both able to reduce TNF-stimulated IκBα degradation and NF-κB p65 nuclear translocation. We established an interaction between Compound A-activated GR and Hsp70, but remarkably, although the presence of the Hsp70 chaperone as such appears pivotal for the Compound A-mediated inflammatory gene repression, subsequent novel Hsp70 protein synthesis is uncoupled from an observed CpdA-induced Hsp70 mRNA upregulation and hence obsolete in mediating CpdA's anti-inflammatory effect. The lack of a Compound A-induced increase in Hsp70 protein levels in A549 cells is not mediated by a rapid proteasomal degradation of Hsp70 or by a Compound A-induced general block on translation. Similar to heat shock, Compound A can upregulate transcription of Hsp70 genes in various cell lines and BALB/c mice. Interestingly, whereas Compound A-dependent Hsp70 promoter activation is GR-dependent but HSF1-independent, heat shock-induced Hsp70 expression alternatively occurs in a GR-independent and HSF1-dependent manner in A549 lung epithelial cells.

  12. Riluzole increases the amount of latent HSF1 for an amplified heat shock response and cytoprotection.

    Directory of Open Access Journals (Sweden)

    Jingxian Yang

    Full Text Available BACKGROUND: Induction of the heat shock response (HSR and increased expression of the heat shock proteins (HSPs provide mechanisms to ensure proper protein folding, trafficking, and disposition. The importance of HSPs is underscored by the understanding that protein mis-folding and aggregation contribute centrally to the pathogenesis of neurodegenerative diseases. METHODOLOGY/PRINCIPAL FINDINGS: We used a cell-based hsp70-luciferease reporter gene assay system to identify agents that modulate the HSR and show here that clinically relevant concentrations of the FDA-approved ALS drug riluzole significantly increased the heat shock induction of hsp70-luciferse reporter gene. Immuno-Western and -cytochemical analysis of HSF1 show that riluzole increased the amount of cytosolic HSF1 to afford a greater activation of HSF1 upon heat shock. The increased HSF1 contributed centrally to the cytoprotective activity of riluzole as hsf1 gene knockout negated the synergistic activity of riluzole and conditioning heat shock to confer cell survival under oxidative stress. Evidence of a post-transcriptional mechanism for the increase in HSF1 include: quantitation of mRNA(hsf1 by RT-PCR showed no effect of either heat shock or riluzole treatment; riluzole also increased the expression of HSF1 from a CMV-promoter; analysis of the turnover of HSF1 by pulse chase and immunoprecipitation show that riluzole slowed the decay of [(35S]labeled-HSF1. The effect of riluzole on HSF1 was qualitatively different from that of MG132 and chloroquine, inhibitors of the proteasome and lysosome, respectively, and appeared to involve the chaperone-mediated autophagy pathway as RNAi-mediated knockdown of CMA negated its effect. CONCLUSION/SIGNIFICANCE: We show that riluzole increased the amount of HSF1 to amplify the HSR for cytoprotection. Our study provides novel insight into the mechanism that regulates HSF1 turnover, and identifies the degradation of HSF1 as a target for

  13. Plasma antibodies to heat shock protein 60 and heat shock protein 70 are associated with increased risk of electrocardiograph abnormalities in automobile workers exposed to noise

    OpenAIRE

    Yuan, Jing; Yang, Miao; Yao, Huiling; Zheng, Jianru; Yang, Qiaoling; Chen, Sheng; Wei, Qingyi; Tanguay, Robert M.; Wu, Tangchun

    2005-01-01

    In the living and working environment, stressful factors, such as noise, can cause health problems including cardiovascular diseases and noise-induced hearing loss. Some heat shock proteins (Hsps) play an important role in protecting cardiac cells against ischemic injury, and antibodies against these Hsps are associated with the development and prognosis of atherogenesis, coronary heart disease, and hypertension. Whether the presence of such antibodies is associated with abnormal electrocardi...

  14. DETECTION OF CENTRIPETAL HEAT-ISLAND CIRCULATIONS FROM TOWER DATA IN ST. LOUIS

    Science.gov (United States)

    Hourly averaged meteorological data gathered by a 25-tower network about St. Louis during 1976 are used in a search for centripetal circulations generated by the urban heat island. Considering data collected when the network resultant speed was less than 1.5 m/s, two data classes...

  15. Study on decay heat removal characteristics by natural circulation for top entry loop-type FBR

    International Nuclear Information System (INIS)

    The thermal-hydraulic circulation characteristics of a top entry loop-type FBR are studied experimentally with a 1/8 scaled three-loop model using water as the working fluid. The model is designed to simulate reactor decay heat removal operations including natural circulation mode as well as three types of decay heat removal systems, a direct reactor auxiliary cooling system (DRACS) with a direct heat exchangers immersed in a hot plenum of a reactor vessel (Immersed type DRACS), a DRACS with DHXs penetrating from a hot plenum to a cold plenum of a reactor vessel (Penetrating type DRACS) and a primary reactor auxiliary cooling system (PRACS). The feasibility of reactor decay heat removal operations including natural circulation mode of a top entry loop-type FBR is confirmed based on the experimental results. The natural circulation performance of the Immersed type DRACS is compared with that of the PRACS for the water test results. The results are used to evaluate the accuracy of the one-dimensional flow-network analysis codes and the multi-dimensional thermal-hydraulic analysis code. The analytical results are generally in good agreement with the measurements. (author)

  16. Efficient global solution of residual heat removal system with natural circulation

    International Nuclear Information System (INIS)

    The mathematical model of the residual heat removal system with multiple coupled natural circulation loops has distinct nonlinear characteristics. The global solution method with high efficiency was developed, implemented and tested. Compared with the original method which uses the nested point iteration procedure, one magnitude of calculation speed improvement is achieved. (authors)

  17. Anopheles gambiae heat shock protein cognate 70B impedes o'nyong-nyong virus replication

    OpenAIRE

    Higgs Stephen; Vanlandingham Dana L; Tsetsarkin Konstantin A; Hong Young S; Sim Cheolho; Collins Frank H

    2007-01-01

    Abstract Background Phylogenetic and functional analysis was conducted on an Anopheles gambiae gene, ENSANGG00000017398. Based on phylogenetic analysis, this gene belongs to the same lineage as Heat shock protein cognate 70-4 (Hsc70-4) in Drosophila. Accordingly, we propose to name this gene Heat shock protein cognate 70B (HSC70B). We previously reported that expression of HSC70B and other genes including elongation factor-1α (EF-1α) and the agglutinin attachment subunit (agglutinin) were up-...

  18. Heat shock pretreatment enhances porcine myoblasts survival after autotransplantation in intact skeletal muscle

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Myoblast transplantation (MT) is a cell-based gene therapy treatment, representing a potential treat-ment for Duchenne muscular dystrophy (DMD), cardiac failure and muscle trauma. The rapid and mas-sive death of transplanted cells after MT is considered as a major hurdle which limits the efficacy of MT treatment. Heat shock proteins (HSPs) are overexpressed when cells undergo various insults. HSPs have been described to protect cells in vivo and in vitro against diverse insults. The aim of our study is to investigate whether HSP overexpression could increase myoblast survival after autotransplantation in pig intact skeletal muscle. HSP expression was induced by warming the cells at 42℃ for 1 h. HSP70 expression was quantified by Western blot and flow cytometry 24 h after the treatment. To investigate the myogenic characteristics of myoblasts, desmin and CD56 were analysed by Western blot and flow cytometry; and the fusion index was measured. We also quantified cell survival after autologous transplantation in pig intact skeletal muscle and followed cell integration. Results showed that heat shock treatment of myoblasts induced a significative overexpression of the HSP70 (P < 0.01) without loss of their myogenic characteristics as assessed by FACS and fusion index. In vivo (n=7), the myoblast survival rate was not significantly different at 24 h between heat shock treated and non- treated cells (67.69% ± 8.35% versus 58.79% ± 8.35%, P > 0.05). However, the myoblast survival rate in the heat shocked cells increased by twofold at 48 h (53.32% ± 8.22% versus 28.27% ± 6.32%, P < 0.01) and more than threefold at 120 h (26.33% ± 5.54% versus 8.79% ± 2.51%, P < 0.01). Histological analy-sis showed the presence of non-heat shocked and heat shocked donor myoblasts fused with host myoblasts. These results suggested that heat shock pretreatment increased the HSP70 expression in porcine myoblasts, and improved the survival rate after autologous transplantation

  19. Expression of the major heat shock gene of Drosophila melanogaster in Saccharomyces cerevisiae.

    OpenAIRE

    de Banzie, J S; Sinclair, L; Lis, J T

    1986-01-01

    A copy of the gene which encodes the major heat shock protein (hsp70) of D. melanogaster was integrated in both orientations into the genome of S. cerevisiae at the leu2 locus. The level of transcript from the D. melanogaster gene was measured under both normal conditions and conditions which are known to give rise to the heat shock response in S. cerevisiae. In both orientations the D. melanogaster gene gave rise to an abundant transcript in uninduced cells. The level of this transcript was ...

  20. Heat shock pretreatment enhances porcine myoblasts survival after autotransplantation in intact skeletal muscle

    Institute of Scientific and Technical Information of China (English)

    YANG Sheng; Thomas LAUMONIER; Jacques MENETREY

    2007-01-01

    Myoblast transplantation (MT) is a cell-based gene therapy treatment, representing a potential treatment for Duchenne muscular dystrophy (DMD), cardiac failure and muscle trauma. The rapid and massive death of transplanted cells after MT is considered as a major hurdle which limits the efficacy of MT treatment. Heat shock proteins (HSPs) are overexpressed when cells undergo various insults. HSPs have been described to protect cells in vivo and in vitro against diverse insults. The aim of our study is to investigate whether HSP overexpression could increase myoblast survival after autotransplantation in pig intact skeletal muscle. HSP expression was induced by warming the cells at 42℃ for 1 h. HSP70 expression was quantified by Western blot and flow cytometry 24 h after the treatment. To investigate the myogenic characteristics of myoblasts, desmin and CD56 were analysed by Western blot and flow cytometry; and the fusion index was measured. We also quantified cell survival after autologous transplantation in pig intact skeletal muscle and followed cell integration. Results showed that heat shock treatment of myoblasts induced a significative overexpression of the HSP70 (P<0.01) without loss of their myogenic characteristics as assessed by FACS and fusion index. In vivo (n=7), the myoblast survival rate was not significantly different at 24 h between heat shock treated and nontreated cells (67.69%±8.35% versus 58.79%±8.35%, P>0.05). However, the myoblast survival rate in the heat shocked cells increased by twofold at 48 h (53.32%±8.22% versus 28.27%±6.32%, P<0.01)and more than threefold at 120 h (26.33%±5.54% versus 8.79%±2.51%, P<0.01). Histological analysis showed the presence of non-heat shocked and heat shocked donor myoblasts fused with host myoblasts. These results suggested that heat shock pretreatment increased the HSP70 expression in porcine myoblasts, and improved the survival rate after autologous transplantation. Therefore, heat shock

  1. Heat Shock proteins expression in different types of classical Hodgkin`s Lymphoma

    Directory of Open Access Journals (Sweden)

    Tumanskiy V.O.

    2013-01-01

    Full Text Available In the study estimation of heat shock proteins hsp60 and hsp90 expression in tumor tissue were conducted in lymphocyte rich, mixed cellularity and ymphocyte depleted (reticular type variants of classical Hodgkins lymphoma. It was shown that HRS-cells and cellular microenvironment in the studied tumor tissues have in their cytoplasm heat shock proteins, what may cause resistance to inner and outer damage effects. Expression increases from lymphocyte rich to mixed cellularity and the most significant in tumor tissue of Hodgkin`s sarcoma.

  2. A heat shock element in the phosphoglycerate kinase gene promoter of yeast.

    OpenAIRE

    Piper, P W; Curran, B; Davies, M W; Hirst, K; Lockheart, A; Ogden, J E; Stanway, C A; Kingsman, A J; Kingsman, S M

    1988-01-01

    The phosphoglycerate kinase (PGK) promoter is often employed in yeast expression vectors due to its very high efficiency. Its activity in unstressed cells has been shown to be due to an upstream activator site (UASPGK) at -402 to -479. Since levels of PGK mRNA can sometimes be elevated by heat shock of yeast cultures this investigation determined how specific deletions of PGK promoter sequences effect levels of PGK mRNA both before and after heat shock. A series of PGK promoter deletions was ...

  3. Heat shock factor 1 binds to and transcribes satellite II and III sequences at several pericentromeric regions in heat-shocked cells

    Energy Technology Data Exchange (ETDEWEB)

    Eymery, Angeline, E-mail: aeymery@gmail.com [Universite Joseph Fourier-Grenoble I (France); INSERM Institut Albert Bonniot U823, La Tronche, F-38700 (France); Souchier, Catherine, E-mail: catherine.souchier@ujf-grenoble.fr [Universite Joseph Fourier-Grenoble I (France); INSERM Institut Albert Bonniot U823, La Tronche, F-38700 (France); Vourc' h, Claire, E-mail: claire.vourch@ujf-grenoble.fr [Universite Joseph Fourier-Grenoble I (France); INSERM Institut Albert Bonniot U823, La Tronche, F-38700 (France); Jolly, Caroline, E-mail: caroline.jolly@upmf-grenoble.fr [Universite Joseph Fourier-Grenoble I (France); INSERM Institut Albert Bonniot U823, La Tronche, F-38700 (France)

    2010-07-01

    Cells respond to stress by activating the synthesis of heat shock proteins (HSPs) which protect the cells against the deleterious effects of stress. This mechanism is controlled by the heat shock factor 1 (HSF1). In parallel to HSP gene transcription, in human cells, HSF1 also binds to and transcribes satellite III repeated sequences present in numerous copies in the 9q12 pericentromeric region of chromosome 9. These HSF1 accumulation sites are termed nuclear stress bodies (nSBs). In tumor cells, however, the number of nSBs is higher than the number of 9q12 copies, suggesting the existence of other HSF1 targets. In this paper, we were interested in characterizing these other HSF1 binding sites. We show that HSF1 indeed binds to the pericentromeric region of 14 chromosomes, thereby directing the formation of 'secondary nSBs'. The appearance of secondary nSBs depends on the number of satellite sequences present in the target locus, and on the cellular amount of HSF1 protein. Moreover, secondary nSBs also correspond to transcription sites, thus demonstrating that heat shock induces a genome-wide transcription of satellite sequences. Finally, by analyzing published transcriptomic data, we show that the derepression of these large heterochromatic blocks does not significantly affect the transcription of neighboring genes.

  4. Differential transcript induction of parsley pathogenesis-related proteins and of a small heat shock protein by ozone and heat shock

    International Nuclear Information System (INIS)

    Parsley (Petroselinum (crispum L.) is known to respond to pathogen attack by the synthesis of furanocoumarins and to UV irradiation by the synthesis of flavone glycosides whereas ozone treatment results in the induction of both pathways. A cDNA library from parsley plants was differentially screened using labelled reverse-transcribed poly(A)+ RNA isolated from ozone-treated parsley plants. This resulted in the isolation of 13 independent cDNA clones representing ozone-induced genes and of 11 cDNA clones representing ozone-repressed genes. DNA sequencing of several clones resulted in the identification of pathogenesis-related protein 1-3 (PR1-3), of a new member of PR1 cDNAs (PRI-4) and of a small heat shock protein (sHSP). Northern blot analyses showed a transient induction of the three mRNA species after ozone fumigation. In contrast, heat shock treatment of parsley plants resulted in an increase of sHSP mRNA whereas no increase for transcripts of PR1-3 and PR1-4 could be observed. This is the first characterized sHSP cDNA clone for plants induced by heat shock, as well as by oxidative stress caused by ozone. (author)

  5. Heat shock factor 1 binds to and transcribes satellite II and III sequences at several pericentromeric regions in heat-shocked cells

    International Nuclear Information System (INIS)

    Cells respond to stress by activating the synthesis of heat shock proteins (HSPs) which protect the cells against the deleterious effects of stress. This mechanism is controlled by the heat shock factor 1 (HSF1). In parallel to HSP gene transcription, in human cells, HSF1 also binds to and transcribes satellite III repeated sequences present in numerous copies in the 9q12 pericentromeric region of chromosome 9. These HSF1 accumulation sites are termed nuclear stress bodies (nSBs). In tumor cells, however, the number of nSBs is higher than the number of 9q12 copies, suggesting the existence of other HSF1 targets. In this paper, we were interested in characterizing these other HSF1 binding sites. We show that HSF1 indeed binds to the pericentromeric region of 14 chromosomes, thereby directing the formation of 'secondary nSBs'. The appearance of secondary nSBs depends on the number of satellite sequences present in the target locus, and on the cellular amount of HSF1 protein. Moreover, secondary nSBs also correspond to transcription sites, thus demonstrating that heat shock induces a genome-wide transcription of satellite sequences. Finally, by analyzing published transcriptomic data, we show that the derepression of these large heterochromatic blocks does not significantly affect the transcription of neighboring genes.

  6. Heat shock factor 1 upregulates transcription of Epstein-Barr Virus nuclear antigen 1 by binding to a heat shock element within the BamHI-Q promoter

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Feng-Wei [The State Key Laboratory of Oncology in South China, Cancer Center, Sun Yat-Sen University, Guangzhou (China); Wu, Xian-Rui [Department of Surgery, Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou (China); Liu, Wen-Ju; Liao, Yi-Ji [The State Key Laboratory of Oncology in South China, Cancer Center, Sun Yat-Sen University, Guangzhou (China); Lin, Sheng [Laboratory of Integrated Biosciences, School of Life Science, Sun Yat-sen University, Guangzhou (China); Zong, Yong-Sheng; Zeng, Mu-Sheng; Zeng, Yi-Xin [The State Key Laboratory of Oncology in South China, Cancer Center, Sun Yat-Sen University, Guangzhou (China); Mai, Shi-Juan, E-mail: maishj@sysucc.org.cn [The State Key Laboratory of Oncology in South China, Cancer Center, Sun Yat-Sen University, Guangzhou (China); Xie, Dan, E-mail: xied@mail.sysu.edu.cn [The State Key Laboratory of Oncology in South China, Cancer Center, Sun Yat-Sen University, Guangzhou (China)

    2011-12-20

    Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA1) is essential for maintenance of the episome and establishment of latency. In this study, we observed that heat treatment effectively induced EBNA1 transcription in EBV-transformed B95-8 and human LCL cell lines. Although Cp is considered as the sole promoter used for the expression of EBNA1 transcripts in the lymphoblastoid cell lines, the RT-PCR results showed that the EBNA1 transcripts induced by heat treatment arise from Qp-initiated transcripts. Using bioinformatics, a high affinity and functional heat shock factor 1 (HSF1)-binding element within the - 17/+4 oligonucleotide of the Qp was found, and was determined by electrophoretic mobility shift assay and chromatin immunoprecipitation assay. Moreover, heat shock and exogenous HSF1 expression induced Qp activity in reporter assays. Further, RNA interference-mediated HSF1 gene silencing attenuated heat-induced EBNA1 expression in B95-8 cells. These results provide evidence that EBNA1 is a new target for the transcription factor HSF1.

  7. Mapping temperature-induced conformational changes in the Escherichia coli heat shock transcription factor sigma 32 by amide hydrogen exchange

    DEFF Research Database (Denmark)

    Rist, Wolfgang; Jørgensen, Thomas J D; Roepstorff, Peter;

    2003-01-01

    degrees C, indicating that sigma 32 adopts a highly flexible structure. At 42 degrees C we observed a slow correlated exchange of 30 additional amide hydrogens and localized it to a helix-loop-helix motif within domain sigma 2 that is responsible for the recognition of the -10 region in heat shock......Stress conditions such as heat shock alter the transcriptional profile in all organisms. In Escherichia coli the heat shock transcription factor, sigma 32, out-competes upon temperature up-shift the housekeeping sigma-factor, sigma 70, for binding to core RNA polymerase and initiates heat shock...... gene transcription. To investigate possible heat-induced conformational changes in sigma 32 we performed amide hydrogen (H/D) exchange experiments under optimal growth and heat shock conditions combined with mass spectrometry. We found a rapid exchange of around 220 of the 294 amide hydrogens at 37...

  8. Effects of Heat Shock on Photosynthetic Properties, Antioxidant Enzyme Activity, and Downy Mildew of Cucumber (Cucumis sativus L.)

    Science.gov (United States)

    Hao, Ting; Jin, Haijun; Zhang, Hongmei; He, Lizhong; Zhou, Qiang; Huang, Danfeng; Hui, Dafeng; Yu, Jizhu

    2016-01-01

    Heat shock is considered an abiotic stress for plant growth, but the effects of heat shock on physiological responses of cucumber plant leaves with and without downy mildew disease are still not clear. In this study, cucumber seedlings were exposed to heat shock in greenhouses, and the responses of photosynthetic properties, carbohydrate metabolism, antioxidant enzyme activity, osmolytes, and disease severity index of leaves with or without the downy mildew disease were measured. Results showed that heat shock significantly decreased the net photosynthetic rate, actual photochemical efficiency, photochemical quenching coefficient, and starch content. Heat shock caused an increase in the stomatal conductance, transpiration rate, antioxidant enzyme activities, total soluble sugar content, sucrose content, soluble protein content and proline content for both healthy leaves and downy mildew infected leaves. These results demonstrate that heat shock activated the transpiration pathway to protect the photosystem from damage due to excess energy in cucumber leaves. Potential resistance mechanisms of plants exposed to heat stress may involve higher osmotic regulation capacity related to an increase of total accumulations of soluble sugar, proline and soluble protein, as well as higher antioxidant enzymes activity in stressed leaves. Heat shock reduced downy mildew disease severity index by more than 50%, and clearly alleviated downy mildew development in the greenhouses. These findings indicate that cucumber may have a complex physiological change to resist short-term heat shock, and suppress the development of the downy mildew disease. PMID:27065102

  9. Effects of Heat Shock on Photosynthetic Properties, Antioxidant Enzyme Activity, and Downy Mildew of Cucumber (Cucumis sativus L..

    Directory of Open Access Journals (Sweden)

    Xiaotao Ding

    Full Text Available Heat shock is considered an abiotic stress for plant growth, but the effects of heat shock on physiological responses of cucumber plant leaves with and without downy mildew disease are still not clear. In this study, cucumber seedlings were exposed to heat shock in greenhouses, and the responses of photosynthetic properties, carbohydrate metabolism, antioxidant enzyme activity, osmolytes, and disease severity index of leaves with or without the downy mildew disease were measured. Results showed that heat shock significantly decreased the net photosynthetic rate, actual photochemical efficiency, photochemical quenching coefficient, and starch content. Heat shock caused an increase in the stomatal conductance, transpiration rate, antioxidant enzyme activities, total soluble sugar content, sucrose content, soluble protein content and proline content for both healthy leaves and downy mildew infected leaves. These results demonstrate that heat shock activated the transpiration pathway to protect the photosystem from damage due to excess energy in cucumber leaves. Potential resistance mechanisms of plants exposed to heat stress may involve higher osmotic regulation capacity related to an increase of total accumulations of soluble sugar, proline and soluble protein, as well as higher antioxidant enzymes activity in stressed leaves. Heat shock reduced downy mildew disease severity index by more than 50%, and clearly alleviated downy mildew development in the greenhouses. These findings indicate that cucumber may have a complex physiological change to resist short-term heat shock, and suppress the development of the downy mildew disease.

  10. Heat transfer in a cooling water pool with tube bundles under natural circulation

    International Nuclear Information System (INIS)

    Highlights: • SMART adopts a passive system to enhance its safety. • Heat transfer tests for the straight tube bundle in the cooling water pool are performed. • Heat transfer is affected by cooling water temperature, and radial location of the tube. • Heat transfer for the tube bundle is slightly high due to turbulence effect. - Abstract: SMART was developed for electricity generation and seawater desalination and adopted a passive system to enhance its safety. This system could passively remove decay heat from the reactor core to the emergency cooldown tank (ECT) through the heat exchanger. A natural circulation flow was established as water covered the tube bundle inside the emergency cooldown tank. Heat transfer tests for the upward straight tube bundle in the emergency cooldown tank were performed to find the characteristics of the passive system design under natural circulation conditions. The heat transfer coefficient at the tube bundle was affected by the cooling water temperature, and the radial location of the tube. However, it has nearly a similar value at the bottom region regardless of the tube location. The average heat transfer coefficient for the tube bundle was slightly higher than that for the single tube owing to the turbulence effect among the tube bundles

  11. Hsc66, an Hsp70 homolog in Escherichia coli, is induced by cold shock but not by heat shock.

    OpenAIRE

    Lelivelt, M J; Kawula, T H

    1995-01-01

    Hsc66 is the second identified Hsp70 protein in Escherichia coli. Mutations in hscA, the gene encoding Hsc66, compensate for some phenotypic effects of a mutation in hns, a gene encoding the cold-inducible, nucleoid-associated protein H-NS. Expression of hscA was not induced upon heat shock but was induced approximately 11-fold 3 h after a shift from 37 to 10 degrees C. Furthermore, hscA was induced upon chloramphenicol addition, which induces the synthesis of other cold-inducible genes. Mapp...

  12. Evaluation of the Natural Circulation Flow Loop with Inclined Downward Heating Channel

    Energy Technology Data Exchange (ETDEWEB)

    Wi, Kyung Jin; Ha, Kwang Soon; Park, Rae Joon [KAERI, Daejeon (Korea, Republic of); Yoo, Seong Yeon [Chungnam National University, Daejeon (Korea, Republic of)

    2015-05-15

    Versatile measures have been suggested and applied to mitigate severe accidents in nuclear power plants as recently presented by Rempe et al. In general, an increase in the natural circulation mass flow rate of the coolant leads to an increase in the critical heat flux (CHF) on the hot wall, thus enhancing the thermal margin. An ex-vessel core catcher under consideration, which is one of the engineered corium cooling systems, is a passive system consisting of an inclined engineered cooling channel made of a single channel between the body of the core catcher and the inside wall of the reactor cavity. Under severe accident conditions, water is supplied from the IRWST to the engineered cooling channel. The water in the inclined channel absorbs the decay heat transferred from the corium through the carbon steel structure of the core catcher body and boils off as steam. The latter is subsequently released into the free volume of the containment above the corium spreading compartment. Water continues to flow from the IRWST to the cooling channel as a result of buoyancy-driven natural circulation. The engineered cooling channel is designed to provide effective long-term cooling and stabilization of the corium mixture in the core catcher body while facilitating steam venting. To maintain the integrity of the ex-vessel core catcher, however, it is necessary that the water coolant be circulated at a sufficiently high rate through the inclined cooling channel for decay heat removal by downward facing boiling of the water circulated from the IRWST. KAERI performed the experimental study to evaluate the cooling performance of ex-vessel core catcher system with inclined downward facing heating surface. A scaling analysis is applied to design the test facility compared with the prototypic core catcher cooling system. The natural circulation flow experiments were performed along with the inlet subcooling, wall heat flux, and water level. The void fraction model with inclined

  13. Heat transfer in a large-scale circulating fluidized bed boiler

    Institute of Scientific and Technical Information of China (English)

    CHENG Leming; WANG Qinhui; SHI Zhenglun; LUO Zhongyang; NI Mingjiang; CEN Kefa

    2007-01-01

    Heat transfer of a furnace in a large-scale circulating fluidized bed (CFB) boiler was studied based on the analysis of available heat transfer coefficient data from typical industrial CFB boilers and measured data from a 12 MWe,a 50 MWe and a 135 MWe CFB boiler.The heat transfer of heat exchanger surfaces in a furnace,in a steam/water cooled cyclone,in an external heat exchanger and in the backpass was also reviewed.Empirical correlation of heat transfer coefficient was suggested after calculating the two key parameters,solids suspension density and furnace temperature.The correlation approach agrees well with the data from the large-scale CFB boilers.

  14. Single-dose oral quercetin improves redox status but does not affect heat shock response in mice.

    Science.gov (United States)

    Chen, Yifan; Islam, Aminul; Abraham, Preetha; Deuster, Patricia

    2014-07-01

    Inflammation and oxidative stress are considered as likely contributors to heat injury. However, their roles in regulating the heat shock response in vivo remain unclear. We tested the hypothesis that acute quercetin treatment would improve redox status and reduce heat shock responses in mice. Mice underwent two heat tests before and after single oral administration of either quercetin (15 mg/kg) or vehicle. We measured physiologic and biochemical responses in mice during and 18 to 22 hours after heat tests, respectively. There were no significant differences in core temperature, heart rate, or blood pressure between quercetin and vehicle groups during heat exposure. Mice with relatively severe hyperthermia during the pretreatment heat test showed a significant trend toward a lower peak core temperature during the heat test after quercetin treatment. Compared with mice not exposed to heat, quercetin-treated mice had significantly lower interleukin 6 (P heat exposure. Heat exposure significantly elevated heat shock proteins (HSPs) 72 and 90 and heat shock factor 1 levels in mouse liver, heart, and skeletal muscles, but no significant differences in tissue HSPs and heat shock factor 1 were found between quercetin- and vehicle-treated mice. These results suggest that a single moderate dose of quercetin is sufficient to alter redox status but not heat stress response in mice. Acute adaptations of peripheral tissues to heat stress may not be mediated by systemic inflammatory and redox state in vivo. PMID:25150121

  15. PP2A mediated AMPK inhibition promotes HSP70 expression in heat shock response.

    Directory of Open Access Journals (Sweden)

    Ting Wang

    Full Text Available BACKGROUND: Under stress, AMP-activated protein kinase (AMPK plays a central role in energy balance, and the heat shock response is a protective mechanism for cell survival. The relationship between AMPK activity and heat shock protein (HSP expression under stress is unclear. METHODOLOGY/PRINCIPAL FINDINGS: We found that heat stress induced dephosphorylation of AMPKα subunit (AMPKα in various cell types from human and rodent. In HepG2 cells, the dephosphorylation of AMPKα under heat stress in turn caused dephosphorylation of acetyl-CoA carboxylase and upregulation of phosphoenolpyruvate carboxykinase, two downstream targets of AMPK, confirming the inhibition of AMPK activity by heat stress. Treatment of HepG2 cells with phosphatase 2A (PP2A inhibitor okadaic acid or inhibition of PP2A expression by RNA interference efficiently reversed heat stress-induced AMPKα dephosphorylation, suggesting that heat stress inhibited AMPK through activation of PP2A. Heat stress- and other HSP inducer (CdCl(2, celastrol, MG132-induced HSP70 expression could be inhibited by AICAR, an AMPK specific activator. Inhibition of AMPKα expression by RNA interference reversed the inhibitory effect of AICAR on HSP70 expression under heat stress. These results indicate that AMPK inhibition under stress contribute to HSP70 expression. Mechanistic studies showed that activation of AMPK by AICAR had no effect on heat stress-induced HSF1 nuclear translocation, phosphorylation and binding with heat response element in the promoter region of HSP70 gene, but significantly decreased HSP70 mRNA stability. CONCLUSIONS/SIGNIFICANCE: These results demonstrate that during heat shock response, PP2A mediated AMPK inhibition upregulates HSP70 expression at least partially through stabilizing its mRNA, which suggests a novel mechanism for HSP induction under stress.

  16. Calculation analysis on the natural circulation of a passive residual heat removal system for IPWR

    International Nuclear Information System (INIS)

    Highlights: • The PRHRS is designed to increase the inherent safety features of the IPWR. • We study the single-phase and two-phase natural circulation characteristics of PRHRS system. • Once-through steam generator still produce superheated steam under accident conditions. • PRHRS parameters study under natural convection condition. - Abstract: The passive residual heat removal system (PRHRS) is designed to increase the inherent safety features of the integrated pressurized water reactor (IPWR). The PRHRS consists of once though steam generator (OTSG) secondary side, a heat exchanger (HX), a cooling water tank (CWT), and corresponding pipes and valves. On the accident conditions, residual heat is transferred to the CWT by the single-phase natural circulation in primary loop and two-phase natural circulation in PRHRS loop, and then the water in CWT is heated and finally evaporates into the air. The calculate results using RELAP5 code show that the PRHRS is sufficient enough to take heat away from primary coolant system. The effect of main parameters on the PRHRS was studied. The results indicate that the effective height between OTSG and HX, the HX areas, the volume of CWT, and the isolation valve actuation time are important parameters which are worth being considered seriously in the design of the PRHRS

  17. An experimental study on the flow instabilities and critical heat flux under natural circulation

    International Nuclear Information System (INIS)

    This study has been carried out to investigate the hydrodynamic stabilities and Critical Heat Flux (CHF) characteristics for the natural and forced circulation. A low pressure experimental loop was constructed, and experiments under various conditions have been performed. In the experiments of the natural circulation, flow oscillations has been observed and the average mass flux under flow oscillation have been measured. Several parameters such as heat flux, the inlet temperature of test section, friction valve opening and riser length have been varied in order to investigate their effects on the flow stability of the natural circulation system. And the CHF data from low flow experiments, namely the natural and forced circulation, have been compared with each other to identify the effects of the flow instabilities on the CHF for the natural circulation mode. The test conditions for the CHF experiments were a low flow of less than 70 kg/m2s of water in a vertical round tube with diameter of 0.008 m at near atmospheric pressure. (author)

  18. Characteristics of fluid flow in a solid particle circulating fluidized heat exchanger

    International Nuclear Information System (INIS)

    The commercial viability of heat exchanger is mainly dependent on their long-term fouling characteristics because the fouling increases the pressure loss and degrades the thermal performance of a heat exchanger. An experimental study was performed to investigate the characteristics of fluid flow in a fluidized bed heat exchanger with circulating various solid particles. The present work showed that the drag force coefficients of particles in the internal flow were higher than in the external flow, in addition, they were lower with the shapes of particles being closer to the spherical geometries

  19. Immunohistochemical evaluation of expression of heat shock proteins HSP70 and HSP90 in mammary gland neoplasms in bitches.

    Science.gov (United States)

    Badowska-Kozakiewicz, A M; Malicka, E

    2012-01-01

    Heat shock proteins have essential roles in a number of pathophysiologic conditions including carcinogenesis and represent a group of novel molecular markers in cancer management. The aim of this study was to investigate heat shock protein expression in correlation with other neoplasm traits such as: histological type, differentiation grade, proliferative activity, estrogenic receptor expression, and cyclooxygenase-2 and p53 proteins. Material for the investigation comprised 133 tumors of the mammary gland collected from bitches. In total 14 adenomas, 66 complex carcinomas, 47 simple carcinomas and 6 solid carcinomas were collected. Evaluations were conducted with histopathological and immunohistochemical methods using suitable antibodies. Expression of heat shock protein 70 was observed in all types of evaluated neoplasms. A higher average number of cells undergoing expression of heat shock protein 70, which was statistically insignificant, was established in complex and simple cancers and in cancers with the 1st and the 2nd degree of histological malignancy. Expression of heat shock protein 90 was observed in all studied neoplasms; it was very insignificant in adenomas, compared to cancers, and the highest expression was established in the solid cancers, as well as in cancers with the 2nd degree of histological malignancy. This high expression of heat shock protein 90 was correlated with proliferative activity. The results suggest that heat shock protein 90 is involved in canine mammary gland carcinogenesis. The results also suggest that heat shock protein 90 may be a prognostic factor, but this requires detailed clinical confirmation. PMID:22844695

  20. Screening Molecular Chaperones Similar to Small Heat Shock Proteins in Schizosaccharomyces pombe

    OpenAIRE

    Han, Jiyoung; Kim, Kanghwa; Lee, Songmi

    2015-01-01

    To screen molecular chaperones similar to small heat shock proteins (sHsps), but without α-crystalline domain, heat-stable proteins from Schizosaccharomyces pombe were analyzed by 2-dimensional electrophoresis and matrix assisted laser desorption/ionization time-of-flight mass spectrometry. Sixteen proteins were identified, and four recombinant proteins, including cofilin, NTF2, pyridoxin biosynthesis protein (Snz1) and Wos2 that has an α-crystalline domain, were purified. Among these protein...

  1. The central role of heat shock factor 1 in synaptic fidelity and memory consolidation.

    Science.gov (United States)

    Hooper, Philip L; Durham, Heather D; Török, Zsolt; Hooper, Paul L; Crul, Tim; Vígh, László

    2016-09-01

    Networks of neuronal synapses are the fundamental basis for making and retaining memory. Reduced synapse number and quality correlates with loss of memory in dementia. Heat shock factor 1 (HSF1), the major transcription factor regulating expression of heat shock genes, plays a central role in proteostasis, in establishing and sustaining synaptic fidelity and function, and in memory consolidation. Support for this thesis is based on these observations: (1) heat shock induces improvements in synapse integrity and memory consolidation; (2) synaptic depolarization activates HSF1; (3) activation of HSF1 alone (independent of the canonical heat shock response) augments formation of essential synaptic elements-neuroligands, vesicle transport, synaptic scaffolding proteins, lipid rafts, synaptic spines, and axodendritic synapses; (4) HSF1 coalesces and activates memory receptors in the post-synaptic dendritic spine; (5) huntingtin or α-synuclein accumulation lowers HSF1 while HSF1 lowers huntingtin and α-synuclein aggregation-a potential vicious cycle; and (6) HSF1 agonists (including physical activity) can improve cognitive function in dementia models. Thus, via direct gene expression of synaptic elements, production of HSPs that assure high protein fidelity, and activation of other neuroprotective signaling pathways, HSF1 agonists could provide breakthrough therapy for dementia-associated disease. PMID:27283588

  2. 热休克蛋白70%Heat shock protein70

    Institute of Scientific and Technical Information of China (English)

    叶春; 王瑞元; 何执静

    2001-01-01

    The heat shock response is a common cellular reaction to external stressers.A characteristic set of proteins is synthesized shortly after the organism is exposed to stress.Heat shock protein 70 family are the most strongly induced heat shock proteins.They are also called stress protein or molecular chaperones.They carry out important cellular functions,such as molecular chaperones,cellular protection.%热休克蛋白(HSP heat shock protein)是应激后细胞内优先合成的一组蛋白质,又称为应激蛋白(CSP,stress protein)或分子伴侣(chaperones)。其中HSP70它具有重要的细胞功能,如细胞保护作用、分子伴侣及抗氧化等。文章重点介绍HSP70的功能、结构、调节及与运动之间的相互影响。

  3. Manipulating heat shock factor-1 in Xenopus tadpoles: neuronal tissues are refractory to exogenous expression.

    Directory of Open Access Journals (Sweden)

    Ron P Dirks

    Full Text Available BACKGROUND: The aging related decline of heat shock factor-1 (HSF1 signaling may be causally related to protein aggregation diseases. To model such disease, we tried to cripple HSF1 signaling in the Xenopus tadpole. RESULTS: Over-expression of heat shock factor binding protein-1 did not inhibit the heat shock response in Xenopus. RNAi against HSF1 mRNA inhibited the heat shock response by 70% in Xenopus A6 cells, but failed in transgenic tadpoles. Expression of XHSF380, a dominant-negative HSF1 mutant, was embryonic lethal, which could be circumvented by delaying expression via a tetracycline inducible promoter. HSF1 signaling is thus essential for embryonic Xenopus development. Surprisingly, transgenic expression of the XHSF380 or of full length HSF1, whether driven by a ubiquitous or a neural specific promoter, was not detectable in the larval brain. CONCLUSIONS: Our finding that the majority of neurons, which have little endogenous HSF1, refused to accept transgene-driven expression of HSF1 or its mutant suggests that HSF1 levels are strictly controlled in neuronal tissue.

  4. Dynamics of the full length and mutated heat shock factor 1 in human cells.

    Directory of Open Access Journals (Sweden)

    Gaëtan Herbomel

    Full Text Available Heat shock factor 1 is the key transcription factor of the heat shock response. Its function is to protect the cell against the deleterious effects of stress. Upon stress, HSF1 binds to and transcribes hsp genes and repeated satellite III (sat III sequences present at the 9q12 locus. HSF1 binding to pericentric sat III sequences forms structures known as nuclear stress bodies (nSBs. nSBs represent a natural amplification of RNA pol II dependent transcription sites. Dynamics of HSF1 and of deletion mutants were studied in living cells using multi-confocal Fluorescence Correlation Spectroscopy (mFCS and Fluorescence Recovery After Photobleaching (FRAP. In this paper, we show that HSF1 dynamics modifications upon heat shock result from both formation of high molecular weight complexes and increased HSF1 interactions with chromatin. These interactions involve both DNA binding with Heat Shock Element (HSE and sat III sequences and a more transient sequence-independent binding likely corresponding to a search for more specific targets. We find that the trimerization domain is required for low affinity interactions with chromatin while the DNA binding domain is required for site-specific interactions of HSF1 with DNA.

  5. Dietary heme adversely affects experimental colitis in rats, despite heat-shock protein induction

    NARCIS (Netherlands)

    Schepens, Marloes A. A.; Vink, Carolien; Schonewille, Arjan J.; Dijkstra, Gerard; van der Meer, Roelof; Bovee-Oudenhoven, Ingeborg M. J.

    2011-01-01

    Objective: Research on dietary modulation of inflammatory bowel disease is in its infancy. Dietary heme, mimicking red meat, is cytotoxic to colonic epithelium and thus may aggravate colitis. Alternatively, heme-induced colonic stress might also result in potential protective heat-shock proteins (HS

  6. Recruitment of phosphorylated small heat shock protein Hsp27 to nuclear speckles without stress

    International Nuclear Information System (INIS)

    During stress, the mammalian small heat shock protein Hsp27 enters cell nuclei. The present study examines the requirements for entry of Hsp27 into nuclei of normal rat kidney (NRK) renal epithelial cells, and for its interactions with specific nuclear structures. We find that phosphorylation of Hsp27 is necessary for the efficient entry into nuclei during heat shock but not sufficient for efficient nuclear entry under control conditions. We further report that Hsp27 is recruited to an RNAse sensitive fraction of SC35 positive nuclear speckles, but not other intranuclear structures, in response to heat shock. Intriguingly, Hsp27 phosphorylation, in the absence of stress, is sufficient for recruitment to speckles found in post-anaphase stage mitotic cells. Additionally, pseudophosphorylated Hsp27 fused to a nuclear localization peptide (NLS) is recruited to nuclear speckles in unstressed interphase cells, but wildtype and nonphosphorylatable Hsp27 NLS fusion proteins are not. The expression of NLS-Hsp27 mutants does not enhance colony forming abilities of cells subjected to severe heat shock, but does regulate nuclear speckle morphology. These data demonstrate that phosphorylation, but not stress, mediates Hsp27 recruitment to an RNAse soluble fraction of nuclear speckles and support a site-specific role for Hsp27 within the nucleus

  7. Expressed sequence tags from heat-shocked seagrass Zostera noltii (Hornemann) from its southern distribution range

    NARCIS (Netherlands)

    Massa, Sonia I.; Pearson, Gareth A.; Aires, Tania; Kube, Michael; Olsen, Jeanine L.; Reinhardt, Richard; Serrao, Ester A.; Arnaud-Haond, Sophie

    2011-01-01

    Predicted global climate change threatens the distributional ranges of species worldwide. We identified genes expressed in the intertidal seagrass Zostera midi during recovery from a simulated low tide heat-shock exposure. Five Expressed Sequence Tag (EST) libraries were compared, corresponding to f

  8. Regulatory coordination between two major intracellular homeostatic systems: heat shock response and autophagy.

    Science.gov (United States)

    Dokladny, Karol; Zuhl, Micah Nathaniel; Mandell, Michael; Bhattacharya, Dhruva; Schneider, Suzanne; Deretic, Vojo; Moseley, Pope Lloyd

    2013-05-24

    The eukaryotic cell depends on multitiered homeostatic systems ensuring maintenance of proteostasis, organellar integrity, function and turnover, and overall cellular viability. At the two opposite ends of the homeostatic system spectrum are heat shock response and autophagy. Here, we tested whether there are interactions between these homeostatic systems, one universally operational in all prokaryotic and eukaryotic cells, and the other one (autophagy) is limited to eukaryotes. We found that heat shock response regulates autophagy. The interaction between the two systems was demonstrated by testing the role of HSF-1, the central regulator of heat shock gene expression. Knockdown of HSF-1 increased the LC3 lipidation associated with formation of autophagosomal organelles, whereas depletion of HSF-1 potentiated both starvation- and rapamycin-induced autophagy. HSP70 expression but not expression of its ATPase mutant inhibited starvation or rapamycin-induced autophagy. We also show that exercise induces autophagy in humans. As predicted by our in vitro studies, glutamine supplementation as a conditioning stimulus prior to exercise significantly increased HSP70 protein expression and prevented the expected exercise induction of autophagy. Our data demonstrate for the first time that heat shock response, from the top of its regulatory cascade (HSF-1) down to the execution stages delivered by HSP70, controls autophagy thus connecting and coordinating the two extreme ends of the homeostatic systems in the eukaryotic cell. PMID:23576438

  9. Heat shock and salicylic acid on postharvest preservation of organic strawberries

    Directory of Open Access Journals (Sweden)

    Sidiane Coltro

    2014-06-01

    Full Text Available Heat shock and salicylic acid have been studied on shelf-life extension of fruits. The benefits of these techniques have been related to their effect on inducing physiological defense responses against the oxidative stress and pathogen development. The objective of this study was to evaluate the effect of heat shock and salicylic acid on the postharvest preservation and contents of total phenolics, anthocyanins, ascorbic acid, fresh weight loss and microbiological quality of organic strawberries cv. Dover. Strawberries produced organically and stored at 5 ºC were subjected to heat shock (45 ºC ± 3 ºC for 3 h, application of salicylic acid (soaking in 2.0 mmol L-1 solution, heat shock in combination with salicylic acid and control. After treatment, the fruits were packed and stored in a climatic chamber at 5 ºC ± 2 ºC. At 1, 7 and 14 days, the experimental units were removed from refrigeration and kept at room temperature of approximately 20 ºC for two days. There was no effect of treatments on fresh weight loss, incidence of pathogens or chemical variations in strawberry fruits during the storage period. In natural conditions, organically grown strawberries remained in good condition for sale up to seven days of storage in all treatments.

  10. Prostaglandins with antiproliferative activity induce the synthesis of a heat shock protein in human cells

    International Nuclear Information System (INIS)

    Prostaglandins (PGs)A1 and J2 were found to potently suppress the proliferation of human K562 erythroleukemia cells and to induce the synthesis of a 74-kDa protein (p74) that was identified as a heat shock protein related to the major 70-kDa heat shock protein group. p74 synthesis was stimulated at doses of PGA1 and PGJ2 that inhibited cell replication, and its accumulation ceased upon removal of the PG-induced proliferation block. PGs that did not affect K562 cell replication did not induce p74 synthesis. p74 was found to be localized mainly in the cytoplasm of PG-treated cells, but moderate amounts were found also in dense areas of the nucleus after PGJ2 treatment. p74 was not necessarily associated with cytotoxicity or with inhibition of cell protein synthesis. The results described support the hypothesis that synthesis of the 70-kDa heat shock proteins is associated with changes in cell proliferation. The observation that PGs can induce the synthesis of heat shock proteins expands our understanding of the mechanism of action of these compounds whose regulatory role is well known in many physiological phenomena, including the control of fever production

  11. Periodic heat shock accelerated the chondrogenic differentiation of human mesenchymal stem cells in pellet culture.

    Directory of Open Access Journals (Sweden)

    Jing Chen

    Full Text Available Osteoarthritis (OA is one of diseases that seriously affect elderly people's quality of life. Human mesenchymal stem cells (hMSCs offer a potential promise for the joint repair in OA patients. However, chondrogenic differentiation from hMSCs in vitro takes a long time (∼ 6 weeks and differentiated cells are still not as functionally mature as primary isolated chondrocytes, though chemical stimulations and mechanical loading have been intensively studied to enhance the hMSC differentiation. On the other hand, thermal stimulations of hMSC chondrogenesis have not been well explored. In this study, the direct effects of mild heat shock (HS on the differentiation of hMSCs into chondrocytes in 3D pellet culture were investigated. Periodic HS at 41 °C for 1 hr significantly increased sulfated glycosaminoglycan in 3D pellet culture at Day 10 of chondrogenesis. Immunohistochemical and Western Blot analyses revealed an increased expression of collagen type II and aggrecan in heat-shocked pellets than non heat-shocked pellets on Day 17 of chondrogenesis. In addition, HS also upregulated the expression of collagen type I and X as well as heat shock protein 70 on Day 17 and 24 of differentiation. These results demonstrate that HS accelerated the chondrogenic differentiation of hMSCs and induced an early maturation of chondrocytes differentiated from hMSCs. The results of this study will guide the design of future protocols using thermal treatments to facilitate cartilage regeneration with human mesenchymal stem cells.

  12. Heat Shock Factor 1: From Fire Chief to Crowd-Control Specialist.

    Science.gov (United States)

    Triandafillou, Catherine G; Drummond, D Allan

    2016-07-01

    HSF1 is the supposed master regulator of the heat shock response. In this issue of Molecular Cell, Solís et al. reveal that it has a much narrower job description: organizing a small team of molecular chaperones that keep the proteome moving. PMID:27392142

  13. Second law analysis of heat transfer surfaces in circulating fluidized beds

    Energy Technology Data Exchange (ETDEWEB)

    Gungor, Afsin [Department of Mechanical Engineering, Faculty of Engineering and Architecture, Nigde University, 51100 Nigde (Turkey)

    2009-07-15

    The correct sizing of the heat transfer surfaces is important to ensure proper operation, load turndown, and optimization of circulating fluidized beds (CFBs). From this point of view, in this study, the thermodynamic second law analysis of heat transfer surfaces in CFBs is investigated theoretically in order to define the parameters that affect the system efficiency. Using a previously developed 2D CFB model which uses the particle-based approach and integrates and simultaneously predicts the hydrodynamics and combustion aspects, second law efficiency and entropy generation values are obtained at different height and volume ratios of the heat transfer surfaces for CFBs. Besides that, the influences of the water flow rates and heat exchanger tube diameters on the second law efficiency are investigated. Through this analysis, the dimensions, arrangement and type of the heat transfer surfaces which achieve maximum efficiency are obtained. (author)

  14. The Impact of Oceanic Heat Transport on the Atmospheric Circulation: a Thermodynamic Perspective

    CERN Document Server

    Schröder, Alexander; Lunkeit, Frank

    2014-01-01

    The present study investigates how global thermodynamic properties of the climate system are affected by the changes in the intensity of the imposed oceanic heat transport in an atmospheric general circulation model in aqua-planet configuration. Increasing the poleward oceanic heat transport results in an overall increase in the surface temperature and a decrease in the equator-to-pole surface temperature difference as a result of the ice-albedo feedback. Following the classical ansatz by Stone, the atmospheric heat transport changes in such a way that the total poleward heat transport remains almost unchanged. We also find that the efficiency of the climate machine, the intensity of the Lorenz energy cycle and the material entropy production of the system decline with increased oceanic heat transport which suggests that the climate system becomes less efficient and turns into a state of reduced entropy production, as the enhanced oceanic transport performs a stronger large-scale mixing between geophysical fl...

  15. Huntingtin interacting protein HYPK is a negative regulator of heat shock response and is downregulated in models of Huntington's Disease.

    Science.gov (United States)

    Das, Srijit; Bhattacharyya, Nitai Pada

    2016-05-01

    Huntingtin interacting protein HYPK (Huntingtin Yeast Partner K) is an intrinsically unstructured protein having chaperone-like activity and can suppress mutant huntingtin aggregates and toxicity in cell model of Huntington's Disease (HD). Heat shock response is an adaptive mechanism of cells characterized by upregulation of heat shock proteins by heat-induced activation of heat shock factor 1 (HSF1). The trans-activation ability of HSF1 is arrested upon restoration of proteostasis. We earlier identified HYPK as a heat-inducible protein and transcriptional target of HSF1. Here we show that HYPK can act as negative regulator of heat shock response by repressing transcriptional activity of HSF1. As part of its role as a repressor of heat shock response, HYPK can also inhibit HSF1-dependent trans-activation of its own promoter. HYPK is downregulated in cell and animal model of HD. We further show that transcriptional downregulation of HYPK in HD cell model is a consequence of reduced occupancy of HSF1 in HYPK promoter. Moreover, presence of mutant huntingtin inhibits effective induction of HYPK in response to heat shock. Taken together, our findings reveal that HYPK can suppress heat shock response via an autoregulatory loop and downregulation of HYPK in HD is caused by impaired transcriptional activity of HSF1 in presence of mutant huntingtin. PMID:27017930

  16. A new analytical model for conduction heating during the SAGD circulation phase

    Energy Technology Data Exchange (ETDEWEB)

    Duong, A.N. [Society of Petroleum Engineers, Canadian Section, Calgary, AB (Canada)]|[ConocoPhillips Canada Resources Corp., Calgary, AB (Canada); Tomberlin, T.A. [ConocoPhillips Canada Resources Corp., Calgary, AB (Canada); Cyrot, M. [Total E and P Canada Ltd., Calgary, AB (Canada)

    2008-10-15

    The steam assisted gravity drainage (SAGD) process has become the common procedure to recover bitumen from Alberta's oilsands. Inter-well communication must be initiated during the start-up phase of a SAGD process. The shape of an initial steam chamber that develops during the circulation phase influences the efficiency of bitumen recovery. As such, the heating conformance distributed along the horizontal wellbores must be well understood. The duration of the start-up phase varies with the characteristics of the oilsand formation and the distance between the wellbores, but it is typically a month to several months. This paper presented a newly developed analytical model that predicts the initial steam chamber. The model improves bitumen recovery efficiency by predicting the mid-point temperature front and heating efficiency of a wellpair during the SAGD circulation phase. The Excel-based model uses the exponential integral solution for radial heating in a long cylinder and superposition in space for multi-heating sources. It can predict the temperature profile if the steam temperatures or pressures are known during the circulation period. Wellbore modeling that includes any variation in distances between the wellbores is critical to both circulation time and heating conformance. This model has an advantage over numerical simulation in terms of reducing computational time and accurately modelling any variation in distance between wellbores. The results can be optimized under various operational conditions, wellbore profiles, tubing sizes and convection flow effects. This easy to use model is currently being used by ConocoPhillips Canada to optimize, predict and guide oilsands projects during the start-up phase of a SAGD process. 5 refs., 13 figs.

  17. Spatial Structure and Collisionless Electron Heating in Balmer-dominated Shocks

    CERN Document Server

    van Adelsberg, Matthew; McCray, Richard; Raymond, John C

    2008-01-01

    Balmer-dominated shocks in supernova remnants (SNRs) produce strong hydrogen lines with a two-component profile composed of a narrow contribution from cold upstream hydrogen atoms, and a broad contribution from hydrogen atoms that have undergone charge transfer reactions with hot protons. Observations of emission lines from edge-wise shocks in SNRs can constrain the gas velocity and collisionless electron heating at the shock front. Downstream hydrogen atoms engage in charge transfer, excitation and ionization reactions, defining an interaction region called the shock transition zone, with characteristic width l_{zone} \\sim 10^{15} cm, for shock velocity v_s \\sim 1000 km s^{-1} and upstream density n_0 \\sim 1 cm^{-3}. The properties of hot hydrogen atoms undergoing charge transfer (called broad neutrals) are critical for accurately calculating the structure and radiation from the shock transition zone. This paper is the third in a series describing the kinetic, fluid and emission properties of Balmer-dominate...

  18. Linear and nonlinear analysis of the dynamic behaviour of natural circulation with internally heated fluids

    International Nuclear Information System (INIS)

    In this paper, the study of the dynamic behaviour of single-phase natural circulation with internal heat generation for a rectangular loop is presented. In order to predict natural circulation stability, two different methods of analysis are developed and compared. The first approach is a linear analysis in which the Navier-Stokes equation is linearized around a steady-state solution of the system. This strategy is adopted to calculate transient evolutions and dimensionless stability maps for several system configurations in case of small perturbations, outlining the geometrical parameters that mainly affect the natural circulation behaviour when internal heat generation is also considered. The second approach consists in directly solving the nonlinear governing equations and it is used to confirm the results of the linear analysis. In this case, the hypothesis that the perturbations on the stationary state variables are negligible is removed. Stability maps and time-dependent simulations represent very useful tools of investigation not only from a theoretical point of view but also in practice. As a matter of fact, stability maps may be used to optimize the configuration of natural circulation loops, while time-dependent simulations allow to completely evaluate the system dynamics showing mass flow and temperature transients. (author)

  19. Effects of tropical cyclones on large-scale circulation and ocean heat transport in the South China Sea

    Science.gov (United States)

    Wang, Xidong; Wang, Chunzai; Han, Guijun; Li, Wei; Wu, Xinrong

    2014-12-01

    In this study, we investigate the influence of tropical cyclones (TCs) on large-scale circulation and ocean heat transport in the South China Sea (SCS) by using an ocean general circulation model at a 1/8° resolution during 2000-2008. The model uses a data assimilation system to assimilate observations in order to improve the representation of SCS circulation. The results reveal an unexpected deep SCS circulation anomaly induced by TCs, which suggests that effects of TC can penetrate deeper into the ocean. This deep effect may result from the near inertial oscillations excited by TCs. The inertial oscillations can propagate downward to the oceanic interior. The analyses confirm that TCs have two effects on ocean heat transport of the SCS. Firstly, the wind stress curl induced by TCs affects the structure of SCS circulation, and then changes heat transport. Secondly, TCs pump surface heat downward to the thermocline, increasing the heat injection from the atmosphere to the ocean. Two effects together amplify the outflow of the surface heat southward away the SCS through the Mindoro and Karimata Straits. The TC-induced heat transports through the Mindoro, Balabac and Karimata Straits account for 20 % of the total heat transport through three straits. An implication of this study is that ocean models need to simulate the TC effect on heat transport in order to correctly evaluate the role of the SCS through flow in regulating upper ocean circulation and climate in the Indonesian maritime continent and its adjacent regions.

  20. Molecular cloning and expression of a human heat shock factor, HSF1

    Energy Technology Data Exchange (ETDEWEB)

    Rabindran, S.K.; Giorgi, G.; Clos, J.; Wu, C. (National Institutes of Health, Bethesda, MD (United States))

    1991-08-15

    Human cells respond to heat stress by inducing the binding of a preexisting transcriptional activator (heat shock factor, HSF) to DNA. The authors isolated recombinant DNA clones for a human cDNA fragment. The human HSF1 probe was produced by the PCR with primers deduced from conserved amino acids in the Drosophila and yeast HSF sequences. The human HSF1 mRNA is constitutively expressed in HeLa cells under nonshock conditions and encodes a protein with four conserved leucine zipper motifs. Like its counterpart in Drosophila, human HSF1 produced in Escherichia coli in the absence of heat shock is active as a DNA binding transcription factor, suggesting that the intrinsic activity of HSF is under negative control in human cells. Surprisingly, an independently isolated human HSF clone, HSF2, is related to but significantly different from HSF.

  1. Genetic variation in resistance of the preimplantation bovine embryo to heat shock.

    Science.gov (United States)

    Hansen, Peter J

    2014-12-01

    Reproduction is among the physiological functions in mammals most susceptible to disruption by hyperthermia. Many of the effects of heat stress on function of the oocyte and embryo involve direct effects of elevated temperature (i.e. heat shock) on cellular function. Mammals limit the effects of heat shock by tightly regulating body temperature. This ability is genetically controlled: lines of domestic animals have been developed with superior ability to regulate body temperature during heat stress. Through experimentation in cattle, it is also evident that there is genetic variation in the resistance of cells to the deleterious effects of elevated temperature. Several breeds that were developed in hot climates, including Bos indicus (Brahman, Gir, Nelore and Sahiwal) and Bos taurus (Romosinuano and Senepol) are more resistant to the effects of elevated temperature on cellular function than breeds that evolved in cooler climates (Angus, Holstein and Jersey). Genetic differences are expressed in the preimplantation embryo by Day 4-5 of development (after embryonic genome activation). It is not clear whether genetic differences are expressed in cells in which transcription is repressed (oocytes >100 µm in diameter or embryos at stages before embryonic genome activation). The molecular basis for cellular thermotolerance has also not been established, although there is some suggestion for involvement of heat shock protein 90 and the insulin-like growth factor 1 system. Given the availability of genomic tools for genetic selection, identification of genes controlling cellular resistance to elevated temperature could be followed by progress in selection for those genes within the populations in which they exist. It could also be possible to introduce genes from thermotolerant breeds into thermally sensitive breeds. The ability to edit the genome makes it possible to design new genes that confer protection of cells from stresses like heat shock. PMID:25472041

  2. Heat-shock protein 70 expression in shrimp Fenneropenaeus chinensis during thermal and immune-challenged stress

    Institute of Scientific and Technical Information of China (English)

    GUO Zhenyu; JIAO Chuanzhen; XIANG Jianhai

    2004-01-01

    Using western immunoblotting, we obtained heat-shock protein 70 (HSP70) induction data and distribution in different tissues from shrimp Fenneropenaeus chinensis during thermal and immune-challenged stresses. This is probably the first report of the effects of various stressors on the expression of HSP70 in shrimp. HSP70 was prominently induced in hepatopancreas and gills, but not in muscle, eyestalk and hemolymph, when the shrimp were exposed to heat shock and Vibrio anguillavium-challenged stresses. Cold shock and WSSV treatment had no significant effects on the levels of HSP70 expression in all tissues examined. HSP70 induction was greatest after 2 h exposure to heat shock stress, which was elevated after acute heat shock exposure of 10℃ above ambient temperature.

  3. Induction of Heat Shock Protein 72 in RGCs of Rat Acute Glaucoma Model after Heat Stress or Zinc Administration

    Institute of Scientific and Technical Information of China (English)

    Guoping Qing; Xuanchu Duan; Youqin Jiang

    2004-01-01

    Purpose :To investigate the dynamics of heat shock protein 72 (HSP72) expression in retinal ganglion cells (RGCs) in rat model of acute glaucoma treated with heat stress or intraperitoneal injection of zinc sulfate.Methods: Twenty-seven male Wistar rats were used to make acute glaucoma models. Five others served as normal control. Acute glaucoma models were made by intracameral irrigation in the right eyes with balanced salt saline (BSS) at 102 mmHg for 2 hours. Nine model rats were killed at different intervals after intracameral irrigation without treatment, which served as damage control. Ten were treated with heat stress 40℃~42℃, and 8 were used for zinc sulfate administration 2 days posterior to intracameral irrigation.Treated model rats were sacrificed at designed intervals after treatment. Right eyes were enucleated immediately, and the retinas were dissected for Western blot.Results: No HSP72 was found in RGCs of normal Wistar rats. In damage control group,slight HSP72 was detected during 6~36 hours posterior to intracameral irrigation. HSP72was detected significantly expressed in RGCs of both heat shock group and zinc sulfate group. But the dynamics of HSP72 production were quite different in these two treated groups. In heat shock group, HSP72 appeared at the sixth hour after treatment, and increased gradually until its peak production emerged at the 48th hour. HSP72 vanished 8days later after treatment. In zinc sulfate group, HSP72 expression began 24 hours later after zinc administration, and reached its highest level at the 72th hour posterior to treatment. HSP72 expression then decreased slowly, and disappeared 21 days later after treatment.Conclusion:HSP72 can be induced in RGCs of rat acute glaucoma models with heat stress or zinc sulfate adddministration. But the dynamics of the HSP72 induction in those two groups were quite different. Eye Science 2004;20:30-33.

  4. Water test of natural circulation for decay heat removal in JSFR

    International Nuclear Information System (INIS)

    Japan Atomic Energy Agency (JAEA) is conducting a design study of Japan Sodium-cooled Fast Reactor (JSFR), in which a decay heat removal system (DHRS) utilizing natural circulation (NC) is applied as an innovative technology. The Central Research Institute of Electric Power Industry (CRIEPI) has carried out a water test to verify the applicability of NC to decay heat removal. The test used a 1/10-scale model of JSFR. Key issues on thermal-hydraulics were identified through simulation tests on representative events. Measures were also proposed to resolve these issues. The present study has demonstrated that a sufficient and stable NC is established in each event. (author)

  5. Simulation of sea surface temperatures with the surface heat fluxes from an atmospheric circulation model

    OpenAIRE

    Karaca, Mehmet; MÜLLER, DETLEV

    2011-01-01

    The global fields of the surface heat fluxes for the December-February period are calculated with the UCLA atmospheric circulation model (ACM). This model operates on a global grid net. The planetary boundary layer (PBL), as the decisive subsystem for the surface fluxes, is parameterized in terms of its bulk properties. For several locations in the north Atlantic, the model heat fluxes are incorporated into the forcing of a simple ocean mixed-layer (OML) model. The OML-model uses a slight gen...

  6. A study of natural circulation in the evaporator of a horizontal-tube heat recovery steam generator

    Science.gov (United States)

    Roslyakov, P. V.; Pleshanov, K. A.; Sterkhov, K. V.

    2014-07-01

    Results obtained from investigations of stable natural circulation in an intricate circulation circuit with a horizontal layout of the tubes of evaporating surface having a negative useful head are presented. The possibility of making a shift from using multiple forced circulation organized by means of a circulation pump to natural circulation in vertical heat recovery steam generator is estimated. Criteria for characterizing the performance reliability and efficiency of a horizontal evaporator with negative useful head are proposed. The influence of various design solutions on circulation robustness is considered. With due regard of the optimal parameters, the most efficient and least costly methods are proposed for achieving more stable circulation in a vertical heat recovery steam generator when a shift is made from multiple forced to natural circulation. A procedure for calculating the circulation parameters and an algorithm for checking evaporator performance reliability are developed, and recommendations for the design of heat recovery steam generator, nonheated parts of natural circulation circuit, and evaporating surface are suggested.

  7. Global Analysis of Heat Shock Response in Desulfovibrio vulgaris Hildenborough.

    Energy Technology Data Exchange (ETDEWEB)

    Chhabra, S.R.; He, Q.; Huang, K.H.; Gaucher, S.P.; Alm, E.J.; He,Z.; Hadi, M.Z.; Hazen, T.C.; Wall, J.D.; Zhou, J.; Arkin, A.P.; Singh, A.K.

    2005-09-16

    Desulfovibrio vulgaris Hildenborough belongs to a class ofsulfate-reducing bacteria (SRB) and is found ubiquitously in nature.Given the importance of SRB-mediated reduction for bioremediation ofmetal ion contaminants, ongoing research on D. vulgaris has been in thedirection of elucidating regulatory mechanisms for this organism under avariety of stress conditions. This work presents a global view of thisorganism's response to elevated growth temperature using whole-celltranscriptomics and proteomics tools. Transcriptional response (1.7-foldchange or greater; Z>1.5) ranged from 1,135 genes at 15 min to 1,463genes at 120 min for a temperature up-shift of 13oC from a growthtemperature of 37oC for this organism and suggested both direct andindirect modes of heat sensing. Clusters of orthologous group categoriesthat were significantly affected included posttranslationalmodifications; protein turnover and chaperones (up-regulated); energyproduction and conversion (down-regulated), nucleotide transport,metabolism (down-regulated), and translation; ribosomal structure; andbiogenesis (down-regulated). Analysis of the genome sequence revealed thepresence of features of both negative and positive regulation whichincluded the CIRCE element and promoter sequences corresponding to thealternate sigma factors ?32 and ?54. While mechanisms of heat shockcontrol for some genes appeared to coincide with those established forEscherichia coli and Bacillus subtilis, the presence of unique controlschemes for several other genes was also evident. Analysis of proteinexpression levels using differential in-gel electrophoresis suggestedgood agreement with transcriptional profiles of several heat shockproteins, including DnaK (DVU0811), HtpG (DVU2643), HtrA (DVU1468), andAhpC (DVU2247). The proteomics study also suggested the possibility ofposttranslational modifications in the chaperones DnaK, AhpC, GroES(DVU1977), and GroEL (DVU1976) and also several periplasmic ABCtransporters.

  8. Design of an additional heat sink based on natural circulation in pressurized water reactors

    International Nuclear Information System (INIS)

    Residual heat removal through the steam generators in Nuclear Power Plant with pressurized water reactors (PWR) or pressurized heavy water reactors (PHWR in pressured vessel or pressured tube types) requires the maintenance of the steam generator inventory and the availability of and appropriate heat sink, which are based on the operability of the steam generators feedwater system. This paper describes the conceptual design of an assured heat removal system which includes only passive elements and is based on natural circulation. The system can supplement the original systems of the plant. The new system includes a condenser/boiler heat exchanger to condense the steam produced in the steam generator, transferring the heat to the water of an open pool at atmospheric pressure. The condensed steam flows back to the steam generators by natural circulation effects. The performance of an Atucha type PHWR nuclear power station with and without the proposed system is calculated in an emergency power case for the first 5000 seconds after the incident. The analysis shows that the proposed system offers the possibility to cool-down the plant to a low energy state during several hours and avoids the repeated actuation of the primary and secondary system safety valves. (Author)

  9. Heat shock induced change in protein ubiquitination in Chlamydomonas

    International Nuclear Information System (INIS)

    Ubiquitin was purified from pea (Pisum sativum L.) and its antibody was produced. Western blot analysis showed that the antibody cross-reacted with ubiquitins from a green alga Chlamydomonas reinhardtii, a brown alga Laminaria angustata and a red alga Porphyridium cruentum but not with ubiquitin from a blue-green alga Synechococcus sp. In Chlamydomonas, the antibody also reacted with some ubiquitinated proteins including 28- and 31-kDa polypeptides. The isoelectric points of Chlamydomonas ubiquitin and the 28- and 31-kDa ubiquitinated proteins were 8.0, 8.9 and 10.3, respectively. The ubiquitinated proteins, including the 28- and 31-kDa polypeptides were detected after in vitro ATP-dependent ubiquitination of Chlamydomonas cell extract with l25I-labeled bovine ubiquitin. Heat treatment of Chlamydomonas cells (>40°C) caused drastic increase of ubiquitinated proteins with high mol wt (>60kDa), and coordinated redistribution or decrease of other ubiquitinated proteins and free ubiquitin. Quantitative analysis revealed that the 28- and 31-kDa ubiquitinated proteins showed different responses against heat stress, i.e. the former being more sensitive than the latter. (author)

  10. Lipoic Acid Exerts Antioxidant and Anti-inflammatory Effects in Response to Heat Shock in C2C12 Myotubes.

    Science.gov (United States)

    Lee, Cheng-Tse; Chang, Li-Ching; Wu, Pei-Fung

    2016-06-01

    This study explored that lipoic acid treatment for 24 h significantly upregulated and promoted heat shock-induced catalase expression and downregulated GPx1 messenger RNA (mRNA) expression, indicating that lipoic acid exhibits antioxidant activity in the decomposition of hydrogen peroxide by upregulating catalase expression. Moreover, lipoic acid treatment for 3 h increased and promoted heat shock-induced interleukin (IL)-6 mRNA and protein levels and that for 24 h downregulated IL-6 mRNA expression, suggesting a dual effect of lipoic acid on IL-6 regulation. Lipoic acid alone failed to increase or reduce tumor necrosis factor (TNF)-α mRNA and protein levels, whereas heat shock alone downregulated TNF-α mRNA and protein expression. These data suggest that lipoic acid does not have a proinflammatory role and that heat shock acts as an anti-inflammatory agent by downregulating TNF-α expression in C2C12 myotubes. Moreover, lipoic acid or heat shock alone upregulated the IL-6 receptor (IL-6R-α) and glycoprotein 130 (gp130) mRNA expression followed by IL-6 expression; these data indicate that the regulation of lipoic acid or heat shock is mediated by IL-6R signaling, thus suggesting that C2C12 myotubes possesses a mechanism for regulating IL-6R and gp130 expression following lipoic acid treatment or heat shock. PMID:27086282

  11. Effect of flue gas recirculation on heat transfer in a supercritical circulating fluidized bed combustor

    Directory of Open Access Journals (Sweden)

    Błaszczuk Artur

    2015-09-01

    Full Text Available This paper focuses on assessment of the effect of flue gas recirculation (FGR on heat transfer behavior in 1296t/h supercritical coal-fired circulating fluidized bed (CFB combustor. The performance test in supercritical CFB combustor with capacity 966 MWth was performed with the low level of flue gas recirculation rate 6.9% into furnace chamber, for 80% unit load at the bed pressure of 7.7 kPa and the ratio of secondary air to the primary air SA/PA = 0.33. Heat transfer behavior in a supercritical CFB furnace between the active heat transfer surfaces (membrane wall and superheater and bed material has been analyzed for Geldart B particle with Sauter mean diameters of 0.219 and 0.246 mm. Bed material used in the heat transfer experiments had particle density of 2700 kg/m3. A mechanistic heat transfer model based on cluster renewal approach was used in this work. A heat transfer analysis of CFB combustion system with detailed consideration of bed-to-wall heat transfer coefficient distributions along furnace height is investigated. Heat transfer data for FGR test were compared with the data obtained for representative conditions without recycled flue gases back to the furnace through star-up burners.

  12. Numerical Analysis on Standing Accretion Shock Instability with Neutrino Heating in the Supernova Cores

    CERN Document Server

    Ohnishi, N; Yamada, S; Ohnishi, Naofumi; Kotake, Kei; Yamada, Shoichi

    2006-01-01

    We have numerically studied the instability of the spherically symmetric standing accretion shock wave against non-spherical perturbations. We have in mind the application to the collapse-driven supernovae in the post bounce phase, where the prompt shock wave generated by core bounce is commonly stalled. We take an experimental stand point in this paper. Using spherically symmetric, completely steady, shocked accretion flows as unperturbed states, we have clearly observed both the linear growth and the subsequent nonlinear saturation of the instability. In so doing, we have employed a realistic equation of state together with heating and cooling via neutrino reactions with nucleons. We have done a mode analysis based on the spherical harmonics decomposition and found that the modes with l=1, 2 are dominant not only in the linear regime, but also after the nonlinear couplings generate various modes and the saturation occurs. Varying the neutrino luminosity, we have constructed the unperturbed states both with ...

  13. Leishmania amazonensis: effects of heat shock on ecto-ATPase activity.

    Science.gov (United States)

    Peres-Sampaio, Carlos Eduardo; de Almeida-Amaral, Elmo Eduardo; Giarola, Naira Ligia Lima; Meyer-Fernandes, José Roberto

    2008-05-01

    In this work we demonstrated that promastigotes of Leishmania amazonensis exhibit an Mg-dependent ecto-ATPase activity, which is stimulated by heat shock. The Mg-dependent ATPase activity of cells grown at 22 and 28 degrees C was 41.0+/-5.2 nmol Pi/h x 10(7)cells and 184.2+/-21.0 nmol Pi/h x 10(7)cells, respectively. When both promastigotes were pre-incubated at 37 degrees C for 2h, the ATPase activity of cells grown at 22 degrees C was increased to 136.4+/-10.6 nmol Pi/h x 10(7) whereas that the ATPase activity of cells grown at 28 degrees C was not modified by the heat shock (189.8+/-10.3 nmol Pi/h x 10(7)cells). It was observed that Km of the enzyme from cells grown at 22 degrees C (Km=980.2+/-88.6 microM) was the same to the enzyme from cells grown at 28 degrees C (Km=901.4+/-91.9 microM). In addition, DIDS (4,4'-diisothiocyanatostilbene 2,2'-disulfonic acid) and suramin, two inhibitors of ecto-ATPases, also inhibited similarly the ATPase activities from promastigotes grown at 22 and 28 degrees C. We also observed that cells grown at 22 degrees C exhibit the same ecto-phosphatase and ecto 3'- and 5'-nucleotidase activities than cells grown at 28 degrees C. Interestingly, cycloheximide, an inhibitor of protein synthesis, suppressed the heat-shock effect on ecto-ATPase activity of cells grown at 22 degrees C were exposed at 37 degrees C for 2h. A comparison between the stimulation of the Mg-dependent ecto-ATPase activity of virulent and avirulent promastigotes by the heat shock showed that avirulent promastigotes had a higher stimulation than virulent promastigotes after heat stress. PMID:18295760

  14. Thermal stress and the heat shock response in embryonic and young of the year juvenile lake whitefish.

    Science.gov (United States)

    Stefanovic, Daniel I; Manzon, Lori A; McDougall, Chance S; Boreham, Douglas R; Somers, Christopher M; Wilson, Joanna Y; Manzon, Richard G

    2016-03-01

    We investigated the effects of thermal stress on embryonic (fin flutter, vitelline circulation stage) and young of the year (YOY) juvenile lake whitefish by characterizing the kinetics of the heat shock response (HSR). Lake whitefish were subjected to one of three different heat shock (HS) temperatures (3, 6, or 9°C above control) for six different lengths of time (0.25, 0.50, 1, 2, 3, or 4h) followed by a 2h recovery period at the control temperature of 2°C or 14°C for embryos and YOY juveniles, respectively. The duration of the HSR was examined by allowing the fish to recover for 1, 2, 4, 8, 12, 16, 24, 36, or 48h following a 2h HS. In embryos, at the fin flutter stage, only hsp70 mRNA levels were upregulated in response to the various HS treatments. By comparison, all three typically inducible hsps, hsp90α, hsp70 and hsp47, were upregulated in the YOY juveniles. In both instances the HSR was long lasting, but much more so in embryos where hsp70 mRNA levels continued to increase for 48h after a 2h HS and remained significantly higher than untreated controls. Collectively our data indicate that both embryo and YOY juvenile lake whitefish have a robust HSR which permits them to survive a 4h, 9°C HS. Moreover, both life history stages are capable of triggering a HSR following a moderate 3°C HS which is likely an important protective mechanism against environmental stressors during embryogenesis and early life history stages of lake whitefish. PMID:26658267

  15. POST-SHOCK-REVIVAL EVOLUTION IN THE NEUTRINO-HEATING MECHANISM OF CORE-COLLAPSE SUPERNOVAE

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Yu; Yamada, Shoichi [Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555 (Japan); Fujimoto, Shin-ichiro [Kumamoto National College of Technology, 2659-2 Suya, Goshi, Kumamoto 861-1102 (Japan); Nagakura, Hiroki [Yukawa Institute for Theoretical Physics, Kyoto University, Oiwake-cho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502 (Japan)

    2013-07-01

    We perform experimental simulations with spherical symmetry and axisymmetry to understand the post-shock-revival evolution of core-collapse supernovae. Assuming that the stalled shock wave is relaunched by neutrino heating and employing the so-called light bulb approximation, we induce shock revival by raising the neutrino luminosity up to the critical value, which is determined by dynamical simulations. A 15 M{sub Sun} progenitor model is employed. We incorporate nuclear network calculations with a consistent equation of state in the simulations to account for the energy release by nuclear reactions and their feedback to hydrodynamics. Varying the shock-relaunch time rather arbitrarily, we investigate the ensuing long-term evolutions systematically, paying particular attention to the explosion energy and nucleosynthetic yields as a function of relaunch time, or equivalently, the accretion rate at shock revival. We study in detail how the diagnostic explosion energy approaches the asymptotic value and which physical processes contribute in what proportions to the explosion energy. Furthermore, we study the dependence of physical processes on the relaunch time and the dimension of dynamics. We find that the contribution of nuclear reactions to the explosion energy is comparable to or greater than that of neutrino heating. In particular, recombinations are dominant over burnings in the contributions of nuclear reactions. Interestingly, one-dimensional (1D) models studied in this paper cannot produce the appropriate explosion energy and nickel mass simultaneously; nickels are overproduced. This problem is resolved in 2D models if the shock is relaunched at 300-400 ms after the bounce.

  16. Synthesis of Differentiation-Specific Proteins in Germlings of the Wheat Stem Rust Fungus after Heat Shock

    OpenAIRE

    Wanner, Reinhard; Förster, Helga; Mendgen, Kurt; Staples, Richard C.

    1985-01-01

    Synthesis of differentiation-specific proteins in germlings of the wheat stem rust fungus after heat shock. Experimental Mycology 9, 279-283. When uredospore germlings of the wheat stem rust fungus (Puccinia graminis tritici) were heat-shocked to induce differentiation, changes in the pattern of proteins synthesized were observed when the substomatal vesicles began to emerge. At this time (1.5 h after end of heat shock) two differentiation-specific proteins of approximately 34.7 and 21.9 kDa ...

  17. Overly persistent circulation in climate models contributes to overestimated frequency and duration of heat waves and cold spells

    Science.gov (United States)

    Plavcová, Eva; Kyselý, Jan

    2016-05-01

    The study examines links of summer heat waves and winter cold spells in Central Europe to atmospheric circulation and specifically its persistence in an ensemble of regional climate models (RCMs). We analyse 13 RCMs driven by the ERA-40 reanalysis and compare them against observations over reference period 1971-2000. Using objective classification of circulation types and an efficiency coefficient with a block resampling test, we identify circulation types significantly conducive to heat waves and cold spells. We show that the RCMs have a stronger tendency to group together days with very high or low temperature and tend to simulate too many heat waves and cold spells, especially those lasting 5 days and more. Circulation types conducive to heat waves in summer are characterized by anticyclonic, southerly and easterly flow, with increasing importance of warm advection during heat waves. Winter cold spells are typically associated with easterly and anticyclonic flow, and the onset of cold spells tends to be linked to northerly and cyclonic flow with cold advection. The RCMs are generally able to reproduce the links between circulation and heat waves or cold spells, including the radiation-to-advection effect for heat waves and the opposite advection-to-radiation effect for cold spells. They capture relatively well also changes of mean temperature anomalies during sequences of given circulation types, namely the tendency towards temperature increase (decrease) during those types conducive to heat waves (cold spells). Since mean lengths of all circulation supertypes are overestimated in the RCMs, we conclude that the overly persistent circulation in climate models contributes to the overestimated frequency of long heat waves and cold spells. As these biases are rather general among the examined RCMs and similar drawbacks are likely to be manifested in climate model simulations for the twenty-first century, the results also suggest that climate change scenarios for

  18. Dishwasher and washing machine heated by a hot water circulation loop

    Energy Technology Data Exchange (ETDEWEB)

    Persson, Tomas [Solar Energy Research Center SERC, Hoegskolan Dalarna, 81 88 Borlaenge (Sweden)

    2007-01-15

    Electric energy (70-90%) used by electrically heated dishwashers and washing machines is used for heating the water, the crockery, the laundry and the machine and could as well be replaced by heat from other sources than electricity. This article evaluates prototypes of a dishwasher and a washing machine, where the machines are heated by a hot water circulation loop and the heat is transferred to the machines via a heat exchanger. The machine therefore uses water from the cold water pipe. Measurements and simulations have been performed showing that all energy for heating can be replaced if the supply water temperature is 65-70{sup o}C. An alternative and common way to save electricity is to connect the machines to the domestic hot water pipe, but the electrical savings with this measure are much smaller, especially for the dishwasher. Computer modelling has been performed and the model has proved to have a high agreement with measured data. However comparison with manufacturers' data indicates that the computer models overestimate the energy demand by about 10%. (author)

  19. Co-localization of the heat shock protein and human immunoglobulin G in hepatocellular carcinoma

    Institute of Scientific and Technical Information of China (English)

    DUAN Chun-guang; LIU Yan-fang; LI Kai-nan; YU Lu; CUI Ji-hong; LI Jing; YANG Shou-jing

    2005-01-01

    @@ Elevated levels of serum immunoglobulin observed in patients with cancers of epithelial origin, including carcinomas of breast, colon, and liver1,2 have been interpreted as humoral responses of host to cancer growth.3 Recently, Qiu et al4 described in detail that human cancers of epithelial origin, including carcinomas of breast, colon, liver, lung, established epithelial cancer lines, produce immunoglobulin G (IgG) in their cytoplasm. Under normal conditions, heat shock proteins (HSPs) have multiple cellular functions, such as folding and translocating newly synthesized proteins. When a cell is injured or under stress, HSPs refold damaged protein or facilitate degradation of proteins. In most cancers, heat shock proteins can capture tumour specific peptide to inhibit the growth of cancer. This study demonstrated that human IgG and HSPs are co-localized in hepatocellular carcinoma.

  20. Heat Shock Followed by Priming Increases the Quality of Agropyron elongatum Seeds under Accelerated Ageing

    Directory of Open Access Journals (Sweden)

    Malihe AKBARPOUR BAHREH

    2014-06-01

    Full Text Available The present study was carried out to examine the possibilities of obtaining primed seeds that maintain high germination quality and the same longevity as the untreated seeds. For Tall wheatgrass tested, we found that the desired longevity could be obtained by keeping the seeds under heat shock for a period of several hours, after a priming treatment. Decreasing germination and seedling vigour in BAP 25 and 50 ppm, for 24 priming, did not happen again due to such a treatment. In addition, following priming, heat shock affects the initial quality of primed seeds in some treatments. Optimal temperature was strongly duration dependent. The method was applied to obtain primed seeds without the loss of storability, which is similar to those procedures used to induce desiccation tolerance in germinated seeds and acquire thermo tolerance in plant vegetative tissues.

  1. Heat shock protein-peptide complex-96 (Vitespen for the treatment of cancer

    Directory of Open Access Journals (Sweden)

    Robert J. Amato

    2011-12-01

    Full Text Available Heat shock proteins (HSPs are the most abundant and ubiquitous soluble intracellular proteins. Members of the HSP family bind peptides, they include antigenic peptides generated within cells. HSPs also interact with antigen-presenting cells (APCs through CD91 and other receptors, eliciting a cascade of events that includes re-presentation of HSP-chaperoned peptides by major histocompatability complex (MHC, translocation of nuclear factorkappaB (NFkB into the nuclei, and maturation of dendritic cells (DCs. These consequences point to a key role of heat shock proteins in fundamental immunological phenomena such as activation of APCs, indirect presentation (or crosspriming of antigenic peptides, and chaperoning of peptides during antigen presentation. The properties of HSPs also allow them to be used for immunotherapy of cancers and infections in novel ways. This paper reviews the development and clinical trial progress of vitespen, an HSP peptide complex vaccine based on tumor-derived glycoprotein 96.

  2. In Vivo Profiling Reveals a Competent Heat Shock Response in Adult Neurons: Implications for Neurodegenerative Disorders.

    Directory of Open Access Journals (Sweden)

    Alisia Carnemolla

    Full Text Available The heat shock response (HSR is the main pathway used by cells to counteract proteotoxicity. The inability of differentiated neurons to induce an HSR has been documented in primary neuronal cultures and has been proposed to play a critical role in ageing and neurodegeneration. However, this accepted dogma has not been demonstrated in vivo. We used BAC transgenic mice generated by the Gene Expression Nervous System Atlas project to investigate the capacity of striatal medium sized spiny neurons to induce an HSR as compared to that of astrocytes and oligodendrocytes. We found that all cell populations were competent to induce an HSR upon HSP90 inhibition. We also show the presence and relative abundance of heat shock-related genes and proteins in these striatal cell populations. The identification of a competent HSR in adult neurons supports the development of therapeutics that target the HSR pathway as treatments for neurodegenerative disorders.

  3. Oligomers of heat-shock proteins: Structures that don't imply function

    CERN Document Server

    Jacobs, William M; Frenkel, Daan

    2015-01-01

    Most proteins must remain soluble in the cytosol in order to perform their biological functions. To protect against undesired protein aggregation, living cells maintain a population of molecular chaperones that ensure the solubility of the proteome. Here we report simulations of a lattice model of interacting proteins to understand how low concentrations of passive molecular chaperones, such as small heat-shock proteins, suppress thermodynamic instabilities in protein solutions. Given fixed concentrations of chaperones and client proteins, the solubility of the proteome can be increased by tuning the chaperone--client binding strength. Surprisingly, we find that the binding strength that optimizes solubility while preventing irreversible chaperone binding also promotes the formation of weakly bound chaperone oligomers, although the presence of these oligomers does not significantly affect the thermodynamic stability of the solution. Such oligomers are commonly observed in experiments on small heat-shock prote...

  4. Regulatory effect of heat shock protein 70 in stress-induced rat intestinal epithelial barrier dysfunction

    Directory of Open Access Journals (Sweden)

    Ping-Chang Yang

    2009-01-01

    Full Text Available Background : Psychological stress is one of the factors associated with many human diseases; the mechanisms need to be further understood. Methods : Rats were subjected to chronic water avoid stress. Intestinal epithelial heat shock protein (HSP 70 was evaluated. The intestinal epithelial permeability was examined with Ussing chamber technique. Results : HSP70 was detected in normal intestinal epithelial cells. Psychological stress decreased HSP70 in the intestinal epithelial cells that correlated with the stress-induced intestinal epithelial hyperpermeability. Pretreatment with HSP70 abrogated stress-induced intestinal barrier dysfunction. Conclusions : Chronic stress inhibits HSP70 activity in rat intestinal epithelial layer that is associated with intestinal epithelial barrier dysfunction, which can be prevented by pretreatment with HSP70 protein. (Yang PC, Tu YH, Perdue MH, Oluwole C, Struiksma S. Regulatory effect of heat shock protein 70 in stress-induced rat intestinal epithelial barrier dysfunction.

  5. Treatment of 39 Nodular Panniculitis Patients withClearing Away Heat to Remove Dampness andPromoting Blood Circulation

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Thirty-nine nodular panniculitis (NP) patients were treated with clearing away Heat to remove Dampness and promoting blood circulation in our hospital from September 1978 to June 1995. The clinical therapeutic effect was good and reported as follows.

  6. Sun-stirred Kraken Mare: Circulation in Titan's seas induced by solar heating and methane precipitation

    Science.gov (United States)

    Tokano, Tetsuya; Lorenz, Ralph D.

    2016-05-01

    Density-driven circulation in Titan's seas forced by solar heating and methane evaporation/precipitation is simulated by an ocean circulation model. If the sea is transparent to sunlight, solar heating can induce anti-clockwise gyres near the sea surface and clockwise gyres near the sea bottom. The gyres are in geostrophic balance between the radially symmetric pressure gradient force and Coriolis force. If instead the sea is turbid and most sunlight is absorbed near the sea surface, the sea gets stratified in warm seasons and the circulation remains weak. Precipitation causes compositional stratification of the sea to an extent that the sea surface temperature can be lower than the sea interior temperature without causing a convective overturning. Non-uniform precipitation can also generate a latitudinal gradient in the methane mole fraction and density, which drives a meridional overturning with equatorward currents near the sea surface and poleward currents near the sea bottom. However, gyres are more ubiquitous than meridional overturning.

  7. The Response to Heat Shock and Oxidative Stress in Saccharomyces cerevisiae

    OpenAIRE

    Morano, Kevin A.; Grant, Chris M.; Moye-Rowley, W. Scott

    2012-01-01

    A common need for microbial cells is the ability to respond to potentially toxic environmental insults. Here we review the progress in understanding the response of the yeast Saccharomyces cerevisiae to two important environmental stresses: heat shock and oxidative stress. Both of these stresses are fundamental challenges that microbes of all types will experience. The study of these environmental stress responses in S. cerevisiae has illuminated many of the features now viewed as central to ...

  8. FTSJ2, a heat shock-inducible mitochondrial protein, suppresses cell invasion and migration.

    Directory of Open Access Journals (Sweden)

    Cheng-Wei Lai

    Full Text Available Ribosomal RNA large subunit methyltransferase J (RrmJ, an Escherichia coli heat shock protein, is responsible for 2'-O-ribose methylation in 23S rRNA. In mammals, three close homologs of RrmJ have been identified and have been designated as FTSJ1, FTSJ2 and FTSJ3; however, little is known about these genes. In this study, we characterized the mammalian FTSJ2, which was the most related protein to RrmJ in a phylogenetic analysis that had similar amino acid sequence features and tertiary protein structures of RrmJ. FTSJ2 was first identified in this study as a nucleus encoded mitochondrial protein that preserves the heat shock protein character in mammals in which the mRNA expressions was increased in porcine lung tissues and A549 cells after heat shock treatment. In addition, a recent study in non-small cell lung cancer (NSCLC suggested that the FTSJ2 gene is located in a novel oncogenic locus. However, our results demonstrate that the expression of FTSJ2 mRNA was decreased in the more invasive subline (CL1-5 of the lung adenocarcinoma cells (CL1 compared with the less invasive subline (CL1-0, and overexpression of FTSJ2 resulted in the inhibition of cell invasion and migration in the rhabdomyosarcoma cell (TE671. In conclusion, our findings indicate that mammalian FTSJ2 is a mitochondrial ortholog of E. coli RrmJ and conserves the heat shock protein properties. Moreover, FTSJ2 possesses suppressive effects on the invasion and migration of cancer cells.

  9. Agonistic encounters and cellular angst: social interactions induce heat shock proteins in juvenile salmonid fish

    OpenAIRE

    Currie, Suzanne; LeBlanc, Sacha; Watters, M. Alexandrea; Gilmour, Kathleen M.

    2009-01-01

    Juvenile salmonid fish readily form dominance hierarchies when faced with limited resources. While these social interactions may result in profound behavioural and physiological stress, it is unknown if this social stress is evident at the level of the cellular stress response—specifically, the induction of stress or heat shock proteins (Hsps). Thus, the goal of our study was to determine if Hsps are induced during hierarchy formation in juvenile rainbow trout (Oncorhynchus mykiss). To this e...

  10. Sprint-Interval Training Induces Heat Shock Protein 72 in Rat Skeletal Muscles

    OpenAIRE

    Yuji Ogura; Hisashi Naito; Mitsutoshi Kurosaka; Takao Sugiura; Junichiro Aoki; Shizuo Katamoto

    2006-01-01

    Previous studies have demonstrated that endurance exercise training increases the level of heat shock proteins (HSPs) in skeletal muscles. However, little attention has been drawn to the effects of high intensity-short duration exercise, or sprint- interval training (SIT) on HSP72 level in rat skeletal muscles. This study performed to test the hypothesis that the SIT would induce the HSP72 in fast and slow skeletal muscles of rats. Young male Wistar rats (8 weeks old) were randomly assigned t...

  11. Aberrant Expression and Secretion of Heat Shock Protein 90 in Patients with Bullous Pemphigoid

    OpenAIRE

    Stefan Tukaj; Konrad Kleszczyński; Katerina Vafia; Stephanie Groth; Damian Meyersburg; Piotr Trzonkowski; Ludwig, Ralf J; Detlef Zillikens; Enno Schmidt; Tobias W Fischer; Michael Kasperkiewicz

    2013-01-01

    The cell stress chaperone heat shock protein 90 (Hsp90) has been implicated in inflammatory responses and its inhibition has proven successful in different mouse models of autoimmune diseases, including epidermolysis bullosa acquisita. Here, we investigated expression levels and secretory responses of Hsp90 in patients with bullous pemphigoid (BP), the most common subepidermal autoimmune blistering skin disease. In comparison to healthy controls, the following observations were made: (i) Hsp9...

  12. Exploiting the Diversity of the Heat-Shock Protein Family for Primary and Secondary Tauopathy Therapeutics

    OpenAIRE

    Abisambra, Jose F.; Jinwal, Umesh K; Jones, Jeffrey R.; Blair, Laura J.; Koren, John; Dickey, Chad A.

    2011-01-01

    The heat shock protein (Hsp) family is an evolutionarily conserved system that is charged with preventing unfolded or misfolded proteins in the cell from aggregating. In Alzheimer’s disease, extracellular accumulation of the amyloid β peptide (Aβ) and intracellular aggregation of the microtubule associated protein tau may result from mechanisms involving chaperone proteins like the Hsps. Due to the ability of Hsps to regulate aberrantly accumulating proteins like Aβ and tau, therapeutic strat...

  13. Heat shock proteins 27, 40, and 70 as combinational and dual therapeutic cancer targets

    OpenAIRE

    McConnell, Jeanette R.; McAlpine, Shelli R.

    2013-01-01

    The heat shock proteins are essential players in the development of cancer and they are prime therapeutic targets. Targeting multiple hsps in dual therapies decreases the likelihood of drug resistance compared to utilizing mono-therapies. Further, employing an hsp inhibitor in combination with another therapy has proven clinically successful. Examples of efficacious strategies include the inhibition of hsp27, which prevents protein aggregation, controlling hsp40’s role as an ATPase modulator,...

  14. Serum heat shock protein 47 levels in patients with drug-induced lung disease

    OpenAIRE

    Kakugawa, Tomoyuki; Yokota, Shin-ichi; Ishimatsu, Yuji; Hayashi, Tomayoshi; Nakashima, Shota; Hara, Shintaro; Sakamoto, Noriho; Matsuoka, Yasuhiro; Kubota, Hiroshi; Mine, Mariko; Mukae, Hiroshi; Nagata, Kazuhiro; Kohno, Shigeru

    2013-01-01

    Background Heat shock protein (HSP) 47 is a collagen-specific molecular chaperone that is required for molecular maturation of various types of collagens. We recently reported that HSP47 serum levels were markedly higher in patients with acute exacerbations of idiopathic pulmonary fibrosis (IPF) when compared with patients with stable IPF, suggesting that serum HSP47 levels correlate with interstitial pneumonia activity. The aim of this study was to evaluate serum HSP47 levels in patients wit...

  15. Serum heat shock protein 47 levels are elevated in acute exacerbation of idiopathic pulmonary fibrosis

    OpenAIRE

    Kakugawa, Tomoyuki; Yokota, Shin-ichi; Ishimatsu, Yuji; Hayashi, Tomayoshi; Nakashima, Shota; Hara, Shintaro; Sakamoto, Noriho; Kubota, Hiroshi; Mine, Mariko; Matsuoka, Yasuhiro; Mukae, Hiroshi; Nagata, Kazuhiro; Kohno, Shigeru

    2013-01-01

    Little is known about the pathophysiology of acute exacerbation (AE) of idiopathic pulmonary fibrosis (IPF). Heat shock protein 47 (HSP47), a collagen-specific molecular chaperone, is essential for biosynthesis and secretion of collagen molecules. Previous studies in experimental animal fibrosis models have shown that downregulation of HSP47 expression reduces collagen production and diminishes fibrosis progression. In this study, serum HSP47 levels were evaluated to elucidate pathogenic diff...

  16. Synergism of Heat Shock Protein 90 and Histone Deacetylase Inhibitors in Synovial Sarcoma

    OpenAIRE

    Poulin, Neal M.; Nielsen, Torsten O.; Belinda Campbell; Le Van Su; Anne Nguyen

    2009-01-01

    Current systemic therapies have little curative benefit for synovial sarcoma. Histone deacetylase (HDAC) inhibitors and the heat shock protein 90 (Hsp90) inhibitor 17-AAG have recently been shown to inhibit synovial sarcoma in preclinical models. We tested combinations of 17-AAG with the HDAC inhibitor MS-275 for synergism by proliferation and apoptosis assays. The combination was found to be synergistic at multiple time points in two synovial sarcoma cell lines. Previous studies have shown t...

  17. Heat-shock proteins in infection-mediated inflammation-induced tumorigenesis

    OpenAIRE

    Li Zihai; Goldstein Mark G

    2009-01-01

    Abstract Inflammation is a necessary albeit insufficient component of tumorigenesis in some cancers. Infectious agents directly implicated in tumorigenesis have been shown to induce inflammation. This process involves both the innate and adaptive components of the immune system which contribute to tumor angiogenesis, tumor tolerance and metastatic properties of neoplasms. Recently, heat-shock proteins have been identified as mediators of this inflammatory process and thus may provide a link b...

  18. Heat Shock Proteins: A Review of the Molecular Chaperones for Plant Immunity

    OpenAIRE

    Park, Chang-Jin; Seo, Young-Su

    2015-01-01

    As sessile organisms, plants are exposed to persistently changing stresses and have to be able to interpret and respond to them. The stresses, drought, salinity, chemicals, cold and hot temperatures, and various pathogen attacks have interconnected effects on plants, resulting in the disruption of protein homeostasis. Maintenance of proteins in their functional native conformations and preventing aggregation of non-native proteins are important for cell survival under stress. Heat shock prote...

  19. Serum heat shock protein 47 levels are elevated in acute interstitial pneumonia

    OpenAIRE

    Kakugawa, Tomoyuki; Yokota, Shin-ichi; Ishimatsu, Yuji; Hayashi, Tomayoshi; Nakashima, Shota; Hara, Shintaro; Sakamoto, Noriho; Kubota, Hiroshi; Mine, Mariko; Matsuoka, Yasuhiro; Mukae, Hiroshi; Nagata, Kazuhiro; Kohno, Shigeru

    2014-01-01

    Background Heat shock protein (HSP) 47, a collagen-specific molecular chaperone, is involved in the processing and/or secretion of procollagen. We hypothesized that HSP47 could be a useful marker for fibrotic lung disease. The aim of this study was to evaluate serum levels of HSP47 in patients with various idiopathic interstitial pneumonias (IIPs). Methods Subjects comprised 9 patients with acute interstitial pneumonia (AIP), 12 with cryptogenic organizing pneumonia (COP), 16 with nonspecific...

  20. HEAT SHOCK PROTEIN AS OXIDATIVE SRESS MARKERS IN RATS SUBIMITTED TO EXHAUSTIVE INTERMITTENT RUNNING TRAINING

    OpenAIRE

    Denise Vaz Macedo; Lúcia Pereira-da-Silva; Joaquim Maria Ferreira Antunes Neto

    2008-01-01

    ANTUNES NETO, J. M. F.; PEREIRA-DA-SILVA, l.; MACEDO, D. V. Heat Shock Proteins as Oxidative Stress Markers in Rats Submitted to Exhaustive Intermittent Running Training. Brazilian Journal of Biomotricity, v. 2, n. 3, p. 160-175, 2008. A novel method to measure oxidative stress resulting from exhaustive Intermittent training in rats submitted to the treadmill running is presented. In this new procedure we evaluated the erythrocyte antioxidant enzymes, catalase (CAT) and glutathione reductase ...

  1. Heat Shock Protein 90 Inhibitors Prolong Survival, Attenuate Inflammation, and Reduce Lung Injury in Murine Sepsis

    OpenAIRE

    Chatterjee, Anuran; Dimitropoulou, Christiana; Drakopanayiotakis, Fotios; ANTONOVA, Galina; Snead, Connie; Cannon, Joseph; Venema, Richard C.; Catravas, John D.

    2007-01-01

    Rationale: Severe sepsis is the leading cause of death for patients in intensive care units. Patients with severe sepsis develop multiple organ failure, including acute lung injury (ALI), resulting from a deregulated inflammatory response. Inhibitors of the ubiquitous chaperone, heat shock protein 90 (Hsp90), block the activity of certain proinflammatory mediators in vitro. We hypothesized that Hsp90 inhibitors may ameliorate the inflammation and ALI associated with severe sepsis.

  2. Experimental pneumococcal meningitis causes central nervous system pathology without inducing the 72-kd heat shock protein.

    OpenAIRE

    Täuber, M G; Kennedy, S L; Tureen, J H; Lowenstein, D. H.

    1992-01-01

    We examined whether experimental pneumococcal meningitis induced the 72-kd heat shock protein (HSP72), a sensitive marker of neuronal stress in other models of central nervous system (CNS) injury. Brain injury was characterized by vasculitis, cerebritis, and abscess formation in the cortex of infected animals. The extent of these changes correlated with the size of the inoculum (P less than 0.003) and with pathophysiologic parameters of disease severity, i.e., cerebrospinal fluid (CSF) lactat...

  3. Antigen capture ELISA for the heat shock protein (hsp60) of Chlamydia trachomatis.

    OpenAIRE

    Horner, P J; Ali, M.; Parker, D.; Weber, J. N.; Taylor-Robinson, D.; McClure, M O

    1996-01-01

    AIMS: To develop an indirect ELISA using the heat shock protein (hsp60) of Chlamydia trachomatis as antigen. METHODS: The hsp60 gene was amplified by PCR, expressed in the vector pDEV-107 and transformed into Escherichia coli. The recombinant protein, expressed as a beta-galactosidase fusion product, was captured onto a solid phase using a monoclonal antibody directed against beta-galactosidase. Following incubation with goat anti-human antibody conjugated to peroxidase and colour development...

  4. Experimental Study of a Stoppage Natural Circulation during a Nuclear Heating Reactor LOCA

    Institute of Scientific and Technical Information of China (English)

    博金海; 张佑杰; 姜胜耀

    2001-01-01

    The 5MW nuclear heating reactor is an integral naturalcirculation reactor. The rupture of the coolant penetrating tube is a typical accident causing coolant loss. When the water level drops down to the upper edge of the inlet of the heat exchanger, the natural circulation stops. This influences the core cooling and the stability of the main loop. A series of tests showed that there is a stable drop of pressure, and the heated element temperature is not too high to cause burnout. But the backward flow or flow oscillation in the primary coolant circuit occurs when the flow breaks completely in the end. The whole flow process is described and the mechanism is discussed.

  5. Jupiter Thermospheric General Circulation Model (JTGCM): Global Structure and Dynamics Driven by Auroral and Joule Heating

    Science.gov (United States)

    Bougher, S. W.; J. Il. Waite, Jr.; Majeed, T.

    2005-01-01

    A growing multispectral database plus recent Galileo descent measurements are being used to construct a self-consistent picture of the Jupiter thermosphere/ionosphere system. The proper characterization of Jupiter s upper atmosphere, embedded ionosphere, and auroral features requires the examination of underlying processes, including the feedbacks of energetics, neutral-ion dynamics, composition, and magnetospheric coupling. A fully 3-D Jupiter Thermospheric General Circulation Model (JTGCM) has been developed and exercised to address global temperatures, three-component neutral winds, and neutral-ion species distributions. The domain of this JTGCM extends from 20-microbar (capturing hydrocarbon cooling) to 1.0 x 10(exp -4) nbar (including aurora/Joule heating processes). The resulting JTGCM has been fully spun-up and integrated for greater than or equal to40 Jupiter rotations. Results from three JTGCM cases incorporating moderate auroral heating, ion drag, and moderate to strong Joule heating processes are presented. The neutral horizontal winds at ionospheric heights vary from 0.5 km/s to 1.2 km/s, atomic hydrogen is transported equatorward, and auroral exospheric temperatures range from approx.1200-1300 K to above 3000 K, depending on the magnitude of Joule heating. The equatorial temperature profiles from the JTGCM are compared with the measured temperature structure from the Galileo AS1 data set. The best fit to the Galileo data implies that the major energy source for maintaining the equatorial temperatures is due to dynamical heating induced by the low-latitude convergence of the high-latitude-driven thermospheric circulation. Overall, the Jupiter thermosphere/ionosphere system is highly variable and is shown to be strongly dependent on magnetospheric coupling which regulates Joule heating.

  6. Impact of Exercise and Metabolic Disorders on Heat Shock Proteins and Vascular Inflammation

    Directory of Open Access Journals (Sweden)

    Earl G. Noble

    2012-01-01

    Full Text Available Heat shock proteins (Hsp play critical roles in the body’s self-defense under a variety of stresses, including heat shock, oxidative stress, radiation, and wounds, through the regulation of folding and functions of relevant cellular proteins. Exercise increases the levels of Hsp through elevated temperature, hormones, calcium fluxes, reactive oxygen species (ROS, or mechanical deformation of tissues. Isotonic contractions and endurance- type activities tend to increase Hsp60 and Hsp70. Eccentric muscle contractions lead to phosphorylation and translocation of Hsp25/27. Exercise-induced transient increases of Hsp inhibit the generation of inflammatory mediators and vascular inflammation. Metabolic disorders (hyperglycemia and dyslipidemia are associated with type 1 diabetes (an autoimmune disease, type 2 diabetes (the common type of diabetes usually associated with obesity, and atherosclerotic cardiovascular disease. Metabolic disorders activate HSF/Hsp pathway, which was associated with oxidative stress, increased generation of inflammatory mediators, vascular inflammation, and cell injury. Knock down of heat shock factor-1 (HSF1 reduced the activation of key inflammatory mediators in vascular cells. Accumulating lines of evidence suggest that the activation of HSF/Hsp induced by exercise or metabolic disorders may play a dual role in inflammation. The benefits of exercise on inflammation and metabolism depend on the type, intensity, and duration of physical activity.

  7. Heat Shock Factor 1 Is a Substrate for p38 Mitogen-Activated Protein Kinases.

    Science.gov (United States)

    Dayalan Naidu, Sharadha; Sutherland, Calum; Zhang, Ying; Risco, Ana; de la Vega, Laureano; Caunt, Christopher J; Hastie, C James; Lamont, Douglas J; Torrente, Laura; Chowdhry, Sudhir; Benjamin, Ivor J; Keyse, Stephen M; Cuenda, Ana; Dinkova-Kostova, Albena T

    2016-09-15

    Heat shock factor 1 (HSF1) monitors the structural integrity of the proteome. Phosphorylation at S326 is a hallmark for HSF1 activation, but the identity of the kinase(s) phosphorylating this site has remained elusive. We show here that the dietary agent phenethyl isothiocyanate (PEITC) inhibits heat shock protein 90 (Hsp90), the main negative regulator of HSF1; activates p38 mitogen-activated protein kinase (MAPK); and increases S326 phosphorylation, trimerization, and nuclear translocation of HSF1, and the transcription of a luciferase reporter, as well as the endogenous prototypic HSF1 target Hsp70. In vitro, all members of the p38 MAPK family rapidly and stoichiometrically catalyze the S326 phosphorylation. The use of stable knockdown cell lines and inhibitors indicated that among the p38 MAPKs, p38γ is the principal isoform responsible for the phosphorylation of HSF1 at S326 in cells. A protease-mass spectrometry approach confirmed S326 phosphorylation and unexpectedly revealed that p38 MAPK also catalyzes the phosphorylation of HSF1 at S303/307, previously known repressive posttranslational modifications. Thus, we have identified p38 MAPKs as highly efficient catalysts for the phosphorylation of HSF1. Furthermore, our findings suggest that the magnitude and persistence of activation of p38 MAPK are important determinants of the extent and duration of the heat shock response. PMID:27354066

  8. Growth enhancement effects of radish sprouts: atmospheric pressure plasma irradiation vs. heat shock

    International Nuclear Information System (INIS)

    We compare growth enhancement effects due to atmospheric air dielectric barrier discharge plasma irradiation and heat shock to seeds of radish sprouts (Raphanus sativus L.). Interactions between radicals and seeds in a short duration of 3 min. lead to the growth enhancement of radish sprouts in a long term of 7 days and the maximum average length is 3.7 times as long as that of control. The growth enhancement effects become gradually weak with time, and hence the ratio of the average length for plasma irradiation to that for control decreases from 3.7 for the first day to 1.3 for 7 day. The average length for heat shock of 60°C for 10 min. and 100°C for 3 min. is longer than that for control, and the maximum average length is 1.3 times as long as that of control. Heat shock has little contribution to the growth enhancement due to plasma irradiation, because the maximum temperature due to plasma irradiation is less than 60°C

  9. Growth enhancement effects of radish sprouts: atmospheric pressure plasma irradiation vs. heat shock

    Science.gov (United States)

    Sarinont, T.; Amano, T.; Kitazaki, S.; Koga, K.; Uchida, G.; Shiratani, M.; Hayashi, N.

    2014-06-01

    We compare growth enhancement effects due to atmospheric air dielectric barrier discharge plasma irradiation and heat shock to seeds of radish sprouts (Raphanus sativus L.). Interactions between radicals and seeds in a short duration of 3 min. lead to the growth enhancement of radish sprouts in a long term of 7 days and the maximum average length is 3.7 times as long as that of control. The growth enhancement effects become gradually weak with time, and hence the ratio of the average length for plasma irradiation to that for control decreases from 3.7 for the first day to 1.3 for 7 day. The average length for heat shock of 60°C for 10 min. and 100°C for 3 min. is longer than that for control, and the maximum average length is 1.3 times as long as that of control. Heat shock has little contribution to the growth enhancement due to plasma irradiation, because the maximum temperature due to plasma irradiation is less than 60°C.

  10. A critical role for heat shock transcription factor in establishing a nucleosome-free region over the TATA-initiation site of the yeast HSP82 heat shock gene.

    OpenAIRE

    Gross, D S; Adams, C C; Lee, S; Stentz, B

    1993-01-01

    Heat shock genes are poised for rapid transcriptional activation in response to environmental stress. A universal structural characteristic of such genes is the presence of a nucleosome-free, DNase I hypersensitive promoter region. Here we investigate the structural and functional effects of mutating HSE1, the preferred heat shock factor (HSF) binding site upstream of the yeast HSP82 gene. In situ deletion or substitution of this sequence reduces both basal and induced transcription by at lea...

  11. Analysis of integral circulation and decay heat removal experiments in the lead-bismuth CIRCE facility with RELAP5 code

    International Nuclear Information System (INIS)

    In this paper, the results of the post-test analysis of some integral circulation experiments conducted on the lead-bismuth CIRCE facility are presented in comparison with the experimental data. These experiments include the simulation of unprotected loss of flow and unprotected loss of heat sink transients in a pool-type heavy liquid metal reactor. Furthermore, the results of the pre-test analysis of a protected loss of heat sink and flow transient with decay heat removal by a heat exchanger immersed in the pool and operating in natural circulation is presented. All transient analyses have been performed with the RELAP5 thermal-hydraulic code. (author)

  12. Cytoprotective effects of cerium and selenium nanoparticles on heat-shocked human dermal fibroblasts: an in vitro evaluation

    Directory of Open Access Journals (Sweden)

    Yuan B

    2016-04-01

    Full Text Available Bo Yuan, Thomas J Webster, Amit K Roy Chemical Engineering Department, College of Engineering, Northeastern University, Boston, MA, USA Abstract: It is a widely accepted fact that environmental factors affect cells by modulating the components of subcellular compartments and altering metabolic enzymes. Factors (such as oxidative stress and heat-shock-induced proteins and heat shock factors, which upregulate stress-response related genes to protect affected cells are commonly altered during changes in environmental conditions. Studies by our group and others have shown that nanoparticles (NPs are able to efficiently attenuate oxidative stress by penetrating into specific tissues or organs. Such findings warrant further investigation on the effects of NPs on heat-shock-induced stress, specifically in cells in the presence or absence (pretreated of NPs. Here, we examined the cytoprotective effects of two different NPs (cerium and selenium on heat-induced cell death for a model cell using dermal fibroblasts. We report for the first time that both ceria and selenium NPs (at 500 µg/mL possess stress-relieving behavior on fibroblasts undergoing heat shock. Such results indicate the need to further develop these NPs as a novel treatment for heat shock. Keywords: ceria, heat shock, nanotechnology, cell death, nanomedicine, protective

  13. Histological, ultrastructural and heat shock protein 70 (HSP70) responses to heat stress in the sea cucumber Apostichopus japonicus.

    Science.gov (United States)

    Xu, Dongxue; Sun, Lina; Liu, Shilin; Zhang, Libin; Yang, Hongsheng

    2015-08-01

    The aquaculture industry for Apostichopus japonicus has suffered severe economic and resource losses due to high temperature in recent summers. There is increasing concern about the effect of high temperature on this species. Histological, ultrastructural and HSP70 responses to heat stress were investigated in the intestine of A. japonicus. Tissue degradation was observed in muscular, submucosal and mucosal layers, with significant decrease in plicae circulares of the mucosal layer. Ultrastructural damage intensified with increasing stress time, and indicators of cell apoptosis were evident after 192 h heat stress. Immunostaining showed HSP70 mainly in mucosa and serosa, with faint staining in non-stressed individuals (the control group) and denser staining under stress (the 6, 48 and 192 h groups). Western blot detection confirmed ocurrence of HSP70 in all groups and significant up-regulation under stress. The rapid and persistent response of HSP70 implies its critical role in the heat shock response of A. japonicus. PMID:25917397

  14. Study on the steady state and transient behaviour of natural circulation loop with various heat transfer media

    International Nuclear Information System (INIS)

    The advanced reactor concepts use, various heat transfer media e.g., sodium, lead alloy, supercritical water, helium and molten salt mixtures etc. The capability of core heat removal by natural circulation is extensively exploited for normal as well as accidental situations. Thus it is necessary to study the steady state and transient behaviour of a natural circulation loop using different heat transfer media. Towards this objective, a general purpose computer code LeBENC (Lead Bismuth Eutectic Natural Circulation) based on finite difference method is developed. The code is first used to obtain the steady state and transient behaviour of a uniform diameter rectangular water-loop. The results obtained for steady state conditions are compared with the experimental data. After validating the code as mentioned above, steady state and transient behaviour of Heavy-metal Alloy Natural Circulation Study (HANS) loop set up in BARC, with LBE as heat transfer media, is predicted. Transient studies for start-up of natural circulation and loss of heat sink circulation in the HANS loop have been carried out. The transient results are subsequently compared with experimental data and are found in good agreement with the latter. A Molten Salt Loop (MSL) is also being constructed at BARC to carry out heat transfer and pressure drop studies. Pre-test analysis for the same is also carried out for steady state and various postulated transients using code LeBENC. (author)

  15. A Self-Circulating Heat Exchanger for Use in Stirling and Thermoacoustic-Stirling Engines

    Science.gov (United States)

    Backhaus, Scott; Reid, Robert S.

    2005-02-01

    A major technical hurdle to the implementation of large Stirling engines or thermoacoustic engines is the reliability, performance, and manufacturability of the hot heat exchanger that brings high-temperature heat into the engine. Unlike power conversion devices that utilize steady flow, the oscillatory nature of the flow in Stirling and thermoacoustic engines restricts the length of a traditional hot heat exchanger to a peak-to-peak gas displacement, which is usually around 0.2 meters or less. To overcome this restriction, a new hot heat exchanger has been devised that uses a fluid diode in a looped pipe, which is resonantly driven by the oscillating gas pressure in the engine itself, to circulate the engine's working fluid around the loop. Instead of thousands of short, intricately interwoven passages that must be individually sealed, this new design consists of a few pipes that are typically 10 meters long. This revolutionary approach eliminates thousands of hermetic joints, pumps the engine's working fluid to and from a remote heat source without using moving parts, and does so without compromising on heat transfer surface area. Test data on a prototype loop integrated with a 1-kW thermoacoustic engine will be presented.

  16. Experimental Study on Heat Transfer Enhancement of Natural Circulation Liquid Cooling System for Electronic Component

    Institute of Scientific and Technical Information of China (English)

    张正国; 李倩侠; 方晓明; 本田博司

    2004-01-01

    The present research is an experimental study on heat transfer characteristics of a natural circulation cooling system for electronic components. A smooth chip and two micro-pin-finned chips were tested. The chip is mounted on the base of a rectangular horizontal duct located at the bottom of 250 mm high natural circulation loop.FC-72 is used as a coolant. The test conditions are set that the operation pressure of experimental system is 1. 013× 105 Pa, the flow rate of FC-72 is 150 g/min and the subcoolings are 10 K, 25 K and 35 k, respectively. Effect of the subcooling on nucleate boiling and critical heat flux(CHF) were investigated. The results show that subcoolingis found to significantly affect CHF for all chips and micro-pin-finned chips sharply enhanced the boiling heat transfer, CHF of micro-pin-finned chips are 2.5~3 times as large as that of smooth chip at the same subcooling.

  17. Stomatal movement in response to long distance- communicated signals initiated by heat shock in partial roots of Commelina communis L.

    Institute of Scientific and Technical Information of China (English)

    YANG; Songjie; HUANG; Conglin; WU; Zhongyi; HU; Jianfang; LI; Tianzhong; LIU; Shigui

    2006-01-01

    The systematic or long-distance signal transmission plays crucial roles in animal lives. Compared with animals, however, much less is known about the roles of long-distance signal communication in plant lives. Using the model plant Commelina communis L., we have probed the root to shoot communication mediated by heat-shock signals. The results showed that a heat shock of 5 min at 40℃ in partial roots, i.e. half or even 1/4 root system, could lead to a significant decrease in stomatal conductance. The regulation capability depends on both heat shock temperature and the amount of root system, i.e. with higher temperature and more roots stressed, the leaf conductance would decrease more significantly. Interestingly, the stomatal regulation by heat shock signal is in a manner of oscillation: when stomata conductance decreased to the lowest level within about 30 min, it would increase rapidly and sometimes even exceed the initial level, and after several cycles the stomata conductance would be finally stabilized at a lower level. Feeding xylem sap collected from heat-shocked plants could lead to a decrease in stomata conductance, suggesting that the heat shock-initiated signal is basically a positive signal. Further studies showed that heat shock was not able to affect ABA content in xylem sap, and also, not able to lead to a decrease in leaf water status, which suggested that the stomatal regulation was neither mediated by ABA nor by a hydraulic signal. Heat shock could lead to an increase in xylem sap H2O2 content, and moreover, the removal of H2O2 by catalase could partially recover the stomatal inhibition by xylem sap collected from heat-shocked plants, suggesting that H2O2 might be able to act as one of the root signals to control the stomatal movement. Due to the fact that heat-shock and drought are usually two concomitant stresses, the stomatal regulation by heat-shock signal should be of significance for plant response to stresses. The observation for the

  18. Increased expression of heat shock protein 70 and heat shock factor 1 in chronic dermal ulcer tissues treated with laser-aided therapy

    Institute of Scientific and Technical Information of China (English)

    ZHOU Jian-da; LUO Cheng-qun; XIE Hui-qing; NIE Xin-min; ZHAO Yan-zhong; WANG Shao-hua; XU Yi; Pashupati Babu Pokharel; XU Dan

    2008-01-01

    Background Chronic dermal ulcers are also referred to as refractory ulcers, This study was conducted to elucidate the therapeutic effect of laser on chronic dermal ulcers and the induced expression of heat shock factor 1 (HSF1) and heat shock protein 70 (HSP70) in wound tissues.Methods Sixty patients with 84 chronic dermal ulcers were randomly divided into traditional therapy and laser therapy groups. Laser treatment was performed in addition to traditional therapy in the laser therapy group. The treatment efficacy was evaluated after three weeks. Five tissue sections of healing wounds were randomly collected along with five normal skin sections as controls. HSP70-positive cells from HSP70 immunohistochemical staining were counted and the gray scale of positive cells was measured for statistical analysis. Reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting were performed to determine the mRNA and protein expressions of HSF1 and HSP70.Results The cure rate of the wounds and the total efficacy in the laser therapy group were significantly higher than those in the traditional therapy group (P<0.05, P<0.01, respectively). Immunohistochemical staining revealed that the HSP70-positive cell count was significantly higher in laser therapy group than those in the traditional therapy group and controls (P<0.01), and the gray scale of the cell signal was obviously lower than traditional therapy group and controls (P <0.05). By contrast, the traditional therapy group and the control group were not significantly different. The RNA levels of HSF1 and HSP70 were higher in the laser therapy group by RT-PCR, but very low in normal skin and the traditional therapy group. The analysis on the gray scale of the Western blot bands indicated that the expression of HSF1 and HSP70 in the laser therapy group was significantly higher than in the traditional therapy group and the control group (P <0.01), and the expression in the traditional therapy group was also

  19. Responses of bovine lymphocytes to heat shock as modified by breed and antioxidant status.

    Science.gov (United States)

    Kamwanja, L A; Chase, C C; Gutierrez, J A; Guerriero, V; Olson, T A; Hammond, A C; Hansen, P J

    1994-02-01

    We tested whether resistance of lymphocytes to heat stress is modified by breed, intracellular glutathione content, and extracellular antioxidants. In the first experiment, lymphocytes from Angus (Bos taurus, non-heat-tolerant), Brahman (B. indicus, heat-tolerant), and Senepol (B. taurus, heat-tolerant) heifers (12 heifers per breed) were cultured at 45 degrees C for 3 h to evaluate thermal killing, at 42 degrees C for 12 h in a 60-h phytohemagglutinin-induced proliferation test, and at 42 degrees C for 1 h to measure induction of heat shock protein 70 (HSP70). Killing at 45 degrees C was affected by breed x temperature (P Angus than for Brahman or Senepol. For phytohemagglutinin-stimulated lymphocytes, heating to 42 degrees C reduced [3H]thymidine incorporation equally for all breeds. Viability at the end of culture was affected (P x temperature interaction because the decrease in viability caused by culture at 42 degrees C was greatest for lymphocytes from Angus heifers. Heat shock for 1 h at 42 degrees C caused a two- to threefold increase in intracellular concentrations of HSP70, but there was no interaction of temperature with breed. In another experiment (with lymphocytes harvested from three Holstein cows), buthionine sulfoximine, a glutathione synthesis inhibitor, inhibited (P < .01) proliferation of phytohemagglutinin-stimulated lymphocytes at 38.5 and 42 degrees C. Addition of the antioxidants glutathione or thioredoxin to culture did not reduce the effects of heating to 42 degrees C on proliferation.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8157528

  20. Myeloma cell line–derived, pooled heat shock proteins as a universal vaccine for immunotherapy of multiple myeloma

    OpenAIRE

    Qian, Jianfei; Hong, Sungyoul; Wang, Siqing; Zhang, Liang; Sun, Luhong; Wang, Michael; Yang, Jing; Kwak, Larry W.; Hou, Jian; Yi, Qing

    2009-01-01

    Tumor cell–derived heat shock proteins are used as vaccines for immunotherapy of cancer patients. However, current approaches require the generation of custom-made products and are clinically ineffective. To improve the applicability of heat shock protein–based immunotherapy in cancers and to enhance clinical efficacy, we explored combinational treatments in a myeloma setting using pooled heterogeneous or allogeneic myeloma cell line–derived glycoprotein 96 (gp96) as universal vaccines, and c...

  1. Emphasizing on heat shock protein 90′s utility in head and neck squamous cell carcinoma treatment

    OpenAIRE

    Samapika Routray; Aparajita Sunkavalli; Niharika Swain; Shankar, Akhil A

    2013-01-01

    Heat shock protein 90 (Hsp90) a member of the heat shock proteins (HSPs) family, is an adenosine triphosphate dependent molecular chaperone protein, which integrates multiple oncogenic pathways. Clinically, encouraging results have been demonstrated in melanoma, acute myeloid leukemia, castrate refractory prostate cancer, non-small cell lung carcinoma and multiple myeloma using the first generation Hsp90 inhibitors. Hsp90 as the target of anticancer activity of geldanamycin sparked much inter...

  2. Cytoprotective effects of cerium and selenium nanoparticles on heat-shocked human dermal fibroblasts: an in vitro evaluation

    OpenAIRE

    Yuan B; Webster TJ; Roy AK

    2016-01-01

    Bo Yuan, Thomas J Webster, Amit K Roy Chemical Engineering Department, College of Engineering, Northeastern University, Boston, MA, USA Abstract: It is a widely accepted fact that environmental factors affect cells by modulating the components of subcellular compartments and altering metabolic enzymes. Factors (such as oxidative stress and heat-shock-induced proteins and heat shock factors, which upregulate stress-response related genes to protect affected cells) are commonly altered during...

  3. Identification of mono- or poly-specific monoclonal antibody to Porphyromonas gingivalis heat-shock protein 60

    OpenAIRE

    Choi, Jeomil; Lee, Sang-Yull; KIM, Koanhoi; Choi, Bong-Kyu; Kim, Myung-Jin

    2011-01-01

    Purpose The aim of this study was to define the immunoreactive specificity of Porphyromonas gingivalis (P. gingivalis) heat shock protein (HSP) 60 in periodontitis and atherosclerosis. Methods In an attempt to define the cross-reactive bacterial heat-shock protein with human self-antigen at molecular level, we have introduced a novel strategy for cloning hybridoma producing anti-P. gingivalis HSP 60 which is polyreactive to bacterial HSPs or to the human homolog. Results Five cross-reactive c...

  4. Heat shock protein expression as guidance for the therapeutic window of retinal laser therapy

    Science.gov (United States)

    Wang, Jenny; Huie, Philip; Dalal, Roopa; Lee, Seungjun; Tan, Gavin; Lee, Daeyoung; Lavinksy, Daniel; Palanker, Daniel

    2016-03-01

    Unlike conventional photocoagulation, non-damaging retinal laser therapy (NRT) limits laser-induced heating to stay below the retinal damage threshold and therefore requires careful dosimetry. Without the adverse effects associated with photocoagulation, NRT can be applied to critical areas of the retina and repeatedly to manage chronic disorders. Although the clinical benefits of NRT have been demonstrated, the mechanism of therapeutic effect and width of the therapeutic window below damage threshold are not well understood. Here, we measure activation of heat shock response via laser-induced hyperthermia as one indication of cellular response. A 577 nm laser is used with the Endpoint Management (EpM) user interface, a titration algorithm, to set experimental pulse energies relative to a barely visible titration lesion. Live/dead staining and histology show that the retinal damage threshold in rabbits is at 40% of titration energy on EpM scale. Heat shock protein 70 (HSP70) expression in the retinal pigment epithelium (RPE) was detected by whole-mount immunohistochemistry after different levels of laser treatment. We show HSP70 expression in the RPE beginning at 25% of titration energy indicating that there is a window for NRT between 25% and 40% with activation of the heat shock protein expression in response to hyperthermia. HSP70 expression is also seen at the perimeter of damaging lesions, as expected based on a computational model of laser heating. Expression area for each pulse energy setting varied between laser spots due to pigmentation changes, indicating the relatively narrow window of non-damaging activation and highlighting the importance of proper titration.

  5. Heat shock effects on seed germination of five Brazilian savanna species.

    Science.gov (United States)

    Ribeiro, L C; Pedrosa, M; Borghetti, F

    2013-01-01

    Fire is considered an important factor in influencing the physiognomy, dynamics and composition of Neotropical savannas. Species of diverse physiognomies exhibit different responses to fire, such as population persistence and seed mortality, according to the fire frequency to which they are submitted. The aim of this study is to investigate the effects of heat shocks on seed germination of Anadenanthera macrocarpa (Benth.) Brenan, Dalbergia miscolobium Benth., Aristolochia galeata Mart. & Zucc., Kielmeyera coriacea (Spreng.) Mart. and Guazuma ulmifolia Lam., which are native species of the Brazilian savanna. The temperatures and exposure times to which the seeds were submitted were established according to data obtained in the field during a prescribed fire: 60 °C (10, 20 and 40 min), 80 °C (5, 10 and 20 min) and 100 °C (2, 5 and 10 min). Untreated seeds were used as controls. Seeds of A. galeata and K. coriacea showed high tolerance to most heat treatments, and seeds of A. macrocarpa showed a significant reduction in germination percentage after treatments of 80 °C and 100 °C. Treatments of 100 °C for 10 min reduced germination percentage for all species except G. ulmifolia, which has dormant seeds. For this species, germination was accelerated by heat treatments. The high temperatures applied did not interfere with the time to 50% germination (T(50) ) of the tolerant seeds. Seeds of the savanna species K. coriacea and A. galeata were more tolerant to heat shocks than seeds of the forest species A. macrocarpa. Guazuma ulmifolia, the forest species with seeds that germinate after heat shock, also occurs in savanna physiognomies. Overall, the high temperatures applied did not affect the germination rate of the tolerant seeds. PMID:22672775

  6. Heat shock response in Chinese hamster (DHFR/sup -/) cells transfected with mouse DHFR and drosophila HSP70 genes

    International Nuclear Information System (INIS)

    In order to understand the role of the M/sub r/ = 70,000 heat shock protein (hsp70) in mammalian cells in response to heat shock, the authors transfected CHO-DHFR/sup -/ cells with the recombinant vectors pSV2-DHFR (cell lines G and M) or with pSV2-DHFR-hsp70 (cell lines H and L). Both vectors express the DHFR gene, with the latter vector containing all the regulatory, coding and termination sequences for the gene coding for hsp70 from Drosophila melanogaster. The parental cell line (CHO-DHFR/sup -/) shows the induction of several hsps (including hsp70, hsp 68 and hsp110) after a 450C heat shock. Some transfected cell lines (M and L) showed a reduced level of hsp110 and failed to show any detectable hsp68 synthesis after a 450C heat shock. A non-tranfected, methotrexate-resistant CHO cell line that expresses high DHFR activity also fails to express or shows very reduced levels of hsp68 after a heat shock. The authors also tranfected cells (G and H) that do express hsp68 and hsp110 after a heat shock. They are currently investigating the effects of hsp68 and DHFR expression on growth and thermotolerance in these cell lines. The authors conclude that there are sequences present in the vector pSV2-DHFR (possibly the DHFR gene) that may be involved in hsp68 expression

  7. Differential expression patterns among heat-shock protein genes and thermal responses in the whitefly Bemisia tabaci (MEAM 1).

    Science.gov (United States)

    Díaz, Fernando; Orobio, Rony F; Chavarriaga, Paul; Toro-Perea, Nelson

    2015-08-01

    There is convincing evidence that heat-shock proteins (HSP) are upregulated by stress conditions in insects; however, the relative contribution of each HSP gene to the heat-shock response remains unclear. Here we considered the whitefly Bemisia tabaci (MEAM 1), a phloem feeder and invasive species whose molecular stress response is an important mechanism for overcoming heat stress. We assessed the expression of the hsp23, 40, 70 and 90 genes at the mRNA level when submitted to heat shocks of 40 and 44°C/1h (control at 25°C). For this, we evaluated a set of available and suitable reference genes in order to perform data normalization using the real-time polymerase chain reaction (qRT-PCR) technique, and then confirmed the production of HSP70 protein based on Western blot. Results were compared with the hardening capacity of B. tabaci, measured by fitness components as a response to heat shocks, using 40°C as the induction temperature. Three of the four genes (hsp23, 70 and 90) were upregulated by heat stress at mRNA, showing differential expression patterns. Hsp70 expression was confirmed at the protein level. Hardening significantly increased fitness following heat stress, suggesting that HSPs may contribute to hardening capacity in B. tabaci. Potential role of each gene in the heat-shock response for whiteflies is discussed. PMID:26267515

  8. Numerical Analysis of Standing Accretion Shock Instability with Neutrino Heating in Supernova Cores

    Science.gov (United States)

    Ohnishi, Naofumi; Kotake, Kei; Yamada, Shoichi

    2006-04-01

    We have numerically studied the instability of the spherically symmetric standing accretion shock wave against nonspherical perturbations. We have in mind the application to collapse-driven supernovae in the postbounce phase, where the prompt shock wave generated by core bounce is commonly stalled. We take an experimental standpoint in this paper. Using spherically symmetric, completely steady, shocked accretion flows as unperturbed states, we have clearly observed both the linear growth and the subsequent nonlinear saturation of the instability. In so doing, we have employed a realistic equation of state, together with heating and cooling via neutrino reactions with nucleons. We have performed a mode analysis based on the spherical harmonics decomposition and found that the modes with l=1,2 are dominant not only in the linear regime but also after nonlinear couplings generate various modes and saturation occurs. By varying the neutrino luminosity, we have constructed unperturbed states both with and without a negative entropy gradient. We have found that in both cases the growth of the instability is similar, suggesting that convection does not play a dominant role, which also appears to be supported by the recent linear analysis of the convection in accretion flows by Foglizzo et al. The oscillation period of the unstable l=1 mode is found to fit better with the advection time rather than with the sound crossing time. Whatever the cause may be, the instability favors a shock revival.

  9. Non-coding RNAs turn up the heat: An emerging layer of novel regulators in the mammalian heat shock response

    OpenAIRE

    Place, Robert F.; Noonan, Emily J.

    2013-01-01

    The field of non-coding RNA (ncRNA) has expanded over the last decade following the discoveries of several new classes of regulatory ncRNA. A growing amount of evidence now indicates that ncRNAs are involved even in the most fundamental of cellular processes. The heat shock response is no exception as ncRNAs are being identified as integral components of this process. Although this area of research is only in its infancy, this article focuses on several classes of regulatory ncRNA (i.e., miRN...

  10. Bed-To-Wall Heat Transfer in a Supercritical Circulating Fluidised Bed Boiler

    Directory of Open Access Journals (Sweden)

    Błaszczuk Artur

    2014-06-01

    Full Text Available The purpose of this work is to find a correlation for heat transfer to walls in a 1296 t/h supercritical circulating fluidised bed (CFB boiler. The effect of bed-to-wall heat transfer coefficient in a long active heat transfer surface was discussed, excluding the radiation component. Experiments for four different unit loads (i.e. 100% MCR, 80% MCR, 60% MCR and 40% MCR were conducted at a constant excess air ratio and high level of bed pressure (ca. 6 kPa in each test run. The empirical correlation of the heat transfer coefficient in a large-scale CFB boiler was mainly determined by two key operating parameters, suspension density and bed temperature. Furthermore, data processing was used in order to develop empirical correlation ranges between 3.05 to 5.35 m·s-1 for gas superficial velocity, 0.25 to 0.51 for the ratio of the secondary to the primary air, 1028 to 1137K for bed temperature inside the furnace chamber of a commercial CFB boiler, and 1.20 to 553 kg·m-3 for suspension density. The suspension density was specified on the base of pressure measurements inside the boiler’s combustion chamber using pressure sensors. Pressure measurements were collected at the measuring ports situated on the front wall of the combustion chamber. The obtained correlation of the heat transfer coefficient is in agreement with the data obtained from typical industrial CFB boilers.

  11. Comparison of effectiveness of heat and cold shocks applied in the induction of gynogenesis in Clarias gariepinus (Burchell)

    OpenAIRE

    Marx, K.K.; Sukumaran, N.

    2007-01-01

    An experiment was conducted to optimize the procedure of gynogenesis in African catfish, Clarias gariepinus by suppressing meiotic and mitotic cell divisions in fertilized eggs. Gynogensis was conducted by fertilizing normal eggs with UV-irradiated sperm followed by either heat or cold shocking Irradiation of spermatozoa was given for a duration of 1 min and the eggs were fertilized in vitro. Cold shock at a temperature of 3± 1°C for a duration of 30 and 60 min and heat shock at a temperat...

  12. Widespread Inhibition of Posttranscriptional Splicing Shapes the Cellular Transcriptome following Heat Shock

    Directory of Open Access Journals (Sweden)

    Reut Shalgi

    2014-06-01

    Full Text Available During heat shock and other proteotoxic stresses, cells regulate multiple steps in gene expression in order to globally repress protein synthesis and selectively upregulate stress response proteins. Splicing of several mRNAs is known to be inhibited during heat stress, often meditated by SRp38, but the extent and specificity of this effect have remained unclear. Here, we examined splicing regulation genome-wide during heat shock in mouse fibroblasts. We observed widespread retention of introns in transcripts from ∼1,700 genes, which were enriched for tRNA synthetase, nuclear pore, and spliceosome functions. Transcripts with retained introns were largely nuclear and untranslated. However, a group of 580+ genes biased for oxidation reduction and protein folding functions continued to be efficiently spliced. Interestingly, these unaffected transcripts are mostly cotranscriptionally spliced under both normal and stress conditions, whereas splicing-inhibited transcripts are mostly spliced posttranscriptionally. Altogether, our data demonstrate widespread repression of splicing in the mammalian heat stress response, disproportionately affecting posttranscriptionally spliced genes.

  13. Modelling Shock Heating in Cluster Mergers: I. Moving Beyond the Spherical Accretion Model

    CERN Document Server

    McCarthy, Ian G; Balogh, Michael L; Voit, G Mark; Pearce, Frazer R; Theuns, Tom; Babul, Arif; Lacey, Cedric G; Frenk, Carlos S; 10.1111/j.1365-2966.2007.11465.x

    2008-01-01

    (Abridged) The thermal history of the intracluster medium (ICM) is complex. Heat input from cluster mergers, AGN, and galaxy winds offsets and may even halt the cooling of the ICM. Consequently, the processes that set the properties of the ICM play a key role in determining how galaxies form. In this paper we focus on the shock heating of the ICM during cluster mergers, with the eventual aim of incorporating this mechanism into semi-analytic models of galaxy formation. We use a suite of hydrodynamic simulations to track the evolution of the ICM in idealised two-body mergers. We find the heating of the ICM can be understood relatively simply by considering the evolution of the gas entropy during the mergers. We examine the processes that generate the entropy in order to understand why previous analytic shock heating models failed. We find that: (1) The energy that is thermalised in the collision greatly exceeds the kinetic energy available when the systems first touch. The smaller system penetrates deep into t...

  14. The long-term effects of a life-prolonging heat treatment on the Drosophila melanogaster transcriptome suggest that heat shock proteins extend lifespan

    DEFF Research Database (Denmark)

    Sarup, Pernille Merete; Sørensen, Peter; Loeschcke, Volker

    2014-01-01

    Heat-induced hormesis, i.e. the beneficial effect of mild heat-induced stress, increases the average lifespan of many organisms. This effect, which depends on the heat shock factor, decreases the log mortality rate weeks after the stress has ceased. To identify candidate genes that mediate this l...... conclude that the heat shock response, and Hsp70 in particular, may be central to the heat-induced increase in the average lifespan in flies that are exposed to mild heat stress early in life.......Heat-induced hormesis, i.e. the beneficial effect of mild heat-induced stress, increases the average lifespan of many organisms. This effect, which depends on the heat shock factor, decreases the log mortality rate weeks after the stress has ceased. To identify candidate genes that mediate this...... lifespan-prolonging effect late in life, we treated flies with mild heat stress (34 °C for 2 h) 3 times early in life and compared the transcriptomic response in these flies versus non-heat-treated controls 10–51 days after the last heat treatment. We found significant transcriptomic changes in the heat...

  15. Circulation features driven by diurnal heating in the lower atmospheric layers of the Po Valley

    International Nuclear Information System (INIS)

    Some meteorological situations with clear sky and without dynamic circulation were considered during summer diurnal heating over the Po Valley and surrounding regions. The pressure field distribution at sea level and the structure of the anemometric field seem to justify the hypothesis of the existence of breeze winds on the synoptic scale, due to the differential heating among mountains and plain and among plain and sea basins. In particular the behaviour was examined of the wind along the vertical at Milano-Linate, during several period of 24 hours favourable to the development of synoptic breezes, which occur among mountains and the Po Valley. The intensity of the breezes was evaluated also by the assessment of the thermic causes involved. (author)

  16. Genome-wide analysis of heat shock transcription factor families in rice and Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Jingkang Guo; Jian Wu; Qian Ji; Chao Wang; Lei Luo; Yi Yuan; Yonghua Wang; Jian Wang

    2008-01-01

    The heat shock transcription factors (HSFs) are the major heat shock factors regulating the heat stress response. They participate in regulating the expression of heat shock proteins (HSPs), which are critical in the protection against stress damage and many other impor tant biological processes. Study of the HSF gene family is important for understanding the mechanism by which plants respond to stress. The completed genome sequences of rice (Oryza sativa) and Arabidopsis (Arabidopsis thaliana) constitute a valuable resource for comparative genomic analysis, as they are representatives of the two major evolutionary lineages within the angiosperms: the monocotyledons and the dicotyledons. The identification of phylogenetic relationships among HSF proteins in these species is a fundamental step to unravel the functionality of new and yet uncharacterized genes belonging to this family.In this study, the full complement of HSF genes in rice and Arabidopsis has probably been identified through the genome-wide scan. Phylogenetic analyses resulted in the identification of three major clusters of orthologous genes that contain members belonging to both species, which must have been represented in their common ancestor before the taxonomic splitting of the angiosperms. Further analysis of the phylogenetic tree reveals a possible dicot specific gene group. We also identified nine pairs of paralogs, as evidence for studies on the evolution history of rice HSF family and rice genome evolution. Expression data analysis indicates that HSF proteins are widely expressed in plants. These results provide a solid base for future functional genomic studies of the HSF gene family in rice and Arabidopsis.

  17. Decrease in penicillin susceptibility due to heat shock protein ClpL in Streptococcus pneumoniae.

    Science.gov (United States)

    Tran, Thao Dang-Hien; Kwon, Hyog-Young; Kim, Eun-Hye; Kim, Ki-Woo; Briles, David E; Pyo, Suhkneung; Rhee, Dong-Kwon

    2011-06-01

    Antibiotic resistance and tolerance are increasing threats to global health as antibiotic-resistant bacteria can cause severe morbidity and mortality and can increase treatment cost 10-fold. Although several genes contributing to antibiotic tolerance among pneumococci have been identified, we report here that ClpL, a major heat shock protein, could modulate cell wall biosynthetic enzymes and lead to decreased penicillin susceptibility. On capsular type 1, 2, and 19 genetic backgrounds, mutants lacking ClpL were more susceptible to penicillin and had thinner cell walls than the parental strains, whereas a ClpL-overexpressing strain showed a higher resistance to penicillin and a thicker cell wall. Although exposure of Streptococcus pneumoniae D39 to penicillin inhibited expression of the major cell wall synthesis gene pbp2x, heat shock induced a ClpL-dependent increase in the mRNA levels and protein synthesized by pbp2x. Inducible ClpL expression correlated with PBP2x expression and penicillin susceptibility. Fractionation and electron micrograph data revealed that ClpL induced by heat shock is localized at the cell wall, and the ΔclpL showed significantly reduced net translocation of PBP2x into the cell wall. Moreover, coimmunoprecipitation with either ClpL or PBP2x antibody followed by reprobing with ClpL or PBP2x antibody showed an interaction between ClpL and PBP2x after heat stress. This interaction was confirmed by His tag pulldown assay with either ClpLHis₆ or PBP2xHis₆. Thus, ClpL stabilized pbp2x expression, interacted with PBP2x, and facilitated translocation of PBP2x, a key protein of cell wall synthesis process, contributing to the decrease of antibiotic susceptibility in S. pneumoniae. PMID:21422206

  18. Serum Heat Shock Protein 70 Concentration in Relation to Polycystic Ovary Syndrome in a Non-Obese Chinese Population.

    Directory of Open Access Journals (Sweden)

    Hui Gao

    Full Text Available Polycystic ovary syndrome (PCOS represents the most common cause of anovulatory infertility and affects 6-15% of women of reproductive age. However, the underlying etiology is still poorly understood. In this study, we attempted to examine the association between circulating heat shock protein 70 (Hsp70 concentrations and PCOS in a non-obese Chinese population.Human peripheral blood from 52 patients with PCOS and 57 healthy controls, matched for age and BMI, were analyzed. Women with PCOS were found to have significantly higher fasting insulin (FI levels, as well as Insulin resistance index (HOMA-IR (P < 0.05. Identically, markers of oxidative stress (malondialdehyde (MDA, 8-Hydroxy-desoxyguanosine (8-OHdG, Nitric oxide (NO and inflammation (tumor necrosis factor-alpha (TNF-α, C-reactive protein (CRP were markedly increased when compared to controls (P < 0.05. Elevated serum Hsp70 was positively correlated with IR, oxidative stress and inflammation in PCOS, even after adjustment for age, BMI and gynecologic inflammation (GI. The receiver-operating characteristic curve (ROC analysis yielded notably different discriminative value for PCOS, with or without an addition of Hsp70 (areas under the curves were 0.884 (95% CI 0.822-0.946 vs. 0.822 (95% CI 0.744-0.900; P for difference = 0.015.Increased serum Hsp70 levels are associated with the combination of IR, oxidative stress and low-grade chronic inflammation in PCOS individuals, which provides supportive evidence that Hsp70 plays a key role in the pathogenesis of PCOS. More consequent studies were warranted to confirm the clinical utility of circulating Hsp70, especially in diagnosis and prognosis of PCOS and its long-term health cost.

  19. Thermal performance of Al2O3/water nanofluid in a natural circulation loop with a mini-channel heat sink and heat source

    International Nuclear Information System (INIS)

    Highlights: • Heat transfer of a natural circulation loop was investigated experimentally. • The loop has mini-channel heat sink and source and contains Al2O3–water nanofluid. • Al2O3–water nanofluid can enhance the heat-transfer performance of the loop. • Heat-transfer effectiveness were 3.5–22% (in heating) and 9.5–62% (in cooling). - Abstract: In this study, the heat transfer characteristics of Al2O3–water nanofluid were investigated experimentally in a rectangular natural circulation loop of 402 mm in height and 205 mm in width. The 120-mm-long heated section and 155-mm-long cooling section in the loop were constructed with mini-channel heat exchangers. The nanometer-sized particles of alumina (Al2O3) were dispersed in pure water (the base fluid) to form the alumina–water nanofluid with mass fractions in the range of 0.1–1 wt.%. The results clearly indicate that Al2O3–water nanofluid can markedly enhance the heat-transfer performance of the natural circulation loop considered. The average heat-transfer effectiveness at the heating and cooling sections were approximately 3.5–22% and 9.5–62% respectively

  20. Electron Heating, Magnetic Field Amplification, and Cosmic Ray Precursor Length at Supernova Remnant Shocks

    CERN Document Server

    Laming, J Martin; Ghavamian, Parviz; Rakowski, Cara

    2014-01-01

    We investigate the observability, by direct and indirect means, of a shock precursor arising from magnetic field amplification by cosmic rays. We estimate the depth of such a precursor under conditions of nonresonant amplification, which can provide magnetic field strengths comparable to those inferred for supernova remnants. Magnetic field generation occurs as the streaming cosmic rays induce a plasma return current, and may be quenched either by nonresonant or resonant channels. In the case of nonresonant saturation, the cosmic rays become magnetized and amplification saturates at higher magnetic fields. The precursor can extend out to $10^{17} - 10^{18}$ cm and is potentially detectable. If resonant saturation occurs, the cosmic rays are scattered by turbulence and the precursor length will likely be much smaller. The dependence of precursor length on shock velocity has implications for electron heating. In the case of resonant saturation, this dependence is similar to that in the more familiar resonantly ...

  1. Genome-Wide Analysis and Molecular Characterization of Heat Shock Transcription Factor Family in Glycine max

    Institute of Scientific and Technical Information of China (English)

    Eunsook Chung; Kyoung-Mi Kim; Jai-Heon Lee

    2013-01-01

    Heat shock transcription factors (Hsfs) play an essential role on the increased tolerance against heat stress by regulating the expression of heat-responsive genes.In this study,a genome-wide analysis was performed to identify all of the soybean (Glycine max) GmHsfgenes based on the latest soybean genome sequence.Chromosomal location,protein domain,motif organization,and phylogenetic relationships of 26 non-redundant GmHsf genes were analyzed compared with AtHsfs (Arabidopsis thaliana Hsfs).According to their structural features,the predicted members were divided into the previously defined classes A-C,as described for AtHsfs.Transcript levels and subcellular localization of five GmHsfs responsive to abiotic stresses were analyzed by real-time RT-PCR.These results provide a fundamental clue for understanding the complexity of the soybean GmHsfgene family and cloning the functional genes in future studies.

  2. Overly persistent circulation in climate models contributes to overestimated frequency and duration of heat waves and cold spells

    Science.gov (United States)

    Plavcova, Eva; Kysely, Jan

    2016-04-01

    The study examines links of summer heat waves and winter cold spells in Central Europe to atmospheric circulation and specifically its persistence in an ensemble of regional climate models (RCMs). We analyse 13 RCMs driven by the ERA-40 reanalysis and compare them against observations over 1971-2000. Using objective classification of circulation types and an efficiency coefficient with a block resampling test, we identify circulation types significantly conducive to heat waves and cold spells. We show that the RCMs have a stronger tendency to group together days with very high or low temperature and tend to simulate too many heat waves and cold spells, especially those lasting 5 days and more. Circulation types conducive to heat waves in summer are characterized by anticyclonic, southerly and easterly flow, with increasing importance of warm advection during heat waves. Winter cold spells are typically associated with easterly and anticyclonic flow, and the onset of cold spells tends to be linked to northerly and cyclonic flow with cold advection. The RCMs are generally able to reproduce the links between circulation and heat waves or cold spells, including the radiation-to-advection effect for heat waves and the opposite advection-to-radiation effect for cold spells. They capture relatively well also changes of mean temperature anomalies during sequences of given circulation types, namely the tendency towards an increase (decrease) of temperature during the types conducive to heat waves (cold spells). Since mean lengths of all circulation supertypes are overestimated in the RCMs, we conclude that the overly persistent circulation in climate models contributes to the overestimated frequency of long heat waves and cold spells. As these biases are rather general among the examined RCMs and similar drawbacks are likely to be manifested in climate model simulations for the 21st century, the results also suggest that climate change scenarios for spells of days with high

  3. Comparison of the heat shock response induced by conventional heating and two methods of delivery of pulsed radiofrequency energy

    International Nuclear Information System (INIS)

    Full text: In 2001, we published a (hypothetical) mechanism by which radiofrequency (RF) radiation from mobile phones could induce cancer, via the chronic induction of the heat shock response (HSR). This hypothesis provides the focus for our research. Other groups have reported induction of the HSR by RF at apparently non thermal levels. The aim of this study was to determine whether the HSR induced by RF is (a) truly non thermal and (b) quantitatively or qualitatively different from that induced by conventional heating of cells. A rat mast cell line, RBL-2H3, was chosen as the target RBL-2H3 cells were exposed in an air incubator at 41.1 deg C for 45 minutes and 75 minutes, and then returned to a 37 deg C incubator. Sham exposures were performed in the same air incubator at 37 deg C. Cells were exposed for 1 hour in the two pulsed RF exposure systems. The first was a converted 750W microwave oven that emits a short burst of 2.45GHz pulses at the start of each contiguous six minute period. This exposes cells to an average specific energy absorption rate (SAR) of 20W/kg. The second system was a TEM cell, which simulates. GSM pulses - the earner frequency is 0.9GHz pulse modulated at 217Hz. The SAR was approx 0.1W/kg. Both of these exposure systems are housed in incubators maintained at 37 deg C. Sham exposures were performed in the two systems with the same conditions but with no RF radiation present. Cell samples for the conventional heating and microwave exposures were taken 0, 2. 5, 5 and 20 hours after exposure, and expression of heat shock proteins hsp 110, 90, 70, 60 and 56 were determined by Western Blotting and compared between exposures

  4. Inhibiting heat shock factor 1 in human cancer cells with a potent RNA aptamer.

    Directory of Open Access Journals (Sweden)

    H Hans Salamanca

    Full Text Available Heat shock factor 1 (HSF1 is a master regulator that coordinates chaperone protein expression to enhance cellular survival in the face of heat stress. In cancer cells, HSF1 drives a transcriptional program distinct from heat shock to promote metastasis and cell survival. Its strong association with the malignant phenotype implies that HSF1 antagonists may have general and effective utilities in cancer therapy. For this purpose, we had identified an avid RNA aptamer for HSF1 that is portable among different model organisms. Extending our previous work in yeast and Drosophila, here we report the activity of this aptamer in human cancer cell lines. When delivered into cells using a synthetic gene and strong promoter, this aptamer was able to prevent HSF1 from binding to its DNA regulation elements. At the cellular level, expression of this aptamer induced apoptosis and abolished the colony-forming capability of cancer cells. At the molecular level, it reduced chaperones and attenuated the activation of the MAPK signaling pathway. Collectively, these data demonstrate the advantage of aptamers in drug target validation and support the hypothesis that HSF1 DNA binding activity is a potential target for controlling oncogenic transformation and neoplastic growth.

  5. Heat transfer and wall temperature effects in shock wave turbulent boundary layer interactions

    CERN Document Server

    Bernardini, Matteo; Pirozzoli, Sergio; Grasso, Francesco

    2016-01-01

    Direct numerical simulations are carried out to investigate the effect of the wall temperature on the behavior of oblique shock-wave/turbulent boundary layer interactions at freestream Mach number $2.28$ and shock angle of the wedge generator $\\varphi = 8^{\\circ}$. Five values of the wall-to-recovery-temperature ratio ($T_w/T_r$) are considered, corresponding to cold, adiabatic and hot wall thermal conditions. We show that the main effect of cooling is to decrease the characteristic scales of the interaction in terms of upstream influence and extent of the separation bubble. The opposite behavior is observed in the case of heating, that produces a marked dilatation of the interaction region. The distribution of the Stanton number shows that a strong amplification of the heat transfer occurs across the interaction, and the maximum values of thermal and dynamic loads are found in the case of cold wall. The analysis reveals that the fluctuating heat flux exhibits a strong intermittent behavior, characterized by ...

  6. An efficient procedure for purification of recombinant human β heat shock protein 90

    Directory of Open Access Journals (Sweden)

    M Bandehpour

    2010-03-01

    Full Text Available "nBackground and the purpose of the study: Heat Shock Protein 90 (Hsp90 is typically the most abundant chaperone in the eukaryotic cell cytoplasm, and its expression is essential for loading immunogenic peptides onto major histocompatibility complex molecules for presentation to T-cells. Therefore, it may act as a good candidate as an adjuvant molecule in vaccine technology. "n Methods: Initially the human Hsp90β gene was cloned into the heat inducible expression vector pGP1-2 and then the recombinant protein was isolated by ion exchange chromatography. After intradermal injection of confirmed purified band of protein to rabbits and isolation of the serum IgG antibody, for its affinity purification, the rabbit’s purified Hsp90 specific IgG was coupled to the cyanogen bromide-activated Sepharose 4B. Results: The recovery of the purified protein of interest by affinity chromatography was 50% . "n "nConclusion: This research enabled purification of human heat shock protein by a laboratory "n "nprepared column chromatography. "n   

  7. Progress in the participation of Ca2+-calmodulin in heat shock signal transduction

    Institute of Scientific and Technical Information of China (English)

    Rengang Zhou; Bing Li; Hongtao Liu; Daye Sun

    2009-01-01

    A novel heat shock (HS) signal transduction pathway in plants for the participation of Ca2+-calmodulin (CAM) in HS signal trans-duction was identified. HS induces a rapid increase in intracellular free calcium ion levels ([Ca2+]i), and the involvement of phospholipase C-inositol 1,4,5-trisphosphate is one of the factors leading to elevation in [Ca2+]i induced by HS. HS also increases the expression of the CaM gene and the accumulation of the CaM protein. The CaM isoform, AtCaM3, in Arabidopsis is a key member in the HS signal trans-duction pathway. AtCaM3 regulates the activity of CaM-binding protein kinase (AtCBK3) or protein phosphatase (AtPP7), promoting the activation of the HS transcription factor, AtHSFA1a, by phosphorylation/dephosphorylation and the expression of heat shock pro-tein genes, then improving heat tolerance in plants.

  8. A study of the sensitivity of the winter mean meridional circulation to sources of heat and momentum

    OpenAIRE

    Crawford, S. L.; SASAMORI, T.

    2011-01-01

    The time and zonally averaged momentum and thermodynamic equations on a spherical earth are combined to formulate an equation for the mean meridional circulation based on the quasi-static assumption discussed in Eliassen (Astrophys. Nor. 1951, 19–60). The forcing terms and coefficients in the equation are taken from previously published zonally and seasonally averaged data, which include the net radiative heating, condensation heating, boundary layer friction and sensible heating, tropical cu...

  9. The small heat shock proteins from Acidithiobacillus ferrooxidans: gene expression, phylogenetic analysis, and structural modeling

    Directory of Open Access Journals (Sweden)

    Ribeiro Daniela A

    2011-12-01

    Full Text Available Abstract Background Acidithiobacillus ferrooxidans is an acidophilic, chemolithoautotrophic bacterium that has been successfully used in metal bioleaching. In this study, an analysis of the A. ferrooxidans ATCC 23270 genome revealed the presence of three sHSP genes, Afe_1009, Afe_1437 and Afe_2172, that encode proteins from the HSP20 family, a class of intracellular multimers that is especially important in extremophile microorganisms. Results The expression of the sHSP genes was investigated in A. ferrooxidans cells submitted to a heat shock at 40°C for 15, 30 and 60 minutes. After 60 minutes, the gene on locus Afe_1437 was about 20-fold more highly expressed than the gene on locus Afe_2172. Bioinformatic and phylogenetic analyses showed that the sHSPs from A. ferrooxidans are possible non-paralogous proteins, and are regulated by the σ32 factor, a common transcription factor of heat shock proteins. Structural studies using homology molecular modeling indicated that the proteins encoded by Afe_1009 and Afe_1437 have a conserved α-crystallin domain and share similar structural features with the sHSP from Methanococcus jannaschii, suggesting that their biological assembly involves 24 molecules and resembles a hollow spherical shell. Conclusion We conclude that the sHSPs encoded by the Afe_1437 and Afe_1009 genes are more likely to act as molecular chaperones in the A. ferrooxidans heat shock response. In addition, the three sHSPs from A. ferrooxidans are not recent paralogs, and the Afe_1437 and Afe_1009 genes could be inherited horizontally by A. ferrooxidans.

  10. Dual-reporter in vivo imaging of transient and inducible heat-shock promoter activation.

    Science.gov (United States)

    Fortin, Pierre-Yves; Genevois, Coralie; Chapolard, Mathilde; Santalucía, Tomàs; Planas, Anna M; Couillaud, Franck

    2014-02-01

    Gene promoter activity can be studied in vivo by molecular imaging methods using reporter gene technology. Transcription of the reporter and the reported genes occurs simultaneously. However, imaging depends on reporter protein translation, stability, and cellular fate that may differ among the various proteins. A double transgenic mouse strain expressing the firefly luciferase (lucF) and fluorescent mPlum protein under the transcriptional control of the thermo-inducible heat-shock protein (Hspa1b) promoter was generated allowing to follow up the reporter proteins by different and complementary in vivo imaging technologies. These mice were used for in vivo imaging by bioluminescence and epi fluorescence reflectance imaging (BLI & FRI) and as a source of embryonic fibroblast (MEF) for in vitro approaches. LucF, mPlum and endogenous Hsp70 mRNAs were transcribed simultaneously. The increase in mRNA was transient, peaking at 3 h and then returning to the basal level about 6 h after the thermal stimulations. The bioluminescent signal was transient and initiated with a 3 h delay versus mRNA expression. The onset of mPlum fluorescence was more delayed, increasing slowly up to 30 h after heat-shock and remaining for several days. This mouse allows for both bioluminescence imaging (BLI) and fluorescence reflectance imaging (FRI) of Hsp70 promoter activation showing an early and transient lucF activity and a retrospective and persistent mPlum fluorescence. This transgenic mouse will allow following the transient local induction of Hsp-70 promoter beyond its induction time-frame and relate into subsequent dynamic biological effects of the heat-shock response. PMID:24575340

  11. Effects of disruption of heat shock genes on susceptibility of Escherichia coli to fluoroquinolones

    Directory of Open Access Journals (Sweden)

    Morioka Mizue

    2003-08-01

    Full Text Available Abstract Background It is well known that expression of certain bacterial genes responds rapidly to such stimuli as exposure to toxic chemicals and physical agents. It is generally believed that the proteins encoded in these genes are important for successful survival of the organism under the hostile conditions. Analogously, the proteins induced in bacterial cells exposed to antibiotics are believed to affect the organisms' susceptibility to these agents. Results We demonstrated that Escherichia coli cells exposed to levofloxacin (LVFX, a fluoroquinolone (FQ, induce the syntheses of heat shock proteins and RecA. To examine whether the heat shock proteins affect the bactericidal action of FQs, we constructed E. coli strains with mutations in various heat shock genes and tested their susceptibility to FQs. Mutations in dnaK, groEL, and lon increased this susceptibility; the lon mutant exhibited the greatest effects. The increased susceptibility of the lon mutant was corroborated by experiments in which the gene encoding the cell division inhibitor, SulA, was subsequently disrupted. SulA is induced by the SOS response and degraded by the Lon protease. The findings suggest that the hypersusceptibility of the lon mutant to FQs could be due to abnormally high levels of SulA protein resulting from the depletion of Lon and the continuous induction of the SOS response in the presence of FQs. Conclusion The present results show that the bactericidal action of FQs is moderately affected by the DnaK and GroEL chaperones and strongly affected by the Lon protease. FQs have contributed successfully to the treatment of various bacterial infections, but their widespread use and often misuse, coupled with emerging resistance, have gradually compromised their utility. Our results suggest that agents capable of inhibiting the Lon protease have potential for combination therapy with FQs.

  12. New Evidence for Efficient Collisionless Heating of Electrons at the Reverse Shock of a Young Supernova Remnant

    Science.gov (United States)

    Yamaguchi, Hiroya; Eriksen, Kristoffer A.; Badenes, Carles; Hughes, John P.; Brickhouse, Nancy S.; Foster, Adam R.; Patnaude, Daniel J.; Petre, Robert; Slane, Patrick O.; Smith, Randall K.

    2013-01-01

    Although collisionless shocks are ubiquitous in astrophysics, certain key aspects of them are not well understood. In particular, the process known as collisionless electron heating, whereby electrons are rapidly energized at the shock front, is one of the main open issues in shock physics. Here, we present the first clear evidence for efficient collisionless electron heating at the reverse shock of Tycho's supernova remnant (SNR), revealed by Fe K diagnostics using high-quality X-ray data obtained by the Suzaku satellite. We detect K beta (3p yields 1s) fluorescence emission from low-ionization Fe ejecta excited by energetic thermal electrons at the reverse shock front, which peaks at a smaller radius than Fe K alpha (2p yields 1s) emission dominated by a relatively highly ionized component. Comparisons with our hydrodynamical simulations imply instantaneous electron heating to a temperature 1000 times higher than expected from Coulomb collisions alone. The unique environment of the reverse shock, which is propagating with a high Mach number into rarefied ejecta with a low magnetic field strength, puts strong constraints on the physical mechanism responsible for this heating and favors a cross-shock potential created by charge deflection at the shock front. Our sensitive observation also reveals that the reverse shock radius of this SNR is about 10% smaller than the previous measurement using the Fe K alpha morphology from the Chandra observations. Since strong Fe K beta fluorescence is expected only from low-ionization plasma where Fe ions still have many 3p electrons, this feature is key to diagnosing the plasma state and distribution of the immediate postshock ejecta in a young SNR.

  13. Warm-season diurnal circulations and heat extremes over the northwest U.S

    Science.gov (United States)

    Brewer, Matthew C.

    Summer synoptic circulations over the northwest U.S., and their interactions with regional terrain, land/water contrasts, and surface heating, give rise to a variety of fascinating meteorological phenomena, many of which have yet to be explored. Furthermore, it is largely unknown how projected future warming associated with increased greenhouse gases will modify these important features. The work herein seeks to ameliorate this with a comprehensive examination of two important aspects of northwest U.S. summer weather and climate: diurnal circulations and changes to the conditions associated with extreme temperatures under anthropogenic global warming. To simulate regional diurnal circulations, GFS model output was obtained for July and August 2009-2011. These data were categorized into hour of the day, composited, and the resulting files were used to initialize and provide boundary conditions to a WRF (version 3.5) model run. It was shown that, when compared to observations, this WRF run sufficiently simulates average diurnal variability. Using this simulation, the diurnal circulations of the region were described, including several important wind features within the Strait of Juan de Fuca, the Snoqualmie Pass, and the Columbia River Gorge. Also, regional nocturnal low-level wind maxima are described, including one over the northern Willamette valley and another over the high plateau of eastern Oregon. Recent work by the authors has elucidated the physical mechanisms that drive heat extremes over the northwest U.S., including the necessity of a ridge aloft, with associated subsidence and advection warming. Also, easterly flow is crucial for keeping the marine air at bay, and producing downslope flow and adiabatic warming on the western slopes of regional north-south terrain barriers. Given the rising temperatures projected under anthropogenic global warming, how are these conditions, and associated low-level temperature distributions, projected to change? As a

  14. Heat shock proteins in porcine ovary: synthesis, accumulation and regulation by stress and hormones

    OpenAIRE

    Sirotkin, Alexander V; Bauer, Miroslav

    2010-01-01

    The present studies aimed to understand the interrelationships between stress, hormones and heat shock proteins (HSPs) in the ovary. We examined (1) whether HSP70.2, HSP72 and HSP105/110 can be produced and accumulated in porcine ovarian tissue, (2) whether these HSPs could be indicators of stress, i.e. whether two kinds of stress (high temperatures and malnutrition/serum deprivation) can affect them, and (3) whether some hormonal regulators of ovarian functions (insulin-like growth factor (I...

  15. Anti-Inflammatory Heat Shock Protein 70 Genes are Positively Associated with Human Survival

    DEFF Research Database (Denmark)

    Singh, Ripudaman; Kølvraa, Steen; Bross, Peter Gerd;

    2010-01-01

    longevity. The involvement of heat shock protein 70 (Hsp70) in cellular maintenance and repair mechanisms, including its role as an anti-inflammatory protein, makes it a suitable candidate for studying such associations. We have studied the association of three single nucleotide polymorphisms, HSPA1A (-110A......>C), HSPA1B (1267A>G), and HSPA1L (2437T>C), present in the three HSP70 genes, with human survival, in a cohort of individuals born in the year 1905. This population cohort is a part of the longitudinal study of Danish nonagenarians. Since DNA samples were already collected in 1998, this gave us the...

  16. Heat Shock Protein 90AB1 and Hyperthermia Rescue Infectivity of HIV with Defective Cores

    OpenAIRE

    Joshi, Pheroze; Sloan, Barbara; Torbett, Bruce E.; Stoddart, Cheryl A.

    2012-01-01

    We previously showed that reduced infectivity of HIV with incompletely processed capsid-spacer protein 1 (CA-SP1) is rescued by cellular activation or increased expression of HSP90AB1, a member of the cytosolic heat shock protein 90 family. Here we show that HSP90AB1 is present in HIV virions and that HSP90AB1, but not nonfunctional mutated HSP90AB1E42A+D88A, restores infectivity to HIV with mutations in CA that alter core stability. Further, the CA mutants were hypersensitive to pharmacologi...

  17. New Insight into the Effects of Small Heat Shock Proteins on Callipyge Lamb Meat Tenderness

    OpenAIRE

    Cramer, Traci; Kim, Yuan H. Brad; Ma, Danyi; Waddell, Jolena N.; Penick, Moriah

    2014-01-01

    Callipyge lambs are a type of sheep that are genetically known to produce tough meat. High expression of calpastatin, which inhibits proteolytic activity of µ-calpain, has been identified as the main factor behind the toughness of callipyge lamb meat. Another group of proteins called small heat shock proteins (sHSP) has recently been suggested for its possible involvement in tenderness development of meat, where up-regulation of sHSP may be associated with toughness. However, the role of sHSP...

  18. Sequence homologies in the 5' regions of four Drosophila heat-shock genes.

    OpenAIRE

    Holmgren, R; Corces, V; Morimoto, R; Blackman, R; Meselson, M

    1981-01-01

    We report nucleotide sequences of the regions surrounding the 5' ends of the genes for Drosophila melanogaster heat-shock proteins hsp83, hsp68, and hsp26, located at chromosome positions 63BC, 95D, and 67B, respectively. As in other eukaryotic genes, the sequence T-A-T-A-A-A-A-T occurs about 30 nucleotides upstream from the sites of mRNA initiation. Three additional sequence homologies and a dyad symmetry were noted at approximately corresponding locations in the three genes and in the gene ...

  19. Heat shock mRNA in mouse epidermis after UV irradiation

    International Nuclear Information System (INIS)

    Total RNA form murine epidermis was extracted at different times after irradiation with erythemogenic doses of ultraviolet light and hybridized to a DNA probe from the gene of a heat shock protein (hsp 70). An intense and transitory enrichment in RNA molecules hybridizeing to the DNA probe was found between 15 and 120 min after irradiation, followed by a return co control levels over the next 70 h. Dose-response analysis indicates that 30 min after the irradiation, the relative amount of RNA hybridizing to the hsp 70 DNA probe increases with the dose up to values greater than 5 times the control. (Author). 14 refs.; 5 figs

  20. Heat shock and other apoptosis-related proteins as therapeutic targets in prostate cancer

    Institute of Scientific and Technical Information of China (English)

    Costantine Albany; Noah M Hahn

    2014-01-01

    Defects within apoptotic pathways have been implicated in prostate cancer (PCa) tumorigenesis, metastatic progression and treatment resistance. A hallmark of cancers is the ability to derail apoptosis by inhibiting the apoptotic signal, reducing the expression of apoptotic proteins and/or amplifying survival signals through increased production of antiapoptotic molecule. This review describes associations between heat shock proteins (HSPs) and the human androgen receptor (AR), the role of HSPs and other stress-induced proteins in PCa development and emerging strategies in targeting these protective proteins to treat PCa.

  1. Heat transfer analysis for the roller shell under the condition of periodic thermal shock

    Institute of Scientific and Technical Information of China (English)

    Lihua Zhan; Xiaoqian Li

    2003-01-01

    According to the actual working conditions of roller shell in the process of continuous roll casting, the Fourier heat transfer law is used to conduct the simulating analysis for the temperature distribution of the roller shell under the condition of periodic thermal shock. The temperature variation law inside the roller shell is studied during the process of continuous roll casting, and the steady temperature distributions of the roller shell at different casting velocities have been obtained when the thermal contact conductance between the roller shell and the casting strip is considered.

  2. Cross-Reactivity between Chlamydia trachomatis Heat Shock Protein 10 and Early Pregnancy Factor

    OpenAIRE

    Betsou, Fotini; Borrego, Maria José; Guillaume, Nicolas; Catry, Maria Anjos; Romão, Sandra; J.A. Machado-Caetano; Sueur, Jean Marie; Mention, Jacques; Faille, Nicole; Orfila, Jeanne

    2003-01-01

    Chlamydia trachomatis heat shock protein 10 (Chsp10) is associated with chronic genital tract infection with C. trachomatis. Chsp10 is homologous to human chaperonin 10 (Cpn10) and early pregnancy factor (EPF), a form of human Cpn10 that is specifically secreted at the start of pregnancy. We investigated cross-reactions between serum anti-Chsp10 antibodies and anti-EPF antibodies in pregnant and nonpregnant patients. Pregnancy was found to be associated with the presence of anti-EPF antibodie...

  3. The importance of seed mass for the tolerance to heat shocks of savanna and forest tree species

    NARCIS (Netherlands)

    Ribeiro, L.C.; Barbosa, E.R.M.; Langevelde, van F.; Borghetti, F.

    2015-01-01

    Questions: Does seed mass influence the tolerance of seeds to the effects of heating in fires? Is the tolerance to heat shocks during fire events dependent mostly on seed mass itself or to other traits linked to the species ecological origin, e.g. non-fire-prone (forest) and fire-prone (savanna) env

  4. Analysis of phosphorylation of human heat shock factor 1 in cells experiencing a stress

    Directory of Open Access Journals (Sweden)

    Lane William S

    2005-03-01

    Full Text Available Abstract Background Heat shock factor (HSF/HSF1 not only is the transcription factor primarily responsible for the transcriptional response of cells to physical and chemical stress but also coregulates other important signaling pathways. The factor mediates the stress-induced expression of heat shock or stress proteins (HSPs. HSF/HSF1 is inactive in unstressed cells and is activated during stress. Activation is accompanied by hyperphosphorylation of the factor. The regulatory importance of this phosphorylation has remained incompletely understood. Several previous studies on human HSF1 were concerned with phosphorylation on Ser303, Ser307 and Ser363, which phosphorylation appears to be related to factor deactivation subsequent to stress, and one study reported stress-induced phosphorylation of Ser230 contributing to factor activation. However, no previous study attempted to fully describe the phosphorylation status of an HSF/HSF1 in stressed cells and to systematically identify phosphoresidues involved in factor activation. The present study reports such an analysis for human HSF1 in heat-stressed cells. Results An alanine scan of all Ser, Thr and Tyr residues of human HSF1 was carried out using a validated transactivation assay, and residues phosphorylated in HSF1 were identified by mass spectrometry and sequencing. HSF1 activated by heat treatment was phosphorylated on Ser121, Ser230, Ser292, Ser303, Ser307, Ser314, Ser319, Ser326, Ser344, Ser363, Ser419, and Ser444. Phosphorylation of Ser326 but none of the other Ser residues was found to contribute significantly to activation of the factor by heat stress. Phosphorylation on Ser326 increased rapidly during heat stress as shown by experiments using a pSer326 phosphopeptide antibody. Heat stress-induced DNA binding and nuclear translocation of a S326A substitution mutant was not impaired in HSF1-negative cells, but the mutant stimulated HSP70 expression several times less well than wild type

  5. Effect of Heat Shock Treatment and Aloe Vera Coating to Chilling Injury Symptom in Tomato (Lycopersicon asculantum Mill.

    Directory of Open Access Journals (Sweden)

    Sutrisno

    2012-04-01

    Full Text Available This research was undertaken to determine the effect of length in heat shock and edible coating as pre-storage treatment to Chilling Injury (CI symptom reflected by ion leakage induced and quality properties in tomato (Lycopersicon asculantum Mill.. Heat Shock Treatment (HST was conducted at three different levels of length, which were, 20; 40 and 60 min. Edible coating was conducted using aloe vera gel. The result showed that HST and Aloe Vera Coating (AVC were more effective to reduce CI symptom at lower chilling storage. Prolong exposure to heated water may delay climacteric peak. The length of heat shock, AVC treatment and low temperature storage significantly affected the tomato quality parameter but not significantly different for each treatment except weight loss. HST for 20 min at ambient temperature was significantly different to other treatment.

  6. Heat-Induced Changes in Heat Shock Protein Genes Expression in Crossbred and Baladi Pregnant Cows and Their Offspring

    International Nuclear Information System (INIS)

    The experiment was carried out during August (hot climate) on twelve pregnant cows of six crossbred (50% native Baladi and 50% Brown Swiss) and six native Baladi pregnant cows in the same age and the second parity during their mid-pregnancy as detected by rectal palpation. The experiment was repeated during December (mild climate) on similar twelve pregnant cows. Blood sample was obtained from each cow at the end of August (first group) and at the end of December (second group) to obtain heat shock protein genes expression (HSP72, HSP70.01, HSP70, HSP47, k Dalton and Actin) in pregnant cows under mild and hot climate to find out, which breed is more tolerant to heat stress and to estimate offspring birth weight and their growth performances during suckling period. Comparison was made between hot climate cows group and mild climate cows group to estimate heat- induced changes in both breeds in expression level of the Hsp genes and to compare with their neonate birth weight and growth performances during suckling period. The results revealed that expression level of the Hsp genes (Hsp72, Hsp70.1, Hsp70 and Hsp 47) was higher (p<0.01) in hot season compared to that of mild season. Expression level of the Hsp genes (Hsp70.1, Hsp70 and Hsp 47) was higher (p<0.05) in crossbred cows than in Baldi cows under summer hot season. This indicates that crossbred cows are less heat tolerant than Baladi cows under heat stress climate. Heat induced decrease (p<0.01) in offspring birth weight in Baladi and crossbred by 18.1% and 25%, respectively, in weaning weight by 14.61% and 23.14%, respectively and in body weight gain by 14.61% and 21.18%, respectively

  7. On the glacial and inter-glacial thermohaline circulation and the associated transports of heat and freshwater

    Directory of Open Access Journals (Sweden)

    M. Ballarotta

    2014-03-01

    Full Text Available The change of the thermohaline circulation (THC between the Last Glacial Maximum (LGM, ≈ 21 kyr ago and the present day climate are explored using an Ocean General Circulation Model and stream functions projected in various coordinates. Compared to the present day period, the LGM circulation is reorganised in the Atlantic Ocean, in the Southern Ocean and particularly in the abyssal ocean, mainly due to the different haline stratification. Due to stronger wind stress, the LGM tropical circulation is more vigorous than under modern conditions. Consequently, the maximum tropical transport of heat is slightly larger during the LGM. In the North Atlantic basin, the large sea-ice extent during the LGM constrains the Gulf Stream to propagate in a more zonal direction, reducing the transport of heat towards high latitudes and reorganising the freshwater transport. The LGM circulation is represented as a large intrusion of saline Antarctic Bottom Water into the Northern Hemisphere basins. As a result, the North Atlantic Deep Water is shallower in the LGM simulation. The stream functions in latitude-salinity coordinates and thermohaline coordinates point out the different haline regimes between the glacial and interglacial period, as well as a LGM Conveyor Belt circulation largely driven by enhanced salinity contrast between the Atlantic and the Pacific basin. The thermohaline structure in the LGM simulation is the result of an abyssal circulation that lifts and deviates the Conveyor Belt cell from the area of maximum volumetric distribution, resulting in a ventilated upper layer above a deep stagnant layer, and an Atlantic circulation more isolated from the Pacific. An estimation of the turnover times reveal a deep circulation almost sluggish during the LGM, and a Conveyor Belt cell more vigorous due to the combination of stronger wind stress and shortened circulation route.

  8. Construction of the adjoint MIT ocean general circulation model and application to Atlantic heat transport sensitivity

    Science.gov (United States)

    Marotzke, Jochem; Giering, Ralf; Zhang, Kate Q.; Stammer, Detlef; Hill, Chris; Lee, Tong

    1999-12-01

    We first describe the principles and practical considerations behind the computer generation of the adjoint to the Massachusetts Institute of Technology ocean general circulation model (GCM) using R. Giering's software tool Tangent-Linear and Adjoint Model Compiler (TAMC). The TAMC's recipe for (FORTRAN-) line-by-line generation of adjoint code is explained by interpreting an adjoint model strictly as the operator that gives the sensitivity of the output of a model to its input. Then, the sensitivity of 1993 annual mean heat transport across 29°N in the Atlantic, to the hydrography on January 1, 1993, is calculated from a global solution of the GCM. The "kinematic sensitivity" to initial temperature variations is isolated, showing how the latter would influence heat transport if they did not affect the density and hence the flow. Over 1 year the heat transport at 29°N is influenced kinematically from regions up to 20° upstream in the western boundary current and up to 5° upstream in the interior. In contrast, the dynamical influences of initial temperature (and salinity) perturbations spread from as far as the rim of the Labrador Sea to the 29°N section along the western boundary. The sensitivities calculated with the adjoint compare excellently to those from a perturbation calculation with the dynamical model. Perturbations in initial interior salinity influence meridional overturning and heat transport when they have propagated to the western boundary and can thus influence the integrated east-west density difference. Our results support the notion that boundary monitoring of meridional mass and heat transports is feasible.

  9. Differential Expression of Heat Shock Transcription Factors and Heat Shock Proteins after Acute and Chronic Heat Stress in Laying Chickens (Gallus gallus)

    OpenAIRE

    Jingjing Xie; Li Tang; Lin Lu; Liyang Zhang; Lin Xi; Hsiao-Ching Liu; Jack Odle; Xugang Luo

    2014-01-01

    Heat stress due to high environmental temperature negatively influences animal performances. To better understand the biological impact of heat stress, laying broiler breeder chickens were subjected either to acute (step-wisely increasing temperature from 21 to 35°C within 24 hours) or chronic (32°C for 8 weeks) high temperature exposure. High temperature challenges significantly elevated body temperature of experimental birds (P

  10. Investigation of interaction between heat transport systems during the natural circulation decay heat removal in FBRs. Influence of decay heat removal system type and the secondary heat transport system

    International Nuclear Information System (INIS)

    Steady state sodium experiments were performed to investigate interactions between the heat transport systems, i.e., the primary system, the secondary system, and the decay heat removal system, during the natural circulation decay heat removal in FBRs. The test rig was used for the experiments. The core model has seven subassemblies; the center assembly simulates pin bundle geometry of a core fuel subassembly in a large scale FBR and consists of 37 pins, six outer subassemblies consists of 7 pins. As the decay heat removal system, Direct Reactor Auxiliary Cooling System (DRACS) and Primary Reactor Auxiliary Cooling System (PRACS) can be selected. Experiments were carried out under natural circulation conditions in the primary loop and force convection conditions in the decay heat removal system. In cases using DRACS, natural circulation flow rate in the primary loop was smaller by 20% than that in cases using PRACS due to the low temperature in the upper plenum and also in the upper non-heated section of the core. When natural circulation was allowed in the secondary heat transport system, the natural circulation flow rate in the primary system increased in spite of the operation of DRACS. In cases using DRACS, inter-subassembly flow redistribution occurred; the center subassembly had larger flow rate than those in outer subassemblies due to the low natural circulation head in the outer subassemblies which were cooled by the inter-wrapper flow (IWF). The highest temperature in the core was reduced by IWF via not only the direct cooling effect but also the inter-subassembly flow redistribution. (J.P.N.)

  11. Heat transfer in horizontal tubes during two phase natural circulation with presence of noncondensing gas

    Science.gov (United States)

    Alt, S.; Lischke, W.

    The condensation process of steam inside horizontal tubes during natural circulation gains in importance regarding the reactor safety research for existing and future nuclear power plants. Experimental investigations due to the condensation process were realized with the rig HORUS to study the behaviour of water-steam-gas mixtures in horizontal tubes. The paper includes statements regarding the flow and heat transfer conditions inside the tube and the temperature distribution inside the small tube wall. The experiments showed a blockade of the heat transfer area with Nitrogen which is connected with an increasing primary pressure followed by a compression of the Nitrogen and a reentry of steam into the tube. The experiments serve for the creation of an experimental data base. A model development for calculation of the heat transfer is described. The model was implemented in the German thermal-hydraulic code ATHLET. The comparison of calculated data and the measured parameters of HORUS rig show the code improvement for the simulation of noncondensing gases.

  12. Heat transfer in horizontal tubes during two phase natural circulation with presence of noncondensing gas

    International Nuclear Information System (INIS)

    The condensation process of steam inside horizontal tubes during natural circulation gains in importance regarding the reactor safety research for existing and future nuclear power plants. Experimental investigations due to the condensation process were realized with the rig HORUS to study the behaviour of water-steam-gas mixtures in horizontal tubes. The paper includes statements regarding the flow and heat transfer conditions inside the tube and the temperature distribution inside the small tube wall. The experiments showed a blockade of the heat transfer area with Nitrogen which is connected with an increasing primary pressure followed by a compression of the Nitrogen and a reentry of steam into the tube. The experiments serve for the creation of an experimental data base. A model development for calculation of the heat transfer is described. The model was implemented in the German thermal-hydraulic code ATHLET. The comparison of calculated data and the measured parameters of HORUS rig show the code improvement for the simulation of noncondensing gases. (orig.)

  13. Numerical investigation of multidimensional natural circulation phenomenon in passive safety systems for decay heat removal in large pools

    International Nuclear Information System (INIS)

    Many advanced designs of nuclear reactors adopt a methodology of passive safety systems in which the decay heat generated from a reactor is transferred by natural circulation into large pool of water called the Gravity Driven Water Pool (GDWP). Three-dimensional convection flows develop, which in turn affect the heat transfer process and hence the temperature pattern. The heat transfer process can get compromised by the possible stratification of the temperature. The objective of this study is to investigate the transient multidimensional natural circulation phenomenon in GDWP having total volume of 9247 m3 using open source CFD code (OpenFOAM-2.2). In order to reduce the thermal stratification, various geometrical modifications have been incorporated on the heat exchanger design, such as distributing and submergence of heat source; provision of passive elements such as draft tube. A detailed CFD analysis has confirmed the mitigation of thermal stratification phenomenon. (author)

  14. Heating and Non-thermal Particle Acceleration in Relativistic, Transverse Magnetosonic Shock Waves in Proton-Electron-Positron Plasmas

    CERN Document Server

    Amato, E; Amato, Elena; Arons, Jonathan

    2006-01-01

    We report the results of 1D particle-in-cell simulations of ultrarelativistic shock waves in proton-electron-positron plasmas. We consider magnetized shock waves, in which the upstream medium carries a large scale magnetic field, directed transverse to the flow. Relativistic cyclotron instability of each species as the incoming particles encounter the increasing magnetic field within the shock front provides the basic plasma heating mechanism. The most significant new results come from simulations with mass ratio $m_p/m_\\pm = 100$. We show that if the protons provide a sufficiently large fraction of the upstream flow energy density (including particle kinetic energy and Poynting flux), a substantial fraction of the shock heating goes into the formation of suprathermal power-law spectra of pairs. Cyclotron absorption by the pairs of the high harmonic ion cyclotron waves, emitted by the protons, provides the non-thermal acceleration mechanism. As the proton fraction increases, the non-thermal efficiency increas...

  15. Isolation of a cDNA for HSF 2: Evidence for two heat shock factor genes in humans

    Energy Technology Data Exchange (ETDEWEB)

    Schuetz, T.J.; Gallo, G.J.; Sheldon, L.; Kingston, R.E. (Massachusetts General Hospital, Boston (United States) Harvard Medical School, Boston, MA (United States)); Tempst, P. (Harvard Medical School, Boston, MA (United States))

    1991-08-15

    The heat shock response is transcriptionally regulated by an evolutionarily conserved protein termed heat shock factor (HSF). The authors report the purification to homogeneity and the partial peptide sequence of HSF from HeLa cells. The peptide sequence was used to isolate a human cDNA with a predicted open reading frame that has homology to the DNA binding domains of both Saccharomyces cerevisiae and Drosophila HSFs. The cDNA directs the synthesis of a protein that binds to the heat shock element with specificity identical to HeLa HSF and stimulates transcription from a heat shock promoter. The expressed protein cross-reacts with anti-HSF antibodies. Surprisingly, however, this cDNA does not encode all of the peptides obtained from purified HeLa HSF. These peptides are encoded by a distinct human cDNA. HSF1. It therefore appears that there is a human heat shock factor gene family and that at least two separate but related HSF proteins regulate the stress response in humans.

  16. Effect of heat shock on the chilling sensitivity of trichomes and petioles of African violet (Saintpaulia ionantha).

    Science.gov (United States)

    Saltveit, Mikal E.; Hepler, Peter K.

    2004-05-01

    Chilling at 6 degrees C caused an immediate cessation of protoplasmic streaming in trichomes from African violets (Saintpaulia ionantha), and a slower aggregation of chloroplasts in the cells. Streaming slowly recovered upon warming to 20 degrees C, reaching fairly stable rates after 4, 15, 25 and 35 min for tissue chilled for 2 min and for 2, 14 and 24 h, respectively. The rate of ion leakage from excised petioles into an isotonic 0.2 M mannitol solution increased after 12 h of chilling and reached a maximum after 3 days of chilling. A heat shock at 45 degrees C for 6 min reduced chilling-induced rates of ion leakage from excised 1-cm petiole segments by over 50%, namely to levels near that from non-chilled control tissue. Heat-shock treatments themselves had no effect on the rate of ion leakage from non-chilled petiole segments. Protoplasmic streaming was stopped by 1 min of heat shock at 45 degrees C, but slowly recovered to normal levels after about 30 min Chloroplasts aggregation was prevented by a 1 or 2 min 45 degrees C heat-shock treatment administered 1.5 h before chilling, but heat-shock treatments up to 6 min only slightly delayed the reduction in protoplasmic streaming caused by chilling. Tradescantia virginiana did not exhibit symptoms associated with chilling injury in sensitive species (i.e. cessation of protoplasmic streaming in stamen hairs and increased ion leakage from leaf tissue). PMID:15086815

  17. Exploring Mbar shock conditions and isochorically heated aluminum at the MEC end station of the LCLS

    Energy Technology Data Exchange (ETDEWEB)

    Fletcher, L. B.; Lee, H. J.; SLAC, aff; Barbrel, B.; Gauthier, M.; Galtier, E.; Nagler, B.; Doppner, T.; LePape, S.; Ma, T.; Pak, A.; Turnbull, D.; White, T.; Gregori, G.; Wei, M.; Falcone, R. W.; Heimann, P.; Zastrau, U.; Hastings, J. B.; Glenzer, S. H.

    2015-02-05

    Recent experiments performed at the Matter in Extreme Conditions end station (MEC) of the Linac Coherent Light Source (LCLS) have demonstrated the first spectrally resolved measurements of plasmons from isochorically heated aluminum. The experiments have been performed using a seeded 8-keV x-ray laser beam as a pump and probe to both volumetrically heat and scatter x-rays from aluminum. Collective x-ray Thomson scattering spectra show a well-resolved plasmon feature that is down-shifted in energy by 19 eV. In addition, Mbar shock pressures from laser-compressed aluminum foils using Velocity Interferometer System for Any Reflector (VISAR) have been measured. The combination of experiments fully demonstrates the possibility to perform warm dense matter studies at the LCLS with unprecedented accuracy and precision.

  18. Thermal shocks in solar boiler tubes and mechanical tolerance to heating velocity

    International Nuclear Information System (INIS)

    The boiler circular cross-section tubes are cooled by an internal flow and are subjected to a non uniform heat flux around their outer circumference that changes very rapidly with time. Thus thermal shocks can develop in the thickness of tube walls and may cause brittle fracture or fatigue damage. We solve the corresponding thermoelastic problem. The determination of temperature distribution through the wall thickness requires the solution of one-dimensional transient heat equation obtained by performing a Fourier expansion in the angular variable. For each harmonic, Galerkin's method with respect to the radial coordinate together with a finite difference scheme with respect to time permit to completely discretize the associated equation. (orig.)

  19. PERAN HEAT SHOCK PROTEINS (HSP DALAM PATOGENESIS PENYAKIT OTOIMUN DI DALAM RONGGA MULUT

    Directory of Open Access Journals (Sweden)

    Endang W. Bachtiar

    2015-08-01

    Full Text Available Heat Shock Proteins (HSP are highly conserved immunoreactive group of proteins found in microorganisms and animal/human tissue. In addition to heat, other stressful conditiions also induce stressed proteins, especially anorexia, heavy metal ion, exposure to H2O2 and infection by DNA or RNA viruses. Recent studies suggest the involvement of HSPs as autoantigens in autoimmune diseases, including rheumatoid arthritis, systemic lupus erythematosus, Bechet's syndrome, recurrent oral uclers, oral lichen planus and other. The HSPs 60 - 65 KDa might be involved in the pathogenesis of autoimmune diseases such as Bechet's syndrome, recurrent oral ulcers, and oral lichen planus. This paper will discuss the immunopathogenesis mechanism of those diseases induced by HSPs.

  20. Relationships of surface air temperature anomalies over Europe to persistence of atmospheric circulation patterns conducive to heat waves

    Directory of Open Access Journals (Sweden)

    J. Kyselý

    2008-04-01

    Full Text Available Heat waves are among natural hazards with the most severe consequences for human society, including pronounced mortality impacts in mid-latitudes. Recent studies have hypothesized that the enhanced persistence of atmospheric circulation may affect surface climatic extremes, mainly the frequency and severity of heat waves. In this paper we examine relationships between the persistence of the Hess-Brezowsky circulation types conducive to summer heat waves and air temperature anomalies at stations over most of the European continent. We also evaluate differences between temperature anomalies during late and early stages of warm circulation types in all seasons. Results show that more persistent circulation patterns tend to enhance the severity of heat waves and support more pronounced temperature anomalies. Recent sharply rising trends in positive temperature extremes over Europe may be related to the greater persistence of the circulation types, and if similar changes towards enhanced persistence affect other mid-latitudinal regions, analogous consequences and implications for temperature extremes may be expected.

  1. Regulation of Corynebacterium glutamicum Heat Shock Response by the Extracytoplasmic-Function Sigma Factor SigH and Transcriptional Regulators HspR and HrcA▿ §

    OpenAIRE

    Ehira, Shigeki; Teramoto, Haruhiko; Inui, Masayuki; Yukawa, Hideaki

    2009-01-01

    Heat shock response in Corynebacterium glutamicum was characterized by whole-genome expression analysis using a DNA microarray. It was indicated that heat shock response of C. glutamicum included not only upregulation of heat shock protein (HSP) genes encoding molecular chaperones and ATP-dependent proteases, but it also increased and decreased expression of more than 300 genes related to disparate physiological functions. An extracytoplasmic-function sigma factor, SigH, was upregulated by he...

  2. Another self-similar blast wave: Early time asymptote with shock heated electrons and high thermal conductivity

    Science.gov (United States)

    Cox, D. P.; Edgar, R. J.

    1982-01-01

    Accurate approximations are presented for the self-similar structures of nonradiating blast waves with adiabatic ions, isothermal electrons, and equation ion and electron temperatures at the shock. The cases considered evolve in cavities with power law ambient densities (including the uniform density case) and have negligible external pressure. The results provide the early time asymptote for systems with shock heating of electrons and strong thermal conduction. In addition, they provide analytical results against which two fluid numerical hydrodynamic codes can be checked.

  3. Heat shock proteins in hepatocellular carcinoma: Molecular mechanism and therapeutic potential.

    Science.gov (United States)

    Wang, Cun; Zhang, Yurong; Guo, Kun; Wang, Ning; Jin, Haojie; Liu, Yinkun; Qin, Wenxin

    2016-04-15

    Heat shock proteins (HSPs) are highly conserved proteins, which are expressed at low levels under normal conditions, but significantly induced in response to cellular stresses. As molecular chaperones, HSPs play crucial roles in protein homeostasis, apoptosis, invasion and cellular signaling transduction. The induction of HSPs is an important part of heat shock response, which could help cancer cells to adapt to stress conditions. Because of the constant stress condition in tumor microenvironment, HSPs overexpression is widely reported in many human cancers. In light of the significance of HSPs for cancer cells to survive and obtain invasive phenotype under stress condition, HSPs are often associated with poor prognosis and treatment resistance in many types of human cancers. It has been described that upregulation of HSPs may serve as diagnostic and prognostic markers in hepatocellular carcinoma (HCC). Targeting HSPs with specific inhibitor alone or in combination with chemotherapy regimens holds promise for the improvement of outcomes for HCC patients. In this review, we summarize the expression profiles, functions and molecular mechanisms of HSPs (HSP27, HSP70 and HSP90) as well as a HSP-like protein (clusterin) in HCC. In addition, we address progression and challenges in targeting these HSPs as novel therapeutic strategies in HCC. PMID:26853533

  4. Virus-Heat Shock Protein Interaction and a Novel Axis for Innate Antiviral Immunity

    Directory of Open Access Journals (Sweden)

    Michael Oglesbee

    2012-09-01

    Full Text Available Virus infections induce heat shock proteins that in turn enhance virus gene expression, a phenomenon that is particularly well characterized for the major inducible 70 kDa heat shock protein (hsp70. However, hsp70 is also readily induced by fever, a phylogenetically conserved response to microbial infections, and when released from cells, hsp70 can stimulate innate immune responses through toll like receptors 2 and 4 (TLR2 and 4. This review examines how the virus-hsp70 relationship can lead to host protective innate antiviral immunity, and the importance of hsp70 dependent stimulation of virus gene expression in this host response. Beginning with the well-characterized measles virus-hsp70 relationship and the mouse model of neuronal infection in brain, we examine data indicating that the innate immune response is not driven by intracellular sensors of pathogen associated molecular patterns, but rather by extracellular ligands signaling through TLR2 and 4. Specifically, we address the relationship between virus gene expression, extracellular release of hsp70 (as a damage associated molecular pattern, and hsp70-mediated induction of antigen presentation and type 1 interferons in uninfected macrophages as a novel axis of antiviral immunity. New data are discussed that examines the more broad relevance of this protective mechanism using vesicular stomatitis virus, and a review of the literature is presented that supports the probable relevance to both RNA and DNA viruses and for infections both within and outside of the central nervous system.

  5. Small heat shock proteins protect against α-synuclein-induced toxicity and aggregation

    International Nuclear Information System (INIS)

    Protein misfolding and inclusion formation are common events in neurodegenerative diseases, such as Parkinson's disease (PD), Alzheimer's disease (AD) or Huntington's disease (HD). α-Synuclein (aSyn) is the main protein component of inclusions called Lewy bodies (LB) which are pathognomic of PD, Dementia with Lewy bodies (DLB), and other diseases collectively known as LB diseases. Heat shock proteins (HSPs) are one class of the cellular quality control system that mediate protein folding, remodeling, and even disaggregation. Here, we investigated the role of the small heat shock proteins Hsp27 and αB-crystallin, in LB diseases. We demonstrate, via quantitative PCR, that Hsp27 messenger RNA levels are ∼2-3-fold higher in DLB cases compared to control. We also show a corresponding increase in Hsp27 protein levels. Furthermore, we found that Hsp27 reduces aSyn-induced toxicity by ∼80% in a culture model while αB-crystallin reduces toxicity by ∼20%. In addition, intracellular inclusions were immunopositive for endogenous Hsp27, and overexpression of this protein reduced aSyn aggregation in a cell culture model

  6. Heat shock transcriptional factors in Malus domestica: identification, classification and expression analysis

    Directory of Open Access Journals (Sweden)

    Giorno Filomena

    2012-11-01

    Full Text Available Abstract Background Heat shock transcriptional factors (Hsfs play a crucial role in plant responses to biotic and abiotic stress conditions and in plant growth and development. Apple (Malus domestica Borkh is an economically important fruit tree whose genome has been fully sequenced. So far, no detailed characterization of the Hsf gene family is available for this crop plant. Results A genome-wide analysis was carried out in Malus domestica to identify heat shock transcriptional factor (Hsf genes, named MdHsfs. Twenty five MdHsfs were identified and classified in three main groups (class A, B and C according to the structural characteristics and to the phylogenetic comparison with Arabidopsis thaliana and Populus trichocarpa. Chromosomal duplications were analyzed and segmental duplications were shown to have occurred more frequently in the expansion of Hsf genes in the apple genome. Furthermore, MdHsfs transcripts were detected in several apple organs, and expression changes were observed by quantitative real-time PCR (qRT-PCR analysis in developing flowers and fruits as well as in leaves, harvested from trees grown in the field and exposed to the naturally increased temperatures. Conclusions The apple genome comprises 25 full length Hsf genes. The data obtained from this investigation contribute to a better understanding of the complexity of the Hsf gene family in apple, and provide the basis for further studies to dissect Hsf function during development as well as in response to environmental stimuli.

  7. Expression of Heat Shock Protein 70 mRNA in Epithelial Cells of Human Lens

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Objective:To try to find out the pathogenesis of the cataract , effects of beat and oxidative stresson heat shock proteins of tissue cultured human lens epithelial cells (LEC-B3) were investigate& Methods:Cells were exposed to heat shock (45℃) and oxidative stress(5OmMH2O2 for 30 min, and then allowed to recoverat different intervals (Oh, 2h, 4h, 6h, 16h, 24h) in physiological medium Reverse transcription polymerasechain reaction (RT-PCR) were used to determined the level of HSP70. Results: HSPs existed in both physiologicaland stressful situation. The level of HSP7OmRNA increased 2h later after both stresses. The expression of HSP70got to the summit during 2h to 6h in each group. Subsequently it decreased gradually in each group, maintaininga high level at 16h. Conclusion: HSP70 exists in lens epithelial cells and can be induced after stress. Thedata suggested it may play an important protective role in lens epithelial cells in respond to cellular stress.

  8. Axial shock wave heating of reversed-field theta-pinch plasmas

    International Nuclear Information System (INIS)

    Reversed-field theta pinches are known to contract rapidly in the axial direction soon after the radial implosion. Under certain conditions the axial implosion can be quite strong. A model is described which simulates both the radial and axial implosions. Among the important features included are realistic plasma density profiles, and current-driven anomalous transport. Given input parameters such as initial fill pressure, bias magnetic field, coil size, applied voltage (or electric field) and compression magnetic field, the model predicts the final plasma temperature, density, radial and axial dimensions, trapped magnetic flux and fraction of particles trapped within the separatrix. The results indicate very strong axial shock heating for high bias field, which leads to temperatures up to several times that predicted for simple field-free plasmas. The model is applied to parameters charcteristic of two recent experiments, and several features of the calculated results are shown to be consistent with experimental observations. It is also applied to a fusion reactor scale plasma: as a result of strong axial shock heating, the model predicts that fusion ignition (e.g., a temperature of 8 keV) can be achieved without resort to large electric field or large magnetic compression

  9. Loading-Induced Heat-Shock Response in Bovine Intervertebral Disc Organ Culture.

    Science.gov (United States)

    Chooi, Wai Hon; Chan, Samantha Chun Wai; Gantenbein, Benjamin; Chan, Barbara Pui

    2016-01-01

    Mechanical loading has been shown to affect cell viability and matrix maintenance in the intervertebral disc (IVD) but there is no investigation on how cells survive mechanical stress and whether the IVD cells perceive mechanical loading as stress and respond by expression of heat shock proteins. This study investigates the stress response in the IVD in response to compressive loading. Bovine caudal disc organ culture was used to study the effect of physiological range static loading and dynamic loading. Cell activity, gene expression and immunofluorescence staining were used to analyze the cell response. Cell activity and cytoskeleton of the cells did not change significantly after loading. In gene expression analysis, significant up-regulation of heat shock protein-70 (HSP70) was observed in nucleus pulposus after two hours of loading. However, the expression of the matrix remodeling genes did not change significantly after loading. Similarly, expressions of stress response and matrix remodeling genes changed with application and removal of the dynamic loading. The results suggest that stress response was induced by physiological range loading without significantly changing cell activity and upregulating matrix remodeling. This study provides direct evidence on loading induced stress response in IVD cells and contributes to our understanding in the mechanoregulation of intervertebral disc cells. PMID:27580124

  10. Experiments on the Heat Transfer and Natural Circulation Characteristics of the Passive Residual Heat Removal System for the Advanced Integral Type Reactor

    International Nuclear Information System (INIS)

    Experiments on the heat transfer characteristics and natural circulation performance of the passive residual heat removal system (PRHRS) for the SMART-P have been performed using the high temperature/high pressure thermal-hydraulic test facility (VISTA). The VISTA facility consists of the primary loop, the secondary loop, the PRHRS loop, and auxiliary systems to simulate the SMART-P, a pilot plant of the SMART. The primary loop is composed of the steam generator (SG) primary side, a simulated core, a main coolant pump, and loop piping, and the PRHRS loop consists of the SG secondary side, a PRHRS heat exchanger, and loop piping. The natural circulation performance of the PRHRS, the heat transfer characteristics of the PRHRS heat exchangers and the emergency cooldown tank (ECT), and the thermal-hydraulic behavior of the primary loop are intensively investigated. The experimental results show that the coolant flows steadily in the PRHRS loop and the heat transfers through the PRHRS heat exchanger and the emergency cooldown tank are sufficient enough to enable the natural circulation of the coolant. The results also show that the core decay heat can be sufficiently removed from the primary loop with the operation of the PRHRS. (authors)

  11. Effects of heat shock on resistance to parasitoids and on life history traits in an aphid/endosymbiont system.

    Science.gov (United States)

    Cayetano, Luis; Vorburger, Christoph

    2013-01-01

    Temperature variation is an important factor determining the outcomes of interspecific interactions, including those involving hosts and parasites. This can apply to variation in average temperature or to relatively short but intense bouts of extreme temperature. We investigated the effect of heat shock on the ability of aphids (Aphis fabae) harbouring protective facultative endosymbionts (Hamiltonella defensa) to resist parasitism by Hymenopteran parasitoids (Lysiphlebus fabarum). Furthermore, we investigated whether heat shocks can modify previously observed genotype-by-genotype (G x G) interactions between different endosymbiont isolates and parasitoid genotypes. Lines of genetically identical aphids possessing different isolates of H. defensa were exposed to one of two heat shock regimes (35°C and 39°C) or to a control temperature (20°C) before exposure to three different asexual lines of the parasitoids. We observed strong G x G interactions on parasitism rates, reflecting the known genetic specificity of symbiont-conferred resistance, and we observed a significant G x G x E interaction induced by heat shocks. However, this three-way interaction was mainly driven by the more extreme heat shock (39°C), which had devastating effects on aphid lifespan and reproduction. Restricting the analysis to the more realistic heat shock of 35°C, the G x G x E interaction was weaker (albeit still significant), and it did not lead to any reversals of the aphid lines' susceptibility rankings to different parasitoids. Thus, under conditions feasibly encountered in the field, the relative fitness of different parasitoid genotypes on hosts protected by particular symbiont strains remains mostly uncomplicated by heat stress, which should simplify biological control programs dealing with this system. PMID:24143175

  12. Effects of heat transfer coefficient treatments on thermal shock fracture prediction for LWR fuel claddings in water quenching

    International Nuclear Information System (INIS)

    Accurate modeling of thermal shock induced stresses has become ever most important to emerging accident-tolerant ceramic cladding concepts, such as silicon carbide (SiC) and SiC coated zircaloy. Since fractures of ceramic (entirely ceramic or coated) occur by excessive tensile stresses with linear elasticity, modeling transient stress distribution in the material provides a direct indication of the structural integrity. Indeed, even for the current zircaloy cladding material, the oxide layer formed on the surface - where cracks starts to develop upon water quenching - essentially behaves as a brittle ceramic. Hence, enhanced understanding of thermal shock fracture of a brittle material would fundamentally contribute to safety of nuclear reactors for both the current fuel design and that of the coming future. Understanding thermal shock fracture of a brittle material requires heat transfer rate between the solid and the fluid for transient temperature fields of the solid, and structural response of the solid under the obtained transient temperature fields. In water quenching, a solid experiences dynamic time-varying heat transfer rates with phase changes of the fluid over a short quenching period. Yet, such a dynamic change of heat transfer rates during the water quenching transience has been overlooked in assessments of mechanisms, predictability, and uncertainties for thermal shock fracture. Rather, a time-constant heat transfer coefficient, named 'effective heat transfer coefficient' has become a conventional input to thermal shock fracture analysis. No single constant heat transfer could suffice to depict the actual stress evolution subject to dynamic heat transfer coefficient changes with fluid phase changes. Use of the surface temperature dependent heat transfer coefficient will remarkably increase predictability of thermal shock fracture of brittle materials and complete the picture of stress evolution in the quenched solid. The presented result

  13. Effects of heat transfer coefficient treatments on thermal shock fracture prediction for LWR fuel claddings in water quenching

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Youho; Lee, Jeong Ik; Cheon, Hee [KAIST, Daejeon (Korea, Republic of)

    2015-05-15

    Accurate modeling of thermal shock induced stresses has become ever most important to emerging accident-tolerant ceramic cladding concepts, such as silicon carbide (SiC) and SiC coated zircaloy. Since fractures of ceramic (entirely ceramic or coated) occur by excessive tensile stresses with linear elasticity, modeling transient stress distribution in the material provides a direct indication of the structural integrity. Indeed, even for the current zircaloy cladding material, the oxide layer formed on the surface - where cracks starts to develop upon water quenching - essentially behaves as a brittle ceramic. Hence, enhanced understanding of thermal shock fracture of a brittle material would fundamentally contribute to safety of nuclear reactors for both the current fuel design and that of the coming future. Understanding thermal shock fracture of a brittle material requires heat transfer rate between the solid and the fluid for transient temperature fields of the solid, and structural response of the solid under the obtained transient temperature fields. In water quenching, a solid experiences dynamic time-varying heat transfer rates with phase changes of the fluid over a short quenching period. Yet, such a dynamic change of heat transfer rates during the water quenching transience has been overlooked in assessments of mechanisms, predictability, and uncertainties for thermal shock fracture. Rather, a time-constant heat transfer coefficient, named 'effective heat transfer coefficient' has become a conventional input to thermal shock fracture analysis. No single constant heat transfer could suffice to depict the actual stress evolution subject to dynamic heat transfer coefficient changes with fluid phase changes. Use of the surface temperature dependent heat transfer coefficient will remarkably increase predictability of thermal shock fracture of brittle materials and complete the picture of stress evolution in the quenched solid. The presented result

  14. Differential expression pattern of heat shock protein 70 gene in tissues and heat stress phenotypes in goats during peak heat stress period.

    Science.gov (United States)

    Rout, P K; Kaushik, R; Ramachandran, N

    2016-07-01

    It has been established that the synthesis of heat shock protein 70 (Hsp70) is temperature-dependent. The Hsp70 response is considered as a cellular thermometer in response to heat stress and other stimuli. The variation in Hsp70 gene expression has been positively correlated with thermotolerance in Drosophila melanogaster, Caenorhabditis elegans, rodents and human. Goats have a wide range of ecological adaptability due to their anatomical and physiological characteristics; however, the productivity of the individual declines during thermal stress. The present study was carried out to analyze the expression of heat shock proteins in different tissues and to contrast heat stress phenotypes in response to chronic heat stress. The investigation has been carried out in Jamunapari, Barbari, Jakhrana and Sirohi goats. These breeds differ in size, coat colour and production performance. The heat stress assessment in goats was carried out at a temperature humidity index (THI) ranging from 85.36-89.80 over the period. Phenotyping for heat stress susceptibility was carried out by combining respiration rate (RR) and heart rate (HR). Based on the distribution of RR and HR over the breeds in the population, individual animals were recognized as heat stress-susceptible (HSS) and heat stress-tolerant (HST). Based on their physiological responses, the selected animals were slaughtered for tissue collection during peak heat stress periods. The tissue samples from different organs such as liver, spleen, heart, testis, brain and lungs were collected and stored at -70 °C for future use. Hsp70 concentrations were analyzed from tissue extract with ELISA. mRNA expression levels were evaluated using the SYBR green method. Kidney, liver and heart had 1.5-2.0-fold higher Hsp70 concentrations as compared to other organs in the tissue extracts. Similarly, the gene expression pattern of Hsp70 in different organs indicated that the liver, spleen, brain and kidney exhibited 5.94, 4.96, 5

  15. Effects of Crack on Heat Flux in Hypersonic Shock/Boundary-Layer Interaction

    Science.gov (United States)

    Ozawa, Hiroshi; Hanai, Katsuhisa; Kitamura, Keiichi; Mori, Koichi; Nakamura, Yoshiaki

    A small crack on body surface led to a tragic accident in 2003, which is the Columbia accident. During the shuttle's re-entry, high temperature gas penetrated crack on leading-edge of the left wing and melted the aluminum structure, finally the Columbia blew up. Since early times, there are many fundamental studies about simple cavity-flow formed on body surface in hypersonic speeds. However, an investigation of Shock/Boundary-Layer Interaction (SBLI) on crack has not been researched. For multistage space transportation vehicle such as TSTO, SBLI is an inevitable problem, and then SBLI on crack becomes a critical issue for TSTO development. In this study, the effects of crack, where SBLI occurs, were investigated for TSTO hypersonic speed (M∞ = 8.1). A square crack locates at SBLI point on the TSTO booster. Results show that a crack and its depth strongly effect on peak heat flux and aerodynamic interaction flow-field. In the cases of shallow crack (d/C ≤ 0.10), there exist two high heat flux regions on crack floor, which locates at a flow reattachment region and a back end wall of crack. In this case, a peak heat flux at flow reattachment region becomes about 2 times as large as the stagnation point heat flux, which value becomes larger compared with a peak heat flux in the case of No-Crack TSTO. While in the case of deep crack (d/C = 0.20), overall heat flux on crack floor decreases to below the stagnation point heat flux. These results provide useful data for a development of TSTO thermal protection system (TPS) such as thermal protection tile.

  16. Reduced heat shock response in human mononuclear cells during aging and its association with polymorphisms in HSP70 genes

    DEFF Research Database (Denmark)

    Singh, Ripudaman; Kølvraa, Steen; Bross, Peter;

    2006-01-01

    Age-dependent changes in heat shock response (HSR) were studied in mononuclear cells (monocytes and lymphocytes) collected from young (mean age = 22.6 +/- 1.7 years) and middle-aged (mean age = 56.3 +/- 4.7 years) subjects after 1 hour of heat shock at 42 degrees C. Genotype-specific HSR was...... measured by genotyping the subjects for 3 single nucleotide polymorphisms, HSPA1A(A-110C), HSPA1B(A1267G), and HSPA1L(T2437C), 1 each in the 3 HSP70 genes. A significant age-related decrease in the induction of Hsp70 occurred after heat shock in both monocytes and lymphocytes. The noninducible and...

  17. Inhibition of HSP70 Gene Expression by Modified Antisense and Its Effects on Embryonic Sensitivity to Heat Shock

    Institute of Scientific and Technical Information of China (English)

    TIAN Wen-ru; DU Li-yin; HE Jian-bin; LI Shou-jun

    2004-01-01

    Experiments were performed to evaluate the efficiency of inhibition of HSP70 gene expression by antisense oligonucleotides complementary to the mRNA of HSP70 and to test the effects of inhibition of HSP70 gene expression on subsequent embryonic sensitivity to heat shock. The results showed that transfection of pre-implantation embryos at 4-cell stage with 5 μM antisense oligo had no effect on in vitro blastocyst development. However, transfection with 10 to 40 μM antisense oligo had reduced in vitro blastocyst development to 15, 10% and 0; For the embryos which exposed to 40 μM As arrested at the 16-cell stage, there was no blastocyst formation within the heat shock groups. In contrast, transfection had no effect on embryonic sensitivity to heat shock, above 25% of embryos developed to blastocyst stage in control groups.

  18. Heat shock response in yeast involves changes in both transcription rates and mRNA stabilities.

    Directory of Open Access Journals (Sweden)

    Laia Castells-Roca

    Full Text Available We have analyzed the heat stress response in the yeast Saccharomyces cerevisiae by determining mRNA levels and transcription rates for the whole transcriptome after a shift from 25 °C to 37 °C. Using an established mathematical algorithm, theoretical mRNA decay rates have also been calculated from the experimental data. We have verified the mathematical predictions for selected genes by determining their mRNA decay rates at different times during heat stress response using the regulatable tetO promoter. This study indicates that the yeast response to heat shock is not only due to changes in transcription rates, but also to changes in the mRNA stabilities. mRNA stability is affected in 62% of the yeast genes and it is particularly important in shaping the mRNA profile of the genes belonging to the environmental stress response. In most cases, changes in transcription rates and mRNA stabilities are homodirectional for both parameters, although some interesting cases of antagonist behavior are found. The statistical analysis of gene targets and sequence motifs within the clusters of genes with similar behaviors shows that both transcriptional and post-transcriptional regulons apparently contribute to the general heat stress response by means of transcriptional factors and RNA binding proteins.

  19. Heat shock protein 70-dependent protective effect of polaprezinc on acetylsalicylic acid-induced apoptosis of rat intestinal epithelial cells.

    Science.gov (United States)

    Qin, Ying; Naito, Yuji; Handa, Osamu; Hayashi, Natsuko; Kuki, Aiko; Mizushima, Katsura; Omatsu, Tatsushi; Tanimura, Yuko; Morita, Mayuko; Adachi, Satoko; Fukui, Akifumi; Hirata, Ikuhiro; Kishimoto, Etsuko; Nishikawa, Taichiro; Uchiyama, Kazuhiko; Ishikawa, Takeshi; Takagi, Tomohisa; Yagi, Nobuaki; Kokura, Satoshi; Yoshikawa, Toshikazu

    2011-11-01

    Protection of the small intestine from mucosal injury induced by nonsteroidal anti-inflammatory drugs including acetylsalicylic acid is a critical issue in the field of gastroenterology. Polaprezinc an anti-ulcer drug, consisting of zinc and L-carnosine, provides gastric mucosal protection against various irritants. In this study, we investigated the protective effect of polaprezinc on acetylsalicylic acid-induced apoptosis of the RIE1 rat intestinal epithelial cell line. Confluent rat intestinal epithelial cells were incubated with 70 µM polaprezinc for 24 h, and then stimulated with or without 15 mM acetylsalicylic acid for a further 15 h. Subsequent cellular viability was quantified by fluorometric assay based on cell lysis and staining. Acetylsalicylic acid-induced cell death was also qualified by fluorescent microscopy of Hoechst33342 and propidium iodide. Heat shock proteins 70 protein expression after adding polaprezinc or acetylsalicylic acid was assessed by western blotting. To investigate the role of Heat shock protein 70, Heat shock protein 70-specific small interfering RNA was applied. Cell viability was quantified by fluorometric assay based on cell lysis and staining and apoptosis was analyzed by fluorescence-activated cell sorting. We found that acetylsalicylic acid significantly induced apoptosis of rat intestinal epithelial cells in a dose- and time-dependent manner. Polaprezinc significantly suppressed acetylsalicylic acid-induced apoptosis of rat intestinal epithelial cells at its late phase. At the same time, polaprezinc increased Heat shock protein 70 expressions of rat intestinal epithelial cells in a time-dependent manner. However, in Heat shock protein 70-silenced rat intestinal epithelial cells, polaprezinc could not suppress acetylsalicylic acid -induced apoptosis at its late phase. We conclude that polaprezinc-increased Heat shock protein 70 expression might be an important mechanism by which polaprezinc suppresses acetylsalicylic

  20. Effect of gibberellin and heat shock on the lipid composition of endoplasmic reticulum in barley aleurone layers

    International Nuclear Information System (INIS)

    The heat-shock responses of barley (Hordeum vulgare L. cv Himalaya) aleurone layers incubated with or without gibberellic acid (GA3) were compared. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that heat shock blocked the synthesis and secretion of secretory proteins from GA3-treated layers but not untreated layers. This suppression of secretory protein synthesis has been correlated with changes in endoplasmic reticulum (ER) membranes (F.C. Belanger, M.R. Brodl, T.-h.D. Ho [1986] Proc Natl Acad Sci USA 83: 1354-1358; L. Sticher, A.K. Biswas, D.S. Bush, R.L. Jones [1990] Plant Physiol 92: 506-513). Our secretion data suggested that the ER membranes of aleurone layers incubated without GA3 may be more heat shock tolerant. To investigate this, the lipid profiles of membrane extracts in aleurone layers labeled with [14C]glycerol were examined. Heat shock markedly increased [14C]glycerol incorporation into phosphatidylcholine (PC), and gas chromatography revealed an increase in the amount of saturated fatty acids associated with thin layer chromatography-purified PC in GA3-treated layers. In contrast, aleurone layers incubated without GA3 at normal temperature contained PC-associated fatty acids with a greater degree of saturation than GA3-treated layers. Heat shock modestly increased the degree of fatty acid saturation in untreated aleurone layers. This same trend was noted in fatty acids isolated from ER membranes purified by continuous sucrose density centrifugation. We propose that increased fatty acid saturation may help sustain ER membrane function in heat-shocked aleurone layers incubated in the absence of GA3

  1. Sodium experiment on fully natural circulation systems for decay heat removal in Japan sodium-cooled fast reactor

    International Nuclear Information System (INIS)

    Fully natural circulation system is adopted in a decay heat removal system (DHRS) of Japan Sodium Cooled Fast Reactor (JSFR). The DHRS of JSFR consists of one unit of DRACS (direct reactor auxiliary cooling system), which has a dipped heat exchanger in the reactor vessel and two units of PRACS, which has a heat exchanger in a primary-side inlet plenum of IHX in each loop. In this study, the sodium experiments were conducted using a sodium test loop PLANDTL in order to investigate the effect of operation mode on transient behavior of thermal hydraulic in PRACS loop. The experimental results revealed the effect of increasing heat removal capacity of PRACS and the forced flow operation in PRACS loop on the thermal transient in the PRACS loop and natural circulation behavior of PRACS. (author)

  2. Collisionless Shock Waves and Turbulent Heating in High Voltage Theta Pinches

    International Nuclear Information System (INIS)

    Based on preceding experiments with smaller systems, a large (46 cm diameter, 100 cm length) theta pinch has been constructed which is driven by a Blumlein-type transmission line (∼0.4Ω) capable of generating a 1 MV pulse (open circuit) of 100 ns duration. For the experiments described herein, it was operated at 40% of design voltage. The corresponding peak field is 3.2 kG, and a strong shock wave (5 x 107 cm/s) is generated in the initial plasma containing a (parallel or antiparallel) bias field. This initial plasma is prepared in typically 5 m Torr D2 by a sequence of auxiliary discharges through the theta-pinch coil. Shock structure and field-vacuum interface are investigated (mainly by magnetic probes). These measurements, besides being compared directly with theoretical predictions, also yield current densities required for the determination of effective (turbulent) electrical conductivities from measured electron heating rates (using X-ray emission). Ion energies are estimated from neutron yields. Indications are that there is an anomalous ion heating mechanism, in addition to anomalous electron heating, as observed in preceding experiments from Thomson scattering measurements. In parallel with these laboratory investigations, a computer simulation program has been developed which permits quantitative discussion of the influence of non-stationarity and cylindrical convergence on the experimental results and of the deviations from classical results caused by anomalous transport processes (with coefficients either estimated theoretically from growth rates of expected microinstabilities or chosen to fit the experimental results). (author)

  3. Quantification of modeling uncertainties based on scaling laws in natural circulation decay heat removal

    International Nuclear Information System (INIS)

    A Best Estimate Plus Uncertainty (BEPU) analysis is one of the good methods to estimate the uncertainty of phenomenon in a nuclear power plant dynamics. In BEPU analysis, a number of numerical analyses, in which input parameters are varied based on their probabilistic distributions, are carried out to obtain statistical characteristics of the output result. In general, the uncertainty of input parameters, such as a probabilistic distribution form and variance, are estimated based on experimental knowledge and/or engineering judgment. In the present research, we focus on a scaling law (dimensionless number) in constitutive equations from a view point of phenomenological theory. An influence of uncertainty in the dimensionless number and its dependency on BEPU analysis has been investigated. Plant dynamics analyses of Super Safe, Small and Simple (4S) reactor, being developed by Toshiba, are carried out under a natural circulation decay heat removal condition. In the analysis, uncertainties of the dimensionless numbers such as Nusselt, Reynolds, and Prandtl numbers are taken into consideration, as well as an uncertainty of decay heat power. The Latin Hypercube Sampling is applied to determine the input deck set. As a result, it is demonstrated that the parameter dependency on the output result can be revealed by using the dimensionless numbers. (author)

  4. High-speed pyrolysis with circulating heat carriers; Schnell-Pyrolyse mit zirkulierenden Waermetraegern

    Energy Technology Data Exchange (ETDEWEB)

    Schmalfeld, J.; Albrecht, J.; Solmaz, S.; Zentner, U. [Lurgi Energie und Umwelt GmbH, Frankfurt am Main (Germany)

    1998-09-01

    Yields and product compositions of pyrolysis reactions depend on the mode of heat supply, the temperature level, and the time of residue at reaction temperature. Using hot circulating granular materials mixed with solid or liquid materials (e.g. biogenic or hydrocarbon-rich residues and waste materials or refinery residues), the following important processes can be investigated: Separation of pyrolysis reaction and heat supply - accurate, optimal temperature levels for pyrolysis, e.g. between 5000 and 850 degrees centigrade - undiluted, unmixed pyrolysis gas - short times of residue of the pyrolysis gas for suppression of secondary reactions. (orig.) [Deutsch] Ausbeuten und Produktzusammensetzung von Pyrolyse-Reaktionen werden weitestgehend durch die Art und Weise der Waermezufuhr, das Temperaturniveau und die Verweilzeit bei Reaktionstemperatur bestimmt. Mit Hilfe des Prinzips heisser, umlaufender, koerniger Waermetraeger in Vermischung - fuer die Pyrolyse-Reaktion - mit festen oder fluessigen Einsatzstoffen (z.B. biogene oder kohlenwasserstoffreiche Rest-/Abfallstoffe, Raffinerie-Rueckstaende) lassen sich folgende wichtige, haeufig gewuenschte Vorgaenge realisieren: - Trennung von Pyrolyse-Reaktion und Waermeversorgung - Temperaturgenaue Pyrolyse-Reaktion auf gewuenschtem, optimalem Niveau waehlbar zwischen z.B. 5000 C und 850 C - Erhalt eines unverduennten, unvermischten Pyrolysegases - Kurze Verweilzeiten des Pyrolysegases zur Unterdrueckung von Sekundaerreaktionen. (orig.)

  5. Heat shock causes destabilization of specific mRNAs and destruction of endoplasmic reticulum in barley aleurone cells.

    OpenAIRE

    Belanger, F. C.; Brodl, M R; Ho, T H

    1986-01-01

    In response to a phytohormone, gibberellic acid, the aleurone layers of barley seeds synthesize and secrete alpha-amylases, which are coded by a set of stable mRNAs. When aleurone layers are subjected to heat shock treatment, the synthesis of alpha-amylase is suppressed while heat shock proteins are induced. The suppression of alpha-amylase synthesis is not the result of translational control as reported in several other systems. Rather, the sequences of alpha-amylase mRNA are rapidly degrade...

  6. Multiple inducers of the Drosophila heat shock locus 93D (hsr omega): inducer-specific patterns of the three transcripts

    OpenAIRE

    1989-01-01

    The Drosophila hsr omega locus produces one of the largest and most active heat shock puffs, yet it does not encode a heat shock protein. Instead, this locus produces a distinctive set of three transcripts, all from the same start site. The largest transcript, omega 1, is limited to the nucleus and appears to have a role there. A second nuclear transcript, omega 2, is produced by alternative termination and contains the sequence found in the 5' 20-25% of omega 1 (depending on the Drosophila s...

  7. Effects of heat stress on serum insulin, adipokines, AMP-activated protein kinase, and heat shock signal molecules in dairy cows.

    Science.gov (United States)

    Min, Li; Cheng, Jian-bo; Shi, Bao-lu; Yang, Hong-jian; Zheng, Nan; Wang, Jia-qi

    2015-06-01

    Heat stress affects feed intake, milk production, and endocrine status in dairy cows. The temperature-humidity index (THI) is employed as an index to evaluate the degree of heat stress in dairy cows. However, it is difficult to ascertain whether THI is the most appropriate measurement of heat stress in dairy cows. This experiment was conducted to investigate the effects of heat stress on serum insulin, adipokines (leptin and adiponectin), AMP-activated protein kinase (AMPK), and heat shock signal molecules (heat shock transcription factor (HSF) and heat shock proteins (HSP)) in dairy cows and to research biomarkers to be used for better understanding the meaning of THI as a bioclimatic index. To achieve these objectives, two experiments were performed. The first experiment: eighteen lactating Holstein dairy cows were used. The treatments were: heat stress (HS, THI average=81.7, n=9) and cooling (CL, THI average=53.4, n=9). Samples of HS were obtained on August 16, 2013, and samples of CL were collected on April 7, 2014 in natural conditions. The second experiment: HS treatment cows (n=9) from the first experiment were fed for 8 weeks from August 16, 2013 to October 12, 2013. Samples for moderate heat stress, mild heat stress, and no heat stress were obtained, respectively, according to the physical alterations of the THI. Results showed that heat stress significantly increased the serum adiponectin, AMPK, HSF, HSP27, HSP70, and HSP90 (Pbiomarkers to supplement the THI and evaluate moderate heat stress in dairy cows in the future. PMID:26055916

  8. Astro fellowship project: heat shock proteins and apoptosis in prostate adenocarcinoma

    International Nuclear Information System (INIS)

    Purpose/Objective: A variety of metabolic stimuli including hyperthermia (HT), oxidative injury, heavy metal exposure, and serum deprivation induce the stress response, an array of cellular activities which include the expression of heat shock proteins (HSPs). HSPs represent one of the most conserved groups of proteins throughout evolution, and have been found in all organisms examined to date including plants and prokaryotes. The biological role of the HSPs is to function as molecular chaperones regulating the functions of other proteins by binding to them and modulating the function, transport, and folding state. In the clinic, HSPs may serve as markers for response to treatment. This study examines the role of heat shock protein 70 (HSP 70) in apoptosis using a p53 negative, androgen independent prostate adenocarcinoma cell line (PC-3). Materials and Methods: Prostate adenocarcinoma cells (PC-3) were grown as a monolayer in RPMI medium supplemented with 10% fetal bovine serum, glutamine, and penicillin/streptomycin, or as a solid subcutaneous tumor in nude mice. In vitro and in vivo hyperthermia treatments were delivered in a water bath. The ApodirectTM kit was used for TUNEL staining PC-3 cells grown as a monolayer. Following treatment, apoptotic cells detached from the petri dish, and were harvested from the media at several time points. After fixation in 1% paraformaldehyde, the free 3'-hydroxyl ends of internucleosomal DNA laddering fragments were labeled with fluroscein tagged deoxyuridine triphosphate (F-dUTP). Cells were also stained with propidium iodide for DNA content and analysed in a dual parameter flow cytometer. TUNEL staining of paraffin sections from tumors grown in vivo was also performed using biotin conjugated dUTP with avidin-alkaline phosphatase detection. RT-PCR was performed on total RNA extracts using an adaptation of the Perkin Elmer Gene Amp RNA kit. Random hexamer priming was used for cDNA synthesis, and gene specific primers

  9. Overly persistent circulation in climate models contributes to overestimated frequency and duration of heat waves and cold spells

    Czech Academy of Sciences Publication Activity Database

    Plavcová, Eva; Kyselý, Jan

    Göttingen: European Geosciences Union, 2016. EGU2016-5492. ISSN 1607-7962. [EGU General Assembly 2016. 17.04.2016-22.04.2016, Vienna] Institutional support: RVO:68378289 Keywords : summer heat waves * winter cold spells * Central Europe * atmospheric circulation Subject RIV: DG - Athmosphere Sciences, Meteorology http://meetingorganizer.copernicus.org/EGU2016/EGU2016-5492.pdf

  10. Non-lethal heat shock increased Hsp70 and immune protein transcripts but not Vibrio tolerance in the white-leg shrimp.

    Directory of Open Access Journals (Sweden)

    Nguyen Hong Loc

    Full Text Available Non-lethal heat shock boosts bacterial and viral disease tolerance in shrimp, possibly due to increases in endogenous heat shock protein 70 (Hsp70 and/or immune proteins. To further understand the mechanisms protecting shrimp against infection, Hsp70 and the mRNAs encoding the immune-related proteins prophenoloxidase (proPO, peroxinectin, penaeidin, crustin and hemocyanin were studied in post-larvae of the white-leg shrimp Litopenaeus vannamei, following a non-lethal heat shock. As indicated by RT-qPCR, a 30 min abrupt heat shock increased Hsp70 mRNA in comparison to non-heated animals. Immunoprobing of western blots and quantification by ELISA revealed that Hsp70 production after heat shock was correlated with enhanced Hsp70 mRNA. proPO and hemocyanin mRNA levels were augmented, whereas peroxinectin and crustin mRNA levels were unchanged following non-lethal heat shock. Penaeidin mRNA was decreased by all heat shock treatments. Thirty min abrupt heat shock failed to improve survival of post-larvae in a standardized challenge test with Vibrio harveyi, indicating that under the conditions of this study, L. vannamei tolerance to Vibrio infection was influenced neither by Hsp70 accumulation nor the changes in the immune-related proteins, observations dissimilar to other shrimp species examined.

  11. Shock-induced heating and millisecond boiling in gels and tissue due to high intensity focused ultrasound.

    Science.gov (United States)

    Canney, Michael S; Khokhlova, Vera A; Bessonova, Olga V; Bailey, Michael R; Crum, Lawrence A

    2010-02-01

    Nonlinear propagation causes high-intensity ultrasound waves to distort and generate higher harmonics, which are more readily absorbed and converted to heat than the fundamental frequency. Although such nonlinear effects have been investigated previously and found to not significantly alter high-intensity focused ultrasound (HIFU) treatments, two results reported here change this paradigm. One is that at clinically relevant intensity levels, HIFU waves not only become distorted but form shock waves in tissue. The other is that the generated shock waves heat the tissue to boiling in much less time than predicted for undistorted or weakly distorted waves. In this study, a 2-MHz HIFU source operating at peak intensities up to 25,000 W/cm(2) was used to heat transparent tissue-mimicking phantoms and ex vivo bovine liver samples. Initiation of boiling was detected using high-speed photography, a 20-MHz passive cavitation detector and fluctuation of the drive voltage at the HIFU source. The time to boil obtained experimentally was used to quantify heating rates and was compared with calculations using weak shock theory and the shock amplitudes obtained from nonlinear modeling and measurements with a fiber optic hydrophone. As observed experimentally and predicted by calculations, shocked focal waveforms produced boiling in as little as 3 ms and the time to initiate boiling was sensitive to small changes in HIFU output. Nonlinear heating as a result of shock waves is therefore important to HIFU, and clinicians should be aware of the potential for very rapid boiling because it alters treatments. PMID:20018433

  12. Plasma autoantibodies against heat shock protein 70, enolase 1 and ribonuclease/angiogenin inhibitor 1 as potential biomarkers for cholangiocarcinoma.

    Directory of Open Access Journals (Sweden)

    Rucksak Rucksaken

    Full Text Available The diagnosis of cholangiocarcinoma (CCA is often challenging, leading to poor prognosis. CCA arises via chronic inflammation which may be associated with autoantibodies production. This study aims to identify IgG antibodies directed at self-proteins and tumor-associated antigens. Proteins derived from immortalized cholangiocyte cell line (MMNK1 and CCA cell lines (M055, M214 and M139 were separated using 2-dimensional electrophoresis and incubated with pooled plasma of patients with CCA and non-neoplastic controls by immunoblotting. Twenty five immunoreactive spots against all cell lines-derived proteins were observed on stained gels and studied by LC-MS/MS. Among these, heat shock protein 70 (HSP70, enolase 1 (ENO1 and ribonuclease/angiogenin inhibitor 1 (RNH1 obtained the highest matching scores and were thus selected for further validation. Western blot revealed immunoreactivity against HSP70 and RNH1 in the majority of CCA cases and weakly in healthy individuals. Further, ELISA showed that plasma HSP70 autoantibody level in CCA was significantly capable to discriminate CCA from healthy individuals with an area under the receiver operating characteristic curve of 0.9158 (cut-off 0.2630, 93.55% sensitivity and 73.91% specificity. Plasma levels of IgG autoantibodies against HSP70 were correlated with progression from healthy individuals to cholangitis to CCA (r = 0.679, P<0.001. In addition, circulating ENO1 and RNH1 autoantibodies levels were also significantly higher in cholangitis and CCA compared to healthy controls (P<0.05. Moreover, the combinations of HSP70, ENO1 or RNH1 autoantibodies positivity rates improved specificity to over 78%. In conclusion, plasma IgG autoantibodies against HSP70, ENO1 and RNH1 may represent new diagnostic markers for CCA.

  13. Extracellular heat shock protein 90 binding to TGFβ receptor I participates in TGFβ-mediated collagen production in myocardial fibroblasts.

    Science.gov (United States)

    García, Raquel; Merino, David; Gómez, Jenny M; Nistal, J Francisco; Hurlé, María A; Cortajarena, Aitziber L; Villar, Ana V

    2016-10-01

    The pathological remodeling heart shows an increase in left ventricular mass and an excess of extracellular matrix deposition that can over time cause heart failure. Transforming growth factor β (TGFβ) is the main cytokine controlling this process. The molecular chaperone heat shock protein 90 (Hsp90) has been shown to play a critical role in TGFβ signaling by stabilizing the TGFβ signaling cascade. We detected extracellular Hsp90 in complex with TGFβ receptor I (TGFβRI) in fibroblasts and determined a close proximity between both proteins suggesting a potential physical interaction between the two at the plasma membrane. This was supported by in silico studies predicting Hsp90 dimers and TGFβRI extracellular domain interaction. Both, Hsp90aa1 and Hsp90ab1 isoforms participate in TGFβRI complex. Extracellular Hsp90 inhibition lessened the yield of collagen production as well as the canonical TGFβ signaling cascade, and collagen protein synthesis was drastically reduced in Hsp90aa1 KO mice. These observations together with the significant increase in activity of Hsp90 at the plasma membrane pointed to a functional cooperative partnership between Hsp90 and TGFβRI in the fibrotic process. We propose that a surface population of Hsp90 extracellularly binds TGFβRI and this complex behaves as an active participant in collagen production in TGFβ-activated fibroblasts. We also offer an in vivo insight into the role of Hsp90 and its isoforms during cardiac remodeling in murine aortic banding model suffering from pathological cardiac remodeling and detect circulating Hsp90 overexpressed in remodeling mice. PMID:27418101

  14. Clinical review: Influence of vasoactive and other therapies on intestinal and hepatic circulations in patients with septic shock

    OpenAIRE

    Asfar, Pierre; De Backer, Daniel; Meier-Hellmann, Andreas; Radermacher, Peter; Sakka, Samir G.

    2003-01-01

    The organs of the hepatosplanchnic system are considered to play a key role in the development of multiorgan failure during septic shock. Impaired oxygenation of the intestinal mucosa can lead to disruption of the intestinal barrier, which may promote a vicious cycle of inflammatory response, increased oxygen demand and inadequate oxygen supply. Standard septic shock therapy includes supportive treatment such as fluid resuscitation, administration of vasopressors (adrenergic and nonadrenergic...

  15. Identification and expression analysis of heat shock transcription factors in the wild Chinese grapevine (Vitis pseudoreticulata).

    Science.gov (United States)

    Hu, Yang; Han, Yong-Tao; Zhang, Kai; Zhao, Feng-Li; Li, Ya-Juan; Zheng, Yi; Wang, Yue-Jin; Wen, Ying-Qiang

    2016-02-01

    Heat shock transcription factors (Hsfs) are known to play pivotal roles in the adaptation of plants to heat stress and other stress stimuli. While grapevine (Vitis vinifera L.) is one of the most important fruit crops worldwide, little is known about the Hsf family in Vitis spp. Here, we identified nineteen putative Hsf genes (VviHsfs) in Vitis spp based on the 12 × grape genome (V. vinifera L.). Phylogenetic analysis revealed three classes of grape Hsf genes (classes A, B, and C). Additional comparisons between grape and Arabidopsis thaliana demonstrated that several VviHsfs genes occurred in corresponding syntenic blocks of Arabidopsis. Moreover, we examined the expression profiles of the homologs of the VviHsfs genes (VpHsfs) in the wild Chinese Vitis pseudoreticulata accession Baihe-35-1, which is tolerant to various environmental stresses. Among the nineteen VpHsfs, ten VpHsfs displayed lower transcript levels under non-stress conditions and marked up-regulation during heat stress treatment; several VpHsfs also displayed altered expression levels in response to cold, salt, and hormone treatments, suggesting their versatile roles in response to stress stimuli. In addition, eight VpHsf-GFP fusion proteins showed differential subcellular localization in V. pseudoreticulata mesophyll protoplasts. Taken together, our data may provide an important reference for further studies of Hsf genes in Vitis spp. PMID:26689772

  16. Exosomal Heat Shock Proteins as New Players in Tumour Cell-to-cell Communication

    Directory of Open Access Journals (Sweden)

    Claudia Campanella

    2014-06-01

    Full Text Available Exosomes have recently been proposed as novel elements in the study of intercellular communication in normal and pathological conditions. The biomolecular composition of exosomes reflects the specialized functions of the original cells. Heat shock proteins (Hsps are a group of chaperone proteins with diverse biological roles. In recent years, many studies have focused on the extracellular roles played by Hsps that appear to be involved in cancer development and immune system stimulation. Hsps localized on the surface of exosomes, secreted by normal and tumour cells, could be key players in intercellular cross-talk, particularly during the course of different diseases, such as cancer. Exosomal Hsps offer significant opportunities for clinical applications, including their use as potential novel biomarkers for the diagnoses or prognoses of different diseases, or for therapeutic applications and drug delivery.

  17. AuNPs modified, disposable, ITO based biosensor: Early diagnosis of heat shock protein 70.

    Science.gov (United States)

    Sonuç Karaboğa, Münteha Nur; Şimşek, Çiğdem Sayıklı; Sezgintürk, Mustafa Kemal

    2016-10-15

    This paper describes a novel, simple, and disposable immunosensor based on indium-tin oxide (ITO) sheets modified with gold nanoparticles to sensitively analyze heat shock protein 70 (HSP70), a potential biomarker that could be evaluated in diagnosis of some carcinomas. Disposable ITO coated Polyethylene terephthalate (PET) electrodes were used and modified with gold nanoparticles in order to construct the biosensors. Optimization and characterization steps were analyzed by electrochemical techniques such as electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). Surface morphology of the biosensor was also identified by electrochemical methods, scanning electron microscopy (SEM), and atomic force microscopy (AFM). To interpret binding characterization of HSP70 to anti-HSP70 single frequency impedance method was successfully operated. Moreover, the proposed HSP70 immunosensor acquired good stability, repeatability, and reproducibility. Ultimately, proposed biosensor was introduced to real human serum samples to determine HSP70 sensitively and accurately. PMID:26318579

  18. Modulation of heat shock protein response in SH-SY5Y by mobile phone microwaves

    Institute of Scientific and Technical Information of China (English)

    Emanuele; Calabrò; Salvatore; Condello; Monica; Currò; Nadia; Ferlazzo; Daniela; Caccamo; Salvatore; Magazù; Riccardo; Ientile

    2012-01-01

    AIM: To investigate putative biological damage caused by GSM mobile phone frequencies by assessing electromagnetic fields during mobile phone working. METHODS: Neuron-like cells, obtained by retinoicacid-induced differentiation of human neuroblastoma SH-SY5Y cells, were exposed for 2 h and 4 h to microwaves at 1800 MHz frequency bands. RESULTS: Cell stress response was evaluated by MTT assay as well as changes in the heat shock protein expression (Hsp20, Hsp27 and Hsp70) and caspase-3 activity levels, as biomarkers of apoptotic pathway. Under our experimental conditions, neither cell viability nor Hsp27 expression nor caspase-3 activity was significantly changed. Interestingly, a significant decrease in Hsp20 expression was observed at both times of exposure, whereas Hsp70 levels were significantly increased only after 4 h exposure. CONCLUSION: The modulation of the expression of Hsps in neuronal cells can be an early response to radiofrequency microwaves.

  19. Management of the endoplasmic reticulum stress by activation of the heat shock response in yeast

    DEFF Research Database (Denmark)

    Hou, Jin; Tang, Hongting; Liu, Zihe;

    2014-01-01

    In yeast Saccharomyces cerevisiae, accumulation of misfolded proteins in the endoplasmic reticulum (ER) causes ER stress and activates the unfolded protein response (UPR), which is mediated by Hac1p. The heat shock response (HSR) mediated by Hsf1p, mainly regulates cytosolic processes and protects......-wide transcriptional response in order to propose regulatory mechanisms that govern the interplay between UPR and HSR and followed up for the hypotheses by experiments in vivo and in vitro. Interestingly, we found that the regulation of ER stress response via HSR is (1) only partially dependent on over-expression of...... Kar2p (ER resident chaperone induced by ER stress); (2) does not involve the increase in protein turnover via the proteasome activity; (3) is related to the oxidative stress response. From the transcription data, we also propose that HSR enhances ER stress resistance mainly through facilitation of...

  20. Heat shock protein translocation and expression response is attenuated in response to repeated eccentric exercise

    DEFF Research Database (Denmark)

    Vissing, K.; Bayer, M.L.; Overgaard, K.;

    2009-01-01

    This study hypothesized that heat shock protein (HSP) translocation and upregulation is more probable to occur after eccentric exercise than after concentric exercise or repeated eccentric exercise. Fourteen young, healthy, untrained male subjects completed two bench-stepping exercise bouts with 8...... cytoskeletal protein fractions. The first bout of exercise reduced muscle strength and increased muscle soreness predominantly in the eccentric leg (P < 0.05). These responses were attenuated after the repeated eccentric exercise bout (P < 0.05), suggesting a repeated bout adaptation. Increases in inducible...... eccentric exercise bout. Our results show that HSP translocation and expression responses are induced by muscle damaging exercise, and suggest that such HSP responses are closely related to the extent of muscle damage Udgivelsesdato: 2009/7...

  1. Effect of TBBPA and EE2 on expression of mouse testicular heat shock proteins in vivo

    Czech Academy of Sciences Publication Activity Database

    Žatecká, Eva; Děd, Lukáš; Elzeinová, Fatima; Kubátová, Alena; Dorosh, Andriy; Dostálová, Pavla; Pěknicová, Jana

    Praha : Biotechnologický ústav v.v AVČR, 2010. s. 56-57. [XVI. symposium českých reprodukčních imunologů s mezinárodní účastí. 28.05.2010-30.05.2010, Žďár nad Sázavou] R&D Projects: GA MŠk(CZ) 1M06011; GA ČR(CZ) GA523/08/H064; GA ČR(CZ) GA523/09/1793 Institutional research plan: CEZ:AV0Z50520701 Keywords : Tetrabromobisphenol A * 17alpha-ethinylestradiol * Heat shock protein Subject RIV: EB - Genetics ; Molecular Biology

  2. Heat Shock Protein 90 and Role of Its Chemical Inhibitors in Treatment of Hematologic Malignancies

    Directory of Open Access Journals (Sweden)

    Haojian Zhang

    2012-07-01

    Full Text Available Heat shock protein 90 (Hsp90 is a conserved and constitutively expressed molecular chaperone and it has been shown to stabilize oncoproteins and facilitate cancer development. Hsp90 has been considered as a therapeutic target for cancers and three classes of Hsp90 inhibitors have been developed: (1 benzoquinone ansamycin and its derivatives, (2 radicicol and its derivates, and (3 small synthetic inhibitors. The roles of these inhibitors in cancer treatment have been studied in laboratories and clinical trials, and some encouraging results have been obtained. Interestingly, targeting of Hsp90 has been shown to be effective in inhibition of cancer stem cells responsible for leukemia initiation and progression, providing a strategy for finding a cure. Because cancer stem cells are well defined in some human leukemias, we will focus on hematologic malignancies in this review.

  3. Members of the heat-shock protein 70 family promote cancer cell growth by distinct mechanisms

    DEFF Research Database (Denmark)

    Rohde, Mikkel; Daugaard, Mads; Jensen, Mette Hartvig;

    2005-01-01

    Whereas the stress-inducible heat-shock protein 70 (Hsp70) has gained plenty of attention as a putative target for tumor therapy, little is known about the role of other Hsp70 proteins in cancer. Here we present the first thorough analysis of the expression and function of the cytosolic Hsp70...... survival of tumorigenic as well as nontumorigenic cells depended on Hsc70. Cancer cells depleted for Hsp70 and Hsp70-2 displayed strikingly different morphologies (detached and round vs. flat senescent-like), cell cycle distributions (G2/M vs. G1 arrest) and gene expression profiles. Only Hsp70-2 depletion...... proteins in human cancer cells and identify Hsp70-2, a protein essential for spermatogenesis, as an important regulator of cancer cell growth. Targeted knock-down of the individual family members by RNA interference revealed that both Hsp70 and Hsp70-2 were required for cancer cell growth, whereas the...

  4. Effects of heat shock protein gp96 on human dendritic cell maturation and CTL expansion.

    Science.gov (United States)

    Zhang, Yuxia; Zan, Yanlu; Shan, Ming; Liu, Changmei; Shi, Ming; Li, Wei; Zhang, Zhixin; Liu, Na; Wang, Fusheng; Zhong, Weidong; Liao, Fulian; Gao, George F; Tien, Po

    2006-06-01

    We reported previously that heat shock protein gp96 and its N-terminal fragment were able to stimulate CTL expansion specific for a HBV peptide (SYVNTNMGL) in BALB/c mice. Here we characterized the adjuvant effects of gp96 on human HLA-A2 restricted T cells. Full-length gp96 isolated from healthy human liver and recombinant fragments both from prokaryotic cells and eukaryotic cells were analyzed for their ability to stimulate maturation of human dendritic cells. It was found that in vitro these proteins were capable of maturating human monocyte-derived dendritic cells (MDDC) isolated from healthy donors as well as from HBV-positive, hepatocellular carcinoma (HCC) patients. In HLA-A2.1/Kb transgenic mice, gp96 and the recombinant fragments were found to augment CTL response specific for the HBcAg(18-27) FLPSDFFPSV peptide of hepatitis B virus. PMID:16630554

  5. Sequence characterization of heat shock protein gene of Cyclospora cayetanensis isolates from Nepal, Mexico, and Peru.

    Science.gov (United States)

    Sulaiman, Irshad M; Torres, Patricia; Simpson, Steven; Kerdahi, Khalil; Ortega, Ynes

    2013-04-01

    We have described the development of a 2-step nested PCR protocol based on the characterization of the 70-kDa heat shock protein (HSP70) gene for rapid detection of the human-pathogenic Cyclospora cayetanensis parasite. We tested and validated these newly designed primer sets by PCR amplification followed by nucleotide sequencing of PCR-amplified HSP70 fragments belonging to 16 human C. cayetanensis isolates from 3 different endemic regions that include Nepal, Mexico, and Peru. No genetic polymorphism was observed among the isolates at the characterized regions of the HSP70 locus. This newly developed HSP70 gene-based nested PCR protocol provides another useful genetic marker for the rapid detection of C. cayetanensis in the future. PMID:22924935

  6. Regulatory effect of heat shock protein 70 in stress-induced rat intestinal epithelial barrier dysfunction

    Directory of Open Access Journals (Sweden)

    Stevie Struiksma

    2009-06-01

    Full Text Available Background: Psychological stress is one of the factors associated with many human diseases; the mechanisms need to be further understood. Methods: Rats were subjected to chronic water avoid stress. Intestinal epithelial heat shock protein (HSP 70 was evaluated. The intestinal epithelial permeability was examined with Ussing chamber technique. Results: HSP70 was detected in normal intestinal epithelial cells. Psychological stress decreased HSP70 in the intestinal epithelial cells that correlated with the stress-induced intestinal epithelial hyperpermeability. Pretreatment with HSP70 abrogated stress-induced intestinal barrier dysfunction. Conclusions: Chronic stress inhibits HSP70 activity in rat intestinal epithelial layer that is associated with intestinal epithelial barrier dysfunction, which can be prevented by pretreatment with HSP70 protein.

  7. Large carbon cluster thin film gauges for measuring aerodynamic heat transfer rates in hypersonic shock tunnels

    International Nuclear Information System (INIS)

    Different types of Large Carbon Cluster (LCC) layers are synthesized by a single-step pyrolysis technique at various ratios of precursor mixture. The aim is to develop a fast responsive and stable thermal gauge based on a LCC layer which has relatively good electrical conduction in order to use it in the hypersonic flow field. The thermoelectric property of the LCC layer has been studied. It is found that these carbon clusters are sensitive to temperature changes. Therefore suitable thermal gauges were developed for blunt cone bodies and were tested in hypersonic shock tunnels at a flow Mach number of 6.8 to measure aerodynamic heating. The LCC layer of this thermal gauge encounters high shear forces and a hostile environment for test duration in the range of a millisecond. The results are favorable to use large carbon clusters as a better sensor than a conventional platinum thin film gauge in view of fast responsiveness and stability. (paper)

  8. AN EXPERIMENTAL STUDY ON THE INDUCTION MECHANISM OF SUPEROXIDE DISMUTASE IN CULTURED CARDIOMYOCYTES DURING HEAT SHOCK

    Institute of Scientific and Technical Information of China (English)

    朱洪生; 王胜; 沈莉; 谢芳; 魏丕敬

    2000-01-01

    Objective To explore the role of reaction oxygen species (ROS) in heat shock (HS) on the tolerance of cardiomyocytes to anoxia - reoxygenation (AO - RO) injury and on the activity of superoxide dismutase (SOD).Methods Cultured neonatal myocytes of rats were divided into 5 groups: normal control, anoxic control, HS,HS- SOD pretreated and exogenous ROS pretreated (n= 6). Results Compared with the 2 control groups, ROS release in HS and ROS pretreated groups increased mildly, but after experiencing 3h anoxia/lh reoxygenation 24hlater, ROS release of the two groups decreased significantly, which was accompanied by enhanced SOD activities and less myocytes damage. Opposite results were found when SOD was insituted during HS. Conclusion HS did enhance myocardial tolerance to AO-RO injury. The mild release of ROS during HS may trigger delayed myocardial protection by altering SOD activity.

  9. Fast electron divergence and transport in laser-driven shock heated warm dense matter

    International Nuclear Information System (INIS)

    Understanding of fast electron source and transport is important for Fast Ignition Inertial Confinement Fusion. Particularly, a detailed investigation of fast electron transport in warm/hot dense matter is important pertinent to fast ignition conditions. We have performed experiments on the Titan laser at LLNL and OMEGA EP laser at LLE to investigate electron source and transport into warm dense matter (WDM) with varying densities and temperatures. On the Titan laser, WDM was created by a long laser pulse (300 J, 3 ns, 600 µm spot) driven shock compression and heating of the low-density foam with initial mass density of 150 mg/cm3. At its maximum compression, a low-Z WDM with approximately solid density and temperature of 5-10 eV was assembled beneath the Au foil. Transport of the high intensity laser (150 J, 0.7 ps, Ipeak∼1020 W/cm2) produced relativistic electrons from the Au foil (mimics the tip of the cone) through WDM, was characterized by measuring the K-shell x-ray emission from the Cu fluorescence layer. A large angular spread (>100°) of fast electrons is observed in the 2D spatial profiles of the Ka emission when fast electrons transport into WDM. In addition, 5x increase in the number of escaped electrons at a large off-normal angle is seen compared to a case with 15 µm thick solid CH insulator as the transport medium, consistent with the observed large angular spread. Collisional PIC simulations including dynamic ionization using the PICLS [1] code suggest that the large angular spread is caused by the deformation of the laser plasma interaction surface due to high laser ponderomotive pressure. The large source divergence is observed to be suppressed by the self-generated fields at the ionization wave front when electrons propagate in the insulator medium. On OMEGA EP, a series of shots have been carried out to, i) characterize the plasma and ii) to study fast electron transport in a large volume of warm dense plasma, which was created by shock

  10. The expression patterns of heat shock genes and proteins and their role during vertebrate's development.

    Science.gov (United States)

    Rupik, Weronika; Jasik, Krzysztof; Bembenek, Jadwiga; Widłak, Wiesława

    2011-08-01

    Highly evolutionary conserved heat shock proteins (HSPs) act as molecular chaperones in regulation of cellular homeostasis and promoting survival. Generally they are induced by a variety of stressors whose effect could be disastrous on the organism, but they are also widely constitutively expressed in the absence of stress. Varied HSP expressions seem to be very essential in the critical steps of embryonic and extra-embryonic structures formation and may correspond to cell movements, proliferation, morphogenesis and apoptosis, which occur during embryonic development. While our knowledge of detailed HSP expression patterns is in constant progress, their functions during embryonic development are not yet fully understood. In the paper, we review available data on HSP expression and discuss their role during vertebrate development. PMID:21527352

  11. Heat shock protein 70 chaperoned alpha-fetoprotein in human hepatocellular carcinoma cell line BEL-7402

    Institute of Scientific and Technical Information of China (English)

    Xiao-Ping Wang; Qiao-Xia Wang; Hai-Yan Li; Rui-Fen Chen

    2005-01-01

    AIM: To investigate the interaction between heat shock protein 70 (HSP70) and α-fetoprotein (AFP) in human hepatocellular carcinoma (HCC) cell line BEL7402.METHODS: The expression and localization of HSP70 and AFP in human HCC cell line BEL-7402 were determined by immunocytochemistry and indirect immunofluorescence cytochemical staining. The interaction between HSP70 and AFP in HCC cells was analyzed by immunoprecipitation and Western blot.RESULTS: Immunocytochemical staining detection showed that HCC cell BEL-7402 expressed a high level of HSP70 and AFP synchronously. Both were stained in cell plasma.AFP existed in the immunoprecipitate of anti-HSP70 mAb,while there was HSP70 in the immunoprecipitate of antiAFP mAb.CONCLUSION: HSP70 chaperones AFP in human HCCcell BEL-7402. The interaction between HSP70 and AFP in human HCC cell can be a new route to study the pathogenesis and immunotherapy of HCC.

  12. Effect of sequential heat and cold shocks on nuclear phenotypes of the blood-sucking insect, Panstrongylus megistus (Burmeister (Hemiptera, Reduviidae

    Directory of Open Access Journals (Sweden)

    Garcia Simone L

    2002-01-01

    Full Text Available Thermal shocks induce changes in the nuclear phenotypes that correspond to survival (heterochromatin decondensation, nuclear fusion or death (apoptosis, necrosis responses in the Malpighian tubules of Panstrongylus megistus. Since thermal tolerance increased survival and molting rate in this species following sequential shocks, we investigated whether changes in nuclear phenotypes accompanied the insect survival response to sequential thermal shocks. Fifth instar nymphs were subjected to a single heat (35 or 40°C, 1 h or cold (5 or 0°C, 1 h shock and then subjected to a second shock for 12 h at 40 or 0°C, respectively, after 8, 18, 24 and 72 h at 28°C (control temperature. As with specimen survival, sequential heat and cold shocks induced changes in frequency of the mentioned nuclear phenotypes although their patterns differed. The heat shock tolerance involved decrease in apoptosis simultaneous to increase in cell survival responses. Sequential cold shocks did not involve cell/nuclear fusion and even elicited increase in necrosis with advancing time after shocks. The temperatures of 40 and 0ºC were more effective than the temperatures of 35 and 5ºC in eliciting the heat and cold shock tolerances, respectively, as shown by cytological analysis of the nuclear phenotypes. It is concluded that different sequential thermal shocks can trigger different mechanisms of cellular protection against stress in P. megistus, favoring the insect to adapt to various ecotopes.

  13. Detailed Design of the Safety Residual Heat Removal System and a Circulation Pump for the KIJANG Research Reactor

    International Nuclear Information System (INIS)

    Primary cooling system (PCS) circulates the coolant from the reactor core to the heat exchanger. Therefore the heat generated from the fuel assembly in the reactor core is removed continuously. The PCS is designed based on the required thermal design flow rate of the reactor core, uncertainty of measuring instruments and the safe functions. Primary coolant is generally dumped into the pool and goes to the reactor core through the flow guide. The fission heat generated from the fuel assembly is transferred to the coolant, and then heated coolant goes to the PCS equipment room in order to remove the heat through the heat exchanger. SRHSR is designed based on the required flow rate and system constraints. Centrifugal pump of Case 1 with a non-dimensional specific speed of 0.97 [-] and specific diameter of 3.33 [-] is chosen as the SRHRS pump for the KJRR

  14. Detailed Design of the Safety Residual Heat Removal System and a Circulation Pump for the KIJANG Research Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Hyungi; Seo, Kyoungwoo; Kim, Seonghoon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    Primary cooling system (PCS) circulates the coolant from the reactor core to the heat exchanger. Therefore the heat generated from the fuel assembly in the reactor core is removed continuously. The PCS is designed based on the required thermal design flow rate of the reactor core, uncertainty of measuring instruments and the safe functions. Primary coolant is generally dumped into the pool and goes to the reactor core through the flow guide. The fission heat generated from the fuel assembly is transferred to the coolant, and then heated coolant goes to the PCS equipment room in order to remove the heat through the heat exchanger. SRHSR is designed based on the required flow rate and system constraints. Centrifugal pump of Case 1 with a non-dimensional specific speed of 0.97 [-] and specific diameter of 3.33 [-] is chosen as the SRHRS pump for the KJRR.

  15. Prophylactic Antitumor Effect of Mixed Heat Shock Proteins/Peptides in Mouse Sarcoma

    Institute of Scientific and Technical Information of China (English)

    Yu Wang; Shu-Yun Liu; Mei Yuan; Yu Tang; Quan-Yi Guo; Xue-Mei Cui; Xiang Sui

    2015-01-01

    Background:To develop a vaccine-based immunotherapy for sarcoma,we evaluated a mixture of heat shock proteins (mHSPs) as a vaccine for sarcoma treatment in a mouse model.Heat shock protein/peptides (HSP/Ps) are autoimmune factors that can induce both adaptive and innate immune responses;HSP/Ps isolated from tumors can induce antitumor immune activity when used as vaccines.Methods:In this study,we evaluated the effects of mHSP/Ps on prophylactic antitumor immunity.We extracted mHSP/Ps,including HSP60,HSP70,GP96,and HSP l 10,from the mouse sarcoma cell lines S 180 and MCA207 using chromatography.The immunity induced by mHSP/Ps was assessed using flow cytometry,ELISPOT,lactate dehydrogenase release,and enzyme-linked immunosorbent assay.Results:Of S180 sarcoma-beating mice immunized with mHSP/Ps isolated from S180 cells,41.2% showed tumor regression and long-term survival,with a tumor growth inhibition rate of 82.3% at 30 days.Of MCA207 sarcoma-bearing mice immunized with mHSP/Ps isolated from MCA207 cells,50% showed tumor regression and long-term survival with a tumor growth inhibition rate of 79.3%.All control mice died within 40 days.The proportions of natural killer cells,CD8+,and interferon-γ-secreting cells and tumor-specific cytotoxic T-lymphocyte activity were increased in the immunized group.Conclusions:Vaccination with a polyvalent mHSP/P cancer vaccine can induce an immunological response and a marked antitumor response to autologous tumors.This mHSP/P vaccine exerted greater antitumor effects than did HSPT0,HSP60,or tumor lysates alone.

  16. Deciphering human heat shock transcription factor 1 regulation via post-translational modification in yeast.

    Directory of Open Access Journals (Sweden)

    Liliana Batista-Nascimento

    Full Text Available Heat shock transcription factor 1 (HSF1 plays an important role in the cellular response to proteotoxic stresses. Under normal growth conditions HSF1 is repressed as an inactive monomer in part through post-translation modifications that include protein acetylation, sumoylation and phosphorylation. Upon exposure to stress HSF1 homotrimerizes, accumulates in nucleus, binds DNA, becomes hyper-phosphorylated and activates the expression of stress response genes. While HSF1 and the mechanisms that regulate its activity have been studied for over two decades, our understanding of HSF1 regulation remains incomplete. As previous studies have shown that HSF1 and the heat shock response promoter element (HSE are generally structurally conserved from yeast to metazoans, we have made use of the genetically tractable budding yeast as a facile assay system to further understand the mechanisms that regulate human HSF1 through phosphorylation of serine 303. We show that when human HSF1 is expressed in yeast its phosphorylation at S303 is promoted by the MAP-kinase Slt2 independent of a priming event at S307 previously believed to be a prerequisite. Furthermore, we show that phosphorylation at S303 in yeast and mammalian cells occurs independent of GSK3, the kinase primarily thought to be responsible for S303 phosphorylation. Lastly, while previous studies have suggested that S303 phosphorylation represses HSF1-dependent transactivation, we now show that S303 phosphorylation also represses HSF1 multimerization in both yeast and mammalian cells. Taken together, these studies suggest that yeast cells will be a powerful experimental tool for deciphering aspects of human HSF1 regulation by post-translational modifications.

  17. Heat shock transcription factor 1-deficiency attenuates overloading-associated hypertrophy of mouse soleus muscle.

    Directory of Open Access Journals (Sweden)

    Tomoyuki Koya

    Full Text Available Hypertrophic stimuli, such as mechanical stress and overloading, induce stress response, which is mediated by heat shock transcription factor 1 (HSF1, and up-regulate heat shock proteins (HSPs in mammalian skeletal muscles. Therefore, HSF1-associated stress response may play a key role in loading-associated skeletal muscle hypertrophy. The purpose of this study was to investigate the effects of HSF1-deficiency on skeletal muscle hypertrophy caused by overloading. Functional overloading on the left soleus was performed by cutting the distal tendons of gastrocnemius and plantaris muscles for 4 weeks. The right muscle served as the control. Soleus muscles from both hindlimbs were dissected 2 and 4 weeks after the operation. Hypertrophy of soleus muscle in HSF1-null mice was partially inhibited, compared with that in wild-type (C57BL/6J mice. Absence of HSF1 partially attenuated the increase of muscle wet weight and fiber cross-sectional area of overloaded soleus muscle. Population of Pax7-positive muscle satellite cells in HSF1-null mice was significantly less than that in wild-type mice following 2 weeks of overloading (p<0.05. Significant up-regulations of interleukin (IL-1β and tumor necrosis factor mRNAs were observed in HSF1-null, but not in wild-type, mice following 2 weeks of overloading. Overloading-related increases of IL-6 and AFT3 mRNA expressions seen after 2 weeks of overloading tended to decrease after 4 weeks in both types of mice. In HSF1-null mice, however, the significant overloading-related increase in the expression of IL-6, not ATF3, mRNA was noted even at 4th week. Inhibition of muscle hypertrophy might be attributed to the greater and prolonged enhancement of IL-6 expression. HSF1 and/or HSF1-mediated stress response may, in part, play a key role in loading-induced skeletal muscle hypertrophy.

  18. Osmotic stress stimulates phosphorylation and cellular expression of heat shock proteins in rhesus macaque sperm.

    Science.gov (United States)

    Cole, Julie A; Meyers, Stuart A

    2011-01-01

    The cryosurvival of sperm requires cell signaling mechanisms to adapt to anisotonic conditions during the freezing and thawing process. Chaperone proteins heat shock protein 70 (HSP 70) and heat shock protein 90 (HSP 90; recently renamed HSPA and HSPC, respectively) facilitate some of these cell signaling events in somatic cells. Sperm were evaluated for their cellular expression and levels of phosphorylation of both HSP 70 and HSP 90 under anisotonic conditions as a potential model for cell signaling during the cryopreservation of macaque spermatozoa. In order to monitor the level of stress, the motility and viability parameters were evaluated at various time points. Cells were then either prepared for phosphoprotein enrichment or indirect immunocytochemistry. As controls, the phosphoserine, phosphothreonine, and phosphotyrosine levels were measured under capacitation and cryopreservation conditions and were compared with the phosphoprotein levels expressed under osmotic conditions. As expected, there was an increase in the level of tyrosine phosphorylation under capacitation and cryopreservation conditions. There was also a significant increase in the level of all phosphoproteins under hyperosmotic conditions. There was no change in the level of expression of HSP 70 or 90 under osmotic stress conditions as measured by Western blot. The enrichment of phosphoproteins followed by Western immunoblotting revealed an increase in the phosphorylation of HSP 70 but not HSP 90 under osmotic stress conditions. Indirect immunofluorescence localized HSP 70 to the postacrosomal region of sperm, and the level of membrane expression of HSP 70 was significantly affected by anisotonic conditions, as measured by flow cytometry. Taken together, these results suggest a differential role for HSP 70 and HSP 90 during osmotic stress conditions in rhesus macaque sperm. PMID:21088232

  19. A sexual dimorphism influences bicyclol-induced hepatic heat shock factor 1 activation and hepatoprotection.

    Science.gov (United States)

    Chen, Xiaosong; Zhang, Jianjian; Han, Conghui; Dai, Huijuan; Kong, Xianming; Xu, Longmei; Xia, Qiang; Zhang, Ming; Zhang, Jianjun

    2015-07-01

    Bicyclol [4,4'-dimethoxy-5,6,5',6'-bis(methylenedioxy)-2-hydroxy-methyl-2'-methoxycarbonyl biphenyl] is a synthetic hepatoprotectant widely used in clinical practice, but resistance to this treatment is often observed. We found that the hepatoprotective effect of bicyclol was greatly compromised in female and castrated male mice. This study was to dissect the molecular basis behind the sex difference, which might underlie the clinical uncertainty. We compared bicyclol-induced hepatoprotection between male and female mice using acute liver damage models. Inducible knockout by the Cre/loxp system was used to decipher the role of heat shock transcription factor 1 (HSF1). Functional experiments, western blot, and histopathological analysis were used to determine the key causative factors which might antagonize bicyclol in female livers. HSF1 activation and heat shock protein 70 (Hsp70) expression, which were responsible for bicyclol-induced hepatoprotection, were compromised in female and castrated male livers. Compromised HSF1 activation was a result of HSF1 phosphorylation at serine 303, which was catalyzed by glycogen synthase kinase 3β (GSK3β). Testosterone was necessary for bicyclol to inhibit hepatic GSK3β activity. Administration of testosterone or GSK3β inhibitors restored bicyclol-induced protection in females. Bicyclol induces sex-specific hepatoprotection based on a sex-specific HSF1/Hsp70 response, in which testosterone and GSK3β play key roles. Because a lot of patients suffering from liver diseases have very low testosterone levels, our results give a possible explanation for the clinical variation in bicyclol-induced hepatoprotection, as well as practicable solutions to improve the effect of bicyclol. PMID:25901028

  20. Ultrastructural effects of heat shock and ionizing radiation on leaf cells of winter wheat

    International Nuclear Information System (INIS)

    Full text: The effects of heat shock (HS) and gamma-radiation (GR) on mesophyll ultrastructure of the first leaf of etiolated 5-day winter wheat seedlings (Triticum aestivum L.) were studied. Two hours after the HS considerable changes in cell ultrastructure were noted. Nuclei were lociniate-shaped as a result of invagination of nuclear membranes, with condensed chromatin. Some nuclei with particularly damaged membranes were present. Etioplasts took rounded shape and were situated next to cell walls in close contact with each other. The distance between the inner membranes, as well as a number of the electron-light vesicles were increased, with electron-dense plastoglobules and large starch grains clearly visible. The majority of mitochondria were smaller than in the control cells, had well-defined cristae and were in contact with plastids and nuclei. Rough endoplasmic reticulum was well developed, which could indicate protein synthesis taking place. Considerable increase in cell wall density was noted. GR (dose 100 Gy, 4 hours following irradiation) caused less considerable changes of cell ultrastructure. Nuclei took lociniate-shape, nuclear chromatin had small-grained structure. Some etioplasts changed their shape. Plastoglobules, as well as large starch grains in the stroma of most etioplasts, were well visible. Mitochondria were in close contact with etioplasts, nuclei, and with each other. Endoplasmic reticulum was well developed but with ribosomes covering the membrane surface less densely compared to cells exposed to HS. The obtained data allowed to conclude that ultrastructure of all studied organelles was changing during 2 h after heat shock. These changes could be either the result of cell damage or adaptation mechanisms. In contrast, a relatively short time interval (4 hours) after exposure to gamma-radiation (dose 100 Gy), was shown to be insufficient for the development of cellular ultrastructural changes

  1. Mild electrical stimulation with heat shock ameliorates insulin resistance via enhanced insulin signaling.

    Directory of Open Access Journals (Sweden)

    Saori Morino

    Full Text Available Low-intensity electrical current (or mild electrical stimulation; MES influences signal transduction and activates phosphatidylinositol-3 kinase (PI3K/Akt pathway. Because insulin resistance is characterized by a marked reduction in insulin-stimulated PI3K-mediated activation of Akt, we asked whether MES could increase Akt phosphorylation and ameliorate insulin resistance. In addition, it was also previously reported that heat shock protein 72 (Hsp72 alleviates hyperglycemia. Thus, we applied MES in combination with heat shock (HS to in vitro and in vivo models of insulin resistance. Here we show that 10-min treatment with MES at 5 V (0.1 ms pulse duration together with HS at 42 degrees C increased the phosphorylation of insulin signaling molecules such as insulin receptor substrate (IRS and Akt in HepG2 cells maintained in high-glucose medium. MES (12 V+mild HS treatment of high fat-fed mice also increased the phosphorylation of insulin receptor beta subunit (IRbeta and Akt in mice liver. In high fat-fed mice and db/db mice, MES+HS treatment for 10 min applied twice a week for 12-15 weeks significantly decreased fasting blood glucose and insulin levels and improved insulin sensitivity. The treated mice showed significantly lower weight of visceral and subcutaneous fat, a markedly improved fatty liver and decreased size of adipocytes. Our findings indicated that the combination of MES and HS alleviated insulin resistance and improved fat metabolism in diabetes mouse models, in part, by enhancing the insulin signaling pathway.

  2. 14-3-3σ induces heat shock protein 70 expression in hepatocellular carcinoma

    International Nuclear Information System (INIS)

    14-3-3σ is implicated in promoting tumor development of various malignancies. However, the clinical relevance of 14-3-3σ in hepatocellular carcinoma (HCC) tumor progression and modulation and pathway elucidation remain unclear. We investigated 14-3-3σ expression in 109 HCC tissues by immunohistochemistry. Overexpression and knockdown experiments were performed by transfection with cDNA or siRNA. Protein expression and cell migration were determined by Western blot and Boyden chamber assay. In this study, we found that 14-3-3σ is abundantly expressed in HCC tumors. Stable or transient overexpression of 14-3-3σ induces the expression of heat shock factor-1α (HSF-1α) and heat shock protein 70 (HSP70) in HCC cells. Moreover, expression of 14-3-3σ significantly correlates with HSF-1α/HSP70 in HCC tumors and both 14-3-3σ and HSP70 overexpression are associated with micro-vascular thrombi in HCC patients, suggesting that 14-3-3σ/HSP70 expression is potentially involved in cell migration/invasion. Results of an in vitro migration assay indicate that 14-3-3σ promotes cell migration and that 14-3-3σ-induced cell migration is impaired by siRNA knockdown of HSP70. Finally, 14-3-3σ-induced HSF-1α/HSP70 expression is abolished by the knockdown of β-catenin or activation of GSK-3β. Our findings indicate that 14-3-3σ participates in promoting HCC cell migration and tumor development via β-catenin/HSF-1α/HSP70 pathway regulation. Thus, 14-3-3σ alone or combined with HSP70 are potential prognostic biomarkers for HCC

  3. Core temperatures during major abdominal surgery in patients warmed with new circulating-water garment, forced-air warming, or carbon-fiber resistive-heating system

    OpenAIRE

    Hasegawa, Kenji; Negishi, Chiharu; Nakagawa, Fumitoshi; Ozaki, Makoto

    2011-01-01

    Purpose It has been reported that recently developed circulating-water garments transfer more heat than a forced-air warming system. The authors evaluated the hypothesis that circulating-water leg wraps combined with a water mattress better maintain intraoperative core temperature ≥36°C than either forced-air warming or carbon-fiber resistive heating during major abdominal surgery. Methods Thirty-six patients undergoing open abdominal surgery were randomly assigned to warming with: (1) circul...

  4. The Stress Granule RNA-Binding Protein TIAR-1 Protects Female Germ Cells from Heat Shock in Caenorhabditis elegans

    Directory of Open Access Journals (Sweden)

    Gabriela Huelgas-Morales

    2016-04-01

    Full Text Available In response to stressful conditions, eukaryotic cells launch an arsenal of regulatory programs to protect the proteome. One major protective response involves the arrest of protein translation and the formation of stress granules, cytoplasmic ribonucleoprotein complexes containing the conserved RNA-binding proteins TIA-1 and TIAR. The stress granule response is thought to preserve mRNA for translation when conditions improve. For cells of the germline—the immortal cell lineage required for sexual reproduction—protection from stress is critically important for perpetuation of the species, yet how stress granule regulatory mechanisms are deployed in animal reproduction is incompletely understood. Here, we show that the stress granule protein TIAR-1 protects the Caenorhabditis elegans germline from the adverse effects of heat shock. Animals containing strong loss-of-function mutations in tiar-1 exhibit significantly reduced fertility compared to the wild type following heat shock. Analysis of a heat-shock protein promoter indicates that tiar-1 mutants display an impaired heat-shock response. We observed that TIAR-1 was associated with granules in the gonad core and oocytes during several stressful conditions. Both gonad core and oocyte granules are dynamic structures that depend on translation; protein synthesis inhibitors altered their formation. Nonetheless, tiar-1 was required for the formation of gonad core granules only. Interestingly, the gonad core granules did not seem to be needed for the germ cells to develop viable embryos after heat shock. This suggests that TIAR-1 is able to protect the germline from heat stress independently of these structures.

  5. Genetic responses of the marine copepod Acartia tonsa (Dana) to heat shock and epibiont infestation

    DEFF Research Database (Denmark)

    Petkeviciute, Egle; Kania, Per Walter; Skovgaard, Alf

    2015-01-01

    Expression of stress-related genes was investigated in the marine copepod Acartia tonsa in relation to heat shock at two different salinities (10 and 32‰), and it was furthermore investigated whether experimentally induced epibiont infestation led to elevated expression of stress-related genes....... Expression of the genes ferritin, Hsp90 and Hsp70 were analyzed in adult copepods by conducting reverse transcription-quantitative real time PCR (RT-qPCR). The expression of Hsp70 and Hsp90 was significantly up-regulated after heat shock and the expression levels were higher in copepods cultivated at 10......‰ salinity seawater than in copepods cultivated at 32‰. Significant up-regulation of ferritin (3.3 fold increase) was observed as a response to infestation with the epibiotic euglenid Colacium vesiculosum. Results suggest that (i) A. tonsa responds more pronounced to thermal shock when cultivated in low...

  6. Recovery from heat, salt and osmotic stress in Physcomitrella patens requires a functional small heat shock protein PpHsp16.4

    OpenAIRE

    Ruibal, Cecilia; Castro, Alexandra; Carballo, Valentina; Szabados, László; Vidal, Sabina

    2013-01-01

    Background Plant small heat shock proteins (sHsps) accumulate in response to various environmental stresses, including heat, drought, salt and oxidative stress. Numerous studies suggest a role for these proteins in stress tolerance by preventing stress-induced protein aggregation as well as by facilitating protein refolding by other chaperones. However, in vivo evidence for the involvement of sHsps in tolerance to different stress factors is still missing, mainly due to the lack of appropriat...

  7. Effects of heat stress on antioxidant defense system, inflammatory injury, and heat shock proteins of Muscovy and Pekin ducks: evidence for differential thermal sensitivities

    OpenAIRE

    Zeng, Tao; Li, Jin-jun; Wang, De-qian; Li, Guo-qin; Wang, Gen-lin; Lu, Li-zhi

    2014-01-01

    Rising temperatures are severely affecting the mortality, laying performance, and meat quality of duck. Our aim was to investigate the effect of acute heat stress on the expression of heat shock proteins (HSPs: HSP90, 70, 60, 40, and 10) and inflammatory factors (nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2)) and antioxidant enzyme activity (superoxide dismutase (SOD), malondialdehybe (MDA), catalase (CAT), total antioxidant capacity (T-AOC)) in livers of ducks and to compare the the...

  8. Heat-shock response and antioxidant defense during air exposure in Patagonian shallow-water limpets from different climatic habitats

    OpenAIRE

    Pöhlmann, Kevin; Koenigstein, Stefan; Alter, Katharina; Abele, Doris; Held, Christoph

    2011-01-01

    Climate warming involves not only a rise of air temperature means, but also more frequent heat waves in many regions on earth, and is predicted to intensify physiological stress especially in extremely changeable habitats like the intertidal. We investigated the heat-shock response (HSR) and enzymatic antioxidant defense levels of Patagonian shallow-water limpets, adapted to distinct tidal exposure conditions in the sub- and intertidal. Limpets were sampled in the temperate Northern Patagonia...

  9. Heat shock response down-regulates IL-18 expression in the murine macrophage cell line, RAW264.7

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Heat shock response is a self-defense mechanism for protection of cells and organisms from a wide range of harmful stressors. Recent studies revealed that it is involved in the regulation of cytokines expression. IL-18 is an important cytokine in mediating immune response. We studied LPS-induced IL-18 expression in heat shock treated RAW264.7 murine macrophages. Our results show that the heat shock response significantly inhibited the expression of LPS-induced pro-inflammatory cytokine IL-18. Further research on the down-regulation mechanism shows that this inhibitory effect is correlated to the great suppression of the binding activity of AP-1, which is a transcription factor binding to the promoter of IL-18 (-1120 to -1083) and regulates the transcription of IL-18. Meanwhile, we observed that the phosphorylation of JNK, which is AP-1 upstream kinase, was greatly decreased. These results confirmed that the down-regulation effect on IL-18 production in heat shock response is related to the suppression of the JNK/AP-1 signaling pathway.

  10. The clonal antibody response to Pseudomonas aeruginosa heat shock protein is highly diverse in cystic fibrosis patients

    DEFF Research Database (Denmark)

    Ulanova, M; Petersen, T D; Ciofu, O;

    1997-01-01

    The GroEL protein of Pseudomonas aeruginosa belongs to the bacterial 60-65 kDa heat shock protein family. A strong antibody response to GroEL has been found in cystic fibrosis (CF) patients with chronic pulmonary infection caused by P. aeruginosa. Clonotypes of IgG1 and IgG2 antibodies against Gro...

  11. RhoA Activation Sensitizes Cells to Proteotoxic Stimuli by Abrogating the HSF1-Dependent Heat Shock Response

    NARCIS (Netherlands)

    Meijering, Roelien A. M.; Wiersma, Marit; van Marion, Denise M. S.; Zhang, Deli; Hoogstra-Berends, Femke; Dijkhuis, Anne-Jan; Schmidt, Martina; Wieland, Thomas; Kampinga, Harm H.; Henning, Robert H.; Brundel, Bianca J. J. M.

    2015-01-01

    Background The heat shock response (HSR) is an ancient and highly conserved program of stress-induced gene expression, aimed at reestablishing protein homeostasis to preserve cellular fitness. Cells that fail to activate or maintain this protective response are hypersensitive to proteotoxic stress.

  12. A novel computational approach of image analysis to quantify behavioural response to heat shock in Chironomus Ramosus larvae (Diptera: Chironomidae

    Directory of Open Access Journals (Sweden)

    Bimalendu B. Nath

    2015-07-01

    Full Text Available All living cells respond to temperature stress through coordinated cellular, biochemical and molecular events known as “heat shock response” and its genetic basis has been found to be evolutionarily conserved. Despite marked advances in stress research, this ubiquitous heat shock response has never been analysed quantitatively at the whole organismal level using behavioural correlates. We have investigated behavioural response to heat shock in a tropical midge Chironomus ramosus Chaudhuri, Das and Sublette. The filter-feeding aquatic Chironomus larvae exhibit characteristic undulatory movement. This innate pattern of movement was taken as a behavioural parameter in the present study. We have developed a novel computer-aided image analysis tool “Chiro” for the quantification of behavioural responses to heat shock. Behavioural responses were quantified by recording the number of undulations performed by each larva per unit time at a given ambient temperature. Quantitative analysis of undulation frequency was carried out and this innate behavioural pattern was found to be modulated as a function of ambient temperature. Midge larvae are known to be bioindicators of aquatic environments. Therefore, the “Chiro” technique can be tested using other potential biomonitoring organisms obtained from natural aquatic habitats using undulatory motion as a behavioural parameter.

  13. Mitochondrial heat-shock protein hsp60 is essential for assembly of proteins imported into yeast mitochondria

    OpenAIRE

    Cheng, Ming Yuan; Hartl, Franz-Ulrich; Martin, Jörg; Pollock, Robert A.; Kalousek, Frantisek; Neupert, Walter; Hallberg, Elisabeth M.; Hallberg, Richard L.; Horwich, Arthur

    1989-01-01

    A nuclear encoded mitochondrial heat-shock protein hsp60 is required for the assembly into oligomeric complexes of proteins imported into the mitochondrial matrix. hsp60 is a member of the 'chaperonin' class of protein factors, which include the Escherichia coli groEL protein and the Rubisco subunit-binding protein of chloroplasts

  14. Heritable variation in heat shock gene expression: a potential mechanism for adaptation to thermal stress in embryos of sea turtles.

    Science.gov (United States)

    Tedeschi, J N; Kennington, W J; Tomkins, J L; Berry, O; Whiting, S; Meekan, M G; Mitchell, N J

    2016-01-13

    The capacity of species to respond adaptively to warming temperatures will be key to their survival in the Anthropocene. The embryos of egg-laying species such as sea turtles have limited behavioural means for avoiding high nest temperatures, and responses at the physiological level may be critical to coping with predicted global temperature increases. Using the loggerhead sea turtle (Caretta caretta) as a model, we used quantitative PCR to characterise variation in the expression response of heat-shock genes (hsp60, hsp70 and hsp90; molecular chaperones involved in cellular stress response) to an acute non-lethal heat shock. We show significant variation in gene expression at the clutch and population levels for some, but not all hsp genes. Using pedigree information, we estimated heritabilities of the expression response of hsp genes to heat shock and demonstrated both maternal and additive genetic effects. This is the first evidence that the heat-shock response is heritable in sea turtles and operates at the embryonic stage in any reptile. The presence of heritable variation in the expression of key thermotolerance genes is necessary for sea turtles to adapt at a molecular level to warming incubation environments. PMID:26763709

  15. Induction of DnaK and GroEL heat shock proteins by fluoroquinolones in Escherichia coli.

    OpenAIRE

    Mizushima, T; Matsuo, M; Sekimizu, K

    1997-01-01

    Various fluoroquinolones (norfloxacin, enoxacin, ofloxacin, levofloxacin, and sparfloxacin) induce DnaK and GroEL heat shock proteins in Escherichia coli. The induction is transient, consistent with the kinetics of cellular DNA relaxation. The concentrations of fluoroquinolones required for induction are similar to those required for DNA relaxation and much higher than those required for cell death.

  16. Hsp60 expression profiles in the reef-building coral Seriatopora caliendrum subjected to heat and cold shock regimes.

    Science.gov (United States)

    Seveso, Davide; Montano, Simone; Strona, Giovanni; Orlandi, Ivan; Galli, Paolo; Vai, Marina

    2016-08-01

    Climate changes have increased the intensity/frequency of extreme thermal events, which represent serious threats to the health of reef-building corals. Since the vulnerability of corals exposed to thermal stresses are related to their ability to regulate Heat shock proteins (Hsps), we have analyzed together the time related expression profiles of the mitochondrial Hsp60 and the associated changes in tissue pigmentation in Seriatopora caliendrum subjected to 48 h of heat and cold treatments characterized by moderate (±2 °C) and severe (±6 °C) shocks. For the first time, an Hsp60 response was observed in a scleractinian coral exposed to cold stresses. Furthermore, the Hsp60 modulations and the changes in the tissue coloration were found to be specific for each treatment. A strong down-regulation at the end of the treatments was observed following both the severe shocks, but only the severe heat stress led to bleaching in concert with the lowest levels of Hsp60, suggesting that a severe heat shock can be more deleterious than an exposure to a severe cold temperature. On the contrary, a moderate cold stress seems to be more harmful than a moderate temperature increase, which could allow coral acclimation. Our results can provide a potential framework for understanding the physiological tolerance of corals under possible future climate changes. PMID:27183199

  17. MORPHOLOGY OF THE MITOCHONDRIA IN HEAT-SHOCK-PROTEIN-60 DEFICIENT FIBROBLASTS FROM MITOCHONDRIAL MYOPATHY PATIENTS - EFFECTS OF STRESS CONDITIONS

    NARCIS (Netherlands)

    HUCKRIEDE, A; HEIKEMA, A; SJOLLEMA, K; BRIONES, P; AGSTERIBBE, E

    1995-01-01

    We have described two mitochondrial (mt) myopathy patients with reduced activities of various mt enzymes associated with significantly decreased amounts of heat shock protein 60 (hsp60). Experimental evidence suggested that the lack of hsp60 was the primary defect. Since hsp60 is essential for the p

  18. The inactivation of RNase G reduces the Stenotrophomonas maltophilia susceptibility to quinolones by triggering the heat shock response.

    Directory of Open Access Journals (Sweden)

    Alejandra eBernardini

    2015-10-01

    Full Text Available Quinolone resistance is usually due to mutations in the genes encoding bacterial topoisomerases. However different reports have shown that neither clinical quinolone resistant isolates nor in vitro obtained S. maltophilia mutants present mutations in such genes. The mechanisms so far described consist on efflux pumps' overexpression. Our objective is to get information on novel mechanisms of S. maltophilia quinolone resistance. For this purpose, a transposon-insertion mutant library was obtained in S. maltophilia D457.. One mutant presenting reduced susceptibility to nalidixic acid was selected. Inverse PCR showed that the inactivated gene encodes RNase G. Complementation of the mutant with wild-type RNase G allele restored the susceptibility to quinolones. Transcriptomic and real-time RT-PCR analyses showed that several genes encoding heat-shock response proteins were expressed at higher levels in the RNase defective mutant than in the wild-type strain. In agreement with this situation, heat-shock reduces the S. maltophilia susceptibility to quinolone. We can then conclude that the inactivation of the RNase G reduces the susceptibility of S. maltophilia to quinolones, most likely by regulating the expression of heat-shock response genes. Heat-shock induces a transient phenotype of quinolone resistance in S. maltophilia.

  19. PUTATIVE CREATINE KINASE M-ISOFORM IN HUMAN SPERM IS IDENTIFIED AS THE 70-KILODALTON HEAT SHOCK PROTEIN HSPA2

    Science.gov (United States)

    THE PUTATIVE CREATINE KINASE M-ISOFORM IN HUMAN SPERM IS IDENTIFIED AS THE 70 kDa HEAT SHOCK PROTEIN HSPA2* Gabor Huszar1, Kathryn Stone2, David Dix3 and Lynne Vigue11The Sperm Physiology Laboratory, Department of Obstetrics and Gynecology, 2 W.M. Keck Foundatio...

  20. Possibilities for observations with the infrared space observatory of emission from shock-heated dust in SNRs

    International Nuclear Information System (INIS)

    The possibilities for observing infrared emission from shock-heated dust in SNRs with the future Infrared Space Observatory (ISO) are illustrated with calculations of the ISOPHOT-P and ISOPHOT-C flux densities and integration times for radiation from six selected SNRs in eight wavelength bands between 4 μm and 180 μm

  1. The inactivation of RNase G reduces the Stenotrophomonas maltophilia susceptibility to quinolones by triggering the heat shock response.

    Science.gov (United States)

    Bernardini, Alejandra; Corona, Fernando; Dias, Ricardo; Sánchez, Maria B; Martínez, Jose L

    2015-01-01

    Quinolone resistance is usually due to mutations in the genes encoding bacterial topoisomerases. However, different reports have shown that neither clinical quinolone resistant isolates nor in vitro obtained Stenotrophomonas maltophilia mutants present mutations in such genes. The mechanisms so far described consist on efflux pumps' overexpression. Our objective is to get information on novel mechanisms of S. maltophilia quinolone resistance. For this purpose, a transposon-insertion mutant library was obtained in S. maltophilia D457. One mutant presenting reduced susceptibility to nalidixic acid was selected. Inverse PCR showed that the inactivated gene encodes RNase G. Complementation of the mutant with wild-type RNase G allele restored the susceptibility to quinolones. Transcriptomic and real-time RT-PCR analyses showed that several genes encoding heat-shock response proteins were expressed at higher levels in the RNase defective mutant than in the wild-type strain. In agreement with this situation, heat-shock reduces the S. maltophilia susceptibility to quinolone. We can then conclude that the inactivation of the RNase G reduces the susceptibility of S. maltophilia to quinolones, most likely by regulating the expression of heat-shock response genes. Heat-shock induces a transient phenotype of quinolone resistance in S. maltophilia. PMID:26539164

  2. Uncertainty correlation in stochastic safety analysis of natural circulation decay heat removal of liquid metal reactor

    International Nuclear Information System (INIS)

    Since various uncertainties of input variables are involved and nonlinearly-correlated in the Best Estimate (BE) plant dynamics code, it is of importance to evaluate the importance of input uncertainty to the computational results and to estimate the accuracy of the confidence level of the results. In order to estimate the importance and the accuracy, the authors have applied the stochastic safety analysis procedure using the Latin Hypercube sampling method to Liquid Metal Reactor (LMR) natural circulation Decay Heat Removal (DHR) phenomenon in the present paper. 17 input variables are chosen for the analyses and 5 influential variables, which affect the maximum coolant temperature at the core in a short period of time (several tens seconds), are selected to investigate the importance by comparing with the full-scope parametric analysis. As a result, it has been demonstrated that a comparative small number of samples is sufficient enough to estimate the dominant input variable and the confidence level. Furthermore, the influence of the sampling method on the accuracy of the upper tolerance limit (confidence level of 95%) has been examined based on the Wilks' formula. (author)

  3. Pre-exposure to heat shock inhibits peroxynitrite-induced activation of poly(ADP) ribosyltransferase and protects against peroxynitrite cytotoxicity in J774 macrophages.

    Science.gov (United States)

    Szabó, C; Wong, H R; Salzman, A L

    1996-11-14

    The reaction of nitric oxide (NO) with superoxide yields the cytotoxic oxidant peroxynitrite, produced during inflammation and shock. A novel pathway of peroxynitrite cytotoxicity involves activation of the nuclear enzyme poly(ADP) ribosyltransferase, and concomitant ADP-ribosylation. NAD+ consumption and exhaustion of intracellular energy stores. In the present report we provide evidence that pre-exposure of J774 macrophages to heat shock reduces peroxynitrite-induced activation of poly(ADP) ribosyltransferase and protects against the peroxynitrite-induced suppression of mitochondrial respiration. The protection was significant at 8 h after heat shock, but was absent at 24 h after heat shock. Thus, the protection showed a temporal correlation with the expression of heat shock protein 70, the expression of which was maximal at 8 h. Exposure to heat shock did not alter the expression of poly(ADP) ribosyltransferase over 24 h. In summary, the heat shock phenotype or heat shock proteins may protect against peroxynitrite induced cytotoxicity. PMID:8960887

  4. 热休克蛋白与肿瘤免疫%The correlation between heat shock protein and tumor immunity

    Institute of Scientific and Technical Information of China (English)

    王小平; 胥冰; 马晓军; 晁旭; 李哲

    2015-01-01

    The heat shock protein( HSP)is a highly conserved group of cellular proteins and is up-regulated under stress conditions. It functions as molecular chaperone and biochemical regulator to mediate cell growth,apoptosis,pro-tein homeostasis and cellular targets of peptides. Aside from their response to heat shock and chemical or physical stress stimuli,HSPs have been reported to be over-expressed in a wide range of human tumors. It has been confirmed that heat shock proteins could combine with tumor peptides,present the antigen to the immune cells through lympho-cyte receptor and elicit specific anti-tumor immunity via CTLs. As novel vaccines,heat shock proteins have a wide therapeutic prospect in biotherapy.%热休克蛋白( heat shock protein,HSP)是一类在生物进化中高度保守、广泛存在于原核及真核生物中的蛋白质。近年热休克蛋白在免疫中的作用已成为当前研究的热点之一。已证实其能与肿瘤细胞内多肽分子结合,通过抗原提呈细胞上的受体,将抗原肽传递给细胞毒T细胞诱导特异性抗肿瘤免疫应答。热休克蛋白肽复合物作为一种疫苗,在生物治疗方面拥有广阔的治疗前景,值得深入研究。

  5. RhoA Activation Sensitizes Cells to Proteotoxic Stimuli by Abrogating the HSF1-Dependent Heat Shock Response.

    Directory of Open Access Journals (Sweden)

    Roelien A M Meijering

    Full Text Available The heat shock response (HSR is an ancient and highly conserved program of stress-induced gene expression, aimed at reestablishing protein homeostasis to preserve cellular fitness. Cells that fail to activate or maintain this protective response are hypersensitive to proteotoxic stress. The HSR is mediated by the heat shock transcription factor 1 (HSF1, which binds to conserved heat shock elements (HSE in the promoter region of heat shock genes, resulting in the expression of heat shock proteins (HSP. Recently, we observed that hyperactivation of RhoA conditions cardiomyocytes for the cardiac arrhythmia atrial fibrillation. Also, the HSR is annihilated in atrial fibrillation, and induction of HSR mitigates sensitization of cells to this disease. Therefore, we hypothesized active RhoA to suppress the HSR resulting in sensitization of cells for proteotoxic stimuli.Stimulation of RhoA activity significantly suppressed the proteotoxic stress-induced HSR in HL-1 atrial cardiomyocytes as determined with a luciferase reporter construct driven by the HSF1 regulated human HSP70 (HSPA1A promoter and HSP protein expression by Western Blot analysis. Inversely, RhoA inhibition boosted the proteotoxic stress-induced HSR. While active RhoA did not preclude HSF1 nuclear accumulation, phosphorylation, acetylation, or sumoylation, it did impair binding of HSF1 to the hsp genes promoter element HSE. Impaired binding results in suppression of HSP expression and sensitized cells to proteotoxic stress.These results reveal that active RhoA negatively regulates the HSR via attenuation of the HSF1-HSE binding and thus may play a role in sensitizing cells to proteotoxic stimuli.

  6. The identification of protein kinase C iota as a regulator of the Mammalian heat shock response using functional genomic screens.

    Directory of Open Access Journals (Sweden)

    Frank Boellmann

    Full Text Available BACKGROUND: The heat shock response is widely used as a surrogate of the general protein quality control system within the cell. This system plays a significant role in aging and many protein folding diseases as well as the responses to other physical and chemical stressors. METHODS/PRINCIPAL FINDINGS: In this study, a broad-based functional genomics approach was taken to identify potential regulators of the mammalian heat shock response. In the primary screen, a total of 13724 full-length genes in mammalian expression vectors were individually co-transfected into human embryonic kidney cells together with a human HSP70B promoter driving firefly luciferase. A subset of the full-length genes that showed significant activation in the primary screen were then evaluated for their ability to hyper-activate the HSP70B under heat shock conditions. Based on the results from the secondary assay and gene expression microarray analyses, eight genes were chosen for validation using siRNA knockdown. Of the eight genes, only PRKCI showed a statistically significant reduction in the heat shock response in two independent siRNA duplexes compared to scrambled controls. Knockdown of the PRKCI mRNA was confirmed using quantitative RT-PCR. Additional studies did not show a direct physical interaction between PRKCI and HSF1. CONCLUSIONS/SIGNIFICANCE: The results suggest that PRKCI is an indirect co-regulator of HSF1 activity and the heat shock response. Given the underlying role of HSF1 in many human diseases and the response to environmental stressors, PRKCI represents a potentially new candidate for gene-environment interactions and therapeutic intervention.

  7. A Novel mouse model of enhanced proteostasis: Full-length human heat shock factor 1 transgenic mice

    Energy Technology Data Exchange (ETDEWEB)

    Pierce, Anson, E-mail: piercea2@uthscsa.edu [Department of Cellular and Structural Biology, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, 78229 (United States); Barshop Institute for Longevity and Aging Studies, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, 78229 (United States); The Department of Veteran' s Affairs, South Texas Veterans Health Care System, San Antonio, Texas, 78284 (United States); Wei, Rochelle; Halade, Dipti [Barshop Institute for Longevity and Aging Studies, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, 78229 (United States); Yoo, Si-Eun [Department of Cellular and Structural Biology, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, 78229 (United States); Barshop Institute for Longevity and Aging Studies, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, 78229 (United States); Ran, Qitao; Richardson, Arlan [Department of Cellular and Structural Biology, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, 78229 (United States); Barshop Institute for Longevity and Aging Studies, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, 78229 (United States); The Department of Veteran' s Affairs, South Texas Veterans Health Care System, San Antonio, Texas, 78284 (United States)

    2010-11-05

    Research highlights: {yields} Development of mouse overexpressing native human HSF1 in all tissues including CNS. {yields} HSF1 overexpression enhances heat shock response at whole-animal and cellular level. {yields} HSF1 overexpression protects from polyglutamine toxicity and favors aggresomes. {yields} HSF1 overexpression enhances proteostasis at the whole-animal and cellular level. -- Abstract: The heat shock response (HSR) is controlled by the master transcriptional regulator heat shock factor 1 (HSF1). HSF1 maintains proteostasis and resistance to stress through production of heat shock proteins (HSPs). No transgenic model exists that overexpresses HSF1 in tissues of the central nervous system (CNS). We generated a transgenic mouse overexpressing full-length non-mutant HSF1 and observed a 2-4-fold increase in HSF1 mRNA and protein expression in all tissues studied of HSF1 transgenic (HSF1{sup +/0}) mice compared to wild type (WT) littermates, including several regions of the CNS. Basal expression of HSP70 and 90 showed only mild tissue-specific changes; however, in response to forced exercise, the skeletal muscle HSR was more elevated in HSF1{sup +/0} mice compared to WT littermates and in fibroblasts following heat shock, as indicated by levels of inducible HSP70 mRNA and protein. HSF1{sup +/0} cells elicited a significantly more robust HSR in response to expression of the 82 repeat polyglutamine-YFP fusion construct (Q82YFP) and maintained proteasome-dependent processing of Q82YFP compared to WT fibroblasts. Overexpression of HSF1 was associated with fewer, but larger Q82YFP aggregates resembling aggresomes in HSF1{sup +/0} cells, and increased viability. Therefore, our data demonstrate that tissues and cells from mice overexpressing full-length non-mutant HSF1 exhibit enhanced proteostasis.

  8. A Novel mouse model of enhanced proteostasis: Full-length human heat shock factor 1 transgenic mice

    International Nuclear Information System (INIS)

    Research highlights: → Development of mouse overexpressing native human HSF1 in all tissues including CNS. → HSF1 overexpression enhances heat shock response at whole-animal and cellular level. → HSF1 overexpression protects from polyglutamine toxicity and favors aggresomes. → HSF1 overexpression enhances proteostasis at the whole-animal and cellular level. -- Abstract: The heat shock response (HSR) is controlled by the master transcriptional regulator heat shock factor 1 (HSF1). HSF1 maintains proteostasis and resistance to stress through production of heat shock proteins (HSPs). No transgenic model exists that overexpresses HSF1 in tissues of the central nervous system (CNS). We generated a transgenic mouse overexpressing full-length non-mutant HSF1 and observed a 2-4-fold increase in HSF1 mRNA and protein expression in all tissues studied of HSF1 transgenic (HSF1+/0) mice compared to wild type (WT) littermates, including several regions of the CNS. Basal expression of HSP70 and 90 showed only mild tissue-specific changes; however, in response to forced exercise, the skeletal muscle HSR was more elevated in HSF1+/0 mice compared to WT littermates and in fibroblasts following heat shock, as indicated by levels of inducible HSP70 mRNA and protein. HSF1+/0 cells elicited a significantly more robust HSR in response to expression of the 82 repeat polyglutamine-YFP fusion construct (Q82YFP) and maintained proteasome-dependent processing of Q82YFP compared to WT fibroblasts. Overexpression of HSF1 was associated with fewer, but larger Q82YFP aggregates resembling aggresomes in HSF1+/0 cells, and increased viability. Therefore, our data demonstrate that tissues and cells from mice overexpressing full-length non-mutant HSF1 exhibit enhanced proteostasis.

  9. Quercetin suppresses heat shock-induced nuclear translocation of Hsp72

    Directory of Open Access Journals (Sweden)

    Antoni Gawron

    2011-08-01

    Full Text Available The effect of quercetin and heat shock on the Hsp72 level and distribution in HeLa cells was studied by Western blotting, indirect immunofluorescence and immunogold electron microscopy. In control cells and after quercetin treatment, Hsp72 was located both in the cytoplasm and in the nucleus in comparable amounts. After hyperthermia, the level of nuclear Hsp72 raised dramatically. Expression of Hsp72 in cytoplasm was also higher but not to such extent as that observed in the nucleus. Preincubation of heated cells with quercetin inhibited strong Hsp72 expression observed after hyperthermia and changed the intracellular Hsp72 distribution. The cytoplasmic level of protein exceeded the nuclear one, especially around the nucleus, where the coat of Hsp72 was noticed. Observations indicating that quercetin was present around and in the nuclear envelope suggested an involvement of this drug in the inhibition of nuclear translocation. Our results indicate that pro-apoptotic activity of quercetin may be correlated not only with the inhibition of Hsp72 expression but also with suppression of its migration to the nucleus.

  10. Expression of Heat Shock Proteins in Human Fibroblast Cells under Magnetic Resonant Coupling Wireless Power Transfer

    Directory of Open Access Journals (Sweden)

    Kohei Mizuno

    2015-10-01

    Full Text Available Since 2007, resonant coupling wireless power transfer (WPT technology has been attracting attention and has been widely researched for practical use. Moreover, dosimetric evaluation has also been discussed to evaluate the potential health risks of the electromagnetic field from this WPT technology based on the International Commission on Non-Ionizing Radiation Protection (ICNIRP guidelines. However, there has not been much experimental evaluation of the potential health risks of this WPT technology. In this study, to evaluate whether magnetic resonant coupling WPT induces cellular stress, we focused on heat shock proteins (Hsps and determined the expression level of Hsps 27, 70 and 90 in WI38VA13 subcloned 2RA human fibroblast cells using a western blotting method. The expression level of Hsps under conditions of magnetic resonant coupling WPT for 24 h was not significantly different compared with control cells, although the expression level of Hsps for cells exposed to heat stress conditions was significantly increased. These results suggested that exposure to magnetic resonant coupling WPT did not cause detectable cell stress.

  11. Heat and Moisture Budgets and Circulation Characteristics of a Frontal Squall Line.

    Science.gov (United States)

    Lin, Xin; Johnson, Richard H.

    1994-06-01

    Heat and moisture budgets and mesoscale circulation features for the developing, mature, and dissipating stages of an intense frontal squall line that occurred in the central United States are investigated. The slow propagating behavior of the squall line made the dataset unique since observations covered a large fraction of the squall line life cycle. Budgets have been performed at six different times at intervals of 90 minutes using 1985 OK PRE-STORM rawinsonde data.The squall line was followed by a low-level cold front. The flow pattern normal to the squall line was generally similar to previous squall line studies except that a low-level rear inflow associated with the cold front was superimposed upon expected squall line FTR/RTF (front to rear/rear to front) flows. The midlevel RTF flow was quite weak well behind the squall line during the developing and mature stages and significantly strengthened during the dissipating stage as the stratiform region developed, suggesting that internal processes within the expanding stratiform region played an important role in RTF flow development.A convergence band resulting from system RTF and FTR flows extended upward and rearward from low levels near the leading edge of the system. During the developing and mature stages, peak convergence was located at low levels around the leading edge. At the dissipating stage, midlevel convergence behind the convective region intensified as the stratiform region developed, while low-level convergence near the leading edge gradually weakened.Both the apparent heat source Q1, and apparent moisture sink Q2 showed an increasing upshear tilt when the stratiform region developed, as did the vertical velocity field. The system-averaged heating peak Q1 was located at middle levels between 500 and 550 hPa throughout the evolution. The moisture sink Q2 exhibited a single drying peak, which resulted from the convective region, at low levels around 700 hPa through most of the developing and

  12. Sodium experiment on fully natural circulation systems for decay heat removal in Japan sodium-cooled fast reactor

    International Nuclear Information System (INIS)

    Fully natural circulation system is adopted in a decay heat removal system (DHRS) of Japan Sodium Cooled Fast Reactor (JSFR). The DHRS of JSFR consists of one unit of DRACS (direct reactor auxiliary cooling system), which has a dipped heat exchanger in the reactor vessel and two units of PRACS, which has a heat exchanger in a primary-side inlet plenum of IHX in each loop. Sodium experiments were carried out for heat transfer characteristics of a sodium-sodium heat exchanger of PRACS and start-up transient of the DHRS loop with parameters of pressure loss coefficients in the loops. The transient experiments for the start-up of DHRS loop showed that quick increase of natural draft in the air duct followed by smooth increase of sodium flow rate in the DHRS loop. Influences of the pressure loss coefficients in the primary loop and the DHRS loop were limited on the core temperature and also heat removal of PRACS, respectively due to recovery of natural circulation head via the increase of temperature difference in each loop. (author)

  13. Use of shock-wave heating for faster and safer ablation of tissue volumes in high intensity focused ultrasound therapy

    Science.gov (United States)

    Khokhlova, V.; Yuldashev, P.; Sinilshchikov, I.; Partanen, A.; Khokhlova, T.; Farr, N.; Kreider, W.; Maxwell, A.; Sapozhnikov, O.

    2015-10-01

    Simulation of enhanced heating of clinically relevant tissue volumes using nonlinear ultrasound waves generated by a multi-element HIFU phased array were conducted based on the combined Westervelt and bio-heat equations. A spatial spectral approach using the fast Fourier transform algorithm and a corresponding analytic solution to the bioheat equation were used to optimize temperature modeling in tissue. Localized shock-wave heating within a much larger treated tissue volume and short, single HIFU pulses within a much longer overall exposure time were accounted for in the algorithm. Separation of processes with different time and spatial scales made the calculations faster and more accurate. With the proposed method it was shown that for the same time-average power, the use of high peak power pulsing schemes that produce high-amplitude shocks at the focus result in faster tissue heating compared to harmonic, continuous-wave sonications. Nonlinear effects can significantly accelerate volumetric heating while also permitting greater spatial control to reduce the impact on surrounding tissues. Such studies can be further used to test and optimize various steering trajectories of shock-wave sonications for faster and more controlled treatment of tissue volumes.

  14. External induction of heat shock stimulates the immune response and longevity of Caenorhabditis elegans towards pathogen exposure.

    Science.gov (United States)

    Prithika, Udayakumar; Deepa, Veerappan; Balamurugan, Krishnaswamy

    2016-08-01

    Heat shock proteins (HSPs) are highly chaperonic molecules that give immediate response during any stress, tissue damage or bacterial infections. In the present study, the role of HSPs upon bacterial encounter is studied by applying external heat induction to live Caenorhabditis elegans Heat shock was observed to increase the life span of wild type C. elegans upon pathogenic encounter, indicating a role of HSPs in bacterial infection and immunity. Similar increase in resistance towards pathogenesis observed in long-lived C. elegans daf-2 mutants and the increase in the lifespan indicated a role for the insulin/IGF-1 signaling (IIS) pathway in HSP-mediated pathogenic resistance. The microscopic observation of C. elegans after external heat induction and sequential exposure of pathogens indicated reduction of egg viability. Results of Real-time PCR and immunoblotting analysis of candidate genes revealed that heat shock and IIS pathways collaborate in the observed pathogenic resistance and further suggested SGK-1 to be the possible factor linking both these pathways. In addition, survival assays carried out using mutants equips us with supporting evidence that HSP and HSF-1 are necessary for the accelerated lifespan of C. elegans Our findings thus confirm that crosstalk between HSPs and SGK-1 influences C. elegans longevity. PMID:27317398

  15. Shock Recovery and Heating Experiments on Baddeleyite: Implications for U-Pb Isotopic Systematics of Martian Meteorites

    Science.gov (United States)

    Misawa, K.; Niihara, T.; Kaiden, H.; Sekine, T.; Mikouchi, T.

    2009-12-01

    Introduction: Radiometric ages of Martian meteorites, shergottites are generally young (i.e., ~165-475 Ma), and are in the late Amazonian chronostratigraphic unit [1]. Bouvier et al. [2-4] reported ~4.1-4.3 Ga old Pb-Pb ages for shergottites, and suggested that young Rb-Sr, Sm-Nd, and Lu-Hf ages so far obtained were affected by alteration of phosphates, interaction with Martian subsurface fluids, or intense shock metamorphism. Baddeleyite (ZrO2) with apparently primary igneous morphology is an important phase in shergottites for U-Pb age determination. In order to investigate shock effects on U-Pb isotopic systematics of baddeleyite, we undertook shock recovery and heating experiments on baddeleyite. Experimental: We used coarse-grained baddeleyite from Phalaborwa for a starting material. The baddeleyite was mixed with a coarse-grained terrestrial basalt with a weight ratio of 1:2. Shock-recovery experiments were performed using a propellant gun at NIMS [5]. The run products were placed in a vertical gas-mixing furnace and heated for 1-3 h at 1000-1300oC under log fO2 of IW+2.5 at 105 Pa. Textures were observed by a scanning electron microprobe and Raman spectra of shocked baddeleyite were obtained. In situ U-Th-Pb isotopic analysis was carried out with the SHRIMP II at NIPR [6]. Results and Discussion: We observed Raman peak shifts of 2-4 cm-1 in the 34-57 GPa samples. Lead loss from baddeleyite was not observed for the experimentally shocked samples. In addition, the U-Pb and Pb-Pb ages of shocked and heated baddeleyites are indistinguishable from those of unshocked baddeleyite within errors except minor lead loss from the baddeleyite shocked at 57 GPa and heated for 1 h at 1300oC. Although duration of peak shock-pressure and grain size of baddeleyite are different from the nature of basaltic shergottites, our experimental results suggest that it is hard to completely reset U-Pb isotopic systematics of baddeleyite in Martian meteorite by shock events below ~60

  16. Clonal mosaic analysis of EMPTY PERICARP2 reveals nonredundant functions of the duplicated HEAT SHOCK FACTOR BINDING PROTEINs during maize shoot development.

    OpenAIRE

    Fu, Suneng; Scanlon, Michael J.

    2004-01-01

    The paralogous maize proteins EMPTY PERICARP2 (EMP2) and HEAT SHOCK FACTOR BINDING PROTEIN2 (HSBP2) each contain a single recognizable motif: the coiled-coil domain. EMP2 and HSBP2 accumulate differentially during maize development and heat stress. Previous analyses revealed that EMP2 is required for regulation of heat shock protein (hsp) gene expression and also for embryo morphogenesis. Developmentally abnormal emp2 mutant embryos are aborted during early embryogenesis. To analyze EMP2 func...

  17. Some questions of fast reactor residual heat removal using coolant natural circulation in the circuits

    International Nuclear Information System (INIS)

    A calculation procedure designed for entire plant dynamics has been used for transients leading the reactor plant of BN-600 type into a natural circulation mode. A detailed description of the mathematical model and comparison of calculated and experimental results are presented. Some peculiarities of coolant natural circulation development in the BN-350 reactor circuits are considered. (author)

  18. Antitumor immunity induced by DNA vaccine encoding alpha-fetoprotein/heat shock protein 70

    Institute of Scientific and Technical Information of China (English)

    Xiao-Ping Wang; Guo-Zhen Liu; Ai-Li Song; Hai-Yan Li; Yu Liu

    2004-01-01

    AIM: To construct a DNA vaccine encoding human alphafetoprotein (hAFP)/heat shock protein 70 (HSP70), and to study its ability to induce specific CTL response and its protective effect against AFP-expressing tumor.METHODS: A DNA vaccine was constructed by combining hAFP gene with HSP70 gene. SP2/0 cells were stably transfected with pBBS212-hAFP and pBBS212-hAFP/HSP70eukaryotic expression vectors. Mice were primed and boosted with DNA vaccine hAFP/HSP70 by intramuscular injection, whereas plasmid with hAFP or HSP70 was used as controls. ELISPOT and ELISA were used to detect IFN-γ-producing splenocytes and the level of serum anti-AFP antibody from immunized mice respectively. In vivo tumor challenge was measured to assess the immune effect of the DNA vaccine.RESULTS: By DNA vaccine immunization, the results of ELISPOT and ELISA showed that the number of IFN-γ-producing splenocytes and the level of serum anti-AFP antibody were significantly higher in rhAFP/HSP70 group than in hAFP and empty plasmid groups (95.50±10.90IFN-γ spots/106 cells vs 23.60±11.80 IFN-γ spots/106 cells,7.17±4.24 IFN-γ spots/106 cells, P<0.01; 126.50±8.22 μg/mL vs 51.72±3.40 μg/mL, 5.83±3.79 μg/mL, P<0.01). The tumor volume in rhAFP/HSP70 group was significantly smaller than that in pBBS212-hAFP and empty plasmid groups (37.41±7.34 mm3 vs381.13±15.48 mm3, 817.51±16.25 mm3,P<0.01).CONCLUSION: Sequential immunization with a recombinant DNA vaccine encoding AFP and heat shock protein70 could generate effective AFP-specific T cell responses and induce definite antitumor effects on AFP-producing tumors, which may be suitable for some clinical testing as a vaccine for HCC.

  19. Sulphoraphane, a naturally occurring isothiocyanate induces apoptosis in breast cancer cells by targeting heat shock proteins

    Energy Technology Data Exchange (ETDEWEB)

    Sarkar, Ruma; Mukherjee, Sutapa [Department of Environmental Carcinogenesis and Toxicology, Chittaranjan National Cancer Institute, 37, SP Mukherjee Road, Kolkata 700 026 (India); Biswas, Jaydip [Chittaranjan National Cancer Institute, 37, SP Mukherjee Road, Kolkata 700 026 (India); Roy, Madhumita, E-mail: mitacnci@yahoo.co.in [Department of Environmental Carcinogenesis and Toxicology, Chittaranjan National Cancer Institute, 37, SP Mukherjee Road, Kolkata 700 026 (India)

    2012-10-12

    Highlights: Black-Right-Pointing-Pointer HSPs (27, 70 and 90) and HSF1 are overexpressed in MCF-7 and MDA-MB-231 cells. Black-Right-Pointing-Pointer Sulphoraphane, a natural isothiocyanate inhibited HSPs and HSF1 expressions. Black-Right-Pointing-Pointer Inhibition of HSPs and HSF1 lead to regulation of apoptotic proteins. Black-Right-Pointing-Pointer Alteration of apoptotic proteins activate of caspases particularly caspase 3 and 9 leading to induction of apoptosis. Black-Right-Pointing-Pointer Alteration of apoptotic proteins induce caspases leading to induction of apoptosis. -- Abstract: Heat shock proteins (HSPs) are involved in protein folding, aggregation, transport and/or stabilization by acting as a molecular chaperone, leading to inhibition of apoptosis by both caspase dependent and/or independent pathways. HSPs are overexpressed in a wide range of human cancers and are implicated in tumor cell proliferation, differentiation, invasion and metastasis. HSPs particularly 27, 70, 90 and the transcription factor heat shock factor1 (HSF1) play key roles in the etiology of breast cancer and can be considered as potential therapeutic target. The present study was designed to investigate the role of sulphoraphane, a natural isothiocyanate on HSPs (27, 70, 90) and HSF1 in two different breast cancer cell lines MCF-7 and MDA-MB-231 cells expressing wild type and mutated p53 respectively, vis-a-vis in normal breast epithelial cell line MCF-12F. It was furthermore investigated whether modulation of HSPs and HSF1 could induce apoptosis in these cells by altering the expressions of p53, p21 and some apoptotic proteins like Bcl-2, Bax, Bid, Bad, Apaf-1 and AIF. Sulphoraphane was found to down-regulate the expressions of HSP70, 90 and HSF1, though the effect on HSP27 was not pronounced. Consequences of HSP inhibition was upregulation of p21 irrespective of p53 status. Bax, Bad, Apaf-1, AIF were upregulated followed by down-regulation of Bcl-2 and this effect was prominent

  20. Sulphoraphane, a naturally occurring isothiocyanate induces apoptosis in breast cancer cells by targeting heat shock proteins

    International Nuclear Information System (INIS)

    Highlights: ► HSPs (27, 70 and 90) and HSF1 are overexpressed in MCF-7 and MDA-MB-231 cells. ► Sulphoraphane, a natural isothiocyanate inhibited HSPs and HSF1 expressions. ► Inhibition of HSPs and HSF1 lead to regulation of apoptotic proteins. ► Alteration of apoptotic proteins activate of caspases particularly caspase 3 and 9 leading to induction of apoptosis. ► Alteration of apoptotic proteins induce caspases leading to induction of apoptosis. -- Abstract: Heat shock proteins (HSPs) are involved in protein folding, aggregation, transport and/or stabilization by acting as a molecular chaperone, leading to inhibition of apoptosis by both caspase dependent and/or independent pathways. HSPs are overexpressed in a wide range of human cancers and are implicated in tumor cell proliferation, differentiation, invasion and metastasis. HSPs particularly 27, 70, 90 and the transcription factor heat shock factor1 (HSF1) play key roles in the etiology of breast cancer and can be considered as potential therapeutic target. The present study was designed to investigate the role of sulphoraphane, a natural isothiocyanate on HSPs (27, 70, 90) and HSF1 in two different breast cancer cell lines MCF-7 and MDA-MB-231 cells expressing wild type and mutated p53 respectively, vis-à-vis in normal breast epithelial cell line MCF-12F. It was furthermore investigated whether modulation of HSPs and HSF1 could induce apoptosis in these cells by altering the expressions of p53, p21 and some apoptotic proteins like Bcl-2, Bax, Bid, Bad, Apaf-1 and AIF. Sulphoraphane was found to down-regulate the expressions of HSP70, 90 and HSF1, though the effect on HSP27 was not pronounced. Consequences of HSP inhibition was upregulation of p21 irrespective of p53 status. Bax, Bad, Apaf-1, AIF were upregulated followed by down-regulation of Bcl-2 and this effect was prominent in MCF-7 than in MDA-MB-231. However, very little change in the expression of Bid was observed. Alteration in Bcl-2 Bax

  1. Chlamydial Heat Shock Proteins and Disease Pathology: New Paradigms for Old Problems?

    Directory of Open Access Journals (Sweden)

    G. I. Byrne

    1999-01-01

    Full Text Available The mucosal pathogen Chlamydia trachomatis affects hundreds of millions of people worldwide and is a significant cause of sexually transmitted disease. Although most acute infections can be easily managed, complications often occur that can be especially severe in women. It has been proposed that increased exposure to conserved chlamydial antigens, such as through reinfection or persistent infection, results in chronic inflammation and tissue scarring and contributes to the pathogenesis of endometrial and fallopian tube damage. This immunopathologic damage is believed to be a principal cause of ectopic pregnancy and tubal factor infertility. The chlamydial heat shock protein Hsp60, a homolog of Escherichia coli GroEL, has been identified as one protein capable of eliciting intense mononuclear inflammation. Furthermore, several studies have revealed a correlation between Hsp60 responses and the immunopathologic manifestations of human chlamydial disease. The role of additional antigens in the immunopathologic response to chlamydiae is currently undefined. A prime candidate, however, is the chlamydial GroES homolog Hspl0, which is genetically and physiologically linked to Hsp60. Recent studies provide data to suggest that immune reactivity to Hspl0 is significantly associated with tubal infertility in a chlamydiae-exposed population. Chlamydia pneumoniae is a more recently defined chlamydial species that has been implicated in a variety of ways with chronic disease processes, such as adult onset asthma and atherosclerosis. Evidence indicates that Hsp60 is present in human atheroma and may play a role in lesion development by direct activation of macrophages. Hsp60 causes the elaboration of inflammatory cytokines, the induction of metalloproteinase, and the oxidation of low density lipoprotein. Each of these events is directly associated with the progress of atherosclerosis. Thus, chlamydial heat shock proteins may function in at least two ways to

  2. Overly persistent circulation in climate models contributes to overestimated frequency and duration of heat waves and cold spells

    Czech Academy of Sciences Publication Activity Database

    Plavcová, Eva; Kyselý, Jan

    2016-01-01

    Roč. 46, č. 9 (2016), s. 2805-2820. ISSN 0930-7575 R&D Projects: GA ČR GAP209/10/2265; GA MŠk 7AMB15AR001 Institutional support: RVO:68378289 Keywords : heat wave * cold spell * atmospheric circulation * persistence * regional climate models * Central Europe Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 4.673, year: 2014 http://link.springer.com/article/10.1007%2Fs00382-015-2733-8

  3. Interannual Variability of Heat Wave in South Korea and theirs Connection with Large-Scale Atmospheric Circulation Pattern

    Science.gov (United States)

    Lee, Woo-Seop; Lee, Myong-In

    2016-04-01

    This study investigates the interannual variation of heat wave frequency (HWF) in South Korea during the past 42 years (1973-2014) and examines its connection with large-scale atmospheric circulation changes. Korean heat waves tend to develop most frequently in late summer during July and August. The leading Empirical Orthogonal Function (EOF) accounting for 50% of the total variance shows a mono-signed pattern over South Korea, suggesting that the dominant mechanisms responsible for the heat wave are linked in a spatial scale much larger than the nation. It also exhibits a regional variation with more occurrences in the southeastern inland area. The regression of the leading principal component (PC) time series of HWF with large-scale atmospheric circulation identifies a north-south dipole pattern between the South China Sea and Northeast Asia. When this large-scale circulation mode facilitates deep convection in South China Sea, it tends to weaken moisture transport from the South China Sea to Northeast Asia. Enhanced deep convection in the South China Sea triggers a source of Rossby wave train along southerly wind that generates positive geopotential height anomalies around Korea. The anomalous high pressure pattern is accompanied by large-scale subsidence in Korea, thereby providing a favorable condition for extreme hot and dry days in Korea. This study highlights that there is a decadal change of the relationship between Korean heat waves and large-scale atmospheric circulation patterns. The tropical forcing tends to be weakened in the recent decade, with more influences from the Arctic variability from the mid-1990s.

  4. Main circulator design features for HTR 100, HTR 500 and space heating plants

    International Nuclear Information System (INIS)

    All design alternatives for modern high-temperature reactors have a common circulator concept: It is based on a vertical shaft design with a flying impeller. The circulators are equipped with active magnetic bearings and are driven by induction motors connected to variable-speed static converters. Due to their multiple functions during normal reactor operation and under accident conditions, extremely high requirements are made to safety-relevant circulators, since with the reactor pressurized as well as under depressurized conditions specified delivery heads and flow rates have to be ensured. The use of active magnetic bearings permits to obtain maintenance-free operation and functional safety to an extent which had not been achieved before. Magnetic bearings are therefore provided for the total range including primary gas circulators of a drive power of several MW as well as circulators for helium loops of reactor auxiliary systems. The essential feature for using active magnetic bearings is the retainer bearing technology, preventing contact between rotor and static circulator parts upon unintended deenergisation of the magnets. Results of current experiments are reported. Another aspect to be considered for reliable long-term operation for several decades is the effect of rotor dynamics. The various natural frequencies resulting from torsion and bending modes in view of a drive by a frequency-controlled induction motor have to be considered as well as the specific characteristics of the active magnetic bearings. Special attention has to be directed to the internal cooling loop so as to ensure that reactor temperature excursions in the event of deviation from normal operation can be overcome without damage. For circulator components exposed to temperature fields the design characteristics are determined by combining experimental and analytical methods. The coordination of all component parts is currently being optimized on a prototype circulator whose detailed

  5. Heat transfer experiments and correlations for natural and forced circulations of water in rod bundles at low Reynolds numbers

    International Nuclear Information System (INIS)

    Experimental heat transfer studies were conducted for fully developed forced and natural flows of water through seven uniformly heated rod bundles, triangularly arrayed with P/D = 1.25, 1.38, and 1.5. In forced circulation experiments, Re ranged from 80 to 50,000 and Pr from 3 to 8.5, while in natural circulation, Re varied from 260 to 2,000, and Raq from 8 x 108 to 2.5 x 108. The forced flow data fell into the two basic flow regimes: turbulent and laminar flow. At the transition between these regimes, Re, which varied from 2,200 for P/D = 1.25 to 5,500 for P/D = 1.5, increased linearly with P/D. The heat transfer data for turbulent flow was within ±15 percent of Weisman's correlation, which was developed for fully developed turbulent flow in rod bundles at Re > 25,000. The laminar flow data showed the dependence of Nu on Re to be weaker than that for turbulent flow, but the exponent of Re increased with P/D: Nu = A ReB Pr1/3, where A is equal to 1.061, 0.511, and 0.346 for P/D = 1.25, 1.38 and 1.5, respectively, and B is a linear function of P/D (B = 0.797 P/D - 0.656). Natural circulation data indicated that rod spacing only slightly affected heat transfer, and Nu increased proportionally to Ra0.25; Nu = 0.272 Raq0.25. The application of the results to SNL's ACRR indicated that although the core is cooled by natural convection, either the natural circulation correlation or the forced turbulent flow correlation can be used to accurately predict the single phase heat transfer coefficient in the ACRR. These results were concluded because of the high Rayleigh and Reynolds numbers in the ACRR. The ACRR operates near the boundary between mixed and forced turbulent flow regimes: consequently, achieving the high heat transfer coefficient was possible with natural circulation. (author)

  6. Experimental investigations of steam bubble entrainment in the down-flow cavity of a natural circulation heat only reactor

    International Nuclear Information System (INIS)

    The ZHM-2 (Zittauer Heizreaktormodell, Zittau Heat Only Reactor Model) experimental facility is described. This facility is used for studying entrainment of gas bubbles during 1800 flow inversion from the up-flow into the down-flow cavity of a natural circulation heat only reactor. Volume gas content, bubble speed, and bubble size can be determined using a special conductivity probe. The gas portion entrained in the down-flow cavity PSI is presented as a function of water level, gas content distribution in the up-flow cavity, and geometry of the upper inverting region. (author)

  7. Development of numerical analysis methods for natural circulation decay heat removal system applied to a large scale JSFR

    International Nuclear Information System (INIS)

    A decay heat removal system utilizing passive natural circulation is applied to a large scale Japan Sodium-cooled Fast Reactor. As preparing for the future licensing, a one-dimensional flow network method and a three-dimensional numerical analysis method were developed to evaluate core cooling capability and thermal transient under decay heat removal modes after reactor trip. The one-dimensional method was applied to a water test simulating the primary system of the reactor, while the three-dimensional method was applied to the water test and a sodium test focusing on the decay heat removal system. The numerical results of both methods have turned out to agree well with the test results. And then the thermal-hydraulic behavior under a typical decay heat removal mode of the reactor has been predicted by the three-dimensional method. (author)

  8. The role of heat shock protein (HSP as inhibitor apoptosis in hypoxic conditions of bone marrow stem cell culture

    Directory of Open Access Journals (Sweden)

    Sri Wigati Mardi Mulyani

    2014-03-01

    Full Text Available Background: The concept of stem cell therapy is one of the new hope as a medical therapy on salivary gland defect. However, the lack of viability of the transplanted stem cells survival rate led to the decrease of effectiveness of stem cell therapy. The underlying assumption in the decrease of viability and function of stem cells is an increase of apoptosis incidence. It suggests that the microenvironment in the area of damaged tissues is not conducive to support stem cell viability. One of the microenvironment is the hypoxia condition. Several scientific journals revealed that the administration of hypoxic cell culture can result in stress cells but on the other hand the stress condition of the cells also stimulates heat shock protein 27 (HSP 27 as antiapoptosis through inhibition of caspase 9. Purpose: The purpose of this study was to examine the role of heat shock protein 27 as inhibitor apoptosis in hypoxic conditions of bone marrow stem cell culture. Methods: Stem cell culture was performed in hypoxic conditions (O2 1% and measured the resistance to apoptosis through HSP 27 and caspase 9 expression of bone marrow mesenchymal stem cells by using immunoflorecence and real time PCR. Results: The result of study showed that preconditioning hypoxia could inhibit apoptosis through increasing HSP 27 and decreasing level of caspase 9. Conclusion: The study suggested that hypoxic precondition could reduce apoptosis by increasing amount of heat shock protein 27 and decreasing caspase 9.Latar belakang: Konsep terapi stem cell merupakan salah satu harapan baru sebagai terapi medis kelainan kelenjar ludah. Namun, rendahnya viabilitas stem cell yang ditransplantasikan menyebabkan penurunan efektivitas terapi. Asumsi yang mendasari rendahnya viabilitas dan fungsi stem cell adalah tingginya kejadian apoptosis. Hal ini menunjukkan bahwa lingkungan mikro di daerah jaringan yang rusak tidak kondusif untuk mendukung viabilitas stem cell. Salah satu lingkungan

  9. Inheritance of resistance of bovine preimplantation embryos to heat shock: relative importance of the maternal versus paternal contribution.

    Science.gov (United States)

    Block, J; Chase, C C; Hansen, P J

    2002-09-01

    Brahman preimplantation embryos are less affected by exposure to heat shock than Holstein embryos. Two experiments were conducted to test whether the ability of Brahman embryos to resist the deleterious effects of heat shock was a result of the genetic and cellular contributions from the oocyte, spermatozoa, or a combination of both. In the first experiment, Brahman and Holstein oocytes were collected from slaughterhouse ovaries and fertilized with spermatozoa from an Angus bull. A different bull was used for each replicate to eliminate bull effects. On day 4 after fertilization, embryos >or= 9 cells were collected and randomly assigned to control (38.5 degrees C) or heat shock (41 degrees C for 6 hr) treatments. The proportion of embryos developing to the blastocyst (BL) and advanced blastocyst (ABL; expanded and hatched) stages was recorded on day 8. Heat shock reduced the number of embryos produced from Holstein oocytes that developed to BL (P Brahman oocytes (BL = 42.1 +/- 4.8% vs. 55.6 +/- 4.8% for 38.5 and 41 degrees C, respectively; ABL = 17.6 +/- 4.2% vs. 32.4 +/- 4.2%). In the second experiment, oocytes from Holstein cows were fertilized with semen from bulls of either Brahman or Angus breeds. Heat shock of embryos >or= 9 cells reduced development to BL (P Brahman (BL = 54.3 +/- 7.7% vs. 23.4 +/- 7.7%; ABL = 43. +/- 7.4% vs. 7.9 +/- 7.4%, for 38.5 and 41 degrees C, respectively) and Angus bulls (BL = 57.9 +/- 7.7% vs. 31.0 +/- 7.7%; ABL = 33.6 +/- 7.4% vs. 18.4 +/- 7.4%, for 38.5 and 41 degrees C, respectively). There were no breed x temperature interactions. Results suggest that the oocyte plays a more significant role in the resistance of Brahman embryos to the deleterious effects of heat shock than the spermatozoa. PMID:12211058

  10. Investigations on biological functions of heat shock transcription factor 1 (HSF1) using a gene knock out mouse model

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    HSF1 is the major heat shock transcription factor that binds heat shock element (HSE) in the promoter of heat shock proteins (HSPs) and controls rapid HSP induction in cells subjected to various stresses such as elevated temperature, chemicals, or exposure to toxins. Although at least four members of the vertebrate HSF have been cloned, details of their individual physiological roles remain relatively obscure. To clarify the exact in vivo functions of HSF1 and assess whether HSF1 exhibits redundant or unique roles, we have created homozygous Hsf1-/- mice using standard gene targeting techniques and isolated Hsf1-/- embryonic fibroblasts. Here we demonstrate that heat shock response (HSR) was not attainable in Hsf1-/- embryonic fibroblasts, and this response was required for thermotolerance and protection against heat-induced apoptosis, and that homozygous Hsf1-/- mice, which survived to adulthood according to genetic background, exhibited multiple phenotypes including: (1) placental defects that reduced embryonic viability after late midgestation (day 13.5); (2) growth retardation; (3) female infertility caused by preimplantation lethality, and (4) increased mortality (+/+ vs -/-, P<0.05) and exaggerated production of proinflammatory cytokine, TNF α (+/- vs -/-, P<0.05) after endotoxin challenge. Interestingly, although Hsf1-/- mice exhibited placental defects and embryonic death, basal HSP expression is not appreciably altered during embryonic development by the HSF1 null mutation, suggesting this factor might be involved in regulating some non-HSP genes or signaling pathways which may be important for development. Taken together, our results established direct causal effects for the HSF1 transactivator in regulating diverse physiological and pathophysiological conditions such as developnent, growth, reproduction, apoptosis and sepsis. The present work also provided a useful mammalian model for further investigating the implications of Hsf1 and its target

  11. The Inhibition of Heat Shock Protein 90 Facilitates the Degradation of Poly-Alanine Expanded Poly (A) Binding Protein Nuclear 1 via the Carboxyl Terminus of Heat Shock Protein 70-Interacting Protein

    OpenAIRE

    Shi, Chao; Huang, Xuan; Zhang, Bin; Zhu, Dan; Luo, Huqiao; Lu, Quqin; Xiong, Wen-Cheng; Mei, Lin; Luo, Shiwen

    2015-01-01

    Background Since the identification of poly-alanine expanded poly(A) binding protein nuclear 1 (PABPN1) as the genetic cause of oculopharyngeal muscular dystrophy (OPMD), considerable progress has been made in our understanding of the pathogenesis of the disease. However, the molecular mechanisms that regulate the onset and progression of the disease remain unclear. Results In this study, we show that PABPN1 interacts with and is stabilized by heat shock protein 90 (HSP90). Treatment with the...

  12. Exercise Training-Induced Changes in Inflammatory Mediators and Heat Shock Proteins in Young Tennis Players

    Science.gov (United States)

    Ziemann, Ewa; Zembroñ-Lacny, Agnieszka; Kasperska, Anna; Antosiewicz, Jȩdrzej; Grzywacz, Tomasz; Garsztka, Tomasz; Laskowski, Radoslaw

    2013-01-01

    Heat shock proteins (Hsp) represent proteins’ groups, whose protective function, may be induced by heat, reactive oxygen species, cytokines etc. We evaluated blood levels of Hsp27 and Hsp70, and their relation to skeletal muscle damage and inflammation in young tennis players before and after the conditioning camp. Blood samples were collected directly after tournament season, 3-day rest and 14-day conditioning camp that followed. Hydrogen peroxide (H2O2) demonstrated the highest concentration directly after tournament season, which significantly decreased at camp’s end. The pro-inflammatory cytokines IL-1β and TNFα decreased, whereas anti-inflammatory cytokines IL-6 and IL-10 increased after 3d rest and 14d camp. Hsp27 increased after 3d rest and remained so after 14d camp, while Hsp70 decreased from baseline to camp’s completion. Hsp27 and Hsp70 correlated significantly with H2O2, IL-1β and TNFα. Muscle damage, observed as creatine kinase (CK) activity changes, increased after 14d camp similarly to Hsp27 and anti-inflammatory cytokines IL-6 and IL-10. Obtained data allows to conclude that decrease of Hsp27 and increase in pro-inflammatory cytokines could be a good indicator of overreaching. Reverse tendencies in these proteins may verify accuracy of conditioning camp. Finally, this training program caused an increase in the anti-inflammatory cytokines concentrations, improving individual status of recovery. Key Points The study demonstrating low grade inflammation-induced by the tournament season in young tennis player. Three days of active rest stimulated the anti-inflammatory response via rise of Hsp27 and anti-inflammatory cytokine IL-10. Observed decrease of blood Hsp70 may support mental recovery. Thirteen-day appropriate training program led to maintaining an immunological response balance. PMID:24149807

  13. Pregermination heat shock and seedling growth of fire-following Fabaceae from four Mediterranean-climate regions

    Science.gov (United States)

    Hanley, Mick E.; Fenner, Michael; Ne'eman, Gidi

    2001-12-01

    The role of heat-shock in stimulating the germination of soil-stored seeds from fire-following plant species is well known. However, the effects of high pre-germination temperatures on subsequent seedling growth are less well understood. In this study, we examined the effect of pre-germination heat shock at five temperatures (60°, 75°, 90°, 105° and 120°C, each applied for 5 min) on the seedling growth of four, fire-following Fabaceae species from four Mediterranean-type ecosystems; Hippocrepis multisiliquosa (Israel), Gastrolobium villosum (Western Australia), Cyclopia pubescens (South Africa) and Lupinus succulentus (California). Following heat treatment and subsequent germination, seedlings were grown in controlled conditions before being harvested at either 10, 20- or 40 d old. A significant increase in mean dry weight biomass was found at 10 days for Hippocrepis seedlings germinated from seeds pre-heated to 90°C. However, subsequent comparison of mean dry weight biomass for seedlings of this species at 20 and 40 d old showed no significant response to heat shock pre-treatment. Similarly, an initial increase in growth of Gastrolobium seedlings germinated from seeds heated to 90° and 105°C disappeared as the plants matured. Seedling growth of Lupinus and Cyclopia was unaffected by the pre-germination heat treatment of their seeds. Since seedling competition is influenced by the size and growth rates of neighbouring plants, any changes in seedling growth rates as a consequence of the temperature environment experienced by their seeds, may therefore influence patterns of post-fire plant community recovery.

  14. EEVD motif of heat shock cognate protein 70 contributes to bacterial uptake by trophoblast giant cells

    Directory of Open Access Journals (Sweden)

    Kim Suk

    2009-12-01

    Full Text Available Abstract Background The uptake of abortion-inducing pathogens by trophoblast giant (TG cells is a key event in infectious abortion. However, little is known about phagocytic functions of TG cells against the pathogens. Here we show that heat shock cognate protein 70 (Hsc70 contributes to bacterial uptake by TG cells and the EEVD motif of Hsc70 plays an important role in this. Methods Brucella abortus and Listeria monocytogenes were used as the bacterial antigen in this study. Recombinant proteins containing tetratricopeptide repeat (TPR domains were constructed and confirmation of the binding capacity to Hsc70 was assessed by ELISA. The recombinant TPR proteins were used for investigation of the effect of TPR proteins on bacterial uptake by TG cells and on pregnancy in mice. Results The monoclonal antibody that inhibits bacterial uptake by TG cells reacted with the EEVD motif of Hsc70. Bacterial TPR proteins bound to the C-terminal of Hsc70 through its EEVD motif and this binding inhibited bacterial uptake by TG cells. Infectious abortion was also prevented by blocking the EEVD motif of Hsc70. Conclusions Our results demonstrate that surface located Hsc70 on TG cells mediates the uptake of pathogenic bacteria and proteins containing the TPR domain inhibit the function of Hsc70 by binding to its EEVD motif. These molecules may be useful in the development of methods for preventing infectious abortion.

  15. Heat Shock Response Associated with Hepatocarcinogenesis in a Murine Model of Hereditary Tyrosinemia Type I

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    Francesca Angileri

    2014-04-01

    Full Text Available Hereditary Tyrosinemia type 1 (HT1 is a metabolic liver disease caused by genetic defects of fumarylacetoacetate hydrolase (FAH, an enzyme necessary to complete the breakdown of tyrosine. The severe hepatic dysfunction caused by the lack of this enzyme is prevented by the therapeutic use of NTBC (2-[2-nitro-4-(trifluoromethylbenzoyl] cyclohexane-1,3-dione. However despite the treatment, chronic hepatopathy and development of hepatocellular carcinoma (HCC are still observed in some HT1 patients. Growing evidence show the important role of heat shock proteins (HSPs in many cellular processes and their involvement in pathological diseases including cancer. Their survival-promoting effect by modulation of the apoptotic machinery is often correlated with poor prognosis and resistance to therapy in a number of cancers. Here, we sought to gain insight into the pathophysiological mechanisms associated with liver dysfunction and tumor development in a murine model of HT1. Differential gene expression patterns in livers of mice under HT1 stress, induced by drug retrieval, have shown deregulation of stress and cell death resistance genes. Among them, genes coding for HSPB and HSPA members, and for anti-apoptotic BCL-2 related mitochondrial proteins were associated with the hepatocarcinogenetic process. Our data highlight the variation of stress pathways related to HT1 hepatocarcinogenesis suggesting the role of HSPs in rendering tyrosinemia-affected liver susceptible to the development of HCC.

  16. Mutant p53 - heat shock response oncogenic cooperation: a new mechanism of cancer cell survival

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    Evguenia eAlexandrova

    2015-04-01

    Full Text Available The main tumor suppressor function of p53 as a ‘guardian of the genome’ is to respond to cellular stress by transcriptional activation of apoptosis, growth arrest or senescence in damaged cells. Not surprisingly, mutations in the p53 gene are the most frequent genetic alteration in human cancers. Importantly, mutant p53 (mutp53 proteins not only lose their wild-type tumor suppressor activity, but also can actively promote tumor development. Two main mechanisms accounting for mutp53 proto-oncogenic activity are inhibition of the wild-type p53 in a dominant-negative fashion and gain of additional oncogenic activities known as gain-of-function (GOF. Here we discuss a novel mechanism of mutp53 GOF, which relies on its oncogenic cooperation with the heat shock machinery. This coordinated adaptive mechanism renders cancer cells more resistant to proteotoxic stress and provides both, a strong survival advantage to cancer cells and a promising means for therapeutic intervention.

  17. Anti-Tumor Effect of Heat Shock Protein 70-Peptide Complexes on A-549 Cells

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Objective: To investigate the anti-tumor immunity in vitro of heat shock protein 70-peptide complexes (HSP70-PC) from human lung cancer tissue. Methods: HSP70-PC was purified from lung tumor tissues and corresponding non-tumor lung samples with the methods of ADP-affinity chromatography, DEAE ion-exchange chromatography and Western-blot. The activation and proliferation of PBMC induced by different HSP70-PC and tumor cytotoxic reactivity to A549 cells in vitro were measured by the MTT cell proliferation assay. Results: The purified HSP70-PC had a very high purity found by SDS-PAGE and Western-blot. Human lymphocytes were sensitized efficiently by HSP70 preparation purified from lung cancer tissues and a definite cytotoxicity to A-549 cells was observed. There was significant difference with HSP70-PC purified from lung cancer, compared with the control group (P<0.001). Conclusion: High purity of HSP70-PC could be achieved from tumor tissues in this study. HSP70-PC purified from human tumor tissues can induce anti-tumor immunity in vitro mainly implemented by eliciting CTL immunity.

  18. Absence of force suppression in rabbit bladder correlates with low expression of heat shock protein 20

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    Murphy Richard A

    2005-11-01

    Full Text Available Abstract Background Nitroglycerin can induce relaxation of swine carotid artery without sustained reductions in [Ca2+]i or myosin regulatory light chain (MRLC phosphorylation. This has been termed force suppression and been found to correlate with ser16-phosphorylation of heat shock protein 20 (HSP20. We tested for the existence of this mechanism in a smooth muscle that is not responsive to nitric oxide. Methods Isometrically mounted mucosa free rabbit bladder strips were contracted with carbachol and relaxed with 8-Br-cGMP, forskolin, or isoprenaline. Results Contraction was associated with a highly cooperative relation between MRLC phosphorylation and force such that very small increases in MRLC phosphorylation induced large increases in force. Relaxation induced by 8-Br-cGMP, forskolin, or isoprenaline did not shift the MRLC phosphorylation-force relation from that observed with carbachol alone, i.e. there was no force suppression. HSP20 content was negligible (approximately two hundred-fold less than swine carotid. Conclusion The lack of force suppression in the absence of HSP20 is consistent with the hypothesized role for HSP20 in the force suppression observed in tonic smooth muscles.

  19. Gut epithelial inducible heat-shock proteins and their modulation by diet and the microbiota.

    Science.gov (United States)

    Arnal, Marie-Edith; Lallès, Jean-Paul

    2016-03-01

    The epidemic of metabolic diseases has raised questions about the interplay between the human diet and the gut and its microbiota. The gut has two vital roles: nutrient absorption and intestinal barrier function. Gut barrier defects are involved in many diseases. Excess energy intake disturbs the gut microbiota and favors body entry of microbial compounds that stimulate chronic metabolic inflammation. In this context, the natural defense mechanisms of gut epithelial cells and the potential to boost them nutritionally warrant further study. One such important defense system is the activation of inducible heat-shock proteins (iHSPs) which protect the gut epithelium against oxidative stress and inflammation. Importantly, various microbial components can induce the expression of iHSPs. This review examines gut epithelial iHSPs as the main targets of microbial signals and nutrients and presents data on diseases involving disturbances of gut epithelial iHSPs. In addition, a broad literature analysis of dietary modulation of gut epithelial iHSPs is provided. Future research aims should include the identification of gut microbes that can optimize gut-protective iHSPs and the evaluation of iHSP-mediated health benefits of nutrients and food components. PMID:26883882

  20. A portable, shock-proof, surface-heated droplet PCR system for Escherichia coli detection.

    Science.gov (United States)

    Angus, Scott V; Cho, Soohee; Harshman, Dustin K; Song, Jae-Young; Yoon, Jeong-Yeol

    2015-12-15

    A novel polymerase chain reaction (PCR) device was developed that uses wire-guided droplet manipulation (WDM) to guide a droplet over three different heating chambers. After PCR amplification, end-point detection is achieved using a smartphone-based fluorescence microscope. The device was tested for identification of the 16S rRNA gene V3 hypervariable region from Escherichia coli genomic DNA. The lower limit of detection was 10(3) genome copies per sample. The device is portable with smartphone-based end-point detection and provides the assay results quickly (15 min for a 30-cycle amplification) and accurately. The system is also shock and vibration resistant, due to the multiple points of contact between the droplet and the thermocouple and the Teflon film on the heater surfaces. The thermocouple also provides real-time droplet temperature feedback to ensure it reaches the set temperature before moving to the next chamber/step in PCR. The device is equipped to use either silicone oil or coconut oil. Coconut oil provides additional portability and ease of transportation by eliminating spilling because its high melting temperature means it is solid at room temperature. PMID:26164008