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Sample records for kda heat shock

  1. A novel 29-kDa chicken heat shock protein.

    PubMed

    Einat, M F; Haberfeld, A; Shamay, A; Horev, G; Hurwitz, S; Yahav, S

    1996-12-01

    The family of small heat shock proteins is the more variable among the highly conserved superfamily of heat shock proteins (HSP). Using a metabolic labeling procedure with tissue explants, we have detected in chickens a new member of the small HSP family with an apparent molecular weight of 29-kDa. This protein was induced in broiler chickens' heart muscle and lungs following an in vivo heat stress. The 29-kDa band appears after 3 h of heat stress, much later than the induction of HSP 90, HSP 70, and HSP 27. The late onset of induction suggests that HSP 29 plays a more specific role of a "second stage defense protein". PMID:9000279

  2. [Alterations in heat shock protein 70 kDa levels in human neutrophils under the heat shock conditions].

    PubMed

    Boĭko, A A; Vetchinin, S S; Sapozhnikov, A M; Kovalenko, E I

    2014-01-01

    Intracellular content of heat shock proteins of 70 kDa family (HSP70) possessing chaperone and cytoprotective functions depends on specialization and functional activity of the cells. The aim of this study was to analyze the dynamics of constitutive and inducible HSP70 levels evoked by heat shock in human neutrophils, the short-lived fraction of white blood cells providing non-specific defense against bacterial pathogens. Biphasic dynamics of the intracellular HSP70 level with an increase and following decrease in 15-30 min after the heat shock was revealed by flow cytometry. This dynamics was similar for constitutive and inducible forms of HSP70. Pre-incubation of neutrophils with cycloheximide, the inhibitor of protein synthesis, did not change the intracellular HSP70 dynamics registered by flow cytometry indicating that the increased HSP70 level detected immediately after the heat shock was not mediated by de novo protein synthesis. It was confirmed by Western blotting analysis of HSP70 intracellular content. It was suggested that the elevated HSP70 level was related to conformational HSP70 molecule changes and to increased availability of HSP70 epitopes for antibody binding. Using a panel of antibodies specific to the N-terminal ATP-binding or C-terminal substrate-binding domains of HSP70 it has been demonstrated by cell immunofluorescence and flow cytometry methods that the heat shock-associated increase of the intracellular HSP70 level was mediated by HSP70 interaction with antibodies recognizing HSP70 substrate-binding domain. It was demonstrated that the decrease of intracellular HSP70 level after heat treatment could be connected with a release of both inducible and constitutive HSP70 into extracellular space. Our data suggest that stress-induced release of HSP70 from neutrophils is regulated by ABC-transporters.

  3. Detrimental Effect of Fungal 60-kDa Heat Shock Protein on Experimental Paracoccidioides brasiliensis Infection

    PubMed Central

    Fernandes, Fabrício Freitas; de Oliveira, Leandro Licursi; Landgraf, Taise Natali; Peron, Gabriela; Costa, Marcelo Vieira; Coelho-Castelo, Arlete A. M.; Bonato, Vânia L. D.; Roque-Barreira, Maria-Cristina; Panunto-Castelo, Ademilson

    2016-01-01

    The genus Paracoccidioides comprises species of dimorphic fungi that cause paracoccidioidomycosis (PCM), a systemic disease prevalent in Latin America. Here, we investigated whether administration of native 60-kDa heat shock protein of P. brasiliensis (nPbHsp60) or its recombinant counterpart (rPbHsp60) affected the course of experimental PCM. Mice were subcutaneously injected with nPbHsp60 or rPbHsp60 emulsified in complete’s Freund Adjuvant (CFA) at three weeks after intravenous injection of P. brasiliensis yeasts. Infected control mice were injected with CFA or isotonic saline solution alone. Thirty days after the nPbHsp60 or rPbHsp60 administration, mice showed remarkably increased fungal load, tissue inflammation, and granulomas in the lungs, liver, and spleen compared with control mice. Further, rPbHsp60 treatment (i) decreased the known protective effect of CFA against PCM and (ii) increased the concentrations of IL-17, TNF-α, IL-12, IFN-γ, IL-4, IL-10, and TGF-β in the lungs. Together, our results indicated that PbHsp60 induced a harmful immune response, exacerbated inflammation, and promoted fungal dissemination. Therefore, we propose that PbHsp60 contributes to the fungal pathogenesis. PMID:27598463

  4. Detrimental Effect of Fungal 60-kDa Heat Shock Protein on Experimental Paracoccidioides brasiliensis Infection.

    PubMed

    Fernandes, Fabrício Freitas; Oliveira, Leandro Licursi de; Landgraf, Taise Natali; Peron, Gabriela; Costa, Marcelo Vieira; Coelho-Castelo, Arlete A M; Bonato, Vânia L D; Roque-Barreira, Maria-Cristina; Panunto-Castelo, Ademilson

    2016-01-01

    The genus Paracoccidioides comprises species of dimorphic fungi that cause paracoccidioidomycosis (PCM), a systemic disease prevalent in Latin America. Here, we investigated whether administration of native 60-kDa heat shock protein of P. brasiliensis (nPbHsp60) or its recombinant counterpart (rPbHsp60) affected the course of experimental PCM. Mice were subcutaneously injected with nPbHsp60 or rPbHsp60 emulsified in complete's Freund Adjuvant (CFA) at three weeks after intravenous injection of P. brasiliensis yeasts. Infected control mice were injected with CFA or isotonic saline solution alone. Thirty days after the nPbHsp60 or rPbHsp60 administration, mice showed remarkably increased fungal load, tissue inflammation, and granulomas in the lungs, liver, and spleen compared with control mice. Further, rPbHsp60 treatment (i) decreased the known protective effect of CFA against PCM and (ii) increased the concentrations of IL-17, TNF-α, IL-12, IFN-γ, IL-4, IL-10, and TGF-β in the lungs. Together, our results indicated that PbHsp60 induced a harmful immune response, exacerbated inflammation, and promoted fungal dissemination. Therefore, we propose that PbHsp60 contributes to the fungal pathogenesis. PMID:27598463

  5. The calmodulin-binding domain of the mouse 90-kDa heat shock protein.

    PubMed

    Minami, Y; Kawasaki, H; Suzuki, K; Yahara, I

    1993-05-01

    The mouse 90-kDa heat shock protein (HSP90) and Ca(2+)-calmodulin were cross-linked at an equimolar ratio using a carbodiimide zero-length cross-linker. To identify the calmodulin-binding domain(s) of HSP90, CNBr-cleaved peptide fragments of HSP90 were mixed with Ca(2+)-calmodulin and cross-linked. Amino acid sequence determination revealed that an HSP90 alpha-derived peptide starting at the 486th amino acid residue was contained in the cross-linked products, which contains a calmodulin-binding motif (from Lys500 to Ile520). A similar motif is present also in HSP90 beta (from Lys491 to Val511). The synthetic peptides corresponding to these putative calmodulin-binding sequences were found to be cross-linked with Ca(2+)-calmodulin and to prevent the cross-linking of HSP90 and Ca(2+)-calmodulin. Both HSP90 alpha and HSP90 beta bind Ca2+. The HSP90 peptides bind HSP90 and thereby inhibit the binding of Ca2+. In addition, the HSP90 peptides augment the self-oligomerization of HSP90 induced at elevated temperatures. These results suggest that the calmodulin-binding domain of HSP90 might interact with another part of the same molecule and that Ca(2+)-calmodulin might modulate the structure and function of HSP90 through abolishing the intramolecular interaction. PMID:8486648

  6. A 21-kDa chloroplast heat shock protein assembles into high molecular weight complexes in vivo and in Organelle.

    PubMed

    Chen, Q; Osteryoung, K; Vierling, E

    1994-05-01

    The conservation of the carboxyl-terminal "heat shock" domain among small (sm) cytoplasmic and chloroplast heat shock proteins (HSPs) suggests that these smHSPs perform similar functions. Previous studies have established that cytoplasmic smHSPs are found in higher order structures in vivo (approximately 500 kDa). To determine if the chloroplast smHSP is found in similar complexes, we examined the size of the 21-kDa chloroplast smHSP from Pisum sativum, PsHSP21, under non-denaturing conditions. Following sedimentation of chloroplast stromal extracts on sucrose gradients PsHSP21 is detected in fractions corresponding to 10-11 S. Upon non-denaturing gel electrophoresis, PsHSP21 was detected in two high molecular mass complexes of approximately 230 and 200 kDa, in good agreement with the sucrose gradient data. These PsHSP21-containing particles were stable under different salt and Mg2+ conditions, and their integrity was not affected by 1.0% Triton X-100 or 10 mM ATP. To study assembly of the high molecular weight complexes containing PsHSP21, in vitro translated PsHSP21 was imported into chloroplasts and its size was examined. Following import into chloroplasts isolated from heat-stressed plants, greater than 50% of PsHSP21 was recovered in the higher molecular weight forms. In contrast, following import into chloroplasts isolated from control plants the protein was recovered exclusively in a 5 S (approximately 42-kDa) form. These data suggest that preexisting PsHSP21 or other heat-induced factors may be required for assembly of the higher molecular weight particles. We propose that the 10-11 S particles are the functional form of PsHSP21.

  7. A DOUBLE KNOCKOUT; A NOVEL APPROACH TO UNDERSTANDING STRESS-INDUCIBLE 70 KDA HEAT SHOCK PROTEINS (HSP70S) ON DEVELOPMENT AND REPRODUCTION

    EPA Science Inventory

    Heat and chemical toxicants which disrupt spermatogenesis and cause male infertility are thought to induce the expression of Hsp70-1 and 70-3, the major inducible heat shock proteins of the 70kDa family. Previous studies from several laboratories including our own have characteri...

  8. Microsporidia, amitochondrial protists, possess a 70-kDa heat shock protein gene of mitochondrial evolutionary origin.

    PubMed

    Peyretaillade, E; Broussolle, V; Peyret, P; Méténier, G; Gouy, M; Vivarès, C P

    1998-06-01

    An intronless gene encoding a protein of 592 amino acid residues with similarity to 70-kDa heat shock proteins (HSP70s) has been cloned and sequenced from the amitochondrial protist Encephalitozoon cuniculi (phylum Microsporidia). Southern blot analyses show the presence of a single gene copy located on chromosome XI. The encoded protein exhibits an N-terminal hydrophobic leader sequence and two motifs shared by proteobacterial and mitochondrially expressed HSP70 homologs. Phylogenetic analysis using maximum likelihood and evolutionary distances place the E. cuniculi sequence in the cluster of mitochondrially expressed HSP70s, with a higher evolutionary rate than those of homologous sequences. Similar results were obtained after cloning a fragment of the homologous gene in the closely related species E. hellem. The presence of a nuclear targeting signal-like sequence supports a role of the Encephalitozoon HSP70 as a molecular chaperone of nuclear proteins. No evidence for cytosolic or endoplasmic reticulum forms of HSP70 was obtained through PCR amplification. These data suggest that Encephalitozoon species have evolved from an ancestor bearing mitochondria, which is in disagreement with the postulated presymbiotic origin of Microsporidia. The specific role and intracellular localization of the mitochondrial HSP70-like protein remain to be elucidated. PMID:9615449

  9. A plastid-targeted heat shock cognate 70 kDa protein interacts with the Abutilon mosaic virus movement protein

    SciTech Connect

    Krenz, Bjoern; Windeisen, Volker; Wege, Christina; Jeske, Holger; Kleinow, Tatjana

    2010-05-25

    The movement protein (MP) of bipartite geminiviruses facilitates cell-to-cell as well as long-distance transport within plants and influences viral pathogenicity. Yeast two-hybrid assays identified a chaperone, the nuclear-encoded and plastid-targeted heat shock cognate 70 kDa protein (cpHSC70-1) of Arabidopsis thaliana, as a potential binding partner for the Abutilon mosaic virus (AbMV) MP. In planta, bimolecular fluorescence complementation (BiFC) analysis showed cpHSC70-1/MP complexes and MP homooligomers at the cell periphery and co-localized with chloroplasts. BiFC revealed cpHSC70-1 oligomers associated with chloroplasts, but also distributed at the cellular margin and in filaments arising from plastids reminiscent of stromules. Silencing the cpHSC70 gene of Nicotiana benthamiana using an AbMV DNA A-derived gene silencing vector induced minute white leaf areas, which indicate an effect on chloroplast stability. Although AbMV DNA accumulated within chlorotic spots, a spatial restriction of these occurred, suggesting a functional relevance of the MP-chaperone interaction for viral transport and symptom induction.

  10. Heat shock protein 70 kDa chaperone/DnaJ cochaperone complex employs an unusual dynamic interface.

    PubMed

    Ahmad, Atta; Bhattacharya, Akash; McDonald, Ramsay A; Cordes, Melissa; Ellington, Benjamin; Bertelsen, Eric B; Zuiderweg, Erik R P

    2011-11-22

    The heat shock protein 70 kDa (Hsp70)/DnaJ/nucleotide exchange factor system assists in intracellular protein (re)folding. Using solution NMR, we obtained a three-dimensional structure for a 75-kDa Hsp70-DnaJ complex in the ADP state, loaded with substrate peptide. We establish that the J domain (residues 1-70) binds with its positively charged helix II to a negatively charged loop in the Hsp70 nucleotide-binding domain. The complex shows an unusual "tethered" binding mode which is stoichiometric and saturable, but which has a dynamic interface. The complex represents part of a triple complex of Hsp70 and DnaJ both bound to substrate protein. Mutagenesis data indicate that the interface is also of relevance for the interaction of Hsp70 and DnaJ in the ATP state. The solution complex is completely different from a crystal structure of a disulfide-linked complex of homologous proteins [Jiang, et al. (2007) Mol Cell 28:422-433].

  11. Microsporidia, amitochondrial protists, possess a 70-kDa heat shock protein gene of mitochondrial evolutionary origin.

    PubMed

    Peyretaillade, E; Broussolle, V; Peyret, P; Méténier, G; Gouy, M; Vivarès, C P

    1998-06-01

    An intronless gene encoding a protein of 592 amino acid residues with similarity to 70-kDa heat shock proteins (HSP70s) has been cloned and sequenced from the amitochondrial protist Encephalitozoon cuniculi (phylum Microsporidia). Southern blot analyses show the presence of a single gene copy located on chromosome XI. The encoded protein exhibits an N-terminal hydrophobic leader sequence and two motifs shared by proteobacterial and mitochondrially expressed HSP70 homologs. Phylogenetic analysis using maximum likelihood and evolutionary distances place the E. cuniculi sequence in the cluster of mitochondrially expressed HSP70s, with a higher evolutionary rate than those of homologous sequences. Similar results were obtained after cloning a fragment of the homologous gene in the closely related species E. hellem. The presence of a nuclear targeting signal-like sequence supports a role of the Encephalitozoon HSP70 as a molecular chaperone of nuclear proteins. No evidence for cytosolic or endoplasmic reticulum forms of HSP70 was obtained through PCR amplification. These data suggest that Encephalitozoon species have evolved from an ancestor bearing mitochondria, which is in disagreement with the postulated presymbiotic origin of Microsporidia. The specific role and intracellular localization of the mitochondrial HSP70-like protein remain to be elucidated.

  12. Similarity of the three-dimensional structures of actin and the ATPase fragment of a 70-kDa heat shock cognate protein.

    PubMed Central

    Flaherty, K M; McKay, D B; Kabsch, W; Holmes, K C

    1991-01-01

    Although there is very little sequence identity between the two proteins, the structures of rabbit skeletal muscle actin (375-amino acid residues) and the 44-kDa ATPase fragment of the bovine 70-kDa heat shock cognate protein (HSC70; 386 residues) are very similar. The alpha-carbon positions of 241 pairs of amino acid residues that are structurally equivalent within the two proteins can be superimposed with a root-mean-square difference in distance of 2.3 A; of these, 39 residues are identical, and 56 are conservative substitutions. In addition, the conformations of ADP are very similar in both proteins. A local sequence "fingerprint," which may be diagnostic of the adenine nucleotide beta-phosphate-binding pocket, has been derived. The fingerprint identifies members of the glycerol kinase family as candidates likely to have a similar structure in their nucleotide-binding domains. The structural differences between the two molecules mainly occur in loop regions of actin known to be involved in interactions with other monomers in the actin filament or in the binding of myosin; the corresponding regions in heat shock proteins may have functions that are as yet undetermined. Placing the Ca2+ ATP of actin on the ATPase fragment structure suggests Asp-206 (corresponding to His-161 of actin) as a candidate proton acceptor for the ATPase reaction. Images PMID:1828889

  13. Cloning, purification and characterization of a 90kDa heat shock protein from Citrus sinensis (sweet orange).

    PubMed

    Mendonça, Yuri A; Ramos, Carlos H I

    2012-01-01

    Protein misfolding is stimulated by stress, such as heat, and heat shock proteins (Hsps) are the first line of defense against these undesirable situations. Plants, which are naturally sessile, are perhaps more exposed to stress factors than some other organisms, and consequently, the role of Hsps is crucial to maintain homeostasis. Hsp90, because of its key role in infection and other stresses, is targeted in therapies that improve plant production by increasing resistance to both biotic and abiotic stress. In addition, Hsp90 is a primary factor in the maintenance of homeostasis in plants. Therefore, we cloned and purified Hsp90 from Citrus sinensis (sweet orange). Recombinant C. sinensis Hsp90 (rCsHsp90) was produced and measured by circular dichroism (CD), intrinsic fluorescence spectroscopy and dynamic light scattering. rCsHsp90 formed a dimer in solution with a Stokes radius of approximately 62Å. In addition, it was resistant to thermal unfolding, was able to protect citrate synthase from aggregation, and Western blot analysis demonstrated that CsHsp90 was constitutively expressed in C. sinensis cells. Our analysis indicated that CsHsp90 is conformationally similar to that of yeast Hsp90, for which structural information is available. Therefore, we showed that C. sinensis expresses an Hsp90 chaperone that has a conformation and function similar to other Hsp90s.

  14. The 59 kDa FK506-binding protein, a 90 kDa heat shock protein binding immunophilin (FKBP59-HBI), is associated with the nucleus, the cytoskeleton and mitotic apparatus.

    PubMed

    Perrot-Applanat, M; Cibert, C; Géraud, G; Renoir, J M; Baulieu, E E

    1995-05-01

    FKBP59-HBI, a 59 kDa FK506 binding protein which binds the 90 kDa heat shock protein hsp90 and thus is a heat shock protein binding immunophilin (HBI), was originally discovered in association with unliganded steroid receptors in their heat shock protein containing heterooligomer form. It belongs to a growing family including other FKBPs which bind the immunosuppressants FK506 and rapamycin, and cyclophilins which bind cyclosporin A, all having rotamase (peptidyl-prolyl cis-trans isomerase) activity which may be involved in protein folding. Targets for drug-immunophilin complexes have been mostly studied in vivo in T lymphocytes; however, immunophilins are present in all cell types, where their role and distribution are still unknown. Here we report the localization of FKBP59-HBI in various non lymphoid cells (mouse fibroblasts (L-929), monkey kidney cells (Cos-7), Madin-Darby canine kidney epithelial cells (MDCK), and mouse neuronal cells (GT1)). Two polyclonal antipeptide antibodies directed against the C-terminal end (amino acids 441-458) (Ab 173) or the sequence 182-201 (Ab 790) of the FKBP59-HBI were used in light and confocal laser immunofluorescence. FKBP59-HBI was found in the cytoplasm and nucleus of interphase cells. Specific immunofluorescence was much stronger in the cytoplasm than in the nucleus when using Ab 173, and stronger in the nucleus than in the cytoplasm with Ab 790. Detailed observations of L-cells, which have a particularly flat morphology, showed a punctate as well as a fibrous cytoskeletal staining in the cytoplasm using antibody 173, a result which suggests interactions of FKBP59-HBI with an organized network. Colocalization experiments (using antibodies against tubulin, vimentin or actin) and use of cytoskeletal-disrupting drugs revealed partial association of FKBP59-HBI with the microtubules. Western blot experiments confirmed that the protein was present in the subcellular fractions containing either 'soluble' proteins released from

  15. Extreme thermotolerance and behavioral induction of 70-kDa heat shock proteins and their encoding genes in honey bees

    PubMed Central

    2008-01-01

    Foraging honey bees frequently leave the hive to gather pollen and nectar for the colony. This period of their lives is marked by periodic extremes of body temperature, metabolic expenditure, and flight muscle activity. Following ecologically relevant episodes of hyperthermia between 33°C and 50°C, heat shock protein 70 (Hsp70) expression and hsp70/hsc70-4 activity in brains of nonflying laboratory-held bees increased by only two to three times baseline at temperatures 46–50°C. Induction was undetectable in thoracic–flight muscles. Yet, thorax hsp70 mRNA (but not hsc70-4 mRNA) levels were up to ten times higher in flight-capable hive bees and foraging bees compared to 1-day-old, flight-incapable bees, while brain hsp70/hsc70-4 mRNA levels were low and varied little among behavioral groups. These data suggest honey bee tissues, especially flight muscles, are extremely thermotolerant. Furthermore, Hsp70 expression in the thoraces of flight-capable bees is probably flight-induced by oxidative and mechanical damage to flight muscle proteins rather than temperature. PMID:18696260

  16. [Effects of noopept and cortexin on the behavior of matured rats treated with corticoliberin or 70-kDa heat shock proteins in early ontogeny].

    PubMed

    Shabanov, P D; Lebedev, A A; Stetsenko, V P; Lavrov, N V; Sablina, G V; Gudasheva, T A; Ostrovaskaia, R U

    2007-01-01

    Young Wistar rats aged 4 days were injected intraperitoneally with corticotropin releasing hormone (CRH), which is an agent activating the stress system, or 70-kDa heat shock proteins (HSP-70)--intracellular shaperons, possessing antistress properties. In grown adult rats aged 90-100 days, the effects of nootropic drugs noopept and cortexin (1 mg/kg, i.p.) were assessed. The activation of stress or antistress systems with CRH or HSP-70 significantly altered the drug action. The effects were different in males and females and depended on animal gender. The spectrum of pharmacological activity of noopept and cortexin changed: noopept demonstrated preferable psychoactivating and antiaggressive effects, whereas cortexin showed mild anxiolytic and antidepressant activity. It is suggested that the behavioral effects of nootropes depend on the conditions of the stress system formation in early ontogeny. PMID:17402584

  17. Characterization of the binding between a 70-kDa heat shock protein, HspA1A, and phosphoinositides.

    PubMed

    McCallister, Chelsea; Kdeiss, Brianna; Oliverio, Ryan; Nikolaidis, Nikolas

    2016-03-25

    HspA1A, a seventy-kilodalton heat shock protein, binds to specific anionic lipids and this interaction regulates important physiological phenomena like apoptosis, tumor growth, and lysosomal rescue. However, whether HspA1A binds to phosphoinositides has yet to be established and quantified. Therefore, in this study, we determined the binding affinity of HspA1A to several phosphoinositides and characterized five aspects of their molecular interaction. First, we established that HspA1A binds phosphatidylinositol monophosphates with higher affinity than di- and triphosphorylated inositides. Second, using high concentrations of potassium we found that HSPA1A embeds within the lipid bilayer of all phosphoinositides tested. However, the effects of the high salt concentrations were significantly different between the different phosphoinositides. Third, using calcium and reaction buffers equilibrated at different pH values we found that these differentially affected HspA1A-phosphoinositide binding, revealing a lipid-specific pattern of binding. Fourth, by assessing the binding properties of the two HspA1A domains, the nucleotide-binding domain and the substrate-binding domain, we determined that in most cases the full-length protein is necessary for binding to phosphoinositides. Fifth, by including in the reactions nucleotides and protein substrates we determined that they minimally and differentially affected phosphoinositide-binding. Collectively, these findings strongly suggest that the HspA1A-phosphoinositide binding is complex yet specific, is mediated by both electrostatic and hydrophobic interactions, is not related to the lipid-head charge, and depends on the physicochemical properties of the lipid. PMID:26923070

  18. Characterization of the binding between a 70-kDa heat shock protein, HspA1A, and phosphoinositides.

    PubMed

    McCallister, Chelsea; Kdeiss, Brianna; Oliverio, Ryan; Nikolaidis, Nikolas

    2016-03-25

    HspA1A, a seventy-kilodalton heat shock protein, binds to specific anionic lipids and this interaction regulates important physiological phenomena like apoptosis, tumor growth, and lysosomal rescue. However, whether HspA1A binds to phosphoinositides has yet to be established and quantified. Therefore, in this study, we determined the binding affinity of HspA1A to several phosphoinositides and characterized five aspects of their molecular interaction. First, we established that HspA1A binds phosphatidylinositol monophosphates with higher affinity than di- and triphosphorylated inositides. Second, using high concentrations of potassium we found that HSPA1A embeds within the lipid bilayer of all phosphoinositides tested. However, the effects of the high salt concentrations were significantly different between the different phosphoinositides. Third, using calcium and reaction buffers equilibrated at different pH values we found that these differentially affected HspA1A-phosphoinositide binding, revealing a lipid-specific pattern of binding. Fourth, by assessing the binding properties of the two HspA1A domains, the nucleotide-binding domain and the substrate-binding domain, we determined that in most cases the full-length protein is necessary for binding to phosphoinositides. Fifth, by including in the reactions nucleotides and protein substrates we determined that they minimally and differentially affected phosphoinositide-binding. Collectively, these findings strongly suggest that the HspA1A-phosphoinositide binding is complex yet specific, is mediated by both electrostatic and hydrophobic interactions, is not related to the lipid-head charge, and depends on the physicochemical properties of the lipid.

  19. Identification of a novel Drosophila melanogaster heat-shock gene, lethal(2)denticleless [l(2)dtl], coding for an 83-kDa protein.

    PubMed

    Kurzik-Dumke, U; Neubauer, M; Debes, A

    1996-06-01

    In this study, we describe the identification of a novel Drosophila melanogaster (Dm) gene, l(2)dtl, characterized by elevated expression under heat-shock (HS) conditions. It encodes a protein of 83 kDa with no homology to known members of the HSP90 family and other proteins. Gene l(2)dtl is located on the right arm of the second chromosome at locus 59F5, close to the tumor suppressor gene l(2)tid, a homolog of the dnaJ encoding a chaperone strongly conserved in evolution. In the following, we present the sequence of l(2)dtl, the putative protein it encodes, and its molecular localization in a closely interspaced gene cluster consisting of at least four nested genes spanning an approximately 10-kb genomic interval. Furthermore, we present the temporal expression of l(2)dtl in the wild type under normal and HS conditions, and describe the isolation and the phenotype of eight embryonic lethal l(2)dtl mutants.

  20. A sequential mechanism for clathrin cage disassembly by 70-kDa heat-shock cognate protein (Hsc70) and auxilin.

    PubMed

    Rothnie, Alice; Clarke, Anthony R; Kuzmic, Petr; Cameron, Angus; Smith, Corinne J

    2011-04-26

    An essential stage in endocytic coated vesicle recycling is the dissociation of clathrin from the vesicle coat by the molecular chaperone, 70-kDa heat-shock cognate protein (Hsc70), and the J-domain-containing protein, auxilin, in an ATP-dependent process. We present a detailed mechanistic analysis of clathrin disassembly catalyzed by Hsc70 and auxilin, using loss of perpendicular light scattering to monitor the process. We report that a single auxilin per clathrin triskelion is required for maximal rate of disassembly, that ATP is hydrolyzed at the same rate that disassembly occurs, and that three ATP molecules are hydrolyzed per clathrin triskelion released. Stopped-flow measurements revealed a lag phase in which the scattering intensity increased owing to association of Hsc70 with clathrin cages followed by serial rounds of ATP hydrolysis prior to triskelion removal. Global fit of stopped-flow data to several physically plausible mechanisms showed the best fit to a model in which sequential hydrolysis of three separate ATP molecules is required for the eventual release of a triskelion from the clathrin-auxilin cage.

  1. The fusion of Toxoplasma gondii SAG1 vaccine candidate to Leishmania infantum heat shock protein 83-kDa improves expression levels in tobacco chloroplasts.

    PubMed

    Albarracín, Romina M; Becher, Melina Laguía; Farran, Inmaculada; Sander, Valeria A; Corigliano, Mariana G; Yácono, María L; Pariani, Sebastián; López, Edwin Sánchez; Veramendi, Jon; Clemente, Marina

    2015-05-01

    Chloroplast transformation technology has emerged as an alternative platform offering many advantages over nuclear transformation. SAG1 is the main surface antigen of the intracellular parasite Toxoplasma gondii and a promising candidate to produce an anti-T. gondii vaccine. The aim of this study was to investigate the expression of SAG1 using chloroplast transformation technology in tobacco plants. In order to improve expression in transplastomic plants, we also expressed the 90-kDa heat shock protein of Leishmania infantum (LiHsp83) as a carrier for the SAG1 antigen. SAG1 protein accumulation in transplastomic plants was approximately 0.1-0.2 μg per gram of fresh weight (FW). Fusion of SAG1 to LiHsp83 significantly increased the level of SAG1 accumulation in tobacco chloroplasts (by up to 500-fold). We also evaluated the functionality of the chLiHsp83-SAG1. Three human seropositive samples reacted with SAG1 expressed in transplastomic chLiHsp83-SAG1 plants. Oral immunization with chLiHsp83-SAG1 elicited a significant reduction of the cyst burden that correlated with an increase of SAG1-specific antibodies. We propose the fusion of foreign proteins to LiHsp83 as a novel strategy to increase the expression level of the recombinant proteins using chloroplast transformation technology, thus addressing one of the current challenges for this approach in antigen protein production.

  2. Antisense oligonucleotide against collagen-specific molecular chaperone 47-kDa heat shock protein suppresses scar formation in rat wounds.

    PubMed

    Wang, Zuolin; Inokuchi, Tsugio; Nemoto, Takayuki K; Uehara, Masataka; Baba, Tomomi T

    2003-05-01

    The 47-kDa heat shock protein (HSP47) is a molecular chaperone specifically targeting the processing and quality control of collagen molecules. This study was performed to investigate whether antisense therapy preventing HSP47 expression might affect the scar formation occurring during wound healing of skin. In wound healing of neonatal rat skin, the number of HSP47-positive cells and the amount of HSP47 protein consistently increased up to 7 days after surgical wounding. The increase in HSP47-positive cell number and protein content was efficiently suppressed by daily injections of HSP47-antisense deoxynucleotide (30 nmol) for 7 days. This treatment also suppressed the accumulation of collagen type I in the wound. Moreover, the disorder of collagenous fibers was relieved in the healed portion of the wounds subjected to the antisense treatment. Taken together, the authors propose that HSP47 is an important determinant in scar formation and that the antisense treatment against HSP47 gene may have a therapeutic potential to suppress the scar formation of skin.

  3. The fusion of Toxoplasma gondii SAG1 vaccine candidate to Leishmania infantum heat shock protein 83-kDa improves expression levels in tobacco chloroplasts.

    PubMed

    Albarracín, Romina M; Becher, Melina Laguía; Farran, Inmaculada; Sander, Valeria A; Corigliano, Mariana G; Yácono, María L; Pariani, Sebastián; López, Edwin Sánchez; Veramendi, Jon; Clemente, Marina

    2015-05-01

    Chloroplast transformation technology has emerged as an alternative platform offering many advantages over nuclear transformation. SAG1 is the main surface antigen of the intracellular parasite Toxoplasma gondii and a promising candidate to produce an anti-T. gondii vaccine. The aim of this study was to investigate the expression of SAG1 using chloroplast transformation technology in tobacco plants. In order to improve expression in transplastomic plants, we also expressed the 90-kDa heat shock protein of Leishmania infantum (LiHsp83) as a carrier for the SAG1 antigen. SAG1 protein accumulation in transplastomic plants was approximately 0.1-0.2 μg per gram of fresh weight (FW). Fusion of SAG1 to LiHsp83 significantly increased the level of SAG1 accumulation in tobacco chloroplasts (by up to 500-fold). We also evaluated the functionality of the chLiHsp83-SAG1. Three human seropositive samples reacted with SAG1 expressed in transplastomic chLiHsp83-SAG1 plants. Oral immunization with chLiHsp83-SAG1 elicited a significant reduction of the cyst burden that correlated with an increase of SAG1-specific antibodies. We propose the fusion of foreign proteins to LiHsp83 as a novel strategy to increase the expression level of the recombinant proteins using chloroplast transformation technology, thus addressing one of the current challenges for this approach in antigen protein production. PMID:25823559

  4. 70-kDa Heat Shock Cognate Protein hsc70 Mediates Calmodulin-dependent Nuclear Import of the Sex-determining Factor SRY*

    PubMed Central

    Kaur, Gurpreet; Lieu, Kim G.; Jans, David A.

    2013-01-01

    We recently showed that the developmentally important family of SOX (SRY (sex determining region on the Y chromosome)-related high mobility group (HMG) box) proteins require the calcium-binding protein calmodulin (CaM) for optimal nuclear accumulation, with clinical mutations in SRY that specifically impair nuclear accumulation via this pathway resulting in XY sex reversal. However, the mechanism by which CaM facilitates nuclear accumulation is unknown. Here, we show, for the first time, that the 70-kDa heat shock cognate protein hsc70 plays a key role in CaM-dependent nuclear import of SRY. Using a reconstituted nuclear import assay, we show that antibodies to hsc70 significantly reduce nuclear accumulation of wild type SRY and mutant derivatives thereof that retain CaM-dependent nuclear import, with an increased rate of nuclear accumulation upon addition of both CaM and hsc70, in contrast to an SRY mutant derivative with impaired CaM binding. siRNA knockdown of hsc70 in intact cells showed similar results, indicating clear dependence upon hsc70 for CaM-dependent nuclear import. Analysis using the technique of fluorescence recovery after photobleaching indicated that hsc70 is required for the maximal rate of SRY nuclear import in living cells but has no impact upon SRY nuclear retention/nuclear dynamics. Finally, we demonstrate direct binding of hsc70 to the SRY·CaM complex, with immunoprecipitation experiments from cell extracts showing association of hsc70 with wild type SRY, but not with a mutant derivative with impaired CaM binding, dependent on Ca2+. Our novel findings strongly implicate hsc70 in CaM-dependent nuclear import of SRY. PMID:23235156

  5. A DNA vaccine against tuberculosis based on the 65 kDa heat-shock protein differentially activates human macrophages and dendritic cells

    PubMed Central

    Franco, Luís H; Wowk, Pryscilla F; Silva, Célio L; Trombone, Ana PF; Coelho-Castelo, Arlete AM; Oliver, Constance; Jamur, Maria C; Moretto, Edson L; Bonato, Vânia LD

    2008-01-01

    Background A number of reports have demonstrated that rodents immunized with DNA vaccines can produce antibodies and cellular immune responses presenting a long-lasting protective immunity. These findings have attracted considerable interest in the field of DNA vaccination. We have previously described the prophylactic and therapeutic effects of a DNA vaccine encoding the Mycobacterium leprae 65 kDa heat shock protein (DNA-HSP65) in a murine model of tuberculosis. As DNA vaccines are often less effective in humans, we aimed to find out how the DNA-HSP65 stimulates human immune responses. Methods To address this question, we analysed the activation of both human macrophages and dendritic cells (DCs) cultured with DNA-HSP65. Then, these cells stimulated with the DNA vaccine were evaluated regarding the expression of surface markers, cytokine production and microbicidal activity. Results It was observed that DCs and macrophages presented different ability to uptake DNA vaccine. Under DNA stimulation, macrophages, characterized as CD11b+/CD86+/HLA-DR+, produced high levels of TNF-alpha, IL-6 (pro-inflammatory cytokines), and IL-10 (anti-inflammatory cytokine). Besides, they also presented a microbicidal activity higher than that observed in DCs after infection with M. tuberculosis. On the other hand, DCs, characterized as CD11c+/CD86+/CD123-/BDCA-4+/IFN-alpha-, produced high levels of IL-12 and low levels of TNF-alpha, IL-6 and IL-10. Finally, the DNA-HSP65 vaccine was able to induce proliferation of peripheral blood lymphocytes. Conclusion Our data suggest that the immune response is differently activated by the DNA-HSP65 vaccine in humans. These findings provide important clues to the design of new strategies for using DNA vaccines in human immunotherapy. PMID:18208592

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

    PubMed

    Loeffler, David A; Klaver, Andrea C; Coffey, Mary P; Aasly, Jan O; LeWitt, Peter A

    2016-01-01

    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 (CSF) 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 (TAC) in CSF samples from 34 healthy subjects ranging from 20 to 75 years of age. Age was negatively associated with HSPA8 (ρ = -0.47; p = 0.005). An age-related increase in oxidative stress was indicated by a positive association between age and 8-OHdG (ρ = 0.61; p = 0.0001). HSPA8 was moderately negatively associated with 8-OHdG (ρ = -0.58; p = 0.0004). Age and HSPA8 were weakly associated with 8-isoprostane and TAC (range of ρ values: -0.15 to 0.16). Our findings in this exploratory study suggest that during healthy aging, CSF 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 CSF. 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 CSF is reflected by a similar change in the brain. PMID:27507943

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

    PubMed Central

    Loeffler, David A.; Klaver, Andrea C.; Coffey, Mary P.; Aasly, Jan O.; LeWitt, Peter A.

    2016-01-01

    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 (CSF) 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 (TAC) in CSF samples from 34 healthy subjects ranging from 20 to 75 years of age. Age was negatively associated with HSPA8 (ρ = –0.47; p = 0.005). An age-related increase in oxidative stress was indicated by a positive association between age and 8-OHdG (ρ = 0.61; p = 0.0001). HSPA8 was moderately negatively associated with 8-OHdG (ρ = –0.58; p = 0.0004). Age and HSPA8 were weakly associated with 8-isoprostane and TAC (range of ρ values: –0.15 to 0.16). Our findings in this exploratory study suggest that during healthy aging, CSF 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 CSF. 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 CSF is reflected by a similar change in the brain. PMID:27507943

  8. Distribution of lactoferrin and 60/65 kDa heat shock protein in normal and inflamed human intestine and liver.

    PubMed Central

    Peen, E; Eneström, S; Skogh, T

    1996-01-01

    Immunisation against the mycobacterial heat shock protein (hsp-65) has been proposed to lead to production of autoantibodies against human lactoferrin. Such antibodies occur in ulcerative colitis and in primary sclerosing cholangitis. This study analysed the distribution of hsp-65 and lactoferrin in biopsy specimens from patients with inflammatory bowel disease and primary sclerosing cholangitis and studied whether immunisation against mycobacterial hsp-65 resulted in production of antilactoferrin antibodies and vice versa. Polyclonal rabbit antihuman lactoferrin and monoclonal mouse anti-hsp-65 (ML30) were used for immunohistochemistry on biopsy specimens from patients with inflammatory bowel disease and primary sclerosing cholangitis. Rats were immunised against human lactoferrin and mycobacterial hsp-65 respectively. Antibody measurements were done by enzyme immunosorbent assays. It was found that lactoferrin and hsp-60/65 were not codistributed. Lactoferrin was found on vascular endothelium and in nonparenchymal liver cells both in inflamed and uninflamed tissues, but only in the hepatocytes of inflamed liver. ML30 reactivity was not inhibited by antilactoferrin antibodies. Rat anti-hsp-65 serum had no detectable antilactoferrin antibodies. In conclusion, antilactoferrin antibodies probably do not arise by immunisation against mycobacterial hsp-65. Both nonparenchymal cells and hepatocytes probably participate in clearance of lactoferrin. Endothelial exposure of lactoferrin may have pathogenic implications in diseases with antilactoferrin autoantibodies. Images Figure 1 Figure 2 PMID:8566841

  9. Brain tumor magnetic targeting and biodistribution of superparamagnetic iron oxide nanoparticles linked with 70-kDa heat shock protein study by nonlinear longitudinal response

    NASA Astrophysics Data System (ADS)

    Shevtsov, Maxim A.; Nikolaev, Boris P.; Ryzhov, Vyacheslav A.; Yakovleva, Ludmila Y.; Dobrodumov, Anatolii V.; Marchenko, Yaroslav Y.; Margulis, Boris A.; Pitkin, Emil; Guzhova, Irina V.

    2015-08-01

    Brain tumor targeting efficiency and biodistribution of the superparamagnetic nanoparticles conjugated with heat shock protein Hsp70 (SPION-Hsp70) were evaluated in experimental glioma model. Synthesized conjugates were characterized using the method of longitudinal nonlinear response of magnetic nanoparticles to a weak ac magnetic field with measurements of second harmonic of magnetization (NLR-M2). Cellular interaction of magnetic conjugates was analyzed in 9L glioma cell culture. The biodistribution of the nanoparticles and their accumulation in tumors was assessed by the latter approach as well. The efficacy of Hsp70-conjugates for contrast enhancement in the orthotopic model of 9L glioma was assessed by MR imaging (11 T). Magnetic nanoparticles conjugated with Hsp70 had the relaxivity properties of the MR-negative contrast agents. Morphological observation and cell viability test demonstrated good biocompatibility of Hsp70-conjugates. Analysis of the T2-weighted MR scans in tumor-bearing rats demonstrated the high efficacy of Hsp70-conjugates in contrast enhancement of the glioma in comparison to non-conjugated nanoparticles. High contrast enhancement of the glioma was provided by the accumulation of the SPION-Hsp70 particles in the glioma tissue (as shown by the histological assay). Biodistribution analysis by NLR-M2 measurements evidenced the many-fold increase (~40) in the tumor-to-normal brain uptake ratio in the Hsp70-conjugates treated animals. Biodistribution pattern of Hsp70-decorated nanoparticles differed from that of non-conjugated SPIONs. Coating of the magnetic nanoparticles with Hsp70 protein enhances the tumor-targeting ability of the conjugates that could be applied in the MR imaging of the malignant brain tumors.

  10. Antibodies directed to the gram-negative bacterium Neisseria gonorrhoeae cross-react with the 60 kDa heat shock protein and lead to impaired neurite outgrowth in NTera2/D1 cells.

    PubMed

    Reuss, B; Asif, A R

    2014-09-01

    Children of mothers with prenatal gonococcal infections are of increased risk to develop schizophrenic psychosis in later life. The present study hypothesizes an autoimmune mechanism for this, investigating interactions of a commercial rabbit antiserum directed to Neisseria gonorrhoeae (α-NG) with human NTera2/D1 cells, an established in vitro model for human neuronal differentiation. Immunocytochemistry demonstrated α-NG to label antigens on an intracellular organelle, which by Western blot analysis showed a molecular weight shortly below 72 kDa. An antiserum directed to Neisseria meningitidis (α-NM) reacts with an antigen shortly below 95 kDa, confirming antibody specificity of these interactions. Two-dimensional gel electrophoresis and partial Western transfer, allowed to localize an α-NG reactive protein spot which was identified by LC-Q-TOF MS/MS analysis as mitochondrial heat shock protein Hsp60. This was confirmed by Western blot analysis of α-NG immunoreactivity with a commercial Hsp60 protein sample, with which α-NM failed to interact. Finally, analysis of neurite outgrowth in retinoic acid-stimulated differentiating NTera2-D1 cells, demonstrates that α-NG but not α-NM treatment reduces neurite length. These results demonstrate that α-NG can interact with Hsp60 in vitro, whereas pathogenetic relevance of this interaction for psychotic symptomatology remains to be clarified. PMID:24577885

  11. Purification of the 70-kDa heat-shock protein from catfish liver: Immunological comparison of the protein in different fish species and its potential use as a stress indicator

    SciTech Connect

    Abukhalaf, I.K.; Zimmerman, E.G.; Dickson, K.L.; Masaracchia, R.A.; Donahue, M.J. ); Covington, S. )

    1994-08-01

    The heat-shock protein or stress-70 family was isolated from catfish liver. The homogeneity of the purified protein was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Fish subjected to whole-body hyperthermia contained the constitutive and the heat-inducible stress-70 with approximate molecular weights of 70 and 68 kDa, respectively. The final purification product from livers of catfish raised under normal temperature was only the constitutive stress-70. Western blot analysis with rabbit antiserum prepared against purified catfish (Ictalurus punctatus) liver stress-70 showed that the antibody cross-reacted with liver, muscle, and gill tissue homogenates of fathead minnows (Pimephales promelas), red shiners (Cyprinella lutrensis), black bass (Micropterus salmoides), and bluegill (Lepomis macrochirus), with various intensities suggesting that stress-70s from different tissues of various fish species share common antigenic determinants of the protein. This substantiates that the antigen/antibody approach of stress-70 is useful as a stress indicator and, consequently, as a potential biomarker for water quality.

  12. Reduction of hypoxia-induced transcription through the repression of hypoxia-inducible factor-1alpha/aryl hydrocarbon receptor nuclear translocator DNA binding by the 90-kDa heat-shock protein inhibitor radicicol.

    PubMed

    Hur, Eunseon; Kim, Hong-Hee; Choi, Su Mi; Kim, Jin Hee; Yim, Sujin; Kwon, Ho Jeong; Choi, Youngyeon; Kim, Dae Kyong; Lee, Mi-Ock; Park, Hyunsung

    2002-11-01

    Under low oxygen tension, cells increase the transcription of specific genes involved in angiogenesis, erythropoiesis, and glycolysis. Hypoxia-induced gene expression depends primarily on stabilization of the alpha subunit of hypoxia-inducible factor-1 (HIF-1alpha), which acts as a heterodimeric trans-activator with the nuclear protein known as the aryl hydrocarbon receptor nuclear translocator (Arnt). The resulting heterodimer (HIF-1alpha/Arnt) interacts specifically with the hypoxia-responsive element (HRE), thereby increasing transcription of the genes under HRE control. Our results indicate that the 90-kDa heat-shock protein (Hsp90) inhibitor radicicol reduces the hypoxia-induced expression of both endogenous vascular endothelial growth factor (VEGF) and HRE-driven reporter plasmids. Radicicol treatment (0.5 microg/ml) does not significantly change the stability of the HIF-1alpha protein and does not inhibit the nuclear localization of HIF-1alpha. However, this dose of radicicol significantly reduces HRE binding by the HIF-1alpha/Arnt heterodimer. Our results, the first to show that radicicol specifically inhibits the interaction between the HIF-1alpha/Arnt heterodimer and HRE, suggest that Hsp90 modulates the conformation of the HIF-1alpha/Arnt heterodimer, making it suitable for interaction with HRE. Furthermore, we demonstrate that radicicol reduces hypoxia-induced VEGF expression to decrease hypoxia-induced angiogenesis.

  13. Sodium L-lactate differently affects brain-derived neurothrophic factor, inducible nitric oxide synthase, and heat shock protein 70 kDa production in human astrocytes and SH-SY5Y cultures.

    PubMed

    Coco, Marinella; Caggia, Silvia; Musumeci, Giuseppe; Perciavalle, Vincenzo; Graziano, Adriana C E; Pannuzzo, Giovanna; Cardile, Venera

    2013-02-01

    The present study analyzed the in vitro effects induced by sodium L-lactate on human astrocytes and the SH-SY5Y cell line, when added at concentrations of 5, 10, and 25 mmol/liter. Expression of brain-derived neurotrophic factor (BDNF), inducible nitric oxide synthase (iNOS), and heat shock protein 70 kDa (HSP70) was evaluated by Western blot analysis. Cell viability with MTT, release of nitric oxide (NO) through the Griess reaction, and production of BDNF by enzyme-linked immunoassay was determined. Data indicate that, in SH-SY5Y as well as in cortical astrocytes, after 4 hr sodium L-lactate increases the expression and release of BDNF, iNOS, and NO; after 24 hr, it turns is ineffective for the production of the neurotrophin in SH-SY5Y and not in astrocytes, but the expression of iNOS and release of NO appear to be further increased compared with those after 4 hr. Sodium L-lactate influences differently the expression of HSP70 in SH-SY5Y compared with astrocytes. We propose, based on these findings, that sodium L-lactate affects the expression of BDNF in SH-SY5Y and astrocytes in a different manner: high levels of iNOS and NO expressed in SH-SY5Y have a profound inhibitory effect on the release of BDNF related to a more limited production of HSP70 by SH-SY5Y. In conclusion, the results demonstrate differences in the responses of SH-SY5Y and astrocytes to stimulation by high levels of sodium L-lactate. Sodium L-lactate differently and dose and time dependently influences the expression and release of BDNF, iNOS, NO, and HSP70 depending on the cell type.

  14. Heat-resistant variants of Chinese hamster fibroblasts altered in expression of heat shock protein.

    PubMed Central

    Laszlo, A; Li, G C

    1985-01-01

    Heat-resistant variants of the Chinese hamster HA-1 line have been isolated after repeated heat treatments. The heat-resistant phenotype has been stable for over 70 passages. One of the members of the 70-kDa heat shock protein family was found to be synthesized at greater levels in the heat-resistant variants under normal growth conditions. Mild heat treatment of the variant lines induced a transient thermotolerance that was accompanied by additional increase in the synthesis of the 70-kDa heat shock proteins. Cell-free translation of total cellular RNA revealed greater amounts of 70-kDa heat shock protein mRNA in both control and heated variant cells. The greater levels of 70-kDa heat shock protein synthesized in the variant cells presumably are a reflection of altered levels of its messenger mRNA. In addition, we found that translational control plays a role in the elevated expression of heat shock proteins in heat-shocked HA-1 cells and their heat-resistant variants. The association of the heat-resistant phenotype with increased levels of a 70-kDa heat shock protein suggests strongly that this gene product plays a role in protecting cells from damage inflicted by elevated temperatures. Images PMID:3865213

  15. Comparative inhibition by hard and soft metal ions of steroid-binding capacity of renal mineralocorticoid receptor cross-linked to the 90-kDa heat-shock protein heterocomplex.

    PubMed Central

    Galigniana, M D; Piwien-Pilipuk, G

    1999-01-01

    We analysed the inhibitory effects in vitro and in vivo of several metal ions on aldosterone binding to the rat kidney mineralocorticoid receptor with the purpose of assessing possible toxic effects of those ions on sodium retention, as well as to obtain information on receptor structural requirements for ligand binding. For the assays in vitro, the inhibitory effects of 20 metal ions were analysed on steroid-binding capacity for renal receptor cross-linked to 90-kDa heat-shock protein (hsp90) by pretreatment with dimethyl pimelimidate. Cross-linking prevented the artifactual dissociation of hsp90 (and, consequently, the loss of steroid binding) from the mineralocorticoid receptor due to the presence of high concentrations of salt in the incubation medium. Cross-linked heterocomplex showed no difference in ligand specificity and affinity with respect to native receptor, but increased stability upon thermal- or ionic-strength-induced destabilization was observed. Treatments in vitro with metal ions in the range 10(-8)-10(-1) M resulted in a differential inhibitory effect for each particular ion on aldosterone binding. Using the negative logarithm of metal concentration for 50% inhibition, the ions could be correlated with their Klopman hardness constants. The analysis of this relationship led us to postulate three types of reaction: with thiol, imidazole and carboxyl groups. The essential role played by these residues in steroid binding was confirmed by chemical modification of cysteines with dithionitrobenzoic acid, histidines with diethyl pyrocarbonate and acidic amino acids with Woodward's reagent (N-ethyl-5-phenylisoxazolium-3'-sulphonate). Importantly, the toxic effects of some metal ions were also observed by treatments in vivo of adrenalectomized rats on both steroid-binding capacity and aldosterone-dependent sodium-retaining properties. We suggest that those amino acid residues are involved in the activation process of the mineralocorticoid receptor upon

  16. A constitutive 70 kDa heat-shock protein is localized on the fibres of spindles and asters at metaphase in an ATP-dependent manner: a new chaperone role is proposed.

    PubMed Central

    Agueli, C; Geraci, F; Giudice, G; Chimenti, L; Cascino, D; Sconzo, G

    2001-01-01

    In the present study, double immunofluorescence and immunoblot analysis have been used to show that centrosomes, isolated from Paracentrotus lividus sea urchin embryos at the first mitotic metaphase, contain the constitutive chaperone, heat-shock protein (HSP) 70. More specifically, we demonstrate that centrosomes contain only the HSP70-d isoform, which is one of the four isoforms identified in P. lividus. We also provide evidence that p34(cell division control kinase-2) and t complex polypeptide-1 (TCP-1) alpha, a subunit of the TCP-1 complex, are localized on the centrosomes. Furthermore, inhibition of TCP-1 in vivo, via microinjecting an anti-(TCP-1 alpha) antibody into P. lividus eggs before fertilization, either impaired mitosis or induced severe malformations in more than 50% of embryos. In addition, we have isolated the whole mitotic apparatus and shown that HSP70 localizes on the fibres of spindles and asters, and binds them in an ATP-dependent manner. These observations suggest that HSP70 has a chaperone role in assisting the TCP-1 complex in tubulin folding, when localized on centrosomes, and during the assembling and disassembling of the mitotic apparatus, when localized on the fibres of spindles and asters. PMID:11716770

  17. Toxoplasma gondii 70 kDa heat shock protein: systemic detection is associated with the death of the parasites by the immune response and its increased expression in the brain is associated with parasite replication.

    PubMed

    Barenco, Paulo Victor Czarnewski; Lourenço, Elaine Vicente; Cunha-Júnior, Jair Pereira; Almeida, Karine Cristine; Roque-Barreira, Maria Cristina; Silva, Deise Aparecida Oliveira; Araújo, Ester Cristina Borges; Coutinho, Loyane Bertagnolli; Oliveira, Mário Cézar; Mineo, Tiago Wilson Patriarca; Mineo, José Roberto; Silva, Neide Maria

    2014-01-01

    The heat shock protein of Toxoplasma gondii (TgHSP70) is a parasite virulence factor that is expressed during T. gondii stage conversion. To verify the effect of dexamethasone (DXM)-induced infection reactivation in the TgHSP70-specific humoral immune response and the presence of the protein in the mouse brain, we produced recombinant TgHSP70 and anti-TgHSP70 IgY antibodies to detect the protein, the specific antibody and levels of immune complexes (ICs) systemically, as well as the protein in the brain of resistant (BALB/c) and susceptible (C57BL/6) mice. It was observed higher TgHSP70-specific antibody titers in serum samples of BALB/c compared with C57BL/6 mice. However, the susceptible mice presented the highest levels of TgHSP70 systemically and no detection of specific ICs. The DXM treatment induced increased parasitism and lower inflammatory changes in the brain of C57BL/6, but did not interfere with the cerebral parasitism in BALB/c mice. Additionally, DXM treatment decreased the serological TgHSP70 concentration in both mouse lineages. C57BL/6 mice presented high expression of TgHSP70 in the brain with the progression of infection and under DXM treatment. Taken together, these data indicate that the TgHSP70 release into the bloodstream depends on the death of the parasites mediated by the host immune response, whereas the increased TgHSP70 expression in the brain depends on the multiplication rate of the parasite.

  18. Hazardous effects of effluent from the chrome plating industry: 70 kDa heat shock protein expression as a marker of cellular damage in transgenic Drosophila melanogaster (hsp70-lacZ).

    PubMed Central

    Mukhopadhyay, Indranil; Saxena, Daya Krishna; Chowdhuri, Debapratim Kar

    2003-01-01

    Hazardous effects of an effluent from the chrome plating industry were examined by exposing transgenic Drosophila melanogaster (hsp70-lacZ) to various concentrations (0.05, 0.1, 1.0, 10.0, and 100.0 micro L/mL) of the effluent through diet. The emergence pattern of adult flies was affected, along with impaired reproductive performance at the higher dietary concentrations of the effluent. Interestingly, the effect of the effluent was more pronounced in male than in female flies. The effect of the effluent on development of adult flies was concurrent with the expression pattern of the heat shock protein 70 gene (hsp70), both in larval tissues and in the reproductive organs of adult flies. We observed a dose- and time-dependent expression of hsp70 in third instar larvae exposed for different time intervals. Absence of hsp70 expression in larvae exposed to 0.1 micro L/mL of the effluent indicated that this is the highest nontoxic concentration for Drosophila. The stress gene assay in the reproductive organs of adult flies revealed hsp70 expression in the testis of male flies only. However, trypan blue dye exclusion tests in these tissues indicate tissue damage in the male accessory gland of adult flies, which was further confirmed by ultrastructural observations. In the present study we demonstrate the utility of transgenic Drosophila as an alternative animal model for evaluating hazardous effects of the effluent from the chrome plating industry and further reveal the cytoprotective role of hsp70 and its expression as an early marker in environmental risk assessment. PMID:14644668

  19. Neural differentiation and the attenuated heat shock response.

    PubMed

    Yang, Jingxian; Oza, Jay; Bridges, Kristen; Chen, Kuang Yu; Liu, Alice Y-C

    2008-04-01

    Differentiation of neural progenitor cells of neuroblastoma, pheochromocytoma, and surrogate stem cell lineages from a state resembling stem cells to a state resembling neurons is accompanied by a marked attenuation in induction of the heat shock protein 70 promoter driven-luciferase reporter gene, and induction of the reporter gene in primary embryonic neurons from hippocampus, cortex, and spinal cord is lower still when compared to the differentiated cells. Neural specificity of this phenotype is demonstrated by a negative correlation of hsp70-reporter gene expression and neurite extension under various experimental conditions. Analysis of biochemical events involved in induction of the heat shock response (HSR) reveal a blunted activation of HSF1 DNA-binding activity, and decreased induction of the mRNA(hsp70) and the 72 kDa HSP70 protein. Immunocytochemical staining for HSP70 demonstrates a cytoplasmic staining pattern; heat shock greatly increased the HSP70 staining intensity in the undifferentiated cells and less so in the differentiated cells. Vulnerability of the differentiated cells towards the oxidizer, arsenite, and the excitotoxic glutamate/glycine is demonstrated by the dose-dependent cytotoxic effects of these agents on cell viability and activation of caspase 3/7. Importantly, conditioning heat shock as well as increased expression of HSP70 by gene transfer conferred protection against such cytotoxicity. Together, our results show that neural differentiation is associated with a decreased induction of the heat shock response and an increased vulnerability to stress induced pathologies and death. PMID:18316066

  20. The Bacillus subtilis heat shock stimulon

    PubMed Central

    Schumann, Wolfgang

    2003-01-01

    All organisms respond to a sudden increase in temperature by the so-called heat shock response. This response results in the induction of a subset of genes, designated heat shock genes coding for heat shock proteins, which allow the cell to cope with the stress regimen. Research carried out during the last 10 years with eubacteria has revealed that the heat shock genes of a given species fall into different classes (regulons), where each class is regulated by a different transcriptional regulator, which could be an alternative sigma factor, a transcriptional activator, or a transcriptional repressor. All regulons of a single species constitute the heat shock stimulon. In Bacillus subtilis, more than 200 genes representing over 7% of the transcriptionally active genes are induced at least 3-fold in response to a heat shock. This response becomes apparent within the first minute after exposure to heat stress, is transient, and is coordinated by at least 5 transcriptional regulator proteins, including 2 repressors, an alternate sigma-factor, and a 2-component signal transduction system. A detailed analysis of the regulation of all known heat shock genes has shown that they belong to at least 6 regulons that together comprise the B subtilis heat shock stimulon. Potential thermosensors are discussed in this article. PMID:14984053

  1. Heat Shock Proteins: Mediators of Atherosclerotic Development.

    PubMed

    Deniset, Justin F; Pierce, Grant N

    2015-01-01

    Heat shock proteins play important housekeeping roles in a variety of cells within the body during normal control conditions. The many different functions for heat shock proteins in the cell depend upon the specific heat shock protein involved. Each protein is nominally differentiated based upon its molecular size. However, in addition to their role in normal cell function, heat shock proteins may play an even more important role as pro-survival proteins conserved through evolution to protect the cell from a variety of stresses. The ability of a cell to withstand these environmental stresses is critical to its capacity to adapt and remain viable. Loss of this ability may lead to pathological states. Abnormal localization, structure or function of the heat shock proteins has been associated with many pathologies, including those involving heart disease. Heat shock proteins like HSP60 and HSP70 in particular have been identified as playing important roles in inflammation and immune reactions. Inflammation has been identified recently as an important pathological risk factor for heart disease. It is perhaps not surprising therefore, that heat shock protein family has been increasingly identified as an important intracellular pathway associated with inflammatory-mediated heart conditions including atherosclerosis. This paper reviews the evidence in support of a role for heat shock proteins in cardiovascular disease and the potential to target these proteins to alter the progression of atherosclerotic disease.

  2. Ultrafast collisional ion heating by electrostatic shocks.

    PubMed

    Turrell, A E; Sherlock, M; Rose, S J

    2015-01-01

    High-intensity lasers can be used to generate shockwaves, which have found applications in nuclear fusion, proton imaging, cancer therapies and materials science. Collisionless electrostatic shocks are one type of shockwave widely studied for applications involving ion acceleration. Here we show a novel mechanism for collisionless electrostatic shocks to heat small amounts of solid density matter to temperatures of ∼keV in tens of femtoseconds. Unusually, electrons play no direct role in the heating and it is the ions that determine the heating rate. Ions are heated due to an interplay between the electric field of the shock, the local density increase during the passage of the shock and collisions between different species of ion. In simulations, these factors combine to produce rapid, localized heating of the lighter ion species. Although the heated volume is modest, this would be one of the fastest heating mechanisms discovered if demonstrated in the laboratory.

  3. Ultrafast collisional ion heating by electrostatic shocks

    NASA Astrophysics Data System (ADS)

    Turrell, A. E.; Sherlock, M.; Rose, S. J.

    2015-11-01

    High-intensity lasers can be used to generate shockwaves, which have found applications in nuclear fusion, proton imaging, cancer therapies and materials science. Collisionless electrostatic shocks are one type of shockwave widely studied for applications involving ion acceleration. Here we show a novel mechanism for collisionless electrostatic shocks to heat small amounts of solid density matter to temperatures of ~keV in tens of femtoseconds. Unusually, electrons play no direct role in the heating and it is the ions that determine the heating rate. Ions are heated due to an interplay between the electric field of the shock, the local density increase during the passage of the shock and collisions between different species of ion. In simulations, these factors combine to produce rapid, localized heating of the lighter ion species. Although the heated volume is modest, this would be one of the fastest heating mechanisms discovered if demonstrated in the laboratory.

  4. Ultrafast collisional ion heating by electrostatic shocks

    PubMed Central

    Turrell, A. E.; Sherlock, M.; Rose, S. J.

    2015-01-01

    High-intensity lasers can be used to generate shockwaves, which have found applications in nuclear fusion, proton imaging, cancer therapies and materials science. Collisionless electrostatic shocks are one type of shockwave widely studied for applications involving ion acceleration. Here we show a novel mechanism for collisionless electrostatic shocks to heat small amounts of solid density matter to temperatures of ∼keV in tens of femtoseconds. Unusually, electrons play no direct role in the heating and it is the ions that determine the heating rate. Ions are heated due to an interplay between the electric field of the shock, the local density increase during the passage of the shock and collisions between different species of ion. In simulations, these factors combine to produce rapid, localized heating of the lighter ion species. Although the heated volume is modest, this would be one of the fastest heating mechanisms discovered if demonstrated in the laboratory. PMID:26563440

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

    PubMed

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

    2006-01-01

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

  6. Fever, hyperthermia and the heat shock response.

    PubMed

    Singh, Ishwar S; Hasday, Jeffrey D

    2013-08-01

    The heat shock response is a highly conserved primitive response that is essential for survival against a wide range of stresses, including extremes of temperature. Fever is a more recently evolved response, during which organisms raise their core body temperature and temporarily subject themselves to thermal stress in the face of infections. The present review documents studies showing the potential overlap between the febrile response and the heat shock response and how both activate the same common transcriptional programme (although with different magnitudes) including the stress-activated transcription factor, heat shock factor-1, to modify host defences in the context of infection, inflammation and injury. The review focuses primarily on how hyperthermia within the febrile range that often accompanies infections and inflammation acts as a biological response modifier and modifies innate immune responses. The characteristic 2-3 °C increase in core body temperature during fever activates and utilises elements of the heat shock response pathway to modify cytokine and chemokine gene expression, cellular signalling and immune cell mobilisation to sites of inflammation, infection and injury. Interestingly, typical proinflammatory agonists such as Toll-like receptor agonists modify the heat shock-induced transcriptional programme and expression of HSP genes following co-exposure to febrile range hyperthermia or heat shock, suggesting a complex reciprocal regulation between the inflammatory pathway and the heat shock response pathway. PMID:23863046

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

    PubMed

    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.

  8. Heat shock response of murine Chlamydia trachomatis.

    PubMed Central

    Engel, J N; Pollack, J; Perara, E; Ganem, D

    1990-01-01

    We have investigated the heat shock response in the mouse pneumonitis strain of Chlamydia trachomatis. The kinetics of the chlamydial heat shock response resembled that of other procaryotes: the induction was rapid, occurring over a 5- to 10-min time period, and was regulated at the level of transcription. Immunoblot analysis and immunoprecipitations with heterologous antisera to the heat shock proteins DnaK and GroEL demonstrated that the rate of synthesis, but not the absolute amount of these two proteins, increased after heat shock. Using a general screen for genes whose mRNAs are induced by heat shock, we identified and cloned two of these. DNA sequence analysis demonstrated that one of the genes is a homolog of dnaK. Further sequence analysis of the region upstream of the dnaK gene revealed that the chlamydial homolog of the grpE gene is located just adjacent to the dnaK gene. The second locus encoded three potential nonoverlapping open reading frames. One of the open reading frames was 52% homologous to the ribosomal protein S18 of Escherichia coli and thus presumably encodes the chlamydial homolog. Interestingly, this ribosomal protein is not known to be induced by heat shock in E. coli. S1 nuclease and primer extension analyses located the start site of the dnaK transcript to the last nucleotide of the grpE coding sequence, suggesting that these two genes, although tandemly arranged, are transcribed separately. No promoter sequences resembling the E. coli consensus heat shock promoter could be identified upstream of either the C. trachomatis dnaK, grpE, or S18 gene. The induction of the dnaK and S18 mRNAs by heat shock occurred at a transcriptional level; their induction could be blocked by rifampin. The mechanisms of induction for these two loci were not the same, however; they were differentially sensitive to chloramphenicol. Whereas the induction of dnaK mRNA required de novo protein synthesis, the induction of the S18 mRNA did not. Thus, C. trachomatis

  9. Chromospheric heating by acoustic shock waves

    NASA Technical Reports Server (NTRS)

    Jordan, Stuart D.

    1993-01-01

    Work by Anderson & Athay (1989) suggests that the mechanical energy required to heat the quiet solar chromosphere might be due to the dissipation of weak acoustic shocks. The calculations reported here demonstrate that a simple picture of chromospheric shock heating by acoustic waves propagating upward through a model solar atmosphere, free of both magnetic fields and local inhomogeneities, cannot reproduce their chromospheric model. The primary reason is the tendency for vertically propagating acoustic waves in the range of allowed periods to dissipate too low in the atmosphere, providing insufficient residual energy for the middle chromosphere. The effect of diverging magnetic fields and the corresponding expanding acoustic wavefronts on the mechanical dissipation length is then discussed as a means of preserving a quasi-acoustic heating hypothesis. It is argued that this effect, in a canopy that overlies the low chromosphere, might preserve the acoustic shock hypothesis consistent with the chromospheric radiation losses computed by Anderson & Athay.

  10. Allergenic Characterization of 27-kDa Glycoprotein, a Novel Heat Stable Allergen, from the Pupa of Silkworm, Bombyx mori

    PubMed Central

    Son, Mina; Lee, June Yong

    2016-01-01

    Boiled silkworm pupa is a traditional food in Asia, and patients with silkworm pupa food allergy are common in these regions. Still now only one allergen from silkworm, arginine kinase, has been identified. The purpose of this study was to identify novel food allergens in silkworm pupa by analyzing a protein extract after heat treatment. Heat treated extracts were examined by proteomic analysis. A 27-kDa glycoprotein was identified, expressed in Escherichia coli, and purified. IgE reactivity of the recombinant protein was investigated by ELISA. High molecular weight proteins (above 100 kDa) elicited increased IgE binding after heat treatment compared to that before heat treatment. The molecular identities of these proteins, however, could not be determined. IgE reactivity toward a 27-kDa glycoprotein was also increased after heating the protein extract. The recombinant protein was recognized by IgE antibodies from allergic subjects (33.3%). Glycation or aggregation of protein by heating may create new IgE binding epitopes. Heat stable allergens are shown to be important in silkworm allergy. Sensitization to the 27-kDa glycoprotein from silkworm may contribute to elevation of IgE to silkworm. PMID:26770033

  11. Allergenic Characterization of 27-kDa Glycoprotein, a Novel Heat Stable Allergen, from the Pupa of Silkworm, Bombyx mori.

    PubMed

    Jeong, Kyoung Yong; Son, Mina; Lee, June Yong; Park, Kyung Hee; Lee, Jae-Hyun; Park, Jung-Won

    2016-01-01

    Boiled silkworm pupa is a traditional food in Asia, and patients with silkworm pupa food allergy are common in these regions. Still now only one allergen from silkworm, arginine kinase, has been identified. The purpose of this study was to identify novel food allergens in silkworm pupa by analyzing a protein extract after heat treatment. Heat treated extracts were examined by proteomic analysis. A 27-kDa glycoprotein was identified, expressed in Escherichia coli, and purified. IgE reactivity of the recombinant protein was investigated by ELISA. High molecular weight proteins (above 100 kDa) elicited increased IgE binding after heat treatment compared to that before heat treatment. The molecular identities of these proteins, however, could not be determined. IgE reactivity toward a 27-kDa glycoprotein was also increased after heating the protein extract. The recombinant protein was recognized by IgE antibodies from allergic subjects (33.3%). Glycation or aggregation of protein by heating may create new IgE binding epitopes. Heat stable allergens are shown to be important in silkworm allergy. Sensitization to the 27-kDa glycoprotein from silkworm may contribute to elevation of IgE to silkworm.

  12. Allergenic Characterization of 27-kDa Glycoprotein, a Novel Heat Stable Allergen, from the Pupa of Silkworm, Bombyx mori.

    PubMed

    Jeong, Kyoung Yong; Son, Mina; Lee, June Yong; Park, Kyung Hee; Lee, Jae-Hyun; Park, Jung-Won

    2016-01-01

    Boiled silkworm pupa is a traditional food in Asia, and patients with silkworm pupa food allergy are common in these regions. Still now only one allergen from silkworm, arginine kinase, has been identified. The purpose of this study was to identify novel food allergens in silkworm pupa by analyzing a protein extract after heat treatment. Heat treated extracts were examined by proteomic analysis. A 27-kDa glycoprotein was identified, expressed in Escherichia coli, and purified. IgE reactivity of the recombinant protein was investigated by ELISA. High molecular weight proteins (above 100 kDa) elicited increased IgE binding after heat treatment compared to that before heat treatment. The molecular identities of these proteins, however, could not be determined. IgE reactivity toward a 27-kDa glycoprotein was also increased after heating the protein extract. The recombinant protein was recognized by IgE antibodies from allergic subjects (33.3%). Glycation or aggregation of protein by heating may create new IgE binding epitopes. Heat stable allergens are shown to be important in silkworm allergy. Sensitization to the 27-kDa glycoprotein from silkworm may contribute to elevation of IgE to silkworm. PMID:26770033

  13. Infrared Images of Shock-Heated Tin

    SciTech Connect

    Craig W. McCluskey; Mark D. Wilke; William D. Turley; Gerald D. Stevens; Lynn R. Veeser; Michael Grover

    2004-09-01

    High-resolution, gated infrared images were taken of tin samples shock heated to just below the 505 K melting point. Sample surfaces were either polished or diamond-turned, with grain sizes ranging from about 0.05 to 10 mm. A high explosive in contact with a 2-mm-thick tin sample induced a peak sample stress of 18 GPa. Interferometer data from similarly-driven tin shots indicate that immediately after shock breakout the samples spall near the free (imaged) surface with a scab thickness of about 0.1 mm.

  14. Shock Heating: Effects on Chondritic Material

    NASA Technical Reports Server (NTRS)

    Desch, S. J.; Ciesla, F. J.; Hood, L. L.; Nakamoto, T.

    2004-01-01

    At the 1994 Conference on Chondrules and the Protoplanetary Disk, shock waves were discussed as mechanisms that may have been responsible for forming chondrules, millimeter-sized igneous spheres which are significant components of chondritic meteorites, and references therein]. At the time, shock waves were appealing because they were thought to be brief, repetitive events that were quantitatively shown to be able to rapidly heat silicates to the appropriate temperatures for chondrule formation. Since that meeting, more detailed models for the thermal processing of material in shock waves have been developed. These models have tracked the thermal evolution of the silicates for longer periods of time and found that their cooling rates are also consistent with what has been inferred for chondrules. In addition to the thermal histories of these particles, shock waves may be able to explain a number of other features observed in primitive meteorites. Here, we review the recent work that has been done in studying the interaction of solids with shock waves in the solar nebula.

  15. AIRAP, a New Human Heat Shock Gene Regulated by Heat Shock Factor 1*

    PubMed Central

    Rossi, Antonio; Trotta, Edoardo; Brandi, Rossella; Arisi, Ivan; Coccia, Marta; Santoro, M. Gabriella

    2010-01-01

    Heat shock factor-1 (HSF1) is the central regulator of heat-induced transcriptional responses leading to rapid expression of molecular chaperones that protect mammalian cells against proteotoxic stress. The main targets for HSF1 are specific promoter elements (HSE) located upstream of heat shock genes encoding a variety of heat shock proteins, including HSP70, HSP90, HSP27, and other proteins of the network. Herein we report that the zinc finger AN1-type domain-2a gene, also known as AIRAP, behaves as a canonical heat shock gene, whose expression is temperature-dependent and strictly controlled by HSF1. Transcription is triggered at temperatures above 40 °C in different types of human cancer and primary cells, including peripheral blood monocytes. As shown by ChIP analysis, HSF1 is recruited to the AIRAP promoter rapidly after heat treatment, with a kinetics that parallels HSP70 promoter HSF1-recruitment. In transfection experiments HSF1-silencing abolished heat-induced AIRAP promoter-driven transcription, which could be rescued by exogenous Flag-HSF1 expression. The HSF1 binding HSE sequence in the AIRAP promoter critical for heat-induced transcription was identified. Because its expression is induced at febrile temperatures in human cells, AIRAP may represent a new potential component of the protective response during fever in humans. PMID:20185824

  16. PUTATIVE CREATINE KINASE M-ISOFORM IN HUMAN SPERM IS IDENTIFIED AS THE 70-KILODALTON HEAT SHOCK PROTEIN HSPA2

    EPA Science Inventory

    THE PUTATIVE CREATINE KINASE M-ISOFORM IN HUMAN SPERM
    IS IDENTIFIED AS THE 70 kDa HEAT SHOCK PROTEIN HSPA2

    * Gabor Huszar1, Kathryn Stone2, David Dix3 and Lynne Vigue1
    1The Sperm Physiology Laboratory, Department of Obstetrics and Gynecology, 2 W.M. Keck Foundatio...

  17. Nitric oxide and reactive oxygen species regulate the accumulation of heat shock proteins in tomato leaves in response to heat shock and pathogen infection.

    PubMed

    Piterková, Jana; Luhová, Lenka; Mieslerová, Barbora; Lebeda, Aleš; Petřivalský, Marek

    2013-06-01

    Heat shock proteins (HSP) are produced in response to various stress stimuli to prevent cell damage. We evaluated the involvement of nitric oxide (NO) and reactive oxygen species (ROS) in the accumulation of Hsp70 proteins in tomato leaves induced by abiotic and biotic stress stimuli. A model system of leaf discs was used with two tomato genotypes, Solanum lycopersicum cv. Amateur and Solanum chmielewskii, differing in their resistance to fungal pathogen Oidium neolycopersici. Leaf discs were exposed to stress factors as heat shock and pathogen infection alone or in a combination, and treated with substances modulating endogenous NO and ROS levels. Two proteins of Hsp70 family were detected in stressed tomato leaf discs: a heat-inducible 72 kDa protein and a constitutive 75 kDa protein. The pathogenesis and mechanical stress influenced Hsp75 accumulation, whereas heat stress induced mainly Hsp72 production. Treatment with NO donor and NO scavenger significantly modulated the level of Hsp70 in variable manner related to the genotype resistance. Hsp70 accumulation correlated with endogenous NO level in S. lycopersicum and ROS levels in S. chmielewskii. We conclude NO and ROS are involved in the regulation of Hsp70 production and accumulation under abiotic and biotic stresses in dependence on plant ability to trigger its defence mechanisms. PMID:23602099

  18. DNA transformation via local heat shock

    NASA Astrophysics Data System (ADS)

    Li, Sha; Meadow Anderson, L.; Yang, Jui-Ming; Lin, Liwei; Yang, Haw

    2007-07-01

    This work describes transformation of foreign DNA into bacterial host cells by local heat shock using a microfluidic system with on-chip, built-in platinum heaters. Plasmid DNA encoding ampicillin resistance and a fluorescent protein can be effectively transformed into the DH5α chemically competent E. coli using this device. Results further demonstrate that only one-thousandth of volume is required to obtain transformation efficiencies as good as or better than conventional practices. As such, this work complements other lab-on-a-chip technologies for potential gene cloning/therapy and protein expression applications.

  19. Heat Shock Proteins in the Human Eye

    PubMed Central

    Urbak, Lærke; Vorum, Henrik

    2010-01-01

    Heat shock proteins (Hsps) are believed to primarily protect and maintain cell viability under stressful conditions such as those occurring during thermal and oxidative challenges chiefly by refolding and stabilizing proteins. Hsps are found throughout the various tissues of the eye where they are thought to confer protection from disease states such as cataract, glaucoma, and cancer. This minireview summarizes the placement, properties, and roles of Hsps in the eye and aims to provide a better comprehension of their function and involvement in ocular disease pathogenesis. PMID:22084677

  20. The Hexameric Structures of Human Heat Shock Protein 90

    PubMed Central

    Lee, Cheng-Chung; Lin, Ta-Wei; Ko, Tzu-Ping; Wang, Andrew H.-J.

    2011-01-01

    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. PMID:21647436

  1. Heat shock proteins in the kidney.

    PubMed

    Sreedharan, Rajasree; Van Why, Scott K

    2016-10-01

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

  2. Small Heat Shock Proteins in Smooth Muscle

    PubMed Central

    Salinthone, Sonemany; Tyagi, Manoj; Gerthoffer, William T.

    2008-01-01

    The small heat shock proteins (HSPs) HSP20, HSP27 and αB-crystallin are chaperone proteins that are abundantly expressed in smooth muscles are important modulators of muscle contraction, cell migration and cell survival. This review focuses on factors regulating expression of small HSPs in smooth muscle, signaling pathways that regulate macromolecular structure and the biochemical and cellular functions of small HSPs. Cellular processes regulated by small HSPs include chaperoning denatured proteins, maintaining cellular redox state and modifying filamentous actin polymerization. These processes influence smooth muscle proliferation, cell migration, cell survival, muscle contraction and synthesis of signaling proteins. Understanding functions of small heat shock proteins is relevant to mechanisms of disease in which dysfunctional smooth muscle causes symptoms, or is a target of drug therapy. One example is that secreted HSP27 may be a useful marker of inflammation during atherogenesis. Another is that phosphorylated HSP20 which relaxes smooth muscle may prove to be highly relevant to treatment of hypertension, vasospasm, asthma, premature labor and overactive bladder. Because small HSPs also modulate smooth muscle proliferation and cell migration they may prove to be targets for developing effective, novel treatments of clinical problems arising from remodeling of smooth muscle in vascular, respiratory and urogenital systems. PMID:18579210

  3. Induction of mycobacterial proteins during phagocytosis and heat shock: a time interval analysis.

    PubMed

    Alavi, M R; Affronti, L F

    1994-05-01

    Mycobacterium tuberculosis survives macrophage bactericidal activities by mechanisms that may include induction of stress proteins. We sought to determine whether the synthesis of any mycobacterial proteins is increased during phagocytosis and whether any of these proteins are also up-regulated during heat shock. Protein synthesis by M. tuberculosis H37Ra during phagocytosis by the mouse macrophage cell line IC-21, and during heat shock at 45 and 48 degrees C, was monitored at various time intervals using 35S-labeled methionine/cysteine and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Our data suggest the existence of certain common elements in the stress response of mycobacteria to the three stress stimuli. This apparent similarity was best characterized by the up-regulation of a 25-kDa protein after exposure to each of the stress conditions. Furthermore, this 25-kDa protein and a 37-kDa protein that was also synthesized during phagocytosis appeared to be extracellular because they were preferentially solubilized when infected macrophages were lysed with 0.5% NP-40. PMID:8182341

  4. Identification, characterization, and analysis of cDNA and genomic sequences encoding two different small heat shock proteins in Hordeum vulgare.

    PubMed

    Marmiroli, N; Pavesi, A; Di Cola, G; Hartings, H; Raho, G; Conte, M R; Perrotta, C

    1993-12-01

    In vitro translation of mRNAs prepared from barley (Hordeum vulgare) seedlings (cv. Onice) exposed at 40 degrees C directed the synthesis of major heat shock proteins (HSPs) with molecular masses of 80-90, 70, 42 and 16-22 kDa. A cDNA library prepared from the 40 degrees C mRNAs and screened by differential hybridization led to the isolation of heat shock specific sequences. One of these (Hv hsp18) was confirmed by hybrid-arrested and hybrid-released translation as encoding for an 18-kDa HSP. The barley hsp18 sequence has an open reading frame encoding a 160 amino acid residue 18-kDa protein that is 63% identical to wheat 16.9-kDa HSP (clone C5-8), 54% identical to soybean (Glycine max) 17.5-kDa HSP, and 49% identical to Arabidopsis thaliana 17.6-kDa HSP. Lower similarities were found with class II plant small HSPs such as soybean 17.9-kDa HSP (27%), Pisum sativum 17.7-kDa HSP (30%), wheat (Triticum aestivum) 17.3-kDa HSP (clone Ta hsp 17.3) (30%), and with animal small HSPs and alpha-crystallins. The Hv hsp18 sequence was used to pick up Hv hsp17 genomic sequence encoding for another class I 17-kDa HSP. By computer analysis of the nucleotide sequence the TATA box, two heat shock promoter elements, a metal-ion response element, and the polyadenylation signals were identified. Barley HSP18 has an additional cysteine-rich region when compared with HSP17 mapping at the carboxy terminal end. PMID:8112573

  5. Effect of prior heat shock on heat resistance of Listeria monocytogenes in meat.

    PubMed Central

    Farber, J M; Brown, B E

    1990-01-01

    The effect of prior heat shock on the thermal resistance of Listeria monocytogenes in meat was investigated. A sausage mix inoculated with approximately 10(7) L. monocytogenes per g was initially subjected to a heat shock temperature of 48 degrees C before being heated at a final test temperature of 62 or 64 degrees C. Although cells heat shocked at 48 degrees C for 30 or 60 min did not show a significant increase in thermotolerance as compared with control cells (non-heat shocked), bacteria heat shocked for 120 min did, showing an average 2.4-fold increase in the D64 degrees C value. Heat-shocked cells shifted to 4 degrees C appeared to maintain their thermotolerance for at least 24 h after heat shock. PMID:2116757

  6. Modulation of Alloimmunity by Heat Shock Proteins.

    PubMed

    Borges, Thiago J; Lang, Benjamin J; Lopes, Rafael L; Bonorino, Cristina

    2016-01-01

    The immunological mechanisms that evolved for host defense against pathogens and injury are also responsible for transplant rejection. Host rejection of foreign tissue was originally thought to be mediated mainly by T cell recognition of foreign MHC alleles. Management of solid organ transplant rejection has thus focused mainly on inhibition of T cell function and matching MHC alleles between donor and host. Recently, however, it has been demonstrated that the magnitude of the initial innate immune responses upon transplantation has a decisive impact on rejection. The exact mechanisms underlying this phenomenon have yet to be characterized. Ischemic cell death and inflammation that occur upon transplantation are synonymous with extracellular release of various heat shock proteins (Hsps), many of which have been shown to have immune-modulatory properties. Here, we review the impact of Hsps upon alloimmunity and discuss the potential use of Hsps as accessory agents to improve solid organ transplant outcomes. PMID:27555846

  7. Modulation of Alloimmunity by Heat Shock Proteins

    PubMed Central

    Borges, Thiago J.; Lang, Benjamin J.; Lopes, Rafael L.; Bonorino, Cristina

    2016-01-01

    The immunological mechanisms that evolved for host defense against pathogens and injury are also responsible for transplant rejection. Host rejection of foreign tissue was originally thought to be mediated mainly by T cell recognition of foreign MHC alleles. Management of solid organ transplant rejection has thus focused mainly on inhibition of T cell function and matching MHC alleles between donor and host. Recently, however, it has been demonstrated that the magnitude of the initial innate immune responses upon transplantation has a decisive impact on rejection. The exact mechanisms underlying this phenomenon have yet to be characterized. Ischemic cell death and inflammation that occur upon transplantation are synonymous with extracellular release of various heat shock proteins (Hsps), many of which have been shown to have immune-modulatory properties. Here, we review the impact of Hsps upon alloimmunity and discuss the potential use of Hsps as accessory agents to improve solid organ transplant outcomes. PMID:27555846

  8. Modulation of Alloimmunity by Heat Shock Proteins.

    PubMed

    Borges, Thiago J; Lang, Benjamin J; Lopes, Rafael L; Bonorino, Cristina

    2016-01-01

    The immunological mechanisms that evolved for host defense against pathogens and injury are also responsible for transplant rejection. Host rejection of foreign tissue was originally thought to be mediated mainly by T cell recognition of foreign MHC alleles. Management of solid organ transplant rejection has thus focused mainly on inhibition of T cell function and matching MHC alleles between donor and host. Recently, however, it has been demonstrated that the magnitude of the initial innate immune responses upon transplantation has a decisive impact on rejection. The exact mechanisms underlying this phenomenon have yet to be characterized. Ischemic cell death and inflammation that occur upon transplantation are synonymous with extracellular release of various heat shock proteins (Hsps), many of which have been shown to have immune-modulatory properties. Here, we review the impact of Hsps upon alloimmunity and discuss the potential use of Hsps as accessory agents to improve solid organ transplant outcomes.

  9. Synergistic impacts of heat shock and spawning on the physiology and immune health of Crassostrea gigas: an explanation for summer mortality in Pacific oysters.

    PubMed

    Li, Yan; Qin, Jian G; Abbott, Catherine A; Li, Xiaoxu; Benkendorff, Kirsten

    2007-12-01

    Mass mortality is often observed in cultured oysters during the period following spawning in the summer season. To examine the underlying causes leading to this phenomenon, thermotolerance of the Pacific oyster Crassostrea gigas was assessed using pre- and postspawning oysters that were sequentially treated with sublethal (37 degrees C) and lethal heat shocks (44 degrees C). The effects were examined on a range of immune and metabolic parameters in addition to mortality rate. A preventative 37 degrees C significantly reduced oyster mortality after exposure to a second heat shock of 44 degrees C, but in postspawning oysters mortality remained at 80%, compared with < 10% in prespawning oysters. Levels of the 72 kDa and 69 kDa heat shock proteins were low in the gill tissue from postspawning oysters stimulated by heat shock, indicating spawning reduced heat shock protein synthesis. The postspawning oysters had depleted glycogen stores in the mantle tissue and reduced adenylate energy charge after heat shock, indicative of lower energy for metabolic activity. A cumulative effect of spawning and heat shock was observed on the immunocompetence of oysters, demonstrated by reduced hemocyte phagocytosis and hemolymph antimicrobial activity. These results support the hypothesis that the energy expended during reproduction compromises the thermotolerance and immune status of oysters, leaving them easily subject to mortality if heat stress occurs in postspawning stage. This study improves our understanding of oyster summer mortality and has implications for the long-term persistence of mollusks under the influence of global warming.

  10. The interactive association between heat shock factor 1 and heat shock proteins in primary myocardial cells subjected to heat stress.

    PubMed

    Tang, Shu; Chen, Hongbo; Cheng, Yanfen; Nasir, Mohammad Abdel; Kemper, Nicole; Bao, Endong

    2016-01-01

    Heat shock factor 1 (HSF1) is a heat shock transcription factor that rapidly induces heat shock gene transcription following thermal stress. In this study, we subjected primary neonatal rat myocardial cells to heat stress in vitro to create a model system for investigating the trends in expression and association between various heat shock proteins (HSPs) and HSF1 under adverse environmental conditions. After the cells were subjected to heat stress at 42˚C for different periods of time, HSP and HSF1 mRNA and protein levels were detected by qPCR and western blot analysis in the heat-stressed cells. The HSF1 expression levels significantly increased in the cells following 120 min of exposure to heat stess compared to the levels observed at the beginning of heat stress exposure. HSP90 followed a similar trend in expression to HSF1, whereas HSP70 followed an opposite trend. However, no significant changes were observed in the crystallin, alpha B (CRYAB, also known as HSP beta-5) expression levels during the 480‑min period of exposure to heat stress. The interaction between the HSPs and HSF1 was analyzed by STRING 9.1, and it was found that HSF1 interacted with HSP90 and HSP70, and that it did not play a role in regulating CRYAB expression. Based on our findings, HSP70 may suppress HSF1 in rat myocardial cells under conditions of heat stress. Furthermore, our data demonstrate that HSF1 is not the key factor for all HSPs, and this was particularly the case for CRYAB.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  12. Heat shock proteins and heat shock factor 1 in carcinogenesis and tumor development: an update

    PubMed Central

    2013-01-01

    Heat shock proteins (HSP) are a subset of the molecular chaperones, best known for their rapid and abundant induction by stress. HSP genes are activated at the transcriptional level by heat shock transcription factor 1 (HSF1). During the progression of many types of cancer, this heat shock transcriptional regulon becomes co-opted by mechanisms that are currently unclear, although evidently triggered in the emerging tumor cell. Concerted activation of HSF1 and the accumulation of HSPs then participates in many of the traits that permit the malignant phenotype. Thus cancers of many histologies exhibit activated HSF1 and increased HSP levels that may help to deter tumor suppression and evade therapy in the clinic. We review here the extensive work that has been carried out and is still in progress aimed at: (1) understanding the oncogenic mechanisms by which HSP genes are switched on, (2) determining the roles of HSF1 / HSP in malignant transformation and, (3) discovering approaches to therapy based on disrupting the influence of the HSF1 controlled transcriptome in cancer. PMID:22885793

  13. A small heat shock protein is essential for thermotolerance and intracellular survival of Leishmania donovani

    PubMed Central

    Hombach, Antje; Ommen, Gabi; MacDonald, Andrea; Clos, Joachim

    2014-01-01

    ABSTRACT Leishmania parasites must survive and proliferate in two vastly different environments – the guts of poikilothermic sandflies and the antigen-presenting cells of homeothermic mammals. The change of temperature during the transmission from sandflies to mammals is both a key trigger for the progression of their life cycle and for elevated synthesis of heat shock proteins, which have been implicated in their survival at higher temperatures. Although the functions of the main heat shock protein families in the Leishmania life cycle have been studied, nothing is known about the roles played by small heat shock proteins. Here, we present the first evidence for the pivotal role played by the Leishmania donovani 23-kDa heat shock protein (which we called HSP23), which is expressed preferentially during the mammalian stage where it assumes a perinuclear localisation. Loss of HSP23 causes increased sensitivity to chemical stressors and renders L. donovani non-viable at 37°C. Consequently, HSP23-null mutants are non-infectious to primary macrophages in vitro. All phenotypic effects could be abrogated by the introduction of a functional HSP23 transgene into the null mutant, confirming the specificity of the mutant phenotype. Thus, HSP23 expression is a prerequisite for L. donovani survival at mammalian host temperatures and a crucial virulence factor. PMID:25179594

  14. Transcriptional activation of heat-shock genes in eukaryotes.

    PubMed

    Tanguay, R M

    1988-06-01

    Prokaryotes and eukaryotes respond to thermal or various chemical stresses by the rapid induction of a group of genes collectively referred to as the heat shock genes. In eucaryotes, the expression of these genes is primarily regulated at the transcriptional level. The early observations that transfected heat shock genes were inducible in heterologous systems suggested the existence of common regulatory elements in these ubiquitous genes. Sequence analysis of cloned Drosophila heat shock genes revealed a conserved 14 base pair (bp) inverted repeat, which is essential for heat induction. This regulatory sequence, referred to as the heat shock element (HSE), is found in multiple imperfect copies upstream of the TATA box of all heat shock genes. While studies in heterologous systems indicated that a single copy of HSE was sufficient for inducibility, further analysis in homologous assays suggests that multiple HSE can act in a cooperative way and that the efficiency of transcriptional activation is related, within limits, to the number of HSE. Comparative analysis of heat shock genes reveals that HSE can be positioned at different distances from the TATA box in either orientation, a behavior reminiscent of enhancer elements. However, the presence of HSE does not necessarily confer heat inducibility, as shown by their presence in the constitutively expressed but non-heat-inducible homologous cognate genes. Footprinting and nuclease mapping have been used to show that a protein factor (HSTF: heat shock transcription factor) binds to the HSE element, activating heat shock gene transcription in a dose-dependent manner. The recent progress in the isolation and characterization of HSTF in Drosophila, yeast, and human cells is reviewed. Finally, different models suggested to account for the positive regulation of heat shock genes by the HSTF are presented.

  15. Infrared Emissions from Shock Heated Hydrocarbons

    NASA Technical Reports Server (NTRS)

    Stephens, K. M.; Bauer, S. H.

    1994-01-01

    The primary objective of this study was to ascertain whether low molecular weight hydrocarbons (LMWH) in the range C4 to C7, upon heating to temperatures above 900 K, emit IR radiations at frequencies that correspond to the 'unidentified infrared' (UIR) features - the recorded emissions from a variety of astronomical sources - reflection nebulae, HII regions, planetary nebulae, spiral galaxies and other extra galactic objects. We describe IR emission spectra recorded from shock-heated gases (C2H2; (H3C)2C = CH2; H2C = C(CH3) - C(CH3) = CH2; (H3C)2C = CH - C(CH3) = CH2), that arise from excitation of the fundamental C-H stretching vibrations. While the IR emissions from LMWH, anticipated over the entire spectra range, do not present a perfect match to UIR, the correspondence over several wavelength regions is better than the emissions anticipated from polycyclic aromatic hydrocarbon (PAH) species. Finally, we briefly review the range of proposals that have been presented for the origin of the UIR bands.

  16. Chronic SIV and morphine treatment increases heat shock protein 5 expression at the synapse.

    PubMed

    Pendyala, Gurudutt; Periyasamy, Palsamy; Callen, Shannon; Fox, Howard S; Lisco, Steven J; Buch, Shilpa J

    2015-10-01

    The abuse of opiates such as morphine in synergy with HIV infection accelerates neurocognitive impairments and neuropathology in the CNS of HIV-infected subjects, collectively referred to as HAND. To identify potential pathogenic markers associated with HIV and morphine in perturbing the synaptic architecture, we performed quantitative mass spectrometry proteomics on purified synaptosomes isolated from the caudate of two groups of rhesus macaques chronically infected with SIV differing by one regimen-morphine treatment. The upregulation of heat shock 70-kDa protein 5 in the SIV + morphine group points to increased cellular stress during SIV/morphine interaction thus leading to CNS dysfunction.

  17. Methodological considerations for heat shock of the nematode Caenorhabditis elegans.

    PubMed

    Zevian, Shannin C; Yanowitz, Judith L

    2014-08-01

    Stress response pathways share commonalities across many species, including humans, making heat shock experiments valuable tools for many biologists. The study of stress response in Caenorhabditis elegans has provided great insight into many complex pathways and diseases. Nevertheless, the heat shock/heat stress field does not have consensus as to the timing, temperature, or duration of the exposure and protocols differ extensively between laboratories. The lack of cohesiveness makes it difficult to compare results between groups or to know where to start when preparing your own protocol. We present a discussion of some of the major hurdles to reproducibility in heat shock experiments as well as detailed protocols for heat shock and hormesis experiments.

  18. Heat-shock protein 70: molecular supertool?

    PubMed

    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.

  19. Multi-Level Interactions Between Heat Shock Factors, Heat Shock Proteins, and the Redox System Regulate Acclimation to Heat

    PubMed Central

    Driedonks, Nicky; Xu, Jiemeng; Peters, Janny L.; Park, Sunghun; Rieu, Ivo

    2015-01-01

    High temperature has become a global concern because it seriously affects the growth and reproduction of plants. Exposure of plant cells to high temperatures result in cellular damage and can even lead to cell death. Part of the damage can be ascribed to the action of reactive oxygen species (ROS), which accumulate during abiotic stresses such as heat stress. ROS are toxic and can modify other biomacromolecules including membrane lipids, DNA, and proteins. In order to protect the cells, ROS scavenging is essential. In contrast with their inherent harms, ROS also function as signaling molecules, inducing stress tolerance mechanisms. This review examines the evidence for crosstalk between the classical heat stress response, which consists of heat shock factors (HSFs) and heat shock proteins (HSPs), with the ROS network at multiple levels in the heat response process. Heat stimulates HSF activity directly, but also indirectly via ROS. HSFs in turn stimulate the expression of HSP chaperones and also affect ROS scavenger gene expression. In the short term, HSFs repress expression of superoxide dismutase scavenger genes via induction of miRNA398, while they also activate scavenger gene expression and stabilize scavenger protein activity via HSP induction. We propose that these contrasting effects allow for the boosting of the heat stress response at the very onset of the stress, while preventing subsequent oxidative damage. The described model on HSFs, HSPs, ROS, and ROS scavenger interactions seems applicable to responses to stresses other than heat and may explain the phenomenon of crossacclimation. PMID:26635827

  20. Multi-Level Interactions Between Heat Shock Factors, Heat Shock Proteins, and the Redox System Regulate Acclimation to Heat.

    PubMed

    Driedonks, Nicky; Xu, Jiemeng; Peters, Janny L; Park, Sunghun; Rieu, Ivo

    2015-01-01

    High temperature has become a global concern because it seriously affects the growth and reproduction of plants. Exposure of plant cells to high temperatures result in cellular damage and can even lead to cell death. Part of the damage can be ascribed to the action of reactive oxygen species (ROS), which accumulate during abiotic stresses such as heat stress. ROS are toxic and can modify other biomacromolecules including membrane lipids, DNA, and proteins. In order to protect the cells, ROS scavenging is essential. In contrast with their inherent harms, ROS also function as signaling molecules, inducing stress tolerance mechanisms. This review examines the evidence for crosstalk between the classical heat stress response, which consists of heat shock factors (HSFs) and heat shock proteins (HSPs), with the ROS network at multiple levels in the heat response process. Heat stimulates HSF activity directly, but also indirectly via ROS. HSFs in turn stimulate the expression of HSP chaperones and also affect ROS scavenger gene expression. In the short term, HSFs repress expression of superoxide dismutase scavenger genes via induction of miRNA398, while they also activate scavenger gene expression and stabilize scavenger protein activity via HSP induction. We propose that these contrasting effects allow for the boosting of the heat stress response at the very onset of the stress, while preventing subsequent oxidative damage. The described model on HSFs, HSPs, ROS, and ROS scavenger interactions seems applicable to responses to stresses other than heat and may explain the phenomenon of crossacclimation.

  1. Multi-Level Interactions Between Heat Shock Factors, Heat Shock Proteins, and the Redox System Regulate Acclimation to Heat.

    PubMed

    Driedonks, Nicky; Xu, Jiemeng; Peters, Janny L; Park, Sunghun; Rieu, Ivo

    2015-01-01

    High temperature has become a global concern because it seriously affects the growth and reproduction of plants. Exposure of plant cells to high temperatures result in cellular damage and can even lead to cell death. Part of the damage can be ascribed to the action of reactive oxygen species (ROS), which accumulate during abiotic stresses such as heat stress. ROS are toxic and can modify other biomacromolecules including membrane lipids, DNA, and proteins. In order to protect the cells, ROS scavenging is essential. In contrast with their inherent harms, ROS also function as signaling molecules, inducing stress tolerance mechanisms. This review examines the evidence for crosstalk between the classical heat stress response, which consists of heat shock factors (HSFs) and heat shock proteins (HSPs), with the ROS network at multiple levels in the heat response process. Heat stimulates HSF activity directly, but also indirectly via ROS. HSFs in turn stimulate the expression of HSP chaperones and also affect ROS scavenger gene expression. In the short term, HSFs repress expression of superoxide dismutase scavenger genes via induction of miRNA398, while they also activate scavenger gene expression and stabilize scavenger protein activity via HSP induction. We propose that these contrasting effects allow for the boosting of the heat stress response at the very onset of the stress, while preventing subsequent oxidative damage. The described model on HSFs, HSPs, ROS, and ROS scavenger interactions seems applicable to responses to stresses other than heat and may explain the phenomenon of crossacclimation. PMID:26635827

  2. Heat shock response and autophagy—cooperation and control

    PubMed Central

    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. PMID:25714619

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

    PubMed

    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.

  4. Three light-inducible heat shock genes of Chlamydomonas reinhardtii.

    PubMed Central

    von Gromoff, E D; Treier, U; Beck, C F

    1989-01-01

    Genomic clones representing three Chlamydomonas reinhardtii genes homologous to the Drosophila hsp70 heat shock gene were isolated. The mRNAs of genes hsp68, hsp70, and hsp80 could be translated in vitro into proteins of Mr 68,000, 70,000, and 80,000, respectively. Transcription of these genes increased dramatically upon heat shock, and the corresponding mRNAs rapidly accumulated, reaching a peak at around 30 min after a shift to the elevated temperature. Light also induced the accumulation of the mRNAs encoded by these heat shock genes. A shift of dark-grown cells to light resulted in a drastic increase in mRNA levels, which reached a maximum at around 1 h after the shift. Thus, in Chlamydomonas, expression of hsp70-homologous heat shock genes appears to be regulated by thermal stress and light. Images PMID:2779571

  5. Effect of heat-shock on Plasmodium falciparum viability, growth and expression of the heat-shock protein 'PFHSP70-I' gene.

    PubMed

    Joshi, B; Biswas, S; Sharma, Y D

    1992-11-01

    Cultures of the human malaria parasite Plasmodium falciparum were subjected to heat-shock for varying times and temperatures and then tested for their viability, growth and expression of heat-shock protein. Results show that the majority of parasites remained viable after heat-shock but their growth was affected. However, the expression of the heat-shock protein 'PFHSP70-I' gene was enhanced after heat-shock. We conclude that malarial parasites are able to survive in vivo during fever probably due to the overexpression of the heat-shock protein gene.

  6. Exciting cell membranes with a blustering heat shock.

    PubMed

    Liu, Qiang; Frerck, Micah J; Holman, Holly A; Jorgensen, Erik M; Rabbitt, Richard D

    2014-04-15

    Brief heat shocks delivered to cells by pulsed laser light can evoke action potentials in neurons and contraction in cardiomyocytes, but the primary biophysical mechanism has been elusive. In this report we show in the neuromuscular junction of Caenorhabditis elegans that application of a 500°C/s heat shock for 500 μs evoked ~35 pA of excitatory current and injected ~23 fC(femtocoulomb) of charge into the cell while raising the temperature only 0.25°C. The key variable driving the current was the rate of change of temperature (dT/dt heat shock), not temperature itself. The photothermal heat shock current was voltage-dependent and was from thermally driven displacement of ions near the plasma membrane. The charge movement was rapid during the heat shock and slow during thermal relaxation, thus leading to an asymmetrical capacitive current that briefly depolarized the cell. A simple quantitative model is introduced to describe modulation of the membrane potential and facilitate practical application of optical heat shock stimuli.

  7. Shock initiation of a heated ammonium perchlorate-based propellant

    SciTech Connect

    Tarver, C.M.; Urtiew, P.A.; Tao, W.C.

    1996-04-01

    Solid propellants are containing ammonium perchlorate (AP), aluminum, and a carboxylterminated polybutadiene binder (CTPB) are known to burn reliably and to be very insensitive to transition to detonation under ambient conditions. In accident scenarios, these propellants may become more shock sensitive when they are subjected to heat and/or multiple impacts. The shock sensitivity of one such propellant, ANB-3066, is determined using embedded manganin pressure gauges at an elevated temperature of 170 C. The measured pressure histories are modeled using the Ignition and Growth reactive flow model of shock initiation and detonation. The experiments clearly show that ANB-3066 is not significant more shock sensitive at 170 C than it is at ambient temperature. The Ignition and Growth reactive flow calculations indicate that less than 20% of the chemical energy of AP and CTPB reactions is released at input shock pressures as high as 21 GPa. The aluminum component does not reach the high temperatures required for it to react. These results indicate that AP-based solid propellants are still extremely resistant to shock to detonation transition even when heated to temperatures close to the thermal decomposition temperature of the propellant formulation. The shock insensitivity of heated AP-based propellants is hypothesized to be due to the melting of the AP component during shock loading and the relatively low temperatures produced by the weakly exothermic decomposition of AP and binder.

  8. Interaction of 70-kDa heat shock protein with glycosaminoglycans and acidic glycopolymers.

    PubMed

    Harada, Yoichiro; Garenáux, Estelle; Nagatsuka, Takehiro; Uzawa, Hirotaka; Nishida, Yoshihiro; Sato, Chihiro; Kitajima, Ken

    2014-10-17

    Interaction of Hsp70 with natural and artificial acidic glycans is demonstrated based on the native PAGE analysis. Hsp70 interacts with acidic glycopolymers that contain clustered sulfated and di-sialylated glycan moieties on a polyacrylamide backbone, but not with neutral or mono-sialylated glycopolymers. Hsp70 also interacts and forms a large complex with heparin, heparan sulfate, and dermatan sulfate that commonly contain 2-O-sulfated iduronic acid residues, but not with other types of glycosaminoglycans (GAGs). Hsp70 consists of the N-terminal ATPase domain and the C-terminal peptide-binding domain. The interaction analyses using the recombinant N- and C-terminal half domains show that the ATPase domain mediates the direct interaction with acidic glycans, while the peptide-binding domain stabilizes the large complexes with particular GAGs. To our knowledge, this is the first demonstration of direct binding of Hsp70 to the particular GAGs. This property may be involved in the physiological functions of Hsp70 at the plasma membrane and extracellular environments.

  9. Heavy Ion Heating at Shocks in the Heliosphere

    NASA Astrophysics Data System (ADS)

    Korreck, K. E.; Stevens, M. L.; Lepri, S. T.; Kasper, J. C.

    2014-12-01

    Ions heavier than protons can be used as tracers for heating mechamisms in solar wind plasma. Measurments by the ACE and WIND satellites provide information on the relative heating of the heavy ions versus the protons. Greater than mass proportional heating has been seen at coronal mass ejections (CME) shock fronts. Using ACE SWICS heavy ions data from CME associated shocks, heavy ion heating and the non-thermal nature of helium and oxygen distributions at 1AU is examined. The WIND SWE data set is used to examine the helium distributions at the shock fronts observed at the spacecraft. Understanding the heating and source of energetic particles and their evolution through the heliosphere is relevant to predicting space weather events and the evolution of the solar wind.

  10. Altered phosphorylation of. tau. protein in heat-shocked rats and patients with Alzheimer disease

    SciTech Connect

    Papasozomenos, S.C.; Yuan Su Baylor College of Medicine, Houston, TX )

    1991-05-15

    Six hours after heat shocking 2- to 3-month-old male and female Sprague-Dawley rats at 42C for 15 min, the authors analyzed {tau} protein immunoreactivity in SDS extracts of cerebrums and peripheral nerves by using immunoblot analysis and immunohistochemistry with the anti-{tau} monoclonal antibody Tau-1, which recognizes a phosphate-dependent nonphosphorylated epitope, and with {sup 125}I-labeled protein A. In the cerebal extracts, the authors found altered phosphorylation of {tau} in heat-shocked females, characterized by a marked reduction in the amount of nonphosphorylated {tau}, a doubling of the ratio of total (phosphorylated plus nonphosphorylated) {tau} to nonphosphorylated {tau}, and the appearance of the slowest moving phosphorylated {tau} polypeptide (68 kDa). Similar, but milder, changes were observed in male rats. Quantitative immunoblot analysis of cortex and the underlying white matter with Tau-1 and {sup 125}I-labeled protein A showed that the amount of phosphorylated {tau} progressively increased in the Alzheimer disease-affected cerebral cortex, while concurrently a proportionally lesser amount of {tau} entered the white matter axons. The similar findings for the rat heat-shock model and Alzheimer disease suggest that life stressors may play a role in the etiopathogenesis of Alzheimer's disease.

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  12. ATF1 Modulates the Heat Shock Response by Regulating the Stress-Inducible Heat Shock Factor 1 Transcription Complex

    PubMed Central

    Takii, Ryosuke; Fujimoto, Mitsuaki; Tan, Ke; Takaki, Eiichi; Hayashida, Naoki; Nakato, Ryuichiro; Shirahige, Katsuhiko

    2014-01-01

    The heat shock response is an evolutionally conserved adaptive response to high temperatures that controls proteostasis capacity and is regulated mainly by an ancient heat shock factor (HSF). However, the regulation of target genes by the stress-inducible HSF1 transcription complex has not yet been examined in detail in mammalian cells. In the present study, we demonstrated that HSF1 interacted with members of the ATF1/CREB family involved in metabolic homeostasis and recruited them on the HSP70 promoter in response to heat shock. The HSF1 transcription complex, including the chromatin-remodeling factor BRG1 and lysine acetyltransferases p300 and CREB-binding protein (CBP), was formed in a manner that was dependent on the phosphorylation of ATF1. ATF1-BRG1 promoted the establishment of an active chromatin state and HSP70 expression during heat shock, whereas ATF1-p300/CBP accelerated the shutdown of HSF1 DNA-binding activity during recovery from acute stress, possibly through the acetylation of HSF1. Furthermore, ATF1 markedly affected the resistance to heat shock. These results revealed the unanticipated complexity of the primitive heat shock response mechanism, which is connected to metabolic adaptation. PMID:25312646

  13. ATF1 modulates the heat shock response by regulating the stress-inducible heat shock factor 1 transcription complex.

    PubMed

    Takii, Ryosuke; Fujimoto, Mitsuaki; Tan, Ke; Takaki, Eiichi; Hayashida, Naoki; Nakato, Ryuichiro; Shirahige, Katsuhiko; Nakai, Akira

    2015-01-01

    The heat shock response is an evolutionally conserved adaptive response to high temperatures that controls proteostasis capacity and is regulated mainly by an ancient heat shock factor (HSF). However, the regulation of target genes by the stress-inducible HSF1 transcription complex has not yet been examined in detail in mammalian cells. In the present study, we demonstrated that HSF1 interacted with members of the ATF1/CREB family involved in metabolic homeostasis and recruited them on the HSP70 promoter in response to heat shock. The HSF1 transcription complex, including the chromatin-remodeling factor BRG1 and lysine acetyltransferases p300 and CREB-binding protein (CBP), was formed in a manner that was dependent on the phosphorylation of ATF1. ATF1-BRG1 promoted the establishment of an active chromatin state and HSP70 expression during heat shock, whereas ATF1-p300/CBP accelerated the shutdown of HSF1 DNA-binding activity during recovery from acute stress, possibly through the acetylation of HSF1. Furthermore, ATF1 markedly affected the resistance to heat shock. These results revealed the unanticipated complexity of the primitive heat shock response mechanism, which is connected to metabolic adaptation.

  14. Coordinate synthesis and turnover of heat shock proteins in Borrelia burgdorferi: degradation of DnaK during recovery from heat shock.

    PubMed Central

    Cluss, R G; Goel, A S; Rehm, H L; Schoenecker, J G; Boothby, J T

    1996-01-01

    The synthesis and turnover of heat shock proteins (Hsps) by Borrelia burgdorferi, the Lyme disease spirochete, was investigated by radiolabeling of whole spirochetes and spheroplasts, comparison of one- and two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and use of immunochemistry. The approximately 72-kDa DnaK homolog and three additional Hsps of 39, 27, and 21 kDa increased in amount by 3- to 15-fold between 2 and 6 h following temperature upshift from 28 to 39 degrees C. Temperature downshift experiments following the transfer of spirochetes from 40 to 28 degrees C showed that within 15 to 30 min, synthesis of most of the major Hsps returned to levels seen in spirochetes statically maintained at the lower temperature. Spheroplasts of B. burgdorferi produced by treatment with EDTA and lysozyme were radiolabeled, and specific Hsps were localized to either the cytoplasm or membrane fraction. Further analysis by two-dimensional electrophoresis demonstrated three constitutively expressed DnaK isoforms with pIs near 5.5. A pattern suggestive of DnaK degradation was observed following recovery from heat shock but not in spirochetes maintained entirely at a low temperature. Some of these putative degradation products were recognized by monoclonal antibodies directed against the B. burgdorferi DnaK protein. These data suggest that following a period of peak synthesis, DnaK is actively degraded as the spirochete reestablishes its metabolic thermometer. These findings provide a new interpretation of previous work suggesting that 10 to 15 B. burgdorferi polypeptides, including DnaK have a common epitope. PMID:8613385

  15. Simple, Economical Heat-Shock Devices for Zebrafish Housing Racks

    PubMed Central

    Duszynski, Robert J.; Topczewski, Jacek

    2011-01-01

    Abstract One reason for the popularity of the zebrafish (Danio rerio) as a model vertebrate is the ability to manipulate gene expression in this organism. A common method is to induce gene expression transiently under control of a heat-shock promoter (e.g., hsp70l). By making simple mechanical adjustments to small aquarium heaters (25–50W), we were able to produce consistent and reliable heat-shock conditions within a conventional zebrafish housing system. Up to two heat-shock intervals per day (>37°C) could be maintained under conditions of continuous flow (5–25 mL/min). Temperature logging every 30 s indicated rapid warm up times, consistent heat-shock lengths, and accurate and precise peak water temperatures (mean±SD=38°C±0.2°C). The biological effects of these heat-shock treatments were confirmed by observing inducible expression of enhanced green fluorescent protein (EGFP) and inhibition of caudal fin regeneration in a transgenic fish line expressing a dominant negative fibroblast growth factor receptor (Tg(hsp70l:dnfgfr1-EGFP)pd1). These devices are inexpensive, easily modified, and can be calibrated to accommodate a variety of experimental designs. After setup on a programmable timer, the heaters require no intervention to produce consistent daily heat shocks, and all other standard care protocols can be followed in the fish facility. The simplicity and stability of these devices make them suitable for long-term heat shocks at any stage of the zebrafish lifecycle (>7 days postfertilization), and useful for both laboratory and classroom experiments on transgenic zebrafish. PMID:21913856

  16. Simple, economical heat-shock devices for zebrafish housing racks.

    PubMed

    Duszynski, Robert J; Topczewski, Jacek; LeClair, Elizabeth E

    2011-12-01

    One reason for the popularity of the zebrafish (Danio rerio) as a model vertebrate is the ability to manipulate gene expression in this organism. A common method is to induce gene expression transiently under control of a heat-shock promoter (e.g., hsp70l). By making simple mechanical adjustments to small aquarium heaters (25-50W), we were able to produce consistent and reliable heat-shock conditions within a conventional zebrafish housing system. Up to two heat-shock intervals per day (>37°C) could be maintained under conditions of continuous flow (5-25 mL/min). Temperature logging every 30 s indicated rapid warm up times, consistent heat-shock lengths, and accurate and precise peak water temperatures (mean±SD=38°C±0.2°C). The biological effects of these heat-shock treatments were confirmed by observing inducible expression of enhanced green fluorescent protein (EGFP) and inhibition of caudal fin regeneration in a transgenic fish line expressing a dominant negative fibroblast growth factor receptor (Tg(hsp70l:dnfgfr1-EGFP)(pd1)). These devices are inexpensive, easily modified, and can be calibrated to accommodate a variety of experimental designs. After setup on a programmable timer, the heaters require no intervention to produce consistent daily heat shocks, and all other standard care protocols can be followed in the fish facility. The simplicity and stability of these devices make them suitable for long-term heat shocks at any stage of the zebrafish lifecycle (>7 days postfertilization), and useful for both laboratory and classroom experiments on transgenic zebrafish.

  17. Global transcriptional response of Bacillus subtilis to heat shock.

    PubMed

    Helmann, J D; Wu, M F; Kobel, P A; Gamo, F J; Wilson, M; Morshedi, M M; Navre, M; Paddon, C

    2001-12-01

    In response to heat stress, Bacillus subtilis activates the transcription of well over 100 different genes. Many of these genes are members of a general stress response regulon controlled by the secondary sigma factor, sigma(B), while others are under control of the HrcA or CtsR heat shock regulators. We have used DNA microarrays to monitor the global transcriptional response to heat shock. We find strong induction of known sigma(B)-dependent genes with a characteristic rapid induction followed by a return to near prestimulus levels. The HrcA and CtsR regulons are also induced, but with somewhat slower kinetics. Analysis of DNA sequences proximal to newly identified heat-induced genes leads us to propose ~70 additional members of the sigma(B) regulon. We have also identified numerous heat-induced genes that are not members of known heat shock regulons. Notably, we observe very strong induction of arginine biosynthesis and transport operons. Induction of several genes was confirmed by quantitative reverse transcriptase PCR. In addition, the transcriptional responses measured by microarray hybridization compare favorably with the numerous previous studies of heat shock in this organism. Since many different conditions elicit both specific and general stress responses, knowledge of the heat-induced general stress response reported here will be helpful for interpreting future microarray studies of other stress responses. PMID:11717291

  18. Molecular cloning, phylogenetic analysis and heat shock response of Babesia gibsoni heat shock protein 90.

    PubMed

    Yamasaki, Masahiro; Tsuboi, Yoshihiro; Taniyama, Yusuke; Uchida, Naohiro; Sato, Reeko; Nakamura, Kensuke; Ohta, Hiroshi; Takiguchi, Mitsuyoshi

    2016-09-01

    The Babesia gibsoni heat shock protein 90 (BgHSP90) gene was cloned and sequenced. The length of the gene was 2,610 bp with two introns. This gene was amplified from cDNA corresponding to full length coding sequence (CDS) with an open reading frame of 2,148 bp. A phylogenetic analysis of the CDS of HSP90 gene showed that B. gibsoni was most closely related to B. bovis and Babesia sp. BQ1/Lintan and lies within a phylogenetic cluster of protozoa. Moreover, mRNA transcription profile for BgHSP90 exposed to high temperature were examined by quantitative real-time reverse transcription-polymerase chain reaction. BgHSP90 levels were elevated when the parasites were incubated at 43°C for 1 hr. PMID:27149891

  19. Molecular cloning, phylogenetic analysis and heat shock response of Babesia gibsoni heat shock protein 90

    PubMed Central

    YAMASAKI, Masahiro; TSUBOI, Yoshihiro; TANIYAMA, Yusuke; UCHIDA, Naohiro; SATO, Reeko; NAKAMURA, Kensuke; OHTA, Hiroshi; TAKIGUCHI, Mitsuyoshi

    2016-01-01

    The Babesia gibsoni heat shock protein 90 (BgHSP90) gene was cloned and sequenced. The length of the gene was 2,610 bp with two introns. This gene was amplified from cDNA corresponding to full length coding sequence (CDS) with an open reading frame of 2,148 bp. A phylogenetic analysis of the CDS of HSP90 gene showed that B. gibsoni was most closely related to B. bovis and Babesia sp. BQ1/Lintan and lies within a phylogenetic cluster of protozoa. Moreover, mRNA transcription profile for BgHSP90 exposed to high temperature were examined by quantitative real-time reverse transcription-polymerase chain reaction. BgHSP90 levels were elevated when the parasites were incubated at 43°C for 1 hr. PMID:27149891

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

    NASA Astrophysics Data System (ADS)

    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.

  1. Heat shock proteins, end effectors of myocardium ischemic preconditioning?

    PubMed Central

    Guisasola, María Concepcion; Desco, Maria del Mar; Gonzalez, Fernanda Silvana; Asensio, Fernando; Dulin, Elena; Suarez, Antonio; Garcia Barreno, Pedro

    2006-01-01

    The purpose of this study was to investigate (1) whether ischemia-reperfusion increased the content of heat shock protein 72 (Hsp72) transcripts and (2) whether myocardial content of Hsp72 is increased by ischemic preconditioning so that they can be considered as end effectors of preconditioning. Twelve male minipigs (8 protocol, 4 sham) were used, with the following ischemic preconditioning protocol: 3 ischemia and reperfusion 5-minute alternative cycles and last reperfusion cycle of 3 hours. Initial and final transmural biopsies (both in healthy and ischemic areas) were taken in all animals. Heat shock protein 72 messenger ribonucleic acid (mRNA) expression was measured by a semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) method using complementary DNA normalized against the housekeeping gene cyclophilin. The identification of heat shock protein 72 was performed by immunoblot. In our “classic” preconditioning model, we found no changes in mRNA hsp72 levels or heat shock protein 72 content in the myocardium after 3 hours of reperfusion. Our experimental model is valid and the experimental techniques are appropriate, but the induction of heat shock proteins 72 as end effectors of cardioprotection in ischemic preconditioning does not occur in the first hours after ischemia, but probably at least 24 hours after it, in the so-called “second protection window.” PMID:17009598

  2. Synergistic Effects of Toxic Elements on Heat Shock Proteins

    PubMed Central

    Mahmood, Khalid; Mahmood, Qaisar; Irshad, Muhammad; Hussain, Jamshaid

    2014-01-01

    Heat shock proteins show remarkable variations in their expression levels under a variety of toxic conditions. A research span expanded over five decades has revealed their molecular characterization, gene regulation, expression patterns, vast similarity in diverse groups, and broad range of functional capabilities. Their functions include protection and tolerance against cytotoxic conditions through their molecular chaperoning activity, maintaining cytoskeleton stability, and assisting in cell signaling. However, their role as biomarkers for monitoring the environmental risk assessment is controversial due to a number of conflicting, validating, and nonvalidating reports. The current knowledge regarding the interpretation of HSPs expression levels has been discussed in the present review. The candidature of heat shock proteins as biomarkers of toxicity is thus far unreliable due to synergistic effects of toxicants and other environmental factors. The adoption of heat shock proteins as “suit of biomarkers in a set of organisms” requires further investigation. PMID:25136596

  3. Chromosome behavior of heat shock induced triploid in Fenneropenaeus chinensis

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaojun; Li, Fuhua; Xiang, Jianhai

    2003-09-01

    Triploidy was induced in Chinese shrimp Fenneropenaeus chinensis by 30±0.5°C heat shock treatment (initiated at 20 min after fertilization) for 10 min to inhibit the release of PB2 at 18.0°C. 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 efficient 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.

  4. Multiple oligomeric structures of a bacterial small heat shock protein

    PubMed Central

    Mani, Nandini; Bhandari, Spraha; Moreno, Rodolfo; Hu, Liya; Prasad, B. V. Venkataram; Suguna, Kaza

    2016-01-01

    Small heat shock proteins are ubiquitous molecular chaperones that form the first line of defence against the detrimental effects of cellular stress. Under conditions of stress they undergo drastic conformational rearrangements in order to bind to misfolded substrate proteins and prevent cellular protein aggregation. Owing to the dynamic nature of small heat shock protein oligomers, elucidating the structural basis of chaperone action and oligomerization still remains a challenge. In order to understand the organization of sHSP oligomers, we have determined crystal structures of a small heat shock protein from Salmonella typhimurium in a dimeric form and two higher oligomeric forms: an 18-mer and a 24-mer. Though the core dimer structure is conserved in all the forms, structural heterogeneity arises due to variation in the terminal regions. PMID:27053150

  5. The Heat Shock Response and Acute Lung Injury

    PubMed Central

    Wheeler, Derek S.; Wong, Hector R.

    2006-01-01

    All cells respond to stress through the activation of primitive, evolutionarily conserved genetic programs that maintain homeostasis and assure cell survival. Stress adaptation, which is known in the literature by a myriad of terms, including tolerance, desensitization, conditioning, and reprogramming, is a common paradigm found throughout nature, in which a primary exposure of a cell or organism to a stressful stimulus (e.g., heat) results in an adaptive response by which a second exposure to the same stimulus produces a minimal response. More interesting is the phenomenon of cross-tolerance, by which a primary exposure to a stressful stimulus results in an adaptive response whereby the cell or organism is resistant to a subsequent stress that is different from the initial stress (i.e. exposure to heat stress leading to resistance to oxidant stress). The heat shock response is one of the more commonly described examples of stress adaptation and is characterized by the rapid expression of a unique group of proteins collectively known as heat shock proteins (also commonly referred to as stress proteins). The expression of heat shock proteins is well described in both whole lungs and in specific lung cells from a variety of species and in response to a variety of stressors. More importantly, in vitro data, as well as data from various animal models of acute lung injury, demonstrate that heat shock proteins, especially Hsp27, Hsp32, Hsp60, and Hsp70 have an important cytoprotective role during lung inflammation and injury. PMID:17157189

  6. Inbreeding interferes with the heat-shock response.

    PubMed

    Franke, Kristin; Fischer, Klaus

    2015-01-01

    Inbreeding is typically detrimental to individual fitness, with negative effects being often exaggerated in stressful environments. However, the causal mechanisms underlying inbreeding depression in general and the often increased susceptibility to stress in particular are not well understood. We here test whether inbreeding interferes with the heat-shock response, comprising an important component of the stress response which may therefore underscore sensitivity to stress. To this end we subjected the tropical butterfly Bicyclus anynana to a full-factorial design with three temperatures and three levels of inbreeding, and measured the expression of heat-shock protein (HSP) 70 via qPCR. HSP70 expression increased after exposure to heat as compared with cold or control conditions. Most strikingly, inbreeding strongly interfered with the heat-shock response, with inbred individuals showing a very weak upregulation of HSP70 only. Our results thus indicate that, in our study organism, interference with the heat-shock response may be one mechanism underlying reduced fitness of inbred individuals, especially when exposed to stressful conditions. However, these indications need to be corroborated using a broader range of different temperatures, genes and taxa.

  7. Inbreeding interferes with the heat-shock response

    PubMed Central

    Franke, Kristin; Fischer, Klaus

    2015-01-01

    Inbreeding is typically detrimental to individual fitness, with negative effects being often exaggerated in stressful environments. However, the causal mechanisms underlying inbreeding depression in general and the often increased susceptibility to stress in particular are not well understood. We here test whether inbreeding interferes with the heat-shock response, comprising an important component of the stress response which may therefore underscore sensitivity to stress. To this end we subjected the tropical butterfly Bicyclus anynana to a full-factorial design with three temperatures and three levels of inbreeding, and measured the expression of heat-shock protein (HSP) 70 via qPCR. HSP70 expression increased after exposure to heat as compared with cold or control conditions. Most strikingly, inbreeding strongly interfered with the heat-shock response, with inbred individuals showing a very weak upregulation of HSP70 only. Our results thus indicate that, in our study organism, interference with the heat-shock response may be one mechanism underlying reduced fitness of inbred individuals, especially when exposed to stressful conditions. However, these indications need to be corroborated using a broader range of different temperatures, genes and taxa. PMID:25074571

  8. Histoplasma capsulatum Heat-Shock 60 Orchestrates the Adaptation of the Fungus to Temperature Stress

    PubMed Central

    Guimarães, Allan Jefferson; Nakayasu, Ernesto S.; Sobreira, Tiago J. P.; Cordero, Radames J. B.; Nimrichter, Leonardo; Almeida, Igor C.; Nosanchuk, Joshua Daniel

    2011-01-01

    Heat shock proteins (Hsps) are among the most widely distributed and evolutionary conserved proteins. Hsps are essential regulators of diverse constitutive metabolic processes and are markedly upregulated during stress. A 62 kDa Hsp (Hsp60) of Histoplasma capsulatum (Hc) is an immunodominant antigen and the major surface ligand to CR3 receptors on macrophages. However little is known about the function of this protein within the fungus. We characterized Hc Hsp60-protein interactions under different temperature to gain insights of its additional functions oncell wall dynamism, heat stress and pathogenesis. We conducted co-immunoprecipitations with antibodies to Hc Hsp60 using cytoplasmic and cell wall extracts. Interacting proteins were identified by shotgun proteomics. For the cell wall, 84 common interactions were identified among the 3 growth conditions, including proteins involved in heat-shock response, sugar and amino acid/protein metabolism and cell signaling. Unique interactions were found at each temperature [30°C (81 proteins), 37°C (14) and 37/40°C (47)]. There were fewer unique interactions in cytoplasm [30°C (6), 37°C (25) and 37/40°C (39)] and four common interactions, including additional Hsps and other known virulence factors. These results show the complexity of Hsp60 function and provide insights into Hc biology, which may lead to new avenues for the management of histoplasmosis. PMID:21347364

  9. Heating of minor ions by the coronal slow shock

    NASA Technical Reports Server (NTRS)

    Whang, Y. C.; Zhao, Xuepu; Ogilvie, K. W.

    1990-01-01

    The coronal slow shock has been predicted to exist embedded in large coronal holes at 4-10 solar radii. In this paper, a three-fluid model is used to study the jumps in minor ion properties across a slow shock such as the coronal slow shock. The jump conditions are formulated in the de Hoffmann-Teller frame of reference. The Rankine-Hugoniot solution determines the MHD flow and the magnetic field across the shocks. For each minor ion species, the fluid equations for the conservation of mass, momentum, and energy can be solved to determine the velocity and the temperature of the ions across the shock. Also obtained is a similarity solution for heavy ions. The results show that, on the downstream side of the slow shock, the ion temperatures are nearly proportional to the ion masses for He, O, Si, and Fe, in agreement with observed ion temperatures in the inner solar wind. This indicates that the possibly existing coronal slow shock can be responsible for the observed heating of minor ions in the solar wind.

  10. Shock structure and shock heating in the Galactic central molecular zone

    NASA Astrophysics Data System (ADS)

    Ott, Jürgen; Burton, Michael; Jones, Paul; Meier, David S.

    2014-05-01

    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 1.3 cm, 7 mm, and 3 mm 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 masses. 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 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 the processes within the extreme star formation region Sgr B2.

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

    NASA Technical Reports Server (NTRS)

    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.

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

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2016-01-01

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

  14. Expression of heat shock protein genes in insect stress responses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The heat shock proteins (HSPs) that are abundantly expressed in insects are important modulators of insect survival. Expression of HSP genes in insects is not only developmentally regulated, but also induced by various stressors in order to confer protection against such stressors. The expression o...

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

    NASA Astrophysics Data System (ADS)

    Inoue, Masayo; Mitarai, Namiko; Trusina, Ala

    2012-12-01

    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 (TFs). We here investigate two heat shock systems: one characteristic to gram negative bacteria, mediated by transcriptional activator σ32 in E. coli, and another characteristic to gram positive bacteria, mediated by transcriptional repressor HrcA in L. lactis. We construct simple mathematical models of the two systems focusing on the negative feedbacks, where free chaperones suppress σ32 activation in the former, while they activate HrcA repression in the latter. We demonstrate that both systems, in spite of the difference at the TF regulation level, are capable of showing very similar heat shock dynamics. We find that differences in regulation impose distinct constraints on chaperone-TF binding affinities: the binding constant of free σ32 to chaperone DnaK, known to be in 100 nM range, set the lower limit of amount of free chaperone that the system can sense the change at the heat shock, while the binding affinity of HrcA to chaperone GroE set the upper limit and have to be rather large extending into the micromolar range.

  16. Sequence characterization of heat shock protein gene of Cyclospora cayetanensis isolates from Nepal, Mexico, and Peru.

    PubMed

    Sulaiman, Irshad M; Torres, Patricia; Simpson, Steven; Kerdahi, Khalil; Ortega, Ynes

    2013-04-01

    We have described the development of a 2-step nested PCR protocol based on the characterization of the 70-kDa heat shock protein (HSP70) gene for rapid detection of the human-pathogenic Cyclospora cayetanensis parasite. We tested and validated these newly designed primer sets by PCR amplification followed by nucleotide sequencing of PCR-amplified HSP70 fragments belonging to 16 human C. cayetanensis isolates from 3 different endemic regions that include Nepal, Mexico, and Peru. No genetic polymorphism was observed among the isolates at the characterized regions of the HSP70 locus. This newly developed HSP70 gene-based nested PCR protocol provides another useful genetic marker for the rapid detection of C. cayetanensis in the future.

  17. The effect of a type 3 and type 4 shock/shock interaction on heat transfer in the stagnation region

    NASA Astrophysics Data System (ADS)

    Wilson, Dennis

    1991-09-01

    One of the major engineering challenges in designing the National Aerospace Plane, NASP, is to overcome augmented heating on the intake cowl lip from shock/shock interactions. The shock/shock interaction arises when the bow shock from the craft's nose interferes with the bow shock from the cowl lip. Considering only the region immediately around the cowl lip, the problem geometry may be simplified as that of an oblique shock impinging on a bow shock from a circular cylinder. Edney classified six different interference patterns resulting from an oblique-shock/curved bow-shock interaction. Of these six types, type 3 and 4 are most significant in that augmented surface heat transfer may be ten to thirty times greater than the case without the shock/shock interaction. The objective was to begin to develop a mathematical model which is capable of predicting the effect of a type 3 and 4 shock/shock interaction in the stagnation region of an arbitrary 2-D body. This model must be capable of predicting the maximum surface heat flux and the surface stagnation point pressure once the outer (effectively inviscid) flowfield is given. Therefore, it must capture the unsteady physics of the impinging shear layer.

  18. The effect of a type 3 and type 4 shock/shock interaction on heat transfer in the stagnation region

    NASA Technical Reports Server (NTRS)

    Wilson, Dennis

    1991-01-01

    One of the major engineering challenges in designing the National Aerospace Plane, NASP, is to overcome augmented heating on the intake cowl lip from shock/shock interactions. The shock/shock interaction arises when the bow shock from the craft's nose interferes with the bow shock from the cowl lip. Considering only the region immediately around the cowl lip, the problem geometry may be simplified as that of an oblique shock impinging on a bow shock from a circular cylinder. Edney classified six different interference patterns resulting from an oblique-shock/curved bow-shock interaction. Of these six types, type 3 and 4 are most significant in that augmented surface heat transfer may be ten to thirty times greater than the case without the shock/shock interaction. The objective was to begin to develop a mathematical model which is capable of predicting the effect of a type 3 and 4 shock/shock interaction in the stagnation region of an arbitrary 2-D body. This model must be capable of predicting the maximum surface heat flux and the surface stagnation point pressure once the outer (effectively inviscid) flowfield is given. Therefore, it must capture the unsteady physics of the impinging shear layer.

  19. Molecular characterization of the gene encoding an 18-kilodalton small heat shock protein associated with the membrane of Leuconostoc oenos.

    PubMed Central

    Jobin, M P; Delmas, F; Garmyn, D; Diviès, C; Guzzo, J

    1997-01-01

    In Leuconostoc oenos, different stresses such as heat, ethanol, and acid shocks dramatically induce the expression of an 18-kDa small heat shock protein called Lo 18. The corresponding gene (hsp18) was cloned from a genomic library of L. oenos constructed in Escherichia coli. A 2.3-kb DNA fragment carrying the hsp18 gene was sequenced. The hsp18 gene encodes a polypeptide of 148 amino acids with a calculated molecular mass of 16,938 Da. The Lo18 protein has a significant identity with small heat shock proteins of the alpha-crystallin family. The transcriptional start site was determined by primer extension. This experiment allowed us to identify the promoter region exhibiting high similarity to consensus promoter sequences of gram-positive bacteria, as well as E. coli. Northern blot analysis showed that hsp18 consists of a unique transcription unit of 0.6 kb. Moreover, hsp18 expression seemed to be controlled at the transcriptional level. This small heat shock protein was found to be peripherally associated with the membrane of L. oenos. PMID:9023938

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

    PubMed Central

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

    2016-01-01

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

  1. Tissue specificity of the heat-shock response in maize.

    PubMed

    Cooper, P; Ho, T H; Hauptmann, R M

    1984-06-01

    The tissue specificity of the heat-shock response in maize was investigated. The ability to synthesize heat shock proteins (hsp) at 40 degrees C, as well as the intensity and duration of that synthesis, was analyzed in coleoptiles, scutella, green and etiolated leaves, suspension-cultured cells, germinating pollen grains, and primary root sections at different stages of development. One-dimensional sodium dodecyl sulfate gel electrophoresis of extracted proteins revealed that most of the tissues synthesized the typical set of 10 hsp, but that the exact characteristics of the response depended upon the tissue type. While elongating portions of the primary root exhibited a strong heat shock response, the more mature portions showed a reduced ability to synthesize hsp. Leaves, whether green or etiolated, excised or intact, constitutively synthesized a low level of hsp at 25 degrees C, and high levels could be induced at 40 degrees C. Suspension-cultures of Black Mexican sweet corn synthesized, besides the typical set of hsp, two additional polypeptides. In contrast to all the other tissues, germinating pollen grains could not be induced to synthesize the typical set of hsp but did synthesize two new polypeptides of 92 and 56 kD molecular weight.The heat shock response was transient for most of the tissues which synthesized the standard set of hsp. Hsp synthesis was detected up to 2 to 3 hours, but not at 10 hours of continuous 40 degrees C treatment. The exception was suspension cultured cells, in which hsp synthesis showed only a slight reduction after 10 hours at 40 degrees C. Tissue-specific differences in the heat-shock response suggest that there are differences in the way a given tissue is able to adapt to high temperature.We have confirmed the previous suggestion that maize hsp do not accumulate in substantial quantities. Using two-dimensional gel analysis, hsp could be detected by autoradiography but not by sensitive silver staining techniques. PMID:16663639

  2. Heat Shock Response in Lactobacillus plantarum

    PubMed Central

    De Angelis, Maria; Di Cagno, Raffaella; Huet, Claude; Crecchio, Carmine; Fox, Patrick F.; Gobbetti, Marco

    2004-01-01

    Heat stress resistance and response were studied in strains of Lactobacillus plantarum. Stationary-phase cells of L. plantarum DPC2739 had decimal reduction times (D values) (D value was the time that it took to reduce the number of cells by 1 log cycle) in sterile milk of 32.9, 14.7, and 7.14 s at 60, 72, and 75°C, respectively. When mid-exponential-phase cells were used, the D values decreased. The temperature increases which caused a 10-fold reduction in the D value ranged from 9 to 20°C, depending on the strain. Part of the cell population treated at 72°C for 90 s recovered viability during incubation at 7°C in sterile milk for 20 days. When mid-exponential- or stationary-phase cells of L. plantarum DPC2739 were adapted to 42°C for 1 h, the heat resistance at 72°C for 90 s increased ca. 3 and 2 log cycles, respectively. Heat-adapted cells also showed increased growth at pH 5 and in the presence of 6% NaCl. Two-dimensional gel electrophoresis of proteins expressed by control and heat-adapted cells revealed changes in the levels of expression of 31 and 18 proteins in mid-exponential- and stationary-phase cells, respectively. Twelve proteins were commonly induced. Nine proteins induced in the heat-adapted mid-exponential- and/or stationary-phase cells of L. plantarum DPC2739 were subjected to N-terminal sequencing. These proteins were identified as DnaK, GroEL, trigger factor, ribosomal proteins L1, L11, L31, and S6, DNA-binding protein II HlbA, and CspC. All of these proteins have been found to play a role in the mechanisms of stress adaptation in other bacteria. Antibodies against GroES detected a protein which was induced moderately, while antibodies against DnaJ and GrpE reacted with proteins whose level of expression did not vary after heat adaptation. This study showed that the heat resistance of L. plantarum is a complex process involving proteins with various roles in cell physiology, including chaperone activity, ribosome stability, stringent

  3. Shock Heating of the Merging Galaxy Cluster A521

    NASA Technical Reports Server (NTRS)

    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.

  4. SHOCK HEATING OF THE MERGING GALAXY CLUSTER A521

    SciTech Connect

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

    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.

  5. Appearance of heat shock proteins during the induction of multiple flagella in Naegleria gruberi.

    PubMed

    Walsh, C

    1980-04-10

    A heat shock to amebae of the amebo-flagellate Naegleria gruberi during differentiation into swimming flagellates results in the induction of heat shock proteins as well as multiple flagella. The principal heat shock proteins migrate on sodium dodecyl sulfate-polyacrylamide gels with apparent molecular weights of 96,000, 77,000, 70,000, and 68,000. These proteins are synthesized preferentially when cells at 25 degrees C are shifted to temperatures above 32 degrees C. The maximal incorporation of methionine into heat shock proteins occurs at 38.2 degrees C, the temperature at which maximal induction of multiple flagella has been reported. Synthesis of heat shock proteins requires new transcription as judged by the ability of actinomycin D to inhibit their synthesis during the first 15 min of heat shock but not thereafter. Although heat shock can induce multiple flagella only when applied during a restricted interval, heat shock proteins are induced at any time cells are shifted to 38.2 degrees C. The response to heat shock of the Naegleria heat shock proteins resembles that of Drosophila heat shock proteins, but the two groups of proteins differ in both size and number. Naegleria heat shock proteins are, however, strikingly similar in size to a group of heat-induced proteins found in chick embryo fibroblast, mouse L, and BHK cells. PMID:7358690

  6. Reproductive costs of heat shock protein in transgenic Drosophila melanogaster.

    PubMed

    Silbermann, R; Tatar, M

    2000-12-01

    Senescence may evolve when genes have antagonistic effects between early reproduction and later age-specific mortality. Although widely consistent with data of quantitative genetics, this model has yet to be validated with the identification of a specific locus presenting such trade-offs. The molecular chaperone hsp70 may be a candidate for such a gene. Heat induced expression of the Hsp70 protein in adults decreases rates of age-specific mortality during normal aging, while maternally experienced heat shock depresses the production of mature progeny. Here we show that maternal heat shock reduces the proportion of egg hatch but not the viability of successfully hatched offspring. To assess whether heat induced maternal expression of hsp70 causes reduced egg hatch, we measured the proportion of eggs that hatch from females engineered to overexpress hsp70 transgenes. We used the same transgenic strains that extend longevity upon hsp70 expression and found that Hsp70 is sufficient to suppress egg hatch. The proportion of egg hatch as a function of hsp70 expression was not reduced in the first eggs laid after maternal heat shock, but appears in later laid eggs, which were at preoogenic and early vitellogenic stages during the maternal expression of hsp70. The contervailing effects of hsp70 upon fecundity and subsequent age-specific mortality exemplify antagonistic pleiotropy, and this trade-off could contribute to the evolution of Drosophila senescence.

  7. Size dependent classification of heat shock proteins: a mini-review.

    PubMed

    Jee, Hyunseok

    2016-08-01

    Molecular chaperones are ubiquitous and abundant within cellular environments, functioning as a defense mechanism against outer environment. The range of molecular chaperones varies from 10 to over 100 kDa. Depending on the size, the specific locations and physiological roles of molecular chaperones vary within the cell. Multifunctionality of heat shock proteins (HSPs) expressed via various cyto-stress including heat shock have been spotlighted as a reliable prognostic target biomarker for therapeutic purpose in neuromuscular disease or cancer related studies. HSP also plays a critical role in the maintenance of proteins and cellular homeostasis in exercise-induced adaptation. Such various functions of HSPs give scientists insights into intracellular protective mechanisms in the living body thus HSPs can be target molecules to know the defense mechanism in cellular environment. Based on experimental results regarding small to large scaled HSPs, this review aims to provide updated important information regarding the modality of responses of intracellular HSPs towards extracellular stimulations. Further, the expressive mechanisms of HSPs data from tremendous in vivo and in vitro studies underlying the enhancement of the functionality of living body will be discussed. PMID:27656620

  8. Size dependent classification of heat shock proteins: a mini-review

    PubMed Central

    Jee, Hyunseok

    2016-01-01

    Molecular chaperones are ubiquitous and abundant within cellular environments, functioning as a defense mechanism against outer environment. The range of molecular chaperones varies from 10 to over 100 kDa. Depending on the size, the specific locations and physiological roles of molecular chaperones vary within the cell. Multifunctionality of heat shock proteins (HSPs) expressed via various cyto-stress including heat shock have been spotlighted as a reliable prognostic target biomarker for therapeutic purpose in neuromuscular disease or cancer related studies. HSP also plays a critical role in the maintenance of proteins and cellular homeostasis in exercise-induced adaptation. Such various functions of HSPs give scientists insights into intracellular protective mechanisms in the living body thus HSPs can be target molecules to know the defense mechanism in cellular environment. Based on experimental results regarding small to large scaled HSPs, this review aims to provide updated important information regarding the modality of responses of intracellular HSPs towards extracellular stimulations. Further, the expressive mechanisms of HSPs data from tremendous in vivo and in vitro studies underlying the enhancement of the functionality of living body will be discussed.

  9. Size dependent classification of heat shock proteins: a mini-review

    PubMed Central

    Jee, Hyunseok

    2016-01-01

    Molecular chaperones are ubiquitous and abundant within cellular environments, functioning as a defense mechanism against outer environment. The range of molecular chaperones varies from 10 to over 100 kDa. Depending on the size, the specific locations and physiological roles of molecular chaperones vary within the cell. Multifunctionality of heat shock proteins (HSPs) expressed via various cyto-stress including heat shock have been spotlighted as a reliable prognostic target biomarker for therapeutic purpose in neuromuscular disease or cancer related studies. HSP also plays a critical role in the maintenance of proteins and cellular homeostasis in exercise-induced adaptation. Such various functions of HSPs give scientists insights into intracellular protective mechanisms in the living body thus HSPs can be target molecules to know the defense mechanism in cellular environment. Based on experimental results regarding small to large scaled HSPs, this review aims to provide updated important information regarding the modality of responses of intracellular HSPs towards extracellular stimulations. Further, the expressive mechanisms of HSPs data from tremendous in vivo and in vitro studies underlying the enhancement of the functionality of living body will be discussed. PMID:27656620

  10. Small heat shock protein message in etiolated Pea seedlings under altered gravity

    NASA Astrophysics Data System (ADS)

    Talalaiev, O.

    Plants are subjected to various environmental changes during their life cycle To protect themselves against unfavorable influences plant cells synthesize several classes of small heat shock proteins sHsp ranging in size from 15 to 30 kDa This proteins are able to enhance the refolding of chemically denatured proteins in an ATP-independent manner in other words they can function as molecular chaperones The potential contribution of effects of space flight at the plant cellular and gene regulation level has not been characterized yet The object of our study is sHsp gene expression in etiolated Pisum sativum seedlings exposed to altered gravity and environmental conditions We designed primers to detect message for two inducible forms of the cytosolic small heat shock proteins sHsp 17 7 and sHsp 18 1 Applying the RT- PCR we explore sHsps mRNA in pea seedling cells subjected to two types of altered gravity achieved by centrifugation from 3 to 8g by clinorotation 2 rpm and temperature elevation 42oC Temperature elevation as the positive control significantly increased PsHspl7 7 PsHspl8 1 expression We investigate the expression of actin it was constant and comparable for unstressed controls for all variants Results are under discussion

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

    PubMed

    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.

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

    PubMed

    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

  13. Regulation of protein turnover by heat shock proteins.

    PubMed

    Bozaykut, Perinur; Ozer, Nesrin Kartal; Karademir, Betul

    2014-12-01

    Protein turnover reflects the balance between synthesis and degradation of proteins, and it is a crucial process for the maintenance of the cellular protein pool. The folding of proteins, refolding of misfolded proteins, and also degradation of misfolded and damaged proteins are involved in the protein quality control (PQC) system. Correct protein folding and degradation are controlled by many different factors, one of the most important of which is the heat shock protein family. Heat shock proteins (HSPs) are in the class of molecular chaperones, which may prevent the inappropriate interaction of proteins and induce correct folding. On the other hand, these proteins play significant roles in the degradation pathways, including endoplasmic reticulum-associated degradation (ERAD), the ubiquitin-proteasome system, and autophagy. This review focuses on the emerging role of HSPs in the regulation of protein turnover; the effects of HSPs on the degradation machineries ERAD, autophagy, and proteasome; as well as the role of posttranslational modifications in the PQC system.

  14. Genetic Transformation of Candida glabrata by Heat Shock

    PubMed Central

    Tscherner, Michael; Kuchler, Karl

    2016-01-01

    Here, we report a method for the transformation of Candida glabrata using a heat shock method. The protocol can be used for transformations in single well or in 96-well scale. It has been employed as an alternative method to the electroporation protocol to construct a genome-scale gene deletion collection in the human fungal pathogen Candida glabrata ATCC2001 and related strains. Furthermore, the protocol can be used to generate gene deletions in clinical isolates of Candida glabrata (C. glabrata).

  15. Transcriptome Profiles of Populus euphratica upon Heat Shock stress.

    PubMed

    Chen, Jinhuan; Yin, Weilun; Xia, Xinli

    2014-10-01

    Heat stress, which strongly affects plant performance and often results in reduced vegetative growth and yields depression, has become an increasingly serious global problem. Populus euphratica Oliv. which has been considered as a tree model for the study of plant response to abiotic stresses, could be resistant to an extremely wide environmental temperature range (-40 °C to 45 °C). Previous study is mainly focused on its gene regulation upon drought and salt stress. However, little is known about gene regulation at the global transcriptome level upon heat stress. To understand the gene network controlling heat stress in P. euphratica, a transcriptome sequencing using Illumina Hiseq 2000 was performed to generate a 10 gigabases depth for each sample in the tissue of leaf. 119,573 unigeneswere generated with an average length of 474 bp. Approximately 49,605 (41.49%) unigenes exhibited significantly different expressions between two libraries. Among these unigenes, 11,165 (9.34%) were upregulated and 38,440 (32.15%) were down regulated. Heat shock proteins classified as molecular chaperones showed a significant percentage (1.13%) in the up regulated group. Heat responsive genes, such as polyubiquitins, were over expressed in heat treated sample. GO enrichment analysis revealed that the Go terms for differentially expressed unigenes were significantly enriched in hormone-mediated signal, biological process regulation and metabolic process regulation. Our data revealed a global transcriptome picture of P. euphratica in response to heat shock. The identified potential heat stress-related transcripts can be used to infer the gene regulation networks underlying the molecular mechanisms of heat response in P. euphratica.

  16. The Role of Outburst Shock Heating in AGN Feedback

    NASA Astrophysics Data System (ADS)

    Randall, Scott W.; Nulsen, Paul; Jones, Christine; Forman, William R.

    2016-04-01

    One of the major discoveries of modern X-ray observatories is that central AGN in galaxies, groups, and clusters can regulate cooling in the diffuse X-ray emitting gas. This connection is demonstrated by the presence of large cavities in the diffuse gas, usually filled with radio-emitting plasma, that have been evacuated by jets from the AGN. This AGN feedback has important consequences for star formation, galaxy evolution, super-massive black hole growth, galaxy/black hole scaling relations, cluster scaling relations, and the growth of structure. Although it has generally been found that the kinetic output of central AGN scales with the gas cooling rate and is energetic enough to offset cooling, the details of how and where this energy is transferred to heat the gas are poorly understood. I will discuss the role of weak AGN outburst shocks in heating the diffuse gas, and present some results from a very deep (650 ks) Chandra observation of the galaxy group NGC 5813. With three three pairs of collinear cavities, each pair associated with an elliptical AGN outburst shock, NGC 5813 is uniquely well-suited to studying the outburst history of the AGN and the mean shock heating rate.

  17. Prosomes and heat shock complexes in Drosophila melanogaster cells.

    PubMed Central

    de Sa, C M; Rollet, E; de Sa, M F; Tanguay, R M; Best-Belpomme, M; Scherrer, K

    1989-01-01

    Prosomes and heat shock protein (HSP) complexes isolated from the cytoplasm of Drosophila cells in culture were biochemically and immunologically characterized. The two complexes were found to separate on sucrose gradients, allowing the analysis of their protein constituents by two-dimensional polyacrylamide gel electrophoresis and by reaction with anti-HSP sera and prosome-specific monoclonal antibodies. All of the prosomal proteins were found to be clearly distinct from the HSP; none of the prosomal proteins was synthesized de novo in heat shock. However, an antiprosome (anti-p27K) monoclonal antibody (mouse anti-duck) recognizing the Drosophila p29K prosomal protein allowed immunoprecipitation from a heat-shocked postmitochondrial supernatant of the crude HSP complex, including the low- and the high-molecular-weight components, in particular the 70 x 10(3)-molecular weight HSP. The highly purified small 16S HSP complex still contained this preexistent p29K prosomal protein, which thus also seems to be a metabolically stable constituent of the HSP complex. The significance of this structural and possibly functional relationship between prosomes and HSP, involving the highly ubiquitous and evolutionarily conserved prosomal protein p27/29K, remains to be elucidated. Images PMID:2503709

  18. Characterization of proteins and RNAs present on polysomes from normal and heat shocked Drosophila cells

    SciTech Connect

    Sanders, M.M.; Bruederle, L.P.

    1987-05-01

    Translational regulation in heat shocked Drosophila cells is characterized by a shutdown in translation of normal cell mRNA and selective translation of mRNAs coding for heat shock polypeptides. They have characterized the sedimentation profiles and macromolecular compositions of ribosomes and polysomes in normal and heat shocked cells in order to implicate factors responsible for the changes in regulation of translation in heat shocked cells. Sucrose gradient analysis of polysome sedimentation carried out under physiological salt conditions confirms the previously reported decrease in polysomes and increase in 80s monosomes in heat shock. The size of the 40s and 60s subunit peaks and the levels of /sup 35/S-methionyl-tRNA associated with the 43s preinitiation complex do not change significantly in heat shock. Titration of specific mRNA levels across the gradients shows that normal cell mRNAs accumulate in the 40 to 80s region of heat shock profiles while heat shock mRNAs are distributed on heat shock polysomes. Analysis of proteins present on the gradients shows a 46 kD protein is present on polysomes from normal cells and polymerized into the insoluble cytoskeleton in heat shocked cells. The rearrangement of the insoluble cytoskeleton follows the same time course as changes in translation regulation in induction and recovery from heat shock and is accompanied by phosphorylation of the 46 kD polypeptide.

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

    NASA Astrophysics Data System (ADS)

    Matsumoto, Takuma

    2016-08-01

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

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

    NASA Astrophysics Data System (ADS)

    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.

  1. Shock tunnel measurements of heat transfer in a model scramjet

    NASA Technical Reports Server (NTRS)

    Morgan, R. G.; Stalker, R. J.

    1985-01-01

    The results of heat transfer measurements to the walls of a two dimensional scramjet combustion chamber in a shock tunnel are presented. Thin film heat transfer gauges on a ceramic glass substrate were used. The range of experimental conditions covered produced boundary layers ranging from laminar to transitional, as was independently checked by flow visualization. Empirical flat plate correlations, corrected for local pressure disturbances were used to make a comparison with the experimental results. In the fully laminar regime the heating rates were found to give approximate agreement with the empirical estimates. In the nonlaminar tests the heating rate is found to be well below the fully turbulent levels. It is not known at present if this is a transition effect, or if the pressure corrected flat plate turbulent correlations do not apply to the configuration used.

  2. Molecular genetics of heat tolerance and heat shock proteins in cereals.

    PubMed

    Maestri, Elena; Klueva, Natalya; Perrotta, Carla; Gulli, Mariolina; Nguyen, Henry T; Marmiroli, Nelson

    2002-01-01

    Heat stress is common in most cereal-growing areas of the world. In this paper, we summarize the current knowledge on the molecular and genetic basis of thermotolerance in vegetative and reproductive tissues of cereals. Significance of heat stress response and expression of heat shock proteins (HSPs) in thermotolerance of cereal yield and quality is discussed. Major avenues for increasing thermotolerance in cereals via conventional breeding or genetic modification are outlined. PMID:11999842

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

    PubMed

    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.

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

    PubMed

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

    2013-08-01

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

  5. Heat shock and cold shock treatments affect the survival of Listeria monocytogenes and Salmonella Typhimurium exposed to disinfectants.

    PubMed

    Lin, Meng-Hsuan; Chiang, Ming-Lun; Pan, Chorng-Liang; Chou, Cheng-Chun

    2012-04-01

    The foodborne pathogens Listeria monocytogenes and Salmonella Typhimurium were subjected to heat shock at 48°C for 10 and 30 min, respectively, and then cold shocked at 15°C for 3 h. The effect of these shocks on the viability of test organisms exposed to chlorine dioxide and quaternary ammonium compounds was then determined. After exposure to the disinfectants, the viable population of each test organism, regardless of heat shock or cold shock treatment, decreased as the exposure period was extended. Both heat shock and cold shock treatments reduced the susceptibility of L. monocytogenes to both disinfectants at 25°C. However, for Salmonella Typhimurium, exposure to the chlorine dioxide disinfectant or quaternary ammonium compounds at 25°C significantly reduced (P < 0.05) survival of heat-shocked cells but significantly increased (P < 0.05) survival of cold-shocked cells compared with control cells. Survival of both L. monocytogenes and Salmonella Typhimurium generally was reduced after exposure to disinfectants at 40°C compared with 25°C.

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

    PubMed

    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.

  7. Two novel heat shock genes encoding proteins produced in response to heterologous protein expression in Escherichia coli.

    PubMed

    Allen, S P; Polazzi, J O; Gierse, J K; Easton, A M

    1992-11-01

    In Escherichia coli high-level production of some heterologous proteins (specifically, human prorenin, renin, and bovine insulin-like growth factor 2) resulted in the induction of two new E. coli heat shock proteins, both of which have molecular masses of 16 kDa and are tightly associated with inclusion bodies formed during heterologous protein production. We named these inclusion body-associated proteins IbpA and IbpB. The coding sequences for IbpA and IbpB were identified and isolated from the Kohara E. coli gene bank. The genes for these proteins (ibpA and ibpB) are located at 82.5 min on the chromosome. Nucleotide sequencing of the two genes revealed that they are transcribed in the same direction and are separated by 110 bp. Putative Shine-Dalgarno sequences are located upstream from the initiation codons of both genes. A putative heat shock promoter is located upstream from ibpA, and a putative transcription terminator is located downstream from ibpB. A temperature upshift experiment in which we used a wild-type E. coli strain and an isogenic rpoH mutant strain indicated that a sigma 32-containing RNA polymerase is involved in the regulation of expression of these genes. There is 57.5% identity between the genes at the nucleotide level and 52.2% identity at the amino acid level. A search of the protein data bases showed that both of these 16-kDa proteins exhibit low levels of homology to low-molecular-weight heat shock proteins from eukaryotic species.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    SciTech Connect

    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.

  10. An ancient developmental induction: heat-shock proteins induced in sporulation and oogenesis.

    PubMed

    Kurtz, S; Rossi, J; Petko, L; Lindquist, S

    1986-03-01

    Every eukaryotic and prokaryotic organism tested to date synthesizes a small number of heat-shock proteins in response to heat and other forms of stress. A particular pattern of heat-shock gene expression was observed during ascospore development in Saccharomyces: heat-shock proteins hsp26 and hsp84 were strongly induced nor inducible by heat shock. Instead, two proteins related to hsp70 were induced. A strikingly similar pattern of expression occurs during oogenesis in Drosophila, suggesting that it may be one of the earliest developmental pathways to evolve in eukaryotic cells.

  11. Small heat shock proteins from extremophiles: a review.

    PubMed

    Laksanalamai, Pongpan; Robb, Frank T

    2004-02-01

    Many microorganisms from extreme environments have been well characterized, and increasing access to genomic sequence data has recently allowed the analysis of the protein families related to stress responses. Heat shock proteins appear to be ubiquitous in extremophiles. In this review, we focus on the family of small heat shock proteins (sHSPs) from extremophiles, which are alpha-crystallin homologues. Like the alpha-crystallin eye lens proteins, sHSPs act as molecular chaperones and prevent aggregation of denatured proteins under heat and desiccation stress. Many putative sHSP homologues have been identified in the genomic sequences of all classes of extremophiles. Current studies of shsp gene expression have revealed mechanisms of regulation and activity distinct from other known hsp gene regulation systems. Biochemical studies on sHSPs are limited to thermophilic and hyperthermophilic organisms, and the only two available crystal structures of sHSPs from Methanocaldococcus jannaschii, a hyperthermophilic archaeon and a mesophilic eukaryote, have contributed significantly to an understanding of the mechanisms of action of sHSPs, although many aspects remain unclear.

  12. HSF3, a new heat shock factor from Arabidopsis thaliana, derepresses the heat shock response and confers thermotolerance when overexpressed in transgenic plants.

    PubMed

    Prändl, R; Hinderhofer, K; Eggers-Schumacher, G; Schöffl, F

    1998-05-01

    Organisms synthesize heat shock proteins (HSPs) in response to sublethal heat stress and concomitantly acquire increased tolerance against a subsequent, otherwise lethal, heat shock. Heat shock factor (HSF) is essential for the transcription of many HSP genes. We report the isolation of two HSF genes, HSF3 and HSF4, from an Arabidopsis cDNA library. Transgenic Arabidopsis plants were generated containing constructs that allow expression of HSF3 and HSF4 or the respective translational beta-glucuronidase (GUS) fusions. Overexpression of HSF3 or HSF3-GUS, but not of HSF4 or HSF4-GUS, causes HSP synthesis at the non-heat-shock temperature of 25 degrees C in transgenic Arabidopsis. In transgenic plants bearing HSF3/HSF3-GUS, transcription of several heat shock genes is derepressed. Electrophoretic mobility shift assays suggest that derepression of the heat shock response is mediated by HSF3/HSF3-GUS functioning as transcription factor. HSF3/HSF3-GUS-overexpressing Arabidopsis plants show an increase in basal thermotolerance, indicating the importance of HSFs and HSF-regulated genes as determinants of thermoprotective processes. Plants transgenic for HSF3/HSF3-GUS exhibit no other obvious phenotypic alterations. Derepression of HSF activity upon overexpression suggests the titration of a negative regulator of HSF3 or an intrinsic constitutive activity of HSF3. We assume that stable overexpression of HSFs may be applied to other organisms as a means of derepressing the heat shock response. PMID:9645433

  13. Basic features of the staphylococcal heat shock response.

    PubMed

    Qoronfleh, M W; Streips, U N; Wilkinson, B J

    1990-08-01

    The major heat shock proteins of Staphylococcus aureus had apparent Mrs of 84,000, 76,000, and 60,000, and other prominent proteins of Mrs 66,000, 51,000, 43,000 and 24,000 were also induced. Staphylococcus epidermidis showed a similar response. These proteins were also induced by CdCl2, ethanol and apparently osmotic stress (1.71 M NaCl or 2.25 M sucrose). Most of the proteins sedimented with the membrane fraction, but the Mr 60,000 protein remained in the cytoplasm.

  14. Basic features of the staphylococcal heat shock response.

    PubMed

    Qoronfleh, M W; Streips, U N; Wilkinson, B J

    1990-08-01

    The major heat shock proteins of Staphylococcus aureus had apparent Mrs of 84,000, 76,000, and 60,000, and other prominent proteins of Mrs 66,000, 51,000, 43,000 and 24,000 were also induced. Staphylococcus epidermidis showed a similar response. These proteins were also induced by CdCl2, ethanol and apparently osmotic stress (1.71 M NaCl or 2.25 M sucrose). Most of the proteins sedimented with the membrane fraction, but the Mr 60,000 protein remained in the cytoplasm. PMID:2264726

  15. Bacterial Heat Shock Protein GroEL (Hsp64) Exerts Immunoregulatory Effects on T Cells by Utilizing Apoptosis

    PubMed Central

    Nalbant, Ayten; Kant, Melis

    2016-01-01

    Aggregatibacter actinomycetemcomitans (Aa) expresses a 64-kDa GroEL protein belonging to the heat shock family of proteins. This protein has been shown to influence human host cells, but the apoptotic capacity of the GroEL protein regarding T cells is not yet known. The purpose of this study was to investigate the ability of A. actinomycetemcomitans GroEL (AaGroEL) protein to induce human peripheral blood T-cell apoptosis. Endogenous, purified AaGroEL protein was used as an antigen. In AaGroEL-treated T cells, the data indicated that phosphatidylserine exposure, an early apoptotic event, was dose- and time-dependent. The AaGroEL-treated T cells were also positive for active caspase-3 in a dose-dependent manner. The rate of AaGroEL-induced apoptosis was suppressed by the addition of the general caspase inhibitor Z-VAD-FMK. Furthermore, cleaved caspase-8 bands (40/36 kDa and 23 kDa) were identified in cells responding to AaGroEL. DNA fragmentation was also detected in the AaGroEL-treated T cells. Overall, we demonstrated that the endogenous GroEL from A. actinomycetemcomitans has the capacity to induce T-cell apoptosis. PMID:27736933

  16. Heat-Shock Response in Heat-Tolerant and Nontolerant Variants of Agrostis palustris Huds.

    PubMed Central

    Park, S. Y.; Shivaji, R.; Krans, J. V.; Luthe, D. S.

    1996-01-01

    The heat-shock response in heat-tolerant variants (SB) and non-tolerant variants (NSB) of creeping bentgrass (Agrostis palustris Huds.) was investigated. Both variants were derived from callus initiated from a single seed of the cultivar Penncross. SB and NSB synthesized heat-shock proteins (HSPs) of 97, 83, 70, 40, 25, and 18 kD. There were no major differences between SB and NSB in the time or temperature required to induce the heat-shock response. When the HSPs synthesized by SB and NSB were analyzed by two-dimensional gel electrophoresis, it was apparent that SB synthesized two to three additional members of the HSP27 family, which were smaller (25 kD) and more basic than those synthesized by NSB. Analysis of F1 progeny of NSB x SB indicated that 7 of the 20 progeny did not synthesize the additional HSP25 polypeptides. These progeny were significantly less heat tolerant than progeny that did synthesize the additional HSP25 polypeptides. The X2 test of independence (X2 = 22.45, P < 0.001) indicated that heat tolerance and the presence of the additional HSP25 polypeptides are linked traits. PMID:12226306

  17. Revival of a stalled supernova shock by neutrino heating

    NASA Astrophysics Data System (ADS)

    Bethe, H. A.; Wilson, J. R.

    1985-08-01

    The mechanism for revival of a stalled supernova shock found by Wilson (1982) in a computation is analyzed. Neutrinos from the hot, inner core of the supernova are absorbed in the outer layers, and although only about 0.1 percent of their energy is so absorbed, this is enough to eject the outer part of the star and leave only enough mass to form a neutron star. The neutrino absorption is independent of the density of material. After the shock recedes to some extent, neutrino heating establishes a sufficient pressure gradient to push the material beyond about 150 km outward, while the material further in falls rapidly toward the core. This makes the density near 150 km decrease spectacularly, creating a quasi-vacuum in which the pressure is mainly carried by radiation. This is a perfect condition to make the internal energy of the matter sufficient to escape from the gravitational attraction of the star. The net energy of the outgoing shock is about 4 x 10 to the 50th ergs.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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) ...

  19. Intra-binary Shock Heating of Black Widow Companions

    NASA Astrophysics Data System (ADS)

    Romani, Roger W.; Sanchez, Nicolas

    2016-09-01

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

  20. DNA damage-responsive Drosophila melanogaster gene is also induced by heat shock

    SciTech Connect

    Vivino, A.A.; Smith, M.D.; Minton, K.W.

    1986-12-01

    A gene isolated by screening Drosophila melanogaster tissue culture cells for DNA damage regulation was also found to be regulated by heat shock. After UV irradiation or heat shock, induction is at the transcriptional level and results in the accumulation of a 1.0-kilobase polyadenylated transcript. The restriction map of the clone bears no resemblance to the known heat shock genes, which are shown to be uninduced by UV irradiation.

  1. Preliminary Investigation of the Heat Shock Resistant Properties of Molybdenum Disilicide Blades Under Centrifugal Load

    NASA Technical Reports Server (NTRS)

    Long, Roger A; Frenche, John C

    1952-01-01

    An investigation to determine the heat-shock resistant properties of two molybdenum disilicide turbine blades under centrifugal loads imposed by turbine rotation is presented. Molybdenum disilicide turbine blades fabricated by hot-pressing techniques withstood heat-shock conditions under blade centrifugal stresses up to 5350 pounds per square inch. Additional development is required before the heat-shock resistant properties of molybdenum disilicide are satisfactory for turbine-blade application.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed Central

    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

  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.

    PubMed

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

    SciTech Connect

    Pack, Chan-Gi; Ahn, Sang-Gun

    2015-07-31

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

  6. In vivo phosphorus-31 nuclear magnetic resonance reveals lowered ATP during heat shock of Tetrahymena

    SciTech Connect

    Findly, R.C.; Gillies, R.J.; Shulman, R.G.

    1983-03-11

    Cells synthesize a characteristic set of proteins--heat shock proteins--in response to a rapid temperature jump or certain other stress treatments. The technique of phosphorus-31 nuclear magnetic resonance spectroscopy was used to examine in vivo the effects of temperature jump on two species of Tetrahymena that initiate the heat shock response at different temperatures. An immediate 50 percent decrease in cellular adenosine triphosphate was observed when either species was jumped to a temperature that strongly induces synthesis of heat shock proteins. This new adenosine triphosphate concentration was maintained at the heat shock temperature.

  7. Transcriptional regulation of the Chlamydia heat shock stress response in an intracellular infection

    PubMed Central

    Hanson, Brett R.; Tan, Ming

    2015-01-01

    Summary Bacteria encode heat shock proteins that aid in survival during stressful growth conditions. In addition, the major heat shock proteins of the intracellular bacterium Chlamydia trachomatis have been associated with immune pathology and disease. We developed a ChIP-qPCR method to study the regulation of chlamydial heat shock gene regulation during an intracellular infection. This approach allowed us to show that chlamydial heat shock genes are regulated by the transcription factor HrcA within an infected cell, providing validation for previous in vitro findings. Induction of chlamydial heat shock gene expression by elevated temperature was due to loss of HrcA binding to heat shock promoters, supporting a mechanism of derepression. This heat shock response was rapid, while recovery of HrcA binding and return to non-stress transcript levels occurred more slowly. We also found that control of heat shock gene expression was differentially regulated over the course of the intracellular Chlamydia infection. There was evidence of HrcA-mediated regulation of heat shock genes throughout the chlamydial developmental cycle but the level of repression was lower at early times. This is the first study of Chlamydia-infected cells showing the effect of an environmental signal on transcription factor-DNA binding and target gene expression in the bacterium. PMID:26075961

  8. Heat shock protein induction and induced thermal tolerance are independent in adult salamanders.

    PubMed

    Easton, D P; Rutledge, P S; Spotila, J R

    1987-02-01

    Ectothermic vertebrates become thermally tolerant (heat hardened) after exposure to heat shock. Eukaryotic cells show a similar response. Cellular thermal tolerance is correlated with the induction of heat shock proteins (hsps). We have investigated the relationship between heat hardening in salamanders and the induction of hsps in the tissues of these organisms. Although the synthesis of hsps can be induced in these animals by sublethal heat shocks, conditions required for hsp induction and heat hardening often do not coincide. We conclude that induced thermal tolerance in adult salamanders is independent of hsp induction in their tissues. PMID:3559509

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

    PubMed Central

    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.

    2006-01-01

    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 ≥ 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 σ32 and σ54. 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 (DVU1976) and also several

  10. Radiative cooling in shock-heated hydrogen-helium plasmas. [for planetary entry probe heat shields

    NASA Technical Reports Server (NTRS)

    Poon, P. T. Y.; Stickford, G. H., Jr.

    1978-01-01

    Axial and off-axis radiative cooling of cylindrical shock-heated hydrogen-helium plasmas is investigated theoretically and experimentally. The coupled fluid dynamic-radiative transfer equations are solved by a combination of approximation techniques aimed at simplifying the computation of the flux divergence term, namely, the quasi-isothermal approximation and the exponential approximation developed for the solid angle integration. The accuracy of the approximation schemes has been assessed and found acceptable for applying the methods to the rapid computation of the radiatively coupled flow problem. Radiative cooling experiments were conducted in a 6-inch annular arc accelerator shock tube (ANAA) for an initial pressure of 1 torr and shock speeds from 35 to 45 Km/sec. The results indicate that the lateral cooling is small compared with the axial cooling, and that better agreement is achieved between the data and the theoretical results by inclusion of the lateral temperature gradient.

  11. Involvement of heat shock protein 47 in Schistosoma japonicum-induced hepatic fibrosis in mice.

    PubMed

    Huang, Jia-Quan; Tao, Ran; Li, Lan; Ma, Ke; Xu, Lei; Ai, Guo; Fan, Xiang-Xue; Jiao, Yun-Tao; Ning, Qin

    2014-01-01

    Chronic infection with the blood fluke Schistosoma japonicum is associated with both liver cirrhosis and liver cancer. Previously, heat shock protein 47, a collagen-specific molecular chaperone, was shown to play a critical role in the maturation of procollagen. However, less is known about the role of heat shock protein 47 in S. japonicum-induced hepatic fibrosis. We therefore investigated the expression of heat shock protein 47 in S. japonicum-induced liver fibrosis and attempted to determine whether inhibition of heat shock protein 47 could have beneficial effects on fibrosis in vitro and in vivo. In this study, we found that the expression of heat shock protein 47 was significantly increased in patients with Schistosoma-induced fibrosis, as well as in rodent models. Immunohistochemistry revealed heat shock protein 47-positive cells were found in the periphery of egg granulomas. Administration of heat shock protein 47-targeted short hairpin (sh)RNA remarkably reduced heat shock protein 47 expression and collagen deposition in NIH3T3 cells and liver tissue of S. japonicum-infected mice. Life-table analysis revealed a dose-dependent prolongation of survival rates with the treatment of heat shock protein 47-shRNA in murine fibrosis models. Moreover, serum alanine aminotransferase and aspartate transaminase activity, splenomegaly, spleen weight index and portal hypertension were also measured, which showed improvement with the anti-fibrosis treatment. The fibrosis-related parameters assessed were expressions of Col1a1, Col3a1, TGF-β1, CTGF, IL-13, IL-17, MMP-9, TIMP-1 and PAI-1 in the liver. This study demonstrated that heat shock protein 47-targeted shRNA directly reduced collagen production of mouse liver fibrosis associated with S. japonicum. We conclude that heat shock protein 47 plays an essential role in S. japonicum-induced hepatic fibrosis in mice and may be a potential target for ameliorating the hepatic fibrosis caused by this parasite. PMID:24295791

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

    PubMed

    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 (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.

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

    PubMed

    LeBlanc, Sacha; Höglund, Erik; Gilmour, Kathleen M; Currie, Suzanne

    2012-01-01

    Acute temperature stress in animals results in increases in heat shock proteins (HSPs) and stress hormones. There is evidence that stress hormones influence the magnitude of the heat shock response; however, their role is equivocal. To determine whether and how stress hormones may affect the heat shock response, we capitalized on two lines of rainbow trout specifically bred for their high (HR) and low (LR) cortisol response to stress. We predicted that LR fish, with a low cortisol but high catecholamine response to stress, would induce higher levels of HSPs after acute heat stress than HR trout. We found that HR fish have significantly higher increases in both catecholamines and cortisol compared with LR fish, and LR fish had no appreciable stress hormone response to heat shock. This unexpected finding prevented further interpretation of the hormonal modulation of the heat shock response but provided insight into stress-coping styles and environmental stress. HR fish also had a significantly greater and faster heat shock response and less oxidative protein damage than LR fish. Despite these clear differences in the physiological and cellular responses to heat shock, there were no differences in the thermal tolerance of HR and LR fish. Our results support the hypothesis that responsiveness to environmental change underpins the physiological differences in stress-coping styles. Here, we demonstrate that the heat shock response is a distinguishing feature of the HR and LR lines and suggest that it may have been coselected with the hormonal responses to stress.

  14. Phylogenetic analysis of the Trypanosoma genus based on the heat-shock protein 70 gene.

    PubMed

    Fraga, Jorge; Fernández-Calienes, Aymé; Montalvo, Ana Margarita; Maes, Ilse; Deborggraeve, Stijn; Büscher, Philippe; Dujardin, Jean-Claude; Van der Auwera, Gert

    2016-09-01

    Trypanosome evolution was so far essentially studied on the basis of phylogenetic analyses of small subunit ribosomal RNA (SSU-rRNA) and glycosomal glyceraldehyde-3-phosphate dehydrogenase (gGAPDH) genes. We used for the first time the 70kDa heat-shock protein gene (hsp70) to investigate the phylogenetic relationships among 11 Trypanosoma species on the basis of 1380 nucleotides from 76 sequences corresponding to 65 strains. We also constructed a phylogeny based on combined datasets of SSU-rDNA, gGAPDH and hsp70 sequences. The obtained clusters can be correlated with the sections and subgenus classifications of mammal-infecting trypanosomes except for Trypanosoma theileri and Trypanosoma rangeli. Our analysis supports the classification of Trypanosoma species into clades rather than in sections and subgenera, some of which being polyphyletic. Nine clades were recognized: Trypanosoma carassi, Trypanosoma congolense, Trypanosoma cruzi, Trypanosoma grayi, Trypanosoma lewisi, T. rangeli, T. theileri, Trypanosoma vivax and Trypanozoon. These results are consistent with existing knowledge of the genus' phylogeny. Within the T. cruzi clade, three groups of T. cruzi discrete typing units could be clearly distinguished, corresponding to TcI, TcIII, and TcII+V+VI, while support for TcIV was lacking. Phylogenetic analyses based on hsp70 demonstrated that this molecular marker can be applied for discriminating most of the Trypanosoma species and clades. PMID:27180897

  15. Monoclonal Antibodies to Heat Shock Protein 60 Alter the Pathogenesis of Histoplasma capsulatum▿ †

    PubMed Central

    Guimarães, Allan J.; Frases, Susana; Gomez, Francisco J.; Zancopé-Oliveira, Rosely M.; Nosanchuk, Joshua D.

    2009-01-01

    Heat shock proteins with molecular masses of ∼60 kDa (Hsp60) are widely distributed in nature and are highly conserved immunogenic molecules that can function as molecular chaperones and enhance cellular survival under physiological stress conditions. The fungus Histoplasma capsulatum displays an Hsp60 on its cell surface that is a key target of the cellular immune response during histoplasmosis, and immunization with this protein is protective. However, the role of humoral responses to Hsp60 has not been fully elucidated. We generated immunoglobulin G (IgG) isotype monoclonal antibodies (MAbs) to H. capsulatum Hsp60. IgG1 and IgG2a MAbs significantly prolonged the survival of mice infected with H. capsulatum. An IgG2b MAb was not protective. The protective MAbs reduced intracellular fungal survival and increased phagolysosomal fusion of macrophages in vitro. Histological examination of infected mice showed that protective MAbs reduced the fungal burden and organ damage. Organs of infected animals treated with protective MAbs had significantly increased levels of interleukin-2 (IL-2), IL-12, and tumor necrosis factor alpha and decreased levels of IL-4 and IL-10. Hence, IgG1 and IgG2a MAbs to Hsp60 can modify H. capsulatum pathogenesis in part by altering the intracellular fate of the fungus and inducing the production of Th1-associated cytokines. PMID:19179416

  16. Monoclonal antibodies to heat shock protein 60 alter the pathogenesis of Histoplasma capsulatum.

    PubMed

    Guimarães, Allan J; Frases, Susana; Gomez, Francisco J; Zancopé-Oliveira, Rosely M; Nosanchuk, Joshua D

    2009-04-01

    Heat shock proteins with molecular masses of approximately 60 kDa (Hsp60) are widely distributed in nature and are highly conserved immunogenic molecules that can function as molecular chaperones and enhance cellular survival under physiological stress conditions. The fungus Histoplasma capsulatum displays an Hsp60 on its cell surface that is a key target of the cellular immune response during histoplasmosis, and immunization with this protein is protective. However, the role of humoral responses to Hsp60 has not been fully elucidated. We generated immunoglobulin G (IgG) isotype monoclonal antibodies (MAbs) to H. capsulatum Hsp60. IgG1 and IgG2a MAbs significantly prolonged the survival of mice infected with H. capsulatum. An IgG2b MAb was not protective. The protective MAbs reduced intracellular fungal survival and increased phagolysosomal fusion of macrophages in vitro. Histological examination of infected mice showed that protective MAbs reduced the fungal burden and organ damage. Organs of infected animals treated with protective MAbs had significantly increased levels of interleukin-2 (IL-2), IL-12, and tumor necrosis factor alpha and decreased levels of IL-4 and IL-10. Hence, IgG1 and IgG2a MAbs to Hsp60 can modify H. capsulatum pathogenesis in part by altering the intracellular fate of the fungus and inducing the production of Th1-associated cytokines.

  17. Molecular characterization of the heat shock protein 70 gene in Mycoplasma ovipneumoniae.

    PubMed

    Zhang, Bin; Han, Xiao; Yue, Hua; Tang, Cheng

    2013-10-01

    Mycoplasma ovipneumoniae is a species of mycoplasma bacteria that commonly infects the respiratory tract, causing respiratory disease in sheep and goats worldwide. In the current study, the 70-kDa heat shock protein (Hsp70) gene was cloned, sequenced and analyzed in 14 clinical isolates of M. ovipneumoniae. Results showed that, compared to the reference Y98 strain, the open-reading frames (ORFs) of Hsp70 gene in all isolates were 1818 base pairs (bp). Three nucleotides of TCA were inserted at 1,776 bp, resulting in insertion of the amino acid glutamine at amino acid position 593. The neighbor-joining trees, constructed using the Hsp70 gene, exhibited that the closest genetic relationship occurred between M. ovipneumoniae and Mycoplasma hyopneumoniae, which was consistent with the one based on the whole genome comparisons between these two mycoplasma species. Therefore, these results suggest that the Hsp70 gene, rather than 16S ribosomal RNA, was suitable as a potential molecular marker for evaluating the genetic relationship of M. ovipneumoniae with other bacterial species.

  18. Heat shock protein 60 activates B cells via the TLR4-MyD88 pathway.

    PubMed

    Cohen-Sfady, Michal; Nussbaum, Gabriel; Pevsner-Fischer, Meirav; Mor, Felix; Carmi, Pnina; Zanin-Zhorov, Alexandra; Lider, Ofer; Cohen, Irun R

    2005-09-15

    We recently reported that soluble 60-kDa heat shock protein (HSP60) can directly activate T cells via TLR2 signaling to enhance their Th2 response. In this study we investigated whether HSP60 might also activate B cells by an innate signaling pathway. We found that human HSP60 (but not the Escherichia coli GroEL or the Mycobacterial HSP65 molecules) induced naive mouse B cells to proliferate and to secrete IL-10 and IL-6. In addition, the HSP60-treated B cells up-regulated their expression of MHC class II and accessory molecules CD69, CD40, and B7-2. We tested the functional ability of HSP60-treated B cells to activate an allogeneic T cell response and found enhanced secretion of both IL-10 and IFN-gamma by the responding T cells. The effects of HSP60 were found to be largely dependent on TLR4 and MyD88 signaling; B cells from TLR4-mutant mice or from MyD88 knockout mice showed decreased responses to HSP60. Care was taken to rule out contamination of the HSP60 with LPS as a causative factor. These findings add B cells to the complex web of interactions by which HSP60 can regulate immune responses. PMID:16148103

  19. Disruption of the glucocorticoid receptor assembly with heat shock protein 90 by a peptidic antiglucocorticoid.

    PubMed

    Dao-Phan, H P; Formstecher, P; Lefebvre, P

    1997-06-01

    Association of glucocorticoid (GR) and progesterone (PR) receptors with a set of molecular chaperones, including the 90-kDa heat shock protein (hsp90), is a dynamic process required for proper folding and maintaining these nuclear receptors under a transcriptionally inactive, ligand-responsive state. Mutational studies of the chicken hsp90 complementary DNA suggested that three regions of this protein (A, B, and Z) interact with the hormone-binding domain of GR, whereas region A is dispensable for hsp90 binding to PR. We found that this 69-amino acid region can be narrowed down to a 35-mer alpha-helical, acidic peptide, which is by itself able to inhibit hsp90 association to GR translated in vitro. The hsp90-free GR did not bind ligand, but was devoid of any specific DNA-binding activity, and higher peptide concentrations specifically inhibited the binding of activated GR to DNA. When overexpressed in cultured cells, this peptide acted as an antiglucocorticoid and inhibited the antiactivating protein-1 activity and the ligand-dependent nuclear transfer of GR. None of these effects, either in vivo and in vitro, was observed for PR. The region from residue 232 to residue 265 of hsp90 is, therefore, a domain critical for its association to GR, an association that is a prerequisite for receptor transcriptional activity. More importantly, these results demonstrate that targeting specific protein/protein interaction interfaces is a powerful means to specifically modulate nuclear receptor signaling pathways in a ligand-independent manner.

  20. A First Line of Stress Defense: Small Heat Shock Proteins and their function in protein homeostasis

    PubMed Central

    Haslbeck, Martin; Vierling, Elizabeth

    2015-01-01

    Small heat shock proteins (sHsps) are virtually ubiquitous molecular chaperones that can prevent the irreversible aggregation of denaturing proteins. To maintain protein homeostasis, sHsps complex with a variety of nonnative proteins in an ATP-independent manner and, in the context of the stress response, form a first line of defense against protein aggregation. In vertebrates they act to maintain the clarity of the eye lens, and in humans sHsp mutations are linked to myopathies and neuropathies. Although found in all domains of life, sHsps are quite diverse and have evolved independently in metazoans, plants and fungi. sHsp monomers range in size from approximately 12 to 42 kDa and are defined by a conserved β-sandwich α-crystallin domain, flanked by variable N- and C-terminal sequences. Most sHsps form large oligomeric ensembles with a broad distribution of different, sphere- or barrel like oligomers, with the size and structure of the oligomers dictated by features of the N- and C-termini. The activity of sHsps is regulated by mechanisms that change the equilibrium distribution in tertiary features and/or quaternary structure of the sHsp ensembles. Cooperation and/or coassembly between different sHsps in the same cellular compartment adds an underexplored level of complexity to sHsp structure and function. PMID:25681016

  1. A first line of stress defense: small heat shock proteins and their function in protein homeostasis.

    PubMed

    Haslbeck, Martin; Vierling, Elizabeth

    2015-04-10

    Small heat shock proteins (sHsps) are virtually ubiquitous molecular chaperones that can prevent the irreversible aggregation of denaturing proteins. sHsps complex with a variety of non-native proteins in an ATP-independent manner and, in the context of the stress response, form a first line of defense against protein aggregation in order to maintain protein homeostasis. In vertebrates, they act to maintain the clarity of the eye lens, and in humans, sHsp mutations are linked to myopathies and neuropathies. Although found in all domains of life, sHsps are quite diverse and have evolved independently in metazoans, plants and fungi. sHsp monomers range in size from approximately 12 to 42kDa and are defined by a conserved β-sandwich α-crystallin domain, flanked by variable N- and C-terminal sequences. Most sHsps form large oligomeric ensembles with a broad distribution of different, sphere- or barrel-like oligomers, with the size and structure of the oligomers dictated by features of the N- and C-termini. The activity of sHsps is regulated by mechanisms that change the equilibrium distribution in tertiary features and/or quaternary structure of the sHsp ensembles. Cooperation and/or co-assembly between different sHsps in the same cellular compartment add an underexplored level of complexity to sHsp structure and function.

  2. Characterization and Expression of Genes Encoding Three Small Heat Shock Proteins in Sesamia inferens (Lepidoptera: Noctuidae)

    PubMed Central

    Sun, Meng; Lu, Ming-Xing; Tang, Xiao-Tian; Du, Yu-Zhou

    2014-01-01

    The pink stem borer, Sesamia inferens (Walker), is a major pest of rice and is endemic in China and other parts of Asia. Small heat shock proteins (sHSPs) encompass a diverse, widespread class of stress proteins that have not been characterized in S. inferens. In the present study, we isolated and characterized three S. inferens genes that encode members of the α-crystallin/sHSP family, namely, Sihsp21.4, Sihsp20.6, and Sihsp19.6. The three cDNAs encoded proteins of 187, 183 and 174 amino acids with calculated molecular weights of 21.4, 20.6 and 19.6 kDa, respectively. The deduced amino acid sequences of the three genes showed strong similarity to sHSPs identified in other lepidopteran insects. Sihsp21.4 contained an intron, but Sihsp20.6 and Sihsp19.6 lacked introns. Real-time quantitative PCR analyses revealed that Sihsp21.4 was most strongly expressed in S. inferens heads; Whereas expression of Sihsp20.6 and Sihsp19.6 was highest in eggs. The three S. inferens sHSP genes were up-regulated during low temperature stress. In summary, our results show that S. inferens sHSP genes have distinct regulatory roles in the physiology of S. inferens. PMID:25514417

  3. Dynamics of heat shock protein 70 concentrations in peripheral blood lymphocyte lysates during pregnancy in lactating Holstein-Friesian cows.

    PubMed

    Yániz, J L; López-Gatius, F; Almería, S; Carretero, T; García-Ispierto, I; Serrano, B; Smith, R F; Dobson, H; Santolaria, P

    2009-11-01

    The aim of this study was to characterize the dynamics of the concentrations of heat shock protein 70 kDa (HSP70) in peripheral blood lymphocytes of lactating Holstein-Friesian dairy cows (Bos taurus) during pregnancy. The detection of pregnancy was carried out and blood samples collected on Days 40, 90, 120, 150, 180, and 210 of gestation from 46 cows (11 primiparous and 35 pluriparous, 34 seropositive and 12 seronegative to Neospora caninum). Peripheral blood lymphocytes were isolated by density gradient centrifugation. Serologic analysis of Neospora infection and determinations of HSP70 concentrations in lymphocyte lysates were carried out using commercial enzyme-linked immunosorbent assay kits. Climate variables were monitored using on-farm data loggers. Heat shock protein 70 concentrations increased in lymphocytes as gestation progressed, particularly in primiparous cows, with no effect from Neospora infection, climate variables, milk production, semen-providing bull, or outcome of gestation (singletons or twins). Our results show that HSP70 concentrations increased in lymphocytes as gestation progressed and were not affected by stressful factors, such as milk production, heat stress, chronic infection (neosporosis), or twin pregnancies.

  4. Activation of kinase phosphorylation by heat-shift and mild heat-shock

    PubMed Central

    Petrocchi, Pamela; Quaresima, Stefania; Patrizia Mongiardi, Maria; Severini, Cinzia; Possenti, Roberta

    2010-01-01

    Most cells activate intracellular signalling to recover from heat damage. An increase of temperature, known as HS (heat shock), induces two major signalling events: the transcriptional induction of HSPs (heat-shock proteins) and the activation of the MAPK (mitogen-activated protein kinase) cascade. We performed the present study to examine the effects of HS, induced by different experimental conditions, on various kinases [ERK (extracellular-signal-regulated kinase), JNK (c-Jun N-terminal kinase), p38, Akt, AMPK (AMP-activated protein kinase) and PKC (protein kinase C)]. We investigated by Western blot analysis the phosphorylation of MAPK as a measure of cellular responsiveness to heat shift (37°C) and mild HS (40°C) in different cell lines. The results of the study indicate that every cell line responded to heat shift, and to a greater extent to HS, increasing ERK and JNK phosphorylation, whereas variable effects on activation or inhibition of PKC, AMPK, Akt and p38 were observed. Besides the implications of intracellular signalling activated by heat variations, these data may be of technical relevance, indicating possible sources of error due to different experimental temperature conditions. PMID:23119140

  5. Activation of kinase phosphorylation by heat-shift and mild heat-shock.

    PubMed

    Petrocchi, Pamela; Quaresima, Stefania; Mongiardi, Maria Patrizia; Severini, Cinzia; Possenti, Roberta

    2010-01-01

    Most cells activate intracellular signalling to recover from heat damage. An increase of temperature, known as HS (heat shock), induces two major signalling events: the transcriptional induction of HSPs (heat-shock proteins) and the activation of the MAPK (mitogen-activated protein kinase) cascade. We performed the present study to examine the effects of HS, induced by different experimental conditions, on various kinases [ERK (extracellular-signal-regulated kinase), JNK (c-Jun N-terminal kinase), p38, Akt, AMPK (AMP-activated protein kinase) and PKC (protein kinase C)]. We investigated by Western blot analysis the phosphorylation of MAPK as a measure of cellular responsiveness to heat shift (37°C) and mild HS (40°C) in different cell lines. The results of the study indicate that every cell line responded to heat shift, and to a greater extent to HS, increasing ERK and JNK phosphorylation, whereas variable effects on activation or inhibition of PKC, AMPK, Akt and p38 were observed. Besides the implications of intracellular signalling activated by heat variations, these data may be of technical relevance, indicating possible sources of error due to different experimental temperature conditions.

  6. Heat Shock Protein 70: Roles in Multiple Sclerosis

    PubMed Central

    Mansilla, María José; Montalban, Xavier; Espejo, Carmen

    2012-01-01

    Heat shock proteins (HSP) have long been considered intracellular chaperones that possess housekeeping and cytoprotective functions. Consequently, HSP overexpression was proposed as a potential therapy for neurodegenerative diseases characterized by the accumulation or aggregation of abnormal proteins. Recently, the discovery that cells release HSP with the capacity to trigger proinflammatory as well as immunoregulatory responses has focused attention on investigating the role of HSP in chronic inflammatory autoimmune diseases such as multiple sclerosis (MS). To date, the most relevant HSP is the inducible Hsp70, which exhibits both cytoprotectant and immunoregulatory functions. Several studies have presented contradictory evidence concerning the involvement of Hsp70 in MS or experimental autoimmune encephalomyelitis (EAE), the MS animal model. In this review, we dissect the functions of Hsp70 and discuss the controversial data concerning the role of Hsp70 in MS and EAE. PMID:22669475

  7. Targeted heat shock protein 72 for pulmonary cytoprotection.

    PubMed

    Parseghian, Missag H; Hobson, Stephen T; Richieri, Richard A

    2016-06-01

    Heat shock protein 72 (HSP72) is perhaps the most important member of the HSP70 family of proteins, given that it is induced in a wide variety of tissues and cells to combat stress, particularly oxidative stress. Here, we review independent observations of the critical role this protein plays as a pulmonary cytoprotectant and discuss the merits of developing HSP72 as a therapeutic for rapid delivery to cells and tissues after a traumatic event. We also discuss the fusion of HSP72 to a cell-penetrating single-chain Fv antibody fragment derived from mAb 3E10, referred to as Fv-HSP70. This fusion construct has been validated in vivo in a cerebral infarction model and is currently in testing as a clinical therapeutic to treat ischemic events and as a fieldable medical countermeasure to treat inhalation of toxicants caused by terrorist actions or industrial accidents. PMID:27152638

  8. Immunity to heat shock proteins and arthritic disorders.

    PubMed Central

    van Eden, W

    1999-01-01

    Adjuvant arthritis (AA) is a frequently used model of experimental arthritis. Because of its histopathology, which is reminiscent of rheumatoid arthritis in humans, AA is used as a model for the development of novel anti-inflammatory drugs. Recently, it has become evident that AA is a typical T-cell-mediated autoimmune condition. Therefore, novel immunotherapies targeted to T cells can be developed in this model. Analysis of responding T cells in AA have now led to the definition of various antigens with potential relevance to arthritis, including human arthritic conditions. One such antigen defined in AA is the 60kD heat shock protein. Both T-cell vaccination approaches and active antigen immunizations and antigen toleration approaches have turned out to be effective in suppressing AA. PMID:10231009

  9. Modification of tooth development by heat shock protein 60

    PubMed Central

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

    2016-01-01

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

  10. Effects of several factors on the heat-shock-induced thermotolerance of Listeria monocytogenes.

    PubMed Central

    Pagán, R; Condón, S; Sala, F J

    1997-01-01

    The influence of the temperature at which Listeria monocytogenes had been grown (4 or 37 degrees C) on the response to heat shocks of different durations at different temperatures was investigated. For cells grown at 4 degrees C, the effect of storage, prior to and after heat shock, on the induced thermotolerance was also studied. Death kinetics of heat-shocked cells is also discussed. For L. monocytogenes grown at 37 degrees C, the greatest response to heat shock was a fourfold increase in thermotolerance. For L. monocytogenes grown at 4 degrees C, the greatest response to heat shock was a sevenfold increase in thermotolerance. The only survival curves of cells to have shoulders were those for cells that had been heat shocked. A 3% concentration of sodium chloride added to the recovery medium made these shoulders disappear and decreased decimal reduction times. The percentage of cells for which thermotolerance increased after a heat shock was smaller the milder the heat shock and the longer the prior storage. PMID:9251209

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

    SciTech Connect

    Mansfield, M.A.; Key, J.L. )

    1987-08-01

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

  12. SPERM MOTILITY IN HSF1 KNOCKOUT MICE AFTER HEAT SHOCK IS ASSOCIATED WITH FERTILITY DEFICITS

    EPA Science Inventory

    SPERM MOTILITY IN HSF1 KNOCKOUT MICE AFTER HEAT SHOCK IS ASSOCIATED WITH FERTILITY DEFICITS. L.F. Strader*, S.D. Perreault, J.C. Luft*, and D.J. Dix*. US EPA/ORD, Reproductive Toxicology Div., Research Triangle Park, NC
    Heat shock proteins (HSPs) protect cells from environm...

  13. Expression of selected Ginkgo biloba heat shock protein genes after cold treatment could be induced by other abiotic stress.

    PubMed

    Cao, Fuliang; Cheng, Hua; Cheng, Shuiyuan; Li, Linling; Xu, Feng; Yu, Wanwen; Yuan, Honghui

    2012-01-01

    Heat shock proteins (HSPs) play various stress-protective roles in plants. In this study, three HSP genes were isolated from a suppression subtractive hybridization (SSH) cDNA library of Ginkgo biloba leaves treated with cold stress. Based on the molecular weight, the three genes were designated GbHSP16.8, GbHSP17 and GbHSP70. The full length of the three genes were predicted to encode three polypeptide chains containing 149 amino acids (Aa), 152 Aa, and 657 Aa, and their corresponding molecular weights were predicted as follows: 16.67 kDa, 17.39 kDa, and 71.81 kDa respectively. The three genes exhibited distinctive expression patterns in different organs or development stages. GbHSP16.8 and GbHSP70 showed high expression levels in leaves and a low level in gynoecia, GbHSP17 showed a higher transcription in stamens and lower level in fruit. This result indicates that GbHSP16.8 and GbHSP70 may play important roles in Ginkgo leaf development and photosynthesis, and GbHSP17 may play a positive role in pollen maturation. All three GbHSPs were up-regulated under cold stress, whereas extreme heat stress only caused up-regulation of GbHSP70, UV-B treatment resulted in up-regulation of GbHSP16.8 and GbHSP17, wounding treatment resulted in up-regulation of GbHSP16.8 and GbHSP70, and abscisic acid (ABA) treatment caused up-regulation of GbHSP70 primarily.

  14. Both near ultraviolet radiation and the oxidizing agent hydrogen peroxide induce a 32-kDa stress protein in normal human skin fibroblasts

    SciTech Connect

    Keyse, S.M.; Tyrrell, R.M.

    1987-10-25

    We have analyzed the pattern of protein synthesis in solar near ultraviolet (334 nm, 365 nm) and near visible (405 nm) irradiated normal human skin fibroblasts. Two hours after irradiation we find that one major stress protein of approximately 32 kDa is induced in irradiated cells. This protein is not induced by ultraviolet radiation at wavelengths shorter than 334 nm and is not inducible by heat shock treatment of these cells. Although sodium arsenite, diamide, and menadione all induced a 32-kDa protein, they also induced the major heat shock proteins. In contrast, the oxidizing agent, hydrogen peroxide, induced the low molecular weight stress protein without causing induction of the major heat shock proteins. A comparison of the 32-kDa proteins induced by sodium arsenite, H/sub 2/O/sub 2/, and solar near ultraviolet radiation using chemical peptide mapping shows that they are closely related. These results imply that the pathways for induction of the heat shock response and the 32-kDa protein are not identical and suggest that, at least in the case of radiation and treatment with H/sub 2/O/sub 2/, the 32-kDa protein might be induced in response to cellular oxidative stress. This conclusion is supported by the observation that depletion of endogenous cellular glutathione prior to solar near ultraviolet irradiation lowers the fluence threshold for induction of the 32-kDa stress protein.

  15. Mathematical Modeling of the Heat-Shock Response in HeLa Cells

    PubMed Central

    Scheff, Jeremy D.; Stallings, Jonathan D.; Reifman, Jaques; Rakesh, Vineet

    2015-01-01

    The heat-shock response is a key factor in diverse stress scenarios, ranging from hyperthermia to protein folding diseases. However, the complex dynamics of this physiological response have eluded mathematical modeling efforts. Although several computational models have attempted to characterize the heat-shock response, they were unable to model its dynamics across diverse experimental datasets. To address this limitation, we mined the literature to obtain a compendium of in vitro hyperthermia experiments investigating the heat-shock response in HeLa cells. We identified mechanisms previously discussed in the experimental literature, such as temperature-dependent transcription, translation, and heat-shock factor (HSF) oligomerization, as well as the role of heat-shock protein mRNA, and constructed an expanded mathematical model to explain the temperature-varying DNA-binding dynamics, the presence of free HSF during homeostasis and the initial phase of the heat-shock response, and heat-shock protein dynamics in the long-term heat-shock response. In addition, our model was able to consistently predict the extent of damage produced by different combinations of exposure temperatures and durations, which were validated against known cellular-response patterns. Our model was also in agreement with experiments showing that the number of HSF molecules in a HeLa cell is roughly 100 times greater than the number of stress-activated heat-shock element sites, further confirming the model’s ability to reproduce experimental results not used in model calibration. Finally, a sensitivity analysis revealed that altering the homeostatic concentration of HSF can lead to large changes in the stress response without significantly impacting the homeostatic levels of other model components, making it an attractive target for intervention. Overall, this model represents a step forward in the quantitative understanding of the dynamics of the heat-shock response. PMID:26200855

  16. Effect of heat shock on intracellular calcium mobilization in neuroblastoma x glioma hybrid cells.

    PubMed

    Katayama, S; Shuntoh, H; Matsuyama, S; Tanaka, C

    1994-06-01

    The effect of heat shock on agonist-stimulated intracellular Ca2+ mobilization and the expression of heat shock protein 72 (hsp72) in neuroblastoma x glioma hybrid cells (NG 108-15 cells) were examined. Hsp72 was expressed at 6 h after heat shock (42.5 degrees C, 2 h), reached a maximum at 12 h, and decreased thereafter. Bradykinin-induced [Ca2+]i rise was attenuated to 28% of control by heat shock at 2 h after heat shock, and reversion to the control level was seen 12 h later. When the cells were treated with quercetin or antisense oligodeoxyribonucleotide against hsp72 cDNA, the synthesis of hsp72 was not induced by heat shock, whereas bradykinin-induced [Ca2+]i rise was abolished and the [Ca2+]i rise was not restored. Recovery from this stressed condition was evident when cells were stimulated by the Ca(2+)-ATPase inhibitor thapsigargin, even in the presence of either quercetin or antisense oligodeoxyribonucleotide. Inositol 1,4,5-trisphosphate (IP3) production was not altered by heat shock at 12 h after heat shock, whereas IP3 receptor binding activity was reduced to 45.3%. In the presence of quercetin or antisense oligodeoxyribonucleotide, IP3 receptor binding activity decreased and reached 27.2% of the control 12 h after heat shock. Our working thesis is that heat shock transiently suppresses the IP3-mediated intracellular Ca2+ signal transduction system and that hsp72 is involved in the recovery of bradykinin-induced [Ca2+]i rise.

  17. The expression and induction of heat shock proteins in molluscs.

    PubMed

    Liu, Dongwu; Chen, Zhiwei

    2013-05-01

    Living cells respond to stress stimuli by triggering rapid changes in the protein profiles, and the induction of heat shock proteins (HSPs) plays an important part in this process. HSPs, mainly acting as molecular chaperones, are constitutively expressed in cells and involved in protein folding, assembly, degradation, and intracellular localization. The overexpression of HSPs represents a ubiquitous molecular mechanism to cope with stress. Compared to vertebrates, molluscs have a biphasic life cycle where pelagic larvae go through settlement and metamorphosis. HSPs may play an important role in the survival strategy of molluscs during the biphasic life stages. Since aquatic environments are highly dynamic, molluscs may be subject to a variety of sources of stress and HSPs might play a more important role in the adaptation of these animals. Moreover, the mechanisms of stress tolerance in molluscs can offer fundamental insights into the adaptation of organisms for a wide range of environmental challenges. The cDNA of HSPs has been cloned from some molluscs, and HSPs can be induced by heat stress, hypoxia, heavy metal contamination, and aestivation, etc. The expression of HSPs was detected in the neuroendocrine system, mollusc development, and reproductive process. Furthermore, the induction of HSPs is related with the phosphorylation of stress-activated p38 mitogen-activated protein kinase (p38 MAPK) and cJun-N-terminal kinases (JNKs) in molluscs.

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

    SciTech Connect

    Gus’kov, S. Yu.; Nicolai, Ph.; Ribeyre, X.; Tikhonchuk, V. T.

    2015-09-15

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

  19. Heat-shock protein 60 kDa and atherogenic dyslipidemia in patients with untreated mild periodontitis: a pilot study.

    PubMed

    Rizzo, Manfredi; Cappello, Francesco; Marfil, Rafael; Nibali, Luigi; Marino Gammazza, Antonella; Rappa, Francesca; Bonaventura, Giuseppe; Galindo-Moreno, Pablo; O'Valle, Francisco; Zummo, Giovanni; Conway de Macario, Everly; Macario, Alberto J L; Mesa, Francisco

    2012-05-01

    Identification of predictors of cardiovascular risk can help in the prevention of pathologic episodes and the management of patients at all stages of illness. Here, we investigated the relationships between serum levels of Hsp60 and dyslipidemia in patients with periodontitis by performing a cross-sectional study of 22 patients with mild periodontitis without any prior treatment for it (i.e., drug naïve) and 22 healthy controls, matched for age and body mass index (BMI). All subjects were evaluated for periodontal status, gingival inflammation, and oral hygiene. Levels of circulating Hsp60, C-reactive protein (CRP), and plasma lipids were measured, and small, dense low-density lipoproteins (LDL) were indirectly assessed by determining the triglycerides/high-density lipoproteins (HDL) cholesterol ratio. We also assessed by immunohistochemistry Hsp60 levels in oral mucosa of patients and controls. No difference was found in CRP levels or plasma lipids between the two groups, but subjects with periodontitis showed, in comparison to controls, higher levels of small, dense LDL (p  = 0.0355) and circulating Hsp60 concentrations (p < 0.0001). However, levels of mucosal Hsp60 did not change significantly between groups. Correlation analysis revealed that circulating Hsp60 inversely correlated with HDL-cholesterol (r  = -0.589, p  = 0.0039), and positively with triglycerides (r  = +0.877, p < 0.0001), and small, dense LDL (r  = +0.925, p < 0.0001). Serum Hsp60 significantly correlated with the degree of periodontal disease (r  = +0.403, p  = 0.0434). In brief, untreated patients with mild periodontitis had increased small, dense LDL and serum Hsp60 concentrations, in comparison to age- and BMI-matched controls and both parameters showed a strong positive correlation. Our data indicate that atherogenic dyslipidemia and elevated circulating Hsp60 tend to be linked and associated to periodontal pathology. Thus, the road is open to investigate the potential value of elevated levels of circulating Hsp60 as predictor of risk for cardiovascular disease when associated to dyslipidemia in periodontitis patients. PMID:22215516

  20. Structural Insights into the Chaperone Activity of the 40-kDa Heat Shock Protein DnaJ

    PubMed Central

    Cuéllar, Jorge; Perales-Calvo, Judit; Muga, Arturo; Valpuesta, José María; Moro, Fernando

    2013-01-01

    Hsp40 chaperones bind and transfer substrate proteins to Hsp70s and regulate their ATPase activity. The interaction of Hsp40s with native proteins modifies their structure and function. A good model for this function is DnaJ, the bacterial Hsp40 that interacts with RepE, the repressor/activator of plasmid F replication, and together with DnaK regulates its function. We characterize here the structure of the DnaJ-RepE complex by electron microscopy, the first described structure of a complex between an Hsp40 and a client protein. The comparison of the complexes of DnaJ with two RepE mutants reveals an intrinsic plasticity of the DnaJ dimer that allows the chaperone to adapt to different substrates. We also show that DnaJ induces conformational changes in dimeric RepE, which increase the intermonomeric distance and remodel both RepE domains enhancing its affinity for DNA. PMID:23580641

  1. Cigarette smoking induces heat shock protein 70 kDa expression and apoptosis in rat brain: Modulation by bacoside A.

    PubMed

    Anbarasi, K; Kathirvel, G; Vani, G; Jayaraman, G; Shyamala Devi, C S

    2006-01-01

    Cigarette smoking is associated with the development of several diseases and antioxidants play a major role in the prevention of smoking-related diseases. Apoptosis is suggested as a possible contributing factor in the pathogenesis of smoking-induced toxicity. Therefore the present study was designed to investigate the influence of chronic cigarette smoke exposure on apoptosis and the modulatory effect of bacoside A (triterpenoid saponin isolated from the plant Bacopa monniera) on smoking-induced apoptosis in rat brain. Adult male albino rats of Wistar strain were exposed to cigarette smoke and simultaneously administered with bacoside A (10 mg/kg b.w./day, orally) for a period of 12 weeks. Expression of brain hsp70 was analyzed by Western blotting. Apoptosis was identified by DNA fragmentation, terminal deoxynucleotidyl transferase-mediated deoxy uridine triphosphate nick end labeling (TUNEL) staining and transmission electron microscopy. The results showed that exposure to cigarette smoke induced hsp70 expression and apoptosis as characterized by DNA laddering, increased TUNEL-positive cells and ultrastructural apoptotic features in the brain. Administration of bacoside A prevented expression of hsp70 and neuronal apoptosis during cigarette smoking. We speculate that apoptosis may be responsible for the smoking-induced brain damage and bacoside A can protect the brain from the toxic effects of cigarette smoking.

  2. Interaction between the inducible 70-kDa heat shock protein and autophagy: effects on fertility and pregnancy.

    PubMed

    Sisti, Giovanni; Kanninen, Tomi T; Ramer, Ilana; Witkin, Steven S

    2015-09-01

    A consequence of hsp70 (HSPA1A) induction is the inhibition of autophagy. Evidence of autophagy involvement in all aspects of the reproductive process is reviewed, and possible consequences of hsp70 induction at each developmental stage are postulated. It is proposed that aberrant external or internal stimuli that result in high levels of hsp70 production interfere with normal autophagy-related functions and lead to a decrease in the number of functional ova and spermatozoa, impaired pre- and post-implantation embryo development, and increased susceptibility to premature labor and delivery. The purpose of this review is to increase understanding of hsp70-autophagy interactions during reproduction. Interventions to modulate this interaction will lead to development of novel protocols to improve fertility and pregnancy outcome. PMID:26081752

  3. Identification of sequence similarity between 60 kDa and 70 kDa molecular chaperones: evidence for a common evolutionary background?

    PubMed Central

    Flores, A I; Cuezva, J M

    1997-01-01

    Recent findings support the premise that chaperonins (60 kDa stress-proteins) and alpha-subunits of F-type ATPases (alpha-ATPase) are evolutionary related protein families. Two-dimensional gel patterns of synthesized proteins in unstressed and heat-shocked embryonic Drosophila melanogaster SL2 cells revealed that antibodies raised against the alpha-subunit of the F1-ATPase complex from rat liver recognize an inducible p71 member of the 70 kDa stress-responsive protein family. Molecular recognition of this stress-responsive 70 kDa protein by antibodies raised against the F1-ATPase alpha-subunit suggests the possibility of partial sequence similarity within these ATP-binding protein families. A multiple sequence alignment between alpha-ATPases and 60 kDa and 70 kDa molecular chaperones is presented. Statistical evaluation of sequence similarity reveals a significant degree of sequence conservation within the three protein families. The finding suggests a common evolutionary origin for the ATPases and molecular chaperone protein families of 60 kDa and 70 kDa, despite the lack of obvious structural resemblance between them. PMID:9065788

  4. Non-Specific Protein Modifications by a Phytochemical Induce Heat Shock Response for Self-Defense

    PubMed Central

    Ohnishi, Kohta; Ohkura, Shinya; Nakahata, Erina; Ishisaka, Akari; Kawai, Yoshichika; Terao, Junji; Mori, Taiki; Ishii, Takeshi; Nakayama, Tsutomu; Kioka, Noriyuki; Matsumoto, Shinya; Ikeda, Yasutaka; Akiyama, Minoru; Irie, Kazuhiro; Murakami, Akira

    2013-01-01

    Accumulated evidence shows that some phytochemicals provide beneficial effects for human health. Recently, a number of mechanistic studies have revealed that direct interactions between phytochemicals and functional proteins play significant roles in exhibiting their bioactivities. However, their binding selectivities to biological molecules are considered to be lower due to their small and simple structures. In this study, we found that zerumbone, a bioactive sesquiterpene, binds to numerous proteins with little selectivity. Similar to heat-denatured proteins, zerumbone-modified proteins were recognized by heat shock protein 90, a constitutive molecular chaperone, leading to heat shock factor 1-dependent heat shock protein induction in hepa1c1c7 mouse hepatoma cells. Furthermore, oral administration of this phytochemical up-regulated heat shock protein expressions in the livers of Sprague-Dawley rats. Interestingly, pretreatment with zerumbone conferred a thermoresistant phenotype to hepa1c1c7 cells as well as to the nematode Caenorhabditis elegans. It is also important to note that several phytochemicals with higher hydrophobicity or electrophilicity, including phenethyl isothiocyanate and curcumin, markedly induced heat shock proteins, whereas most of the tested nutrients did not. These results suggest that non-specific protein modifications by xenobiotic phytochemicals cause mild proteostress, thereby inducing heat shock response and leading to potentiation of protein quality control systems. We considered these bioactivities to be xenohormesis, an adaptation mechanism against xenobiotic chemical stresses. Heat shock response by phytochemicals may be a fundamental mechanism underlying their various bioactivities. PMID:23536805

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

    PubMed

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

    2015-07-01

    When organisms are exposed to an increase in temperature, they undergo a heat shock response (HSR) regulated by the transcription factor heat shock factor 1 (HSF-1). The heat shock response includes the rapid changes in gene expression initiated by binding of HSF-1 to response elements in the promoters of heat shock genes. Heat shock proteins function as molecular chaperones to protect proteins during periods of elevated temperature and other stress. During infection, hookworm infective third stage larvae (L3) undergo a temperature shift from ambient to host temperature. This increased temperature is required for the resumption of feeding and activation of L3, but whether this increase initiates a heat shock response is unknown. To investigate the role of the heat shock in hookworm L3 activation and parasitic development, we identified and characterized the expression profile of several components of the heat shock response in the hookworm Ancylostoma caninum. We cloned DNAs encoding an hsp70 family member (Aca-hsp-1) and an hsp90 family member (Aca-daf-21). Exposure to a heat shock of 42°C for one hour caused significant up-regulation of both genes, which slowly returned to near baseline levels following one hour attenuation at 22°C. Neither gene was up-regulated in response to host temperature (37°C). Conversely, levels of hsf-1 remained unchanged during heat shock, but increased in response to incubation at 37°C. During activation, both hsp-1 and daf-21 are down regulated early, although daf-21 levels increase significantly in non-activated control larvae after 12h, and slightly in activated larvae by 24h incubation. The heat shock response modulators celastrol and KNK437 were tested for their effects on gene expression during heat shock and activation. Pre-incubation with celastrol, an HSP90 inhibitor that promotes heat shock gene expression, slightly up-regulated expression of both hsp-1 and daf-21 during heat shock. KNK437, an inhibitor of heat shock

  6. Effects of feed restriction on the upper temperature tolerance and heat shock response in juvenile green and white sturgeon.

    PubMed

    Lee, Seunghyung; Hung, Silas S O; Fangue, Nann A; Haller, Liran; Verhille, Christine E; Zhao, Juan; Todgham, Anne E

    2016-08-01

    The objective of the current study was to investigate the effects of feed restriction on whole-organism upper thermal tolerance and the heat shock response of green and white sturgeon to determine how changes in food amount might influence physiological performance of each species when faced with temperature stress. Two parallel feed restriction trials were carried out for juvenile green (202g; 222-day post hatch: dph) and white sturgeon (205g; 197-dph) to manipulate nutritional status at 12.5%, 25%, 50%, or 100% of optimum feeding rate (100% OFR were 1.6% and 1.8% body weight/day, respectively) for four weeks. Following the trials, the critical thermal maximum (CTMax, 0.3°C/min) of sturgeon (N=12/treatment/species) was assessed as an indicator of whole-organism upper thermal tolerance. To assess temperature sensitivity, sturgeon (N=9/treatment/species) were acutely transferred to two temperature treatments (28°C and 18°C as a handling control) for 2h followed by 2h of recovery at 18°C before being sacrificed, and gill, brain, and mucus sampled for measurements of 70-kDa heat shock protein levels (Hsc/Hsp70). Feeding rate had species-specific effects on CTMax in green and white sturgeon such that CTMax of green sturgeon decreased as the magnitude of feed restriction increased; whereas, CTMax of white sturgeon did not change with feed restriction. Elevated temperature (28°C) and feed restriction increased Hsc/Hsp70 levels in the gill tissue of green sturgeon, while heat shock increased Hsc/Hsp70 levels in the mucus of white sturgeon. Our results suggest that green sturgeon may be more susceptible to temperature stress under food-limited conditions.

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

    PubMed

    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.

  8. Escape of heated ions upstream of quasi-parallel shocks

    NASA Technical Reports Server (NTRS)

    Edmiston, J. P.; Kennel, C. F.; Eichler, D.

    1982-01-01

    A simple theoretical criterion by which quasi-parallel and quasi-perpendicular collisionless shocks may be distinguished is proposed on the basis of an investigation of the free escape of ions from the post-shock plasma into the region upstream of a fast collisionless shock. It was determined that the accessibility of downstream ions to the upstream region depends on upstream magnetic field shock normal angle, in addition to the upstream plasma parameters, with post-shock ions escaping upstream for shock normal angles of less than 45 deg, in agreement with the observed transition between quasi-parallel and quasi-perpendicular shock structure. Upstream ion distribution functions resembling those of observed intermediate ions and beams are also calculated.

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

    PubMed

    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.

  10. High dietary protein combats the stress of Labeo rohita fingerlings exposed to heat shock.

    PubMed

    Kumar, Shivendra; Sahu, N P; Pal, A K; Subramanian, Saravanan; Priyadarshi, Himanshu; Kumar, Vikas

    2011-12-01

    The amelioration effect of high dietary protein against stress was evaluated in Labeo rohita fingerlings, exposed to heat shock. Two hundred and forty fingerlings (6.57 ± 0.04 g, average weight ± SE) were randomly distributed into 4 treatment groups, each with 4 replicates was fed with either of four diets containing different levels of protein (20, 30, 40 or 45%). Water temperatures of all the treatments were within the range of 25.5-26.5°C throughout the experimental period of 30 days. After 30 days of feeding, fish were given heat shock by exposing to 38°C for 2 h. Heat shock significantly decreased (P < 0.05) liver glycogen content in treatment groups fed with 20 and 30% dietary protein, whereas unaffected in the 40 and 45% protein-fed groups. Heat shock significantly increased (P < 0.05) serum glucose and cortisol level in all the treatments. The 40 and 45% dietary protein-fed groups registered significantly higher survival (%) after the heat shock compared with their lower-protein counterparts. Heat shock increased the glycolytic, gluconeogenic, protein metabolic and antioxidative enzymes to cope up with thermal stress. Our results indicate that high-protein diet (≥40%) combats the stress due to heat shock in Labeo rohita.

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

    PubMed

    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.

  12. Post-transcriptional regulation of the trypanosome heat shock response by a zinc finger protein.

    PubMed

    Droll, Dorothea; Minia, Igor; Fadda, Abeer; Singh, Aditi; Stewart, Mhairi; Queiroz, Rafael; Clayton, Christine

    2013-01-01

    In most organisms, the heat-shock response involves increased heat-shock gene transcription. In Kinetoplastid protists, however, virtually all control of gene expression is post-transcriptional. Correspondingly, Trypanosoma brucei heat-shock protein 70 (HSP70) synthesis after heat shock depends on regulation of HSP70 mRNA turnover. We here show that the T. brucei CCCH zinc finger protein ZC3H11 is a post-transcriptional regulator of trypanosome chaperone mRNAs. ZC3H11 is essential in bloodstream-form trypanosomes and for recovery of insect-form trypanosomes from heat shock. ZC3H11 binds to mRNAs encoding heat-shock protein homologues, with clear specificity for the subset of trypanosome chaperones that is required for protein refolding. In procyclic forms, ZC3H11 was required for stabilisation of target chaperone-encoding mRNAs after heat shock, and the HSP70 mRNA was also decreased upon ZC3H11 depletion in bloodstream forms. Many mRNAs bound to ZC3H11 have a consensus AUU repeat motif in the 3'-untranslated region. ZC3H11 bound preferentially to AUU repeats in vitro, and ZC3H11 regulation of HSP70 mRNA in bloodstream forms depended on its AUU repeat region. Tethering of ZC3H11 to a reporter mRNA increased reporter expression, showing that it is capable of actively stabilizing an mRNA. These results show that expression of trypanosome heat-shock genes is controlled by a specific RNA-protein interaction. They also show that heat-shock-induced chaperone expression in procyclic trypanosome enhances parasite survival at elevated temperatures.

  13. Heat Shock Proteins in Dermatophytes: Current Advances and Perspectives

    PubMed Central

    Martinez-Rossi, Nilce M.; Jacob, Tiago R.; Sanches, Pablo R.; Peres, Nalu T.A.; Lang, Elza A.S.; Martins, Maíra P.; Rossi, Antonio

    2016-01-01

    Heat shock proteins (HSPs) are proteins whose transcription responds rapidly to temperature shifts. They constitute a family of molecular chaperones, involved in the proper folding and stabilisation of proteins under physiological and adverse conditions. HSPs also assist in the protection and recovery of cells exposed to a variety of stressful conditions, including heat. The role of HSPs extends beyond chaperoning proteins, as they also participate in diverse cellular functions, such as the assembly of macromolecular complexes, protein transport and sorting, dissociation of denatured protein aggregates, cell cycle control, and programmed cell death. They are also important antigens from a variety of pathogens, are able to stimulate innate immune cells, and are implicated in acquired immunity. In fungi, HSPs have been implicated in virulence, dimorphic transition, and drug resistance. Some HSPs are potential targets for therapeutic strategies. In this review, we discuss the current understanding of HSPs in dermatophytes, which are a group of keratinophilic fungi responsible for superficial mycoses in humans and animals. Computational analyses were performed to characterise the group of proteins in these dermatophytes, as well as to assess their conservation and to identify DNA-binding domains (5′-nGAAn-3′) in the promoter regions of the hsp genes. In addition, the quantification of the transcript levels of few genes in a pacC background helped in the development of an extended model for the regulation of the expression of the hsp genes, which supports the participation of the pH-responsive transcriptional regulator PacC in this process. PMID:27226766

  14. Repeat mild heat shock increases dermal fibroblast activity and collagen production.

    PubMed

    Mayes, Andrew E; Holyoak, Caroline D

    2008-04-01

    Repeat mild heat shock (RMHS) has been shown to have anti-aging effects on cellular and biological processes within human dermal fibroblasts. We have investigated the potential of an abridged mild heat shock regime to impact upon the functional properties of human dermal fibroblasts derived from three donors (male, 12 years; female, 22 years; female, 65 years). For each donor mild heat shock increased the rate of contraction of fibroblast-containing collagen gels and increased the de novo synthesis of collagen. Thus, hormetic mechanisms are proposed to provide functional anti-aging benefits to skin cells.

  15. Heat-shock induction of ultraviolet light resistance in Saccharomyces cerevisiae

    SciTech Connect

    Mitchel, R.E.J.; Morrison, D.P.

    1983-10-01

    When exponentially growing diploid wild type Saccharomyces cervisiae cells were subjected to a sudden rise in temperature (heat shock) they responded by increasing their resistance to the lethal effects of ultraviolet light. We have previously reported heat shock-induced increases in heat and ionizing radiation resistance. The shock-induced rise in resistance to uv light reported here was examined in terms of DNA repair capacity, and we find that the increase is due to induction of the recombinational repair system with no significant response from the uv-excision repair process.

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

    PubMed

    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.

  17. Heat shock proteins: essential proteins for apoptosis regulation

    PubMed Central

    Lanneau, D; Brunet, M; Frisan, E; Solary, E; Fontenay, M; Garrido, C

    2008-01-01

    Abstract Many different external and intrinsic apoptotic stimuli induce the accumulation in the cells of a set of proteins known as stress or heat shock proteins (HSPs). HSPs are conserved proteins present in both prokaryotes and eukaryotes. These proteins play an essential role as molecular chaperones by assisting the correct folding of nascent and stress-accumulated misfolded proteins, and by preventing their aggregation. HSPs have a protective function, that is they allow the cells to survive to otherwise lethal conditions. Various mechanisms have been proposed to account for the cytoprotective functions of HSPs. Several of these proteins have demonstrated to directly interact with components of the cell signalling pathways, for example those of the tightly regulated caspasedependent programmed cell death machinery, upstream, downstream and at the mitochondrial level. HSPs can also affect caspase-independent apoptosis-like process by interacting with apoptogenic factors such as apoptosis-inducing factor (AIF) or by acting at the lysosome level. This review will describe the different key apoptotic proteins interacting with HSPs and the consequences of these interactions in cell survival, proliferation and apoptotic processes. Our purpose will be illustrated by emerging strategies in targeting these protective proteins to treat haematological malignancies. PMID:18266962

  18. Heat Shock Factor 1 Mediates Latent HIV Reactivation

    PubMed Central

    Pan, Xiao-Yan; Zhao, Wei; Zeng, Xiao-Yun; Lin, Jian; Li, Min-Min; Shen, Xin-Tian; Liu, Shu-Wen

    2016-01-01

    HSF1, a conserved heat shock factor, has emerged as a key regulator of mammalian transcription in response to cellular metabolic status and stress. To our knowledge, it is not known whether HSF1 regulates viral transcription, particularly HIV-1 and its latent form. Here we reveal that HSF1 extensively participates in HIV transcription and is critical for HIV latent reactivation. Mode of action studies demonstrated that HSF1 binds to the HIV 5′-LTR to reactivate viral transcription and recruits a family of closely related multi-subunit complexes, including p300 and p-TEFb. And HSF1 recruits p300 for self-acetylation is also a committed step. The knockout of HSF1 impaired HIV transcription, whereas the conditional over-expression of HSF1 improved that. These findings demonstrate that HSF1 positively regulates the transcription of latent HIV, suggesting that it might be an important target for different therapeutic strategies aimed at a cure for HIV/AIDS. PMID:27189267

  19. Heat shock proteins: stimulators of innate and acquired immunity.

    PubMed

    Colaco, Camilo A; Bailey, Christopher R; Walker, K Barry; Keeble, James

    2013-01-01

    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.

  20. Responses to heat shock, arsenite and cadmium in soybean

    SciTech Connect

    Edelman, L. ); Key, J.L. )

    1989-04-01

    Heat shock (HS), arsenite (As) and cadmium (Cd) treatments induced the HS response in soybean seedlings but differed in their abilities to induce stress tolerance. Pretreatment of seedlings with sub-lethal HS protected them from subsequent normally lethal HS treatment. However, the protection was much more pronounced in 1 day-old than in 2 day-old plants. Sublethal arsenite pretreatment resulted in only a low level of protection against lethal As or HS treatment and severe damage still occurred in specific tissues. Cadmium did not induce any self- or cross-protection. DNA sequence analyses revealed that HS, As and Cd induced the transcription of similar sequences. However, Northern blot analyses of HS mRNAs, and analyses of in vitro translation products and in vivo-labeled proteins by 1D and 2D SDS-PAGE demonstrated that, compared to HS, the response to the chemical stresses was slower, less intense and not as selective. Apparently any causal relationship between HS proteins and induced stress tolerance must also involve developmental-, tissue-, and/or quantitative-specificities.

  1. Heat Shock Factor 1 Mediates Latent HIV Reactivation.

    PubMed

    Pan, Xiao-Yan; Zhao, Wei; Zeng, Xiao-Yun; Lin, Jian; Li, Min-Min; Shen, Xin-Tian; Liu, Shu-Wen

    2016-05-18

    HSF1, a conserved heat shock factor, has emerged as a key regulator of mammalian transcription in response to cellular metabolic status and stress. To our knowledge, it is not known whether HSF1 regulates viral transcription, particularly HIV-1 and its latent form. Here we reveal that HSF1 extensively participates in HIV transcription and is critical for HIV latent reactivation. Mode of action studies demonstrated that HSF1 binds to the HIV 5'-LTR to reactivate viral transcription and recruits a family of closely related multi-subunit complexes, including p300 and p-TEFb. And HSF1 recruits p300 for self-acetylation is also a committed step. The knockout of HSF1 impaired HIV transcription, whereas the conditional over-expression of HSF1 improved that. These findings demonstrate that HSF1 positively regulates the transcription of latent HIV, suggesting that it might be an important target for different therapeutic strategies aimed at a cure for HIV/AIDS.

  2. Role of Heat Shock Proteins in Stem Cell Behavior

    PubMed Central

    Fan, Guo-Chang

    2015-01-01

    Stress response is well appreciated to induce the expression of heat shock proteins (Hsps) in the cell. Numerous studies have demonstrated that Hsps function as molecular chaperones in the stabilization of intracellular proteins, repairing damaged proteins, and assisting in protein translocation. Various kinds of stem cells (embryonic stem cells, adult stem cells, or induced pluripotent stem cells) have to maintain their stemness and, under certain circumstances, undergo stress. Therefore, Hsps should have an important influence on stem cells. Actually, numerous studies have indicated that some Hsps physically interact with a number of transcription factors as well as intrinsic and extrinsic signaling pathways. Importantly, alterations in Hsp expression have been demonstrated to affect stem cell behavior including self-renewal, differentiation, sensitivity to environmental stress, and aging. This chapter summarizes recent findings related to (1) the roles of Hsps in maintenance of stem cell dormancy, proliferation, and differentiation; (2) the expression signature of Hsps in embryonic/adult stem cells and differentiated stem cells; (3) the protective roles of Hsps in transplanted stem cells; and (4) the possible roles of Hsps in stem cell aging. PMID:22917237

  3. Heat Shock Proteins: Conditional Mediators of Inflammation in Tumor Immunity

    PubMed Central

    Calderwood, Stuart K.; Murshid, Ayesha; Gong, Jianlin

    2012-01-01

    Heat shock protein (HSP)-based anticancer vaccines have undergone successful preclinical testing and are now entering clinical trial. Questions still remain, however regarding the immunological properties of HSPs. It is now accepted that many of the HSPs participate in tumor immunity, at least in part by chaperoning tumor antigenic peptides, introducing them into antigen presenting cells such as dendritic cells (DC) that display the antigens on MHC class I molecules on the cell surface and stimulate cytotoxic lymphocytes (CTL). However, in order for activated CD8+ T cells to function as effective CTL and kill tumor cells, additional signals must be induced to obtain a sturdy CTL response. These include the expression of co-stimulatory molecules on the DC surface and inflammatory events that can induce immunogenic cytokine cascades. That such events occur is indicated by the ability of Hsp70 vaccines to induce antitumor immunity and overcome tolerance to tumor antigens such as mucin1. Secondary activation of CTL can be induced by inflammatory signaling through Toll-like receptors and/or by interaction of antigen-activated T helper cells with the APC. We will discuss the role of the inflammatory properties of HSPs in tumor immunity and the potential role of HSPs in activating T helper cells and DC licensing. PMID:22566956

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

    PubMed

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

    2016-04-01

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

  5. The Role of Heat Shock Proteins in Antigen Cross Presentation

    PubMed Central

    Murshid, Ayesha; Gong, Jianlin; Calderwood, Stuart K.

    2012-01-01

    Heat shock proteins (HSPs) are molecular chaperones that bind tumor antigens and mediate their uptake into antigen presenting cells. HSP–antigen complexes are then directed toward either the MHC class I pathway through antigen cross presentation or the conventional class II pathway, leading to activation of T cell subsets. Uptake of HSP-chaperoned polypeptides can involve both receptor-mediated and receptor-independent routes, and mechanisms of antigen sorting between the Class I and II pathways after uptake are currently under investigation. The processes involved in internalization of HSP–antigen complexes differ somewhat from the mechanisms previously determined for (unchaperoned) particulate and free soluble antigens. A number of studies show that HSP-facilitated antigen cross presentation requires uptake of the complexes by scavenger receptors (SR) followed by processing in the proteasome, and loading onto MHC class I molecules. In this review we have examined the roles of HSPs and SR in antigen uptake, sorting, processing, cell signaling, and activation of innate and adaptive immunity. PMID:22566944

  6. Shock

    MedlinePlus

    ... several kinds of shock. Hypovolemic shock happens when you lose a lot of blood or fluids. Causes include internal or external bleeding, dehydration, burns, and severe vomiting and/or diarrhea. Septic shock is caused by ...

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

    PubMed

    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

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

    PubMed

    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.

  9. Heat shock protein Hsp90-2 expression in the Arabidopsis thaliana seedlings under clinorotation

    NASA Astrophysics Data System (ADS)

    Kozeko, Liudmyla

    Heat shock proteins 90 kDa (Hsp90) are abundant under normal conditions and induced by stress. This family is distinguished from other chaperones in that most of its substrates are signal transduction proteins. Previously, we determined some time-dependent increase in the Hsp90 level in pea seedlings in response to simulated microgravity that indicated a stress-reaction. However, expression of the individual members of the Hsp90 family have specific pattern. The purpose of this study was to investigate possible alterations in the gene expression pattern of cytosolic Hsp90-2 in Arabidopsis thaliana seedlings under 2D-clinorotation. To obtain detailed expression pattern of the HSP90-2 genes we used seeds that provides a resource of loss-of-function mutations gene expression patterns via translational fusions with the reporter gene, GUS (a line N 166718, NASC). There were two variants of the experiment: 1) seedlings grew under clinorotation for 10, 12, 14 d; 2) seedlings grew in the stationary conditions for 10 d followed by clinorotation for 3 h -at 22o C and 16h light cycle. The seedlings grown in the stationary conditions were used as a control. GUS staining showed that HSP90-2 expression was regulated during seedling development and affected by clinorotation in the heterozygous mutant plants. In the homozygous for the mutation plants, HSP90-2 expression was stable during seedling development and not affected by clinorotation. GUS staining was observed in cotyledons, leaves and hypocotyls of the seedlings (especially intense in vascular bundles), indicating intensive cellular processes with participation of this chaperone. Possible pathways of influence of clinorotation on HSP90-2 expression are discussed.

  10. Molecular cloning and characterization of a novel heat shock protein 20 of Babesia orientalis.

    PubMed

    He, Lan; Yu, Qian; Zhang, Wen-Jie; Zhang, Qing-Li; Fan, Li-Zhe; Miao, Xiao-Yan; Khan, Muhammad Kasib; Hu, Min; Zhou, Yan-Qin; Zhao, Jun-Long

    2014-08-29

    The heat shock protein 20 (HSP20) gene of Babesia orientalis (BoHSP20) was identified from both genomic DNA and cDNA. The full-length BoHSP20 gene was 690bp with one intron from position 88-243bp. The amplicon obtained from cDNA corresponded to a full-length open reading frame (ORF) with a length of 534bp, encoding a polypeptide of 178 amino acid residues with a predicted size of 20kDa. The ORF was cloned into a pET-28a plasmid and subsequently expressed as a His-fusion protein. The recombinant HSP20 of B. orientalis (rBoHSP20) was purified and evaluated as an antigen using Western blotting. Anti-B. orientalis water buffalo serum reacted with rBoHSP20, indicating that this protein was an immunodominant antigen and could be a useful diagnostic reagent to detect antibodies against B. orientalis in water buffalo. The native BoHSP20 was recognized by polyclonal antibody from the serum of rabbit immunized with rBoHSP20. Strong immunofluorescence signals were observed from B. orientalis in blood smears by fluorescence microscopy. Bacterial survival experiments indicated that HSP20 can significantly increase the viability of bacteria when the culture is exposed to thermal stress. The results suggest that BoHSP20 might play an important role during B. orientalis transmission from tick to host animal, given the sudden shifts in temperature involved. Phylogenetic analysis revealed that B. orientalis is in the Babesia clade and most closely related to Babesia bovis. Similar topologies were obtained from trees based on 18S rRNA and the HSP70 gene. The present study suggests that BoHSP20 might be a potential diagnostic antigen and that the HSP20 genes can aid in the classification of Babesia and Theileria species.

  11. Aerobic heat shock activates trehalose synthesis in embryos of Artemia franciscana.

    PubMed

    Clegg, J S; Jackson, S A

    1992-05-25

    Encysted embryos (cysts) of the brine shrimp, Artemia franciscana, contain large amounts of trehalose which they use as a major substrate for energy metabolism and biosynthesis for development under aerobic conditions at 25 degrees C. When cysts are placed at 42 degrees C (heat shock) these pathways stop, and the cysts re-synthesize the trehalose that was utilized during the previous incubation at 25 degrees C. Glycogen and glycerol, produced from trehalose at 25 degrees C, appear to be substrates for trehalose synthesis during heat shock. Anoxia prevents trehalose synthesis in cysts undergoing heat shock. These results are consistent with the view that trehalose may play a protective role in cells exposed to heat shock, and other environmental insults, in addition to being a storage form of energy and organic carbon for development. PMID:1592115

  12. Exploring systems affected by the heat shock response in Plasmodium falciparum via protein association networks

    PubMed Central

    Lilburn, Timothy G.; Cai, Hong; Gu, Jianying; Zhou, Zhan; Wang, Yufeng

    2015-01-01

    The heat shock response is a general mechanism by which organisms deal with physical insults such as sudden changes in temperature, osmotic and oxidative stresses, and exposure to toxic substances. Plasmodium falciparum is exposed to drastic temperature changes as a part of its life cycle and maintains an extensive repertoire of heat shock response-related proteins. As these proteins serve to maintain the parasite in the face of anti-malarial drugs as well, better understanding of the heat shock-related systems in the malaria parasite will lead to therapeutic approaches that frustrate these systems, leading to more effective use of anti-malarials. Here we use protein association networks to broaden our understanding of the systems impacted by and/or implicated in the heat shock response. PMID:25539848

  13. Glycosylation of stress glycoprotein GP62 in cells exposed to heat-shock and subculturing.

    PubMed

    Dumić, J; Lauc, G; Flögel, M

    1999-11-01

    GP62 is a member of the stress glycoprotein family that was proposed to have a chaperone-like function in the heat-shock response. Using lectin blotting we have studied glycosylation of GP62 and determined that in addition to heat-shock, even simple subculturing of cells is a sufficient stimulus to provoke induction of GP62. Interestingly, both kinetics of induction and glycosylation of GP62 induced by subculturing were different than when GP62 was induced by heat-shock. While GP62 induced by heat-shock was recognized by SNA, DSA and PHA-E lectins, and not by BSA I, Con A, RCA I, SJA, UEA I, VVA, and WGA lectins, GP62 induced by subculturing was also recognized by RCA I and WGA lectins.

  14. Heat shock proteins: the 'Swiss Army Knife' vaccines against cancers and infectious agents.

    PubMed

    Srivastava, P K; Amato, R J

    2001-03-21

    The ability of heat shock proteins to: (a) chaperone peptides, including antigenic peptides; (b) interact with antigen presenting cells through a receptor; (c) stimulate antigen presenting cells to secrete inflammatory cytokines; and (d) mediate maturation of dendritic cells, makes them a one-stop shop for the immune system. These properties also permit the utilization of heat shock proteins for development of a new generation of prophylactic and therapeutic vaccines against cancers and infectious diseases.

  15. Solute composition and heat shock proteins in rat renal medulla.

    PubMed

    Ohno, A; Müller, E; Fraek, M L; Thurau, K; Beck, F

    1997-05-01

    The high content of heat shock proteins (HSPs) 25 and 72 in the hyperosmotic inner medulla of the concentrating kidney has been ascribed to the high NaCl and urea concentrations in this kidney zone. To assess the effects of variations in the composition of solutes in the renal medulla on the intrarenal distribution of HSPs, rats were fed either a high- or low-Na diet for 3 weeks. These diets result in greatly differing urine and inner medullary solute composition. Sodium dodecyl sulphate polyacrylamide gel electrophoresis and Western blot techniques were used to analyse HSP25 and HSP72 in the cortex, outer medulla and inner medulla. In addition, the amounts of organic osmolytes (sorbitol, myo-inositol, betaine and glycerophosphorylcholine) and urea in the tissue were determined by high-performance liquid chromatography. Intra- and extracellular electrolyte concentrations at the papillary tip were measured by electron microprobe analysis. In the high-Na group, urine osmolality was about 1000 mosmol/kg lower than in rats fed a low-Na diet, due to lower urea concentrations. The sum of urine sodium and potassium concentrations, however, did not differ between the two groups. Neither in the outer nor in the inner medulla was the sum of the concentrations of organic osmolytes affected by the dietary treatment. The sum of sodium, potassium and chloride concentrations did not differ between the two experimental groups, neither in the interstitial nor in the intracellular compartments. However, the urea content and the amounts of HSP25 and HSP72 were significantly lower in the inner medulla of the group of rats fed a high-Na diet. Our results suggest that urea participates in the regulation of the medullary levels of the HSPs and that both HSP25 and HSP72 are components of mechanisms protecting medullary cells against the deleterious effects of high urea concentrations.

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

    PubMed

    Xu, Shu-Jun; Liu, Chun-Jiang; Jiang, Ping-An; Cai, Wei-Min; Wang, Yan

    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 degrees C. On the other hand, drying showed antagonism with heat shock when the moss was subjected to temperatures higher than 40 degrees 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.

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

    PubMed

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

    1999-12-01

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

  18. Aging results in an unusual expression of Drosophila heat shock proteins

    SciTech Connect

    Fleming, J.E.; Walton, J.K.; Dubitsky, R.; Bensch, K.G. )

    1988-06-01

    The authors used high-resolution two-dimensional polyacrylamide gel electrophoresis to evaluate the effect of aging on the heat shock response in Drosophila melanogaster. Although the aging process is not well understood at the molecular level, recent observations suggest that quantitative changes in gene expression occur as these fruit flies approach senescence. Such genetic alterations are in accord with our present data, which clearly show marked differences in the synthesis of heat shock proteins between young and old fruit flies. In 10-day-old flies, a heat shock of 20 min results in the expression of 14 new proteins as detectable by two-dimensional electrophoresis of ({sup 35}S)methionine-labeled polypeptides, whereas identical treatment of 45-day-old flies leads to the expression of at least 50 new or highly up-regulated proteins. In addition, there is also a concomitant increase in the rate of synthesis of a number of the normal proteins in the older animals. Microdensitometric determinations of the low molecular weight heat shock polypeptides on autoradiographs of five age groups revealed that their maximum expression occurs at 47 days for a population of flies with a mean life span of 33.7 days. Moreover, a heat shock effect similar to that observed in senescent flies occurs in young flies fed canavanine, an arginine analogue, before heat shock.

  19. Heat-Shock Promoters: Targets for Evolution by P Transposable Elements in Drosophila

    PubMed Central

    Walser, Jean-Claude; Chen, Bing; Feder, Martin E

    2006-01-01

    Transposable elements are potent agents of genomic change during evolution, but require access to chromatin for insertion—and not all genes provide equivalent access. To test whether the regulatory features of heat-shock genes render their proximal promoters especially susceptible to the insertion of transposable elements in nature, we conducted an unbiased screen of the proximal promoters of 18 heat-shock genes in 48 natural populations of Drosophila. More than 200 distinctive transposable elements had inserted into these promoters; greater than 96% are P elements. By contrast, few or no P element insertions segregate in natural populations in a “negative control” set of proximal promoters lacking the distinctive regulatory features of heat-shock genes. P element transpositions into these same genes during laboratory mutagenesis recapitulate these findings. The natural P element insertions cluster in specific sites in the promoters, with up to eight populations exhibiting P element insertions at the same position; laboratory insertions are into similar sites. By contrast, a “positive control” set of promoters resembling heat-shock promoters in regulatory features harbors few P element insertions in nature, but many insertions after experimental transposition in the laboratory. We conclude that the distinctive regulatory features that typify heat-shock genes (in Drosophila) are especially prone to mutagenesis via P elements in nature. Thus in nature, P elements create significant and distinctive variation in heat-shock genes, upon which evolutionary processes may act. PMID:17029562

  20. Effects of heat shock on survival, proliferation and differentiation of mouse neural stem cells.

    PubMed

    Omori, Hiroyuki; Otsu, Masahiro; Suzuki, Asami; Nakayama, Takashi; Akama, Kuniko; Watanabe, Masaru; Inoue, Nobuo

    2014-02-01

    Hyperthermia during pregnancy is a significant cause of reproductive problems ranging from abortion to congenital defects of the central nervous system (CNS), including neural tube defects and microcephaly. Neural stem cells (NSCs) can proliferate and differentiate into neurons and glia, playing a key role in the formation of the CNS. Here, we examined the effects of heat shock on homogeneous proliferating NSCs derived from mouse embryonic stem cells. After heat shock at 42 °C for 20 min, the proliferating NSCs continued to proliferate, although subtle changes were observed in gene expression and cell survival and proliferation. In contrast, heat shock at 43 °C caused a variety of responses: the up-regulation of genes encoding heat shock proteins (HSP), induction of apoptosis, temporal inhibition of cell proliferation and retardation of differentiation. Finally, effects of heat shock at 44 °C were severe, with almost all cells disappearing and the remaining cells losing the capacity to proliferate and differentiate. These temperature-dependent effects of heat shock on NSCs may be valuable in elucidating the mechanisms by which hyperthermia during pregnancy causes various reproductive problems.

  1. EFFECTS OF HEAT AND BROMOCHLOROACETIC ACID ON MALE REPRODUCTION IN HEAT SHOCK FACTOR-1 GENE KNOCKOUT MICE

    EPA Science Inventory

    Effects of heat and bromochloroacetic acid on male reproduction in heat shock factor-1 gene knockout mice.
    Luft JC1, IJ Benjamin2, JB Garges1 and DJ Dix1. 1Reproductive Toxicology Division, USEPA, RTP, NC, 27711 and 2Dept of Internal Medicine, Univ.of Texas Southwestern Med C...

  2. Spectroradiometric pyrometry of shock-heated gases by infrared emission and absorption measurements.

    PubMed

    Penzias, G J; Dolin, S A; Kruegle, H A

    1966-02-01

    A spectroradiometric pyrometer was developed to measure temperatures of shock-heated gases with time resolution of about 10 microsec. Gas temperatures in shock-heated CO(2)-N(2) mixtures and in self-sustaining detonations were determined by simultaneously measuring infrared spectral radiance and absorptance at selected wavelengths in CO(2) and H(2)O band spectra. By Kirchhoff's law, the ratio (radiance/absorptance) equals the Planck blackbody radiance, from which the temperature is easily found. The measured temperatures agreed with values calculated from the measured shock velocities. PMID:20048824

  3. Experimental Study of Shock Wave Interference Heating on a Cylindrical Leading Edge. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Wieting, Allan R.

    1987-01-01

    An experimental study of shock wave interference heating on a cylindrical leading edge representative of the cowl of a rectangular hypersonic engine inlet at Mach numbers of 6.3, 6.5, and 8.0 is presented. Stream Reynolds numbers ranged from 0.5 x 106 to 4.9 x 106 per ft. and stream total temperature ranged from 2100 to 3400 R. The model consisted of a 3" dia. cylinder and a shock generation wedge articulated to angles of 10, 12.5, and 15 deg. A fundamental understanding was obtained of the fluid mechanics of shock wave interference induced flow impingement on a cylindrical leading edge and the attendant surface pressure and heat flux distributions. The first detailed heat transfer rate and pressure distributions for two dimensional shock wave interference on a cylinder was provided along with insight into the effects of specific heat variation with temperature on the phenomena. Results show that the flow around a body in hypersonic flow is altered significantly by the shock wave interference pattern that is created by an oblique shock wave from an external source intersecting the bow shock wave produced in front of the body.

  4. Heat shock proteins in relation to heat stress tolerance of creeping bentgrass at different N levels.

    PubMed

    Wang, Kehua; Zhang, Xunzhong; Goatley, Mike; Ervin, Erik

    2014-01-01

    Heat stress is a primary factor causing summer bentgrass decline. Changes in gene expression at the transcriptional and/or translational level are thought to be a fundamental mechanism in plant response to environmental stresses. Heat stress redirects protein synthesis in higher plants and results in stress protein synthesis, particularly heat shock proteins (HSPs). The goal of this work was to analyze the expression pattern of major HSPs in creeping bentgrass (Agrostis stolonifera L.) during different heat stress periods and to study the influence of nitrogen (N) on the HSP expression patterns. A growth chamber study on 'Penn-A4' creeping bentgrass subjected to 38/28°C day/night for 50 days, was conducted with four nitrate rates (no N-0, low N-2.5, medium N-7.5, and high N-12.5 kg N ha-1) applied biweekly. Visual turfgrass quality (TQ), normalized difference vegetation index (NDVI), photochemical efficiency of photosystem II (Fv/Fm), shoot electrolyte leakage (ShEL), and root viability (RV) were monitored, along with the expression pattern of HSPs. There was no difference in measured parameters between treatments until week seven, except TQ at week five. At week seven, grass at medium N had better TQ, NDVI, and Fv/Fm accompanied by lower ShEL and higher RV, suggesting a major role in improved heat tolerance. All the investigated HSPs (HSP101, HSP90, HSP70, and sHSPs) were up-regulated by heat stress. Their expression patterns indicated cooperation between different HSPs and their roles in bentgrass thermotolerance. In addition, their production seems to be resource dependent. This study could further improve our understanding about how different N levels affect bentgrass thermotolerance.

  5. Heat Shock Proteins in Relation to Heat Stress Tolerance of Creeping Bentgrass at Different N Levels

    PubMed Central

    Wang, Kehua; Zhang, Xunzhong; Goatley, Mike; Ervin, Erik

    2014-01-01

    Heat stress is a primary factor causing summer bentgrass decline. Changes in gene expression at the transcriptional and/or translational level are thought to be a fundamental mechanism in plant response to environmental stresses. Heat stress redirects protein synthesis in higher plants and results in stress protein synthesis, particularly heat shock proteins (HSPs). The goal of this work was to analyze the expression pattern of major HSPs in creeping bentgrass (Agrostis stolonifera L.) during different heat stress periods and to study the influence of nitrogen (N) on the HSP expression patterns. A growth chamber study on ‘Penn-A4’ creeping bentgrass subjected to 38/28°C day/night for 50 days, was conducted with four nitrate rates (no N-0, low N-2.5, medium N-7.5, and high N-12.5 kg N ha−1) applied biweekly. Visual turfgrass quality (TQ), normalized difference vegetation index (NDVI), photochemical efficiency of photosystem II (Fv/Fm), shoot electrolyte leakage (ShEL), and root viability (RV) were monitored, along with the expression pattern of HSPs. There was no difference in measured parameters between treatments until week seven, except TQ at week five. At week seven, grass at medium N had better TQ, NDVI, and Fv/Fm accompanied by lower ShEL and higher RV, suggesting a major role in improved heat tolerance. All the investigated HSPs (HSP101, HSP90, HSP70, and sHSPs) were up-regulated by heat stress. Their expression patterns indicated cooperation between different HSPs and their roles in bentgrass thermotolerance. In addition, their production seems to be resource dependent. This study could further improve our understanding about how different N levels affect bentgrass thermotolerance. PMID:25050702

  6. Estrogen deprivation does not affect vascular heat shock response in female rats: a comparison with oxidative stress markers.

    PubMed

    Miragem, Antônio Azambuja; Ludwig, Mirna Stela; Heck, Thiago Gomes; Baldissera, Fernanda Giesel; dos Santos, Analu Bender; Frizzo, Matias Nunes; Homem de Bittencourt, Paulo Ivo

    2015-09-01

    Hot flashes, which involve a tiny rise in core temperature, are the most common complaint of peri- and post-menopausal women, being tightly related to decrease in estrogen levels. On the other hand, estradiol (E2) induces the expression of HSP72, a member of the 70 kDa family of heat shock proteins (HSP70), which are cytoprotective, cardioprotective, and heat inducible. Since HSP70 expression is compromised in age-related inflammatory diseases, we argued whether the capacity of triggering a robust heat shock (HS) response would be still present after E2 withdrawal. Hence, we studied the effects of HS treatment (hot tub) in female Wistar rats subjected to bilateral ovariectomy (OVX) after a 7-day washout period. Twelve h after HS, the animals were killed and aortic arches were surgically excised for molecular analyses. The results were compared with oxidative stress markers in the plasma (superoxide dismutase, catalase, and lipoperoxidation) because HSP70 expression is also sensitive to redox regulation. Extracellular (plasma) to intracellular HSP70 ratio, an index of systemic inflammatory status, was also investigated. The results showed that HS response was preserved in OVX animals, as inferred from HSP70 expression (up to 40% rise, p < 0.01) in the aortas, which was accompanied by no further alterations in oxidative stress, hematological parameters, and glycemic control either. This suggests that the lack of estrogen per se could not be solely ascribed as the unique source of low HSP70 expression as observed in long-term post-menopausal individuals. As a consequence, periodic evaluation of HSP70 status (iHSP70 vs. eHSP70) may be of clinical relevance because decreased HS response capacity is at the center of the onset of menopause-related dysfunctions.

  7. [Kinetics of heat shock response upon disfunction of general transcription factor (HSF)].

    PubMed

    Funikov, S Iu; Garbuz, D G; Zatsepina, O G

    2014-01-01

    The heat shock transcription factor (HSF) is a universal activator of hsp gene expression in eukaryotes. A temperature sensitive Drosophila melanogaster strain (hsf4) with a mutation in the hsfgene was originally described as a strain lacking the transcription of hsp genes in response to heat shock. Our results demonstrated that physiological function of HSF4 is not fully abrogated after heat exposure and is able to recover even after severe heat stress, causing the induction of hsp gene expression. We have studied the kinetics of accumulation and degradation of hsp gene products at transcriptional and translational levels and shown that induction of hsp genes, particularly hsp68, in mutant strain is weaker than that in the wild type. Thus, despite the fact that the HSF4 causes a delayed ac- tivation of hsp, response to heat shock in hsf4 strain remains defective.

  8. RNAi screen in Drosophila larvae identifies histone deacetylase 3 as a positive regulator of the hsp70 heat shock gene expression during heat shock.

    PubMed

    Achary, Bhavana G; Campbell, Katie M; Co, Ivy S; Gilmour, David S

    2014-05-01

    The transcription regulation of the Drosophila hsp70 gene is a complex process that involves the regulation of multiple steps, including the establishment of paused Pol II and release of Pol II into elongation upon heat shock activation. While the major players involved in the regulation of gene expression have been studied in detail, additional factors involved in this process continue to be discovered. To identify factors involved in hsp70 expression, we developed a screen that capitalizes on a visual assessment of heat shock activation using a hsp70-beta galactosidase reporter and publicly available RNAi fly lines to deplete candidate proteins. We validated the screen by showing that the depletion of HSF, CycT, Cdk9, Nurf 301, or ELL prevented the full induction of hsp70 by heat shock. Our screen also identified the histone deacetylase HDAC3 and its associated protein SMRTER as positive regulators of hsp70 activation. Additionally, we show that HDAC3 and SMRTER contribute to hsp70 gene expression at a step subsequent to HSF-mediated activation and release of the paused Pol II that resides at the promoter prior to heat shock induction.

  9. The pattern of protein synthesis induced by heat-shock of the moderately halophilic bacterium Chromobacterium marismortui: protective effect of high salt concentration against the thermal shock.

    PubMed

    Katinakis, P

    1989-01-01

    The protein synthetic response to heat shock of the moderately halophilic bacterium Chromobacterium marismortui was examined. Upon exposure to elevated temperature there is an increased synthesis of a specific subset of proteins (heat shock proteins-hsps) in the molecular weight region of 15 to 90 kD, while normal protein synthesis is severely repressed. The synthesis of hsps reaches a maximum 5 min after heat shock at 42 degrees C. Cells recovered their normal protein synthesis patterns rapidly upon returning to their normal growth temperature following heat shock. When cells grown in 2.5M NaCl were challenged with heat shock at 42 degrees C, the synthesis of some normal proteins was permitted. Furthermore, growth in high salt concentration resulted in an extension of the upper temperature limits at which C. marismortui could synthesize hsps. Adaptation of C. marismortui to decreasing salinity stimulated the synthesis of new proteins distinct from the hsps.

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

    PubMed

    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.

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

    PubMed

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

    PubMed

    Zeng, Ximin; Ardeshna, Devarshi; Lin, Jun

    2015-07-01

    Campylobacter jejuni, the leading bacterial cause of human gastroenteritis in the United States, displays significant strain diversity due to horizontal gene transfer. Conjugation is an important horizontal gene transfer mechanism contributing to the evolution of bacterial pathogenesis and antimicrobial resistance. It has been observed that heat shock could increase transformation efficiency in some bacteria. In this study, the effect of heat shock on C. jejuni conjugation efficiency and the underlying mechanisms were examined. With a modified Escherichia coli donor strain, different C. jejuni recipient strains displayed significant variation in conjugation efficiency ranging from 6.2 × 10(-8) to 6.0 × 10(-3) CFU per recipient cell. Despite reduced viability, heat shock of standard C. jejuni NCTC 11168 and 81-176 strains (e.g., 48 to 54°C for 30 to 60 min) could dramatically enhance C. jejuni conjugation efficiency up to 1,000-fold. The phenotype of the heat shock-enhanced conjugation in C. jejuni recipient cells could be sustained for at least 9 h. Filtered supernatant from the heat shock-treated C. jejuni cells could not enhance conjugation efficiency, which suggests that the enhanced conjugation efficiency is independent of secreted substances. Mutagenesis analysis indicated that the clustered regularly interspaced short palindromic repeats system and the selected restriction-modification systems (Cj0030/Cj0031, Cj0139/Cj0140, Cj0690c, and HsdR) were dispensable for heat shock-enhanced conjugation in C. jejuni. Taking all results together, this study demonstrated a heat shock-enhanced conjugation efficiency in standard C. jejuni strains, leading to an optimized conjugation protocol for molecular manipulation of this organism. The findings from this study also represent a significant step toward elucidation of the molecular mechanism of conjugative gene transfer in C. jejuni.

  13. Role of HMGB1 in propofol protection of rat intestinal epithelial cells injured by heat shock.

    PubMed

    Tang, Jing; Deng, Peng; Jiang, Yu; Tang, Youqing; Chen, Bin; Su, Lei; Liu, Zhifeng

    2013-03-01

    Gut-derived endotoxin and pathogenic bacteria may be important causative factors of morbidity and death during heat stroke. However, as the key component of intestinal mucosal barrier, the molecular mechanism of how intestinal epithelial cells are injured by heat shock is remains unclear. After rat intestinal epithelial cells (IEC-6) had been exposed to heat shock, their viability was measured. Propofol, which plays an important role in anti-inflammation and organ protection, was investigated to see how it affected viability under this stress. Changes of high mobility group box 1 (HMGB1) in IEC-6 cells were measured with RT-PCR and Western blot assay at transcription and translational levels, respectively. Ethyl pyruvate (EP), a specific inhibitor of HMGB1 that can inhibit the release of HMGB1 without affecting its intracellular synthesis, was also investigated. Heat shock significantly reduced the intracellular level of HMGB1, and propofol inhibit its reduction. Propofol protected the heat shock-injured cells, at least partly through inhibiting the release of intracellular HMGB1 to reduce the direct or indirect cell damage caused by HMGB1. Pretreatment with high concentrations of EP also attenuated heat-shock injury.

  14. Regulation of Cyclooxygenase-2 Expression by Heat: A Novel Aspect of Heat Shock Factor 1 Function in Human Cells

    PubMed Central

    Trotta, Edoardo; Angelini, Mara; Santoro, M. Gabriella

    2012-01-01

    The heat-shock response, a fundamental defense mechanism against proteotoxic stress, is regulated by a family of heat-shock transcription factors (HSF). In humans HSF1 is considered the central regulator of heat-induced transcriptional responses. The main targets for HSF1 are specific promoter elements (HSE) located upstream of heat-shock genes encoding cytoprotective heat-shock proteins (HSP) with chaperone function. In addition to its cytoprotective function, HSF1 was recently hypothesized to play a more complex role, regulating the expression of non-HSP genes; however, the non-canonical role of HSF1 is still poorly understood. Herein we report that heat-stress promotes the expression of cyclooxygenase-2 (COX-2), a key regulator of inflammation controlling prostanoid and thromboxane synthesis, resulting in the production of high levels of prostaglandin-E2 in human cells. We show that heat-induced COX-2 expression is regulated at the transcriptional level via HSF1-mediated signaling and identify, by in-vitro reporter gene activity assay and deletion-mutant constructs analysis, the COX-2 heat-responsive promoter region and a new distal cis-acting HSE located at position −2495 from the transcription start site. As shown by ChIP analysis, HSF1 is recruited to the COX-2 promoter rapidly after heat treatment; by using shRNA-mediated HSF1 suppression and HSE-deletion from the COX-2 promoter, we demonstrate that HSF1 plays a central role in the transcriptional control of COX-2 by heat. Finally, COX-2 transcription is also induced at febrile temperatures in endothelial cells, suggesting that HSF1-dependent COX-2 expression could contribute to increasing blood prostaglandin levels during fever. The results identify COX-2 as a human non-classical heat-responsive gene, unveiling a new aspect of HSF1 function. PMID:22347460

  15. Nuclear proteins in Drosophila melanogaster cells after heat shock and their binding to homologous DNA.

    PubMed Central

    Falkner, F G; Biessmann, H

    1980-01-01

    After 5 minutes heat shock at 37 degrees C Drosophila melanogaster Kc-cell nuclear proteins were extracted wit 0.4M NaCl and compared by SDS gel electrophoresis with extracts from cells grown at 25 degrees C. Two proteins (39 000 and 46 000) were only found in heat shock nuclei. Reconstitution with total Drosophila DNA or a DNA fragment from the heat inducible locus 87A/C covalently coupled to sepharose was performed. In the presence of calf thymus competitor DNA these proteins and also others of lower molecular weight showed preferential binding to the homologous DNA. Images PMID:6777762

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

    PubMed

    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. Shock compression and flash-heating of molecular adsorbates on the picosecond time scale

    NASA Astrophysics Data System (ADS)

    Berg, Christopher Michael

    An ultrafast nonlinear coherent laser spectroscopy termed broadband multiplex vibrational sum-frequency generation (SFG) with nonresonant suppression was employed to monitor vibrational transitions of molecular adsorbates on metallic substrates during laser-driven shock compression and flash-heating. Adsorbates were in the form of well-ordered self-assembled monolayers (SAMs) and included molecular explosive simulants, such as nitroaromatics, and long chain-length alkanethiols. Based on reflectance measurements of the metallic substrates, femtosecond flash-heating pulses were capable of producing large-amplitude temperature jumps with DeltaT = 500 K. Laser-driven shock compression of SAMs produced pressures up to 2 GPa, where 1 GPa ≈ 1 x 104 atm. Shock pressures were estimated via comparison with frequency shifts observed in the monolayer vibrational transitions during hydrostatic pressure measurements in a SiC anvil cell. Molecular dynamics during flash-heating and shock loading were probed with vibrational SFG spectroscopy with picosecond temporal resolution and sub-nanometer spatial resolution. Flash-heating studies of 4-nitrobenzenethiolate (NBT) on Au provided insight into effects from hot-electron excitation of the molecular adsorbates at early pump-probe delay times. At longer delay times, effects from the excitation of SAM lattice modes and lower-energy NBT vibrations were shown. In addition, flash-heating studies of alkanethiolates demonstrated chain disordering behaviors as well as interface thermal conductances across the Au-SAM junction, which was of specific interest within the context of molecular electronics. Shock compression studies of molecular explosive simulants, such as 4-nitrobenzoate (NBA), demonstrated the proficiency of this technique to observe shock-induced molecular dynamics, in this case orientational dynamics, on the picosecond time scale. Results validated the utilization of these refined shock loading techniques to probe the shock

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

    PubMed

    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.

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

    PubMed

    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. PMID:20866940

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

    NASA Technical Reports Server (NTRS)

    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.

  1. Heat shock protein 70 and anti–heat shock protein 70 antibodies in nasal secretions of patients with chronic rhinosinusitis

    PubMed Central

    Tsybikov, Namjil N.; Egorova, Elena V.; Kuznik, Boris I.; Fefelova, Elena V.

    2016-01-01

    Background: The issue of heat shock protein (HSP) 70 and anti-HSP70 antibodies in chronic rhinosinusitis (CRS) has never been explored. Objective: To determine the nasal secretion (NS) levels of HSP70 and anti-HSP70 antibodies in patients with CRS with nasal polyps (CRSwNP) and patients with CRS without nasal polyps (CRSsNP), and to evaluate their associations with CRS clinical severity and correlation with NS interleukin (IL), IL-5 and interferon λ. Methods: CRS severity was determined by Lund-Mackay scores. Levels of immunoglobulin E (IgE), IL-4, IL-5, interferon λ, HSP70, and anti-HSP70 antibody levels in NS were measured by enzyme-linked immunosorbent assay. Results: Forty-six patients with CRSsNP (25 women [54.3%] and 21 men [45.7%], mean [standard deviation {SD}]) age, 34.1 ± 12.3 years; 54 patients with CRSwNP (24 women [44.4%] and 30 men [55.6%], mean [SD] age, 37.9 ± 17.5 years). A group of 40 healthy subjects served as controls. Compared with the controls (with a mean [SD] NS HSP70 level of 0.05 ± 0.03 μg/mL), mean [SD] NS HSP70 levels in both the CRSsNP group (0.16 ± 0.07 μg/mL) and CRSwNP group (0.21 ± 0.10 μg/mL) were increased (p < 0.001). Similarly, the mean (SD) NS anti-HSP70 antibody levels were significantly higher in patients with CRSwNP (0.25 ± 0.09 optical density value [ODV]) compared with CRSsNP (0.13 ± 0.04 ODV) (p < 0.001) and healthy controls (0.14 ± 0.02 ODV) (p < 0.001). NS HSP70 in subjects with CRSwNP showed a significant positive correlation with the Lund-Mackay score (r = 0.31; p < 0.05). NS levels of either HSP70 or anti-HSP70 antibodies were strongly correlated with NS IL-4 in the CRSwNP group (r = 0.62, p < 0.001; and r = 0.69, p < 0.001, respectively). Conclusion: NS concentrations of HSP70 and secretory IgA anti HSP70 antibodies are increased in CRSwNP (but not in CRSsNP) and correlate positively with the Lund-Mackay score, NS IL-4, and NS IL-5. PMID:27103555

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

    PubMed

    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. Overexpression of small heat shock protein 21 protects the Chinese oak silkworm Antheraea pernyi against thermal stress.

    PubMed

    Liu, Qiu-Ning; Zhu, Bao-Jian; Dai, Li-Shang; Fu, Wei-Wei; Lin, Kun-Zhang; Liu, Chao-Liang

    2013-08-01

    Small heat shock proteins (sHSPs) usually act as molecular chaperones to prevent proteins from being denatured in extreme conditions. We first report the sHSP21 gene, named as Ap-sHSP21, in the Chinese oak silkworm Antheraea pernyi (Lepidoptera: Saturniidae). The full-length cDNA of Ap-sHSP21 is 976 bp, including a 5'-untranslated region (UTR) of 99 bp, a 3'-UTR of 316 bp and an open reading frame (ORF) of 561 bp encoding a polypeptide of 186 amino acids. The deduced A. pernyi sHSP21 protein sequence reveals the percent identity is 82-93% in comparison to other sHSPs from insects. Real-time quantitative reverse transcription-PCR (qRT-PCR) analysis shows that Ap-sHSP21 expression is higher in testis than that in other examined tissues and significantly up-regulated after heat shock. In addition, prokaryotic expression and purification of the Ap-sHSP21 protein were performed. SDS-PAGE and Western blot analysis demonstrated that a 25 kDa recombinant protein was successfully expressed in Escherichia coli cells and the purified recombinant protein was also confirmed to protect restriction enzymes from thermal inactivation. The expression of Ap-sHSP21 was significantly down-regulated after RNA interference, which was confirmed by qRT-PCR and Western blot analysis. All together, these results suggest that Ap-sHSP21 play a key role in thermal tolerance.

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

    PubMed

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

    2015-02-01

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

  5. Heat shock in the developmentally sensitive period of butterfly eyespots fails to increase fluctuating asymmetry.

    PubMed

    Breuker, Casper J; Brakefield, Paul M

    2003-01-01

    Fluctuating asymmetry (FA) is considered to provide a means of evaluating developmental stability and to reflect an individual's quality or the stress experienced during development. Stress is predicted to increase the phenotypic variation of both FA and trait size. In this study we examined the effect of a particular heat shock on both FA and size of eyespots in the butterfly, Bicyclus anynana. We also examined whether those eyespots thought to be involved in partner choice and sexual selection were particularly sensitive to stress. We applied a heat shock of 39.5 degrees C for 3 h before, during, and after a sensitive period in eyespot development. We examined the FA, variation in FA, size, and variation in size of five eyespots, two on the dorsal forewing (sexually selected traits), two on the ventral forewing, and one on the ventral hindwing (nonsexually selected traits). For each sex and treatment, the heat shock did not result in significant changes in mean trait size and FA nor in the variation of size and FA. There were no differences in the response to the heat shock between sexually and nonsexually selected traits. We discuss how the increased production of heat shock proteins, including HSP60, may have stabilized development and how this might explain the results. PMID:12752762

  6. Genetic Modification of the Salmonella Membrane Physical State Alters the Pattern of Heat Shock Response ▿

    PubMed Central

    Porta, Amalia; Török, Zsolt; Horvath, Ibolya; Franceschelli, Silvia; Vígh, László; Maresca, Bruno

    2010-01-01

    It is now recognized that membranes are not simple physical barriers but represent a complex and dynamic environment that affects membrane protein structures and their functions. Recent data emphasize the role of membranes in sensing temperature changes, and it has been shown that the physical state of the plasma membrane influences the expression of a variety of genes such as heat shock genes. It has been widely shown that minor alterations in lipid membranes are critically involved in the conversion of signals from the environment to the transcriptional activation of heat shock genes. Previously, we have proposed that the composition, molecular arrangement, and physical state of lipid membranes and their organization have crucial roles in cellular responses during stress caused by physical and chemical factors as well as in pathological states. Here, we show that transformation of Salmonella enterica serovar Typhimurium LT2 (Salmonella Typhimurium) with a heterologous Δ12-desaturase (or with its trans-membrane regions) causes major changes in the pathogen's membrane dynamic. In addition, this pathogen is strongly impaired in the synthesis of major stress proteins (heat shock proteins) under heat shock. These data support the hypothesis that the perception of temperature in Salmonella is strictly controlled by membrane order and by a specific membrane lipid/protein ratio that ultimately causes transcriptional activation of heat shock genes. These results represent a previously unrecognized mode of sensing temperature variation used by this pathogen at the onset of infection. PMID:20139186

  7. Heat shock in the developmentally sensitive period of butterfly eyespots fails to increase fluctuating asymmetry.

    PubMed

    Breuker, Casper J; Brakefield, Paul M

    2003-01-01

    Fluctuating asymmetry (FA) is considered to provide a means of evaluating developmental stability and to reflect an individual's quality or the stress experienced during development. Stress is predicted to increase the phenotypic variation of both FA and trait size. In this study we examined the effect of a particular heat shock on both FA and size of eyespots in the butterfly, Bicyclus anynana. We also examined whether those eyespots thought to be involved in partner choice and sexual selection were particularly sensitive to stress. We applied a heat shock of 39.5 degrees C for 3 h before, during, and after a sensitive period in eyespot development. We examined the FA, variation in FA, size, and variation in size of five eyespots, two on the dorsal forewing (sexually selected traits), two on the ventral forewing, and one on the ventral hindwing (nonsexually selected traits). For each sex and treatment, the heat shock did not result in significant changes in mean trait size and FA nor in the variation of size and FA. There were no differences in the response to the heat shock between sexually and nonsexually selected traits. We discuss how the increased production of heat shock proteins, including HSP60, may have stabilized development and how this might explain the results.

  8. Impact of ecologically relevant heat shocks on Hsp developmental function in the vetigastropod Haliotis asinina.

    PubMed

    Gunter, Helen M; Degnan, Bernard M

    2008-07-15

    Heat shock proteins (Hsps) are essential for cellular maintenance, normal differentiation and morphogenesis, and protection against a range of environmental stresses. It is unknown which of these roles takes precedence when they are required simultaneously. Here we examined the impact of thermal stress on the complex developmental expression patterns of HasHsp70 and HasHsp90A in the vetigastropod Haliotis asinina. We find that near-lethal heat shocks do not alter the spatial demarcation of Hsp expression despite such treatments impacting on the external character of the embryos. Using a suite of molecular markers that are both coexpressed with the Hsps (i.e. in ventrolateral ectoderm and prototroch) and expressed in tissues that have lower (basal) Hsp expression (e.g. serotonergic nervous system and shell gland), we determined that Hsp-expressing tissues do not incur markedly less thermal damage than adjacent tissues. To explore the relationship of Hsp expression with sensitivity of specific cell territories to heat shock, we focused on the formation of the prototroch, a tissue where HasHsp70 and HasHsp90A are coexpressed. By heat shocking at specific developmental stages, we determined that the most sensitive period of prototroch development is during its early specification and differentiation, which overlaps with the time the Hsps are expressed at their highest levels in these cells. This correlation is consistent with heat shock impairing the function of Hsps in regions of the H. asinina embryo undergoing morphogenesis.

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

    NASA Astrophysics Data System (ADS)

    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.

  10. Flow and heat transfer measurements in a pseudo-shock region with surface cooling

    NASA Technical Reports Server (NTRS)

    Cuffel, R. F.; Back, L. H.

    1976-01-01

    An experimental investigation was conducted to acquire information on the flow structure, mean flowfield, and temperature distributions in a pseudo-shock region in a supersonic diffuser with surface cooling. The Mach number upstream was 2.9, and the wall to stagnation temperature ratio was 0.44. A Mach-disk-like shock wave emanated from the thin separated flow region near the beginning of the compression region, and reattachment occurred one diameter downstream so that the flow was not separated over most of the pseudo-shock region. The flow compression was a shock-free, predominantly viscous process. Along the pseudo-shock region the measured heat-transfer coefficient increased approximately as the 0.8 power of the measured wall static pressure. The estimated wall shear stress increased downstream of flow attachment, but was still considerably less than the upstream value.

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

    NASA Technical Reports Server (NTRS)

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

    1983-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

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

  13. Interaction of ATP with a small heat shock protein from Mycobacterium leprae: effect on its structure and function.

    PubMed

    Nandi, Sandip Kumar; Chakraborty, Ayon; Panda, Alok Kumar; Ray, Sougata Sinha; Kar, Rajiv Kumar; Bhunia, Anirban; Biswas, Ashis

    2015-03-01

    Adenosine-5'-triphosphate (ATP) is an important phosphate metabolite abundantly found in Mycobacterium leprae bacilli. This pathogen does not derive ATP from its host but has its own mechanism for the generation of ATP. Interestingly, this molecule as well as several antigenic proteins act as bio-markers for the detection of leprosy. One such bio-marker is the 18 kDa antigen. This 18 kDa antigen is a small heat shock protein (HSP18) whose molecular chaperone function is believed to help in the growth and survival of the pathogen. But, no evidences of interaction of ATP with HSP18 and its effect on the structure and chaperone function of HSP18 are available in the literature. Here, we report for the first time evidences of "HSP18-ATP" interaction and its consequences on the structure and chaperone function of HSP18. TNP-ATP binding experiment and surface plasmon resonance measurement showed that HSP18 interacts with ATP with a sub-micromolar binding affinity. Comparative sequence alignment between M. leprae HSP18 and αB-crystallin identified the sequence 49KADSLDIDIE58 of HSP18 as the Walker-B ATP binding motif. Molecular docking studies revealed that β4-β8 groove/strands as an ATP interactive region in M. leprae HSP18. ATP perturbs the tertiary structure of HSP18 mildly and makes it less susceptible towards tryptic cleavage. ATP triggers exposure of additional hydrophobic patches at the surface of HSP18 and induces more stability against chemical and thermal denaturation. In vitro aggregation and thermal inactivation assays clearly revealed that ATP enhances the chaperone function of HSP18. Our studies also revealed that the alteration in the chaperone function of HSP18 is reversible and is independent of ATP hydrolysis. As the availability and binding of ATP to HSP18 regulates its chaperone function, this functional inflection may play an important role in the survival of M. leprae in hosts.

  14. Inactivation of Aspergillus niger in mango nectar by high-pressure homogenization combined with heat shock.

    PubMed

    Tribst, Alline A L; Franchi, Mark A; Cristianini, Marcelo; de Massaguer, Pilar R

    2009-01-01

    This research evaluated the inactivation of a heat-resistant Aspergillus niger conidia in mango nectar by high-pressure homogenization (HPH) combined with heat shock. A. niger were inoculated in mango nectar (10(6) conidia mL(-1)) and subjected to HPH (300 to 100 MPa) and heat shock (80 degrees C for 5 to 20 min) before or after HPH. Processes were evaluated according to number of decimal reductions reached by each isolated or combined process. Scanning electron microscopy was performed to observe conidia wall after pressure treatment. Pressures below 150 MPa did not inactivate A. niger while pressures of 200 and 300 MPa resulted in 2 and more than 6 log reductions, respectively. D(80 degrees C) of A. niger was determined as 5.03 min. A heat shock of 80 degrees C/15 min, reaching 3 decimal conidia reductions, was applied before or after a 200 MPa pressure treatment to improve the decimal reduction to 5 log cycles. Results indicated that HPH inactivated A. niger in mango nectar at 300 MPa (>6.24 log cycles) and that, with pressure (200 MPa) combined with post heat shock, it was possible to obtain the same decimal reduction, showing a synergistic effect. On the other hand, pre heat shock associated with HPH resulted in an additive effect. The observation of A. niger conidia treated by HPH at 100 and 200 MPa by scanning electron microscopy indicated that HPH promoted intense cell wall damage, which can sensitize the conidia to post heat shock and possibly explain the synergistic effect observed. Practical Application: The results obtained in this paper are relevant to elucidate the mechanism of conidia inactivation in order to develop the application of HPH as an alternative pasteurization process for the fruit nectar industry.

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

    PubMed

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

    2014-08-01

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

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

    NASA Astrophysics Data System (ADS)

    Janka, H.-Th.

    2001-03-01

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

  17. Shock waves and phase changes in a large-heat-capacity fluid emerging from a tube

    NASA Astrophysics Data System (ADS)

    Thompson, P. A.; Kim, Y.-G.; Carofano, G. C.

    1986-05-01

    The emergence of a shockwave from the open end of a shock tube is studied, with special emphasis on test fluids of high molar heat capacity, i.e. retrograde fluids. A variety of wavelike vapour-liquid phase changes are observed in such fluids, including the liquefaction shock, mixture-evaporation shock, condensation waves associated with shock splitting and liquid-evaporation waves (these phenomena have analogues in the polymorphic phase changes of solids; only the first two are treated in this paper). The open end of the shock-tube test section discharges into an observation chamber where photographs of the emerging flow are taken. Calculations were performed with the Benedict-Webb-Rubin, van der Waals and other equations of state. Numerical (finite-difference) predictions of the flow were made for single-phase and two-phase flows: solutions were tested against the experimental shock diffraction and vortex data of Skews. The phase-change properties of the test fluid can be quantified by the 'retrogradicity' r(T), measuring the difference in slope between the P, T isentrope and the vapour-pressure curve, and the 'kink' k(T), measuring the difference between the single-phase and mixture sound speeds. Mixture-evaporation (i.e. rerefaction) shocks appear to have a sonic-sonic or double Chapman-Jouguet structure and show agreement with amplitude predictions based on k(T). Liquefaction shocks are found to show a reproducible transition from regular, smooth shock fronts to irregular, chaotic shock fronts with increasing shock Mach number. This transition can be correlated with published stability limits.

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

    SciTech Connect

    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.

  19. Thermal transport in shock wave–compressed solids using pulsed laser heating

    SciTech Connect

    La Lone, B. M. Capelle, G.; Stevens, G. D.; Turley, W. D.; Veeser, L. R.

    2014-07-15

    A pulsed laser heating method was developed for determining thermal transport properties of solids under shock-wave compression. While the solid is compressed, a laser deposits a known amount of heat onto the sample surface, which is held in the shocked state by a transparent window. The heat from the laser briefly elevates the surface temperature and then diffuses into the interior via one-dimensional heat conduction. The thermal effusivity is determined from the time history of the resulting surface temperature pulse, which is recorded with optical pyrometry. Thermal effusivity is the square root of the product of thermal conductivity and volumetric heat capacity and is the key thermal transport parameter for relating the surface temperature to the interior temperature of the sample in a dynamic compression experiment. Therefore, this method provides information that is needed to determine the thermodynamic state of the interior of a compressed metal sample from a temperature measurement at the surface. The laser heat method was successfully demonstrated on tin that was shock compressed with explosives to a stress and temperature of ∼25 GPa and ∼1300 K. In this state, tin was observed to have a thermal effusivity of close to twice its ambient value. The implications on determining the interior shock wave temperature of tin are discussed.

  20. Thermal transport in shock wave-compressed solids using pulsed laser heating.

    PubMed

    La Lone, B M; Capelle, G; Stevens, G D; Turley, W D; Veeser, L R

    2014-07-01

    A pulsed laser heating method was developed for determining thermal transport properties of solids under shock-wave compression. While the solid is compressed, a laser deposits a known amount of heat onto the sample surface, which is held in the shocked state by a transparent window. The heat from the laser briefly elevates the surface temperature and then diffuses into the interior via one-dimensional heat conduction. The thermal effusivity is determined from the time history of the resulting surface temperature pulse, which is recorded with optical pyrometry. Thermal effusivity is the square root of the product of thermal conductivity and volumetric heat capacity and is the key thermal transport parameter for relating the surface temperature to the interior temperature of the sample in a dynamic compression experiment. Therefore, this method provides information that is needed to determine the thermodynamic state of the interior of a compressed metal sample from a temperature measurement at the surface. The laser heat method was successfully demonstrated on tin that was shock compressed with explosives to a stress and temperature of ~25 GPa and ~1300 K. In this state, tin was observed to have a thermal effusivity of close to twice its ambient value. The implications on determining the interior shock wave temperature of tin are discussed.

  1. The dissociation of shock-heated carbon monoxide

    NASA Technical Reports Server (NTRS)

    Hanson, R. K.

    1973-01-01

    Investigation of the dissociation kinetics of undiluted carbon monoxide over the 5,600 to 12,000 K temperature range. Data are presented that have been obtained as time-resolved pressure measurements on the end wall of a shock tube and radiation emission of a C2 Swan system (0-0 band) behind incident shock waves. The decomposition of CO is complex and includes a chain with C2 as an intermediate species. The dissociation rate for the overall process has been found to be independent of the proportions of the collision partners M = CO, C, and O. The rate constant found is on the average about 10 times that previously measured with argon as the collision partner.

  2. Heat flux and shock shape measurements on an Aeroassist Flight Experiment model in a high enthalpy free piston shock tunnel

    NASA Technical Reports Server (NTRS)

    Gai, S. L.; Mudford, N. R.; Hackett, C.

    1992-01-01

    This paper describes measurements of heat flux and shock shapes made on a 2.08 percent scale model of the proposed Aeroassist Flight Experiment model in a high enthalpy free piston shock tunnel T3 at the Australian National University in Canberra, Australia. The enthalpy and Reynolds number range covered were 7.5 MJ/kg to 20 MJ/kg and 150,000 to 270,000 per meter respectively. The test Mach number varied between 7.5 and 8. Two test gases, air and nitrogen, were used and the model angle of attack varied from -10 deg to +10 deg to the free stream. The results are discussed and compared to the Mach 10 cold hypersonic air data as obtained in the Langley 31 inch Mach 10 Facility as well as the perfect gas CFD calculations of NASA LaRC.

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

    PubMed

    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

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

    PubMed

    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

  5. Transportable, Chemical Genetic Methodology for the Small Molecule-Mediated Inhibition of Heat Shock Factor 1.

    PubMed

    Moore, Christopher L; Dewal, Mahender B; Nekongo, Emmanuel E; Santiago, Sebasthian; Lu, Nancy B; Levine, Stuart S; Shoulders, Matthew D

    2016-01-15

    Proteostasis in the cytosol is governed by the heat shock response. The master regulator of the heat shock response, heat shock factor 1 (HSF1), and key chaperones whose levels are HSF1-regulated have emerged as high-profile targets for therapeutic applications ranging from protein misfolding-related disorders to cancer. Nonetheless, a generally applicable methodology to selectively and potently inhibit endogenous HSF1 in a small molecule-dependent manner in disease model systems remains elusive. Also problematic, the administration of even highly selective chaperone inhibitors often has the side effect of activating HSF1 and thereby inducing a compensatory heat shock response. Herein, we report a ligand-regulatable, dominant negative version of HSF1 that addresses these issues. Our approach, which required engineering a new dominant negative HSF1 variant, permits dosable inhibition of endogenous HSF1 with a selective small molecule in cell-based model systems of interest. The methodology allows us to uncouple the pleiotropic effects of chaperone inhibitors and environmental toxins from the concomitantly induced compensatory heat shock response. Integration of our method with techniques to activate HSF1 enables the creation of cell lines in which the cytosolic proteostasis network can be up- or down-regulated by orthogonal small molecules. Selective, small molecule-mediated inhibition of HSF1 has distinctive implications for the proteostasis of both chaperone-dependent globular proteins and aggregation-prone intrinsically disordered proteins. Altogether, this work provides critical methods for continued exploration of the biological roles of HSF1 and the therapeutic potential of heat shock response modulation.

  6. Overexpression of the HspL Promotes Agrobacterium tumefaciens Virulence in Arabidopsis Under Heat Shock Conditions.

    PubMed

    Hwang, Hau-Hsuan; Liu, Yin-Tzu; Huang, Si-Chi; Tung, Chin-Yi; Huang, Fan-Chen; Tsai, Yun-Long; Cheng, Tun-Fang; Lai, Erh-Min

    2015-02-01

    Agrobacterium tumefaciens transfers a specific DNA fragment from the resident tumor-inducing (Ti) plasmid and effector virulence (Vir) proteins to plant cells during infection. A. tumefaciens VirB1-11 and VirD4 proteins assemble as the type IV secretion system (T4SS), which mediates transfer of the T-DNA and effector Vir protein into plant cells, thus resulting in crown gall disease in plants. Previous studies revealed that an α-crystallin-type, small heat-shock protein (HspL) is a more effective VirB8 chaperone than three other small heat-shock proteins (HspC, HspAT1, and HspAT2). Additionally, HspL contributes to efficient T4SS-mediated DNA transfer and tumorigenesis under room-temperature growth. In this study, we aimed to characterize the impact of HspL on Agrobacterium-mediated transformation efficiency under heat-shock treatment. During heat shock, transient transformation efficiency and VirB8 protein accumulation were lower in the hspL deletion mutant than in the wild type. Overexpression of HspL in A. tumefaciens enhanced the transient transformation efficiency in root explants of both susceptible and recalcitrant Arabidopsis ecotypes. In addition, the reduced transient transformation efficiency during heat stress was recovered by overexpression of HspL in A. tumefaciens. HspL may help maintain VirB8 homeostasis and elevate Agrobacterium-mediated transformation efficiency under both heat-shock and nonheat-shock growth. PMID:25163013

  7. Small heat shock proteins in redox metabolism: implications for cardiovascular diseases.

    PubMed

    Christians, Elisabeth S; Ishiwata, Takahiro; Benjamin, Ivor J

    2012-10-01

    A timely review series on small heat shock proteins has to appropriately examine their fundamental properties and implications in the cardiovascular system since several members of this chaperone family exhibit robust expression in the myocardium and blood vessels. Due to energetic and metabolic demands, the cardiovascular system maintains a high mitochondrial activity but irreversible oxidative damage might ensue from increased production of reactive oxygen species. How equilibrium between their production and scavenging is achieved becomes paramount for physiological maintenance. For example, heat shock protein B1 (HSPB1) is implicated in maintaining this equilibrium or redox homeostasis by upholding the level of glutathione, a major redox mediator. Studies of gain or loss of function achieved by genetic manipulations have been highly informative for understanding the roles of those proteins. For example, genetic deficiency of several small heat shock proteins such as HSPB5 and HSPB2 is well-tolerated in heart cells whereas a single missense mutation causes human pathology. Such evidence highlights both the profound genetic redundancy observed among the multigene family of small heat shock proteins while underscoring the role proteotoxicity plays in driving disease pathogenesis. We will discuss the available data on small heat shock proteins in the cardiovascular system, redox metabolism and human diseases. From the medical perspective, we envision that such emerging knowledge of the multiple roles small heat shock proteins exert in the cardiovascular system will undoubtedly open new avenues for their identification and possible therapeutic targeting in humans. This article is part of a Directed Issue entitled: Small HSPs in physiology and pathology.

  8. Development of a heat-shock inducible gene expression system in the red alga Cyanidioschyzon merolae.

    PubMed

    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

  9. Heat shock decreases the embryonic quality of frozen-thawed bovine blastocysts produced in vitro.

    PubMed

    Mori, Miyuki; Hayashi, Takeshi; Isozaki, Yoshihiro; Takenouchi, Naoki; Sakatani, Miki

    2015-01-01

    In this study, the effect of heat shock on frozen-thawed blastocysts was evaluated using in vitro-produced (IVP) bovine embryos. In experiment 1, the effects of 6 h of heat shock at 41.0 C on fresh blastocysts were evaluated. HSPA1A expression as a reflection of stress was increased by heat shock (P < 0.05), but the expressions of the quality markers IFNT and POU5F1 were not affected. In experiment 2, frozen-thawed blastocysts were incubated at 38.5 C for 6 h (cryo-con) or exposed to heat shock at 41.0 C for 6 h (cryo-HS). Then, blastocysts were cultured at 38.5 C until 48 h after thawing (both conditions). Cryo-HS blastocysts exhibited a decreased recovery rate: HSPA1A expression was dramatically increased compared with that in fresh or cryo-con blastocysts at 6 h, and IFNT expression was decreased compared with that in cryo-con blastocysts at 6 h (both P < 0.05). Cryo-con blastocysts at 6 h also exhibited higher HSPA1A expression than fresh blastocysts (P < 0.05). At 48 h after thawing, the number of hatched blastocysts and blastocyst diameter were lower in cryo-HS blastocysts (P < 0.05). Cryo-con blastocysts showed lower POU5F1 levels at 48 h than fresh, cryo-con or cryo-HS blastocysts at 6 h (P < 0.05), but their POU5F1 levels were not different from those of cryo-HS blastocysts at 48 h. These results indicated that application of heat shock to frozen-thawed blastocysts was highly damaging. The increase in damage by the interaction of freezing-thawing and heat shock might be one reason for the low conception rate in frozen-thawed embryo transfer in summer.

  10. Development of a heat-shock inducible gene expression system in the red alga Cyanidioschyzon merolae.

    PubMed

    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.

  11. Overexpression of the HspL Promotes Agrobacterium tumefaciens Virulence in Arabidopsis Under Heat Shock Conditions.

    PubMed

    Hwang, Hau-Hsuan; Liu, Yin-Tzu; Huang, Si-Chi; Tung, Chin-Yi; Huang, Fan-Chen; Tsai, Yun-Long; Cheng, Tun-Fang; Lai, Erh-Min

    2015-02-01

    Agrobacterium tumefaciens transfers a specific DNA fragment from the resident tumor-inducing (Ti) plasmid and effector virulence (Vir) proteins to plant cells during infection. A. tumefaciens VirB1-11 and VirD4 proteins assemble as the type IV secretion system (T4SS), which mediates transfer of the T-DNA and effector Vir protein into plant cells, thus resulting in crown gall disease in plants. Previous studies revealed that an α-crystallin-type, small heat-shock protein (HspL) is a more effective VirB8 chaperone than three other small heat-shock proteins (HspC, HspAT1, and HspAT2). Additionally, HspL contributes to efficient T4SS-mediated DNA transfer and tumorigenesis under room-temperature growth. In this study, we aimed to characterize the impact of HspL on Agrobacterium-mediated transformation efficiency under heat-shock treatment. During heat shock, transient transformation efficiency and VirB8 protein accumulation were lower in the hspL deletion mutant than in the wild type. Overexpression of HspL in A. tumefaciens enhanced the transient transformation efficiency in root explants of both susceptible and recalcitrant Arabidopsis ecotypes. In addition, the reduced transient transformation efficiency during heat stress was recovered by overexpression of HspL in A. tumefaciens. HspL may help maintain VirB8 homeostasis and elevate Agrobacterium-mediated transformation efficiency under both heat-shock and nonheat-shock growth.

  12. Heat-transfer measurements and computations of swept-shock-wave boundary-layer interactions

    NASA Technical Reports Server (NTRS)

    Lee, Y.; Settles, G. S.; Horstman, C. C.

    1994-01-01

    An experimental and computational research program providing new knowledge of the heat transfer in swept-shock-wave/boundary-layer interactions is described. An equilibrium turbulent boundary layer on a flat plate is subjected to impingement by a swept planar shock wave generated by a sharp fin. Five different interactions with fin angles ranging from 10 to 20 deg at freestream Mach numbers of 3 and 4 produce a variety of interaction strengths ranging from weak to very strong. A foil heater generates a uniform heat flux over the flat plate surface, and miniature thin-film-resistance sensors are used to measure the local surface temperature. The heat convection equation is then solved for the heat transfer distribution within an interaction, yielding an uncertainty of about +/- 10%. These data are compared with numerical Navier-Stokes solutions that employ a k-epsilon turbulence model. A simple peak heat transfer correlation for fin interactions is suggested.

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

    PubMed

    Yang, Sheng; Laumonier, Thomas; Menetrey, Jacques

    2007-08-01

    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 degrees C 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

  14. Nitric oxide induces heat-shock protein 70 expression in vascular smooth muscle cells via activation of heat shock factor 1.

    PubMed Central

    Xu, Q; Hu, Y; Kleindienst, R; Wick, G

    1997-01-01

    Current data suggest that nitric oxide (NO) is a double-edged sword that could result in relaxation and/or cytotoxicity of vascular smooth muscle cells (SMCs) via cGMP- dependent or -independent signal pathways. Stress or heat shock proteins (hsps) have been shown to be augmented in arterial SMCs during acute hypertension and atherosclerosis, both conditions that are believed to correlate with disturbed NO production. In the present study, we demonstrate that NO generated from sodium nitroprusside (SNP), S-nitroso-N-acetylpenicillamine, and spermine/nitric oxide complex leads to hsp70 induction in cultured SMCs. Western blot analysis demonstrated that hsp70 protein expression peaked between 6 and 12 h after treatment with SNP, and elevated protein levels were preceded by induction of hsp70 mRNA within 3 h. Induction of hsp70 mRNA was associated with the activation of heat shock transcription factor 1 (HSF1), suggesting that the response was regulated at the transcriptional level. HSF1 activation was completely blocked by hemoglobin, dithiothreitol, and cycloheximide, suggesting that the protein damage and nascent polypeptide formation induced by NO may initiate this activation. Furthermore, SMCs pretreated with heat shock (42 degrees C) for 30 min were significantly protected from death induced by NO. Thus, we provide evidence that NO induces hsp70 expression in SMCs via HSF1 activation. Induction of hsp70 could be important in protecting SMCs from injury resulting from NO stimulation. PMID:9276725

  15. Sequence and expression of the mRNA encoding HSP22, the mitochondrial small heat-shock protein in pea leaves.

    PubMed Central

    Lenne, C; Block, M A; Garin, J; Douce, R

    1995-01-01

    A 3 h treatment at 40 degrees C of pea (Pisum sativum var. Douce Provence) plants induces production and accumulation of a small heat-shock protein of 22 kDa apparent molecular mass, designated HSP22, in the matrix compartment of mitochondria [Lenne and Douce (1994) Plant Physiol. 105, 1255-1261]. We show here that the HSP22 precursor (i.e. the mature protein plus the transit peptide) has an apparent molecular mass of 26 kDa after in vitro translation of mRNA extracted from heat-stressed pea plants and immunodetection. We have isolated, cloned and sequenced the full-length cDNA encoding the precursor of the mitochondrial HSP22. An analysis of the amino acid sequence of the mitochondrial HSP22 reveals that this protein is a representative member of the low-molecular-mass heat shock protein (HSP) superfamily, exhibiting the specific consensus regions that are typical of the small HSPs. Most importantly, comparison of the mitochondrial HSP22 sequence with that of chloroplast small HSPs indicates that HSP22 does not contain the typical chloroplast consensus region III. We have also analysed the kinetics of HSP22 induction, and report results on the temporal expression of HSP22 at the transcriptional level. HSP22 mRNA was detected as soon as 10 min after the temperature was raised to a high temperature of 40 degrees C. Then the amount of HSP22 mRNA declined considerably even though pea plants were still submitted to the heat treatment. These results are discussed in light of the translation data previously published [Lenne and Douce (1994) Plant Physiol. 105, 1255-1261], particularly concerning the physiological behaviour of mitochondria when plants are heat-stressed. Furthermore, we have studied the dependence of HSP22 accumulation with temperature and demonstrate that the pea mitochondrial heat-shock response is only developed under extreme environmental growth conditions. Images Figure 2 Figure 3 Figure 7 Figure 8 PMID:7487935

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

    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.

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

    PubMed

    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. PMID:27065102

  19. Recombinant HSP70 and mild heat shock stimulate growth of aged mesenchymal stem cells.

    PubMed

    Andreeva, N V; Zatsepina, O G; Garbuz, D G; Evgen'ev, M B; Belyavsky, A V

    2016-07-01

    Heat shock proteins including the major stress protein HSP70 support intracellular homeostasis and prevent protein damage after a temperature increase and other stressful environmental stimuli, as well as during aging. We have shown earlier that prolonged administration of recombinant human HSP70 to mice exhibiting Alzheimer's-like neurodegeneration as well as during sepsis reduces the clinical manifestations of these pathologies. Herein, we studied the action of recombinant human HSP70 on young and aged mouse mesenchymal stem cells (MSCs) in culture. The results obtained indicate that HSP70 at concentrations of 2 μg/ml and higher significantly stimulates growth of aged but not young MSCs. A similar effect is produced by application of a mild heat shock (42 °C 5 min) to the cells. Importantly, responses of young and aged MSCs to heat shock treatment of various durations differed drastically, and aged MSCs were significantly more sensitive to higher heat stress exposures than the young cells. Western blotting and protein labeling experiments demonstrated that neither mild heat shock nor exogenous HSP70 administration resulted in significant endogenous HSP70 induction in young and aged MSCs, whereas mild heat shock increased HSC70 levels in aged MSCs. The results of this study suggest that the administration of exogenous HSP70 and the application of mild heat stress may produce a certain "rejuvenating" effect on MSCs and possibly other cell types in vivo, and these interventions may potentially be used for life extension by delaying various manifestations of aging at the molecular and cellular level. PMID:27091568

  20. Phylogeny disambiguates the evolution of heat-shock cis-regulatory elements in Drosophila.

    PubMed

    Tian, Sibo; Haney, Robert A; Feder, Martin E

    2010-01-01

    Heat-shock genes have a well-studied control mechanism for their expression that is mediated through cis-regulatory motifs known as heat-shock elements (HSEs). The evolution of important features of this control mechanism has not been investigated in detail, however. Here we exploit the genome sequencing of multiple Drosophila species, combined with a wealth of available information on the structure and function of HSEs in D. melanogaster, to undertake this investigation. We find that in single-copy heat shock genes, entire HSEs have evolved or disappeared 14 times, and the phylogenetic approach bounds the timing and direction of these evolutionary events in relation to speciation. In contrast, in the multi-copy gene Hsp70, the number of HSEs is nearly constant across species. HSEs evolve in size, position, and sequence within heat-shock promoters. In turn, functional significance of certain features is implicated by preservation despite this evolutionary change; these features include tail-to-tail arrangements of HSEs, gapped HSEs, and the presence or absence of entire HSEs. The variation among Drosophila species indicates that the cis-regulatory encoding of responsiveness to heat and other stresses is diverse. The broad dimensions of variation uncovered are particularly important as they suggest a substantial challenge for functional studies.

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

    PubMed

    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.

  2. OLA1 protects cells in heat shock by stabilizing HSP70

    PubMed Central

    Mao, R-F; Rubio, V; Chen, H; Bai, L; Mansour, O C; Shi, Z-Z

    2013-01-01

    The heat-shock response is an evolutionarily conserved cellular defense mechanism against environmental stresses, characterized by the rapid synthesis of heat-shock proteins (HSPs). HSP70, a highly inducible molecular chaperone, assists in refolding or clearance of damaged proteins, thereby having a central role in maintaining intracellular homeostasis and thermotolerance. To date, induction of HSP70 expression has been described extensively at the transcriptional level. However, post-translational regulation of HSP70, such as protein stability, is only partially understood. In this study, we investigated the role of OLA1 (Obg-like ATPase 1), a previously uncharacterized cytosolic ATPase, in regulating the turnover of HSP70. Downregulation of OLA1 in mammalian cells by either RNAi or targeted gene disruption results in reduced steady-state levels of HSP70, impaired HSP70 induction by heat, and functionally, increased cellular sensitivity to heat shock. Conversely, overexpression of OLA1 correlates with elevated HSP70 protein levels and improved thermal resistance. Protein–protein interaction assays demonstrated that binding of OLA1 to the HSP70 carboxyl terminus variable domain hinders the recruitment of CHIP (C-terminus of Hsp70-binding protein), an E3 ubiquitin ligase for HSP70, and thus prevents HSP70 from the CHIP-mediated ubiquitination. These findings suggest a novel molecular mechanism by which OLA1 stabilizes HSP70, leading to upregulation of HSP70 as well as increased survival during heat shock. PMID:23412384

  3. Absolute protein quantification of the yeast chaperome under conditions of heat shock

    PubMed Central

    Mackenzie, Rebecca J.; Lawless, Craig; Holman, Stephen W.; Lanthaler, Karin; Beynon, Robert J.; Grant, Chris M.; Hubbard, Simon J.

    2016-01-01

    Chaperones are fundamental to regulating the heat shock response, mediating protein recovery from thermal‐induced misfolding and aggregation. Using the QconCAT strategy and selected reaction monitoring (SRM) for absolute protein quantification, we have determined copy per cell values for 49 key chaperones in Saccharomyces cerevisiae under conditions of normal growth and heat shock. This work extends a previous chemostat quantification study by including up to five Q‐peptides per protein to improve confidence in protein quantification. In contrast to the global proteome profile of S. cerevisiae in response to heat shock, which remains largely unchanged as determined by label‐free quantification, many of the chaperones are upregulated with an average two‐fold increase in protein abundance. Interestingly, eight of the significantly upregulated chaperones are direct gene targets of heat shock transcription factor‐1. By performing absolute quantification of chaperones under heat stress for the first time, we were able to evaluate the individual protein‐level response. Furthermore, this SRM data was used to calibrate label‐free quantification values for the proteome in absolute terms, thus improving relative quantification between the two conditions. This study significantly enhances the largely transcriptomic data available in the field and illustrates a more nuanced response at the protein level. PMID:27252046

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

    PubMed

    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. PMID:20866140

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

    PubMed

    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.

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

    PubMed Central

    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

  7. Heat shock protein 60 enhances CD4+ CD25+ regulatory T cell function via innate TLR2 signaling.

    PubMed

    Zanin-Zhorov, Alexandra; Cahalon, Liora; Tal, Guy; Margalit, Raanan; Lider, Ofer; Cohen, Irun R

    2006-07-01

    CD4+CD25+ Tregs regulate immunity, but little is known about their own regulation. We now report that the human 60-kDa heat shock protein (HSP60) acts as a costimulator of human Tregs, both CD4+CD25int and CD4+CD25hi. Treatment of Tregs with HSP60, or its peptide p277, before anti-CD3 activation significantly enhanced the ability of relatively low concentrations of the Tregs to downregulate CD4+CD25- or CD8+ target T cells, detected as inhibition of target T cell proliferation and IFN-gamma and TNF-alpha secretion. The enhancing effects of HSP60 costimulation on Tregs involved innate signaling via TLR2, led to activation of PKC, PI3K, and p38, and were further enhanced by inhibition of ERK. HSP60-treated Tregs suppressed target T cells both by cell-to-cell contact and by secretion of TGF-beta and IL-10. In addition, the expression of ERK, NF-kappaB, and T-bet by downregulated target T cells was inhibited. Thus, HSP60, a self-molecule, can downregulate adaptive immune responses by upregulating Tregs innately through TLR2 signaling. PMID:16767222

  8. Metallothioneins and heat shock proteins 70 in marine mussels as sensors of environmental pollution in Northern Adriatic Sea.

    PubMed

    Mićović, Vladimir; Bulog, Aleksandar; Kučić, Natalia; Jakovac, Hrvoje; Radošević-Stašić, Biserka

    2009-11-01

    In an attempt to assess the intensity of environmental pollution in industrial zones of Kvarnerian Bay in Northern Adriatic Sea and the reactivity of Mytilus galloprovincialis to these changes, in this study we estimated the concentration of heavy metals at four locations in both sea-sediment and in the mussels. Further we tried to correlate these changes with seasonal variations in environmental temperature, pH and salinity, as well as with the expression of metallothioneins (MTs) and heat shock proteins (HSPs) in the digestive tract of the mussels. Sampling in vivo was performed monthly, during the year 2008, while under the laboratory conditions the reactivity of acclimated mussels were tested to increasing concentrations of CdCl(2) and to thermal stress. The data have shown that the induction of MTs and HSP isoforms of the 70-kDa size class were highly affected by model agents treatment including contamination of sea-sediment by Pb, Hg and Cd, implying that these stress proteins might be power biomarkers of marine pollution.

  9. Molecular cloning and expression analysis of heat shock protein 20 (HSP20) from the pearl oyster Pinctada martensii.

    PubMed

    Lei, Q N; Wu, Y Y; Liang, H Y; Wang, Z X; Zheng, Z; Deng, Y W

    2016-01-01

    Small heat shock proteins (HSPs) are molecular chaperones with ATP-independent properties. They are involved in a variety of physiological and stress processes. In this study, the full-length HSP 20 (HSP20) from Pinctada martensii, designated as PmHSP20, was obtained from hemocytes using rapid amplification of cDNA ends technology. The PmHSP20 cDNA was 952 bp in length, containing an open reading frame of 534 bp that encoded 177-amino acid residues, with an isoelectric point of 5.86 and molecular weight of 20.24 kDa. The sequence of this deduced polypeptide contained typical structure and function domains conserved in the HSP20 family, providing evidence that PmHSP20 belongs to the HSP20 family. The PmHSP20 mRNA expression levels were detected in various tissues of P. martensii and in hemocytes after challenges with the bacteria Vibrio harveyi and lipopolysaccharide (LPS) using quantitative real-time polymerase chain reaction amplification. The results indicated that PmHSP20 is constitutively expressed in all tissues tested and might be involved in the immune response. The upregulation of PmHSP20 after V. harveyi and LPS challenge suggests that PmHSP20 plays an important role in anti-bacterial immunity. Studies on PmHSP20 are a valuable resource to further explore the immune system in pearl oysters and might enhance our knowledge of molluscan innate immunity. PMID:27420982

  10. Genome-Wide Analysis of the Yeast Transcriptome Upon Heat and Cold Shock

    PubMed Central

    Becerra, M.; Lombardía, L. J.; González-Siso, M. I.; Rodríguez-Belmonte, E.; Hauser, N. C.

    2003-01-01

    DNA arrays were used to measure changes in transcript levels as yeast cells responded to temperature shocks. The number of genes upregulated by temperature shifts from 30 ℃ to 37℃ or 45℃ was correlated with the severity of the stress. Pre-adaptation of cells, by growth at 37 ℃ previous to the 45℃ shift, caused a decrease in the number of genes related to this response. Heat shock also caused downregulation of a set of genes related to metabolism, cell growth and division, transcription, ribosomal proteins, protein synthesis and destination. Probably all of these responses combine to slow down cell growth and division during heat shock, thus saving energy for cell rescue. The presence of putative binding sites for Xbp1p in the promoters of these genes suggests a hypothetical role for this transcriptional repressor, although other mechanisms may be considered. The response to cold shock (4℃) affected a small number of genes, but the vast majority of those genes induced by exposure to 4 ℃ were also induced during heat shock; these genes share in their promoters cis-regulatory elements previously related to other stress responses. PMID:18629074

  11. Shock heated dust in L1551: L(IR) greater than 20 solar luminosities

    NASA Technical Reports Server (NTRS)

    Clark, F. O.; Laureijs, R. J.; Chlewicki, G.; Zhang, C. Y.; Vanoosterom, W.; Kester, D.

    1987-01-01

    The infrared bolometric luminosity of the extended emission from the L1551 flow exceeds 20 solar luminosities. Ultraviolet radiation from the shock associated with the flow appears to heat the dust requiring shock temperatures from 10,000 to 90,000 K in L1551, velocities of approximately 50 km/s near the end of the flow, and a minimum mechanical luminosity of approximately 40 solar luminosities. The total energy requirement of the infrared emission over a 10,000 year lifetime is 10 to the 46th to 47th ergs, two orders of magnitude higher than previous estimates for L1551. Infrared radiation offers a method of probing interstellar shocks, by sampling the untraviolet halo surrounding the shock. At least one current model for bipolar flows is capable of meeting the energetic requirements.

  12. Heating of Sunspot Chromospheres by Slow-mode Acoustic Shock Waves

    NASA Astrophysics Data System (ADS)

    Lee, Myung Gyoon; Yun, Hong Sik

    1985-06-01

    Making use of the arbitrary shock theory developed by Ulmschneider (1967, 1971) and Ulmscneider and Kalkofen (1978), we have calculated the dissipation rates of upward-traveling slow-mode acoustic shock waves in umbral chromospheres for two umbral chromosphere models, a plateau model by Avrett (1981) and a gradient model by Yun and Beebe (1984). The computed shock dissipation rates are compared with the radiative cooling rate given by Avrett(1981). The results show that the slow-mode acoustic shock waves with a period of about 20 seconds can heat the low umbral chromospheres traveling with a mechanical energy flux of 2.6*10^6 erg/cm^2s at a height of 300-400 km above the temperature minimum region.

  13. Interference heating due to shock wave impingement on laminar boundary layers.

    NASA Technical Reports Server (NTRS)

    Hung, F. T.

    1973-01-01

    Laminar interference heating correlations have been developed based on recent experimental data obtained with wedge/flat plate models for wide ranges of Reynolds number and shock strength. Two correlation techniques were developed using the Eckert reference method. The peak interference Stanton number was first correlated with shock strength, Reynolds number, and Prandtl number based on flow conditions upstream of the interference region. The second approach was made by correlating peak interference Stanton number with only Reynolds number and Prandtl number based on downstream flow conditions. The laminar boundary layer remains laminar when both Reynolds number and shock strength are low but becomes transitional or turbulent when Reynolds number or/and shock strength are increased.

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

    PubMed

    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.

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

    PubMed Central

    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. PMID:24621956

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

    EPA Science Inventory

    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...

  17. EFFECT OF EXPOSURE PROTOCOL AND HEAT SHOCK PROTEIN EXPRESSION ON ARSENITE INDUCED GENOTOXICITY IN MCF-7 BREAST CANCER CELLS

    EPA Science Inventory


    Effect of exposure protocol and heat shock protein expression on arsenite induced genotoxicity in MCF-7 breast cancer cells

    The genotoxic effects of arsenic (As) are well accepted, yet its mechanism of action is not clearly defined. Heat-shock proteins (HSPs) protect...

  18. Heat shock pretreatment may protect against heatstroke-induced circulatory shock and cerebral ischemia by reducing oxidative stress and energy depletion.

    PubMed

    Wang, Jui-Ling; Ke, Der-Shin; Lin, Mao-Tsun

    2005-02-01

    The mechanisms underlying the protective effects of heat shock pretreatment on heatstroke remain unclear. Here we attempted to ascertain whether the possible occurrence of oxidative stress and energy depletion exhibited during heatstroke can be reduced by heat shock preconditioning. In the present study, colonic temperature, mean arterial pressure, heart rate, striatal levels of heat shock protein 72 (HSP72), local Po2, brain temperature, cerebral blood flow, cellular ischemia and damage markers, dihydroxybenzoic acid (DHBA), lipid peroxidation, glutathione, glutathione peroxidase and reductase activities, and ATP were assayed in normothermic control rats and in heatstroke rats with or without preconditioning 16 or 96 h before initiation of heatstroke. Heatstroke was induced by exposing the anesthetized rats to a high ambient temperature (Ta = 43 degrees C) until the moment at which MAP decreased from its peak level. Sublethal heat shock pretreatment 16 h before initiation of heatstroke, in addition to increasing striatal HSP72 levels, conferred significant protection against heatstroke-induced arterial hypotension, striatal ischemia and damage, increment of hydroxyl radical formation, lipid peroxidation, glutathione oxidation, and decrement of glutathione peroxidase activity and ATP. However, at 96 h after heat shock, when striatal HSP72 expression returned to basal levels, the above responses that occurred during onset of heatstroke were indistinguishable between the two groups. These results suggest that heat shock pretreatment induces HSP72 overexpression in striatum and confers protection against heatstroke-induced striatal ischemia and damage by reducing oxidative stress and energy depletion.

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

    PubMed

    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.

  20. Uncertainty quantification of bacterial aerosol neutralization in shock heated gases

    NASA Astrophysics Data System (ADS)

    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

  1. Effects of heat shock protein 90 expression on pectoralis major oxidation in broilers exposed to acute heat stress.

    PubMed

    Hao, Y; Gu, X H

    2014-11-01

    This study was conducted to determine the effects of heat shock protein 90 (HSP90) expression on pH, lipid peroxidation, heat shock protein 70 (HSP70), and glucocorticoid receptor (GR) expression of pectoralis major in broilers exposed to acute heat stress. In total, 90 male broilers were randomly allocated to 3 groups: control (CON), heat stress (HS), or geldanamycin treatment (GA). On d 41, the broilers in the GA group were injected intraperitoneally with GA (5 μg/kg of BW), and the broilers in the CON and HS groups were injected intraperitoneally with saline. Twenty-four hours later, the broilers in the CON group were moved to environmental chambers controlled at 22°C for 2 h, and the broilers in the HS and GA groups were moved to environmental chambers controlled at 40°C for 2 h. The pH values of the pectoralis major after 30 min and 24 h of chilling after slaughter of HS and GA broilers were significantly lower (P < 0.01) than those of the CON broilers. Heat stress caused significant increases in sera corticosterone and lactic dehydrogenase, the activity of malondialdehyde and superoxide dismutase, the expression of HSP90 and HSP70, and nuclear expression of GR protein in the pectoralis major (P < 0.05). Heat stress induced a significant decrease in GR protein expression in the cytoplasm and GR mRNA expression. Furthermore, the low expression of HSP90 significantly increased levels of lactic dehydrogenase and malondialdehyde and GR protein expression in the cytoplasm under heat stress (P < 0.01), and significantly decreased nuclear GR protein expression (P < 0.01). Heat shock protein 90 was positively correlated with corticosterone and superoxide dismutase activities (P < 0.01), and HSP90 mRNA was negatively correlated with pH after chilling for 24 h. The results demonstrated that HSP90 plays a pivotal role in protecting cells from oxidation.

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

    PubMed

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

    2013-05-24

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

  3. CHEMOSENSITIZATION BY A NON-APOPTOGENIC HEAT SHOCK PROTEIN 70-BINDING APOPTOSIS INDUCING FACTOR MUTANT

    EPA Science Inventory

    Chemosensitization by a non-apoptogenic heat shock protein 70-binding apoptosis inducing factor mutant

    Abstract
    HSP70 inhibits apoptosis by neutralizing the caspase activator Apaf-1 and by interacting with apoptosis inducing factor (AIF), a mitochondrial flavoprotein wh...

  4. Complexity and Genetic Variability of Heat-Shock Protein Expression in Isolated Maize Microspores.

    PubMed Central

    Magnard, J. L.; Vergne, P.; Dumas, C.

    1996-01-01

    The expression of heat-shock proteins (HSPs) in isolated maize (Zea mays L.) microspores has been investigated using high-resolution two-dimensional electrophoresis coupled to immunodetection and fluorography of in vivo synthesized proteins. To this end, homogeneous and viable populations of microspores have been purified in sufficient amounts for molecular analysis from plants grown in controlled conditions. Appropriate conditions for thermal stress application have been defined. The analysis revealed that isolated microspores from maize display a classical heat-shock response characterized by the repression of the normal protein synthesis and the expression of a set of HSPs. A high complexity of the response was demonstrated, with numerous different HSPs being resolved in each known major HSP molecular weight class. However, the extent of this heat-shock response is limited in that some of these HSPs do not accumulate at high levels following temperature elevation. Comparative analysis of the heat-shock responses of microspores isolated from five genotypes demonstrated high levels of genetic variability. Furthermore, many HSPs were detected in microspores at control temperature, indicating a possible involvement of these proteins in pollen development at stages close to first pollen mitosis. PMID:12226349

  5. Effect of heat shock pretreatment on apoptosis and metallothionein expression in rat cardiomyocytes

    PubMed Central

    Zhang, Xian; Sha, Ming-Lei; Yao, Yu-Ting; Da, Jia; Ni, Xiu-Shi

    2015-01-01

    To investigate the effect of heat shock pretreatment on apoptosis and mitochondrial metallothionein (MT) expression in rat cardiomyocytes. In vitro cultured H9C2 cells were randomly divided into three groups: control, hydrogen peroxide (H2O2) injury, and H2O2 injury after heat shock pretreatment (n = 6 per group). Cardiomyocyte apoptosis and caspase-3 activity were assayed after treatment. Mitochondrial cytochrome (cyt) c and MT expression was assayed by Western blotting. Compared with the control group, the H2O2 injury group had a growing number of apoptotic cardiomyocytes (P < 0.01) and significantly elevated caspase-3 activity (P < 0.01) with markedly increased mitochondrial cyt c and MT expression (P < 0.01). After heat shock pretreatment, the numbers of apoptotic and necrotic cardiomyocytes (P < 0.01) and the caspase-3 activity significantly declined (P < 0.01), while mitochondrial cyt c and MT expression continued to increase (P < 0.01) compared with the H2O2 injury group. Heat shock pretreatment inhibits cardiomyocyte apoptosis, which may have a protective effect on cardiomyocytes by increasing the expression of myocardial protective MT and reducing the release of mitochondrial cyt c. PMID:26221315

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

    PubMed

    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.

  7. Interference heating from interactions of shock waves with turbulent boundary layers at Mach 6

    NASA Technical Reports Server (NTRS)

    Johnson, C. B.; Kaufman, L. G., II

    1974-01-01

    An experimental investigation of interference heating resulting from interactions of shock waves and turbulent boundary layers was conducted. Pressure and heat-transfer distributions were measured on a flat plate in the free stream and on the wall of the test section of the Langley Mach 6 high Reynolds number tunnel for Reynolds numbers ranging from 2 million to 400 million. Various incident shock strengths were obtained by varying a wedge-shock generator angle (from 10 deg to 15 deg) and by placing a spherical-shock generator at different vertical positions above the instrumented flat plate and tunnel wall. The largest heating-rate amplification factors obtained for completely turbulent boundary layers were 22.1 for the flat plate and 11.6 for the tunnel wall experiments. Maximum heating correlated with peak pressures using a power law with a 0.85 exponent. Measured pressure distributions were compared with those calculated using turbulent free-interaction pressure rise theories, and separation lengths were compared with values calculated by using different methods.

  8. Baculovirus replication induces the expression of heat shock proteins in vivo and in vitro

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A recent handful of studies have linked baculovirus infection with the induction of heat shock proteins, a highly conserved family of cytoprotective proteins. Here, we demonstrate baculovirus-stimulated upregulation of hsp70 transcription in the natural host, Helicoverpa zea. Larvae lethally infec...

  9. Response of a mouse hybridoma cell line to heat shock, agitation, and sparging

    NASA Technical Reports Server (NTRS)

    Passini, Cheryl A.; Goochee, Charles F.

    1989-01-01

    A mouse hybridoma cell line is used as a model system for studying the effect of environmental stress on attachment-independent mammalian cells. The full time course of recovery for a mouse hybridoma cell line from both a mild and intermediate heat shock is examined. The pattern of intracellular synthesis is compared for actively growing, log phase cells and nondividing, stationary phase cells.

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

    PubMed

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

    2016-09-01

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

  11. THE EFFECTS OF HEAT SHOCK PROTEIN 70 (HSP70) AND EXPOSURE PROTOCOL ON ARSENITE INDUCED GENOTOXICITY

    EPA Science Inventory

    The Effects of Heat Shock Protein 70 (Hsp70) and Exposure Protocol on Arsenite Induced Genotoxicity

    Barnes, J.A.1,2, Collins, B.W.2, Dix, D.J.3 and Allen J.W2.
    1National Research Council, 2Environmental Carcinogenesis Division, 3Reproductive Toxicology Division, Office...

  12. Complexity and Genetic Variability of Heat-Shock Protein Expression in Isolated Maize Microspores.

    PubMed

    Magnard, J. L.; Vergne, P.; Dumas, C.

    1996-08-01

    The expression of heat-shock proteins (HSPs) in isolated maize (Zea mays L.) microspores has been investigated using high-resolution two-dimensional electrophoresis coupled to immunodetection and fluorography of in vivo synthesized proteins. To this end, homogeneous and viable populations of microspores have been purified in sufficient amounts for molecular analysis from plants grown in controlled conditions. Appropriate conditions for thermal stress application have been defined. The analysis revealed that isolated microspores from maize display a classical heat-shock response characterized by the repression of the normal protein synthesis and the expression of a set of HSPs. A high complexity of the response was demonstrated, with numerous different HSPs being resolved in each known major HSP molecular weight class. However, the extent of this heat-shock response is limited in that some of these HSPs do not accumulate at high levels following temperature elevation. Comparative analysis of the heat-shock responses of microspores isolated from five genotypes demonstrated high levels of genetic variability. Furthermore, many HSPs were detected in microspores at control temperature, indicating a possible involvement of these proteins in pollen development at stages close to first pollen mitosis. PMID:12226349

  13. Heat shock inhibits lipopolysaccharide-induced tissue factor activity in human whole blood

    PubMed Central

    Sucker, Christoph; Zacharowski, Kai; Thielmann, Matthias; Hartmann, Matthias

    2007-01-01

    Background During gram-negative sepsis, lipopolysaccharide (LPS) induces tissue factor expression on monocytes. The resulting disseminated intravascular coagulation leads to tissue ischemia and worsens the prognosis of septic patients. There are indications, that fever reduces the mortality of sepsis, the effect on tissue factor activity on monocytes is unknown. Therefore, we investigated whether heat shock modulates LPS-induced tissue factor activity in human blood. Methods Whole blood samples and leukocyte suspensions, respectively, from healthy probands (n = 12) were incubated with LPS for 2 hours under heat shock conditions (43°C) or control conditions (37°C), respectively. Subsequent to further 3 hours of incubation at 37°C the clotting time, a measure of tissue factor expression, was determined. Cell integrity was verified by trypan blue exclusion test and FACS analysis. Results Incubation of whole blood samples with LPS for 5 hours at normothermia resulted in a significant shortening of clotting time from 357 ± 108 sec to 82 ± 8 sec compared to samples incubated without LPS (n = 12; p < 0.05). This LPS effect was mediated by tissue factor, as inhibition with active site-inhibited factor VIIa (ASIS) abolished the effect of LPS on clotting time. Blockade of protein synthesis using cycloheximide demonstrated that LPS exerted its procoagulatory effect via an induction of tissue factor expression. Upon heat shock treatment, the LPS effect was blunted: clotting times were 312 ± 66 s in absence of LPS and 277 ± 65 s in presence of LPS (n = 8; p > 0.05). Similarly, heat shock treatment of leukocyte suspensions abolished the LPS-induced tissue factor activity. Clotting time was 73 ± 31 s, when cells were treated with LPS (100 ng/mL) under normothermic conditions, and 301 ± 118 s, when treated with LPS (100 ng/mL) and heat shock (n = 8, p < 0.05). Control experiments excluded cell damage as a potential cause of the observed heat shock effect. Conclusion Heat

  14. Molecular cloning of the heat shock protein 20 gene from Paphia textile and its expression in response to heat shock

    NASA Astrophysics Data System (ADS)

    Li, Jiakai; Wu, Xiangwei; Tan, Jing; Zhao, Ruixiang; Deng, Lingwei; Liu, Xiande

    2015-07-01

    P. textile is an important aquaculture species in China and is mainly distributed in Fujian, Guangdong, and Guangxi Provinces. In this study, an HSP20 cDNA designated PtHSP20 was cloned from P. textile. The full-length cDNA of PtHSP20 is 1 090 bp long and contains a 5' untranslated region (UTR) of 93 bp, a 3' UTR of 475 bp, and an open reading frame (ORF) of 522 bp. The PtHSP20 cDNA encodes 173 amino acid residues and has a molecular mass of 20.22 kDa and an isoelectric point of 6.2. Its predicted amino acid sequence shows that PtHSP20 contains a typical α-crystallin domain (residues 77-171) and three polyadenylation signal-sequences at the C-terminus. According to an amino acid sequence alignment, PtHSP20 shows moderate homology to other mollusk sHSPs. PtHSP20 mRNA was present in all of the test tissues including the heart, digestive gland, adductor muscle, gonad, gill, and mantle, with the highest concentration found in the gonad. Under the stress of high temperature, the expression of PtHSP20 mRNA was down-regulated in all of the tissues except the adductor muscle and gonad.

  15. Insights into the role of heat shock protein 72 to whole-body heat acclimation in humans

    PubMed Central

    Amorim, Fabiano Trigueiro; Fonseca, Ivana T; Machado-Moreira, Christiano A; Magalhães, Flávio de Castro

    2015-01-01

    Abstract Heat acclimation results in systemic and cellular adaptions that reduce the negative effect of heat and, consequently, the risk of heat illness. Although the classical changes observed with heat acclimation lead to increased tolerance to exercise in the heat by reducing heat storage (reflected in reduced core and skin temperatures) and increasing whole-body capacity for heat dissipation (greater plasma volume, sweat output, and skin blood flow), it appears that heat acclimation also induces changes at the cellular level that might increase tolerance of the whole organism to a higher core temperature for the development of fatigue. Thermotolerance is a process that involves increased resilience to an otherwise lethal heat stress that follows a sublethal exposure to heat. Thermotolerance is believed to be the result of increased content of heat shock proteins (Hsp), specially a member of the 70 kDa family, Hsp72 kDa. In humans, we and others have reported that heat acclimation increases intracellular Hsp72 levels. This increase in intracellular Hsp72 could improve whole-body organism thermotolerance by maintaining intestinal epithelial tight junction barriers, by increasing resistance to gut-associated endotoxin translocation, or by reducing the inflammatory response. In this review, we will initially provide an overview of the physiological adaptations induced by heat acclimation and emphasize the main cellular changes that occur with heat acclimation associated with intracellular accumulation of Hsp72. Finally, we will present an argument for a role of whole-body heat acclimation in augmenting cellular thermotolerance, which may protect vital organs from deleterious effects of heat stress in humans. PMID:27227070

  16. Insights into the role of heat shock protein 72 to whole-body heat acclimation in humans.

    PubMed

    Amorim, Fabiano Trigueiro; Fonseca, Ivana T; Machado-Moreira, Christiano A; Magalhães, Flávio de Castro

    2015-01-01

    Heat acclimation results in systemic and cellular adaptions that reduce the negative effect of heat and, consequently, the risk of heat illness. Although the classical changes observed with heat acclimation lead to increased tolerance to exercise in the heat by reducing heat storage (reflected in reduced core and skin temperatures) and increasing whole-body capacity for heat dissipation (greater plasma volume, sweat output, and skin blood flow), it appears that heat acclimation also induces changes at the cellular level that might increase tolerance of the whole organism to a higher core temperature for the development of fatigue. Thermotolerance is a process that involves increased resilience to an otherwise lethal heat stress that follows a sublethal exposure to heat. Thermotolerance is believed to be the result of increased content of heat shock proteins (Hsp), specially a member of the 70 kDa family, Hsp72 kDa. In humans, we and others have reported that heat acclimation increases intracellular Hsp72 levels. This increase in intracellular Hsp72 could improve whole-body organism thermotolerance by maintaining intestinal epithelial tight junction barriers, by increasing resistance to gut-associated endotoxin translocation, or by reducing the inflammatory response. In this review, we will initially provide an overview of the physiological adaptations induced by heat acclimation and emphasize the main cellular changes that occur with heat acclimation associated with intracellular accumulation of Hsp72. Finally, we will present an argument for a role of whole-body heat acclimation in augmenting cellular thermotolerance, which may protect vital organs from deleterious effects of heat stress in humans. PMID:27227070

  17. Target heating due to the shock produced hot electrons in the shock ignition scheme

    NASA Astrophysics Data System (ADS)

    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.

  18. Heat shock modulates the subcellular localization, stability, and activity of HIPK2.

    PubMed

    Upadhyay, Mamta; Bhadauriya, Pratibha; Ganesh, Subramaniam

    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. PMID:26972256

  19. Oxidative Stress and Heat-Shock Responses in Desulfovibrio vulgaris by Genome-Wide Transcriptomic Analysis

    SciTech Connect

    Zhang, Weiwen; Culley, David E.; Hogan, Mike; Vitiritti, Luigi; Brockman, Fred J.

    2006-05-30

    Abstract Sulfate-reducing bacteria, like Desulfovibrio vulgaris have developed a set of reactions allowing them to survive in environments. To obtain further knowledge of the protecting mechanisms employed in D. vulgaris against the oxidative stress and heat shock, we performed a genome-wide transcriptomic analysis to determine the cellular responses to both stimuli. The results showed that 130 genes were responsive to oxidative stress, while 427 genes responsive to heat-shock, respectively. Functional analyses suggested that the genes regulated were involved in a variety of cellular functions. Metabolic analysis showed that amino acid biosynthetic pathways were induced by both oxidative stress and heat shock treatments, while fatty acid metabolism, purine and cofactor biosynthesis were induced by heat shock only. Rubrerythrin gene (rbR) were upregulated by the oxidative stress, suggesting its important role in the oxidative resistance, whereas the expression of rubredoxin oxidoreductase (rbO), superoxide ismutase (sodB) and catalase (katA) genes were not subjected to regulation by oxidative stress in D. vulgaris. In addition, the results showed that thioredoxin reductase (trxB) was responsive to oxidative stress, suggesting the thiol-specific redox system might be involved in oxidative protection in D. vulgaris. Comparison of cellular responses to oxidative stress and heat-shock allowed the identification of 66 genes that showed a similar drastic response to both environmental stimuli, implying that they might be part of the general stress response (GSR) network in D. vulgaris, which was further supported by the finding of a conserved motif upstream these common-responsive genes.

  20. Unraveling Biological Design Principles Using Engineering Methods: The Heat Shock Response as a Case Study

    NASA Astrophysics Data System (ADS)

    El-Samad, Hana

    2006-03-01

    The bacterial heat shock response refers to the mechanism by which bacteria react to a sudden increase in the ambient temperature. The consequences of such an unmediated temperature increase at the cellular level is the unfolding, misfolding, or aggregation of cell proteins, which threatens the life of the cell. To combat such effects, cells have evolved an intricate set of feedback and feedforward mechanisms. In this talk, we present a mathematical model that describes the core functionality of these mechanisms. We illustrate how such a model provides valuable insight, explaining dynamic phenomena exhibited by wild type and mutant heat shock responses, corroborating experimental data and guiding novel biological experiments. Furthermore, we demonstrate, through the careful control analysis of the model, several design principles that appear to have shaped the feedback structure of the heat shock system. Specifically, we itemize the roles of the various feedback strategies and demonstrate their necessity in achieving performance objectives such as efficiency, robustness, stability, good transient response, and noise rejection in the presence of limited cellular energies and materials. Examined from this perspective, the heat shock model can be decomposed, both conceptually and mathematically, into functional modules. These modules possess the characteristics of more familiar modular structures: sensors, actuators and controllers present in a typical technological control system. We finally point to various theoretical research challenges inspired by the heat shock response system, and discuss the crucial relevance of these challenges in the modeling and analysis of many classes of systems that are likely to arise in the study of gene regulatory networks.

  1. Heat shock modulates the subcellular localization, stability, and activity of HIPK2.

    PubMed

    Upadhyay, Mamta; Bhadauriya, Pratibha; Ganesh, Subramaniam

    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.

  2. Limits of shock heating for the chromospheres of low-gravity stars

    NASA Astrophysics Data System (ADS)

    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.

  3. Effect of temperature shock and inventory surprises on natural gas and heating oil futures returns.

    PubMed

    Hu, John Wei-Shan; Hu, Yi-Chung; Lin, Chien-Yu

    2014-01-01

    The aim of this paper is to examine the impact of temperature shock on both near-month and far-month natural gas and heating oil futures returns by extending the weather and storage models of the previous study. Several notable findings from the empirical studies are presented. First, the expected temperature shock significantly and positively affects both the near-month and far-month natural gas and heating oil futures returns. Next, significant temperature shock has effect on both the conditional mean and volatility of natural gas and heating oil prices. The results indicate that expected inventory surprises significantly and negatively affects the far-month natural gas futures returns. Moreover, volatility of natural gas futures returns is higher on Thursdays and that of near-month heating oil futures returns is higher on Wednesdays than other days. Finally, it is found that storage announcement for natural gas significantly affects near-month and far-month natural gas futures returns. Furthermore, both natural gas and heating oil futures returns are affected more by the weighted average temperature reported by multiple weather reporting stations than that reported by a single weather reporting station.

  4. Catabolite control of the elevation of PGK mRNA levels by heat shock in Saccharomyces cerevisiae.

    PubMed

    Piper, P W; Curran, B; Davies, M W; Hirst, K; Lockheart, A; Seward, K

    1988-05-01

    Heat shock enhances the very high level of transcription of the phosphoglycerate kinase (PGK) gene in fermentative cultures of Saccharomyces cerevisiae. This response of PGK mRNA levels was not found on gluconeogenic carbon sources, and could be switched on or off subject to availability of fermentable carbon source. The addition of glucose to yeast growing on glycerol resulted in acquisition, within 30-60 min, of the ability to elevate PGK mRNA levels after heat shock. In addition, in aerobic cultures growing on glucose the exhaustion of the medium glucose coincided with a loss of the heat-shock effect on PGK mRNA and a switch-over to slower growth by aerobic respiration. Levels of hsp26 mRNA were analysed during these experiments. Contrasting with this requirement for fermentable catabolite for manifestation of a heat-shock response of PGK mRNA levels, the PGK enzyme was not synthesized at a greater level in heat-shocked fermentative than in gluconeogenic cultures. PGK is one of only a few proteins made efficiently after mild heat shock of yeast. Thus, heat-stress-induced elevation of PGK mRNA levels does not appreciably increase PGK synthesis during exposure to high temperatures and so its role may be to assist cells repressed in mitochondrial function during recovery following a heat shock.

  5. Functional conservation of cis-regulatory elements of heat-shock genes over long evolutionary distances.

    PubMed

    He, Zhengying; Eichel, Kelsie; Ruvinsky, Ilya

    2011-01-01

    Transcriptional control of gene regulation is an intricate process that requires precise orchestration of a number of molecular components. Studying its evolution can serve as a useful model for understanding how complex molecular machines evolve. One way to investigate evolution of transcriptional regulation is to test the functions of cis-elements from one species in a distant relative. Previous results suggested that few, if any, tissue-specific promoters from Drosophila are faithfully expressed in C. elegans. Here we show that, in contrast, promoters of fly and human heat-shock genes are upregulated in C. elegans upon exposure to heat. Inducibility under conditions of heat shock may represent a relatively simple "on-off" response, whereas complex expression patterns require integration of multiple signals. Our results suggest that simpler aspects of regulatory logic may be retained over longer periods of evolutionary time, while more complex ones may be diverging more rapidly.

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

    SciTech Connect

    Rabindran, S.K.; Giorgi, G.; Clos, J.; Wu, C. )

    1991-08-15

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

  7. Trypanosoma cruzi: effects of heat shock on ecto-ATPase activity.

    PubMed

    Giarola, Naira Lígia Lima; de Almeida-Amaral, Elmo Eduardo; Collopy-Júnior, Itallo; Fonseca-de-Souza, André Luiz; Majerowicz, David; Paes, Lisvane Silva; Gondim, Katia C; Meyer-Fernandes, José Roberto

    2013-04-01

    In this work, we demonstrate that Trypanosoma cruzi Y strain epimastigotes exhibit Mg2+-dependent ecto-ATPase activity that is stimulated by heat shock. When the epimastigotes were incubated at 37°C for 2h, the ecto-ATPase activity of the cells was 43.95±0.97 nmol Pi/h×10(7) cells, whereas the ecto-ATPase activity of cells that were not exposed to heat shock stress was 16.97±0.30 nmol Pi/h×10(7) cells. The ecto-ATPase activities of cells, that were exposed or not exposed to heat shock stress had approximately the same Km values (2.25±0.26 mM ATP and 1.55±0.23 mM ATP, respectively) and different Vmax values. The heat-shocked cells had higher Vmax values (54.38±3.07 nmol Pi/h×10(7) cells) than the cells that were not exposed to heat shock (19.38±1.76 nmol Pi/h×10(7) cells). We also observed that the ecto-phosphatase and ecto-5'nucleotidase activities of cells that had been incubated at 28°C or 37°C were the same. Interestingly, cycloheximide, an inhibitor of protein synthesis, suppressed the heat shock effect of ecto-ATPase activity on T. cruzi. The Mg2+-dependent ecto-ATPase activity from the Y strain (high virulence) was approximately 2-fold higher than that of Dm28c (a clone with low virulence). In addition, these two strains presented different responses to heat shock with regard to their ecto-ATPase activities; Y strain epimastigotes had a stimulation of 2.52-fold while the Dm28c strain had a 1.71-fold stimulation. In this context, the virulent trypomastigote form of T. cruzi, Dm28c, had an ecto-ATPase activity that was more than 7-fold higher (66.67±5.98 nmol Pi/h×10(7) cells) than that of the insect epimastigote forms (8.91±0.76 nmol Pi/h×10(7) cells). This difference increased to approximately 10-fold when both forms were subjected to heat shock stress (181.14±16.48 nmol Pi/h×10(7) cells for trypomastigotes and 16.71±1.17 nmol Pi/h×10(7) cells for epimastigotes at 37°C). The ecto-ATPase activity of a plasma membrane-enriched fraction

  8. Highly resolved measurements of defect evolution under heated-and-shocked conditions

    SciTech Connect

    Lanier, N. E.; Workman, J.; Holmes, R. L.; Graham, P.; Moore, A.

    2007-05-15

    One of the principal advantages of a double-shell capsule design is the potential for ignition without requiring cryogenic implosions. These designs compress deuterium fuel by transferring kinetic energy from a laser-ablated outer shell to an inner shell by means of a nearly elastic symmetric collision. However, prior to this collision the inner shell experiences varying levels of preheat such that any nonuniformities can evolve significantly. It is the condition of these perturbations at the time the collision-induced shock compresses the inner shell that ultimately dictates capsule performance. With this in mind, a series of experiments have been performed on the OMEGA laser facility [R. T. Boehly et al., Opt. Comm. 133, 495 (1997)] that produce highly resolved measurements of defect evolution under heated-and-shocked conditions. Tin L-shell radiation is used to heat a layered package of epoxy and foam. The epoxy can be engineered with a variety of surface perturbations or defects. As the system evolves, a strong shock can be introduced with the subsequent hydrodynamic behavior imaged on calibrated film via x-ray radiography. This technique allows density variations of the evolving system to be quantitatively measured. This paper summarizes the hydrodynamic behavior of rectangular gaps under heated conditions with detailed experimental measurements of their residual density perturbations. Moreover, the impact of these residual density perturbations on shock deformation and material flow is discussed.

  9. Laser-based platform for studying material hydrodynamics under heated and shocked conditions

    SciTech Connect

    Lanier, N. E.; Holmes, R. L.; Workman, J.; Graham, P.; Chambers, D. M.; Moore, A.

    2006-10-15

    Understanding how target defects and surface finish perturbations affect ignition capsule mixing is a critical goal of the inertial confinement fusion (ICF) community. While initial characterization of these features is essential to understanding the physics of ICF implosions, it is the condition of the features at the time of shock passage that ultimately dictates their impact on capsule performance. The Off-Hugoniot experiment was designed to quantify the evolution of material interfaces under heated and subsequently shocked conditions. The platform uses tin L-shell radiation to uniformly heat an epoxy/foam-layered package. As the epoxy expands into the foam, an independently controlled shock impacts the evolving interface. The resulting hydrodynamics are imaged via x-ray radiography. Beyond the flexibility of independent heating and shock control, the epoxy can be configured with any desired features, such as gaps, chamfers, and single and multimode perturbations. An overview of the experimental platform, data from the ongoing OMEGA campaign, and future plans are presented.

  10. X66, a novel N-terminal heat shock protein 90 inhibitor, exerts antitumor effects without induction of heat shock response

    PubMed Central

    Quan, Haitian; Wang, Guimin; Li, Bo; Zhu, Weiliang; Xie, Chengying; Lou, Liguang

    2016-01-01

    Heat shock protein 90 (HSP90) is essential for cancer cells to assist the function of various oncoproteins, and it has been recognized as a promising target in cancer therapy. Although the HSP90 inhibitors in clinical trials have shown encouraging clinical efficacy, these agents induce heat shock response (HSR), which undermines their therapeutic effects. In this report, we detailed the pharmacologic properties of 4-(2-((1H-indol-3-yl)methylene)hydrazinyl)-N-(4-bromophenyl)-6-(3,5- dimethyl-1H -pyrazol-1-yl)-1,3,5-triazin-2-amine (X66), a novel and potent HSP90 inhibitor. X66 binds to the N-terminal domain in a different manner from the classic HSP90 inhibitors. Cellular study showed that X66 depleted HSP90 client proteins, resulted in cell cycle arrest and apoptosis, and inhibition of proliferation in cancer cell lines. X66 did not activate heat shock factor-1 (HSF-1) or stimulate transcription of HSPs. Moreover, the combination of X66 with HSP90 and proteasome inhibitors yielded synergistic cytotoxicity which was involved in X66-mediated abrogation of HSR through inhibition of HSF-1 activity. The intraperitoneal administration of X66 alone depleted client protein and inhibited tumor growth, and led to enhanced activity when combined with celastrol as compared to either agent alone in BT-474 xenograft model. Collectively, the HSP90 inhibitory action and the potent antitumor activity, with the anti-HSR action, promise X66 a novel HSP90-targeted agent, which merits further research and development. PMID:27105490

  11. Evidence for shock-heated gas in the Hopkins Ultraviolet Telescope spectrum of NGC 1068

    NASA Technical Reports Server (NTRS)

    Kriss, Gerard A.; Davidsen, Arthur F.; Blair, William P.; Ferguson, Henry C.; Long, Knox S.

    1992-01-01

    The paper presents FUV spectra of the NGC 1068 Seyfert 2 galaxy, obtained with the Hopkins Ultraviolet Telescope (HUT) during the flight of Astro-1 aboard the Space Shuttle Columbia in December 1990, revealing moderately strong C III 977-A and N III 991-A emission lines, which have never been seen before in spectra of AGNs. It is noted that the emission-line spectrum of NGC 1068 qualitatively resemble the HUT spectrum of a radiative shock in the Cygnus Loop supernova remnant (Blair et al., 1991), suggesting that shock heating may contribute significantly to the line emission.

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

    PubMed

    Hansen, Peter J

    2014-12-01

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

  13. Crosstalk between HSF1 and HSF2 during the heat shock response in mouse testes.

    PubMed

    Korfanty, Joanna; Stokowy, Tomasz; Widlak, Piotr; Gogler-Piglowska, Agnieszka; Handschuh, Luiza; Podkowiński, Jan; Vydra, Natalia; Naumowicz, Anna; Toma-Jonik, Agnieszka; Widlak, Wieslawa

    2014-12-01

    Heat Shock Factor 1 (HSF1) is the primary transcription factor responsible for the response to cellular stress, while HSF2 becomes activated during development and differentiation, including spermatogenesis. Although both factors are indispensable for proper spermatogenesis, activation of HSF1 by heat shock initiates apoptosis of spermatogenic cells leading to infertility of males. To characterize mechanisms assisting such heat induced apoptosis we studied how HSF1 and HSF2 cooperate during the heat shock response. For this purpose we used chromatin immunoprecipitation and the proximity ligation approaches. We looked for co-occupation of binding sites by HSF1 and HSF2 in untreated (32 °C) or heat shocked (at 38 °C or 43 °C) spermatocytes, which are cells the most sensitive to hyperthermia. At the physiological temperature or after mild hyperthermia at 38 °C, the sharing of binding sites for both HSFs was observed mainly in promoters of Hsp genes and other stress-related genes. Strong hyperthermia at 43 °C resulted in an increased binding of HSF1 and releasing of HSF2, hence co-occupation of promoter regions was not detected any more. The close proximity of HSF1 and HSF2 (and/or existence of HSF1/HSF2 complexes) was frequent at the physiological temperature. Temperature elevation resulted in a decreased number of such complexes and they were barely detected after strong hyperthermia at 43 °C. We have concluded that at the physiological temperature HSF1 and HSF2 cooperate in spermatogenic cells. However, temperature elevation causes remodeling of chromatin binding and interactions between HSFs are disrupted. This potentially affects the regulation of stress response and contributes to the heat sensitivity of these cells.

  14. Heat shock inhibits. alpha. -amylase synthesis in barley aleurone without inhibiting the activity of endoplasmic reticulum marker enzymes

    SciTech Connect

    Sticher, L.; Biswas, A.K.; Bush, D.S.; Jones, R.L. )

    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.

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

    SciTech Connect

    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.

  16. An artificial HSE promoter for efficient and selective detection of heat shock pathway activity.

    PubMed

    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.

  17. Escherichia coli Heat Shock Protein DnaK: Production and Consequences in Terms of Monitoring Cooking

    PubMed Central

    Seyer, Karine; Lessard, Martin; Piette, Gabriel; Lacroix, Monique; Saucier, Linda

    2003-01-01

    Through use of commercially available DnaK proteins and anti-DnaK monoclonal antibodies, a competitive enzyme-linked immunosorbent assay was developed to quantify this heat shock protein in Escherichia coli ATCC 25922 subjected to various heating regimens. For a given process lethality (F7010 of 1, 3, and 5 min), the intracellular concentration of DnaK in E. coli varied with the heating temperature (50 or 55°C). In fact, the highest DnaK concentrations were found after treatments at the lower temperature (50°C) applied for a longer time. Residual DnaK after heating was found to be necessary for cell recovery, and additional DnaK was produced during the recovery process. Overall, higher intracellular concentrations of DnaK tended to enhance cell resistance to a subsequent lethal stress. Indeed, E. coli cells that had undergone a sublethal heat shock (105 min at 55°C, F7010 = 3 min) accompanied by a 12-h recovery (containing 76,786 ± 25,230 molecules/cell) resisted better than exponentially growing cells (38,500 ± 6,056 molecules/cell) when later heated to 60°C for 50 min (F7010 = 5 min). Results reported here suggest that using stress protein to determine cell adaptation and survival, rather than cell counts alone, may lead to more efficient heat treatment. PMID:12788720

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

    PubMed

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

    2016-06-01

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

  19. Fish in hot water: hypoxaemia does not trigger catecholamine mobilization during heat shock in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Currie, S; Ahmady, E; Watters, M A; Perry, S F; Gilmour, K M

    2013-06-01

    Rainbow trout (Oncorhynchus mykiss) exposed to an acute heat shock (1 h at 25 °C after raising water temperature from 13 °C to 25 °C over 4 h) mount a significant catecholamine response. The present study investigated the proximate mechanisms underlying catecholamine mobilization. Trout exposed to heat shock in vivo exhibited a significant reduction in arterial O(2) tension, but arterial O(2) concentration was not affected by heat shock, nor was catecholamine release during heat shock prevented by prior and concomitant exposure to hyperoxia (to prevent the fall in arterial O(2) tension). Thus, catecholamine mobilization probably was not triggered by impaired blood O(2) transport. Heat-shocked trout also exhibited an elevation of arterial CO(2) tension coupled with a fall in arterial pH, but these factors are not expected to trigger catecholamine release. The changes in blood O(2) and CO(2) tension occurred despite a significant hyperventilatory response to heat shock. Future studies should investigate whether catecholamine mobilization during heat shock in rainbow trout is triggered by a specific effect of high temperature activating the sympathetic nervous system via a thermosensitive transient receptor potential channel.

  20. Modelling of ultrasound therapeutic heating and numerical study of the dynamics of the induced heat shock response

    NASA Astrophysics Data System (ADS)

    Mizera, Andrzej; Gambin, Barbara

    2011-05-01

    In this presentation we consider hyperthermia, a procedure of raising the temperature above 43 °C, as a treatment modality. To this purpose, a numerical model of in vivo soft tissue ultrasound heating is proposed by extending a previously presented in vitro model. Based on the numerical simulations, a heating scheme satisfying some constraints related to potential clinical applications is established, and the resulting temperature time-course profile is composed with the temperature-dependent protein denaturation formula of a recently published mathematical model for the eukaryotic heat shock response. The obtained simulation results of the combined models are discussed in view of potential application of ultrasound soft tissue heating in clinical treatment.

  1. Prostaglandin E synthase interacts with inducible heat shock protein 70 after heat stress in bovine primary dermal fibroblast cells.

    PubMed

    Richter, Constanze; Viergutz, Torsten; Schwerin, Manfred; Weitzel, Joachim M

    2015-01-01

    Exposure to heat stress in dairy cows leads to undesired side effects that are reflected by complex alterations in endocrine parameters, such as reduced progesterone, estradiol, and thyroid hormone concentrations. These endocrine maladaptation leads to failure to resume cyclicity, a poor uterine environment and inappropriate immune responses in postpartum dairy cows. Prostaglandins (PG's) are lipid mediators, which serve as signal molecules in response to various external stimuli as well as to cell-specific internal signal molecules. A central role in PG synthesis plays prostaglandin E synthase (PGES) that catalyzes the isomerization of PGH2 to PGE2 .The present study was conducted to investigate heat stress associated PGES expression. Expression of PGES and inducible heat shock protein 70 (HSP70), as a putative chaperonic protein, was studied in bovine primary fibroblasts under different heat shock conditions. Bovine primary fibroblasts produce PGE2 at homoiothermical norm temperature (38.5°C in bovine), but reduce PGE2 production rates under extreme heat stress (at 45°C for 6 h). By contrast, PGE2 production rates are maintained after a milder heat stress (at 41.5°C for 6 h). PGE2 synthesis is abolished by application of cyclooxygenase inhibitor indomethacin, indicating de novo synthesis. Heat stress increases HSP70 but not PGES protein concentrations. HSP70 physically interacts with PGES and the PGES-HSP70 complex did not dissociate upon heat stress at 45°C even after returning the cells to 37°C. The PGE2 production negatively correlates with the portion of PGES-HSP70 complex. These results suggest a protein interaction between HSP70 and PGES in dermal fibroblast cells. Blockage of PGES protein by HSP70 seems to interfere with the regulatory processes essential for cellular adaptive protection. © 2014 International Society for Advancement of Cytometry.

  2. Role of Heat-Shock Proteins in Cellular Function and in the Biology of Fungi

    PubMed Central

    Tiwari, Shraddha; Thakur, Raman; Shankar, Jata

    2015-01-01

    Stress (biotic or abiotic) is an unfavourable condition for an organism including fungus. To overcome stress, organism expresses heat-shock proteins (Hsps) or chaperons to perform biological function. Hsps are involved in various routine biological processes such as transcription, translation and posttranslational modifications, protein folding, and aggregation and disaggregation of proteins. Thus, it is important to understand holistic role of Hsps in response to stress and other biological conditions in fungi. Hsp104, Hsp70, and Hsp40 are found predominant in replication and Hsp90 is found in transcriptional and posttranscriptional process. Hsp90 and Hsp70 in combination or alone play a major role in morphogenesis and dimorphism. Heat stress in fungi expresses Hsp60, Hsp90, Hsp104, Hsp30, and Hsp10 proteins, whereas expression of Hsp12 protein was observed in response to cold stress. Hsp30, Hsp70, and Hsp90 proteins showed expression in response to pH stress. Osmotic stress is controlled by small heat-shock proteins and Hsp60. Expression of Hsp104 is observed under high pressure conditions. Out of these heat-shock proteins, Hsp90 has been predicted as a potential antifungal target due to its role in morphogenesis. Thus, current review focuses on role of Hsps in fungi during morphogenesis and various stress conditions (temperature, pH, and osmotic pressure) and in antifungal drug tolerance. PMID:26881084

  3. Microinjection of ubiquitin: changes in protein degradation in HeLa cells subjected to heat-shock

    PubMed Central

    1987-01-01

    Ubiquitin was radiolabeled by reaction with 125I-Bolton-Hunter reagent and introduced into HeLa cells using erythrocyte-mediated microinjection. The injected cells were then incubated at 45 degrees C for 5 min (reversible heat-shock) or for 30 min (lethal heat-shock). After either treatment, there were dramatic changes in the levels of ubiquitin conjugates. Under normal culture conditions, approximately 10% of the injected ubiquitin is linked to histones, 40% is found in conjugates with molecular weights greater than 25,000, and the rest is unconjugated. After heat-shock, the free ubiquitin pool and the level of histone-ubiquitin conjugates decreased rapidly, and high molecular weight conjugates predominated. Formation of large conjugates did not require protein synthesis; when analyzed by two-dimensional electrophoresis, the major conjugates did not co-migrate with heat- shock proteins before or after thermal stress. Concomitant with the loss of free ubiquitin, the degradation of endogenous proteins, injected hemoglobin, BSA, and ubiquitin was reduced in heat-shocked HeLa cells. After reversible heat-shock, the decrease in proteolysis was small, and both the rate of proteolysis and the size of the free ubiquitin pool returned to control levels upon incubation at 37 degrees C. In contrast, neither proteolysis nor free ubiquitin pools returned to control levels after lethal heat-shock. However, lethally heat- shocked cells degraded denatured hemoglobin more rapidly than native hemoglobin and ubiquitin-globin conjugates formed within them. Therefore, stabilization of proteins after heat-shock cannot be due to the loss of ubiquitin conjugation or inability to degrade proteins that form conjugates with ubiquitin. PMID:3029142

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

    PubMed

    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. PMID:25604531

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

    PubMed

    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.

  6. Heat shock protein-mediated protection against Cisplatin-induced hair cell death.

    PubMed

    Baker, Tiffany G; Roy, Soumen; Brandon, Carlene S; Kramarenko, Inga K; Francis, Shimon P; Taleb, Mona; Marshall, Keely M; Schwendener, Reto; Lee, Fu-Shing; Cunningham, Lisa L

    2015-02-01

    Cisplatin is a highly successful and widely used chemotherapy for the treatment of various solid malignancies in both adult and pediatric patients. Side effects of cisplatin treatment include nephrotoxicity and ototoxicity. Cisplatin ototoxicity results from damage to and death of cells in the inner ear, including sensory hair cells. We showed previously that heat shock inhibits cisplatin-induced hair cell death in whole-organ cultures of utricles from adult mice. Since heat shock protein 70 (HSP70) is the most upregulated HSP in response to heat shock, we investigated the role of HSP70 as a potential protectant against cisplatin-induced hair cell death. Our data using utricles from HSP70 (-/-) mice indicate that HSP70 is necessary for the protective effect of heat shock against cisplatin-induced hair cell death. In addition, constitutive expression of inducible HSP70 offered modest protection against cisplatin-induced hair cell death. We also examined a second heat-inducible protein, heme oxygenase-1 (HO-1, also called HSP32). HO-1 is an enzyme responsible for the catabolism of free heme. We previously showed that induction of HO-1 using cobalt protoporphyrin IX (CoPPIX) inhibits aminoglycoside-induced hair cell death. Here, we show that HO-1 also offers significant protection against cisplatin-induced hair cell death. HO-1 induction occurred primarily in resident macrophages, with no detectable expression in hair cells or supporting cells. Depletion of macrophages from utricles abolished the protective effect of HO-1 induction. Together, our data indicate that HSP induction protects against cisplatin-induced hair cell death, and they suggest that resident macrophages mediate the protective effect of HO-1 induction.

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

    PubMed

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

    2008-05-01

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

  8. The Role of the Membrane-Initiated Heat Shock Response in Cancer

    PubMed Central

    Bromberg, Zohar; Weiss, Yoram

    2016-01-01

    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. PMID:27200359

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

    PubMed Central

    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

  10. Heat shock protein-mediated protection against Cisplatin-induced hair cell death.

    PubMed

    Baker, Tiffany G; Roy, Soumen; Brandon, Carlene S; Kramarenko, Inga K; Francis, Shimon P; Taleb, Mona; Marshall, Keely M; Schwendener, Reto; Lee, Fu-Shing; Cunningham, Lisa L

    2015-02-01

    Cisplatin is a highly successful and widely used chemotherapy for the treatment of various solid malignancies in both adult and pediatric patients. Side effects of cisplatin treatment include nephrotoxicity and ototoxicity. Cisplatin ototoxicity results from damage to and death of cells in the inner ear, including sensory hair cells. We showed previously that heat shock inhibits cisplatin-induced hair cell death in whole-organ cultures of utricles from adult mice. Since heat shock protein 70 (HSP70) is the most upregulated HSP in response to heat shock, we investigated the role of HSP70 as a potential protectant against cisplatin-induced hair cell death. Our data using utricles from HSP70 (-/-) mice indicate that HSP70 is necessary for the protective effect of heat shock against cisplatin-induced hair cell death. In addition, constitutive expression of inducible HSP70 offered modest protection against cisplatin-induced hair cell death. We also examined a second heat-inducible protein, heme oxygenase-1 (HO-1, also called HSP32). HO-1 is an enzyme responsible for the catabolism of free heme. We previously showed that induction of HO-1 using cobalt protoporphyrin IX (CoPPIX) inhibits aminoglycoside-induced hair cell death. Here, we show that HO-1 also offers significant protection against cisplatin-induced hair cell death. HO-1 induction occurred primarily in resident macrophages, with no detectable expression in hair cells or supporting cells. Depletion of macrophages from utricles abolished the protective effect of HO-1 induction. Together, our data indicate that HSP induction protects against cisplatin-induced hair cell death, and they suggest that resident macrophages mediate the protective effect of HO-1 induction. PMID:25261194

  11. Evolution of X-Ray Clusters of Galaxies and Shock Heating of the Intracluster Medium

    NASA Astrophysics Data System (ADS)

    Takizawa, Motokazu; Mineshige, Shin

    1998-05-01

    Evolutions of spherical X-ray clusters of galaxies are studied by using an N-body+total variation diminishing (TVD) mesh code. We consider a growth of density perturbation of 1015 M⊙ composed of dark matter and gas in a cold dark matter-dominated universe with Ω0 = 1 or 0.2. When the perturbation collapsed at z ~ 1, a shock front appears at r ~ 0.1 Mpc, moving outward as ambient gas accretes toward cluster center. The shock front separates the inner X-ray-emitting, hot region from the outer cool region. In the former, gas is almost in hydrostatic equilibrium but with small radial infall (~100 km s-1) being left, while in the latter, gas falls almost freely and emits no X-rays. Gas inside the shock is strongly compressed and heated by shock so that X-ray luminosity rapidly rises in the early stage (until temperature reaches about virial). In the late stage, on the other hand, the X-ray luminosity rises only gradually due partly to the expansion of the inner high-temperature region and partly to the increase of X-ray emissivity of gas as the result of continuous adiabatic compression inside the shock. We also find that the density distribution is generally less concentrated in a lower density universe and, hence, X-ray luminosity rises more slowly than in a higher density universe. The shock front structure, which was not clearly resolved in the previous SPH simulations, is clearly captured by the present simulations. Our results confirm that shock heating plays an important role in the heating process of the intracluster medium. In addition, we find that a sound wave propagates outward, thereby producing modulations with amplitudes of ~10% in the radial temperature and density profiles which, in turn, cause time variations in the strength of the shock. Such modulations, if observed, could be used as a probe to investigate the internal structure of clusters and the initial temperature of gas.

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

    SciTech Connect

    Yamamoto, Yu; Yamada, Shoichi; Fujimoto, Shin-ichiro; Nagakura, Hiroki

    2013-07-01

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

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

    NASA Astrophysics Data System (ADS)

    Laming, J. M.; Hwang, U.; Ghavamian, P.; Rakowski, C. E.

    2014-01-01

    We investigate the observability, by direct and indirect means, of a shock precursor arising from magnetic field amplification by cosmic rays. We estimate the depth of such a precursor under conditions of nonresonant amplification, which provides magnetic field strengths comparable to those inferred for supernova remnants. Magnetic field generation occurs as the streaming cosmic rays induce a plasma return current, and may be quenched either by nonresonant or resonant channels. In the former case, the cosmic rays become magnetized and amplification saturates at higher magnetic fields. The precursor can extend out to 10^17 - 10^18 cm and is potentially resolvable in Galactic supernova remnants. If the saturation occurs instead by resonant channels, the cosmic rays are scattered by turbulence and the precursor length will likely be too small to be resolvable with current instruments. The dependence of precursor length on shock velocity has implications for electron heating. In the case of resonant saturation, this dependence is similar to that in the more familiar resonantly generated shock precursor, which when expressed in terms of the cosmic ray diffusion coefficient κ and shock velocity v_s is κ /v_s. In the nonresonantly saturated case, the precursor length declines less quickly with increasing v_s. Where precursor length proportional to 1/v_s gives constant electron heating, as observed for instance by Ghavamian et al. and van Adelsberg et al., this increased precursor length would be expected to lead to higher electron temperatures at faster supernova remnant shocks than studied by these previous works as an indirect observation of the shock precursor. Existing results and new data analysis of SN 1006 and Cas A suggests some observational support for this idea. Work supported by NASA ADAP program and by basic research funds of the Office of Naval Research.

  14. Heat shock protein synthesis and trehalose accumulation are not required for induced thermotolerance in depressed Saccharomyces cerevisiae.

    PubMed

    Gross, C; Watson, K

    1996-03-27

    Intrinsic and heat shock induced thermotolerance of Saccharomyces cerevisiae was investigated in cells grown on glucose and acetate supplemented media. Heat shocked cells (37 degrees C/30 min), in either medium, exhibited induced synthesis of heat shock proteins (hsp) and trehalose. In all cases, with the notable exception of repressed cells of a relatively thermosensitive strain, heat shock acquisition of thermotolerance also occurred in the absence of protein synthesis and coincident decrease in trehalose accumulation. Results indicted that the marked increase in thermotolerance exhibited by non-fermenting (acetate) cells compared with fermenting (glucose) cells was not closely correlated with levels of hsp or trehalose. It was concluded that mechanisms for intrinsic and induced thermotolerance appear to be different and that growth on acetate endows cells with a biochemical predisposition, other than hsp or trehalose, that confers intrinsic tolerance, a factor which may be subject to heat induced modification.

  15. Measurements of shock heating using Al absorption spectroscopy in planar targets (abstract)

    SciTech Connect

    Boehly, T. R.; Yaakobi, B.; Knauer, J. P.; Meyerhofer, D. D.; Town, R.; Hoarty, D.; Bahr, R.; Millecchia, M.

    2001-01-01

    In direct-drive laser fusion, the tradeoff between stability and overall efficiency requires precise control of the implosion isentrope. Most target designs use the temporal shape of the drive pulse to create shocks that slightly preheat the capsule shell and establish the isentrope for the rest of the implosion. Also, the use of foam overcoatings has been proposed as a means to reduce laser imprinting. These foams can alter the structure and intensity of the initial shock. To ensure that our hydrocodes adequately model these effects it is important that shock heating of targets be measured and understood. We report on measurements of shock heating in planar targets irradiated with the OMEGA laser system. Planar 20-{mu}m-thick CH targets were irradiated with six ultraviolet (UV) beams at intensities of {approx}2x10{sup 14}W/cm{sup 2} with temporally square and ramped pulses. Some targets also have low-density foam (30 mg/cc) on the irradiated surface. A thin (0.5 {mu}m) Al layer, imbedded in the target, is probed with x rays from a Sm backlighter. The 1s-2p absorption lines in the Al are observed with a streaked x-ray spectrometer. The absorption lines from the F-like to Ne-like ion populations provide a measure of the temperature of the target as a function of time. We present data on measurements that show the relative shock heating by square and ramp pulses. We also present results of atomic physics calculations1 of the absorption spectra that are used to infer the target temperature and show results from hydrodynamic simulations of the experiments.

  16. Comparison of nonequilibrium viscous-shock-layer solutions with windward surface Shuttle heating data

    NASA Technical Reports Server (NTRS)

    Thompson, R. A.

    1987-01-01

    A three-dimensional viscous-shock-layer code has been modified and used to compute the nonequilibrium flowfield over the windward surface of the Space Shuttle Orbiter for reentry conditions between 75 and 60 km. Effects of the modifications are demonstrated by comparison of present heat-transfer predictions with earlier results. The present predictions show a roughly 30 percent decrease in heat transfer along the windward centerline in comparison with previous results and are in agreement with two-dimensional viscous-shock-layer results. The latter agreement indicates that three-dimensional effects are not as significant as previously reported. Windward symmetry plane and off-centerline heating predictions with the modified code are compared with flight data from STS-2 and STS-3. Windward-centerline heating predictions obtained with a recent expression for oxygen recombination at the Shuttle surface were found to be in generally good agreement with the flight data. Comparisons of heating predictions on the off-centerline windward surface were also in good agreement with the data, and the calculated results followed trends in the crossflow heating distributions.

  17. Interaction of ATP with a Small Heat Shock Protein from Mycobacterium leprae: Effect on Its Structure and Function

    PubMed Central

    Nandi, Sandip Kumar; Chakraborty, Ayon; Panda, Alok Kumar; Sinha Ray, Sougata; Kar, Rajiv Kumar; Bhunia, Anirban; Biswas, Ashis

    2015-01-01

    Adenosine-5’-triphosphate (ATP) is an important phosphate metabolite abundantly found in Mycobacterium leprae bacilli. This pathogen does not derive ATP from its host but has its own mechanism for the generation of ATP. Interestingly, this molecule as well as several antigenic proteins act as bio-markers for the detection of leprosy. One such bio-marker is the 18 kDa antigen. This 18 kDa antigen is a small heat shock protein (HSP18) whose molecular chaperone function is believed to help in the growth and survival of the pathogen. But, no evidences of interaction of ATP with HSP18 and its effect on the structure and chaperone function of HSP18 are available in the literature. Here, we report for the first time evidences of “HSP18-ATP” interaction and its consequences on the structure and chaperone function of HSP18. TNP-ATP binding experiment and surface plasmon resonance measurement showed that HSP18 interacts with ATP with a sub-micromolar binding affinity. Comparative sequence alignment between M. leprae HSP18 and αB-crystallin identified the sequence 49KADSLDIDIE58 of HSP18 as the Walker-B ATP binding motif. Molecular docking studies revealed that β4-β8 groove/strands as an ATP interactive region in M. leprae HSP18. ATP perturbs the tertiary structure of HSP18 mildly and makes it less susceptible towards tryptic cleavage. ATP triggers exposure of additional hydrophobic patches at the surface of HSP18 and induces more stability against chemical and thermal denaturation. In vitro aggregation and thermal inactivation assays clearly revealed that ATP enhances the chaperone function of HSP18. Our studies also revealed that the alteration in the chaperone function of HSP18 is reversible and is independent of ATP hydrolysis. As the availability and binding of ATP to HSP18 regulates its chaperone function, this functional inflection may play an important role in the survival of M. leprae in hosts. PMID:25811190

  18. Heat-induced mortality and expression of heat shock proteins in Colorado potato beetles treated with imidacloprid.

    PubMed

    Chen, Jie; Kitazumi, Ai; Alpuerto, Jasper; Alyokhin, Andrei; de Los Reyes, Benildo

    2016-08-01

    The Colorado potato beetle is an important pest of solanaceous plants in the Northern Hemisphere. Better understanding of its physiological responses to temperature stress and their interactions with still-prevalent chemical control has important implications for the management of this insect. We measured mortality and expression of the Hsp70 heat shock proteins in the Colorado potato beetle larvae exposed to sublethal concentration of the commonly used insecticide imidacloprid, and to supraoptimal temperatures. Both turned out to be significant stress factors, although induction of Hsp70 by imidacloprid observed in the present study was low compared to its induction by the heat. The two factors also interacted with each other. At an extreme temperature of 43 °C, exposure to a sublethal dose of imidacloprid resulted in a significant rise in larval mortality, which was not observed at an optimal temperature of 25 °C. Heat-stressed larvae also failed to respond to imidacloprid by producing more Hsp70. These findings suggest that when field rates of insecticides become insufficient for killing the exposed beetles under optimal temperature conditions due to the evolution of resistance in beetle populations, they may still reduce the probability of resistant beetles surviving the heat shock created by using propane flamers as a rescue treatment. PMID:25504556

  19. Heat-induced mortality and expression of heat shock proteins in Colorado potato beetles treated with imidacloprid.

    PubMed

    Chen, Jie; Kitazumi, Ai; Alpuerto, Jasper; Alyokhin, Andrei; de Los Reyes, Benildo

    2016-08-01

    The Colorado potato beetle is an important pest of solanaceous plants in the Northern Hemisphere. Better understanding of its physiological responses to temperature stress and their interactions with still-prevalent chemical control has important implications for the management of this insect. We measured mortality and expression of the Hsp70 heat shock proteins in the Colorado potato beetle larvae exposed to sublethal concentration of the commonly used insecticide imidacloprid, and to supraoptimal temperatures. Both turned out to be significant stress factors, although induction of Hsp70 by imidacloprid observed in the present study was low compared to its induction by the heat. The two factors also interacted with each other. At an extreme temperature of 43 °C, exposure to a sublethal dose of imidacloprid resulted in a significant rise in larval mortality, which was not observed at an optimal temperature of 25 °C. Heat-stressed larvae also failed to respond to imidacloprid by producing more Hsp70. These findings suggest that when field rates of insecticides become insufficient for killing the exposed beetles under optimal temperature conditions due to the evolution of resistance in beetle populations, they may still reduce the probability of resistant beetles surviving the heat shock created by using propane flamers as a rescue treatment.

  20. Human heat shock protein 70 (hsp70) protects murine cells from injury during metabolic stress.

    PubMed Central

    Williams, R S; Thomas, J A; Fina, M; German, Z; Benjamin, I J

    1993-01-01

    Expression of heat shock protein 70 (hsp70) is stimulated during ischemia, but its proposed cytoprotective function during metabolic stress has remained conjectural. We introduced a human hsp70 gene into mouse 10T1/2 cells and assessed the susceptibility of these cells to injury in response to conditions that mimic ischemia. Transiently transfected cells, in the absence of stress, expressed human hsp70 to levels equal to or greater than those induced by heat shock, as assessed by RNAse protection, immunoblot, and immunohistochemical analyses. By comparison to cells transfected with a control plasmid, cells expressing the human hsp70 transgene were resistant to injury induced by glucose deprivation and inhibition of mitochondrial respiration. These results provide direct evidence for a cytoprotective function of hsp70 during metabolic stress. Images PMID:8326014

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

    PubMed Central

    Carnemolla, Alisia; Lazell, Hayley; Moussaoui, Saliha; Bates, Gillian P.

    2015-01-01

    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. PMID:26134141

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

    PubMed

    Carnemolla, Alisia; Lazell, Hayley; Moussaoui, Saliha; Bates, Gillian P

    2015-01-01

    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. PMID:26134141

  3. Expression of heat shock gene construct in transformed fish cell culture (RTG-2) after toxicant exposure

    SciTech Connect

    Rexrode, M.; Gedamu, L.; Chen, T.T.

    1995-12-31

    The authors have developed a transformed fish cell line (RTG-2) that can be used as a noninvasive compliment for the evaluation of toxicants (metals and organometal compounds) in the laboratory. Gene transfer and integration into the cell line was accomplished through the insertion of multiple copies of a heat shock gene that had been fused to the structural gene for firefly luciferase (luc). Transcription of the hsp70-luc transgene was inducible through heat-shock and acute exposure to metals (Cd, Cu) and organometal (TBT) compounds in the laboratory. Induction resulted in a rapid luminescence intensity proportional to the concentration of luciferase activity and presents a novel noninvasive diagnostic tool that produced dose-response curves comparable to conventional trout acute studies.

  4. Induction of heat-shock protein synthesis in chondrocytes at physiological temperatures

    SciTech Connect

    Madreperla, S.A.; Louwerenburg, B.; Mann, R.W.; Towle, C.A.; Mankin, H.J.; Treadwell, B.V.

    1985-01-01

    Induction of heat-shock protein (HSP) synthesis is demonstrated in cultured calf-chondrocytes at temperatures shown to occur in normal human cartilage during experiments subjecting intact cadaverous hip joints to the parameters of level walking. A 70,000 MW heat-shock protein (HSP-70) is synthesized by chondrocytes at temperatures above 39 degrees C, while induction of synthesis of a 110,000 MW HSP only occurs at temperatures of 45 degrees C or greater. These differences in critical temperatures for induction, and data showing differences in kinetics of induction and repression of synthesis, suggest that there are differences in the mechanism of induction of the two HSPs. The duration of HSP synthesis and inhibition of synthesis of normal cellular proteins is directly proportional to the duration and magnitude of the temperature rise. Possible relationships between these new findings and the initiation and progression of degenerative joint disease are discussed.

  5. [Effect of heat shock on cells of phytopathogenic mycoplasma Acholeplasma laidlawii PG-8A].

    PubMed

    Vishniakov, I E; Levitskiĭ, S A; Borkhsenius, S N

    2015-01-01

    Heat shock caused a more active formation of the "dormant" forms (minibodies), as well as increased production of extracellular membrane vesicles by Acholeplasma laidlawii PG-8A cells. Raise of the amount of the minibodies that have increased resistance to biogenic and abiogenic stress factors and pathogenicity may lead to more successful persistence of mycoplasmas in their hosts. Increased production of the extracellular membrane vesicles containing virulence factors by Acholeplasma laidlawii cells during stress may be an additional burden for the infected organism. It has been recently revealed that the vesicles of A. laidlawii contain appreciable quantities of small heat shock protein IbpA (Hsp20). In this paper, using immune-electron microscopy, have shown that at elevated temperature IbpA is associated with A. laidlawii minibodies. Perhaps, IbpA contributes to increased resistance and pathogenicity of the minibodies, keeping their proteins and polypeptides, including protein virulence factors in the folding-competent state.

  6. The 21 cm signature of shock heated and diffuse cosmic string wakes

    SciTech Connect

    Hernández, Oscar F.; Brandenberger, Robert H. E-mail: rhb@physics.mcgill.ca

    2012-07-01

    The analysis of the 21 cm signature of cosmic string wakes is extended in several ways. First we consider the constraints on Gμ from the absorption signal of shock heated wakes laid down much later than matter radiation equality. Secondly we analyze the signal of diffuse wake, that is those wakes in which there is a baryon overdensity but which have not shock heated. Finally we compare the size of these signals to the expected thermal noise per pixel which dominates over the background cosmic gas brightness temperature and find that the cosmic string signal will exceed the thermal noise of an individual pixel in the Square Kilometre Array for string tensions Gμ > 2.5 × 10{sup −8}.

  7. Induction temperature of human heat shock factor is reprogrammed in a Drosophila cell environment

    NASA Astrophysics Data System (ADS)

    Clos, Joachim; Rabindran, Sridhar; Wisniewski, Jan; Wu, Carl

    1993-07-01

    HEAT shock factor (HSF)1,2, the transcriptional activator of eukaryotic heat shock genes, is induced to bind DNA by a monomer to trimer transition involving leucine zipper interactions3,4. Although this mode of regulation is shared among many eukaryotic species, there is variation in the temperature at which HSF binding activity is induced. We investigated the basis of this variation by analysing the response of a human HSF expressed in Drosophila cells and Drosophila HSF expressed in human cells. We report here that the temperature that induces DNA binding and trimerization of human HSF in Drosophila was decreased by ~10 °C to the induction temperature for the host cell, whereas Drosophila HSF expressed in human cells was constitutively active. The results indicate that the activity of HSF in vivo is not a simple function of the absolute environmental temperature.

  8. MEASUREMENT OF THE SHOCK-HEATED MELT CURVE OF LEAD USING PYROMETRY AND REFLECTOMETRY

    SciTech Connect

    D. Partouche-Sebban and J. L. Pelissier, Commissariat a` l'Energie Atomique, F. G. Abeyta, Los Alamos National Laboratory; W. W. Anderson, Los Alamos National Laboratory; M. E. Byers, Los Alamos National Laboratory; D. Dennis-Koller, Los Alamos National Laboratory; J. S. Esparza, Los Alamos National Laboratory; S. D. Borror, Bechtel Nevada; C. A. Kruschwitz, Bechtel Nevada

    2004-01-01

    Data on the high-pressure melting temperatures of metals is of great interest in several fields of physics including geophysics. Measuring melt curves is difficult but can be performed in static experiments (with laser-heated diamond-anvil cells for instance) or dynamically (i.e., using shock experiments). However, at the present time, both experimental and theoretical results for the melt curve of lead are at too much variance to be considered definitive. As a result, we decided to perform a series of shock experiments designed to provide a measurement of the melt curve of lead up to about 50 GPa in pressure. At the same time, we developed and fielded a new reflectivity diagnostic, using it to make measurements on tin. The results show that the melt curve of lead is somewhat higher than the one previously obtained with static compression and heating techniques.

  9. On the brotherhood of the mitochondrial chaperones mortalin and heat shock protein 60

    PubMed Central

    Deocaris, Custer C.; Kaul, Sunil C.; Wadhwa, Renu

    2006-01-01

    The heat shock chaperones mortalin/mitochondrial heat shock protein 70 (mtHsp70) and Hsp60 are found in multiple subcellular sites and function in the folding and intracellular trafficking of many proteins. The chaperoning activity of these 2 proteins involves different structural and functional mechanisms. In spite of providing an excellent model for an evolutionarily conserved molecular “brotherhood,” their individual functions, although overlapping, are nonredundant. As they travel to various locations, both chaperones acquire different binding partners and exert a more divergent involvement in tumorigenesis, cellular senescence, and immunology. An understanding of their functional biology may lead to novel designing and development of therapeutic strategies for cancer and aging. PMID:16817317

  10. 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

    PubMed Central

    2014-01-01

    Background 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. Methods 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. Results 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. Conclusion Extracellular Hsp70 negatively regulates the production of pro-inflammatory cytokines of monocytes exposed to TLR agonists and contributes to dampen the inflammatory response. PMID:25053922

  11. Different transcriptional responses of heat shock protein 70/90 in the marine diatom Ditylum brightwellii exposed to metal compounds and endocrine-disrupting chemicals.

    PubMed

    Guo, R; Lee, M-A; Ki, J-S

    2013-07-01

    Environmental hazard assessments using diatoms have been well documented; however, their molecular toxicology has not been sufficiently studied. In this study, we characterized heat shock protein (HSP) 70/90 of the diatom Ditylum brightwellii (Db) and evaluated their transcriptional profiles in response to various environmental stresses (e.g., thermal shocks and metal and non-metal pollutants). Putative DbHSP70 (658aa, 71.7 kDa) and DbHSP90 (707aa, 80.2 kDa) proteins had conserved HSP family motifs but different C-terminus motifs, that is, "EEVD" in DbHSP70 and "MEEVD" in DbHSP90. Phylogenetic analyses of both proteins showed that D. brightwellii was well clustered with other diatoms. Real-time PCR analysis showed that thermal stress considerably upregulated DbHSP70 and DbHSP90. As for chemical pollutants, DbHSP70 greatly responded to CuSO4 and NiSO4 exposure, but not CuCl2 or NiCl2. However, DbHSP90 was significantly upregulated by all the metal compounds tested (CuSO4, NiSO4, CuCl2, and NiCl2). Strikingly, the expression of both genes was not induced by the organic pollutants tested, such as endocrine-disrupting chemicals. These data suggest that DbHSP70 and DbHSP90 are differentially involved in the defense response against various environmental stressors. Moreover, metal toxicity may be specifically affected by the conjugated anion in the metal compounds (e.g., SO4(2-) and Cl(-)). PMID:23622879

  12. Influence of heat conductivity on an intense shock wave that converges onto the center of symmetry

    NASA Astrophysics Data System (ADS)

    Makhmudov, A. A.; Popov, S. P.

    1980-04-01

    In the motion of a shock wave near the axis of a cylinder or the center of a sphere, there occurs a self-similar flow. This region is of practical importance, since many nonself-similar problems reduce to self-similar ones. In the present paper, the transformation of Guderley's (1942) self-simulating solution to an isothermal wave under the influence of nonlinear heat conductivity is analyzed numerically.

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

    PubMed

    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.

  14. Dynamic m6A mRNA methylation directs translational control of heat shock response

    PubMed Central

    Zhou, Jun; Wan, Ji; Gao, Xiangwei; Zhang, Xingqian; Qian, Shu-Bing

    2015-01-01

    The most abundant mRNA post-transcriptional modification is N6-methyladenosine (m6A) that has broad roles in RNA biology1-5. In mammalian cells, the asymmetric distribution of m6A along mRNAs leaves relatively less methylation in the 5′ untranslated region (5′UTR) compared to other regions6,7. However, whether and how 5′UTR methylation is regulated is poorly understood. Despite the crucial role of the 5′UTR in translation initiation, very little is known whether m6A modification influences mRNA translation. Here we show that in response to heat shock stress, m6A is preferentially deposited to the 5′UTR of newly transcribed mRNAs. We found that the dynamic 5′UTR methylation is a result of stress-induced nuclear localization of YTHDF2, a well characterized m6A “reader”. Upon heat shock stress, the nuclear YTHDF2 preserves 5′UTR methylation of stress-induced transcripts by limiting the m6A “eraser” FTO from demethylation. Remarkably, the increased 5′UTR methylation in the form of m6A promotes cap-independent translation initiation, providing a mechanism for selective mRNA translation under heat shock stress. Using Hsp70 mRNA as an example, we demonstrate that a single site m6A modification in the 5′UTR enables translation initiation independent of the 5′ end m7G cap. The elucidation of the dynamic feature of 5′UTR methylation and its critical role in cap-independent translation not only expands the breadth of physiological roles of m6A, but also uncovers a previously unappreciated translational control mechanism in heat shock response. PMID:26458103

  15. Brief alcohol exposure alters transcription in astrocytes via the heat shock pathway

    PubMed Central

    Pignataro, Leonardo; Varodayan, Florence P; Tannenholz, Lindsay E; Protiva, Petr; Harrison, Neil L

    2013-01-01

    Astrocytes are critical for maintaining homeostasis in the central nervous system (CNS), and also participate in the genomic response of the brain to drugs of abuse, including alcohol. In this study, we investigated ethanol regulation of gene expression in astrocytes. A microarray screen revealed that a brief exposure of cortical astrocytes to ethanol increased the expression of a large number of genes. Among the alcohol-responsive genes (ARGs) are glial-specific immune response genes, as well as genes involved in the regulation of transcription, cell proliferation, and differentiation, and genes of the cytoskeleton and extracellular matrix. Genes involved in metabolism were also upregulated by alcohol exposure, including genes associated with oxidoreductase activity, insulin-like growth factor signaling, acetyl-CoA, and lipid metabolism. Previous microarray studies performed on ethanol-treated hepatocyte cultures and mouse liver tissue revealed the induction of almost identical classes of genes to those identified in our microarray experiments, suggesting that alcohol induces similar signaling mechanisms in the brain and liver. We found that acute ethanol exposure activated heat shock factor 1 (HSF1) in astrocytes, as demonstrated by the translocation of this transcription factor to the nucleus and the induction of a family of known HSF1-dependent genes, the heat shock proteins (Hsps). Transfection of a constitutively transcriptionally active Hsf1 construct into astrocytes induced many of the ARGs identified in our microarray study supporting the hypothesis that HSF1 transcriptional activity, as part of the heat shock cascade, may mediate the ethanol induction of these genes. These data indicate that acute ethanol exposure alters gene expression in astrocytes, in part via the activation of HSF1 and the heat shock cascade. PMID:23533150

  16. Thermally induced apoptosis, necrosis, and heat shock protein expression in 3D culture.

    PubMed

    Song, Alfred S; Najjar, Amer M; Diller, Kenneth R

    2014-07-01

    This study was conducted to compare the heat shock responses of cells grown in 2D and 3D culture environments as indicated by the level of heat shock protein 70 expression and the incidence of apoptosis and necrosis of prostate cancer cell lines in response to graded hyperthermia. PC3 cells were stably transduced with a dual reporter system composed of two tandem expression cassettes-a conditional heat shock protein promoter driving the expression of green fluorescent protein (HSPp-GFP) and a cytomegalovirus (CMV) promoter controlling the constitutive expression of a "beacon" red fluorescent protein (CMVp-RFP). Two-dimensional and three-dimensional cultures of PC3 prostate cancer cells were grown in 96-well plates for evaluation of their time-dependent response to supraphysiological temperature. To induce controlled hyperthermia, culture plates were placed on a flat copper surface of a circulating water manifold that maintained the specimens within ±0.1°C of a target temperature. Hyperthermia protocols included various combinations of temperature, ranging from 37°C to 57°C, and exposure times of up to 2 h. The majority of protocols were focused on temperature and time permutations, where the response gradient was greatest. Post-treatment analysis by flow cytometry analysis was used to measure the incidences of apoptosis (annexin V-FITC stain), necrosis (propidium iodide (PI) stain), and HSP70 transcription (GFP expression). Cells grown in 3D compared with 2D culture showed reduced incidence of apoptosis and necrosis and a higher level of HSP70 expression in response to heat shock at the temperatures tested. Cells responded differently to hyperthermia when grown in 2D and 3D cultures. Three-dimensional culture appears to enhance survival plausibly by activating protective processes related to enhanced-HSP70 expression. These differences highlight the importance of selecting physiologically relevant 3D models in assessing cellular responses to hyperthermia in

  17. Identification, tissue distribution and characterization of two heat shock factors (HSFs) in goldfish (Carassius auratus).

    PubMed

    Kim, So-Sun; Chang, Ziwei; Park, Jang-Su

    2015-04-01

    Heat shock proteins (HSPs) are synthesized rapidly in response to a variety of physiological or environmental stressors, whereas the transcriptional activation of HSPs is regulated by a family of heat shock factors (HSFs). In vertebrates, multiple HSFs (HSF1-4) have been reported to have different roles in response to a range of stresses. This paper reports the cDNA cloning of two goldfish (Carassius auratus) HSF gene families, HSF1 and three isoforms of HSF2. Both HSF1 and HSF2s showed high homology to the known HSFs from other organisms, particularly the zebrafish. Different patterns of HSF1 and HSF2 mRNA expression were detected in several goldfish tissues, highlighting their distinct roles. In cadmium (Cd)-treated tissues, the responses of HSP70 showed less difference. However, the increase in HSF1 and HSF2 in these tissues differs considerable. In particular, HSF2 was induced strongly in the heart and liver. On the other hand, in heart tissue, HSF1 showed the smallest increment. These results suggest the potential role of HSF2 in assisting HSF1 in these tissues. In another in vitro experiment of hepatocyte cultures, Cd exposure caused similar patterns of goldfish HSF1 and HSF2 mRNA expression and induction of the HSP70 protein. On the other hand, an examination of the characterization of recombinant proteins showed that HSF1 undergoes a conformation change induced by heat shock above 30 °C and approaches each other in the trimer, whereas HSF2 could not sense thermal stress directly. Furthermore, immune-blot analysis of HSFs showed that both monomers and trimmers of HSF1 were observed in cadmium-induced tissues, whereas HSF2 were all in monomeric. These results show that HSF1 and HSF2 play different roles in the transcription of heat shock proteins.

  18. Evaporation and Accompanying Isotopic Fractionation of Sulfur from FE-S Melt During Shock Wave Heating

    NASA Technical Reports Server (NTRS)

    Tachibana, S.; Huss, G. R.; Miura, H.; Nakamoto, T.

    2004-01-01

    Chondrules probably formed by melting and subsequent cooling of solid precursors. Evaporation during chondrule melting may have resulted in depletion of volatile elements in chondrules. It is known that kinetic evaporation, especially evaporation from a melt, often leads to enrichment of heavy isotopes in an evaporation residue. However, no evidence for a large degree of heavy-isotope enrichment has been reported in chondrules for K, Mg, Si, and Fe (as FeO). The lack of isotopic fractionation has also been found for sulfur in troilites (FeS) within Bishunpur (LL3.1) and Semarkona (LL3.0) chondrules by an ion microprobe study. The largest fractionation, found in only one grain, was 2.7 +/- 1.4 %/amu, while all other troilite grains showed isotopic fractionations of <1 %/amu. The suppressed isotopic fractionation has been interpreted as results of (i) rapid heating of precursors at temperatures below the silicate solidus and (ii) diffusion-controlled evaporation through a surrounding silicate melt at temperatures above the silicate solidus. The kinetic evaporation model suggests that a rapid heating rate of >10(exp 4)-10(exp 6) K/h for a temperature range of 1000-1300 C is required to explain observed isotopic fractionations. Such a rapid heating rate seems to be difficult to be achieved in the X-wind model, but can be achieved in shock wave heating models. In this study, we have applied the sulfur evaporation model to the shock wave heating conditions of to evaluate evaporation of sulfur and accompanying isotopic fractionation during shock wave heating at temperatures below the silicate solidus.

  19. High transcript levels of heat-shock genes are associated with shorter lifespan of Caenorhabditis elegans.

    PubMed

    Manière, X; Krisko, A; Pellay, F X; Di Meglio, J-M; Hersen, P; Matic, I

    2014-12-01

    Individual lifespans of isogenic organisms, such as Caenorhabditis elegans nematodes, fruit flies, and mice, vary greatly even under identical environmental conditions. To study the molecular mechanisms responsible for such variability, we used an assay based on the measurement of post-reproductive nematode movements stimulated by a moderate electric field. This assay allows for the separation of individual nematodes based on their speed. We show that this phenotype could be used as a biomarker for aging because it is a better predictor of lifespan than chronological age. Fast nematodes have longer lifespans, fewer protein carbonyls, higher heat-shock resistance, and higher transcript levels of the daf-16 and hsf-1 genes, which code for the stress response transcription factors, than slow nematodes. High transcript levels of the genes coding for heat-shock proteins observed in slow nematodes correlate with lower heat-shock resistance, more protein carbonyls, and shorter lifespan. Taken together, our data suggests that shorter lifespan results from early-life damage accumulation that causes subsequent faster age-related deterioration.

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

    NASA Astrophysics Data System (ADS)

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

    2014-06-01

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

  1. Seed germination of montane forest species in response to ash, smoke and heat shock in Mexico

    NASA Astrophysics Data System (ADS)

    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.

  2. genome-wide analysis and expression profiling of the small heat shock proteins in zebrafish

    PubMed Central

    elicker, kimberly s.; hutson, lara d.

    2008-01-01

    Small Heat Shock Proteins (sHSPs) have important roles in preventing disease and promoting resistance to environmental stressors. Mutations in any one of a number of sHSPs, including HSP27 (HSPB1), HSP22 (HSPB8), αA-crystallin (HSPB4), or αB-crystallin (HSPB5) can result in neuronal degeneration, myopathy, and/or cataract in humans. Ten sHSPs are known in humans, and thirteen have been identified in teleost fish. Here we report the identification of thirteen zebrafish sHSPs. Using a combination of phylogenetic analysis and analysis of synteny, we have determined that ten are likely orthologs of human sHSPs. We have used quantitative RT-PCR to determine the relative expression levels of all thirteen sHSPs during development and in response to heat shock. Our findings indicate that most of the zebrafish sHSPs are expressed during development, and five of these genes are transcriptionally upregulated by heat shock at one or more stages of development. PMID:17888590

  3. Hsp42 is the general small heat shock protein in the cytosol of Saccharomyces cerevisiae

    PubMed Central

    Haslbeck, Martin; Braun, Nathalie; Stromer, Thusnelda; Richter, Bettina; Model, Natascha; Weinkauf, Sevil; Buchner, Johannes

    2004-01-01

    Small heat shock proteins (sHsps) are ubiquitous molecular chaperones that prevent the unspecific aggregation of proteins. So far, Hsp26 was the only unambiguously identified member of the sHsp family in Saccharomyces cerevisiae. We show here that the sHsp system in the cytosol of S. cerevisiae consists of two proteins, Hsp26 and Hsp42. Hsp42 forms large dynamic oligomers with a barrel-like structure. In contrast to Hsp26, which functions predominantly at heat shock temperatures, Hsp42 is active as a chaperone under all conditions tested in vivo and in vitro. Under heat shock conditions, both Hsp42 and Hsp26 suppress the aggregation of one-third of the cytosolic proteins. This subset is about 90% overlapping for Hsp42 and Hsp26. The sHsp substrates belong to different biochemical pathways. This indicates a general protective function of sHsps for proteome stability in S. cerevisiae. Consistent with this observation, sHsp knockout strains show phenotypical defects. Taken together, our results define Hsp42 as an important player for protein homeostasis at physiological and under stress conditions. PMID:14749732

  4. Effect of heat shock on poly(ADP-ribose) synthetase and DNA repair in Drosophila cells

    SciTech Connect

    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.

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

    PubMed Central

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

    2016-01-01

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

  6. Dendritic-tumor fusion cells derived heat shock protein70-peptide complex has enhanced immunogenicity.

    PubMed

    Zhang, Yunfei; Zhang, Yong; Chen, Jun; Liu, Yunyan; Luo, Wen

    2015-01-01

    Tumor-derived heat shock protein70-peptide complexes (HSP70.PC-Tu) have shown great promise in tumor immunotherapy due to numerous advantages. However, large-scale phase III clinical trials showed that the limited immunogenicity remained to be enhanced. In previous research, we demonstrated that heat shock protein 70-peptide complexes (HSP70.PC-Fc) derived from dendritic cell (DC)-tumor fusions exhibit enhanced immunogenicity compared with HSP70.PCs from tumor cells. However, the DCs used in our previous research were obtained from healthy donors and not from the patient population. In order to promote the clinical application of these complexes, HSP70.PC-Fc was prepared from patient-derived DC fused directly with patient-derived tumor cells in the current study. Our results showed that compared with HSP70.PC-Tu, HSP70.PC-Fc elicited much more powerful immune responses against the tumor from which the HSP70 was derived, including enhanced T cell activation, and CTL responses that were shown to be antigen specific and HLA restricted. Our results further indicated that the enhanced immunogenicity is related to the activation of CD4+ T cells and increased association with other heat shock proteins, such as HSP90. Therefore, the current study confirms the enhanced immunogenicity of HSP70.PC derived from DC-tumor fusions and may provide direct evidence promoting their future clinical use.

  7. Relationship between heat shock protein 70 expression and life span in Daphnia.

    PubMed

    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. PMID:24814302

  8. Small Heat Shock Proteins Are Novel Common Determinants of Alcohol and Nicotine Sensitivity in Caenorhabditis elegans

    PubMed Central

    Johnson, James R.; Rajamanoharan, Dayani; McCue, Hannah V.; Rankin, Kim

    2016-01-01

    Addiction to drugs is strongly determined by multiple genetic factors. Alcohol and nicotine produce distinct pharmacological effects within the nervous system through discrete molecular targets; yet, data from family and twin analyses support the existence of common genetic factors for addiction in general. The mechanisms underlying addiction, however, are poorly described and common genetic factors for alcohol and nicotine remain unidentified. We investigated the role that the heat shock transcription factor, HSF-1, and its downstream effectors played as common genetic modulators of sensitivity to addictive substances. Using Caenorhabditis elegans, an exemplary model organism with substance dose-dependent responses similar to mammals, we demonstrate that HSF-1 altered sensitivity to both alcohol and nicotine. Using a combination of a targeted RNAi screen of downstream factors and transgenic approaches we identified that these effects were contingent upon the constitutive neuronal expression of HSP-16.48, a small heat shock protein (HSP) homolog of human α-crystallin. Furthermore we demonstrated that the function of HSP-16.48 in drug sensitivity surprisingly was independent of chaperone activity during the heat shock stress response. Instead we identified a distinct domain within the N-terminal region of the HSP-16.48 protein that specified its function in comparison to related small HSPs. Our findings establish and characterize a novel genetic determinant underlying sensitivity to diverse addictive substances. PMID:26773049

  9. Biological stress responses to radio frequency electromagnetic radiation: are mobile phones really so (heat) shocking?

    PubMed

    Cotgreave, Ian A

    2005-03-01

    Cells phenotypically adapt to alterations in their intra- and extracellular environment via organised alterations to gene and protein expression. Many chemical and physical stimuli are known to drive such responses, including the induction of oxidative stress and heat shock. Increasing use of mobile telephones in our society, has brought focus on the potential for radio frequency (microwave) electromagnetic radiation to elicit biological stress responses, in association with potentially detrimental effects of this to human health. Here we review evidence suggesting altered gene and protein expression in response to such emissions, with particular focus on heat shock proteins. Non-thermal induction of heat shock proteins has been claimed by a number of investigations in in vitro cellular systems, and appears pleiotropic for many other regulatory events. However, many of these studies are flawed by inconsistencies in exposure models, cell types used and the independent reproducibility of the findings. Further, the paucity of evidence from in vivo experimentation is largely contradictory. Therefore, the validity of these effects in human health risk assessment remain unsubstantiated. Where possible, suggestions for further experimental clarification have been provided.

  10. Arginine methylation in yeast proteins during stationary-phase growth and heat shock.

    PubMed

    Lakowski, Ted M; Pak, Magnolia L; Szeitz, András; Thomas, Dylan; Vhuiyan, Mynol I; Clement, Bernd; Frankel, Adam

    2015-12-01

    Arginine methyltransferases (RMTs) catalyze the methylation of arginine residues on proteins. We examined the effects of log-phase growth, stationary-phase growth, and heat shock on the formation of methylarginines on yeast proteins to determine if the conditions favor a particular type of methylation. Utilizing linear ion trap mass spectrometry, we identify methylarginines in wild-type and RMT deletion yeast strains using secondary product ion scans (MS(3)), and quantify the methylarginines using multiple reaction monitoring (MRM). Employing MS(3) and isotopic incorporation, we demonstrate for the first time that Nη1, Nη2-dimethylarginine (sDMA) is present on yeast proteins, and make a detailed structural determination of the fragment ions from the spectra. Nη-monomethylarginine (ηMMA), Nδ-monomethylarginine (δMMA), Nη1, Nη1-dimethylarginine (aDMA), and sDMA were detected in RMT deletion yeast using MS(3) and MRM with and without isotopic incorporation, suggesting that additional RMT enzymes remain to be discovered in yeast. The concentrations of ηMMA and δMMA decreased by half during heat shock and stationary phase compared to log-phase growth of wild-type yeast, whereas sDMA increased by as much as sevenfold and aDMA decreased by 11-fold. Therefore, upon entering stressful conditions like heat shock or stationary-phase growth, there is a net increase in sDMA and decreases in aDMA, ηMMA, and δMMA on yeast proteins.

  11. Acquired thermotolerance and heat shock in the extremely thermophilic archaebacterium Sulfolobus sp. strain B12

    SciTech Connect

    Trent, J.D.; Osipiuk, J.; Pinkau, T. )

    1990-03-01

    The extreme thermophile Sulfolobus sp. strain B12 exhibits an acquired thermotolerance response. Thus, survival of cells from a 70{degrees}C culture at the lethal temperature of 92{degrees}C was enhanced by as much as 6 orders of magnitude over a 2-h period if the culture was preheated to 88{degrees}C for 60 min or longer before being exposed to the lethal temperature. In eubacteria and eucaryotes, acquired thermotolerance correlates with the induced synthesis of a dozen or so proteins known as heat shock proteins. In this Sulfolobus species, it correlates with the preferential synthesis of primarily one major protein (55 kilodaltons) and, to a much lesser extent, two minor proteins (28 and 35 kilodaltons). Since the synthesis of all other proteins was radically reduced and these proteins were apparently not degraded or exported, their relative abundance within the cell increased during the time the cells were becoming thermotolerant. They could not yet be related to known heat shock proteins. In immunoassays, they were not cross-reactive with antibodies against heat shock proteins from Escherichia coli (DnaK and GroE), which are highly conserved between eubacteria and eucaryotes. However, it appears that if acquired thermotolerance depends on the synthesis of protective proteins, then in this extremely thermophilic archaebacterium it depends primarily on one protein.

  12. Heat Shock Proteins: Intestinal Gatekeepers that Are Influenced by Dietary Components and the Gut Microbiota

    PubMed Central

    Liu, Haoyu; Dicksved, Johan; Lundh, Torbjörn; Lindberg, Jan Erik

    2014-01-01

    Trillions of microorganisms that inhabit the intestinal tract form a diverse and intricate ecosystem with a deeply embedded symbiotic relationship with their hosts. As more detailed information on gut microbiota complexity and functional diversity accumulates, we are learning more about how diet-microbiota interactions can influence the immune system within and outside the gut and host health in general. Heat shock proteins are a set of highly conserved proteins that are present in all types of cells, from microbes to mammals. These proteins carry out crucial intracellular housekeeping functions and unexpected extracellular immuno-regulatory features in order to maintain the mucosal barrier integrity and gut homeostasis. It is becoming evident that the enteric microbiota is one of the major determinants of heat shock protein production in intestinal epithelial cells. This review will focus on the interactions between diet, gut microbiota and their role for regulating heat shock protein production and, furthermore, how these interactions influence the immune system and the integrity of the mucosal barrier. PMID:25437614

  13. Chlorella saccharophila cytochrome f and its involvement in the heat shock response

    PubMed Central

    Zuppini, Anna; Gerotto, Caterina; Moscatiello, Roberto; Bergantino, Elisabetta; Baldan, Barbara

    2009-01-01

    Cytochrome f is an essential component of the major redox complex of the thylakoid membrane. Cloning and characterization are presented here of a novel partial cDNA (ChspetA) encoding cytochrome f in the psychrophile unicellular green alga Chlorella saccharophila and its involvement in the heat shock (HS) response pathway has been analysed. Semi-quantitative reverse transcriptase PCR analysis showed that ChspetA expression is up-regulated in heat-shocked cells and the protein profile of cytochrome f highlighted a release of cytochrome f into the cytosol depending on the time lapse from the HS. Evans Blue assay, analysis of chromatin condensation, and chloroplast alterations showed the induction of cell death in cell suspensions treated with cytosolic extracts from heat-shocked cells. This study identifies cytochrome f in C. saccharophila that seems to be involved in the HS-induced programmed cell death process. The data suggest that cytochrome f fulfils its role through a modulation of its transcription and translation levels, together with its intracellular localization. This work focuses on a possible role of cytochrome f into the programmed cell death-like process in a unicellular chlorophyte and suggests the existence of chloroplast-mediated programmed cell death machinery in an organism belonging to one of the primary lineages of photosynthetic eukaryotes. PMID:19773387

  14. Prediction and measurement of heat transfer rates for the shock-induced unsteady laminar boundary layer on a flat plate

    NASA Technical Reports Server (NTRS)

    Cook, W. J.

    1972-01-01

    The unsteady laminar boundary layer induced by the flow-initiating shock wave passing over a flat plate mounted in a shock tube was theoretically and experimentally studied in terms of heat transfer rates to the plate for shock speeds ranging from 1.695 to 7.34 km/sec. The theory presented by Cook and Chapman for the shock-induced unsteady boundary layer on a plate is reviewed with emphasis on unsteady heat transfer. A method of measuring time-dependent heat-transfer rates using thin-film heat-flux gages and an associated data reduction technique are outlined in detail. Particular consideration is given to heat-flux measurement in short-duration ionized shocktube flows. Experimental unsteady plate heat transfer rates obtained in both air and nitrogen using thin-film heat-flux gages generally agree well with theoretical predictions. The experimental results indicate that the theory continues to predict the unsteady boundary layer behavior after the shock wave leaves the trailing edge of the plate even though the theory is strictly applicable only for the time interval in which the shock remains on the plate.

  15. Seasonal effects of heat shock on bacterial populations, including artificial Vibrio parahaemolyticus exposure, in the Pacific oyster, Crassostrea gigas.

    PubMed

    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.

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

    PubMed

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

    2014-07-01

    Inflammation and oxidative stress are considered as likely contributors to heat injury. However, their roles in regulating the heat shock response in vivo remain unclear. We tested the hypothesis that acute quercetin treatment would improve redox status and reduce heat shock responses in mice. Mice underwent two heat tests before and after single oral administration of either quercetin (15 mg/kg) or vehicle. We measured physiologic and biochemical responses in mice during and 18 to 22 hours after heat tests, respectively. There were no significant differences in core temperature, heart rate, or blood pressure between quercetin and vehicle groups during heat exposure. Mice with relatively severe hyperthermia during the pretreatment heat test showed a significant trend toward a lower peak core temperature during the heat test after quercetin treatment. Compared with mice not exposed to heat, quercetin-treated mice had significantly lower interleukin 6 (P < .01) and higher superoxide dismutase levels (P < .01), whereas vehicle-treated mice had significantly lower total glutathione and higher 8-isoprostane levels in the circulation after heat exposure. Heat exposure significantly elevated heat shock proteins (HSPs) 72 and 90 and heat shock factor 1 levels in mouse liver, heart, and skeletal muscles, but no significant differences in tissue HSPs and heat shock factor 1 were found between quercetin- and vehicle-treated mice. These results suggest that a single moderate dose of quercetin is sufficient to alter redox status but not heat stress response in mice. Acute adaptations of peripheral tissues to heat stress may not be mediated by systemic inflammatory and redox state in vivo.

  17. T cells respond to heat shock protein 60 via TLR2: activation of adhesion and inhibition of chemokine receptors.

    PubMed

    Zanin-Zhorov, Alexandra; Nussbaum, Gabriel; Franitza, Susanne; Cohen, Irun R; Lider, Ofer

    2003-08-01

    Soluble 60 kDa heat shock protein (HSP60) activates macrophages via TLR4. We now report that soluble HSP60 activates T cells via the innate receptor TLR2. HSP60 activated T cell adhesion to fibronectin to a degree similar to other activators: IL-2, SDF-1alpha, and RANTES. T cell type and state of activation was important; nonactivated CD45RA+ and IL-2-activated CD45RO+ T cells responded optimally (1 h) at low concentrations (0.1-1 ng/ml), but nonactivated CD45RO+ T cells required higher concentrations (approximately 1 microg/ml) of HSP60. T cell HSP60 signaling was inhibited specifically by monoclonal antibodies (mAb) to TLR2 but not by a mAb to TLR4. Indeed, T cells from mice with mutated TLR4 could still respond to HSP60, whereas Chinese hamster T cells with mutated TLR2 did not respond. The human T cell response to soluble HSP60 depended on phosphatidylinositol 3-kinase and protein kinase C signaling and involved the phosphorylation of Pyk-2. Soluble HSP60 also inhibited actin polymerization and T cell chemotaxis through extracellular matrix-like gels toward the chemokines SDF-1alpha (CXCL12) or ELC (CCL19). Exposure to HSP60 for longer times (18 h) down-regulated chemokine receptor expression: CXCR4 and CCR7. These results suggest that soluble HSP60, through TLR2-dependent interactions, can regulate T cell behavior in inflammation. PMID:12824285

  18. Comprehensive Characterization of Heat Shock Protein 27 Phosphorylation in Human Endothelial Cells Stimulated by the Microbial Dithiole Thiolutin

    PubMed Central

    Dai, Shujia; Jia, Yifeng; Wu, Shiaw-Lin; Isenberg, Jeff S.; Ridnour, Lisa A.; Bandle, Russell W.; Wink, David A.; Roberts, David D.; Karger, Barry L.

    2009-01-01

    Thiolutin is a sulfur-based microbial compound with known activity as an angiogenesis inhibitor. Relative to previously studied angiogenesis inhibitors, thiolutin is a remarkably potent inducer of heat shock protein 27 (Hsp27) phosphorylation. This phosphorylation requires p38 kinase but is independent of increased p38 phosphorylation. To elucidate how thiolutin regulates Hsp27 phosphorylation and ultimately angiogenesis, Hsp27 was immunoprecipitated using nonphosphorylated and phospho-Ser78 specific antibodies from lysates of thiolutin treated and untreated human umbilical vein endothelial cells and analyzed by LC–MS. Separate LC–MS analyses of Lys-C, Lys-C plus trypsin, and Lys-C plus Glu-C digests provided 100% sequence coverage, including the identification of a very large 13 kDa Lys-C fragment using a special sample handling procedure (4 M guanidine HCl) prior to the LC–MS analysis to improve the large peptide recovery. The analysis revealed a novel post-translational modification of Hsp27 involving truncation of the N-terminal Met and acetylation of the penultimate Thr. Analysis of a Glu-C fragment containing two phosphorylation sites, Ser78 and Ser82, and a tryptic fragment containing the other phosphorylation site, Ser15, enabled quantitative stoichiometry of Hsp27 phosphorylation by LC–MS. The strategy revealed details of Hsp27 phosphorylation, including significant di-phosphorylation at both Ser78 and Ser82, that would be difficult to obtain by traditional approaches because oligomerization of the hydrophobic N-terminal region of the molecule prevents efficient enzymatic cleavage. The combination of Western blotting, immunoprecipation, and LC–MS provides a quantitative analysis of thiolutin-stimulated Hsp27 phosphorylation and further defines the role of Hsp27 in the antiangiogenic activities of thiolutin and related dithiolethiones. PMID:18720982

  19. Post-transcriptional Repair of a Split Heat Shock Protein 90 Gene by mRNA trans-Splicing*♦

    PubMed Central

    Nageshan, Rishi Kumar; Roy, Nainita; Hehl, Adrian B.; Tatu, Utpal

    2011-01-01

    Heat shock protein 90 participates in diverse biological processes ranging from protein folding, cell cycle, signal transduction and development to evolution in all eukaryotes. It is also critically involved in regulating growth of protozoa such as Dictyostelium discoideum, Leishmania donovani, Plasmodium falciparum, Trypanosoma cruzi, and Trypanosoma evansi. Selective inhibition of Hsp90 has also been explored as an intervention strategy against important human diseases such as cancer, malaria, or trypanosomiasis. Giardia lamblia, a simple protozoan parasite of humans and animals, is an important cause of diarrheal disease with significant morbidity and some mortality in tropical countries. Here we show that the G. lamblia cytosolic hsp90 (glhsp90) is split in two similar sized fragments located 777 kb apart on the same scaffold. Intrigued by this unique arrangement, which appears to be specific for the Giardiinae, we have investigated the biosynthesis of GlHsp90. We used genome sequencing to confirm the split nature of the giardial hsp90. However, a specific antibody raised against the peptide detected a product with a mass of about 80 kDa, suggesting a post-transcriptional rescue of the genomic defect. We show evidence for the joining of the two independent Hsp90 transcripts in-trans to one long mature mRNA presumably by RNA splicing. The splicing junction carries hallmarks of classical cis-spliced introns, suggesting that the regular cis-splicing machinery may be sufficient for repair of the open reading frame. A complementary 26-nt sequence in the “intron” regions adjacent to the splice sites may assist in positioning the two pre-mRNAs for processing. This is the first example of post-transcriptional rescue of a split gene by trans-splicing. PMID:21209094

  20. Post-transcriptional repair of a split heat shock protein 90 gene by mRNA trans-splicing.

    PubMed

    Nageshan, Rishi Kumar; Roy, Nainita; Hehl, Adrian B; Tatu, Utpal

    2011-03-01

    Heat shock protein 90 participates in diverse biological processes ranging from protein folding, cell cycle, signal transduction and development to evolution in all eukaryotes. It is also critically involved in regulating growth of protozoa such as Dictyostelium discoideum, Leishmania donovani, Plasmodium falciparum, Trypanosoma cruzi, and Trypanosoma evansi. Selective inhibition of Hsp90 has also been explored as an intervention strategy against important human diseases such as cancer, malaria, or trypanosomiasis. Giardia lamblia, a simple protozoan parasite of humans and animals, is an important cause of diarrheal disease with significant morbidity and some mortality in tropical countries. Here we show that the G. lamblia cytosolic hsp90 (glhsp90) is split in two similar sized fragments located 777 kb apart on the same scaffold. Intrigued by this unique arrangement, which appears to be specific for the Giardiinae, we have investigated the biosynthesis of GlHsp90. We used genome sequencing to confirm the split nature of the giardial hsp90. However, a specific antibody raised against the peptide detected a product with a mass of about 80 kDa, suggesting a post-transcriptional rescue of the genomic defect. We show evidence for the joining of the two independent Hsp90 transcripts in-trans to one long mature mRNA presumably by RNA splicing. The splicing junction carries hallmarks of classical cis-spliced introns, suggesting that the regular cis-splicing machinery may be sufficient for repair of the open reading frame. A complementary 26-nt sequence in the "intron" regions adjacent to the splice sites may assist in positioning the two pre-mRNAs for processing. This is the first example of post-transcriptional rescue of a split gene by trans-splicing. PMID:21209094

  1. Molecular cloning and expression analysis of a pearl oyster (Pinctada martensii) heat shock protein 90 (HSP90).

    PubMed

    Liang, H Y; Wang, Z X; Lei, Q N; Huang, R L; Deng, Y W; Wang, Q H; Jiao, Y; Du, X D

    2015-01-01

    Heat shock protein 90 (HSP90) is an important molecular chaperone required for proper folding of cellular proteins, and thus, it plays an essential role in protecting cells from damage during stress. In this study, an HSP90 cDNA designated PmHSP90 was cloned from the mantle tissue of the pearl oyster Pinctada martensii using reverse transcription polymerase chain reaction (RT-PCR) coupled with the rapid amplification of cDNA ends (RACE) approach. PmHSP90 cDNA was 2584 bp in length, including an open reading frame of 2160 bp, which encodes a polypeptide of 719 amino acid residues, with predicted molecular mass and isoelectric point of 83.0 kDa and 4.87, respectively. Multiple-sequence alignment indicated that HSP90 is highly conserved among species, and PmHSP90 showed 89% sequence identity to Crassostrea gigas HSP90. Five conserved amino acid blocks defined as HSP90 protein family signatures were also observed in PmHSP90, indicating that PmHSP90 may be a cytosolic member of the HSP90 family. Expression levels of PmHSP90 were detected in various tissues of P. martensii and in hemocytes under three different stress conditions using quantitative real-time PCR (qPCR). The results demonstrate that PmHSP90 mRNA is constitutively expressed in all the tested tissues and may be involved in the immune response against thermal stress, lipopolysaccharide stimulation, and nucleus insertion operations. Studies on PmHSP90 are a valuable source to further explore the immune system in pearl oysters during the production of pearls, and may enhance our knowledge of molluscan innate immunity. PMID:26782528

  2. Expression pattern of heat-shock cognate 70 gene of humphead snapper, Lutjanus sanguineus (Cuvier), infected by Vibrio harveyi.

    PubMed

    Zhang, X Z; Wu, Z H; Yang, S P; Pang, H Y; Jian, J C; Lu, Y S

    2011-10-01

    The heat-shock cognate 70 (HSC70) gene of humphead snapper, Lutjanus sanguineus, designated as ByHSC70, was cloned by rapid amplification of cDNA ends (RACE) with the primers designed from the known expressed sequence tag (EST) identified from the subtracted cDNA library of the head kidney of humphead snapper. The full-length cDNA of ByHSC70 is 2313 bp, containing a 5' terminal untranslated region (UTR) of 96 bp, a 3' terminal UTR of 267 bp, and an open reading frame (ORF) of 1950 bp encoding a polypeptide of 650 amino acids with a theoretical molecular weight of 71.21 kDa and an estimated isoelectric point (pI) of 5.08. ByHSC70 contained three classical HSP70 family signatures. BLAST analysis showed that the amino acid sequence of ByHSC70 had the highest similarity of 99% when compared with other HSC70s. Fluorescent real-time quantitative RT-PCR was used to examine the expression of ByHSC70 gene in eight kinds of tissues/organs of humphead snapper after challenge with Vibrio harveyi. There was a clear time-dependent expression pattern of ByHSC70 in head kidney, spleen and thymus after bacterial challenge, and the expression of mRNA reached a maximum level at 9, 6 and 24 h post-infection and then returned to control levels after 15, 24 and 36 h, respectively. Our results suggest that HSC70 is an important component in the immune system of humphead snapper, its their rapid transcriptional upregulation in response to V. harveyi infection might be important for survival of humphead snapper.

  3. Expression pattern of heat shock protein 90 gene of humphead snapper Lutjanus sanguineus during pathogenic Vibrio harveyi stress.

    PubMed

    Zhang, X Z; Dai, L P; Wu, Z H; Jian, J C; Lu, Y S

    2011-07-01

    The full-length cDNA of heat shock protein 90 (HSP90) of humphead snapper Lutjanus sanguineus, designated as rsHSP90, was cloned by rapid amplification of complementary (c)DNA ends (RACE) techniques with the primers designed from the known expressed sequence tag (EST) sequence identified from the subtracted cDNA library of the head kidney of L. sanguineus. Sequence analysis showed that the full-length cDNA of rsHSP90 was 2745 bp, containing a 5' terminal untranslated region (UTR) of 99 bp, a 3' terminal UTR of 471 bp and an open reading frame (ORF) of 2175 bp encoding a polypeptide of 725 amino acids. On the basis of the deduced amino acid sequence, the theoretical molecular mass of rsHSP90 was calculated to be 83·18 kDa with an isoelectric point of 4·79. Moreover, five classical HSP90 family signatures were found in the amino acids sequence of rsHSP90 by PredictProtein. Basic local-alignment search-tool (BLAST) analysis revealed that the amino acids sequence of rsHSP90 had the highest similarity of 97% when compared with other HSP90s. Fluorescent real-time quantitative reverse-transcription (RT)-PCR was used to examine the expression pattern of rsHSP90 in eight kinds of tissues and organs of L. sanguineus challenged with Vibrio harveyi. There was a clear time-dependent expression pattern of rsHSP90 in head kidney, spleen and thymus after bacterial challenge and the expression of messenger (m)RNA reached the maximum level at the time points of 9, 15 and 24 h, respectively. The up-regulated mRNA expression of rsHSP90 in L. sanguineus after bacterial challenge indicated that rsHSP90 was inducible and might be involved in immune response.

  4. Assessment of Aerothermal Heating Augmentation Attributed to Surface Catalysis in High Enthalpy Shock Tunnel Flows

    NASA Astrophysics Data System (ADS)

    MacLean, M.; Holden, M.

    2009-01-01

    The effect of gas/surface interaction in making CFD predictions of convective heating has been considered with application to ground tests performed in high enthalpy shock tunnels where additional heating augmentation attributable to surface recombination has been observed for nitrogen, air and carbon dioxide flows. For test articles constructed of stainless steel and aluminum, measurements have been made with several types of heat transfer instrumentation including thin- film, calorimeter, and coaxial thermocouple sensors. These experiments have been modeled by computations made with the high quality, chemically reacting, Navier- Stokes solver, DPLR and the heating results compared. Some typical cases considered include results on an axisymmetric sphere-cone, axisymmetric spherical capsule, spherical capsule at angle of attack, and two- dimensional cylinder. In nitrogen flows, cases considered show a recombination probability on the order of 10-3, which agrees with published data. In many cases in air and CO2, measurements exceeding the predicted level of convective heating have been observed which are consistent with approximately complete recombination (to O2/N2 or CO2) on the surface of the model (sometimes called a super-catalytic wall). It has been recognized that the conclusion that this behavior is tied to an excessively high degree of catalytic efficiency is dependent on the current understanding of the freestream and shock-layer state of the gas.

  5. Shock heating in numerical simulations of kink-unstable coronal loops.

    PubMed

    Bareford, M R; Hood, A W

    2015-05-28

    An analysis of the importance of shock heating within coronal magnetic fields has hitherto been a neglected area of study. We present new results obtained from nonlinear magnetohydrodynamic simulations of straight coronal loops. This work shows how the energy released from the magnetic field, following an ideal instability, can be converted into thermal energy, thereby heating the solar corona. Fast dissipation of magnetic energy is necessary for coronal heating and this requirement is compatible with the time scales associated with ideal instabilities. Therefore, we choose an initial loop configuration that is susceptible to the fast-growing kink, an instability that is likely to be created by convectively driven vortices, occurring where the loop field intersects the photosphere (i.e. the loop footpoints). The large-scale deformation of the field caused by the kinking creates the conditions for the formation of strong current sheets and magnetic reconnection, which have previously been considered as sites of heating, under the assumption of an enhanced resistivity. However, our simulations indicate that slow mode shocks are the primary heating mechanism, since, as well as creating current sheets, magnetic reconnection also generates plasma flows that are faster than the slow magnetoacoustic wave speed. PMID:25897092

  6. Shock heating in numerical simulations of kink-unstable coronal loops

    PubMed Central

    Bareford, M. R.; Hood, A. W.

    2015-01-01

    An analysis of the importance of shock heating within coronal magnetic fields has hitherto been a neglected area of study. We present new results obtained from nonlinear magnetohydrodynamic simulations of straight coronal loops. This work shows how the energy released from the magnetic field, following an ideal instability, can be converted into thermal energy, thereby heating the solar corona. Fast dissipation of magnetic energy is necessary for coronal heating and this requirement is compatible with the time scales associated with ideal instabilities. Therefore, we choose an initial loop configuration that is susceptible to the fast-growing kink, an instability that is likely to be created by convectively driven vortices, occurring where the loop field intersects the photosphere (i.e. the loop footpoints). The large-scale deformation of the field caused by the kinking creates the conditions for the formation of strong current sheets and magnetic reconnection, which have previously been considered as sites of heating, under the assumption of an enhanced resistivity. However, our simulations indicate that slow mode shocks are the primary heating mechanism, since, as well as creating current sheets, magnetic reconnection also generates plasma flows that are faster than the slow magnetoacoustic wave speed. PMID:25897092

  7. Heat transfer measurements and CFD comparison of swept shock wave/boundary-layer interactions

    NASA Technical Reports Server (NTRS)

    Lee, Y.; Settles, G. S.; Horstman, C. C.

    1992-01-01

    An experimental research program providing basic knowledge and establishing new data on the heat transfer in swept shock wave/boundary-layer interactions is described. An equilibrium turbulent boundary-layer on a flat plate is subjected to impingement by swept planar shock waves generated by a sharp fin. Five different interactions with fin angles ranging from 10 to 20 deg at freestream Mach numbers of 3.0 and 4.0 produce a variety of interaction strengths from weak to very strong. A foil heater generates a uniform heat flux over the flat plate surface and miniature thin-film-resistance sensors mounted on it are used to measure the local surface temperature. The heat convection equation is then solved for the heat transfer distribution within an interaction, yielding a total uncertainty of about +/- 10 percent. These experimental data are compared with the results of numerical Navier-Stokes solutions which employ a kappa-epsilon turbulence model. Finally, a simplified form of the peak heat transfer correlation for fin interactions is suggested.

  8. Overexpression of heat shock protein 70 in stomach of stress-induced gastric ulcer-resistant rats.

    PubMed

    Shichijo, Kazuko; Ihara, Makoto; Matsuu, Mutsumi; Ito, Masahiro; Okumura, Yutaka; Sekine, Ichiro

    2003-02-01

    Expression of heat shock protein 70, induced by an antiulcer drug, provides protection against gastric ulcers. However, the mechanisms responsible for this protection are not known. The expression in ulcer-resistant, spontaneously hypertensive rats was 2.8-fold higher than in normotensive rats. One hour after restraint and water immersion stress, strong nuclear immunoreactivity was observed in nuclei of surface epithelial cells at the crest of gastric mucosal folds, the first site of ulceration, only in spontaneously hypertensive rats. Heat shock cognate protein 70, which is expressed in mucus-secreting cells, was not overexpressed in spontaneously hypertensive rats. Heat shock protein 70 expression was attenuated by chemical sympathectomy, which also resulted in abolition of the increase of mucosal blood flow and aggravation of ulcers. Our results indicate that overexpression of heat shock protein 70 in the stomach seems to protect against gastric ulcers through its cytoprotective effects on gastric mucosa by increasing mucosal blood flow. PMID:12643613

  9. Electron heating, magnetic field amplification, and cosmic-ray precursor length at supernova remnant shocks

    SciTech Connect

    Laming, J. Martin; Hwang, Una; Ghavamian, Parviz; Rakowski, Cara E-mail: Una.Hwang-1@nasa.gov

    2014-07-20

    We investigate the observability, by direct and indirect means, of a shock precursor arising from magnetic field amplification by cosmic rays. We estimate the depth of such a precursor under conditions of nonresonant amplification, which can provide magnetic field strengths comparable to those inferred for supernova remnants. Magnetic field generation occurs as the streaming cosmic rays induce a plasma return current, and it may be quenched by either nonresonant or resonant channels. In the case of nonresonant saturation, the cosmic rays become magnetized and amplification saturates at higher magnetic fields. The precursor can extend out to 10{sup 17}-10{sup 18} cm and is potentially detectable. If resonant saturation occurs, the cosmic rays are scattered by turbulence and the precursor length will likely be much smaller. The dependence of precursor length on shock velocity has implications for electron heating. In the case of resonant saturation, this dependence is similar to that in the more familiar resonantly generated shock precursor, which when expressed in terms of the cosmic-ray diffusion coefficient kappav and shock velocity v{sub s} is kappav/v{sub s} . In the nonresonantly saturated case, the precursor length declines less quickly with increasing v{sub s} . Where precursor length proportional to 1/v{sub s} gives constant electron heating, this increased precursor length could be expected to lead to higher electron temperatures for nonresonant amplification. This should be expected at faster supernova remnant shocks than studied by previous works. Existing results and new data analysis of SN 1006 and Cas A suggest some observational support for this idea.

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

    PubMed

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

    1994-02-01

    We tested whether resistance of lymphocytes to heat stress is modified by breed, intracellular glutathione content, and extracellular antioxidants. In the first experiment, lymphocytes from Angus (Bos taurus, non-heat-tolerant), Brahman (B. indicus, heat-tolerant), and Senepol (B. taurus, heat-tolerant) heifers (12 heifers per breed) were cultured at 45 degrees C for 3 h to evaluate thermal killing, at 42 degrees C for 12 h in a 60-h phytohemagglutinin-induced proliferation test, and at 42 degrees C for 1 h to measure induction of heat shock protein 70 (HSP70). Killing at 45 degrees C was affected by breed x temperature (P < .01); the decrease in viability caused by a temperature of 45 degrees C was greater for Angus than for Brahman or Senepol. For phytohemagglutinin-stimulated lymphocytes, heating to 42 degrees C reduced [3H]thymidine incorporation equally for all breeds. Viability at the end of culture was affected (P < .001) by a breed x temperature interaction because the decrease in viability caused by culture at 42 degrees C was greatest for lymphocytes from Angus heifers. Heat shock for 1 h at 42 degrees C caused a two- to threefold increase in intracellular concentrations of HSP70, but there was no interaction of temperature with breed. In another experiment (with lymphocytes harvested from three Holstein cows), buthionine sulfoximine, a glutathione synthesis inhibitor, inhibited (P < .01) proliferation of phytohemagglutinin-stimulated lymphocytes at 38.5 and 42 degrees C. Addition of the antioxidants glutathione or thioredoxin to culture did not reduce the effects of heating to 42 degrees C on proliferation.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8157528

  11. Al 1s-2p Absorption Spectroscopy of Shock-Wave Heating and Compression in Laser-Driven Planar Foil

    SciTech Connect

    Sawada, H.; Regan, S.P.; Radha, P.B.; Epstein, R.; Li, D.; Goncharov, V.N.; Hu, S.X.; Meyerhofer, D.D.; Delettrez, J.A.; Jaanimagi, P.A.; Smalyuk, V.A.; Boehly, T.R.; Sangster, T.C.; Yaakobi, B.; Mancini, R.C.

    2009-05-19

    Time-resolved Al 1s-2p absorption spectroscopy is used to diagnose direct-drive, shock-wave heating and compression of planar targets having nearly Fermi-degenerate plasma conditions (Te ~ 10–40 eV, rho ~ 3–11 g/cm^3) on the OMEGA Laser System [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)]. A planar plastic foil with a buried Al tracer layer was irradiated with peak intensities of 10^14–10^15 W/cm^2 and probed with the pseudocontinuum M-band emission from a point-source Sm backlighter in the range of 1.4–1.7 keV. The laser ablation process launches 10–70 Mbar shock waves into the CH/Al/CH target. The Al 1s-2p absorption spectra were analyzed using the atomic physic code PRISMSPECT to infer Te and rho in the Al layer, assuming uniform plasma conditions during shock-wave heating, and to determine when the heat front penetrated the Al layer. The drive foils were simulated with the one-dimensional hydrodynamics code LILAC using a flux-limited (f =0.06 and f =0.1) and nonlocal thermal-transport model [V. N. Goncharov et al., Phys. Plasmas 13, 012702 (2006)]. The predictions of simulated shock-wave heating and the timing of heat-front penetration are compared to the observations. The experimental results for a wide variety of laser-drive conditions and buried depths have shown that the LILAC predictions using f = 0.06 and the nonlocal model accurately model the shock-wave heating and timing of the heat-front penetration while the shock is transiting the target. The observed discrepancy between the measured and simulated shock-wave heating at late times of the drive can be explained by the reduced radiative heating due to lateral heat flow in the corona.

  12. A bipartite operator interacts with a heat shock element to mediate early meiotic induction of Saccharomyces cerevisiae HSP82

    SciTech Connect

    Szent-Gyorgyi, C.

    1995-12-01

    This report seeks to characterize the activation of meiotic gene in terms of cis-acting DNA elements and their associated factors in Saccharomyces cerevisiae. It was found that vegetative repression and meiotic induction depend on interactions of the promoter-proximal heat shock element with a nearby bipartite repression element. The experiments described explore how two different regulatory pathways induce transcription by stimulating a single classical activation element, a nonspecific heat shock element. 81 refs., 10 figs., 1 tab.

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

    NASA Astrophysics Data System (ADS)

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

    2016-03-01

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

  14. Overall picture of expressed Heat Shock Factors in Glycine max, Lotus japonicus and Medicago truncatula.

    PubMed

    Soares-Cavalcanti, Nina M; Belarmino, Luís C; Kido, Ederson A; Pandolfi, Valesca; Marcelino-Guimarães, Francismar C; Rodrigues, Fabiana A; Pereira, Gonçalo A G; Benko-Iseppon, Ana M

    2012-06-01

    Heat shock (HS) leads to the activation of molecular mechanisms, known as HS-response, that prevent damage and enhance survival under stress. Plants have a flexible and specialized network of Heat Shock Factors (HSFs), which are transcription factors that induce the expression of heat shock proteins. The present work aimed to identify and characterize the Glycine max HSF repertory in the Soybean Genome Project (GENOSOJA platform), comparing them with other legumes (Medicago truncatula and Lotus japonicus) in view of current knowledge of Arabidopsis thaliana. The HSF characterization in leguminous plants led to the identification of 25, 19 and 21 candidate ESTs in soybean, Lotus and Medicago, respectively. A search in the SuperSAGE libraries revealed 68 tags distributed in seven HSF gene types. From the total number of obtained tags, more than 70% were related to root tissues (water deficit stress libraries vs. controls), indicating their role in abiotic stress responses, since the root is the first tissue to sense and respond to abiotic stress. Moreover, as heat stress is related to the pressure of dryness, a higher HSF expression was expected at the water deficit libraries. On the other hand, expressive HSF candidates were obtained from the library inoculated with Asian Soybean Rust, inferring crosstalk among genes associated with abiotic and biotic stresses. Evolutionary relationships among sequences were consistent with different HSF classes and subclasses. Expression profiling indicated that regulation of specific genes is associated with the stage of plant development and also with stimuli from other abiotic stresses pointing to the maintenance of HSF expression at a basal level in soybean, favoring its activation under heat-stress conditions.

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

    PubMed Central

    Muranova, Lydia K.; Weeks, Stephen D.; Strelkov, Sergei V.; Gusev, Nikolai B.

    2015-01-01

    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. PMID:25965061

  16. Heat shock proteins in Trypanosoma cruzi: identification and localization of HSP70 and HSP60 proteins and structure of HSP60 genes (brief report).

    PubMed

    de Marval, M G; Souto-Padron, T; Gottesdiener, K; Silva, R; van der Ploeg, L H; Rondinelli, E

    1993-01-01

    To identify the members of the HSP70 and HSP60 families of Trypanosoma cruzi, we analysed 35S methionine epimastigote cells by two dimensional Western blot. At 29 degrees C, an HSP70 monoclonal antibody (anti-D. melanogaster) recognized eight isotypes. At least five of these were heat-induced. Polyclonal antibody against the 65 KDa antigen (anti-M. tuberculosis) recognized three isotypes with identical molecular weights, but different microliters. Only one isoform was heat induced. The cellular distribution of HSP70 and HSP60 was studied by immunoelectron microscopy. Anti-HSP70 reactive protein was localized in the cytoplasm, mitochondria and nucleus, while anti-HSP60 protein was found in the mitochondrion and in close association with the kinetoplast. To characterize the HSP60 gene and its proteins, we isolated a genomic T. cruzi clone encoding the HSP60 gene. T. cruzi HSP60 genes could be shown to be organized in 2100 nt tandem arrays. RELP in the HSP60 genes revealed that at least three different types of HSP60 genes were encoded in the T cruzi genome. The predicted open reading frame measured exhibits about 50% identity to other HSP60 described. Expression of these HSP60 genes could not be induced by 2 hours heat shock at 37 degrees C. Post-transcriptional mechanisms may be responsible for HSP60 induction in T. cruzi. PMID:7670543

  17. Assessment of Heat Shock Protein 70 Induction by Heat in Alfalfa Varieties and Constitutive Overexpression in Transgenic Plants

    PubMed Central

    Ferradini, Nicoletta; Iannacone, Rina; Capomaccio, Stefano; Metelli, Alessandra; Armentano, Nadia; Semeraro, Lucia; Cellini, Francesco; Veronesi, Fabio; Rosellini, Daniele

    2015-01-01

    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. PMID:25951604

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

    PubMed

    Ferradini, Nicoletta; Iannacone, Rina; Capomaccio, Stefano; Metelli, Alessandra; Armentano, Nadia; Semeraro, Lucia; Cellini, Francesco; Veronesi, Fabio; Rosellini, Daniele

    2015-01-01

    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. PMID:25951604

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

    PubMed

    Ferradini, Nicoletta; Iannacone, Rina; Capomaccio, Stefano; Metelli, Alessandra; Armentano, Nadia; Semeraro, Lucia; Cellini, Francesco; Veronesi, Fabio; Rosellini, Daniele

    2015-01-01

    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.

  20. Different transcriptional responses of heat shock protein 20 in the marine diatom Ditylum brightwellii exposed to metals and endocrine-disrupting chemicals.

    PubMed

    Lee, Min-Ah; Guo, Ruoyu; Ki, Jang-Seu

    2014-12-01

    Diatoms are sensitive indicators of water quality, and hence used for environmental hazard assessments; however, their toxicogenomic studies have been insufficiently attempted. In the present study, we determined the cDNA sequence of heat shock protein 20 (Hsp20) gene from the diatom Ditylum brightwellii, and examined the transcriptional responses of the gene after exposing it to environmental stressors such as thermal shock, metals, and endocrine-disrupting chemicals (EDCs). The open reading frame (ORF) of DbHsp20 was 531 bp long, encoding 177 amino acid residues (19.49 kDa) with a conserved C-terminal and α-crystallin domain. The genomic region of DbHsp20 did not contain introns. Phylogeny of eukaryotic Hsp20s showed D. brightwellii was closely related to other diatoms. With regard to the gene expressional profile, real-time PCR results showed that the gene was significantly upregulated (P < 0.001) under thermal stress, with the highest change of 3.2-fold. Metals' (copper and nickel) treatments showed that it was induced after a certain point of treated concentration. On the contrary, EDCs did not display noticeable change on the expression of DbHsp20. These results suggest that the diatom Hsp20 basically responds to thermal stress, but may differentially respond to toxic substances such as metals and organic compounds such as EDCs. PMID:23661567

  1. Different transcriptional responses of heat shock protein 20 in the marine diatom Ditylum brightwellii exposed to metals and endocrine-disrupting chemicals.

    PubMed

    Lee, Min-Ah; Guo, Ruoyu; Ki, Jang-Seu

    2014-12-01

    Diatoms are sensitive indicators of water quality, and hence used for environmental hazard assessments; however, their toxicogenomic studies have been insufficiently attempted. In the present study, we determined the cDNA sequence of heat shock protein 20 (Hsp20) gene from the diatom Ditylum brightwellii, and examined the transcriptional responses of the gene after exposing it to environmental stressors such as thermal shock, metals, and endocrine-disrupting chemicals (EDCs). The open reading frame (ORF) of DbHsp20 was 531 bp long, encoding 177 amino acid residues (19.49 kDa) with a conserved C-terminal and α-crystallin domain. The genomic region of DbHsp20 did not contain introns. Phylogeny of eukaryotic Hsp20s showed D. brightwellii was closely related to other diatoms. With regard to the gene expressional profile, real-time PCR results showed that the gene was significantly upregulated (P < 0.001) under thermal stress, with the highest change of 3.2-fold. Metals' (copper and nickel) treatments showed that it was induced after a certain point of treated concentration. On the contrary, EDCs did not display noticeable change on the expression of DbHsp20. These results suggest that the diatom Hsp20 basically responds to thermal stress, but may differentially respond to toxic substances such as metals and organic compounds such as EDCs.

  2. A description of electron heating with an electrostatic potential jump in a parallel, collisionless, fire hose shock

    NASA Technical Reports Server (NTRS)

    Ellison, Donald C.; Jones, Frank C.

    1988-01-01

    The electron heating required if protons scatter elastically in a parallel, collisionless shock is calculated. Near-elastic proton scattering off large amplitude background magnetic field fluctuations might be expected if the waves responsible for the shock dissipation are generated by the fire hose instability. The effects of an electrostatic potential jump in the shock layer are included by assuming that the energy lost by protons in traversing the potential jump is converted into electron thermal pressure. It is found that the electron temperature increase is a strong function of the potential jump. Comparison is made to the parallel shock plasma simulation of Quest (1987).

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

    PubMed

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

    2015-08-01

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

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

    PubMed

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

    2015-08-01

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

  5. Effect of thermal manipulation during embryogenesis on liver heat shock protein expression in chronic heat stressed colored broiler chickens.

    PubMed

    Vinoth, A; Thirunalasundari, T; Tharian, Jenny Anne; Shanmugam, M; Rajkumar, U

    2015-10-01

    Thermal manipulation during embryogenesis has been shown to improve thermo tolerance in broilers. Heat shock proteins are a family of proteins produced in response to variety of stress and protect cells from damage. The aim of this study was to evaluate the effect of thermal manipulation (TM) during embryogenesis on HSP gene and protein expression in the embryos and in chronic heat stressed 42nd day old chicks. On 15th day of incubation, fertile eggs from two breeds-Naked neck (NN) and Punjab Broiler-2 (PB-2) were randomly divided in to two groups, namely Control (C) eggs were incubated under standard incubation conditions and Thermal Conditioning (TC) eggs were exposed to higher incubation temperature (40.5°C) for 3h on 15th, 16th and 17th day of incubation. The chicks so obtained from each group were further subdivided and reared from 15th-42nd day as normal (N; 25±1°C, 70% RH) and heat exposed (HE; 35±1°C, 50% RH) resulting in four treatment groups (CN, CHE, TCN and TCHE). Embryos of two groups (C and TC) on 17th day and birds from four treatment groups on 42nd day were sacrificed. Liver was collected for analysis of gene expression by real-time PCR and protein expression by Western blot of Heat Shock Proteins (HSP 90 alpha, HSP 90 beta, HSP 70, HSP 60, HSP 27 and ubiquitin). The plasma collected on 42nd day was analyzed for biochemical parameters. Thermal challenging of embryos of both the breeds caused significant (P≤0.05) increase in all the HSPs gene and protein expression. The TCHE chicks had significantly (P≤0.05) lower HSPs gene and protein expressions and oxidative stress compared to CHE groups in both NN and PB-2. Based on these findings it can be concluded that TM during incubation provides adaptation to broiler chicks during chronic heat stress. PMID:26590469

  6. Cloning of the heat shock protein 90 and 70 genes from the beet armyworm, Spodoptera exigua, and expression characteristics in relation to thermal stress and development

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two full-length complementary DNAs (cDNAs) of heat shock protein (HSP) genes (Se-hsp90 and Se-hsp70) were cloned from the beet armyworm, Spodoptera exigua, and their expression was investigated in relation to cold shock, heat shock, and development. The open reading frames of Se-hsp90 and Sehsp70 ar...

  7. Heat shock protein 70, heat shock protein 32, and vascular endothelial growth factor production and their effects on lipopolysaccharide-induced apoptosis in porcine aortic endothelial cells

    PubMed Central

    Bernardini, Chiara; Zannoni, Augusta; Turba, Maria Elena; Fantinati, Paolo; Tamanini, Carlo; Bacci, Maria Laura; Forni, Monica

    2005-01-01

    Lipopolysaccharide (LPS) is a highly proactive molecule that causes in vivo a systemic inflammatory response syndrome and activates in vitro the inflammatory pathway in different cellular types, including endothelial cells (EC). Because the proinflammatory status could lead to EC injury and apoptosis, the expression of proinflammatory genes must be finely regulated through the induction of protective genes. This study aimed at determining whether an LPS exposure is effective in inducing apoptosis in primary cultures of porcine aortic endothelial cells and in stimulating heat shock protein (Hsp)70 and Hsp32 production as well as vascular endothelial growth factor (VEGF) secretion. Cells between third and eighth passage were exposed to 10 μg/mL LPS for 1, 7, 15, and 24 hours (time-course experiments) or to 1, 10, and 100 μg/mL LPS for 7 and 15 hours (dose-response experiments). Apoptosis was not affected by 1 μg/mL LPS but significantly increased in a dose-dependent manner with the highest LPS doses. Furthermore, apoptosis rate increased only till 15 hours of LPS exposure. LPS stimulated VEGF secretion in a dose-dependent manner; its effect became significant after 7 hours and reached a plateau after 15 hours. Both Hsp70 and Hsp32 expressions were induced by LPS in a dose-dependent manner after 7 hours. Subsequent studies were addressed to evaluate the protective role of Hsp32, Hsp70, and VEGF. Hemin, an Hsp32 inducer (5, 20, 50 μM), and recombinant VEGF (100 and 200 ng/mL), were added to the culture 2 hours before LPS (10 μg/mL for 24 hours); to induce Hsp70 expression, cells were heat shocked (42°C for 1 hour) 15 hours before LPS (10 μg/mL for 24 hours). Hemin exposure upregulated Hsp32 expression in a dose-dependent manner and protected cells against LPS-induced apoptosis. Heat shock (HS) stimulated Hsp70 expression but failed to reduce LPS-induced apoptosis; VEGF addition did not protect cells against LPS-induced apoptosis at any dose tested. Nevertheless

  8. Ultrafast Measurement of the Optical Properties of Shocked Nickel and Laser Heated Gold

    NASA Astrophysics Data System (ADS)

    Funk, David J.; Moore, D. S.; Reho, J. H.; Gahagan, K. T.; McGrane, S. D.; Rabie, R. L.

    2002-07-01

    We have used high-resolution Frequency Domain Interferometry (FDI) to make the first ultrafast measurement of shock-induced changes in the optical properties of thin nickel (approx500 nm) targets. Data taken at several angles of incidence allowed the separation of optical effects from material motion, yielding an effective complex index for the shocked material. In contrast to our previous studies of aluminum, measurements with an 800 nm probe wavelength found a phase shift attributable to optical property changes with the same sign as that due to surface motion, during an 11.5 GPa shock breakout. A similar experiment was attempted with thin gold films (approx180 nm) using Ultrafast Spatial Interferometry (USI). However, since the electron-phonon coupling in gold is extremely weak, a shock is observed as it "forms". Ballistic electrons and electron-electron equilibrium cause fast heating of the electrons in the entire thickness of the thin film, followed by lattice excitation through electron-phonon coupling, eventually leading to melt and frustrated thermal expansion yielding the observed surface motion. We suggest that these experiments offer a new path for observation of phase changes or for temperature measurements, by allowing a determination of the complex index under dynamic loading conditions and comparing the measured values to those obtained under static conditions.

  9. Numerical study of shock wave interaction in steady flows of a viscous heat-conducting gas with a low ratio of specific heats

    NASA Astrophysics Data System (ADS)

    Shoev, G. V.; Ivanov, M. S.

    2016-05-01

    Specific features of shock wave interaction in a viscous heat-conducting gas with a low ratio of specific heats are numerically studied. The case of the Mach reflection of shock waves with a negative angle of the reflected wave with respect to the free-stream velocity vector is considered, and the influence of viscosity on the flow structure is analyzed. Various issues of nonuniqueness of the shock wave configuration for different Reynolds numbers are discussed. Depending on the initial conditions and Reynolds numbers, two different shock wave configurations may exist: regular configuration interacting with an expansion fan and Mach configuration. In the dual solution domain, a possibility of the transition from regular to the Mach reflection of shock waves is considered.

  10. In vivo chaperone activity of heat shock protein 70 and thermotolerance.

    PubMed

    Nollen, E A; Brunsting, J F; Roelofsen, H; Weber, L A; Kampinga, H H

    1999-03-01

    Heat shock protein 70 (Hsp70) is thought to play a critical role in the thermotolerance of mammalian cells, presumably due to its chaperone activity. We examined the chaperone activity and cellular heat resistance of a clonal cell line in which overexpression of Hsp70 was transiently induced by means of the tetracycline-regulated gene expression system. This single-cell-line approach circumvents problems associated with clonal variation and indirect effects resulting from constitutive overexpression of Hsp70. The in vivo chaperone function of Hsp70 was quantitatively investigated by using firefly luciferase as a reporter protein. Chaperone activity was found to strictly correlate to the level of Hsp70 expression. In addition, we observed an Hsp70 concentration dependent increase in the cellular heat resistance. In order to study the contribution of the Hsp70 chaperone activity, heat resistance of cells that expressed tetracycline-regulated Hsp70 was compared to thermotolerant cells expressing the same level of Hsp70 plus all of the other heat shock proteins. Overexpression of Hsp70 alone was sufficient to induce a similar recovery of cytoplasmic luciferase activity, as does expression of all Hsps in thermotolerant cells. However, when the luciferase reporter protein was directed to the nucleus, expression of Hsp70 alone was not sufficient to yield the level of recovery observed in thermotolerant cells. In addition, cells expressing the same level of Hsp70 found in heat-induced thermotolerant cells containing additional Hsps showed increased resistance to thermal killing but were more sensitive than thermotolerant cells. These results suggest that the inducible form of Hsp70 contributes to the stress-tolerant state by increasing the chaperone activity in the cytoplasm. However, its expression alone is apparently insufficient for protection of other subcellular compartments to yield clonal heat resistance to the level observed in thermotolerant cells.

  11. Expression of Small Heat-Shock Proteins at Low Temperatures1

    PubMed Central

    Sabehat, Adnan; Lurie, Susan; Weiss, David

    1998-01-01

    We previously reported that short exposure of tomato (Lycopersicon esculentum L.) fruits to high temperature protects them from chilling injury. To study the involvement of heat-shock proteins (HSPs) in the acquisition of low-temperature tolerance, we cloned two heat-shock-induced genes that are also expressed at low temperatures. The cloned cDNAs belong to the small HSP group. Sequence analyses of the clones showed perfect homology to the tomato-ripening gene tom66 and to the tomato chloroplastic HSP21 gene tom111. The expression of both genes was induced by high temperature in fruits, flowers, leaves, and stems, but not by low or ambient temperatures or by other stresses such as drought and anaerobic conditions. When the heated fruits were transferred to low temperature, tom66 and tom111 mRNA levels first decreased but were then reinduced. Induction was not observed in nonheated fruits at low temperature. Immunodetection of tom111-encoded protein indicated that this protein is present at low temperatures in the heated fruits. The results of this study show that the expression of tom66 and tom111 is correlated with protection against some, but not all, symptoms of chilling injury. PMID:9625718

  12. Genetic and phenotypic characterization of the heat shock response in Pseudomonas putida.

    PubMed

    Ito, Fumihiro; Tamiya, Takayuki; Ohtsu, Iwao; Fujimura, Makoto; Fukumori, Fumiyasu

    2014-12-01

    Molecular chaperones function in various important physiological processes. Null mutants of genes for the molecular chaperone ClpB (Hsp104), and those that encode J-domain proteins (DnaJ, CbpA, and DjlA), which may act as Hsp40 co-chaperones of DnaK (Hsp70), were constructed from Pseudomonas putida KT2442 (KT) to elucidate their roles. The KTΔclpB mutant showed the same heat shock response (HSR) as the wild-type, both in terms of heat-shock protein (Hsp) synthesis (other than ClpB) and in hsp gene expression; however, the mutant was quite sensitive to high temperatures and was unable to disaggregate into thermo-mediated protein aggregates, indicating that ClpB is important for cell survival after heat stress and essential for solubilization of protein aggregates. On the other hand, the KTΔdnaJ mutant was temperature-sensitive, and formed more protein aggregates (especially of high molecular weight) upon heat stress than did KT. P. putida CbpA, a probable Hsp, partially substituted the functions of DnaJ in cell growth and solubilization of thermo-mediated protein aggregates, and might be involved in the HSR which was regulated by a fine-tuning system(s) that could sense subtle changes in the ambient temperature and control the levels of σ(32) activity and quantity, as well as the mRNA levels of hsp genes.

  13. Genetic and phenotypic characterization of the heat shock response in Pseudomonas putida

    PubMed Central

    Ito, Fumihiro; Tamiya, Takayuki; Ohtsu, Iwao; Fujimura, Makoto; Fukumori, Fumiyasu

    2014-01-01

    Molecular chaperones function in various important physiological processes. Null mutants of genes for the molecular chaperone ClpB (Hsp104), and those that encode J-domain proteins (DnaJ, CbpA, and DjlA), which may act as Hsp40 co-chaperones of DnaK (Hsp70), were constructed from Pseudomonas putida KT2442 (KT) to elucidate their roles. The KTΔclpB mutant showed the same heat shock response (HSR) as the wild-type, both in terms of heat-shock protein (Hsp) synthesis (other than ClpB) and in hsp gene expression; however, the mutant was quite sensitive to high temperatures and was unable to disaggregate into thermo-mediated protein aggregates, indicating that ClpB is important for cell survival after heat stress and essential for solubilization of protein aggregates. On the other hand, the KTΔdnaJ mutant was temperature-sensitive, and formed more protein aggregates (especially of high molecular weight) upon heat stress than did KT. P. putida CbpA, a probable Hsp, partially substituted the functions of DnaJ in cell growth and solubilization of thermo-mediated protein aggregates, and might be involved in the HSR which was regulated by a fine-tuning system(s) that could sense subtle changes in the ambient temperature and control the levels of σ32 activity and quantity, as well as the mRNA levels of hsp genes. PMID:25303383

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

    PubMed

    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.

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

    PubMed

    Sarup, P; Sørensen, P; Loeschcke, V

    2014-02-01

    Heat-induced hormesis, i.e. the beneficial effect of mild heat-induced stress, increases the average lifespan of many organisms. This effect, which depends on the heat shock factor, decreases the log mortality rate weeks after the stress has ceased. To identify candidate genes that mediate this lifespan-prolonging effect late in life, we treated flies with mild heat stress (34 °C for 2 h) 3 times early in life and compared the transcriptomic response in these flies versus non-heat-treated controls 10-51 days after the last heat treatment. We found significant transcriptomic changes in the heat-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<0.01). This result was unexpected as the major Drosophila heat shock protein, Hsp70, is reported to return to normal levels of expression shortly after heat stress. We 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.

  16. Radio frequency induced hyperthermia mediated by dextran stabilized LSMO nanoparticles: in vitro evaluation of heat shock protein response

    NASA Astrophysics Data System (ADS)

    Bhayani, K. R.; Rajwade, J. M.; Paknikar, K. M.

    2013-01-01

    Dextran stabilized La0.7Sr0.3MnO3 (Dex-LSMO) is an alternative cancer hyperthermia agent holding considerable promise. Here, we have carried out a comparative study on radio frequency (˜264 kHz) induced Dex-LSMO mediated heating and extraneous heating (mimicking generalized hyperthermia) in terms of changes in the morphology, proliferation pattern and induction of heat shock proteins in a human melanoma cell line (A375). Our results clearly show that the cellular effects seen with extraneous heating (60 min at 43 °C) could be reproduced by just six minutes of radio frequency induced Dex-LSMO mediated heating. More importantly, the observed enhanced levels of HSP 70 and 90 (molecular markers of heat shock that trigger favorable immunological reactions) seen with Dex-LSMO mediated heating were comparable to extraneous heating. These results suggest the possible utility of Dex-LSMO as a cancer hyperthermia agent.

  17. Molecular chaperone function of the Rana catesbeiana small heat shock protein, hsp30.

    PubMed

    Kaldis, Angelo; Atkinson, Burr G; Heikkila, John J

    2004-10-01

    Eukaryotic small heat shock proteins (shps) act as molecular chaperones by binding to denaturing proteins, preventing their heat-induced aggregation and maintaining their solubility until they can be refolded back to their normal state by other chaperones. In this study we report on the functional characterization of a developmentally regulated shsp, hsp30, from the American bullfrog, Rana catesbeiana. An expression vector containing the open reading frame of the hsp30 gene was expressed in Escherichia coli. Purified recombinant hsp30 was recovered as multimeric complexes and was composed of a mixture of alpha-helical and beta-sheet-like structures as determined by circular dichroism analysis. Hsp30 displayed chaperone activity since it inhibited heat-induced aggregation of citrate synthase. Furthermore hsp30 maintained heat-treated luciferase in a folding competent state. For example, heat denatured luciferase when microinjected into Xenopus oocytes did not regain enzyme activity whereas luciferase heat denatured with hsp30 regained 100% enzyme activity. Finally, hsp30 protected the DNA restriction endonuclease, PstI, from heat inactivation. PstI incubated alone at 42 degrees C lost its enzymatic function after 1 h whereas PstI supplemented with hsp30 accurately digested plasmid DNA after 4 h at the elevated temperature. These results clearly indicate a molecular chaperone role for R. catesbeiana hsp30.

  18. Two hybrid plasmids with D. melanogaster DNA sequences complementary to mRNA coding for the major heat shock protein.

    PubMed

    Schedl, P; Artavanis-Tsakonas, S; Steward, R; Gehring, W J; Mirault, M E; Goldschmidt-Clermont, M; Moran, L; Tissières, A

    1978-08-01

    The isolation and partial characterization of two cloned segments of Drosophila melanogaster DNA containing "heat shock" gene sequences is described. We have inserted sheared embryonic D. melanogaster DNA by the poly(dA-dt) connector method (Lobban and Kaiser, 1973) into the R1 restriction site of the ampicillin-resistant plasmid pSF2124 (So, Gill and Falkow, 1975). A collection of independent hybrid plasmids was screened by colony hybridization (Grunstein and Hogness, 1975) for sequences complementary to in vitro labeled polysomal poly(A)+ heat shock RNA. Two clones were identified which contain sequences complementary to a heat shock mRNA species that directs the in vitro synthesis of the 70,000 dalton heat-induced polypeptide. Both cloned segments hybridize in situ to the heat-induced puff sites located at 87A and 87C of the salivary gland polytene chromosomes. PMID:99246

  19. Application of the cis-regulatory region of a heat-shock protein 70 gene to heat-inducible gene expression in the ascidian Ciona intestinalis.

    PubMed

    Kawaguchi, Akane; Utsumi, Nanami; Morita, Maki; Ohya, Aya; Wada, Shuichi

    2015-01-01

    Temporally controlled induction of gene expression is a useful technique for analyzing gene function. To make such a technique possible in Ciona intestinalis embryos, we employed the cis-regulatory region of the heat-shock protein 70 (HSP70) gene Ci-HSPA1/6/7-like for heat-inducible gene expression in C. intestinalis embryos. We showed that Ci-HSPA1/6/7-like becomes heat shock-inducible by the 32-cell stage during embryogenesis. The 5'-upstream region of Ci-HSPA1/6/7-like, which contains heat-shock elements indispensable for heat-inducible gene expression, induces the heat shock-dependent expression of a reporter gene in the whole embryo from the 32-cell to the middle gastrula stages and in progressively restricted areas of embryos in subsequent stages. We assessed the effects of heat-shock treatments in different conditions on the normality of embryos and induction of transgene expression. We evaluated the usefulness of this technique through overexpression experiments on the well-characterized, developmentally relevant gene, Ci-Bra, and showed that this technique is applicable for inferring the gene function in C. intestinalis.

  20. Linking physiological and cellular responses to thermal stress: β-adrenergic blockade reduces the heat shock response in fish.

    PubMed

    Templeman, Nicole M; LeBlanc, Sacha; Perry, Steve F; Currie, Suzanne

    2014-08-01

    When faced with stress, animals use physiological and cellular strategies to preserve homeostasis. We were interested in how these high-level stress responses are integrated at the level of the whole animal. Here, we investigated the capacity of the physiological stress response, and specifically the β-adrenergic response, to affect the induction of the cellular heat shock proteins, HSPs, following a thermal stress in vivo. We predicted that blocking β-adrenergic stimulation during an acute heat stress in the whole animal would result in reduced levels of HSPs in red blood cells (RBCs) of rainbow trout compared to animals where adrenergic signaling remained intact. We first determined that a 1 h heat shock at 25 °C in trout acclimated to 13 °C resulted in RBC adrenergic stimulation as determined by a significant increase in cell swelling, a hallmark of the β-adrenergic response. A whole animal injection with the β2-adrenergic antagonist, ICI-118,551, successfully reduced this heat-induced RBC swelling. The acute heat shock caused a significant induction of HSP70 in RBCs of 13 °C-acclimated trout as well as a significant increase in plasma catecholamines. When heat-shocked fish were treated with ICI-118,551, we observed a significant attenuation of the HSP70 response. We conclude that circulating catecholamines influence the cellular heat shock response in rainbow trout RBCs, demonstrating physiological/hormonal control of the cellular stress response.

  1. Similarity solution for the flow behind a shock wave in a non-ideal gas with heat conduction and radiation heat-flux in magnetogasdynamics

    NASA Astrophysics Data System (ADS)

    Nath, G.; Vishwakarma, J. P.

    2014-05-01

    The propagation of a spherical (or cylindrical) shock wave in a non-ideal gas with heat conduction and radiation heat-flux, in the presence of a spacially decreasing azimuthal magnetic field, driven out by a moving piston is investigated. The heat conduction is expressed in terms of Fourier's law and the radiation is considered to be of the diffusion type for an optically thick grey gas model. The thermal conductivity K and the absorption coefficient αR are assumed to vary with temperature and density. The gas is assumed to have infinite electrical conductivity and to obey a simplified van der Waals equation of state. The shock wave moves with variable velocity and the total energy of the wave is non-constant. Similarity solutions are obtained for the flow-field behind the shock and the effects of variation of the heat transfer parameters, the parameter of the non-idealness of the gas, both, decreases the compressibility of the gas and hence there is a decrease in the shock strength. Further, it is investigated that with an increase in the parameters of radiative and conductive heat transfer the tendency of formation of maxima in the distributions of heat flux, density and isothermal speed of sound decreases. The pressure and density vanish at the inner surface (piston) and hence a vacuum is form at the center of symmetry. The shock waves in conducting non-ideal gas with conductive and radiative heat fluxes can be important for description of shocks in supernova explosions, in the study of central part of star burst galaxies, nuclear explosion, chemical detonation, rupture of a pressurized vessels, in the analysis of data from exploding wire experiments, and cylindrically symmetric hypersonic flow problems associated with meteors or reentry vehicles, etc. The findings of the present works provided a clear picture of whether and how the non-idealness parameter, conductive and radiative heat transfer parameters and the magnetic field affect the flow behind the shock

  2. Laser heating of solid matter by light pressure-driven shocks

    SciTech Connect

    Akli, K; Hansen, S B; Kemp, A J; Freeman, R R; Beg, F N; Clark, D; Chen, S; Hey, D; Highbarger, K; Giraldez, E; Green, J; Gregori, G; Lancaster, K; Ma, T; MacKinnon, A J; Norreys, P A; Patel, N; Patel, P; Shearer, C; Stephens, R B; Stoeckl, C; Storm, M; Theobald, W; Van Woerkom, L; Weber, R; Key, M H

    2007-05-04

    Heating by irradiation of a solid surface in vacuum with 5 x 10{sup 20} W cm{sup -2}, 0.8 ps, 1.05 {micro}m wavelength laser light is studied by x-ray spectroscopy of the K-shell emission from thin layers of Ni, Mo and V. A surface layer is heated to {approx} 5 keV with an axial temperature gradient of 0.6 {micro}m scale length. Images of Ni Ly{sub {alpha}} show the hot region has a {approx} 25 {micro}m diameter, much smaller than {approx} 70 {micro}m region of K{sub {alpha}} emission. 2D particle-in-cell (PIC) simulations suggest that the surface heating is due to a light pressure driven shock.

  3. Effect of acquisition of improved thermotolerance on the induction of heat shock proteins in broiler chickens.

    PubMed

    Yahav, S; Shamay, A; Horev, G; Bar-Ilan, D; Genina, O; Friedman-Einat, M

    1997-10-01

    The role of heat shock proteins (HSP) in the protection of cells from heat stress is well established. However, very little is known about their contribution to thermotolerance in the complexity of a whole homeotherm animal. Here we report on the analysis of protein synthesis in lung and heart muscle tissues of broiler chickens following exposure to high ambient temperature. Half of the flock was treated by an early age exposure to heat (conditioning), to improve thermotolerance. In contrast to what has been expected, lower levels of HSP induction was observed in the treated chickens. We suggest that 1) the induction of HSP in the heart and lung tissues of the whole animal correlates with the body temperature and 2) HSP response does not represent a part of the long-term mechanism that is evoked by the early age conditioning. PMID:9316120

  4. [Heat shock proteins of freshwater protists and their involvement in adaptation to changes in the environmental salinity].

    PubMed

    Plekhanov, A Iu; Smurov, A O; Podlipaeva, Iu I; Ivanova, L O; Gudkov, A V

    2006-01-01

    Changes in the level of heat shock proteins (HSP) in cells of freshwater protists, amoebae Amoeba proteus and ciliates Paramecium jenningsi, in response to changes in the environmental salinity were investigated. Changes in salinity levels were considered as a stress factor. The immunoblotting method revealed a polypeptide antigen cross-reacting with antibodies against bovine HSP70 in total protein extracts of both intact cells and cells subjected to salinity stress. The same polypeptide antigen was revealed in A. proteus cells subjected to heat shock. Therefore, it may be supposed that the polypeptide revealed after salinity shock is a heat shock protein related to the vertebrate HSP70. Under the impact of stress factor, well acclimated protists mostly spend their own previously accumulated HSP70. A conclusion is made that freshwater protists, living under conditions of increased salinity, appear to be preadapted to changes in environmental factors.

  5. The influence of state-to-state kinetics on diffusion and heat transfer behind shock waves

    SciTech Connect

    Kunova, O.; Kustova, E.; Mekhonoshina, M.; Nagnibeda, E.

    2014-12-09

    In the paper, the influence of vibrational and chemical kinetics on heat transfer and diffusion in hypersonic flows of N{sub 2}/N mixture in the relaxation zone behind shock waves is studied on the basis of the state-to-state kinetic theory approach. The results of calculations of vibrational level populations ni, gas temperature T, total energy flux q, diffusion velocities of molecules at different vibrational states V{sub i} and atoms V{sub a} in the relaxation zone behind a shock front are presented for the free stream Mach number M = 10, 15. The contribution of different dissipative processes to the total energy flux is estimated for various flow conditions. The impact of non-equilibrium vibrational distributions in the free stream on molecular level populations and transport properties in the relaxation zone is shown.

  6. The effect of temperature and length of heat shock treatment on the thermal tolerance and cell leakage of Cronobacter sakazakii BCRC 13988.

    PubMed

    Chang, Chia-Hsiang; Chiang, Ming-Lun; Chou, Cheng-Chun

    2009-09-15

    Enterobacter sakazakii is an emerging opportunistic pathogen associated with life-threatening illnesses in infants, with infant formula serving as the principal mode of transmission. In the present study, C. sakazakii (formely E. sakazakii) BCRC 13988 was subjected to various heat shock treatments (42-48 degrees C for 5-15 min). Its subsequent survival at 51 degrees C and the leakage of intracellular materials was investigated. It was found that 47 degrees C was the maximum growth temperature of the test organism. In addition, heat shock enhanced the thermal tolerance of C. sakazakii BCRC 13988. Within heat shock temperatures between 42 and 47 degrees C, the thermal tolerance enhancing effect increased as the length or temperature of the heat shock treatment was increased. However, increasing the heat shock temperature to 48 degrees C reduced the thermal tolerance enhancing effect. Among the various heat shocked cells examined, the 47 degrees C-15 min-heat shocked C. sakazakii exhibited the highest thermal tolerance. Moreover, electron micrograph analysis showed that heat shock treatment caused damage and disruption in C. sakazakii cells. There was a significant increase (P<0.05) in the leakage of nucleic acid and protein in the supernatant of the heat shocked cell suspension that increased as the temperature and duration of heat shock increased.

  7. Ion heating and energy partition at the heliospheric termination shock: hybrid simulations and analytical model

    SciTech Connect

    Gary, S Peter; Winske, Dan; Wu, Pin; Schwadron, N A; Lee, M

    2009-01-01

    The Los Alamos hybrid simulation code is used to examine heating and the partition of dissipation energy at the perpendicular heliospheric termination shock in the presence of pickup ions. The simulations are one-dimensional in space but three-dimensional in field and velocity components, and are carried out for a range of values of pickup ion relative density. Results from the simulations show that because the solar wind ions are relatively cold upstream, the temperature of these ions is raised by a relatively larger factor than the temperature of the pickup ions. An analytic model for energy partition is developed on the basis of the Rankine-Hugoniot relations and a polytropic energy equation. The polytropic index {gamma} used in the Rankine-Hugoniot relations is varied to improve agreement between the model and the simulations concerning the fraction of downstream heating in the pickup ions as well as the compression ratio at the shock. When the pickup ion density is less than 20%, the polytropic index is about 5/3, whereas for pickup ion densities greater than 20%, the polytropic index tends toward 2.2, suggesting a fundamental change in the character of the shock, as seen in the simulations, when the pickup ion density is large. The model and the simulations both indicate for the upstream parameters chosen for Voyager 2 conditions that the pickup ion density is about 25% and the pickup ions gain the larger share (approximately 90%) of the downstream thermal pressure, consistent with Voyager 2 observations near the shock.

  8. Cloning, sequencing, and mapping of the human chromosome 14 heat shock protein gene (HSPA2)

    SciTech Connect

    Bonnycastle, L.L.C.; Chang-En Yu; Schellenberg, G.D.

    1994-09-01

    A genomic clone for the human heat shock protein (HSP) 70 gene located on chromosome 14 was isolated and sequenced. The gene, designated HSPA2, has a single open reading frame of 1917 bp that encodes a 639-amino acid protein with a predicted molecular weight of 70,030 Da. Analysis of the sequence indicates that HLPA2 is the human homologue of the murine Hsp 70-2 gene with 91.7% identity in the nucleotide coding sequence and 98.2% in the corresponding amino acid sequence. HSPA2 has less amino acid homology to other members of the human HSP70 gene family, 83.3% to the heat-inducible HSP70-1 gene and 86.1% with the human heat shock cognate gene HSC70. HSPA2 is constitutively expressed in most tissues, with very high levels in testis and skeletal muscle. Significant but lower levels are also expressed in ovary, small intestine, colon, brain, placenta, and kidney. A yeast artificial chromosome (YAC) clone containing HSPA2 (YAC741H4) that also contained the polymorphic marker D14S63 was identified. This 670-kb YAC was mapped to 14q24.1 by fluorescence in situ hybridization (FISH). Subsequent two-color FISH and genetic mapping placed HSPA2/D14S63 proximal to the markers D14S57 and D14S77. 50 refs., 3 figs., 1 tab.

  9. Inhibiting hea