WorldWideScience

Sample records for chaperone heat shock

  1. 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.

  2. The small heat shock proteins family : The long forgotten chaperones

    NARCIS (Netherlands)

    Garrido, C.; Paul, C.; Seigneuric, R.; Kampinga, H. H.

    2012-01-01

    Small heat shock proteins are a rather heterogeneous family of ATP-independent chaperones, some of which have been proven to block protein aggregation and help the cells to survive stressful conditions. Although much less studied than high molecular weight HSPs like HSP70/HSPA or HSP90/HSPC, their i

  3. The small heat shock proteins family : The long forgotten chaperones

    NARCIS (Netherlands)

    Garrido, C.; Paul, C.; Seigneuric, R.; Kampinga, H. H.

    2012-01-01

    Small heat shock proteins are a rather heterogeneous family of ATP-independent chaperones, some of which have been proven to block protein aggregation and help the cells to survive stressful conditions. Although much less studied than high molecular weight HSPs like HSP70/HSPA or HSP90/HSPC, their

  4. The heat-shock protein/chaperone network and multiple stress resistance.

    Science.gov (United States)

    Jacob, Pierre; Hirt, Heribert; Bendahmane, Abdelhafid

    2017-04-01

    Crop yield has been greatly enhanced during the last century. However, most elite cultivars are adapted to temperate climates and are not well suited to more stressful conditions. In the context of climate change, stress resistance is a major concern. To overcome these difficulties, scientists may help breeders by providing genetic markers associated with stress resistance. However, multistress resistance cannot be obtained from the simple addition of single stress resistance traits. In the field, stresses are unpredictable and several may occur at once. Consequently, the use of single stress resistance traits is often inadequate. Although it has been historically linked with the heat stress response, the heat-shock protein (HSP)/chaperone network is a major component of multiple stress responses. Among the HSP/chaperone 'client proteins', many are primary metabolism enzymes and signal transduction components with essential roles for the proper functioning of a cell. HSPs/chaperones are controlled by the action of diverse heat-shock factors, which are recruited under stress conditions. In this review, we give an overview of the regulation of the HSP/chaperone network with a focus on Arabidopsis thaliana. We illustrate the role of HSPs/chaperones in regulating diverse signalling pathways and discuss several basic principles that should be considered for engineering multiple stress resistance in crops through the HSP/chaperone network. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  5. Discovery of Benzisoxazoles as Potent Inhibitors of Chaperone Heat Shock Protein 90

    Energy Technology Data Exchange (ETDEWEB)

    Gopalsamy, Ariamala; Shi, Mengxiao; Golas, Jennifer; Vogan, Erik; Jacob, Jaison; Johnson, Mark; Lee, Frederick; Nilakantan, Ramaswamy; Petersen, Roseann; Svenson, Kristin; Chopra, Rajiv; Tam, May S.; Wen, Yingxia; Ellingboe, John; Arndt, Kim; Boschelli, Frank (Wyeth)

    2008-08-11

    Heat shock protein 90 (Hsp90) is a molecular chaperone that is responsible for activating many signaling proteins and is a promising target in tumor biology. We have identified small-molecule benzisoxazole derivatives as Hsp90 inhibitors. Crystallographic studies show that these compounds bind in the ATP binding pocket interacting with the Asp93. Structure based optimization led to the identification of potent analogues, such as 13, with good biochemical profiles.

  6. Investigating the Chaperone Properties of a Novel Heat Shock Protein, Hsp70.c, from Trypanosoma brucei

    Directory of Open Access Journals (Sweden)

    Adélle Burger

    2014-01-01

    Full Text Available The neglected tropical disease, African Trypanosomiasis, is fatal and has a crippling impact on economic development. Heat shock protein 70 (Hsp70 is an important molecular chaperone that is expressed in response to stress and Hsp40 acts as its co-chaperone. These proteins play a wide range of roles in the cell and they are required to assist the parasite as it moves from a cold blooded insect vector to a warm blooded mammalian host. A novel cytosolic Hsp70, from Trypanosoma brucei, TbHsp70.c, contains an acidic substrate binding domain and lacks the C-terminal EEVD motif. The ability of a cytosolic Hsp40 from Trypanosoma brucei J protein 2, Tbj2, to function as a co-chaperone of TbHsp70.c was investigated. The main objective was to functionally characterize TbHsp70.c to further expand our knowledge of parasite biology. TbHsp70.c and Tbj2 were heterologously expressed and purified and both proteins displayed the ability to suppress aggregation of thermolabile MDH and chemically denatured rhodanese. ATPase assays revealed a 2.8-fold stimulation of the ATPase activity of TbHsp70.c by Tbj2. TbHsp70.c and Tbj2 both demonstrated chaperone activity and Tbj2 functions as a co-chaperone of TbHsp70.c. In vivo heat stress experiments indicated upregulation of the expression levels of TbHsp70.c.

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

    Science.gov (United States)

    Han, Jiyoung; Kim, Kanghwa; Lee, Songmi

    2015-09-01

    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 proteins, only Snz1 showed the anti-aggregation activity against thermal denaturation of citrate synthase. However, pre-heating of NTF2 and Wos2 at 70℃ for 30 min, efficiently prevented thermal aggregation of citrate synthase. These results indicate that Snz1 and NTF2 possess molecular chaperone activity similar to sHsps, even though there is no α-crystalline domain in their sequences.

  8. Investigation of the chaperone function of the small heat shock protein — AgsA

    Directory of Open Access Journals (Sweden)

    Nagamune Hideaki

    2010-07-01

    Full Text Available Abstract Background A small heat shock protein AgsA was originally isolated from Salmonella enterica serovar Typhimurium. We previously demonstrated that AgsA was an effective chaperone that could reduce the amount of heat-aggregated proteins in an Escherichia coli rpoH mutant. AgsA appeared to promote survival at lethal temperatures by cooperating with other chaperones in vivo. To investigate the aggregation prevention mechanisms of AgsA, we constructed N- or C-terminal truncated mutants and compared their properties with wild type AgsA. Results AgsA showed significant overall homology to wheat sHsp16.9 allowing its three-dimensional structure to be predicted. Truncations of AgsA until the N-terminal 23rd and C-terminal 11th amino acid (AA from both termini preserved its in vivo chaperone activity. Temperature-controlled gel filtration chromatography showed that purified AgsA could maintain large oligomeric complexes up to 50°C. Destabilization of oligomeric complexes was observed for N-terminal 11- and 17-AA truncated AgsA; C-terminal 11-AA truncated AgsA could not form large oligomeric complexes. AgsA prevented the aggregation of denatured lysozyme, malate dehydrogenase (MDH and citrate synthase (CS but did not prevent the aggregation of insulin at 25°C. N-terminal 17-AA truncated AgsA showed no chaperone activity towards MDH. C-terminal 11-AA truncated AgsA showed weak or no chaperone activity towards lysozyme, MDH and CS although it prevented the aggregation of insulin at 25°C. When the same amount of AgsA and C-terminal 11-AA truncated AgsA were mixed (half of respective amount required for efficient chaperone activities, good chaperone activity for all substrates and temperatures was observed. Detectable intermolecular exchanges between AgsA oligomers at 25°C were not observed using fluorescence resonance energy transfer analysis; however, significant exchanges between AgsA oligomers and C-terminal truncated AgsA were observed at 25

  9. The heat shock protein/chaperone network and multiple stress resistance

    KAUST Repository

    Jacob, Pierre

    2016-11-15

    Crop yield has been greatly enhanced during the last century. However, most elite cultivars are adapted to temperate climates and are not well suited to more stressful conditions. In the context of climate change, stress resistance is a major concern. To overcome these difficulties, scientists may help breeders by providing genetic markers associated with stress resistance. However, multi-stress resistance cannot be obtained from the simple addition of single stress resistance traits. In the field, stresses are unpredictable and several may occur at once. Consequently, the use of single stress resistance traits is often inadequate. Although it has been historically linked with the heat stress response, the heat shock protein (HSP)/chaperone network is a major component of multiple stress responses. Among the HSP/chaperone

  10. Malaria heat shock proteins: drug targets that chaperone other drug targets.

    Science.gov (United States)

    Pesce, E-R; Cockburn, I L; Goble, J L; Stephens, L L; Blatch, G L

    2010-06-01

    Ongoing research into the chaperone systems of malaria parasites, and particularly of Plasmodium falciparum, suggests that heat shock proteins (Hsps) could potentially be an excellent class of drug targets. The P. falciparum genome encodes a vast range and large number of chaperones, including 43 Hsp40, six Hsp70, and three Hsp90 proteins (PfHsp40s, PfHsp70s and PfHsp90s), which are involved in a number of fundamental cellular processes including protein folding and assembly, protein translocation, signal transduction and the cellular stress response. Despite the fact that Hsps are relatively conserved across different species, PfHsps do exhibit a considerable number of unique structural and functional features. One PfHsp90 is thought to be sufficiently different to human Hsp90 to allow for selective targeting. PfHsp70s could potentially be used as drug targets in two ways: either by the specific inhibition of Hsp70s by small molecule modulators, as well as disruption of the interactions between Hsp70s and co-chaperones such as the Hsp70/Hsp90 organising protein (Hop) and Hsp40s. Of the many PfHsp40s present on the parasite, there are certain unique or essential members which are considered to have good potential as drug targets. This review critically evaluates the potential of Hsps as malaria drug targets, as well as the use of chaperones as aids in the heterologous expression of other potential malarial drug targets.

  11. A review of acquired thermotolerance, heat shock proteins, and molecular chaperones in archaea

    Energy Technology Data Exchange (ETDEWEB)

    Trent, J.D.

    1996-05-01

    Acquired thermotolerance, the associated synthesis of heat-shock proteins (HSPs) under stress conditions, and the role of HSPs as molecular chaperones under normal growth conditions have been studied extensively in eukaryotes and bacteria, whereas research in these areas in archaea is only beginning. All organisms have evolved a variety of strategies for coping with high-temperature stress, and among these strategies is the increased synthesis of HSPs. The facts that both high temperatures and chemical stresses induce the HSPs and that some of the HSPs recognize and bind to unfolded proteins in vitro have led to the theory that the function of HSPs is to prevent protein aggregation in vivo. The facts that some HSPs are abundant under normal growth conditions and that they assist in protein folding in vitro have led to the theory that they assist protein folding in vivo; in this role, they are referred to as molecular chaperones. The limited research on acquired thermotolerance, HSPs, and molecular chaperones in archaea, particularly the hyperthermophilic archaea, suggests that these extremophiles provide a new perspective in these areas of research, both because they are members of a separate phylogenetic domain and because they have evolved to live under extreme conditions.

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

    Directory of Open Access Journals (Sweden)

    Chang-Jin Park

    2015-12-01

    Full Text Available 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 proteins (HSPs functioning as molecular chaperones are the key components responsible for protein folding, assembly, translocation, and degradation under stress conditions and in many normal cellular processes. Plants respond to pathogen invasion using two different innate immune responses mediated by pattern recognition receptors (PRRs or resistance (R proteins. HSPs play an indispensable role as molecular chaperones in the quality control of plasma membrane-resident PRRs and intracellular R proteins against potential invaders. Here, we specifically discuss the functional involvement of cytosolic and endoplasmic reticulum (ER HSPs/chaperones in plant immunity to obtain an integrated understanding of the immune responses in plant cells.

  13. Molecular chaperone activity of tomato (Lycopersicon esculentum) endoplasmic reticulum-located small heat shock protein.

    Science.gov (United States)

    Mamedov, Tarlan G; Shono, Mariko

    2008-03-01

    The gene encoding the small heat shock protein (sHSP), LeHSP21.5, has been previously cloned from tomato (GenBank accession no. AB026983). The deduced amino acid sequence of this tomato sHSP was most similar to that of other endoplasmic reticulum (ER)-localized sHSPs (ER-sHSP) and can be predicted to target the ER. We examined whether the gene product of LeHSP21.5 (probable ER-sHSP) can act as molecular chaperone. For functional analysis, LeHSP21.5 protein was expressed in Escherichia coli as His(6)-tagged protein in the C-terminal and purified. We confirmed that ER-sHSP could provide thermal protection of soluble proteins in vitro. We compared the thermal stability of E. coli strain BL21 (DE3) transformed with pET-ER-sHSP with the control E. coli strain BL21(DE3) transformed with only the pET vector under heat shock and IPTG-induced conditions. Most of the protein extracts from E. coli cells expressing ER-sHSP were protected from heat-induced denaturation, whereas extracts from cells not expressing ER-sHSP were very heat-sensitive under these conditions. A similar protective effect was observed when purified ER-sHSP was added to an E. coli cell extract. ER-sHSP prevented the thermal aggregation and inactivation of citrate synthase. These collective findings indicate that ER-sHSP can function as a molecular chaperone in vitro.

  14. 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.

  15. Structural and functional homology between periplasmic bacterial molecular chaperones and small heat shock proteins.

    Science.gov (United States)

    Zav'yalov, V P; Zav'yalova, G A; Denesyuk, A I; Gaestel, M; Korpela, T

    1995-07-01

    The periplasmic Yersinia pestis molecular chaperone Caf1M belongs to a superfamily of bacterial proteins for one of which (PapD protein of Escherichia coli) the immunoglobulin-like fold was solved by X-ray analysis. The N-terminal domain of Caf1M was found to share a 20% amino acid sequence identity with an inclusion body-associated protein IbpB of Escherichia coli. One of the regions that was compared, was 32 amino acids long, and displayed more than 40% identity, probability of random coincidence was 1.2 x 10(-4). IbpB is involved in a superfamily of small heat shock proteins which fulfil the function of molecular chaperone. On the basis of the revealed homology, an immunoglobulin-like one-domain model of IbpB three-dimensional structure was designed which could be a prototype conformation of sHsp's. The structure suggested is in good agreement with the known experimental data obtained for different members of sHsp's superfamily.

  16. Antimyeloma Effects of the Heat Shock Protein 70 Molecular Chaperone Inhibitor MAL3-101

    Directory of Open Access Journals (Sweden)

    Marc J. Braunstein

    2011-01-01

    Full Text Available Multiple myeloma (MM is the second most common hematologic malignancy and remains incurable, primarily due to the treatment-refractory/resistant nature of the disease. A rational approach to this compelling challenge is to develop new drugs that act synergistically with existing effective agents. This approach will reduce drug concentrations, avoid treatment resistance, and also improve treatment effectiveness by targeting new and nonredundant pathways in MM. Toward this goal, we examined the antimyeloma effects of MAL3-101, a member of a new class of non-ATP-site inhibitors of the heat shock protein (Hsp 70 molecular chaperone. We discovered that MAL3-101 exhibited antimyeloma effects on MM cell lines in vitro and in vivo in a xenograft plasmacytoma model, as well as on primary tumor cells and bone marrow endothelial cells from myeloma patients. In combination with a proteasome inhibitor, MAL3-101 significantly potentiated the in vitro and in vivo antimyeloma effects. These data support a preclinical rationale for small molecule inhibition of Hsp70 function, either alone or in combination with other agents, as an effective therapeutic strategy for MM.

  17. Prion-like nuclear aggregation of TDP-43 during heat shock is regulated by HSP40/70 chaperones

    Science.gov (United States)

    Udan-Johns, Maria; Bengoechea, Rocio; Bell, Shaughn; Shao, Jieya; Diamond, Marc I.; True, Heather L.; Weihl, Conrad C.; Baloh, Robert H.

    2014-01-01

    TDP-43 aggregation in the cytoplasm or nucleus is a key feature of the pathology of amyotrophic lateral sclerosis and frontotemporal dementia and is observed in numerous other neurodegenerative diseases, including Alzheimer's disease. Despite this fact, the inciting events leading to TDP-43 aggregation remain unclear. We observed that endogenous TDP-43 undergoes reversible aggregation in the nucleus after the heat shock and that this behavior is mediated by the C-terminal prion domain. Substitution of the prion domain from TIA-1 or an authentic yeast prion domain from RNQ1 into TDP-43 can completely recapitulate heat shock-induced aggregation. TDP-43 is constitutively bound to members of the Hsp40/Hsp70 family, and we found that heat shock-induced TDP-43 aggregation is mediated by the availability of these chaperones interacting with the inherently disordered C-terminal prion domain. Finally, we observed that the aggregation of TDP-43 during heat shock led to decreased binding to hnRNPA1, and a change in TDP-43 RNA-binding partners suggesting that TDP-43 aggregation alters its function in response to misfolded protein stress. These findings indicate that TDP-43 shares properties with physiologic prions from yeast, in that self-aggregation is mediated by a Q/N-rich disordered domain, is modulated by chaperone proteins and leads to altered function of the protein. Furthermore, they indicate that TDP-43 aggregation is regulated by chaperone availability, explaining the recurrent observation of TDP-43 aggregates in degenerative diseases of both the brain and muscle where protein homeostasis is disrupted. PMID:23962724

  18. Modulation of the chaperone heat shock cognate 70 by embryonic (pro)insulin correlates with prevention of apoptosis

    Science.gov (United States)

    de la Rosa, Enrique J.; Vega-Núñez, Elena; Morales, Aixa V.; Serna, José; Rubio, Eva; de Pablo, Flora

    1998-01-01

    Insights have emerged concerning insulin function during development, from the finding that apoptosis during chicken embryo neurulation is prevented by prepancreatic (pro)insulin. While characterizing the molecules involved in this survival effect of insulin, we found insulin-dependent regulation of the molecular chaperone heat shock cognate 70 kDa (Hsc70), whose cloning in chicken is reported here. This chaperone, generally considered constitutively expressed, showed regulation of its mRNA and protein levels in unstressed embryos during early development. More important, Hsc70 levels were found to depend on endogenous (pro)insulin, as shown by using antisense oligodeoxynucleotides against (pro)insulin mRNA in cultured neurulating embryos. Further, in the cultured embryos, apoptosis affected mainly cells with the lowest level of Hsc70, as shown by simultaneous Hsc70 immunostaining and terminal deoxynucleotidyltransferase-mediated UTP nick end labeling. These results argue in favor of Hsc70 involvement, modulated by embryonic (pro)insulin, in the prevention of apoptosis during early development and suggest a role for a molecular chaperone in normal embryogenesis. PMID:9707581

  19. Heat Treatment of Small Heat Shock Proteins α-Crystallin and Hsp16.3: Structural Changes vs. Chaperone-like Activity

    Institute of Scientific and Technical Information of China (English)

    毛启龙; 柯丹霞; 昌增益

    2001-01-01

    Both α-crystallin from bovine eye lens and Hsp16.3 from Mycobacterium tuberculosis are members of the small heat shock protein family, They were preincubated at 100 C for 15 min and then cooled on ice immediately. The chaperone-like activities of preheated proteins were measured at 37 C using DTT-treated insulin B chains as substrates. Both preheated proteins exhibited greatly enhanced chaperone-like activities, accompanied with almost unchanged secondary structures and surface hydrophobicity but with a minor change in tertiary structures. The dramatically enhanced chaperone-like activities of preheated α-crystallln and Hsp16.3 may have resulted from the irreversible change in the tertiary structure as detected by near-UV CD spectra.

  20. Unrestrained AMPylation targets cytosolic chaperones and activates the heat shock response

    Science.gov (United States)

    Truttmann, Matthias C.; Zheng, Xu; Hanke, Leo; Damon, Jadyn R.; Grootveld, Monique; Krakowiak, Joanna; Pincus, David; Ploegh, Hidde L.

    2017-01-01

    Protein AMPylation is a conserved posttranslational modification with emerging roles in endoplasmic reticulum homeostasis. However, the range of substrates and cell biological consequences of AMPylation remain poorly defined. We expressed human and Caenorhabditis elegans AMPylation enzymes—huntingtin yeast-interacting protein E (HYPE) and filamentation-induced by cyclic AMP (FIC)-1, respectively—in Saccharomyces cerevisiae, a eukaryote that lacks endogenous protein AMPylation. Expression of HYPE and FIC-1 in yeast induced a strong cytoplasmic Hsf1-mediated heat shock response, accompanied by attenuation of protein translation, massive protein aggregation, growth arrest, and lethality. Overexpression of Ssa2, a cytosolic heat shock protein (Hsp)70, was sufficient to partially rescue growth. In human cell lines, overexpression of active HYPE similarly induced protein aggregation and the HSF1-dependent heat shock response. Excessive AMPylation also abolished HSP70-dependent influenza virus replication. Our findings suggest a mode of Hsp70 inactivation by AMPylation and point toward a role for protein AMPylation in the regulation of cellular protein homeostasis beyond the endoplasmic reticulum. PMID:28031489

  1. Isolation of a Latimeria menadoensis heat shock protein 70 (Lmhsp70) that has all the features of an inducible gene and encodes a functional molecular chaperone.

    Science.gov (United States)

    Modisakeng, Keoagile W; Jiwaji, Meesbah; Pesce, Eva-Rachele; Robert, Jacques; Amemiya, Chris T; Dorrington, Rosemary A; Blatch, Gregory L

    2009-08-01

    Molecular chaperones facilitate the correct folding of other proteins, and heat shock proteins form one of the major classes of molecular chaperones. Heat shock protein 70 (Hsp70) has been extensively studied, and shown to be critically important for cellular protein homeostasis in almost all prokaryotic and eukaryotic systems studied to date. Since there have been very limited studies conducted on coelacanth chaperones, the main objective of this study was to genetically and biochemically characterize a coelacanth Hsp70. We have successfully isolated an Indonesian coelacanth (L. menadoensis) hsp70 gene, Lmhsp70, and found that it contained an intronless coding region and a potential upstream regulatory region. Lmhsp70 encoded a typical Hsp70 based on conserved structural and functional features, and the predicted upstream regulatory region was found to contain six potential promoter elements, and three potential heat shock elements (HSEs). The intronless nature of the coding region and the presence of HSEs suggested that Lmhsp70 was stress-inducible. Phylogenetic analyses provided further evidence that Lmhsp70 was probably inducible, and that it branched as a clade intermediate between bony fish and tetrapods. Recombinant LmHsp70 was successfully overproduced, purified and found to be functional using ATPase activity assays. Taken together, these data provide evidence for the first time that the coelacanth encodes a functional molecular chaperone system.

  2. The role of the molecular chaperone heat shock protein A2 (HSPA2) in regulating human sperm-egg recognition.

    Science.gov (United States)

    Nixon, Brett; Bromfield, Elizabeth G; Dun, Matthew D; Redgrove, Kate A; McLaughlin, Eileen A; Aitken, R John

    2015-01-01

    One of the most common lesions present in the spermatozoa of human infertility patients is an idiopathic failure of sperm-egg recognition. Although this unique cellular interaction can now be readily by-passed by assisted reproductive strategies such as intracytoplasmic sperm injection (ICSI), recent large-scale epidemiological studies have encouraged the cautious use of this technology and highlighted the need for further research into the mechanisms responsible for defective sperm-egg recognition. Previous work in this field has established that the sperm domains responsible for oocyte interaction are formed during spermatogenesis prior to being dynamically modified during epididymal maturation and capacitation in female reproductive tract. While the factors responsible for the regulation of these sequential maturational events are undoubtedly complex, emerging research has identified the molecular chaperone, heat shock protein A2 (HSPA2), as a key regulator of these events in human spermatozoa. HSPA2 is a testis-enriched member of the 70 kDa heat shock protein family that promotes the folding, transport, and assembly of protein complexes and has been positively correlated with in vitro fertilization (IVF) success. Furthermore, reduced expression of HSPA2 from the human sperm proteome leads to an impaired capacity for cumulus matrix dispersal, sperm-egg recognition and fertilization following both IVF and ICSI. In this review, we consider the evidence supporting the role of HSPA2 in sperm function and explore the potential mechanisms by which it is depleted in the spermatozoa of infertile patients. Such information offers novel insights into the molecular mechanisms governing sperm function.

  3. The role of the molecular chaperone heat shock protein A2 (HSPA2 in regulating human sperm-egg recognition

    Directory of Open Access Journals (Sweden)

    Brett Nixon

    2015-01-01

    Full Text Available One of the most common lesions present in the spermatozoa of human infertility patients is an idiopathic failure of sperm-egg recognition. Although this unique cellular interaction can now be readily by-passed by assisted reproductive strategies such as intracytoplasmic sperm injection (ICSI, recent large-scale epidemiological studies have encouraged the cautious use of this technology and highlighted the need for further research into the mechanisms responsible for defective sperm-egg recognition. Previous work in this field has established that the sperm domains responsible for oocyte interaction are formed during spermatogenesis prior to being dynamically modified during epididymal maturation and capacitation in female reproductive tract. While the factors responsible for the regulation of these sequential maturational events are undoubtedly complex, emerging research has identified the molecular chaperone, heat shock protein A2 (HSPA2, as a key regulator of these events in human spermatozoa. HSPA2 is a testis-enriched member of the 70 kDa heat shock protein family that promotes the folding, transport, and assembly of protein complexes and has been positively correlated with in vitro fertilization (IVF success. Furthermore, reduced expression of HSPA2 from the human sperm proteome leads to an impaired capacity for cumulus matrix dispersal, sperm-egg recognition and fertilization following both IVF and ICSI. In this review, we consider the evidence supporting the role of HSPA2 in sperm function and explore the potential mechanisms by which it is depleted in the spermatozoa of infertile patients. Such information offers novel insights into the molecular mechanisms governing sperm function.

  4. Purification and in vitro chaperone activity of a class I small heat-shock protein abundant in recalcitrant chestnut seeds.

    Science.gov (United States)

    Collada, C; Gomez, L; Casado, R; Aragoncillo, C

    1997-09-01

    A 20-kD protein has been purified from cotyledons of recalcitrant (desiccation-sensitive) chestnut (Castanea sativa) seeds, where it accumulates at levels comparable to those of major seed storage proteins. This protein, termed Cs smHSP 1, forms homododecameric complexes under nondenaturing conditions and appears to be homologous to cytosolic class I small heat-shock proteins (smHSPs) from plant sources. In vitro evidence has been obtained that the isolated protein can function as a molecular chaperone; it increases, at stoichiometric levels, the renaturation yields of chemically denatured citrate synthase and also prevents the irreversible thermal inactivation of this enzyme. Although a role in desiccation tolerance has been hypothesized for seed smHSPs, this does not seem to be the case for Cs smHSP 1. We have investigated the presence of immunologically related proteins in orthodox and recalcitrant seeds of 13 woody species. Our results indicate that the presence of Cs smHSP 1-like proteins, even at high levels, is not enough to confer desiccation tolerance, and that the amount of these proteins does not furnish a reliable criterion to identify desiccation-sensitive seeds. Additional proteins or mechanisms appear necessary to keep the viability of orthodox seeds upon shedding.

  5. Universal Stress Protein exhibits a redox-dependent chaperone function in Arabidopsis and enhances plant tolerance to heat shock and oxidative stress

    Directory of Open Access Journals (Sweden)

    Jung eYoung Jun

    2015-12-01

    Full Text Available Although a wide range of physiological information on Universal Stress Proteins (USPs is available from many organisms, their biochemical and molecular functions remain unidentified. The biochemical function of AtUSP (At3g53990 from Arabidopsis thaliana was therefore investigated. Plants over-expressing AtUSP showed a strong resistance to heat shock and oxidative stress, compared with wild-type and Atusp knock-out plants, confirming the crucial role of AtUSP in stress tolerance. AtUSP was present in a variety of structures including monomers, dimers, trimers, and oligomeric complexes, and switched in response to external stresses from low molecular weight (LMW species to high molecular weight (HMW complexes. AtUSP exhibited a strong chaperone function under stress conditions in particular, and this activity was significantly increased by heat treatment. Chaperone activity of AtUSP was critically regulated by the redox status of cells and accompanied by structural changes to the protein. Over-expression of AtUSP conferred a strong tolerance to heat shock and oxidative stress upon Arabidopsis, primarily via its chaperone function.

  6. Blind cavefish and heat shock protein chaperones: a novel role for hsp90alpha in lens apoptosis.

    Science.gov (United States)

    Hooven, Thomas A; Yamamoto, Yoshiyuki; Jeffery, William R

    2004-01-01

    Lens apoptosis plays a central role in cavefish eye degeneration. Heat shock proteins (hsps) can regulate apoptosis; therefore, we examined the relationship between constitutive hsp70 and hsp90 expression and lens apoptosis. The model system is Astyanax mexicanus, a teleost species consisting of an eyed surface-dwelling (surface fish) form and numerous blind cave-dwelling (cavefish) forms. Optic primordia are formed in the cavefish embryo but they subsequently undergo lens apoptosis, arrest in development and degenerate. Astyanax hsp90 and hsp70 DNAs were isolated to use as probes to compare gene expression during surface fish and cavefish development. Hsp90beta, which encodes one of two hsp90 isoforms, was not expressed in the surface fish or cavefish lens, whereas hsp70 was expressed in the lens of both forms, suggesting that neither is directly involved in lens apoptosis. In contrast, hsp90alpha, the other hsp90 isoform, was expressed in the cavefish but not the surface fish lens. Hsp90alpha expression peaked shortly before the beginning of lens apoptosis in three convergent cavefish populations, suggesting a close relationship with lens apoptosis. The absence of hsp90beta in the lens allowed us to use geldanamycin and radicicol, specific inhibitors of hsp90 chaperone function, to determine whether lens cell death requires hsp90alpha expression. Both inhibitors blocked TUNEL labeling in the cavefish lens, suggesting that hsp90alpha is required for apoptosis. In contrast to their effects on the lens, these inhibitors induced TUNEL labeling in the surface epidermis, presumably due to effects on hsp90beta function, implying that the two-hsp90 isoforms may have contrasting roles in cell survival. We conclude that hsp90alpha plays a novel role in lens apoptosis and cavefish eye degeneration.

  7. A novel C-terminal homologue of Aha1 co-chaperone binds to heat shock protein 90 and stimulates its ATPase activity in Entamoeba histolytica.

    Science.gov (United States)

    Singh, Meetali; Shah, Varun; Tatu, Utpal

    2014-04-17

    Cytosolic heat shock protein 90 (Hsp90) has been shown to be essential for many infectious pathogens and is considered a potential target for drug development. In this study, we have carried out biochemical characterization of Hsp90 from a poorly studied protozoan parasite of clinical importance, Entamoeba histolytica. We have shown that Entamoeba Hsp90 can bind to both ATP and its pharmacological inhibitor, 17-AAG (17-allylamino-17-demethoxygeldanamycin), with Kd values of 365.2 and 10.77 μM, respectively, and it has a weak ATPase activity with a catalytic efficiency of 4.12×10(-4) min(-1) μM(-1). Using inhibitor 17-AAG, we have shown dependence of Entamoeba on Hsp90 for its growth and survival. Hsp90 function is regulated by various co-chaperones. Previous studies suggest a lack of several important co-chaperones in E. histolytica. In this study, we describe the presence of a novel homologue of co-chaperone Aha1 (activator of Hsp90 ATPase), EhAha1c, lacking a canonical Aha1 N-terminal domain. We also show that EhAha1c is capable of binding and stimulating ATPase activity of EhHsp90. In addition to highlighting the potential of Hsp90 inhibitors as drugs against amoebiasis, our study highlights the importance of E. histolytica in understanding the evolution of Hsp90 and its co-chaperone repertoire.

  8. Hydroimidazolone modification of the conserved Arg12 in small heat shock proteins: studies on the structure and chaperone function using mutant mimics.

    Directory of Open Access Journals (Sweden)

    Ram H Nagaraj

    Full Text Available Methylglyoxal (MGO is an α-dicarbonyl compound present ubiquitously in the human body. MGO reacts with arginine residues in proteins and forms adducts such as hydroimidazolone and argpyrimidine in vivo. Previously, we showed that MGO-mediated modification of αA-crystallin increased its chaperone function. We identified MGO-modified arginine residues in αA-crystallin and found that replacing such arginine residues with alanine residues mimicked the effects of MGO on the chaperone function. Arginine 12 (R12 is a conserved amino acid residue in Hsp27 as well as αA- and αB-crystallin. When treated with MGO at or near physiological concentrations (2-10 µM, R12 was modified to hydroimidazolone in all three small heat shock proteins. In this study, we determined the effect of arginine substitution with alanine at position 12 (R12A to mimic MGO modification on the structure and chaperone function of these proteins. Among the three proteins, the R12A mutation improved the chaperone function of only αA-crystallin. This enhancement in the chaperone function was accompanied by subtle changes in the tertiary structure, which increased the thermodynamic stability of αA-crystallin. This mutation induced the exposure of additional client protein binding sites on αA-crystallin. Altogether, our data suggest that MGO-modification of the conserved R12 in αA-crystallin to hydroimidazolone may play an important role in reducing protein aggregation in the lens during aging and cataract formation.

  9. One out of four: HspL but no other small heat shock protein of Agrobacterium tumefaciens acts as efficient virulence-promoting VirB8 chaperone.

    Directory of Open Access Journals (Sweden)

    Yun-Long Tsai

    Full Text Available Alpha-crystallin-type small heat shock proteins (sHsps are ubiquitously distributed in most eukaryotes and prokaryotes. Four sHsp genes named hspL, hspC, hspAT1, and hspAT2 were identified in Agrobacterium tumefaciens, a plant pathogenic bacterium capable of unique interkingdom DNA transfer via type IV secretion system (T4SS. HspL is highly expressed in virulence-induced growth condition and functions as a VirB8 chaperone to promote T4SS-mediated DNA transfer. Here, we used genetic and biochemical approaches to investigate the involvement of the other three sHsps in T4SS and discovered the molecular basis underlying the dominant function of HspL in promoting T4SS function. While single deletion of hspL but no other sHsp gene reduced T4SS-mediated DNA transfer and tumorigenesis efficiency, additional deletion of other sHsp genes in the hspL deletion background caused synergistic effects in the virulence phenotypes. This is correlated with the high induction of hspL and only modest increase of hspC, hspAT1, and hspAT2 at their mRNA and protein abundance in virulence-induced growth condition. Interestingly, overexpression of any single sHsp gene alone in the quadruple mutant caused increased T4SS-mediated DNA transfer and tumorigenesis. Thermal aggregation protecting assays in vitro indicated that all four sHsps exhibit chaperone activity for the model substrate citrate synthase but only HspL functions as efficient chaperone for VirB8. The higher VirB8 chaperone activity of HspL was also demonstrated in vivo, in which lower amounts of HspL than other sHsps were sufficient in maintaining VirB8 homeostasis in A. tumefaciens. Domain swapping between HspL and HspAT2 indicated that N-terminal, central alpha-crystallin, and C-terminal domains of HspL all contribute to HspL function as an efficient VirB8 chaperone. Taken together, we suggest that the dominant role of HspL in promoting T4SS function is based on its higher expression in virulence

  10. Single methyl group determines prion propagation and protein degradation activities of yeast heat shock protein (Hsp)-70 chaperones Ssa1p and Ssa2p.

    Science.gov (United States)

    Sharma, Deepak; Masison, Daniel C

    2011-08-16

    Organisms encode multiple homologous heat shock protein (Hsp)-70s, which are essential protein chaperones that play the major role in cellular protein "quality control." Although Hsp70s are functionally redundant and highly homologous, many possess distinct functions. A regulatory motif underlying such distinctions, however, is unknown. The 98% identical cytoplasmic Hsp70s Ssa1p and Ssa2p function differently with regard to propagation of yeast [URE3] prions and in the vacuolar-mediated degradation of gluconeogenesis enzymes, such as FBPase. Here, we show that the Hsp70 nucleotide binding domain (NBD) regulates these functional specificities. We find little difference in ATPase, protein refolding, and amyloid inhibiting activities of purified Ssa1p and Ssa2p, but show that interchanging NBD residue alanine 83 (Ssa1p) and glycine 83 (Ssa2p) switched functions of Ssa1p and Ssa2p in [URE3] propagation and FBPase degradation. Disrupting the degradation pathway did not affect prion propagation, however, indicating these are two distinct processes where Ssa1/2p chaperones function differently. Our results suggest that the primary evolutionary pressure for Hsp70 functional distinctions is not to specify interactions of Hsp70 with substrate, but to specify the regulation of this activity. Our data suggest a rationale for maintaining multiple Hsp70s and suggest that subtle differences among Hsp70s evolved to provide functional specificity without affecting overall enzymatic activity.

  11. The endoplasmic reticulum-resident chaperone heat shock protein 47 protects the Golgi apparatus from the effects of O-glycosylation inhibition.

    Science.gov (United States)

    Miyata, Shingo; Mizuno, Tatsunori; Koyama, Yoshihisa; Katayama, Taiichi; Tohyama, Masaya

    2013-01-01

    The Golgi apparatus is important for the transport of secretory cargo. Glycosylation is a major post-translational event. Recognition of O-glycans on proteins is necessary for glycoprotein trafficking. In this study, specific inhibition of O-glycosylation (Golgi stress) induced the expression of endoplasmic reticulum (ER)-resident heat shock protein (HSP) 47 in NIH3T3 cells, although cell death was not induced by Golgi stress alone. When HSP47 expression was downregulated by siRNA, inhibition of O-glycosylation caused cell death. Three days after the induction of Golgi stress, the Golgi apparatus was disassembled, many vacuoles appeared near the Golgi apparatus and extended into the cytoplasm, the nuclei had split, and cell death assay-positive cells appeared. Six hours after the induction of Golgi stress, HSP47-knockdown cells exhibited increased cleavage of Golgi-resident caspase-2. Furthermore, activation of mitochondrial caspase-9 and ER-resident unfolded protein response (UPR)-related molecules and efflux of cytochrome c from the mitochondria to the cytoplasm was observed in HSP47-knockdown cells 24 h after the induction of Golgi stress. These findings indicate that (i) the ER-resident chaperon HSP47 protected cells from Golgi stress, and (ii) Golgi stress-induced cell death caused by the inhibition of HSP47 expression resulted from caspase-2 activation in the Golgi apparatus, extending to the ER and mitochondria.

  12. The heat shock protein-90 co-chaperone, Cyclophilin 40, promotes ALK-positive, anaplastic large cell lymphoma viability and its expression is regulated by the NPM-ALK oncoprotein

    Directory of Open Access Journals (Sweden)

    Pearson Joel D

    2012-06-01

    Full Text Available Abstract Background Anaplastic lymphoma kinase-positive, anaplastic large cell lymphoma (ALK+ ALCL is a T cell lymphoma defined by the presence of chromosomal translocations involving the ALK tyrosine kinase gene. These translocations generate fusion proteins (e.g. NPM-ALK with constitutive tyrosine kinase activity, which activate numerous signalling pathways important for ALK+ ALCL pathogenesis. The molecular chaperone heat shock protein-90 (Hsp90 plays a critical role in allowing NPM-ALK and other signalling proteins to function in this lymphoma. Co-chaperone proteins are important for helping Hsp90 fold proteins and for directing Hsp90 to specific clients; however the importance of co-chaperone proteins in ALK+ ALCL has not been investigated. Our preliminary findings suggested that expression of the immunophilin co-chaperone, Cyclophilin 40 (Cyp40, is up-regulated in ALK+ ALCL by JunB, a transcription factor activated by NPM-ALK signalling. In this study we examined the regulation of the immunophilin family of co-chaperones by NPM-ALK and JunB, and investigated whether the immunophilin co-chaperones promote the viability of ALK+ ALCL cell lines. Methods NPM-ALK and JunB were knocked-down in ALK+ ALCL cell lines with siRNA, and the effect on the expression of the three immunophilin co-chaperones: Cyp40, FK506-binding protein (FKBP 51, and FKBP52 examined. Furthermore, the effect of knock-down of the immunophilin co-chaperones, either individually or in combination, on the viability of ALK+ ALCL cell lines and NPM-ALK levels and activity was also examined. Results We found that NPM-ALK promoted the transcription of Cyp40 and FKBP52, but only Cyp40 transcription was promoted by JunB. We also observed reduced viability of ALK+ ALCL cell lines treated with Cyp40 siRNA, but not with siRNAs directed against FKBP52 or FKBP51. Finally, we demonstrate that the decrease in the viability of ALK+ ALCL cell lines treated with Cyp40 siRNA does not appear to

  13. Small heat shock proteins, protein degradation and protein aggregation diseases

    NARCIS (Netherlands)

    Vos, Michel J.; Zijlstra, Marianne P.; Carra, Serena; Sibon, Ody C. M.; Kampinga, Harm H.

    Small heat shock proteins have been characterized in vitro as ATP-independent molecular chaperones that can prevent aggregation of un- or misfolded proteins and assist in their refolding with the help of ATP-dependent chaperone machines (e. g., the Hsp70 proteins). Comparison of the functionality of

  14. A bacteriophage-encoded J-domain protein interacts with the DnaK/Hsp70 chaperone and stabilizes the heat-shock factor σ32 of Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Elsa Perrody

    Full Text Available The universally conserved J-domain proteins (JDPs are obligate cochaperone partners of the Hsp70 (DnaK chaperone. They stimulate Hsp70's ATPase activity, facilitate substrate delivery, and confer specific cellular localization to Hsp70. In this work, we have identified and characterized the first functional JDP protein encoded by a bacteriophage. Specifically, we show that the ORFan gene 057w of the T4-related enterobacteriophage RB43 encodes a bona fide JDP protein, named Rki, which specifically interacts with the Escherichia coli host multifunctional DnaK chaperone. However, in sharp contrast with the three known host JDP cochaperones of DnaK encoded by E. coli, Rki does not act as a generic cochaperone in vivo or in vitro. Expression of Rki alone is highly toxic for wild-type E. coli, but toxicity is abolished in the absence of endogenous DnaK or when the conserved J-domain of Rki is mutated. Further in vivo analyses revealed that Rki is expressed early after infection by RB43 and that deletion of the rki gene significantly impairs RB43 proliferation. Furthermore, we show that mutations in the host dnaK gene efficiently suppress the growth phenotype of the RB43 rki deletion mutant, thus indicating that Rki specifically interferes with DnaK cellular function. Finally, we show that the interaction of Rki with the host DnaK chaperone rapidly results in the stabilization of the heat-shock factor σ(32, which is normally targeted for degradation by DnaK. The mechanism by which the Rki-dependent stabilization of σ(32 facilitates RB43 bacteriophage proliferation is discussed.

  15. 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...

  16. Structural model of dodecameric heat-shock protein Hsp21: Flexible N-terminal arms interact with client proteins while C-terminal tails maintain the dodecamer and chaperone activity.

    Science.gov (United States)

    Rutsdottir, Gudrun; Härmark, Johan; Weide, Yoran; Hebert, Hans; Rasmussen, Morten I; Wernersson, Sven; Respondek, Michal; Akke, Mikael; Højrup, Peter; Koeck, Philip J B; Söderberg, Christopher A G; Emanuelsson, Cecilia

    2017-05-12

    Small heat-shock proteins (sHsps) prevent aggregation of thermosensitive client proteins in a first line of defense against cellular stress. The mechanisms by which they perform this function have been hard to define due to limited structural information; currently, there is only one high-resolution structure of a plant sHsp published, that of the cytosolic Hsp16.9. We took interest in Hsp21, a chloroplast-localized sHsp crucial for plant stress resistance, which has even longer N-terminal arms than Hsp16.9, with a functionally important and conserved methionine-rich motif. To provide a framework for investigating structure-function relationships of Hsp21 and understanding these sequence variations, we developed a structural model of Hsp21 based on homology modeling, cryo-EM, cross-linking mass spectrometry, NMR, and small-angle X-ray scattering. Our data suggest a dodecameric arrangement of two trimer-of-dimer discs stabilized by the C-terminal tails, possibly through tail-to-tail interactions between the discs, mediated through extended IXVXI motifs. Our model further suggests that six N-terminal arms are located on the outside of the dodecamer, accessible for interaction with client proteins, and distinct from previous undefined or inwardly facing arms. To test the importance of the IXVXI motif, we created the point mutant V181A, which, as expected, disrupts the Hsp21 dodecamer and decreases chaperone activity. Finally, our data emphasize that sHsp chaperone efficiency depends on oligomerization and that client interactions can occur both with and without oligomer dissociation. These results provide a generalizable workflow to explore sHsps, expand our understanding of sHsp structural motifs, and provide a testable Hsp21 structure model to inform future investigations. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  17. HBP21: a novel member of TPR motif family, as a potential chaperone of heat shock protein 70 in proliferative vitreoretinopathy (PVR) and breast cancer.

    Science.gov (United States)

    Liu, Qinghuai; Gao, Juanyu; Chen, Xi; Chen, Yuxin; Chen, Jie; Wang, Saiqun; Liu, Jin; Liu, Xiaoyi; Li, Jianmin

    2008-11-01

    A large number of tetratricopeptide repeat (TPR)-containing proteins have been shown to interact with the C-terminal domain of the 70 kDa heat-shock protein (Hsp70), especially those with three consecutive TPR motifs. The TPR motifs in these proteins are necessary and sufficient for mediating the interaction with Hsp70. Here, we investigate HBP21, a novel human protein of unknown function having three tandem TPR motifs predicted by computational sequence analysis. We confirmed the high expression of HBP21 in breast cancer and proliferative vitreoretinopathy (PVR) proliferative membrane and examined whether HBP21 could interact with Hsp70 using a yeast two-hybrid system and glutathione S-transferase pull-down assay. Previous studies have demonstrated the importance of Hsp70 C-terminal residues EEVD and PTIEEVD for interaction with TPR-containing proteins. Here, we tested an assortment of truncation and amino acid substitution mutants of Hsp70 to determine their ability to bind to HBP21 using a yeast two-hybrid system. The newly discovered interaction between HBP21 and Hsp70 along with observations from other studies leads to our hypothesis that HBP21 may be involved in the inhibition of progression and metastasis of tumor cells.

  18. Heat Shock Proteins and Diabetes.

    Science.gov (United States)

    Zilaee, Marzie; Shirali, Saeed

    2016-12-01

    Diabetes is a chronic disease, and its prevalence continues to rise and can increase the risk for the progression of microvascular (such as nephropathy, retinopathy and neuropathy) and also macrovascular complications. Diabetes is a condition in which the oxidative stress and inflammation rise. Heat shock proteins (HSPs) are a highly conserved family of proteins that are expressed by all cells exposed to environmental stress, and they have diverse functions. In patients with diabetes, the expression and levels of HSPs decrease, but these chaperones can aid in improving some complications of diabetes, such as oxidative stress and inflammation. (The suppression of some HSPs is associated with a generalized increase in tissue inflammation.) In this review, we summarize the current understanding of HSPs in diabetes as well as their complications, and we also highlight their potential role as therapeutic targets in diabetes. Copyright © 2016 Canadian Diabetes Association. Published by Elsevier Inc. All rights reserved.

  19. Oolemmal proteomics – identification of highly abundant heat shock proteins and molecular chaperones in the mature mouse egg and their localization on the plasma membrane

    Science.gov (United States)

    Calvert, Meredith E; Digilio, Laura C; Herr, John C; Coonrod, Scott A

    2003-01-01

    Background The mature mouse egg contains the full complement of maternal proteins required for fertilization, the transition to zygotic transcription, and the beginning stages of embryogenesis. Many of these proteins remain to be characterized, therefore in this study we have identified highly abundant egg proteins using a proteomic approach and found that several of these proteins also appear to localize to the egg surface. Characterization of such molecules will provide important insight into the cellular events of fertilization and early development. Methods In order to identify some of the more abundant egg proteins, whole egg extracts were resolved on coomassie-stained two-dimensional (2D) PAGE gels. Several highly abundant protein spots were cored and microsequenced by tandem mass spectrometry (TMS), and determined to be molecular chaperone proteins. Concurrent experiments were performed to identify oolemmal proteins using 2D avidin blotting. Proteins spots that appeared to be surface labeled by biotinylation were correlated with the initial coomassie-stained reference gel. Surprisingly, some of the surface labelled proteins corresponded to those abundant chaperone proteins previously identified. To confirm whether these molecules are accumulating at the oolemmal surface in eggs, we performed immunofluoresence on live, zona-free eggs using antibodies to HSP70, HSP90, GRP94, GRP78, calreticulin and calnexin. Results The putative surface-labeled proteins identified by biotinylation included the molecular chaperones HSP70 (MW 70 KDa, pI 5.5), HSP90a (MW 85 KDa, pI 4.9), GRP94 (MW 92 KDa, pI 4.7), GRP78 (MW 72 KDa, pI 5.0), Oxygen regulated protein 150 (ORP150; MW 111 KDa, pI 5.1), Calreticulin (MW 48 KDa, pI 4.3), Calnexin (MW 65 KDa, pI 4.5), and Protein disulfide isomerase (PDI; MW 57 KDa, pI 4.8). Immunofluoresence results showed that antibodies to HSP90, GRP94, GRP78 and calreticulin were reactive with oolemmal proteins. We were unable to confirm surface

  20. Oolemmal proteomics – identification of highly abundant heat shock proteins and molecular chaperones in the mature mouse egg and their localization on the plasma membrane

    Directory of Open Access Journals (Sweden)

    Herr John C

    2003-02-01

    Full Text Available Abstract Background The mature mouse egg contains the full complement of maternal proteins required for fertilization, the transition to zygotic transcription, and the beginning stages of embryogenesis. Many of these proteins remain to be characterized, therefore in this study we have identified highly abundant egg proteins using a proteomic approach and found that several of these proteins also appear to localize to the egg surface. Characterization of such molecules will provide important insight into the cellular events of fertilization and early development. Methods In order to identify some of the more abundant egg proteins, whole egg extracts were resolved on coomassie-stained two-dimensional (2D PAGE gels. Several highly abundant protein spots were cored and microsequenced by tandem mass spectrometry (TMS, and determined to be molecular chaperone proteins. Concurrent experiments were performed to identify oolemmal proteins using 2D avidin blotting. Proteins spots that appeared to be surface labeled by biotinylation were correlated with the initial coomassie-stained reference gel. Surprisingly, some of the surface labelled proteins corresponded to those abundant chaperone proteins previously identified. To confirm whether these molecules are accumulating at the oolemmal surface in eggs, we performed immunofluoresence on live, zona-free eggs using antibodies to HSP70, HSP90, GRP94, GRP78, calreticulin and calnexin. Results The putative surface-labeled proteins identified by biotinylation included the molecular chaperones HSP70 (MW 70 KDa, pI 5.5, HSP90a (MW 85 KDa, pI 4.9, GRP94 (MW 92 KDa, pI 4.7, GRP78 (MW 72 KDa, pI 5.0, Oxygen regulated protein 150 (ORP150; MW 111 KDa, pI 5.1, Calreticulin (MW 48 KDa, pI 4.3, Calnexin (MW 65 KDa, pI 4.5, and Protein disulfide isomerase (PDI; MW 57 KDa, pI 4.8. Immunofluoresence results showed that antibodies to HSP90, GRP94, GRP78 and calreticulin were reactive with oolemmal proteins. We were unable to

  1. Oolemmal proteomics--identification of highly abundant heat shock proteins and molecular chaperones in the mature mouse egg and their localization on the plasma membrane.

    Science.gov (United States)

    Calvert, Meredith E; Digilio, Laura C; Herr, John C; Coonrod, Scott A

    2003-02-14

    The mature mouse egg contains the full complement of maternal proteins required for fertilization, the transition to zygotic transcription, and the beginning stages of embryogenesis. Many of these proteins remain to be characterized, therefore in this study we have identified highly abundant egg proteins using a proteomic approach and found that several of these proteins also appear to localize to the egg surface. Characterization of such molecules will provide important insight into the cellular events of fertilization and early development. In order to identify some of the more abundant egg proteins, whole egg extracts were resolved on coomassie-stained two-dimensional (2D) PAGE gels. Several highly abundant protein spots were cored and microsequenced by tandem mass spectrometry (TMS), and determined to be molecular chaperone proteins. Concurrent experiments were performed to identify oolemmal proteins using 2D avidin blotting. Proteins spots that appeared to be surface labeled by biotinylation were correlated with the initial coomassie-stained reference gel. Surprisingly, some of the surface labelled proteins corresponded to those abundant chaperone proteins previously identified. To confirm whether these molecules are accumulating at the oolemmal surface in eggs, we performed immunofluoresence on live, zona-free eggs using antibodies to HSP70, HSP90, GRP94, GRP78, calreticulin and calnexin. The putative surface-labeled proteins identified by biotinylation included the molecular chaperones HSP70 (MW 70 KDa, pI 5.5), HSP90a (MW 85 KDa, pI 4.9), GRP94 (MW 92 KDa, pI 4.7), GRP78 (MW 72 KDa, pI 5.0), Oxygen regulated protein 150 (ORP150; MW 111 KDa, pI 5.1), Calreticulin (MW 48 KDa, pI 4.3), Calnexin (MW 65 KDa, pI 4.5), and Protein disulfide isomerase (PDI; MW 57 KDa, pI 4.8). Immunofluoresence results showed that antibodies to HSP90, GRP94, GRP78 and calreticulin were reactive with oolemmal proteins. We were unable to confirm surface localization of HSP70 or

  2. Thermotolerance and Human Performance: Role of Heat Shock Proteins

    Science.gov (United States)

    2009-10-01

    of the significant teratogens in humans, animals, and insects. However, protection from teratogenic effects as is true for various aspects of the...heat shock proteins as molecular chaperones. Annu Rev Cell Biol. 1993;9:601–634 Germain M, Webster W, Edwards M. Hyperthermia as a teratogen ...physical or chemical teratogens are expressed later as enhanced induction of heat shock proteins when embryonic hearts are cultured in

  3. Heat shock protein 90 acts as a molecular chaperone in late-phase acti-vation of extracellular signal-regulated kinase 1/2 stimulated by oxida-tive stress in vascular smooth muscle cells

    Institute of Scientific and Technical Information of China (English)

    Dai-hua LIU; Hao-yu YUAN; Chun-ya CAO; Zhi-ping GAO; Bing-yang ZHU; Hong-lin HUANG; Duan-fang LIAO

    2007-01-01

    Aim: To investigate whether cytosolic heat shock protein 90 (HSP90) acts as a molecular chaperone on the activated extracellular signal-regulated kinase 1/2 (ERK1/2) and cell proliferation stimulated by reactive oxygen species (ROS) in rat vascular smooth muscle cells (VSMC). Methods: VSMC were exposed to 1 μmol/L LY83583 (6-anilinoquinoline-5,8-quinolinedione, producer of ROS) for 120 min in the presence or absence of 5 μmol/L geldanamycin, a specific inhibitor of HSP90. Then the total, soluble, and insoluble proteins of the ceils were collected. HSP90, ERK1/2, and phosphor-ERK 1/2 in the cell lysate were measured by Western blotting. The interaction of HSP90 and phosphor-ERK1/2 was analyzed by immunoprecipi- tation assay, and the nuclear phosphor-ERK1/2 was measured by Western blot- ting and immunofluorescence. Cell proliferation was tested by cell counting and 3-(4,5-dimethylthiazol-2-yl)-3,5-di-phenyltetrazoliumbromide (MTT). Results: The cytosolic HSP90 of VSMC was upregulated by LY83583 in a time-dependent man- ner with the peak at 120 min, which is consistent with the late peak of phosphor- ERK1/2. Immunoprecipitation and Western blotting analyses showed that LY83583 increased the interaction of HSP90 with phosphor-ERK1/2, the phosphor-ERK1/2 level, and the soluble phosphor-ERK1/2 level by 1.8-, 2.5-, and 2.9-fold, respectively. In contrast, the insoluble phosphor-ERK1/2 of VSMC was decreased. Interestingly, LY83583 treatment promoted the nuclear phosphor-ERK1/2 by 7.6-fold as con- finned by Western blotting and immunofluorescence assays. Furthermore, cell counting and the MTT assay showed that LY83583 stimulated VSMC prolifera- tion with the increased expression of HSP90 and levels of soluble and nuclear phosphor-ERK1/2. Pretreatment of geldanamycin antagonized the effect of LY83583. Conclusion: HSP90 could mediate the oxidative stress-stimulated, late- phase activation of ERK1/2 and VSMC proliferation by promoting the ERK1/2 phosphorylation, the

  4. 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...

  5. 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.

  6. Heat shock factors: integrators of cell stress, development and lifespan.

    Science.gov (United States)

    Akerfelt, Malin; Morimoto, Richard I; Sistonen, Lea

    2010-08-01

    Heat shock factors (HSFs) are essential for all organisms to survive exposures to acute stress. They are best known as inducible transcriptional regulators of genes encoding molecular chaperones and other stress proteins. Four members of the HSF family are also important for normal development and lifespan-enhancing pathways, and the repertoire of HSF targets has thus expanded well beyond the heat shock genes. These unexpected observations have uncovered complex layers of post-translational regulation of HSFs that integrate the metabolic state of the cell with stress biology, and in doing so control fundamental aspects of the health of the proteome and ageing.

  7. Transcriptional Modulation of Heat-Shock Protein Gene Expression

    OpenAIRE

    Anastasis Stephanou; Latchman, David S.

    2011-01-01

    Heat-shock proteins (Hsps) are molecular chaperones that are ubiquitously expressed but are also induced in cells exposed to stressful stimuli. Hsps have been implicated in the induction and propagation of several diseases. This paper focuses on regulatory factors that control the transcription of the genes encoding Hsps. We also highlight how distinct transcription factors are able to interact and modulate Hsps in different pathological states. Thus, a better understanding of the complex sig...

  8. Transcriptional modulation of heat-shock protein gene expression.

    OpenAIRE

    A. Stephanou; Latchman, D S

    2011-01-01

    Heat-shock proteins (Hsps) are molecular chaperones that are ubiquitously expressed but are also induced in cells exposed to stressful stimuli. Hsps have been implicated in the induction and propagation of several diseases. This paper focuses on regulatory factors that control the transcription of the genes encoding Hsps. We also highlight how distinct transcription factors are able to interact and modulate Hsps in different pathological states. Thus, a better understanding of the complex sig...

  9. 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.

  10. Heat Shock Protein and Innate Immunity

    Institute of Scientific and Technical Information of China (English)

    Min-FuTsan; BaochongGao

    2004-01-01

    In addition to serving as molecular chaperones, heat shock proteins (HSPs) have been implicated in autoimmune diseases, antigen presentation and tumor immunity. Extensive work in the last 10 years has also suggested that HSPs such as Hsp60, Hsp70, Hsp90 and gp96, may be potent activators of the innate immune system capable of inducing the production of pro-inflammatory cytokines by the monocyte-macrophage system, and the activation and maturation of dendritic cells via the Toll-like receptor 2 and 4 signal transduction pathways. However, recent evidence suggests that the reported cytokine effects of HSPs may be a result of the contaminating bacterial cell-wall products. This concise review summarizes the current controversy over the role of HSPs in innate immunity. Cellular & Molecular Immunology.

  11. Heat Shock Protein and Innate Immunity

    Institute of Scientific and Technical Information of China (English)

    Min-Fu Tsan; Baochong Gao

    2004-01-01

    In addition to serving as molecular chaperones, heat shock proteins (HSPs) have been implicated in autoimmune diseases, antigen presentation and tumor immunity. Extensive work in the last 10 years has also suggested that HSPs such as Hsp60, Hsp70, Hsp90 and gp96, may be potent activators of the innate immune system capable of inducing the production of pro-inflammatory cytokines by the monocyte-macrophage system, and the activation and maturation of dendritic cells via the Toll-like receptor 2 and 4 signal transduction pathways. However, recent evidence suggests that the reported cytokine effects of HSPs may be a result of the contaminating bacterial cell-wall products. This concise review summarizes the current controversy over the role of HSPs in innate immunity.

  12. 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...... stress response, which facilitates the cell recovery from many forms of stress, e.g., heat stress. In S. cerevisiae, HSR is regulated mainly by the transcription factor heat shock factor (Hsf1p) and many of its targets are genes coding for molecular chaperones that promote protein folding and prevent...... 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...

  13. Heat Shock Proteins, Autoimmunity, and Cancer Treatment

    Directory of Open Access Journals (Sweden)

    Stuart K. Calderwood

    2012-01-01

    Full Text Available Heat shock proteins (HSPs have been linked to the therapy of both cancer and inflammatory diseases, approaches that utilize contrasting immune properties of these proteins. It would appear that HSP family members Hsp60 and Hsp70, whether from external sources or induced locally during inflammation, can be processed by antigen-presenting cells and that HSP-derived epitopes then activate regulatory T cells and suppress inflammatory diseases. These effects also extend to the HSP-rich environments of cancer cells where elevated HSP concentrations may participate in the immunosuppressive tumor milieu. However, HSPs can also be important mediators of tumor immunity. Due to their molecular chaperone properties, some HSPs can bind tumor-specific peptides and deliver them deep into the antigen-processing pathways of antigen-presenting cells (APCs. In this context, HSP-based vaccines can activate tumor-specific immunity, trigger the proliferation and CTL capabilities of cancer-specific CD8+ T cells, and inhibit tumor growth. Further advances in HSP-based anticancer immunotherapy appear to involve improving the properties of the molecular chaperone vaccines by enhancing their antigen-binding properties and combating the immunosuppressive tumor milieu to permit programming of active CTL capable of penetrating the tumor milieu and specifically targeting tumor cells.

  14. Conserved TRAM Domain Functions as an Archaeal Cold Shock Protein via RNA Chaperone Activity

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    Bo Zhang

    2017-08-01

    Full Text Available Cold shock proteins (Csps enable organisms to acclimate to and survive in cold environments and the bacterial CspA family exerts the cold protection via its RNA chaperone activity. However, most Archaea do not contain orthologs to the bacterial csp. TRAM, a conserved domain among RNA modification proteins ubiquitously distributed in organisms, occurs as an individual protein in most archaeal phyla and has a structural similarity to Csp proteins, yet its biological functions remain unknown. Through physiological and biochemical studies on four TRAM proteins from a cold adaptive archaeon Methanolobus psychrophilus R15, this work demonstrated that TRAM is an archaeal Csp and exhibits RNA chaperone activity. Three TRAM encoding genes (Mpsy_0643, Mpsy_3043, and Mpsy_3066 exhibited remarkable cold-shock induced transcription and were preferentially translated at lower temperature (18°C, while the fourth (Mpsy_2002 was constitutively expressed. They were all able to complement the cspABGE mutant of Escherichia coli BX04 that does not grow in cold temperatures and showed transcriptional antitermination. TRAM3066 (gene product of Mpsy_3066 and TRAM2002 (gene product of Mpsy_2002 displayed sequence-non-specific RNA but not DNA binding activity, and TRAM3066 assisted RNases in degradation of structured RNA, thus validating the RNA chaperone activity of TRAMs. Given the chaperone activity, TRAM is predicted to function beyond a Csp.

  15. 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

    of 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 m......, HrcA , is dependent of the chaperone function of the GroELS complex and that an insertion mutant in dnaK did not have any effect on the expression of the heat shock proteins. The present data from Lactococcus lactis suggest that the DnaK protein could be involved in maturation of the homologous Hrc......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...

  16. HSF transcription factor family, heat shock response, and protein intrinsic disorder.

    Science.gov (United States)

    Westerheide, Sandy D; Raynes, Rachel; Powell, Chase; Xue, Bin; Uversky, Vladimir N

    2012-02-01

    Intrinsically disordered proteins are highly abundant in all kingdoms of life, and several protein functional classes, such as transcription factors, transcriptional regulators, hub and scaffold proteins, signaling proteins, and chaperones are especially enriched in intrinsic disorder. One of the unique cellular reactions to protein damaging stress is the so-called heat shock response that results in the upregulation of heat shock proteins including molecular chaperones. This molecular protective mechanism is conserved from prokaryotes to eukaryotes and allows an organism to respond to various proteotoxic stressors, such as heat shock, oxidative stress, exposure to heavy metals, and drugs. The heat shock response- related proteins can be expressed during normal conditions (e.g., during the cell growth and development) or can be induced by various pathological conditions, such as infection, inflammation, and protein conformation diseases. The initiation of the heat shock response is manifested by the activation of the heat shock transcription factors HSF 1, part of a family of related HSF transcription factors. This review analyzes the abundance and functional roles of intrinsic disorder in various heat shock transcription factors and clearly shows that the heat shock response requires HSF flexibility to be more efficient. © 2012 Bentham Science Publishers

  17. Oligomers of Heat-Shock Proteins: Structures That Don't Imply Function.

    Directory of Open Access Journals (Sweden)

    William M Jacobs

    2016-02-01

    Full Text Available 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 proteins, but their connection to the biological function of these chaperones has remained unclear. Our simulations suggest that this clustering may not have any essential biological function, but rather emerges as a natural side-effect of optimizing the thermodynamic stability of the proteome.

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

    Science.gov (United States)

    Triandafillou, Catherine G; Drummond, D Allan

    2016-07-07

    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.

  19. Transcriptional Modulation of Heat-Shock Protein Gene Expression

    Directory of Open Access Journals (Sweden)

    Anastasis Stephanou

    2011-01-01

    Full Text Available Heat-shock proteins (Hsps are molecular chaperones that are ubiquitously expressed but are also induced in cells exposed to stressful stimuli. Hsps have been implicated in the induction and propagation of several diseases. This paper focuses on regulatory factors that control the transcription of the genes encoding Hsps. We also highlight how distinct transcription factors are able to interact and modulate Hsps in different pathological states. Thus, a better understanding of the complex signaling pathways regulating Hsp expression may lead to novel therapeutic targets.

  20. Transcriptional modulation of heat-shock protein gene expression.

    Science.gov (United States)

    Stephanou, Anastasis; Latchman, David S

    2011-01-01

    Heat-shock proteins (Hsps) are molecular chaperones that are ubiquitously expressed but are also induced in cells exposed to stressful stimuli. Hsps have been implicated in the induction and propagation of several diseases. This paper focuses on regulatory factors that control the transcription of the genes encoding Hsps. We also highlight how distinct transcription factors are able to interact and modulate Hsps in different pathological states. Thus, a better understanding of the complex signaling pathways regulating Hsp expression may lead to novel therapeutic targets.

  1. Heat-shock protein 70: molecular supertool?

    Science.gov (United States)

    Aufricht, Christoph

    2005-06-01

    The cellular stress response decreases cellular injury, either via primary induction of cytoresistance or by secondary enhancement of cellular repair mechanisms. The most frequently studied and best understood effectors of the cellular stress response are the heat shock proteins (HSP). HSP are among the oldest tools in the cellular protein machinery, demonstrating extremely high conservation of the genetic code since bacteria. Molecular chaperons, with the HSP-70 being the prototype, cooperate in transport and folding of proteins, preventing aggregation, and even resolubilizing injured proteins. Increasing evidence supports a role for HSP during the recovery from renal ischemia, in particular in cellular salvage from apoptotic cell death and cytoskeletal restoration. Recent studies also report the potential for biomolecular profiling of newborns for the risk of acute renal failure. In peritoneal dialysis novel data suggest the use of HSP expression for biocompatibility testing. More importantly, HSP are prime therapeutic candidates for clinical situations associated with predictable insults, such as organ procurement in transplant medicine and repetitive exposure to hyperosmolar and acidotic peritoneal dialysis fluids. The next challenge will be to define the regulatory pathways of the cellular stress response in these models to introduce novel therapeutic interventions, such as new pharmaceutics enhancing the HSP expression.

  2. Heat-shock proteins in clinical neurology.

    Science.gov (United States)

    Romi, Fredrik; Helgeland, Geir; Gilhus, Nils Erik

    2011-01-01

    Heat-shock proteins (HSPs) are antigen-presenting protein-aggregation-preventing chaperones, induced by cellular stress in eukaryotic cells. In this review, we focus on recent HSP advances in neurological disorders. In myasthenia gravis, patients responding to immunosuppressive therapy have reduced serum HSP-71 antibodies. Generalized and ocular myasthenia gravis patients have elevated serum HSP-70 antibodies, indicating common pathogenic mechanisms. In Guillain-Barré syndrome, HSP-70 antibodies are elevated in serum and cerebrospinal fluid, and serum levels are higher than in myasthenia gravis and multiple sclerosis. In multiple sclerosis, serum HSP-27 antibodies are elevated during relapses providing disease activation marker, while α,β-crystallin expression in brain lesions indicates remission phase initiation. In acute stroke, serum HSP-27 antibodies are elevated irrespective of stroke type and duration. In epilepsy, HSP-27 is induced in patients' astrocytes and cerebral blood vessel walls, and α,β-crystallin is expressed in epileptic foci. In neurodegenerative disorders such as Alzheimer dementia and Parkinson's disease, HSPs are upregulated in brain tissue, and α,β-crystallin modulates superoxide dismutase-1 (SOD-1) tissue accumulation in familial amyotrophic lateral sclerosis. HSPs play an important role in antigen-presentation and tolerance development. Antibody-mediated interference with their function alters immune responses causing neuropathology. The role of HSPs in clinical neurology should be the subject of future investigation.

  3. 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。

  4. 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.

  5. Specific Binding of Tetratricopeptide Repeat Proteins to Heat Shock Protein 70 (Hsp70) and Heat Shock Protein 90 (Hsp90) Is Regulated by Affinity and Phosphorylation.

    Science.gov (United States)

    Assimon, Victoria A; Southworth, Daniel R; Gestwicki, Jason E

    2015-12-01

    Heat shock protein 70 (Hsp70) and heat shock protein 90 (Hsp90) require the help of tetratricopeptide repeat (TPR) domain-containing cochaperones for many of their functions. Each monomer of Hsp70 or Hsp90 can interact with only a single TPR cochaperone at a time, and each member of the TPR cochaperone family brings distinct functions to the complex. Thus, competition for TPR binding sites on Hsp70 and Hsp90 appears to shape chaperone activity. Recent structural and biophysical efforts have improved our understanding of chaperone-TPR contacts, focusing on the C-terminal EEVD motif that is present in both chaperones. To better understand these important protein-protein interactions on a wider scale, we measured the affinity of five TPR cochaperones, CHIP, Hop, DnaJC7, FKBP51, and FKBP52, for the C-termini of four members of the chaperone family, Hsc70, Hsp72, Hsp90α, and Hsp90β, in vitro. These studies identified some surprising selectivity among the chaperone-TPR pairs, including the selective binding of FKBP51/52 to Hsp90α/β. These results also revealed that other TPR cochaperones are only able to weakly discriminate between the chaperones or between their paralogs. We also explored whether mimicking phosphorylation of serine and threonine residues near the EEVD motif might impact affinity and found that pseudophosphorylation had selective effects on binding to CHIP but not other cochaperones. Together, these findings suggest that both intrinsic affinity and post-translational modifications tune the interactions between the Hsp70 and Hsp90 proteins and the TPR cochaperones.

  6. 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.

  7. Effects of Heat Shock on Glucocorticoid Receptor

    Institute of Scientific and Technical Information of China (English)

    宋亮年

    1994-01-01

    The changes of glucocorticoid receptor (GR) during the heat shock response have been studied using a human osteosarcoma cell line (HOS-8603) as the model. The expression of the heat shock protein 70 (hsp70) mRNA in HOS-8603 cells has been enhanced markedly after a heat treatment at 43 ℃ for 30 min. A mild thermal pretreatment (42℃ for 1 h) protects the HOS-8603 cells against a subsequent heat challenge (46℃). This induced thermotolerance is reflected by the increase of cell viability of HOS-8603 cells. The GR binding activity in HOS-8603 cells decreased rapidly after the heat treatment at 43℃; only 42. 61% of controls were detected 60 min after the heat treatment. However, there was no significant change in the dissociation constant value (Kd). These results indicate that the heat shock induce not only the heat shock mRNA expression, but also the rapid reduction in GR binding activity, suggesting that there might be a functional relationship between GR action and the heat shock response.

  8. Shock Heated Dust in Young Supernova Remnants

    Science.gov (United States)

    Braun, R.; Strom, R. G.; van der Laan, H.; Greidanus, H.

    Infrared emission in young supernova remnants is interpreted as coming from shock-heated dust. Using models and data from other wavelength regimes, many physical parameters of the remnants can accurately be derived.

  9. Structure and function of small heat shock/alpha-crystallin proteins: established concepts and emerging ideas.

    Science.gov (United States)

    MacRae, T H

    2000-06-01

    Small heat shock/alpha-crystallin proteins are defined by conserved sequence of approximately 90 amino acid residues, termed the alpha-crystallin domain, which is bounded by variable amino- and carboxy-terminal extensions. These proteins form oligomers, most of uncertain quaternary structure, and oligomerization is prerequisite to their function as molecular chaperones. Sequence modelling and physical analyses show that the secondary structure of small heat shock/alpha-crystallin proteins is predominately beta-pleated sheet. Crystallography, site-directed spin-labelling and yeast two-hybrid selection demonstrate regions of secondary structure within the alpha-crystallin domain that interact during oligomer assembly, a process also dependent on the amino terminus. Oligomers are dynamic, exhibiting subunit exchange and organizational plasticity, perhaps leading to functional diversity. Exposure of hydrophobic residues by structural modification facilitates chaperoning where denaturing proteins in the molten globule state associate with oligomers. The flexible carboxy-terminal extension contributes to chaperone activity by enhancing the solubility of small heat shock/alpha-crystallin proteins. Site-directed mutagenesis has yielded proteins where the effect of the change on structure and function depends upon the residue modified, the organism under study and the analytical techniques used. Most revealing, substitution of a conserved arginine residue within the alpha-crystallin domain has a major impact on quaternary structure and chaperone action probably through realignment of beta-sheets. These mutations are linked to inherited diseases. Oligomer size is regulated by a stress-responsive cascade including MAPKAP kinase 2/3 and p38. Phosphorylation of small heat shock/alpha-crystallin proteins has important consequences within stressed cells, especially for microfilaments.

  10. 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.

  11. 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.

  12. A minimal titration model of the mammalian dynamical heat shock response

    Science.gov (United States)

    Sivéry, Aude; Courtade, Emmanuel; Thommen, Quentin

    2016-12-01

    Environmental stress, such as oxidative or heat stress, induces the activation of the heat shock response (HSR) and leads to an increase in the heat shock proteins (HSPs) level. These HSPs act as molecular chaperones to maintain cellular proteostasis. Controlled by highly intricate regulatory mechanisms, having stress-induced activation and feedback regulations with multiple partners, the HSR is still incompletely understood. In this context, we propose a minimal molecular model for the gene regulatory network of the HSR that reproduces quantitatively different heat shock experiments both on heat shock factor 1 (HSF1) and HSPs activities. This model, which is based on chemical kinetics laws, is kept with a low dimensionality without altering the biological interpretation of the model dynamics. This simplistic model highlights the titration of HSF1 by chaperones as the guiding line of the network. Moreover, by a steady states analysis of the network, three different temperature stress regimes appear: normal, acute, and chronic, where normal stress corresponds to pseudo thermal adaption. The protein triage that governs the fate of damaged proteins or the different stress regimes are consequences of the titration mechanism. The simplicity of the present model is of interest in order to study detailed modelling of cross regulation between the HSR and other major genetic networks like the cell cycle or the circadian clock.

  13. The hexameric structures of human heat shock protein 90.

    Directory of Open Access Journals (Sweden)

    Cheng-Chung Lee

    Full Text Available BACKGROUND: The human 90-kDa heat shock protein (HSP90 functions as a dimeric molecular chaperone. HSP90 identified on the cell surface has been found to play a crucial role in cancer invasion and metastasis, and has become a validated anti-cancer target for drug development. It has been shown to self-assemble into oligomers upon heat shock or divalent cations treatment, but the functional role of the oligomeric states in the chaperone cycle is not fully understood. PRINCIPAL FINDINGS: Here we report the crystal structure of a truncated HSP90 that contains the middle segment and the carboxy-terminal domain, termed MC-HSP90. The structure reveals an architecture with triangular bipyramid geometry, in which the building block of the hexameric assembly is a dimer. In solution, MC-HSP90 exists in three major oligomer states, namely dimer, tetramer and hexamer, which were elucidated by size exclusion chromatography and analytical ultracentrifugation. The newly discovered HSP90 isoform HSP90N that lacks the N-terminal ATPase domain also exhibited similar oligomerization states as did MC-HSP90. CONCLUSIONS: While lacking the ATPase domain, both MC-HSP90 and HSP90N can self-assemble into a hexameric structure, spontaneously. The crystal structure of MC-HSP90 reveals that, in addition to the C-terminal dimerization domain, the residue W320 in the M domain plays a critical role in its oligomerization. This study not only demonstrates how the human MC-HSP90 forms a hexamer, but also justifies the similar formation of HSP90N by using 3D modeling analysis.

  14. Heat shock factor 1 prevents the reduction in thrashing due to heat shock in Caenorhabditis elegans.

    Science.gov (United States)

    Furuhashi, Tsubasa; Sakamoto, Kazuichi

    2015-07-01

    Heat shock factor 1 (HSF-1) is activated by heat stress and induces the expression of heat shock proteins. However, the role of HSF-1 in thermotolerance remains unclear. We previously reported that heat stress reversibly reduces thrashing movement in Caenorhabditis elegans. In this study, we analyzed the function of HSF-1 on thermotolerance by monitoring thrashing movement. hsf-1 RNAi suppressed the restoration of thrashing reduced by heat stress. In contrast, hsf-1 knockdown cancelled prevention of movement reduction in insulin/IGF-1-like growth factor 1 receptor (daf-2) mutant, but didn't suppress thrashing restoration in daf-2 mutant. In addition, hsf-1 RNAi accelerated the reduction of thrashing in heat-shocked wild-type C. elegans. And, daf-16 KO didn't accelerate the reduction of thrashing by heat stress. Taken together, these results suggest that HSF-1 prevents the reduction of thrashing caused by heat shock.

  15. The role of small heat shock proteins in parasites.

    Science.gov (United States)

    Pérez-Morales, Deyanira; Espinoza, Bertha

    2015-09-01

    The natural life cycle of many protozoan and helminth parasites involves exposure to several hostile environmental conditions. Under these circumstances, the parasites arouse a cellular stress response that involves the expression of heat shock proteins (HSPs). Small HSPs (sHSPs) constitute one of the main families of HSPs. The sHSPs are very divergent at the sequence level, but their secondary and tertiary structures are conserved and some of its members are related to α-crystallin from vertebrates. They are involved in a variety of cellular processes. As other HSPs, the sHSPs act as molecular chaperones; however, they have shown other activities apparently not related to chaperone action. In this review, the diverse activities of sHSPs in the major genera of protozoan and helminth parasites are described. These include stress response, development, and immune response, among others. In addition, an analysis comparing the sequences of sHSPs from some parasites using a distance analysis is presented. Because many parasites face hostile conditions through its life cycles the study of HSPs, including sHSPs, is fundamental.

  16. Heat Shock Proteins: Stimulators of Innate and Acquired Immunity

    Directory of Open Access Journals (Sweden)

    Camilo A. Colaco

    2013-01-01

    Full Text Available Adjuvants were reintroduced into modern immunology as the dirty little secret of immunologists by Janeway and thus began the molecular definition of innate immunity. It is now clear that the binding of pathogen-associated molecular patterns (PAMPs by pattern recognition receptors (PRRs on antigen presenting cells (APCs activates the innate immune response and provides the host with a rapid mechanism for detecting infection by pathogens and initiates adaptive immunity. Ironically, in addition to advancing the basic science of immunology, Janeway’s revelation on induction of the adaptive system has also spurred an era of rational vaccine design that exploits PRRs. Thus, defined PAMPs that bind to known PRRs are being specifically coupled to antigens to improve their immunogenicity. However, while PAMPs efficiently activate the innate immune response, they do not mediate the capture of antigen that is required to elicit the specific responses of the acquired immune system. Heat shock proteins (HSPs are molecular chaperones that are found complexed to client polypeptides and have been studied as potential cancer vaccines. In addition to binding PRRs and activating the innate immune response, HSPs have been shown to both induce the maturation of APCs and provide chaperoned polypeptides for specific triggering of the acquired immune response.

  17. 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.

  18. The pleiotropic activity of heat-shock proteins

    Directory of Open Access Journals (Sweden)

    Arleta Kaźmierczuk

    2009-10-01

    Full Text Available Stress or heat-shock proteins (HSPs are highly conserved proteins present in cells of both prokaryotes and eukaryotes, providing them with protection from cellular and environmental stress factors. Based on molecular-weight, HSPs can be divided into the large (HSP100: 100–110 kDa and HSP90: 75–96 kDa, intermediate (HSP70: 66–78 kDa, HSP60, and HSP40, and small (sHSP: 8.5–40 kDa subfamilies. These proteins play an essential role as molecular chaperones/co-chaperones by assisting the correct folding of nascent and stress-accumulated protein-substrate assembly, preventing the aggregation of these proteins, as well as transport across membranes and the degradation of other proteins. Members of HSP family display dual activity depending on their intra- or extracellular distribution. Intracellular HSPs mainly play a protective role. Extracellular or membrane-bound HSPs mediate immunological functions. Among the functions of HSPs is their participation in cell signaling. This review deals with the structure and properties of the main members of the HSPs and their role in a large number of cellular/extracellular processes.

  19. Small Heat Shock Proteins and Distal Hereditary Neuropathies.

    Science.gov (United States)

    Nefedova, V V; Muranova, L K; Sudnitsyna, M V; Ryzhavskaya, A S; Gusev, N B

    2015-12-01

    Classification of small heat shock proteins (sHsp) is presented and processes regulated by sHsp are described. Symptoms of hereditary distal neuropathy are described and the genes whose mutations are associated with development of this congenital disease are listed. The literature data and our own results concerning physicochemical properties of HspB1 mutants associated with Charcot-Marie-Tooth disease are analyzed. Mutations of HspB1, associated with hereditary motor neuron disease, can be accompanied by change of the size of HspB1 oligomers, by decreased stability under unfavorable conditions, by changes in the interaction with protein partners, and as a rule by decrease of chaperone-like activity. The largest part of these mutations is accompanied by change of oligomer stability (that can be either increased or decreased) or by change of intermonomer interaction inside an oligomer. Data on point mutation of HspB3 associated with axonal neuropathy are presented. Data concerning point mutations of Lys141 of HspB8 and those associated with hereditary neuropathy and different forms of Charcot-Marie-Tooth disease are analyzed. It is supposed that point mutations of sHsp associated with distal neuropathies lead either to loss of function (for instance, decrease of chaperone-like activity) or to gain of harmful functions (for instance, increase of interaction with certain protein partners).

  20. 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.

  1. Heat Shock Protein 96 Induces Maturation of Dendritic Cells

    Institute of Scientific and Technical Information of China (English)

    Chunxia Cao; Wei Yang; Yonglie Chu; Qingguang Liu; Liang Yu; Cheng'en Pan

    2006-01-01

    Objective: Heat shock protein (HSP) has the promiscuous abilities to chaperone and present a broad repertoire of tumor antigens to antigen presenting cells including DCs. In this report, we analyzed the modulation of immature DC by HSP 96 (gp96).Method: Murine bone marrow-derived DC was induced by GM-CSF plus IL-4, which aped the immunostimulatory effects of DC.Cocultured DC and gp96-peptide complexes (gp96-PC) or inactivated H22 cells, the expression of MHC class Ⅱ, CD40, CD80 was quantified by flow cytometry. The concentration of IL-12 and TNF- in culture supernatants were determined by ELISA.[51] Cr release assay was used to test specific cytotoxic T cell. Results: Our study demonstrated that the extent of DC maturation induced by gp96-PC, which was reflected in surface density of costimulatory and MHC Ⅱ molecules, was correlated with the secretion of IL-12 and with the T cellactivating potential in vitro. Conclusion: Heat shock protein 96 could be isolated and purified from H22 cells and could induce maturation of dendritic cell. Our findings might be relevance to the use of DC vaccine in therapy of human tumors.

  2. Heat shock response and insulin-associated neurodegeneration.

    Science.gov (United States)

    Urban, Michael J; Dobrowsky, Rick T; Blagg, Brian S J

    2012-03-01

    Dysfunctional insulin and insulin-like growth factor-I (IGF-I) signaling contributes to the pathological progression of diabetes, diabetic peripheral neuropathy (DPN), Alzheimer's (AD), Parkinson's (PD) and Huntington's diseases (HD). Despite their prevalence, there are limited therapeutic options available for the treatment of these neurodegenerative disorders. Therefore, establishing a link between insulin/IGF-I and the pathoetiology of these diseases may provide alternative approaches toward their management. Many of the heat shock proteins (Hsps) are well-known molecular chaperones that solubilize and clear damaged proteins and protein aggregates. Recent studies suggest that modulating Hsps may represent a promising therapeutic avenue for improving insulin and IGF-I signaling. Pharmacological induction of the heat shock response (HSR) may intersect with insulin/IGF-I signaling to improve aspects of neurodegenerative phenotypes. Herein, we review the intersection between Hsps and the insulin/IGF systems under normal and pathological conditions. The discussion will emphasize the potential of non-toxic HSR inducers as viable therapeutic agents.

  3. Destabilization and recovery of a yeast prion after mild heat shock.

    Science.gov (United States)

    Newnam, Gary P; Birchmore, Jennifer L; Chernoff, Yury O

    2011-05-06

    Yeast prion [PSI(+)] is a self-perpetuating amyloid of the translational termination factor Sup35. Although [PSI(+)] propagation is modulated by heat shock proteins (Hsps), high temperature was previously reported to have little or no effect on [PSI(+)]. Our results show that short-term exposure of exponentially growing yeast culture to mild heat shock, followed by immediate resumption of growth, leads to [PSI(+)] destabilization, sometimes persisting for several cell divisions after heat shock. Prion loss occurring in the first division after heat shock is preferentially detected in a daughter cell, indicating the impairment of prion segregation that results in asymmetric prion distribution between a mother cell and a bud. Longer heat shock or prolonged incubation in the absence of nutrients after heat shock led to [PSI(+)] recovery. Both prion destabilization and recovery during heat shock depend on protein synthesis. Maximal prion destabilization coincides with maximal imbalance between Hsp104 and other Hsps such as Hsp70-Ssa. Deletions of individual SSA genes increase prion destabilization and/or counteract recovery. The dynamics of prion aggregation during destabilization and recovery are consistent with the notion that efficient prion fragmentation and segregation require a proper balance between Hsp104 and other (e.g., Hsp70-Ssa) chaperones. In contrast to heat shock, [PSI(+)] destabilization by osmotic stressors does not always depend on cell proliferation and/or protein synthesis, indicating that different stresses may impact the prion via different mechanisms. Our data demonstrate that heat stress causes asymmetric prion distribution in a cell division and confirm that the effects of Hsps on prions are physiologically relevant.

  4. 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.

  5. The future of molecular chaperones and beyond.

    Science.gov (United States)

    Giffard, Rona G; Macario, Alberto J L; de Macario, Everly Conway

    2013-08-01

    Protection of hair cells by HSP70 released by supporting cells is reported by May et al. in this issue of the JCI. Their findings suggest a new way to reduce ototoxicity from therapeutic medications and raise larger questions about the role and integration of heat shock proteins in non–cell-autonomous responses to stress. Increasing evidence suggests an important role for extracellular heat shock proteins in both the nervous system and the immune system. The work also suggests that defective chaperones could cause ear disease and supports the potential use of chaperone therapeutics.

  6. Heating Cooling Flows with Weak Shock Waves

    CERN Document Server

    Mathews, W G; Brighenti, F

    2006-01-01

    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 is heated by (intermittent) weak shocks for several Gyrs, the gas within 30-50 kpc is heated to temperatures that far exceed observed values. This heating can be avoided if dissipating shocks are sufficiently infrequent or weak so as not to be the primary source of global heating. Local PV and viscous heating associated with newly formed X-ray cavities are likely to be small, which is consistent with the low gas temperatures generally observed near the centers of groups and clusters where the cavities are located.

  7. [Heat shock proteins and their characteristics].

    Science.gov (United States)

    Dzaman-Serafin, Sylwia; Telatyńska-Mieszek, Bogumiła; Ciechanowski, Kazimierz

    2005-08-01

    The main adaptable response to increased temperature is heat shock response resulting in induction of proteins called heat shock proteins (HSP). They are present in all cells under proper growth conditions and they create 5-10% of the whole protein contents. HSP were divided into five basic groups according to their approximate molecular mass, expressed in kDa and called respectively: HSP 100, HSP 90, HSP 70, HSP 60 and small HSP. Heat shock proteins can act like antigens in many infectious diseases. Immunological response against proteins from HSP 60, HSP 70 and HSP 90 families was observed in diseases caused by bacterial and protozoan pathogens. It is known that ischemia and reperfusion activate HSP genes transcription in heart cells of various experimental animals. Human and Chlamydia pneumoniae HSP 60 were found in patients with stable coronary disease. Hence many researchers connect the increase of ischaemia with the passed infection caused by Chlamydia pneumoniae, which can influence the origin or development of atheromatous plaque in the vascular wall. HSPs play an important role in hyperthermic therapy commonly used together with irradiation. Moreover, works on the possibility of HSP application to delay of disease process in neurodegenerative diseases, such as Parkinson or Alzheimer diseases are conducted. The paper presents characteristics of heat shock proteins, role in the state of health and disease and possibilities of their usage in monitoring and/or treatment of diseases, e.g. cancers.

  8. Global analysis of heat shock response in Desulfovibrio vulgaris Hildenborough.

    Energy Technology Data Exchange (ETDEWEB)

    Arkin, A. P. (Physical Biosciences Division, Berkeley, CA); Wall, J. D. (University of Missouri-Columbia, Columbia, MO); Hazen, T. C. (Physical Biosciences Division, Berkeley, CA); He, Z. (Oak Ridge National Laboratory, Oak Ridge, TN); Zhou, J. (Oak Ridge National Laboratory, Oak Ridge, TN); Huang, K. H. (Physical Biosciences Division, Berkeley, CA); Gaucher, Sara P.; He, Q. (Oak Ridge National Laboratory, Oak Ridge, TN); Hadi, Masood Z.; Chhabra, Swapnil R.; Alm, Eric J. (Physical Biosciences Division, Berkeley, CA); Singh, A. K.

    2005-08-01

    Desulfovibrio vulgaris Hildenborough belongs to a class of sulfate-reducing bacteria (SRB) and is found ubiquitously in nature. Given the importance of SRB-mediated reduction for bioremediation of metal ion contaminants, ongoing research on D. vulgaris has been in the direction of elucidating regulatory mechanisms for this organism under a variety of stress conditions. This work presents a global view of this organism's response to elevated growth temperature using whole-cell transcriptomics and proteomics tools. Transcriptional response (1.7-fold change or greater; Z {ge} 1.5) ranged from 1,135 genes at 15 min to 1,463 genes at 120 min for a temperature up-shift of 13 C from a growth temperature of 37 C for this organism and suggested both direct and indirect modes of heat sensing. Clusters of orthologous group categories that were significantly affected included posttranslational modifications; protein turnover and chaperones (up-regulated); energy production and conversion (down-regulated), nucleotide transport, metabolism (down-regulated), and translation; ribosomal structure; and biogenesis (down-regulated). Analysis of the genome sequence revealed the presence of features of both negative and positive regulation which included the CIRCE element and promoter sequences corresponding to the alternate sigma factors {sigma}{sup 32} and {sigma}{sup 54}. While mechanisms of heat shock control for some genes appeared to coincide with those established for Escherichia coli and Bacillus subtilis, the presence of unique control schemes for several other genes was also evident. Analysis of protein expression levels using differential in-gel electrophoresis suggested good agreement with transcriptional profiles of several heat shock proteins, including DnaK (DVU0811), HtpG (DVU2643), HtrA (DVU1468), and AhpC (DVU2247). The proteomics study also suggested the possibility of posttranslational modifications in the chaperones DnaK, AhpC, GroES (DVU1977), and GroEL (DVU

  9. Chaperone effects on prion and nonprion aggregates.

    Science.gov (United States)

    Rikhvanov, Eugene G; Romanova, Nina V; Chernoff, Yury O

    2007-01-01

    Exposure to high temperature or other stresses induces a synthesis of heat shock proteins. Many of these proteins are molecular chaperones, and some of them help cells to cope with heat-induced denaturation and aggregation of other proteins. In the last decade, chaperones have received increased attention in connection with their role in maintenance and propagation of the Saccharomyces cerevisiae prions, infectious or heritable agents transmitted at the protein level. Recent data suggest that functioning of the chaperones in reactivation of heat-damaged proteins and in propagation of prions is based on the same molecular mechanisms but may lead to different consequences depending on the type of aggregate. In both cases the concerted and balanced action of "chaperones' team," including Hsp104, Hsp70, Hsp40 and possibly other proteins, determines whether a misfolded protein is to be incorporated into an aggregate, rescued to the native state or targeted for degradation.

  10. Heat shock and heat shock protein 70i enhance the oncolytic effect of replicative adenovirus.

    Science.gov (United States)

    Haviv, Y S; Blackwell, J L; Li, H; Wang, M; Lei, X; Curiel, D T

    2001-12-01

    Replication-competent viruses are currently being evaluated for their cancer cell-killing properties. These vectors are designed to induce tumor regression after selective viral propagation within the tumor. However, replication-competent viruses have not resulted heretofore in complete tumor eradication in the clinical setting. Recently, heat shock has been reported to partially alleviate replication restriction on an avian adenovirus (Ad) in a human lung cancer cell line. Therefore, we hypothesized that heat shock and overexpression of heat shock protein (hsp) would support the oncolytic effect of a replication-competent human Ad. To this end, we tested the oncolytic and burst kinetics of a replication-competent Ad after exposure to heat shock or to inducible hsp 70 overexpression by a replication-deficient Ad (Adhsp 70i). Heat-shock resulted in augmentation of Ad burst and oncolysis while decreasing total intracellular Ad DNA. Overexpression of hsp 70i also enhanced Ad-mediated oncolysis but did not decrease intracellular Ad DNA levels. We conclude that heat shock and Adhsp 70i enhance the Ad cell-killing potential via distinct mechanisms. A potential therapeutic implication would be the use of local hyperthermia to augment oncolysis by increasing the burst of replication-competent Ad. The role of hsp in Ad-mediated oncolysis should be additionally explored.

  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. Heterogeneous nuclear ribonucleoprotein K inhibits heat shock-induced transcriptional activity of heat shock factor 1.

    Science.gov (United States)

    Kim, Hee-Jung; Lee, Jae-Jin; Cho, Jin-Hwan; Jeong, Jaeho; Park, A Young; Kang, Wonmo; Lee, Kong-Joo

    2017-08-04

    When cells are exposed to heat shock and various other stresses, heat shock factor 1 (HSF1) is activated, and the heat shock response (HSR) is elicited. To better understand the molecular regulation of the HSR, we used 2D-PAGE-based proteome analysis to screen for heat shock-induced post-translationally modified cellular proteins. Our analysis revealed that two protein spots typically present on 2D-PAGE gels and containing heterogeneous nuclear ribonucleoprotein K (hnRNP K) with trioxidized Cys(132) disappeared after the heat shock treatment and reappeared during recovery, but the total amount of hnRNP K protein remained unchanged. We next tested whether hnRNP K plays a role in HSR by regulating HSF1 and found that hnRNP K inhibits HSF1 activity, resulting in reduced expression of hsp70 and hsp27 mRNAs. hnRNP K also reduced binding affinity of HSF1 to the heat shock element by directly interacting with HSF1 but did not affect HSF1 phosphorylation-dependent activation or nuclear localization. hnRNP K lost its ability to induce these effects when its Cys(132) was substituted with Ser, Asp, or Glu. These findings suggest that hnRNP K inhibits transcriptional activity of HSF1 by inhibiting its binding to heat shock element and that the oxidation status of Cys(132) in hnRNP K is critical for this inhibition. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  13. The role of the membrane-initiated Heat Shock Response in cancer

    Directory of Open Access Journals (Sweden)

    Zohar eBromberg

    2016-04-01

    Full Text Available The heat shock response (HSR is a cellular response to diverse environmental and physiological stressors resulting in the induction of genes encoding molecular chaperones, proteases and other proteins that are essential for protection and recovery from cellular damage. Since different perturbations cause accumulation of misfolded proteins, cells frequently encounter fluctuations in the environment which alter proteostasis. Since tumor cells use their natural adaptive mechanism of coping with stress and misfolded proteins, in recent years, the proteostasis network became a promising target for anti-tumor therapy. The membrane is the first to be affected by heat shock and therefore may be the first one to sense heat shock. The membrane also connects between the extracellular and the intracellular signals. Hence, there is a cross talk between the HSR and the membranes since heat shock can induce changes in the fluidity of membranes, leading to membrane lipid remodeling that occurs in several diseases such as cancer. During the last decade, a new possible therapy has emerged in which an external molecule is used that could induce membrane lipid re-organization. Since at the moment there are very few substances that regulate the HSR effectively, an alternative way has been searched to modulate chaperone activities through the plasma membrane. Recently, we suggested that the use of the membrane Transient Receptor Potential Vanilloid-1 (TRPV1 modulators regulated the HSR in cancer cells. However, the primary targets of the signal transduction pathway are yet un-known. This review provides an overview of the current literature regarding the role of HSR in membrane remodeling in cancer since a deep understanding of the membrane biology in cancer and the membrane heat sensing pathway is essential to design novel efficient therapies.

  14. Regulation of apoptotic signal transduction pathways by the heat shock proteins

    Institute of Scientific and Technical Information of China (English)

    LI; Zhengyu; ZHAO; Xia; WEI; Yuquan

    2004-01-01

    The study about apoptotic signal transductions has become a project to reveal the molecular mechanisms of apoptosis. Heat shock proteins (hsps), which play an important role in cell growth and apoptosis, have attracted great attentions. A lot of researches have showed there is a hsps superfamily including hsp90, hsp70, hsp60 and hsp27, etc., which regulates the biological behaviors of cells, particularly apoptotic signal transduction in Fas pathway, JNK/SAPK pathway and caspases pathway at different levels, partly by the function of molecular chaperone.

  15. Influence of selenium on heat shock protein 70 expression in heat stressed turkey embryos (Meleagris gallopavo).

    Science.gov (United States)

    Rivera, Rafael E; Christensen, V L; Edens, F W; Wineland, M J

    2005-12-01

    Heat shock protein 70 (hsp70) family of proteins, which functions as molecular chaperones, has been associated with tolerance to stressors in avian species. Selenium (Se) is an essential trace mineral incorporated into the seleno-enzymes such as glutathione peroxidase (GSHpx). GSHpx reduces oxidized glutathione (GSSG) to reduced glutathione (GSH) in the GSH/GSSG antioxidant system and protects cells from oxidative damage. This study was conducted to examine if the relationship between dietary supplementation of selenium to turkey (Meleagris gallopavo) hens and the embryonic expression of hsp70 and GSHpx activity in heat stressed embryos. Livers of embryos developing in eggs from turkey hens fed diets with or without supplemental Se were analyzed for hsp70 concentration and GSHpx activity before and after recovery from a heating episode. Before heat stress, hsp70 concentrations were equivalent in each treatment, but GSHpx activity was maximized in the SE treatment group. After recovery from the heating episode, hsp70 concentrations were significantly higher (P<0.05) in the non-Se-supplemented groups, but in the Se-supplemented groups the hsp70 concentrations were not different from pre-stress concentrations. In the pre-stress Se-supplemented group, liver GSHpx activity was significantly higher than GSHpx activity in the non-Se-supplemented embryo livers, and in the livers from embryos recovering from heat stress, GSHpx activity in the non-Se-supplemented group was lower than the pre-stress activity and significantly lower than the GSHpx activity in liver from Se-supplemented embryos recovering from heat distress. Se supplementation to the dams resulted in a significant increase in their embryos and that condition would facilitate a decreased incidence of oxidative damage to cells. A more reduced redox status in embryos from Se-supplemented dams decreased the need for cellular protection attributed to stress induced hsp70 and presumably allows heat distressed embryos

  16. 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

  17. Heat shock proteins: a therapeutic target worth to consider

    Science.gov (United States)

    Dubey, Amita; Prajapati, K. S.; Swamy, Madhu; Pachauri, V.

    2015-01-01

    Heat shock proteins (HSPs) are the molecular chaperones, that are not only expressed during the normal growth process of cell cycle consecutively, but also get induced in cells during various stress conditions produced by cellular insult, environmental changes, temperature, infections, tumors etc. According to their molecular weight and functions, HSPs are divided into five major families. HSP90, HSP70, HSP60 and HSP100 are the most studied members of the family. Experimental studies have proved that overexpression and/or inhibition of HSPs play an important role in maintaining the tolerance and cell viability under above-described stress conditions. HSP90 is found to be a promising the candidate for the diagnosis, prognosis and treatment of cancer. Similarly, HSP70, HSP60 and small HSPs experimentally and clinically have potential for the treatment of neurodegenerative disease, ischemia, cell death, autoimmunity, graft rejection, etc. In a way, exploring, the cytoprotective and immunoregulatory role of HSPs can open a new avenue for the drug discovery and treatment of critical diseases. PMID:27046995

  18. Extracellular heat shock proteins: a new location, a new function.

    Science.gov (United States)

    De Maio, Antonio; Vazquez, Daniel

    2013-10-01

    The expression of heat shock proteins (HSPs) is a basic and well-conserved cellular response to an array of stresses. These proteins are involved in the repair of cellular damage induced by the stress, which is necessary for the salutary resolution from the insult. Moreover, they confer protection from subsequent insults, which has been coined stress tolerance. Because these proteins are expressed in subcellular compartments, it was thought that their function during stress conditions was circumscribed to the intracellular environment. However, it is now well established that HSPs can also be present outside cells where they appear to display a function different than the well-understood chaperone role. Extracellular HSPs act as alert stress signals priming other cells, particularly of the immune system, to avoid the propagation of the insult and favor resolution. Because the majority of HSPs do not possess a secretory peptide signal, they are likely to be exported by a nonclassic secretory pathway. Different mechanisms have been proposed to explain the export of HSPs, including translocation across the plasma membrane and release associated with lipid vesicles, as well as the passive release after cell death by necrosis. Extracellular HSPs appear in various flavors, including membrane-bound and membrane-free forms. All of these variants of extracellular HSPs suggest that their interactions with cells may be quite diverse, both in target cell types and the activation signaling pathways. This review addresses some of our current knowledge about the release and relevance of extracellular HSPs.

  19. 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.

  20. 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.

    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

  1. Developmental control of the heat shock response in Xenopus.

    OpenAIRE

    Bienz, M

    1984-01-01

    Xenopus cells express two major proteins on heat shock, designated hsp 70 and hsp 30. Several cDNA clones for the corresponding mRNAs were identified and sequenced. Inducibility and abundance of heat shock mRNAs in various cell types and developmental stages was determined by nuclease S1-mapping. The only cells found to contain hsp 70 mRNA without heat shock are the oocytes. The level of this stored hsp 70 mRNA is not increased by heat shock. After fertilization, hsp 70 mRNA becomes undetecta...

  2. Heat Shock Protein-Peptide and HSP-Based Immunotherapies for the Treatment of Cancer.

    Science.gov (United States)

    Shevtsov, Maxim; Multhoff, Gabriele

    2016-01-01

    Intracellular residing heat shock proteins (HSPs) with a molecular weight of approximately 70 and 90 kDa function as molecular chaperones that assist folding/unfolding and transport of proteins across membranes and prevent protein aggregation after environmental stress. In contrast to normal cells, tumor cells have higher cytosolic heat shock protein 70 and Hsp90 levels, which contribute to tumor cell propagation, metastasis, and protection against apoptosis. In addition to their intracellular chaperoning functions, extracellular localized and membrane-bound HSPs have been found to play key roles in eliciting antitumor immune responses by acting as carriers for tumor-derived immunogenic peptides, as adjuvants for antigen presentation, or as targets for the innate immune system. The interaction of HSP-peptide complexes or peptide-free HSPs with receptors on antigen-presenting cells promotes the maturation of dendritic cells, results in an upregulation of major histocompatibility complex class I and class II molecules, induces secretion of pro- and anti-inflammatory cytokines, chemokines, and immune modulatory nitric oxides, and thus integrates adaptive and innate immune phenomena. Herein, we aim to recapitulate the history and current status of HSP-based immunotherapies and vaccination strategies in the treatment of cancer.

  3. Caffeine Induces the Stress Response and Up-Regulates Heat Shock Proteins in Caenorhabditis elegans.

    Science.gov (United States)

    Al-Amin, Mohammad; Kawasaki, Ichiro; Gong, Joomi; Shim, Yhong-Hee

    2016-02-01

    Caffeine has both positive and negative effects on physiological functions in a dose-dependent manner. C. elegans has been used as an animal model to investigate the effects of caffeine on development. Caffeine treatment at a high dose (30 mM) showed detrimental effects and caused early larval arrest. We performed a comparative proteomic analysis to investigate the mode of action of high-dose caffeine treatment in C. elegans and found that the stress response proteins, heat shock protein (HSP)-4 (endoplasmic reticulum [ER] chaperone), HSP-6 (mitochondrial chaperone), and HSP-16 (cytosolic chaperone), were induced and their expression was regulated at the transcriptional level. These findings suggest that high-dose caffeine intake causes a strong stress response and activates all three stress-response pathways in the worms, including the ER-, mitochondrial-, and cytosolic pathways. RNA interference of each hsp gene or in triple combination retarded growth. In addition, caffeine treatment stimulated a food-avoidance behavior (aversion phenotype), which was enhanced by RNAi depletion of the hsp-4 gene. Therefore, up-regulation of hsp genes after caffeine treatment appeared to be the major responses to alleviate stress and protect against developmental arrest.

  4. Pathology-Dependent Effects Linked to Small Heat Shock Proteins Expression: An Update

    Directory of Open Access Journals (Sweden)

    A.-P. Arrigo

    2012-01-01

    Full Text Available Small heat shock proteins (small Hsps are stress-induced molecular chaperones that act as holdases towards polypeptides that have lost their folding in stress conditions or consequently of mutations in their coding sequence. A cellular protection against the deleterious effects mediated by damaged proteins is thus provided to cells. These chaperones are also highly expressed in response to protein conformational and inflammatory diseases and cancer pathologies. Through specific and reversible modifications in their phospho-oligomeric organization, small Hsps can chaperone appropriate client proteins in order to provide cells with resistance to different types of injuries or pathological conditions. By helping cells to better cope with their pathological status, their expression can be either beneficial, such as in diseases characterized by pathological cell degeneration, or deleterious when they are required for tumor cell survival. Moreover, small Hsps are actively released by cells and can act as immunogenic molecules that have dual effects depending on the pathology. The cellular consequences linked to their expression levels and relationships with other Hsps as well as therapeutic strategies are discussed in view of their dynamic structural organization required to interact with specific client polypeptides.

  5. Differential recognition of heat shock elements by members of the heat shock transcription factor family.

    Science.gov (United States)

    Yamamoto, Noritaka; Takemori, Yukiko; Sakurai, Mayumi; Sugiyama, Kazuhisa; Sakurai, Hiroshi

    2009-04-01

    Heat shock transcription factor (HSF), an evolutionarily conserved stress response regulator, forms trimers and binds to heat shock element (HSE), comprising at least three continuous inverted repeats of the sequence 5'-nGAAn-3'. The single HSF of yeast is also able to bind discontinuously arranged nGAAn units. We investigated interactions between three human HSFs and various HSE types in vitro, in yeast cells, and in HeLa cells. Human HSF1, a stress-activated regulator, preferentially bound to continuous HSEs rather than discontinuous HSEs, and heat shock of HeLa cells caused expression of reporter genes containing continuous HSEs. HSF2, whose function is implicated in neuronal specification and spermatogenesis, exhibited a slightly higher binding affinity to discontinuous HSEs than did HSF1. HSF4, a protein required for ocular lens development, efficiently recognized discontinuous HSEs in a trimerization-dependent manner. Among four human gamma-crystallin genes encoding structural proteins of the lens, heat-induced HSF1 preferred HSEs on the gammaA-crystallin and gammaB-crystallin promoters, whereas HSF4 preferred HSE on the gammaC-crystallin promoter. These results suggest that the HSE architecture is an important determinant of which HSF members regulate genes in diverse cellular processes.

  6. The heat shock response plays an important role in TDP-43 clearance: evidence for dysfunction in amyotrophic lateral sclerosis.

    Science.gov (United States)

    Chen, Han-Jou; Mitchell, Jacqueline C; Novoselov, Sergey; Miller, Jack; Nishimura, Agnes L; Scotter, Emma L; Vance, Caroline A; Cheetham, Michael E; Shaw, Christopher E

    2016-05-01

    Detergent-resistant, ubiquitinated and hyperphosphorylated Tar DNA binding protein 43 (TDP-43, encoded by TARDBP) neuronal cytoplasmic inclusions are the pathological hallmark in ∼95% of amyotrophic lateral sclerosis and ∼60% of frontotemporal lobar degeneration cases. We sought to explore the role for the heat shock response in the clearance of insoluble TDP-43 in a cellular model of disease and to validate our findings in transgenic mice and human amyotrophic lateral sclerosis tissues. The heat shock response is a stress-responsive protective mechanism regulated by the transcription factor heat shock factor 1 (HSF1), which increases the expression of chaperones that refold damaged misfolded proteins or facilitate their degradation. Here we show that manipulation of the heat shock response by expression of dominant active HSF1 results in a dramatic reduction of insoluble and hyperphosphorylated TDP-43 that enhances cell survival, whereas expression of dominant negative HSF1 leads to enhanced TDP-43 aggregation and hyperphosphorylation. To determine which chaperones were mediating TDP-43 clearance we over-expressed a range of heat shock proteins (HSPs) and identified DNAJB2a (encoded by DNAJB2, and also known as HSJ1a) as a potent anti-aggregation chaperone for TDP-43. DNAJB2a has a J domain, allowing it to interact with HSP70, and ubiquitin interacting motifs, which enable it to engage the degradation of its client proteins. Using functionally deleted DNAJB2a constructs we demonstrated that TDP-43 clearance was J domain-dependent and was not affected by ubiquitin interacting motif deletion or proteasome inhibition. This indicates that TDP-43 is maintained in a soluble state by DNAJB2a, leaving the total levels of TDP-43 unchanged. Additionally, we have demonstrated that the levels of HSF1 and heat shock proteins are significantly reduced in affected neuronal tissues from a TDP-43 transgenic mouse model of amyotrophic lateral sclerosis and patients with

  7. A novel protein quality control mechanism contributes to heat shock resistance of worldwide-distributed Pseudomonas aeruginosa clone C strains.

    Science.gov (United States)

    Lee, Changhan; Wigren, Edvard; Trček, Janja; Peters, Verena; Kim, Jihong; Hasni, Muhammad Sharif; Nimtz, Manfred; Lindqvist, Ylva; Park, Chankyu; Curth, Ute; Lünsdorf, Heinrich; Römling, Ute

    2015-11-01

    Pseudomonas aeruginosa is a highly successful nosocomial pathogen capable of causing a wide variety of infections with clone C strains most prevalent worldwide. In this study, we initially characterize a molecular mechanism of survival unique to clone C strains. We identified a P. aeruginosa clone C-specific genomic island (PACGI-1) that contains the highly expressed small heat shock protein sHsp20c, the founding member of a novel subclass of class B bacterial small heat shock proteins. sHsp20c and adjacent gene products are involved in resistance against heat shock. Heat stable sHsp20c is unconventionally expressed in stationary phase in a wide temperature range from 20 to 42°C. Purified sHsp20c has characteristic features of small heat shock protein class B as it is monodisperse, forms sphere-like 24-meric oligomers and exhibits significant chaperone activity. As the P. aeruginosa clone C population is significantly more heat shock resistant than genetically unrelated P. aeruginosa strains without sHsp20c, the horizontally acquired shsp20c operon might contribute to the survival of worldwide-distributed clone C strains.

  8. Ste20-like kinase, SLK, activates the heat shock factor 1 - Hsp70 pathway.

    Science.gov (United States)

    Cybulsky, Andrey V; Guillemette, Julie; Papillon, Joan

    2016-09-01

    Expression and activation of SLK increases during renal ischemia-reperfusion injury. When highly expressed, SLK signals via c-Jun N-terminal kinase and p38 to induce apoptosis, and it exacerbates apoptosis induced by ischemia-reperfusion injury. Overexpression of SLK in glomerular epithelial cells (GECs)/podocytes in vivo induces injury and proteinuria. In response to various stresses, cells enhance expression of chaperones or heat shock proteins (e.g. Hsp70), which are involved in the folding and maturation of newly synthesized proteins, and can refold denatured or misfolded proteins. We address the interaction of SLK with the heat shock factor 1 (HSF1)-Hsp70 pathway. Increased expression of SLK in GECs (following transfection) induced HSF1 transcriptional activity. Moreover, HSF1 transcriptional activity was increased by in vitro ischemia-reperfusion injury (chemical anoxia/recovery) and heat shock, and in both instances was amplified further by SLK overexpression. HSF1 binds to promoters of target genes, such as Hsp70 and induces their transcription. By analogy to HSF1, SLK stimulated Hsp70 expression. Hsp70 was also enhanced by anoxia/recovery and was further amplified by SLK overexpression. Induction of HSF1 and Hsp70 was dependent on the kinase activity of SLK, and was mediated via polo-like kinase-1. Transfection of constitutively active HSF1 enhanced Hsp70 expression and inhibited SLK-induced apoptosis. Conversely, the proapoptotic action of SLK was augmented by HSF1 shRNA, or the Hsp70 inhibitor, pifithrin-μ. In conclusion, increased expression/activity of SLK activates the HSF1-Hsp70 pathway. Hsp70 attenuates the primary proapoptotic effect of SLK. Modulation of chaperone expression may potentially be harnessed as cytoprotective therapy in renal cell injury.

  9. Molecular Cloning and Identification of a Heat Shock Cognate Protein 70 Gene, Thhsc70, in Thellungiella halophila

    Institute of Scientific and Technical Information of China (English)

    ZHANGXia; GUOShan-Li; YINHai-Bo; XIONGDong-Jin; ZHANGHui; ZHAOYan-Xiu

    2004-01-01

    Heat shock cognate proteins 70 (hsp70s) act as molecular chaperones. Some hsp70s are also expressed in unstressed plants, known as hsc70. To gain further knowledge about the hsc70, the Thellungiella halophila hsc70 (Thhsc70) gene that encoded the cytosolic hsc70 in salt cress (T.halophila (C.A.Mey.) O.E.Schulz) was identified. In unstressed plants the expression of Thhsc70was shown to be tissue-specific. The Thhsc70 gene was induced by heat and cold stresses, but almost not by salt and drought stresses. Overexpression of Thhsc7Ocould increase thermctolerance and chilling tolerance in transgenic Arabidopsis plants.

  10. The expression and function of hsp30-like small heat shock protein genes in amphibians, birds, fish, and reptiles.

    Science.gov (United States)

    Heikkila, John J

    2017-01-01

    Small heat shock proteins (sHSPs) are a superfamily of molecular chaperones with important roles in protein homeostasis and other cellular functions. Amphibians, reptiles, fish and birds have a shsp gene called hsp30, which was also referred to as hspb11 or hsp25 in some fish and bird species. Hsp30 genes, which are not found in mammals, are transcribed in response to heat shock or other stresses by means of the heat shock factor that is activated in response to an accumulation of unfolded protein. Amino acid sequence analysis revealed that representative HSP30s from different classes of non-mammalian vertebrates were distinct from other sHSPs including HSPB1/HSP27. Studies with amphibian and fish recombinant HSP30 determined that they were molecular chaperones since they inhibited heat- or chemically-induced aggregation of unfolded protein. During non-mammalian vertebrate development, hsp30 genes were differentially expressed in selected tissues. Also, heat shock-induced stage-specific expression of hsp30 genes in frog embryos was regulated at the level of chromatin structure. In adults and/or tissue culture cells, hsp30 gene expression was induced by heat shock, arsenite, cadmium or proteasomal inhibitors, all of which enhanced the production of unfolded/damaged protein. Finally, immunocytochemical analysis of frog and chicken tissue culture cells revealed that proteotoxic stress-induced HSP30 accumulation co-localized with aggresome-like inclusion bodies. The congregation of damaged protein in aggresomes minimizes the toxic effect of aggregated protein dispersed throughout the cell. The current availability of probes to detect the presence of hsp30 mRNA or encoded protein has resulted in the increased use of hsp30 gene expression as a marker of proteotoxic stress in non-mammalian vertebrates.

  11. Heterologous expression of a plant small heat-shock protein enhances Escherichia coli viability under heat and cold stress.

    Science.gov (United States)

    Soto, A; Allona, I; Collada, C; Guevara, M A; Casado, R; Rodriguez-Cerezo, E; Aragoncillo, C; Gomez, L

    1999-06-01

    A small heat-shock protein (sHSP) that shows molecular chaperone activity in vitro was recently purified from mature chestnut (Castanea sativa) cotyledons. This protein, renamed here as CsHSP17. 5, belongs to cytosolic class I, as revealed by cDNA sequencing and immunoelectron microscopy. Recombinant CsHSP17.5 was overexpressed in Escherichia coli to study its possible function under stress conditions. Upon transfer from 37 degrees C to 50 degrees C, a temperature known to cause cell autolysis, those cells that accumulated CsHSP17.5 showed improved viability compared with control cultures. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of cell lysates suggested that such a protective effect in vivo is due to the ability of recombinant sHSP to maintain soluble cytosolic proteins in their native conformation, with little substrate specificity. To test the recent hypothesis that sHSPs may be involved in protection against cold stress, we also studied the viability of recombinant cells at 4 degrees C. Unlike the major heat-induced chaperone, GroEL/ES, the chestnut sHSP significantly enhanced cell survivability at this temperature. CsHSP17.5 thus represents an example of a HSP capable of protecting cells against both thermal extremes. Consistent with these findings, high-level induction of homologous transcripts was observed in vegetative tissues of chestnut plantlets exposed to either type of thermal stress but not salt stress.

  12. Macrocycles that inhibit the binding between heat shock protein 90 and TPR-containing proteins.

    Science.gov (United States)

    Ardi, Veronica C; Alexander, Leslie D; Johnson, Victoria A; McAlpine, Shelli R

    2011-12-16

    Heat shock protein 90 (Hsp90) accounts for 1-2% of the total proteins in normal cells and functions as a molecular chaperone that folds, assembles, and stabilizes client proteins. Hsp90 is overexpressed (3- to 6-fold increase) in stressed cells, including cancer cells, and regulates over 200 client and co-chaperone proteins. Hsp90 client proteins are involved in a plethora of cellular signaling events including numerous growth and apoptotic pathways. Since pathway-specific inhibitors can be problematic in drug-resistant cancers, shutting down multiple pathways at once is a promising approach when developing new therapeutics. Hsp90's ability to modulate many growth and signaling pathways simultaneously makes this protein an attractive target in the field of cancer therapeutics. Herein we present evidence that a small molecule modulates Hsp90 via binding between the N and middle domain and allosterically inhibiting the binding interaction between Hsp90 and four C-terminal binding client proteins: IP6K2, FKBP38, FKBP52, and HOP. These last three clients contain a tetratricopeptide-repeat (TPR) region, which is known to interact with the MEEVD sequence on the C-terminus of Hsp90. Thus, this small molecule modulates the activity between co-chaperones that contain TPR motifs and Hsp90's MEEVD region. This mechanism of action is unique from that of all Hsp90 inhibitors currently in clinical trials where these molecules have no effect on proteins that bind to the C-terminus of Hsp90. Further, our small molecule induces a Caspase-3 dependent apoptotic event. Thus, we describe the mechanism of a novel scaffold that is a useful tool for studying cell-signaling events that result when blocking the MEEVD-TPR interaction between Hsp90 and co-chaperone proteins.

  13. Small Heat Shock Proteins Can Release Light Dependence of Tobacco Seed during Germination1[OPEN

    Science.gov (United States)

    Koo, Hyun Jo; Park, Soo Min; Kim, Keun Pill; Suh, Mi Chung; Lee, Mi Ok; Lee, Seong-Kon; Xinli, Xia

    2015-01-01

    Small heat shock proteins (sHSPs) function as ATP-independent molecular chaperones, and although the production and function of sHSPs have often been described under heat stress, the expression and function of sHSPs in fundamental developmental processes, such as pollen and seed development, have also been confirmed. Seed germination involves the breaking of dormancy and the resumption of embryo growth that accompany global changes in transcription, translation, and metabolism. In many plants, germination is triggered simply by imbibition of water; however, different seeds require different conditions in addition to water. For small-seeded plants, like Arabidopsis (Arabidopsis thaliana), lettuce (Lactuca sativa), tomato (Solanum lycopersicum), and tobacco (Nicotiana tabacum), light is an important regulator of seed germination. The facts that sHSPs accumulate during seed development, sHSPs interact with various client proteins, and seed germination accompanies synthesis and/or activation of diverse proteins led us to investigate the role of sHSPs in seed germination, especially in the context of light dependence. In this study, we have built transgenic tobacco plants that ectopically express sHSP, and the effect was germination of the seeds in the dark. Administering heat shock to the seeds also resulted in the alleviation of light dependence during seed germination. Subcellular localization of ectopically expressed sHSP was mainly observed in the cytoplasm, whereas heat shock-induced sHSPs were transported to the nucleus. We hypothesize that ectopically expressed sHSPs in the cytoplasm led the status of cytoplasmic proteins involved in seed germination to function during germination without additional stimulus and that heat shock can be another signal that induces seed germination. PMID:25604531

  14. Small heat shock proteins can release light dependence of tobacco seed during germination.

    Science.gov (United States)

    Koo, Hyun Jo; Park, Soo Min; Kim, Keun Pill; Suh, Mi Chung; Lee, Mi Ok; Lee, Seong-Kon; Xinli, Xia; Hong, Choo Bong

    2015-03-01

    Small heat shock proteins (sHSPs) function as ATP-independent molecular chaperones, and although the production and function of sHSPs have often been described under heat stress, the expression and function of sHSPs in fundamental developmental processes, such as pollen and seed development, have also been confirmed. Seed germination involves the breaking of dormancy and the resumption of embryo growth that accompany global changes in transcription, translation, and metabolism. In many plants, germination is triggered simply by imbibition of water; however, different seeds require different conditions in addition to water. For small-seeded plants, like Arabidopsis (Arabidopsis thaliana), lettuce (Lactuca sativa), tomato (Solanum lycopersicum), and tobacco (Nicotiana tabacum), light is an important regulator of seed germination. The facts that sHSPs accumulate during seed development, sHSPs interact with various client proteins, and seed germination accompanies synthesis and/or activation of diverse proteins led us to investigate the role of sHSPs in seed germination, especially in the context of light dependence. In this study, we have built transgenic tobacco plants that ectopically express sHSP, and the effect was germination of the seeds in the dark. Administering heat shock to the seeds also resulted in the alleviation of light dependence during seed germination. Subcellular localization of ectopically expressed sHSP was mainly observed in the cytoplasm, whereas heat shock-induced sHSPs were transported to the nucleus. We hypothesize that ectopically expressed sHSPs in the cytoplasm led the status of cytoplasmic proteins involved in seed germination to function during germination without additional stimulus and that heat shock can be another signal that induces seed germination.

  15. The FNIP co-chaperones decelerate the Hsp90 chaperone cycle and enhance drug binding

    Science.gov (United States)

    Woodford, Mark R.; Dunn, Diana M.; Blanden, Adam R.; Capriotti, Dante; Loiselle, David; Prodromou, Chrisostomos; Panaretou, Barry; Hughes, Philip F.; Smith, Aaron; Ackerman, Wendi; Haystead, Timothy A.; Loh, Stewart N.; Bourboulia, Dimitra; Schmidt, Laura S.; Marston Linehan, W.; Bratslavsky, Gennady; Mollapour, Mehdi

    2016-01-01

    Heat shock protein-90 (Hsp90) is an essential molecular chaperone in eukaryotes involved in maintaining the stability and activity of numerous signalling proteins, also known as clients. Hsp90 ATPase activity is essential for its chaperone function and it is regulated by co-chaperones. Here we show that the tumour suppressor FLCN is an Hsp90 client protein and its binding partners FNIP1/FNIP2 function as co-chaperones. FNIPs decelerate the chaperone cycle, facilitating FLCN interaction with Hsp90, consequently ensuring FLCN stability. FNIPs compete with the activating co-chaperone Aha1 for binding to Hsp90, thereby providing a reciprocal regulatory mechanism for chaperoning of client proteins. Lastly, downregulation of FNIPs desensitizes cancer cells to Hsp90 inhibitors, whereas FNIPs overexpression in renal tumours compared with adjacent normal tissues correlates with enhanced binding of Hsp90 to its inhibitors. Our findings suggest that FNIPs expression can potentially serve as a predictive indicator of tumour response to Hsp90 inhibitors. PMID:27353360

  16. Assessment of heat shock protein 70 induction by heat in alfalfa varieties and constitutive overexpression in transgenic plants.

    Directory of Open Access Journals (Sweden)

    Nicoletta Ferradini

    Full Text Available Heat shock proteins (HSPs are molecular chaperones involved in many cellular functions. It has been shown that mammalian cytosolic HSP70 binds antigenic peptides mediating the activation of the immune system, and that it plays a determining role in tumour immunogenicity. This suggests that HSP70 may be used for the production of conjugated vaccines. Human and plant HSPs share high sequence similarity and some important biological functions in vitro. In addition, plant HSPs have no endotoxic side effects. Extraction of HSP70 from plants for use as vaccine adjuvant requires enhancing its concentration in plant tissues. In this work, we explored the possibility to produce HSP70 in both transgenic and non-transgenic plants, using alfalfa as a model species. First, a transcriptional analysis of a constitutive and an inducible HSP70 genes was conducted in Arabidopsis thaliana. Then the coding sequence of the inducible form was cloned and introduced into alfalfa by Agrobacterium-mediated transformation, and the accumulation of the protein in leaf tissue of transgenic plants was demonstrated. We also tested diverse alfalfa varieties for heat-inducible expression of endogenous HSP70, revealing variety-specific responses to heat shock.

  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 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.

  19. Modulation of heat shock transcription factor 1 as a therapeutic target for small molecule intervention in neurodegenerative disease.

    Directory of Open Access Journals (Sweden)

    Daniel W Neef

    2010-01-01

    Full Text Available Neurodegenerative diseases such as Huntington disease are devastating disorders with no therapeutic approaches to ameliorate the underlying protein misfolding defect inherent to poly-glutamine (polyQ proteins. Given the mounting evidence that elevated levels of protein chaperones suppress polyQ protein misfolding, the master regulator of protein chaperone gene transcription, HSF1, is an attractive target for small molecule intervention. We describe a humanized yeast-based high-throughput screen to identify small molecule activators of human HSF1. This screen is insensitive to previously characterized activators of the heat shock response that have undesirable proteotoxic activity or that inhibit Hsp90, the central chaperone for cellular signaling and proliferation. A molecule identified in this screen, HSF1A, is structurally distinct from other characterized small molecule human HSF1 activators, activates HSF1 in mammalian and fly cells, elevates protein chaperone expression, ameliorates protein misfolding and cell death in polyQ-expressing neuronal precursor cells and protects against cytotoxicity in a fly model of polyQ-mediated neurodegeneration. In addition, we show that HSF1A interacts with components of the TRiC/CCT complex, suggesting a potentially novel regulatory role for this complex in modulating HSF1 activity. These studies describe a novel approach for the identification of new classes of pharmacological interventions for protein misfolding that underlies devastating neurodegenerative disease.

  20. Heat shock response and autophagy--cooperation and control.

    Science.gov (United States)

    Dokladny, Karol; Myers, Orrin B; Moseley, Pope L

    2015-01-01

    Protein quality control (proteostasis) depends on constant protein degradation and resynthesis, and is essential for proper homeostasis in systems from single cells to whole organisms. Cells possess several mechanisms and processes to maintain proteostasis. At one end of the spectrum, the heat shock proteins modulate protein folding and repair. At the other end, the proteasome and autophagy as well as other lysosome-dependent systems, function in the degradation of dysfunctional proteins. In this review, we examine how these systems interact to maintain proteostasis. Both the direct cellular data on heat shock control over autophagy and the time course of exercise-associated changes in humans support the model that heat shock response and autophagy are tightly linked. Studying the links between exercise stress and molecular control of proteostasis provides evidence that the heat shock response and autophagy coordinate and undergo sequential activation and downregulation, and that this is essential for proper proteostasis in eukaryotic systems.

  1. Molecular chaperones and hypoxic-ischemic encephalopathy

    Directory of Open Access Journals (Sweden)

    Cong Hua

    2017-01-01

    Full Text Available Hypoxic-ischemic encephalopathy (HIE is a disease that occurs when the brain is subjected to hypoxia, resulting in neuronal death and neurological deficits, with a poor prognosis. The mechanisms underlying hypoxic-ischemic brain injury include excitatory amino acid release, cellular proteolysis, reactive oxygen species generation, nitric oxide synthesis, and inflammation. The molecular and cellular changes in HIE include protein misfolding, aggregation, and destruction of organelles. The apoptotic pathways activated by ischemia and hypoxia include the mitochondrial pathway, the extrinsic Fas receptor pathway, and the endoplasmic reticulum stress-induced pathway. Numerous treatments for hypoxic-ischemic brain injury caused by HIE have been developed over the last half century. Hypothermia, xenon gas treatment, the use of melatonin and erythropoietin, and hypoxic-ischemic preconditioning have proven effective in HIE patients. Molecular chaperones are proteins ubiquitously present in both prokaryotes and eukaryotes. A large number of molecular chaperones are induced after brain ischemia and hypoxia, among which the heat shock proteins are the most important. Heat shock proteins not only maintain protein homeostasis; they also exert anti-apoptotic effects. Heat shock proteins maintain protein homeostasis by helping to transport proteins to their target destinations, assisting in the proper folding of newly synthesized polypeptides, regulating the degradation of misfolded proteins, inhibiting the aggregation of proteins, and by controlling the refolding of misfolded proteins. In addition, heat shock proteins exert anti-apoptotic effects by interacting with various signaling pathways to block the activation of downstream effectors in numerous apoptotic pathways, including the intrinsic pathway, the endoplasmic reticulum-stress mediated pathway and the extrinsic Fas receptor pathway. Molecular chaperones play a key role in neuroprotection in HIE. In

  2. DETECTION OF IMMUNOGLOBULINS, ANTIBODIES TO HEAT-SHOCK PROTEINS AND IL-8 CYTOKINE IN SALIVA FROM THE PATIENTS WITH CHRONIC PERIODONTAL DISEASES

    Directory of Open Access Journals (Sweden)

    N. N. Tsybikov

    2010-01-01

    Full Text Available  Examination of the patients with chronic generalized periodontitis revealed a sufficient increase in all immunoglobulin classes, i.e., IgG, IgM, IgA, sIgA, as well as increased IL-8 concentration in their salivary samples. Emergence of antibodies to heat-shock proteins suggests a pathogenetic role of chaperon-like proteins in development of periodontal diseases.

  3. 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...

  4. 热休克蛋白60的研究进展%Recent advances in heat shock protein 60

    Institute of Scientific and Technical Information of China (English)

    龚兴国; 于红

    2004-01-01

    The family of HSP60 belongs to heat shock proteins with highly species conservatism and some important biologic functions. It can help other proteins for their assembling, folding and translocating, and plays a role in protecting cells against injuries and other types of stress. In addition, HSP60 is frequently recognized by the immune system as predominant antigens during infections and the progression of certain autoimmune diseases and might provide a novel strategy for the development of immunotherapeutics. This review focuses on distribution, molecular chaperone mechanism, function and gene expression regulation of HSP60.

  5. Small heat shock protein Hsp27 is required for proper heart tube formation.

    Science.gov (United States)

    Brown, Daniel D; Christine, Kathleen S; Showell, Christopher; Conlon, Frank L

    2007-11-01

    The small heat shock protein Hsp27 has been shown to be involved in a diverse array of cellular processes, including cellular stress response, protein chaperone activity, regulation of cellular glutathione levels, apoptotic signaling, and regulation of actin polymerization and stability. Furthermore, mutation within Hsp27 has been associated with the human congenital neuropathy Charcot-Marie Tooth (CMT) disease. Hsp27 is known to be expressed in developing embryonic tissues; however, little has been done to determine the endogenous requirement for Hsp27 in developing embryos. In this study, we show that depletion of XHSP27 protein results in a failure of cardiac progenitor fusion resulting in cardia bifida. Furthermore, we demonstrate a concomitant disorganization of actin filament organization and defects in myofibril assembly. Moreover, these defects are not associated with alterations in specification or differentiation. We have thus demonstrated a critical requirement for XHSP27 in developing cardiac and skeletal muscle tissues.

  6. Heat-shock protein dysregulation is associated with functional and pathological TDP-43 aggregation

    Science.gov (United States)

    Chang, Hsiang-Yu; Hou, Shin-Chen; Way, Tzong-Der; Wong, Chi-Huey; Wang, I.-Fan

    2013-11-01

    Conformational disorders are involved in various neurodegenerative diseases. Reactive oxygen species (ROS) are the major contributors to neurodegenerative disease; however, ROS that affect the structural changes in misfolded disease proteins have yet to be well characterized. Here we demonstrate that the intrinsic propensity of TDP-43 to aggregate drives the assembly of TDP-43-positive stress granules and soluble toxic TDP-43 oligomers in response to a ROS insult via a disulfide crosslinking-independent mechanism. Notably, ROS-induced TDP-43 protein assembly correlates with the dynamics of certain TDP-43-associated chaperones. The heat-shock protein (HSP)-90 inhibitor 17-AAG prevents ROS-induced TDP-43 aggregation, alters the type of TDP-43 multimers and reduces the severity of pathological TDP-43 inclusions. In summary, our study suggests that a common mechanism could be involved in the pathogenesis of conformational diseases that result from HSP dysregulation.

  7. 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   

  8. CHIP Knockdown Reduced Heat Shock Response and Protein Quality Control Capacity in Lens Epithelial Cells.

    Science.gov (United States)

    Zhang, W; Liu, Z; Bao, X; Qin, Y; Taylor, A; Shang, F; Wu, M

    2015-01-01

    Protein quality control (PQC) systems, including molecular chaperones and ubiquitin-proteasome pathway (UPP), plays an important role in maintaining intracellular protein homeostasis. Carboxyl terminus of Hsc70- interacting protein (CHIP) links the chaperone and UPPs, thus contributing to the repair or removal of damaged proteins. Over-expression of CHIP had previously been used to protect cells from environmental stress. In order to gain a more physiologic mechanism of the advantage conferred by CHIP, we induced a CHIP knockdown and monitored the ability of cells to cope with environmental stress. To knockdown CHIP, the human lens epithelial cell line HLE B3 was transfected with lentiviral particles that encode a CHIP short hairpin RNA (shRNA) or negative control lentiviral particles. Stable CHIP-knock down cells (KD) and negative control cells (NC) were selected with puromycin. After exposure to heat shock stress, there was no change observed in the expression of Hsp90. In contrast, Hsp70 levels increased significantly in NC cells but less so in KD cells. Hsp27 levels also increased after heat shock, but only in NC cells. Protein ubiquitination was reduced when CHIP was knocked down. CHIP knockdown reduced the ability to clear aggregation proteins. When same levels of aggregation-prone RFP-mutant crystallin fusion protein, RFP/V76D-γD, was expressed, there was ~9- fold more aggregates in KD cells as compared to that observed in NC cells. Furthermore, KD cells were more sensitive to toxicity of amino acid analog canavanine as compared to NC cells. Together, these data indicate that CHIP is required for PQC and that CHIP knockdown diminished cellular PQC capacity in lens cells.

  9. 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.

  10. 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

  11. Heat shock protein-90-beta facilitates enterovirus 71 viral particles assembly.

    Science.gov (United States)

    Wang, Robert Y L; Kuo, Rei-Lin; Ma, Wei-Chieh; Huang, Hsing-I; Yu, Jau-Song; Yen, Sih-Min; Huang, Chi-Ruei; Shih, Shin-Ru

    2013-09-01

    Molecular chaperones are reported to be crucial for virus propagation, but are not yet addressed in Human Enterovirus 71 (EV71). Here we describe the specific association of heat shock protein-90-beta (Hsp90β), but not alpha form (Hsp90α), with EV71 viral particles by the co-purification with virions using sucrose density gradient ultracentrifugation, and by the colocalization with viral particles, as assessed by immunogold electron microscopy. The reduction of the Hsp90β protein using RNA interference decreased the correct assembly of viral particles, without affecting EV71 replication levels. Tracking ectopically expressed Hsp90β protein associated with EV71 virions revealed that Hsp90β protein was transmitted to new host cells through its direct association with infectious viral particles. Our findings suggest a new antiviral strategy in which extracellular Hsp90β protein is targeted to decrease the infectivity of EV71 and other enteroviruses, without affecting the broader functions of this constitutively expressed molecular chaperone.

  12. Heat shock protein-90-beta facilitates enterovirus 71 viral particles assembly

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Robert Y.L., E-mail: yuwang@mail.cgu.edu.tw [Research Center for Emerging Viral Infections, College of Medicine, Chang Gung University, Tao-Yuan 333, Taiwan (China); Department of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan 333 Taiwan (China); Kuo, Rei-Lin [Research Center for Emerging Viral Infections, College of Medicine, Chang Gung University, Tao-Yuan 333, Taiwan (China); Department of Medical Biotechnology and Laboratory Science and Graduate Program of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan 333, Taiwan (China); Ma, Wei-Chieh [Department of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan 333 Taiwan (China); Huang, Hsing-I [Research Center for Emerging Viral Infections, College of Medicine, Chang Gung University, Tao-Yuan 333, Taiwan (China); Department of Medical Biotechnology and Laboratory Science and Graduate Program of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan 333, Taiwan (China); Yu, Jau-Song [Department of Cell and Molecular Biology, College of Medicine, Chang Gung University, Tao-Yuan 333, Taiwan (China); Molecular Medicine Research Center, Chang Gung University, Tao-Yuan 333, Taiwan (China); Yen, Sih-Min [Department of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan 333 Taiwan (China); Huang, Chi-Ruei [Research Center for Emerging Viral Infections, College of Medicine, Chang Gung University, Tao-Yuan 333, Taiwan (China); Department of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan 333 Taiwan (China); Shih, Shin-Ru [Research Center for Emerging Viral Infections, College of Medicine, Chang Gung University, Tao-Yuan 333, Taiwan (China); Department of Medical Biotechnology and Laboratory Science and Graduate Program of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan 333, Taiwan (China)

    2013-09-01

    Molecular chaperones are reported to be crucial for virus propagation, but are not yet addressed in Human Enterovirus 71 (EV71). Here we describe the specific association of heat shock protein-90-beta (Hsp90β), but not alpha form (Hsp90α), with EV71 viral particles by the co-purification with virions using sucrose density gradient ultracentrifugation, and by the colocalization with viral particles, as assessed by immunogold electron microscopy. The reduction of the Hsp90β protein using RNA interference decreased the correct assembly of viral particles, without affecting EV71 replication levels. Tracking ectopically expressed Hsp90β protein associated with EV71 virions revealed that Hsp90β protein was transmitted to new host cells through its direct association with infectious viral particles. Our findings suggest a new antiviral strategy in which extracellular Hsp90β protein is targeted to decrease the infectivity of EV71 and other enteroviruses, without affecting the broader functions of this constitutively expressed molecular chaperone. - Highlights: • Hsp90β is associated with EV71 virion and is secreted with the release virus. • Hsp90β effects on the correct assembly of viral particles. • Viral titer of cultured medium was reduced in the presence of geldanamycin. • Viral titer was also reduced when Hsp90β was suppressed by siRNA treatment. • The extracellular Hsp90β was also observed in other RNA viruses-infected cells.

  13. 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.

  14. Heat Shock Protein (HSP peptide and HSP-based immunotherapies for the treatment of cancer

    Directory of Open Access Journals (Sweden)

    Gabriele eMulthoff

    2016-04-01

    Full Text Available Intracellular residing heat shock proteins (HSPs with a molecular weight of approximately 70 and 90 kDa function as molecular chaperones that assist folding/unfolding and transport of proteins across membranes and prevent protein aggregation after environmental stress. In contrast to normal cells, tumor cells have higher cytosolic HSP70 and Hsp90 levels which contribute to tumor cell propagation, metastasis and protection against apoptosis. In addition to their intracellular chaperoning functions, extracellular localized and membrane-bound HSPs have been found to play key roles in eliciting anti-tumor immune responses either by acting as carriers for tumor-derived, immunogenic peptides, as adjuvants for antigen presentation or as targets for the innate immune system. The interaction of HSP-peptide complexes or peptide-free HSPs with receptors on antigen presenting cells (APCs promotes the maturation of dendritic cells (DCs, results in an up-regulation of MHC class I and class II molecules, induces secretion of pro- and anti-inflammatory cytokines, chemokines, and immune modulatory nitric oxides and thus integrate adaptive and innate immune phenomena. Herein, we aim to recapitulate the history and current status of HSP-based immunotherapies and vaccination strategies in the treatment of cancer.

  15. Heat shock protein 70 down-regulates the production of toll-like receptor-induced pro-inflammatory cytokines by a heat shock factor-1/constitutive heat shock element-binding factor-dependent mechanism.

    Science.gov (United States)

    Ferat-Osorio, Eduardo; Sánchez-Anaya, Aldair; Gutiérrez-Mendoza, Mireille; Boscó-Gárate, Ilka; Wong-Baeza, Isabel; Pastelin-Palacios, Rodolfo; Pedraza-Alva, Gustavo; Bonifaz, Laura C; Cortés-Reynosa, Pedro; Pérez-Salazar, Eduardo; Arriaga-Pizano, Lourdes; López-Macías, Constantino; Rosenstein, Yvonne; Isibasi, Armando

    2014-01-01

    Heat shock protein 70 (Hsp70) is an intracellular chaperone protein with regulatory and cytoprotective functions. Hsp70 can also be found in the extracellular milieu, as a result of active secretion or passive release from damaged cells. The role of extracellular Hsp70 is not fully understood. Some studies report that it activates monocytes, macrophages and dendritic cells through innate immune receptors (such as Toll-like receptors, TLRs), while others report that Hsp70 is a negative regulator of the inflammatory response. In order to address this apparent inconsistency, in this study we evaluated the response of human monocytes to a highly purified recombinant Hsp70. Human peripheral blood monocytes were stimulated with Hsp70, alone or in combination with TLR agonists. Cytokines were quantified in culture supernatants, their mRNAs were measured by RT-PCR, and the binding of transcription factors was evaluated by electrophoretic mobility shift assay (EMSA). Kruskal-Wallis test or one-way or two-way ANOVA were used to analyze the data. The addition of Hsp70 to TLR-activated monocytes down-regulated TNF-α as well as IL-6 levels. This effect was independent of a physical interaction between Hsp70 and TLR agonists; instead it resulted of changes at the TNF-α gene expression level. The decrease in TNF-α expression correlated with the binding of HSF-1 (heat shock transcription factor 1, a transcription factor activated in response to Hsp70) and CHBF (constitutive HSE-binding factor) to the TNF-α gene promoter. Extracellular Hsp70 negatively regulates the production of pro-inflammatory cytokines of monocytes exposed to TLR agonists and contributes to dampen the inflammatory response.

  16. Emerging Role of Nitric Oxide and Heat Shock Proteins in Insulin Resistance.

    Science.gov (United States)

    Molina, Marisa Nile; Ferder, León; Manucha, Walter

    2016-01-01

    Insulin resistance (IR) is present in pathologies such as diabetes, obesity, metabolic syndrome, impaired glucose tolerance, hypertension, inflammation, cardiac disease, and dyslipidemias. Population studies show that IR is multifactorial and has genetic components, such as defects in the insulin-signaling pathway (as serine phosphorylation on insulin substrate or decreased activation of signaling molecules) and RAS/MAPK-dependent pathways. IR is connected to mitochondrial dysfunction, overproduction of oxidants, accumulation of fat, and an over-activation of the renin-angiotensin system linked to the NADPH oxidase activity. In addition, nitric oxide (NO), synthesized by nitric oxide synthases (endothelial and inducible), is also associated with IR when both impaired release and reduced bioavailability of all which lead to inflammation and hypertension. However, increased NO may promote vasculoprotection. Moreover, reduced NO release induces heat shock protein 70 kDa (HSP70) expression in IR and diabetes, mediating beneficial effects against oxidative stress injury, inflammation and apoptosis. HSP70 may be used as biomarker of the chronicity of diabetes. Hsp72 (inducible protein) is linked to vascular complications with a high-fat diet by blocking inflammation signaling (cytoprotective and anti-cytotoxicity intracellular role). Elucidating the IR signaling pathways and the roles of NO and HSPs is relevant to the application of new treatments, such as heat shock and thermal therapy, nitrosylated drugs, chemical chaperones or exercise training.

  17. Heat shock protein defenses in the neocortex and allocortex of the telencephalon.

    Science.gov (United States)

    Posimo, Jessica M; Weilnau, Justin N; Gleixner, Amanda M; Broeren, Matthew T; Weiland, Nicole L; Brodsky, Jeffrey L; Wipf, Peter; Leak, Rehana K

    2015-05-01

    The telencephalic allocortex develops protein inclusions before the neocortex in many age-related proteinopathies. One major defense mechanism against proteinopathic stress is the heat shock protein (Hsp) network. We therefore contrasted Hsp defenses in stressed primary neocortical and allocortical cells. Neocortical neurons were more resistant to the proteasome inhibitor MG132 than neurons from 3 allocortical subregions: entorhinal cortex, piriform cortex, and hippocampus. However, allocortical neurons exhibited higher MG132-induced increases in Hsp70 and heat shock cognate 70 (Hsc70). MG132-treated allocortical neurons also exhibited greater levels of protein ubiquitination. Inhibition of Hsp70/Hsc70 activity synergistically exacerbated MG132 toxicity in allocortical neurons more than neocortical neurons, suggesting that the allocortex is more reliant on these Hsp defenses. In contrast, astrocytes harvested from the neocortex or allocortex did not differ in their response to Hsp70/Hsc70 inhibition. Consistent with the idea that chaperones are maximally engaged in allocortical neurons, an increase in Hsp70/Hsc70 activity was protective only in neocortical neurons. Finally, the levels of select Hsps were altered in the neocortex and allocortex in vivo with aging.

  18. Distribution of Mayaro virus RNA in polysomes during heat shock.

    Science.gov (United States)

    Rosas, S L; Herculano, S; Carvalho, M da G

    1997-05-01

    Mayaro virus (alphavirus) infection of Aedes albopictus cells results in inhibition of cell protein synthesis and viral proteins are preferably synthesized. When infected cells are heat shocked, however, there is also an inhibition of viral protein synthesis, and there is preferential synthesis of heat shock proteins. Based on these observations, the distribution of Mayaro viral RNA in polysomes and the association of p34 (capsid protein) with ribosomal fractions of the cells under such conditions have been analyzed. During infection, the viral RNA is mainly observed in light polysomes (60% of total viral RNA in the cell) and also in heavy polysomes (13%). However, when infected cells are heat-shocked, the viral RNA is strongly mobilized from heavy polysomes to the light polysomes fraction and an enrichment in the unbound fraction can be noticed. The amount of p34 associated with the ribosomal fraction was also shown to be decreased in the heat shocked cells. These data lead to the suggestion that two mechanisms could be involved in the inhibition of Mayaro virus protein synthesis in response to heat shock: (1) mobilization of Mayaro virus RNA from heavy to light polysomes; (2) a decrease in the amount of the p34 within the ribosomal fraction.

  19. Mechanical analysis of a heat-shock induced developmental defect

    Science.gov (United States)

    Crews, Sarah M.; McCleery, W. Tyler; Hutson, M. Shane

    2014-03-01

    Embryonic development in Drosophila is a complex process involving coordinated movements of mechanically interacting tissues. Perturbing this system with a transient heat shock can result in a number of developmental defects. In particular, a heat shock applied during the earliest morphogenetic movements of gastrulation can lead to apparent recovery, but then subsequent morphogenetic failure 5-6 hours later during germ band retraction. The process of germ band retraction requires an intact amnioserosa - a single layered extra-embryonic epithelial tissue - and heat shock at gastrulation can induce the later opening of holes in the amnioserosa. These holes are highly correlated with failures of germ band retraction. These holes could be caused by a combination of mechanical weakness in the amnioserosa or local increases in mechanical stress. Here, we assess the role of mechanical stress using confocal imaging to compare cell and tissue morphology in the amnioserosa of normal and heat-shocked embryos and laser hole drilling to map the stress field around the times and locations at which heat-shock induced holes open.

  20. Overexpression of Colligin 2 in Glioma Vasculature is Associated with Overexpression of Heat Shock Factor 2.

    Science.gov (United States)

    Mustafa, Dana A M; Sieuwerts, Anieta M; Zheng, Ping Pin; Kros, Johan M

    2010-10-20

    In previous studies we found expression of the protein colligin 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 mammals, three heat shock transcription factors, HSF-1, -2, and -4, have been isolated. Here we investigated the relation between the expression of colligin 2 and these heat shock factors at the mRNA level using real-time reverse transcriptase PCR (qRT-PCR) in different grades of astrocytic tumorigenesis, viz., low-grade glioma and glioblastoma. Endometrium samples, representing physiological angiogenesis, were included as controls. Since colligin 2 is a chaperon for collagens, the gene expression of collagen I (COL1A1) was also investigated. The blood vessel density of the samples was monitored by expression of the endothelial marker CD31 (PECAM1). Because NG2-immunopositive pericytic cells are involved in glioma neovascularization, the expression of NG2 (CSPG4) was also measured.We demonstrate overexpression of HSF2 in both stages of glial tumorigenesis (reaching significance only in low-grade glioma) and also minor elevated levels of HSF1 as compared to normal brain. There were no differences in expression of HSF4 between low-grade glioma and normal brain while HSF4 was downregulated in glioblastoma. In the endometrium samples, none of the HSFs were upregulated. In the low-grade gliomas SERPINH appeared to be slightly overexpressed with a parallel 4-fold upregulation of COL1A1, while in glioblastoma there was over 5-fold overexpression of SERPINH1 and more than 150-fold overexpression of COL1A1. In both the lowgrade gliomas and the glioblastomas overexpression of CSPG4 was found and overexpression of PECAM1 was only found in the latter. Our data suggest that the upregulated expression of colligin 2 in glioma is accompanied by upregulation of COL1A1, CSPG4, HSF2 and to a lesser extent

  1. Atypical Particle Heating at a Supercritical Interplanetary Shock

    Science.gov (United States)

    Wilson, Lynn B., III

    2010-01-01

    We present the first observations at an interplanetary shock of large amplitude (> 100 mV/m pk-pk) solitary waves and large amplitude (approx.30 mV/m pk-pk) waves exhibiting characteristics consistent with electron Bernstein waves. The Bernstein-like waves show enhanced power at integer and half-integer harmonics of the cyclotron frequency with a broadened power spectrum at higher frequencies, consistent with the electron cyclotron drift instability. The Bernstein-like waves are obliquely polarized with respect to the magnetic field but parallel to the shock normal direction. Strong particle heating is observed in both the electrons and ions. The observed heating and waveforms are likely due to instabilities driven by the free energy provided by reflected ions at this supercritical interplanetary shock. These results offer new insights into collisionless shock dissipation and wave-particle interactions in the solar wind.

  2. AGN Heating Through Cavities and Shocks

    NARCIS (Netherlands)

    P.E.J. Nulsen; C. Jones; W.R. Forman; L.P. David; B.R. McNamara; D.A. Rafferty; L. Bîrzan; M. Wise

    2007-01-01

    Three comments are made on AGN heating of cooling flows. A simple physical argument is used to show that the enthalpy of a buoyant radio lobe is converted to heat in its wake. Thus, a significant part of ``cavity'' enthalpy is likely to end up as heat. Second, the properties of the repeated weak sho

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

    Science.gov (United States)

    Yamaguchi, Yuko; Tomoyasu, Toshifumi; Takaya, Akiko; Morioka, Mizue; Yamamoto, Tomoko

    2003-01-01

    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. PMID:12911840

  4. 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.

  5. 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.

  6. Heat Shock Proteins in Tendinopathy: Novel Molecular Regulators

    Science.gov (United States)

    Millar, Neal L.; Murrell, George A. C.

    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-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. PMID:23258952

  7. AGN feedback in clusters: shock and sound heating

    CERN Document Server

    Nulsen, P E J

    2013-01-01

    Observations support the view that feedback, in the form of radio outbursts from active nuclei in central galaxies, prevents catastrophic cooling of gas and rapid star formation in many groups and clusters of galaxies. Variations in jet power drive a succession of weak shocks that can heat regions close to the active galactic nuclei (AGN). On larger scales, shocks fade into sound waves. The Braginskii viscosity determines a well-defined sound damping rate in the weakly magnetized intracluster medium (ICM) that can provide sufficient heating on larger scales. It is argued that weak shocks and sound dissipation are the main means by which radio AGN heat the ICM, in which case, the power spectrum of AGN outbursts plays a central role in AGN feedback.

  8. 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.

  9. ACUPUNCTURE-MOXIBUSTION, HEAT SHOCK PROTEIN 70 AND CYTOPROTECTION

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Heat shock protein 70 (HSP70) is a kind of non-specific cytoprotective protein, and its generation can be induced by acupuncture and moxibustion. In the present paper, the authors review the protective actions of HSP70 on the heart, gastric mucosa, liver, brain tissues, kidney, etc., and the relationship among acupuncture/moxibustion, heat shock protein and the cytoprotective actions. It is worth studying the cytoprotective effect of acupuncture and moxibustion by way of the resultant generation of HSP70 in the organism.

  10. The stress protein heat shock cognate 70 (Hsc70) inhibits the Transient Receptor Potential Vanilloid type 1 (TRPV1) channel

    Science.gov (United States)

    Iftinca, Mircea; Flynn, Robyn; Basso, Lilian; Melo, Helvira; Aboushousha, Reem; Taylor, Lauren

    2016-01-01

    Background Specialized cellular defense mechanisms prevent damage from chemical, biological, and physical hazards. The heat shock proteins have been recognized as key chaperones that maintain cell survival against a variety of exogenous and endogenous stress signals including noxious temperature. However, the role of heat shock proteins in nociception remains poorly understood. We carried out an expression analysis of the constitutively expressed 70 kDa heat-shock cognate protein, a member of the stress-induced HSP70 family in lumbar dorsal root ganglia from a mouse model of Complete Freund’s Adjuvant-induced chronic inflammatory pain. We used immunolabeling of dorsal root ganglion neurons, behavioral analysis and patch clamp electrophysiology in both dorsal root ganglion neurons and HEK cells transfected with Hsc70 and Transient Receptor Potential Channels to examine their functional interaction in heat shock stress condition. Results We report an increase in protein levels of Hsc70 in mouse dorsal root ganglia, 3 days post Complete Freund’s Adjuvant injection in the hind paw. Immunostaining of Hsc70 was observed in most of the dorsal root ganglion neurons, including the small size nociceptors immunoreactive to the TRPV1 channel. Standard whole-cell patch-clamp technique was used to record Transient Receptor Potential Vanilloid type 1 current after exposure to heat shock. We found that capsaicin-evoked currents are inhibited by heat shock in dorsal root ganglion neurons and transfected HEK cells expressing Hsc70 and TRPV1. Blocking Hsc70 with matrine or spergualin compounds prevented heat shock-induced inhibition of the channel. We also found that, in contrast to TRPV1, both the cold sensor channels TRPA1 and TRPM8 were unresponsive to heat shock stress. Finally, we show that inhibition of TRPV1 depends on the ATPase activity of Hsc70 and involves the rho-associated protein kinase. Conclusions Our work identified Hsc70 and its ATPase activity as a central

  11. Important role of class I heat shock genes hrcA and dnaK in the heat shock response and the response to pH and NaCl stress of group I Clostridium botulinum strain ATCC 3502.

    Science.gov (United States)

    Selby, Katja; Lindström, Miia; Somervuo, Panu; Heap, John T; Minton, Nigel P; Korkeala, Hannu

    2011-05-01

    Class I heat shock genes (HSGs) code for molecular chaperones which play a major role in the bacterial response to sudden increases of environmental temperature by assisting protein folding. Quantitative reverse transcriptase real-time PCR gene expression analysis of the food-borne pathogen Clostridium botulinum grown at 37°C showed that the class I HSGs grpE, dnaK, dnaJ, groEL, and groES and their repressor, hrcA, were expressed at constant levels in the exponential and transitional growth phases, whereas strong downregulation of all six genes was observed during stationary phase. After heat shock from 37 to 45°C, all HSGs were transiently upregulated. A mutant with insertionally inactivated hrcA expressed higher levels of class I HSGs during exponential growth than the wild type, followed by upregulation of only groES and groES after heat shock. Inactivation of hrcA or of dnaK encoding a major chaperone resulted in lower maximum growth temperatures than for the wild type and reduced growth rates under optimal conditions compared to the wild type. The dnaK mutant showed growth inhibition under all tested temperature, pH, and NaCl stress conditions. In contrast, the growth of an hrcA mutant was unaffected by mild temperature or acid stress compared to the wild-type strain, indicating that induced class I HSGs support growth under moderately nonoptimal conditions. We show that the expression of class I HSGs plays a major role for survival and growth of C. botulinum under the stressful environmental conditions that may be encountered during food processing or growth in food products, in the mammalian intestine, or in wounds.

  12. Intracellular protozoan parasites of humans: the role of molecular chaperones in development and pathogenesis.

    Science.gov (United States)

    Shonhai, Addmore; Maier, Alexander G; Przyborski, Jude M; Blatch, Gregory L

    2011-02-01

    Certain kinetoplastid (Leishmania spp. and Tryapnosoma cruzi) and apicomplexan parasites (Plasmodium falciparum and Toxoplasma gondii) are capable of invading human cells as part of their pathology. These parasites appear to have evolved a relatively expanded or diverse complement of genes encoding molecular chaperones. The gene families encoding heat shock protein 90 (Hsp90) and heat shock protein 70 (Hsp70) chaperones show significant expansion and diversity (especially for Leishmania spp. and T. cruzi), and in particular the Hsp40 family appears to be an extreme example of phylogenetic radiation. In general, Hsp40 proteins act as co-chaperones of Hsp70 chaperones, forming protein folding pathways that integrate with Hsp90 to ensure proteostasis in the cell. It is tempting to speculate that the diverse environmental insults that these parasites endure have resulted in the evolutionary selection of a diverse and expanded chaperone network. Hsp90 is involved in development and growth of all of these intracellular parasites, and so far represents the strongest candidate as a target for chemotherapeutic interventions. While there have been some excellent studies on the molecular and cell biology of Hsp70 proteins, relatively little is known about the biological function of Hsp70-Hsp40 interactions in these intracellular parasites. This review focuses on intracellular protozoan parasites of humans, and provides a critique of the role of heat shock proteins in development and pathogenesis, especially the molecular chaperones Hsp90, Hsp70 and Hsp40.

  13. Inducing Muscle Heat Shock Protein 70 Improves Insulin Sensitivity and Muscular Performance in Aged Mice.

    Science.gov (United States)

    Silverstein, Marnie G; Ordanes, Diane; Wylie, Ashley T; Files, D Clark; Milligan, Carol; Presley, Tennille D; Kavanagh, Kylie

    2015-07-01

    Heat shock proteins (HSPs) are molecular chaperones with roles in longevity and muscular preservation. We aimed to show elevating HSP70 improves indices of health span. Aged C57/BL6 mice acclimated to a western diet were randomized into: geranylgeranylacetone (GGA)-treated (100 mg/kg/d), biweekly heat therapy (HT), or control. The GGA and HT are well-known pharmacological and environmental inducers of HSP70, respectively. Assessments before and after 8 weeks of treatment included glycemic endpoints, body composition, and muscular endurance, power, and perfusion. An HT mice had more than threefold, and GGA mice had a twofold greater HSP70 compared with control. Despite comparable body compositions, both treatment groups had significantly better insulin sensitivity and insulin signaling capacity. Compared with baseline, HT mice ran 23% longer than at study start, which was significantly more than GGA or control. Hanging ability (muscular endurance) also tended to be best preserved in HT mice. Muscle power, contractile force, capillary perfusion, and innervation were not different. Heat treatment has a clear benefit on muscular endurance, whereas HT and GGA both improved insulin sensitivity. Different effects may relate to muscle HSP70 levels. An HSP induction could be a promising approach for improving health span in the aged mice. © The Author 2014. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  14. Variation of the ratio of specific heats across a detached bow shock

    Science.gov (United States)

    Chao, J. K.; Wiskerchen, M. J.

    1974-01-01

    Equations are derived which allow the ratio of specific heats behind the earth's bow shock to be evaluated if several pre-shock parameters (the specific-heat ratio, the Alfvenic Mach number, the sonic Mach number, and the angle between the shock normal at the stagnation point and the magnetic field) and the density jump across the shock are known. Numerical examples show that the dependence of the post-shock ratio on the pre-shock ratio is weak.

  15. Heat Shock Protein (HSP) Drug Discovery and Development: Targeting Heat Shock Proteins in Disease

    Science.gov (United States)

    Shrestha, Liza; Bolaender, Alexander; Patel, Hardik J.; Taldone, Tony

    2016-01-01

    Heat shock proteins (HSPs) present as a double edged sword. While they play an important role in maintaining protein homeostasis in a normal cell, cancer cells have evolved to co-opt HSP function to promote their own survival. As a result, HSPs such as HSP90 have attracted a great deal of interest as a potential anticancer target. These efforts have resulted in over 20 distinct compounds entering clinical evaluation for the treatment of cancer. However, despite the potent anticancer activity demonstrated in preclinical models, to date no HSP90 inhibitor has obtained regulatory approval. In this review we discuss the unique challenges faced in targeting HSPs that have likely contributed to their lack of progress in the clinic and suggest ways to overcome these so that the enormous potential of these compounds to benefit patients can finally be realized. We also provide a guideline for the future development of HSP-targeted agents based on the many lessons learned during the last two decades in developing HSP90 inhibitors. PMID:27072696

  16. Guidelines for the nomenclature of the human heat shock proteins

    NARCIS (Netherlands)

    Kampinga, Harm H.; Hageman, Jurre; Vos, Michel J.; Kubota, Hiroshi; Tanguay, Robert M.; Bruford, Elspeth A.; Cheetham, Michael E.; Chen, B.; Hightower, Lawrence E.

    The expanding number of members in the various human heat shock protein (HSP) families and the inconsistencies in their nomenclature have often led to confusion. Here, we propose new guidelines for the nomenclature of the human HSP families, HSPH (HSP110), HSPC (HSP90), HSPA (HSP70), DNAJ (HSP40),

  17. Guidelines for the nomenclature of the human heat shock proteins

    NARCIS (Netherlands)

    Kampinga, Harm H.; Hageman, Jurre; Vos, Michel J.; Kubota, Hiroshi; Tanguay, Robert M.; Bruford, Elspeth A.; Cheetham, Michael E.; Chen, B.; Hightower, Lawrence E.

    2009-01-01

    The expanding number of members in the various human heat shock protein (HSP) families and the inconsistencies in their nomenclature have often led to confusion. Here, we propose new guidelines for the nomenclature of the human HSP families, HSPH (HSP110), HSPC (HSP90), HSPA (HSP70), DNAJ (HSP40), a

  18. Shock Structure and Shock Heating in the Galactic Central Molecular Zone

    CERN Document Server

    Ott, Juergen; Jones, Paul; Meier, David S

    2014-01-01

    We present maps of a large number of dense molecular gas tracers across the Central Molecular Zone of our Galaxy. The data were taken with the CSIRO/CASS Mopra telescope in Large Projects in the 1.3cm, 7mm, and 3mm wavelength regimes. Here, we focus on the brightness of the shock tracers SiO and HNCO, molecules that are liberated from dust grains under strong (SiO) and weak (HNCO) shocks. The shocks may have occurred when the gas enters the bar regions and the shock differences could be due to differences in the moving cloud mass. Based on tracers of ionizing photons, it is unlikely that the morphological differences are due to selective photo-dissociation of the molecules. We also observe direct heating of molecular gas in strongly shocked zones, with a high SiO/HNCO ratios, where temperatures are determined from the transitions of ammonia. Strong shocks appear to be the most efficient heating source of molecular gas, apart from high energy emission emitted by the central supermassive black hole Sgr A* and t...

  19. 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.

  20. 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.

  1. 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.

  2. Cloning and characterization of carboxyl terminus of heat shock cognate 70-interacting protein gene from the silkworm, Bombyx mori.

    Science.gov (United States)

    Ohsawa, Takeshi; Fujimoto, Shota; Tsunakawa, Akane; Shibano, Yuka; Kawasaki, Hideki; Iwanaga, Masashi

    2016-11-01

    Carboxyl terminus of heat shock cognate 70-interacting protein (CHIP) is an evolutionarily conserved E3 ubiquitin ligase across different eukaryotic species and is known to play a key role in protein quality control. CHIP has two distinct functional domains, an N-terminal tetratricopeptide repeat (TPR) and a C-terminal U-box domain, which are required for the ubiquitination of numerous labile client proteins that are chaperoned by heat shock proteins (HSPs) and heat shock cognate proteins (HSCs). During our screen for CHIP-like proteins in the Bombyx mori databases, we found a novel silkworm gene, Bombyx mori CHIP. Phylogenetic analysis showed that BmCHIP belongs to Lepidopteran lineages. Quantitative reverse transcription-PCR analysis indicated that BmCHIP was relatively highly expressed in the gonad and fat body. A pull-down experiment and auto-ubiquitination assay showed that BmCHIP interacted with BmHSC70 and had E3 ligase activity. Additionally, immunohistochemical analysis revealed that BmCHIP was partially co-localized with ubiquitin in BmN4 cells. These data support that BmCHIP plays an important role in the ubiquitin proteasome system as an E3 ubiquitin ligase in B. mori.

  3. A tricistronic heat shock operon is important for stress tolerance of Pseudomonas putida and conserved in many environmental bacteria.

    Science.gov (United States)

    Krajewski, Stefanie S; Joswig, Matthias; Nagel, Miriam; Narberhaus, Franz

    2014-06-01

    Small heat shock proteins (sHsps) including the well-studied IbpA protein from Escherichia coli are molecular chaperones that bind to non-native proteins and prevent them from aggregation. We discovered an entirely unexplored tricistronic small heat shock gene cluster in Pseudomonas putida. The genes pp3314, pp3313 and pp3312 (renamed to hspX, hspY and hspZ respectively) are transcribed in a single transcript. In addition to σ(32) -dependent transcriptional control, translation of the first and second gene of the operon is controlled by RNA thermometers with novel architectures. Biochemical analysis of HspY, HspZ and P. putida IbpA demonstrated that they assemble into homo-oligomers of different sizes whose quaternary structures alter in a temperature-dependent manner. IbpA and HspY are able to prevent the model substrate citrate synthase from thermal aggregation in vitro. Increased stress sensitivity of a P. putida strain lacking HspX, HspY and HspZ revealed an important role of these sHsps in stress adaptation. The hspXYZ operon is conserved among metabolically related bacteria that live in hostile environments including polluted soils. This heat shock operon might act as a protective system to promote survival in such ecological niches.

  4. Experimental Milestones in the Discovery of Molecular Chaperones as Polypeptide Unfolding Enzymes.

    Science.gov (United States)

    Finka, Andrija; Mattoo, Rayees U H; Goloubinoff, Pierre

    2016-06-01

    Molecular chaperones control the cellular folding, assembly, unfolding, disassembly, translocation, activation, inactivation, disaggregation, and degradation of proteins. In 1989, groundbreaking experiments demonstrated that a purified chaperone can bind and prevent the aggregation of artificially unfolded polypeptides and use ATP to dissociate and convert them into native proteins. A decade later, other chaperones were shown to use ATP hydrolysis to unfold and solubilize stable protein aggregates, leading to their native refolding. Presently, the main conserved chaperone families Hsp70, Hsp104, Hsp90, Hsp60, and small heat-shock proteins (sHsps) apparently act as unfolding nanomachines capable of converting functional alternatively folded or toxic misfolded polypeptides into harmless protease-degradable or biologically active native proteins. Being unfoldases, the chaperones can proofread three-dimensional protein structures and thus control protein quality in the cell. Understanding the mechanisms of the cellular unfoldases is central to the design of new therapies against aging, degenerative protein conformational diseases, and specific cancers.

  5. Requirements for chromatin reassembly during transcriptional downregulation of a heat shock gene in S. cerevisiae

    DEFF Research Database (Denmark)

    Jensen, Mette Moesgaard; Christensen, Marianne Skovgaard; Bonven, Bjarne Juul

    2008-01-01

    , but not Asf1p, reassociation of H3 with DNA is compromised. However, despite a lasting open chromatin structure, transcription ceases normally in the spt6 mutant. Thus, transcriptional downregulation can be uncoupled from histone redepositioning and ongoing transcription is not required to prevent chromatin......Heat shock genes respond to moderate heat stress by a wave of transcription. The induction phase is accompanied by massive eviction of histones, which later reassemble with DNA during the ensuing phase of transcription downregulation. Here, we identify determinants of this reassembly throughout...... the HSP104 transcription unit. The results show that while histone H3 lacking amino acids 4 through 30 of its N-terminal tail (H3Δ4-30) is normally deposited, reassembly of H3Δ4-40 is obliterated with an accompanying sustained transcription. Upon mutation of histone chaperones Spt6p and Spt16p...

  6. HSP-molecular chaperones in cancer biogenesis and tumor therapy: an overview.

    Science.gov (United States)

    Rappa, Francesca; Farina, Felicia; Zummo, Giovanni; David, Sabrina; Campanella, Claudia; Carini, Francesco; Tomasello, Giovanni; Damiani, Provvidenza; Cappello, Francesco; DE Macario, Everly Conway; Macario, Alberto J L

    2012-12-01

    Molecular chaperones, many of which are heat-shock proteins (HSPs), are an important class of molecules with various functions. Pathological conditions in which chaperones become etiological and/or pathogenic factors are called chaperonopathies, and are classified into by defect, by excess, and by 'mistake'. In the latter case, the chaperone is structurally and functionally normal but participates in pathways that favor disease, although in some cases the chaperone may have post-translational modifications that may lead it to change its location and function and, thus, to become pathogenic. For example, HSP-chaperones are involved in carcinogenesis in various ways, so that some forms of cancer may be considered 'chaperonopathies by mistake'. This concept suggests new strategies for anticancer therapy (chaperonotherapy), in which the primary targets or therapeutic agents are chaperones. Chaperonotherapy consists of the utilization of HSP-chaperones for treating chaperonopathies, including cancer. Negative chaperonotherapy is aimed at eliminating or blocking the action of chaperones that favor carcinogenesis or other diseases, whereas positive chaperonotherapy uses chaperones, genes or proteins, to fight against diseases, such as cancer, by stimulating the immune system or the cellular defenses against stress.

  7. Chaperoning Proteins for Destruction: Diverse Roles of Hsp70 Chaperones and their Co-Chaperones in Targeting Misfolded Proteins to the Proteasome

    Directory of Open Access Journals (Sweden)

    Ayala Shiber

    2014-07-01

    Full Text Available Molecular chaperones were originally discovered as heat shock-induced proteins that facilitate proper folding of proteins with non-native conformations. While the function of chaperones in protein folding has been well documented over the last four decades, more recent studies have shown that chaperones are also necessary for the clearance of terminally misfolded proteins by the Ub-proteasome system. In this capacity, chaperones protect misfolded degradation substrates from spontaneous aggregation, facilitate their recognition by the Ub ligation machinery and finally shuttle the ubiquitylated substrates to the proteasome. The physiological importance of these functions is manifested by inefficient proteasomal degradation and the accumulation of protein aggregates during ageing or in certain neurodegenerative diseases, when chaperone levels decline. In this review, we focus on the diverse roles of stress-induced chaperones in targeting misfolded proteins to the proteasome and the consequences of their compromised activity. We further discuss the implications of these findings to the identification of new therapeutic targets for the treatment of amyloid diseases.

  8. Expression of the heat shock gene clpL of Streptococcus thermophilus is induced by both heat and cold shock

    Directory of Open Access Journals (Sweden)

    Naclerio Gino

    2006-02-01

    Full Text Available Abstract Background Heat and cold shock response are normally considered as independent phenomena. A small amount of evidence suggests instead that interactions may exist between them in two Lactococcus strains. Results We show the occurrence of molecular relationships between the mechanisms of cold and heat adaptations in Streptococcus thermophilus, a lactic acid bacterium widely used in dairy fermentation, where it undergoes both types of stress. We observed that cryotolerance is increased when cells are pre-incubated at high temperature. In addition, the production of a protein, identified as ClpL, a member of the heat-shock ATPase family Clp A/B, is induced at both high and low temperature. A knock-out clpL mutant is deficient in both heat and cold tolerance. However lack of production of this protein does not abolish the positive effect of heat pre-treatment towards cryotolerance. Conclusion Dual induction of ClpL by cold and heat exposure of cells and reduced tolerance to both temperature shocks in a clpL mutant indicates that the two stress responses are correlated in S. thermophilus. However this protein is not responsible by itself for cryotolerance of cells pre-treated at high temperature, indicating that ClpL is necessary for the two phenomena, but does not account by itself for the relationships between them.

  9. SHOCK HEATING OF THE MERGING GALAXY CLUSTER A521

    Energy Technology Data Exchange (ETDEWEB)

    Bourdin, H.; Mazzotta, P. [Dipartimento di Fisica, Universita degli Studi di Roma ' Tor Vergata' , via della Ricerca Scientifica, 1, I-00133 Roma (Italy); Markevitch, M. [NASA Goddard Space Flight Center, Code 662, Greenbelt, MD 20771 (United States); Giacintucci, S. [Joint Space-Science Institute, University of Maryland, College Park, MD 20742-2421 (United States); Brunetti, G., E-mail: herve.bourdin@roma2.infn.it [INAF-Istituto di Radioastronomia, via Gobetti 101, I-40129 Bologna (Italy)

    2013-02-10

    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.

  10. 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.

  11. 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

  12. Heat shock protein 70 regulates platelet integrin activation, granule secretion and aggregation.

    Science.gov (United States)

    Rigg, Rachel A; Healy, Laura D; Nowak, Marie S; Mallet, Jérémy; Thierheimer, Marisa L D; Pang, Jiaqing; McCarty, Owen J T; Aslan, Joseph E

    2016-04-01

    Molecular chaperones that support protein quality control, including heat shock protein 70 (Hsp70), participate in diverse aspects of cellular and physiological function. Recent studies have reported roles for specific chaperone activities in blood platelets in maintaining hemostasis; however, the functions of Hsp70 in platelet physiology remain uninvestigated. Here we characterize roles for Hsp70 activity in platelet activation and function. In vitro biochemical, microscopy, flow cytometry, and aggregometry assays of platelet function, as well as ex vivo analyses of platelet aggregate formation in whole blood under shear, were carried out under Hsp70-inhibited conditions. Inhibition of platelet Hsp70 blocked platelet aggregation and granule secretion in response to collagen-related peptide (CRP), which engages the immunoreceptor tyrosine-based activation motif-bearing collagen receptor glycoprotein VI (GPVI)-Fc receptor-γ chain complex. Hsp70 inhibition also reduced platelet integrin-αIIbβ3 activation downstream of GPVI, as Hsp70-inhibited platelets showed reduced PAC-1 and fibrinogen binding. Ex vivo, pharmacological inhibition of Hsp70 in human whole blood prevented the formation of platelet aggregates on collagen under shear. Biochemical studies supported a role for Hsp70 in maintaining the assembly of the linker for activation of T cells signalosome, which couples GPVI-initiated signaling to integrin activation, secretion, and platelet function. Together, our results suggest that Hsp70 regulates platelet activation and function by supporting linker for activation of T cells-associated signaling events downstream of platelet GPVI engagement, suggesting a role for Hsp70 in the intracellular organization of signaling systems that mediate platelet secretion, "inside-out" activation of platelet integrin-αIIbβ3, platelet-platelet aggregation, and, ultimately, hemostatic plug and thrombus formation.

  13. Advances in the discovery and development of heat-shock protein 90 inhibitors for cancer treatment

    Science.gov (United States)

    Patel, Hardik J; Modi, Shanu; Chiosis, Gabriela; Taldone, Tony

    2011-01-01

    Introduction Over the last 15 – 20 years, targeted anticancer strategies have focused on therapies aimed at abrogating a single malignant protein. Agents that are directed towards the inhibition of a single oncoprotein have resulted in a number of useful drugs in the treatment of cancers (i.e., Gleevec, BCR-ABL; Tarceva and Iressa, EGFR). However, such a strategy relies on the notion that a cancer cell is dependent on a single signaling pathway for its survival. The possibility that a cancer cell may mutate or switch its dependence to another signaling pathway can result in the ineffectiveness of such agents. Recent advances in the biology of heat-shock protein 90 (Hsp90) have revealed intimate details into the complexity of the chaperoning process that Hsp90 is engaged in and, at the same time, have offered those involved in drug discovery several unique ways to interfere in this process. Areas covered This review provides the current understanding of the chaperone cycle of Hsp90 and presents the multifaceted approaches used by researchers in the discovery of potential Hsp90 drugs. It discusses the phenotypic outcomes in cancer cells on Hsp90 inhibition by these several approaches and also addresses several distinctions observed among direct Hsp90 ATP-pocket competitors providing commentary on the potential biological outcomes as well as the clinical relevance of such features. Expert opinion The significantly different phenotypic outcomes observed from Hsp90 inhibition by the many inhibitors developed suggest that the clinical development of Hsp90 inhibitors would be better served by careful consideration of the pharmacokinetic/pharmacodynamic properties of individual candidates rather than a generic approach directed towards the target. PMID:22400044

  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. Multiple mild heat-shocks decrease the Gompertz component of mortality in Caenorhabditis elegans.

    Science.gov (United States)

    Wu, Deqing; Cypser, James R; Yashin, Anatoli I; Johnson, Thomas E

    2009-09-01

    Exposure to mild heat-stress (heat-shock) can significantly increase the life expectancy of the nematode Caenorhabditis elegans. A single heat-shock early in life extends longevity by 20% or more and affects life-long mortality by decreasing initial mortality only; the rate of increase in subsequent mortality (Gompertz component) is unchanged. Repeated mild heat-shocks throughout life have a larger effect on life span than does a single heat-shock early in life. Here, we ask how multiple heat-shocks affect the mortality trajectory in nematodes and find increases of life expectancy of close to 50% and of maximum longevity as well. We examined mortality using large numbers of animals and found that multiple heat-shocks not only decrease initial mortality, but also slow the Gompertz rate of increase in mortality. Thus, multiple heat-shocks have anti-aging hormetic effects and represent an effective approach for modulating aging.

  16. Transcriptional regulation of heat shock proteins and ascorbate peroxidase by CtHsfA2b from African bermudagrass conferring heat tolerance in Arabidopsis

    Science.gov (United States)

    Wang, Xiuyun; Huang, Wanlu; Yang, Zhimin; Liu, Jun; Huang, Bingru

    2016-01-01

    Heat stress transcription factor A2s (HsfA2s) are key regulators in plant response to high temperature. Our objectives were to isolate an HsfA2 gene (CtHsfA2b) from a warm-season grass species, African bermudagrass (Cynodon transvaalensis Burtt-Davy), and to determine the physiological functions and transcriptional regulation of HsfA2 for improving heat tolerance. Gene expression analysis revealed that CtHsfA2b was heat-inducible and exhibited rapid response to increasing temperature. Ectopic expression of CtHsfA2b improved heat tolerance in Arabidopsis and restored heat-sensitive defects of Arabidopsis hsfa2 mutant, which was demonstrated by higher survival rate and photosynthetic parameters, and lower electrolyte leakage in transgenic plants compared to the WT or hsfa2 mutant. CtHsfA2b transgenic plants showed elevated transcriptional regulation of several downstream genes, including those encoding ascorbate peroxidase (AtApx2) and heat shock proteins [AtHsp18.1-CI, AtHsp22.0-ER, AtHsp25.3-P and AtHsp26.5-P(r), AtHsp70b and AtHsp101-3]. CtHsfA2b was found to bind to the heat shock element (HSE) on the promoter of AtApx2 and enhanced transcriptional activity of AtApx2. These results suggested that CtHsfA2b could play positive roles in heat protection by up-regulating antioxidant defense and chaperoning mechanisms. CtHsfA2b has the potential to be used as a candidate gene to genetically modify cool-season species for improving heat tolerance. PMID:27320381

  17. Protein kinase Cmu plays an essential role in hypertonicity-induced heat shock protein 70 expression.

    Science.gov (United States)

    Lim, Yun Sook; Lee, Jae Seon; Huang, Tai Qin; Seo, Jeong Sun

    2008-12-31

    Heat shock protein 70 (HSP70), which evidences important functions as a molecular chaperone and anti-apoptotic molecule, is substantially induced in cells exposed to a variety of stresses, including hypertonic stress, heavy metals, heat shock, and oxidative stress, and prevents cellular damage under these conditions. However, the molecular mechanism underlying the induction of HSP70 in response to hypertonicity has been characterized to a far lesser extent. In this study, we have investigated the cellular signaling pathway of HSP70 induction under hypertonic conditions. Initially, we applied a variety of kinase inhibitors to NIH3T3 cells that had been exposed to hypertonicity. The induction of HSP70 was suppressed specifically by treatment with protein kinase C (PKC) inhibitors (Gö6976 and GF109203X). As hypertonicity dramatically increased the phosphorylation of PKCmu, we then evaluated the role of PKCmu in hypertonicity-induced HSP70 expression and cell viability. The depletion of PKCmu with siRNA or the inhibition of PKCmu activity with inhibitors resulted in a reduction in HSP70 induction and cell viability. Tonicity-responsive enhancer binding protein (TonEBP), a transcription factor for hypertonicity-induced HSP70 expression, was translocated rapidly into the nucleus and was modified gradually in the nucleus under hypertonic conditions. When we administered treatment with PKC inhibitors, the mobility shift of TonEBP was affected in the nucleus. However, PKCmu evidenced no subcellular co-localization with TonEBP during hypertonic exposure. From our results, we have concluded that PKCmu performs a critical function in hypertonicity-induced HSP70 induction, and finally cellular protection, via the indirect regulation of TonEBP modification.

  18. Shock heating of the merging galaxy cluster A521

    CERN Document Server

    Bourdin, H; Markevitch, M; Giacintucci,; Brunetti, G; 10.1088/0004-637X/764/1/82

    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 this shock is responsible for the generation of cosmi...

  19. Transcriptome analysis of adaptive heat shock response of Streptococcus thermophilus.

    Directory of Open Access Journals (Sweden)

    Jin-song Li

    Full Text Available Streptococcus thermophilus, a gram-positive facultative anaerobe, is one of the most important lactic acid bacteria widely used in the dairy fermentation industry. In this study, we have analyzed the global transcriptional profiling of S. thermophilus upon temperature change. During a temperature shift from 42°C to 50°C, it is found that 196 (10.4% genes show differential expression with 102 up-regulated and 94 down-regulated at 50°C. In particular, 1 Heat shock genes, such as DnaK, GroESL and clpL, are identified to be elevated at 50°C; 2 Transcriptional regulators, such as HrcA, CtsR, Fur, MarR and MerR family, are differentially expressed, indicating the complex molecular mechanisms of S. thermophilus adapting to heat shock; 3 Genes associated with signal transduction, cell wall genes, iron homeostasis, ABC transporters and restriction-modification system were induced; 4 A large number of the differentially expressed genes are hypothetical genes of unknown function, indicating that much remains to be investigated about the heat shock response of S. thermophilus. Experimental investigation of selected heat shock gene ClpL shows that it plays an important role in the physiology of S. thermophilus at high temperature and meanwhile we confirmed ClpL as a member of the CtsR regulon. Overall, this study has contributed to the underlying adaptive molecular mechanisms of S. thermophilus upon temperature change and provides a basis for future in-depth functional studies.

  20. Acquired Thermotolerance and Heat Shock Proteins in Thermophiles from the Three Phylogenetic Domains

    DEFF Research Database (Denmark)

    Trent, Jonathan D.; Gabrielsen, Mette; Jensen, Bo

    1994-01-01

    at 70 degrees C and heat shocked at 88 degrees C for 60 min showed thermotolerance at 95 degrees C, and Thermomyces lanuginosus grown at 50 degrees C and heat shocked at 55 degrees C for 60 min showed thermotolerance at 58 degrees C. Determinations of protein synthesis during heat shock revealed...... differences in the dominant heat shock proteins for each species. For B. caldolyticus, a 70-kDa protein dominated while for S. shibatae, a 55-kDa protein dominated and for T. lanuginosus, 31- to 33-kDa proteins dominated. Reagents that disrupted normal protein synthesis during heat shock prevented......Thermophilic organisms from each of the three phylogenetic domains (Bacteria, Archaea, and Eucarya) acquired thermotolerance after heat shock. Bacillus caldolyticus grown at 60 degrees C and heat shocked at 69 degrees C for 10 min showed thermotolerance at 74 degrees C, Sulfolobus shibatae grown...

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

    Science.gov (United States)

    Matsumoto, Takuma

    2016-11-01

    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 this 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 per cent 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 this study would significantly impact on the prospects of successful MHD turbulence theory in the solar chromosphere.

  2. 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...

  3. `The HSP70 chaperone machinery : J proteins as drivers of functional specificity

    NARCIS (Netherlands)

    Kampinga, Harm H.; Craig, Elizabeth A.

    Heat shock 70 kDa proteins (HSP70s) are ubiquitous molecular chaperones that function in a myriad of biological processes, modulating polypeptide folding, degradation and translocation across membranes, and protein-protein interactions. This multitude of roles is not easily reconciled with the

  4. Heat shock proteins and heat therapy for type 2 diabetes: pros and cons.

    Science.gov (United States)

    Krause, Mauricio; Ludwig, Mirna Stela; Heck, Thiago Gomes; Takahashi, Hilton Kenji

    2015-07-01

    Heat therapy, such as sauna and hot tub, has become an increasingly regular therapeutical practice around the world since several studies have shown benefits of heat therapy in metabolic and cardiovascular diseases. The use of heat therapy in people with type 2 diabetes mellitus revealed a striking reduction of 1% unit in the glycated hemoglobin, suggesting this therapy for the treatment of diabetes. Herein, we shall discuss the use of heat therapy and the mechanisms involved, and suggest a provisional guide for the use of heat therapy in obesity and diabetes. Human studies indicate that heat therapy reduces fasting glycemia, glycated hemoglobin, body weight, and adiposity. Animal studies have indicated that nitric oxide and the increase in heat shock protein 70 expression is involved in the improvements induced by heat therapy on insulin sensitivity, adiposity, inflammation, and vasomotricity. Heat therapy is a promising and inexpensive tool for the treatment of obesity and diabetes. We proposed that transient increments in nitric oxide and heat shock protein 70 levels may explain the benefits of heat therapy. We suggest that heat therapy (sauna: 80-100°C; hot tub: at 40°C) for 15 min, three times a week, for 3 months, is a safe method to test its efficiency.

  5. Heat-shock responsive genes identified and validated in Atlantic cod (Gadus morhua liver, head kidney and skeletal muscle using genomic techniques

    Directory of Open Access Journals (Sweden)

    Kimball Jennifer

    2010-01-01

    Full Text Available Abstract Background Daily and seasonal changes in temperature are challenges that fish within aquaculture settings cannot completely avoid, and are known to elicit complex organismal and cellular stress responses. We conducted a large-scale gene discovery and transcript expression study in order to better understand the genes that are potentially involved in the physiological and cellular aspects of stress caused by heat-shock. We used suppression subtractive hybridization (SSH cDNA library construction and characterization to identify transcripts that were dysregulated by heat-shock in liver, skeletal muscle and head kidney of Atlantic cod. These tissues were selected due to their roles in metabolic regulation, locomotion and growth, and immune function, respectively. Fish were exposed for 3 hours to an 8°C elevation in temperature, and then allowed to recover for 24 hours at the original temperature (i.e. 10°C. Tissue samples obtained before heat-shock (BHS, at the cessation of heat-shock (CS, and 3, 12, and 24 hours after the cessation of heat-shock (ACS, were used for reciprocal SSH library construction and quantitative reverse transcription - polymerase chain reaction (QPCR analysis of gene expression using samples from a group that was transferred but not heat-shocked (CT as controls. Results We sequenced and characterized 4394 ESTs (1524 from liver, 1451 from head kidney and 1419 from skeletal muscle from three "forward subtracted" libraries (enriched for genes up-regulated by heat-shock and 1586 from the liver "reverse subtracted" library (enriched for genes down-regulated by heat-shock, for a total of 5980 ESTs. Several cDNAs encoding putative chaperones belonging to the heat-shock protein (HSP family were found in these libraries, and "protein folding" was among the gene ontology (GO terms with the highest proportion in the libraries. QPCR analysis of HSP90α and HSP70-1 (synonym: HSPA1A mRNA expression showed significant up

  6. The conformational dynamics of the mitochondrial Hsp70 chaperone.

    Science.gov (United States)

    Mapa, Koyeli; Sikor, Martin; Kudryavtsev, Volodymyr; Waegemann, Karin; Kalinin, Stanislav; Seidel, Claus A M; Neupert, Walter; Lamb, Don C; Mokranjac, Dejana

    2010-04-09

    Heat shock proteins 70 (Hsp70) represent a ubiquitous and conserved family of molecular chaperones involved in a plethora of cellular processes. The dynamics of their ATP hydrolysis-driven and cochaperone-regulated conformational cycle are poorly understood. We used fluorescence spectroscopy to analyze, in real time and at single-molecule resolution, the effects of nucleotides and cochaperones on the conformation of Ssc1, a mitochondrial member of the family. We report that the conformation of its ADP state is unexpectedly heterogeneous, in contrast to a uniform ATP state. Substrates are actively involved in determining the conformation of Ssc1. The J protein Mdj1 does not interact transiently with the chaperone, as generally believed, but rather is released slowly upon ATP hydrolysis. Analysis of the major bacterial Hsp70 revealed important differences between highly homologous members of the family, possibly explaining tuning of Hsp70 chaperones to meet specific functions in different organisms and cellular compartments.

  7. Improvement of inhibitor identification for heat shock protein 90α by utilizing a red-shifted fluorescence polarization probe.

    Science.gov (United States)

    Qian, Jie; Holskin, Beverly P; Theroff, Jay; Underiner, Ted; Meyer, Sheryl L; Angeles, Thelma S

    2012-08-01

    Heat shock protein-90 (HSP90) is an ATP-dependent molecular chaperone with intrinsic ATPase activity. HSP90 is required for the stability and function of client proteins, many of which are involved in oncogenesis. Thus, identification of HSP90 inhibitors would potentially lead to the discovery of cancer therapeutics. Here, we present a high-throughput screening campaign utilizing two geldanamycin (GM)-labeled probes in a fluorescence polarization (FP) assay. For the primary screen, a previously reported green BODIPY-labeled GM (GM-BODIPY) was used to evaluate a library collection of about 400,000 compounds. From this screen, 3058 compounds showed >30% inhibition. To distinguish true positives from compound interference, a confirmatory screen was deemed necessary. Accordingly, a red-shifted FP binding assay was developed using GM labeled with red BODIPY. This tool enabled reliable identification of promising HSP90α inhibitors.

  8. The transcriptional coactivator PGC1α protects against hyperthermic stress via cooperation with the heat shock factor HSF1.

    Science.gov (United States)

    Xu, L; Ma, X; Bagattin, A; Mueller, E

    2016-02-18

    Heat shock proteins (HSPs) are required for the clearance of damaged and aggregated proteins and have important roles in protein homeostasis. It has been shown that the heat shock transcription factor, HSF1, orchestrates the transcriptional induction of these stress-regulated chaperones; however, the coregulatory factors responsible for the enhancement of HSF1 function on these target genes have not been fully elucidated. Here, we demonstrate that the cold-inducible coactivator, PGC1α, also known for its role as a regulator of mitochondrial and peroxisomal biogenesis, thermogenesis and cytoprotection from oxidative stress, regulates the expression of HSPs in vitro and in vivo and modulates heat tolerance. Mechanistically, we show that PGC1α physically interacts with HSF1 on HSP promoters and that cells and mice lacking PGC1α have decreased HSPs levels and are more sensitive to thermal challenges. Taken together, our findings suggest that PGC1α protects against hyperthermia by cooperating with HSF1 in the induction of a transcriptional program devoted to the cellular protection from thermal insults.

  9. The heat shock protein 90 of Plasmodium falciparum and antimalarial activity of its inhibitor, geldanamycin

    Directory of Open Access Journals (Sweden)

    Barik Sailen

    2003-09-01

    Full Text Available Abstract Background The naturally occurring benzoquinone ansamycin compound, geldanamycin (GA, is a specific inhibitor of heat shock protein 90 (Hsp90 and is a potential anticancer agent. Since Plasmodium falciparum has been reported to have an Hsp90 ortholog, we tested the possibility that GA might inhibit it and thereby display antiparasitic activity. Results We provide direct recombinant DNA evidence for the Hsp90 protein of Plasmodium falciparum, the causative agent of fatal malaria. While the mRNA of Hsp90 was mainly expressed in ring and trophozoite stages, the protein was found in all stages, although schizonts contained relatively lower amounts. In vitro the parasitic Hsp90 exhibited an ATP-binding activity that could be specifically inhibited by GA. Plasmodium growth in human erythrocyte culture was strongly inhibited by GA with an IC50 of 20 nM, compared to the IC50 of 15 nM for chloroquine (CQ under identical conditions. When used in combination, the two drugs acted synergistically. GA was equally effective against CQ-sensitive and CQ-resistant strains (3D7 and W2, respectively and on all erythrocytic stages of the parasite. Conclusions Together, these results suggest that an active and essential Hsp90 chaperone cycle exists in Plasmodium and that the ansamycin antibiotics will be an important tool to dissect its role in the parasite. Additionally, the favorable pharmacology of GA, reported in human trials, makes it a promising antimalarial drug.

  10. Signaling mechanisms in alcoholic liver injury: Role of transcription factors,kinases and heat shock proteins

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Alcoholic liver injury comprises of interactions of various intracellular signaling events in the liver. Innate immune responses in the resident Kupffer cells of the liver, oxidative stress-induced activation of hepatocytes,fibrotic events in liver stellate cells and activation of liver sinusoidal endothelial cells all contribute to alcoholic liver injury. The signaling mechanisms associated with alcoholic liver injury vary based on the cell type involved and the extent of alcohol consumption. In this review we will elucidate the oxidative stress and signaling pathways affected by alcohol in hepatocytes and Kupffer cells in the liver by alcohol. The toll-like receptors and their down-stream signaling events that play an important role in alcohol-induced inflammation will be discussed. Alcohol-induced alterations of various intracellular transcription factors such as NFκB, PPARs and AP-1, as well as MAPK kinases in hepatocytes and macrophages leading to induction of target genes that contribute to liver injury will be reviewed. Finally, we will discuss the significance of heat shock proteins as chaperones and their functional regulation in the liver that could provide new mechanistic insights into the contributions of stress-induced signaling mechanisms in alcoholic liver injury.

  11. Human heat shock protein-specific cytotoxic T lymphocytes display potent antitumour immunity in multiple myeloma

    Science.gov (United States)

    Li, Rong; Qian, Jianfei; Zhang, Wenhao; Fu, Weijun; Du, Juan; Jiang, Hua; Zhang, Hui; Zhang, Chunyang; Xi, Hao; Yi, Qing; Hou, Jian

    2014-01-01

    Tumour cell–derived heat shock proteins (HSPs) are used as vaccines for immunotherapy of cancer patients. However, it is proposed that the peptide chaperoned on HSPs, not HSPs themselves, elicited a potent immune response. Given that HSPs are highly expressed by most myeloma cells and vital to myeloma cell survival, we reasoned that HSPs themselves might be an ideal myeloma antigen. In the present study, we explored the feasibility of targeting HSPs themselves for treating multiple myeloma. We identified and chose HLA-A*0201-binding peptides from human HSPB1 (HSP27) and HSP90AA1 (HSP90), and confirmed their immunogenicity in HLA-A*0201 transgenic mice. Dendritic cells pulsed with HSPB1 and HSP90AA1 peptides were used to stimulate peripheral blood mononuclear cells from healthy volunteers and myeloma patients to generate HSP peptide-specific cytotoxic T lymphocytes (CTLs). HSP peptide-specific CTLs efficiently lysed HLA-A*0201+ myeloma cells (established cell lines and primary plasma cells) but not HLA-A*0201− myeloma cells in vitro, indicating that myeloma cells naturally express HSP peptides in the context of major histocompatibility complex class I molecules. More importantly, HSP peptide-specific CTLs effectively reduced tumour burden in the xenograft mouse model of myeloma. Our study clearly demonstrated that HSPs might be novel tumour antigens for immunotherapy of myeloma. PMID:24824351

  12. Heat shock protein B1-deficient mice display impaired wound healing.

    Directory of Open Access Journals (Sweden)

    Jonathan Crowe

    Full Text Available There is large literature describing in vitro experiments on heat shock protein (hspB1 but understanding of its function in vivo is limited to studies in mice overexpressing human hspB1 protein. Experiments in cells have shown that hspB1 has chaperone activity, a cytoprotective role, regulates inflammatory gene expression, and drives cell proliferation. To investigate the function of the protein in vivo we generated hspB1-deficient mice. HspB1-deficient fibroblasts display increased expression of the pro-inflammatory cytokine, interleukin-6, compared to wild-type cells, but reduced proliferation. HspB1-deficient fibroblasts exhibit reduced entry into S phase and increased expression of cyclin-dependent kinase inhibitors p27(kip1 and p21(waf1. The expression of hspB1 protein and mRNA is also controlled by the cell cycle. To investigate the physiological function of hspB1 in regulating inflammation and cell proliferation we used an excisional cutaneous wound healing model. There was a significant impairment in the rate of healing of wounds in hspB1-deficient mice, characterised by reduced re-epithelialisation and collagen deposition but also increased inflammation. HspB1 deficiency augments neutrophil infiltration in wounds, driven by increased chemokine (C-X-C motif ligand 1 expression. This appears to be a general mechanism as similar results were obtained in the air-pouch and peritonitis models of acute inflammation.

  13. Heat shock protein 27 expression in the human testis showing normal and abnormal spermatogenesis.

    Science.gov (United States)

    Adly, Mohamed A; Assaf, Hanan A; Hussein, Mahmoud Rezk A

    2008-10-01

    Heat shock proteins (HSPs) are molecular chaperones involved in protein folding, assembly and transport, and which play critical roles in the regulation of cell growth, survival and differentiation. We set out to test the hypothesis that HSP27 protein is expressed in the human testes and its expression varies with the state of spermatogenesis. HSP27 expression was examined in 30 human testicular biopsy specimens (normal spermatogenesis, maturation arrest and Sertoli cell only syndrome, 10 cases each) using immunofluorescent methods. The biopsies were obtained from patients undergoing investigations for infertility. The seminiferous epithelium of the human testes showing normal spermatogenesis had a cell type-specific expression of HSP27. HSP27 expression was strong in the cytoplasm of the Sertoli cells, spermatogonia, and Leydig cells. Alternatively, the expression was moderate in the spermatocytes, weak in the spermatids and absent in the spermatozoa. In testes showing maturation arrest, HSP27 expression was strong in the Sertoli cells, weak in the spermatogonia, and spermatocytes. It was absent in the spermatids and Leydig cells. In Sertoli cell only syndrome, HSP27 expression was strong in the Sertoli cells and absent in the Leydig cells. We report for the first time the expression patterns of HSP27 in the human testes and show differential expression during normal spermatogenesis, indicating a possible role in this process. The altered expression of this protein in testes showing abnormal spermatogenesis may be related to the pathogenesis of male infertility.

  14. The protective and therapeutic function of small heat shock proteins in neurological diseases.

    Science.gov (United States)

    Brownell, Sara E; Becker, Rachel A; Steinman, Lawrence

    2012-01-01

    Historically, small heat shock proteins (sHSPs) have been extensively studied in the context of being intracellular molecular chaperones. However, recent studies looking at the role of sHSPs in neurological diseases have demonstrated a near universal upregulation of certain sHSPs in damaged and diseased brains. Initially, it was thought that sHSPs are pathological in these disease states because they are found in the areas of damage. However, transgenic overexpression and exogenous administration of sHSPs in various experimental disease paradigms have shown just the contrary - that sHSPs are protective, not pathological. This review examines sHSPs in neurological diseases and highlights the potential for using these neuroprotective sHSPs as novel therapeutics. It first addresses the endogenous expression of sHSPs in a variety of neurological disorders. Although many studies have examined the expression of sHSPs in neurological diseases, there are no review articles summarizing these data. Furthermore, it focuses on recent studies that have investigated the therapeutic potential of sHSPs for neurological diseases. Finally, it will explain what we think is the function of endogenous sHSPs in neurological diseases.

  15. The upregulation of heat shock protein 47 expression in human buccal fibroblasts stimulated with arecoline.

    Science.gov (United States)

    Yang, Shun-Fa; Tsai, Chung-Hung; Chang, Yu-Chao

    2008-04-01

    Heat shock protein (HSP) 47, a collagen-specific molecular chaperone, is involved in the processing and/or secretion of procollagen. HSP47 is consistently and dramatically upregulated in a variety of fibrotic diseases. The aim of this study was to compare HSP47 expression in normal human buccal mucosa and oral submucous fibrosis (OSF) specimens and further to explore the potential mechanisms that may lead to induce HSP47 expression. The mRNA levels of HSP47 from fibroblasts cultured from 20 OSF and 10 normal buccal mucosal fibroblasts (BMFs) were evaluated by reverse transcription polymerase chain reaction. The effect of arecoline, the major areca nut alkaloid, was added to explore the potential mechanisms that may lead to induce HSP47 expression. Furthermore, mitogen-activated protein kinase kinase (MEK) inhibitor U0126, phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002, p38 inhibitor SB203580, cyclo-oxygenase-2 (COX-2) inhibitor NS-398, and glutathione precursor N-acetyl-l-cysteine were added to find the possible mechanisms. OSF demonstrated significantly higher HSP47 mRNA expression than BMFs (P Arecoline was also found to elevate HSP47 mRNA expression in a dose-dependent manner (P arecoline when compared with control (P arecoline-induced HSP47 mRNA expression (P arecoline in fibroblasts may be mediated by MEK, PI3K, and COX-2 signal transduction pathways.

  16. Heat Shock Proteins: Old and Novel Roles in Neurodegenerative Diseases in the Central Nervous System.

    Science.gov (United States)

    van Noort, Johannes M; Bugiani, Marianna; Amor, Sandra

    2016-10-31

    Heat shock proteins (HSPs) are families of molecular chaperones that play important homeostatic functions in the central nervous system (CNS) by preventing protein misfolding, promoting degradation of improperly folded proteins, and protecting against apoptosis and inflammatory damage especially during hyperthermia, hypoxia, or oxidative stress. Under stress conditions, HSPs are upregulated to protect cells from damage that accumulates during ageing as well as pathological conditions. An important, yet frequently overlooked function of some HSPs is their ability to function as extracellular messengers (also termed chaperokines) that modulate immune responses within the CNS. Given the strong association between protein aggregation, innate immune cell activation and neurodegeneration, the expression and roles of HSPs in the CNS is attracting attention in many neurodegenerative disorders including inflammatory diseases such as multiple sclerosis, protein folding diseases such as Alzheimer's disease and amyotrophic lateral sclerosis, and genetic white matter diseases. This is especially so since several studies show that HSPs act therapeutically by modulating innate immune activation and may thus serve as neuroprotective agents. Here we review the evidence linking HSPs with neurodegenerative disorders in humans and the experimental animal models of these disorders. We discuss the mechanisms by which HSP protect cells, and how the knowledge of their endogenous functions can be exploited to treat disorders of the CNS.

  17. Tandem Duplication Events in the Expansion of the Small Heat Shock Protein Gene Family in Solanum lycopersicum (cv. Heinz 1706)

    Science.gov (United States)

    Krsticevic, Flavia J.; Arce, Débora P.; Ezpeleta, Joaquín; Tapia, Elizabeth

    2016-01-01

    In plants, fruit maturation and oxidative stress can induce small heat shock protein (sHSP) synthesis to maintain cellular homeostasis. Although the tomato reference genome was published in 2012, the actual number and functionality of sHSP genes remain unknown. Using a transcriptomic (RNA-seq) and evolutionary genomic approach, putative sHSP genes in the Solanum lycopersicum (cv. Heinz 1706) genome were investigated. A sHSP gene family of 33 members was established. Remarkably, roughly half of the members of this family can be explained by nine independent tandem duplication events that determined, evolutionarily, their functional fates. Within a mitochondrial class subfamily, only one duplicated member, Solyc08g078700, retained its ancestral chaperone function, while the others, Solyc08g078710 and Solyc08g078720, likely degenerated under neutrality and lack ancestral chaperone function. Functional conservation occurred within a cytosolic class I subfamily, whose four members, Solyc06g076570, Solyc06g076560, Solyc06g076540, and Solyc06g076520, support ∼57% of the total sHSP RNAm in the red ripe fruit. Subfunctionalization occurred within a new subfamily, whose two members, Solyc04g082720 and Solyc04g082740, show heterogeneous differential expression profiles during fruit ripening. These findings, involving the birth/death of some genes or the preferential/plastic expression of some others during fruit ripening, highlight the importance of tandem duplication events in the expansion of the sHSP gene family in the tomato genome. Despite its evolutionary diversity, the sHSP gene family in the tomato genome seems to be endowed with a core set of four homeostasis genes: Solyc05g014280, Solyc03g082420, Solyc11g020330, and Solyc06g076560, which appear to provide a baseline protection during both fruit ripening and heat shock stress in different tomato tissues. PMID:27565886

  18. Tandem Duplication Events in the Expansion of the Small Heat Shock Protein Gene Family in Solanum lycopersicum (cv. Heinz 1706

    Directory of Open Access Journals (Sweden)

    Flavia J. Krsticevic

    2016-10-01

    Full Text Available In plants, fruit maturation and oxidative stress can induce small heat shock protein (sHSP synthesis to maintain cellular homeostasis. Although the tomato reference genome was published in 2012, the actual number and functionality of sHSP genes remain unknown. Using a transcriptomic (RNA-seq and evolutionary genomic approach, putative sHSP genes in the Solanum lycopersicum (cv. Heinz 1706 genome were investigated. A sHSP gene family of 33 members was established. Remarkably, roughly half of the members of this family can be explained by nine independent tandem duplication events that determined, evolutionarily, their functional fates. Within a mitochondrial class subfamily, only one duplicated member, Solyc08g078700, retained its ancestral chaperone function, while the others, Solyc08g078710 and Solyc08g078720, likely degenerated under neutrality and lack ancestral chaperone function. Functional conservation occurred within a cytosolic class I subfamily, whose four members, Solyc06g076570, Solyc06g076560, Solyc06g076540, and Solyc06g076520, support ∼57% of the total sHSP RNAm in the red ripe fruit. Subfunctionalization occurred within a new subfamily, whose two members, Solyc04g082720 and Solyc04g082740, show heterogeneous differential expression profiles during fruit ripening. These findings, involving the birth/death of some genes or the preferential/plastic expression of some others during fruit ripening, highlight the importance of tandem duplication events in the expansion of the sHSP gene family in the tomato genome. Despite its evolutionary diversity, the sHSP gene family in the tomato genome seems to be endowed with a core set of four homeostasis genes: Solyc05g014280, Solyc03g082420, Solyc11g020330, and Solyc06g076560, which appear to provide a baseline protection during both fruit ripening and heat shock stress in different tomato tissues.

  19. Molecular communications between plant heat shock responses and disease resistance.

    Science.gov (United States)

    Lee, Jae-Hoon; Yun, Hye Sup; Kwon, Chian

    2012-08-01

    As sessile, plants are continuously exposed to potential dangers including various abiotic stresses and pathogen attack. Although most studies focus on plant responses under an ideal condition to a specific stimulus, plants in nature must cope with a variety of stimuli at the same time. This indicates that it is critical for plants to fine-control distinct signaling pathways temporally and spatially for simultaneous and effective responses to various stresses. Global warming is currently a big issue threatening the future of humans. Reponses to high temperature affect many physiological processes in plants including growth and disease resistance, resulting in decrease of crop yield. Although plant heat stress and defense responses share important mediators such as calcium ions and heat shock proteins, it is thought that high temperature generally suppresses plant immunity. We therefore specifically discuss on interactions between plant heat and defense responses in this review hopefully for an integrated understanding of these responses in plants.

  20. Effect of heat release on movement characteristics of shock train in an isolator

    Science.gov (United States)

    Zhang, Chenlin; Chang, Juntao; Liu, MengMeng; Feng, Shuo; Shi, Wen; Bao, Wen

    2017-04-01

    In this paper, the effect of heat release on movement characteristics of shock train is numerically investigated in an isolator. It is found that the combustion heat release has a distinct effect on the shock train movement characteristics in the isolator. With increasing heat release, a shock train gradually forms and then propagates toward isolator entrance. In process of shock train formation, separation bubbles before injection ports entrain the high temperature burning gas into the boundary layer, which causes the shock train to shrink and stretch, and changes in configuration and number of shock waves. At the same time, the system force fluctuates. In addition, the shock train movement is divided into three stages, which have different wall pressure distribution. It is believed that these findings have a help the better understanding of the effect of heat release on the movement characteristics of shock train in an isolator.

  1. Systems analysis of chaperone networks in the malarial parasite Plasmodium falciparum.

    Directory of Open Access Journals (Sweden)

    Soundara Raghavan Pavithra

    2007-09-01

    Full Text Available Molecular chaperones participate in the maintenance of cellular protein homeostasis, cell growth and differentiation, signal transduction, and development. Although a vast body of information is available regarding individual chaperones, few studies have attempted a systems level analysis of chaperone function. In this paper, we have constructed a chaperone interaction network for the malarial parasite, Plasmodium falciparum. P. falciparum is responsible for several million deaths every year, and understanding the biology of the parasite is a top priority. The parasite regularly experiences heat shock as part of its life cycle, and chaperones have often been implicated in parasite survival and growth. To better understand the participation of chaperones in cellular processes, we created a parasite chaperone network by combining experimental interactome data with in silico analysis. We used interolog mapping to predict protein-protein interactions for parasite chaperones based on the interactions of corresponding human chaperones. This data was then combined with information derived from existing high-throughput yeast two-hybrid assays. Analysis of the network reveals the broad range of functions regulated by chaperones. The network predicts involvement of chaperones in chromatin remodeling, protein trafficking, and cytoadherence. Importantly, it allows us to make predictions regarding the functions of hypothetical proteins based on their interactions. It allows us to make specific predictions about Hsp70-Hsp40 interactions in the parasite and assign functions to members of the Hsp90 and Hsp100 families. Analysis of the network provides a rational basis for the anti-malarial activity of geldanamycin, a well-known Hsp90 inhibitor. Finally, analysis of the network provides a theoretical basis for further experiments designed toward understanding the involvement of this important class of molecules in parasite biology.

  2. Analogs of the Allosteric Heat Shock Protein 70 (Hsp70) Inhibitor, MKT-077, as Anti-Cancer Agents.

    Science.gov (United States)

    Li, Xiaokai; Srinivasan, Sharan R; Connarn, Jamie; Ahmad, Atta; Young, Zapporah T; Kabza, Adam M; Zuiderweg, Erik R P; Sun, Duxin; Gestwicki, Jason E

    2013-11-14

    The rhodacyanine, MKT-077, has anti-proliferative activity against cancer cell lines through its ability to inhibit members of the heat shock protein 70 (Hsp70) family of molecular chaperones. However, MKT-077 is rapidly metabolized, which limits its use as either a chemical probe or potential therapeutic. We report the synthesis and characterization of MKT-077 analogs designed for greater stability. The most potent molecules, such as 30 (JG-98), were at least 3-fold more active than MKT-077 against the breast cancer cell lines MDA-MB-231 and MCF-7 (EC50 values of 0.4 ± 0.03 μM and 0.7 ± 0.2 μM, respectively). The analogs modestly destabilized the chaperone "clients", Akt1 and Raf1, and induced apoptosis in these cells. Further, the microsomal half-life of JG-98 was improved at least 7-fold (t1/2 = 37 min) compared to MKT-077 (t1/2 MKT-077. These studies advance MKT-077 analogs as chemical probes for studying Hsp70's roles in cancer.

  3. Review: What we know about ST13, a co-factor of heat shock protein, or a tumor suppressor?

    Institute of Scientific and Technical Information of China (English)

    SHI Zheng-zheng; ZHANG Jia-wei; ZHENG Shu

    2007-01-01

    This article is to summarize the molecular and functional analysis of the gene "suppression of tumorigenicity 13"(ST13). ST13 is in fact the gene encoding Hsp70 interacting protein (Hip), a co-factor (co-chaperone) of the 70-kDa heat shock proteins (Hsc/Hsp70). By collaborating with other positive co-factors such as Hsp40 and the Hsp70-Hsp90 organizing protein (Hop), or competing with negative co-factors such as Bc12-associated athanogen 1 (Bag1), Hip facilitates may facilitate the chaperone function of Hsc/Hsp70 in protein folding and repair, and in controlling the activity of regulatory proteins such as steroid receptors and regulators of proliferation or apoptosis. Although the nomenclature of ST13 implies a role in the suppression of tumorigenicity (ST), to date available experimental data are not sufficient to support its role in cancer development, except for the possible down-regulation of ST13 in gastric and colorectal cancers. Further investigation of this gene at the physiological level would benefit our understanding of diseases such as endocrinological disorders, cancer, and neurodegeneration commonly associated with protein misfolding.

  4. Sequence and domain conservation of the coelacanth Hsp40 and Hsp90 chaperones suggests conservation of function.

    Science.gov (United States)

    Bishop, Özlem Tastan; Edkins, Adrienne Lesley; Blatch, Gregory Lloyd

    2014-09-01

    Molecular chaperones and their associated co-chaperones play an important role in preserving and regulating the active conformational state of cellular proteins. The chaperone complement of the Indonesian Coelacanth, Latimeria menadoensis, was elucidated using transcriptomic sequences. Heat shock protein 90 (Hsp90) and heat shock protein 40 (Hsp40) chaperones, and associated co-chaperones were focused on, and homologous human sequences were used to search the sequence databases. Coelacanth homologs of the cytosolic, mitochondrial and endoplasmic reticulum (ER) homologs of human Hsp90 were identified, as well as all of the major co-chaperones of the cytosolic isoform. Most of the human Hsp40s were found to have coelacanth homologs, and the data suggested that all of the chaperone machinery for protein folding at the ribosome, protein translocation to cellular compartments such as the ER and protein degradation were conserved. Some interesting similarities and differences were identified when interrogating human, mouse, and zebrafish homologs. For example, DnaJB13 is predicted to be a non-functional Hsp40 in humans, mouse, and zebrafish due to a corrupted histidine-proline-aspartic acid (HPD) motif, while the coelacanth homolog has an intact HPD. These and other comparisons enabled important functional and evolutionary questions to be posed for future experimental studies.

  5. 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.

    Directory of Open Access Journals (Sweden)

    Chao Shi

    Full Text Available 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.In this study, we show that PABPN1 interacts with and is stabilized by heat shock protein 90 (HSP90. Treatment with the HSP90 inhibitor 17-AAG disrupted the interaction of mutant PABPN1 with HSP90 and reduced the formation of intranuclear inclusions (INIs. Furthermore, mutant PABPN1 was preferentially degraded in the presence of 17-AAG compared with wild-type PABPN1 in vitro and in vivo. The effect of 17-AAG was mediated through an increase in the interaction of PABPN1 with the carboxyl terminus of heat shock protein 70-interacting protein (CHIP. The overexpression of CHIP suppressed the aggregation of mutant PABPN1 in transfected cells.Our results demonstrate that the HSP90 molecular chaperone system plays a crucial role in the selective elimination of abnormal PABPN1 proteins and also suggest a potential therapeutic application of the HSP90 inhibitor 17-AAG for the treatment of OPMD.

  6. Gene Expression Profiling of Clostridium botulinum under Heat Shock Stress

    Directory of Open Access Journals (Sweden)

    Wan-dong Liang

    2013-01-01

    Full Text Available During growth, C. botulinum is always exposed to different environmental changes, such as temperature increase, nutrient deprivation, and pH change; however, its corresponding global transcriptional profile is uncharacterized. This study is the first description of the genome-wide gene expression profile of C. botulinum in response to heat shock stress. Under heat stress (temperature shift from 37°C to 45°C over a period of 15 min, 176 C. botulinum ATCC 3502 genes were differentially expressed. The response included overexpression of heat shock protein genes (dnaK operon, groESL, hsp20, and htpG and downregulation of aminoacyl-tRNA synthetase genes (valS, queA, tyrR, and gatAB and ribosomal and cell division protein genes (ftsZ and ftsH. In parallel, several transcriptional regulators (marR, merR, and ompR families were induced, suggesting their involvement in reshuffling of the gene expression profile. In addition, many ABC transporters (oligopeptide transport system, energy production and conversion related genes (glpA and hupL, cell wall and membrane biogenesis related genes (fabZ, fabF, and fabG, flagella-associated genes (flhA, flhM, flhJ, flhS, and motAB, and hypothetical genes also showed changed expression patterns, indicating that they may play important roles in survival under high temperatures.

  7. C-terminal heat shock protein 90 inhibitor decreases hyperglycemia-induced oxidative stress and improves mitochondrial bioenergetics in sensory neurons.

    Science.gov (United States)

    Zhang, Liang; Zhao, Huiping; Blagg, Brian S J; Dobrowsky, Rick T

    2012-04-06

    Diabetic peripheral neuropathy (DPN) is a common complication of diabetes in which hyperglycemia-induced mitochondrial dysfunction and enhanced oxidative stress contribute to sensory neuron pathology. KU-32 is a novobiocin-based, C-terminal inhibitor of the molecular chaperone, heat shock protein 90 (Hsp90). KU-32 ameliorates multiple sensory deficits associated with the progression of DPN and protects unmyelinated sensory neurons from glucose-induced toxicity. Mechanistically, KU-32 increased the expression of Hsp70, and this protein was critical for drug efficacy in reversing DPN. However, it remained unclear if KU-32 had a broader effect on chaperone induction and if its efficacy was linked to improving mitochondrial dysfunction. Using cultures of hyperglycemically stressed primary sensory neurons, the present study investigated whether KU-32 had an effect on the translational induction of other chaperones and improved mitochondrial oxidative stress and bioenergetics. A variation of stable isotope labeling with amino acids in cell culture called pulse SILAC (pSILAC) was used to unbiasedly assess changes in protein translation. Hyperglycemia decreased the translation of numerous mitochondrial proteins that affect superoxide levels and respiratory activity. Importantly, this correlated with a decrease in mitochondrial oxygen consumption and an increase in superoxide levels. KU-32 increased the translation of Mn superoxide dismutase and several cytosolic and mitochondrial chaperones. Consistent with these changes, KU-32 decreased mitochondrial superoxide levels and significantly enhanced respiratory activity. These data indicate that efficacy of modulating molecular chaperones in DPN may be due in part to improved neuronal mitochondrial bioenergetics and decreased oxidative stress.

  8. A C-Terminal Heat Shock Protein 90 Inhibitor Decreases Hyperglycemia-induced Oxidative Stress and Improves Mitochondrial Bioenergetics in Sensory Neurons

    Science.gov (United States)

    Zhang, Liang; Zhao, Huiping; Blagg, Brian S.J.; Dobrowsky, Rick T.

    2012-01-01

    Summary Diabetic peripheral neuropathy (DPN) is a common complication of diabetes in which hyperglycemia-induced mitochondrial dysfunction and enhanced oxidative stress contribute to sensory neuron pathology. KU-32 is a novobiocin-based, C-terminal inhibitor of the molecular chaperone, heat shock protein 90 (Hsp90). KU-32 ameliorates multiple sensory deficits associated with the progression of DPN and protects unmyelinated sensory neurons from glucose-induced toxicity. Mechanistically, KU-32 increased the expression of Hsp70 and this protein was critical for drug efficacy in reversing DPN. However, it remained unclear if KU-32 had a broader effect on chaperone induction and if its efficacy was linked to improving mitochondrial dysfunction. Using cultures of hyperglycemically stressed primary sensory neurons, the present study investigated whether KU-32 had an effect on the translational induction of other chaperones and improved mitochondrial oxidative stress and bioenergetics. A variation of stable isotope labeling with amino acids in cell culture called pulse SILAC (pSILAC) was used to unbiasedly assess changes in protein translation. Hyperglycemia decreased the translation of numerous mitochondrial proteins that affect superoxide levels and respiratory activity. Importantly, this correlated with a decrease in mitochondrial oxygen consumption and an increase in superoxide levels. KU-32 increased the translation of Mn superoxide dismutase and several cytosolic and mitochondrial chaperones. Consistent with these changes, KU-32 decreased mitochondrial superoxide levels and significantly enhanced respiratory activity. These data indicate that efficacy of modulating molecular chaperones in DPN may be due in part to improved neuronal mitochondrial bioenergetics and decreased oxidative stress. PMID:22413817

  9. Effect of heat shock protein 70 on cerebral ischemia

    Institute of Scientific and Technical Information of China (English)

    Wen Yan; Xiulian Chen; Rui Chen; Shiming Xu; Lijuan Zhang; Hongjuan Wang; Chunyue Huo

    2006-01-01

    OBJECTIVE: To summarize the relationship between heat shock protein 70 (HSP70) and cerebral ischemia.DATA SOURCES: An online search of Medline database was undertaken to identify relevant articles published in English from January 1980 to December 2005 by using the keywords of "heat shock protein 70, ischemia". Meanwhile, Chinese relevant articles published from January 2000 to December 2005 were searched in China National Knowledge Infrastructure (CNKI) database and Chinese Journal of Clinical Rehabilitation with the keywords of "heat shock protein 70, cerebral ischemia" in Chinese.STUDY SELECTION: More than 100 related articles were screened, and 29 references mainly about HSP70and cerebral ischemia were selected, including basic and clinical researches. As to the articles with similar content, those published in the authoritative journals in recent 3 years were preferential.DATA EXTRACTION : A total of 29 articles were collected and classified according to the structure, function and clinical application of HSP70. Among them, 1 article is about the structure of HSP70, 27 about the relationship between HSP70 and cerebral ischemia, and 2 about the clinical application of HSP70.DATA SYNTHESTS: HSP70 is one of the most conservative proteins during biological evolution. Experiments in cerebral ischemia revealed that HSP70 expression was time-dependent, also correlated with the injured site and severity. The cerebral ischemia induced HSP70 gene expression in hippocampus of gerbil had protection to tolerance of fatal ischemic injury for neurons. The increase of HSP70 expression may be one of the endogenous protective mechanisms during cerebral ischemia, and can effectively alleviate cerebral ischemia. Thus HSP70 protein and HSP70 mRNA have been taken as important indexes extensively applied in the basic study of cerebral ischemia by some scholars abroad.CONCLUSTON: HSP70 plays a protective role in cerebral ischemia, and a deeper research into the biological function of

  10. Associations between heat shock protein 70 genetic polymorphisms and calving traits in crossbred Brahman cows

    Science.gov (United States)

    Stressors such as heat, cold, toxins, and oxygen deprivation are known to induce heat shock proteins. Genetic polymorphisms associated with heat shock protein genes have been associated with decreased male and female fertility. Our objectives were to 1) confirm single nucleotide polymorphisms (SNP) ...

  11. Heat shock proteiners inhibering af programmeret celledød

    OpenAIRE

    Cohen, Malene; Jantzen, Kim; Olsson, Kim; Rohde, Anders

    2007-01-01

    Heat shock proteiner (Hsp) har i de seneste år været genstand for interesse indenfor forskellige grene af biologien på grund af deres egenskaber indenfor programmeret celledød. Den etablerede viden er størst indenfor oncologi, hvor Hsps apoptosehæmmende egenskaber fortsat er genstand for forskning, men proteinernes præventive effekt på toksin- eller stressinduceret celledød har spredt interessen til felter som neurologi og toksologi. Målet med denne rapport har været at sammenf...

  12. Negative effect of heat shock on feline calicivirus release from infected cells is associated with the control of apoptosis.

    Science.gov (United States)

    Alvarez-Sanchez, Cristal; Cancio-Lonches, Clotilde; Mora-Heredia, José Eduardo; Santos-Valencia, Juan Carlos; Barrera-Vázquez, Oscar Salvador; Yocupicio-Monroy, Martha; Gutiérrez-Escolano, Ana Lorena

    2015-02-16

    FCV infection causes rapid cytopathic effects, and its replication results in the induction of apoptosis changes in cultured cells. It is well established that the survival of apoptotic cells can be enhanced by the expression of heat-shock proteins (Hsp) to prevent damage or facilitate recovery. Hsps can act as molecular chaperones, but they can also have anti-apoptotic roles by binding to apoptotic proteins and inhibiting the activation of caspases, the primary mediators of apoptosis. Because apoptosis occurs during FCV infection and heat shock (HS) treatment has a cytoprotective role due to the expression of Hsps, we studied the effect of the HS response to hyperthermia during FCV infection in cultured cells. We found that FCV infection does not inhibit the expression of Hsp70 induced by HS and that non-structural and structural protein synthesis was not modified during HS treatment. However, HS caused a delay in the appearance of a cytopathic effect in infected cells, as well as a reduction in the extracellular but not in the cell-associated viral yield. This antiviral effect of HS correlates with the inhibition of caspase-3 activation. Thus, the HS-induced reduction in virus production appeared to be associated with the control of apoptosis, supporting previous data that indicate that apoptosis is necessary for FCV release. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. The Arabian camel Camelus dromedarius heat shock protein 90α: cDNA cloning, characterization and expression.

    Science.gov (United States)

    Saeed, Hesham; Shalaby, Manal; Embaby, Amira; Ismael, Mohammad; Pathan, Akbar; Ataya, Farid; Alanazi, Mohammad; Bassiouny, Khalid

    2015-11-01

    Heat shock protein 90 (Hsp90) is a highly conserved ubiquitous molecular chaperone contributing to assisting folding, maintenance of structural integrity and proper regulation of a subset of cytosolic proteins. In the present study, a heat shock protein 90α full length coding cDNA was isolated and cloned from the Arabian one-humped camel by reverse transcription polymerase chain reaction (RT-PCR). The full length cDNA sequence was submitted to NCBI GeneBank under the accession number KF612338. The sequence analysis of the Arabian camel Hsp90α cDNA showed 2202bp encoding a protein of 733 amino acids with estimated molecular mass of 84.827kDa and theoretical isoelectric point (pI) of 5.31. Blast search analysis revealed that the C. dromedarius Hsp90α shared high similarity with other known Hsp90α. Comparative analyses of camel Hsp90α protein sequence with other mammalian Hsp90s showed high identity (85-94%). Heterologous expression of camel Hsp90α cDNA in E. coli JM109 (DE3) gave a fusion protein band of 86.0kDa after induction with IPTG for 4h.

  14. PredHSP: Sequence Based Proteome-Wide Heat Shock Protein Prediction and Classification Tool to Unlock the Stress Biology.

    Directory of Open Access Journals (Sweden)

    Ravindra Kumar

    Full Text Available Heat shock proteins are chaperonic proteins, which are present in every domain of life. They play a crucial role in folding/unfolding of proteins, their sorting and assembly into multi-protein complex, cell cycle control and also protect the cell during stress. Considering the fact that no web-based predictor is available for simultaneous prediction and classification of HSPs, it is imperative to develop a method, which can predict and classify them efficiently. In this study, we have developed coupled amino acid composition and support vector machine based two-tier method, PredHSP that identifies heat shock proteins (1st tier and classifies it to different families (at 2nd tier. At 1st tier, we achieved maximum accuracy 76.66% with MCC 0.43, while at 2nd tier we achieved maximum accuracy 96.36% with MCC 0.87 for HSP20, 91.91% with MCC 0.83 for HSP40, 95.96% with MCC 0.72 for HSP60, 91.87% with MCC 0.71 for HSP70, 98.43% with MCC 0.70 for HSP90 and 97.48% with MCC 0.71 for HSP100. We have also developed a webserver, as well as standalone package for the use of scientific community, which can be accessed at http://14.139.227.92/mkumar/predhsp/index.html.

  15. Destabilization and recovery of a yeast prion after mild heat shock

    OpenAIRE

    Newnam, Gary P.; Birchmore, Jennifer L.; Chernoff, Yury O.

    2011-01-01

    Yeast prion [PSI+] is a self-perpetuating amyloid of the translational termination factor Sup35. Although [PSI+] propagation is modulated by heat shock proteins (Hsps), high temperature was previously reported to have little or no effect on [PSI+]. Our results show that short-term exposure of exponentially growing yeast culture to mild heat shock, followed by immediate resumption of growth, leads to [PSI+] destabilization, sometimes persisting for several cell divisions after heat shock. Prio...

  16. 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...

  17. The L-type cyclin CYL-1 and the heat-shock-factor HSF-1 are required for heat-shock-induced protein expression in Caenorhabditis elegans.

    Science.gov (United States)

    Hajdu-Cronin, Yvonne M; Chen, Wen J; Sternberg, Paul W

    2004-12-01

    In a screen for suppressors of activated GOA-1 (Galpha(o)) under the control of the hsp-16.2 heat-shock promoter, we identified three genetic loci that affected heat-shock-induced GOA-1 expression. The cyl-1 mutants are essentially wild type in appearance, while hsf-1 and sup-45 mutants have egg-laying defects. The hsf-1 mutation also causes a temperature-sensitive developmental arrest, and hsf-1 mutants have decreased life span. Western analysis indicated that mutations in all three loci suppressed the activated GOA-1 transgene by decreasing its expression. Heat-shock-induced expression of hsp-16.2 mRNA was reduced in cyl-1 mutants and virtually eliminated in hsf-1 and sup-45 mutants, as compared to wild-type expression. The mutations could also suppress other transgenes under heat-shock control. cyl-1 and sup-45, but not hsf-1, mutations suppressed a defect caused by a transgene not under heat-shock control, suggesting a role in general transcription or a post-transcriptional aspect of gene expression. hsf-1 encodes the C. elegans homolog of the human heat-shock factor HSF1, and cyl-1 encodes a cyclin most similar to cyclin L. We believe HSF-1 acts in heat-shock-inducible transcription and CYL-1 acts more generally in gene expression.

  18. Developmental and hyperthermia-induced expression of the heat shock proteins HSP60 and HSP70 in tissues of the housefly Musca domestica: an in vitro study

    Directory of Open Access Journals (Sweden)

    Sunita Sharma

    2007-01-01

    Full Text Available The expression pattern of two major chaperones, the heat shock proteins (HSPs HSP60 and HSP70 was studied in vitro in tissues of the housefly Musca domestica during larval and adult stages of development to identify their immunological relatives and understand their functional significance in normal cellular activities and during thermal stress. Fluorographs of labeled polypeptides and western blots demonstrated that both HSPs are expressed constitutively and heat-induced in all the larval and adult cell types examined. The pattern of whole tissue immunocytochemical staining using anti-HSP60 and anti-HSP70 antibodies corresponded well with the observations from western blots or fluorographs. In developing oocytes, both constitutive and heat inducible expression of HSP60 were regulated in an oocyte stage-specific manner. In unstressed ovaries the expression of these proteins was less pronounced in early stage oocytes (1st - 8th than at later stages (9th and onward. The heat shock, however, induced both HSP70 and HSP60 to a significantly high level in early stage oocytes (1st-8th as compared to their respective controls. Our findings indicate the involvement of the HSP60 and HSP70 proteins in the development, growth and differentiation of both somatic and germ line tissues. Furthermore, the enhanced co-expression of HSP70 and HSP60 upon heat shock in various larval and adult cell types suggests the possible role of HSP60 in thermoprotection.

  19. Effect of viscosity and wall heat conduction on shock attenuation in narrow channels

    Science.gov (United States)

    Deshpande, A.; Puranik, B.

    2016-07-01

    In the present work, the effects due to viscosity and wall heat conduction on shock propagation and attenuation in narrow channels are numerically investigated. A two-dimensional viscous shock tube configuration is simulated, and heat conduction in the channel walls is explicitly included. The simulation results indicate that the shock attenuation is significantly less in the case of an adiabatic wall, and the use of an isothermal wall model is adequate to take into account the wall heat conduction. A parametric study is performed to characterize the effects of viscous forces and wall heat conduction on shock attenuation, and the behaviour is explained on the basis of boundary layer formation in the post-shock region. A dimensionless parameter that describes the shock attenuation is correlated with the diaphragm pressure ratio and a dimensionless parameter which is expressed using the characteristic Reynolds number and the dimensionless shock travel.

  20. Exploring temporal transcription regulation structure of Aspergillus fumigatus in heat shock by state space model

    Directory of Open Access Journals (Sweden)

    Miyano Satoru

    2009-07-01

    Full Text Available Abstract Background The thermotolerance of Aspergillus fumigatus plays a critical role in mammalian and avian infections. Thus, the identification of its adaptation mechanism to higher temperature is very important for an efficient anti-fungal drug development as well as fundamental understanding of its pathogenesis. We explored the temporal transcription regulation structure of this pathogenic fungus under heat shock conditions using the time series microarray data reported by Nierman et al. (Nature 2005, 438:1151-1156. Results The estimated transcription regulation structure of A. fumigatus shows that the heat shock proteins are strongly negatively associated with central metabolic pathway genes such as the tricarboxylic acid cycle (TCA cycle and carbohydrate metabolism. It was 60 min and 120 min, respectively, after the growth temperature changes from 30°C (corresponding to environments of tropical soil to 37°C and 48°C (corresponding to temperatures in the human body and compost, respectively that some of genes in TCA cycle were started to be upregulated. In these points, most of heat shock proteins showed lowest expression level after heat shocks. Among the heat shock proteins, the HSP30 (AFU6G06470, a single integral plasma membrane heat shock protein, presented most active role in transcription regulation structure in both heat shock conditions of 37°C and 48°C. The metabolic genes associated with multiple genes in the gene regulation network showed a tendency to have opposite expression patterns of heat shock proteins. The role of those metabolic genes was second regulator in the coherent feed-forward loop type of regulation structure having heat shock protein as its first regulator. This type of regulation structure might be very advantageous for the thermal adaptation of A. fumigatus under heat shock because a small amount of heat shock proteins can rapidly magnify their regulation effect on target genes. However, the coherent

  1. 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.

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

    OpenAIRE

    Dolan, E. B.; 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 ...

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

    National Research Council Canada - National Science Library

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

    2016-01-01

    ...), 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...

  4. KPNA3-knockdown eliminates the second heat shock protein peak associated with the heat shock response of male silkworm pupae (Bombyx mori) by reducing heat shock factor transport into the nucleus.

    Science.gov (United States)

    Li, Jun; Wei, Guoqing; Wang, Lei; Qian, Cen; Li, Kedong; Zhang, Congfen; Dai, Lishang; Sun, Yu; Liu, Dongran; Zhu, Baojian; Liu, Chaoliang

    2016-01-10

    In this study, we investigated the role of karyopherin alpha 3 in the heat shock response in male silkworm pupae. Karyopherin alpha recognizes the classical nuclear location sequence on proteins and transports them into the nucleus by forming a trimetric complex with karyopherin beta. Three predicted karyopherin alphas (KPNA1, KPNA2 and KPNA3) have been identified from the silkworm Bombyx mori. Pull-down assay result showed that KPNA3 can pull down heat shock transcription factor (HSF) from proteins extracted from tissues using non-denature lysis buffer. After 45 °C heat shock on male B. mori pupae for 30 min, we identified two heat shock protein (HSP) mRNA expression peaks correlating with HSP19.9, HSP20.4 and HSP25.4 at 4 h (peak 1) and 24 h (peak 2). The second peak was eliminated after knockdown of KPNA3. Similar results were obtained following knockdown of HSF, which is the trans-activating factor of heat shock. However, KPNA3 knockdown was not accompanied by the decreased HSF protein levels at 24 h after heat shock which were observed following HSF knockdown. We also expressed recombinant protein GST-KPNA3 and His-HSF in Escherichia coli to perform GST pull-down assay and the result confirmed the interaction between KPNA3 and HSF. We concluded that KPNA3 knockdown eliminates the second heat shock protein peak in the heat shock response of male silkworm pupae by reducing HSF transport into the nucleus.

  5. Molecular cloning and expression of a heat-shock cognate 70 (hsc70) gene from swordtail fish (Xiphophorus helleri)

    Institute of Scientific and Technical Information of China (English)

    LI Ningqiu; FU Xiaozhe; HAN Jingang; SHI Cunbin; HUANG Zhibin; WU Shuqin

    2013-01-01

    Heat shock proteins are a family of molecular chaperones that are involved in many aspects of protein homeostasis.In the present study,a full-length cDNA,encoding the constitutively expressed 70-kDa heat shock cognate protein (Hsc70),was isolated from swordtail fish (Xiphophorus helleri) and designated as XheHsc70.The Xhehsc70 cDNA was 2 104 bp long with an open reading frame of 1 941 bp,and it encoded a protein of 646 amino acids with a theoretical molecular weight of 70.77 kDa and an isoelectric point of 5.04.The deduced amino acid sequence shared 94.1%-98.6% identities with the Hsc70s from a number of other fish species.Tissue distribution results show that the Xhehsc70 mRNA was expressed in brain,heart,head kidney,kidney,spleen,liver,muscle,gill,and peripheral blood.After immunization with formalin-killed Vibrio alginolyticus cells there was a significant increase in the Xhehsc70 rnRNA transcriptional level in the head kidney of the vaccinated fish compared with in the control at 6,12,24,and 48 h as shown by quantitative real time RT-PCR.Based on an analysis of the amino acid sequence of XheHsc70,its phylogeny,and Xhehsc70 mRNA expression,XheHsc70 was identified as a member of the cytoplasmic Hsc70 (constitutive) subfamily of the Hsp70 family of heat shock proteins,suggesting that it may play a role in the immune response.The Xhehsc70 cDNA sequence reported in this study was submitted to GenBank under the accession number JF739182.

  6. Molecular cloning and expression of a heat-shock cognate 70 (hsc70) gene from swordtail fish ( Xiphophorus helleri)

    Science.gov (United States)

    Li, Ningqiu; Fu, Xiaozhe; Han, Jingang; Shi, Cunbin; Huang, Zhibin; Wu, Shuqin

    2013-07-01

    Heat shock proteins are a family of molecular chaperones that are involved in many aspects of protein homeostasis. In the present study, a full-length cDNA, encoding the constitutively expressed 70-kDa heat shock cognate protein (Hsc70), was isolated from swordtail fish ( Xiphophorus helleri) and designated as XheHsc70. The Xhehsc70 cDNA was 2 104 bp long with an open reading frame of 1 941 bp, and it encoded a protein of 646 amino acids with a theoretical molecular weight of 70.77 kDa and an isoelectric point of 5.04. The deduced amino acid sequence shared 94.1%-98.6% identities with the Hsc70s from a number of other fish species. Tissue distribution results show that the Xhehsc70 mRNA was expressed in brain, heart, head kidney, kidney, spleen, liver, muscle, gill, and peripheral blood. After immunization with formalin-killed Vibrio alginolyticus cells there was a significant increase in the Xhehsc70 mRNA transcriptional level in the head kidney of the vaccinated fish compared with in the control at 6, 12, 24, and 48 h as shown by quantitative real time RT-PCR. Based on an analysis of the amino acid sequence of XheHsc70, its phylogeny, and Xhehsc70 mRNA expression, XheHsc70 was identified as a member of the cytoplasmic Hsc70 (constitutive) subfamily of the Hsp70 family of heat shock proteins, suggesting that it may play a role in the immune response. The Xhehsc70 cDNA sequence reported in this study was submitted to GenBank under the accession number JF739182.

  7. Over-expression of gene encoding heat shock protein 70 from Mycobacterium tuberculosis and its evaluation as vaccine adjuvant

    Directory of Open Access Journals (Sweden)

    J Dhakal

    2013-01-01

    Full Text Available Background: Heat shock proteins (Hsps are evolutionary ancient and highly conserved molecular chaperons found in prokaryotes as well as eukaryotes. Hsp70 is a predominant member of Hsp family. Microbial Hsp70s (mHsp70s have acquired special significance in immunity since they have been shown to be potent activators of the innate immune system and generate specific immune responses against tumours and infectious agents. Objectives: The present study was aimed to clone express and purify recombinant Hsp70 from the Mycobacterium tuberculosis and characterise it immunologically. The study also aimed at determining the potential of recombinant M. tuberculosis heat shock protein (rMTB-Hsp70 as adjuvant or antigen carrier. Materials and Methods: Cloning of M. tuberculosis heat shock protein (MTB-Hsp70 amplicon was carried out using the pGEMT-Easy vector although for expression, pProExHTb prokaryotic expression vector was used. Purification of recombinant Hsp70 was carried out by nickel-nitrilotriacetic acid (Ni-NTA affinity chromatography. For immunological characterization and determining the adjuvant effect of MTB-Hsp70, BALB/c mice were used. The data obtained was statistically analysed. Results: Hsp70 gene was cloned, sequenced and the sequence data were submitted to National Center for Biotechnology Information (NCBI. Recombinant MTB-Hsp70 was successfully over-expressed using the prokaryotic expression system and purified to homogeneity. The protein was found to be immunodominant. Significant adjuvant effect was produced by the rMTB-Hsp70 when inoculated with recombinant outer membrane protein 31; however, effect was less than the conventionally used the Freund′s adjuvant. Conclusion: Protocol standardised can be followed for bulk production of rHsp70 in a cost-effective manner. Significant adjuvant effect was produced by rMTB-Hsp70; however, the effect was than Freund′s adjuvant. Further, studies need to be carried out to explore its

  8. Modification of tooth development by heat shock protein 60

    Institute of Scientific and Technical Information of China (English)

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

    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.

  9. 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

    2016-03-30

    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.

  10. Heat shock protein 90 from neglected protozoan parasites.

    Science.gov (United States)

    Roy, Nainita; Nageshan, Rishi Kumar; Ranade, Shatakshi; Tatu, Utpal

    2012-03-01

    Significant advances have been made in our understanding of heat shock protein 90 (Hsp90) in terms of its structure, biochemical characteristics, post-translational modifications, interactomes, regulation and functions. In addition to yeast as a model several new systems have now been examined including flies, worms, plants as well as mammalian cells. This review discusses themes emerging out of studies reported on Hsp90 from infectious disease causing protozoa. A common theme of sensing and responding to host cell microenvironment emerges out of analysis of Hsp90 in Malaria, Trypanosmiasis as well as Leishmaniasis. In addition to their functional roles, the potential of Hsp90 from these infectious disease causing organisms to serve as drug targets and the current status of this drug development endeavor are discussed. Finally, a unique and the only known example of a split Hsp90 gene from another disease causing protozoan Giardia lamblia and its evolutionary significance are discussed. Clearly studies on Hsp90 from protozoan parasites promise to reveal important new paradigms in Hsp90 biology while exploring its potential as an anti-infective drug target. This article is part of a Special Issue entitled: Heat Shock Protein 90 (HSP90). Copyright © 2011 Elsevier B.V. All rights reserved.

  11. Protein disorder reduced in Saccharomyces cerevisiae to survive heat shock

    Science.gov (United States)

    Vicedo, Esmeralda; Gasik, Zofia; Dong, Yu-An; Goldberg, Tatyana; Rost, Burkhard

    2015-01-01

    Recent experiments established that a culture of Saccharomyces cerevisiae (baker’s yeast) survives sudden high temperatures by specifically duplicating the entire chromosome III and two chromosomal fragments (from IV and XII). Heat shock proteins (HSPs) are not significantly over-abundant in the duplication. In contrast, we suggest a simple algorithm to “ postdict ” the experimental results: Find a small enough chromosome with minimal protein disorder and duplicate this region. This algorithm largely explains all observed duplications. In particular, all regions duplicated in the experiment reduced the overall content of protein disorder. The differential analysis of the functional makeup of the duplication remained inconclusive. Gene Ontology (GO) enrichment suggested over-representation in processes related to reproduction and nutrient uptake. Analyzing the protein-protein interaction network (PPI) revealed that few network-central proteins were duplicated. The predictive hypothesis hinges upon the concept of reducing proteins with long regions of disorder in order to become less sensitive to heat shock attack. PMID:26673203

  12. Extracts Obtained from Pterocarpus angolensis DC and Ziziphus mucronata Exhibit Antiplasmodial Activity and Inhibit Heat Shock Protein 70 (Hsp70 Function

    Directory of Open Access Journals (Sweden)

    Tawanda Zininga

    2017-07-01

    Full Text Available Malaria parasites are increasingly becoming resistant to currently used antimalarial therapies, therefore there is an urgent need to expand the arsenal of alternative antimalarial drugs. In addition, it is also important to identify novel antimalarial drug targets. In the current study, extracts of two plants, Pterocarpus angolensis and Ziziphus mucronata were obtained and their antimalarial functions were investigated. Furthermore, we explored the capability of the extracts to inhibit Plasmodium falciparum heat shock protein 70 (Hsp70 function. Heat shock protein 70 (Hsp70 are molecular chaperones whose function is to facilitate protein folding. Plasmodium falciparum the main agent of malaria, expresses two cytosol-localized Hsp70s: PfHsp70-1 and PfHsp70-z. The PfHsp70-z has been reported to be essential for parasite survival, while inhibition of PfHsp70-1 function leads to parasite death. Hence both PfHsp70-1 and PfHsp70-z are potential antimalarial drug targets. Extracts of P. angolensis and Z. mucronata inhibited the basal ATPase and chaperone functions of the two parasite Hsp70s. Furthermore, fractions of P. angolensis and Z. mucronata inhibited P. falciparum 3D7 parasite growth in vitro. The extracts obtained in the current study exhibited antiplasmodial activity as they killed P. falciparum parasites maintained in vitro. In addition, the findings further suggest that some of the compounds in P. angolensis and Z. mucronata may target parasite Hsp70 function.

  13. Conserved region 2.1 of Escherichia coli heat shock transcription factor sigma32 is required for modulating both metabolic stability and transcriptional activity.

    Science.gov (United States)

    Horikoshi, Mina; Yura, Takashi; Tsuchimoto, Sachie; Fukumori, Yoshihiro; Kanemori, Masaaki

    2004-11-01

    Escherichia coli heat shock transcription factor sigma32 is rapidly degraded in vivo, with a half-life of about 1 min. A set of proteins that includes the DnaK chaperone team (DnaK, DnaJ, GrpE) and ATP-dependent proteases (FtsH, HslUV, etc.) are involved in degradation of sigma32. To gain further insight into the regulation of sigma32 stability, we isolated sigma32 mutants that were markedly stabilized. Many of the mutants had amino acid substitutions in the N-terminal half (residues 47 to 55) of region 2.1, a region highly conserved among bacterial sigma factors. The half-lives ranged from about 2-fold to more than 10-fold longer than that of the wild-type protein. Besides greater stability, the levels of heat shock proteins, such as DnaK and GroEL, increased in cells producing stable sigma32. Detailed analysis showed that some stable sigma32 mutants have higher transcriptional activity than the wild type. These results indicate that the N-terminal half of region 2.1 is required for modulating both metabolic stability and the activity of sigma32. The evidence suggests that sigma32 stabilization does not result from an elevated affinity for core RNA polymerase. Region 2.1 may, therefore, be involved in interactions with the proteolytic machinery, including molecular chaperones.

  14. Extracts Obtained from Pterocarpus angolensis DC and Ziziphus mucronata Exhibit Antiplasmodial Activity and Inhibit Heat Shock Protein 70 (Hsp70) Function.

    Science.gov (United States)

    Zininga, Tawanda; Anokwuru, Chinedu P; Sigidi, Muendi T; Tshisikhawe, Milingoni P; Ramaite, Isaiah I D; Traoré, Afsatou N; Hoppe, Heinrich; Shonhai, Addmore; Potgieter, Natasha

    2017-07-28

    Malaria parasites are increasingly becoming resistant to currently used antimalarial therapies, therefore there is an urgent need to expand the arsenal of alternative antimalarial drugs. In addition, it is also important to identify novel antimalarial drug targets. In the current study, extracts of two plants, Pterocarpus angolensis and Ziziphus mucronata were obtained and their antimalarial functions were investigated. Furthermore, we explored the capability of the extracts to inhibit Plasmodium falciparum heat shock protein 70 (Hsp70) function. Heat shock protein 70 (Hsp70) are molecular chaperones whose function is to facilitate protein folding. Plasmodium falciparum the main agent of malaria, expresses two cytosol-localized Hsp70s: PfHsp70-1 and PfHsp70-z. The PfHsp70-z has been reported to be essential for parasite survival, while inhibition of PfHsp70-1 function leads to parasite death. Hence both PfHsp70-1 and PfHsp70-z are potential antimalarial drug targets. Extracts of P. angolensis and Z. mucronata inhibited the basal ATPase and chaperone functions of the two parasite Hsp70s. Furthermore, fractions of P. angolensis and Z. mucronata inhibited P. falciparum 3D7 parasite growth in vitro. The extracts obtained in the current study exhibited antiplasmodial activity as they killed P. falciparum parasites maintained in vitro. In addition, the findings further suggest that some of the compounds in P. angolensis and Z. mucronata may target parasite Hsp70 function.

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

    Science.gov (United States)

    Xie, Jingjing; Tang, Li; Lu, Lin; Zhang, Liyang; Xi, Lin; Liu, Hsiao-Ching; Odle, Jack; Luo, Xugang

    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 (Pheat 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 (Pheat treatment, the HSP 70 mRNA level was increased (Pheat challenge (Pheat 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.

  16. Heat-shock protein 70 binds microtubules and interacts with kinesin in tobacco pollen tubes.

    Science.gov (United States)

    Parrotta, Luigi; Cresti, Mauro; Cai, Giampiero

    2013-09-01

    The heat-shock proteins of 70 kDa are a family of ubiquitously expressed proteins important for protein folding. Heat-shock protein 70 assists other nascent proteins to achieve the spatial structure and ultimately helps the cell to protect against stress factors, such as heat. These proteins are localized in different cellular compartments and are associated with the cytoskeleton. We identified a heat-shock protein 70 isoform in the pollen tube of tobacco that binds to microtubules in an ATP-dependent manner. The heat-shock protein 70 was identified as part of the so-called ATP-MAP (ATP-dependent microtubule-associated protein) fraction, which also includes the 90-kDa kinesin, a mitochondria-associated motor protein. The identity of heat-shock protein 70 was validated by immunological assays and mass spectrometry. Sequence analysis showed that this heat-shock protein 70 is more similar to specific heat-shock proteins of Arabidopsis than to corresponding proteins of tobacco. Two-dimensional electrophoresis indicated that this heat-shock protein 70 isoform only is part of the ATP-MAP fraction and that is associated with the mitochondria of pollen tubes. Sedimentation assays showed that the binding of heat-shock protein 70 to microtubules is not affected by AMPPNP but it increases in the presence of the 90-kDa kinesin. Binding of heat-shock protein 70 to microtubules occurs only partially in the presence of ATP but it does not occur if, in addition to ATP, the 90-kDa kinesin is also present. Data suggest that the binding (but not the release) of heat-shock protein 70 to microtubules is facilitated by the 90-kDa kinesin.

  17. Molecular chaperones encoded by a reduced nucleus: the cryptomonad nucleomorph.

    Science.gov (United States)

    Archibald, J M; Cavalier-Smith, T; Maier, U; Douglas, S

    2001-06-01

    Molecular chaperones mediate the correct folding of nascent or denatured proteins and are found in both the organelles and cytoplasm of eukaryotic cells. Cryptomonad algae are unusual in possessing an extra cytoplasmic compartment (the periplastid space), the result of having engulfed and retained a photosynthetic eukaryote. Within the periplastid space is a diminutive nucleus (the nucleomorph) that encodes mostly genes for its own expression as well as a few needed by the plastid. Two plastid-encoded chaperones (GroEL and DnaK) and a nucleomorph-encoded chaperone (Cpn60) have been reported from the cryptomonad, Guillardia theta. Here we analyse G. theta nucleomorph genes for members of the cytosolic HSP70 and HSP90 families of molecular chaperones, a heat shock transcription factor (HSF), and all eight subunits of the group II chaperonin, CCT. These are presumably all active in the periplastid space, assisting in the maturation of polypeptides required by the cell; we propose a central role for them also in the structure and assembly of a putative relict mitotic apparatus. Curiously, none of the genes for co-chaperones of HSP70, HSP90, or CCT have been detected in the nucleomorph genome; they are either not needed or are encoded in the host nuclear genome and targeted back into the periplastid space. Endoplasmic reticulum (ER) homologs of HSP70 and HSP90 are also not present. Striking differences in the degree of conservation of the various nucleomorph-encoded molecular chaperones were observed. While the G. theta HSP70 and HSP90 homologs are well conserved, each of the eight CCT subunits (alpha, beta, gamma, delta, epsilon, eta, theta, and zeta) is remarkably divergent. Such differences are likely evidence for reduced/different functional constraints on the various molecular chaperones functioning in the periplastid space.

  18. 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.

  19. Examination of KNK437- and quercetin-mediated inhibition of heat shock-induced heat shock protein gene expression in Xenopus laevis cultured cells.

    Science.gov (United States)

    Manwell, Laurie A; Heikkila, John J

    2007-11-01

    We examined the effect of quercetin (3,3',4',5,7-pentahydroxyflavon) and KNK437 (N-formyl-3,4-methylenedioxy-benzylidene-gamma-butyrolactam), a benzylidene lactam compound, on heat-induced heat shock protein (hsp) gene expression in Xenopus laevis A6 kidney epithelial cells. In previous studies, both quercetin and KNK437 inhibited heat shock factor activity resulting in a repression of hsp mRNA and protein accumulation in human cultured cells. In this first study of the effect of these hsp gene expression inhibitors in a non-mammalian cell line, we report that both quercetin and KNK437 reduced the heat shock-induced accumulation of hsp30, hsp47 and hsp70 mRNA in X. laevis cultured cells. However, these inhibitors had no effect on the relative level of a non-heat shock protein mRNA, ef1alpha, in either control or heat shocked cells. Western blot and immunocytochemical analyses revealed that quercetin partially inhibited HSP30 protein accumulation. In contrast, HSP30 protein was not detectable in KNK437-treated cells. Finally, treatment of A6 cells with KNK437 inhibited the heat shock-induced acquisition of thermotolerance, as determined by preservation of actin filaments and cellular morphology using immunocytochemistry and laser scanning confocal microscopy.

  20. Heat-shock protein 27 (Hsp27) as a target of methylglyoxal in gastrointestinal cancer.

    Science.gov (United States)

    Oya-Ito, Tomoko; Naito, Yuji; Takagi, Tomohisa; Handa, Osamu; Matsui, Hirofumi; Yamada, Masaki; Shima, Keisuke; Yoshikawa, Toshikazu

    2011-07-01

    The molecular mechanisms underlying the posttranslational modification of proteins in gastrointestinal cancer are still unknown. Here, we investigated the role of methylglyoxal modifications in gastrointestinal tumors. Methylglyoxal is a reactive dicarbonyl compound produced from cellular glycolytic intermediates that reacts non-enzymatically with proteins. By using a monoclonal antibody to methylglyoxal-modified proteins, we found that murine heat-shock protein 25 and human heat-shock protein 27 were the major adducted proteins in rat gastric carcinoma mucosal cell line and human colon cancer cell line, respectively. Furthermore, we found that heat-shock protein 27 was modified by methylglyoxal in ascending colon and rectum of patients with cancer. However, methylglyoxal-modified heat-shock protein 25/heat-shock protein 27 was not detected in non cancerous cell lines or in normal subject. Matrix-associated laser desorption/ionization mass spectrometry/mass spectrometry analysis of peptide fragments identified Arg-75, Arg-79, Arg-89, Arg-94, Arg-127, Arg-136, Arg-140, Arg-188, and Lys-123 as methylglyoxal modification sites in heat-shock protein 27 and in phosphorylated heat-shock protein 27. The transfer of methylglyoxal-modified heat-shock protein 27 into rat intestinal epithelial cell line RIE was even more effective in preventing apoptotic cell death than that of native control heat-shock protein 27. Furthermore, methylglyoxal modification of heat-shock protein 27 protected the cells against both the hydrogen peroxide- and cytochrome c-mediated caspase activation, and the hydrogen peroxide-induced production of intracellular reactive oxygen species. The levels of lactate converted from methylglyoxal were increased in carcinoma mucosal cell lines. Our results suggest that posttranslational modification of heat-shock protein 27 by methylglyoxal may have important implications for epithelial cell injury in gastrointestinal cancer.

  1. 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

    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......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....... 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...

  2. GroEL to DnaK chaperone network behind the stability modulation of σ(32) at physiological temperature in Escherichia coli.

    Science.gov (United States)

    Patra, Monobesh; Roy, Sourav Singha; Dasgupta, Rakhi; Basu, Tarakdas

    2015-12-21

    The stability of heat-shock transcription factor σ(32) in Escherichia coli has long been known to be modulated only by its own transcribed chaperone DnaK. Very few reports suggest a role for another heat-shock chaperone, GroEL, for maintenance of cellular σ(32) level. The present study demonstrates in vivo physical association between GroEL and σ(32) in E. coli at physiological temperature. This study further reveals that neither DnaK nor GroEL singly can modulate σ(32) stability in vivo; there is an ordered network between them, where GroEL acts upstream of DnaK.

  3. Non-Lethal Heat Shock of the Asian Green Mussel, Perna viridis, Promotes Hsp70 Synthesis, Induces Thermotolerance and Protects Against Vibrio Infection.

    Science.gov (United States)

    Aleng, Nor Afiqah; Sung, Yeong Yik; MacRae, Thomas H; Abd Wahid, Mohd Effendy

    2015-01-01

    Mild heat stress promotes thermotolerance and protection against several different stresses in aquatic animals, consequences correlated with the accumulation of heat shock protein 70 (Hsp70). The purpose of this study was to determine if non-lethal heat shock (NLHS) of the Asian green mussel, Perna viridis, an aquatic species of commercial value, promoted the production of Hsp70 and enhanced its resistance to stresses. Initially, the LT50 and LHT for P. viridis were determined to be 42°C and 44°C, respectively, with no heat shock induced death of mussels at 40°C or less. Immunoprobing of western blots revealed augmentation of constitutive (PvHsp70-1) and inducible (PvHsp70-2) Hsp70 in tissue from adductor muscle, foot, gill and mantel of P. viridis exposed to 38°C for 30 min followed by 6 h recovery, NLHS conditions for this organism. Characterization by liquid chromatography-tandem mass spectrometry (LC-MS/MS) revealed that PvHsp70-1 and PvHsp70-2 respectively corresponded most closely to Hsp70 from P. viridis and Mytilus galloprovincialis. Priming of adult mussels with NLHS promoted thermotolerance and increased resistance to V. alginolyticus. The induction of Hsp70 in parallel with enhanced thermotolerance and improved protection against V. alginolyticus, suggests Hsp70 functions in P. viridis as a molecular chaperone and as a stimulator of the immune system.

  4. Non-Lethal Heat Shock of the Asian Green Mussel, Perna viridis, Promotes Hsp70 Synthesis, Induces Thermotolerance and Protects Against Vibrio Infection.

    Directory of Open Access Journals (Sweden)

    Nor Afiqah Aleng

    Full Text Available Mild heat stress promotes thermotolerance and protection against several different stresses in aquatic animals, consequences correlated with the accumulation of heat shock protein 70 (Hsp70. The purpose of this study was to determine if non-lethal heat shock (NLHS of the Asian green mussel, Perna viridis, an aquatic species of commercial value, promoted the production of Hsp70 and enhanced its resistance to stresses. Initially, the LT50 and LHT for P. viridis were determined to be 42°C and 44°C, respectively, with no heat shock induced death of mussels at 40°C or less. Immunoprobing of western blots revealed augmentation of constitutive (PvHsp70-1 and inducible (PvHsp70-2 Hsp70 in tissue from adductor muscle, foot, gill and mantel of P. viridis exposed to 38°C for 30 min followed by 6 h recovery, NLHS conditions for this organism. Characterization by liquid chromatography-tandem mass spectrometry (LC-MS/MS revealed that PvHsp70-1 and PvHsp70-2 respectively corresponded most closely to Hsp70 from P. viridis and Mytilus galloprovincialis. Priming of adult mussels with NLHS promoted thermotolerance and increased resistance to V. alginolyticus. The induction of Hsp70 in parallel with enhanced thermotolerance and improved protection against V. alginolyticus, suggests Hsp70 functions in P. viridis as a molecular chaperone and as a stimulator of the immune system.

  5. Effect of short-term pre-hatch heat shock of incubating eggs on ...

    African Journals Online (AJOL)

    Effect of short-term pre-hatch heat shock of incubating eggs on subsequent. ... of thermal conditioning of broiler chickens during embryonic development on subsequent ... Keywords: Heat stress, incubation, parent age, live weight, mortality

  6. Magnetogasdynamic Cylindrical Shock Waves in a Rotating Nonideal Gas with Radiation Heat Flux

    Science.gov (United States)

    Vishwakarma, J. P.; Patel, Nanhey

    2015-03-01

    A similarity solution is presented for a cylindrical magnetogasdynamic shock wave in a rotating nonideal gas in the presence of a variable axial magnetic field in the case where the radiation heat flux is of importance. The initial angular velocity of the medium is assumed to vary as some power of the distance from the symmetry axis. The radiation heat flux is evaluated from the equation of motion without explicit use of the radiation transfer equations. It is shown that the gas nonidealness increases the shock strength but decreases the shock velocity. On the other hand, the presence of a magnetic field decreases the shock strength but increases the shock velocity. Moreover, the shock velocity increases with the ratio of specific heats. The total energy of the shock wave increases with time.

  7. Inhibiting heat-shock protein 90 reverses sensory hypoalgesia in diabetic mice

    Directory of Open Access Journals (Sweden)

    Brian S J Blagg

    2010-08-01

    Full Text Available Increasing the expression of Hsp70 (heat-shock protein 70 can inhibit sensory neuron degeneration after axotomy. Since the onset of DPN (diabetic peripheral neuropathy is associated with the gradual decline of sensory neuron function, we evaluated whether increasing Hsp70 was sufficient to improve several indices of neuronal function. Hsp90 is the master regulator of the heat-shock response and its inhibition can up-regulate Hsp70. KU-32 (N-{7-[(2R,3R,4S,5R-3,4-dihydroxy-5-methoxy-6,6-dimethyl-tetrahydro-2H-pyran-2-yloxy]-8-methyl-2-oxo-2H-chromen-3-yl}acetamide was developed as a novel, novobiocin-based, C-terminal inhibitor of Hsp90 whose ability to increase Hsp70 expression is linked to the presence of an acetamide substitution of the prenylated benzamide moiety of novobiocin. KU-32 protected against glucose-induced death of embryonic DRG (dorsal root ganglia neurons cultured for 3 days in vitro. Similarly, KU-32 significantly decreased neuregulin 1-induced degeneration of myelinated Schwann cell DRG neuron co-cultures prepared from WT (wild-type mice. This protection was lost if the co-cultures were prepared from Hsp70.1 and Hsp70.3 KO (knockout mice. KU-32 is readily bioavailable and was administered once a week for 6 weeks at a dose of 20 mg/kg to WT and Hsp70 KO mice that had been rendered diabetic with streptozotocin for 12 weeks. After 12 weeks of diabetes, both WT and Hsp70 KO mice developed deficits in NCV (nerve conduction velocity and a sensory hypoalgesia. Although KU-32 did not improve glucose levels, HbA1c (glycated haemoglobin or insulin levels, it reversed the NCV and sensory deficits in WT but not Hsp70 KO mice. These studies provide the first evidence that targeting molecular chaperones reverses the sensory hypoalgesia associated with DPN.

  8. Inhibiting heat-shock protein 90 reverses sensory hypoalgesia in diabetic mice.

    Science.gov (United States)

    Urban, Michael J; Li, Chengyuan; Yu, Cuijuan; Lu, Yuanming; Krise, Joanna M; McIntosh, Michelle P; Rajewski, Roger A; Blagg, Brian S J; Dobrowsky, Rick T

    2010-08-11

    Increasing the expression of Hsp70 (heat-shock protein 70) can inhibit sensory neuron degeneration after axotomy. Since the onset of DPN (diabetic peripheral neuropathy) is associated with the gradual decline of sensory neuron function, we evaluated whether increasing Hsp70 was sufficient to improve several indices of neuronal function. Hsp90 is the master regulator of the heat-shock response and its inhibition can up-regulate Hsp70. KU-32 (N-{7-[(2R,3R,4S,5R)-3,4-dihydroxy-5-methoxy-6,6-dimethyl-tetrahydro-2H-pyran-2-yloxy]-8-methyl-2-oxo-2H-chromen-3-yl}acetamide) was developed as a novel, novobiocin-based, C-terminal inhibitor of Hsp90 whose ability to increase Hsp70 expression is linked to the presence of an acetamide substitution of the prenylated benzamide moiety of novobiocin. KU-32 protected against glucose-induced death of embryonic DRG (dorsal root ganglia) neurons cultured for 3 days in vitro. Similarly, KU-32 significantly decreased neuregulin 1-induced degeneration of myelinated Schwann cell DRG neuron co-cultures prepared from WT (wild-type) mice. This protection was lost if the co-cultures were prepared from Hsp70.1 and Hsp70.3 KO (knockout) mice. KU-32 is readily bioavailable and was administered once a week for 6 weeks at a dose of 20 mg/kg to WT and Hsp70 KO mice that had been rendered diabetic with streptozotocin for 12 weeks. After 12 weeks of diabetes, both WT and Hsp70 KO mice developed deficits in NCV (nerve conduction velocity) and a sensory hypoalgesia. Although KU-32 did not improve glucose levels, HbA1c (glycated haemoglobin) or insulin levels, it reversed the NCV and sensory deficits in WT but not Hsp70 KO mice. These studies provide the first evidence that targeting molecular chaperones reverses the sensory hypoalgesia associated with DPN.

  9. The small heat shock protein p26 aids development of encysting Artemia embryos, prevents spontaneous diapause termination and protects against stress.

    Science.gov (United States)

    King, Allison M; MacRae, Thomas H

    2012-01-01

    Artemia franciscana embryos enter diapause as encysted gastrulae, a physiological state of metabolic dormancy and enhanced stress resistance. The objective of this study was to use RNAi to investigate the function of p26, an abundant, diapause-specific small heat shock protein, in the development and behavior of encysted Artemia embryos (cysts). RNAi methodology was developed where injection of Artemia females with dsRNA specifically eliminated p26 from cysts. p26 mRNA and protein knock down were, respectively, confirmed by RT-PCR and immuno-probing of western blots. ArHsp21 and ArHsp22, diapause-related small heat shock proteins in Artemia cysts sharing a conserved α-crystallin domain with p26, were unaffected by injection of females with dsRNA for p26, demonstrating the specificity of protein knock down. Elimination of p26 delayed cyst release from females demonstrating that this molecular chaperone influences the development of diapause-destined embryos. Although development was slowed the metabolic activities of cysts either containing or lacking p26 were similar. p26 inhibited diapause termination after prolonged incubation of cysts in sea water perhaps by a direct effect on termination or indirectly because p26 is necessary for the preservation of diapause maintenance. Cyst diapause was however, terminated by desiccation and freezing, a procedure leading to high mortality within cyst populations lacking p26 and indicating the protein is required for stress tolerance. Cysts lacking p26 were also less resistant to heat shock. This is the first in vivo study to show that knock down of a small heat shock protein slows the development of diapause-destined embryos, suggesting a role for p26 in the developmental process. The same small heat shock protein prevents spontaneous termination of diapause and provides stress protection to encysted embryos.

  10. The small heat shock protein p26 aids development of encysting Artemia embryos, prevents spontaneous diapause termination and protects against stress.

    Directory of Open Access Journals (Sweden)

    Allison M King

    Full Text Available Artemia franciscana embryos enter diapause as encysted gastrulae, a physiological state of metabolic dormancy and enhanced stress resistance. The objective of this study was to use RNAi to investigate the function of p26, an abundant, diapause-specific small heat shock protein, in the development and behavior of encysted Artemia embryos (cysts. RNAi methodology was developed where injection of Artemia females with dsRNA specifically eliminated p26 from cysts. p26 mRNA and protein knock down were, respectively, confirmed by RT-PCR and immuno-probing of western blots. ArHsp21 and ArHsp22, diapause-related small heat shock proteins in Artemia cysts sharing a conserved α-crystallin domain with p26, were unaffected by injection of females with dsRNA for p26, demonstrating the specificity of protein knock down. Elimination of p26 delayed cyst release from females demonstrating that this molecular chaperone influences the development of diapause-destined embryos. Although development was slowed the metabolic activities of cysts either containing or lacking p26 were similar. p26 inhibited diapause termination after prolonged incubation of cysts in sea water perhaps by a direct effect on termination or indirectly because p26 is necessary for the preservation of diapause maintenance. Cyst diapause was however, terminated by desiccation and freezing, a procedure leading to high mortality within cyst populations lacking p26 and indicating the protein is required for stress tolerance. Cysts lacking p26 were also less resistant to heat shock. This is the first in vivo study to show that knock down of a small heat shock protein slows the development of diapause-destined embryos, suggesting a role for p26 in the developmental process. The same small heat shock protein prevents spontaneous termination of diapause and provides stress protection to encysted embryos.

  11. 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.

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

    Directory of Open Access Journals (Sweden)

    P. C. Giraldo

    1999-01-01

    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.

  13. Acquired Thermotolerance and Heat Shock Proteins in Thermophiles from the Three Phylogenetic Domains

    DEFF Research Database (Denmark)

    Trent, Jonathan D.; Gabrielsen, Mette; Jensen, Bo;

    1994-01-01

    Thermophilic organisms from each of the three phylogenetic domains (Bacteria, Archaea, and Eucarya) acquired thermotolerance after heat shock. Bacillus caldolyticus grown at 60 degrees C and heat shocked at 69 degrees C for 10 min showed thermotolerance at 74 degrees C, Sulfolobus shibatae grown...

  14. Proteomic Analysis of Trypanosoma cruzi Epimastigotes Subjected to Heat Shock

    Directory of Open Access Journals (Sweden)

    Deyanira Pérez-Morales

    2012-01-01

    Full Text Available Trypanosoma cruzi is exposed to sudden temperature changes during its life cycle. Adaptation to these variations is crucial for parasite survival, reproduction, and transmission. Some of these conditions may change the pattern of genetic expression of proteins involved in homeostasis in the course of stress treatment. In the present study, the proteome of T. cruzi epimastigotes subjected to heat shock and epimastigotes grow normally was compared by two-dimensional gel electrophoresis followed by mass spectrometry for protein identification. Twenty-four spots differing in abundance were identified. Of the twenty-four changed spots, nineteen showed a greater intensity and five a lower intensity relative to the control. Several functional categories of the identified proteins were determined: metabolism, cell defense, hypothetical proteins, protein fate, protein synthesis, cellular transport, and cell cycle. Proteins involved in the interaction with the cellular environment were also identified, and the implications of these changes are discussed.

  15. Heat Shock Protein 70 in Alzheimer’s Disease

    Directory of Open Access Journals (Sweden)

    Rui-Chun Lu

    2014-01-01

    Full Text Available Alzheimer’s disease (AD is the most common neurodegenerative disease that caused dementia which has no effective treatment. Growing evidence has demonstrated that AD is a “protein misfolding disorder” that exhibits common features of misfolded, aggregation-prone proteins and selective cell loss in the mature nervous system. Heat shock protein 70 (HSP70 attracts extensive attention worldwide, because it plays a crucial role in preventing protein misfolding and inhibiting aggregation and represents a class of proteins potentially involved in AD pathogenesis. Numerous studies have indicated that HSP70 could suppress the progression of AD with in vitro and in vivo experiments. Thus, targeting HSP70 and the related compounds might represent a promising strategy for the treatment of AD.

  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. Induction of Heat Shock Protein 70 Ameliorates Ultraviolet-Induced Photokeratitis in Mice

    Directory of Open Access Journals (Sweden)

    Yukihiro Horie

    2013-01-01

    Full Text Available Acute ultraviolet (UV B exposure causes photokeratitis and induces apoptosis in corneal cells. Geranylgeranylacetone (GGA is an acyclic polyisoprenoid that induces expression of heat shock protein (HSP70, a soluble intracellular chaperone protein expressed in various tissues, protecting cells against stress conditions. We examined whether induction of HSP70 has therapeutic effects on UV-photokeratitis in mice. C57 BL/6 mice were divided into four groups, GGA-treated (500 mg/kg/mouse and UVB-exposed (400 mJ/cm2, GGA-untreated UVB-exposed (400 mJ/cm2, GGA-treated (500 mg/kg/mouse but not exposed and naive controls. Eyeballs were collected 24 h after irradiation, and corneas were stained with hematoxylin and eosin (H&E and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL. HSP70, reactive oxygen species (ROS production, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB and protein kinase B (Akt expression were also evaluated. Irradiated corneal epithelium was significantly thicker in the eyes of mice treated with GGA compared with those given the vehicle alone (p < 0.01. Significantly fewer TUNEL-positive cells were observed in the eyes of GGA-treated mice than controls after irradiation (p < 0.01. Corneal HSP70 levels were significantly elevated in corneas of mice treated with GGA (p < 0.05. ROS signal was not affected by GGA. NF-κB activation was reduced but phospho-(Ser/Ther Akt substrate expression was increased in corneas after irradiation when treated with GGA. GGA-treatment induced HSP70 expression and ameliorated UV-induced corneal damage through the reduced NF-κB activation and possibly increased Akt phosphorilation.

  18. Increased heat shock protein 70 expression in the pancreas of rats with endotoxic shock

    Institute of Scientific and Technical Information of China (English)

    Xue-Lian Wang; Ying Li; Jin-Song Kuang; Yue Zhao; Pei Liu

    2006-01-01

    AIM: To investigate the ultra-structural changes and heat shock protein 70 (HSP70) expression in the pancreas of rats with endotoxic shock and to detect their possible relationship.METHODS: A total of 33 Wistar rats were randomly divided into three groups: control group (given normal saline), small dose lipopolysaccharide (LPS) group (given LPS 5 mg/kg) and large dose LPS group (given LPS 10mg/kg). Pancreas was explanted to detect the ultrastructural changes by TEM and the HSP70 expression by immunohistochemistry and Western blot.RESULTS: Rats given small doses of LPS showed swelling and loss of mitochondrial cristae of acinar cells and increased number of autophagic vacuoles in the cytoplasm of acinar cells. Rats given large doses of LPS showed swelling, vacuolization, and obvious myeloid changes of mitochondrial cristae of acinar cells, increased number of autophagic vacuoles in the cytoplasm of acinar cells. HSP70 expression was increased compared to the control group (P<0.05).CONCLUSION: Small doses of LPS may induce stronger expression of HSP70, promote autophagocytosis and ameliorate ultra-structural injuries.

  19. Characterization of Mutants of Human Small Heat Shock Protein HspB1 Carrying Replacements in the N-Terminal Domain and Associated with Hereditary Motor Neuron Diseases.

    Directory of Open Access Journals (Sweden)

    Lydia K Muranova

    Full Text Available Physico-chemical properties of the mutations G34R, P39L and E41K in the N-terminal domain of human heat shock protein B1 (HspB1, which have been associated with hereditary motor neuron neuropathy, were analyzed. Heat-induced aggregation of all mutants started at lower temperatures than for the wild type protein. All mutations decreased susceptibility of the N- and C-terminal parts of HspB1 to chymotrypsinolysis. All mutants formed stable homooligomers with a slightly larger apparent molecular weight compared to the wild type protein. All mutations analyzed decreased or completely prevented phosphorylation-induced dissociation of HspB1 oligomers. When mixed with HspB6 and heated, all mutants yielded heterooligomers with apparent molecular weights close to ~400 kDa. Finally, the three HspB1 mutants possessed lower chaperone-like activity towards model substrates (lysozyme, malate dehydrogenase and insulin compared to the wild type protein, conversely the environmental probe bis-ANS yielded higher fluorescence with the mutants than with the wild type protein. Thus, in vitro the analyzed N-terminal mutations increase stability of large HspB1 homooligomers, prevent their phosphorylation-dependent dissociation, modulate their interaction with HspB6 and decrease their chaperoning capacity, preventing normal functioning of HspB1.

  20. Chlamydia trachomatis responds to heat shock, penicillin induced persistence, and IFN-gamma persistence by altering levels of the extracytoplasmic stress response protease HtrA

    Directory of Open Access Journals (Sweden)

    Mathews Sarah A

    2008-11-01

    Full Text Available Abstract Background Chlamydia trachomatis, an obligate intracellular human pathogen, is the most prevalent bacterial sexually transmitted infection worldwide and a leading cause of preventable blindness. HtrA is a virulence and stress response periplasmic serine protease and molecular chaperone found in many bacteria. Recombinant purified C. trachomatis HtrA has been previously shown to have both activities. This investigation examined the physiological role of Chlamydia trachomatis HtrA. Results The Chlamydia trachomatis htrA gene complemented the lethal high temperature phenotype of Escherichia coli htrA- (>42°C. HtrA levels were detected to increase by western blot and immunofluorescence during Chlamydia heat shock experiments. Confocal laser scanning microscopy revealed a likely periplasmic localisation of HtrA. During penicillin induced persistence of Chlamydia trachomatis, HtrA levels (as a ratio of LPS were initially less than control acute cultures (20 h post infection but increased to more than acute cultures at 44 h post infection. This was unlike IFN-γ persistence where lower levels of HtrA were observed, suggesting Chlamydia trachomatis IFN-γ persistence does not involve a broad stress response. Conclusion The heterologous heat shock protection for Escherichia coli, and increased HtrA during cell wall disruption via penicillin and heat shock, indicates an important role for HtrA during high protein stress conditions for Chlamydia trachomatis.

  1. 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.

  2. Previous heat shock treatment inhibits Mayaro virus replication in human lung adenocarcinoma (A549) cells.

    Science.gov (United States)

    Virgilio, P L; Godinho-Netto, M C; Carvalho Mda, G

    1997-01-01

    Human lung adenocarcinoma cells (A549) were submitted to mild or severe heat shock (42 degrees C or 44 degrees C) for 1 h, while another group of cells was double-heat-shocked (submitted to 42 degrees C for 1 h, returned to 37 degrees C for 3 h, then exposed to 44 degrees C for 1 h). After each heat treatment, the cells were infected with Mayaro virus for 24 h and incubated at 37 degrees C. The results showed that the double-heat-shocked thermotolerant cells exhibited a 10(4)-fold virus titre inhibition, despite the recovery of protein synthesis and original morphology 24 h post-infection. In contrast, cells submitted to mild or severe heat shock exhibited weaker inhibition of Mayaro virus titre (10(2)-fold). The mildly heat-shocked cells also presented a full recovery in protein synthesis, which was not observed in severely heat-shocked cells. These results indicate that exposure of A549 cells to a mild or to a double heat shock treatment before Mayaro virus infection induces an antiviral state.

  3. 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

    of 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...

  4. The Role of Co-chaperones in Synaptic Proteostasis and Neurodegenerative Disease

    Directory of Open Access Journals (Sweden)

    Erica L. Gorenberg

    2017-05-01

    Full Text Available Synapses must be preserved throughout an organism's lifespan to allow for normal brain function and behavior. Synapse maintenance is challenging given the long distances between the termini and the cell body, reliance on axonal transport for delivery of newly synthesized presynaptic proteins, and high rates of synaptic vesicle exo- and endocytosis. Hence, synapses rely on efficient proteostasis mechanisms to preserve their structure and function. To this end, the synaptic compartment has specific chaperones to support its functions. Without proper synaptic chaperone activity, local proteostasis imbalances lead to neurotransmission deficits, dismantling of synapses, and neurodegeneration. In this review, we address the roles of four synaptic chaperones in the maintenance of the nerve terminal, as well as their genetic links to neurodegenerative disease. Three of these are Hsp40 co-chaperones (DNAJs: Cysteine String Protein alpha (CSPα; DNAJC5, auxilin (DNAJC6, and Receptor-Mediated Endocytosis 8 (RME-8; DNAJC13. These co-chaperones contain a conserved J domain through which they form a complex with heat shock cognate 70 (Hsc70, enhancing the chaperone's ATPase activity. CSPα is a synaptic vesicle protein known to chaperone the t-SNARE SNAP-25 and the endocytic GTPase dynamin-1, thereby regulating synaptic vesicle exocytosis and endocytosis. Auxilin binds assembled clathrin cages, and through its interactions with Hsc70 leads to the uncoating of clathrin-coated vesicles, a process necessary for the regeneration of synaptic vesicles. RME-8 is a co-chaperone on endosomes and may have a role in clathrin-coated vesicle endocytosis on this organelle. These three co-chaperones maintain client function by preserving folding and assembly to prevent client aggregation, but they do not break down aggregates that have already formed. The fourth synaptic chaperone we will discuss is Heat shock protein 110 (Hsp110, which interacts with Hsc70, DNAJAs, and

  5. Tissue-type-specific heat-shock response and immunolocalization of class I low-molecular-weight heat-shock proteins in soybean

    Energy Technology Data Exchange (ETDEWEB)

    Tsung-Luo Jinn; Pi-Fang Linda Chang; Yih-Ming Chen [National Taiwan Univ. (China)] [and others

    1997-06-01

    A monospecific polyclonal antibody was used to study the tissue-type specificity and intracellular localization of class I low-molecular-weight (LMW) heat-shock proteins (HSPs) in soybean (Glycine max) under different heat-shock regimes. In etiolated soy-bean seedlings, the root meristematic regions contained the highest levels of LMW HSP. No tissue-type-specific expression of class I LMW HSP was detected using the tissue-printing method. In immunolocalization studies of seedlings treated with HS (40{degrees}C for 2 h) the class I LMW HSPs were found in the aggregated granular structures, which were distributed randomly in the cytoplasm and in the nucleus. When the heat shock was released, the granular structures disappeared and the class I LMW HSPs became distributed homogeneously in the cytoplasm. When the seedlings were then given a more severe heat shock following the initial 40{degrees}C {yields} 28{degrees}C treatment, a large proportion of the class I LMW HSPs that originally localized in the cytoplasm were translocated into the nucleus and nucleolus. Class I LMW HSPs may assist in the resolubilization of proteins denatured or aggregated by heat and may also participate in the restoration of organellar function after heat shock.

  6. Progress in research on insect small heat shock proteins%昆虫小分子量热激蛋白的研究进展

    Institute of Scientific and Technical Information of China (English)

    陆明星; 徐静; 杜予州

    2015-01-01

    昆虫小分子量热激蛋白(Small heat shock proteins, sHSPs)是最早被发现的热激蛋白,但是有关它们的研究相对较少。本文对昆虫小分子量热激蛋白的最新研究成果进行了总结,旨在引起人们对该类蛋白的关注,以便进一步研究其功能,探讨其可能的应用前景。目前研究表明:昆虫小分子量热激蛋白是其所有热激蛋白中最不保守的家族。同时,它们通常拥有一个α-晶状体结构域;分子量范围一般在12~43 ku;具有分子伴侣的活性。每种昆虫体内拥有多种sHSPs,而且其功能也各不相同。这些热激蛋白在昆虫的生长发育、生殖以及滞育等重要生命活动中起着重要的作用;同时在抵御不良环境以及适应性进化中也具有重要意义。随着研究的深入,还将会有更多的昆虫sHSPs被鉴定,它们更多的功能也将被逐渐发掘。%Insect small heat shock proteins are an infrequently studied part of the superfamily of heat shock proteins. This article summarizes the latest research on these proteins and also discusses prospects for further research on their functions and possible applications. Current research demonstrates that insect small heat shock proteins are the most poorly conserved family of insect heat shock proteins. However, they usually have a conservedα-crystallin domain, a small molecular mass of 12-43 ku, and act as molecular chaperones. All insects possess many kinds of small heat shock proteins with diverse functions that play important roles in insects’ development, reproduction and diapause. They also have a strong influence on insects’ ability to withstand adverse environmental conditions and adaptive evolution. With further in-depth research, more and more insect small heat shock proteins and their functions will be identified.

  7. 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,

  8. The pertinence of expression of heat shock proteins (HSPs) to the efficacy of cryopreservation in HELAs.

    Science.gov (United States)

    Wang, Peitao; Shu, Zhiquan; He, Liqun; Cui, Xiangdong; Wang, Yuzhen; Gao, Dayong

    2005-01-01

    HELAs (Hela cells, passed cells of human cervical carcinoma) were heat or cold treated (named heat or cold shock) and then resumed normal culture for 2, 4 or 8 hours respectively. The expressions of heat shock protein 70 (HSP70) and 90 (HSP90) of the HELAs were measured by Northern and Western blotting. HELAs after 4-hour culture were exposed to or cryopreserved with different concentration of dimethyl sulfoxide (Me2SO, 2.5%, 5%, 10%, 15% and 20% respectively, V/V). Meanwhile, the HELAs after different culture time (2, 4 and 6 hours of culture) were cryopreserved with 5% Me2SO. After exposure or cryopreservation, the number of live HELAs was counted and the survival rate was calculated. The results showed that heat shock increased the expression of HSP70 and HSP90 of HELAs, while cold shock decreased the expression of the two proteins. When the concentrations of Me2SO were 10%, 15% and 20%, the survival rates of HELAs after exposure to Me2SO or cryopreservation were much lower than those when the concentrations were small. The survival rates of the heat shocked HELAs were significantly higher than those of the cold shocked and control HELAs. After cryopreservation with 5% Me2SO, the survival rate of heat shocked HELAs group with 2 hours culture time was the lowest among all the groups of HELAs with different cultural time. From the results of this study, we conclude that the expressions of HSP70 and HSP90 in HELAs increased significantly after heat shock, while cold shock decreased the expressions of these two proteins. The over-expressions of HSPs in the heat shocked HELAs could protect the cells from both injury caused by potential toxicity of high concentrations of Me2SO and cryoinjury caused by the freeze-thawing/cryopreservation procedure.

  9. BH3-only protein BIM mediates heat shock-induced apoptosis.

    Science.gov (United States)

    Mahajan, Indra M; Chen, Miao-Der; Muro, Israel; Robertson, John D; Wright, Casey W; Bratton, Shawn B

    2014-01-01

    Acute heat shock can induce apoptosis through a canonical pathway involving the upstream activation of caspase-2, followed by BID cleavage and stimulation of the intrinsic pathway. Herein, we report that the BH3-only protein BIM, rather than BID, is essential to heat shock-induced cell death. We observed that BIM-deficient cells were highly resistant to heat shock, exhibiting short and long-term survival equivalent to Bax(-/-)Bak(-/-) cells and better than either Bid(-/-) or dominant-negative caspase-9-expressing cells. Only Bim(-/-) and Bax(-/-)Bak(-/-) cells exhibited resistance to mitochondrial outer membrane permeabilization and loss of mitochondrial inner membrane potential. Moreover, while dimerized caspase-2 failed to induce apoptosis in Bid(-/-) cells, it readily did so in Bim(-/-) cells, implying that caspase-2 kills exclusively through BID, not BIM. Finally, BIM reportedly associates with MCL-1 following heat shock, and Mcl-1(-/-) cells were indeed sensitized to heat shock-induced apoptosis. However, pharmacological inhibition of BCL-2 and BCL-X(L) with ABT-737 also sensitized cells to heat shock, most likely through liberation of BIM. Thus, BIM mediates heat shock-induced apoptosis through a BAX/BAK-dependent pathway that is antagonized by antiapoptotic BCL-2 family members.

  10. The Entamoeba histolytica methylated LINE-binding protein EhMLBP provides protection against heat shock.

    Science.gov (United States)

    Katz, Sophia; Kushnir, Oded; Tovy, Ayala; Siman Tov, Rama; Ankri, Serge

    2012-01-01

    Adaptation to environmental stress is a key process that allows the unicellular parasite Entamoeba histolytica to survive in its human host. We previously characterized EhMLBP as an essential protein for the growth and the virulence of the parasite. EhMLBP binds to methylated repetitive DNA, and is one of the core proteins of the parasite's epigenetic machinery. Here, we show that EhMLBP and heat shock proteins have common properties. EhMLBP is induced by heat shock and its expression is regulated by a heat shock element binding site that is located in its 5' non-coding region. Following heat shock, the perinuclear localization of EhMLBP in control trophozoites is replaced by an even distribution within the nucleus alongside with an enhanced recruitment of EhMLBP to the reverse transcriptase of a long interspersed nucleotide element (LINE) DNA. Constitutive overexpression of EhMLBP protects trophozoites against heat shock and reduces protein aggregation. This protective function is lost in trophozoites that overexpress a mutated form of EhMLBP which is devoid of its heat shock domain. To the best of our knowledge, this is the first report of a methyl DNA-binding protein that plays a protective role against heat shock.

  11. 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

  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

    2012-12-07

    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.

  13. Different contributions of HtrA protease and chaperone activities to Campylobacter jejuni stress tolerance and physiology

    DEFF Research Database (Denmark)

    Bæk, Kristoffer Torbjørn; Vegge, Christina Skovgaard; Skórko-Glonek, Joanna;

    2011-01-01

    The microaerophilic bacterium Campylobacter jejuni is the most common cause of bacterial food-borne infections in the developed world. Tolerance to environmental stress relies on proteases and chaperones in the cell envelope such as HtrA and SurA. HtrA displays both chaperone and protease activity......, but little is known about how each of these activities contributes to stress tolerance in bacteria. In vitro experiments showed temperature dependent protease and chaperone activities of C. jejuni HtrA. A C. jejuni mutant lacking only the protease activity of HtrA was used to show that the HtrA chaperone...... activity is sufficient for growth at high temperature or oxidative stress, whereas the HtrA protease activity is only essential at conditions close to the growth limit for C. jejuni. However, the protease activity was required to prevent induction of the cytoplasmic heat-shock response even at optimal...

  14. 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

  15. Heat Shock Induction of Manganese Peroxidase Gene Transcription in Phanerochaete chrysosporium

    OpenAIRE

    Brown, Julie A.; Li, Dan; Alic, Margaret; Gold, Michael H.

    1993-01-01

    The expression of manganese peroxidase (MnP) in nitrogen-limited cultures of Phanerochaete chrysosporium is regulated by heat shock at the level of gene transcription. Nitrogen limitation and manganous ion [Mn(II)] previously have been shown to regulate mnp gene transcription. Northern (RNA) blot analysis demonstrates that 45°C heat shock results in the accumulation of mnp mRNA, even in cells grown in the absence of Mn. Heat shock induces mnp gene transcription in 4- or 5-day-old cells, and m...

  16. Role of TRP channels in the induction of heat shock proteins (Hsps) by heating skin.

    Science.gov (United States)

    Hsu, Wen-Li; Yoshioka, Tohru

    2015-01-01

    Transient receptor potential (TRP) channels in skin are crucial for achieving temperature sensitivity to maintain internal temperature balance and thermal homeostasis, as well as to protect skin cells from environmental stresses such as infrared (IR) or near-infrared (NIR) radiation via heat shock protein (Hsp) production. However, the mechanisms by which IR and NIR activate TRP channels and produce Hsps intracellularly have been independently reported. In this review, we discuss the relationship between TRP channel activation and Hsp production, and introduce the roles of several skin TRP channels in the regulation of HSP production by IR and NIR exposure.

  17. Effect of methylglyoxal modification on the structure and properties of human small heat shock protein HspB6 (Hsp20).

    Science.gov (United States)

    Muranova, Lydia K; Perfilov, Maxim M; Serebryakova, Marina V; Gusev, Nikolai B

    2016-07-01

    Human small heat shock protein HspB6 (Hsp20) was modified by metabolic α-dicarbonyl compound methylglyoxal (MGO). At low MGO/HspB6 molar ratio, Arg13, Arg14, Arg27, and Arg102 were the primary sites of MGO modification. At high MGO/HspB6 ratio, practically, all Arg and Lys residues of HspB6 were modified. Both mild and extensive MGO modification decreased susceptibility of HspB6 to trypsinolysis and prevented its heat-induced aggregation. Modification by MGO was accompanied by formation of small quantities of chemically crosslinked dimers and did not dramatically affect quaternary structure of HspB6. Mild modification by MGO did not affect whereas extensive modification decreased interaction of HspB6 with HspB1. Phosphorylation of HspB6 by cyclic adenosine monophosphate (cAMP)-dependent protein kinase was inhibited after mild modification and completely prevented after extensive modification by MGO. Chaperone-like activity of HspB6 measured with subfragment 1 of skeletal myosin was enhanced after MGO modifications. It is concluded that Arg residues located in the N-terminal domain of HspB6 are easily accessible to MGO modification and that even mild modification by MGO affects susceptibility to trypsinolysis, phosphorylation by cAMP-dependent protein kinase, and chaperone-like activity of HspB6.

  18. Redox regulation of heat shock protein expression in aging and neurodegenerative disorders associated with oxidative stress: a nutritional approach.

    Science.gov (United States)

    Calabrese, V; Scapagnini, G; Colombrita, C; Ravagna, A; Pennisi, G; Giuffrida Stella, A M; Galli, F; Butterfield, D A

    2003-12-01

    Oxidative stress has been implicated in mechanisms leading to neuronal cell injury in various pathological states of the brain. Alzheimer's disease (AD) is a progressive disorder with cognitive and memory decline, speech loss, personality changes and synapse loss. Many approaches have been undertaken to understand AD, but the heterogeneity of the etiologic factors makes it difficult to define the clinically most important factor determining the onset and progression of the disease. However, increasing evidence indicates that factors such as oxidative stress and disturbed protein metabolism and their interaction in a vicious cycle are central to AD pathogenesis. Brains of AD patients undergo many changes, such as disruption of protein synthesis and degradation, classically associated with the heat shock response, which is one form of stress response. Heat shock proteins are proteins serving as molecular chaperones involved in the protection of cells from various forms of stress.Recently, the involvement of the heme oxygenase (HO) pathway in anti-degenerative mechanisms operating in AD has received considerable attention, as it has been demonstrated that the expression of HO is closely related to that of amyloid precursor protein (APP). HO induction occurs together with the induction of other HSPs during various physiopathological conditions. The vasoactive molecule carbon monoxide and the potent antioxidant bilirubin, products of HO-catalyzed reaction, represent a protective system potentially active against brain oxidative injury. Given the broad cytoprotective properties of the heat shock response there is now strong interest in discovering and developing pharmacological agents capable of inducing the heat shock response. Increasing interest has been focused on identifying dietary compounds that can inhibit, retard or reverse the multi-stage pathophysiological events underlying AD pathology. Alzheimer's disease, in fact, involves a chronic inflammatory response

  19. Heat shock protein 22 (HSPB8) limits TGF-β-stimulated migration of osteoblasts.

    Science.gov (United States)

    Yamamoto, Naohiro; Tokuda, Haruhiko; Kuroyanagi, Gen; Kainuma, Shingo; Matsushima-Nishiwaki, Rie; Fujita, Kazuhiko; Kozawa, Osamu; Otsuka, Takanobu

    2016-11-15

    Heat shock proteins (HSPs) are induced in response to various physiological and environmental conditions such as chemical and heat stress, and recognized to function as molecular chaperones. HSP22 (HSPB8), a low-molecular weight HSP, is ubiquitously expressed in many cell types. However, the precise role of HSP22 in bone metabolism remains to be clarified. In the present study, we investigated whether HSP22 is implicated in the transforming growth factor-β (TGF-β)-stimulated migration of osteoblast-like MC3T3-E1 cells. Although protein levels of HSP22 were clearly detected in unstimulated MC3T3-E1 cells, TGF-β failed to induce the protein levels. The TGF-β-stimulated migration was significantly up-regulated by knockdown of HSP22 expression. The cell migration stimulated by platelet-derived growth factor-BB was also enhanced by HSP22 knockdown. SB203580, an inhibitor of p38 mitogen-activated protein kinase, PD98059, an inhibitor of MEK1/2, or SP600125, an inhibitor of stress-activated protein kinase/c-Jun N-terminal kinase had no effects on the TGF-β-induced migration. SIS3, a specific inhibitor of TGF-β-dependent Smad3 phosphorylation, significantly reduced the migration with or without TGF-β stimulation. Smad2, Smad3, Smad4 or Smad7 was not coimmunoprecipitated with HSP22. On the other hand, the TGF-β-induced Smad2 phosphorylation was enhanced by HSP22 down-regulation. The protein levels of TGF-β type II receptor (TGF-β RII) but not TGF-β type I receptor (TGF-β RI) was significantly up-regulated in HSP22 knockdown cells compared with those in the control cells. However, the levels of TGF-β RII mRNA in HSP22 knockdown cells were little different from those of the control cells. Neither TGF-β RI nor TGF-β RII was coimmunoprecipitated with HSP22. SIS3 reduced the amplification by HSP22 knockdown of the TGF-β-stimulated cell migration almost to the basal level. Our results strongly suggest that HSP22 functions as a negative regulator in the TGF

  20. Changes in the transcriptome of morula-stage bovine embryos caused by heat shock: relationship to developmental acquisition of thermotolerance

    Directory of Open Access Journals (Sweden)

    Sakatani Miki

    2013-01-01

    Full Text Available Abstract Background While initially sensitive to heat shock, the bovine embryo gains thermal resistance as it progresses through development so that physiological heat shock has little effect on development to the blastocyst stage by Day 5 after insemination. Here, experiments using 3’ tag digital gene expression (3’DGE and real-time PCR were conducted to determine changes in the transcriptome of morula-stage bovine embryos in response to heat shock (40 degrees C for 8 h that could be associated with thermotolerance. Results Using 3’DGE, expression of 173 genes were modified by heat shock, with 94 genes upregulated by heat shock and 79 genes downregulated by heat shock. A total of 38 differentially-regulated genes were associated with the ubiquitin protein, UBC. Heat shock increased expression of one heat shock protein gene, HSPB11, and one heat shock protein binding protein, HSPBP1, tended to increase expression of HSPA1A and HSPB1, but did not affect expression of 64 other genes encoding heat shock proteins, heat shock transcription factors or proteins interacting with heat shock proteins. Moreover, heat shock increased expression of five genes associated with oxidative stress (AKR7A2, CBR1, GGH, GSTA4, and MAP2K5, decreased expression of HIF3A, but did not affect expression of 42 other genes related to free radical metabolism. Heat shock also had little effect on genes involved in embryonic development. Effects of heat shock for 2, 4 and 8 h on selected heat shock protein and antioxidant genes were also evaluated by real-time PCR. Heat shock increased steady-state amounts of mRNA for HSPA1A (PHSP90AA1 (PSOD1 or CAT. Conclusions Changes in the transcriptome of the heat-shocked bovine morula indicate that the embryo is largely resistant to effects of heat shock. As a result, transcription of genes involved in thermal protection is muted and there is little disruption of gene networks involved in embryonic development. It is likely that

  1. Loss of proteostatic control as a substrate for Atrial Fibrillation; a novel target for upstream therapy by Heat Shock Proteins

    Directory of Open Access Journals (Sweden)

    Roelien Amanda Marjolein Meijering

    2012-02-01

    Full Text Available Atrial Fibrillation (AF is the most common, sustained clinical tachyarrhythmia associated with significant morbidity and mortality. AF is a persistent condition with progressive structural remodeling of the atrial cardiomyocytes due to the AF itself, resulting in cellular changes commonly observed in ageing and in other heart diseases. While rhythm control by electrocardioversion or drug treatment is the treatment of choice in symptomatic AF patients, its effectiveness is still limited. Current research is directed at preventing new-onset AF by limiting the development of substrates underlying AF promotion and resembles mechanism-based therapy. Upstream therapy refers to the use of non-ion channel anti-arrhythmic drugs that modify the atrial substrate- or target-specific mechanisms of AF, with the ultimate aim to prevent the occurrence (primary prevention or recurrence of the arrhythmia following (spontaneous conversion (secondary prevention.Heat shock proteins (HSPs are molecular chaperones and comprise a large family of proteins involved in the protection against various forms of cellular stress. Their classical function is the conservation of proteostasis via prevention of toxic protein aggregation by binding to (partially unfolded proteins. Our recent data reveal that HSPs prevent electrical, contractile and structural remodeling of cardiomyocytes, thus attenuating the AF substrate in cellular, Drosophila melanogaster and animal experimental models. Furthermore, studies in humans suggest a protective role for HSPs against the progression from paroxysmal AF to persistent AF and in recurrence of AF. In this review, we discuss upregulation of the heat shock response system as a novel target for upstream therapy to prevent derailment of proteostasis and consequently promotion and recurrence of AF.

  2. The heat-shock response co-inducer arimoclomol protects against retinal degeneration in rhodopsin retinitis pigmentosa

    Science.gov (United States)

    Parfitt, D A; Aguila, M; McCulley, C H; Bevilacqua, D; Mendes, H F; Athanasiou, D; Novoselov, S S; Kanuga, N; Munro, P M; Coffey, P J; Kalmar, B; Greensmith, L; Cheetham, M E

    2014-01-01

    Retinitis pigmentosa (RP) is a group of inherited diseases that cause blindness due to the progressive death of rod and cone photoreceptors in the retina. There are currently no effective treatments for RP. Inherited mutations in rhodopsin, the light-sensing protein of rod photoreceptor cells, are the most common cause of autosomal-dominant RP. The majority of mutations in rhodopsin, including the common P23H substitution, lead to protein misfolding, which is a feature in many neurodegenerative disorders. Previous studies have shown that upregulating molecular chaperone expression can delay disease progression in models of neurodegeneration. Here, we have explored the potential of the heat-shock protein co-inducer arimoclomol to ameliorate rhodopsin RP. In a cell model of P23H rod opsin RP, arimoclomol reduced P23H rod opsin aggregation and improved viability of mutant rhodopsin-expressing cells. In P23H rhodopsin transgenic rat models, pharmacological potentiation of the stress response with arimoclomol improved electroretinogram responses and prolonged photoreceptor survival, as assessed by measuring outer nuclear layer thickness in the retina. Furthermore, treated animal retinae showed improved photoreceptor outer segment structure and reduced rhodopsin aggregation compared with vehicle-treated controls. The heat-shock response (HSR) was activated in P23H retinae, and this was enhanced with arimoclomol treatment. Furthermore, the unfolded protein response (UPR), which is induced in P23H transgenic rats, was also enhanced in the retinae of arimoclomol-treated animals, suggesting that arimoclomol can potentiate the UPR as well as the HSR. These data suggest that pharmacological enhancement of cellular stress responses may be a potential treatment for rhodopsin RP and that arimoclomol could benefit diseases where ER stress is a factor. PMID:24853414

  3. Heat shock proteins as gatekeepers of proteolytic pathways-Implications for age-related macular degeneration (AMD).

    Science.gov (United States)

    Kaarniranta, Kai; Salminen, Antero; Eskelinen, Eeva-Liisa; Kopitz, Jürgen

    2009-04-01

    Age-related macular degeneration (AMD) is the major diagnosis for severe and irreversible central loss of vision in elderly people in the developed countries. The loss of vision involves primarily a progressive degeneration and cell death of postmitotic retinal pigment epithelial cells (RPE), which secondarily evokes adverse effects on photoreceptor cells. The RPE cells are exposed to chronic oxidative stress from three sources: their high levels of oxygen consumption, their exposure to the high levels of lipid peroxidation derived from the photoreceptor outer segments and their exposure to constant light stimuli. Cells increase the expression of heat shock proteins (HSPs) in order to normalize their growth conditions in response to various environmental stress factors, e.g. oxidative stress. The HSPs function as molecular chaperones by preventing the accumulation of cellular cytotoxic protein aggregates and assisting in correct folding of both nascent and misfolded proteins. Increased HSPs levels are observed in the retina of AMD patients, evidence of stressed tissue. A hallmark of RPE cell aging is lysosomal lipofuscin accumulation reflecting a weakened capacity to degrade proteins in lysosomes. The presence of lipofuscin increases the misfolding of intracellular proteins, which evokes additional stress in the RPE cells. If the capacity of HSPs to repair protein damages is overwhelmed, then the proteins are mainly cleared in proteasomes or in lysosomes. In this review, we discuss the role of heat shock proteins, proteasomes, and lysosomes and autophagic processes in RPE cell proteolysis and how these might be involved in development of AMD. In addition to classical lysosomal proteolysis, we focus on the increasing evidence that, HSPs, proteasomes and autophagy regulate protein turnover in the RPE cells and thus have important roles in AMD disease.

  4. Circulating Heat Shock Protein 70 in Health, Aging and Disease

    Directory of Open Access Journals (Sweden)

    Demanet Christian

    2011-03-01

    Full Text Available Abstract Background Heat shock proteins (Hsp are ubiquitously synthesised in virtually all species and it is hypothesised that they might have beneficial health effects. Recent studies have identified circulating Hsp as an important mediator in inflammation - the effects of low-grade inflammation in the aging process are overwhelming. While much is known about intracellular Hsp70, scant data exist on circulating Hsp70 in the aging context. Therefore, the objectives of this study were to investigate the effect of age and disease on circulating Hsp70 and, in particular, to evaluate the association between circulating Hsp70 and inflammatory parameters. Results Serum Hsp70, Interleukin (IL -10, IL-6 and Tumor Necrosis Factor (TNF alpha concentrations were determined in 90 hospitalised geriatric patients (aged 83 ± 6 years and in 200 community-dwelling control subjects (100 elderly, aged 74 ± 5 years, and 100 young, aged 23 ± 3 years. In the community-dwelling elderly, serum Hsp70 and IL-10 concentrations were significantly lower and IL-6 was significantly higher when compared to healthy young control subjects. Elderly patients presenting inflammation (CRP serum levels ≥5 mg/L showed significantly (p = 0.007 higher Hsp70 values; and Hsp70 correlated positively (p Conclusions The present data provide new evidence that serum concentration of Hsp70 decreases with age in a normal population. Our study also shows that higher levels of Hsp70 are associated with inflammation and frailty in elderly patients.

  5. The Immunosuppressive Activity of Heat Shock Protein 70

    Directory of Open Access Journals (Sweden)

    Pawel Stocki

    2012-01-01

    Full Text Available Heat shock protein 70 (HSP70 has previously been described as a potent antitumour vaccine. The mechanism relied on the ability of tumour derived HSP70 to associate with antigenic peptides, which, when cross presented, elicited a T cell mediated antitumour response. Subsequently, HSP70 was incorrectly described as a potent adjuvant of innate immunity, and although mistakes in the experimental approaches were exposed and associated with endotoxin contamination in the recombinant HSP70 specimen, questions still remain regarding this matter. Here we review only publications that have cautiously addressed the endotoxin contamination problem in HSP70 in order to reveal the real immunological function of the protein. Accordingly, “endotoxin free” HSP70 stimulates macrophages and delivers antigenic peptides to APCs, which effectively prime T cells mediating an antitumour reaction. Conversely, HSP70 has potent anti-inflammatory functions as follows: regulating T cell responses, reducing stimulatory capacity of DCs, and inducing development of immunosuppressive regulatory T cells. These activities were further associated with the immune evasive mechanism of tumours and implicated in the modulation of immune reactivity in autoimmune diseases and transplant-related clinical conditions. Consequently, the role of HSP70 in immune regulation is newly emerging and contrary to what was previously anticipated.

  6. Heat-shock protein expression in canine corneal wound healing.

    Science.gov (United States)

    Peterson, Cornelia W M; Carter, Renee T; Bentley, Ellison; Murphy, Christopher J; Chandler, Heather L

    2016-05-01

    Heat-shock proteins, particularly the 70-kDa member (Hsp70), have been implicated in facilitating wound healing in multiple tissues. Expression and localization of three HSPs were assessed in normal and wounded canine corneas to elucidate a role in epithelial healing. Paraffin-embedded normal corneas, acute and repeatedly abraded corneas, and keratectomies of spontaneous chronic corneal epithelial defects (SCCEDs) were subjected to routine immunohistochemistry for Hsp27, 47, and 70 expression. Ex vivo corneal defects were created and treated with anti-HSPs or IgG controls, and wound healing was monitored. Primary cultures of canine corneal stromal fibroblasts and corneal epithelial cells were treated with exogenous Hsp70, and an artificial wound was created in vitro to monitor restoration of the monolayer. Normal canine corneas exhibited constitutive expression of all HSPs evaluated. Inducible expression was demonstrated in acutely wounded tissues, and expression in the chronically abraded corneas was relocalized. All HSP expression was below the limits of detection in the epithelium of SCCED samples. Inhibition of HSPs in culture resulted in delayed wound healing when compared to controls. Hsp70-treated fibroblasts demonstrated significantly (P healing response, and suppressed expression may contribute to the pathophysiology of nonhealing defects. © 2015 American College of Veterinary Ophthalmologists.

  7. 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.

  8. Increased heat shock protein expression after stress in Japanese quail.

    Science.gov (United States)

    Hoekstra, K A; Iwama, G K; Nichols, C R; Godin, D V; Cheng, K M

    1998-12-01

    Heat shock proteins (HSPs) have been shown to provide information on the biological impact of environmental stress to organisms, yet none have investigated the HSP response to stress in birds. Japanese quail were exposed to seven different stressors (mild restraint, loud noise, inescapable irritation, cold temperature, isolation in darkness, and two stressful social situations) and expression of HSP30, 60, 70, and 90 in heart, liver, lung, kidney and gonads was examined. Tonic Immobility (TI) tests were also conducted to assess whether the stressors increased fear response. Increased expression of HSP70 was found in the myocardial tissue of birds exposed to loud noise, inescapable irritation, cold temperature, and isolation in darkness. Increased expression of other HSPs was not apparent in the heart or any of the other all tissues examined. Longer TI was observed only in birds exposed to the noise stress. Evidence is presented that a fairly wide range of stressors caused increased expression of HSP70 in the Japanese quail myocardial tissue and that HSPs may provide useful biomarkers for the study of environmental stress in birds.

  9. Gene expression profiles of cytosolic heat shock proteins Hsp70 and Hsp90 from symbiotic dinoflagellates in response to thermal stress: possible implications for coral bleaching.

    Science.gov (United States)

    Rosic, Nedeljka N; Pernice, Mathieu; Dove, Sophie; Dunn, Simon; Hoegh-Guldberg, Ove

    2011-01-01

    Unicellular photosynthetic dinoflagellates of the genus Symbiodinium are the most common endosymbionts of reef-building scleractinian corals, living in a symbiotic partnership known to be highly susceptible to environmental changes such as hyperthermic stress. In this study, we identified members of two major heat shock proteins (HSPs) families, Hsp70 and Hsp90, in Symbiodinium sp. (clade C) with full-length sequences that showed the highest similarity and evolutionary relationship with other known HSPs from dinoflagellate protists. Regulation of HSPs gene expression was examined in samples of the scleractinian coral Acropora millepora subjected to elevated temperatures progressively over 18 h (fast) and 120 h (gradual thermal stress). Moderate to severe heat stress at 26°C and 29°C (+3°C and +6°C above average sea temperature) resulted in an increase in algal Hsp70 gene expression from 39% to 57%, while extreme heat stress (+9°C) reduced Hsp70 transcript abundance by 60% (after 18 h) and 70% (after 120 h). Elevated temperatures decreased an Hsp90 expression under both rapid and gradual heat stress scenarios. Comparable Hsp70 and Hsp90 gene expression patterns were observed in Symbiodinium cultures and in hospite, indicating their independent regulation from the host. Differential gene expression profiles observed for Hsp70 and Hsp90 suggests diverse roles of these molecular chaperones during heat stress response. Reduced expression of the Hsp90 gene under heat stress can indicate a reduced role in inhibiting the heat shock transcription factor which may lead to activation of heat-inducible genes and heat acclimation.

  10. Posttranslational modulation on the biological activities of molecular chaperones

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Molecular chaperones are a family of proteins that were first noticed to exist about 45 years ago from their increased transcription under heat shock conditions.As a result,the regulation of their encoding genes has been subject to extensive studies.Recent studies revealed that the biological activities of molecular chaperones can also be effectively modulated at the protein level.The ways of modulation so far elucidated include allosteric effect,covalent modification,protein-protein interaction,and con-formational alteration induced by such macro-environmental conditions as temperature and pH.These latter aspects were reviewed here.Emphasized here is the importance of such immediate structural alterations that lead to an immediate activity increase,providing the immediate protection needed for the cells to survive the stress conditions.

  11. Posttranslational modulation on the biological activities of molecular chaperones

    Institute of Scientific and Technical Information of China (English)

    CHANG ZengYi

    2009-01-01

    Molecular chaperones are a family of proteins that were first noticed to exist about 45 years ago from their increased transcription under heat shock conditions. As a result, the regulation of their encoding genes has been subject to extensive studies. Recent studies revealed that the biological activities of molecular chaperones can also be effectively modulated at the protein level. The ways of modulation so far elucidated include allosteric effect, covalent modification, protein-protein interaction, and con-formational alteration induced by such macro-environmental conditions as temperature and pH. These latter aspects were reviewed here. Emphasized here is the importance of such immediate structural alterations that lead to an immediate activity increase, providing the immediate protection needed for the cells to survive the stress conditions.

  12. Anti-inflammatory peptide regulates the supply of heat shock protein 70 monomers: implications for aging and age-related disease.

    Science.gov (United States)

    Cunningham, Timothy J; Greenstein, Jeffrey I; Loewenstern, Joshua; Degermentzidis, Elias; Yao, Lihua

    2015-04-01

    Reducing the levels of toxic protein aggregates has become a focus of therapy for disorders like Alzheimer's and Parkinson's diseases, as well as for the general deterioration of cells and tissues during aging. One approach has been an attempt to influence the production or activity of a class of reparative chaperones called heat shock proteins (HSPs), of which HSP70 is a promising candidate. Manipulation of HSP70 expression results in disposal of misfolded protein aggregates that accumulate in aging and disease models. Recently, HSP70 has been shown to bind specifically to an amino-terminal sequence of a human diffusible survival evasion peptide (DSEP), dermcidin. This sequence includes CHEC-9, an orally available anti-inflammatory and cell survival peptide. In the present study, we found that the CHEC-9 peptide also binds HSP70 in the cytosol of the cerebral cortex after oral delivery in normal rats. Western analysis of non-heat-denatured, unreduced samples suggested that peptide treatment increased the level of active HSP70 monomers from the pool of chaperone oligomers, a process that may be stimulated by potentiation of the chaperone's adenosine triphosphatase (ATPase). In these samples, a small but consistent gel shift was observed for glyceraldehyde 3-phosphate dehydrogenase (GAPDH), a multifunctional protein whose aggregation is influenced by HSP70. CHEC-9 treatment of an in vitro model of α-synuclein aggregation also results in HSP70-dependent dissolution of these aggregates. HSP70 oligomer-monomer equilibrium and its potential to control protein aggregate disease warrant increased experimental attention, especially if a peptide fragment of an endogenous human protein can influence the process.

  13. Mathematical modeling of heat shock protein synthesis in response to temperature change.

    Science.gov (United States)

    Szymańska, Zuzanna; Zylicz, Maciej

    2009-08-07

    One of the most important questions in cell biology is how cells cope with rapid changes in their environment. The range of common molecular responses includes a dramatic change in the pattern of gene expression and the elevated synthesis of so-called heat shock (or stress) proteins (HSPs). Induction of HSPs increases cell survival under stress conditions [Morimoto, R.I., 1993. Cells in stress: transcriptional activation of heat shock genes. Science 259, 1409-1410]. In this paper we propose a mathematical model of heat shock protein synthesis induced by an external temperature stimulus. Our model consists of a system of nine nonlinear ordinary differential equations describing the temporal evolution of the key variables involved in the regulation of HSP synthesis. Computational simulations of our model are carried out for different external temperature stimuli. We compare our model predictions with experimental data for three different cases-one corresponding to heat shock, the second corresponding to slow heating conditions and the third corresponding to a short heat shock (lasting about 40 min). We also present our model predictions for heat shocks carried out up to different final temperatures and finally we present a new hypothesis concerning the molecular response to stress that explains some phenomena observed in experiments.

  14. Heat shock suppresses mating and sperm transfer in the rice leaf folder Cnaphalocrocis medinalis.

    Science.gov (United States)

    Liao, H J; Qian, Q; Liu, X D

    2014-06-01

    Temperature is a key environmental factor in determining the population size of Cnaphalocrocis medinalis in summer. High temperatures inhibit survival, development and fecundity of this insect. However, biological responses of female and male adults to heat shock, and physiological mechanism of high temperature suppressing population development are still ambiguous. We experimentally tested the impact of heat shock (5 h day-1) on biological traits, spermatogenesis and sperm transfer of adults of C. medinalis. The result showed that heat exposure to 39 and 40 °C for 5 h reduced longevity and copulation frequency of adults, and hatchability of eggs. Immediate survival rate of males was lower than that of females after 3 days of exposure to 41 °C. The oviposition period, copulation frequency, fecundity of adults and hatchability of eggs were significantly lower when male adults were exposed to 40 or 41 °C for 3 days. Heat shock decreased frequency and success rate of mating when males were exposed, and it also resulted in postponement of mating behaviour and prolongation of mating duration as both the female and male adults were exposed. Heat shock did not affect spermatogenesis, but significantly inhibited sperms maturation. Moreover, males could not ejaculate sperm into females during copulation when these male moths received heat shock. Heat shock remarkably suppressed mating behaviour and sperm transfer, which led to a dramatic decline of rice leaf folder populations.

  15. 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......, 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 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....

  16. 壽Activation of the mitogen-activated protein kinase pathways by heat shock

    OpenAIRE

    Dorion, Sonia; Landry, Jacques

    2002-01-01

    In addition to inducing new transcriptional activities that lead within a few hours to the accumulation of heat shock proteins (Hsps), heat shock activates within minutes the major signaling transduction pathways involving mitogen-activated protein kinases, extracellular signal–regulated kinase, stress-activated protein kinase 1 (SAPK1)–c-Jun N-terminal kinase, and SAPK2-p38. These kinases are involved in both survival and death pathways in response to other stresses and may, therefore, contr...

  17. Phosphoproteome dynamics reveal heat-shock protein complexes specific to the Leishmania donovani infectious stage

    OpenAIRE

    Morales, M. A.; R. WATANABE; Dacher, M.; Chafey, P.; Osorio y Fortea, J.; Scott, D A; Beverley, S. M.; van Ommen, G.; CLOS, J.; Hem, S.; Lenormand, P.; Rousselle, J.-C.; Namane, A.; Spath, G. F.

    2010-01-01

    Leishmania is exposed to a sudden increase in environmental temperature during the infectious cycle that triggers stage differentiation and adapts the parasite phenotype to intracellular survival in the mammalian host. The absence of classical promoter-dependent mechanisms of gene regulation and constitutive expression of most of the heat-shock proteins (HSPs) in these human pathogens raise important unresolved questions as to regulation of the heat-shock response and stage-specific functions...

  18. 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.

  19. 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.

  20. Molecular Dynamics Simulations of Shocks Including Electronic Heat Conduction and Electron-Phonon Coupling

    Science.gov (United States)

    Ivanov, Dmitriy S.; Zhigilei, Leonid V.; Bringa, Eduardo M.; De Koning, Maurice; Remington, Bruce A.; Caturla, Maria Jose; Pollaine, Stephen M.

    2004-07-01

    Shocks are often simulated using the classical molecular dynamics (MD) method in which the electrons are not included explicitly and the interatomic interaction is described by an effective potential. As a result, the fast electronic heat conduction in metals and the coupling between the lattice vibrations and the electronic degrees of freedom can not be represented. Under conditions of steep temperature gradients that can form near the shock front, however, the electronic heat conduction can play an important part in redistribution of the thermal energy in the shocked target. We present the first atomistic simulation of a shock propagation including the electronic heat conduction and electron-phonon coupling. The computational model is based on the two-temperature model (TTM) that describes the time evolution of the lattice and electron temperatures by two coupled non-linear differential equations. In the combined TTM-MD method, MD substitutes the TTM equation for the lattice temperature. Simulations are performed with both MD and TTM-MD models for an EAM Al target shocked at 300 kbar. The target includes a tilt grain boundary, which provides a region where shock heating is more pronounced and, therefore, the effect of the electronic heat conduction is expected to be more important. We find that the differences between the predictions of the MD and TTM-MD simulations are significantly smaller as compared to the hydrodynamics calculations performed at similar conditions with and without electronic heat conduction.

  1. Expression of the stress-response regulators CtsR and HrcA in the uropathogen Staphylococcus saprophyticus during heat shock.

    Science.gov (United States)

    Rossi, Ciro César; de Oliveira, Lorayne Lauria; de Carvalho Rodrigues, Deivid; Ürményi, Turán Peter; Laport, Marinella Silva; Giambiagi-deMarval, Marcia

    2017-08-01

    The uropathogen Staphylococcus saprophyticus is an ubiquitous bacterium but little is known about mechanisms that allow its persistence in diverse environments. Here we evaluated S. saprophyticus growth and survival during heat shock, the expression of stress response regulators ctsR and hrcA through qRT-PCR and heat shock protein synthesis through (35)S-Met metabolic labeling. S. saprophyticus does not tolerate temperatures much higher than the optimal 37 °C, as its growth is greatly affected at 42 °C, though viability is maintained up to 48 °C. At 42 °C, the expression of ctsR and hrcA repressor genes approximately triple when compared to 37 °C and continue to increase together with temperature till 48 °C. Expression of hrcA peaks after 20 min of heat shock and decreases significantly after 30 min, indicating that heat stress response regulated by this gene may last 20-30 min. An increase in temperature is accompanied by the synthesis of at least eight proteins, three of which are likely the chaperones DnaK, GroEL and ClpB. In silico analysis indicate that the groEL gene may be regulated by HrcA, clpB by CtsR and dnaK by both repressors. This is the first work to discuss heat stress response in S. saprophyticus and a step forward in the understanding of mechanisms that make this a widespread and emergent pathogen.

  2. Transcriptional activation of heat shock protein 90 mediated via a proximal promoter region as trigger of caspofungin resistance in Aspergillus fumigatus.

    Science.gov (United States)

    Lamoth, Frédéric; Juvvadi, Praveen R; Gehrke, Christopher; Asfaw, Yohannes G; Steinbach, William J

    2014-02-01

    Invasive aspergillosis is a deadly infection for which new antifungal therapies are needed. Heat shock protein 90 (Hsp90) is an essential chaperone in Aspergillus fumigatus representing an attractive antifungal target. Using a thiamine-repressible promoter (pthiA), we showed that genetic repression of Hsp90 significantly reduced virulence in a murine model of invasive aspergillosis. Moreover, substituting the A. fumigatus hsp90 promoter with 2 artificial promoters (potef, pthiA) and the Candida albicans hsp90 promoter resulted in hypersensitivity to caspofungin and abolition of the paradoxical effect (resistance at high caspofungin concentrations). By inducing truncations in the hsp90 promoter, we identified a 100-base pair proximal sequence that triggers a significant increase of hsp90 expression (≥1.5-fold) and is essential for the paradoxical effect. Preventing this increase of hsp90 expression was sufficient to abolish the paradoxical effect and therefore optimize the antifungal activity of caspofungin.

  3. Heat shock protein 90 inhibition results in altered downstream signaling of mutant KIT and exerts synergistic effects on Kasumi-1 cells when combining with histone deacetylase inhibitor.

    Science.gov (United States)

    Yu, Wenjuan; Wang, Jianxiang; Jin, Jie; Qian, Wenbin; Qian, Jiejing; Cheng, Yizhi; Wang, Lei

    2011-09-01

    KIT mutations may be associated with a poor prognosis in t(8;21) AML. Heat shock protein 90 (Hsp90) is a molecular chaperone frequently used by cancer cells to stabilize mutant oncoproteins. Inhibition of Hsp90 by 17-allylamino-17-demethoxygeldanamycin (17-AAG) disrupted downstream signaling pathways of mutant KIT in Kasumi-1 cells. AML1-ETO fusion gene and mutated KIT act as "two-hit" factors in Kasumi-1 cells. Histone deacetylation (HDAC) inhibitors sodium phenylbutyrate (PB) and valproic acid (VPA) block AML1-ETO. Co-treatment with 17-AAG and PB or 17-AAG and VPA resulted in a synergistic effect in Kasumi-1 cells. Our results confirmed that Hsp90 and mutated KIT were valid molecular targets in the therapy of AML. Copyright © 2011 Elsevier Ltd. All rights reserved.

  4. Testis-enriched heat shock protein A2 (HSPA2): Adaptive advantages of the birds with internal testes over the mammals with testicular descent.

    Science.gov (United States)

    Padhi, Abinash; Ghaly, Mona M; Ma, Li

    2016-01-06

    The molecular chaperone heat shock protein A2 (HSPA2), a member of the 70 kDa heat shock protein (HSP70) family, plays an important role in spermatogenesis and male fertility. Although HSPA2 is evolutionarily highly conserved across the metazoan lineages, the observation of striking differences in temperature-sensitive expressions, testicular physiology, spermatogenesis, as well as its role in male fertility indicates that avian and mammalian HSPA2 may exhibit distinct evolutionary trajectory. The present study reports that while mammalian HSPA2 is constrained by intense purifying selection, avian HSPA2 has been subjected to positive selection. The majority of the positively selected amino acid residues fall on the α-helix and β-sheets of the peptide-binding domain located at the carboxyl-terminal region of the avian HSPA2. The detection of positively selected sites at the helix and β-sheets, which are less tolerant to molecular adaptation, indicates an important functional consequence and contribution to the structural and functional diversification of the avian HSPA2. Collectively, avian HSPA2 may have an adaptive advantage over the mammals in response to heat stress, and therefore, mammals with testicular descent may be at a greater risk in the event of scrotal temperature rise.

  5. Role of heat shock protein Hsp25 in the response of the orofacial nuclei motor system to physiological stress

    Science.gov (United States)

    Murashov, A. K.; Talebian, S.; Wolgemuth, D. J.

    1998-01-01

    Although expression of the small heat shock protein family member Hsp25 has been previously observed in the central nervous system (CNS), both constitutively and upon induction, its function in the CNS remains far from clear. In the present study we have characterized the spatial pattern of expression of Hsp25 in the normal adult mouse brain as well as the changes in expression patterns induced by subjecting mice to experimental hyperthermia or hypoxia. Immunohistochemical analysis revealed a surprisingly restricted pattern of constitutive expression of Hsp25 in the brain, limited to the facial, trigeminal, ambiguus, hypoglossal and vagal motor nuclei of the brainstem. After hyperthermia or hypoxia treatment, significant increases in the levels of Hsp25 were observed in these same areas and also in fibers of the facial and trigeminal nerve tracts. Immunoblot analysis of protein lysates from brainstem also showed the same pattern of induction of Hsp25. Surprisingly, no other area in the brain showed expression of Hsp25, in either control or stressed animals. The highly restricted expression of Hsp25 implies that this protein may have a specific physiological role in the orofacial motor nuclei, which govern precise coordination between muscles of mastication and the pharynx, larynx, and face. Its rapid induction after stress further suggests that Hsp25 may serve as a specific molecular chaperone in the lower cholinergic motor neurons and along their fibers under conditions of stress or injury. Copyright 1998 Elsevier Science B.V.

  6. Efficacy of heterologous and homologous heat shock protein 70s as protective agents to Artemia franciscana challenged with Vibrio campbellii.

    Science.gov (United States)

    Baruah, Kartik; Ranjan, Jayant; Sorgeloos, Patrick; Bossier, Peter

    2010-11-01

    The Hsp70 class of heat shock proteins (Hsps) has been implicated at multiple points in the immune response of both vertebrates and invertebrates. This class of chaperones is highly conserved in both sequence and structure, from prokaryotes to higher eukaryotes. In view of their high degree of homology, it was assumed that these Hsp70 proteins derived either from the prokaryotes or eukaryotes would have similar functions, especially in relation to their protective ability in a challenge assay. To verify this, we compared two evolutionary diverse Hsp70s, Artemia Hsp70 and Escherichia coli Hsp70 equivalent DnaK (each overproduced in E.coli), for their ability to protect Artemia against Vibrio challenge. Results showed that Artemia fed with E. coli producing Artemia Hsp70 or DnaK proteins, as assessed by immune-probing in western blots, survived better in a Vibrio challenge assay. The observed effects could be due to enhancement of the Artemia immune system as phenoloxidase activity was found to be increased by these proteins. These two Hsp70 proteins exhibit a high degree of homology, particularly in the peptide-binding domain (the putative innate immunity-activating portion) with 59.6% identity, indicating that the observed protective capacity of homologous or heterologous Hsp70 proteins might reside within this peptide-binding domain.

  7. Role of heat shock protein Hsp25 in the response of the orofacial nuclei motor system to physiological stress

    Science.gov (United States)

    Murashov, A. K.; Talebian, S.; Wolgemuth, D. J.

    1998-01-01

    Although expression of the small heat shock protein family member Hsp25 has been previously observed in the central nervous system (CNS), both constitutively and upon induction, its function in the CNS remains far from clear. In the present study we have characterized the spatial pattern of expression of Hsp25 in the normal adult mouse brain as well as the changes in expression patterns induced by subjecting mice to experimental hyperthermia or hypoxia. Immunohistochemical analysis revealed a surprisingly restricted pattern of constitutive expression of Hsp25 in the brain, limited to the facial, trigeminal, ambiguus, hypoglossal and vagal motor nuclei of the brainstem. After hyperthermia or hypoxia treatment, significant increases in the levels of Hsp25 were observed in these same areas and also in fibers of the facial and trigeminal nerve tracts. Immunoblot analysis of protein lysates from brainstem also showed the same pattern of induction of Hsp25. Surprisingly, no other area in the brain showed expression of Hsp25, in either control or stressed animals. The highly restricted expression of Hsp25 implies that this protein may have a specific physiological role in the orofacial motor nuclei, which govern precise coordination between muscles of mastication and the pharynx, larynx, and face. Its rapid induction after stress further suggests that Hsp25 may serve as a specific molecular chaperone in the lower cholinergic motor neurons and along their fibers under conditions of stress or injury. Copyright 1998 Elsevier Science B.V.

  8. Heat shock cognate protein 70 controls Borna disease virus replication via interaction with the viral non-structural protein X.

    Science.gov (United States)

    Hayashi, Yohei; Horie, Masayuki; Daito, Takuji; Honda, Tomoyuki; Ikuta, Kazuyoshi; Tomonaga, Keizo

    2009-03-01

    Borna disease virus (BDV) is a non-segmented, negative-sense RNA virus and has the property of persistently infecting the cell nucleus. BDV encodes a 10-kDa non-structural protein, X, which is a negative regulator of viral polymerase activity but is essential for virus propagation. Recently, we have demonstrated that interaction of X with the viral polymerase cofactor, phosphoprotein (P), facilitates translocation of P from the nucleus to the cytoplasm. However, the mechanism by which the intracellular localization of X is controlled remains unclear. In this report, we demonstrate that BDV X interacts with the 71kDa molecular chaperon protein, Hsc70. Immunoprecipitation assays revealed that Hsc70 associates with the same region of X as P and, interestingly, that expression of P interferes competitively with the interaction between X and Hsc70. A heat shock experiment revealed that BDV X translocates into the nucleus, dependent upon the nuclear accumulation of Hsc70. Furthermore, we show that knockdown of Hsc70 by short interfering RNA decreases the nuclear localization of both X and P and markedly reduces the expression of viral genomic RNA in persistently infected cells. These data indicate that Hsc70 may be involved in viral replication by regulating the intracellular distribution of X.

  9. Human heat shock protein (Hsp) 90 interferes with Neisseria meningitidis adhesin A (NadA)-mediated adhesion and invasion.

    Science.gov (United States)

    Montanari, Paolo; Bozza, Giuseppe; Capecchi, Barbara; Caproni, Elena; Barrile, Riccardo; Norais, Nathalie; Capitani, Mirco; Sallese, Michele; Cecchini, Paola; Ciucchi, Laura; Gao, Zhenai; Rappuoli, Rino; Pizza, Mariagrazia; Aricò, Beatrice; Merola, Marcello

    2012-03-01

    NadA (N eisseria meningitidisadhesin A), a meningococcal surface protein, mediates adhesion to and invasion of human cells, an activity in which host membrane proteins have been implicated. While investigating these host factors in human epithelial cells by affinity chromatography, we discovered an unanticipated interaction of NadA with heat shock protein (Hsp) 90, a molecular chaperone. The specific in vitro interaction of recombinant soluble NadA and Hsp90 was confirmed by co-immunoprecipitations, dot and far-Western blot. Intriguingly, ADP, but not ATP, was required for this association, and the Hsp90 inhibitor 17-AAG promoted complex formation. Hsp90 binding to an Escherichia coli strain used as carrier to express surface exposed NadA confirmed these results in live bacteria. We also examined RNA interference, plasmid-driven overexpression, addition of exogenous rHsp90 and 17-AAG inhibition in human epithelial cells to further elucidate the involvement of Hsp90 in NadA-mediated adhesion and invasion. Together, these data suggest an inverse correlation between the amount of host Hsp90 and the NadA adhesive/invasive phenotype. Confocal microscopy also demonstrated that meningococci interact with cellular Hsp90, a completely novel finding. Altogether our results show that variation of host Hsp90 expression or activity interferes with adhesive and invasive events driven by NadA.

  10. Nitric oxide and heat shock protein 90 co-regulate temperature-induced bleaching in the soft coral Eunicea fusca

    Science.gov (United States)

    Ross, Cliff

    2014-06-01

    Coral bleaching represents a complex physiological process that is affected not only by environmental conditions but by the dynamic internal cellular biology of symbiotic dinoflagellates ( Symbiodinium spp.) and their cnidarian hosts. Recently, nitric oxide (NO) has emerged as a key molecule involved with the expulsion of Symbiodinium from host cnidarian cells. However, the site of production remains under debate, and the corresponding signaling pathways within and between host and endosymbiont remain elusive. In this study, using freshly isolated Symbiodinium from the soft coral Eunicea fusca, I demonstrate that thermally induced stress causes an upregulation in Symbiodinium heat shock protein 90 (Hsp90). In turn, Hsp90 shows a concomitant ability to enhance the activity of a constitutively expressed isoform of NO synthase. The resulting production of NO constitutes a signaling molecule capable of inducing Symbiodinium expulsion. Using nitric oxide synthase (NOS) and Hsp90 polyclonal antibodies, thermal stress-induced Hsp90 was shown to co-immunoprecipitate with a constitutive isoform of NOS. The specific blocking of Hsp90 activity, with the Hsp90 inhibitor geldanamycin, was capable of inhibiting NO production implicating the involvement of a coordinated regulatory system. These results have strong evolutionary implications for Hsp90-NOS chaperone complexes among biological kingdoms and provide evidence for a new functional role in symbiotic associations.

  11. Diversity of cytosolic HSP70 Heat Shock Protein from decapods and their phylogenetic placement within Arthropoda.

    Science.gov (United States)

    Baringou, Stephane; Rouault, Jacques-Deric; Koken, Marcel; Hardivillier, Yann; Hurtado, Luis; Leignel, Vincent

    2016-10-10

    The 70kDa heat shock proteins (HSP70) are considered the most conserved members of the HSP family. These proteins are primordial to the cell, because of their implications in many cellular pathways (e. g., development, immunity) and also because they minimize the effects of multiple stresses (e. g., temperature, pollutants, salinity, radiations). In the cytosol, two ubiquitous HSP70s with either a constitutive (HSC70) or an inducible (HSP70) expression pattern are found in all metazoan species, encoded by 5 or 6 genes (Drosophila melanogaster or yeast and human respectively). The cytosolic HSP70 protein family is considered a major actor in environmental adaptation, and widely used in ecology as an important biomarker of environmental stress. Nevertheless, the diversity of cytosolic HSP70 remains unclear amongst the Athropoda phylum, especially within decapods. Using 122 new and 311 available sequences, we carried out analyses of the overall cytosolic HSP70 diversity in arthropods (with a focus on decapods) and inferred molecular phylogenies. Overall structural and phylogenetic analyses showed a surprisingly high diversity in cytosolic HSP70 and revealed the existence of several unrecognised groups. All crustacean HSP70 sequences present signature motifs and molecular weights characteristic of non-organellar HSP70, with multiple specific substitutions in the protein sequence. The cytosolic HSP70 family in arthropods appears to be constituted of at least three distinct groups (annotated as A, B and C), which comprise several subdivisions, including both constitutive and inducible forms. Group A is constituted by several classes of Arthropods, while group B and C seem to be specific to Malacostraca and Hexapoda/Chelicerata, respectively. The HSP70 organization appeared much more complex than previously suggested, and far beyond a simple differentiation according to their expression pattern (HSC70 versus HSP70). This study proposes a new classification of cytosolic

  12. 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.

  13. 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.

  14. A cytosolic relay of heat shock proteins HSP70-1A and HSP90β monitors the folding trajectory of the serotonin transporter.

    Science.gov (United States)

    El-Kasaby, Ali; Koban, Florian; Sitte, Harald H; Freissmuth, Michael; Sucic, Sonja

    2014-10-17

    Mutations in the C terminus of the serotonin transporter (SERT) disrupt folding and export from the endoplasmic reticulum. Here we examined the hypothesis that a cytosolic heat shock protein relay was recruited to the C terminus to assist folding of SERT. This conjecture was verified by the following observations. (i) The proximal portion of the SERT C terminus conforms to a canonical binding site for DnaK/heat shock protein of 70 kDa (HSP70). A peptide covering this segment stimulated ATPase activity of purified HSP70-1A. (ii) A GST fusion protein comprising the C terminus of SERT pulled down HSP70-1A. The interaction between HSP70-1A and SERT was visualized in live cells by Förster resonance energy transfer: it was restricted to endoplasmic reticulum-resident transporters and enhanced by an inhibitor that traps HSP70-1A in its closed state. (iv) Co-immunoprecipitation confirmed complex formation of SERT with HSP70-1A and HSP90β. Consistent with an HSP relay, co-chaperones (e.g. HSC70-HSP90-organizing protein) were co-immunoprecipitated with the stalled mutants SERT-R607A/I608A and SERT-P601A/G602A. (v) Depletion of HSP90β by siRNA or its inhibition increased the cell surface expression of wild type SERT and SERT-F604Q. In contrast, SERT-R607A/I608A and SERT-P601A/G602A were only rendered susceptible to inhibition of HSP70 and HSP90 by concomitant pharmacochaperoning with noribogaine. (vi) In JAR cells, inhibition of HSP90 also increased the levels of SERT, indicating that endogenously expressed transporter was also susceptible to control by HSP90β. These findings support the concept that the folding trajectory of SERT is sampled by a cytoplasmic chaperone relay.

  15. Gene expression and functional studies of small heat shock protein 37 (MrHSP37) from Macrobrachium rosenbergii challenged with infectious hypodermal and hematopoietic necrosis virus (IHHNV).

    Science.gov (United States)

    Arockiaraj, Jesu; Vanaraja, Puganeshwaran; Easwvaran, Sarasvathi; Singh, Arun; Othman, Rofina Yasmin; Bhassu, Subha

    2012-06-01

    In this study, we have reported a full length of small heat shock protein 37 (designated MrHSP37) gene, identified from the transcriptome database of freshwater prawn Macrobrachium rosenbergii. The complete gene sequence of the MrHSP37 is 2,425 base pairs in length, and encodes 338 amino acids. MrHSP37 contains a long heat shock protein family profile in the amino acid sequence between 205 and 288. The mRNA expressions of MrHSP37 in healthy and the infectious hypodermal and hematopoietic necrosis virus (IHHNV) challenged M. rosenbergii were examined using quantitative real time polymerase chain reaction (qRT-PCR). MrHSP37 is highly expressed in hepatopancreas and all the other tissues (walking leg, gills, muscle, stomach, haemocyte, intestine, pleopods, brain and eye stalk) of M. rosenbergii taken for analysis. The expression is strongly up-regulated after IHHNV challenge. To understand its biological activity, the recombinant MrHSP37 gene was constructed and expressed in Escherichia coli BL21 (DE3). The results of ATPase assay showed that the recombinant MrHSP37 protein exhibited apparent ATPase activity which increased with the concentration of the protein. And also the purified recombinant MrHSP37 protein was used for thermal aggregation assay (chaperone activity). It showed that the recombinant MrHSP37 protein is an active chaperone in this assay. Taken together, these results suggest that MrHSP37 is potentially involved in the immune responses against IHHNV challenge in M. rosenbergii.

  16. Global transcriptional analysis of Bacillus licheniformis reveals an overlap between heat shock and iron limitation stimulon.

    Science.gov (United States)

    Nielsen, Allan K; Breüner, Anne; Krzystanek, Marcin; Andersen, Jens T; Poulsen, Thomas A; Olsen, Peter B; Mijakovic, Ivan; Rasmussen, Michael D

    2010-01-01

    In this study, we characterized the heat shock stimulon of the important industrial microorganism Bacillus licheniformis using DNA microarrays. While sharing a high degree of homology with the closely related model organism Bacillus subtilis, the heat shock stimulon of B. licheniformis exhibited several novel and unexpected features. Most notably, heat shock in B. licheniformis resulted in decreased amounts of mRNA from the ytrABCEF operon, encoding a putative acetoin uptake system, and stimulated the transcription of purine biosynthesis and iron uptake genes. Unexpectedly, deletion of the ytrEF genes did not affect acetoin uptake, but increased heat sensitivity. To investigate the connection between heat stress and iron uptake further, we analyzed the iron limitation response of B. licheniformis by DNA microarrays and concluded that the response mostly involves the genes related to iron uptake and metabolism, while the only heat shock gene affected by iron limitation was clpE. We also attempted to delete the fur gene (encoding the ferric uptake repressor), but unexpectedly found it to be essential in B. licheniformis. Using the fluorescent protein-encoding reporter gene under control of the dhb promoter, which responded to both heat shock and iron-starvation, we confirmed the overlap between these responses.

  17. Possible involvement of phosphorylated heat-shock factor-1 in changes in heat shock protein 72 induction in the failing rat heart following myocardial infarction.

    Science.gov (United States)

    Marunouchi, Tetsuro; Murata, Mao; Takagi, Norio; Tanonaka, Kouichi

    2013-01-01

    It is supposed that an increase in the level of heat shock protein 72 (HSP72) in the failing heart would be beneficial for reducing the myocardial damage. However, the induction of HSP72 after an exposure to heat shock is blunted in the failing rat heart following myocardial infarction. In this study, to clarify the possible mechanisms underlying this reduction in the ability for HSP72 induction in the failing heart, the possible involvement of heat-shock factor-1 (HSF1), an HSP transcription factor, in this reduction was examined. When hemodynamic parameters of rats with myocardial infarction 8 weeks after coronary artery ligation were measured, the animals showed the signs of chronic heart failure. The HSF1 content was increased in the viable myocardium in the failing heart. The ability to induce cardiac HSP72 was reduced after an exposure to hyperthermia. The level of HSF1 in the cytosolic fraction from the failing heart with or without exposure to hyperthermia was increased, whereas that of HSF1 in the nuclear fraction was reduced. In the failing heart, the level of HSF1 on its serine 303 (Ser303) residue, which phosphorylation represses HSF1, was increased. These findings suggest that HSF1 translocation from the cytosol into the nucleus was attenuated after an exposure to hyperthermia and that an increase in the phosphorylation of HSF1 Ser303 was involved in the impairment of heat shock-induced HSP72 induction in the failing heart following myocardial infarction.

  18. A thermochemical model for shock-induced reactions (heat detonations) in solids

    Energy Technology Data Exchange (ETDEWEB)

    Boslough, M.B. (Sandia National Laboratories, Albuquerque, New Mexico 87185 (US))

    1990-02-01

    Recent advances in studies of shock-induced chemistry in reactive solids have led to the recognition of a new class of energetic materials which are unique in their response to shock waves. Experimental work has shown that chemical energy can be released on a time scale shorter than shock-transit times in laboratory samples. However, for many compositions, the reaction products remain in the condensed state upon release from high pressure, and no sudden expansion takes place. Nevertheless, if such a reaction is sufficiently rapid, it can be modeled as a type of detonation, termed heat detonation'' in the present paper. It is shown that unlike an explosive detonation, an unsupported heat detonation will decay to zero unless certain conditions are met. An example of such a reaction is Fe{sub 2}O{sub 3} +2Al+shock{r arrow}Al{sub 2} O{sub 3} +2Fe (the standard thermite reaction). A shock-wave equation of state is determined from a mixture theory for reacted and unreacted porous thermite. The calculated shock temperatures are compared to experimentally measured shock temperatures, demonstrating that a shock-induced reaction takes place. Interpretation of the measured temperature history in the context of the thermochemical model implies that the principal rate-controlling kinetic mechanism is dynamic mixing at the shock front. Despite the similarity in thermochemical modeling of heat detonations to explosive detonations, the two processes are qualitatively very different in reaction mechanism as well as in the form the energy takes upon release, with explosives producing mostly work and heat detonations producing mostly heat.

  19. Peripheral blood mononuclear cells: a potential cellular system to understand differential heat shock response across native cattle (Bos indicus), exotic cattle (Bos taurus), and riverine buffaloes (Bubalus bubalis) of India.

    Science.gov (United States)

    Kishore, Amit; Sodhi, Monika; Kumari, Parvesh; Mohanty, A K; Sadana, D K; Kapila, Neha; Khate, K; Shandilya, Umesh; Kataria, R S; Mukesh, M

    2014-09-01

    Circulating leukocytes can be used as an effective model to understand the heat stress response of different cattle types and buffaloes. This investigation aimed to determine the temporal profile of HSPs (HSP40, HSP60, HSP70, and HSP90) expression in circulating peripheral blood mononuclear cells (PBMCs) of Murrah buffaloes, Holstein-Friesian (HF), and Sahiwal cows in response to sublethal heat shock at 42 °C. The viability data indicated HF PBMCs to be the most affected to the heat shock, whereas Sahiwal PBMCs were least affected, indicating its better survivability during the heat stress condition. The qRT-PCR expression data showed significant increase in mRNA expression of the analyzed HSPs genes after heat stimuli to the PBMCs under in vitro condition. In each case, the HSPs were most upregulated at 2 h after the heat stress. Among the HSPs, HSP70 was relatively more expressed followed by HSP60 indicating the action of molecular chaperones to stabilize the native conformation of proteins. However, PBMCs from different cattle types and buffaloes showed difference in the extent of transcriptional response. The level of expression of HSPs throughout the time period of heat stress was highest in buffaloes, followed by HF and Sahiwal cows. The higher abundance of HSP70 mRNA at each time point after heat stress showed prolonged effect of heat stress in HF PBMCs. The data presented here provided initial evidence of transcriptional differences in PBMCs of different cattle types and buffaloes and warrant further research.

  20. Relationship between the induction of heat shock proteins and the decrease in glucocorticoid receptor during heat shock response in human osteosarcoma cells

    Institute of Scientific and Technical Information of China (English)

    宋亮年

    1995-01-01

    Previously,it has been found that glucocorticoid receptor(GR)binding activity decreasedrapidly during heat shock response in HOS-8603,a human osteosarcorna cell line.In this study,Therelationship between the induction of heat shock proteins(HSPs)and the decrease in GR was furtherstudied in the same cell line.It was found that even though quercetin could specifically inhibit the ex-pression of hsp90α and hsp70 mRNA,it could not prevent GR from the decrease in response to the heatshock treatment.This represents the first reported evidence that the induction of HSPs and the decrease inGR during heat shock response were 2 independent biological events.The results of the present study furthershowed that although the heat shock treatment alone had no effects on alkaline phosphatase(AKP)activity,itcould completely block the induction of AKP activity in HOS-8603 cells by dexamethasone(Dex),a syntheticglucocorticoid.These results demonstrate that the heat shock-induced alteration in GR was accompanied by adecrease in GR functional activity.Furthermore,when the induction of HSPs was inhibited by the treatmentof cells with quercetin,the stimulatory effects of Dex on AKP activity could still be inhibited completely bythe heat shock treatment.The results of this part,on the basis of GR functional activity,further demonstratethat quercetin could not inhibit the heat shock-induced decrease in GR,even though it could inhibit the induc-tion of HSPs.To clarify further the effects of quercetin alone on GR binding activity in HOS-8603 cells,theregulation of GR by quercetin was also studied.It was found for the first time that quercetin coulddown-regulate GR in a time-dependent manner significantly,and that the down-regulation of GR by quercetinin HOS-8603 cells paralelled with a decrease in glucocorticoid-mediated functional responses,suggesting thatthe down-regulation of GR by quercetin is of biological significance.

  1. Disaggregases, molecular chaperones that resolubilize protein aggregates

    Directory of Open Access Journals (Sweden)

    David Z. Mokry

    2015-08-01

    Full Text Available The process of folding is a seminal event in the life of a protein, as it is essential for proper protein function and therefore cell physiology. Inappropriate folding, or misfolding, can not only lead to loss of function, but also to the formation of protein aggregates, an insoluble association of polypeptides that harm cell physiology, either by themselves or in the process of formation. Several biological processes have evolved to prevent and eliminate the existence of non-functional and amyloidogenic aggregates, as they are associated with several human pathologies. Molecular chaperones and heat shock proteins are specialized in controlling the quality of the proteins in the cell, specifically by aiding proper folding, and dissolution and clearance of already formed protein aggregates. The latter is a function of disaggregases, mainly represented by the ClpB/Hsp104 subfamily of molecular chaperones, that are ubiquitous in all organisms but, surprisingly, have no orthologs in the cytosol of metazoan cells. This review aims to describe the characteristics of disaggregases and to discuss the function of yeast Hsp104, a disaggregase that is also involved in prion propagation and inheritance.

  2. Viable and morphologically normal boar spermatozoa alter the expression of heat-shock protein genes in oviductal epithelial cells during co-culture in vitro.

    Science.gov (United States)

    Yeste, Marc; Holt, William V; Bonet, Sergi; Rodríguez-Gil, Joan E; Lloyd, Rhiannon E

    2014-09-01

    The principal aim of this study was to determine if boar spermatozoa influence the expression of four selected chaperone and heat-shock protein (HSP) genes-namely clusterin (CLU), HSP90AA1, HSPA5, and HSPA8-in oviductal epithelial cells (OECs) during in vitro co-culture. All corresponding proteins of these genes were previously identified in a sperm-interacting, 70-kDa soluble fraction derived from apical plasma membranes of OECs. The present study also sought to determine whether or not: (i) spermatozoa must directly bind to OEC for an effect on gene expression to be elicited and (ii) reproductive and nonreproductive epithelial cell types (LLC-PK1, pig kidney) respond equivalently, in terms of alterations in chaperone and HSP gene expression, during co-culture with sperm. Spermatozoa induced a significant upregulation (P sperm-binding index and on the viability and morphological quality of the bound sperm population. In conclusion, the upregulation of HSP genes caused by direct contact between spermatozoa and OECs, rather than nonreproductive epithelial cells, suggests HSPs could play an integral role in the modulation of sperm function in the oviductal reservoir.

  3. Down-regulation of heat shock protein HSP90ab1 in radiation-damaged lung cells other than mast cells.

    Science.gov (United States)

    Haase, Michael G; Geyer, Peter; Fitze, Guido; Baretton, Gustavo B

    2014-05-01

    Ionizing radiation (IR) leads to fibrosing alveolitis (FA) after a lag period of several weeks to months. In a rat model, FA starts at 8 weeks after IR. Before that, at 5.5 weeks after IR, the transcription factors Sp1 (stimulating protein 1) and AP-1 (activator protein 1) are inactivated. To find genes/proteins that were down-regulated at that time, differentially expressed genes were identified in a subtractive cDNA library and verified by quantitative RT-PCR (reverse transcriptase polymerase chain reaction), western blotting and immunohistochemistry (IH). The mRNA of the molecular chaperone HSP90AB1 (heat shock protein 90 kDa alpha, class B member 1) was down-regulated 5.5 weeks after IR. Later, when FA manifested, HSP90ab1 protein was down-regulated by more than 90% in lung cells with the exception of mast cells. In most mast cells of the normal lung, both HSP90ab1 and HSP70, another major HSP, show a very low level of expression. HSP70 was massively up-regulated in all mast cells three months after irradiation whereas HSP90AB1 was up-regulated only in a portion of mast cells. The strong changes in the expression of central molecular chaperones may contribute to the well-known disturbance of cellular functions in radiation-damaged lung tissue.

  4. Skeletal muscle Heat shock protein 60 increases after endurance training and induces peroxisome proliferator-activated receptor gamma coactivator 1 α1 expression.

    Science.gov (United States)

    Barone, Rosario; Macaluso, Filippo; Sangiorgi, Claudia; Campanella, Claudia; Marino Gammazza, Antonella; Moresi, Viviana; Coletti, Dario; Conway de Macario, Everly; Macario, Alberto Jl; Cappello, Francesco; Adamo, Sergio; Farina, Felicia; Zummo, Giovanni; Di Felice, Valentina

    2016-01-27

    Heat shock protein 60 (Hsp60) is a chaperone localizing in skeletal muscle mitochondria, whose role is poorly understood. In the present study, the levels of Hsp60 in fibres of the entire posterior group of hindlimb muscles (gastrocnemius, soleus, and plantaris) were evaluated in mice after completing a 6-week endurance training program. The correlation between Hsp60 levels and the expression of four isoforms of peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC1α) were investigated only in soleus. Short-term overexpression of hsp60, achieved by in vitro plasmid transfection, was then performed to determine whether this chaperone could have a role in the activation of the expression levels of PGC1α isoforms. The levels of Hsp60 protein were fibre-type specific in the posterior muscles and endurance training increased its content in type I muscle fibers. Concomitantly with the increased levels of Hsp60 released in the blood stream of trained mice, mitochondrial copy number and the expression of three isoforms of PGC1α increased. Overexpressing hsp60 in cultured myoblasts induced only the expression of PGC1 1α, suggesting a correlation between Hsp60 overexpression and PGC1 1 α activation.

  5. In vivo effects of UV radiation on multiple endpoints and expression profiles of DNA repair and heat shock protein (Hsp) genes in the cycloid copepod Paracyclopina nana.

    Science.gov (United States)

    Won, Eun-Ji; Han, Jeonghoon; Lee, Yeonjung; Kumar, K Suresh; Shin, Kyung-Hoon; Lee, Su-Jae; Park, Heum Gi; Lee, Jae-Seong

    2015-08-01

    To evaluate the effects of ultraviolet (UV) radiation on energy acquisition and consumption, the copepod Paracyclopina nana was irradiated with several doses (0-3kJ/m(2)) of UV. After UV radiation, we measured the re-brooding success, growth pattern of newly hatched nauplii, ingestion rate, and assimilation of diet. In addition, we checked the modulated patterns of DNA repair and heat shock protein (hsp) chaperoning genes of P. nana. UV-B radiation induced a significant reduction (7-87%) of the re-brooding rate of ovigerous females, indicating that UV-induced egg sac damage is closely correlated with a reduction in the hatching rate of UV-irradiated ovigerous female offspring. Using chlorophyll a and stable carbon isotope incubation experiments, we found a dose-dependent decrease (Pnana has an underlying ability to shift its balanced-energy status from growth and reproduction to DNA repair and adaptation. Also, expression of P. nana base excision repair (BER)-associated genes and hsp chaperoning genes was significantly increased in response to UV radiation in P. nana. These findings indicate that even 1kJ/m(2) of UV radiation induces a reduction in reproduction and growth patterns, alters the physiological balance and inhibits the ability to cope with UV-induced damage in P. nana.

  6. In vivo effects of UV radiation on multiple endpoints and expression profiles of DNA repair and heat shock protein (Hsp) genes in the cycloid copepod Paracyclopina nana

    Energy Technology Data Exchange (ETDEWEB)

    Won, Eun-Ji; Han, Jeonghoon [Department of Biological Science, College of Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Lee, Yeonjung; Kumar, K. Suresh; Shin, Kyung-Hoon [Department of Marine Sciences and Convergent Technology, College of Science and Technology, Hanyang University, Ansan 426-791 (Korea, Republic of); Lee, Su-Jae [Department of Life Sciences, College of Natural Sciences, Hanyang University, Seoul 133-791 (Korea, Republic of); Park, Heum Gi, E-mail: hgpark@gwnu.ac.kr [Department of Marine Resource Development, College of Life Sciences, Gangneung-Wonju National University, Gangneung 210-702 (Korea, Republic of); Lee, Jae-Seong, E-mail: jslee2@skku.edu [Department of Biological Science, College of Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

    2015-08-15

    Highlights: • UV-B radiation induced a significant reduction of the re-brooding rate of ovigerous females. • A dose-dependent decrease in food ingestion and the rate of assimilation to the body upon UV radiation. • Expression of base excision repair-associated and hsp chaperoning genes was significantly increased upon UV radiation in P. nana. - Abstract: To evaluate the effects of ultraviolet (UV) radiation on energy acquisition and consumption, the copepod Paracyclopina nana was irradiated with several doses (0–3 kJ/m{sup 2}) of UV. After UV radiation, we measured the re-brooding success, growth pattern of newly hatched nauplii, ingestion rate, and assimilation of diet. In addition, we checked the modulated patterns of DNA repair and heat shock protein (hsp) chaperoning genes of P. nana. UV-B radiation induced a significant reduction (7–87%) of the re-brooding rate of ovigerous females, indicating that UV-induced egg sac damage is closely correlated with a reduction in the hatching rate of UV-irradiated ovigerous female offspring. Using chlorophyll a and stable carbon isotope incubation experiments, we found a dose-dependent decrease (P < 0.05) in food ingestion and the rate of assimilation to the body in response to UV radiation, implying that P. nana has an underlying ability to shift its balanced-energy status from growth and reproduction to DNA repair and adaptation. Also, expression of P. nana base excision repair (BER)-associated genes and hsp chaperoning genes was significantly increased in response to UV radiation in P. nana. These findings indicate that even 1 kJ/m{sup 2} of UV radiation induces a reduction in reproduction and growth patterns, alters the physiological balance and inhibits the ability to cope with UV-induced damage in P. nana.

  7. Differentially expressed seed aging responsive heat shock protein OsHSP18.2 implicates in seed vigor, longevity and improves germination and seedling establishment under abiotic stress.

    Science.gov (United States)

    Kaur, Harmeet; Petla, Bhanu P; Kamble, Nitin U; Singh, Ajeet; Rao, Venkateswara; Salvi, Prafull; Ghosh, Shraboni; Majee, Manoj

    2015-01-01

    Small heat shock proteins (sHSPs) are a diverse group of proteins and are highly abundant in plant species. Although majority of these sHSPs were shown to express specifically in seed, their potential function in seed physiology remains to be fully explored. Our proteomic analysis revealed that OsHSP18.2, a class II cytosolic HSP is an aging responsive protein as its abundance significantly increased after artificial aging in rice seeds. OsHSP18.2 transcript was found to markedly increase at the late maturation stage being highly abundant in dry seeds and sharply decreased after germination. Our biochemical study clearly demonstrated that OsHSP18.2 forms homooligomeric complex and is dodecameric in nature and functions as a molecular chaperone. OsHSP18.2 displayed chaperone activity as it was effective in preventing thermal inactivation of Citrate Synthase. Further, to analyze the function of this protein in seed physiology, seed specific Arabidopsis overexpression lines for OsHSP18.2 were generated. Our subsequent functional analysis clearly demonstrated that OsHSP18.2 has ability to improve seed vigor and longevity by reducing deleterious ROS accumulation in seeds. In addition, transformed Arabidopsis seeds also displayed better performance in germination and cotyledon emergence under adverse conditions. Collectively, our work demonstrates that OsHSP18.2 is an aging responsive protein which functions as a molecular chaperone and possibly protect and stabilize the cellular proteins from irreversible damage particularly during maturation drying, desiccation and aging in seeds by restricting ROS accumulation and thereby improves seed vigor, longevity and seedling establishment.

  8. Age-Related Decrease in Heat Shock 70-kDa Protein 8 in Cerebrospinal Fluid is Associated with Increased Oxidative Stress

    Directory of Open Access Journals (Sweden)

    David Loeffler

    2016-07-01

    Full Text Available Age-associated declines in protein homeostasis mechanisms (proteostasis are thought to contribute to age-related neurodegenerative disorders. The increased oxidative stress which occurs with aging can activate a key proteostatic process, chaperone-mediated autophagy. This study investigated age-related alteration in cerebrospinal fluid concentrations of heat shock 70-kDa protein 8 (HSPA8, a molecular chaperone involved in proteostatic mechanisms including chaperone-mediated autophagy, and its associations with indicators of oxidative stress (8-hydroxy-2’-deoxyguanosine [8-OHdG] and 8-isoprostane and total anti-oxidant capacity. We examined correlations between age, HSPA8, 8-OHdG, 8-isoprostane, and total antioxidant capacity in CSF samples from 34 healthy subjects ranging from 20 to 75 years of age. Age was negatively associated with HSPA8 (rho = -0.47; p = .005. An age-related increase in oxidative stress was indicated by a positive association between age and 8-OHdG (rho = 0.61; p = .0001. HSPA8 was moderately negatively associated with 8-OHdG (rho = -0.58; p = .0004. Age and HSPA8 were weakly associated with 8-isoprostane and total antioxidant capacity (range of rho values: -0.15 to 0.16. Our findings in this exploratory study suggest that during healthy aging, cerebrospinal fluid HSPA8 may decrease, perhaps due in part to an increase in oxidative stress. Our results also suggest that 8-OHdG may be more sensitive than 8-isoprostane for measuring oxidative stress in cerebrospinal fluid. Further studies are indicated to determine if our findings can be replicated with a larger cohort, and if the age-related decrease in HSPA8 in cerebrospinal fluid is reflected by a similar change in the brain.

  9. 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

  10. Olfactory conditioning in the third instar larvae of Drosophila melanogaster using heat shock reinforcement.

    Science.gov (United States)

    Khurana, Sukant; Robinson, Brooks G; Wang, Zihe; Shropshire, William C; Zhong, Allen C; Garcia, Laura E; Corpuz, Jonathan; Chow, Jonathan; Hatch, Michael M; Precise, Eric F; Cady, Amanda; Godinez, Ryan M; Pulpanyawong, Terapat; Nguyen, Andrew T; Li, Wen-Ke; Seiter, Max; Jahanian, Kambiz; Sun, Jeffrey C; Shah, Ruchita; Rajani, Sunaina; Chen, William Y; Ray, Sofia; Ryazanova, Natalie V; Wakou, Dorah; Prabhu, Rohith K; Atkinson, Nigel S

    2012-01-01

    Adult Drosophila melanogaster has long been a popular model for learning and memory studies. Now the larval stage of the fruit fly is also being used in an increasing number of classical conditioning studies. In this study, we employed heat shock as a novel negative reinforcement for larvae and obtained high learning scores following just one training trial. We demonstrated heat-shock conditioning in both reciprocal and non-reciprocal paradigms and observed that the time window of association for the odor and heat shock reinforcement is on the order of a few minutes. This is slightly wider than the time window for electroshock conditioning reported in previous studies, possibly due to lingering effects of the high temperature. To test the utility of this simplified assay for the identification of new mutations that disrupt learning, we examined flies carrying mutations in the dnc gene. While the sensitivity to heat shock, as tested by writhing, was similar for wild type and dnc homozygotes, dnc mutations strongly diminished learning. We confirmed that the learning defect in dnc flies was indeed due to mutation in the dnc gene using non-complementation analysis. Given that heat shock has not been employed as a reinforcement for larvae in the past, we explored learning as a function of heat shock intensity and found that optimal learning occurred around 41 °C, with higher and lower temperatures both resulting in lower learning scores. In summary, we have developed a very simple, robust paradigm of learning in fruit fly larvae using heat shock reinforcement.

  11. Lysosomal responses to heat-shock of seasonal temperature extremes in Cd-exposed mussels.

    Science.gov (United States)

    Múgica, M; Izagirre, U; Marigómez, I

    2015-07-01

    The present study was aimed at determining the effect of temperature extremes on lysosomal biomarkers in mussels exposed to a model toxic pollutant (Cd) at different seasons. For this purpose, temperature was elevated 10°C (from 12°C to 22°C in winter and from 18°C to 28°C in summer) for a period of 6h (heat-shock) in control and Cd-exposed mussels, and then returned back to initial one. Lysosomal membrane stability and lysosomal structural changes in digestive gland were investigated. In winter, heat-shock reduced the labilisation period (LP) of the lysosomal membrane, especially in Cd-exposed mussels, and provoked transient lysosomal enlargement. LP values recovered after the heat-shock cessation but lysosomal enlargement prevailed in both experimental groups. In summer, heat-shock induced remarkable reduction in LP and lysosomal enlargement (more markedly in Cd-exposed mussels), which recovered within 3 days. Besides, whilst heat-shock effects on LP were practically identical for Cd-exposed mussels in winter and summer, the effects were longer-lasting in summer than in winter for control mussels. Thus, lysosomal responsiveness after heat-shock was higher in summer than in winter but recovery was faster as well, and therefore the consequences of the heat shock seem to be more decisive in winter. In contrast, inter-season differences were attenuated in the presence of Cd. Consequently, mussels seem to be better prepared in summer than in winter to stand short periods of abrupt temperature change; this is, however, compromised when mussels are exposed to pollutants such as Cd.

  12. Effect of heat shock on the susceptibility ofFrankliniella occidentalis (Thysanoptera:Thripidae) to insecticides

    Institute of Scientific and Technical Information of China (English)

    ZHANG Bin; ZUO Tai-qiang; LI Hong-gang; SUN Li-juan; WANG Si-fang; ZHENG Chang-ying; WAN Fang-hao

    2016-01-01

    Currently, insecticides are considered as the primary approach for controling western lfower thrips,Frankliniela occidentalis (Pergande) (Thysanoptera: Thripidae). However, the heavy use of insecticides resulted in high insect resistance and serious environmental polution. Given its characteristics of ease of operation and environmental friendliness, insect control using high temperature is receiving considerable renewed research interest. However, although the combination of insecticides and high temperature to controlF. occidentalis has been studied before, few studies have focused on the short-term effect of such treatment. In a laboratory study,F. occidentalis adults and second-instar nymphs were exposed to 45°C for 2 h. Then, their susceptibility to acetamiprid, spinosad, methomyl, and beta-cypermethrin was tested after different periods of recovery time (2–36 h). Additionaly, the speciifc activity of three detoxiifcation enzymes (esterase, glutathioneS-trans-ferase, and cytochrome p450 (CYP) monooxygenase) of the treated insects was determined. The results indicated that the lfuctuation of susceptibility to insecticides and detoxiifcation enzyme activity duringF. occidentalis recovery from heat shock are related. Furthermore, several recovery time points (2, 30, and 36 h) of signiifcant susceptibility to four tested insecticides compared with the control were found during the treatment of adults that were heat-shocked. Recovery time points of higher susceptibility compared with the control depended on different insecticides during the second-instar nymph recovery from heat shock. Interestingly, the lfuctuation of CYP monooxygenase activity exhibited a trend that was similar to the lfuctuation of susceptibility to insecticides (especialy spinosad) during the recovery from heat shock of adults. In addition, the glutathioneS-transferase and CYP monooxygenase activity trend was similar to the trend of susceptibility to spinosad during the recovery from heat

  13. Genetic variation in heat shock protein 70 is associated with septic shock: narrowing the association to a specific haplotype.

    Science.gov (United States)

    Kee, C; Cheong, K Y; Pham, K; Waterer, G W; Temple, S E L

    2008-12-01

    Heat shock protein 70 (HSP70) plays a major role in immune responses. Polymorphisms within the gene have been associated with development of septic shock. This study refines the region of the HSP70 gene associated with development of septic shock and confirms its functionality. Subjects (n = 31) were grouped into one of three haplotypes based on their HSPA1B-179C>T and HSPA1B1267A>G genotypes. Mononuclear cells from these subjects were stimulated with heat-killed bacteria (10(7 )colony-forming units/mL Escherichia coli or Streptococcus pneumoniae) for 8 and 21 h. HSP70 and tumour necrosis factor (TNF) mRNA and protein levels were measured by reverse transcriptase-polymerase chain reaction and ELISA, respectively. The HSPA1B-179*C:1267*A haplotype was associated with significantly lower levels of HSPA1B mRNA and protein and higher production of TNF mRNA and protein compared to the other haplotypes. Induction of HSP70 was TNF independent. These results suggest that the HSPA1B-179C>T:1267A>G haplotype is functional and may explain the association of the HSP70 gene with development of septic shock.

  14. 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...

  15. Heat-shock effects on photosynthesis and sink-source dynamics in wheat (Triticum aestivum L.)

    NARCIS (Netherlands)

    Schapendonk, A.H.C.M.; Xu, H.Y.; Putten, van der P.E.L.; Spiertz, J.H.J.

    2007-01-01

    To assess the mechanisms causing genotypic differences in heat tolerance of wheat (Triticum aestivum L.), physiological responses to a heat shock in a vegetative (`end of tillering¿) or a reproductive (`early grain filling¿) stage were studied. Three cultivars ¿ Lavett, Ciano-79 and Attila ¿

  16. Stimulation of cysteinyl leukotriene production in mast cells by heat shock and acetylsalicylic acid.

    Science.gov (United States)

    Mortaz, Esmaeil; Redegeld, Frank A; Dunsmore, Kathy; Odoms, Kelli; Wong, Hector R; Nijkamp, Frans P; Engels, Ferdi

    2007-04-30

    Immunoglobulin (Ig) E-dependent activation of mast cells is central to the allergic response. The engagement of IgE-occupied receptors initiates a series of molecular events that causes the release of preformed, and de novo synthesis of, allergic mediators. Cysteinyl leukotrienes are able to contract airway smooth muscle and increase mucus secretion and vascular permeability and recruit eosinophils. Mast cells have also recently been recognized as active participants in innate immune responses. Heat stress can modulate innate immunity by inducing stress proteins such as heat-shock proteins (HSPs). We previously demonstrated that treatment of mast cells with heat shock or acetylsalicylic acid results in an increase of TNF-alpha and IL-6 release. This effect was paralleled by expression of HSP70. In the current study, we further investigated the effects of heat shock and acetylsalicylic acid on the activation of mast cells and the release of cysteinyl leukotrienes. In mouse mast cells, derived from a culture of bone marrow cells, responsiveness to heat shock, acetylsalicylic acid and exogenous or endogenous HSP70 was monitored by measuring leukotriene C4 release. We show that after heat shock treatment and exposure to acetylsalicylic acid leukotriene production was increased. Moreover, exogenous rHSP70 also induced leukotriene production. Because it has been reported that leukotriene production in mast cells may be mediated by Toll like receptor (TLR) activation, and HSP70 also activates TLRs signaling, we further explored these issues by using mast cells that are not able to produce HSP70, i.e. heat shock factor-1 (HSF-1) knockout cells. We found that in HSF-1 knockout bone marrow derived mast cells, heat shock and acetylsalicylic acid failed to induce release of leukotrienes. Moreover, in wild type cells the surface expression of TLR4 was attenuated, whereas the intracellular expression was up-regulated. We conclude that heat shock and acetylsalicylic acid induce

  17. Identification of a heat shock cognate protein 70 gene in Chinese soft-shell turtle (Pelodiscus sinensis) and its expression profiles under thermal stress.

    Science.gov (United States)

    Li, Xiao-liang; Kang, Yue; Zhang, Xiao-yan; Zhu, Bing-lin; Fang, Wei-huan

    2012-06-01

    The heat shock cognate protein 70 (Hsc70) is a member of a 70-kDa heat shock protein (HSP70) family that functions as molecular chaperones. In this study, a novel Hsc70 gene from Chinese soft-shelled turtle (Pelodiscus sinensis) (tHsc70) was identified. The tHsc70 full-length complementary DNA (cDNA) is 2272 bp long with a 1941-bp open reading frame (ORF) encoding 646 amino acids. Three characteristic signature regions of the HSP70 family, two major domains of an adenosine triphosphate (ATP)/guanosine triphosphate (GTP) binding domain (ABD), and a substrate-binding domain (SBD) were present in the predicted tHsc70 amino acid sequence. The tHsc70 gene was expressed in Escherichia coli BL21 and the expression product reacted with the anti-Hsc70 mouse monoclonal antibody by Western blotting. Homology analysis revealed that tHsc70 shared identity from 53.9% to 87.7% at the nucleotide level, and 49.1% to 99.5% at the amino acid level with the known Hsc70s. Phylogenetic analysis showed that tHsc70 was clustered together with the Hsc70 gene of another reptile species (Alligator mississippiensis). The tHsc70 was expressed in the liver, lung, heart, and skeletal muscle. The expression patterns of tHsc70 messenger RNA (mRNA) differed among different tissues under different durations of heat stress at 40 °C. Adaptation at 25 °C for 1 h after heat stress was also different among tissues and length of heat stress. Irrespective of different profiles of expression under heat stress, tHsc70 may play roles in protecting turtles from thermal stress.

  18. Flat plate heat transfer for laminar transition and turbulent boundary layers using a shock tube

    Science.gov (United States)

    Brostmeyer, J. D.; Nagamatsu, H. T.

    1984-01-01

    Heat transfer results are presented for laminar, transition, and turbulent boundary layers for a Mach number of 0.12 with gas temperatures of 425 K and 1000 K over a flat plate at room temperature. The measurements were made in air for a Reynolds number range of 600 to 6 million. The heat transfer measurements were conducted in a 70-ft long, 4 in. diameter shock tube. Reflecting wedges were used to reflect the incident shock wave to produce a flow Mach number of 0.12 behind the reflected shock wave. Thin film platinum heat gages were mounted on the plate surface to measure the local heat flux. The laminar results for gas temperatures of 425 K to 1000 K agree well with theory. The turbulent results are also close to incompressible theory, with the 1000 K flow case being slightly higher. The transition results lie between the laminar and turbulent predictions.

  19. Heat-flow equation motivated by the ideal-gas shock wave.

    Science.gov (United States)

    Holian, Brad Lee; Mareschal, Michel

    2010-08-01

    We present an equation for the heat-flux vector that goes beyond Fourier's Law of heat conduction, in order to model shockwave propagation in gases. Our approach is motivated by the observation of a disequilibrium among the three components of temperature, namely, the difference between the temperature component in the direction of a planar shock wave, versus those in the transverse directions. This difference is most prominent near the shock front. We test our heat-flow equation for the case of strong shock waves in the ideal gas, which has been studied in the past and compared to Navier-Stokes solutions. The new heat-flow treatment improves the agreement with nonequilibrium molecular-dynamics simulations of hard spheres under strong shockwave conditions.

  20. The Malarial Exported PFA0660w Is an Hsp40 Co-Chaperone of PfHsp70-x.

    Directory of Open Access Journals (Sweden)

    Michael O Daniyan

    Full Text Available Plasmodium falciparum, the human pathogen responsible for the most dangerous malaria infection, survives and develops in mature erythrocytes through the export of proteins needed for remodelling of the host cell. Molecular chaperones of the heat shock protein (Hsp family are prominent members of the exportome, including a number of Hsp40s and a Hsp70. PFA0660w, a type II Hsp40, has been shown to be exported and possibly form a complex with PfHsp70-x in the infected erythrocyte cytosol. However, the chaperone properties of PFA0660w and its interaction with human and parasite Hsp70s are yet to be investigated. Recombinant PFA0660w was found to exist as a monomer in solution, and was able to significantly stimulate the ATPase activity of PfHsp70-x but not that of a second plasmodial Hsp70 (PfHsp70-1 or a human Hsp70 (HSPA1A, indicating a potential specific functional partnership with PfHsp70-x. Protein binding studies in the presence and absence of ATP suggested that the interaction of PFA0660w with PfHsp70-x most likely represented a co-chaperone/chaperone interaction. Also, PFA0660w alone produced a concentration-dependent suppression of rhodanese aggregation, demonstrating its chaperone properties. Overall, we have provided the first biochemical evidence for the possible role of PFA0660w as a chaperone and as co-chaperone of PfHsp70-x. We propose that these chaperones boost the chaperone power of the infected erythrocyte, enabling successful protein trafficking and folding, and thereby making a fundamental contribution to the pathology of malaria.

  1. Quantitative analysis of the interplay between hsc70 and its co-chaperone HspBP1

    Directory of Open Access Journals (Sweden)

    Hicham Mahboubi

    2015-12-01

    Full Text Available Background. Chaperones and their co-factors are components of a cellular network; they collaborate to maintain proteostasis under normal and harmful conditions. In particular, hsp70 family members and their co-chaperones are essential to repair damaged proteins. Co-chaperones are present in different subcellular compartments, where they modulate chaperone activities.Methods and Results. Our studies assessed the relationship between hsc70 and its co-factor HspBP1 in human cancer cells. HspBP1 promotes nucleotide exchange on hsc70, but has also chaperone-independent functions. We characterized the interplay between hsc70 and HspBP1 by quantitative confocal microscopy combined with automated image analyses and statistical evaluation. Stress and the recovery from insult changed significantly the subcellular distribution of hsc70, but had little effect on HspBP1. Single-cell measurements and regression analysis revealed that the links between the chaperone and its co-factor relied on (i the physiological state of the cell and (ii the subcellular compartment. As such, we identified a linear relationship and strong correlation between hsc70 and HspBP1 distribution in control and heat-shocked cells; this correlation changed in a compartment-specific fashion during the recovery from stress. Furthermore, we uncovered significant stress-induced changes in the colocalization between hsc70 and HspBP1 in the nucleus and cytoplasm.Discussion. Our quantitative approach defined novel properties of the co-chaperone HspBP1 as they relate to its interplay with hsc70. We propose that changes in cell physiology promote chaperone redistribution and thereby stimulate chaperone-independent functions of HspBP1.

  2. Detection of the host immune response to Burkholderia mallei heat-shock proteins GroEL and DnaK in a glanders patient and infected mice.

    Science.gov (United States)

    Amemiya, Kei; Meyers, Jennifer L; Deshazer, David; Riggins, Renaldo N; Halasohoris, Stephanie; England, Marilyn; Ribot, Wilson; Norris, Sarah L; Waag, David M

    2007-10-01

    We examined, by enzyme-linked immunosorbent assay and Western blot analysis, the host immune response to 2 heat-shock proteins (hsps) in a patient and mice previously infected with Burkholderia mallei. The patient was the first reported human glanders case in 50 years in the United States. The expression of the groEL and dnaK operons appeared to be dependent upon a sigma(32) RNA polymerase as suggested by conserved heat-shock promoter sequences, and the groESL operon may be negatively regulated by a controlling invert repeat of chaperone expression (CIRCE) site. In the antisera, the GroEL protein was found to be more immunoreactive than the DnaK protein in both a human patient and mice previously infected with B. mallei. Examination of the supernatant of a growing culture of B. mallei showed that more GroEL protein than DnaK protein was released from the cell. This may occur similarly within an infected host causing an elevated host immune response to the B. mallei hsps.

  3. Heat shock protein 90 is a potential therapeutic target for ameliorating skeletal muscle abnormalities in Parkinson’s disease

    Institute of Scientific and Technical Information of China (English)

    Nour Erekat; Ahed Al-Khatib; Muhammed Al-Jarrah

    2014-01-01

    Previous studies have conifrmed that heat shock protein 90 overexpression can lead to dopami-nergic neuronal death. This study was designed to further investigate what effects are produced by heat shock protein 90 after endurance exercise training. Immunohistochemistry results showed that exercise training signiifcantly inhibited heat shock protein 90 overexpression in the soleus and gastrocnemius in Parkinson’s disease rats, which is a potential therapeutic target for ameliorating skeletal muscle abnormalities in Parkinson’s disease.

  4. Antibodies to two major chicken heat shock proteins cross-react with similar proteins in widely divergent species.

    OpenAIRE

    Kelley, P M; Schlesinger, M J

    1982-01-01

    Three of the proteins induced by heat shock of chicken embryo fibroblasts have been purified, and rabbit antibodies have been raised against them. These antibodies have been used in radioimmune precipitation reactions and in a solid-phase immune assay to detect antigenic material in non-heat-shocked chicken tissues and in extracts of widely different species ranging from yeast to mammalian tissue culture cells and human erythrocyte ghosts. Antibodies to two of the major chicken heat shock pro...

  5. Normal human epidermal keratinocytes treated with 7-dehydrocholesterol express increased levels of heat shock protein.

    Science.gov (United States)

    Mammone, Thomas; Muizzuddin, Neelam; Goyarts, Earl; Gan, David; Giacomoni, Paolo; Marenus, Ken; Maes, Daniel

    2004-01-01

    Human skin, and its isolated cells, respond to insults with a variety of repair and protective mechanisms. One such mechanism is the production of heat shock proteins (HSPs). Heat shock proteins help the other cellular proteins fold correctly into their active three-dimensional structures. Therefore, they can enhance the survival of cells under harsh, denaturing conditions. In order to develop a means of promoting the heat shock response to prepare the skin to withstand insult, we are investigating materials that appear to protect the skin biologically. One such material is vitamin D3 and its precursors. We have observed that keratinocytes treated with 7-dehydrocholesterol (7-DHC), a precursor of vitamin D3, have increased levels of protein and mRNA for heat shock proteins. In addition, we observed that topically applied 7-DHC increases the minimal dose of UVB required to induce erythema. These data suggest that 7-DHC can induce heat shock proteins in skin keratinocytes and that they will be more resistant to UVB insult.

  6. 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.

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

    Science.gov (United States)

    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 that an extract from Fructus Arctii markedly suppressed the expression of Hsp induced by heat shock. A component of the extract arctigenin, but not the component arctiin, suppressed the response at the level of the activation of heat shock transcription factor, the induction of mRNA, and the synthesis and accumulation of Hsp. Furthermore, arctigenin inhibited the acquisition of thermotolerance in mammalian cells, including cancer cells. Thus, arctigenin seemed to be a new suppressive regulator of heat shock response in mammalian cells, and may be useful for hyperthermia cancer therapy. PMID:16817321

  8. Heat-shock and stress response of the parasitic nematode Haemonchus contortus.

    Science.gov (United States)

    van Leeuwen, M A

    1995-01-01

    Before and after a stress treatment, larval stages and adult worms of Haemonchus contortus were tested for the induction and expression of heat-shock proteins (HSPs) using immunoblot analysis with HSP70-and HSP65-specific monoclonal antibodies. Stress treatment or heat shock did not alter the signals obtained with these antibodies, but the amount of HSP70 differed between the successive stages. In addition, the different stages were metabolically labeled with [35S]-methionine during a temperature-shock or chemical treatment and proteins were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The shocks resulted in an altered protein pattern. New was the de novo expression of a 20-kDa protein of adult worms after anthelmintic treatment.

  9. PBX-9502 Shock Sensitivity Correlation with Specific Heat and Reactive Temperature Magnitudes

    Science.gov (United States)

    Billingsley, James

    2005-07-01

    This work is a supplementary follow-on to papers [1 and 2], presented in two previous SCCM conferences, that related plane impact shock sensitivity of CHNO energetic materials to specific heat (Cp per average atom) magnitude and reactive temperature (TR) conditions. More specifically, plane impact shock energy input that is equal to the thermal vibratory energy increment (the area under the Cp versus temperature data curve between an experimental temperature, TEXP, and a reactive temperature) is sufficient to cause shock induced reactions, up to and including detonation, in CHNO energetic materials. This statement is demonstratively verified at four different test temperatures for PBX-9502 in this proposed paper. *Billingsley, J. P., paper in Shock Compression of Condensed Matter -- 1995, AIP Conference Proceedings 370, Part I, pages 429 -- 432. *Billingsley, J. P., paper in Shock Compression of Condensed Matter -- 1999, AIP Conference Proceedings, 505, Part II, pages 899 -- 902.

  10. 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.

  11. Identification of Genes Differentially Expressed During Heat Shock Treatment in Aedes aegypti

    Science.gov (United States)

    2009-01-01

    expressions of a vector mosquito population. Several families of heat shock proteins (HSPs) are known to be expressed in insects and may have a...stress con- ditions (such as pathogen infection, heavy metal ions, hypoxia, and osmotic stress) in many other animals and insects including mosquitoes...shockÐtreated female Ae. aegypti may provide infor- mationneeded to identifyproteins critical tomosquito survival. Using RNAi technology to knock down these

  12. Heat shock at higher cell densities improves measles hemagglutinin translocation and human GRP78/BiP secretion in Saccharomyces cerevisiae.

    Science.gov (United States)

    Zinkevičiūtė, Rūta; Bakūnaitė, Edita; Čiplys, Evaldas; Ražanskas, Raimundas; Raškevičiūtė, Jurgita; Slibinskas, Rimantas

    2015-12-25

    The yield of heterologous proteins is often limited by several bottlenecks in the secretory pathway of yeast Saccharomyces cerevisiae. It was shown earlier that synthesis of measles virus hemagglutinin (MeH) is inefficient mostly due to a bottleneck in the translocation of viral protein precursors into the endoplasmic reticulum (ER) of yeast cells. Here we report that heat shock with subsequent induction of MeH expression at 37°C improved translocation of MeH precursors when applied at higher cell densities. The amount of MeH glycoprotein increased by about 3-fold after heat shock in the late-log phases of both glucose and ethanol growth. The same temperature conditions increased both secretion titer and yield of another heterologous protein human GRP78/BiP by about 50%. Furthermore, heat shock at the late-log glucose growth phase also improved endogenous invertase yield by approximately 2.7-fold. In contrast, a transfer of yeast culture to lower temperature at diauxic shift followed by protein expression at 20°C almost totally inhibited translocation of MeH precursors. The difference in amounts of MeH glycoprotein under expression at 37°C and 20°C was about 80-fold, while amounts of unglycosylated MeH polypeptides were similar under both conditions. Comparative proteomic analysis revealed that besides over-expressed ER-resident chaperone Kar2, an increased expression of several cytosolic proteins (such as Hsp104, Hsp90 and eEF1A) may contribute to improved translocation of MeH.

  13. Molecular Chaperones of Leishmania: Central Players in Many Stress-Related and -Unrelated Physiological Processes

    Science.gov (United States)

    Requena, Jose M.; Montalvo, Ana M.; Fraga, Jorge

    2015-01-01

    Molecular chaperones are key components in the maintenance of cellular homeostasis and survival, not only during stress but also under optimal growth conditions. Folding of nascent polypeptides is supported by molecular chaperones, which avoid the formation of aggregates by preventing nonspecific interactions and aid, when necessary, the translocation of proteins to their correct intracellular localization. Furthermore, when proteins are damaged, molecular chaperones may also facilitate their refolding or, in the case of irreparable proteins, their removal by the protein degradation machinery of the cell. During their digenetic lifestyle, Leishmania parasites encounter and adapt to harsh environmental conditions, such as nutrient deficiency, hypoxia, oxidative stress, changing pH, and shifts in temperature; all these factors are potential triggers of cellular stress. We summarize here our current knowledge on the main types of molecular chaperones in Leishmania and their functions. Among them, heat shock proteins play important roles in adaptation and survival of this parasite against temperature changes associated with its passage from the poikilothermic insect vector to the warm-blooded vertebrate host. The study of structural features and the function of chaperones in Leishmania biology is providing opportunities (and challenges) for drug discovery and improving of current treatments against leishmaniasis. PMID:26167482

  14. Affinity chromatography of chaperones based on denatured proteins: Analysis of cell lysates of different origin.

    Science.gov (United States)

    Marchenko, N Yu; Sikorskaya, E V; Marchenkov, V V; Kashparov, I A; Semisotnov, G V

    2016-03-01

    Molecular chaperones are involved in folding, oligomerization, transport, and degradation of numerous cellular proteins. Most of chaperones are heat-shock proteins (HSPs). A number of diseases of various organisms are accompanied by changes in the structure and functional activity of chaperones, thereby revealing their vital importance. One of the fundamental properties of chaperones is their ability to bind polypeptides lacking a rigid spatial structure. Here, we demonstrate that affinity chromatography using sorbents with covalently attached denatured proteins allows effective purification and quantitative assessment of their bound protein partners. Using pure Escherichia coli chaperone GroEL (Hsp60), the capacity of denatured pepsin or lysozyme-based affinity sorbents was evaluated as 1 mg and 1.4 mg of GroEL per 1 ml of sorbent, respectively. Cell lysates of bacteria (E. coli, Thermus thermophilus, and Yersinia pseudotuberculosis), archaea (Halorubrum lacusprofundi) as well as the lysate of rat liver mitochondria were analyzed using affinity carrier with denatured lysozyme. It was found that, apart from Hsp60, other proteins with a molecular weight of about 100, 50, 40, and 20 kDa are able to interact with denatured lysozyme.

  15. Molecular Chaperones of Leishmania: Central Players in Many Stress-Related and -Unrelated Physiological Processes

    Directory of Open Access Journals (Sweden)

    Jose M. Requena

    2015-01-01

    Full Text Available Molecular chaperones are key components in the maintenance of cellular homeostasis and survival, not only during stress but also under optimal growth conditions. Folding of nascent polypeptides is supported by molecular chaperones, which avoid the formation of aggregates by preventing nonspecific interactions and aid, when necessary, the translocation of proteins to their correct intracellular localization. Furthermore, when proteins are damaged, molecular chaperones may also facilitate their refolding or, in the case of irreparable proteins, their removal by the protein degradation machinery of the cell. During their digenetic lifestyle, Leishmania parasites encounter and adapt to harsh environmental conditions, such as nutrient deficiency, hypoxia, oxidative stress, changing pH, and shifts in temperature; all these factors are potential triggers of cellular stress. We summarize here our current knowledge on the main types of molecular chaperones in Leishmania and their functions. Among them, heat shock proteins play important roles in adaptation and survival of this parasite against temperature changes associated with its passage from the poikilothermic insect vector to the warm-blooded vertebrate host. The study of structural features and the function of chaperones in Leishmania biology is providing opportunities (and challenges for drug discovery and improving of current treatments against leishmaniasis.

  16. 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.

  17. 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.

  18. Molecular cloning and expression of a hexameric Drosophila heat shock factor subject to negative regulation.

    Science.gov (United States)

    Clos, J; Westwood, J T; Becker, P B; Wilson, S; Lambert, K; Wu, C

    1990-11-30

    We report the cloning of the transcriptional activator of heat shock genes, HSF, from Drosophila. The predicted sequence of Drosophila HSF protein is surprisingly divergent from that of yeast HSF, except in regions important for DNA binding and oligomerization. A segment of the DNA binding domain of HSF bears an intriguing similarity to the putative DNA recognition helix of bacterial sigma factors, while the oligomerization domain contains an unusual arrangement of conserved hydrophobic heptad repeats. Drosophila HSF produced in E. coli under nonshock conditions forms a hexamer that binds specifically to DNA with high affinity and activates transcription from a heat shock promoter in vitro. In contrast, when HSF is expressed in Xenopus oocytes, maximal DNA binding affinity is observed only after heat shock induction. These results suggest that Drosophila HSF has an intrinsic affinity for DNA, which is repressed under nonshock conditions in vivo.

  19. The Hsp90/Cdc37p chaperone system is a determinant of molybdate resistance in Saccharomyces cerevisiae.

    Science.gov (United States)

    Millson, Stefan H; Nuttall, James M; Mollapour, Mehdi; Piper, Peter W

    2009-06-01

    Saccharomyces cerevisiae lacks enzymes that contain the molybdopterin co-factor and therefore any requirement for molybdenum as a trace mineral supplement. Instead, high molybdate levels are inhibitory to its growth. Low cellular levels of heat shock protein 90 (Hsp90), an essential chaperone, were found to enhance this sensitivity to molybdate. Certain Hsp90 point mutations and co-chaperone protein defects that partially compromise the function of the Hsp90/Cdc37p chaperone system also rendered S. cerevisiae hypersensitive to high molybdate levels. Sensitivity was especially apparent with mutations close to the Hsp90 nucleotide binding site, with the loss of the non-essential co-chaperone Sti1p (the equivalent of mammalian Hop), and with the abolition of residue Ser14 phosphorylation on the essential co-chaperone Cdc37p. While it remains to be proved that these effects reflect direct inhibition of the Hsp90 of the cell by the MoO(4) (2+) oxyanion in vivo; this possibility is suggested by molybdate sensitivity arising with a mutation in the Hsp90 nucleotide binding site that does not generate stress sensitivity or an impaired stress response. Molybdate sensitivity may therefore be a useful phenotype to score when studying mutations in this chaperone system.

  20. Increased expression of Hsp40 chaperones, transcriptional factors, and ribosomal protein Rpp0 can cure yeast prions.

    Science.gov (United States)

    Kryndushkin, Dmitry S; Smirnov, Vladimir N; Ter-Avanesyan, Michael D; Kushnirov, Vitaly V

    2002-06-28

    The Sup35 (eRF3) translation termination factor of Saccharomyces cerevisiae can undergo a prion-like conformational conversion, thus resulting in the [PSI(+)] nonsense-suppressor determinant. In vivo this process depends critically on the chaperone Hsp104, whose lack or overexpression can cure [PSI(+)]. The use of artificial prion [PSI(+)PS] based on a hybrid Sup35PS with prion domain from the yeast Pichia methanolica allowed us to uncover three more chaperones, Ssb1, Ssa1, and Ydj1, whose overexpression can cure prion determinants. Here, we used the [PSI(+)PS] to search a multicopy yeast genomic library for novel factors able to cure prions. It was found that overexpression of the Hsp40 family chaperones Sis1 and Ynl077w, chaperone Sti1, transcriptional factors Sfl1 and Ssn8, and acidic ribosomal protein Rpp0 can interfere with propagation and manifestation of [PSI(+)PS] in a prion strain-specific manner. Some of these factors also affected the manifestation and propagation of conventional [PSI(+)]. Excess of Sfl1, Ssn8, and Rpp0 influenced at least one of the tested chaperone-specific promoters, SSA4, HSP104, and model promoters, with either the heat shock or stress response elements. Thus, the induction of chaperone expression by these proteins could explain their prion-curing effects.

  1. Development of a Heat-Shock Inducible Gene Expression System in the Red Alga Cyanidioschyzon merolae

    Science.gov (United States)

    Sumiya, Nobuko; Fujiwara, Takayuki; Kobayashi, Yusuke; Misumi, Osami; Miyagishima, Shin-ya

    2014-01-01

    The cell of the unicellular red alga Cyanidioschyzon merolae contains a single chloroplast and mitochondrion, the division of which is tightly synchronized by a light/dark cycle. The genome content is extremely simple, with a low level of genetic redundancy, in photosynthetic eukaryotes. In addition, transient transformation and stable transformation by homologous recombination have been reported. However, for molecular genetic analyses of phenomena that are essential for cellular growth and survival, inducible gene expression/suppression systems are needed. Here, we report the development of a heat-shock inducible gene expression system in C. merolae. CMJ101C, encoding a small heat shock protein, is transcribed only when cells are exposed to an elevated temperature. Using a superfolder GFP as a reporter protein, the 200-bp upstream region of CMJ101C orf was determined to be the optimal promoter for heat-shock induction. The optimal temperature to induce expression is 50°C, at which C. merolae cells are able to proliferate. At least a 30-min heat shock is required for the expression of a protein of interest and a 60-min heat shock yields the maximum level of protein expression. After the heat shock, the mRNA level decreases rapidly. As an example of the system, the expression of a dominant negative form of chloroplast division DRP5B protein, which has a mutation in the GTPase domain, was induced. Expression of the dominant negative DRP5B resulted in the appearance of aberrant-shaped cells in which two daughter chloroplasts and the cells are still connected by a small DRP5B positive tube-like structure. This result suggests that the dominant negative DRP5B inhibited the final scission of the chloroplast division site, but not the earlier stages of division site constriction. It is also suggested that cell cycle progression is not arrested by the impairment of chloroplast division at the final stage. PMID:25337786

  2. Thermochemical model for shock-induced chemical reactions in porous thermite: The heat detonation model

    Energy Technology Data Exchange (ETDEWEB)

    Boslough, M.B.

    1989-01-01

    A thermochemical model has been developed that treats a shock-induced solid state chemical reaction as a special type of detonation, called a ''heat detonation'' to distinguish it from an ordinary explosive detonation and describe the final form that the chemical energy takes. According to shock temperature measurements, chemical energy can be released from porous reactive solids on a time scale shorter than shock-transit times in laboratory samples. By comparing the experimental shock temperature for porous thermite to that calculated by the model, the amount of thermite reacted when shocked to about 4 GPa was estimated to be between 60 and 70%. Calculated shock temperatures are extremely strong functions of the extent of reaction, but are relatively insensitive to the initial porosity and amount of volatile impurities. Thus, shock temperature measurements are the most useful for real-time studies of shock-induced exothermic chemical reactions in solids. 11 refs., 5 figs., 1 tab.

  3. Heat Shock Protein 90 (Hsp90 Expression and Breast Cancer

    Directory of Open Access Journals (Sweden)

    Christos A. Papadimitriou

    2012-09-01

    Full Text Available Hsp90 is an abundant protein in mammalian cells. It forms several discrete complexes, each containing distinct groups of co-chaperones that assist protein folding and refolding during stress, protein transport and degradation. It interacts with a variety of proteins that play key roles in breast neoplasia including estrogen receptors, tumor suppressor p53 protein, angiogenesis transcription factor HIF-1alpha, antiapoptotic kinase Akt, Raf-1 MAP kinase and a variety of receptor tyrosine kinases of the erbB family. Elevated Hsp90 expression has been documented in breast ductal carcinomas contributing to the proliferative activity of breast cancer cells; whilst a significantly decreased Hsp90 expression has been shown in infiltrative lobular carcinomas and lobular neoplasia. Hsp90 overexpression has been proposed as a component of a mechanism through which breast cancer cells become resistant to various stress stimuli. Therefore, pharmacological inhibition of HSPs can provide therapeutic opportunities in the field of cancer treatment. 17-allylamino,17-demethoxygeldanamycin is the first Hsp90 inhibitor that has clinically been investigated in phase II trial, yielding promising results in patients with HER2-overexpressing metastatic breast cancer, whilst other Hsp90 inhibitors (retaspimycin HCL, NVP-AUY922, NVP-BEP800, CNF2024/BIIB021, SNX-5422, STA-9090, etc. are currently under evaluation.

  4. 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

  5. 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

  6. Expression of Heat Shock and Other Stress Response Proteins in Ticks and Cultured Tick Cells in Response to Anaplasma spp. Infection and Heat Shock

    Directory of Open Access Journals (Sweden)

    Margarita Villar

    2010-01-01

    Full Text Available Ticks are ectoparasites of animals and humans that serve as vectors of Anaplasma and other pathogens that affect humans and animals worldwide. Ticks and the pathogens that they transmit have coevolved molecular interactions involving genetic traits of both the tick and the pathogen that mediate their development and survival. In this paper, the expression of heat shock proteins (HSPs and other stress response proteins (SRPs was characterized in ticks and cultured tick cells by proteomics and transcriptomics analyses in response to Anaplasma spp. infection and heat shock. The results of these studies demonstrated that the stress response was activated in ticks and cultured tick cells after Anaplasma spp. infection and heat shock. However, in the natural vector-pathogen relationship, HSPs and other SRPs were not strongly activated, which likely resulted from tick-pathogen coevolution. These results also demonstrated pathogen- and tick-specific differences in the expression of HSPs and other SRPs in ticks and cultured tick cells infected with Anaplasma spp. and suggested the existence of post-transcriptional mechanisms induced by Anaplasma spp. to control tick response to infection. These results illustrated the complexity of the stress response in ticks and suggested a function for the HSPs and other SRPs during Anaplasma spp. infection.

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

    Science.gov (United States)

    Ding, Xiaotao; Jiang, Yuping; 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.

  8. 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.

  9. 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.

  10. Heat shock proteins: in vivo heat treatments reveal adipose tissue depot-specific effects.

    Science.gov (United States)

    Rogers, Robert S; Beaudoin, Marie-Soleil; Wheatley, Joshua L; Wright, David C; Geiger, Paige C

    2015-01-01

    Heat treatments (HT) and the induction of heat shock proteins (HSPs) improve whole body and skeletal muscle insulin sensitivity while decreasing white adipose tissue (WAT) mass. However, HSPs in WAT have been understudied. The purpose of the present study was to examine patterns of HSP expression in WAT depots, and to examine the effects of a single in vivo HT on WAT metabolism. Male Wistar rats received HT (41°C, 20 min) or sham treatment (37°C), and 24 h later subcutaneous, epididymal, and retroperitoneal WAT depots (SCAT, eWAT, and rpWAT, respectively) were removed for ex vivo experiments and Western blotting. SCAT, eWAT, and rpWAT from a subset of rats were also cultured separately and received a single in vitro HT or sham treatment. HSP72 and HSP25 expression was greatest in more metabolically active WAT depots (i.e., eWAT and rpWAT) compared with the SCAT. Following HT, HSP72 increased in all depots with the greatest induction occurring in the SCAT. In addition, HSP25 increased in the rpWAT and eWAT, while HSP60 increased in the rpWAT only in vivo. Free fatty acid (FFA) release from WAT explants was increased following HT in the rpWAT only, and fatty acid reesterification was decreased in the rpWAT but increased in the SCAT following HT. HT increased insulin responsiveness in eWAT, but not in SCAT or rpWAT. Differences in HSP expression and induction patterns following HT further support the growing body of literature differentiating distinct WAT depots in health and disease.

  11. Plants contain a novel multi-member class of heat shock factors without transcriptional activator potential.

    Science.gov (United States)

    Czarnecka-Verner, E; Yuan, C X; Scharf, K D; Englich, G; Gurley, W B

    2000-07-01

    Based on phylogeny of DNA-binding domains and the organization of hydrophobic repeats, two families of heat shock transcription factors (HSFs) exist in plants. Class A HSFs are involved in the activation of the heat shock response, but the role of class B HSFs is not clear. When transcriptional activities of full-length HSFs were monitored in tobacco protoplasts, no class B HSFs from soybean or Arabidopsis showed activity under control or heat stress conditions. Additional assays confirmed the finding that the class B HSFs lacked the capacity to activate transcription. Fusion of a heterologous activation domain from human HSF1 (AD2) to the C-terminus of GmHSFB1-34 gave no evidence of synergistic enhancement of AD2 activity, which would be expected if weak activation domains were present. Furthermore, activity of AtHSFB1-4 (class B) was not rescued by coexpression with AtHSFA4-21 (class A) indicating that the class A HSF was not able to provide a missing function required for class B activity. The transcriptional activation potential of Arabidopsis AtHSFA4-21 was mapped primarily to a 39 amino acid fragment in the C-terminus enriched in bulky hydrophobic and acidic residues. Deletion mutagenesis of the C-terminal activator regions of tomato and Arabidopsis HSFs indicated that these plant HSFs lack heat-inducible regulatory regions analogous to those of mammalian HSF1. These findings suggest that heat shock regulation in plants may differ from metazoans by partitioning negative and positive functional domains onto separate HSF proteins. Class A HSFs are primarily responsible for stress-inducible activation of heat shock genes whereas some of the inert class B HSFs may be specialized for repression, or down-regulation, of the heat shock response.

  12. Induction of heat shock gene expression in RAT1 primary fibroblast cells by ELF electric fields.

    Science.gov (United States)

    Frisch, Paul; Li, Gloria C; McLeod, Kenneth; Laramee, Craig B

    2013-07-01

    Recent studies have demonstrated that the Ku70 gene fragment can be placed in the anti-sense orientation under the control of a heat-inducible heat shock protein 70 (HSP70) promoter and activated through heat shock exposure. This results in attenuation of the Ku70 protein expression, inhibiting cellular repair processes, and sensitizing the transfected cells to exposures such as the ionizing radiation exposures used clinically. However, achieving the tissue temperatures necessary to thermally induce the HSP70 response presents significant limitations to the clinical application of this strategy. Previous findings suggest an alternative approach to inducing a heat shock response, specifically through the use of extremely low frequency (ELF) electrical field stimulation. To further pursue this approach, we investigated HSP70 responses in transfected rat primary fibroblast (RAT1) cells exposed to 10 Hz electric fields at intensities of 20-500 V/m. We confirmed that low frequency electric fields can induce HSP70 heat shock expression, with peak responses obtained at 8 h following a 2 h field exposure. However, the approximate threefold increase in expression is substantially lower than that obtained using thermal stimulation, raising questions of the clinical utility of the response.

  13. Test of a new heat-flow equation for dense-fluid shock waves.

    Science.gov (United States)

    Holian, Brad Lee; Mareschal, Michel; Ravelo, Ramon

    2010-09-21

    Using a recently proposed equation for the heat-flux vector that goes beyond Fourier's Law of heat conduction, we model shockwave propagation in the dense Lennard-Jones fluid. Disequilibrium among the three components of temperature, namely, the difference between the kinetic temperature in the direction of a planar shock wave and those in the transverse directions, particularly in the region near the shock front, gives rise to a new transport (equilibration) mechanism not seen in usual one-dimensional heat-flow situations. The modification of the heat-flow equation was tested earlier for the case of strong shock waves in the ideal gas, which had been studied in the past and compared to Navier-Stokes-Fourier solutions. Now, the Lennard-Jones fluid, whose equation of state and transport properties have been determined from independent calculations, allows us to study the case where potential, as well as kinetic contributions are important. The new heat-flow treatment improves the agreement with nonequilibrium molecular-dynamics simulations under strong shock wave conditions, compared to Navier-Stokes.

  14. Pilot study of intratumoral injection of recombinant heat shock protein 70 in the treatment of malignant brain tumors in children

    Directory of Open Access Journals (Sweden)

    Shevtsov MA

    2014-06-01

    of recombinant Hsp70 in patients with cancer. Further randomized clinical trials are recommended to assess the optimum dose of the chaperone, the treatment schedule, and clinical efficacy. Keywords: heat shock protein 70, malignant brain tumors, immunotherapy, glioblastoma

  15. Heat Shock Protein 90 Inhibitors repurposed against Entamoeba histolytica

    Directory of Open Access Journals (Sweden)

    Dea eShahinas

    2015-04-01

    Full Text Available Hsp90 is an essential chaperone responsible for trafficking a vast array of client proteins, which are substrates that Hsp90 regulates in eukaryotic cells under stress conditions. The ATP-binding N-terminal domain of Hsp90 (also known as a GHKL type ATPase domain can serve as a specific drug target, because sufficient structural diversity in the ATP-binding pocket of Hsp90 allows for ortholog selectivity of Hsp90 inhibitors. The primary objective of this study is to identify inhibitors specific for the ATP-binding domain of Entamoeba histolytica Hsp90 (EhHsp90. An additional aim, using a combination of site-directed mutagenesis and a protein in vitro assay, is to show that the antiparasitic activity of Hsp90 inhibitors is dependent on specific residues within the ATP-binding domain. Here, we tested the activity of 43 inhibitors of Hsp90 that we previously identified using a high-throughput screen. Of the 43 compounds tested, 19 competed for binding of the EhHsp90 ATP-binding domain. Five out of the 19 EhHsp90 protein hits demonstrated activity against E. histolytica in vitro culture: rifabutin, rutilantin, cetylpyridinium chloride, pararosaniline pamoate and gentian violet. These 5 top E. histolytica Hsp90 inhibitors showed 30-100% inhibition of E. histolytica in culture in the micromolar range. These data suggest that E. histolytica-specific Hsp90 inhibitors are possible to identify and provide important lead compounds for the development of novel antiamebic drugs.

  16. Heat conduction: hyperbolic self-similar shock-waves in solids

    CERN Document Server

    Barna, Imre Ferenc

    2012-01-01

    Analytic solutions for cylindrical thermal waves in solid medium is given based on the nonlinear hyperbolic system of heat flux relaxation and energy conservation equations. The Fourier-Cattaneo phenomenological law is generalized where the relaxation time and heat propagation coefficient have a general power law temperature dependence. From such laws one cannot form a second order parabolic or telegraph-type equation. We consider the original non-linear hyperbolic system itself with the self-similar Ansatz for the temperature distribution and for the heat flux. As results continuous and shock-wave solutions are presented. For physical establishment numerous materials with various temperature dependent heat conduction coefficients are mentioned.

  17. HEAT SHOCK FACTOR 1-MEDIATED THERMOTOLERANCE PREVENTS CELL DEATH AND RESULTS IN G2/M CELL CYCLE ARREST

    Science.gov (United States)

    Mammalian cells respond to stress by activating heat shock transcription factors (e.g., HSF1) that regulate increased synthesis of heat shock proteins (HSPs). HSPs mediate protection from deleterious effects of stress by preventing permanent disruption of normal cellular mitosis...

  18. HEAT SHOCK FACTOR 1-MEDIATED THERMOTOLERANCE PREVENTS CELL DEATH AND RESULTS IN G2/M CELL CYCLE ARREST

    Science.gov (United States)

    Mammalian cells respond to stress by activating heat shock transcription factors (e.g., HSF1) that regulate increased synthesis of heat shock proteins (HSPs). HSPs mediate protection from deleterious effects of stress by preventing permanent disruption of normal cellular mitosis...

  19. Asymmetric shock heating and the terrestrial magma ocean origin of the Moon.

    Science.gov (United States)

    Karato, Shun-ichiro

    2014-01-01

    One of the difficulties of the current giant impact model for the origin of the Moon is to explain the marked similarity in the isotopic compositions and the substantial differences in the major element chemistry. Physics of shock heating is analyzed to show that the degree of heating is asymmetric between the impactor and the target, if the target (the proto-Earth) had a magma-ocean but the impactor did not. The magma ocean is heated much more than the solid impactor and the vapor-rich jets come mainly from the magma-ocean from which the Moon might have been formed. In this scenario, the similarity and differences in the composition between the Moon and Earth would be explained as a natural consequence of a collision in the later stage of planetary formation. Including the asymmetry in shock heating is the first step toward explaining the chemical composition of the Moon.

  20. Translational control of small heat shock genes in mesophilic and thermophilic cyanobacteria by RNA thermometers.

    Science.gov (United States)

    Cimdins, Annika; Klinkert, Birgit; Aschke-Sonnenborn, Ursula; Kaiser, Friederike M; Kortmann, Jens; Narberhaus, Franz

    2014-01-01

    Cyanobacteria constitute a heterogeneous phylum of oxygen-producing, photosynthetic prokaryotes. They are susceptible to various stress conditions like heat, salt, or light stress, all inducing the cyanobacterial heat shock response (HSR). Cyanobacterial small heat shock proteins (sHsps) are known to preserve thylakoid membrane integrity under stress conditions, thereby protecting the photosynthesis machinery. In Synechocystis sp PCC 6803, synthesis of the sHsp Hsp17 is regulated by an RNA thermometer (RNAT) in the 5'-untranslated region (5'-UTR) of the hsp17 mRNA. RNATs are direct temperature sensors that control expression of many bacterial heat shock and virulence genes. They hinder translation at low temperatures by base pairing, thus blocking ribosome access to the mRNA.   To explore the temperature range in which RNATs act, we studied various RNAT candidates upstream of sHsp genes from mesophilic and thermophilic cyanobacteria. The mesophilic cyanobacteria Anabaena variabilis and Nostoc sp chromosomally encode two sHsps each. Reporter gene studies suggested RNAT-mediated post-transcriptional regulation of shsp expression in both organisms. Detailed structural analysis of the two A. variabilis candidates revealed two novel RNAT types. The first, avashort, regulates translation primarily by masking of the AUG translational start codon. The second, featuring an extended initial hairpin, thus named avalong, presumably makes use of complex tertiary interaction. The 5'-UTR of the small heat shock gene hspA in the thermophile Thermosynechococcus elongatus is predicted to adopt an extended secondary structure. Structure probing revealed that the ribosome binding site was blocked at temperatures below 55 °C. The results of this study demonstrate that cyanobacteria commonly use RNATs to control expression of their small heat shock genes.

  1. Induction of Antioxidant and Heat Shock Protein Responses During Torpor in the Gray Mouse Lemur, Microcebus murinus

    Institute of Scientific and Technical Information of China (English)

    Cheng-Wei Wu; Kyle K Biggar; Jing Zhang; Shannon N Tessier; Fabien Pifferi; Martine Perret; Kenneth B Storey

    2015-01-01

    A natural tolerance of various environmental stresses is typically supported by various cytoprotective mechanisms that protect macromolecules and promote extended viability. Among these are antioxidant defenses that help to limit damage from reactive oxygen species and chaper-ones that help to minimize protein misfolding or unfolding under stress conditions. To understand the molecular mechanisms that act to protect cells during primate torpor, the present study charac-terizes antioxidant and heat shock protein (HSP) responses in various organs of control (aroused)and torpid gray mouse lemurs, Microcebus murinus. Protein expression of HSP70 and HSP90a was elevated to 1.26 and 1.49 fold, respectively, in brown adipose tissue during torpor as compared with control animals, whereas HSP60 in liver of torpid animals was 1.15 fold of that in control (P<0.05). Among antioxidant enzymes, protein levels of thioredoxin 1 were elevated to 2.19 fold in white adipose tissue during torpor, whereas Cu–Zn superoxide dismutase 1 levels rose to 1.1 fold in skeletal muscle (P<0.05). Additionally, total antioxidant capacity was increased to 1.6 fold in liver during torpor (P<0.05), while remaining unchanged in the five other tissues. Overall, our data suggest that antioxidant and HSP responses are modified in a tissue-specific manner during daily torpor in gray mouse lemurs. Furthermore, our data also show that cytoprotective strategies employed during primate torpor are distinct from the strategies in rodent hibernation as reported in previous studies.

  2. Evidence of prognostic relevant expression profiles of heat-shock proteins and glucose-regulated proteins in oesophageal adenocarcinomas.

    Directory of Open Access Journals (Sweden)

    Julia Slotta-Huspenina

    Full Text Available A high percentage of oesophageal adenocarcinomas show an aggressive clinical behaviour with a significant resistance to chemotherapy. Heat-shock proteins (HSPs and glucose-regulated proteins (GRPs are molecular chaperones that play an important role in tumour biology. Recently, novel therapeutic approaches targeting HSP90/GRP94 have been introduced for treating cancer. We performed a comprehensive investigation of HSP and GRP expression including HSP27, phosphorylated (p-HSP27((Ser15, p-HSP27((Ser78, p-HSP27((Ser82, HSP60, HSP70, HSP90, GRP78 and GRP94 in 92 primary resected oesophageal adenocarcinomas by using reverse phase protein arrays (RPPA, immunohistochemistry (IHC and real-time quantitative RT-PCR (qPCR. Results were correlated with pathologic features and survival. HSP/GRP protein and mRNA expression was detected in all tumours at various levels. Unsupervised hierarchical clustering showed two distinct groups of tumours with specific protein expression patterns: The hallmark of the first group was a high expression of p-HSP27((Ser15, Ser78, Ser82 and low expression of GRP78, GRP94 and HSP60. The second group showed the inverse pattern with low p-HSP27 and high GRP78, GRP94 and HSP60 expression. The clinical outcome for patients from the first group was significantly improved compared to patients from the second group, both in univariate analysis (p = 0.015 and multivariate analysis (p = 0.029. Interestingly, these two groups could not be distinguished by immunohistochemistry or qPCR analysis. In summary, two distinct and prognostic relevant HSP/GRP protein expression patterns in adenocarcinomas of the oesophagus were detected by RPPA. Our approach may be helpful for identifying candidates for specific HSP/GRP-targeted therapies.

  3. Evidence of prognostic relevant expression profiles of heat-shock proteins and glucose-regulated proteins in oesophageal adenocarcinomas.

    Science.gov (United States)

    Slotta-Huspenina, Julia; Berg, Daniela; Bauer, Karina; Wolff, Claudia; Malinowsky, Katharina; Bauer, Lukas; Drecoll, Enken; Bettstetter, Marcus; Feith, Marcus; Walch, Axel; Höfler, Heinz; Becker, Karl-Friedrich; Langer, Rupert

    2012-01-01

    A high percentage of oesophageal adenocarcinomas show an aggressive clinical behaviour with a significant resistance to chemotherapy. Heat-shock proteins (HSPs) and glucose-regulated proteins (GRPs) are molecular chaperones that play an important role in tumour biology. Recently, novel therapeutic approaches targeting HSP90/GRP94 have been introduced for treating cancer. We performed a comprehensive investigation of HSP and GRP expression including HSP27, phosphorylated (p)-HSP27((Ser15)), p-HSP27((Ser78)), p-HSP27((Ser82)), HSP60, HSP70, HSP90, GRP78 and GRP94 in 92 primary resected oesophageal adenocarcinomas by using reverse phase protein arrays (RPPA), immunohistochemistry (IHC) and real-time quantitative RT-PCR (qPCR). Results were correlated with pathologic features and survival. HSP/GRP protein and mRNA expression was detected in all tumours at various levels. Unsupervised hierarchical clustering showed two distinct groups of tumours with specific protein expression patterns: The hallmark of the first group was a high expression of p-HSP27((Ser15, Ser78, Ser82)) and low expression of GRP78, GRP94 and HSP60. The second group showed the inverse pattern with low p-HSP27 and high GRP78, GRP94 and HSP60 expression. The clinical outcome for patients from the first group was significantly improved compared to patients from the second group, both in univariate analysis (p = 0.015) and multivariate analysis (p = 0.029). Interestingly, these two groups could not be distinguished by immunohistochemistry or qPCR analysis. In summary, two distinct and prognostic relevant HSP/GRP protein expression patterns in adenocarcinomas of the oesophagus were detected by RPPA. Our approach may be helpful for identifying candidates for specific HSP/GRP-targeted therapies.

  4. Tumor-derived heat shock protein 70 peptide complexes are cross-presented by human dendritic cells.

    Science.gov (United States)

    Noessner, Elfriede; Gastpar, Robert; Milani, Valeria; Brandl, Anna; Hutzler, Peter J S; Kuppner, Maria C; Roos, Miriam; Kremmer, Elisabeth; Asea, Alexzander; Calderwood, Stuart K; Issels, Rolf D

    2002-11-15

    Our study demonstrates that tumor-derived heat shock protein (HSP)70 chaperones a tyrosinase peptide and mediates its transfer to human immature dendritic cells (DCs) by receptor-dependent uptake. Human tumor-derived HSP70 peptide complexes (HSP70-PC) thus have the immunogenic potential to instruct DCs to cross-present endogenously expressed, nonmutated, and tumor antigenic peptides that are shared among tumors of the melanocytic lineage for T cell recognition. T cell stimulation by HSP70-instructed DCs is dependent on the Ag bound to HSP70 in that only DCs incubated with HSP70-PC purified from tyrosinase-positive (HSP70-PC/tyr(+)) but not from tyrosinase-negative (HSP70-PC/tyr(-)) melanoma cells resulted in the specific activation of the HLA-A*0201-restricted tyrosinase peptide-specific cytotoxic T cell clone. HSP70-PC-mediated T cell stimulation is very efficient, delivering the tyrosinase peptide at concentrations as low as 30 ng/ml of HSP70-PC for T cell recognition. Receptor-dependent binding of HSP70-PC and active cell metabolism are prerequisites for MHC class I-restricted cross-presentation and T cell stimulation. T cell stimulation does not require external DC maturation signals (e.g., exogenously added TNF-alpha), suggesting that signaling DC maturation is an intrinsic property of the HSP70-PC itself and related to receptor-mediated binding. The cross-presentation of a shared human tumor Ag together with the exquisite efficacy are important new aspects for HSP70-based immunotherapy in clinical anti-cancer vaccination strategies, and suggest a potential extension of HSP70-based vaccination protocols from a patient-individual treatment modality to its use in an allogeneic setting.

  5. The Role of Heat Shock Response in Insulin Resistance and Diabetes

    OpenAIRE

    Tatsuya Kondo; Hiroyuki Motoshima; Motoyuki Igata; Junji Kawashima; Takeshi Matsumura; Hirofumi Kai; Eiichi Araki

    2014-01-01

    The expansion of life-style related diseases, such as metabolic syndrome (MS) and type 2 diabetes mellitus (T2DM), appears to be unstoppable. It is also difficult to cease their complications in spite of many antidiabetic medications or intervention of public administration. We and our collaborators found that physical medicine using simultaneous stimulation of heat with mild electric current activates heat shock response, thereby reducing visceral adiposity, insulin resistance, chronic infla...

  6. Effects of heat shock, stannous chloride, and gallium nitrate on the rat inflammatory response

    OpenAIRE

    House, S.D.; Guidon, P T; Perdrizet, G.A.; Rewinski, M.; Kyriakos, R.; Bockman, R S; Mistry, T.; Gallagher, P.A.; Hightower, L E

    2001-01-01

    Heat and a variety of other stressors cause mammalian cells and tissues to acquire cytoprotection. This transient state of altered cellular physiology is nonproliferative and antiapoptotic. In this study, male Wistar rats were stress conditioned with either stannous chloride or gallium nitrate, which have immunosuppressive effects in vivo and in vitro, or heat shock, the most intensively studied inducer of cytoprotection. The early stages of inflammation in response to topical suffusion of me...

  7. The Role of Heat Shock Response in Insulin Resistance and Diabetes

    OpenAIRE

    Tatsuya Kondo; Hiroyuki Motoshima; Motoyuki Igata; Junji Kawashima; Takeshi Matsumura; Hirofumi Kai; Eiichi Araki

    2014-01-01

    The expansion of life-style related diseases, such as metabolic syndrome (MS) and type 2 diabetes mellitus (T2DM), appears to be unstoppable. It is also difficult to cease their complications in spite of many antidiabetic medications or intervention of public administration. We and our collaborators found that physical medicine using simultaneous stimulation of heat with mild electric current activates heat shock response, thereby reducing visceral adiposity, insulin resistance, chronic infla...

  8. Fe I oscillator strengths determined from anomalous dispersion of shock-heated gases.

    Science.gov (United States)

    Huber, M. C. E.; Parkinson, W. H.

    1972-01-01

    Determination of Fe I oscillator strengths by the hook method on shock-heated gases. Within the given errors these values agree with oscillator strengths obtained by other methods, including wall-stabilized arc and shock-tube emission, the beam-foil technique, and delayed-coincidence measurements, except that the data reported in the present article tend to be somewhat higher. If it is assumed that no change occurs in atmospheric models, the authors' f-value scale would suggest a solar abundance at the lower limit of the recently published values - namely, log (A sub Fe/A sub H) + 12 = 7.4. This study demonstrates the effectiveness of the hook method for quantitative spectroscopy on shock-heated gases and points up its usefulness for gas diagnostics on optically thick lines.

  9. 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

    -treated flies. Several hsp70 probe sets were up-regulated 1.7–2-fold in the mildly stressed flies weeks after the last heat treatment (P heat shock protein, Hsp70, is reported to return to normal levels of expression shortly after heat stress. We......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...... 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....

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

    Science.gov (United States)

    Bernardini, M.; Asproulias, I.; Larsson, J.; Pirozzoli, S.; Grasso, F.

    2016-12-01

    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 free-stream Mach number 2.28 and shock angle of the wedge generator φ =8∘ . Five values of the wall-to-recovery-temperature ratio (Tw/Tr ) 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, which 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, with the maximum thermal and dynamic loads found for the case of the cold wall. The analysis reveals that the fluctuating heat flux exhibits a strong intermittent behavior, characterized by scattered spots with extremely high values compared to the mean. Furthermore, the analogy between momentum and heat transfer, typical of compressible, wall-bounded, equilibrium turbulent flows, does not apply for most of the interaction domain. The premultiplied spectra of the wall heat flux do not show any evidence of the influence of the low-frequency shock motion, and the primary mechanism for the generation of peak heating is found to be linked with the turbulence amplification in the interaction region.

  11. 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.

  12. Associations among heat shock protein 70 genotype, forage system, and horn fly infestation of beef cattle

    Science.gov (United States)

    Horn fly infestations on beef cattle results in decreased productivity and challenges enterprise sustainability. Objective of this experiment was to determine the relationships among, cattle breed, heat shock protein 70 (Hsp70) genotype, and horn fly density. Angus (n = 20), Brahman (n = 17), and ...

  13. HIFI observations of warm gas in DR21 : Shock versus radiative heating

    NARCIS (Netherlands)

    Ossenkopf, Volker; Roellig, M.; Simon, R.; Schneider, N.; Okada, Y.; Stutzki, J.; Gerin, M.; Akyilmaz, M.; Beintema, D; Benz, A. O.; Berne, O.; Boulanger, F.; Bumble, B.; Coeur-Joly, O.; Dedes, C.; Diez-Gonzalez, M. C.; France, K.; Fuente, A.; Gallego, J. D.; Goicoechea, J. R.; Guesten, R.; Harris, A.; Higgins, R.; Jackson, B.; Jarchow, C.; Joblin, C.; Klein, T.; Kramer, C.; Lord, S.; Martin, P.; Martin-Pintado, J.; Mookerjea, B.; Neufeld, D. A.; Phillips, T.; Rizzo, J. R.; van der Tak, F. F. S.; Teyssier, D.; Yorke, H.

    2010-01-01

    Context. The molecular gas in the DR21 massive star formation region is known to be affected by the strong UV field from the central star cluster and by a fast outflow creating a bright shock. The relative contribution of both heating mechanisms is the matter of a long debate. Aims. By better sampli

  14. Heat-shock protein ClpL/HSP100 increases penicillin tolerance 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

    2011-01-01

    Penicillin resistance and tolerance has been an increasing threat to the treatment of pneumococcal pneumoniae. However, no penicillin tolerance-related genes have been claimed. Here we show that a major heat shock protein ClpL/HSP100 could modulate the expression of a cell wall synthesis enzyme PBP2x, and subsequently increase cell wall thickness and penicillin tolerance in Streptococus pneumoniae.

  15. 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

  16. 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.

  17. A new case of multiple mitochondrial enzyme deficiencies with decreased amount of heat shock protein 60

    NARCIS (Netherlands)

    Briones, P; Vilaseca, MA; Ribes, A; Vernet, A; Lluch, M; Cusi, [No Value; Huckriede, A; Agsteribbe, E

    1997-01-01

    Heat shock protein 60 (hsp60) is a mitochondrial matrix protein involved in the folding and correct assembly of polypeptides into complex mitochondrial enzymes. Its deficiency has recently been described as the most likely primary cause of congenital lactic acidaemia with multiple mitochondrial enzy

  18. 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...

  19. Identification of genes specifically expressed during heat shock treatment in Aedes aegypti

    Science.gov (United States)

    Temperature is important for mosquito development and physiological response. Several genes of heat shock protein (HSP) families are known to be expressed in mosquitoes and may be crucial in responding to stress induced by elevated temperature. Suppression subtractive hybridization (SSH) was used to...

  20. The role of the heat shock response in the cytoprotection of the intestinal epithelium

    NARCIS (Netherlands)

    Malago, Joshua Joseph

    2003-01-01

    Under normal conditions, the intestinal epithelial cells produce constitutive amount of heat shock proteins (Hsps) that are elevated following stressful stimuli. As the intestine is constantly exposed to variety of agents like diet, normal flora, infectious microorganisms, chemicals, and immune medi

  1. The growing world of small heat shock proteins : from structure to functions

    NARCIS (Netherlands)

    Carra, Serena; Alberti, Simon; Arrigo, Patrick A; Benesch, Justin L; Benjamin, Ivor J; Boelens, Wilbert; Bartelt-Kirbach, Britta; Brundel, Bianca J J M; Buchner, Johannes; Bukau, Bernd; Carver, John A; Ecroyd, Heath; Emanuelsson, Cecilia; Finet, Stephanie; Golenhofen, Nikola; Goloubinoff, Pierre; Gusev, Nikolai; Haslbeck, Martin; Hightower, Lawrence E; Kampinga, Harm H; Klevit, Rachel E; Liberek, Krzysztof; Mchaourab, Hassane S; McMenimen, Kathryn A; Poletti, Angelo; Quinlan, Roy; Strelkov, Sergei V; Toth, Melinda E; Vierling, Elizabeth; Tanguay, Robert M

    2017-01-01

    Small heat shock proteins (sHSPs) are present in all kingdoms of life and play fundamental roles in cell biology. sHSPs are key components of the cellular protein quality control system, acting as the first line of defense against conditions that affect protein homeostasis and proteome stability,

  2. Accumulation of Stable Full-Length Circular Group I Intron RNAs during Heat-Shock

    DEFF Research Database (Denmark)

    Andersen, Kasper L.; Beckert, Bertrand; Masquida, Benoit;

    2016-01-01

    the copy number of circular intron RNA from the myxomycete Didymium iridis. In exponentially growing amoebae, the circular introns are nuclear and found in 70 copies per cell. During heat-shock, the circular form is up-regulated to more than 500 copies per cell. The intron harbours two ribozymes that have...

  3. The declined phosphorylation of Heat shock protein 27 in rat cardiac muscle after hindlimb unloading

    Science.gov (United States)

    Yuan, Ming; Jiang, Shizhong; Li, Zhili; Yuan, Min; Ting, Li; Ying, Zhang; Wang, Desheng

    2009-07-01

    Hindlimb unloading can induce the cardiac atrophy and diminished cardiac function, however, the mechanisms responsible for which remain elusive. The chronic volume unloading of heart, which decreases the local mechanical stress, may lead to cardiac atrophy after hindlimb unloading. Many studies showed that integrin signaling, p38 MAPK, Heat shock protein 27 and cytoskeleton involved in the hypertrophic growth induced by mechanical stress. However, the mechanisms responsible for cardiac atrophy after hindlimb unloading are still unclear. In this study, we used the tail-suspended, hindlimb unloading rat model to simulate the effects of microgravity. Western blot analysis was used to detect the protein expression of Heat shock protein 27, focal adhesion kinase, p38 MAPK and their phosphorylation levels in rat cardiac muscle after 14d hindlimb unloading. The results showed that the phosphorylation levels of both Heat shock protein 27 and p38 MAPK were decreased significantly in rat cardiac muscle after hindlimb unloading. However, the phosphorylation level of focal adhesion kinase was not decreased significantly. The results suggested that Heat shock protein 27, the downstream of p38 MAPK, might play a critical role in the cardiac atrophy in response to simulated microgravity induced by hindlimb unloading.

  4. Derivation of Varying Specific Heat Gasdynamic Functions,Normal Shock Analytical Solution and its Improvements

    Institute of Scientific and Technical Information of China (English)

    TsuiChih-Ya

    1992-01-01

    A set of new gasdynamic functions with varying specific heat are deriveo for the first time.An original analytical solution of normal shock waves is owrked out therewith.This solution is thereafter further improved by not involving total temperature,Illustrative examples of comparison are given,including also some approximate solutions to show the orders of their errors.

  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.

    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

  6. Accumulation of Stable Full-Length Circular Group I Intron RNAs during Heat-Shock

    DEFF Research Database (Denmark)

    Andersen, Kasper L.; Beckert, Bertrand; Masquida, Benoit

    2016-01-01

    the copy number of circular intron RNA from the myxomycete Didymium iridis. In exponentially growing amoebae, the circular introns are nuclear and found in 70 copies per cell. During heat-shock, the circular form is up-regulated to more than 500 copies per cell. The intron harbours two ribozymes that have...

  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. Functional characterization of the small heat shock protein Hsp12p from Candida albicans.

    Directory of Open Access Journals (Sweden)

    Man-Shun Fu

    Full Text Available Hsp12p is considered to be a small heat shock protein and conserved among fungal species. To investigate the expression of this heat shock protein in the fungal pathogen Candida albicans we developed an anti-CaHsp12p antibody. We show that this protein is induced during stationary phase growth and under stress conditions including heat shock, osmotic, oxidative and heavy metal stress. Furthermore, we find that CaHsp12p expression is influenced by the quorum sensing molecule farnesol, the change of CO(2 concentration and pH. Notably we show that the key transcription factor Efg1p acts as a positive regulator of CaHsp12p in response to heat shock and oxidative stress and demonstrate that CaHsp12p expression is additionally modulated by Hog1p and the cAMP-PKA signaling pathway. To study the function of Hsp12p in C. albicans we generated a null mutant, in which all four CaHSP12 genes have been deleted. Phenotypic analysis of the strain shows that CaHSP12 is not essential for stress resistance, morphogenesis or virulence when tested in a Drosophila model of infection. However, when overexpressed, CaHSP12 significantly enhanced cell-cell adhesion, germ tube formation and susceptibility to azole antifungal agents whilst desensitizing C. albicans to the quorum sensing molecule farnesol.

  9. 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...

  10. 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.

  11. 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. E...

  12. Heat Shock Protein Induction in Human Cells by CO2 Laser Irradiation

    Science.gov (United States)

    1993-06-14

    Boorstein W. A review of the role of 70 kD heat shock proteins in protein translocation across membranes. Antonie Van Leeuwenhoek 1990:58:137-46. 32...1991;65:363-366. 55. Young DB. Stress proteins and the immune response. Antonie Van Leeuwenhoek 1990;58:203-208. 56. Craig EA, Kramer J, Kosic-Smithers

  13. 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.

  14. Uncertainty quantification of bacterial aerosol neutralization in shock heated gases

    Science.gov (United States)

    Schulz, J. C.; Gottiparthi, K. C.; Menon, S.

    2015-01-01

    A potential method for the neutralization of bacterial endospores is the use of explosive charges since the high thermal and mechanical stresses in the post-detonation flow are thought to be sufficient in reducing the endospore survivability to levels that pose no significant health threat. While several experiments have attempted to quantify endospore survivability by emulating such environments in shock tube configurations, numerical simulations are necessary to provide information in scenarios where experimental data are difficult to obtain. Since such numerical predictions require complex, multi-physics models, significant uncertainties could be present. This work investigates the uncertainty in determining the endospore survivability from using a reduced order model based on a critical endospore temperature. Understanding the uncertainty in such a model is necessary in quantifying the variability in predictions using large-scale, realistic simulations of bacterial endospore neutralization by explosive charges. This work extends the analysis of previous large-scale simulations of endospore neutralization [Gottiparthi et al. in (Shock Waves, 2014. doi:10.1007/s00193-014-0504-9)] by focusing on the uncertainty quantification of predicting endospore neutralization. For a given initial mass distribution of the bacterial endospore aerosol, predictions of the intact endospore percentage using nominal values of the input parameters match the experimental data well. The uncertainty in these predictions are then investigated using the Dempster-Shafer theory of evidence and polynomial chaos expansion. The studies show that the endospore survivability is governed largely by the endospore's mass distribution and their exposure or residence time at the elevated temperatures and pressures. Deviations from the nominal predictions can be as much as 20-30 % in the intermediate temperature ranges. At high temperatures, i.e., strong shocks, which are of the most interest, the

  15. Heat shock modulates the subcellular localization, stability, and activity of HIPK2

    Energy Technology Data Exchange (ETDEWEB)

    Upadhyay, Mamta; Bhadauriya, Pratibha; Ganesh, Subramaniam, E-mail: sganesh@iitk.ac.in

    2016-04-15

    The homeodomain-interacting protein kinase-2 (HIPK2) is a highly conserved serine/threonine kinase and is involved in transcriptional regulation. HIPK2 is a highly unstable protein, and is kept at a low level under normal physiological conditions. However, exposure of cells to physiological stress – such as hypoxia, oxidative stress, or UV damage – is known to stabilize HIPK2, leading to the HIPK2-dependent activation of p53 and the cell death pathway. Therefore HIPK2 is also known as a stress kinase and as a stress-activated pro-apoptotic factor. We demonstrate here that exposure of cells to heat shock results in the stabilization of HIPK2 and the stabilization is mediated via K63-linked ubiquitination. Intriguingly, a sub-lethal heat shock (42 °C, 1 h) results in the cytoplasmic localization of HIPK2, while a lethal heat shock (45 °C, 1 h) results in its nuclear localization. Cells exposed to the lethal heat shock showed significantly higher levels of the p53 activity than those exposed to the sub-lethal thermal stress, suggesting that both the level and the nuclear localization are essential for the pro-apoptotic activity of HIPK2 and that the lethal heat shock could retain the HIPK2 in the nucleus to promote the cell death. Taken together our study underscores the importance of HIPK2 in stress mediated cell death, and that the HIPK2 is a generic stress kinase that gets activated by diverse set of physiological stressors.

  16. Teratogens induce a subset of small heat shock proteins in Drosophila primary embryonic cell cultures.

    Science.gov (United States)

    Buzin, C H; Bournias-Vardiabasis, N

    1984-01-01

    Drosophila embryonic cells placed into culture just after gastrulation differentiate in vitro over the next 24 hr. A number of drugs that are teratogenic in mammalian systems have been found to inhibit muscle or neuron differentiation (or both) in these developing cultures. We have examined, by two-dimensional gel electrophoresis, the effects of these drugs on protein synthesis in embryonic cells. For nine teratogens tested, cells treated for 20 hr with the drug show a dramatic induction of three proteins of about 20 kilodaltons, in addition to the normal proteins synthesized by untreated cells. Three teratogens as well as all eight nonteratogens tested did not show this induction. The induced proteins appear to be identical to three of the heat shock proteins (hsp 23, 22a, and 22b), as shown by electrophoretic mobilities and peptide mapping by partial proteolysis. A 37 degrees C heat shock of the embryonic cells produces the full complement of heat shock proteins, whereas drug-treated cells induce only the subset hsp 23, 22a, and 22b but not hsp 26 or 27. beta-Ecdysterone, the Drosophila molting hormone, also inhibits embryonic differentiation and induces hsp 23, 22a, and 22b, a partial subset of the heat shock proteins (hsp 22, 23, 26, and 27) induced by the hormone in imaginal discs and some Drosophila continuous cell lines. Dose-response studies of several drugs show a correlation between the degree of inhibition of differentiation and the level of induction of hsp 23, 22a, and 22b. The induction of heat shock proteins by drugs may reflect specific types of stress that can also give rise to teratogenesis. Images PMID:6588379

  17. Putative cis-regulatory elements associated with heat shock genes activated during excystation of Cryptosporidium parvum.

    Directory of Open Access Journals (Sweden)

    Benjamin Cohn

    Full Text Available BACKGROUND: Cryptosporidiosis is a ubiquitous infectious disease, caused by the protozoan parasites Cryptosporidium hominis and C. parvum, leading to acute, persistent and chronic diarrhea worldwide. Although the complications of this disease can be serious, even fatal, in immunocompromised patients of any age, they have also been found to lead to long term effects, including growth inhibition and impaired cognitive development, in infected immunocompetent children. The Cryptosporidium life cycle alternates between a dormant stage, the oocyst, and a highly replicative phase that includes both asexual vegetative stages as well as sexual stages, implying fine genetic regulatory mechanisms. The parasite is extremely difficult to study because it cannot be cultured in vitro and animal models are equally challenging. The recent publication of the genome sequence of C. hominis and C. parvum has, however, significantly advanced our understanding of the biology and pathogenesis of this parasite. METHODOLOGY/PRINCIPAL FINDINGS: Herein, our goal was to identify cis-regulatory elements associated with heat shock response in Cryptosporidium using a combination of in silico and real time RT-PCR strategies. Analysis with Gibbs-Sampling algorithms of upstream non-translated regions of twelve genes annotated as heat shock proteins in the Cryptosporidium genome identified a highly conserved over-represented sequence motif in eleven of them. RT-PCR analyses, described herein and also by others, show that these eleven genes bearing the putative element are induced concurrent with excystation of parasite oocysts via heat shock. CONCLUSIONS/SIGNIFICANCE: Our analyses suggest that occurrences of a motif identified in the upstream regions of the Cryptosporidium heat shock genes represent parts of the transcriptional apparatus and function as stress response elements that activate expression of these genes during excystation, and possibly at other stages in the life

  18. Molecular Cloning and Induced Expression of Six Small Heat Shock Proteins Mediating Cold-Hardiness in Harmonia axyridis (Coleoptera: Coccinellidae).

    Science.gov (United States)

    Wang, Hui-Juan; Shi, Zuo-Kun; Shen, Qi-Da; Xu, Cai-Di; Wang, Bing; Meng, Zhao-Jun; Wang, Shi-Gui; Tang, Bin; Wang, Su

    2017-01-01

    The main function of small heat shock proteins (sHSPs) as molecular chaperones is to protect proteins from denaturation under adverse conditions. Molecular and physiological data were used to examine the sHSPs underlying cold-hardiness in Harmonia axyridis. Complementary DNA sequences were obtained for six H. axyridis sHSPs based on its transcriptome, and the expression of the genes coding for these sHSPs was evaluated by quantitative real-time PCR (qRT-PCR) in several developmental stages, under short-term cooling or heating conditions, and in black and yellow females of experimental and overwintering populations under low-temperature storage. In addition, we measured water content and the super cooling and freezing points (SCP and FP, respectively) of H. axyridis individuals from experimental and overwintering populations. The average water content was not significantly different between adults of both populations, but the SCP and FP of the overwintering population were significantly lower than that of the experimental population. Overall, the six sHSPs genes showed different expression patterns among developmental stages. In the short-term cooling treatment, Hsp16.25 and Hsp21.00 expressions first increased and then decreased, while Hsp10.87 and Hsp21.56 expressions increased during the entire process. Under short-term heating, the expressions of Hsp21.00, Hsp21.62, Hsp10.87, and Hsp16.25 showed an increasing trend, whereas Hsp36.77 first decreased and then increased. Under low-temperature storage conditions, the expression of Hsp36.77 decreased, while the expressions of Hsp21.00 and Hsp21.62 were higher than that of the control group in the experimental population. The expression of Hsp36.77 first increased and then decreased, whereas Hsp21.56 expression was always higher than that of the control group in the overwintering population. Thus, differences in sHSPs gene expression were correlated with the H. axyridis forms, suggesting that the mechanism of cold

  19. Molecular Cloning and Induced Expression of Six Small Heat Shock Proteins Mediating Cold-Hardiness in Harmonia axyridis (Coleoptera: Coccinellidae)

    Science.gov (United States)

    Wang, Hui-Juan; Shi, Zuo-Kun; Shen, Qi-Da; Xu, Cai-Di; Wang, Bing; Meng, Zhao-Jun; Wang, Shi-Gui; Tang, Bin; Wang, Su

    2017-01-01

    The main function of small heat shock proteins (sHSPs) as molecular chaperones is to protect proteins from denaturation under adverse conditions. Molecular and physiological data were used to examine the sHSPs underlying cold-hardiness in Harmonia axyridis. Complementary DNA sequences were obtained for six H. axyridis sHSPs based on its transcriptome, and the expression of the genes coding for these sHSPs was evaluated by quantitative real-time PCR (qRT-PCR) in several developmental stages, under short-term cooling or heating conditions, and in black and yellow females of experimental and overwintering populations under low-temperature storage. In addition, we measured water content and the super cooling and freezing points (SCP and FP, respectively) of H. axyridis individuals from experimental and overwintering populations. The average water content was not significantly different between adults of both populations, but the SCP and FP of the overwintering population were significantly lower than that of the experimental population. Overall, the six sHSPs genes showed different expression patterns among developmental stages. In the short-term cooling treatment, Hsp16.25 and Hsp21.00 expressions first increased and then decreased, while Hsp10.87 and Hsp21.56 expressions increased during the entire process. Under short-term heating, the expressions of Hsp21.00, Hsp21.62, Hsp10.87, and Hsp16.25 showed an increasing trend, whereas Hsp36.77 first decreased and then increased. Under low-temperature storage conditions, the expression of Hsp36.77 decreased, while the expressions of Hsp21.00 and Hsp21.62 were higher than that of the control group in the experimental population. The expression of Hsp36.77 first increased and then decreased, whereas Hsp21.56 expression was always higher than that of the control group in the overwintering population. Thus, differences in sHSPs gene expression were correlated with the H. axyridis forms, suggesting that the mechanism of cold

  20. Limits of shock heating for the chromospheres of low-gravity stars

    Science.gov (United States)

    Gadelmavla, Diaa

    2016-07-01

    This work discusses theoretical limits of chromospheric heating by shock waves in stars with low surface gravity. The computations are self consistent, and based on waves generated in stellar convection zones. We employ the new finding of the mixing length parameter α = 1.8. The Ca~II~H+K and Mg~II~h+k fluxes are computed assuming partial redistribution (PRD). The results show the strong dependence of the number of formed shocks and their transmission through the atmosphere on the value of the surface gravity. For stars with solar gravity, heating by shock waves is very efficient, this efficiency decreases with decreasing the value of G. For fixed effective temperature and solar metallicity, the temperature of the chromosphere increase with increasing the stellar surface gravity. A linear correlation is found between the surface gravity and the number of transmitted shocks. The emitted Mg~II and Ca~II fluxes show also a linear dependance on G. It has been found that there is a clear threshold value of G where no shocks are formed. The theoretically computed basal Ca~II and Mg~II fluxes follow simple formulae as a function of stellar surface gravity.

  1. 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.

  2. 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

    with 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...... the opportunity to perform survival analysis on these subjects. Haplotype relative risk, and genotype relative risk were calculated to measure the effects of haplotypes and genotypes on human survival in a sex-specific manner. A significant association of HSPA1A-AA (RR=3.864; p=0.016) and HSPA1B-AA (RR=2.764; p=0...... observations from heat shock response (HSR) study where we had shown that after heat stimulation, mononuclear cells from the carriers of genotype HSPA1L-TT had better HSR than cells with the HSPA1L-CC genotype....

  3. Observation of extremely strong shock waves in solids launched by petawatt laser heating

    Science.gov (United States)

    Lancaster, K. L.; Robinson, A. P. L.; Pasley, J.; Hakel, P.; Ma, T.; Highbarger, K.; Beg, F. N.; Chen, S. N.; Daskalova, R. L.; Freeman, R. R.; Green, J. S.; Habara, H.; Jaanimagi, P.; Key, M. H.; King, J.; Kodama, R.; Krushelnick, K.; Nakamura, H.; Nakatsutsumi, M.; MacKinnon, A. J.; MacPhee, A. G.; Stephens, R. B.; Van Woerkom, L.; Norreys, P. A.

    2017-08-01

    Understanding hydrodynamic phenomena driven by fast electron heating is important for a range of applications including fast electron collimation schemes for fast ignition and the production and study of hot, dense matter. In this work, detailed numerical simulations modelling the heating, hydrodynamic evolution, and extreme ultra-violet (XUV) emission in combination with experimental XUV images indicate shock waves of exceptional strength (200 Mbar) launched due to rapid heating of materials via a petawatt laser. We discuss in detail the production of synthetic XUV images and how they assist us in interpreting experimental XUV images captured at 256 eV using a multi-layer spherical mirror.

  4. 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...

  5. 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.

  6. Heat shock inhibits. alpha. -amylase synthesis in barley aleurone without inhibiting the activity of endoplasmic reticulum marker enzymes

    Energy Technology Data Exchange (ETDEWEB)

    Sticher, L.; Biswas, A.K.; Bush, D.S.; Jones, R.L. (Univ. of California, Berkeley (USA))

    1990-02-01

    The effects of heat shock on the synthesis of {alpha}-amylase and on the membranes of the endoplasmic reticulum (ER) of barley (Hordeum vulgare) aleurone were studied. Heat shock, imposed by raising the temperature of incubation from 25{degree}C to 40{degree}C for 3 hours, inhibits the accumulation of {alpha}-amylase and other proteins in the incubation medium of barley aleurone layers treated with gibberellic acid and Ca{sup 2+}. When ER is isolated from heat-shocked aleurone layers, less newly synthesized {alpha}-amylase is found associated with this membrane system. ER membranes, as indicated by the activities of NADH cytochrome c reductase and ATP-dependent Ca{sup 2+} transport, are not destroyed by heat stress, however. Although heat shock did not reduce the activity of ER membrane marker enzymes, it altered the buoyant density of these membranes. Whereas ER from control tissue showed a peak of marker enzyme activity at 27% to 28% sucrose (1.113-1.120 grams per cubic centimeter), ER from heat-shocked tissue peaked at 30% to 32% sucrose (1.127-1.137 grams per cubic centimeter). The synthesis of a group of proteins designated as heat-shock proteins (HSPs) was stimulated by heat shock. These HSPs were localized to different compartments of the aleurone cell. Several proteins ranging from 15 to 30 kilodaltons were found in the ER and the mitochondrial/plasma membrane fractions of heat-shocked cells, but none of the HSPs accumulated in the incubation medium of heat-shocked aleurone layers.

  7. Target heating due to the shock produced hot electrons in the shock ignition scheme

    Science.gov (United States)

    Rezaei, Somayeh; Farahbod, Amir Hossein; Jafari, Mohammad Jafar; Sobhanian, Samad

    2016-09-01

    Hot electrons are produced as a result of ignitor-corona interaction of the shock ignition scheme. In the present paper, penetration depth and energy deposition of such energetic electrons have been qualitatively discussed applying Monte Carlo simulations. Target real conditions for propagating hot electrons were taken from 1-D hydrodynamic simulations. It has been found that compressing target up to 10.4 ns helps to stop hot electrons at a proper distance thus, preventing fuel preheating. In addition, embedding hot electron energy source into the hydrodynamic code, changes of parameters p, ρ and ρR are calculated. Monoenergetic electron beams have been launched at different times of target compression. The simulation results indicate the creation of high ablation pressure as well as maximum shell areal density by a 50 keV monoenergetic electron beam with intensity 1 PW/cm2 irradiated on the compressed target at a proper time which indeed improves the implosion processes.

  8. ZERO DISSIPATION LIMIT OF THE COMPRESSIBLE HEAT-CONDUCTING NAVIER-STOKES EQUATIONS IN HE PRESENCE OF THE SHOCK

    Institute of Scientific and Technical Information of China (English)

    Wang Yi

    2008-01-01

    The zero dissipation limit of the compressible heat-conducting Navier-Stokes equations in the presence of the shock is investigated. It is shown that when the heat ε→ 0 (see (1.3)), if the solution of the corresponding Euler equations is piecewise smooth with shock wave satisfying the Lax entropy condition, then there exists a smooth solution to the Navier-Stokes equations, which converges to the piecewise smooth shock solution of the Euler equations away from the shock discontinuity at a rate of ε. The proof is given by a combination of the energy estimates and the matched asymptotic analysis introduced in [3].

  9. The chicken ubiquitin gene contains a heat shock promoter and expresses an unstable mRNA in heat-shocked cells.

    OpenAIRE

    Bond, U; Schlesinger, M J

    1986-01-01

    A chicken genomic library was screened to obtain genomic clones for ubiquitin genes. Two genes that differ in their genomic location and organization were identified. One gene, designated Ub I, contains four copies of the protein-coding sequence arranged in tandem, while the second gene, Ub II, contains three. The origin of the two major mRNAs that are induced after heat shock in chicken embryo fibroblasts was determined by generating DNA probes from the 5'-and 3'-noncoding regions of the two...

  10. An artificial HSE promoter for efficient and selective detection of heat shock pathway activity.

    Science.gov (United States)

    Ortner, Viktoria; Ludwig, Alfred; Riegel, Elisabeth; Dunzinger, Sarah; Czerny, Thomas

    2015-03-01

    Detection of cellular stress is of major importance for the survival of cells. During evolution, a network of stress pathways developed, with the heat shock (HS) response playing a major role. The key transcription factor mediating HS signalling activity in mammalian cells is the HS factor HSF1. When activated it binds to the heat shock elements (HSE) in the promoters of target genes like heat shock protein (HSP) genes. They are induced by HSF1 but in addition they integrate multiple signals from different stress pathways. Here, we developed an artificial promoter consisting only of HSEs and therefore selectively reacting to HSF-mediated pathway activation. The promoter is highly inducible but has an extreme low basal level. Direct comparison with the HSPA1A promoter activity indicates that heat-dependent expression can be fully recapitulated by isolated HSEs in human cells. Using this sensitive reporter, we measured the HS response for different temperatures and exposure times. In particular, long heat induction times of 1 or 2 h were compared with short heat durations down to 1 min, conditions typical for burn injuries. We found similar responses to both long and short heat durations but at completely different temperatures. Exposure times of 2 h result in pathway activation at 41 to 44 °C, whereas heat pulses of 1 min lead to a maximum HS response between 47 and 50 °C. The results suggest that the HS response is initiated by a combination of temperature and exposure time but not by a certain threshold temperature.

  11. Shock experiments on pre-heated alpha- and beta-quartz: 1. Optical and density data

    Science.gov (United States)

    Langenhorst, Falko; Deutsch, Alexander

    1994-07-01

    Discs of single crystal quartz, unheated, and pre-heated to 275 C and 540 C (i.e., alpha-quartz) and 630 C (i.e., beta-quartz) were experimentally shocked to pressures ranging from 20 to 40 GPa, with the shock front propagating parallel to either (10-10) or (0001). Refractive indices, density and the orientation of planar deformation features (PDFs) were determined on the recovered quartz samples. Refractive indices of pre-heated quartz are unaffected up to 25 GPa but density starts to decrease slightly up to this pressure. Above 25 GPa, pre-heating causes drastic variations: Refractive indices and birefringence of quartz shocked at ambient temperature decrease continuously, until complete isotropization is reached at 35 GPa. In quartz shocked at 630 C, refractivity drops discontinuously in the interval from 25 to 26 GPa, and complete transformation to diaplectic glass is reached at 26 GPa. Density follows the trends demonstrated by the optical parameters, with higher pre-shock temperatures yielding lower density at a given shock pressure. These results indicate that the threshold pressure for the onset of transformation to diaplectic quartz glass is largely temperature-invariant, lying at 25 GPa, whereas the pressure limit for complete transformation decreases with increasing pre-shock temperature from approximately equal 35 to approximately equal 26 GPa. Quartz shocked parallel to (0001) always has a higher density and refractivity than that shocked parallel to (10-10), indicating a significant influence of the structural anisotropy. This is also evident from the distribution of PDF orientations. Pressures greater than or equal 25 GPa cause, in quartz shocked parallel to (10-10), PDFs that are predominantly oriented parallel to set of (10-12) planes, while quartz shocked to the same pressures but parallel to (0001) contains almost exclusively PDFs parallel to set of (10-13) planes. PDF orientations in quartz shocked at ambient temperature parallel to (10-10) show

  12. Three-dimensional structure of heat shock protein 90 from Plasmodium falciparum: molecular modelling approach to rational drug design against malaria

    Indian Academy of Sciences (India)

    Ranjit Kumar; Soundara Raghavan Pavithra; Utpal Tatu

    2007-04-01

    We have recently implicated heat shock protein 90 from Plasmodium falciparum (PfHsp90) as a potential drug target against malaria. Using inhibitors specific to the nucleotide binding domain of Hsp90, we have shown potent growth inhibitory effects on development of malarial parasite in human erythrocytes. To gain better understanding of the vital role played by PfHsp90 in parasite growth, we have modeled its three dimensional structure using recently described full length structure of yeast Hsp90. Sequence similarity found between PfHsp90 and yeast Hsp90 allowed us to model the core structure with high confidence. The superimposition of the predicted structure with that of the template yeast Hsp90 structure reveals an RMSD of 3.31 Å. The N-terminal and middle domains showed the least RMSD (1.76 Å) while the more divergent C–terminus showed a greater RMSD (2.84 Å) with respect to the template. The structure shows overall conservation of domains involved in nucleotide binding, ATPase activity, co-chaperone binding as well as inter-subunit interactions. Important co-chaperones known to modulate Hsp90 function in other eukaryotes are conserved in malarial parasite as well. An acidic stretch of amino acids found in the linker region, which is uniquely extended in PfHsp90 could not be modeled in this structure suggesting a flexible conformation. Our results provide a basis to compare the overall structure and functional pathways dependent on PfHsp90 in malarial parasite. Further analysis of differences found between human and parasite Hsp90 may make it possible to design inhibitors targeted specifically against malaria.

  13. Correlation between Extracellular Heat Shock Protein 60 (exHSP60 and Homeostatic Model Assessment of Insulin Resistance (HOMA-IR in Non Diabetic Men

    Directory of Open Access Journals (Sweden)

    Meiriza Djohari

    2013-04-01

    Full Text Available BACKGROUND: Adipose tissue expansion in obesity leads to abnormal adipocyte function, chronic low grade inflammation, primary reticulum stress, and mitochondrial stress. This induces mitochondrial unfolded protein response (UPRmt that selectively upregulates mitochondrial chaperone protein. Heat shock Protein 60 (HSP60 is the primary chaperone in mitochondrial matrix. Inflammatory stress promotes HSP60 released from adipocytes and induces insulin resistance. In this study we attempted to investigate the correlation between exHSP60 and HOMA-IR in men with different ranges of waist circumference (WC. METHODS: This study was an observational cross sectional study carried out on 141 non diabetic men, aged 30-55 years old, who were divided into three groups based on WC; WC ≤90 cm, 90 cm 100 cm. Fasting plasma glucose, triglyceride, HDL-C, hsCRP, HSP60 serum and anti-HSP60 antibody, serum IL-1β serum, insulin, were examined. For statistical analysis, Kolmogorov-Smirnov and Spearman’s correlation analysis were conducted. RESULTS: There were a significant correlation between exHSP60 and HOMA-IR (r=0.281; p=0.041 in WC ≤90 cm group; and a negative significant correlation between exHSP60 and HOMA-IR (r=-0.508; p=0.007 in WC >100 cm group. CONCLUSIONS: This study showed that there was a dynamic correlation between exHSP60 and HOMA-IR in WC ≤90 cm group compared with WC >100 cm group. We also found inverse correlation patterns between exHSP60 and HOMA-IR, and between anti-HSP60 antibody and HOMA-IR in non diabetic subjects. KEYWORDS: obesity, insulin resistance, mitochondrial stress, exHSP60, hsCRP, HOMA-IR.

  14. Heat shock increases oxidative stress to modulate growth and physico-chemical attributes in diverse maize cultivars

    Science.gov (United States)

    Hussain, Iqbal; Ashraf, Muhammad Arslan; Rasheed, Rizwan; Iqbal, Muhammad; Ibrahim, Muhammad; Ashraf, Shamila

    2016-10-01

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

  15. A Cytosolic Relay of Heat Shock Proteins HSP70-1A and HSP90β Monitors the Folding Trajectory of the Serotonin Transporter*

    Science.gov (United States)

    El-Kasaby, Ali; Koban, Florian; Sitte, Harald H.; Freissmuth, Michael; Sucic, Sonja

    2014-01-01

    Mutations in the C terminus of the serotonin transporter (SERT) disrupt folding and export from the endoplasmic reticulum. Here we examined the hypothesis that a cytosolic heat shock protein relay was recruited to the C terminus to assist folding of SERT. This conjecture was verified by the following observations. (i) The proximal portion of the SERT C terminus conforms to a canonical binding site for DnaK/heat shock protein of 70 kDa (HSP70). A peptide covering this segment stimulated ATPase activity of purified HSP70-1A. (ii) A GST fusion protein comprising the C terminus of SERT pulled down HSP70-1A. The interaction between HSP70-1A and SERT was visualized in live cells by Förster resonance energy transfer: it was restricted to endoplasmic reticulum-resident transporters and enhanced by an inhibitor that traps HSP70-1A in its closed state. (iv) Co-immunoprecipitation confirmed complex formation of SERT with HSP70-1A and HSP90β. Consistent with an HSP relay, co-chaperones (e.g. HSC70-HSP90-organizing protein) were co-immunoprecipitated with the stalled mutants SERT-R607A/I608A and SERT-P601A/G602A. (v) Depletion of HSP90β by siRNA or its inhibition increased the cell surface expression of wild type SERT and SERT-F604Q. In contrast, SERT-R607A/I608A and SERT-P601A/G602A were only rendered susceptible to inhibition of HSP70 and HSP90 by concomitant pharmacochaperoning with noribogaine. (vi) In JAR cells, inhibition of HSP90 also increased the levels of SERT, indicating that endogenously expressed transporter was also susceptible to control by HSP90β. These findings support the concept that the folding trajectory of SERT is sampled by a cytoplasmic chaperone relay. PMID:25202009

  16. Wind Observations of Wave Heating and/or Particle Energization at Supercritical Interplanetary Shocks

    Science.gov (United States)

    Wilson, Lynn Bruce, III; Szabo, Adam; Koval, Andriy; Cattell, Cynthia A.; Kellogg, Paul J.; Goetz, Keith; Breneman, Aaron; Kersten, Kris; Kasper, Justin C.; Pulupa, Marc

    2011-01-01

    We present the first observations at supercritical interplanetary shocks of large amplitude (> 100 mV/m pk-pk) solitary waves, approx.30 mV/m pk-pk waves exhibiting characteristics consistent with electron Bernstein waves, and > 20 nT pk-pk electromagnetic lower hybrid-like waves, with simultaneous evidence for wave heating and particle energization. The solitary waves and the Bernstein-like waves were likely due to instabilities driven by the free energy provided by reflected ions [Wilson III et al., 2010]. They were associated with strong particle heating in both the electrons and ions. We also show a case example of parallel electron energization and perpendicular ion heating due to a electromagnetic lower hybrid-like wave. Both studies provide the first experimental evidence of wave heating and/or particle energization at interplanetary shocks. Our experimental results, together with the results of recent Vlasov [Petkaki and Freeman, 2008] and PIC [Matsukyo and Scholer, 2006] simulations using realistic mass ratios provide new evidence to suggest that the importance of wave-particle dissipation at shocks may be greater than previously thought.

  17. More than mass proportional heating of heavy ions by supercritical collisionless shocks in the solar corona

    CERN Document Server

    Zimbardo, Gaetano

    2009-01-01

    We propose a new model for explaining the observations of more than mass proportional heating of heavy ions in the polar solar corona. We point out that a large number of small scale intermittent shock waves can be present in the solar corona. The energization mechanism is, essentially, the ion reflection off supercritical quasi-perpendicular collisionless shocks in the corona and the subsequent acceleration by the motional electric field ${\\bf E} = - (1/c) {\\bf V} \\times {\\bf B}$. The acceleration due to ${\\bf E}$ is perpendicular to the magnetic field, in agreement with observations, and is more than mass proportional with respect to protons, because the heavy ion orbit is mostly upstream of the quasi-perpendicular shock foot. The observed temperature ratios between O$^{5+}$ ions and protons in the polar corona, and between $\\alpha$ particles and protons in the solar wind are easily recovered.

  18. Identification and functional characterization of Siberian wild rye (Elymus sibiricus L.) small heat shock protein 16.9 gene (EsHsp16.9) conferring diverse stress tolerance in prokaryotic cells.

    Science.gov (United States)

    Lee, Sang-Hoon; Lee, Ki-Won; Lee, Dong-Gi; Son, Daeyoung; Park, Su Jung; Kim, Ki-Yong; Park, Hyung Soo; Cha, Joon-Yung

    2015-04-01

    Small heat shock proteins (Hsps) protect against stress-inducible denaturation of substrates. Our objectives were to clone and examine the mRNA expression of the Hsp16.9 gene from Siberian wild rye grown under diverse stress treatments. We characterized EsHsp16.9 from Elymus sibiricus L. EsHsp16.9 has a 456-bp open reading frame that encodes a 151-amino acid protein with a conserved α-crystallin domain. Northern blot analysis showed that EsHsp16.9 transcripts were enhanced by heat, drought, arsenate, methyl viologen, and H2O2 treatment. In addition, recombinant EsHsp16.9 protein acts as a molecular chaperone to prevent the denaturation of malate dehydrogenase. Growth of cells overexpressing EsHsp16.9 was up to 200% more rapid in the presence of NaCl, arsenate, and polyethylene glycol than that of cells harboring an empty vector. These data suggest that EsHsp16.9 acts as a molecular chaperone that enhances stress tolerance in living organisms.

  19. Expression, localization and functional divergence of alphaB-crystallin and heat shock protein 27 in core myopathies and neurogenic atrophy.

    Science.gov (United States)

    Fischer, Dirk; Matten, Jens; Reimann, Jens; Bönnemann, Carsten; Schröder, Rolf

    2002-09-01

    AlphaB-crystallin (alphaBC) and heat shock protein 27 (hsp 27) are members of the family of small heat shock proteins (shsps), which exert a role as molecular chaperones by binding unfolded or denatured proteins, thereby suppressing irreversible protein aggregation and consecutive cell damage. The essential role of shsps in human neuromuscular disorders is highlighted by the observation that a mutation of the human alphaBC gene causes an autosomal dominant "myofibrillar myopathy" characterized by alphaBC and desmin accumulation. Furthermore, an aberrant immunostaining of alphaBC was recently reported in sporadic inclusion body myositis. In the present study we analyzed the expression and localization of alphaB-crystallin and hsp 27 in various congenital myopathies by means of indirect immunofluorescence, immunogold electron microscopy and Western blotting. We demonstrate an increased immunoreactivity of alphaBC and hsp 27 in central and minicore lesions as well as in target fibers, which renders both shsps as reliable, but nonspecific, markers for core and target structures. In contrast, Western blotting demonstrated a normal expression level of alphaBC and hsp 27, which indicates that the increased immunostaining is not the result of an enhanced protein expression. Furthermore, thiocyanate-induced degradation of actin filaments led to a dramatic decrease of hsp 27 immunostaining in core and target lesions, whereas the increased alphaBC and desmin immunostaining was found to be even more enhanced. The latter findings imply a functional diversity of both shsps with a preferential association of hsp 27 with the actin microfilament system and alphaBC with the intermyofibrillar desmin cytoskeleton in human skeletal muscle.

  20. Protein cryoprotective activity of a cytosolic small heat shock protein that accumulates constitutively in chestnut stems and is up-regulated by low and high temperatures.

    Science.gov (United States)

    Lopez-Matas, Maria-Angeles; Nuñez, Paulina; Soto, Alvaro; Allona, Isabel; Casado, Rosa; Collada, Carmen; Guevara, Maria-Angeles; Aragoncillo, Cipriano; Gomez, Luis

    2004-04-01

    Heat shock, and other stresses that cause protein misfolding and aggregation, trigger the accumulation of heat shock proteins (HSPs) in virtually all organisms. Among the HSPs of higher plants, those belonging to the small HSP (sHSP) family remain the least characterized in functional terms. We analyzed the occurrence of sHSPs in vegetative organs of Castanea sativa (sweet chestnut), a temperate woody species that exhibits remarkable freezing tolerance. A constitutive sHSP subject to seasonal periodic changes of abundance was immunodetected in stems. This protein was identified by matrix-assisted laser-desorption ionization time of flight mass spectrometry and internal peptide sequencing as CsHSP17.5, a cytosolic class I sHSP previously described in cotyledons. Expression of the corresponding gene in stems was confirmed through cDNA cloning and reverse transcription-PCR. Stem protein and mRNA profiles indicated that CsHSP17.5 is significantly up-regulated in spring and fall, reaching maximal levels in late summer and, especially, in winter. In addition, cold exposure was found to quickly activate shsp gene expression in both stems and roots of chestnut seedlings kept in growth chambers. Our main finding is that purified CsHSP17.5 is very effective in protecting the cold-labile enzyme lactate dehydrogenase from freeze-induced inactivation (on a molar basis, CsHSP17.5 is about 400 times more effective as cryoprotectant than hen egg-white lysozyme). Consistent with these observations, repeated freezing/thawing did not affect appreciably the chaperone activity of diluted CsHSP17.5 nor its ability to form dodecameric complexes in vitro. Taken together, these results substantiate the hypothesis that sHSPs can play relevant roles in the acquisition of freezing tolerance.

  1. Physico-chemical properties of R140G and K141Q mutants of human small heat shock protein HspB1 associated with hereditary peripheral neuropathies.

    Science.gov (United States)

    Nefedova, Victoria V; Datskevich, Petr N; Sudnitsyna, Maria V; Strelkov, Sergei V; Gusev, Nikolai B

    2013-08-01

    Some physico-chemical properties of R140G and K141Q mutants of human small heat shock protein HspB1 associated with hereditary peripheral neuropathy were analyzed. Mutation K141Q did not affect intrinsic Trp fluorescence and interaction with hydrophobic probe bis-ANS, whereas mutation R140G decreased both intrinsic fluorescence and fluorescence of bis-ANS bound to HspB1. Both mutations decreased thermal stability of HspB1. Mutation R140G increased, whereas mutation K141Q decreased the rate of trypsinolysis of the central part (residues 5-188) of HspB1. Both the wild type HspB1 and its K141Q mutant formed large oligomers with apparent molecular weight ∼560 kDa. The R140G mutant formed two types of oligomers, i.e. large oligomers tending to aggregate and small oligomers with apparent molecular weight ∼70 kDa. The wild type HspB1 formed mixed homooligomers with R140G mutant with apparent molecular weight ∼610 kDa. The R140G mutant was unable to form high molecular weight heterooligomers with HspB6, whereas the K141Q mutant formed two types of heterooligomers with HspB6. In vitro measured chaperone-like activity of the wild type HspB1 was comparable with that of K141Q mutant and was much higher than that of R140G mutant. Mutations of homologous hot-spot Arg (R140G of HspB1 and R120G of αB-crystallin) induced similar changes in the properties of two small heat shock proteins, whereas mutations of two neighboring residues (R140 and K141) induced different changes in the properties of HspB1.

  2. Heat shock-induced apoptosis in germ line cells of Triatoma infestans Klug

    Directory of Open Access Journals (Sweden)

    Maria Luiza S. Mello

    2000-06-01

    Full Text Available The survival of Triatoma infestans and of somatic cells from this species is affected by heat shock. In this study, we examined the cell death responses of male germ line cells from 5th instar nymphs 7 and 30 days after heat shock exposure (40ºC, 1 h. The preparations were stained by the Feulgen reaction and the TUNEL immunocytochemical assay. Apoptosis was elicited by heat shock, with positive TUNEL responses in spermatogonial chromatin and chromosomes, spermatids and sperm cells. Spermatogonia were most affected seven days after the shock whereas some spermatids and sperm cells exhibited DNA fragmentation only thirty days after heat shock. The rate of cell death varied among the cells. In some cases, cellular differentiation was unaffected by heat shock, with DNA fragmentation occurring towards the end of spermatogenesis.Uma vez que em Triatoma infestans a sobrevivência de células somáticas e dos próprios espécimes é afetada por choques de temperatura, foi estudada a indução de morte celular em células da linhagem germinativa masculina de ninfas de 5o. estadio 7 e 30 dias após choque de 1 h a 40ºC. Os preparados foram submetidos à reação de Feulgen e ao teste imunocitoquímico TUNEL. Foi encontrada apoptose induzida pelo choque de temperatura, sendo que respostas positivas ao TUNEL foram vistas na cromatina e em cromossomos de espermatogônias e em espermátides e espermatozóides. As espermatogônias foram afetadas principalmente 7 dias após o choque, enquanto algumas espermátides e espermatozóides exibiram fragmentação de DNA apenas 30 dias após o choque. Admite-se que a velocidade com a qual avança o processo de morte celular varie nessas células. Diferenciação celular não é impedida em parte das células afetadas, permitindo que a fragmentação de seu DNA ocorra mais tardiamente, inclusive no fim da espermatogênese.

  3. Shock

    Science.gov (United States)

    Shock can be caused by any condition that reduces blood flow, including: Heart problems (such as heart attack or heart failure ) Low blood volume (as with heavy bleeding or dehydration ) Changes in blood vessels (as with infection ...

  4. Shock-Wave Heating Model for Chondrule Formation: Prevention of Isotopic Fractionation

    CERN Document Server

    Miura, H; Miura, Hitoshi; Nakamoto, Taishi

    2006-01-01

    Chondrules are considered to have much information on dust particles and processes in the solar nebula. It is naturally expected that protoplanetary disks observed in present star forming regions have similar dust particles and processes, so study of chondrule formation may provide us great information on the formation of the planetary systems. Evaporation during chondrule melting may have resulted in depletion of volatile elements in chondrules. However, no evidence for a large degree of heavy-isotope enrichment has been reported in chondrules. In order to meet this observed constraint, the rapid heating rate at temperatures below the silicate solidus is required to suppress the isotopic fractionation. We have developed a new shock-wave heating model taking into account the radiative transfer of the dust thermal continuum emission and the line emission of gas molecules and calculated the thermal history of chondrules. We have found that optically-thin shock waves for the thermal continuum emission from dust ...

  5. 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.

  6. 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.

  7. 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.

  8. SWATH-MS dataset of heat-shock treated Drosophila melanogaster embryos.

    Science.gov (United States)

    Fabre, Bertrand; Korona, Dagmara; Nightingale, Daniel J H; Russell, Steven; Lilley, Kathryn S

    2016-12-01

    Data independent acquisition (DIA) has emerged as a promising mass spectrometry based approach, combining the advantages of shotgun and targeted proteomics. Here we applied a DIA approach (termed SWATH) to monitor the dynamics of the Drosophila melanogaster embryonic proteome upon heat-shock treatment. Embryos were incubated for 0.5, 1 or 3 h at 37 °C to induce heat-shock or maintained at 25 °C. The present dataset contains SWATH files acquired on a Sciex Triple-TOF 6600. A spectral library built in-house was used to analyse these data and led to the quantification of more than 2500 proteins at every timepoint. The files presented here are permanent digital maps and can be reanalysed to search for new questions. The data have been deposited with the ProteomeXchange Consortium with the dataset identifier PRIDE: PXD004753.

  9. SWATH-MS dataset of heat-shock treated Drosophila melanogaster embryos

    Directory of Open Access Journals (Sweden)

    Bertrand Fabre

    2016-12-01

    Full Text Available Data independent acquisition (DIA has emerged as a promising mass spectrometry based approach, combining the advantages of shotgun and targeted proteomics. Here we applied a DIA approach (termed SWATH to monitor the dynamics of the Drosophila melanogaster embryonic proteome upon heat-shock treatment. Embryos were incubated for 0.5, 1 or 3 h at 37 °C to induce heat-shock or maintained at 25 °C. The present dataset contains SWATH files acquired on a Sciex Triple-TOF 6600. A spectral library built in-house was used to analyse these data and led to the quantification of more than 2500 proteins at every timepoint. The files presented here are permanent digital maps and can be reanalysed to search for new questions. The data have been deposited with the ProteomeXchange Consortium with the dataset identifier PRIDE: PXD004753.

  10. Heat shock increases conjugation efficiency in Clostridium difficile.

    Science.gov (United States)

    Kirk, Joseph A; Fagan, Robert P

    2016-12-01

    Clostridium difficile infection has increased in incidence and severity over the past decade, and poses a unique threat to human health. However, genetic manipulation of C. difficile remains in its infancy and the bacterium remains relatively poorly characterised. Low-efficiency conjugation is currently the only available method for transfer of plasmid DNA into C. difficile. This is practically limiting and has slowed progress in understanding this important pathogen. Conjugation efficiency varies widely between strains, with important clinically relevant strains such as R20291 being particularly refractory to plasmid transfer. Here we present an optimised conjugation method in which the recipient C. difficile is heat treated prior to conjugation. This significantly improves conjugation efficiency in all C. difficile strains tested including R20291. Conjugation efficiency was also affected by the choice of media on which conjugations were performed, with standard BHI media giving most transconjugant recovery. Using our optimised method greatly increased the ease with which the chromosome of R20291 could be precisely manipulated by homologous recombination. Our method improves on current conjugation protocols and will help speed genetic manipulation of strains otherwise difficult to work with. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  11. Modeling the Intra- and Extracellular Cytokine Signaling Pathway under Heat Stroke in the Liver

    Science.gov (United States)

    2013-09-05

    SensSB files needed to reproduce the results are provided as Supporting Information S4. Matlab figures containing the estimated time course for all the...values. (ZIP) Supporting Information S5 Matlab figures with the simulated results for all the variables for WT, TNFR KO, IL-10 KO, high temperature, and...regulation of the heat shock response in mammalian cells. Cell Stress & Chaperones 1: 33– 39. 65. Santoro N, Johansson N, Thiele D (1998) Heat shock

  12. Blood heat shock proteins evoked by some Salmonella strains infection in ducks.

    Science.gov (United States)

    Osman, Kamelia; Ibrahim, Ihab; Yousef, Ashgan; Nabil, Tanios; Nayerah, Alatfeehy

    2012-05-01

    Bacterial heat-shock response is a global regulatory system required for effective adaptation to changes (stress) in the environment. An in vitro study was conducted to investigate the impact of a sublethal temperature (42°C) on heat shock protein (HSP) expression in 6 Salmonella strains (Salmonella Enteritidis, S. Typhimurium, S. Virchow, S. Shubra, S. Haifa and S. Eingedi). The 6 Salmonella strains were isolated from the tissues of ducklings that had died from avian salmonellosis. To determine the induction of HSP in the 6 Salmonella strains, they were exposed to the selected temperature level for 24 h and further kept for 48 h at culturing condition of 42°C. Growth under a sublethal temperature of 42°C increased the expression of several proteins of Salmonella, including a 63 kDa protein in addition to the generation and/or overexpression of 143 proteins which were specific to heat shock, concurrent to this acquired thermotolerance. The 6 Salmonella strains responded to 24 h of thermal stress at an elevated temperature 42°C by synthesizing different heat shock proteins (HSP) with molecular weights ranging between 13.62 and 96.61 kDa. At 48 h, the 6 Salmonella strains synthesized different HSPs with molecular weights ranging between 14.53 and 103.43 kDa. It follows that salmonellae would produce HSPs during the course of the infectious process. Salmonellosis produced several proteins after 24 and 48 h of infection. Seven of these proteins (100, 80, 60, 40, 30, 20 and 10 kDa) were recognized in the serum obtained from the ducklings infected with S. Enteritidis, S. Typhimurium, S. Virchow, S. Shubra, S. Haifa and S. Eingedi after 24 h of infection. After 48 h, the 1-7 kDa HSP became more evident and indicated their de novo generation.

  13. Heat Shock Protein-27 Delays Acute Rejection After Cardiac Transplantation: An Experimental Model

    OpenAIRE

    2014-01-01

    Background Rejection is the major obstacle to survival after cardiac transplantation. We investigated whether overexpression of heat shock protein (Hsp)-27 in mouse hearts protects against acute rejection and the mechanisms of such protection. Methods Hearts from B10.A mice overexpressing human Hsp-27 (Hsp-27tg), or Hsp-27–negative hearts from littermate controls (LCs) were transplanted into allogeneic C57BL/6 mice. The immune response to B10.A hearts was investigated using quantitative polym...

  14. Mathematical Modeling of the Heat-Shock Response in HeLa Cells

    Science.gov (United States)

    2015-07-01

    Rakesh1 1Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research...NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) U.S. Army Medical Research and Materiel Command,DoD Biotechnology High...shock response have already been used as components of larger mathematical models for predicting inflammation in heat stroke (33) and optimizing cancer

  15. Involvement of heat shock proteins on Mn-induced toxicity in Caenorhabditis elegans.

    Science.gov (United States)

    Avila, Daiana Silva; Benedetto, Alexandre; Au, Catherine; Bornhorst, Julia; Aschner, Michael

    2016-11-02

    All living cells display a rapid molecular response to adverse environmental conditions, and the heat shock protein family reflects one such example. Hence, failing to activate heat shock proteins can impair the cellular response. In the present study, we evaluated whether the loss of different isoforms of heat shock protein (hsp) genes in Caenorhabditis elegans would affect their vulnerability to Manganese (Mn) toxicity. We exposed wild type and selected hsp mutant worms to Mn (30 min) and next evaluated further the most susceptible strains. We analyzed survival, protein carbonylation (as a marker of oxidative stress) and Parkinson's disease related gene expression immediately after Mn exposure. Lastly, we observed dopaminergic neurons in wild type worms and in hsp-70 mutants following Mn treatment. Analysis of the data was performed by one-way or two way ANOVA, depending on the case, followed by post-hoc Bonferroni test if the overall p value was less than 0.05. We verified that the loss of hsp-70, hsp-3 and chn-1 increased the vulnerability to Mn, as exposed mutant worms showed lower survival rate and increased protein oxidation. The importance of hsp-70 against Mn toxicity was then corroborated in dopaminergic neurons, where Mn neurotoxicity was aggravated. The lack of hsp-70 also blocked the transcriptional upregulation of pink1, a gene that has been linked to Parkinson's disease. Taken together, our data suggest that Mn exposure modulates heat shock protein expression, particularly HSP-70, in C. elegans. Furthermore, loss of hsp-70 increases protein oxidation and dopaminergic neuronal degeneration following manganese exposure, which is associated with the inhibition of pink1 increased expression, thus potentially exacerbating the vulnerability to this metal.

  16. Flat Plate and Turbine Vane Cascade Heat Transfer Investigation Using a Shock Tube.

    Science.gov (United States)

    1985-12-01

    piece of -. work would not have been possible without the superior and talented AFIT Shop personnel lead by Mr. Carl Shortt. I would also like to...tube. Curves were presented showing the time required to reach steady state for a given flow condition and model size. Davies and Berstein (1969...inverse of Davies’ and Bersteins ’ I alpha as the transition requirement. Dunn and Stoddard (1977) .. * .conducted heat transfer experiments in a shock

  17. Interplay between RNA interference and heat shock response systems in Drosophila melanogaster

    OpenAIRE

    2016-01-01

    The genome expression pattern is strongly modified during the heat shock response (HSR) to form an adaptive state. This may be partly achieved by modulating microRNA levels that control the expression of a great number of genes that are embedded within the gene circuitry. Here, we investigated the cross-talk between two highly conserved and universal house-keeping systems, the HSR and microRNA machinery, in Drosophila melanogaster. We demonstrated that pronounced interstrain differences in th...

  18. Seasonal effects of heat shock on bacterial populations, including artificial Vibrio parahaemolyticus exposure, in the Pacific oyster, Crassostrea gigas.

    Science.gov (United States)

    Aagesen, Alisha M; Häse, Claudia C

    2014-04-01

    During the warmer summer months, oysters are conditioned to spawn, resulting in massive physiological efforts for gamete production. Moreover, the higher temperatures during the summer typically result in increased bacteria populations in oysters. We hypothesized that these animals are under multiple stresses that lead to possible immune system impairments during the summer months that can possibly lead to death. Here we show that in the summer and the fall animals exposed to a short heat stress respond similarly, resulting in a general trend of more bacteria being found in heat shocked animals than their non-heat shocked counterparts. We also show that naturally occurring bacterial populations are effected by a heat shock. In addition, oysters artificially contaminated with Vibrio parahaemolyticus were also affected by a heat shock. Heat shocked animals contained higher concentrations of V. parahaemolyticus in their tissues and hemolymph than control animals and this was consistent for animals examined during summer and fall. Finally, oyster hemocyte interactions with V. parahaemolyticus differed based on the time of the year. Overall, these findings demonstrate that seasonal changes and/or a short heat shock is sufficient to impact bacterial retention, particularly V. parahaemolyticus, in oysters and this line of research might lead to important considerations for animal harvesting procedures.

  19. 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

  20. Elevation of heat shock gene expression from static magnetic field exposure in vitro.

    Science.gov (United States)

    Laramee, Craig B; Frisch, Paul; McLeod, Kenneth; Li, Gloria C

    2014-09-01

    Previously, we found that extremely low frequency (ELF) electric fields were able to elicit an approximate 3.5-fold increase in heat shock gene expression, a response which may have applicability to cancer therapy. Based on recent studies demonstrating the ability of magnetic fields to influence gene expression, we hypothesized that low level static magnetic fields may be able to affect heat shock gene expression while avoiding some of the clinical difficulties that arise with electric fields. Transfected rat primary cells in monolayer were exposed to magnetic fields of 1 to 440 mT for 16, 24, or 48 h starting at 24 and 48 h post transfection. Heat shock protein (HSP70) expression, as indicated by a promoter linked luciferase reporter, was followed for up to 96 h and showed a dependence on flux density, exposure duration, and start time post transfection. A nonlinear response was observed for increasing flux density with a maximum of a 3.5-fold increase in expression for 48 h of exposure starting 48 h after transfection. These results demonstrate an enhancement of gene expression similar in magnitude to that observed with external electric field exposure, while eliminating many of the clinical complications.

  1. Heat Shock Protein A2 (HSPA2): Regulatory Roles in Germ Cell Development and Sperm Function.

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    Nixon, Brett; Bromfield, Elizabeth G; Cui, Jinwei; De Iuliis, Geoffry N

    2017-01-01

    Among the numerous families of heat shock protein (HSP) that have been implicated in the regulation of reproductive system development and function, those belonging to the 70 kDa HSP family have emerged as being indispensable for male fertility. In particular, the testis-enriched heat shock 70 kDa protein 2 (HSPA2) has been shown to be critical for the progression of germ cell differentiation during spermatogenesis in the mouse model. Beyond this developmentally important window, mounting evidence has also implicated HSPA2 in the functional transformation of the human sperm cell during their ascent of the female reproductive tract. Specifically, HSPA2 appears to coordinate the remodelling of specialised sperm domains overlying the anterior region of the sperm head compatible with their principle role in oocyte recognition. The fact that levels of the HSPA2 protein in mature spermatozoa tightly correlate with the efficacy of oocyte binding highlight its utility as a powerful prognostic biomarker of male fertility. In this chapter, we consider the unique structural and biochemical characteristics of HSPA2 that enable this heat shock protein to fulfil its prominent roles in orchestrating the morphological differentiation of male germ cells during spermatogenesis as well as their functional transformation during post-testicular sperm maturation.

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

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    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.

  3. Effect of heat shock on poly(ADP-ribose) synthetase and DNA repair in Drosophila cells

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    Nolan, N.L.; Kidwell, W.R.

    1982-04-01

    Poly(ADP-ribose) synthetase, a chromatin-bound enzyme which attaches polyanionic chains of ADP-ribose to nuclear proteins, was found to be temperature sensitive in intact Drosophila melanogaster cells. The synthetase was completely inactivated by heat-shocking the cells at 37/sup 0/C for 5 min, a condition which had no appreciable effect on the subsequent growth of Drosophila cells at their physiological temperature. The heat-shock effect on synthetase was reversible; enzyme activity began to reappear about 2 hr post heat shock. During the 2-hr interval when poly(ADP-ribose) synthetase was absent, the cells were competent in repair of ..gamma..-ray-induced DNA strand breaks as shown by DNA sedimentation studies on alkaline sucrose gradients. It is thus concluded that poly(ADP-ribose) synthesis is unnecessary for repair of DNA strand breaks introduced by irradiation. The same conclusion was reached from the fact that two inhibitors of poly(ADP-ribose) synthetase 3-aminobenzamide and 5-methylnicotinamide, failed to block repair of ..gamma..-ray-induced DNA chain breaks even though both inhibitors reduced the amount of poly(ADP-ribose) synthesized in cells by 50-75%. Although it was found that the repair of DNA strand breaks is independent of poly(ADP-ribose) synthesis, irradiation does activate the synthetase in control cells, as shown by radioimmunoassay of poly(ADP-ribose) levels.

  4. Seed germination of montane forest species in response to ash, smoke and heat shock in Mexico

    Science.gov (United States)

    Zuloaga-Aguilar, Susana; Briones, Oscar; Orozco-Segovia, Alma

    2011-05-01

    In many fire-prone ecosystems, seed germination is triggered by heat shock, smoke, ash and charred wood. However, few studies concerning the effect of these fire products on the germination of tropical and subtropical species exist. We assessed the effect of fire products and their interactions on seed germination in 12 species that frequently grow in burned areas of pine-oak and mixed forest in a mountainous subtropical area. Each species was exposed to a predetermined treatment of heat shock, which was optimised in accordance with a previous study. For smoke treatments, seeds were immersed in smoke water, whereas for ash treatments, 1.5 g of ash was added to the incubation medium. Germination increased in 92% of the species in response to the products of fire. Both the smoke water and the ash treatments promoted germination in four species that had permeable seed covers and physiological dormancy. Six species with physical dormancy required both heat shock and smoke water or ash to break dormancy. Our results indicate that seed germination response to fire products depends on the species and/or dormancy type. The germination response to the fire products varied between species; therefore, fire products may influence the species composition in post-fire regeneration.

  5. Module-based analysis of robustness tradeoffs in the heat shock response system.

    Directory of Open Access Journals (Sweden)

    Hiroyuki Kurata

    2006-07-01

    Full Text Available Biological systems have evolved complex regulatory mechanisms, even in situations where much simpler designs seem to be sufficient for generating nominal functionality. Using module-based analysis coupled with rigorous mathematical comparisons, we propose that in analogy to control engineering architectures, the complexity of cellular systems and the presence of hierarchical modular structures can be attributed to the necessity of achieving robustness. We employ the Escherichia coli heat shock response system, a strongly conserved cellular mechanism, as an example to explore the design principles of such modular architectures. In the heat shock response system, the sigma-factor sigma32 is a central regulator that integrates multiple feedforward and feedback modules. Each of these modules provides a different type of robustness with its inherent tradeoffs in terms of transient response and efficiency. We demonstrate how the overall architecture of the system balances such tradeoffs. An extensive mathematical exploration nevertheless points to the existence of an array of alternative strategies for the existing heat shock response that could exhibit similar behavior. We therefore deduce that the evolutionary constraints facing the system might have steered its architecture toward one of many robustly functional solutions.

  6. Shock-tube studies of radiative base heating of Jovian probe

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    Shirai, H.; Park, C.

    1980-01-01

    A 6.4-cm-diameter scale model of the Jovian entry vehicle is tested in an electric-arc-driven shock tube and a 5-cm-diameter sphere model is tested in a combustion-driven shock tube and in an electric-arc-driven shock tunnel. The radiative heat-transfer rate and pressure on the front and the base regions are measured in the absence of ablation with sensors imbedded in the models in a stream consisting of 10% hydrogen in a bath of either neon or argon. The measured radiative heat-transfer rates and pressures range to about 22 kW/sq cm and 12 atm, respectively, at the front stagnation point. The ratio of the radiative heat-transfer rate at the base stagnation point to that at the front stagnation point is found to be about 1/4 for the sphere at Mach 1.8, about 1/30 for the sphere at Mach 4.8, and about 1/6 for the scale model at Mach 1.7. The present experimental results agree well with the theoretical predictions of Park, thus indicating that Park's theory is valid.

  7. Relationship between heat shock protein 70 expression and life span in Daphnia.

    Science.gov (United States)

    Schumpert, Charles; Handy, Indhira; Dudycha, Jeffry L; Patel, Rekha C

    2014-07-01

    The longevity of an organism is directly related to its ability to effectively cope with cellular stress. Heat shock response (HSR) protects the cells against accumulation of damaged proteins after exposure to elevated temperatures and also in aging cells. To understand the role of Hsp70 in regulating life span of Daphnia, we examined the expression of Hsp70 in two ecotypes that exhibit strikingly different life spans. Daphnia pulicaria, the long lived ecotype, showed a robust Hsp70 induction as compared to the shorter lived Daphnia pulex. Interestingly, the short-lived D. pulex isolates showed no induction of Hsp70 at the mid point in their life span. In contrast to this, the long-lived D. pulicaria continued to induce Hsp70 expression at an equivalent age. We further show that the Hsp70 expression was induced at transcriptional level in response to heat shock. The transcription factor responsible for Hsp70 induction, heat shock factor-1 (HSF-1), although present in aged organisms did not exhibit DNA-binding capability. Thus, the decline of Hsp70 induction in old organisms could be attributed to a decline in HSF-1's DNA-binding activity. These results for the first time, present a molecular analysis of the relationship between HSR and life span in Daphnia. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.