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Heat-shock Protein (heat-shock + protein)

Distribution by Scientific Domains
Medical Sciences36%
Life Sciences35%
Chemistry24%
Earth and Environmental Science3%

Kinds of Heat-shock Protein

  • small heat-shock protein
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    Selected Abstracts

    Serum Antibodies to Helicobacter pylori and its Heat-Shock Protein 60 Correlate with the Response of Gastric Mucosa-Associated Lymphoid Tissue Lymphoma to Eradication of H. pylori

    HELICOBACTER, Issue 3 2004
    Ryuta Takenaka
    ABSTRACT Background and aims., Eradication of Helicobacter pylori leads to regression of mucosa-associated lymphoid tissue (MALT) lymphomas. In this study, we measured serum antibodies to H. pylori and H. pylori- recombinant heat-shock protein 60 (rHSP60) in patients with gastric MALT lymphoma to determine whether humoral immune responses to the bacterial antigens correlate with the efficacy of eradication therapy. Methods., Serum samples were obtained from 33 patients with H. pylori -positive gastric MALT lymphoma before undergoing therapy to eradicate the bacteria. Anti- H. pylori antibodies were measured in a commercial assay and in immunoassays to lysates and rHSP60 which were prepared from ATCC 43504 strain. Results.,Helicobacter pylori were eradicated in all 33 patients, and the lymphoma completely regressed histologically in 26 patients (79%). Pre-treatment titers of serum antibody to H. pylori and to rHSP60 in the patients whose tumor regressed were significantly higher than titers in patients whose tumors did not regress (p = .0011 and .035, respectively). By logistic regression analysis, age (odds ratio = 0.88, 95% confidence interval = 0.80,0.99), endoscopic appearance (0.053, 0.004,0.65), titers of anti- H. pylori antibodies (67.6, 2.5,1800), and titers of anti-rHSP60 antibody (6.4, 1.2,36) were identified as significantly associated factors with the outcome of MALT lymphoma. Conclusions., Measurement of serum antibodies to H. pylori and HSP60 might be useful for predicting the response of gastric MALT lymphoma to eradication of H. pylori. [source]

    Biosynthesis of the Heat-Shock Protein 90 Inhibitor Geldanamycin: New Insight into the Formation of the Benzoquinone Moiety

    CHEMBIOCHEM, Issue 2 2006
    Dongho Lee Dr.
    A clue towards determining the biosynthetic origin of ansamycin benzoquinone formation by spontaneous oxidation from a corresponding hydroquinone has been provided by ACDL3172 (1), a tricyclic geldanamycin derivative produced by the gel8 gene-inactivated strain of S. hygroscopicus subsp. duamyceticus JCM4427. [source]

    Photochemical Internalization of Transgenes Controlled by the Heat-shock Protein 70 Promoter

    PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 3 2006
    Lina Prasmickaite
    ABSTRACT Photochemical internalization (PCI) is a targeting technique that facilitates endosomal escape of macromolecules, such as transgenes, in response to photochemical treatment with endosome/lysosome-localized photosensitizers, such as disul-fonated meso-tetraphenylporphine (TPPS2a). In gene therapy this leads to enhanced transgene expression. Moreover, photochemical treatment generally activates transcription of stress-response genes, such as heat-shock proteins (HSPs), via stimulation of corresponding promoters. Therefore, we used HSP70 (HSPp; a promoter from the HSP family gene) and investigated whether the PCI stimulus could also activate HSPp and thereby stimulate transcription (expression) of the HSPp-controlled transgene internalized via PCI. Using human colorectal carcinoma and hepatoma cell lines in vitro, we showed that TPPS2a -based photochemical treatment enhances expression of cellular HSP70, which correlated with a photo-chemically enhanced expression (approximately 2-fold, at PCI-optimal doses) of the HSPp-controlled transgene integrated in the genome. Furthermore, PCI enhanced expression of the HSPp-controlled episomal transgene delivered as a plas-mid. However, in plasmid-based transfection, PCI-mediated enhancement with HSPp did not exceed the enhancement achieved with the constitutive active CMV promoter. In conclusion, we demonstrated that the PCI-relevant treatment initiates HSP70 response and that the HSP70 promoter can be used in combination with PCI, leading to PCI-enhanced expression of the HSPp-controlled transgene. [source]

    Variation in Heat-shock Proteins and Photosynthetic Thermotolerance among Natural Populations of Chenopodium album L. from Contrasting Thermal Environments: Implications for Plant Responses to Global Warming

    JOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 11 2008
    Deepak Barua
    Abstract Production of heat-shock proteins (Hsps) is a key adaptation to acute heat stress and will be important in determining plant responses to climate change. Further, intraspecifc variation in Hsps, which will influence species-level response to global warming, has rarely been examined in naturally occurring plants. To understand intraspecific variation in plant Hsps and its relevance to global warming, we examined Hsp content and thermotolerance in five naturally occurring populations of Chenopodium album L. from contrasting thermal environments grown at low and high temperatures. As expected, Hsp accumulation varied between populations, but this was related more to habitat variability than to mean temperature. Unexpectedly, Hsp accumulation decreased with increasing variability of habitat temperatures. Hsp accumulation also decreased with increased experimental growth temperatures. Physiological thermotolerance was partitioned into basal and induced components. As with Hsps, induced thermotolerance decreased with increasing temperature variability. Thus, populations native to the more stressful habitats, or grown at higher temperatures, had lower Hsp levels and induced thermotolerance, suggesting a greater reliance on basal mechanisms for thermotolerance. These results suggest that future global climate change will differentially impact ecotypes within species, possibly by selecting for increased basal versus inducible thermotolerance. [source]

    HIV-1 viral envelope glycoprotein gp120 produces oxidative stress and regulates the functional expression of multidrug resistance protein-1 (Mrp1) in glial cells

    JOURNAL OF NEUROCHEMISTRY, Issue 3 2008
    Patrick T. Ronaldson
    Abstract Brain human immunodeficiency virus type-1 (HIV-1) infection is associated with oxidative stress, which may lead to HIV-1 encephalitis, a chronic neurodegenerative condition. In vitro, oxidative stress can be induced in glial cells by exposure to HIV-1 envelope protein glycoprotein (gp120). Multidrug resistance proteins (Mrps) are known to efflux endogenous substrates (i.e. GSH and GSSG) involved in cellular defense against oxidative stress. Altered GSH/GSSG export may contribute to oxidative damage during HIV-1 encephalitis. At present, it is unknown if gp120 exposure can alter the functional expression of Mrp isoforms. Heat-shock protein 70, inducible nitric oxide synthase, intracellular GSSG, 2,,7,-dichlorofluorescein fluorescence, and extracellular nitrite were increased in primary cultures of rat astrocytes triggered with gp120, suggesting an oxidative stress response. RT-PCR and immunoblot analysis demonstrated increased Mrp1 mRNA (2.3-fold) and protein (2.2-fold), respectively, in gp120 treated astrocytes while Mrp4 mRNA or protein expression was not changed. Cellular retention of 2,,7,-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein, an established Mrp substrate, was reduced (twofold) in gp120-treated astrocytes, suggesting increased Mrp-mediated transport. In addition, GSH and GSSG export were enhanced in gp120-triggered cells. These data suggest that gp120 can up-regulate Mrp1, but not Mrp4, functional expression in cultured astrocytes. Our observation of increased GSH/GSSG efflux in response to gp120 treatment implies that Mrp isoforms may be involved in regulating the oxidative stress response in glial cells. [source]

    Cloning, expression, purification and preliminary X-­ray crystallographic studies of yeast Hsp40 Sis1 complexed with Hsp70 Ssa1 C-terminal lid domain

    ACTA CRYSTALLOGRAPHICA SECTION D, Issue 5 2001
    Xinguo Qian
    Heat-shock protein 70 (Hsp70) plays essential roles in a number of cellular processes such as protein folding, assembly and translocation. Heat-shock protein 40 (Hsp40) transiently interacts with Hsp70 and facilitates Hsp70 functions in these processes within cells. Hsp40 recognizes and binds non-native polypeptide and delivers it to Hsp70. Hsp40 can then stimulate the ATPase activity of Hsp70 to refold the polypeptide. To investigate the molecular mechanism by which Hsp40 interacts with Hsp70 to transport the non-native polypeptide, Saccharomyces cerevisiae Hsp40 Sis1 C-terminal peptide-binding fragment complexed with Hsp70 Ssa1 C-terminal lid domain has been produced and crystallized. The complex crystals diffract to 3.3,Å and belong to the space group P41212 or P43212, with unit-cell parameters a = 112.17, c = 171.31,Å. Structure determination by the MAD method is under way. [source]

    Suspension Culture Process of MethA Tumor Cell for the Production of Heat-Shock Protein Glycoprotein 96: Process Optimization in Spinner Flasks

    BIOTECHNOLOGY PROGRESS, Issue 6 2007
    Ya-Jie Tang
    Heat-shock proteins (HSPs) act like "chaperones", making sure that the cellapos;s proteins are in the right shape and in the right place at the right time. Heat-shock protein glycoprotein 96 (gp96) is a member of the HSP90 protein family, which chaperones a number of molecules in protein folding and transportation. Heat-shock protein gp96 serves as a natural adjuvant for chaperoning antigenic peptides into the immune surveillance pathways. Currently, heat-shock protein gp96 was only isolated from murine and human tissues and cell lines. An animal cell suspension culture process for the production of heat-shock protein gp96 by MethA tumor cell was developed for the first time in spinner flasks. Effects of culture medium and condition were studied to enhance the MethA tumor cell density and the production and productivity of heat-shock protein gp96. Initial glucose concentration had a significant effect on the heat-shock protein gp96 accumulation, and an initial glucose level of 7.0 g/L was desirable for MethA tumor cell growth and heat-shock protein gp96 production and productivity. Cultures at an initial glutamine concentration of 3 and 6 mM were nutritionally limited by glutamine. At an initial glutamine concentration of 6 mM, the maximal viable cell density of 19.90 × 105 cells/mL and the maximal heat-shock protein gp96 production of 4.95 mg/L was obtained. The initial concentration of RPMI 1640 and serum greatly affected the MethA tumor cell culture process. Specifically cultures with lower initial concentration of RPMI 1640 resulted in lower viable cell density and lower heat-shock protein gp96 production. At an initial serum concentration of 8%, the maximal viable cell density of 19.18 × 105 cells/mL and the maximal heat-shock protein gp96 production of 5.67 mg/L was obtained. The spin rate significantly affected the cell culture process in spinner flasks, and a spin rate of 150 rpm was desirable for MethA tumor cell growth and heat-shock protein gp96 production and productivity. Not only the cell density but also the production and productivity of heat-shock protein gp96 attained in this work are the highest reported in the culture of MethA tumor cell. This work offers an effective approach for producing heat-shock protein glycoprotein 96 from the cell culture process. The fundamental information obtained in this study may be useful for the efficient production of heat-shock protein by animal cell suspension culture on a large scale. [source]

    Heat-shock protein 70 gene polymorphism is associated with the severity of diabetic foot ulcer and the outcome of surgical treatment

    BRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 10 2009
    K. A. Mir
    Background: Foot ulcer is a significant cause of morbidity in diabetics. Genetic make-up can determine inflammatory and healing responses. This study examined the hypothesis that specific polymorphisms of the heat-shock protein 70 gene could predispose to the severity of diabetic foot ulceration. Methods: Some 106 consecutive diabetic patients (101 evaluable) with foot ulceration admitted to a tertiary care hospital were managed according to a standard protocol. DNA was extracted from venous blood and examined by polymerase chain reaction,restriction fragment length analysis for two specific polymorphisms: G1538A in the HSPA1B and C2437T in the HSPA1L gene. Results: HSPA1B genotyping showed that 70 patients were AG and 30 GG (one not amplified). The AG genotype was significantly associated with the severity of foot ulceration (Wagner grade) (P = 0·008, ,2 test), need for amputation (relative risk 2·02, 95 per cent confidence interval 1·02 to 4·01; P = 0·025) and median length of hospital stay (8 versus 5 days for GG; P = 0·043). HSPA1L genotypes (78 TT, 22 CT, one CC) did not show any significant association with these parameters. Conclusion: The HSPA1B genotype, was associated with the severity of diabetic foot ulceration, need for amputation and duration of hospitalization in these patients. Copyright © 2009 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. [source]

    Gossypium arboreum GHSP26 enhances drought tolerance in Gossypium hirsutum

    BIOTECHNOLOGY PROGRESS, Issue 1 2010
    Asma Maqbool
    Abstract Heat-shock proteins (HSP) are molecular chaperones for protein molecules. These proteins play an important role in protein,protein interactions such as, folding and assisting in the establishment of proper protein conformation and prevention of unwanted protein aggregation. A small HSP gene GHSP26 present in Gossypium arboreum responds to dehydration. In the present study, an attempt was made to overcome the problem of drought stress in cotton. A cDNA of GHSP26 was isolated from G. arboreum, cloned in plant expression vector, pCAMBIA-1301 driven by the cauliflower mosaic virus 35S promoter and introduced into Gossypium hirsutum. The integration and expression studies of putative transgenic plants were performed through GUS assay; PCR from genomic DNA, and quantitative real-time PCR analysis. Transgenic cotton plants showed an enhanced drought tolerance, suggesting that GHSP26 may play a role in plant responsiveness to drought. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2010 [source]

    Suspension Culture Process of MethA Tumor Cell for the Production of Heat-Shock Protein Glycoprotein 96: Process Optimization in Spinner Flasks

    BIOTECHNOLOGY PROGRESS, Issue 6 2007
    Ya-Jie Tang
    Heat-shock proteins (HSPs) act like "chaperones", making sure that the cellapos;s proteins are in the right shape and in the right place at the right time. Heat-shock protein glycoprotein 96 (gp96) is a member of the HSP90 protein family, which chaperones a number of molecules in protein folding and transportation. Heat-shock protein gp96 serves as a natural adjuvant for chaperoning antigenic peptides into the immune surveillance pathways. Currently, heat-shock protein gp96 was only isolated from murine and human tissues and cell lines. An animal cell suspension culture process for the production of heat-shock protein gp96 by MethA tumor cell was developed for the first time in spinner flasks. Effects of culture medium and condition were studied to enhance the MethA tumor cell density and the production and productivity of heat-shock protein gp96. Initial glucose concentration had a significant effect on the heat-shock protein gp96 accumulation, and an initial glucose level of 7.0 g/L was desirable for MethA tumor cell growth and heat-shock protein gp96 production and productivity. Cultures at an initial glutamine concentration of 3 and 6 mM were nutritionally limited by glutamine. At an initial glutamine concentration of 6 mM, the maximal viable cell density of 19.90 × 105 cells/mL and the maximal heat-shock protein gp96 production of 4.95 mg/L was obtained. The initial concentration of RPMI 1640 and serum greatly affected the MethA tumor cell culture process. Specifically cultures with lower initial concentration of RPMI 1640 resulted in lower viable cell density and lower heat-shock protein gp96 production. At an initial serum concentration of 8%, the maximal viable cell density of 19.18 × 105 cells/mL and the maximal heat-shock protein gp96 production of 5.67 mg/L was obtained. The spin rate significantly affected the cell culture process in spinner flasks, and a spin rate of 150 rpm was desirable for MethA tumor cell growth and heat-shock protein gp96 production and productivity. Not only the cell density but also the production and productivity of heat-shock protein gp96 attained in this work are the highest reported in the culture of MethA tumor cell. This work offers an effective approach for producing heat-shock protein glycoprotein 96 from the cell culture process. The fundamental information obtained in this study may be useful for the efficient production of heat-shock protein by animal cell suspension culture on a large scale. [source]

    Proteomic analysis of liver cancer cells treated with 5-Aza-2,-deoxycytidine (AZA),

    DRUG DEVELOPMENT RESEARCH, Issue 1 2009
    Shujun Bai
    Abstract 5-Aza-2,-deoxycytidine (AZA) is a potent inhibitor of DNA methylation that exhibits anti-tumor activity in a variety of tumor cells via reactivation of tumor suppressor genes. However, few studies have been done on the biological and clinical significance of AZA in human hepatocellular carcinoma. To identify potential genes that may be aberrantly methylated and confer growth advantage to neoplastic cells and to better understand the molecular mechanism(s) underlying AZA anti-tumor activity, a proteomics approach was used to annotate global gene expression changes of HepG2 cell line pre- and post-treatment with AZA. A total of 56 differentially expressed proteins were identified by 2D gel analysis, 48 of which were up-regulated while the remaining 8 were down regulated. Among the identified proteins, eight of these showed marked changed proteins, including seven up-regulated proteins: glutathione S-transferase P, protein DJ-1, peroxiredoxin-2, UMP-CMP kinase, cytochrome c-type heme lyase, enhancer of rudimentary homolog, profilin-1, and one down-regulated protein, heat-shock protein ,,1. The possible implication of these proteins in hepatocarcinogenesis is discussed. We tested two up-regulated proteins, glutathione S-transferase P and peroxiredoxin-2, using RT-PCR and their expression was consistent with the results obtained in the protein level. Both of these genes were methylated when methylation-specific PCR was used against their promoter regions. Following treatment with AZA, the gene promoter regions were found to be unmethylated, concomitant with overexpression of the proteins compared to HepG2 cells without treatment. These data provide useful information in evaluating the therapeutic potential of AZA for the treatment of HCC. Drug Dev Res 69, 2009. © 2009 Wiley-Liss, Inc. [source]

    Transgenic strains of the nematode Caenorhabditis elegans as biomonitors of metal contamination

    ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 8 2000
    L. K. Cioci
    Abstract Transition metal contamination poses a serious environmental and human health threat. The bioavailability of transition metals in environmental samples can best be assessed with living organisms. A transgenic strain of the free-living soil nematode Caenorhabditis elegans has been engineered for monitoring the bioavailability of metals. A reporter transgene consisting of a fragment of the promoter from the C. elegans metallothionein-2 gene (mtl-2) that controls the transcription of a ,-galactosidase reporter (lacZ) has been integrated into the genome of this organism. By using these transgenic C. elegans, the toxicological response to metals in samples can be quickly measured with a simple histochemical staining assay. The C. elegans that contain the mtl-2:lacZ transgene provide a more sensitive assay of exposure to cadmium, mercury, zinc, and nickel than 24-h LC50 assays or those using nematodes with heat-shock protein,based reporter transgenes. This study demonstrates that C. elegans that contain mtl-2:lacZ transgenes can function as sensitive toxicological indicators of metals. [source]

    Structural myocardial changes after coronary artery surgery

    EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 11 2000
    F. Eberhardt
    Background Postoperative contractile dysfunction or ,myocardial stunning' has been described after coronary artery bypass grafting (CABG). In the present study we sought to determine if and to what extent clinical, structural and histochemical evidence of myocardial changes associated with stunning could be found in patients after CABG and cold crystalloid cardioplegia. Materials and methods Left ventricular (LV) biopsies were obtained from CABG patients (n = 10) prior to and at the end of cardiopulmonary bypass (CPB). These biopsies were immunostained for the inducible heat-shock protein 70 (HSP-70i), intercellular adhesion molecule-1 (ICAM-1) and actin. ATP was measured by bioluminescence. Results Biopsies pre-CPB showed no evidence of myocardial damage as HSP-70i was absent and a regular actin cross-striation pattern and only constitutive ICAM-1-expression were present. After CPB we found significantly increased HSP-70i and ICAM-1 levels as well as a deranged actin cross-striation pattern with a widening of actin bands. ATP levels declined from 10 mmol L,1 pre-CPB to 4.9 mmol L,1 after CPB. Correspondingly, coronary sinus effluent showed a significant lactate production. Although, cardiac function determined by transoesophageal echocardiography did not deteriorate, significant inotropic support was necessary to maintain cardiac output. Conclusions Our results present clinical and structural evidence of ,myocardial stunning' after CABG and cold crystalloid cardioplegia. Increased HSP-70i and ICAM-1 expression, as well as a deranged actin cross-striation pattern, might be structural markers to determine ,myocardial stunning' in clinical settings. [source]

    The genetic response to Snowball Earth: role of HSP90 in the Cambrian explosion

    GEOBIOLOGY, Issue 1 2006
    M. E. BAKER
    ABSTRACT The events that shaped the Cambrian explosion from 545 to 530 Ma, when multicellular animals suddenly appeared in the fossil record, are not fully understood. It is likely that the evolution of new transcription factors and other signal transduction proteins that regulated developmental networks was important in the emergence of diverse animal phyla seen in the Cambrian. I propose that one or both extensive glaciations that ended about 670 and 635 Ma were important in the evolution of signal transduction proteins in small animals in the Neoproterozoic/Proterozoic. These glaciations have been called Snowball Earth. One consequence of these glaciations is that they increased the expression of genetic diversity in animals due to the effect of extreme climatic stress on heat-shock protein 90 (HSP90). Climatic stress diverted HSP90 from chaperoning the folding and proper intracellular localization of many signal transduction proteins that regulate development in animals. As a result, pre-existing mutant signal transduction proteins and developmental pathways were expressed in animals. Selectively advantageous mutations were fixed in stem group animals and later were a source for the expansion of animal phyla during the Cambrian. [source]

    Serum Antibodies to Helicobacter pylori and its Heat-Shock Protein 60 Correlate with the Response of Gastric Mucosa-Associated Lymphoid Tissue Lymphoma to Eradication of H. pylori

    HELICOBACTER, Issue 3 2004
    Ryuta Takenaka
    ABSTRACT Background and aims., Eradication of Helicobacter pylori leads to regression of mucosa-associated lymphoid tissue (MALT) lymphomas. In this study, we measured serum antibodies to H. pylori and H. pylori- recombinant heat-shock protein 60 (rHSP60) in patients with gastric MALT lymphoma to determine whether humoral immune responses to the bacterial antigens correlate with the efficacy of eradication therapy. Methods., Serum samples were obtained from 33 patients with H. pylori -positive gastric MALT lymphoma before undergoing therapy to eradicate the bacteria. Anti- H. pylori antibodies were measured in a commercial assay and in immunoassays to lysates and rHSP60 which were prepared from ATCC 43504 strain. Results.,Helicobacter pylori were eradicated in all 33 patients, and the lymphoma completely regressed histologically in 26 patients (79%). Pre-treatment titers of serum antibody to H. pylori and to rHSP60 in the patients whose tumor regressed were significantly higher than titers in patients whose tumors did not regress (p = .0011 and .035, respectively). By logistic regression analysis, age (odds ratio = 0.88, 95% confidence interval = 0.80,0.99), endoscopic appearance (0.053, 0.004,0.65), titers of anti- H. pylori antibodies (67.6, 2.5,1800), and titers of anti-rHSP60 antibody (6.4, 1.2,36) were identified as significantly associated factors with the outcome of MALT lymphoma. Conclusions., Measurement of serum antibodies to H. pylori and HSP60 might be useful for predicting the response of gastric MALT lymphoma to eradication of H. pylori. [source]

    Expression profiling in multistage hepatocarcinogenesis: Identification of HSP70 as a molecular marker of early hepatocellular carcinoma

    HEPATOLOGY, Issue 1 2003
    Makoto Chuma
    Hepatocellular carcinoma (HCC) associated with chronic liver disease evolves from precancerous lesions and early HCC to a progressed form. Nodule-in-nodule,type HCC (progressed HCC within early HCC) represents the transition from early to progressed HCC and, therefore, is useful in molecular genetic analysis of HCC progression during multistage carcinogenesis. We compared expression profiles among 7 early components and 7 progressed components of nodule-in-nodule,type HCCs and their corresponding noncancerous liver tissues with oligonucleotide array. Of the approximately 12,600 genes that were analyzed, a set of 95 genes provided a molecular signature that distinguished between early HCC components and their noncancerous liver tissues, and a set of 92 genes distinguished between progressed and early HCC components. Of these genes, the most abundantly up-regulated gene in early HCC components (P < .001) was heat-shock protein 70 (HSP70). Real-time quantitative reverse transcription polymerase chain reaction (RT-PCR) confirmed this finding. Further immunohistochemical examination of HSP70 revealed its significant overexpression in early HCC compared with precancerous lesions (P < .001) and in progressed HCC compared with early HCC (P < .001). In conclusion, molecular signatures were clearly different in noncancerous liver tissue as compared with the early and progressed components of nodule-in-nodule,type HCC. Moreover, HSP70 could be a sensitive marker for the differential diagnosis of early HCC from precancerous lesion or noncancerous liver, a difficult distinction for pathologists due to very well differentiated histology with little atypia in early HCC. [source]

    Cytochrome c oxidase as the target of the heat shock protective effect in septic liver

    INTERNATIONAL JOURNAL OF EXPERIMENTAL PATHOLOGY, Issue 5 2004
    Hsiang-Wen Chen
    Summary Liver function failure is one of the characteristics of critically ill, septic patients and is associated with worse outcome. Our previous studies have demonstrated that heat-shock response protects cells and tissue from subsequent insults and improves survival during sepsis. In this study, we have shown that mitochondrial cytochrome c oxidase (CCO) is one of the major sources of that protective effect. Experimental sepsis was induced by the cecal ligation and puncture (CLP) method. Heat-shock treatment was induced in rats by hyperthermia 24 h before CLP operation. The results showed that ATP content of the liver declined significantly, and the enzymatic activity of mitochondrial CCO was apparently suppressed during the late stages of sepsis. The mitochondrial ultrastructure of septic liver showed the deformity, mild swelling and inner membrane budding. Heat-shock treatment led to heat-shock protein 72 overexpression and prevented the downregulation of Grp75 during sepsis. On the contrary, the expression of the enzyme complex and its activity were preserved, associated with the minimization of ultrastructural deformities. In conclusion, the maintenance of mitochondrial function, especially the CCO, may be an important strategy in therapeutic interventions of a septic liver. [source]

    Oxidative stress increases levels of endogenous amyloid-, peptides secreted from primary chick brain neurons

    AGING CELL, Issue 5 2008
    Claire Goldsbury
    Summary Oxidative damage is associated with Alzheimer's disease and mild cognitive impairment, but its relationship to the development of neuropathological lesions involving accumulation of amyloid-, (A,) peptides and hyperphosphorylated tau protein remains poorly understood. We show that inducing oxidative stress in primary chick brain neurons by exposure to sublethal doses of H2O2 increases levels of total secreted endogenous A, by 2.4-fold after 20 h. This occurs in the absence of changes to intracellular amyloid precursor protein or tau protein levels, while heat-shock protein 90 is elevated 2.5-fold. These results are consistent with the hypothesis that aging-associated oxidative stress contributes to increasing A, generation and up-regulation of molecular chaperones in Alzheimer's disease. [source]

    Detection and identification of aquatic mycobacteria in formalin-fixed, paraffin-embedded fish tissues

    JOURNAL OF FISH DISEASES, Issue 5 2009
    F Pourahmad
    Abstract The isolation of mycobacteria from field samples is problematic, and isolation of the bacterium is sometimes not even attempted. The detection of mycobacteria through traditional histology using formalin-fixed, paraffin-embedded (FFPE) tissues is neither sensitive nor specific. However, detection of mycobacterial DNA from FFPE specimens, suspected of being infected with mammalian mycobacteriosis, is a routine clinical procedure. In the present study, a polymerase chain reaction (PCR)-based method was used to detect and identify mycobacteria in FFPE specimens sampled from fish suspected of being infected with fish mycobacteriosis. A total of 45 fish tissue samples, comprising of 12 tissue samples obtained from experimentally infected fish and the remainder from fish naturally infected with mycobacteria, were analysed using a PCR protocol which amplifies a fragment of the mycobacterial 65 kDa heat-shock protein (hsp65) gene. PCR-restriction enzyme analysis and/or sequencing were employed to further analyse the PCR amplicons. The PCR results were compared with those obtained by histology and culture. Mycobacterial DNA was detected in 34 of the 45 samples examined, of which 16 samples (47%) showed granulomatous reactions on histological examination. Using histology as the gold standard, no false-negative PCR results were obtained. Also, considering the presence or absence of granulomas as a diagnostic criterion, the sensitivity and specificity of PCR in 42 of the FFPE tissues were 16/16 (100%) and 8/26 (,30.8%), respectively. Corresponding microbiological cultures were available for 15 cases, of which 13 were pure Mycobacterium cultures. Of these, 13 were PCR positive (100% sensitivity and 50% specificity). The PCR-based methods used here proved sensitive, specific and rapid for the detection of mycobacteria in routinely processed paraffin wax-embedded and formalin-fixed histological samples, and the results of the study suggest that this method has potential use in retrospective epidemiological studies. [source]

    Increased heat-shock protein 90 expression contributes to impaired adaptive cytoprotection in the gastric mucosa of portal hypertensive rats

    JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 6 2009
    Masayuki Tominaga
    Abstract Background and Aims:, Portal hypertensive (PHT) gastropathy results in an increased susceptibility to damage. Adaptive cytoprotection against ethanol-induced damage is impaired in the gastric mucosa of rats with portal hypertension. Excessive nitric oxide (NO) production occurs in portal hypertension and is mediated in part via heat-shock protein (Hsp)90 production. The aim of this study was to investigate the relation between adaptive cytoprotection after exposure to ethanol and gastric expression of Hsp90 in PHT rats. Methods:, Portal hypertension was induced in rats by staged portal vein occlusion. Adaptive cytoprotection to 70% ethanol was evaluated by assessing the injury index of the gastric mucosa with or without pretreatment with 10% ethanol. Expression of Hsp90 mRNA was evaluated by real-time polymerase chain reaction, and expression of Hsp90 protein was evaluated by western blotting. The effect of Hsp90 inhibition in PHT rats was evaluated by administration of geldanamycin. Results:, Gastric Hsp90 mRNA expression in PHT rats was significantly less than that in sham-operated (SO) controls. However, after 10% ethanol pretreatment, Hsp90 mRNA expression was significantly greater in PHT rats than in SO controls. In PHT rats, gastric Hsp90 protein expression after 10% ethanol pretreatment was significantly greater than that without the pretreatment. However, the pretreatment had no effect on the injury index compared to SO rats. Administration of geldanamycin prior to 10% ethanol pretreatment significantly decreased the injury index in response to 70% ethanol in the PHT rats. Conclusions:, These results show that 10% ethanol pretreatment markedly increases gastric Hsp90 expression in PHT rats. Excessive production of Hsp90 may contribute impaired adaptive cytoprotection. [source]

    Salivary immunoglobulin A directed to oral microbial GroEL in patients with periodontitis and their potential protective role

    MOLECULAR ORAL MICROBIOLOGY, Issue 5 2006
    M. Fukui
    The aim of this study was to identify salivary immunoglobulin A (IgA) directed to oral microbial GroEL in patients with periodontitis and to demonstrate their potential protective role through a reduction of inflammatory cytokine production induced by microbial GroEL. Using five different proteins belonging to the heat-shock protein 60 family, Western immunoblot analysis of salivary IgA from 63 subjects revealed immunoreactivities with Campylobacter rectus GroEL and Porphyromonas gingivalis GroEL in subjects with periodontitis (P < 0.05) compared to control subjects. Using the BIACORE 1000 to measure the salivary IgA titers directed towards C. rectus GroEL, high resonance unit (RU) values were observed in the saliva samples from patients with periodontitis (P < 0.01). Furthermore, the number of teeth with deep pocket depth (,5 mm) showed a high correlation coefficient with the RU value (r = 0.50, P < 0.01). C. rectus GroEL possessed the ability to stimulate the production of interleukin-6 by gingival fibroblasts. Interestingly, salivary IgA antibody directed to C. rectus GroEL caused a partial inhibition of interleukin-6 production. This study showed a relationship between high levels of salivary IgA directed to GroEL and periodontal disease severity. Although additional investigations are required, salivary IgA to GroEL may have a protective role by reducing the inflammatory response induced by GroEL derived from periodontopathogenic bacteria. [source]

    Proteomic profiling of hepatocellular carcinoma in Chinese cohort reveals heat-shock proteins (Hsp27, Hsp70, GRP78) up-regulation and their associated prognostic values

    PROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 3 2006
    John M. Luk Dr.
    Abstract To facilitate the identification of candidate molecular biomarkers that are linked to the pathogenesis of hepatocellular carcinoma (HCC), we investigated protein-expression profiles of 146 tissue specimens including 67 pairs of tumors and adjacent non-tumors resected from HCC patients as well as 12 normal livers by 2-DE. Among the 1800 spots displayed in the liver proteome, a total of 90 protein species were found to be significantly different between the three groups (P,<,0.05). Three of the top candidate markers up-regulated in HCC, with high receiver operating characteristic (ROC) curves, were identified by MS/MS analysis and belonged to the chaperone members: heat-shock protein (Hsp)27, Hsp70 and glucose-regulated protein (GRP)78. Over-expression of these chaperone proteins in HCC tissues was confirmed by Western blotting and immunohistochemistry. In correlation with clinico-pathological parameters, expression of Hsp27 was linked to ,-fetoprotein level (P,=,0.007) whereas up-regulation of GRP78 was associated with tumor venous infiltration (P,=,0.035). No significant association of Hsp70 with any pathologic features was observed. The present HCC proteome analysis revealed that in response to the stressful cancerous microenvironment, tumor cells strived to increase the expression of chaperone proteins for cyto-protective function and to enhance tumor growth and metastasis. [source]

    Search for the tumor-related proteins of transition cell carcinoma in Taiwan by proteomic analysis

    PROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 3 2006
    Kun-Hung Sheng
    Abstract To better understand the carcinogenesis of bladder cancer in Taiwan, we utilized the proteomic approach to search for potential biomarkers of transitional cell carcinoma,(TCC). Analysis by 2-DE and MS/MS indicated that seven proteins are down-regulated and three proteins up-regulated in grade III samples as compared with those of grade,II. Of these deregulated proteins, fatty acid binding proteins, annexin,V, heat-shock protein,27, and lactate dehydrogenase have been shown to be associated with bladder cancer. Our studies also found altered expression of a group of proteins that have not been documented previously in bladder cancer, including annexin,I, 15-hydroxyprostaglandin dehydrogenase, galectin-1, lysophospholipase and mitochondrial short-chain enoyl-coenzyme,A hydratase,1 precursor. These results illustrate a pattern of differential protein expression between low- and high-grade tumors and it may be utilized as the molecular fingerprinting of a subset of bladder cancers. In addition, the present study provides a valuable resource in the study of pathological mechanisms in cancers of urothelial origin. The immunohistochemical staining of grade,II and III TCC samples with antiserum to annexin,I protein was utilized to confirm that the annexin,I protein is up-regulated in grade,III TCC. [source]

    Proteome analysis of the responses of Panax ginseng C. A. Meyer leaves to high light: Use of electrospray ionization quadrupole-time of flight mass spectrometry and expressed sequence tag data

    PROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 12 2003
    Myung Hee Nam
    Abstract We performed comparative proteomic analyses in order to understand the physiological responses of ginseng (Panax ginseng C. A. Meyer) to high light (HL). As a first step, we analyzed the proteins expressed in ginseng leaves. Proteins extracted from leaves were separated by two-dimensional polyacrylamide gel electrophoresis. Protein spots were identified by tandem mass spectra analysis using electrospray ionization quadrupole-time of flight mass spectrometry (ESI Q-TOF MS). We used a ginseng expressed sequence tag (EST) database as well as a nonredundant protein database from NCBI to identify proteins. Eighty-one proteins were identified using the nr protein database, 51 of which were also verified from the ginseng EST database. An additional 66 proteins were identified only from the ginseng EST database. Proteins that function in energy metabolism, protein stabilization, and protection against oxidative stress were abundant. To understand the light responses of ginseng leaves, we studied time dependent changes in expressed proteins produced by 0,4 h of HL exposure. Six HL-responsive proteins were identified: three proteins were up-regulated (cytosolic small heat-shock protein, cytosolic ascorbate peroxidase, and putative major latex-like protein) and three proteins were down-regulated (Rieske Fe/S protein, putative 3-beta hydroxysteroid dehydrogenase/isomerase-like protein, and oxygen-evolving enhancer-like protein). Our results show that the ginseng EST database combined with ESI Q-TOF MS analysis can be used to identify ginseng proteins and to elucidate the protective mechanism of ginseng against HL induced damage. [source]

    Plant endoplasmin supports the protein secretory pathway and has a role in proliferating tissues

    THE PLANT JOURNAL, Issue 5 2006
    Eva M. Klein
    Summary Endoplasmin is a molecular chaperone of the heat-shock protein 90 class located in the endoplasmic reticulum and its activity is poorly characterized in plants. We assessed the ability of endoplasmin to alleviate stress via its transient overexpression in tobacco protoplasts treated with tunicamycin, an inhibitor of glycosylation and inducer of the unfolded protein response (UPR). Endoplasmin supported the secretion of a model secretory protein but was less effective than BiP, the endoplasmic reticulum member of the heat-shock protein 70 family. Consistently, immunoprecipitation experiments with in vivo radioactively labelled proteins using an antiserum prepared against Arabidopsis endoplasmin showed that a much smaller number of newly synthesized polypeptides associated with endoplasmin than with BiP. Synthesis of endoplasmin was enhanced by UPR inducers in tobacco seedlings but not protoplasts. As BiP synthesis was induced in both systems, we conclude that the UPR acts differently, at least in part, on the expression of the two chaperones. Endoplasmin was not detectable in extracts of leaves and stems of the Arabidopsis endoplasmin T-DNA insertion mutant shepherd. However, the chaperone is present, albeit at low levels, in shepherd mutant callus, mature roots and tunicamycin-treated seedlings, demonstrating that the mutation is leaky. Reduced endoplasmin in the shepherd mutant has no effect on BiP protein levels in callus or mature roots, leaves and stems, but is compensated by increased BiP in seedlings. This increase occurs in proliferating rather than expanding leaf cells, indicating an important role for endoplasmin in proliferating plant tissues. [source]

    Silencing a prohibitin alters plant development and senescence

    THE PLANT JOURNAL, Issue 1 2005
    Jen-Chih Chen
    Summary Prohibitins, highly conserved mitochondrial proteins, have been shown to play important roles in cell cycling and senescence in animals and yeast. Sequences with high similarity to prohibitins have been identified in a number of plant species, but their function has not yet been demonstrated. The deduced amino acid sequences of PhPHB1 and PhPHB2, sequences that we identified in a petunia floral expressed sequence tag (EST) database, show high similarity to those of prohibitin-1 and prohibitin-2 proteins, respectively, reported from yeast, animals and plants. Southern analysis suggested that these genes were members of small gene families with at least two prohibitin-1 homologs and four prohibitin-2 homologs. When we downregulated expression of prohibitin-1 using a Tobacco rattle virus-based (TRV), virus-induced gene silencing system (VIGS), we observed plants with smaller and distorted leaves and flowers. Cells in silenced flowers were larger than in control flowers, indicating a substantial reduction in the number of cell divisions that took place during corolla development. The life of silenced flowers was shorter than that of controls, whether on the plant or detached. The respiration of silenced flowers was higher than that of controls, and we observed a marked increase in the abundance of transcripts of a catalase and a small heat-shock protein in the silenced flowers. Our data indicate that prohibitins play a key role in plant development and senescence. [source]

    A novel heat-shock protein coinducer boosts stress protein Hsp70 to activate T cell regulation of inflammation in autoimmune arthritis

    ARTHRITIS & RHEUMATISM, Issue 4 2010
    Lotte Wieten
    Objective Stress proteins, such as members of the heat-shock protein (HSP) family, are up-regulated by cells in inflamed tissue and can be viewed functionally as "biomarkers" for the immune system to monitor inflammation. Exogenous administration of stress proteins has induced immunoregulation in various models of inflammation and has also been shown to be effective in clinical trials in humans. This study was undertaken to test the hypothesis that boosting of endogenous HSP expression can restore effective immunoregulation through T cells specific for stress proteins. Methods Stress protein expression was manipulated in vivo and in vitro with a food component (carvacrol), and immune recognition of stress proteins was studied. Results Carvacrol, a major compound in the oil of many Origanum species, had a notable capacity to coinduce cellular Hsp70 expression in vitro and, upon intragastric administration, in Peyer's patches of mice in vivo. As a consequence, carvacrol specifically promoted T cell recognition of endogenous Hsp70, as demonstrated in vitro by the activation of an Hsp70-specific T cell hybridoma and in vivo by amplified T cell responses to Hsp70. Carvacrol administration also increased the number of CD4+CD25+FoxP3+ T cells, systemically in the spleen and locally in the joint, and almost completely suppressed proteoglycan-induced experimental arthritis. Furthermore, protection against arthritis could be transferred with T cells isolated from carvacrol-fed mice. Conclusion These findings illustrate that a food component can boost protective T cell responses to a self stress protein and down-regulate inflammatory disease, i.e., that the immune system can respond to diet. [source]

    Reactivity of ,/, T cells to human 60-kd heat-shock protein and their cytotoxicity to aortic endothelial cells in Takayasu arteritis

    ARTHRITIS & RHEUMATISM, Issue 8 2007
    Sunil Kumar Chauhan
    Objective Increased numbers of circulating ,/, T cells with a restricted T cell receptor repertoire, as well as colocalization of the expression of heat-shock protein Hsp60/65 and ,/, T cells in the arterial lesions of patients with Takayasu arteritis (TA), indicate that ,/, T cells may react to Hsp60 and cause damage to the arterial endothelium. In this study we investigated the proliferative responses of ,/, T cells to human Hsp60 and their cytotoxicity to human aortic endothelial cells (ECs) in patients with TA. Methods Blood samples were obtained from 12 patients with TA, 8 patients with systemic lupus erythematosus (SLE) (as disease controls), and 10 healthy control subjects. Proliferative responses of circulating ,/, T cells to human Hsp60 were detected by flow cytometry,based bromodeoxyuridine incorporation assay. Cytotoxicity of the ,/, T cells to human aortic ECs was analyzed by colorimetric lactate dehydrogenase release assay. Results The ,/, T cells of 11 of 12 patients with TA exhibited reactivity to Hsp60, whereas none of the ,/, T cells from patients with SLE or healthy controls showed reactivity (both P < 0.001). The mean ± SD proliferative response of ,/, T cells in patients with TA was 21.4 ± 11.3%, compared with 4.2 ± 1.2% in patients with SLE and 4.01 ± 1.82% in healthy controls (both P < 0.001). In addition, compared with the control groups, the ,/, T cells of patients with TA had increased spontaneous cytotoxicity to aortic ECs (22.1 ± 15.0% versus 9.6 ± 2.13% in SLE patients and 8.1 ± 4.7% in healthy controls; both P < 0.005), which was further enhanced following stimulation of ,/, T cells with Hsp60. The cytotoxicity of the ,/, T cells was significantly inhibited by treatment of these cells with concanamycin A and anti,Fas ligand,blocking antibodies. Conclusion The results show that ,/, T cells in patients with TA are reactive to Hsp60 and exhibit cytotoxicity to aortic ECs, suggesting a key role of Hsp60 and ,/, T cells in the pathogenesis of TA. [source]

    Mycobacterial Hsp65-IgG,expressing tolerogenic B cells confer protection against adjuvant-induced arthritis in Lewis rats

    ARTHRITIS & RHEUMATISM, Issue 5 2007
    Shailesh R. Satpute
    Objective Tolerization of T cells directed against a target autoantigen is a desired goal of experimental approaches for the treatment of autoimmune diseases, and novel and improved methods of tolerance induction are continuously being sought. Because most traditional methods of tolerance induction using soluble antigen are effective in the prevention of autoimmunity but fail to control established disease, this study was carried out to explore an innovative tolerogenic approach for the treatment of ongoing disease, using the rat adjuvant-induced arthritis (AIA) model of human rheumatoid arthritis. Methods Lewis (RT.1l) rats were injected subcutaneously with heat-killed Mycobacterium tuberculosis H37Ra to induce AIA. Before or after AIA induction, Lewis rats were treated intraperitoneally (IP) with tolerogenic B cells expressing a fusion construct of mycobacterial 65-kd heat-shock protein (Hsp65) and IgG heavy-chain. For comparison, control rats were treated IP with ovalbumin (OVA),IgG,expressing B cells or soluble mycobacterial Hsp65, and the effects on AIA were observed. We also tested the immune response to mycobacterial Hsp65 in B cell,tolerized rats. Results Administration of tolerogenic mycobacterial Hsp65,expressing B cells as well as soluble mycobacterial Hsp65, but not OVA-expressing B cells, resulted in a significant decrease in the severity of subsequent AIA. However, in rats with established disease, only the B cell regimen of mycobacterial Hsp65, but not the soluble antigen, suppressed ongoing AIA. Conclusion Mycobacterial Hsp65-IgG,expressing B cells can successfully attenuate the progression of AIA. This study introduces a promising approach for the treatment of arthritis that should be further explored. [source]

    Structural genomics of Caenorhabditis elegans: structure of the BAG domain

    ACTA CRYSTALLOGRAPHICA SECTION D, Issue 9 2004
    J. Symersky
    Binding of the BAG domain to the eukaryotic chaperone heat-shock protein (Hsp70) promotes ATP-dependent release of the protein substrate from Hsp70. Although the murine and human BAG domains have been shown to form an antiparallel three-helix bundle, the Caenorhabditis elegans BAG domain is formed by two antiparallel helices, while the third helix is extended away and stabilized by crystal-packing interactions. A small ,-sheet between helices 2 and 3 interferes with formation of the intramolecular three-helix bundle. However, intermolecular three-helix bundles are observed throughout the crystal packing and suggest that stable functional dimers and tetramers can be formed in solution. The structure may represent a new folding type of the BAG domain. [source]